tree-wide: s/getpid()/lxc_raw_getpid()/g

[mirror_lxc.git] / src / lxc / lxccontainer.c

/* liblxcapi
 *
 * Copyright © 2012 Serge Hallyn <serge.hallyn@ubuntu.com>.
 * Copyright © 2012 Canonical Ltd.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.

 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Lesser General Public License for more details.

 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#define _GNU_SOURCE
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <grp.h>
#include <libgen.h>
#include <pthread.h>
#include <sched.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdio.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <sys/sysmacros.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <sys/wait.h>

#include "af_unix.h"
#include "attach.h"
#include "cgroup.h"
#include "conf.h"
#include "config.h"
#include "commands.h"
#include "commands_utils.h"
#include "confile.h"
#include "confile_legacy.h"
#include "confile_utils.h"
#include "console.h"
#include "criu.h"
#include "initutils.h"
#include "log.h"
#include "lxc.h"
#include "lxccontainer.h"
#include "lxclock.h"
#include "monitor.h"
#include "namespace.h"
#include "network.h"
#include "start.h"
#include "state.h"
#include "storage.h"
#include "storage_utils.h"
#include "storage/btrfs.h"
#include "storage/overlay.h"
#include "sync.h"
#include "utils.h"
#include "version.h"

/* major()/minor() */
#ifdef MAJOR_IN_MKDEV
#    include <sys/mkdev.h>
#endif

#if HAVE_IFADDRS_H
#include <ifaddrs.h>
#else
#include <../include/ifaddrs.h>
#endif

#if IS_BIONIC
#include <../include/lxcmntent.h>
#else
#include <mntent.h>
#endif

#define MAX_BUFFER 4096

#define NOT_SUPPORTED_ERROR "the requested function %s is not currently supported with unprivileged containers"

/* Define faccessat() if missing from the C library */
#ifndef HAVE_FACCESSAT
static int faccessat(int __fd, const char *__file, int __type, int __flag)
{
#ifdef __NR_faccessat
return syscall(__NR_faccessat, __fd, __file, __type, __flag);
#else
errno = ENOSYS;
return -1;
#endif
}
#endif

lxc_log_define(lxc_container, lxc);

static bool do_lxcapi_destroy(struct lxc_container *c);
static const char *lxcapi_get_config_path(struct lxc_container *c);
#define do_lxcapi_get_config_path(c) lxcapi_get_config_path(c)
static bool do_lxcapi_set_config_item(struct lxc_container *c, const char *key, const char *v);
static bool container_destroy(struct lxc_container *c,
                              struct lxc_storage *storage);
static bool get_snappath_dir(struct lxc_container *c, char *snappath);
static bool lxcapi_snapshot_destroy_all(struct lxc_container *c);
static bool do_lxcapi_save_config(struct lxc_container *c, const char *alt_file);

static bool config_file_exists(const char *lxcpath, const char *cname)
{
        /* $lxcpath + '/' + $cname + '/config' + \0 */
        int ret, len = strlen(lxcpath) + strlen(cname) + 9;
        char *fname = alloca(len);

        ret = snprintf(fname, len,  "%s/%s/config", lxcpath, cname);
        if (ret < 0 || ret >= len)
                return false;

        return file_exists(fname);
}

/*
 * A few functions to help detect when a container creation failed.
 * If a container creation was killed partway through, then trying
 * to actually start that container could harm the host.  We detect
 * this by creating a 'partial' file under the container directory,
 * and keeping an advisory lock.  When container creation completes,
 * we remove that file.  When we load or try to start a container, if
 * we find that file, without a flock, we remove the container.
 */
static int ongoing_create(struct lxc_container *c)
{
        int len = strlen(c->config_path) + strlen(c->name) + 10;
        char *path = alloca(len);
        int fd, ret;
        struct flock lk;

        ret = snprintf(path, len, "%s/%s/partial", c->config_path, c->name);
        if (ret < 0 || ret >= len) {
                ERROR("Error writing partial pathname");
                return -1;
        }

        if (!file_exists(path))
                return 0;
        fd = open(path, O_RDWR);
        if (fd < 0) {
                /* give benefit of the doubt */
                SYSERROR("Error opening partial file");
                return 0;
        }
        lk.l_type = F_WRLCK;
        lk.l_whence = SEEK_SET;
        lk.l_start = 0;
        lk.l_len = 0;
        lk.l_pid = -1;
        if (fcntl(fd, F_GETLK, &lk) == 0 && lk.l_pid != -1) {
                /* create is still ongoing */
                close(fd);
                return 1;
        }
        /* create completed but partial is still there. */
        close(fd);
        return 2;
}

static int create_partial(struct lxc_container *c)
{
        /* $lxcpath + '/' + $name + '/partial' + \0 */
        int len = strlen(c->config_path) + strlen(c->name) + 10;
        char *path = alloca(len);
        int fd, ret;
        struct flock lk;

        ret = snprintf(path, len, "%s/%s/partial", c->config_path, c->name);
        if (ret < 0 || ret >= len) {
                ERROR("Error writing partial pathname");
                return -1;
        }
        if ((fd=open(path, O_RDWR | O_CREAT | O_EXCL, 0755)) < 0) {
                SYSERROR("Error creating partial file");
                return -1;
        }
        lk.l_type = F_WRLCK;
        lk.l_whence = SEEK_SET;
        lk.l_start = 0;
        lk.l_len = 0;
        if (fcntl(fd, F_SETLKW, &lk) < 0) {
                SYSERROR("Error locking partial file %s", path);
                close(fd);
                return -1;
        }

        return fd;
}

static void remove_partial(struct lxc_container *c, int fd)
{
        /* $lxcpath + '/' + $name + '/partial' + \0 */
        int len = strlen(c->config_path) + strlen(c->name) + 10;
        char *path = alloca(len);
        int ret;

        close(fd);
        ret = snprintf(path, len, "%s/%s/partial", c->config_path, c->name);
        if (ret < 0 || ret >= len) {
                ERROR("Error writing partial pathname");
                return;
        }
        if (unlink(path) < 0)
                SYSERROR("Error unlink partial file %s", path);
}

/* LOCKING
 * 1. container_mem_lock(c) protects the struct lxc_container from multiple threads.
 * 2. container_disk_lock(c) protects the on-disk container data - in particular the
 *    container configuration file.
 *    The container_disk_lock also takes the container_mem_lock.
 * 3. thread_mutex protects process data (ex: fd table) from multiple threads.
 * NOTHING mutexes two independent programs with their own struct
 * lxc_container for the same c->name, between API calls.  For instance,
 * c->config_read(); c->start();  Between those calls, data on disk
 * could change (which shouldn't bother the caller unless for instance
 * the rootfs get moved).  c->config_read(); update; c->config_write();
 * Two such updaters could race.  The callers should therefore check their
 * results.  Trying to prevent that would necessarily expose us to deadlocks
 * due to hung callers.  So I prefer to keep the locks only within our own
 * functions, not across functions.
 *
 * If you're going to clone while holding a lxccontainer, increment
 * c->numthreads (under privlock) before forking.  When deleting,
 * decrement numthreads under privlock, then if it hits 0 you can delete.
 * Do not ever use a lxccontainer whose numthreads you did not bump.
 */

static void lxc_container_free(struct lxc_container *c)
{
        if (!c)
                return;

        free(c->configfile);
        c->configfile = NULL;
        free(c->error_string);
        c->error_string = NULL;
        if (c->slock) {
                lxc_putlock(c->slock);
                c->slock = NULL;
        }
        if (c->privlock) {
                lxc_putlock(c->privlock);
                c->privlock = NULL;
        }
        free(c->name);
        c->name = NULL;
        if (c->lxc_conf) {
                lxc_conf_free(c->lxc_conf);
                c->lxc_conf = NULL;
        }
        free(c->config_path);
        c->config_path = NULL;

        free(c);
}

/*
 * Consider the following case:
freer                         |    racing get()er
==================================================================
lxc_container_put()           |   lxc_container_get()
\ lxclock(c->privlock)        |   c->numthreads < 1? (no)
\ c->numthreads = 0           |   \ lxclock(c->privlock) -> waits
\ lxcunlock()                 |   \
\ lxc_container_free()        |   \ lxclock() returns
                              |   \ c->numthreads < 1 -> return 0
\ \ (free stuff)              |
\ \ sem_destroy(privlock)     |

 * When the get()er checks numthreads the first time, one of the following
 * is true:
 * 1. freer has set numthreads = 0.  get() returns 0
 * 2. freer is between lxclock and setting numthreads to 0.  get()er will
 *    sem_wait on privlock, get lxclock after freer() drops it, then see
 *    numthreads is 0 and exit without touching lxclock again..
 * 3. freer has not yet locked privlock.  If get()er runs first, then put()er
 *    will see --numthreads = 1 and not call lxc_container_free().
*/

int lxc_container_get(struct lxc_container *c)
{
        if (!c)
                return 0;

        /* If someone else has already started freeing the container, don't try
         * to take the lock, which may be invalid.
         */
        if (c->numthreads < 1)
                return 0;

        if (container_mem_lock(c))
                return 0;

        /* Bail without trying to unlock, bc the privlock is now probably in
         * freed memory.
         */
        if (c->numthreads < 1)
                return 0;

        c->numthreads++;
        container_mem_unlock(c);
        return 1;
}

int lxc_container_put(struct lxc_container *c)
{
        if (!c)
                return -1;
        if (container_mem_lock(c))
                return -1;
        if (--c->numthreads < 1) {
                container_mem_unlock(c);
                lxc_container_free(c);
                return 1;
        }
        container_mem_unlock(c);
        return 0;
}

static bool do_lxcapi_is_defined(struct lxc_container *c)
{
        struct stat statbuf;
        bool ret = false;
        int statret;

        if (!c)
                return false;

        if (container_mem_lock(c))
                return false;
        if (!c->configfile)
                goto out;
        statret = stat(c->configfile, &statbuf);
        if (statret != 0)
                goto out;
        ret = true;

out:
        container_mem_unlock(c);
        return ret;
}

#define WRAP_API(rettype, fnname)                                       \
static rettype fnname(struct lxc_container *c)                          \
{                                                                       \
        rettype ret;                                                    \
        bool reset_config = false;                                      \
                                                                        \
        if (!current_config && c && c->lxc_conf) {                      \
                current_config = c->lxc_conf;                           \
                reset_config = true;                                    \
        }                                                               \
                                                                        \
        ret = do_##fnname(c);                                           \
        if (reset_config)                                               \
                current_config = NULL;                                  \
                                                                        \
        return ret;                                                     \
}

#define WRAP_API_1(rettype, fnname, t1)                                 \
static rettype fnname(struct lxc_container *c, t1 a1)                   \
{                                                                       \
        rettype ret;                                                    \
        bool reset_config = false;                                      \
                                                                        \
        if (!current_config && c && c->lxc_conf) {                      \
                current_config = c->lxc_conf;                           \
                reset_config = true;                                    \
        }                                                               \
                                                                        \
        ret = do_##fnname(c, a1);                                       \
        if (reset_config)                                               \
                current_config = NULL;                                  \
                                                                        \
        return ret;                                                     \
}

#define WRAP_API_2(rettype, fnname, t1, t2)                             \
static rettype fnname(struct lxc_container *c, t1 a1, t2 a2)            \
{                                                                       \
        rettype ret;                                                    \
        bool reset_config = false;                                      \
                                                                        \
        if (!current_config && c && c->lxc_conf) {                      \
                current_config = c->lxc_conf;                           \
                reset_config = true;                                    \
        }                                                               \
                                                                        \
        ret = do_##fnname(c, a1, a2);                                   \
        if (reset_config)                                               \
                current_config = NULL;                                  \
                                                                        \
        return ret;                                                     \
}

#define WRAP_API_3(rettype, fnname, t1, t2, t3)                         \
static rettype fnname(struct lxc_container *c, t1 a1, t2 a2, t3 a3)     \
{                                                                       \
        rettype ret;                                                    \
        bool reset_config = false;                                      \
                                                                        \
        if (!current_config && c && c->lxc_conf) {                      \
                current_config = c->lxc_conf;                           \
                reset_config = true;                                    \
        }                                                               \
                                                                        \
        ret = do_##fnname(c, a1, a2, a3);                               \
        if (reset_config)                                               \
                current_config = NULL;                                  \
                                                                        \
        return ret;                                                     \
}

WRAP_API(bool, lxcapi_is_defined)

static const char *do_lxcapi_state(struct lxc_container *c)
{
        lxc_state_t s;

        if (!c)
                return NULL;
        s = lxc_getstate(c->name, c->config_path);
        return lxc_state2str(s);
}

WRAP_API(const char *, lxcapi_state)

static bool is_stopped(struct lxc_container *c)
{
        lxc_state_t s;
        s = lxc_getstate(c->name, c->config_path);
        return (s == STOPPED);
}

static bool do_lxcapi_is_running(struct lxc_container *c)
{
        const char *s;

        if (!c)
                return false;
        s = do_lxcapi_state(c);
        if (!s || strcmp(s, "STOPPED") == 0)
                return false;
        return true;
}

WRAP_API(bool, lxcapi_is_running)

static bool do_lxcapi_freeze(struct lxc_container *c)
{
        int ret;
        if (!c)
                return false;

        ret = lxc_freeze(c->name, c->config_path);
        if (ret)
                return false;
        return true;
}

WRAP_API(bool, lxcapi_freeze)

static bool do_lxcapi_unfreeze(struct lxc_container *c)
{
        int ret;
        if (!c)
                return false;

        ret = lxc_unfreeze(c->name, c->config_path);
        if (ret)
                return false;
        return true;
}

WRAP_API(bool, lxcapi_unfreeze)

static int do_lxcapi_console_getfd(struct lxc_container *c, int *ttynum, int *masterfd)
{
        int ttyfd;
        if (!c)
                return -1;

        ttyfd = lxc_console_getfd(c, ttynum, masterfd);
        return ttyfd;
}

WRAP_API_2(int, lxcapi_console_getfd, int *, int *)

static int lxcapi_console(struct lxc_container *c, int ttynum, int stdinfd,
                          int stdoutfd, int stderrfd, int escape)
{
        int ret;

        if (!c)
                return -1;

        current_config = c->lxc_conf;
        ret = lxc_console(c, ttynum, stdinfd, stdoutfd, stderrfd, escape);
        current_config = NULL;
        return ret;
}

static int do_lxcapi_console_log(struct lxc_container *c, struct lxc_console_log *log)
{
        int ret;

        ret = lxc_cmd_console_log(c->name, do_lxcapi_get_config_path(c), log);
        if (ret < 0) {
                if (ret == -ENODATA)
                        NOTICE("The console log is empty");
                else if (ret == -EFAULT)
                        NOTICE("The container does not keep a console log");
                else if (ret == -ENOENT)
                        NOTICE("The container does not keep a console log file");
                else if (ret == -EIO)
                        NOTICE("Failed to write console log to log file");
                else
                        ERROR("Failed to retrieve console log");
        }

        return ret;
}

WRAP_API_1(int, lxcapi_console_log, struct lxc_console_log *)

static pid_t do_lxcapi_init_pid(struct lxc_container *c)
{
        if (!c)
                return -1;

        return lxc_cmd_get_init_pid(c->name, c->config_path);
}

WRAP_API(pid_t, lxcapi_init_pid)

static bool load_config_locked(struct lxc_container *c, const char *fname)
{
        if (!c->lxc_conf)
                c->lxc_conf = lxc_conf_init();
        if (!c->lxc_conf)
                return false;
        if (lxc_config_read(fname, c->lxc_conf, false) != 0)
                return false;
        return true;
}

static bool do_lxcapi_load_config(struct lxc_container *c, const char *alt_file)
{
        bool ret = false, need_disklock = false;
        int lret;
        const char *fname;
        if (!c)
                return false;

        fname = c->configfile;
        if (alt_file)
                fname = alt_file;
        if (!fname)
                return false;
        /*
         * If we're reading something other than the container's config,
         * we only need to lock the in-memory container.  If loading the
         * container's config file, take the disk lock.
         */
        if (strcmp(fname, c->configfile) == 0)
                need_disklock = true;

        if (need_disklock)
                lret = container_disk_lock(c);
        else
                lret = container_mem_lock(c);
        if (lret)
                return false;

        ret = load_config_locked(c, fname);

        if (need_disklock)
                container_disk_unlock(c);
        else
                container_mem_unlock(c);
        return ret;
}

WRAP_API_1(bool, lxcapi_load_config, const char *)

static bool do_lxcapi_want_daemonize(struct lxc_container *c, bool state)
{
        if (!c || !c->lxc_conf)
                return false;
        if (container_mem_lock(c)) {
                ERROR("Error getting mem lock");
                return false;
        }
        c->daemonize = state;
        container_mem_unlock(c);
        return true;
}

WRAP_API_1(bool, lxcapi_want_daemonize, bool)

static bool do_lxcapi_want_close_all_fds(struct lxc_container *c, bool state)
{
        if (!c || !c->lxc_conf)
                return false;
        if (container_mem_lock(c)) {
                ERROR("Error getting mem lock");
                return false;
        }
        c->lxc_conf->close_all_fds = state;
        container_mem_unlock(c);
        return true;
}

WRAP_API_1(bool, lxcapi_want_close_all_fds, bool)

static bool do_lxcapi_wait(struct lxc_container *c, const char *state, int timeout)
{
        int ret;

        if (!c)
                return false;

        ret = lxc_wait(c->name, state, timeout, c->config_path);
        return ret == 0;
}

