[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
 */

#define _GNU_SOURCE
#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 <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 "error.h"

#include <lxc/lxc.h>

LXC_TTY_HANDLER(SIGINT);
LXC_TTY_HANDLER(SIGQUIT);

int lxc_start(const char *name, char *argv[])
{
	char init[MAXPATHLEN];
	char *val = NULL;
	int fd, lock, sv[2], sync = 0, err = -LXC_ERROR_INTERNAL;
	pid_t pid;
	int clone_flags;

	lock = lxc_get_lock(name);
	if (lock < 0) {
		if (lock == -EWOULDBLOCK)
			return -LXC_ERROR_BUSY;
		if (lock == -ENOENT)
			return -LXC_ERROR_NOT_FOUND;
		return -LXC_ERROR_LOCK;
	}

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

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

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

	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 */
	pid = fork_ns(clone_flags);
	if (pid < 0) {
		lxc_log_syserror("failed to fork into a new namespace");
		goto err_fork_ns;
	}

	if (!pid) {

		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) {
			lxc_log_syserror("failed to write socket");
			goto out_child;
		}

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

		/* Setup the container, ip, names, utsname, ... */
		err = lxc_setup(name);
		if (err) {
			lxc_log_error("failed to setup the container");
			if (write(sv[0], &err, sizeof(err)) < 0)
				lxc_log_syserror("failed to write the socket");
			goto out_child;
		}

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

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

		/* If the exec fails, tell that to our father */
		if (write(sv[0], &err, sizeof(err)) < 0)
			lxc_log_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) {
		lxc_log_syserror("failed to read the socket");
		goto err_pipe_read;
	}

	if (lxc_link_nsgroup(name, pid))
		lxc_log_warning("cgroupfs not found: cgroup disabled");

	/* Create the network configuration */
	if (clone_flags & CLONE_NEWNET && conf_create_network(name, pid)) {
		lxc_log_error("failed to create the configured network");
		goto err_create_network;
	}

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

	/* Wait for the child to exec or returning an error */
	err = read(sv[1], &sync, sizeof(sync));
	if (err < 0) {
		lxc_log_error("failed to read the socket");
		goto err_pipe_read2;
	}

	if (err > 0) {
		err = sync;
		printf("error value is %d\n", err);
		/* TODO : check status etc ... */
		waitpid(pid, NULL, 0);
		goto err_child_failed;
	}

	asprintf(&val, "%d\n", pid);

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

	fd = open(init, O_WRONLY|O_CREAT|O_TRUNC, S_IRUSR|S_IWUSR);
	if (fd < 0) {
		lxc_log_syserror("failed to open '%s'", init);
		goto err_write;
	}
	
	if (write(fd, val, strlen(val)) < 0) {
		lxc_log_syserror("failed to write the init pid");
		goto err_write;
	}

	close(fd);

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

wait_again:
	if (waitpid(pid, NULL, 0) < 0) {
		if (errno == EINTR) 
			goto wait_again;
		lxc_log_syserror("failed to wait the pid %d", pid);
		goto err_waitpid_failed;
	}

	if (lxc_setstate(name, STOPPING))
		lxc_log_error("failed to set state %s", lxc_state2str(STOPPING));

#ifdef NETWORK_DESTROY
	if (clone_flags & CLONE_NEWNET && conf_destroy_network(name))
		lxc_log_error("failed to destroy the network");
#endif

	err = 0;
out:
	if (lxc_setstate(name, STOPPED))
		lxc_log_error("failed to set state %s", lxc_state2str(STOPPED));

	lxc_unlink_nsgroup(name);
	unlink(init);
	free(val);
	lxc_put_lock(lock);
	LXC_TTY_DEL_HANDLER(SIGQUIT);
	LXC_TTY_DEL_HANDLER(SIGINT);

	return err;

err_write:
	close(fd);

err_state_failed:
err_child_failed:
err_pipe_read2:
err_pipe_write:
#ifdef NETWORK_DESTROY
	if (clone_flags & CLONE_NEWNET)
		conf_destroy_network(name);
#endif
err_create_network:
err_pipe_read:
err_waitpid_failed:
	if (lxc_setstate(name, ABORTING))
		lxc_log_error("failed to set state %s", lxc_state2str(STOPPED));

