+++ /dev/null
-/*
- * lxc: linux Container library
- *
- * (C) Copyright IBM Corp. 2007, 2008
- *
- * Authors:
- * Daniel Lezcano <daniel.lezcano at free.fr>
- *
- * 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
- */
-
-#include "config.h"
-
-#include <stdio.h>
-#include <unistd.h>
-#include <errno.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <fcntl.h>
-#include <sys/inotify.h>
-#include <sys/ioctl.h>
-#ifdef HAVE_SYS_TIMERFD_H
-#include <sys/timerfd.h>
-#else
-#include <sys/syscall.h>
-#ifndef TFD_NONBLOCK
-#define TFD_NONBLOCK O_NONBLOCK
-#endif
-
-#ifndef TFD_CLOEXEC
-#define TFD_CLOEXEC O_CLOEXEC
-#endif
-static int timerfd_create (clockid_t __clock_id, int __flags) {
- return syscall(__NR_timerfd_create, __clock_id, __flags);
-}
-
-static int timerfd_settime (int __ufd, int __flags,
- const struct itimerspec *__utmr,
- struct itimerspec *__otmr) {
-
- return syscall(__NR_timerfd_settime, __ufd, __flags,
- __utmr, __otmr);
-}
-
-#endif
-
-#include "conf.h"
-#include "cgroup.h"
-#include "start.h"
-#include "mainloop.h"
-#include "lxc.h"
-#include "log.h"
-
-#ifndef __USE_GNU
-#define __USE_GNU
-#endif
-#ifdef HAVE_UTMPX_H
-#include <utmpx.h>
-#ifndef HAVE_UTMPXNAME
-#include <utmp.h>
-#endif
-
-#else
-#include <utmp.h>
-
-#ifndef RUN_LVL
-#define RUN_LVL 1
-#endif
-
-static void setutxent(void) {
- return setutent();
-}
-
-static struct utmp * getutxent (void) {
- return (struct utmp *) getutent();
-}
-
-static void endutxent (void) {
-#ifdef IS_BIONIC
- /* bionic isn't exporting endutend */
- return;
-#else
- return endutent();
-#endif
-}
-#endif
-
-#ifndef HAVE_UTMPXNAME
-static int utmpxname(const char *file) {
- int result;
- result = utmpname(file);
-
-#ifdef IS_BIONIC
- /* Yeah bionic is that weird */
- result = result - 1;
-#endif
-
- return result;
-}
-#endif
-
-#undef __USE_GNU
-
-/* This file watches the /var/run/utmp file in the container
- * (that should probably be configurable)
- * We use inotify to put a watch on the /var/run directory for
- * create and modify events. These can trigger a read of the
- * utmp file looking for runlevel changes. If a runlevel change
- * to reboot or halt states is detected, we set up an itimer to
- * regularly check for the container shutdown, and reboot or halt
- * as appropriate when we get down to 1 task remaining.
- */
-
-lxc_log_define(lxc_utmp, lxc);
-
-struct lxc_utmp {
- struct lxc_handler *handler;
-#define CONTAINER_STARTING 0
-#define CONTAINER_REBOOTING 1
-#define CONTAINER_HALTING 2
-#define CONTAINER_RUNNING 4
- char container_state;
- int timer_fd;
- int prev_runlevel, curr_runlevel;
-};
-
-typedef void (*lxc_mainloop_timer_t) (void *data);
-
-static int utmp_get_runlevel(struct lxc_utmp *utmp_data);
-static int utmp_get_ntasks(struct lxc_handler *handler);
-static int utmp_shutdown_handler(int fd, uint32_t events, void *data,
- struct lxc_epoll_descr *descr);
-static int lxc_utmp_add_timer(struct lxc_epoll_descr *descr,
- lxc_mainloop_callback_t callback, void *data);
-static int lxc_utmp_del_timer(struct lxc_epoll_descr *descr,
- struct lxc_utmp *utmp_data);
-
-static int utmp_handler(int fd, uint32_t events, void *data,
- struct lxc_epoll_descr *descr)
-{
- struct inotify_event *ie;
- int size, ret, length;
-
- struct lxc_utmp *utmp_data = (struct lxc_utmp *)data;
-
- /*
- * we're monitoring a directory. ie->name is not included in
- * sizeof(struct inotify_event) if we don't read it all at once,
- * read gives us EINVAL, so we read and cast to struct ie
- */
- char buffer[MAXPATHLEN];