WRAP_API_2(bool, lxcapi_wait, const char *, int)

static bool am_single_threaded(void)
{
        struct dirent *direntp;
        DIR *dir;
        int count=0;

        dir = opendir("/proc/self/task");
        if (!dir) {
                INFO("failed to open /proc/self/task");
                return false;
        }

        while ((direntp = readdir(dir))) {
                if (!strcmp(direntp->d_name, "."))
                        continue;

                if (!strcmp(direntp->d_name, ".."))
                        continue;
                if (++count > 1)
                        break;
        }
        closedir(dir);
        return count == 1;
}

static void push_arg(char ***argp, char *arg, int *nargs)
{
        char **argv;
        char *copy;

        do {
                copy = strdup(arg);
        } while (!copy);
        do {
                argv = realloc(*argp, (*nargs + 2) * sizeof(char *));
        } while (!argv);
        *argp = argv;
        argv[*nargs] = copy;
        (*nargs)++;
        argv[*nargs] = NULL;
}

static char **split_init_cmd(const char *incmd)
{
        size_t len;
        int nargs = 0;
        char *copy, *p, *saveptr = NULL;
        char **argv;

        if (!incmd)
                return NULL;

        len = strlen(incmd) + 1;
        copy = alloca(len);
        strncpy(copy, incmd, len);
        copy[len-1] = '\0';

        do {
                argv = malloc(sizeof(char *));
        } while (!argv);
        argv[0] = NULL;
        for (p = strtok_r(copy, " ", &saveptr); p != NULL;
                        p = strtok_r(NULL, " ", &saveptr))
                push_arg(&argv, p, &nargs);

        if (nargs == 0) {
                free(argv);
                return NULL;
        }
        return argv;
}

static void free_init_cmd(char **argv)
{
        int i = 0;

        if (!argv)
                return;
        while (argv[i])
                free(argv[i++]);
        free(argv);
}

static int lxc_rcv_status(int state_socket)
{
        int ret;
        int state = -1;

again:
        /* Receive container state. */
        ret = lxc_abstract_unix_rcv_credential(state_socket, &state,
                                               sizeof(int));
        if (ret <= 0) {
                if (errno != EINTR)
                        return -1;
                TRACE("Caught EINTR; retrying");
                goto again;
        }

        return state;
}

static bool wait_on_daemonized_start(struct lxc_handler *handler, int pid)
{
        int state, status;

        /* Close write end of the socket pair. */
        close(handler->state_socket_pair[1]);
        handler->state_socket_pair[1] = -1;

        state = lxc_rcv_status(handler->state_socket_pair[0]);

        /* Close read end of the socket pair. */
        close(handler->state_socket_pair[0]);
        handler->state_socket_pair[0] = -1;

        /* The first child is going to fork() again and then exits. So we reap
         * the first child here.
         */
        if (waitpid(pid, &status, 0) < 0)
                DEBUG("Failed waiting on first child");
        else if (!WIFEXITED(status))
                DEBUG("Failed to retrieve exit status of first child");
        else if (WEXITSTATUS(status) != 0)
                DEBUG("First child exited with: %d", WEXITSTATUS(status));

        if (state < 0) {
                SYSERROR("Failed to receive the container state");
                return false;
        }

        /* If we receive anything else then running we know that the container
         * failed to start.
         */
        if (state != RUNNING) {
                ERROR("Received container state \"%s\" instead of \"RUNNING\"",
                      lxc_state2str(state));
                return false;
        }

        TRACE("Container is in \"RUNNING\" state");
        return true;
}

static bool do_lxcapi_start(struct lxc_container *c, int useinit, char * const argv[])
{
        int ret;
        struct lxc_handler *handler;
        struct lxc_conf *conf;
        bool daemonize = false;
        FILE *pid_fp = NULL;
        char *default_args[] = {
                "/sbin/init",
                NULL,
        };
        char **init_cmd = NULL;
        int keepfds[3] = {-1, -1, -1};

        /* container does exist */
        if (!c)
                return false;

        /* If anything fails before we set error_num, we want an error in there.
         */
        c->error_num = 1;

        /* Container has not been setup. */
        if (!c->lxc_conf)
                return false;

        ret = ongoing_create(c);
        if (ret < 0) {
                ERROR("Failed checking for incomplete container creation");
                return false;
        } else if (ret == 1) {
                ERROR("Ongoing container creation detected");
                return false;
        } else if (ret == 2) {
                ERROR("Failed to create container");
                do_lxcapi_destroy(c);
                return false;
        }

        if (container_mem_lock(c))
                return false;
        conf = c->lxc_conf;
        daemonize = c->daemonize;

        /* initialize handler */
        handler = lxc_init_handler(c->name, conf, c->config_path, daemonize);
        container_mem_unlock(c);
        if (!handler)
                return false;

        if (!argv) {
                if (useinit && conf->execute_cmd)
                        argv = init_cmd = split_init_cmd(conf->execute_cmd);
                else
                        argv = init_cmd = split_init_cmd(conf->init_cmd);
        }

        /* ... otherwise use default_args. */
        if (!argv) {
                if (useinit) {
                        ERROR("No valid init detected");
                        lxc_free_handler(handler);
                        return false;
                }
                argv = default_args;
        }

        /* I'm not sure what locks we want here.Any? Is liblxc's locking enough
         * here to protect the on disk container?  We don't want to exclude
         * things like lxc_info while the container is running.
         */
        if (daemonize) {
                bool started;
                char title[2048];
                pid_t pid;

                pid = fork();
                if (pid < 0) {
                        free_init_cmd(init_cmd);
                        lxc_free_handler(handler);
                        return false;
                }

                /* first parent */
                if (pid != 0) {
                        /* Set to NULL because we don't want father unlink
                         * the PID file, child will do the free and unlink.
                         */
                        c->pidfile = NULL;

                        /* Wait for container to tell us whether it started
                         * successfully.
                         */
                        started = wait_on_daemonized_start(handler, pid);

                        free_init_cmd(init_cmd);
                        lxc_free_handler(handler);
                        return started;
                }

                /* first child */

                /* We don't really care if this doesn't print all the
                 * characters. All that it means is that the proctitle will be
                 * ugly. Similarly, we also don't care if setproctitle() fails.
                 * */
                snprintf(title, sizeof(title), "[lxc monitor] %s %s", c->config_path, c->name);
                INFO("Attempting to set proc title to %s", title);
                setproctitle(title);

                /* We fork() a second time to be reparented to init. Like
                 * POSIX's daemon() function we change to "/" and redirect
                 * std{in,out,err} to /dev/null.
                 */
                pid = fork();
                if (pid < 0) {
                        SYSERROR("Failed to fork first child process");
                        exit(EXIT_FAILURE);
                }

                /* second parent */
                if (pid != 0) {
                        free_init_cmd(init_cmd);
                        lxc_free_handler(handler);
                        exit(EXIT_SUCCESS);
                }

                /* second child */

                /* change to / directory */
                ret = chdir("/");
                if (ret < 0) {
                        SYSERROR("Failed to change to \"/\" directory");
                        exit(EXIT_FAILURE);
                }

                keepfds[0] = handler->conf->maincmd_fd;
                keepfds[1] = handler->state_socket_pair[0];
                keepfds[2] = handler->state_socket_pair[1];
                ret = lxc_check_inherited(conf, true, keepfds,
                                          sizeof(keepfds) / sizeof(keepfds[0]));
                if (ret < 0)
                        exit(EXIT_FAILURE);

                /* redirect std{in,out,err} to /dev/null */
                ret = null_stdfds();
                if (ret < 0) {
                        ERROR("Failed to redirect std{in,out,err} to /dev/null");
                        exit(EXIT_FAILURE);
                }

                /* become session leader */
                ret = setsid();
                if (ret < 0)
                        TRACE("Process %d is already process group leader", lxc_raw_getpid());
        } else {
                if (!am_single_threaded()) {
                        ERROR("Cannot start non-daemonized container when threaded");
                        free_init_cmd(init_cmd);
                        lxc_free_handler(handler);
                        return false;
                }
        }

        /* We need to write PID file after daemonize, so we always
         * write the right PID.
         */
        if (c->pidfile) {
                pid_fp = fopen(c->pidfile, "w");
                if (pid_fp == NULL) {
                        SYSERROR("Failed to create pidfile '%s' for '%s'",
                                 c->pidfile, c->name);
                        free_init_cmd(init_cmd);
                        lxc_free_handler(handler);
                        if (daemonize)
                                exit(EXIT_FAILURE);
                        return false;
                }

                if (fprintf(pid_fp, "%d\n", lxc_raw_getpid()) < 0) {
                        SYSERROR("Failed to write '%s'", c->pidfile);
                        fclose(pid_fp);
                        pid_fp = NULL;
                        free_init_cmd(init_cmd);
                        lxc_free_handler(handler);
                        if (daemonize)
                                exit(EXIT_FAILURE);
                        return false;
                }

                fclose(pid_fp);
                pid_fp = NULL;
        }

        conf->reboot = 0;

        /* Unshare the mount namespace if requested */
        if (conf->monitor_unshare) {
                ret = unshare(CLONE_NEWNS);
                if (ret < 0) {
                        SYSERROR("failed to unshare mount namespace");
                        lxc_free_handler(handler);
                        ret = 1;
                        goto on_error;
                }

                ret = mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL);
                if (ret < 0) {
                        SYSERROR("Failed to make / rslave at startup");
                        lxc_free_handler(handler);
                        ret = 1;
                        goto on_error;
                }
        }

reboot:
        if (conf->reboot == 2) {
                /* initialize handler */
                handler = lxc_init_handler(c->name, conf, c->config_path, daemonize);
                if (!handler) {
                        ret = 1;
                        goto on_error;
                }
        }

        keepfds[0] = handler->conf->maincmd_fd;
        keepfds[1] = handler->state_socket_pair[0];
        keepfds[2] = handler->state_socket_pair[1];
        ret = lxc_check_inherited(conf, daemonize, keepfds,
                                  sizeof(keepfds) / sizeof(keepfds[0]));
        if (ret < 0) {
                lxc_free_handler(handler);
                ret = 1;
                goto on_error;
        }

        if (useinit)
                ret = lxc_execute(c->name, argv, 1, handler, c->config_path, daemonize);
        else
                ret = lxc_start(c->name, argv, handler, c->config_path, daemonize);
        c->error_num = ret;

        if (conf->reboot == 1) {
                INFO("Container requested reboot");
                conf->reboot = 2;
                goto reboot;
        }

on_error:
        if (c->pidfile) {
                unlink(c->pidfile);
                free(c->pidfile);
                c->pidfile = NULL;
        }
        free_init_cmd(init_cmd);

        if (daemonize && ret != 0)
                exit(EXIT_FAILURE);
        else if (daemonize)
                exit(EXIT_SUCCESS);

        if (ret != 0)
                return false;

        return true;
}

static bool lxcapi_start(struct lxc_container *c, int useinit, char * const argv[])
{
        bool ret;
        current_config = c ? c->lxc_conf : NULL;
        ret = do_lxcapi_start(c, useinit, argv);
        current_config = NULL;
        return ret;
}

/*
 * note there MUST be an ending NULL
 */
static bool lxcapi_startl(struct lxc_container *c, int useinit, ...)
{
        va_list ap;
        char **inargs = NULL;
        bool bret = false;

        /* container exists */
        if (!c)
                return false;

        current_config = c->lxc_conf;

        va_start(ap, useinit);
        inargs = lxc_va_arg_list_to_argv(ap, 0, 1);
        va_end(ap);

        if (!inargs) {
                ERROR("Memory allocation error.");
                goto out;
        }

        /* pass NULL if no arguments were supplied */
        bret = do_lxcapi_start(c, useinit, *inargs ? inargs : NULL);

out:
        if (inargs) {
                char **arg;
                for (arg = inargs; *arg; arg++)
                        free(*arg);
                free(inargs);
        }

        current_config = NULL;
        return bret;
}

static bool do_lxcapi_stop(struct lxc_container *c)
{
        int ret;

        if (!c)
                return false;

        ret = lxc_cmd_stop(c->name, c->config_path);

        return ret == 0;
}

WRAP_API(bool, lxcapi_stop)

static int do_create_container_dir(const char *path, struct lxc_conf *conf)
{
        int ret = -1, lasterr;
        char *p = alloca(strlen(path)+1);
        mode_t mask = umask(0002);
        ret = mkdir(path, 0770);
        lasterr = errno;
        umask(mask);
        errno = lasterr;
        if (ret) {
                if (errno == EEXIST)
                        ret = 0;
                else {
                        SYSERROR("failed to create container path %s", path);
                        return -1;
                }
        }
        strcpy(p, path);
        if (!lxc_list_empty(&conf->id_map) && chown_mapped_root(p, conf) != 0) {
                ERROR("Failed to chown container dir");
                ret = -1;
        }
        return ret;
}

/*
 * create the standard expected container dir
 */
static bool create_container_dir(struct lxc_container *c)
{
        char *s;
        int len, ret;

        len = strlen(c->config_path) + strlen(c->name) + 2;
        s = malloc(len);
        if (!s)
                return false;
        ret = snprintf(s, len, "%s/%s", c->config_path, c->name);
        if (ret < 0 || ret >= len) {
                free(s);
                return false;
        }
        ret = do_create_container_dir(s, c->lxc_conf);
        free(s);
        return ret == 0;
}

/* do_storage_create: thin wrapper around storage_create(). Like
 * storage_create(), it returns a mounted bdev on success, NULL on error.
 */
static struct lxc_storage *do_storage_create(struct lxc_container *c,
                                             const char *type,
                                             struct bdev_specs *specs)
{
        int ret;
        size_t len;
        char *dest;
        struct lxc_storage *bdev;

        /* rootfs.path or lxcpath/lxcname/rootfs */
        if (c->lxc_conf->rootfs.path &&
            (access(c->lxc_conf->rootfs.path, F_OK) == 0)) {
                const char *rpath = c->lxc_conf->rootfs.path;
                len = strlen(rpath) + 1;
                dest = alloca(len);
                ret = snprintf(dest, len, "%s", rpath);
        } else {
                const char *lxcpath = do_lxcapi_get_config_path(c);
                len = strlen(c->name) + strlen(lxcpath) + 9;
                dest = alloca(len);
                ret = snprintf(dest, len, "%s/%s/rootfs", lxcpath, c->name);
        }
        if (ret < 0 || (size_t)ret >= len)
                return NULL;

        bdev = storage_create(dest, type, c->name, specs);
        if (!bdev) {
                ERROR("Failed to create \"%s\" storage", type);
                return NULL;
        }

        if (!c->set_config_item(c, "lxc.rootfs.path", bdev->src)) {
                ERROR("Failed to set \"lxc.rootfs.path = %s\"", bdev->src);
                return NULL;
        }

        /* If we are not root, chown the rootfs dir to root in the target user
         * namespace.
         */
        ret = geteuid();
        if (ret != 0 || (c->lxc_conf && !lxc_list_empty(&c->lxc_conf->id_map))) {
                ret = chown_mapped_root(bdev->dest, c->lxc_conf);
                if (ret < 0) {
                        ERROR("Error chowning \"%s\" to container root", bdev->dest);
                        suggest_default_idmap();
                        storage_put(bdev);
                        return NULL;
                }
        }

        return bdev;
}

static char *lxcbasename(char *path)
{
        char *p = path + strlen(path) - 1;
        while (*p != '/' && p > path)
                p--;
        return p;
}

static bool create_run_template(struct lxc_container *c, char *tpath, bool need_null_stdfds,
                                char *const argv[])
{
        pid_t pid;

        if (!tpath)
                return true;

        pid = fork();
        if (pid < 0) {
                SYSERROR("failed to fork task for container creation template");
                return false;
        }

        if (pid == 0) { /* child */
                char *patharg, *namearg, *rootfsarg;
                struct lxc_storage *bdev = NULL;
                int i;
                int ret, len, nargs = 0;
                char **newargv;
                struct lxc_conf *conf = c->lxc_conf;

                if (need_null_stdfds && null_stdfds() < 0) {
                        exit(1);
                }

                bdev = storage_init(c->lxc_conf);
                if (!bdev) {
                        ERROR("Error opening rootfs");
                        exit(1);
                }

                if (geteuid() == 0) {
                        if (unshare(CLONE_NEWNS) < 0) {
                                ERROR("error unsharing mounts");
                                exit(1);
                        }
                        if (detect_shared_rootfs()) {
                                if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL)) {
                                        SYSERROR("Failed to make / rslave to run template");
                                        ERROR("Continuing...");
                                }
                        }
                }
                if (strcmp(bdev->type, "dir") && strcmp(bdev->type, "btrfs")) {
                        if (geteuid() != 0) {
                                ERROR("non-root users can only create btrfs and directory-backed containers");
                                exit(EXIT_FAILURE);
                        }

                        if (!strcmp(bdev->type, "overlay") || !strcmp(bdev->type, "overlayfs")) {
                                /* If we create an overlay container we need to
                                 * rsync the contents into
                                 * <container-path>/<container-name>/rootfs.
                                 * However, the overlay mount function will
                                 * mount will mount
                                 * <container-path>/<container-name>/delta0
                                 * over
                                 * <container-path>/<container-name>/rootfs
                                 * which means we would rsync the rootfs into
                                 * the delta directory. That doesn't make sense
                                 * since the delta directory only exists to
                                 * record the differences to
                                 * <container-path>/<container-name>/rootfs. So
                                 * let's simply bind-mount here and then rsync
                                 * directly into
                                 * <container-path>/<container-name>/rootfs.
                                 */
                                char *src;

                                src = ovl_get_rootfs(bdev->src, &(size_t){0});
                                if (!src) {
                                        ERROR("Failed to get rootfs");
                                        exit(EXIT_FAILURE);
                                }

                                ret = mount(src, bdev->dest, "bind", MS_BIND | MS_REC, NULL);
                                if (ret < 0) {
                                        ERROR("Failed to mount rootfs");
                                        return -1;
                                }
                        } else {
                                if (bdev->ops->mount(bdev) < 0) {
                                        ERROR("Failed to mount rootfs");
                                        exit(EXIT_FAILURE);
                                }
                        }
                } else { /* TODO come up with a better way here! */
                        const char *src;
                        free(bdev->dest);
                        src = lxc_storage_get_path(bdev->src, bdev->type);
                        bdev->dest = strdup(src);
                }