	kill(pid, SIGKILL);
err_fork_ns:
	close(sv[0]);
	close(sv[1]);
	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
	24	#define _GNU_SOURCE
	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>
0ad19a3f	33	#include <sys/param.h>
0ad19a3f	34	#include <sys/file.h>
f4d507d5	35	#include <sys/mount.h>
0ad19a3f	36	#include <sys/types.h>
0ad19a3f	37	#include <sys/prctl.h>
42ff343d	38	#include <sys/capability.h>
0ad19a3f	39	#include <sys/wait.h>
0ad19a3f	40
e2bcd7db	41	#include "error.h"
e2bcd7db	42
b113348e	43	#include <lxc/lxc.h>
0ad19a3f	44
	45	LXC_TTY_HANDLER(SIGINT);
	46	LXC_TTY_HANDLER(SIGQUIT);
	47
05f05512	48	int lxc_start(const char name, char argv[])
0ad19a3f	49	{
22ebac19	50	char init[MAXPATHLEN];
22ebac19	51	char *val = NULL;
e2bcd7db	52	int fd, lock, sv[2], sync = 0, err = -LXC_ERROR_INTERNAL;
0ad19a3f	53	pid_t pid;
0ad19a3f	54	int clone_flags;
f4d507d5	55
0ad19a3f	56	lock = lxc_get_lock(name);
e5bda9ee	57	if (lock < 0) {
	58	if (lock == -EWOULDBLOCK)
	59	return -LXC_ERROR_BUSY;
	60	if (lock == -ENOENT)
	61	return -LXC_ERROR_NOT_FOUND;
	62	return -LXC_ERROR_LOCK;
	63	}
0ad19a3f	64
0ad19a3f	65	/* Begin the set the state to STARTING*/
0ad19a3f	66	if (lxc_setstate(name, STARTING)) {
8b8b04f8	67	lxc_log_error("failed to set state '%s'",
8b8b04f8	68	lxc_state2str(STARTING));
0ad19a3f	69	goto out;
	70	}
	71
	72	/* Synchro socketpair */
	73	if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sv)) {
	74	lxc_log_syserror("failed to create communication socketpair");
f4d507d5	75	goto out;
0ad19a3f	76	}
	77
	78	/* Avoid signals from terminal */
	79	LXC_TTY_ADD_HANDLER(SIGINT);
	80	LXC_TTY_ADD_HANDLER(SIGQUIT);
	81
f4d507d5	82	clone_flags = CLONE_NEWPID\|CLONE_NEWIPC\|CLONE_NEWNS;
0ad19a3f	83	if (conf_has_utsname(name))
	84	clone_flags \|= CLONE_NEWUTS;
	85	if (conf_has_network(name))
	86	clone_flags \|= CLONE_NEWNET;
	87
	88	/* Create a process in a new set of namespaces */
	89	pid = fork_ns(clone_flags);
	90	if (pid < 0) {
	91	lxc_log_syserror("failed to fork into a new namespace");
	92	goto err_fork_ns;
	93	}
	94
	95	if (!pid) {
	96
	97	close(sv[1]);
	98
	99	/* Be sure we don't inherit this after the exec */
	100	fcntl(sv[0], F_SETFD, FD_CLOEXEC);
	101
	102	/* Tell our father he can begin to configure the container */
	103	if (write(sv[0], &sync, sizeof(sync)) < 0) {
	104	lxc_log_syserror("failed to write socket");
57545890	105	goto out_child;
0ad19a3f	106	}
	107
	108	/* Wait for the father to finish the configuration */
	109	if (read(sv[0], &sync, sizeof(sync)) < 0) {
	110	lxc_log_syserror("failed to read socket");
57545890	111	goto out_child;
0ad19a3f	112	}
	113
	114	/* Setup the container, ip, names, utsname, ... */
e5bda9ee	115	err = lxc_setup(name);
e5bda9ee	116	if (err) {
0ad19a3f	117	lxc_log_error("failed to setup the container");
e5bda9ee	118	if (write(sv[0], &err, sizeof(err)) < 0)
0ad19a3f	119	lxc_log_syserror("failed to write the socket");
57545890	120	goto out_child;
0ad19a3f	121	}
0ad19a3f	122
42ff343d	123	if (prctl(PR_CAPBSET_DROP, CAP_SYS_BOOT, 0, 0, 0)) {
	124	lxc_log_syserror("failed to remove CAP_SYS_BOOT capability");
	125	goto out_child;
	126	}
	127
0ad19a3f	128	execvp(argv[0], argv);
	129	lxc_log_syserror("failed to exec %s", argv[0]);
	130
	131	/* If the exec fails, tell that to our father */
e5bda9ee	132	if (write(sv[0], &err, sizeof(err)) < 0)
0ad19a3f	133	lxc_log_syserror("failed to write the socket");
