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

/*
 * lxc: linux Container library
 *
 * (C) Copyright IBM Corp. 2007, 2008
 *
 * Authors:
 * Daniel Lezcano <dlezcano at fr.ibm.com>
 *
 * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "../config.h"
#include <stdio.h>
#undef _GNU_SOURCE
#include <string.h>
#include <stdlib.h>
#include <dirent.h>
#include <errno.h>
#include <unistd.h>
#include <signal.h>
#include <fcntl.h>
#include <termios.h>
#include <sys/param.h>
#include <sys/file.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/prctl.h>
#include <sys/capability.h>
#include <sys/wait.h>
#include <sys/un.h>
#include <sys/poll.h>

#ifdef HAVE_SYS_SIGNALFD_H 
#  include <sys/signalfd.h>
#else
#  ifndef __NR_signalfd4
/* assume kernel headers are too old */
#    if __i386__
#      define __NR_signalfd4 327
#    elif __x86_64__
#      define __NR_signalfd4 289
#    elif __powerpc__
#      define __NR_signalfd4 313
#    elif __s390x__
#      define __NR_signalfd4 322
#    endif
#endif

#  ifndef __NR_signalfd
/* assume kernel headers are too old */
#    if __i386__
#      define __NR_signalfd 321
#    elif __x86_64__
#      define __NR_signalfd 282
#    elif __powerpc__
#      define __NR_signalfd 305
#    elif __s390x__
#      define __NR_signalfd 316
#    endif
#endif

int signalfd(int fd, const sigset_t *mask, int flags)
{
	int retval;

	retval = syscall (__NR_signalfd4, fd, mask, _NSIG / 8, flags);
	if (errno == ENOSYS && flags == 0)
		retval = syscall (__NR_signalfd, fd, mask, _NSIG / 8);
	return retval;
}
#endif

#if !HAVE_DECL_PR_CAPBSET_DROP
#define PR_CAPBSET_DROP 24
#endif

#include "error.h"
#include "af_unix.h"
#include "mainloop.h"

#include <lxc/lxc.h>
#include <lxc/log.h>

lxc_log_define(lxc_start, lxc);

LXC_TTY_HANDLER(SIGINT);
LXC_TTY_HANDLER(SIGQUIT);

static int setup_sigchld_fd(sigset_t *oldmask)
{
	sigset_t mask;
	int fd;

	if (sigprocmask(SIG_BLOCK, NULL, &mask)) {
		SYSERROR("failed to get mask signal");
		return -1;
	}

	if (sigaddset(&mask, SIGCHLD) || sigprocmask(SIG_BLOCK, &mask, oldmask)) {
		SYSERROR("failed to set mask signal");
		return -1;
	}

	fd = signalfd(-1, &mask, 0);
	if (fd < 0) {
		SYSERROR("failed to create the signal fd");
		return -1;
	}

	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
		SYSERROR("failed to set sigfd to close-on-exec");
		close(fd);
		return -1;
	}

	return fd;
}

static int setup_tty_service(const char *name, int *ttyfd)
{
	int fd;
	struct sockaddr_un addr = { 0 };
	char *offset = &addr.sun_path[1];
	
	strcpy(offset, name);
	addr.sun_path[0] = '\0';

	fd = lxc_af_unix_open(addr.sun_path, SOCK_STREAM, 0);
	if (fd < 0)
		return -1;

	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
		SYSERROR("failed to close-on-exec flag");
		close(fd);
		return -1;
	}

	*ttyfd = fd;

	return 0;
}

static int sigchld_handler(int fd, void *data, 
			   struct lxc_epoll_descr *descr)
{
	return 1;
}

static int ttyclient_handler(int fd, void *data,
			     struct lxc_epoll_descr *descr)
{
	int i;
 	struct lxc_tty_info *tty_info = data;

	for (i = 0; i < tty_info->nbtty; i++) {

		if (tty_info->pty_info[i].busy != fd)
			continue;

		lxc_mainloop_del_handler(descr, fd);
		tty_info->pty_info[i].busy = 0;
		close(fd);
	}

	return 0;
}

static int ttyservice_handler(int fd, void *data,
			      struct lxc_epoll_descr *descr)
{
	int conn, ttynum, val = 1, ret = -1;
	struct lxc_tty_info *tty_info = data;
	
	conn = accept(fd, NULL, 0);
	if (conn < 0) {
		SYSERROR("failed to accept tty client");
		return -1;
	}
	
	if (setsockopt(conn, SOL_SOCKET, SO_PASSCRED, &val, sizeof(val))) {
		SYSERROR("failed to enable credential on socket");
		goto out_close;
	}

	if (lxc_af_unix_rcv_credential(conn, &ttynum, sizeof(ttynum)))
		goto out_close;

	if (ttynum > 0) {
		if (ttynum > tty_info->nbtty)
			goto out_close;

		if (tty_info->pty_info[ttynum - 1].busy)
			goto out_close;

		goto out_send;
	}

	/* fixup index tty1 => [0] */
	for (ttynum = 1;
	     ttynum <= tty_info->nbtty && tty_info->pty_info[ttynum - 1].busy;
	     ttynum++);