                /*
                 * create our new array, pre-pend the template name and
                 * base args
                 */
                if (argv)
                        for (nargs = 0; argv[nargs]; nargs++) ;
                nargs += 4; /* template, path, rootfs and name args */

                newargv = malloc(nargs * sizeof(*newargv));
                if (!newargv)
                        exit(1);
                newargv[0] = lxcbasename(tpath);

                len = strlen(c->config_path) + strlen(c->name) + strlen("--path=") + 2;
                patharg = malloc(len);
                if (!patharg)
                        exit(1);
                ret = snprintf(patharg, len, "--path=%s/%s", c->config_path, c->name);
                if (ret < 0 || ret >= len)
                        exit(1);
                newargv[1] = patharg;
                len = strlen("--name=") + strlen(c->name) + 1;
                namearg = malloc(len);
                if (!namearg)
                        exit(1);
                ret = snprintf(namearg, len, "--name=%s", c->name);
                if (ret < 0 || ret >= len)
                        exit(1);
                newargv[2] = namearg;

                len = strlen("--rootfs=") + 1 + strlen(bdev->dest);
                rootfsarg = malloc(len);
                if (!rootfsarg)
                        exit(1);
                ret = snprintf(rootfsarg, len, "--rootfs=%s", bdev->dest);
                if (ret < 0 || ret >= len)
                        exit(1);
                newargv[3] = rootfsarg;

                /* add passed-in args */
                if (argv)
                        for (i = 4; i < nargs; i++)
                                newargv[i] = argv[i-4];

                /* add trailing NULL */
                nargs++;
                newargv = realloc(newargv, nargs * sizeof(*newargv));
                if (!newargv)
                        exit(1);
                newargv[nargs - 1] = NULL;

                /*
                 * If we're running the template in a mapped userns, then
                 * we prepend the template command with:
                 * lxc-usernsexec <-m map1> ... <-m mapn> --
                 * and we append "--mapped-uid x", where x is the mapped uid
                 * for our geteuid()
                 */
                if (!lxc_list_empty(&conf->id_map)) {
                        int n2args = 1;
                        char txtuid[20];
                        char txtgid[20];
                        char **n2 = malloc(n2args * sizeof(*n2));
                        struct lxc_list *it;
                        struct id_map *map;

                        if (!n2) {
                                SYSERROR("out of memory");
                                exit(1);
                        }
                        newargv[0] = tpath;
                        tpath = "lxc-usernsexec";
                        n2[0] = "lxc-usernsexec";
                        lxc_list_for_each(it, &conf->id_map) {
                                map = it->elem;
                                n2args += 2;
                                n2 = realloc(n2, n2args * sizeof(char *));
                                if (!n2)
                                        exit(1);
                                n2[n2args-2] = "-m";
                                n2[n2args-1] = malloc(200);
                                if (!n2[n2args-1])
                                        exit(1);
                                ret = snprintf(n2[n2args-1], 200, "%c:%lu:%lu:%lu",
                                        map->idtype == ID_TYPE_UID ? 'u' : 'g',
                                        map->nsid, map->hostid, map->range);
                                if (ret < 0 || ret >= 200)
                                        exit(1);
                        }
                        int hostid_mapped = mapped_hostid(geteuid(), conf, ID_TYPE_UID);
                        int extraargs = hostid_mapped >= 0 ? 1 : 3;
                        n2 = realloc(n2, (nargs + n2args + extraargs) * sizeof(char *));
                        if (!n2)
                                exit(1);
                        if (hostid_mapped < 0) {
                                hostid_mapped = find_unmapped_nsid(conf, ID_TYPE_UID);
                                n2[n2args++] = "-m";
                                if (hostid_mapped < 0) {
                                        ERROR("Could not find free uid to map");
                                        exit(1);
                                }
                                n2[n2args++] = malloc(200);
                                if (!n2[n2args-1]) {
                                        SYSERROR("out of memory");
                                        exit(1);
                                }
                                ret = snprintf(n2[n2args-1], 200, "u:%d:%d:1",
                                        hostid_mapped, geteuid());
                                if (ret < 0 || ret >= 200) {
                                        ERROR("string too long");
                                        exit(1);
                                }
                        }
                        int hostgid_mapped = mapped_hostid(getegid(), conf, ID_TYPE_GID);
                        extraargs = hostgid_mapped >= 0 ? 1 : 3;
                        n2 = realloc(n2, (nargs + n2args + extraargs) * sizeof(char *));
                        if (!n2)
                                exit(1);
                        if (hostgid_mapped < 0) {
                                hostgid_mapped = find_unmapped_nsid(conf, ID_TYPE_GID);
                                n2[n2args++] = "-m";
                                if (hostgid_mapped < 0) {
                                        ERROR("Could not find free uid to map");
                                        exit(1);
                                }
                                n2[n2args++] = malloc(200);
                                if (!n2[n2args-1]) {
                                        SYSERROR("out of memory");
                                        exit(1);
                                }
                                ret = snprintf(n2[n2args-1], 200, "g:%d:%d:1",
                                        hostgid_mapped, getegid());
                                if (ret < 0 || ret >= 200) {
                                        ERROR("string too long");
                                        exit(1);
                                }
                        }
                        n2[n2args++] = "--";
                        for (i = 0; i < nargs; i++)
                                n2[i + n2args] = newargv[i];
                        n2args += nargs;
                        /* Finally add "--mapped-uid $uid" to tell template
                         * what to chown cached images to.
                         */
                        n2args += 4;
                        n2 = realloc(n2, n2args * sizeof(char *));
                        if (!n2) {
                                SYSERROR("out of memory");
                                exit(1);
                        }
                        /* note n2[n2args-1] is NULL */
                        n2[n2args-5] = "--mapped-uid";
                        snprintf(txtuid, 20, "%d", hostid_mapped);
                        n2[n2args-4] = txtuid;
                        n2[n2args-3] = "--mapped-gid";
                        snprintf(txtgid, 20, "%d", hostgid_mapped);
                        n2[n2args-2] = txtgid;
                        n2[n2args-1] = NULL;
                        free(newargv);
                        newargv = n2;
                }
                /* execute */
                execvp(tpath, newargv);
                SYSERROR("Failed to execute template %s", tpath);
                exit(1);
        }

        if (wait_for_pid(pid) != 0) {
                ERROR("container creation template for %s failed", c->name);
                return false;
        }

        return true;
}

static bool prepend_lxc_header(char *path, const char *t, char *const argv[])
{
        long flen;
        char *contents;
        FILE *f;
        int ret = -1;
#if HAVE_LIBGNUTLS
        int i;
        unsigned char md_value[SHA_DIGEST_LENGTH];
        char *tpath;
#endif

        f = fopen(path, "r");
        if (f == NULL)
                return false;

        if (fseek(f, 0, SEEK_END) < 0)
                goto out_error;
        if ((flen = ftell(f)) < 0)
                goto out_error;
        if (fseek(f, 0, SEEK_SET) < 0)
                goto out_error;
        if ((contents = malloc(flen + 1)) == NULL)
                goto out_error;
        if (fread(contents, 1, flen, f) != flen)
                goto out_free_contents;

        contents[flen] = '\0';
        ret = fclose(f);
        f = NULL;
        if (ret < 0)
                goto out_free_contents;

#if HAVE_LIBGNUTLS
        tpath = get_template_path(t);
        if (!tpath) {
                ERROR("bad template: %s", t);
                goto out_free_contents;
        }

        ret = sha1sum_file(tpath, md_value);
        if (ret < 0) {
                ERROR("Error getting sha1sum of %s", tpath);
                free(tpath);
                goto out_free_contents;
        }
        free(tpath);
#endif

        f = fopen(path, "w");
        if (f == NULL) {
                SYSERROR("reopening config for writing");
                free(contents);
                return false;
        }
        fprintf(f, "# Template used to create this container: %s\n", t);
        if (argv) {
                fprintf(f, "# Parameters passed to the template:");
                while (*argv) {
                        fprintf(f, " %s", *argv);
                        argv++;
                }
                fprintf(f, "\n");
        }
#if HAVE_LIBGNUTLS
        fprintf(f, "# Template script checksum (SHA-1): ");
        for (i=0; i<SHA_DIGEST_LENGTH; i++)
                fprintf(f, "%02x", md_value[i]);
        fprintf(f, "\n");
#endif
        fprintf(f, "# For additional config options, please look at lxc.container.conf(5)\n");
        fprintf(f, "\n# Uncomment the following line to support nesting containers:\n");
        fprintf(f, "#lxc.include = " LXCTEMPLATECONFIG "/nesting.conf\n");
        fprintf(f, "# (Be aware this has security implications)\n\n");
        if (fwrite(contents, 1, flen, f) != flen) {
                SYSERROR("Writing original contents");
                free(contents);
                fclose(f);
                return false;
        }
        ret = 0;
out_free_contents:
        free(contents);
out_error:
        if (f) {
                int newret;
                newret = fclose(f);
                if (ret == 0)
                        ret = newret;
        }
        if (ret < 0) {
                SYSERROR("Error prepending header");
                return false;
        }
        return true;
}

static void lxcapi_clear_config(struct lxc_container *c)
{
        if (c) {
                if (c->lxc_conf) {
                        lxc_conf_free(c->lxc_conf);
                        c->lxc_conf = NULL;
                }
        }
}

#define do_lxcapi_clear_config(c) lxcapi_clear_config(c)

/*
 * lxcapi_create:
 * create a container with the given parameters.
 * @c: container to be created.  It has the lxcpath, name, and a starting
 *     configuration already set
 * @t: the template to execute to instantiate the root filesystem and
 *     adjust the configuration.
 * @bdevtype: backing store type to use.  If NULL, dir will be used.
 * @specs: additional parameters for the backing store, i.e. LVM vg to
 *         use.
 *
 * @argv: the arguments to pass to the template, terminated by NULL.  If no
 * arguments, you can just pass NULL.
 */
static bool do_lxcapi_create(struct lxc_container *c, const char *t,
                const char *bdevtype, struct bdev_specs *specs, int flags,
                char *const argv[])
{
        int partial_fd;
        pid_t pid;
        bool ret = false;
        char *tpath = NULL;

        if (!c)
                return false;

        if (t) {
                tpath = get_template_path(t);
                if (!tpath) {
                        ERROR("Unknown template \"%s\"", t);
                        goto out;
                }
        }

        /* If a template is passed in, and the rootfs already is defined in the
         * container config and exists, then the caller is trying to create an
         * existing container. Return an error, but do NOT delete the container.
         */
        if (do_lxcapi_is_defined(c) && c->lxc_conf && c->lxc_conf->rootfs.path &&
                        access(c->lxc_conf->rootfs.path, F_OK) == 0 && tpath) {
                ERROR("Container \"%s\" already exists in \"%s\"", c->name,
                      c->config_path);
                goto free_tpath;
        }

        if (!c->lxc_conf) {
                if (!do_lxcapi_load_config(c, lxc_global_config_value("lxc.default_config"))) {
                        ERROR("Error loading default configuration file %s",
                              lxc_global_config_value("lxc.default_config"));
                        goto free_tpath;
                }
        }

        if (!create_container_dir(c))
                goto free_tpath;

        /* If both template and rootfs.path are set, template is setup as
         * rootfs.path. The container is already created if we have a config and
         * rootfs.path is accessible
         */
        if (!c->lxc_conf->rootfs.path && !tpath) {
                /* No template passed in and rootfs does not exist. */
                if (!c->save_config(c, NULL)) {
                        ERROR("Failed to save initial config for \"%s\"", c->name);
                        goto out;
                }
                ret = true;
                goto out;
        }

        /* Rootfs passed into configuration, but does not exist. */
        if (c->lxc_conf->rootfs.path && access(c->lxc_conf->rootfs.path, F_OK) != 0)
                goto out;

        if (do_lxcapi_is_defined(c) && c->lxc_conf->rootfs.path && !tpath) {
                /* Rootfs already existed, user just wanted to save the loaded
                 * configuration.
                 */
                if (!c->save_config(c, NULL))
                        ERROR("Failed to save initial config for \"%s\"", c->name);
                ret = true;
                goto out;
        }

        /* Mark that this container is being created */
        partial_fd = create_partial(c);
        if (partial_fd < 0)
                goto out;

        /* No need to get disk lock bc we have the partial lock. */

        /* Create the storage.
         * Note we can't do this in the same task as we use to execute the
         * template because of the way zfs works.
         * After you 'zfs create', zfs mounts the fs only in the initial
         * namespace.
         */
        pid = fork();
        if (pid < 0) {
                SYSERROR("Failed to fork task for container creation template");
                goto out_unlock;
        }

        if (pid == 0) { /* child */
                struct lxc_storage *bdev = NULL;

                bdev = do_storage_create(c, bdevtype, specs);
                if (!bdev) {
                        ERROR("Failed to create %s storage for %s",
                              bdevtype ? bdevtype : "(none)", c->name);
                        exit(EXIT_FAILURE);
                }

                /* Save config file again to store the new rootfs location. */
                if (!do_lxcapi_save_config(c, NULL)) {
                        ERROR("Failed to save initial config for %s", c->name);
                        /* Parent task won't see the storage driver in the
                         * config so we delete it.
                         */
                        bdev->ops->umount(bdev);
                        bdev->ops->destroy(bdev);
                        exit(EXIT_FAILURE);
                }
                exit(EXIT_SUCCESS);
        }
        if (wait_for_pid(pid) != 0)
                goto out_unlock;

        /* Reload config to get the rootfs. */
        lxc_conf_free(c->lxc_conf);
        c->lxc_conf = NULL;
        if (!load_config_locked(c, c->configfile))
                goto out_unlock;

        if (!create_run_template(c, tpath, !!(flags & LXC_CREATE_QUIET), argv))
                goto out_unlock;

        /* Now clear out the lxc_conf we have, reload from the created
         * container.
         */
        do_lxcapi_clear_config(c);

        if (t) {
                if (!prepend_lxc_header(c->configfile, tpath, argv)) {
                        ERROR("Failed to prepend header to config file");
                        goto out_unlock;
                }
        }
        ret = load_config_locked(c, c->configfile);

out_unlock:
        if (partial_fd >= 0)
                remove_partial(c, partial_fd);
out:
        if (!ret)
                container_destroy(c, NULL);
free_tpath:
        free(tpath);
        return ret;
}

static bool lxcapi_create(struct lxc_container *c, const char *t,
                          const char *bdevtype, struct bdev_specs *specs,
                          int flags, char *const argv[])
{
        bool ret;
        current_config = c ? c->lxc_conf : NULL;
        ret = do_lxcapi_create(c, t, bdevtype, specs, flags, argv);
        current_config = NULL;
        return ret;
}

static bool do_lxcapi_reboot(struct lxc_container *c)
{
        pid_t pid;
        int rebootsignal = SIGINT;

        if (!c)
                return false;
        if (!do_lxcapi_is_running(c))
                return false;
        pid = do_lxcapi_init_pid(c);
        if (pid <= 0)
                return false;
        if (c->lxc_conf && c->lxc_conf->rebootsignal)
                rebootsignal = c->lxc_conf->rebootsignal;
        if (kill(pid, rebootsignal) < 0) {
                WARN("Could not send signal %d to pid %d.", rebootsignal, pid);
                return false;
        }
        return true;

}

WRAP_API(bool, lxcapi_reboot)

static bool do_lxcapi_reboot2(struct lxc_container *c, int timeout)
{
        int killret, ret;
        pid_t pid;
        int rebootsignal = SIGINT, state_client_fd = -1;
        lxc_state_t states[MAX_STATE] = {0};

        if (!c)
                return false;

        if (!do_lxcapi_is_running(c))
                return true;

        pid = do_lxcapi_init_pid(c);
        if (pid <= 0)
                return true;

        if (c->lxc_conf && c->lxc_conf->rebootsignal)
                rebootsignal = c->lxc_conf->rebootsignal;

        /* Add a new state client before sending the shutdown signal so that we
         * don't miss a state.
         */
        if (timeout != 0) {
                states[RUNNING] = 2;
                ret = lxc_cmd_add_state_client(c->name, c->config_path, states,
                                               &state_client_fd);
                if (ret < 0)
                        return false;

                if (state_client_fd < 0)
                        return false;

                if (ret == RUNNING)
                        return true;

                if (ret < MAX_STATE)
                        return false;
        }

        /* Send reboot signal to container. */
        killret = kill(pid, rebootsignal);
        if (killret < 0) {
                WARN("Could not send signal %d to pid %d", rebootsignal, pid);
                if (state_client_fd >= 0)
                        close(state_client_fd);
                return false;
        }
        TRACE("Sent signal %d to pid %d", rebootsignal, pid);

        if (timeout == 0)
                return true;

        ret = lxc_cmd_sock_rcv_state(state_client_fd, timeout);
        close(state_client_fd);
        if (ret < 0)
                return false;

        TRACE("Received state \"%s\"", lxc_state2str(ret));
        if (ret != RUNNING)
                return false;

        return true;
}

WRAP_API_1(bool, lxcapi_reboot2, int)

static bool do_lxcapi_shutdown(struct lxc_container *c, int timeout)
{
        int killret, ret;
        pid_t pid;
        int haltsignal = SIGPWR, state_client_fd = -1;
        lxc_state_t states[MAX_STATE] = {0};

        if (!c)
                return false;

        if (!do_lxcapi_is_running(c))
                return true;

        pid = do_lxcapi_init_pid(c);
        if (pid <= 0)
                return true;

        /* Detect whether we should send SIGRTMIN + 3 (e.g. systemd). */
        if (task_blocking_signal(pid, (SIGRTMIN + 3)))
                haltsignal = (SIGRTMIN + 3);

        if (c->lxc_conf && c->lxc_conf->haltsignal)
                haltsignal = c->lxc_conf->haltsignal;

        /* Add a new state client before sending the shutdown signal so that we
         * don't miss a state.
         */
        if (timeout != 0) {
                states[STOPPED] = 1;
                ret = lxc_cmd_add_state_client(c->name, c->config_path, states,
                                               &state_client_fd);
                if (ret < 0)
                        return false;

                if (state_client_fd < 0)
                        return false;

                if (ret == STOPPED)
                        return true;

                if (ret < MAX_STATE)
                        return false;
        }

        /* Send shutdown signal to container. */
        killret = kill(pid, haltsignal);
        if (killret < 0) {
                WARN("Could not send signal %d to pid %d", haltsignal, pid);
                if (state_client_fd >= 0)
                        close(state_client_fd);
                return false;
        }
        TRACE("Sent signal %d to pid %d", haltsignal, pid);

        if (timeout == 0)
                return true;

        ret = lxc_cmd_sock_rcv_state(state_client_fd, timeout);
        close(state_client_fd);
        if (ret < 0)
                return false;

