[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 <errno.h>
#include <fcntl.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/syscall.h>
#include <sys/un.h>

#include "log.h"
#include "utils.h"

#ifndef HAVE_STRLCPY
#include "include/strlcpy.h"
#endif

lxc_log_define(lxc_af_unix, lxc);

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

	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]);
	/* do not enforce \0-termination */
	if (len >= sizeof(addr.sun_path)) {
		close(fd);
		errno = ENAMETOOLONG;
		return -1;
	}

	/* do not enforce \0-termination */
	memcpy(&addr.sun_path[1], &path[1], len);

	ret = bind(fd, (struct sockaddr *)&addr,
		   offsetof(struct sockaddr_un, sun_path) + len + 1);
	if (ret < 0) {
		int tmp = errno;
		close(fd);
		errno = tmp;
		return -1;
	}

	if (type == SOCK_STREAM) {
		ret = listen(fd, 100);
		if (ret < 0) {
			int tmp = errno;
			close(fd);
			errno = tmp;
			return -1;
		}

	}

	return fd;
}

int lxc_abstract_unix_close(int fd)
{
	close(fd);
	return 0;
}

int lxc_abstract_unix_connect(const char *path)
{
	int fd, ret;
	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]);
	/* do not enforce \0-termination */
	if (len >= sizeof(addr.sun_path)) {
		close(fd);
		errno = ENAMETOOLONG;
		return -1;
	}

	/* do not enforce \0-termination */
	memcpy(&addr.sun_path[1], &path[1], len);

	ret = connect(fd, (struct sockaddr *)&addr,
		      offsetof(struct sockaddr_un, sun_path) + len + 1);
	if (ret < 0) {
		close(fd);
		return -1;
	}

	return fd;
}

int lxc_abstract_unix_send_fds(int fd, int *sendfds, int num_sendfds,
			       void *data, size_t size)
{
	int ret;
	struct msghdr msg;
	struct iovec iov;
	struct cmsghdr *cmsg = NULL;
	char buf[1] = {0};
	char *cmsgbuf;
	size_t cmsgbufsize = CMSG_SPACE(num_sendfds * sizeof(int));

	memset(&msg, 0, sizeof(msg));
	memset(&iov, 0, sizeof(iov));

	cmsgbuf = malloc(cmsgbufsize);
	if (!cmsgbuf)
		return -1;

	msg.msg_control = cmsgbuf;
	msg.msg_controllen = cmsgbufsize;

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

	msg.msg_controllen = cmsg->cmsg_len;

	memcpy(CMSG_DATA(cmsg), sendfds, num_sendfds * sizeof(int));

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

	ret = sendmsg(fd, &msg, MSG_NOSIGNAL);
	free(cmsgbuf);
	return ret;
}

int lxc_abstract_unix_recv_fds(int fd, int *recvfds, int num_recvfds,
			       void *data, size_t size)
{
	int ret;
	struct msghdr msg;
	struct iovec iov;
	struct cmsghdr *cmsg = NULL;
	char buf[1] = {0};
	char *cmsgbuf;
	size_t cmsgbufsize = CMSG_SPACE(num_recvfds * sizeof(int));

	memset(&msg, 0, sizeof(msg));
	memset(&iov, 0, sizeof(iov));

	cmsgbuf = malloc(cmsgbufsize);
	if (!cmsgbuf)
		return -1;

	msg.msg_control = cmsgbuf;
	msg.msg_controllen = cmsgbufsize;

	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);

	memset(recvfds, -1, num_recvfds * sizeof(int));
	if (cmsg && cmsg->cmsg_len == CMSG_LEN(num_recvfds * sizeof(int)) &&
	    cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
		memcpy(recvfds, CMSG_DATA(cmsg), num_recvfds * sizeof(int));
	}

out:
	free(cmsgbuf);
	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 = lxc_raw_getpid(), .uid = getuid(), .gid = getgid(),
	};
	char cmsgbuf[CMSG_SPACE(sizeof(cred))] = {0};
	char buf[1] = {0};

	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;
	int ret;
	char cmsgbuf[CMSG_SPACE(sizeof(cred))] = {0};
	char buf[1] = {0};