-
- if (ioctl(fd, FIONREAD, &size) < 0) {
- SYSERROR("cannot determine the size of this notification");
- return -1;
- }
-
- if (read(fd, buffer, size) < size) {
- SYSERROR("failed to read notification");
- return -1;
- }
-
- ie = (struct inotify_event *)buffer;
-
- if (ie->len <= 0) {
-
- if (ie->mask & IN_UNMOUNT) {
- DEBUG("watched directory removed");
- goto out;
- }
-
- SYSERROR("inotify event with no name (mask %d)", ie->mask);
- return -1;
- }
-
- ret = 0;
-
- DEBUG("got inotify event %d for %s", ie->mask, ie->name);
-
- length = (4 < ie->len) ? 4 : ie->len;
-
- /* only care about utmp */
-
- if (strncmp(ie->name, "utmp", length))
- return 0;
-
- if (ie->mask & (IN_MODIFY | IN_CREATE))
- ret = utmp_get_runlevel(utmp_data);
-
- if (ret < 0)
- goto out;
-
- /* container halting, from running or starting state */
- if (utmp_data->curr_runlevel == '0'
- && ((utmp_data->container_state == CONTAINER_RUNNING)
- || (utmp_data->container_state == CONTAINER_STARTING))) {
- utmp_data->container_state = CONTAINER_HALTING;
- if (utmp_data->timer_fd == -1)
- lxc_utmp_add_timer(descr, utmp_shutdown_handler, data);
- DEBUG("Container halting");
- goto out;
- }
-
- /* container rebooting, from running or starting state */
- if (utmp_data->curr_runlevel == '6'
- && ((utmp_data->container_state == CONTAINER_RUNNING)
- || (utmp_data->container_state == CONTAINER_STARTING))) {
- utmp_data->container_state = CONTAINER_REBOOTING;
- if (utmp_data->timer_fd == -1)
- lxc_utmp_add_timer(descr, utmp_shutdown_handler, data);
- DEBUG("Container rebooting");
- goto out;
- }
-
- /* normal operation, running, from starting state. */
- if (utmp_data->curr_runlevel > '0' && utmp_data->curr_runlevel < '6') {
- utmp_data->container_state = CONTAINER_RUNNING;
- if (utmp_data->timer_fd > 0)
- lxc_utmp_del_timer(descr, utmp_data);
- DEBUG("Container running");
- goto out;
- }
-
-out:
- return 0;
-}
-
-static int utmp_get_runlevel(struct lxc_utmp *utmp_data)
-{
- #if HAVE_UTMPX_H
- struct utmpx *utmpx;
- #else
- struct utmp *utmpx;
- #endif
- char path[MAXPATHLEN];
- struct lxc_handler *handler = utmp_data->handler;
-
- if (snprintf(path, MAXPATHLEN, "/proc/%d/root/run/utmp",
- handler->pid) > MAXPATHLEN) {
- ERROR("path is too long");
- return -1;
- }
-
- if (!access(path, F_OK) && !utmpxname(path))
- goto utmp_ok;
-
- if (snprintf(path, MAXPATHLEN, "/proc/%d/root/var/run/utmp",
- handler->pid) > MAXPATHLEN) {
- ERROR("path is too long");
- return -1;
- }
-
- if (utmpxname(path)) {
- SYSERROR("failed to 'utmpxname'");
- return -1;
- }
-
-utmp_ok:
-
- setutxent();
-
- while ((utmpx = getutxent())) {
-
- if (utmpx->ut_type == RUN_LVL) {
- utmp_data->prev_runlevel = utmpx->ut_pid / 256;
- utmp_data->curr_runlevel = utmpx->ut_pid % 256;
- DEBUG("utmp handler - run level is %c/%c",
- utmp_data->prev_runlevel,
- utmp_data->curr_runlevel);
- }
- }
-
- endutxent();
-
- return 0;
-}
-
-static int utmp_get_ntasks(struct lxc_handler *handler)
-{
- int ntasks;
-
- ntasks = cgroup_nrtasks(handler);
-
- if (ntasks < 0) {
- ERROR("failed to get the number of tasks");
- return -1;
- }
-
- DEBUG("there are %d tasks running", ntasks);
-
- return ntasks;
-}
-
-int lxc_utmp_mainloop_add(struct lxc_epoll_descr *descr,
- struct lxc_handler *handler)
-{
- char path[MAXPATHLEN];
- char path2[MAXPATHLEN];
- int fd, wd;
- struct lxc_utmp *utmp_data;
-
- /* We set up a watch for the /var/run directory. We're only interested
- * in utmp at the moment, but want to watch for delete and create
- * events as well.