        TRACE("Received state \"%s\"", lxc_state2str(ret));
        if (ret != STOPPED)
                return false;

        return true;
}

WRAP_API_1(bool, lxcapi_shutdown, int)

static bool lxcapi_createl(struct lxc_container *c, const char *t,
                const char *bdevtype, struct bdev_specs *specs, int flags, ...)
{
        bool bret = false;
        char **args = NULL;
        va_list ap;

        if (!c)
                return false;

        current_config = c->lxc_conf;

        /*
         * since we're going to wait for create to finish, I don't think we
         * need to get a copy of the arguments.
         */
        va_start(ap, flags);
        args = lxc_va_arg_list_to_argv(ap, 0, 0);
        va_end(ap);
        if (!args) {
                ERROR("Failed to allocate memory");
                goto out;
        }

        bret = do_lxcapi_create(c, t, bdevtype, specs, flags, args);

out:
        free(args);
        current_config = NULL;
        return bret;
}

static void do_clear_unexp_config_line(struct lxc_conf *conf, const char *key)
{
        if (!strcmp(key, "lxc.cgroup"))
                return clear_unexp_config_line(conf, key, true);

        if (!strcmp(key, "lxc.network"))
                return clear_unexp_config_line(conf, key, true);

        if (!strcmp(key, "lxc.net"))
                return clear_unexp_config_line(conf, key, true);

        /* Clear a network with a specific index. */
        if (!strncmp(key, "lxc.net.", 8)) {
                int ret;
                const char *idx;

                idx = key + 8;
                ret = lxc_safe_uint(idx, &(unsigned int){0});
                if (!ret)
                        return clear_unexp_config_line(conf, key, true);
        }

        if (!strcmp(key, "lxc.hook"))
                return clear_unexp_config_line(conf, key, true);

        return clear_unexp_config_line(conf, key, false);
}

static bool do_lxcapi_clear_config_item(struct lxc_container *c,
                                        const char *key)
{
        int ret = 1;
        struct lxc_config_t *config;

        if (!c || !c->lxc_conf)
                return false;

        if (container_mem_lock(c))
                return false;

        config = lxc_get_config(key);
        /* Verify that the config key exists and that it has a callback
         * implemented.
         */
        if (config && config->clr)
                ret = config->clr(key, c->lxc_conf, NULL);
        if (!ret)
                do_clear_unexp_config_line(c->lxc_conf, key);

        container_mem_unlock(c);
        return ret == 0;
}

WRAP_API_1(bool, lxcapi_clear_config_item, const char *)

static inline bool enter_net_ns(struct lxc_container *c)
{
        pid_t pid = do_lxcapi_init_pid(c);

        if ((geteuid() != 0 || (c->lxc_conf && !lxc_list_empty(&c->lxc_conf->id_map))) && access("/proc/self/ns/user", F_OK) == 0) {
                if (!switch_to_ns(pid, "user"))
                        return false;
        }
        return switch_to_ns(pid, "net");
}

/* Used by qsort and bsearch functions for comparing names. */
static inline int string_cmp(char **first, char **second)
{
        return strcmp(*first, *second);
}

/* Used by qsort and bsearch functions for comparing container names. */
static inline int container_cmp(struct lxc_container **first,
                                struct lxc_container **second)
{
        return strcmp((*first)->name, (*second)->name);
}

static bool add_to_array(char ***names, char *cname, int pos)
{
        char **newnames = realloc(*names, (pos+1) * sizeof(char *));
        if (!newnames) {
                ERROR("Out of memory");
                return false;
        }

        *names = newnames;
        newnames[pos] = strdup(cname);
        if (!newnames[pos])
                return false;

        /* Sort the arrray as we will use binary search on it. */
        qsort(newnames, pos + 1, sizeof(char *),
              (int (*)(const void *, const void *))string_cmp);

        return true;
}

static bool add_to_clist(struct lxc_container ***list, struct lxc_container *c,
                         int pos, bool sort)
{
        struct lxc_container **newlist = realloc(*list, (pos + 1) * sizeof(struct lxc_container *));
        if (!newlist) {
                ERROR("Out of memory");
                return false;
        }

        *list = newlist;
        newlist[pos] = c;

        /* Sort the arrray as we will use binary search on it. */
        if (sort)
                qsort(newlist, pos + 1, sizeof(struct lxc_container *),
                      (int (*)(const void *, const void *))container_cmp);

        return true;
}

static char** get_from_array(char ***names, char *cname, int size)
{
        return (char **)bsearch(&cname, *names, size, sizeof(char *), (int (*)(const void *, const void *))string_cmp);
}


static bool array_contains(char ***names, char *cname, int size) {
        if(get_from_array(names, cname, size) != NULL)
                return true;
        return false;
}

static bool remove_from_array(char ***names, char *cname, int size)
{
        char **result = get_from_array(names, cname, size);
        if (result != NULL) {
                free(result);
                return true;
        }
        return false;
}

static char ** do_lxcapi_get_interfaces(struct lxc_container *c)
{
        pid_t pid;
        int i, count = 0, pipefd[2];
        char **interfaces = NULL;
        char interface[IFNAMSIZ];

        if(pipe(pipefd) < 0) {
                SYSERROR("pipe failed");
                return NULL;
        }

        pid = fork();
        if (pid < 0) {
                SYSERROR("failed to fork task to get interfaces information");
                close(pipefd[0]);
                close(pipefd[1]);
                return NULL;
        }

        if (pid == 0) { /* child */
                int ret = 1, nbytes;
                struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;

                /* close the read-end of the pipe */
                close(pipefd[0]);

                if (!enter_net_ns(c)) {
                        SYSERROR("failed to enter namespace");
                        goto out;
                }

                /* Grab the list of interfaces */
                if (getifaddrs(&interfaceArray)) {
                        SYSERROR("failed to get interfaces list");
                        goto out;
                }

                /* Iterate through the interfaces */
                for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
                        nbytes = write(pipefd[1], tempIfAddr->ifa_name, IFNAMSIZ);
                        if (nbytes < 0) {
                                ERROR("write failed");
                                goto out;
                        }
                        count++;
                }
                ret = 0;

        out:
                if (interfaceArray)
                        freeifaddrs(interfaceArray);

                /* close the write-end of the pipe, thus sending EOF to the reader */
                close(pipefd[1]);
                exit(ret);
        }

        /* close the write-end of the pipe */
        close(pipefd[1]);

        while (read(pipefd[0], &interface, IFNAMSIZ) == IFNAMSIZ) {
                interface[IFNAMSIZ - 1] = '\0';

                if (array_contains(&interfaces, interface, count))
                                continue;

                if(!add_to_array(&interfaces, interface, count))
                        ERROR("Failed to add \"%s\" to array", interface);

                count++;
        }

        if (wait_for_pid(pid) != 0) {
                for(i=0;i<count;i++)
                        free(interfaces[i]);
                free(interfaces);
                interfaces = NULL;
        }

        /* close the read-end of the pipe */
        close(pipefd[0]);

        /* Append NULL to the array */
        if(interfaces)
                interfaces = (char **)lxc_append_null_to_array((void **)interfaces, count);

        return interfaces;
}

WRAP_API(char **, lxcapi_get_interfaces)

static char** do_lxcapi_get_ips(struct lxc_container *c, const char* interface, const char* family, int scope)
{
        pid_t pid;
        int i, count = 0, pipefd[2];
        char **addresses = NULL;
        char address[INET6_ADDRSTRLEN];

        if(pipe(pipefd) < 0) {
                SYSERROR("pipe failed");
                return NULL;
        }

        pid = fork();
        if (pid < 0) {
                SYSERROR("failed to fork task to get container ips");
                close(pipefd[0]);
                close(pipefd[1]);
                return NULL;
        }

        if (pid == 0) { /* child */
                int ret = 1, nbytes;
                struct ifaddrs *interfaceArray = NULL, *tempIfAddr = NULL;
                char addressOutputBuffer[INET6_ADDRSTRLEN];
                void *tempAddrPtr = NULL;
                char *address = NULL;

                /* close the read-end of the pipe */
                close(pipefd[0]);

                if (!enter_net_ns(c)) {
                        SYSERROR("failed to enter namespace");
                        goto out;
                }

                /* Grab the list of interfaces */
                if (getifaddrs(&interfaceArray)) {
                        SYSERROR("failed to get interfaces list");
                        goto out;
                }

                /* Iterate through the interfaces */
                for (tempIfAddr = interfaceArray; tempIfAddr != NULL; tempIfAddr = tempIfAddr->ifa_next) {
                        if (tempIfAddr->ifa_addr == NULL)
                                continue;

                        if(tempIfAddr->ifa_addr->sa_family == AF_INET) {
                                if (family && strcmp(family, "inet"))
                                        continue;
                                tempAddrPtr = &((struct sockaddr_in *)tempIfAddr->ifa_addr)->sin_addr;
                        }
                        else {
                                if (family && strcmp(family, "inet6"))
                                        continue;

                                if (((struct sockaddr_in6 *)tempIfAddr->ifa_addr)->sin6_scope_id != scope)
                                        continue;

                                tempAddrPtr = &((struct sockaddr_in6 *)tempIfAddr->ifa_addr)->sin6_addr;
                        }

                        if (interface && strcmp(interface, tempIfAddr->ifa_name))
                                continue;
                        else if (!interface && strcmp("lo", tempIfAddr->ifa_name) == 0)
                                continue;

                        address = (char *)inet_ntop(tempIfAddr->ifa_addr->sa_family,
                                                tempAddrPtr,
                                                addressOutputBuffer,
                                                sizeof(addressOutputBuffer));
                        if (!address)
                                        continue;

                        nbytes = write(pipefd[1], address, INET6_ADDRSTRLEN);
                        if (nbytes < 0) {
                                ERROR("write failed");
                                goto out;
                        }
                        count++;
                }
                ret = 0;

        out:
                if(interfaceArray)
                        freeifaddrs(interfaceArray);

                /* close the write-end of the pipe, thus sending EOF to the reader */
                close(pipefd[1]);
                exit(ret);
        }

        /* close the write-end of the pipe */
        close(pipefd[1]);

        while (read(pipefd[0], &address, INET6_ADDRSTRLEN) == INET6_ADDRSTRLEN) {
                if(!add_to_array(&addresses, address, count))
                        ERROR("PARENT: add_to_array failed");
                count++;
        }

        if (wait_for_pid(pid) != 0) {
                for(i=0;i<count;i++)
                        free(addresses[i]);
                free(addresses);
                addresses = NULL;
        }

        /* close the read-end of the pipe */
        close(pipefd[0]);

        /* Append NULL to the array */
        if(addresses)
                addresses = (char **)lxc_append_null_to_array((void **)addresses, count);

        return addresses;
}

WRAP_API_3(char **, lxcapi_get_ips, const char *, const char *, int)

static int do_lxcapi_get_config_item(struct lxc_container *c, const char *key, char *retv, int inlen)
{
        int ret = -1;
        struct lxc_config_t *config;

        if (!c || !c->lxc_conf)
                return -1;

        if (container_mem_lock(c))
                return -1;

        config = lxc_get_config(key);
        /* Verify that the config key exists and that it has a callback
         * implemented.
         */
        if (config && config->get)
                ret = config->get(key, retv, inlen, c->lxc_conf, NULL);

        container_mem_unlock(c);
        return ret;
}

WRAP_API_3(int, lxcapi_get_config_item, const char *, char *, int)

static char* do_lxcapi_get_running_config_item(struct lxc_container *c, const char *key)
{
        char *ret;

        if (!c || !c->lxc_conf)
                return NULL;
        if (container_mem_lock(c))
                return NULL;
        ret = lxc_cmd_get_config_item(c->name, key, do_lxcapi_get_config_path(c));
        container_mem_unlock(c);
        return ret;
}

WRAP_API_1(char *, lxcapi_get_running_config_item, const char *)

static int do_lxcapi_get_keys(struct lxc_container *c, const char *key, char *retv, int inlen)
{
        int ret = -1;

        /* List all config items. */
        if (!key)
                return lxc_list_config_items(retv, inlen);

        if (!c || !c->lxc_conf)
                return -1;

        if (container_mem_lock(c))
                return -1;

        /* Support 'lxc.net.<idx>', i.e. 'lxc.net.0'
         * This is an intelligent result to show which keys are valid given the
         * type of nic it is.
         */
        if (!strncmp(key, "lxc.net.", 8))
                ret = lxc_list_net(c->lxc_conf, key, retv, inlen);
        else if (strncmp(key, "lxc.network.", 12) == 0)
                ret = lxc_list_nicconfigs_legacy(c->lxc_conf, key, retv, inlen);
        else
                ret = lxc_list_subkeys(c->lxc_conf, key, retv, inlen);

        container_mem_unlock(c);
        return ret;
}

WRAP_API_3(int, lxcapi_get_keys, const char *, char *, int)

static bool do_lxcapi_save_config(struct lxc_container *c, const char *alt_file)
{
        FILE *fout;
        bool ret = false, need_disklock = false;
        int lret;

        if (!alt_file)
                alt_file = c->configfile;
        if (!alt_file)
                return false;

        /* If we haven't yet loaded a config, load the stock config. */
        if (!c->lxc_conf) {
                if (!do_lxcapi_load_config(c, lxc_global_config_value("lxc.default_config"))) {
                        ERROR("Error loading default configuration file %s while saving %s", lxc_global_config_value("lxc.default_config"), c->name);
                        return false;
                }
        }

        if (!create_container_dir(c))
                return false;

        /* If we're writing to the container's config file, take the disk lock.
         * Otherwise just take the memlock to protect the struct lxc_container
         * while we're traversing it.
         */
        if (strcmp(c->configfile, alt_file) == 0)
                need_disklock = true;

        if (need_disklock)
                lret = container_disk_lock(c);
        else
                lret = container_mem_lock(c);

        if (lret)
                return false;

        fout = fopen(alt_file, "w");
        if (!fout)
                goto out;
        write_config(fout, c->lxc_conf);
        fclose(fout);
        ret = true;

out:
        if (need_disklock)
                container_disk_unlock(c);
        else
                container_mem_unlock(c);
        return ret;
}

WRAP_API_1(bool, lxcapi_save_config, const char *)


static bool mod_rdep(struct lxc_container *c0, struct lxc_container *c, bool inc)
{
        FILE *f1;
        struct stat fbuf;
        void *buf = NULL;
        char *del = NULL;
        char path[MAXPATHLEN];
        char newpath[MAXPATHLEN];
        int fd, ret, n = 0, v = 0;
        bool bret = false;
        size_t len = 0, bytes = 0;

        if (container_disk_lock(c0))
                return false;

        ret = snprintf(path, MAXPATHLEN, "%s/%s/lxc_snapshots", c0->config_path, c0->name);
        if (ret < 0 || ret > MAXPATHLEN)
                goto out;
        ret = snprintf(newpath, MAXPATHLEN, "%s\n%s\n", c->config_path, c->name);
        if (ret < 0 || ret > MAXPATHLEN)
                goto out;

        /* If we find an lxc-snapshot file using the old format only listing the
         * number of snapshots we will keep using it. */
        f1 = fopen(path, "r");
        if (f1) {
                n = fscanf(f1, "%d", &v);
                fclose(f1);
                if (n == 1 && v == 0) {
                        remove(path);
                        n = 0;
                }
        }
        if (n == 1) {
                v += inc ? 1 : -1;
                f1 = fopen(path, "w");
                if (!f1)
                        goto out;
                if (fprintf(f1, "%d\n", v) < 0) {
                        ERROR("Error writing new snapshots value");
                        fclose(f1);
                        goto out;
                }
                ret = fclose(f1);
                if (ret != 0) {
                        SYSERROR("Error writing to or closing snapshots file");
                        goto out;
                }
        } else {
                /* Here we know that we have or can use an lxc-snapshot file
                 * using the new format. */
                if (inc) {
                        f1 = fopen(path, "a");
                        if (!f1)
                                goto out;

                        if (fprintf(f1, "%s", newpath) < 0) {
                                ERROR("Error writing new snapshots entry");
                                ret = fclose(f1);
                                if (ret != 0)
                                        SYSERROR("Error writing to or closing snapshots file");
                                goto out;
                        }

                        ret = fclose(f1);
                        if (ret != 0) {
                                SYSERROR("Error writing to or closing snapshots file");
                                goto out;
                        }
                } else if (!inc) {
                        if ((fd = open(path, O_RDWR | O_CLOEXEC)) < 0)
                                goto out;

                        if (fstat(fd, &fbuf) < 0) {
                                close(fd);
                                goto out;
                        }

                        if (fbuf.st_size != 0) {

                                buf = lxc_strmmap(NULL, fbuf.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
                                if (buf == MAP_FAILED) {
                                        SYSERROR("Failed to create mapping %s", path);
                                        close(fd);
                                        goto out;
                                }

                                len = strlen(newpath);
                                while ((del = strstr((char *)buf, newpath))) {
                                        memmove(del, del + len, strlen(del) - len + 1);
                                        bytes += len;
                                }

                                lxc_strmunmap(buf, fbuf.st_size);
                                if (ftruncate(fd, fbuf.st_size - bytes) < 0) {
                                        SYSERROR("Failed to truncate file %s", path);
                                        close(fd);
                                        goto out;
                                }
                        }
                        close(fd);
                }

