[lttng-tools.git] / src / common / sessiond-comm / unix.c

/*
 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
 *                      Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program 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 General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#define _GNU_SOURCE
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <errno.h>

#include <common/common.h>

#include "unix.h"

/*
 * Connect to unix socket using the path name.
 */
LTTNG_HIDDEN
int lttcomm_connect_unix_sock(const char *pathname)
{
	struct sockaddr_un sun;
	int fd, ret, closeret;

	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	if (fd < 0) {
		PERROR("socket");
		ret = fd;
		goto error;
	}

	memset(&sun, 0, sizeof(sun));
	sun.sun_family = AF_UNIX;
	strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
	sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';

	ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
	if (ret < 0) {
		/*
		 * Don't print message on connect error, because connect is used in
		 * normal execution to detect if sessiond is alive.
		 */
		goto error_connect;
	}

	return fd;

error_connect:
	closeret = close(fd);
	if (closeret) {
		PERROR("close");
	}
error:
	return ret;
}

/*
 * Do an accept(2) on the sock and return the new file descriptor. The socket
 * MUST be bind(2) before.
 */
LTTNG_HIDDEN
int lttcomm_accept_unix_sock(int sock)
{
	int new_fd;
	struct sockaddr_un sun;
	socklen_t len = 0;

	/* Blocking call */
	new_fd = accept(sock, (struct sockaddr *) &sun, &len);
	if (new_fd < 0) {
		PERROR("accept");
	}

	return new_fd;
}

/*
 * Creates a AF_UNIX local socket using pathname bind the socket upon creation
 * and return the fd.
 */
LTTNG_HIDDEN
int lttcomm_create_unix_sock(const char *pathname)
{
	struct sockaddr_un sun;
	int fd;
	int ret = -1;

	/* Create server socket */
	if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
		PERROR("socket");
		goto error;
	}

	memset(&sun, 0, sizeof(sun));
	sun.sun_family = AF_UNIX;
	strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
	sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';

	/* Unlink the old file if present */
	(void) unlink(pathname);
	ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
	if (ret < 0) {
		PERROR("bind");
		goto error;
	}

	return fd;

error:
	if (fd >= 0) {
		if (close(fd) < 0) {
			PERROR("close create unix sock");
		}
	}
	return ret;
}

/*
 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
 */
LTTNG_HIDDEN
int lttcomm_listen_unix_sock(int sock)
{
	int ret;

	ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
	if (ret < 0) {
		PERROR("listen");
	}

	return ret;
}

/*
 * Receive data of size len in put that data into the buf param. Using recvmsg
 * API.
 *
 * Return the size of received data.
 */
LTTNG_HIDDEN
ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
{
	struct msghdr msg;
	struct iovec iov[1];
	ssize_t ret = -1;
	size_t len_last;

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

	iov[0].iov_base = buf;
	iov[0].iov_len = len;
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;

	do {
		len_last = iov[0].iov_len;
		ret = recvmsg(sock, &msg, 0);
		if (ret > 0) {
			iov[0].iov_base += ret;
			iov[0].iov_len -= ret;
			assert(ret <= len_last);
		}
	} while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));
	if (ret < 0) {
		PERROR("recvmsg");
	} else if (ret > 0) {
		ret = len;
	}
	/* Else ret = 0 meaning an orderly shutdown. */

	return ret;
}

/*
 * Send buf data of size len. Using sendmsg API.
 *
 * Return the size of sent data.
 */
LTTNG_HIDDEN
ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
{
	struct msghdr msg;
	struct iovec iov[1];
	ssize_t ret = -1;

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

	iov[0].iov_base = buf;
	iov[0].iov_len = len;
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;

	ret = sendmsg(sock, &msg, 0);
	if (ret < 0) {
		/*
		 * Only warn about EPIPE when quiet mode is deactivated.
		 * We consider EPIPE as expected.
		 */
		if (errno != EPIPE || !lttng_opt_quiet) {
			PERROR("sendmsg");
		}
	}

	return ret;
}

/*
 * Shutdown cleanly a unix socket.
 */
LTTNG_HIDDEN
int lttcomm_close_unix_sock(int sock)
{
	int ret, closeret;