	/* we didn't find any available slot for tty */
	if (ttynum > tty_info->nbtty)
		goto out_close;

out_send:
	if (lxc_af_unix_send_fd(conn, tty_info->pty_info[ttynum - 1].master,
				&ttynum, sizeof(ttynum)) < 0) {
		ERROR("failed to send tty to client");
		goto out_close;
	}

	if (lxc_mainloop_add_handler(descr, conn,
				     ttyclient_handler, tty_info)) {
		ERROR("failed to add tty client handler");
		goto out_close;
	}

	tty_info->pty_info[ttynum - 1].busy = conn;

	ret = 0;
out:
	return ret;
out_close:
	close(conn);
	goto out;
}

int lxc_poll(const char *name, struct lxc_handler *handler)
{
	int sigfd = handler->sigfd;
	int pid = handler->pid;
	const struct lxc_tty_info *tty_info = &handler->tty_info;

	int nfds, ttyfd = -1, ret = -1;
	struct lxc_epoll_descr descr;

	if (tty_info->nbtty && setup_tty_service(name, &ttyfd)) {
		ERROR("failed to create the tty service point");
		goto out_sigfd;
	}

	/* sigfd + nb tty + tty service 
	 * if tty is enabled */
	nfds = tty_info->nbtty + 1 + tty_info->nbtty ? 1 : 0;

	if (lxc_mainloop_open(nfds, &descr)) {
		ERROR("failed to create mainloop");
		goto out_ttyfd;
	}

	if (lxc_mainloop_add_handler(&descr, sigfd, sigchld_handler, &pid)) {
		ERROR("failed to add handler for the signal");
		goto out_mainloop_open;
	}

	if (tty_info->nbtty) {
		if (lxc_mainloop_add_handler(&descr, ttyfd, 
					     ttyservice_handler, 
					     (void *)tty_info)) {
			ERROR("failed to add handler for the tty");
			goto out_mainloop_open;
		}
	}

	ret = lxc_mainloop(&descr);

out:
	return ret;

out_mainloop_open:
	lxc_mainloop_close(&descr);
out_ttyfd:
	close(ttyfd);
out_sigfd:
	close(sigfd);
	goto out;
}

static int save_init_pid(const char *name, pid_t pid)
{
	char init[MAXPATHLEN];
	char *val;
	int fd, err = -1;

	snprintf(init, MAXPATHLEN, LXCPATH "/%s/init", name);

	if (!asprintf(&val, "%d\n", pid)) {
		SYSERROR("failed to allocate memory");
		goto out;
	}

	fd = open(init, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
	if (fd < 0) {
		SYSERROR("failed to open '%s'", init);
		goto out_free;
	}

	if (write(fd, val, strlen(val)) < 0) {
		SYSERROR("failed to write the init pid");
		goto out_close;
	}

	err = 0;

out_close:
	close(fd);
out_free:
	free(val);
out:
	return err;
}

static void remove_init_pid(const char *name, pid_t pid)
{
	char init[MAXPATHLEN];

	snprintf(init, MAXPATHLEN, LXCPATH "/%s/init", name);
	unlink(init);
}

int lxc_init(const char *name, struct lxc_handler *handler)
{
	int err = -1;

	memset(handler, 0, sizeof(*handler));

	handler->lock = lxc_get_lock(name);
	if (handler->lock < 0)
		goto out;

	/* Begin the set the state to STARTING*/
	if (lxc_setstate(name, STARTING)) {
		ERROR("failed to set state '%s'", lxc_state2str(STARTING));
		goto out_put_lock;
	}

	/* If we are not attached to a tty, disable it */
	if (ttyname_r(0, handler->tty, sizeof(handler->tty)))
		handler->tty[0] = '\0';

	if (lxc_create_tty(name, &handler->tty_info)) {
		ERROR("failed to create the ttys");
		goto out_aborting;
	}

	/* the signal fd has to be created before forking otherwise
	 * if the child process exits before we setup the signal fd,
	 * the event will be lost and the command will be stuck */
	handler->sigfd = setup_sigchld_fd(&handler->oldmask);
	if (handler->sigfd < 0) {
		ERROR("failed to set sigchild fd handler");
		goto out_delete_tty;
	}