                /* If the lxc-snapshot file is empty, remove it. */
                if (stat(path, &fbuf) < 0)
                        goto out;
                if (!fbuf.st_size) {
                        remove(path);
                }
        }

        bret = true;

out:
        container_disk_unlock(c0);
        return bret;
}

static void strip_newline(char *p)
{
        size_t len = strlen(p);
        if (len < 1)
                return;
        if (p[len-1] == '\n')
                p[len-1] = '\0';
}

void mod_all_rdeps(struct lxc_container *c, bool inc)
{
        struct lxc_container *p;
        char *lxcpath = NULL, *lxcname = NULL, path[MAXPATHLEN];
        size_t pathlen = 0, namelen = 0;
        FILE *f;
        int ret;

        ret = snprintf(path, MAXPATHLEN, "%s/%s/lxc_rdepends",
                c->config_path, c->name);
        if (ret < 0 || ret >= MAXPATHLEN) {
                ERROR("Path name too long");
                return;
        }
        f = fopen(path, "r");
        if (f == NULL)
                return;
        while (getline(&lxcpath, &pathlen, f) != -1) {
                if (getline(&lxcname, &namelen, f) == -1) {
                        ERROR("badly formatted file %s", path);
                        goto out;
                }
                strip_newline(lxcpath);
                strip_newline(lxcname);
                if ((p = lxc_container_new(lxcname, lxcpath)) == NULL) {
                        ERROR("Unable to find dependent container %s:%s",
                                lxcpath, lxcname);
                        continue;
                }
                if (!mod_rdep(p, c, inc))
                        ERROR("Failed to update snapshots file for %s:%s",
                                lxcpath, lxcname);
                lxc_container_put(p);
        }
out:
        free(lxcpath);
        free(lxcname);
        fclose(f);
}

static bool has_fs_snapshots(struct lxc_container *c)
{
        FILE *f;
        char path[MAXPATHLEN];
        int ret, v;
        struct stat fbuf;
        bool bret = false;

        ret = snprintf(path, MAXPATHLEN, "%s/%s/lxc_snapshots", c->config_path,
                        c->name);
        if (ret < 0 || ret > MAXPATHLEN)
                goto out;
        /* If the file doesn't exist there are no snapshots. */
        if (stat(path, &fbuf) < 0)
                goto out;
        v = fbuf.st_size;
        if (v != 0) {
                f = fopen(path, "r");
                if (!f)
                        goto out;
                ret = fscanf(f, "%d", &v);
                fclose(f);
                /* TODO: Figure out what to do with the return value of fscanf. */
                if (ret != 1)
                        INFO("Container uses new lxc-snapshots format %s", path);
        }
        bret = v != 0;

out:
        return bret;
}

static bool has_snapshots(struct lxc_container *c)
{
        char path[MAXPATHLEN];
        struct dirent *direntp;
        int count=0;
        DIR *dir;

        if (!get_snappath_dir(c, path))
                return false;
        dir = opendir(path);
        if (!dir)
                return false;
        while ((direntp = readdir(dir))) {
                if (!direntp)
                        break;

                if (!strcmp(direntp->d_name, "."))
                        continue;

                if (!strcmp(direntp->d_name, ".."))
                        continue;
                count++;
                break;
        }
        closedir(dir);
        return count > 0;
}

static bool do_destroy_container(struct lxc_conf *conf) {
        int ret;

        if (am_unpriv()) {
                ret = userns_exec_full(conf, storage_destroy_wrapper, conf,
                                       "storage_destroy_wrapper");
                if (ret < 0)
                        return false;

                return true;
        }

        return storage_destroy(conf);
}

static int lxc_rmdir_onedev_wrapper(void *data)
{
        char *arg = (char *) data;
        return lxc_rmdir_onedev(arg, "snaps");
}

static int lxc_unlink_exec_wrapper(void *data)
{
        char *arg = data;
        return unlink(arg);
}

static bool container_destroy(struct lxc_container *c,
                              struct lxc_storage *storage)
{
        const char *p1;
        size_t len;
        struct lxc_conf *conf;
        char *path = NULL;
        bool bret = false;
        int ret = 0;

        if (!c || !do_lxcapi_is_defined(c))
                return false;

        conf = c->lxc_conf;
        if (container_disk_lock(c))
                return false;

        if (!is_stopped(c)) {
                /* We should queue some sort of error - in c->error_string? */
                ERROR("container %s is not stopped", c->name);
                goto out;
        }

        if (conf && !lxc_list_empty(&conf->hooks[LXCHOOK_DESTROY])) {
                /* Start of environment variable setup for hooks */
                if (c->name && setenv("LXC_NAME", c->name, 1))
                        SYSERROR("Failed to set environment variable for container name");

                if (conf->rcfile && setenv("LXC_CONFIG_FILE", conf->rcfile, 1))
                        SYSERROR("Failed to set environment variable for config path");

                if (conf->rootfs.mount && setenv("LXC_ROOTFS_MOUNT", conf->rootfs.mount, 1))
                        SYSERROR("Failed to set environment variable for rootfs mount");

                if (conf->rootfs.path && setenv("LXC_ROOTFS_PATH", conf->rootfs.path, 1))
                        SYSERROR("Failed to set environment variable for rootfs mount");

                if (conf->console.path && setenv("LXC_CONSOLE", conf->console.path, 1))
                        SYSERROR("Failed to set environment variable for console path");

                if (conf->console.log_path && setenv("LXC_CONSOLE_LOGPATH", conf->console.log_path, 1))
                        SYSERROR("Failed to set environment variable for console log");
                /* End of environment variable setup for hooks */

                if (run_lxc_hooks(c->name, "destroy", conf, NULL)) {
                        ERROR("Failed to execute clone hook for \"%s\"", c->name);
                        goto out;
                }
        }

        if (current_config && conf == current_config) {
                current_config = NULL;
                if (conf->logfd != -1) {
                        close(conf->logfd);
                        conf->logfd = -1;
                }
        }

        if (conf && conf->rootfs.path && conf->rootfs.mount) {
                if (!do_destroy_container(conf)) {
                        ERROR("Error destroying rootfs for %s", c->name);
                        goto out;
                }
                INFO("Destroyed rootfs for %s", c->name);
        }

        mod_all_rdeps(c, false);

        p1 = do_lxcapi_get_config_path(c);
        /* strlen(p1)
         * +
         * /
         * +
         * strlen(c->name)
         * +
         * /
         * +
         * strlen("config") = 6
         * +
         * \0
         */
        len = strlen(p1) + 1 + strlen(c->name) + 1 + 6 + 1;
        path = malloc(len);
        if (!path) {
                ERROR("Failed to allocate memory");
                goto out;
        }

        /* For an overlay container the rootfs is considered immutable and
         * cannot be removed when restoring from a snapshot.
         */
        if (storage && (!strcmp(storage->type, "overlay") ||
                        !strcmp(storage->type, "overlayfs")) &&
            (storage->flags & LXC_STORAGE_INTERNAL_OVERLAY_RESTORE)) {
                ret = snprintf(path, len, "%s/%s/config", p1, c->name);
                if (ret < 0 || (size_t)ret >= len)
                        goto out;

                if (am_unpriv())
                        ret = userns_exec_1(conf, lxc_unlink_exec_wrapper, path,
                                            "lxc_unlink_exec_wrapper");
                else
                        ret = unlink(path);
                if (ret < 0) {
                        SYSERROR("Failed to destroy config file \"%s\" for \"%s\"",
                                 path, c->name);
                        goto out;
                }
                INFO("Destroyed config file \"%s\" for \"%s\"", path, c->name);

                bret = true;
                goto out;
        }

        ret = snprintf(path, len, "%s/%s", p1, c->name);
        if (ret < 0 || (size_t)ret >= len)
                goto out;
        if (am_unpriv())
                ret = userns_exec_full(conf, lxc_rmdir_onedev_wrapper, path,
                                       "lxc_rmdir_onedev_wrapper");
        else
                ret = lxc_rmdir_onedev(path, "snaps");
        if (ret < 0) {
                ERROR("Failed to destroy directory \"%s\" for \"%s\"", path,
                      c->name);
                goto out;
        }
        INFO("Destroyed directory \"%s\" for \"%s\"", path, c->name);

        bret = true;

out:
        if (path)
                free(path);
        container_disk_unlock(c);
        return bret;
}

static bool do_lxcapi_destroy(struct lxc_container *c)
{
        if (!c || !lxcapi_is_defined(c))
                return false;
        if (has_snapshots(c)) {
                ERROR("Container %s has snapshots;  not removing", c->name);
                return false;
        }

        if (has_fs_snapshots(c)) {
                ERROR("container %s has snapshots on its rootfs", c->name);
                return false;
        }

        return container_destroy(c, NULL);
}

WRAP_API(bool, lxcapi_destroy)

static bool do_lxcapi_destroy_with_snapshots(struct lxc_container *c)
{
        if (!c || !lxcapi_is_defined(c))
                return false;
        if (!lxcapi_snapshot_destroy_all(c)) {
                ERROR("Error deleting all snapshots");
                return false;
        }
        return lxcapi_destroy(c);
}

WRAP_API(bool, lxcapi_destroy_with_snapshots)

int lxc_set_config_item_locked(struct lxc_conf *conf, const char *key,
                               const char *v)
{
        int ret;
        struct lxc_config_t *config;
        bool bret = true;

        config = lxc_get_config(key);
        if (!config)
                return -EINVAL;

        ret = config->set(key, v, conf, NULL);
        if (ret < 0)
                return -EINVAL;

        if (lxc_config_value_empty(v))
                do_clear_unexp_config_line(conf, key);
        else
                bret = do_append_unexp_config_line(conf, key, v);
        if (!bret)
                return -ENOMEM;

        return 0;
}

static bool do_set_config_item_locked(struct lxc_container *c, const char *key,
                                      const char *v)
{
        int ret;

        if (!c->lxc_conf)
                c->lxc_conf = lxc_conf_init();

        if (!c->lxc_conf)
                return false;

        ret = lxc_set_config_item_locked(c->lxc_conf, key, v);
        if (ret < 0)
                return false;

        return true;
}

static bool do_lxcapi_set_config_item(struct lxc_container *c, const char *key, const char *v)
{
        bool b = false;

        if (!c)
                return false;

        if (container_mem_lock(c))
                return false;

        b = do_set_config_item_locked(c, key, v);

        container_mem_unlock(c);
        return b;
}

WRAP_API_2(bool, lxcapi_set_config_item, const char *, const char *)

static bool do_lxcapi_set_running_config_item(struct lxc_container *c, const char *key, const char *v)
{
        int ret;

        if (!c)
                return false;

        if (container_mem_lock(c))
                return false;

        ret = lxc_cmd_set_config_item(c->name, key, v, do_lxcapi_get_config_path(c));
        if (ret < 0)
                SYSERROR("%s - Failed to live patch container", strerror(-ret));

        container_mem_unlock(c);
        return ret == 0;
}

WRAP_API_2(bool, lxcapi_set_running_config_item, const char *, const char *)

static char *lxcapi_config_file_name(struct lxc_container *c)
{
        if (!c || !c->configfile)
                return NULL;
        return strdup(c->configfile);
}

static const char *lxcapi_get_config_path(struct lxc_container *c)
{
        if (!c || !c->config_path)
                return NULL;
        return (const char *)(c->config_path);
}

/*
 * not for export
 * Just recalculate the c->configfile based on the
 * c->config_path, which must be set.
 * The lxc_container must be locked or not yet public.
 */
static bool set_config_filename(struct lxc_container *c)
{
        char *newpath;
        int len, ret;

        if (!c->config_path)
                return false;

        /* $lxc_path + "/" + c->name + "/" + "config" + '\0' */
        len = strlen(c->config_path) + strlen(c->name) + strlen("config") + 3;
        newpath = malloc(len);
        if (!newpath)
                return false;

        ret = snprintf(newpath, len, "%s/%s/config", c->config_path, c->name);
        if (ret < 0 || ret >= len) {
                fprintf(stderr, "Error printing out config file name\n");
                free(newpath);
                return false;
        }

        free(c->configfile);
        c->configfile = newpath;

        return true;
}

static bool do_lxcapi_set_config_path(struct lxc_container *c, const char *path)
{
        char *p;
        bool b = false;
        char *oldpath = NULL;

        if (!c)
                return b;

        if (container_mem_lock(c))
                return b;

        p = strdup(path);
        if (!p) {
                ERROR("Out of memory setting new lxc path");
                goto err;
        }

        b = true;
        if (c->config_path)
                oldpath = c->config_path;
        c->config_path = p;

        /* Since we've changed the config path, we have to change the
         * config file name too */
        if (!set_config_filename(c)) {
                ERROR("Out of memory setting new config filename");
                b = false;
                free(c->config_path);
                c->config_path = oldpath;
                oldpath = NULL;
        }
err:
        free(oldpath);
        container_mem_unlock(c);
        return b;
}

WRAP_API_1(bool, lxcapi_set_config_path, const char *)

static bool do_lxcapi_set_cgroup_item(struct lxc_container *c, const char *subsys, const char *value)
{
        int ret;

        if (!c)
                return false;

        if (is_stopped(c))
                return false;

        if (container_disk_lock(c))
                return false;

        ret = lxc_cgroup_set(subsys, value, c->name, c->config_path);

        container_disk_unlock(c);
        return ret == 0;
}

WRAP_API_2(bool, lxcapi_set_cgroup_item, const char *, const char *)

static int do_lxcapi_get_cgroup_item(struct lxc_container *c, const char *subsys, char *retv, int inlen)
{
        int ret;

        if (!c)
                return -1;

        if (is_stopped(c))
                return -1;

        if (container_disk_lock(c))
                return -1;

        ret = lxc_cgroup_get(subsys, retv, inlen, c->name, c->config_path);

        container_disk_unlock(c);
        return ret;
}

WRAP_API_3(int, lxcapi_get_cgroup_item, const char *, char *, int)

const char *lxc_get_global_config_item(const char *key)
{
        return lxc_global_config_value(key);
}

const char *lxc_get_version(void)
{
        return LXC_VERSION;
}

static int copy_file(const char *old, const char *new)
{
        int in, out;
        ssize_t len, ret;
        char buf[8096];
        struct stat sbuf;

        if (file_exists(new)) {
                ERROR("copy destination %s exists", new);
                return -1;
        }
        ret = stat(old, &sbuf);
        if (ret < 0) {
                INFO("Error stat'ing %s", old);
                return -1;
        }

        in = open(old, O_RDONLY);
        if (in < 0) {
                SYSERROR("Error opening original file %s", old);
                return -1;
        }
        out = open(new, O_CREAT | O_EXCL | O_WRONLY, 0644);
        if (out < 0) {
                SYSERROR("Error opening new file %s", new);
                close(in);
                return -1;
        }

        while (1) {
                len = read(in, buf, 8096);
                if (len < 0) {
                        SYSERROR("Error reading old file %s", old);
                        goto err;
                }
                if (len == 0)
                        break;
                ret = write(out, buf, len);
                if (ret < len) { /* should we retry? */
                        SYSERROR("Error: write to new file %s was interrupted", new);
                        goto err;
                }
        }
        close(in);
        close(out);

        /* We set mode, but not owner/group. */
        ret = chmod(new, sbuf.st_mode);
        if (ret) {
                SYSERROR("Error setting mode on %s", new);
                return -1;
        }

        return 0;

err:
        close(in);
        close(out);
        return -1;
}

static int copyhooks(struct lxc_container *oldc, struct lxc_container *c)
{
        int i, len, ret;
        struct lxc_list *it;
        char *cpath;

        len = strlen(oldc->config_path) + strlen(oldc->name) + 3;
        cpath = alloca(len);
        ret = snprintf(cpath, len, "%s/%s/", oldc->config_path, oldc->name);
        if (ret < 0 || ret >= len)
                return -1;

        for (i=0; i<NUM_LXC_HOOKS; i++) {
                lxc_list_for_each(it, &c->lxc_conf->hooks[i]) {
                        char *hookname = it->elem;
                        char *fname = strrchr(hookname, '/');
                        char tmppath[MAXPATHLEN];
                        if (!fname) /* relative path - we don't support, but maybe we should */
                                return 0;
                        if (strncmp(hookname, cpath, len - 1) != 0) {
                                /* this hook is public - ignore */
                                continue;
                        }
                        /* copy the script, and change the entry in confile */
                        ret = snprintf(tmppath, MAXPATHLEN, "%s/%s/%s",
                                        c->config_path, c->name, fname+1);
                        if (ret < 0 || ret >= MAXPATHLEN)
                                return -1;
                        ret = copy_file(it->elem, tmppath);
                        if (ret < 0)
                                return -1;
                        free(it->elem);
                        it->elem = strdup(tmppath);
                        if (!it->elem) {
                                ERROR("out of memory copying hook path");
                                return -1;
                        }
                }
        }

        if (!clone_update_unexp_hooks(c->lxc_conf, oldc->config_path,
                        c->config_path, oldc->name, c->name)) {
                ERROR("Error saving new hooks in clone");
                return -1;
        }
        do_lxcapi_save_config(c, NULL);
        return 0;
}


static int copy_fstab(struct lxc_container *oldc, struct lxc_container *c)
{
        char newpath[MAXPATHLEN];
        char *oldpath = oldc->lxc_conf->fstab;
        int ret;

        if (!oldpath)
                return 0;