	/* Shutdown receptions and transmissions */
	ret = shutdown(sock, SHUT_RDWR);
	if (ret < 0) {
		PERROR("shutdown");
	}

	closeret = close(sock);
	if (closeret) {
		PERROR("close");
	}

	return ret;
}

/*
 * Send a message accompanied by fd(s) over a unix socket.
 *
 * Returns the size of data sent, or negative error value.
 */
LTTNG_HIDDEN
ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
{
	struct msghdr msg;
	struct cmsghdr *cmptr;
	struct iovec iov[1];
	ssize_t ret = -1;
	unsigned int sizeof_fds = nb_fd * sizeof(int);
	char tmp[CMSG_SPACE(sizeof_fds)];
	char dummy = 0;

	memset(&msg, 0, sizeof(msg));
	memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));

	if (nb_fd > LTTCOMM_MAX_SEND_FDS)
		return -EINVAL;

	msg.msg_control = (caddr_t)tmp;
	msg.msg_controllen = CMSG_LEN(sizeof_fds);

	cmptr = CMSG_FIRSTHDR(&msg);
	cmptr->cmsg_level = SOL_SOCKET;
	cmptr->cmsg_type = SCM_RIGHTS;
	cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
	memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
	/* Sum of the length of all control messages in the buffer: */
	msg.msg_controllen = cmptr->cmsg_len;

	iov[0].iov_base = &dummy;
	iov[0].iov_len = 1;
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;

	do {
		ret = sendmsg(sock, &msg, 0);
	} while (ret < 0 && errno == EINTR);
	if (ret < 0) {
		/*
		 * Only warn about EPIPE when quiet mode is deactivated.
		 * We consider EPIPE as expected.
		 */
		if (errno != EPIPE || !lttng_opt_quiet) {
			PERROR("sendmsg");
		}
	}
	return ret;
}

/*
 * Recv a message accompanied by fd(s) from a unix socket.
 *
 * Returns the size of received data, or negative error value.
 *
 * Expect at most "nb_fd" file descriptors. Returns the number of fd
 * actually received in nb_fd.
 */
LTTNG_HIDDEN
ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
{
	struct iovec iov[1];
	ssize_t ret = 0;
	struct cmsghdr *cmsg;
	size_t sizeof_fds = nb_fd * sizeof(int);
	char recv_fd[CMSG_SPACE(sizeof_fds)];
	struct msghdr msg;
	char dummy;

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

	/* Prepare to receive the structures */
	iov[0].iov_base = &dummy;
	iov[0].iov_len = 1;
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;
	msg.msg_control = recv_fd;
	msg.msg_controllen = sizeof(recv_fd);

	do {
		ret = recvmsg(sock, &msg, 0);
	} while (ret < 0 && errno == EINTR);
	if (ret < 0) {
		PERROR("recvmsg fds");
		goto end;
	}
	if (ret != 1) {
		fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
				ret, 1);
		goto end;
	}
	if (msg.msg_flags & MSG_CTRUNC) {
		fprintf(stderr, "Error: Control message truncated.\n");
		ret = -1;
		goto end;
	}
	cmsg = CMSG_FIRSTHDR(&msg);
	if (!cmsg) {
		fprintf(stderr, "Error: Invalid control message header\n");
		ret = -1;
		goto end;
	}
	if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
		fprintf(stderr, "Didn't received any fd\n");
		ret = -1;
		goto end;
	}
	if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
		fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
				(size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
		ret = -1;
		goto end;
	}
	memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
	ret = sizeof_fds;
end:
	return ret;
}

/*
 * Send a message with credentials over a unix socket.
 *
 * Returns the size of data sent, or negative error value.
 */
LTTNG_HIDDEN
ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
{
	struct msghdr msg;
	struct iovec iov[1];
	ssize_t ret = -1;
#ifdef __linux__
	struct cmsghdr *cmptr;
	size_t sizeof_cred = sizeof(lttng_sock_cred);
	char anc_buf[CMSG_SPACE(sizeof_cred)];
	lttng_sock_cred *creds;
#endif /* __linux__ */

	memset(&msg, 0, sizeof(msg));
	memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));

	iov[0].iov_base = buf;
	iov[0].iov_len = len;
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;