	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
94ac256f CB	25	#include <errno.h>
	26	#include <fcntl.h>
	27	#include <stddef.h>
ae467c54 CB	28	#include <stdio.h>
ae467c54 CB	29	#include <stdlib.h>
b0a33c1e	30	#include <string.h>
b0a33c1e	31	#include <unistd.h>
b0a33c1e	32	#include <sys/socket.h>
94ac256f	33	#include <sys/syscall.h>
b0a33c1e	34	#include <sys/un.h>
b0a33c1e	35
2dcb28a9	36	#include "log.h"
0059379f	37	#include "utils.h"
2dcb28a9	38
9de31d5a CB	39	#ifndef HAVE_STRLCPY
	40	#include "include/strlcpy.h"
	41	#endif
	42
2dcb28a9	43	lxc_log_define(lxc_af_unix, lxc);
b0a33c1e	44
aae93dd3	45	int lxc_abstract_unix_open(const char *path, int type, int flags)
b0a33c1e	46	{
77b0073a	47	int fd, ret;
ddb17f1f	48	size_t len;
b0a33c1e	49	struct sockaddr_un addr;
b0a33c1e	50
b0a33c1e	51	fd = socket(PF_UNIX, type, 0);
	52	if (fd < 0)
	53	return -1;
	54
aae93dd3	55	/* Clear address structure */
b0a33c1e	56	memset(&addr, 0, sizeof(addr));
	57
	58	if (!path)
	59	return fd;
	60
	61	addr.sun_family = AF_UNIX;
aae93dd3	62
caf3beb0 CB	63	len = strlen(&path[1]);
	64	/* do not enforce \0-termination */
	65	if (len >= sizeof(addr.sun_path)) {
aae93dd3	66	close(fd);
aae93dd3 ÇO	67	errno = ENAMETOOLONG;
aae93dd3 ÇO	68	return -1;
ddb17f1f	69	}
9de31d5a CB	70
	71	/* do not enforce \0-termination */
	72	memcpy(&addr.sun_path[1], &path[1], len);
b0a33c1e	73
77b0073a CB	74	ret = bind(fd, (struct sockaddr *)&addr,
	75	offsetof(struct sockaddr_un, sun_path) + len + 1);
	76	if (ret < 0) {
dba104c8	77	int tmp = errno;
b0a33c1e	78	close(fd);
dba104c8	79	errno = tmp;
b0a33c1e	80	return -1;
b0a33c1e	81	}
ddb17f1f	82
77b0073a CB	83	if (type == SOCK_STREAM) {
	84	ret = listen(fd, 100);
	85	if (ret < 0) {
	86	int tmp = errno;
	87	close(fd);
	88	errno = tmp;
	89	return -1;
	90	}
	91
b0a33c1e	92	}
	93
	94	return fd;
	95	}
	96
aae93dd3	97	int lxc_abstract_unix_close(int fd)
b0a33c1e	98	{
b0a33c1e	99	close(fd);
b0a33c1e	100	return 0;
	101	}
	102
aae93dd3	103	int lxc_abstract_unix_connect(const char *path)
b0a33c1e	104	{
77b0073a	105	int fd, ret;
aae93dd3	106	size_t len;
b0a33c1e	107	struct sockaddr_un addr;
	108
	109	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	110	if (fd < 0)
	111	return -1;
	112
	113	memset(&addr, 0, sizeof(addr));
	114
	115	addr.sun_family = AF_UNIX;
b0a33c1e	116
caf3beb0 CB	117	len = strlen(&path[1]);
	118	/* do not enforce \0-termination */
	119	if (len >= sizeof(addr.sun_path)) {
aae93dd3	120	close(fd);
aae93dd3 ÇO	121	errno = ENAMETOOLONG;
	122	return -1;
	123	}
9de31d5a CB	124
	125	/* do not enforce \0-termination */
	126	memcpy(&addr.sun_path[1], &path[1], len);
aae93dd3	127