        /* REMOVE IN LXC 3.0
           legacy mount key
         */
        clear_unexp_config_line(c->lxc_conf, "lxc.mount", false);

        clear_unexp_config_line(c->lxc_conf, "lxc.mount.fstab", false);

        char *p = strrchr(oldpath, '/');
        if (!p)
                return -1;
        ret = snprintf(newpath, MAXPATHLEN, "%s/%s%s",
                        c->config_path, c->name, p);
        if (ret < 0 || ret >= MAXPATHLEN) {
                ERROR("error printing new path for %s", oldpath);
                return -1;
        }
        if (file_exists(newpath)) {
                ERROR("error: fstab file %s exists", newpath);
                return -1;
        }

        if (copy_file(oldpath, newpath) < 0) {
                ERROR("error: copying %s to %s", oldpath, newpath);
                return -1;
        }
        free(c->lxc_conf->fstab);
        c->lxc_conf->fstab = strdup(newpath);
        if (!c->lxc_conf->fstab) {
                ERROR("error: allocating pathname");
                return -1;
        }
        if (!do_append_unexp_config_line(c->lxc_conf, "lxc.mount.fstab", newpath)) {
                ERROR("error saving new lxctab");
                return -1;
        }

        return 0;
}

static void copy_rdepends(struct lxc_container *c, struct lxc_container *c0)
{
        char path0[MAXPATHLEN], path1[MAXPATHLEN];
        int ret;

        ret = snprintf(path0, MAXPATHLEN, "%s/%s/lxc_rdepends", c0->config_path,
                c0->name);
        if (ret < 0 || ret >= MAXPATHLEN) {
                WARN("Error copying reverse dependencies");
                return;
        }
        ret = snprintf(path1, MAXPATHLEN, "%s/%s/lxc_rdepends", c->config_path,
                c->name);
        if (ret < 0 || ret >= MAXPATHLEN) {
                WARN("Error copying reverse dependencies");
                return;
        }
        if (copy_file(path0, path1) < 0) {
                INFO("Error copying reverse dependencies");
                return;
        }
}

static bool add_rdepends(struct lxc_container *c, struct lxc_container *c0)
{
        int ret;
        char path[MAXPATHLEN];
        FILE *f;
        bool bret;

        ret = snprintf(path, MAXPATHLEN, "%s/%s/lxc_rdepends", c->config_path,
                c->name);
        if (ret < 0 || ret >= MAXPATHLEN)
                return false;
        f = fopen(path, "a");
        if (!f)
                return false;
        bret = true;
        /* If anything goes wrong, just return an error. */
        if (fprintf(f, "%s\n%s\n", c0->config_path, c0->name) < 0)
                bret = false;
        if (fclose(f) != 0)
                bret = false;
        return bret;
}

/*
 * If the fs natively supports snapshot clones with no penalty,
 * then default to those even if not requested.
 * Currently we only do this for btrfs.
 */
bool should_default_to_snapshot(struct lxc_container *c0,
                                struct lxc_container *c1)
{
        size_t l0 = strlen(c0->config_path) + strlen(c0->name) + 2;
        size_t l1 = strlen(c1->config_path) + strlen(c1->name) + 2;
        char *p0 = alloca(l0 + 1);
        char *p1 = alloca(l1 + 1);
        char *rootfs = c0->lxc_conf->rootfs.path;

        snprintf(p0, l0, "%s/%s", c0->config_path, c0->name);
        snprintf(p1, l1, "%s/%s", c1->config_path, c1->name);

        if (!is_btrfs_fs(p0) || !is_btrfs_fs(p1))
                return false;

        if (is_btrfs_subvol(rootfs) <= 0)
                return false;

        return btrfs_same_fs(p0, p1) == 0;
}

static int copy_storage(struct lxc_container *c0, struct lxc_container *c,
                        const char *newtype, int flags, const char *bdevdata,
                        uint64_t newsize)
{
        struct lxc_storage *bdev;
        bool need_rdep;

        if (should_default_to_snapshot(c0, c))
                flags |= LXC_CLONE_SNAPSHOT;

        bdev = storage_copy(c0, c->name, c->config_path, newtype, flags,
                            bdevdata, newsize, &need_rdep);
        if (!bdev) {
                ERROR("Error copying storage.");
                return -1;
        }

        /* Set new rootfs. */
        free(c->lxc_conf->rootfs.path);
        c->lxc_conf->rootfs.path = strdup(bdev->src);
        storage_put(bdev);

        if (!c->lxc_conf->rootfs.path) {
                ERROR("Out of memory while setting storage path.");
                return -1;
        }

        /* REMOVE IN LXC 3.0
         * legacy rootfs key
         */
        clear_unexp_config_line(c->lxc_conf, "lxc.rootfs", false);

        /* Append a new lxc.rootfs.path entry to the unexpanded config. */
        clear_unexp_config_line(c->lxc_conf, "lxc.rootfs.path", false);
        if (!do_append_unexp_config_line(c->lxc_conf, "lxc.rootfs.path",
                                         c->lxc_conf->rootfs.path)) {
                ERROR("Error saving new rootfs to cloned config.");
                return -1;
        }

        /* REMOVE IN LXC 3.0
         * legacy rootfs.backend key
         */
        clear_unexp_config_line(c->lxc_conf, "lxc.rootfs.backend", false);

        if (flags & LXC_CLONE_SNAPSHOT)
                copy_rdepends(c, c0);
        if (need_rdep) {
                if (!add_rdepends(c, c0))
                        WARN("Error adding reverse dependency from %s to %s",
                             c->name, c0->name);
        }

        mod_all_rdeps(c, true);

        return 0;
}

struct clone_update_data {
        struct lxc_container *c0;
        struct lxc_container *c1;
        int flags;
        char **hookargs;
};

static int clone_update_rootfs(struct clone_update_data *data)
{
        struct lxc_container *c0 = data->c0;
        struct lxc_container *c = data->c1;
        int flags = data->flags;
        char **hookargs = data->hookargs;
        int ret = -1;
        char path[MAXPATHLEN];
        struct lxc_storage *bdev;
        FILE *fout;
        struct lxc_conf *conf = c->lxc_conf;

        /* update hostname in rootfs */
        /* we're going to mount, so run in a clean namespace to simplify cleanup */

        if (setgid(0) < 0) {
                ERROR("Failed to setgid to 0");
                return -1;
        }
        if (setuid(0) < 0) {
                ERROR("Failed to setuid to 0");
                return -1;
        }
        if (setgroups(0, NULL) < 0)
                WARN("Failed to clear groups");

        if (unshare(CLONE_NEWNS) < 0)
                return -1;
        bdev = storage_init(c->lxc_conf);
        if (!bdev)
                return -1;
        if (strcmp(bdev->type, "dir") != 0) {
                if (unshare(CLONE_NEWNS) < 0) {
                        ERROR("error unsharing mounts");
                        storage_put(bdev);
                        return -1;
                }
                if (detect_shared_rootfs()) {
                        if (mount(NULL, "/", NULL, MS_SLAVE|MS_REC, NULL)) {
                                SYSERROR("Failed to make / rslave");
                                ERROR("Continuing...");
                        }
                }
                if (bdev->ops->mount(bdev) < 0) {
                        storage_put(bdev);
                        return -1;
                }
        } else { /* TODO come up with a better way */
                free(bdev->dest);
                bdev->dest = strdup(bdev->src);
        }

        if (!lxc_list_empty(&conf->hooks[LXCHOOK_CLONE])) {
                /* Start of environment variable setup for hooks */
                if (c0->name && setenv("LXC_SRC_NAME", c0->name, 1)) {
                        SYSERROR("failed to set environment variable for source container name");
                }
                if (c->name && setenv("LXC_NAME", c->name, 1)) {
                        SYSERROR("failed to set environment variable for container name");
                }
                if (conf->rcfile && setenv("LXC_CONFIG_FILE", conf->rcfile, 1)) {
                        SYSERROR("failed to set environment variable for config path");
                }
                if (bdev->dest && setenv("LXC_ROOTFS_MOUNT", bdev->dest, 1)) {
                        SYSERROR("failed to set environment variable for rootfs mount");
                }
                if (conf->rootfs.path && setenv("LXC_ROOTFS_PATH", conf->rootfs.path, 1)) {
                        SYSERROR("failed to set environment variable for rootfs mount");
                }

                if (run_lxc_hooks(c->name, "clone", conf, hookargs)) {
                        ERROR("Error executing clone hook for %s", c->name);
                        storage_put(bdev);
                        return -1;
                }
        }

        if (!(flags & LXC_CLONE_KEEPNAME)) {
                ret = snprintf(path, MAXPATHLEN, "%s/etc/hostname", bdev->dest);
                storage_put(bdev);

                if (ret < 0 || ret >= MAXPATHLEN)
                        return -1;
                if (!file_exists(path))
                        return 0;
                if (!(fout = fopen(path, "w"))) {
                        SYSERROR("unable to open %s: ignoring", path);
                        return 0;
                }
                if (fprintf(fout, "%s", c->name) < 0) {
                        fclose(fout);
                        return -1;
                }
                if (fclose(fout) < 0)
                        return -1;
        } else {
                storage_put(bdev);
        }

        return 0;
}

static int clone_update_rootfs_wrapper(void *data)
{
        struct clone_update_data *arg = (struct clone_update_data *) data;
        return clone_update_rootfs(arg);
}

/*
 * We want to support:
sudo lxc-clone -o o1 -n n1 -s -L|-fssize fssize -v|--vgname vgname \
        -p|--lvprefix lvprefix -t|--fstype fstype  -B backingstore

-s [ implies overlay]
-s -B overlay
-s -B aufs

only rootfs gets converted (copied/snapshotted) on clone.
*/

static int create_file_dirname(char *path, struct lxc_conf *conf)
{
        char *p = strrchr(path, '/');
        int ret = -1;

        if (!p)
                return -1;
        *p = '\0';
        ret = do_create_container_dir(path, conf);
        *p = '/';
        return ret;
}

static struct lxc_container *do_lxcapi_clone(struct lxc_container *c, const char *newname,
                const char *lxcpath, int flags,
                const char *bdevtype, const char *bdevdata, uint64_t newsize,
                char **hookargs)
{
        char newpath[MAXPATHLEN];
        int ret;
        struct clone_update_data data;
        size_t saved_unexp_len;
        FILE *fout;
        pid_t pid;
        int storage_copied = 0;
        char *origroot = NULL, *saved_unexp_conf = NULL;
        struct lxc_container *c2 = NULL;

        if (!c || !do_lxcapi_is_defined(c))
                return NULL;

        if (container_mem_lock(c))
                return NULL;

        if (!is_stopped(c)) {
                ERROR("error: Original container (%s) is running", c->name);
                goto out;
        }

        /* Make sure the container doesn't yet exist. */
        if (!newname)
                newname = c->name;
        if (!lxcpath)
                lxcpath = do_lxcapi_get_config_path(c);
        ret = snprintf(newpath, MAXPATHLEN, "%s/%s/config", lxcpath, newname);
        if (ret < 0 || ret >= MAXPATHLEN) {
                SYSERROR("clone: failed making config pathname");
                goto out;
        }

        if (file_exists(newpath)) {
                ERROR("error: clone: %s exists", newpath);
                goto out;
        }

        ret = create_file_dirname(newpath, c->lxc_conf);
        if (ret < 0 && errno != EEXIST) {
                ERROR("Error creating container dir for %s", newpath);
                goto out;
        }

        /* Copy the configuration. Tweak it as needed. */
        if (c->lxc_conf->rootfs.path) {
                origroot = c->lxc_conf->rootfs.path;
                c->lxc_conf->rootfs.path = NULL;
        }
        fout = fopen(newpath, "w");
        if (!fout) {
                SYSERROR("open %s", newpath);
                goto out;
        }

        saved_unexp_conf = c->lxc_conf->unexpanded_config;
        saved_unexp_len = c->lxc_conf->unexpanded_len;
        c->lxc_conf->unexpanded_config = strdup(saved_unexp_conf);
        if (!c->lxc_conf->unexpanded_config) {
                ERROR("Out of memory");
                fclose(fout);
                goto out;
        }

        /* REMOVE IN LXC 3.0
         * legacy rootfs key
         */
        clear_unexp_config_line(c->lxc_conf, "lxc.rootfs", false);

        clear_unexp_config_line(c->lxc_conf, "lxc.rootfs.path", false);
        write_config(fout, c->lxc_conf);
        fclose(fout);
        c->lxc_conf->rootfs.path = origroot;
        free(c->lxc_conf->unexpanded_config);
        c->lxc_conf->unexpanded_config = saved_unexp_conf;
        saved_unexp_conf = NULL;
        c->lxc_conf->unexpanded_len = saved_unexp_len;

        ret = snprintf(newpath, MAXPATHLEN, "%s/%s/rootfs", lxcpath, newname);
        if (ret < 0 || ret >= MAXPATHLEN) {
                SYSERROR("clone: failed making rootfs pathname");
                goto out;
        }

        ret = mkdir(newpath, 0755);
        if (ret < 0) {
                /* For an overlay container the rootfs is considered immutable
                 * and will not have been removed when restoring from a
                 * snapshot.
                 */
                if (errno != ENOENT &&
                    !(flags & LXC_STORAGE_INTERNAL_OVERLAY_RESTORE)) {
                        SYSERROR("Failed to create directory \"%s\"", newpath);
                        goto out;
                }
        }

        if (am_unpriv()) {
                if (chown_mapped_root(newpath, c->lxc_conf) < 0) {
                        ERROR("Error chowning %s to container root", newpath);
                        goto out;
                }
        }

        c2 = lxc_container_new(newname, lxcpath);
        if (!c2) {
                ERROR("clone: failed to create new container (%s %s)", newname,
                                lxcpath);
                goto out;
        }

        /* copy/snapshot rootfs's */
        ret = copy_storage(c, c2, bdevtype, flags, bdevdata, newsize);
        if (ret < 0)
                goto out;


        /* update utsname */
        if (!(flags & LXC_CLONE_KEEPNAME)) {
                clear_unexp_config_line(c2->lxc_conf, "lxc.utsname", false);
                clear_unexp_config_line(c2->lxc_conf, "lxc.uts.name", false);

                if (!do_set_config_item_locked(c2, "lxc.uts.name", newname)) {
                        ERROR("Error setting new hostname");
                        goto out;
                }
        }

        /* copy hooks */
        ret = copyhooks(c, c2);
        if (ret < 0) {
                ERROR("error copying hooks");
                goto out;
        }

        if (copy_fstab(c, c2) < 0) {
                ERROR("error copying fstab");
                goto out;
        }

        /* update macaddrs */
        if (!(flags & LXC_CLONE_KEEPMACADDR)) {
                if (!network_new_hwaddrs(c2->lxc_conf)) {
                        ERROR("Error updating mac addresses");
                        goto out;
                }
        }

        /* Update absolute paths for overlay mount directories. */
        if (ovl_update_abs_paths(c2->lxc_conf, c->config_path, c->name, lxcpath, newname) < 0)
                goto out;

        /* We've now successfully created c2's storage, so clear it out if we
         * fail after this.
         */
        storage_copied = 1;

        if (!c2->save_config(c2, NULL))
                goto out;

        if ((pid = fork()) < 0) {
                SYSERROR("fork");
                goto out;
        }
        if (pid > 0) {
                ret = wait_for_pid(pid);
                if (ret)
                        goto out;
                container_mem_unlock(c);
                return c2;
        }
        data.c0 = c;
        data.c1 = c2;
        data.flags = flags;
        data.hookargs = hookargs;
        if (am_unpriv())
                ret = userns_exec_full(c->lxc_conf, clone_update_rootfs_wrapper,
                                       &data, "clone_update_rootfs_wrapper");
        else
                ret = clone_update_rootfs(&data);
        if (ret < 0)
                exit(1);

        container_mem_unlock(c);
        exit(0);

out:
        container_mem_unlock(c);
        if (c2) {
                if (!storage_copied)
                        c2->lxc_conf->rootfs.path = NULL;
                c2->destroy(c2);
                lxc_container_put(c2);
        }

        return NULL;
}

static struct lxc_container *lxcapi_clone(struct lxc_container *c, const char *newname,
                const char *lxcpath, int flags,
                const char *bdevtype, const char *bdevdata, uint64_t newsize,
                char **hookargs)
{
        struct lxc_container * ret;
        current_config = c ? c->lxc_conf : NULL;
        ret = do_lxcapi_clone(c, newname, lxcpath, flags, bdevtype, bdevdata, newsize, hookargs);
        current_config = NULL;
        return ret;
}

static bool do_lxcapi_rename(struct lxc_container *c, const char *newname)
{
        struct lxc_storage *bdev;
        struct lxc_container *newc;

        if (!c || !c->name || !c->config_path || !c->lxc_conf)
                return false;

        if (has_fs_snapshots(c) || has_snapshots(c)) {
                ERROR("Renaming a container with snapshots is not supported");
                return false;
        }
        bdev = storage_init(c->lxc_conf);
        if (!bdev) {
                ERROR("Failed to find original backing store type");
                return false;
        }

        newc = lxcapi_clone(c, newname, c->config_path, LXC_CLONE_KEEPMACADDR, NULL, bdev->type, 0, NULL);
        storage_put(bdev);
        if (!newc) {
                lxc_container_put(newc);
                return false;
        }

        if (newc && lxcapi_is_defined(newc))
                lxc_container_put(newc);

        if (!container_destroy(c, NULL)) {
                ERROR("Could not destroy existing container %s", c->name);
                return false;
        }
        return true;
}

WRAP_API_1(bool, lxcapi_rename, const char *)

static int lxcapi_attach(struct lxc_container *c, lxc_attach_exec_t exec_function, void *exec_payload, lxc_attach_options_t *options, pid_t *attached_process)
{
        int ret;

        if (!c)
                return -1;

        current_config = c->lxc_conf;

        ret = lxc_attach(c->name, c->config_path, exec_function, exec_payload, options, attached_process);
        current_config = NULL;
        return ret;
}

static int do_lxcapi_attach_run_wait(struct lxc_container *c, lxc_attach_options_t *options, const char *program, const char * const argv[])
{
        lxc_attach_command_t command;
        pid_t pid;
        int r;

        if (!c)
                return -1;

        command.program = (char*)program;
        command.argv = (char**)argv;
        r = lxc_attach(c->name, c->config_path, lxc_attach_run_command, &command, options, &pid);
        if (r < 0) {
                ERROR("ups");
                return r;
        }
        return lxc_wait_for_pid_status(pid);
}

static int lxcapi_attach_run_wait(struct lxc_container *c, lxc_attach_options_t *options, const char *program, const char * const argv[])
{
        int ret;
        current_config = c ? c->lxc_conf : NULL;
        ret = do_lxcapi_attach_run_wait(c, options, program, argv);
        current_config = NULL;
        return ret;
}

static int get_next_index(const char *lxcpath, char *cname)
{
        char *fname;
        struct stat sb;
        int i = 0, ret;

        fname = alloca(strlen(lxcpath) + 20);
        while (1) {
                sprintf(fname, "%s/snap%d", lxcpath, i);
                ret = stat(fname, &sb);
                if (ret != 0)
                        return i;
                i++;
        }
}

static bool get_snappath_dir(struct lxc_container *c, char *snappath)
{
        int ret;
        /*
         * If the old style snapshot path exists, use it
         * /var/lib/lxc -> /var/lib/lxcsnaps
         */
        ret = snprintf(snappath, MAXPATHLEN, "%ssnaps", c->config_path);
        if (ret < 0 || ret >= MAXPATHLEN)
                return false;
        if (dir_exists(snappath)) {
                ret = snprintf(snappath, MAXPATHLEN, "%ssnaps/%s", c->config_path, c->name);
                if (ret < 0 || ret >= MAXPATHLEN)
                        return false;
                return true;
        }