#ifdef __linux__
	msg.msg_control = (caddr_t) anc_buf;
	msg.msg_controllen = CMSG_LEN(sizeof_cred);

	cmptr = CMSG_FIRSTHDR(&msg);
	cmptr->cmsg_level = SOL_SOCKET;
	cmptr->cmsg_type = LTTNG_SOCK_CREDS;
	cmptr->cmsg_len = CMSG_LEN(sizeof_cred);

	creds = (lttng_sock_cred*) CMSG_DATA(cmptr);

	LTTNG_SOCK_SET_UID_CRED(creds, geteuid());
	LTTNG_SOCK_SET_GID_CRED(creds, getegid());
	LTTNG_SOCK_SET_PID_CRED(creds, getpid());
#endif /* __linux__ */

	do {
		ret = sendmsg(sock, &msg, 0);
	} while (ret < 0 && errno == EINTR);
	if (ret < 0) {
		/*
		 * Only warn about EPIPE when quiet mode is deactivated.
		 * We consider EPIPE as expected.
		 */
		if (errno != EPIPE || !lttng_opt_quiet) {
			PERROR("sendmsg");
		}
	}
	return ret;
}

/*
 * Recv a message accompanied with credentials from a unix socket.
 *
 * Returns the size of received data, or negative error value.
 */
LTTNG_HIDDEN
ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
		lttng_sock_cred *creds)
{
	struct msghdr msg;
	struct iovec iov[1];
	ssize_t ret;
#ifdef __linux__
	struct cmsghdr *cmptr;
	size_t sizeof_cred = sizeof(lttng_sock_cred);
	char anc_buf[CMSG_SPACE(sizeof_cred)];
#endif	/* __linux__ */

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

	/* Not allowed */
	if (creds == NULL) {
		ret = -1;
		goto end;
	}

	/* Prepare to receive the structures */
	iov[0].iov_base = buf;
	iov[0].iov_len = len;
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;

#ifdef __linux__
	msg.msg_control = anc_buf;
	msg.msg_controllen = sizeof(anc_buf);
#endif /* __linux__ */

	do {
		ret = recvmsg(sock, &msg, 0);
	} while (ret < 0 && errno == EINTR);
	if (ret < 0) {
		PERROR("recvmsg fds");
		goto end;
	}

#ifdef __linux__
	if (msg.msg_flags & MSG_CTRUNC) {
		fprintf(stderr, "Error: Control message truncated.\n");
		ret = -1;
		goto end;
	}

	cmptr = CMSG_FIRSTHDR(&msg);
	if (cmptr == NULL) {
		fprintf(stderr, "Error: Invalid control message header\n");
		ret = -1;
		goto end;
	}

	if (cmptr->cmsg_level != SOL_SOCKET ||
			cmptr->cmsg_type != LTTNG_SOCK_CREDS) {
		fprintf(stderr, "Didn't received any credentials\n");
		ret = -1;
		goto end;
	}

	if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) {
		fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
				(size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred));
		ret = -1;
		goto end;
	}

	memcpy(creds, CMSG_DATA(cmptr), sizeof_cred);
#elif (defined(__FreeBSD__) || defined(__CYGWIN__))
	{
		int peer_ret;

		peer_ret = getpeereid(sock, &creds->uid, &creds->gid);
		if (peer_ret != 0) {
			return peer_ret;
		}
	}
#else
#error "Please implement credential support for your OS."
#endif	/* __linux__ */

end:
	return ret;
}

/*
 * Set socket option to use credentials passing.
 */
#ifdef __linux__
LTTNG_HIDDEN
int lttcomm_setsockopt_creds_unix_sock(int sock)
{
	int ret, on = 1;