	/* Avoid signals from terminal */
	LXC_TTY_ADD_HANDLER(SIGINT);
	LXC_TTY_ADD_HANDLER(SIGQUIT);

	err = 0;
out:
	return err;

out_delete_tty:
	lxc_delete_tty(&handler->tty_info);
out_aborting:
	lxc_setstate(name, ABORTING);
out_put_lock:
	lxc_put_lock(handler->lock);
	goto out;
}

void lxc_fini(const char *name, struct lxc_handler *handler)
{
	/* The STOPPING state is there for future cleanup code
	 * which can take awhile
	 */
	lxc_setstate(name, STOPPING);

	lxc_setstate(name, STOPPED);

	remove_init_pid(name, handler->pid);

	lxc_delete_tty(&handler->tty_info);

	lxc_unlink_nsgroup(name);

	lxc_put_lock(handler->lock);

	LXC_TTY_DEL_HANDLER(SIGQUIT);
	LXC_TTY_DEL_HANDLER(SIGINT);
}

void lxc_abort(const char *name, struct lxc_handler *handler)
{
	lxc_setstate(name, ABORTING);
	kill(handler->pid, SIGKILL);
}

int lxc_spawn(const char *name, struct lxc_handler *handler, char *const argv[])
{
	int sv[2];
	int clone_flags;
	int err = -1, sync;

	/* Synchro socketpair */
	if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sv)) {
		SYSERROR("failed to create communication socketpair");
		goto out;
	}

	clone_flags = CLONE_NEWPID|CLONE_NEWIPC|CLONE_NEWNS;
	if (conf_has_utsname(name))
		clone_flags |= CLONE_NEWUTS;
	if (conf_has_network(name))
		clone_flags |= CLONE_NEWNET;

	/* Create a process in a new set of namespaces */
	handler->pid = fork_ns(clone_flags);
	if (handler->pid < 0) {
		SYSERROR("failed to fork into a new namespace");
		goto out_close;
	}

	if (!handler->pid) {

		if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL)) {
			SYSERROR("failed to set sigprocmask");
			goto out_child;
		}

		close(sv[1]);

		/* Be sure we don't inherit this after the exec */
		fcntl(sv[0], F_SETFD, FD_CLOEXEC);
		
		/* Tell our father he can begin to configure the container */
		if (write(sv[0], &sync, sizeof(sync)) < 0) {
			SYSERROR("failed to write socket");
			goto out_child;
		}

		/* Wait for the father to finish the configuration */
		if (read(sv[0], &sync, sizeof(sync)) < 0) {
			SYSERROR("failed to read socket");
			goto out_child;
		}

		/* Setup the container, ip, names, utsname, ... */
		if (lxc_setup(name, handler->tty, &handler->tty_info)) {
			ERROR("failed to setup the container");
			goto out_warn_father;
		}

		if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) {
			SYSERROR("failed to remove CAP_SYS_BOOT capability");
			goto out_child;
		}

		execvp(argv[0], argv);
		SYSERROR("failed to exec %s", argv[0]);

	out_warn_father:
		/* If the exec fails, tell that to our father */
		if (write(sv[0], &err, sizeof(err)) < 0)
			SYSERROR("failed to write the socket");
	out_child:
		exit(err);
	}

	close(sv[0]);
	
	/* Wait for the child to be ready */
	if (read(sv[1], &sync, sizeof(sync)) < 0) {
		SYSERROR("failed to read the socket");
		goto out_abort;
	}

	if (lxc_link_nsgroup(name, handler->pid))
		WARN("cgroupfs not found: cgroup disabled");

	/* Create the network configuration */
	if (clone_flags & CLONE_NEWNET && conf_create_network(name, handler->pid)) {
		ERROR("failed to create the configured network");
		goto out_abort;
	}

	/* Tell the child to continue its initialization */
	if (write(sv[1], &sync, sizeof(sync)) < 0) {
		SYSERROR("failed to write the socket");
		goto out_abort;
	}