        /*
         * Use the new style path
         * /var/lib/lxc -> /var/lib/lxc + c->name + /snaps + \0
         */
        ret = snprintf(snappath, MAXPATHLEN, "%s/%s/snaps", c->config_path, c->name);
        if (ret < 0 || ret >= MAXPATHLEN)
                return false;
        return true;
}

static int do_lxcapi_snapshot(struct lxc_container *c, const char *commentfile)
{
        int i, flags, ret;
        struct lxc_container *c2;
        char snappath[MAXPATHLEN], newname[20];

        if (!c || !lxcapi_is_defined(c))
                return -1;

        if (!storage_can_backup(c->lxc_conf)) {
                ERROR("%s's backing store cannot be backed up.", c->name);
                ERROR("Your container must use another backing store type.");
                return -1;
        }

        if (!get_snappath_dir(c, snappath))
                return -1;

        i = get_next_index(snappath, c->name);

        if (mkdir_p(snappath, 0755) < 0) {
                ERROR("Failed to create snapshot directory %s", snappath);
                return -1;
        }

        ret = snprintf(newname, 20, "snap%d", i);
        if (ret < 0 || ret >= 20)
                return -1;

        /*
         * We pass LXC_CLONE_SNAPSHOT to make sure that a rdepends file entry is
         * created in the original container
         */
        flags = LXC_CLONE_SNAPSHOT | LXC_CLONE_KEEPMACADDR | LXC_CLONE_KEEPNAME |
                LXC_CLONE_KEEPBDEVTYPE | LXC_CLONE_MAYBE_SNAPSHOT;
        if (storage_is_dir(c->lxc_conf)) {
                ERROR("Snapshot of directory-backed container requested.");
                ERROR("Making a copy-clone.  If you do want snapshots, then");
                ERROR("please create an aufs or overlay clone first, snapshot that");
                ERROR("and keep the original container pristine.");
                flags &= ~LXC_CLONE_SNAPSHOT | LXC_CLONE_MAYBE_SNAPSHOT;
        }
        c2 = do_lxcapi_clone(c, newname, snappath, flags, NULL, NULL, 0, NULL);
        if (!c2) {
                ERROR("clone of %s:%s failed", c->config_path, c->name);
                return -1;
        }

        lxc_container_put(c2);

        /* Now write down the creation time. */
        time_t timer;
        char buffer[25];
        struct tm* tm_info;
        FILE *f;

        time(&timer);
        tm_info = localtime(&timer);

        strftime(buffer, 25, "%Y:%m:%d %H:%M:%S", tm_info);

        char *dfnam = alloca(strlen(snappath) + strlen(newname) + 5);
        sprintf(dfnam, "%s/%s/ts", snappath, newname);
        f = fopen(dfnam, "w");
        if (!f) {
                ERROR("Failed to open %s", dfnam);
                return -1;
        }
        if (fprintf(f, "%s", buffer) < 0) {
                SYSERROR("Writing timestamp");
                fclose(f);
                return -1;
        }
        ret = fclose(f);
        if (ret != 0) {
                SYSERROR("Writing timestamp");
                return -1;
        }

        if (commentfile) {
                /* $p / $name / comment \0 */
                int len = strlen(snappath) + strlen(newname) + 10;
                char *path = alloca(len);
                sprintf(path, "%s/%s/comment", snappath, newname);
                return copy_file(commentfile, path) < 0 ? -1 : i;
        }

        return i;
}

WRAP_API_1(int, lxcapi_snapshot, const char *)

static void lxcsnap_free(struct lxc_snapshot *s)
{
        free(s->name);
        free(s->comment_pathname);
        free(s->timestamp);
        free(s->lxcpath);
}

static char *get_snapcomment_path(char* snappath, char *name)
{
        /* $snappath/$name/comment */
        int ret, len = strlen(snappath) + strlen(name) + 10;
        char *s = malloc(len);

        if (s) {
                ret = snprintf(s, len, "%s/%s/comment", snappath, name);
                if (ret < 0 || ret >= len) {
                        free(s);
                        s = NULL;
                }
        }
        return s;
}

static char *get_timestamp(char* snappath, char *name)
{
        char path[MAXPATHLEN], *s = NULL;
        int ret, len;
        FILE *fin;

        ret = snprintf(path, MAXPATHLEN, "%s/%s/ts", snappath, name);
        if (ret < 0 || ret >= MAXPATHLEN)
                return NULL;
        fin = fopen(path, "r");
        if (!fin)
                return NULL;
        (void) fseek(fin, 0, SEEK_END);
        len = ftell(fin);
        (void) fseek(fin, 0, SEEK_SET);
        if (len > 0) {
                s = malloc(len+1);
                if (s) {
                        s[len] = '\0';
                        if (fread(s, 1, len, fin) != len) {
                                SYSERROR("reading timestamp");
                                free(s);
                                s = NULL;
                        }
                }
        }
        fclose(fin);
        return s;
}

static int do_lxcapi_snapshot_list(struct lxc_container *c, struct lxc_snapshot **ret_snaps)
{
        char snappath[MAXPATHLEN], path2[MAXPATHLEN];
        int count = 0, ret;
        struct dirent *direntp;
        struct lxc_snapshot *snaps =NULL, *nsnaps;
        DIR *dir;

        if (!c || !lxcapi_is_defined(c))
                return -1;

        if (!get_snappath_dir(c, snappath)) {
                ERROR("path name too long");
                return -1;
        }
        dir = opendir(snappath);
        if (!dir) {
                INFO("failed to open %s - assuming no snapshots", snappath);
                return 0;
        }

        while ((direntp = readdir(dir))) {
                if (!direntp)
                        break;

                if (!strcmp(direntp->d_name, "."))
                        continue;

                if (!strcmp(direntp->d_name, ".."))
                        continue;

                ret = snprintf(path2, MAXPATHLEN, "%s/%s/config", snappath, direntp->d_name);
                if (ret < 0 || ret >= MAXPATHLEN) {
                        ERROR("pathname too long");
                        goto out_free;
                }
                if (!file_exists(path2))
                        continue;
                nsnaps = realloc(snaps, (count + 1)*sizeof(*snaps));
                if (!nsnaps) {
                        SYSERROR("Out of memory");
                        goto out_free;
                }
                snaps = nsnaps;
                snaps[count].free = lxcsnap_free;
                snaps[count].name = strdup(direntp->d_name);
                if (!snaps[count].name)
                        goto out_free;
                snaps[count].lxcpath = strdup(snappath);
                if (!snaps[count].lxcpath) {
                        free(snaps[count].name);
                        goto out_free;
                }
                snaps[count].comment_pathname = get_snapcomment_path(snappath, direntp->d_name);
                snaps[count].timestamp = get_timestamp(snappath, direntp->d_name);
                count++;
        }

        if (closedir(dir))
                WARN("failed to close directory");

        *ret_snaps = snaps;
        return count;

out_free:
        if (snaps) {
                int i;
                for (i=0; i<count; i++)
                        lxcsnap_free(&snaps[i]);
                free(snaps);
        }
        if (closedir(dir))
                WARN("failed to close directory");
        return -1;
}

WRAP_API_1(int, lxcapi_snapshot_list, struct lxc_snapshot **)

static bool do_lxcapi_snapshot_restore(struct lxc_container *c, const char *snapname, const char *newname)
{
        char clonelxcpath[MAXPATHLEN];
        int flags = 0;
        struct lxc_container *snap, *rest;
        struct lxc_storage *bdev;
        bool b = false;

        if (!c || !c->name || !c->config_path)
                return false;

        if (has_fs_snapshots(c)) {
                ERROR("container rootfs has dependent snapshots");
                return false;
        }

        bdev = storage_init(c->lxc_conf);
        if (!bdev) {
                ERROR("Failed to find original backing store type");
                return false;
        }

        /* For an overlay container the rootfs is considered immutable
         * and cannot be removed when restoring from a snapshot. We pass this
         * internal flag along to communicate this to various parts of the
         * codebase.
         */
        if (!strcmp(bdev->type, "overlay") || !strcmp(bdev->type, "overlayfs"))
                bdev->flags |= LXC_STORAGE_INTERNAL_OVERLAY_RESTORE;

        if (!newname)
                newname = c->name;

        if (!get_snappath_dir(c, clonelxcpath)) {
                storage_put(bdev);
                return false;
        }
        /* how should we lock this? */

        snap = lxc_container_new(snapname, clonelxcpath);
        if (!snap || !lxcapi_is_defined(snap)) {
                ERROR("Could not open snapshot %s", snapname);
                if (snap)
                        lxc_container_put(snap);
                storage_put(bdev);
                return false;
        }

        if (!strcmp(c->name, newname)) {
                if (!container_destroy(c, bdev)) {
                        ERROR("Could not destroy existing container %s", newname);
                        lxc_container_put(snap);
                        storage_put(bdev);
                        return false;
                }
        }

        if (strcmp(bdev->type, "dir") != 0 && strcmp(bdev->type, "loop") != 0)
                flags = LXC_CLONE_SNAPSHOT | LXC_CLONE_MAYBE_SNAPSHOT;

        if (!strcmp(bdev->type, "overlay") || !strcmp(bdev->type, "overlayfs"))
                flags |= LXC_STORAGE_INTERNAL_OVERLAY_RESTORE;
        rest = lxcapi_clone(snap, newname, c->config_path, flags, bdev->type,
                            NULL, 0, NULL);
        storage_put(bdev);
        if (rest && lxcapi_is_defined(rest))
                b = true;
        if (rest)
                lxc_container_put(rest);

        lxc_container_put(snap);
        return b;
}

WRAP_API_2(bool, lxcapi_snapshot_restore, const char *, const char *)

static bool do_snapshot_destroy(const char *snapname, const char *clonelxcpath)
{
        struct lxc_container *snap = NULL;
        bool bret = false;

        snap = lxc_container_new(snapname, clonelxcpath);
        if (!snap) {
                ERROR("Could not find snapshot %s", snapname);
                goto err;
        }

        if (!do_lxcapi_destroy(snap)) {
                ERROR("Could not destroy snapshot %s", snapname);
                goto err;
        }
        bret = true;

err:
        if (snap)
                lxc_container_put(snap);
        return bret;
}

static bool remove_all_snapshots(const char *path)
{
        DIR *dir;
        struct dirent *direntp;
        bool bret = true;

        dir = opendir(path);
        if (!dir) {
                SYSERROR("opendir on snapshot path %s", path);
                return false;
        }
        while ((direntp = readdir(dir))) {
                if (!strcmp(direntp->d_name, "."))
                        continue;
                if (!strcmp(direntp->d_name, ".."))
                        continue;
                if (!do_snapshot_destroy(direntp->d_name, path)) {
                        bret = false;
                        continue;
                }
        }

        closedir(dir);

        if (rmdir(path))
                SYSERROR("Error removing directory %s", path);

        return bret;
}

static bool do_lxcapi_snapshot_destroy(struct lxc_container *c, const char *snapname)
{
        char clonelxcpath[MAXPATHLEN];

        if (!c || !c->name || !c->config_path || !snapname)
                return false;

        if (!get_snappath_dir(c, clonelxcpath))
                return false;

        return do_snapshot_destroy(snapname, clonelxcpath);
}

WRAP_API_1(bool, lxcapi_snapshot_destroy, const char *)

static bool do_lxcapi_snapshot_destroy_all(struct lxc_container *c)
{
        char clonelxcpath[MAXPATHLEN];

        if (!c || !c->name || !c->config_path)
                return false;

        if (!get_snappath_dir(c, clonelxcpath))
                return false;

        return remove_all_snapshots(clonelxcpath);
}

WRAP_API(bool, lxcapi_snapshot_destroy_all)

static bool do_lxcapi_may_control(struct lxc_container *c)
{
        return lxc_try_cmd(c->name, c->config_path) == 0;
}

WRAP_API(bool, lxcapi_may_control)

static bool do_add_remove_node(pid_t init_pid, const char *path, bool add,
                               struct stat *st)
{
        int ret;
        char *tmp;
        pid_t pid;
        char chrootpath[MAXPATHLEN];
        char *directory_path = NULL;

        pid = fork();
        if (pid < 0) {
                SYSERROR("Failed to fork()");
                return false;
        }

        if (pid) {
                ret = wait_for_pid(pid);
                if (ret != 0) {
                        ERROR("Failed to create device node");
                        return false;
                }

                return true;
        }

        /* prepare the path */
        ret = snprintf(chrootpath, MAXPATHLEN, "/proc/%d/root", init_pid);
        if (ret < 0 || ret >= MAXPATHLEN)
                return false;

        ret = chroot(chrootpath);
        if (ret < 0)
                exit(EXIT_FAILURE);

        ret = chdir("/");
        if (ret < 0)
                exit(EXIT_FAILURE);

        /* remove path if it exists */
        ret = faccessat(AT_FDCWD, path, F_OK, AT_SYMLINK_NOFOLLOW);
        if(ret == 0) {
                ret = unlink(path);
                if (ret < 0) {
                        ERROR("%s - Failed to remove \"%s\"", strerror(errno), path);
                        exit(EXIT_FAILURE);
                }
        }

        if (!add)
                exit(EXIT_SUCCESS);

        /* create any missing directories */
        tmp = strdup(path);
        if (!tmp)
                exit(EXIT_FAILURE);

        directory_path = dirname(tmp);
        ret = mkdir_p(directory_path, 0755);
        if (ret < 0 && errno != EEXIST) {
                ERROR("%s - Failed to create path \"%s\"", strerror(errno), directory_path);
                free(tmp);
                exit(EXIT_FAILURE);
        }

        /* create the device node */
        ret = mknod(path, st->st_mode, st->st_rdev);
        free(tmp);
        if (ret < 0) {
                ERROR("%s - Failed to create device node at \"%s\"", strerror(errno), path);
                exit(EXIT_FAILURE);
        }

        exit(EXIT_SUCCESS);
}

static bool add_remove_device_node(struct lxc_container *c, const char *src_path, const char *dest_path, bool add)
{
        int ret;
        struct stat st;
        char value[MAX_BUFFER];
        const char *p;

        /* make sure container is running */
        if (!do_lxcapi_is_running(c)) {
                ERROR("container is not running");
                return false;
        }

        /* use src_path if dest_path is NULL otherwise use dest_path */
        p = dest_path ? dest_path : src_path;

        /* make sure we can access p */
        if(access(p, F_OK) < 0 || stat(p, &st) < 0)
                return false;

        /* continue if path is character device or block device */
        if (S_ISCHR(st.st_mode))
                ret = snprintf(value, MAX_BUFFER, "c %d:%d rwm", major(st.st_rdev), minor(st.st_rdev));
        else if (S_ISBLK(st.st_mode))
                ret = snprintf(value, MAX_BUFFER, "b %d:%d rwm", major(st.st_rdev), minor(st.st_rdev));
        else
                return false;

        /* check snprintf return code */
        if (ret < 0 || ret >= MAX_BUFFER)
                return false;

        if (!do_add_remove_node(do_lxcapi_init_pid(c), p, add, &st))
                return false;

        /* add or remove device to/from cgroup access list */
        if (add) {
                if (!do_lxcapi_set_cgroup_item(c, "devices.allow", value)) {
                        ERROR("set_cgroup_item failed while adding the device node");
                        return false;
                }
        } else {
                if (!do_lxcapi_set_cgroup_item(c, "devices.deny", value)) {
                        ERROR("set_cgroup_item failed while removing the device node");
                        return false;
                }
        }

        return true;
}

static bool do_lxcapi_add_device_node(struct lxc_container *c, const char *src_path, const char *dest_path)
{
        if (am_unpriv()) {
                ERROR(NOT_SUPPORTED_ERROR, __FUNCTION__);
                return false;
        }
        return add_remove_device_node(c, src_path, dest_path, true);
}

WRAP_API_2(bool, lxcapi_add_device_node, const char *, const char *)

static bool do_lxcapi_remove_device_node(struct lxc_container *c, const char *src_path, const char *dest_path)
{
        if (am_unpriv()) {
                ERROR(NOT_SUPPORTED_ERROR, __FUNCTION__);
                return false;
        }
        return add_remove_device_node(c, src_path, dest_path, false);
}

WRAP_API_2(bool, lxcapi_remove_device_node, const char *, const char *)

static bool do_lxcapi_attach_interface(struct lxc_container *c,
                                       const char *ifname,
                                       const char *dst_ifname)
{
        pid_t init_pid;
        int ret = 0;

        if (am_unpriv()) {
                ERROR(NOT_SUPPORTED_ERROR, __FUNCTION__);
                return false;
        }

        if (!ifname) {
                ERROR("No source interface name given");
                return false;
        }

        ret = lxc_netdev_isup(ifname);
        if (ret > 0) {
                /* netdev of ifname is up. */
                ret = lxc_netdev_down(ifname);
                if (ret)
                        goto err;
        }

        init_pid = do_lxcapi_init_pid(c);
        ret = lxc_netdev_move_by_name(ifname, init_pid, dst_ifname);
        if (ret)
                goto err;

        INFO("Moved network device \"%s\" to network namespace of %d", ifname, init_pid);
        return true;

err:
        return false;
}

WRAP_API_2(bool, lxcapi_attach_interface, const char *, const char *)

static bool do_lxcapi_detach_interface(struct lxc_container *c,
                                       const char *ifname,
                                       const char *dst_ifname)
{
        int ret;
        pid_t pid, pid_outside;

        if (am_unpriv()) {
                ERROR(NOT_SUPPORTED_ERROR, __FUNCTION__);
                return false;
        }

        if (!ifname) {
                ERROR("No source interface name given");
                return false;
        }

        pid_outside = lxc_raw_getpid();
        pid = fork();
        if (pid < 0) {
                ERROR("Failed to fork");
                return false;
        }

        if (pid == 0) { /* child */
                pid_t init_pid;

                init_pid = do_lxcapi_init_pid(c);
                if (!switch_to_ns(init_pid, "net")) {
                        ERROR("Failed to enter network namespace");
                        exit(EXIT_FAILURE);
                }

                ret = lxc_netdev_isup(ifname);
                if (ret < 0) {
                        ERROR("Failed to determine whether network device \"%s\" is up", ifname);
                        exit(EXIT_FAILURE);
                }