	/* Set socket for credentials retrieval */
	ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
	if (ret < 0) {
		PERROR("setsockopt creds unix sock");
	}
	return ret;
}
#elif (defined(__FreeBSD__) || defined(__CYGWIN__))
LTTNG_HIDDEN
int lttcomm_setsockopt_creds_unix_sock(int sock)
{
	return 0;
}
#else
#error "Please implement credential support for your OS."
#endif /* __linux__ */
Commit	Line	Data
0d37f2bc DG	1	/*
	2	* Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
	3	* Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License, version 2 only,
	7	* as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along
	15	* with this program; if not, write to the Free Software Foundation, Inc.,
	16	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
	17	*/
	18
	19	#define _GNU_SOURCE
	20	#include <assert.h>
	21	#include <limits.h>
	22	#include <stdio.h>
	23	#include <stdlib.h>
	24	#include <string.h>
	25	#include <sys/stat.h>
	26	#include <sys/types.h>
	27	#include <unistd.h>
	28	#include <errno.h>
	29
90e535ef	30	#include <common/common.h>
0d37f2bc DG	31
	32	#include "unix.h"
	33
	34	/*
	35	* Connect to unix socket using the path name.
	36	*/
90e535ef	37	LTTNG_HIDDEN
0d37f2bc DG	38	int lttcomm_connect_unix_sock(const char *pathname)
	39	{
	40	struct sockaddr_un sun;
	41	int fd, ret, closeret;
	42
	43	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	44	if (fd < 0) {
	45	PERROR("socket");
	46	ret = fd;
	47	goto error;
	48	}
	49
	50	memset(&sun, 0, sizeof(sun));
	51	sun.sun_family = AF_UNIX;
	52	strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
	53	sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
	54
	55	ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
	56	if (ret < 0) {
	57	/*
	58	* Don't print message on connect error, because connect is used in
	59	* normal execution to detect if sessiond is alive.
	60	*/
	61	goto error_connect;
	62	}
	63
	64	return fd;
	65
	66	error_connect:
	67	closeret = close(fd);
	68	if (closeret) {
	69	PERROR("close");
	70	}
	71	error:
	72	return ret;
	73	}
	74
	75	/*
	76	* Do an accept(2) on the sock and return the new file descriptor. The socket
	77	* MUST be bind(2) before.
	78	*/
90e535ef	79	LTTNG_HIDDEN
0d37f2bc DG	80	int lttcomm_accept_unix_sock(int sock)
	81	{
	82	int new_fd;
	83	struct sockaddr_un sun;
	84	socklen_t len = 0;
	85
	86	/* Blocking call */
	87	new_fd = accept(sock, (struct sockaddr *) &sun, &len);
	88	if (new_fd < 0) {
	89	PERROR("accept");
	90	}
	91
	92	return new_fd;
	93	}
	94
	95	/*
	96	* Creates a AF_UNIX local socket using pathname bind the socket upon creation
	97	* and return the fd.
	98	*/
90e535ef	99	LTTNG_HIDDEN
0d37f2bc DG	100	int lttcomm_create_unix_sock(const char *pathname)
	101	{
	102	struct sockaddr_un sun;
	103	int fd;
	104	int ret = -1;
	105
	106	/* Create server socket */
	107	if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
	108	PERROR("socket");
	109	goto error;
	110	}
	111
	112	memset(&sun, 0, sizeof(sun));
	113	sun.sun_family = AF_UNIX;
	114	strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
	115	sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
	116
	117	/* Unlink the old file if present */
	118	(void) unlink(pathname);
	119	ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
	120	if (ret < 0) {
	121	PERROR("bind");
	122	goto error;
	123	}
	124
	125	return fd;
	126
	127	error:
17e75273 DG	128	if (fd >= 0) {
	129	if (close(fd) < 0) {
	130	PERROR("close create unix sock");
	131	}
	132	}
0d37f2bc DG	133	return ret;
	134	}
	135
	136	/*