	/* Wait for the child to exec or returning an error */
	if (read(sv[1], &sync, sizeof(sync)) < 0) {
		ERROR("failed to read the socket");
		goto out_abort;
	}

	if (save_init_pid(name, handler->pid)) {
		ERROR("failed to save the init pid info");
		goto out_abort;
	}

	if (lxc_setstate(name, RUNNING)) {
		ERROR("failed to set state to %s",
			      lxc_state2str(RUNNING));
		goto out_abort;
	}

	err = 0;

out_close:
	close(sv[0]);
	close(sv[1]);
out:
	return err;

out_abort:
	lxc_abort(name, handler);
	goto out_close;
}

int lxc_start(const char *name, char *const argv[])
{
	struct lxc_handler handler = { 0 };
	int err = -1;
	int status;

	if (lxc_init(name, &handler)) {
		ERROR("failed to initialize the container");
		goto out;
	}

	err = lxc_spawn(name, &handler, argv);
	if (err) {
		ERROR("failed to spawn '%s'", argv[0]);
		goto out;
	}

	err = lxc_poll(name, &handler);
	if (err) {
		ERROR("mainloop exited with an error");
		goto out_abort;
	}

	while (waitpid(handler.pid, &status, 0) < 0 && errno == EINTR)
		continue;

	err =  lxc_error_set_and_log(handler.pid, status);
out:
	lxc_fini(name, &handler);
	return err;