                /* netdev of ifname is up. */
                if (ret) {
                        ret = lxc_netdev_down(ifname);
                        if (ret) {
                                ERROR("Failed to set network device \"%s\" down", ifname);
                                exit(EXIT_FAILURE);
                        }
                }

                ret = lxc_netdev_move_by_name(ifname, pid_outside, dst_ifname);
                /* -EINVAL means there is no netdev named as ifname. */
                if (ret < 0) {
                        if (ret == -EINVAL)
                                ERROR("Network device \"%s\" not found", ifname);
                        else
                                ERROR("Failed to remove network device \"%s\"", ifname);
                        exit(EXIT_FAILURE);
                }

                exit(EXIT_SUCCESS);
        }

        ret = wait_for_pid(pid);
        if (ret != 0)
                return false;

        INFO("Moved network device \"%s\" to network namespace of %d", ifname, pid_outside);
        return true;
}

WRAP_API_2(bool, lxcapi_detach_interface, const char *, const char *)

static int do_lxcapi_migrate(struct lxc_container *c, unsigned int cmd,
                             struct migrate_opts *opts, unsigned int size)
{
        int ret = -1;
        struct migrate_opts *valid_opts = opts;
        uint64_t features_to_check = 0;

        /* If the caller has a bigger (newer) struct migrate_opts, let's make
         * sure that the stuff on the end is zero, i.e. that they didn't ask us
         * to do anything special.
         */
        if (size > sizeof(*opts)) {
                unsigned char *addr;
                unsigned char *end;

                addr = (void *)opts + sizeof(*opts);
                end  = (void *)opts + size;
                for (; addr < end; addr++) {
                        if (*addr) {
                                return -E2BIG;
                        }
                }
        }

        /* If the caller has a smaller struct, let's zero out the end for them
         * so we don't accidentally use bits of it that they didn't know about
         * to initialize.
         */
        if (size < sizeof(*opts)) {
                valid_opts = malloc(sizeof(*opts));
                if (!valid_opts)
                        return -ENOMEM;

                memset(valid_opts, 0, sizeof(*opts));
                memcpy(valid_opts, opts, size);
        }

        switch (cmd) {
        case MIGRATE_PRE_DUMP:
                if (!do_lxcapi_is_running(c)) {
                        ERROR("container is not running");
                        goto on_error;
                }
                ret = !__criu_pre_dump(c, valid_opts);
                break;
        case MIGRATE_DUMP:
                if (!do_lxcapi_is_running(c)) {
                        ERROR("container is not running");
                        goto on_error;
                }
                ret = !__criu_dump(c, valid_opts);
                break;
        case MIGRATE_RESTORE:
                if (do_lxcapi_is_running(c)) {
                        ERROR("container is already running");
                        goto on_error;
                }
                ret = !__criu_restore(c, valid_opts);
                break;
        case MIGRATE_FEATURE_CHECK:
                features_to_check = valid_opts->features_to_check;
                ret = !__criu_check_feature(&features_to_check);
                if (ret) {
                        /* Something went wrong. Let's let the caller
                         * know which feature checks failed. */
                        valid_opts->features_to_check = features_to_check;
                }
                break;
        default:
                ERROR("invalid migrate command %u", cmd);
                ret = -EINVAL;
        }

on_error:
        if (size < sizeof(*opts))
                free(valid_opts);

        return ret;
}

WRAP_API_3(int, lxcapi_migrate, unsigned int, struct migrate_opts *, unsigned int)

static bool do_lxcapi_checkpoint(struct lxc_container *c, char *directory, bool stop, bool verbose)
{
        struct migrate_opts opts;

        memset(&opts, 0, sizeof(opts));

        opts.directory = directory;
        opts.stop = stop;
        opts.verbose = verbose;

        return !do_lxcapi_migrate(c, MIGRATE_DUMP, &opts, sizeof(opts));
}

WRAP_API_3(bool, lxcapi_checkpoint, char *, bool, bool)

static bool do_lxcapi_restore(struct lxc_container *c, char *directory, bool verbose)
{
        struct migrate_opts opts;

        memset(&opts, 0, sizeof(opts));

        opts.directory = directory;
        opts.verbose = verbose;

        return !do_lxcapi_migrate(c, MIGRATE_RESTORE, &opts, sizeof(opts));
}

WRAP_API_2(bool, lxcapi_restore, char *, bool)

static int lxcapi_attach_run_waitl(struct lxc_container *c, lxc_attach_options_t *options, const char *program, const char *arg, ...)
{
        va_list ap;
        const char **argv;
        int ret;

        if (!c)
                return -1;

        current_config = c->lxc_conf;

        va_start(ap, arg);
        argv = lxc_va_arg_list_to_argv_const(ap, 1);
        va_end(ap);

        if (!argv) {
                ERROR("Memory allocation error.");
                ret = -1;
                goto out;
        }
        argv[0] = arg;

        ret = do_lxcapi_attach_run_wait(c, options, program, (const char * const *)argv);
        free((void*)argv);
out:
        current_config = NULL;
        return ret;
}

struct lxc_container *lxc_container_new(const char *name, const char *configpath)
{
        struct lxc_container *c;

        if (!name)
                return NULL;

        c = malloc(sizeof(*c));
        if (!c) {
                fprintf(stderr, "Failed to allocate memory for %s\n", name);
                return NULL;
        }
        memset(c, 0, sizeof(*c));

        if (configpath)
                c->config_path = strdup(configpath);
        else
                c->config_path = strdup(lxc_global_config_value("lxc.lxcpath"));

        if (!c->config_path) {
                fprintf(stderr, "Failed to allocate memory for %s\n", name);
                goto err;
        }

        remove_trailing_slashes(c->config_path);
        c->name = malloc(strlen(name)+1);
        if (!c->name) {
                fprintf(stderr, "Failed to allocate memory for %s\n", name);
                goto err;
        }
        strcpy(c->name, name);

        c->numthreads = 1;
        c->slock = lxc_newlock(c->config_path, name);
        if (!c->slock) {
                fprintf(stderr, "Failed to create lock for %s\n", name);
                goto err;
        }

        c->privlock = lxc_newlock(NULL, NULL);
        if (!c->privlock) {
                fprintf(stderr, "Failed to create private lock for %s\n", name);
                goto err;
        }

        if (!set_config_filename(c)) {
                fprintf(stderr, "Failed to create config file name for %s\n", name);
                goto err;
        }

        if (file_exists(c->configfile) && !lxcapi_load_config(c, NULL)) {
                fprintf(stderr, "Failed to load config for %s\n", name);
                goto err;
        }

        if (ongoing_create(c) == 2) {
                ERROR("Failed to complete container creation for %s", c->name);
                container_destroy(c, NULL);
                lxcapi_clear_config(c);
        }
        c->daemonize = true;
        c->pidfile = NULL;

        /* Assign the member functions. */
        c->is_defined = lxcapi_is_defined;
        c->state = lxcapi_state;
        c->is_running = lxcapi_is_running;
        c->freeze = lxcapi_freeze;
        c->unfreeze = lxcapi_unfreeze;
        c->console = lxcapi_console;
        c->console_getfd = lxcapi_console_getfd;
        c->init_pid = lxcapi_init_pid;
        c->load_config = lxcapi_load_config;
        c->want_daemonize = lxcapi_want_daemonize;
        c->want_close_all_fds = lxcapi_want_close_all_fds;
        c->start = lxcapi_start;
        c->startl = lxcapi_startl;
        c->stop = lxcapi_stop;
        c->config_file_name = lxcapi_config_file_name;
        c->wait = lxcapi_wait;
        c->set_config_item = lxcapi_set_config_item;
        c->destroy = lxcapi_destroy;
        c->destroy_with_snapshots = lxcapi_destroy_with_snapshots;
        c->rename = lxcapi_rename;
        c->save_config = lxcapi_save_config;
        c->get_keys = lxcapi_get_keys;
        c->create = lxcapi_create;
        c->createl = lxcapi_createl;
        c->shutdown = lxcapi_shutdown;
        c->reboot = lxcapi_reboot;
        c->reboot2 = lxcapi_reboot2;
        c->clear_config = lxcapi_clear_config;
        c->clear_config_item = lxcapi_clear_config_item;
        c->get_config_item = lxcapi_get_config_item;
        c->get_running_config_item = lxcapi_get_running_config_item;
        c->set_running_config_item = lxcapi_set_running_config_item;
        c->get_cgroup_item = lxcapi_get_cgroup_item;
        c->set_cgroup_item = lxcapi_set_cgroup_item;
        c->get_config_path = lxcapi_get_config_path;
        c->set_config_path = lxcapi_set_config_path;
        c->clone = lxcapi_clone;
        c->get_interfaces = lxcapi_get_interfaces;
        c->get_ips = lxcapi_get_ips;
        c->attach = lxcapi_attach;
        c->attach_run_wait = lxcapi_attach_run_wait;
        c->attach_run_waitl = lxcapi_attach_run_waitl;
        c->snapshot = lxcapi_snapshot;
        c->snapshot_list = lxcapi_snapshot_list;
        c->snapshot_restore = lxcapi_snapshot_restore;
        c->snapshot_destroy = lxcapi_snapshot_destroy;
        c->snapshot_destroy_all = lxcapi_snapshot_destroy_all;
        c->may_control = lxcapi_may_control;
        c->add_device_node = lxcapi_add_device_node;
        c->remove_device_node = lxcapi_remove_device_node;
        c->attach_interface = lxcapi_attach_interface;
        c->detach_interface = lxcapi_detach_interface;
        c->checkpoint = lxcapi_checkpoint;
        c->restore = lxcapi_restore;
        c->migrate = lxcapi_migrate;
        c->console_log = lxcapi_console_log;

        return c;

err:
        lxc_container_free(c);
        return NULL;
}

int lxc_get_wait_states(const char **states)
{
        int i;

        if (states)
                for (i=0; i<MAX_STATE; i++)
                        states[i] = lxc_state2str(i);
        return MAX_STATE;
}

/*
 * These next two could probably be done smarter with reusing a common function
 * with different iterators and tests...
 */
int list_defined_containers(const char *lxcpath, char ***names, struct lxc_container ***cret)
{
        DIR *dir;
        int i, cfound = 0, nfound = 0;
        struct dirent *direntp;
        struct lxc_container *c;

        if (!lxcpath)
                lxcpath = lxc_global_config_value("lxc.lxcpath");

        dir = opendir(lxcpath);
        if (!dir) {
                SYSERROR("opendir on lxcpath");
                return -1;
        }

        if (cret)
                *cret = NULL;
        if (names)
                *names = NULL;

        while ((direntp = readdir(dir))) {
                if (!direntp)
                        break;

                /* Ignore '.', '..' and any hidden directory. */
                if (!strncmp(direntp->d_name, ".", 1))
                        continue;

                if (!config_file_exists(lxcpath, direntp->d_name))
                        continue;

                if (names) {
                        if (!add_to_array(names, direntp->d_name, cfound))
                                goto free_bad;
                }
                cfound++;

                if (!cret) {
                        nfound++;
                        continue;
                }

                c = lxc_container_new(direntp->d_name, lxcpath);
                if (!c) {
                        INFO("Container %s:%s has a config but could not be loaded",
                                lxcpath, direntp->d_name);
                        if (names)
                                if(!remove_from_array(names, direntp->d_name, cfound--))
                                        goto free_bad;
                        continue;
                }
                if (!do_lxcapi_is_defined(c)) {
                        INFO("Container %s:%s has a config but is not defined",
                                lxcpath, direntp->d_name);
                        if (names)
                                if(!remove_from_array(names, direntp->d_name, cfound--))
                                        goto free_bad;
                        lxc_container_put(c);
                        continue;
                }

                if (!add_to_clist(cret, c, nfound, true)) {
                        lxc_container_put(c);
                        goto free_bad;
                }
                nfound++;
        }

        closedir(dir);
        return nfound;

free_bad:
        if (names && *names) {
                for (i=0; i<cfound; i++)
                        free((*names)[i]);
                free(*names);
        }
        if (cret && *cret) {
                for (i=0; i<nfound; i++)
                        lxc_container_put((*cret)[i]);
                free(*cret);
        }
        closedir(dir);
        return -1;
}

int list_active_containers(const char *lxcpath, char ***nret,
                           struct lxc_container ***cret)
{
        int i, ret = -1, cret_cnt = 0, ct_name_cnt = 0;
        int lxcpath_len;
        char *line = NULL;
        char **ct_name = NULL;
        size_t len = 0;
        struct lxc_container *c = NULL;
        bool is_hashed;

        if (!lxcpath)
                lxcpath = lxc_global_config_value("lxc.lxcpath");
        lxcpath_len = strlen(lxcpath);

        if (cret)
                *cret = NULL;
        if (nret)
                *nret = NULL;

        FILE *f = fopen("/proc/net/unix", "r");
        if (!f)
                return -1;

        while (getline(&line, &len, f) != -1) {

                char *p = strrchr(line, ' '), *p2;
                if (!p)
                        continue;
                p++;
                if (*p != 0x40)
                        continue;
                p++;

                is_hashed = false;
                if (strncmp(p, lxcpath, lxcpath_len) == 0) {
                        p += lxcpath_len;
                } else if (strncmp(p, "lxc/", 4) == 0) {
                        p += 4;
                        is_hashed = true;
                } else {
                        continue;
                }

                while (*p == '/')
                        p++;

                /* Now p is the start of lxc_name. */
                p2 = strchr(p, '/');
                if (!p2 || strncmp(p2, "/command", 8) != 0)
                        continue;
                *p2 = '\0';

                if (is_hashed) {
                        char *recvpath = lxc_cmd_get_lxcpath(p);
                        if (!recvpath)
                                continue;
                        if (strncmp(lxcpath, recvpath, lxcpath_len) != 0)
                                continue;
                        p = lxc_cmd_get_name(p);
                }

                if (array_contains(&ct_name, p, ct_name_cnt))
                        continue;

                if (!add_to_array(&ct_name, p, ct_name_cnt))
                        goto free_cret_list;

                ct_name_cnt++;

                if (!cret)
                        continue;

                c = lxc_container_new(p, lxcpath);
                if (!c) {
                        INFO("Container %s:%s is running but could not be loaded",
                                lxcpath, p);
                        remove_from_array(&ct_name, p, ct_name_cnt--);
                        continue;
                }

                /*
                 * If this is an anonymous container, then is_defined *can*
                 * return false.  So we don't do that check.  Count on the
                 * fact that the command socket exists.
                 */

                if (!add_to_clist(cret, c, cret_cnt, true)) {
                        lxc_container_put(c);
                        goto free_cret_list;
                }
                cret_cnt++;
        }

        if (nret && cret && cret_cnt != ct_name_cnt) {
                if (c)
                        lxc_container_put(c);
                goto free_cret_list;
        }

        ret = ct_name_cnt;
        if (nret)
                *nret = ct_name;
        else
                goto free_ct_name;
        goto out;

free_cret_list:
        if (cret && *cret) {
                for (i = 0; i < cret_cnt; i++)
                        lxc_container_put((*cret)[i]);
                free(*cret);
        }

free_ct_name:
        if (ct_name) {
                for (i = 0; i < ct_name_cnt; i++)
                        free(ct_name[i]);
                free(ct_name);
        }

out:
        free(line);

        fclose(f);
        return ret;
}

int list_all_containers(const char *lxcpath, char ***nret,
                        struct lxc_container ***cret)
{
        int i, ret, active_cnt, ct_cnt, ct_list_cnt;
        char **active_name;
        char **ct_name;
        struct lxc_container **ct_list = NULL;

        ct_cnt = list_defined_containers(lxcpath, &ct_name, NULL);
        if (ct_cnt < 0)
                return ct_cnt;

        active_cnt = list_active_containers(lxcpath, &active_name, NULL);
        if (active_cnt < 0) {
                ret = active_cnt;
                goto free_ct_name;
        }

        for (i = 0; i < active_cnt; i++) {
                if (!array_contains(&ct_name, active_name[i], ct_cnt)) {
                        if (!add_to_array(&ct_name, active_name[i], ct_cnt)) {
                                ret = -1;
                                goto free_active_name;
                        }
                        ct_cnt++;
                }
                free(active_name[i]);
                active_name[i] = NULL;
        }
        free(active_name);
        active_name = NULL;
        active_cnt = 0;

        for (i = 0, ct_list_cnt = 0; i < ct_cnt && cret; i++) {
                struct lxc_container *c;

                c = lxc_container_new(ct_name[i], lxcpath);
                if (!c) {
                        WARN("Container %s:%s could not be loaded", lxcpath, ct_name[i]);
                        remove_from_array(&ct_name, ct_name[i], ct_cnt--);
                        continue;
                }

                if (!add_to_clist(&ct_list, c, ct_list_cnt, false)) {
                        lxc_container_put(c);
                        ret = -1;
                        goto free_ct_list;
                }
                ct_list_cnt++;
        }

        if (cret)
                *cret = ct_list;

        if (nret)
                *nret = ct_name;
        else {
                ret = ct_cnt;
                goto free_ct_name;
        }
        return ct_cnt;

free_ct_list:
        for (i = 0; i < ct_list_cnt; i++) {
                lxc_container_put(ct_list[i]);
        }
        free(ct_list);

free_active_name:
        for (i = 0; i < active_cnt; i++) {
                free(active_name[i]);
        }
        free(active_name);

free_ct_name:
        for (i = 0; i < ct_cnt; i++) {
                free(ct_name[i]);
        }
        free(ct_name);
        return ret;
}

bool lxc_config_item_is_supported(const char *key)
{
        return !!lxc_get_config(key);
}