	137	* Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
	138	*/
90e535ef	139	LTTNG_HIDDEN
0d37f2bc DG	140	int lttcomm_listen_unix_sock(int sock)
	141	{
	142	int ret;
	143
	144	ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
	145	if (ret < 0) {
	146	PERROR("listen");
	147	}
	148
	149	return ret;
	150	}
	151
	152	/*
	153	* Receive data of size len in put that data into the buf param. Using recvmsg
	154	* API.
	155	*
	156	* Return the size of received data.
	157	*/
90e535ef	158	LTTNG_HIDDEN
0d37f2bc DG	159	ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
	160	{
	161	struct msghdr msg;
	162	struct iovec iov[1];
	163	ssize_t ret = -1;
7c5aef62	164	size_t len_last;
0d37f2bc DG	165
	166	memset(&msg, 0, sizeof(msg));
	167
	168	iov[0].iov_base = buf;
	169	iov[0].iov_len = len;
	170	msg.msg_iov = iov;
	171	msg.msg_iovlen = 1;
	172
	173	do {
7c5aef62 DG	174	len_last = iov[0].iov_len;
	175	ret = recvmsg(sock, &msg, 0);
	176	if (ret > 0) {
	177	iov[0].iov_base += ret;
	178	iov[0].iov_len -= ret;
	179	assert(ret <= len_last);
	180	}
	181	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
0d37f2bc DG	182	if (ret < 0) {
0d37f2bc DG	183	PERROR("recvmsg");
7c5aef62 DG	184	} else if (ret > 0) {
7c5aef62 DG	185	ret = len;
0d37f2bc	186	}
7c5aef62	187	/* Else ret = 0 meaning an orderly shutdown. */
0d37f2bc DG	188
	189	return ret;
	190	}
	191
	192	/*
	193	* Send buf data of size len. Using sendmsg API.
	194	*
	195	* Return the size of sent data.
	196	*/
90e535ef	197	LTTNG_HIDDEN
0d37f2bc DG	198	ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
	199	{
	200	struct msghdr msg;
	201	struct iovec iov[1];
	202	ssize_t ret = -1;
	203
	204	memset(&msg, 0, sizeof(msg));
	205
	206	iov[0].iov_base = buf;
	207	iov[0].iov_len = len;
	208	msg.msg_iov = iov;
	209	msg.msg_iovlen = 1;
	210
	211	ret = sendmsg(sock, &msg, 0);
	212	if (ret < 0) {
	213	/*
	214	* Only warn about EPIPE when quiet mode is deactivated.
	215	* We consider EPIPE as expected.
	216	*/
	217	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	218	PERROR("sendmsg");
	219	}
	220	}
	221
	222	return ret;
	223	}
	224
	225	/*
	226	* Shutdown cleanly a unix socket.
	227	*/
90e535ef	228	LTTNG_HIDDEN
0d37f2bc DG	229	int lttcomm_close_unix_sock(int sock)
	230	{
	231	int ret, closeret;
	232
	233	/* Shutdown receptions and transmissions */
	234	ret = shutdown(sock, SHUT_RDWR);
	235	if (ret < 0) {
	236	PERROR("shutdown");
	237	}
	238
	239	closeret = close(sock);
	240	if (closeret) {
	241	PERROR("close");
	242	}
	243
	244	return ret;
	245	}
	246
	247	/*
	248	* Send a message accompanied by fd(s) over a unix socket.
	249	*
	250	* Returns the size of data sent, or negative error value.
	251	*/
90e535ef	252	LTTNG_HIDDEN
0d37f2bc DG	253	ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	254	{
	255	struct msghdr msg;
	256	struct cmsghdr *cmptr;
	257	struct iovec iov[1];
	258	ssize_t ret = -1;
	259	unsigned int sizeof_fds = nb_fd * sizeof(int);
	260	char tmp[CMSG_SPACE(sizeof_fds)];
	261	char dummy = 0;
	262
	263	memset(&msg, 0, sizeof(msg));
c617c0c6	264	memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
0d37f2bc DG	265
	266	if (nb_fd > LTTCOMM_MAX_SEND_FDS)
	267	return -EINVAL;
	268
	269	msg.msg_control = (caddr_t)tmp;
	270	msg.msg_controllen = CMSG_LEN(sizeof_fds);
	271
	272	cmptr = CMSG_FIRSTHDR(&msg);
	273	cmptr->cmsg_level = SOL_SOCKET;
	274	cmptr->cmsg_type = SCM_RIGHTS;
	275	cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
	276	memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
