[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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#define __USE_GNU
#include <sys/socket.h>
#undef __USE_GNU
#include <sys/un.h>

#include "log.h"

lxc_log_define(lxc_af_unix, lxc);

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

	if (flags & O_TRUNC)
		unlink(path);

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

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

	if (!path)
		return fd;

	addr.sun_family = AF_UNIX;
	/* copy entire buffer in case of abstract socket */
	memcpy(addr.sun_path, path,
	       path[0]?strlen(path):sizeof(addr.sun_path));

	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr))) {
		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_af_unix_close(int fd)
{
	struct sockaddr_un addr;
	socklen_t addrlen;
	
	if (!getsockname(fd, (struct sockaddr *)&addr, &addrlen) &&
	    addr.sun_path[0])
		unlink(addr.sun_path);

	close(fd);

	return 0;
}

int lxc_af_unix_connect(const char *path)
{
	int fd;
	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;
	/* copy entire buffer in case of abstract socket */
	memcpy(addr.sun_path, path,
	       path[0]?strlen(path):sizeof(addr.sun_path));

	if (connect(fd, (struct sockaddr *)&addr, sizeof(addr))) {
		int tmp = errno;
		close(fd);
		errno = tmp;
		return -1;
	}

	return fd;
}

int lxc_af_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, 0);
}

int lxc_af_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_af_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, 0);
}