77b0073a CB	128	ret = connect(fd, (struct sockaddr *)&addr,
	129	offsetof(struct sockaddr_un, sun_path) + len + 1);
	130	if (ret < 0) {
b0a33c1e	131	close(fd);
	132	return -1;
	133	}
	134
	135	return fd;
	136	}
	137
ae467c54 CB	138	int lxc_abstract_unix_send_fds(int fd, int *sendfds, int num_sendfds,
ae467c54 CB	139	void *data, size_t size)
b0a33c1e	140	{
ae467c54 CB	141	int ret;
ae467c54 CB	142	struct msghdr msg;
604f0955	143	struct iovec iov;
ae467c54	144	struct cmsghdr *cmsg = NULL;
caf3beb0	145	char buf[1] = {0};
ae467c54 CB	146	char *cmsgbuf;
	147	size_t cmsgbufsize = CMSG_SPACE(num_sendfds * sizeof(int));
	148
	149	memset(&msg, 0, sizeof(msg));
	150	memset(&iov, 0, sizeof(iov));
	151
	152	cmsgbuf = malloc(cmsgbufsize);
	153	if (!cmsgbuf)
	154	return -1;
b0a33c1e	155
604f0955	156	msg.msg_control = cmsgbuf;
ae467c54	157	msg.msg_controllen = cmsgbufsize;
b0a33c1e	158
604f0955	159	cmsg = CMSG_FIRSTHDR(&msg);
604f0955 ÇO	160	cmsg->cmsg_level = SOL_SOCKET;
604f0955 ÇO	161	cmsg->cmsg_type = SCM_RIGHTS;
ae467c54	162	cmsg->cmsg_len = CMSG_LEN(num_sendfds * sizeof(int));
b0a33c1e	163
ae467c54 CB	164	msg.msg_controllen = cmsg->cmsg_len;
	165
	166	memcpy(CMSG_DATA(cmsg), sendfds, num_sendfds * sizeof(int));
b0a33c1e	167
604f0955 ÇO	168	iov.iov_base = data ? data : buf;
	169	iov.iov_len = data ? size : sizeof(buf);
	170	msg.msg_iov = &iov;
	171	msg.msg_iovlen = 1;
b0a33c1e	172
ae467c54 CB	173	ret = sendmsg(fd, &msg, MSG_NOSIGNAL);
	174	free(cmsgbuf);
	175	return ret;
b0a33c1e	176	}
b0a33c1e	177
ae467c54 CB	178	int lxc_abstract_unix_recv_fds(int fd, int *recvfds, int num_recvfds,
ae467c54 CB	179	void *data, size_t size)
b0a33c1e	180	{
ae467c54 CB	181	int ret;
ae467c54 CB	182	struct msghdr msg;
604f0955	183	struct iovec iov;
ae467c54	184	struct cmsghdr *cmsg = NULL;
caf3beb0	185	char buf[1] = {0};
ae467c54 CB	186	char *cmsgbuf;
	187	size_t cmsgbufsize = CMSG_SPACE(num_recvfds * sizeof(int));
	188
	189	memset(&msg, 0, sizeof(msg));
	190	memset(&iov, 0, sizeof(iov));
	191
	192	cmsgbuf = malloc(cmsgbufsize);
	193	if (!cmsgbuf)
	194	return -1;
b0a33c1e	195
604f0955	196	msg.msg_control = cmsgbuf;
ae467c54	197	msg.msg_controllen = cmsgbufsize;
b0a33c1e	198
604f0955 ÇO	199	iov.iov_base = data ? data : buf;
	200	iov.iov_len = data ? size : sizeof(buf);
	201	msg.msg_iov = &iov;
	202	msg.msg_iovlen = 1;
b0a33c1e	203
	204	ret = recvmsg(fd, &msg, 0);
	205	if (ret <= 0)
	206	goto out;
	207
604f0955	208	cmsg = CMSG_FIRSTHDR(&msg);
b0a33c1e	209
ae467c54 CB	210	memset(recvfds, -1, num_recvfds * sizeof(int));
	211	if (cmsg && cmsg->cmsg_len == CMSG_LEN(num_recvfds * sizeof(int)) &&
	212	cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