out_abort:
	lxc_abort(name, &handler);
	goto out;
}
Commit	Line	Data
0ad19a3f	1	/*
	2	* lxc: linux Container library
	3	*
	4	* (C) Copyright IBM Corp. 2007, 2008
	5	*
	6	* Authors:
	7	* Daniel Lezcano <dlezcano at fr.ibm.com>
	8	*
	9	* This library is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU Lesser General Public
	11	* License as published by the Free Software Foundation; either
	12	* version 2.1 of the License, or (at your option) any later version.
	13	*
	14	* This library is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* Lesser General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU Lesser General Public
	20	* License along with this library; if not, write to the Free Software
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	22	*/
	23
ff218c25	24	#include "../config.h"
0ad19a3f	25	#include <stdio.h>
	26	#undef _GNU_SOURCE
	27	#include <string.h>
	28	#include <stdlib.h>
	29	#include <dirent.h>
	30	#include <errno.h>
	31	#include <unistd.h>
	32	#include <signal.h>
b0a33c1e	33	#include <fcntl.h>
b0a33c1e	34	#include <termios.h>
0ad19a3f	35	#include <sys/param.h>
0ad19a3f	36	#include <sys/file.h>
f4d507d5	37	#include <sys/mount.h>
0ad19a3f	38	#include <sys/types.h>
0ad19a3f	39	#include <sys/prctl.h>
42ff343d	40	#include <sys/capability.h>
0ad19a3f	41	#include <sys/wait.h>
b0a33c1e	42	#include <sys/un.h>
b0a33c1e	43	#include <sys/poll.h>
ff218c25	44
ff218c25	45	#ifdef HAVE_SYS_SIGNALFD_H
8ca61733	46	# include <sys/signalfd.h>
ff218c25	47	#else
8ca61733 MJ	48	# ifndef __NR_signalfd4
	49	/* assume kernel headers are too old */
	50	# if __i386__
	51	# define __NR_signalfd4 327
	52	# elif __x86_64__
	53	# define __NR_signalfd4 289
bfa38025 MH	54	# elif __powerpc__
bfa38025 MH	55	# define __NR_signalfd4 313
47f38330 SH	56	# elif __s390x__
47f38330 SH	57	# define __NR_signalfd4 322
8ca61733 MJ	58	# endif
	59	#endif
	60
	61	# ifndef __NR_signalfd
	62	/* assume kernel headers are too old */
	63	# if __i386__
	64	# define __NR_signalfd 321
	65	# elif __x86_64__
	66	# define __NR_signalfd 282
bfa38025 MH	67	# elif __powerpc__
bfa38025 MH	68	# define __NR_signalfd 305
47f38330 SH	69	# elif __s390x__
47f38330 SH	70	# define __NR_signalfd 316
8ca61733 MJ	71	# endif
	72	#endif
	73
	74	int signalfd(int fd, const sigset_t *mask, int flags)
	75	{
	76	int retval;
	77
	78	retval = syscall (__NR_signalfd4, fd, mask, _NSIG / 8, flags);
	79	if (errno == ENOSYS && flags == 0)
	80	retval = syscall (__NR_signalfd, fd, mask, _NSIG / 8);
	81	return retval;
	82	}
ff218c25	83	#endif
0ad19a3f	84
656994bb MH	85	#if !HAVE_DECL_PR_CAPBSET_DROP
	86	#define PR_CAPBSET_DROP 24
	87	#endif
	88
e2bcd7db	89	#include "error.h"
b0a33c1e	90	#include "af_unix.h"
b0a33c1e	91	#include "mainloop.h"
e2bcd7db	92
b113348e	93	#include <lxc/lxc.h>
36eb9bde CLG	94	#include <lxc/log.h>
	95
	96	lxc_log_define(lxc_start, lxc);
	97
0ad19a3f	98	LXC_TTY_HANDLER(SIGINT);
	99	LXC_TTY_HANDLER(SIGQUIT);
	100
b0a33c1e	101	static int setup_sigchld_fd(sigset_t *oldmask)
	102	{
	103	sigset_t mask;
	104	int fd;
	105
	106	if (sigprocmask(SIG_BLOCK, NULL, &mask)) {
36eb9bde	107	SYSERROR("failed to get mask signal");
b0a33c1e	108	return -1;
	109	}
	110
	111	if (sigaddset(&mask, SIGCHLD) \|\| sigprocmask(SIG_BLOCK, &mask, oldmask)) {
36eb9bde	112	SYSERROR("failed to set mask signal");
b0a33c1e	113	return -1;
	114	}
	115
	116	fd = signalfd(-1, &mask, 0);
	117	if (fd < 0) {
36eb9bde	118	SYSERROR("failed to create the signal fd");
b0a33c1e	119	return -1;
	120	}
	121
	122	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
36eb9bde	123	SYSERROR("failed to set sigfd to close-on-exec");
b0a33c1e	124	close(fd);
	125	return -1;
	126	}
	127
	128	return fd;
	129	}
	130
	131	static int setup_tty_service(const char name, int ttyfd)
	132	{
	133	int fd;
	134	struct sockaddr_un addr = { 0 };
	135	char *offset = &addr.sun_path[1];
	136
	137	strcpy(offset, name);
	138	addr.sun_path[0] = '\0';
	139
	140	fd = lxc_af_unix_open(addr.sun_path, SOCK_STREAM, 0);
	141	if (fd < 0)
	142	return -1;
	143
	144	if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