- */
- if (snprintf(path, MAXPATHLEN, "/proc/%d/root/run",
- handler->pid) > MAXPATHLEN) {
- ERROR("path is too long");
- return -1;
- }
- if (snprintf(path2, MAXPATHLEN, "/proc/%d/root/run/utmp",
- handler->pid) > MAXPATHLEN) {
- ERROR("path is too long");
- return -1;
- }
- if (!access(path2, F_OK))
- goto run_ok;
-
- if (snprintf(path, MAXPATHLEN, "/proc/%d/root/var/run",
- handler->pid) > MAXPATHLEN) {
- ERROR("path is too long");
- return -1;
- }
-
- if (access(path, F_OK)) {
- WARN("'%s' not found", path);
- return 0;
- }
-
-run_ok:
-
- utmp_data = (struct lxc_utmp *)malloc(sizeof(struct lxc_utmp));
-
- if (NULL == utmp_data) {
- SYSERROR("failed to malloc handler utmp_data");
- return -1;
- }
-
- memset(utmp_data, 0, sizeof(struct lxc_utmp));
-
- fd = inotify_init();
- if (fd < 0) {
- SYSERROR("failed to inotify_init");
- goto out;
- }
-
- if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
- SYSERROR("failed to set inotify fd to close-on-exec");
- goto out_close;
-
- }
-
- wd = inotify_add_watch(fd, path, IN_MODIFY | IN_CREATE);
- if (wd < 0) {
- SYSERROR("failed to add watch for '%s'", path);
- goto out_close;
- }
-
- utmp_data->handler = handler;
- utmp_data->container_state = CONTAINER_STARTING;
- utmp_data->timer_fd = -1;
- utmp_data->prev_runlevel = 'N';
- utmp_data->curr_runlevel = 'N';
-
- if (lxc_mainloop_add_handler
- (descr, fd, utmp_handler, (void *)utmp_data)) {
- SYSERROR("failed to add mainloop");
- goto out_close;
- }
-
- DEBUG("Added '%s' to inotifywatch", path);
-
- return 0;
-out_close:
- close(fd);
-out:
- free(utmp_data);
- return -1;
-}
-
-static int utmp_shutdown_handler(int fd, uint32_t events, void *data,
- struct lxc_epoll_descr *descr)
-{
- int ntasks;
- ssize_t nread;
- struct lxc_utmp *utmp_data = (struct lxc_utmp *)data;
- struct lxc_handler *handler = utmp_data->handler;
- struct lxc_conf *conf = handler->conf;
- uint64_t expirations;
-
- /* read and clear notifications */
- nread = read(fd, &expirations, sizeof(expirations));
- if (nread < 0)
- SYSERROR("Failed to read timer notification");
-
- ntasks = utmp_get_ntasks(handler);
-
- if (ntasks == 1 && (utmp_data->container_state == CONTAINER_HALTING)) {
- INFO("container has shutdown");
- /* shutdown timer */
- lxc_utmp_del_timer(descr, utmp_data);
-
- kill(handler->pid, SIGKILL);
- }
-
- if (ntasks == 1 && (utmp_data->container_state == CONTAINER_REBOOTING)) {
- INFO("container has rebooted");
- conf->reboot = 1;
- /* shutdown timer */
- lxc_utmp_del_timer(descr, utmp_data);
- /* this seems a bit rough. */
- kill(handler->pid, SIGKILL);
- }
- return 0;
-
-}
-
-int lxc_utmp_add_timer(struct lxc_epoll_descr *descr,
- lxc_mainloop_callback_t callback, void *data)
-{
- int fd, result;
- struct itimerspec timeout;
- struct lxc_utmp *utmp_data = (struct lxc_utmp *)data;
-
- fd = timerfd_create(CLOCK_MONOTONIC, TFD_NONBLOCK | TFD_CLOEXEC);
- if (fd < 0) {
- SYSERROR("failed to create timer");
- return -1;
- }
-
- DEBUG("Setting up utmp shutdown timer");
-
- /* set a one second timeout. Repeated. */
- timeout.it_value.tv_sec = 1;
- timeout.it_value.tv_nsec = 0;
-
- timeout.it_interval.tv_sec = 1;
- timeout.it_interval.tv_nsec = 0;
-
- result = timerfd_settime(fd, 0, &timeout, NULL);
-
- if (result < 0) {
- SYSERROR("timerfd_settime:");
- return -1;
- }
-
- if (lxc_mainloop_add_handler(descr, fd, callback, utmp_data)) {
- SYSERROR("failed to add utmp timer to mainloop");
- close(fd);
- return -1;
- }
-
- utmp_data->timer_fd = fd;
-
- return 0;
-}
-
-int lxc_utmp_del_timer(struct lxc_epoll_descr *descr,
- struct lxc_utmp *utmp_data)
-{
- int result;
-
- DEBUG("Clearing utmp shutdown timer");
-
- result = lxc_mainloop_del_handler(descr, utmp_data->timer_fd);
- if (result < 0)
- SYSERROR("failed to del utmp timer from mainloop");
-
- /* shutdown timer_fd */
- close(utmp_data->timer_fd);
- utmp_data->timer_fd = -1;
-
- if (result < 0)
- return -1;
- else
- return 0;
-}
#include "lxccontainer.h"
#include "lxclock.h"
#include "lxcseccomp.h"
-#include "lxcutmp.h"
#include "mainloop.h"
#include "monitor.h"
#include "namespace.h"
goto out_mainloop_open;
}
- if (handler->conf->need_utmp_watch) {
- #if HAVE_LIBCAP
- if (lxc_utmp_mainloop_add(&descr, handler)) {
- ERROR("Failed to add utmp handler to LXC mainloop.");
- goto out_mainloop_open;
- }
- #else
- DEBUG("Not starting utmp handler as CAP_SYS_BOOT cannot be dropped without capabilities support.");
- #endif
- }
TRACE("lxc mainloop is ready");
return lxc_mainloop(&descr, -1);
}
}
-#include <sys/reboot.h>
-#include <linux/reboot.h>
-
-/* reboot(LINUX_REBOOT_CMD_CAD_ON) will return -EINVAL in a child pid namespace
- * if container reboot support exists. Otherwise, it will either succeed or
- * return -EPERM.