	213	memcpy(recvfds, CMSG_DATA(cmsg), num_recvfds * sizeof(int));
604f0955	214	}
ae467c54	215
b0a33c1e	216	out:
ae467c54	217	free(cmsgbuf);
604f0955	218	return ret;
b0a33c1e	219	}
b0a33c1e	220
aae93dd3	221	int lxc_abstract_unix_send_credential(int fd, void *data, size_t size)
b0a33c1e	222	{
77b0073a	223	struct msghdr msg = {0};
604f0955 ÇO	224	struct iovec iov;
604f0955 ÇO	225	struct cmsghdr *cmsg;
b0a33c1e	226	struct ucred cred = {
0059379f	227	.pid = lxc_raw_getpid(), .uid = getuid(), .gid = getgid(),
b0a33c1e	228	};
caf3beb0 CB	229	char cmsgbuf[CMSG_SPACE(sizeof(cred))] = {0};
caf3beb0 CB	230	char buf[1] = {0};
b0a33c1e	231
604f0955 ÇO	232	msg.msg_control = cmsgbuf;
604f0955 ÇO	233	msg.msg_controllen = sizeof(cmsgbuf);
b0a33c1e	234
604f0955 ÇO	235	cmsg = CMSG_FIRSTHDR(&msg);
	236	cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
	237	cmsg->cmsg_level = SOL_SOCKET;
	238	cmsg->cmsg_type = SCM_CREDENTIALS;
0e391e57	239	memcpy(CMSG_DATA(cmsg), &cred, sizeof(cred));
b0a33c1e	240
604f0955 ÇO	241	msg.msg_name = NULL;
604f0955 ÇO	242	msg.msg_namelen = 0;
b0a33c1e	243
604f0955 ÇO	244	iov.iov_base = data ? data : buf;
	245	iov.iov_len = data ? size : sizeof(buf);
	246	msg.msg_iov = &iov;
	247	msg.msg_iovlen = 1;
b0a33c1e	248
6168ff15	249	return sendmsg(fd, &msg, MSG_NOSIGNAL);
b0a33c1e	250	}
b0a33c1e	251
aae93dd3	252	int lxc_abstract_unix_rcv_credential(int fd, void *data, size_t size)
b0a33c1e	253	{
77b0073a	254	struct msghdr msg = {0};
604f0955 ÇO	255	struct iovec iov;
604f0955 ÇO	256	struct cmsghdr *cmsg;
b0a33c1e	257	struct ucred cred;
b0a33c1e	258	int ret;
caf3beb0 CB	259	char cmsgbuf[CMSG_SPACE(sizeof(cred))] = {0};
caf3beb0 CB	260	char buf[1] = {0};
b0a33c1e	261
604f0955 ÇO	262	msg.msg_name = NULL;
	263	msg.msg_namelen = 0;
	264	msg.msg_control = cmsgbuf;
	265	msg.msg_controllen = sizeof(cmsgbuf);
b0a33c1e	266
604f0955 ÇO	267	iov.iov_base = data ? data : buf;
	268	iov.iov_len = data ? size : sizeof(buf);
	269	msg.msg_iov = &iov;
	270	msg.msg_iovlen = 1;
b0a33c1e	271
	272	ret = recvmsg(fd, &msg, 0);
	273	if (ret <= 0)
	274	goto out;
	275
604f0955	276	cmsg = CMSG_FIRSTHDR(&msg);
b0a33c1e	277
604f0955	278	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) &&
77b0073a CB	279	cmsg->cmsg_level == SOL_SOCKET &&
77b0073a CB	280	cmsg->cmsg_type == SCM_CREDENTIALS) {
0e391e57	281	memcpy(&cred, CMSG_DATA(cmsg), sizeof(cred));
77b0073a CB	282	if (cred.uid &&
77b0073a CB	283	(cred.uid != getuid() \|\| cred.gid != getgid())) {
2dcb28a9	284	INFO("message denied for '%d/%d'", cred.uid, cred.gid);
d8cc9804	285	return -EACCES;
2dcb28a9	286	}
604f0955	287	}
b0a33c1e	288	out:
604f0955	289	return ret;
b0a33c1e	290	}