36eb9bde	145	SYSERROR("failed to close-on-exec flag");
b0a33c1e	146	close(fd);
	147	return -1;
	148	}
	149
	150	*ttyfd = fd;
	151
	152	return 0;
	153	}
	154
	155	static int sigchld_handler(int fd, void *data,
	156	struct lxc_epoll_descr *descr)
	157	{
b0a33c1e	158	return 1;
	159	}
	160
	161	static int ttyclient_handler(int fd, void *data,
	162	struct lxc_epoll_descr *descr)
	163	{
	164	int i;
	165	struct lxc_tty_info *tty_info = data;
	166
	167	for (i = 0; i < tty_info->nbtty; i++) {
	168
	169	if (tty_info->pty_info[i].busy != fd)
	170	continue;
	171
	172	lxc_mainloop_del_handler(descr, fd);
	173	tty_info->pty_info[i].busy = 0;
	174	close(fd);
	175	}
	176
	177	return 0;
	178	}
	179
	180	static int ttyservice_handler(int fd, void *data,
	181	struct lxc_epoll_descr *descr)
	182	{
	183	int conn, ttynum, val = 1, ret = -1;
	184	struct lxc_tty_info *tty_info = data;
	185
	186	conn = accept(fd, NULL, 0);
	187	if (conn < 0) {
36eb9bde	188	SYSERROR("failed to accept tty client");
b0a33c1e	189	return -1;
	190	}
	191
	192	if (setsockopt(conn, SOL_SOCKET, SO_PASSCRED, &val, sizeof(val))) {
36eb9bde	193	SYSERROR("failed to enable credential on socket");
b0a33c1e	194	goto out_close;
	195	}
	196
	197	if (lxc_af_unix_rcv_credential(conn, &ttynum, sizeof(ttynum)))
	198	goto out_close;
	199
be43f17e DL	200	if (ttynum > 0) {
	201	if (ttynum > tty_info->nbtty)
	202	goto out_close;
	203
	204	if (tty_info->pty_info[ttynum - 1].busy)
	205	goto out_close;
b0a33c1e	206
be43f17e DL	207	goto out_send;
be43f17e DL	208	}
b0a33c1e	209
be43f17e DL	210	/* fixup index tty1 => [0] */
	211	for (ttynum = 1;
	212	ttynum <= tty_info->nbtty && tty_info->pty_info[ttynum - 1].busy;
	213	ttynum++);
	214
	215	/* we didn't find any available slot for tty */
	216	if (ttynum > tty_info->nbtty)
b0a33c1e	217	goto out_close;
b0a33c1e	218
be43f17e DL	219	out_send:
	220	if (lxc_af_unix_send_fd(conn, tty_info->pty_info[ttynum - 1].master,
	221	&ttynum, sizeof(ttynum)) < 0) {
36eb9bde	222	ERROR("failed to send tty to client");
b0a33c1e	223	goto out_close;
	224	}
	225
be43f17e	226	if (lxc_mainloop_add_handler(descr, conn,
b0a33c1e	227	ttyclient_handler, tty_info)) {
36eb9bde	228	ERROR("failed to add tty client handler");
b0a33c1e	229	goto out_close;
	230	}
	231
be43f17e	232	tty_info->pty_info[ttynum - 1].busy = conn;
b0a33c1e	233
b0a33c1e	234	ret = 0;
b0a33c1e	235	out:
	236	return ret;
	237	out_close:
	238	close(conn);
	239	goto out;
	240	}
	241
1bc5cc8c	242	int lxc_poll(const char name, struct lxc_handler handler)
b0a33c1e	243	{
ca5f7926 DL	244	int sigfd = handler->sigfd;
	245	int pid = handler->pid;
	246	const struct lxc_tty_info *tty_info = &handler->tty_info;
	247
b0a33c1e	248	int nfds, ttyfd = -1, ret = -1;
	249	struct lxc_epoll_descr descr;
	250
	251	if (tty_info->nbtty && setup_tty_service(name, &ttyfd)) {
36eb9bde	252	ERROR("failed to create the tty service point");
b0a33c1e	253	goto out_sigfd;
	254	}
	255
	256	/* sigfd + nb tty + tty service
	257	* if tty is enabled */
	258	nfds = tty_info->nbtty + 1 + tty_info->nbtty ? 1 : 0;
	259
	260	if (lxc_mainloop_open(nfds, &descr)) {
36eb9bde	261	ERROR("failed to create mainloop");
b0a33c1e	262	goto out_ttyfd;
	263	}
	264
	265	if (lxc_mainloop_add_handler(&descr, sigfd, sigchld_handler, &pid)) {
36eb9bde	266	ERROR("failed to add handler for the signal");
b0a33c1e	267	goto out_mainloop_open;
	268	}
	269
	270	if (tty_info->nbtty) {
	271	if (lxc_mainloop_add_handler(&descr, ttyfd,
	272	ttyservice_handler,
	273	(void *)tty_info)) {
36eb9bde	274	ERROR("failed to add handler for the tty");
b0a33c1e	275	goto out_mainloop_open;
	276	}
	277	}
	278
	279	ret = lxc_mainloop(&descr);
	280
	281	out:
	282	return ret;
	283
	284	out_mainloop_open:
	285	lxc_mainloop_close(&descr);
	286	out_ttyfd:
	287	close(ttyfd);
	288	out_sigfd:
	289	close(sigfd);
	290	goto out;
	291	}
	292
59eb99ba	293	static int save_init_pid(const char *name, pid_t pid)
0ad19a3f	294	{
22ebac19	295	char init[MAXPATHLEN];
59eb99ba DL	296	char *val;
	297	int fd, err = -1;
	298
	299	snprintf(init, MAXPATHLEN, LXCPATH "/%s/init", name);
	300
