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

/*
 * 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 <stddef.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/socket.h>
#include <sys/un.h>

#include "log.h"

lxc_log_define(lxc_af_unix, lxc);

int lxc_abstract_unix_open(const char *path, int type, int flags)
{
	int fd;
	size_t len;
	struct sockaddr_un addr;

	if (flags & O_TRUNC)
		unlink(path);

	fd = socket(PF_UNIX, type, 0);
	if (fd < 0)
		return -1;

	/* Clear address structure */
	memset(&addr, 0, sizeof(addr));

	if (!path)
		return fd;

	addr.sun_family = AF_UNIX;

	len = strlen(&path[1]) + 1;
	if (len >= sizeof(addr.sun_path) - 1) {
		close(fd);
		errno = ENAMETOOLONG;
		return -1;
	}
	/* addr.sun_path[0] has already been set to 0 by memset() */
	strncpy(&addr.sun_path[1], &path[1], strlen(&path[1]));

	if (bind(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len)) {
		int tmp = errno;
		close(fd);
		errno = tmp;
		return -1;
	}

	if (type == SOCK_STREAM && listen(fd, 100)) {
		int tmp = errno;
		close(fd);
		errno = tmp;
		return -1;
	}

	return fd;
}

int lxc_abstract_unix_close(int fd)
{
	struct sockaddr_un addr;
	socklen_t addrlen = sizeof(addr);

	if (!getsockname(fd, (struct sockaddr *)&addr, &addrlen) &&
			addr.sun_path[0])
		unlink(addr.sun_path);

	close(fd);

	return 0;
}

int lxc_abstract_unix_connect(const char *path)
{
	int fd;
	size_t len;
	struct sockaddr_un addr;

	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	if (fd < 0)
		return -1;

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

	addr.sun_family = AF_UNIX;

	len = strlen(&path[1]) + 1;
	if (len >= sizeof(addr.sun_path) - 1) {
		close(fd);
		errno = ENAMETOOLONG;
		return -1;
	}
	/* addr.sun_path[0] has already been set to 0 by memset() */
	strncpy(&addr.sun_path[1], &path[1], strlen(&path[1]));

	if (connect(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len)) {
		int tmp = errno;
		/* special case to connect to older containers */
		if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) == 0)
			return fd;
		close(fd);
		errno = tmp;
		return -1;
	}

	return fd;
}

int lxc_abstract_unix_send_fd(int fd, int sendfd, void *data, size_t size)
{
	struct msghdr msg = { 0 };
	struct iovec iov;
	struct cmsghdr *cmsg;
	char cmsgbuf[CMSG_SPACE(sizeof(int))];
	char buf[1];
	int *val;

	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);

	cmsg = CMSG_FIRSTHDR(&msg);
	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
	cmsg->cmsg_level = SOL_SOCKET;
	cmsg->cmsg_type = SCM_RIGHTS;
	val = (int *)(CMSG_DATA(cmsg));
	*val = sendfd;

	msg.msg_name = NULL;
	msg.msg_namelen = 0;

	iov.iov_base = data ? data : buf;
	iov.iov_len = data ? size : sizeof(buf);
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;

	return sendmsg(fd, &msg, MSG_NOSIGNAL);
}

int lxc_abstract_unix_recv_fd(int fd, int *recvfd, void *data, size_t size)
{
	struct msghdr msg = { 0 };
	struct iovec iov;
	struct cmsghdr *cmsg;
	char cmsgbuf[CMSG_SPACE(sizeof(int))];
	char buf[1];
	int ret, *val;

	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);

	iov.iov_base = data ? data : buf;
	iov.iov_len = data ? size : sizeof(buf);
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;

	ret = recvmsg(fd, &msg, 0);
	if (ret <= 0)
		goto out;

	cmsg = CMSG_FIRSTHDR(&msg);

	/* if the message is wrong the variable will not be
	 * filled and the peer will notified about a problem */
	*recvfd = -1;

	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(int)) &&
			cmsg->cmsg_level == SOL_SOCKET &&
			cmsg->cmsg_type == SCM_RIGHTS) {
		val = (int *) CMSG_DATA(cmsg);
		*recvfd = *val;
	}
out:
	return ret;
}

int lxc_abstract_unix_send_credential(int fd, void *data, size_t size)
{
	struct msghdr msg = { 0 };
	struct iovec iov;
	struct cmsghdr *cmsg;
	struct ucred cred = {
		.pid = getpid(),
		.uid = getuid(),
		.gid = getgid(),
	};
	char cmsgbuf[CMSG_SPACE(sizeof(cred))];
	char buf[1];