int lxc_af_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
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	22	*/
	23	#include <string.h>
	24	#include <unistd.h>
	25	#include <fcntl.h>
2dcb28a9	26	#include <errno.h>
b0a33c1e	27	#define __USE_GNU
	28	#include <sys/socket.h>
	29	#undef __USE_GNU
	30	#include <sys/un.h>
	31
2dcb28a9 MN	32	#include "log.h"
	33
	34	lxc_log_define(lxc_af_unix, lxc);
b0a33c1e	35
	36	int lxc_af_unix_open(const char *path, int type, int flags)
	37	{
	38	int fd;
	39	struct sockaddr_un addr;
	40
	41	if (flags & O_TRUNC)
	42	unlink(path);
	43
	44	fd = socket(PF_UNIX, type, 0);
	45	if (fd < 0)
	46	return -1;
	47
	48	memset(&addr, 0, sizeof(addr));
	49
	50	if (!path)
	51	return fd;
	52
	53	addr.sun_family = AF_UNIX;
	54	/* copy entire buffer in case of abstract socket */
f79d43bb	55	memcpy(addr.sun_path, path,
b0a33c1e	56	path[0]?strlen(path):sizeof(addr.sun_path));
	57
	58	if (bind(fd, (struct sockaddr *)&addr, sizeof(addr))) {
dba104c8	59	int tmp = errno;
b0a33c1e	60	close(fd);
dba104c8	61	errno = tmp;
b0a33c1e	62	return -1;
	63	}
	64
31c53c2e	65	if (type == SOCK_STREAM && listen(fd, 100)) {
dba104c8	66	int tmp = errno;
b0a33c1e	67	close(fd);
dba104c8	68	errno = tmp;
b0a33c1e	69	return -1;
	70	}
	71
	72	return fd;
	73	}
	74
	75	int lxc_af_unix_close(int fd)
	76	{
	77	struct sockaddr_un addr;
	78	socklen_t addrlen;
	79
f79d43bb	80	if (!getsockname(fd, (struct sockaddr *)&addr, &addrlen) &&
b0a33c1e	81	addr.sun_path[0])
	82	unlink(addr.sun_path);
	83
	84	close(fd);
	85
	86	return 0;
	87	}
	88
	89	int lxc_af_unix_connect(const char *path)
	90	{
	91	int fd;
	92	struct sockaddr_un addr;
	93
	94	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	95	if (fd < 0)
	96	return -1;
	97
	98	memset(&addr, 0, sizeof(addr));
	99
	100	addr.sun_family = AF_UNIX;
	101	/* copy entire buffer in case of abstract socket */
f79d43bb	102	memcpy(addr.sun_path, path,
b0a33c1e	103	path[0]?strlen(path):sizeof(addr.sun_path));
	104
	105	if (connect(fd, (struct sockaddr *)&addr, sizeof(addr))) {
dba104c8	106	int tmp = errno;
b0a33c1e	107	close(fd);
dba104c8	108	errno = tmp;
b0a33c1e	109	return -1;
	110	}
	111
	112	return fd;
	113	}
	114
	115	int lxc_af_unix_send_fd(int fd, int sendfd, void *data, size_t size)
	116	{
	117	struct msghdr msg = { 0 };
	118	struct iovec iov;
	119	struct cmsghdr *cmsg;
	120	char cmsgbuf[CMSG_SPACE(sizeof(int))];
	121	char buf[1];
0e391e57	122	int *val;
b0a33c1e	123
	124	msg.msg_control = cmsgbuf;
	125	msg.msg_controllen = sizeof(cmsgbuf);
	126
	127	cmsg = CMSG_FIRSTHDR(&msg);
	128	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
	129	cmsg->cmsg_level = SOL_SOCKET;
	130	cmsg->cmsg_type = SCM_RIGHTS;
0e391e57 DL	131	val = (int *)(CMSG_DATA(cmsg));
0e391e57 DL	132	*val = sendfd;
b0a33c1e	133
	134	msg.msg_name = NULL;
	135	msg.msg_namelen = 0;
	136
	137	iov.iov_base = data ? data : buf;
	138	iov.iov_len = data ? size : sizeof(buf);
	139	msg.msg_iov = &iov;
	140	msg.msg_iovlen = 1;
	141
	142	return sendmsg(fd, &msg, 0);
	143	}
	144
	145	int lxc_af_unix_recv_fd(int fd, int recvfd, void data, size_t size)
	146	{
	147	struct msghdr msg = { 0 };
	148	struct iovec iov;
	149	struct cmsghdr *cmsg;
	150	char cmsgbuf[CMSG_SPACE(sizeof(int))];
	151	char buf[1];
0e391e57	152	int ret, *val;
b0a33c1e	153
	154	msg.msg_name = NULL;
	155	msg.msg_namelen = 0;
	156	msg.msg_control = cmsgbuf;
	157	msg.msg_controllen = sizeof(cmsgbuf);
	158
	159	iov.iov_base = data ? data : buf;
	160	iov.iov_len = data ? size : sizeof(buf);
	161	msg.msg_iov = &iov;
	162	msg.msg_iovlen = 1;
	163
	164	ret = recvmsg(fd, &msg, 0);
	165	if (ret <= 0)
	166	goto out;
	167
	168	cmsg = CMSG_FIRSTHDR(&msg);
	169
f79d43bb	170	/* if the message is wrong the variable will not be
b0a33c1e	171	* filled and the peer will notified about a problem */
	172	*recvfd = -1;
	173
	174	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(int)) &&
	175	cmsg->cmsg_level == SOL_SOCKET &&
	176	cmsg->cmsg_type == SCM_RIGHTS) {
0e391e57 DL	177	val = (int *) CMSG_DATA(cmsg);
0e391e57 DL	178	recvfd = val;
b0a33c1e	179	}
	180	out:
	181	return ret;
	182	}
	183
	184	int lxc_af_unix_send_credential(int fd, void *data, size_t size)
	185	{
	186	struct msghdr msg = { 0 };
	187	struct iovec iov;
	188	struct cmsghdr *cmsg;
	189	struct ucred cred = {
	190	.pid = getpid(),
	191	.uid = getuid(),
	192	.gid = getgid(),
	193	};
	194	char cmsgbuf[CMSG_SPACE(sizeof(cred))];
	195	char buf[1];
	196
	197	msg.msg_control = cmsgbuf;
	198	msg.msg_controllen = sizeof(cmsgbuf);
	199
	200	cmsg = CMSG_FIRSTHDR(&msg);
	201	cmsg->cmsg_len = CMSG_LEN(sizeof(struct ucred));
	202	cmsg->cmsg_level = SOL_SOCKET;
	203	cmsg->cmsg_type = SCM_CREDENTIALS;
0e391e57	204	memcpy(CMSG_DATA(cmsg), &cred, sizeof(cred));
b0a33c1e	205
	206	msg.msg_name = NULL;
	207	msg.msg_namelen = 0;
	208
	209	iov.iov_base = data ? data : buf;
	210	iov.iov_len = data ? size : sizeof(buf);
	211	msg.msg_iov = &iov;
	212	msg.msg_iovlen = 1;
	213
	214	return sendmsg(fd, &msg, 0);
	215	}
	216
	217	int lxc_af_unix_rcv_credential(int fd, void *data, size_t size)
	218	{
	219	struct msghdr msg = { 0 };
	220	struct iovec iov;
	221	struct cmsghdr *cmsg;
	222	struct ucred cred;
	223	char cmsgbuf[CMSG_SPACE(sizeof(cred))];
	224	char buf[1];
	225	int ret;
	226
	227	msg.msg_name = NULL;
	228	msg.msg_namelen = 0;
	229	msg.msg_control = cmsgbuf;
	230	msg.msg_controllen = sizeof(cmsgbuf);
	231
	232	iov.iov_base = data ? data : buf;
	233	iov.iov_len = data ? size : sizeof(buf);
	234	msg.msg_iov = &iov;
	235	msg.msg_iovlen = 1;
	236
	237	ret = recvmsg(fd, &msg, 0);
	238	if (ret <= 0)
	239	goto out;
	240
	241	cmsg = CMSG_FIRSTHDR(&msg);
	242
b0a33c1e	243	if (cmsg && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)) &&
	244	cmsg->cmsg_level == SOL_SOCKET &&
	245	cmsg->cmsg_type == SCM_CREDENTIALS) {
0e391e57	246	memcpy(&cred, CMSG_DATA(cmsg), sizeof(cred));
d8cc9804	247	if (cred.uid && (cred.uid != getuid() \|\| cred.gid != getgid())) {
2dcb28a9	248	INFO("message denied for '%d/%d'", cred.uid, cred.gid);
d8cc9804	249	return -EACCES;
2dcb28a9	250	}
b0a33c1e	251	}
	252	out:
	253	return ret;
	254	}