	301	if (!asprintf(&val, "%d\n", pid)) {
	302	SYSERROR("failed to allocate memory");
	303	goto out;
	304	}
	305
	306	fd = open(init, O_WRONLY\|O_CREAT\|O_TRUNC, S_IRUSR\|S_IWUSR);
	307	if (fd < 0) {
	308	SYSERROR("failed to open '%s'", init);
	309	goto out_free;
	310	}
	311
	312	if (write(fd, val, strlen(val)) < 0) {
	313	SYSERROR("failed to write the init pid");
	314	goto out_close;
	315	}
f4d507d5	316
59eb99ba DL	317	err = 0;
	318
	319	out_close:
	320	close(fd);
	321	out_free:
	322	free(val);
	323	out:
	324	return err;
	325	}
	326
	327	static void remove_init_pid(const char *name, pid_t pid)
	328	{
	329	char init[MAXPATHLEN];
	330
	331	snprintf(init, MAXPATHLEN, LXCPATH "/%s/init", name);
	332	unlink(init);
	333	}
	334
1bc5cc8c	335	int lxc_init(const char name, struct lxc_handler handler)
59eb99ba DL	336	{
	337	int err = -1;
	338
	339	memset(handler, 0, sizeof(*handler));
	340
	341	handler->lock = lxc_get_lock(name);
	342	if (handler->lock < 0)
	343	goto out;
0ad19a3f	344
0ad19a3f	345	/* Begin the set the state to STARTING*/
0ad19a3f	346	if (lxc_setstate(name, STARTING)) {
59eb99ba DL	347	ERROR("failed to set state '%s'", lxc_state2str(STARTING));
59eb99ba DL	348	goto out_put_lock;
0ad19a3f	349	}
0ad19a3f	350
caf249f4	351	/* If we are not attached to a tty, disable it */
59eb99ba DL	352	if (ttyname_r(0, handler->tty, sizeof(handler->tty)))
59eb99ba DL	353	handler->tty[0] = '\0';
939229eb	354
59eb99ba	355	if (lxc_create_tty(name, &handler->tty_info)) {
36eb9bde	356	ERROR("failed to create the ttys");
59eb99ba	357	goto out_aborting;
b0a33c1e	358	}
	359
	360	/* the signal fd has to be created before forking otherwise
	361	* if the child process exits before we setup the signal fd,
	362	* the event will be lost and the command will be stuck */
59eb99ba DL	363	handler->sigfd = setup_sigchld_fd(&handler->oldmask);
59eb99ba DL	364	if (handler->sigfd < 0) {
36eb9bde	365	ERROR("failed to set sigchild fd handler");
59eb99ba	366	goto out_delete_tty;
b0a33c1e	367	}
b0a33c1e	368
59eb99ba DL	369	/* Avoid signals from terminal */
	370	LXC_TTY_ADD_HANDLER(SIGINT);
	371	LXC_TTY_ADD_HANDLER(SIGQUIT);
	372
	373	err = 0;
	374	out:
	375	return err;
	376
	377	out_delete_tty:
	378	lxc_delete_tty(&handler->tty_info);
	379	out_aborting:
	380	lxc_setstate(name, ABORTING);
	381	out_put_lock:
	382	lxc_put_lock(handler->lock);
	383	goto out;
	384	}
	385
1bc5cc8c	386	void lxc_fini(const char name, struct lxc_handler handler)
59eb99ba DL	387	{
	388	/* The STOPPING state is there for future cleanup code
	389	* which can take awhile
	390	*/
	391	lxc_setstate(name, STOPPING);
	392
	393	lxc_setstate(name, STOPPED);
	394
	395	remove_init_pid(name, handler->pid);
	396
	397	lxc_delete_tty(&handler->tty_info);
	398
	399	lxc_unlink_nsgroup(name);
	400
	401	lxc_put_lock(handler->lock);
	402
	403	LXC_TTY_DEL_HANDLER(SIGQUIT);
	404	LXC_TTY_DEL_HANDLER(SIGINT);
	405	}
	406
1bc5cc8c	407	void lxc_abort(const char name, struct lxc_handler handler)
59eb99ba DL	408	{
	409	lxc_setstate(name, ABORTING);
	410	kill(handler->pid, SIGKILL);
	411	}
	412
9618063c	413	int lxc_spawn(const char name, struct lxc_handler handler, char *const argv[])
59eb99ba DL	414	{
	415	int sv[2];
	416	int clone_flags;
	417	int err = -1, sync;
	418
0ad19a3f	419	/* Synchro socketpair */
0ad19a3f	420	if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sv)) {
36eb9bde	421	SYSERROR("failed to create communication socketpair");
f4d507d5	422	goto out;
0ad19a3f	423	}
0ad19a3f	424
f4d507d5	425	clone_flags = CLONE_NEWPID\|CLONE_NEWIPC\|CLONE_NEWNS;
0ad19a3f	426	if (conf_has_utsname(name))
	427	clone_flags \|= CLONE_NEWUTS;
	428	if (conf_has_network(name))
	429	clone_flags \|= CLONE_NEWNET;
	430
	431	/* Create a process in a new set of namespaces */
59eb99ba DL	432	handler->pid = fork_ns(clone_flags);
59eb99ba DL	433	if (handler->pid < 0) {
36eb9bde	434	SYSERROR("failed to fork into a new namespace");
59eb99ba	435	goto out_close;
0ad19a3f	436	}
0ad19a3f	437
59eb99ba	438	if (!handler->pid) {
0ad19a3f	439
59eb99ba	440	if (sigprocmask(SIG_SETMASK, &handler->oldmask, NULL)) {