	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);

	cmsg = CMSG_FIRSTHDR(&msg);
	cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
	cmsg->cmsg_level = SOL_SOCKET;
	cmsg->cmsg_type = SCM_CREDENTIALS;
	memcpy(CMSG_DATA(cmsg), &cred, sizeof(cred));

	msg.msg_name = NULL;
	msg.msg_namelen = 0;

	iov.iov_base = data ? data : buf;
	iov.iov_len = data ? size : sizeof(buf);
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;

	return sendmsg(fd, &msg, MSG_NOSIGNAL);
}

int lxc_abstract_unix_rcv_credential(int fd, void *data, size_t size)
{
	struct msghdr msg = { 0 };
	struct iovec iov;
	struct cmsghdr *cmsg;
	struct ucred cred;
	char cmsgbuf[CMSG_SPACE(sizeof(cred))];
	char buf[1];
	int ret;

	msg.msg_name = NULL;
	msg.msg_namelen = 0;
	msg.msg_control = cmsgbuf;
	msg.msg_controllen = sizeof(cmsgbuf);

	iov.iov_base = data ? data : buf;
	iov.iov_len = data ? size : sizeof(buf);
	msg.msg_iov = &iov;
	msg.msg_iovlen = 1;

	ret = recvmsg(fd, &msg, 0);
	if (ret <= 0)
		goto out;

	cmsg = CMSG_FIRSTHDR(&msg);