0ad19a3f	134
57545890	135	out_child:
e5bda9ee	136	exit(err);
0ad19a3f	137	}
	138
	139	close(sv[0]);
	140
	141	/* Wait for the child to be ready */
	142	if (read(sv[1], &sync, sizeof(sync)) < 0) {
	143	lxc_log_syserror("failed to read the socket");
	144	goto err_pipe_read;
	145	}
	146
218d4250	147	if (lxc_link_nsgroup(name, pid))
	148	lxc_log_warning("cgroupfs not found: cgroup disabled");
	149
0ad19a3f	150	/* Create the network configuration */
	151	if (clone_flags & CLONE_NEWNET && conf_create_network(name, pid)) {
	152	lxc_log_error("failed to create the configured network");
	153	goto err_create_network;
	154	}
	155
	156	/* Tell the child to continue its initialization */
	157	if (write(sv[1], &sync, sizeof(sync)) < 0) {
	158	lxc_log_syserror("failed to write the socket");
	159	goto err_pipe_write;
	160	}
	161
	162	/* Wait for the child to exec or returning an error */
	163	err = read(sv[1], &sync, sizeof(sync));
	164	if (err < 0) {
	165	lxc_log_error("failed to read the socket");
	166	goto err_pipe_read2;
	167	}
	168
	169	if (err > 0) {
e5bda9ee	170	err = sync;
e5bda9ee	171	printf("error value is %d\n", err);
0ad19a3f	172	/* TODO : check status etc ... */
	173	waitpid(pid, NULL, 0);
	174	goto err_child_failed;
	175	}
	176
	177	asprintf(&val, "%d\n", pid);
22ebac19	178
	179	snprintf(init, MAXPATHLEN, LXCPATH "/%s/init", name);
	180
0ad19a3f	181	fd = open(init, O_WRONLY\|O_CREAT\|O_TRUNC, S_IRUSR\|S_IWUSR);
	182	if (fd < 0) {
	183	lxc_log_syserror("failed to open '%s'", init);
	184	goto err_write;
	185	}
	186
	187	if (write(fd, val, strlen(val)) < 0) {
	188	lxc_log_syserror("failed to write the init pid");
	189	goto err_write;
	190	}
	191
	192	close(fd);
	193
0ad19a3f	194	if (lxc_setstate(name, RUNNING)) {
	195	lxc_log_error("failed to set state to %s",
	196	lxc_state2str(RUNNING));
	197	goto err_state_failed;
	198	}
	199
	200	wait_again:
	201	if (waitpid(pid, NULL, 0) < 0) {
	202	if (errno == EINTR)
	203	goto wait_again;
	204	lxc_log_syserror("failed to wait the pid %d", pid);
	205	goto err_waitpid_failed;
	206	}
	207
	208	if (lxc_setstate(name, STOPPING))
	209	lxc_log_error("failed to set state %s", lxc_state2str(STOPPING));
	210
b7c9b199	211	#ifdef NETWORK_DESTROY
0ad19a3f	212	if (clone_flags & CLONE_NEWNET && conf_destroy_network(name))
0ad19a3f	213	lxc_log_error("failed to destroy the network");
b7c9b199	214	#endif
0ad19a3f	215
	216	err = 0;
	217	out:
	218	if (lxc_setstate(name, STOPPED))
	219	lxc_log_error("failed to set state %s", lxc_state2str(STOPPED));
	220
	221	lxc_unlink_nsgroup(name);
	222	unlink(init);
0ad19a3f	223	free(val);
0ad19a3f	224	lxc_put_lock(lock);
536b97f0	225	LXC_TTY_DEL_HANDLER(SIGQUIT);
536b97f0	226	LXC_TTY_DEL_HANDLER(SIGINT);
0ad19a3f	227
	228	return err;
	229
	230	err_write:
	231	close(fd);
	232
	233	err_state_failed:
	234	err_child_failed:
	235	err_pipe_read2:
	236	err_pipe_write:
b7c9b199	237	#ifdef NETWORK_DESTROY
0ad19a3f	238	if (clone_flags & CLONE_NEWNET)
0ad19a3f	239	conf_destroy_network(name);
b7c9b199	240	#endif
0ad19a3f	241	err_create_network:
	242	err_pipe_read:
	243	err_waitpid_failed:
	244	if (lxc_setstate(name, ABORTING))
	245	lxc_log_error("failed to set state %s", lxc_state2str(STOPPED));
	246
	247	kill(pid, SIGKILL);
	248	err_fork_ns:
0ad19a3f	249	close(sv[0]);
0ad19a3f	250	close(sv[1]);
0ad19a3f	251	goto out;
0ad19a3f	252	}