- */
-static int container_reboot_supported(void *arg)
-{
- int *cmd = arg;
- int ret;
-
- ret = reboot(*cmd);
- if (ret == -1 && errno == EINVAL)
- return 1;
- return 0;
-}
-
-static int must_drop_cap_sys_boot(struct lxc_conf *conf)
-{
- FILE *f;
- int ret, cmd, v, flags;
- long stack_size = 4096;
- void *stack = alloca(stack_size);
- int status;
- pid_t pid;
-
- f = fopen("/proc/sys/kernel/ctrl-alt-del", "r");
- if (!f) {
- DEBUG("failed to open /proc/sys/kernel/ctrl-alt-del");
- return 1;
- }
-
- ret = fscanf(f, "%d", &v);
- fclose(f);
- if (ret != 1) {
- DEBUG("Failed to read /proc/sys/kernel/ctrl-alt-del.");
- return 1;
- }
- cmd = v ? LINUX_REBOOT_CMD_CAD_ON : LINUX_REBOOT_CMD_CAD_OFF;
-
- flags = CLONE_NEWPID | SIGCHLD;
- if (!lxc_list_empty(&conf->id_map))
- flags |= CLONE_NEWUSER;
-
-#ifdef __ia64__
- pid = __clone2(container_reboot_supported, stack, stack_size, flags, &cmd);
-#else
- stack += stack_size;
- pid = clone(container_reboot_supported, stack, flags, &cmd);
-#endif
- if (pid < 0) {
- if (flags & CLONE_NEWUSER)
- ERROR("Failed to clone (%#x): %s (includes CLONE_NEWUSER).", flags, strerror(errno));
- else
- ERROR("Failed to clone (%#x): %s.", flags, strerror(errno));
- return -1;
- }
- if (wait(&status) < 0) {
- SYSERROR("Unexpected wait error: %s.", strerror(errno));
- return -1;
- }
-
- if (WEXITSTATUS(status) != 1)
- return 1;
-
- return 0;
-}
-
/* netpipe is used in the unprivileged case to transfer the ifindexes from
* parent to child
*/
goto out_warn_father;
}
- #if HAVE_LIBCAP
- if (handler->conf->need_utmp_watch) {
- if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) {
- SYSERROR("Failed to remove the CAP_SYS_BOOT capability.");
- goto out_warn_father;
- }
- DEBUG("Dropped the CAP_SYS_BOOT capability.");
- }
- #endif
-
ret = snprintf(path, sizeof(path), "%s/dev/null", handler->conf->rootfs.mount);
if (ret < 0 || ret >= sizeof(path))
goto out_warn_father;
handler->backgrounded = backgrounded;
handler->netnsfd = -1;
- if (must_drop_cap_sys_boot(handler->conf)) {
- #if HAVE_LIBCAP
- DEBUG("Dropping CAP_SYS_BOOT capability.");
- #else
- DEBUG("Not dropping CAP_SYS_BOOT capability as capabilities aren't supported.");
- #endif
- } else {
- DEBUG("Not dropping CAP_SYS_BOOT or watching utmp.");
- handler->conf->need_utmp_watch = 0;
- }
-
if (!attach_block_device(handler->conf)) {
ERROR("Failed to attach block device.");
goto out_fini_nonet;
.argv = argv,
};
- handler->conf->need_utmp_watch = 1;
return __lxc_start(name, handler, &start_ops, &start_arg, lxcpath, backgrounded);
}
projects / mirror_lxc.git / commitdiff