	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) &&
			cmsg->cmsg_level == SOL_SOCKET &&
			cmsg->cmsg_type == SCM_CREDENTIALS) {
		memcpy(&cred, CMSG_DATA(cmsg), sizeof(cred));
		if (cred.uid && (cred.uid != getuid() || cred.gid != getgid())) {
			INFO("message denied for '%d/%d'", cred.uid, cred.gid);
			return -EACCES;
		}
	}
out:
	return ret;
}
Commit	Line	Data
b0a33c1e	1	/*
	2	* lxc: linux Container library
	3	*
	4	* (C) Copyright IBM Corp. 2007, 2008
	5	*
	6	* Authors:
9afe19d6	7	* Daniel Lezcano <daniel.lezcano at free.fr>
b0a33c1e	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
250b1eec	21	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
b0a33c1e	22	*/
d06245b8 NC	23	#include "config.h"
d06245b8 NC	24
aae93dd3	25	#include <stddef.h>
b0a33c1e	26	#include <string.h>
	27	#include <unistd.h>
	28	#include <fcntl.h>
2dcb28a9	29	#include <errno.h>
b0a33c1e	30	#include <sys/socket.h>
b0a33c1e	31	#include <sys/un.h>
b0a33c1e	32
2dcb28a9 MN	33	#include "log.h"
	34
	35	lxc_log_define(lxc_af_unix, lxc);
b0a33c1e	36
aae93dd3	37	int lxc_abstract_unix_open(const char *path, int type, int flags)
b0a33c1e	38	{
b0a33c1e	39	int fd;
ddb17f1f	40	size_t len;
b0a33c1e	41	struct sockaddr_un addr;
	42
	43	if (flags & O_TRUNC)
	44	unlink(path);
	45
	46	fd = socket(PF_UNIX, type, 0);
	47	if (fd < 0)
	48	return -1;
	49
aae93dd3	50	/* Clear address structure */
b0a33c1e	51	memset(&addr, 0, sizeof(addr));
	52
	53	if (!path)
	54	return fd;
	55
	56	addr.sun_family = AF_UNIX;
aae93dd3 ÇO	57
	58	len = strlen(&path[1]) + 1;
	59	if (len >= sizeof(addr.sun_path) - 1) {
aae93dd3	60	close(fd);
aae93dd3 ÇO	61	errno = ENAMETOOLONG;
aae93dd3 ÇO	62	return -1;
ddb17f1f	63	}
aae93dd3 ÇO	64	/* addr.sun_path[0] has already been set to 0 by memset() */
aae93dd3 ÇO	65	strncpy(&addr.sun_path[1], &path[1], strlen(&path[1]));
b0a33c1e	66
aae93dd3	67	if (bind(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len)) {
dba104c8	68	int tmp = errno;
b0a33c1e	69	close(fd);
dba104c8	70	errno = tmp;
b0a33c1e	71	return -1;
b0a33c1e	72	}
ddb17f1f	73
31c53c2e	74	if (type == SOCK_STREAM && listen(fd, 100)) {
dba104c8	75	int tmp = errno;
b0a33c1e	76	close(fd);
dba104c8	77	errno = tmp;
b0a33c1e	78	return -1;
	79	}
	80
	81	return fd;
	82	}
	83
aae93dd3	84	int lxc_abstract_unix_close(int fd)
b0a33c1e	85	{
b0a33c1e	86	struct sockaddr_un addr;
af41709c	87	socklen_t addrlen = sizeof(addr);
ddb17f1f	88
f79d43bb	89	if (!getsockname(fd, (struct sockaddr *)&addr, &addrlen) &&
604f0955	90	addr.sun_path[0])
b0a33c1e	91	unlink(addr.sun_path);
	92
	93	close(fd);
	94
	95	return 0;
	96	}
	97
aae93dd3	98	int lxc_abstract_unix_connect(const char *path)
b0a33c1e	99	{
b0a33c1e	100	int fd;
aae93dd3	101	size_t len;
b0a33c1e	102	struct sockaddr_un addr;
	103
	104	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	105	if (fd < 0)
	106	return -1;
	107
	108	memset(&addr, 0, sizeof(addr));
	109
	110	addr.sun_family = AF_UNIX;
b0a33c1e	111
aae93dd3 ÇO	112	len = strlen(&path[1]) + 1;
aae93dd3 ÇO	113	if (len >= sizeof(addr.sun_path) - 1) {
aae93dd3	114	close(fd);
aae93dd3 ÇO	115	errno = ENAMETOOLONG;
	116	return -1;
	117	}
	118	/* addr.sun_path[0] has already been set to 0 by memset() */
	119	strncpy(&addr.sun_path[1], &path[1], strlen(&path[1]));
	120
	121	if (connect(fd, (struct sockaddr *)&addr, offsetof(struct sockaddr_un, sun_path) + len)) {
dba104c8	122	int tmp = errno;
bdb3f441 SH	123	/* special case to connect to older containers */
	124	if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) == 0)
	125	return fd;
b0a33c1e	126	close(fd);
dba104c8	127	errno = tmp;
b0a33c1e	128	return -1;
	129	}
	130
	131	return fd;
	132	}
	133
aae93dd3	134	int lxc_abstract_unix_send_fd(int fd, int sendfd, void *data, size_t size)
b0a33c1e	135	{
604f0955 ÇO	136	struct msghdr msg = { 0 };
	137	struct iovec iov;
	138	struct cmsghdr *cmsg;
	139	char cmsgbuf[CMSG_SPACE(sizeof(int))];
	140	char buf[1];
0e391e57	141	int *val;
b0a33c1e	142
604f0955 ÇO	143	msg.msg_control = cmsgbuf;
604f0955 ÇO	144	msg.msg_controllen = sizeof(cmsgbuf);
b0a33c1e	145
604f0955 ÇO	146	cmsg = CMSG_FIRSTHDR(&msg);