	277	/* Sum of the length of all control messages in the buffer: */
	278	msg.msg_controllen = cmptr->cmsg_len;
	279
	280	iov[0].iov_base = &dummy;
	281	iov[0].iov_len = 1;
	282	msg.msg_iov = iov;
	283	msg.msg_iovlen = 1;
	284
	285	do {
	286	ret = sendmsg(sock, &msg, 0);
	287	} while (ret < 0 && errno == EINTR);
	288	if (ret < 0) {
	289	/*
	290	* Only warn about EPIPE when quiet mode is deactivated.
	291	* We consider EPIPE as expected.
	292	*/
	293	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	294	PERROR("sendmsg");
	295	}
	296	}
	297	return ret;
	298	}
	299
	300	/*
	301	* Recv a message accompanied by fd(s) from a unix socket.
	302	*
	303	* Returns the size of received data, or negative error value.
	304	*
	305	* Expect at most "nb_fd" file descriptors. Returns the number of fd
	306	* actually received in nb_fd.
	307	*/
90e535ef	308	LTTNG_HIDDEN
0d37f2bc DG	309	ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	310	{
	311	struct iovec iov[1];
	312	ssize_t ret = 0;
	313	struct cmsghdr *cmsg;
	314	size_t sizeof_fds = nb_fd * sizeof(int);
	315	char recv_fd[CMSG_SPACE(sizeof_fds)];
	316	struct msghdr msg;
	317	char dummy;
	318
	319	memset(&msg, 0, sizeof(msg));
	320
	321	/* Prepare to receive the structures */
	322	iov[0].iov_base = &dummy;
	323	iov[0].iov_len = 1;
	324	msg.msg_iov = iov;
	325	msg.msg_iovlen = 1;
	326	msg.msg_control = recv_fd;
	327	msg.msg_controllen = sizeof(recv_fd);
	328
	329	do {
	330	ret = recvmsg(sock, &msg, 0);
	331	} while (ret < 0 && errno == EINTR);
	332	if (ret < 0) {
	333	PERROR("recvmsg fds");
	334	goto end;
	335	}
	336	if (ret != 1) {
	337	fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
	338	ret, 1);
	339	goto end;
	340	}
	341	if (msg.msg_flags & MSG_CTRUNC) {
	342	fprintf(stderr, "Error: Control message truncated.\n");
	343	ret = -1;
	344	goto end;
	345	}
	346	cmsg = CMSG_FIRSTHDR(&msg);
	347	if (!cmsg) {
	348	fprintf(stderr, "Error: Invalid control message header\n");
	349	ret = -1;
	350	goto end;
	351	}
	352	if (cmsg->cmsg_level != SOL_SOCKET \|\| cmsg->cmsg_type != SCM_RIGHTS) {
	353	fprintf(stderr, "Didn't received any fd\n");
	354	ret = -1;
	355	goto end;
	356	}
	357	if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
	358	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	359	(size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
	360	ret = -1;
	361	goto end;
	362	}
	363	memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
	364	ret = sizeof_fds;
	365	end:
	366	return ret;
	367	}
	368
	369	/*
	370	* Send a message with credentials over a unix socket.
	371	*
	372	* Returns the size of data sent, or negative error value.
373	*/
90e535ef	374	LTTNG_HIDDEN
0d37f2bc DG	375	ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
	376	{
	377	struct msghdr msg;
	378	struct iovec iov[1];
	379	ssize_t ret = -1;
	380	#ifdef __linux__
	381	struct cmsghdr *cmptr;
	382	size_t sizeof_cred = sizeof(lttng_sock_cred);
	383	char anc_buf[CMSG_SPACE(sizeof_cred)];
	384	lttng_sock_cred *creds;
	385	#endif /* __linux__ */
	386
	387	memset(&msg, 0, sizeof(msg));
c617c0c6	388	memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));
0d37f2bc DG	389
	390	iov[0].iov_base = buf;
	391	iov[0].iov_len = len;
	392	msg.msg_iov = iov;
	393	msg.msg_iovlen = 1;
	394
	395	#ifdef __linux__
	396	msg.msg_control = (caddr_t) anc_buf;
	397	msg.msg_controllen = CMSG_LEN(sizeof_cred);
	398
	399	cmptr = CMSG_FIRSTHDR(&msg);
	400	cmptr->cmsg_level = SOL_SOCKET;
	401	cmptr->cmsg_type = LTTNG_SOCK_CREDS;
	402	cmptr->cmsg_len = CMSG_LEN(sizeof_cred);
	403