36eb9bde	441	SYSERROR("failed to set sigprocmask");
e043236e	442	goto out_child;
b0a33c1e	443	}
b0a33c1e	444
0ad19a3f	445	close(sv[1]);
	446
	447	/* Be sure we don't inherit this after the exec */
	448	fcntl(sv[0], F_SETFD, FD_CLOEXEC);
	449
	450	/* Tell our father he can begin to configure the container */
	451	if (write(sv[0], &sync, sizeof(sync)) < 0) {
36eb9bde	452	SYSERROR("failed to write socket");
57545890	453	goto out_child;
0ad19a3f	454	}
	455
	456	/* Wait for the father to finish the configuration */
	457	if (read(sv[0], &sync, sizeof(sync)) < 0) {
36eb9bde	458	SYSERROR("failed to read socket");
57545890	459	goto out_child;
0ad19a3f	460	}
	461
	462	/* Setup the container, ip, names, utsname, ... */
e043236e	463	if (lxc_setup(name, handler->tty, &handler->tty_info)) {
36eb9bde	464	ERROR("failed to setup the container");
e043236e	465	goto out_warn_father;
0ad19a3f	466	}
0ad19a3f	467
42ff343d	468	if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) {
36eb9bde	469	SYSERROR("failed to remove CAP_SYS_BOOT capability");
42ff343d	470	goto out_child;
	471	}
	472
0ad19a3f	473	execvp(argv[0], argv);
36eb9bde	474	SYSERROR("failed to exec %s", argv[0]);
0ad19a3f	475
e043236e	476	out_warn_father:
0ad19a3f	477	/* If the exec fails, tell that to our father */
e5bda9ee	478	if (write(sv[0], &err, sizeof(err)) < 0)
36eb9bde	479	SYSERROR("failed to write the socket");
57545890	480	out_child:
e5bda9ee	481	exit(err);
0ad19a3f	482	}
	483
	484	close(sv[0]);
	485
	486	/* Wait for the child to be ready */
	487	if (read(sv[1], &sync, sizeof(sync)) < 0) {
36eb9bde	488	SYSERROR("failed to read the socket");
59eb99ba	489	goto out_abort;
0ad19a3f	490	}
0ad19a3f	491
59eb99ba	492	if (lxc_link_nsgroup(name, handler->pid))
36eb9bde	493	WARN("cgroupfs not found: cgroup disabled");
218d4250	494
0ad19a3f	495	/* Create the network configuration */
59eb99ba	496	if (clone_flags & CLONE_NEWNET && conf_create_network(name, handler->pid)) {
36eb9bde	497	ERROR("failed to create the configured network");
59eb99ba	498	goto out_abort;
0ad19a3f	499	}
	500
	501	/* Tell the child to continue its initialization */
	502	if (write(sv[1], &sync, sizeof(sync)) < 0) {
36eb9bde	503	SYSERROR("failed to write the socket");
59eb99ba	504	goto out_abort;
0ad19a3f	505	}
	506
	507	/* Wait for the child to exec or returning an error */
e043236e	508	if (read(sv[1], &sync, sizeof(sync)) < 0) {
36eb9bde	509	ERROR("failed to read the socket");
59eb99ba	510	goto out_abort;
0ad19a3f	511	}
0ad19a3f	512
59eb99ba DL	513	if (save_init_pid(name, handler->pid)) {
	514	ERROR("failed to save the init pid info");
	515	goto out_abort;
0ad19a3f	516	}
0ad19a3f	517
59eb99ba DL	518	if (lxc_setstate(name, RUNNING)) {
	519	ERROR("failed to set state to %s",
	520	lxc_state2str(RUNNING));
	521	goto out_abort;
3f21c114	522	}
22ebac19	523
59eb99ba	524	err = 0;
22ebac19	525
59eb99ba DL	526	out_close:
	527	close(sv[0]);
	528	close(sv[1]);
	529	out:
	530	return err;
0ad19a3f	531
59eb99ba DL	532	out_abort:
	533	lxc_abort(name, handler);
	534	goto out_close;
	535	}
0ad19a3f	536
9618063c	537	int lxc_start(const char name, char const argv[])
59eb99ba DL	538	{
59eb99ba DL	539	struct lxc_handler handler = { 0 };
e043236e	540	int err = -1;
59eb99ba DL	541	int status;
	542
	543	if (lxc_init(name, &handler)) {
	544	ERROR("failed to initialize the container");
	545	goto out;
0ad19a3f	546	}
0ad19a3f	547
59eb99ba DL	548	err = lxc_spawn(name, &handler, argv);
	549	if (err) {
	550	ERROR("failed to spawn '%s'", argv[0]);
	551	goto out;
0ad19a3f	552	}
0ad19a3f	553
e043236e MN	554	err = lxc_poll(name, &handler);
e043236e MN	555	if (err) {
59eb99ba DL	556	ERROR("mainloop exited with an error");
	557	goto out_abort;
	558	}
0ad19a3f	559
1bc5cc8c DL	560	while (waitpid(handler.pid, &status, 0) < 0 && errno == EINTR)
1bc5cc8c DL	561	continue;
e043236e MN	562
e043236e MN	563	err = lxc_error_set_and_log(handler.pid, status);
0ad19a3f	564	out:
59eb99ba	565	lxc_fini(name, &handler);
0ad19a3f	566	return err;
0ad19a3f	567
59eb99ba DL	568	out_abort:
59eb99ba DL	569	lxc_abort(name, &handler);
0ad19a3f	570	goto out;
0ad19a3f	571	}