	147	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
	148	cmsg->cmsg_level = SOL_SOCKET;
	149	cmsg->cmsg_type = SCM_RIGHTS;
0e391e57 DL	150	val = (int *)(CMSG_DATA(cmsg));
0e391e57 DL	151	*val = sendfd;
b0a33c1e	152
604f0955 ÇO	153	msg.msg_name = NULL;
604f0955 ÇO	154	msg.msg_namelen = 0;
b0a33c1e	155
604f0955 ÇO	156	iov.iov_base = data ? data : buf;
	157	iov.iov_len = data ? size : sizeof(buf);
	158	msg.msg_iov = &iov;
	159	msg.msg_iovlen = 1;
b0a33c1e	160
6168ff15	161	return sendmsg(fd, &msg, MSG_NOSIGNAL);
b0a33c1e	162	}
b0a33c1e	163
aae93dd3	164	int lxc_abstract_unix_recv_fd(int fd, int recvfd, void data, size_t size)
b0a33c1e	165	{
604f0955 ÇO	166	struct msghdr msg = { 0 };
	167	struct iovec iov;
	168	struct cmsghdr *cmsg;
	169	char cmsgbuf[CMSG_SPACE(sizeof(int))];
	170	char buf[1];
0e391e57	171	int ret, *val;
b0a33c1e	172
604f0955 ÇO	173	msg.msg_name = NULL;
	174	msg.msg_namelen = 0;
	175	msg.msg_control = cmsgbuf;
	176	msg.msg_controllen = sizeof(cmsgbuf);
b0a33c1e	177
604f0955 ÇO	178	iov.iov_base = data ? data : buf;
	179	iov.iov_len = data ? size : sizeof(buf);
	180	msg.msg_iov = &iov;
	181	msg.msg_iovlen = 1;
b0a33c1e	182
	183	ret = recvmsg(fd, &msg, 0);
	184	if (ret <= 0)
	185	goto out;
	186
604f0955	187	cmsg = CMSG_FIRSTHDR(&msg);
b0a33c1e	188
f79d43bb	189	/* if the message is wrong the variable will not be
b0a33c1e	190	* filled and the peer will notified about a problem */
	191	*recvfd = -1;
	192
604f0955 ÇO	193	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(int)) &&
	194	cmsg->cmsg_level == SOL_SOCKET &&
	195	cmsg->cmsg_type == SCM_RIGHTS) {
0e391e57	196	val = (int *) CMSG_DATA(cmsg);
604f0955 ÇO	197	recvfd = val;
604f0955 ÇO	198	}
b0a33c1e	199	out:
604f0955	200	return ret;
b0a33c1e	201	}
b0a33c1e	202
aae93dd3	203	int lxc_abstract_unix_send_credential(int fd, void *data, size_t size)
b0a33c1e	204	{
604f0955 ÇO	205	struct msghdr msg = { 0 };
	206	struct iovec iov;
	207	struct cmsghdr *cmsg;
b0a33c1e	208	struct ucred cred = {
	209	.pid = getpid(),
	210	.uid = getuid(),
	211	.gid = getgid(),
	212	};
604f0955 ÇO	213	char cmsgbuf[CMSG_SPACE(sizeof(cred))];
604f0955 ÇO	214	char buf[1];
b0a33c1e	215
604f0955 ÇO	216	msg.msg_control = cmsgbuf;
604f0955 ÇO	217	msg.msg_controllen = sizeof(cmsgbuf);
b0a33c1e	218
604f0955 ÇO	219	cmsg = CMSG_FIRSTHDR(&msg);
	220	cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
	221	cmsg->cmsg_level = SOL_SOCKET;
	222	cmsg->cmsg_type = SCM_CREDENTIALS;
0e391e57	223	memcpy(CMSG_DATA(cmsg), &cred, sizeof(cred));
b0a33c1e	224
604f0955 ÇO	225	msg.msg_name = NULL;
604f0955 ÇO	226	msg.msg_namelen = 0;
b0a33c1e	227
604f0955 ÇO	228	iov.iov_base = data ? data : buf;
	229	iov.iov_len = data ? size : sizeof(buf);
	230	msg.msg_iov = &iov;
	231	msg.msg_iovlen = 1;
b0a33c1e	232
6168ff15	233	return sendmsg(fd, &msg, MSG_NOSIGNAL);
b0a33c1e	234	}
b0a33c1e	235
aae93dd3	236	int lxc_abstract_unix_rcv_credential(int fd, void *data, size_t size)
b0a33c1e	237	{
604f0955 ÇO	238	struct msghdr msg = { 0 };
	239	struct iovec iov;
	240	struct cmsghdr *cmsg;
b0a33c1e	241	struct ucred cred;
604f0955 ÇO	242	char cmsgbuf[CMSG_SPACE(sizeof(cred))];
604f0955 ÇO	243	char buf[1];
b0a33c1e	244	int ret;
b0a33c1e	245
604f0955 ÇO	246	msg.msg_name = NULL;
	247	msg.msg_namelen = 0;
	248	msg.msg_control = cmsgbuf;
	249	msg.msg_controllen = sizeof(cmsgbuf);
b0a33c1e	250
604f0955 ÇO	251	iov.iov_base = data ? data : buf;
	252	iov.iov_len = data ? size : sizeof(buf);
	253	msg.msg_iov = &iov;
	254	msg.msg_iovlen = 1;
b0a33c1e	255
	256	ret = recvmsg(fd, &msg, 0);
	257	if (ret <= 0)
	258	goto out;
	259
604f0955	260	cmsg = CMSG_FIRSTHDR(&msg);
b0a33c1e	261
604f0955 ÇO	262	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) &&
	263	cmsg->cmsg_level == SOL_SOCKET &&
	264	cmsg->cmsg_type == SCM_CREDENTIALS) {
0e391e57	265	memcpy(&cred, CMSG_DATA(cmsg), sizeof(cred));
d8cc9804	266	if (cred.uid && (cred.uid != getuid() \|\| cred.gid != getgid())) {
2dcb28a9	267	INFO("message denied for '%d/%d'", cred.uid, cred.gid);
d8cc9804	268	return -EACCES;
2dcb28a9	269	}
604f0955	270	}
b0a33c1e	271	out:
604f0955	272	return ret;
b0a33c1e	273	}