	404	creds = (lttng_sock_cred*) CMSG_DATA(cmptr);
	405
	406	LTTNG_SOCK_SET_UID_CRED(creds, geteuid());
	407	LTTNG_SOCK_SET_GID_CRED(creds, getegid());
	408	LTTNG_SOCK_SET_PID_CRED(creds, getpid());
	409	#endif /* __linux__ */
	410
	411	do {
	412	ret = sendmsg(sock, &msg, 0);
	413	} while (ret < 0 && errno == EINTR);
	414	if (ret < 0) {
	415	/*
	416	* Only warn about EPIPE when quiet mode is deactivated.
	417	* We consider EPIPE as expected.
	418	*/
	419	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	420	PERROR("sendmsg");
	421	}
	422	}
	423	return ret;
	424	}
	425
	426	/*
	427	* Recv a message accompanied with credentials from a unix socket.
	428	*
	429	* Returns the size of received data, or negative error value.
	430	*/
90e535ef	431	LTTNG_HIDDEN
0d37f2bc DG	432	ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
	433	lttng_sock_cred *creds)
	434	{
	435	struct msghdr msg;
	436	struct iovec iov[1];
	437	ssize_t ret;
	438	#ifdef __linux__
	439	struct cmsghdr *cmptr;
	440	size_t sizeof_cred = sizeof(lttng_sock_cred);
	441	char anc_buf[CMSG_SPACE(sizeof_cred)];
	442	#endif /* __linux__ */
	443
	444	memset(&msg, 0, sizeof(msg));
	445
	446	/* Not allowed */
	447	if (creds == NULL) {
	448	ret = -1;
	449	goto end;
	450	}
	451
	452	/* Prepare to receive the structures */
	453	iov[0].iov_base = buf;
	454	iov[0].iov_len = len;
	455	msg.msg_iov = iov;
	456	msg.msg_iovlen = 1;
	457
	458	#ifdef __linux__
	459	msg.msg_control = anc_buf;
	460	msg.msg_controllen = sizeof(anc_buf);
	461	#endif /* __linux__ */
	462
	463	do {
	464	ret = recvmsg(sock, &msg, 0);
	465	} while (ret < 0 && errno == EINTR);
	466	if (ret < 0) {
	467	PERROR("recvmsg fds");
	468	goto end;
	469	}
	470
	471	#ifdef __linux__
	472	if (msg.msg_flags & MSG_CTRUNC) {
	473	fprintf(stderr, "Error: Control message truncated.\n");
	474	ret = -1;
	475	goto end;
	476	}
	477
	478	cmptr = CMSG_FIRSTHDR(&msg);
	479	if (cmptr == NULL) {
	480	fprintf(stderr, "Error: Invalid control message header\n");
	481	ret = -1;
	482	goto end;
	483	}
	484
	485	if (cmptr->cmsg_level != SOL_SOCKET \|\|
	486	cmptr->cmsg_type != LTTNG_SOCK_CREDS) {
	487	fprintf(stderr, "Didn't received any credentials\n");
	488	ret = -1;
	489	goto end;
	490	}
	491
	492	if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) {
	493	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	494	(size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred));
	495	ret = -1;
496	goto end;
497	}
498
499	memcpy(creds, CMSG_DATA(cmptr), sizeof_cred);
500	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__))
501	{
502	int peer_ret;
503
504	peer_ret = getpeereid(sock, &creds->uid, &creds->gid);
505	if (peer_ret != 0) {
506	return peer_ret;
507	}
508	}
509	#else
510	#error "Please implement credential support for your OS."
511	#endif /* __linux__ */
512
513	end:
514	return ret;
515	}
516
517	/*
518	* Set socket option to use credentials passing.
519	*/
520	#ifdef __linux__
90e535ef	521	LTTNG_HIDDEN
0d37f2bc DG	522	int lttcomm_setsockopt_creds_unix_sock(int sock)
	523	{
	524	int ret, on = 1;
	525
	526	/* Set socket for credentials retrieval */
	527	ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
	528	if (ret < 0) {
	529	PERROR("setsockopt creds unix sock");
	530	}
	531	return ret;
	532	}
	533	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__))
90e535ef	534	LTTNG_HIDDEN
0d37f2bc DG	535	int lttcomm_setsockopt_creds_unix_sock(int sock)
	536	{
	537	return 0;
	538	}
	539	#else
	540	#error "Please implement credential support for your OS."
	541	#endif /* __linux__ */