[lttng-tools.git] / src / common / 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 _LGPL_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 <common/sessiond-comm/sessiond-comm.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 s_un;
	int fd, ret, closeret;

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

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

	ret = connect(fd, (struct sockaddr *) &s_un, sizeof(s_un));
	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 s_un;
	socklen_t len = 0;

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

	return new_fd;
}

LTTNG_HIDDEN
int lttcomm_create_anon_unix_socketpair(int *fds)
{
	if (socketpair(PF_UNIX, SOCK_STREAM, 0, fds) < 0) {
		PERROR("socketpair");
		return -1;
	}
	return 0;
}

/*
 * 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 s_un;
	int fd;
	int ret = -1;

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

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

	/* Unlink the old file if present */
	(void) unlink(pathname);
	ret = bind(fd, (struct sockaddr *) &s_un, sizeof(s_un));
	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 = lttng_recvmsg_nosigpipe(sock, &msg);
		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, const 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 = (void *) 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);
	if (!cmptr) {
		return -1;
	}
	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;

	memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));
#endif /* __linux__ */

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

	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);
	if (!cmptr) {
		return -1;
	}
	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;
	size_t len_last;
#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 {
		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 fds");
		goto end;
	} else if (ret > 0) {
		ret = len;
	}
	/* Else ret = 0 meaning an orderly shutdown. */

#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__) || defined(__sun__))
	{
		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__) || defined(__sun__))
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
6c1c0768	19	#define _LGPL_SOURCE
0d37f2bc DG	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>
2038dd6c	31	#include <common/sessiond-comm/sessiond-comm.h>
0d37f2bc DG	32
	33	#include "unix.h"
	34
	35	/*
	36	* Connect to unix socket using the path name.
	37	*/
90e535ef	38	LTTNG_HIDDEN
0d37f2bc DG	39	int lttcomm_connect_unix_sock(const char *pathname)
0d37f2bc DG	40	{
665886a6	41	struct sockaddr_un s_un;
0d37f2bc DG	42	int fd, ret, closeret;
	43
	44	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	45	if (fd < 0) {
	46	PERROR("socket");
	47	ret = fd;
	48	goto error;
	49	}
	50
665886a6 MJ	51	memset(&s_un, 0, sizeof(s_un));
	52	s_un.sun_family = AF_UNIX;
	53	strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
	54	s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
0d37f2bc	55
665886a6	56	ret = connect(fd, (struct sockaddr *) &s_un, sizeof(s_un));
0d37f2bc DG	57	if (ret < 0) {
	58	/*
	59	* Don't print message on connect error, because connect is used in
	60	* normal execution to detect if sessiond is alive.
	61	*/
	62	goto error_connect;
	63	}
	64
	65	return fd;
	66
	67	error_connect:
	68	closeret = close(fd);
	69	if (closeret) {
	70	PERROR("close");
	71	}
	72	error:
	73	return ret;
	74	}
	75
	76	/*
	77	* Do an accept(2) on the sock and return the new file descriptor. The socket
	78	* MUST be bind(2) before.
	79	*/
90e535ef	80	LTTNG_HIDDEN
0d37f2bc DG	81	int lttcomm_accept_unix_sock(int sock)
	82	{
	83	int new_fd;
665886a6	84	struct sockaddr_un s_un;
0d37f2bc DG	85	socklen_t len = 0;
	86
	87	/* Blocking call */
665886a6	88	new_fd = accept(sock, (struct sockaddr *) &s_un, &len);
0d37f2bc DG	89	if (new_fd < 0) {
	90	PERROR("accept");
	91	}
	92
	93	return new_fd;
	94	}
	95
7567352f MD	96	LTTNG_HIDDEN
	97	int lttcomm_create_anon_unix_socketpair(int *fds)
	98	{
	99	if (socketpair(PF_UNIX, SOCK_STREAM, 0, fds) < 0) {
	100	PERROR("socketpair");
	101	return -1;
	102	}
	103	return 0;
	104	}
	105
0d37f2bc DG	106	/*
	107	* Creates a AF_UNIX local socket using pathname bind the socket upon creation
	108	* and return the fd.
	109	*/
90e535ef	110	LTTNG_HIDDEN
0d37f2bc DG	111	int lttcomm_create_unix_sock(const char *pathname)
0d37f2bc DG	112	{
665886a6	113	struct sockaddr_un s_un;
0d37f2bc DG	114	int fd;
	115	int ret = -1;
	116
	117	/* Create server socket */
	118	if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
	119	PERROR("socket");
	120	goto error;
	121	}
	122
665886a6 MJ	123	memset(&s_un, 0, sizeof(s_un));
	124	s_un.sun_family = AF_UNIX;
	125	strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
	126	s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
0d37f2bc DG	127
	128	/* Unlink the old file if present */
	129	(void) unlink(pathname);
665886a6	130	ret = bind(fd, (struct sockaddr *) &s_un, sizeof(s_un));
0d37f2bc DG	131	if (ret < 0) {
	132	PERROR("bind");
	133	goto error;
	134	}
	135
	136	return fd;
	137
	138	error:
17e75273 DG	139	if (fd >= 0) {
	140	if (close(fd) < 0) {
	141	PERROR("close create unix sock");
	142	}
	143	}
0d37f2bc DG	144	return ret;
	145	}
	146
	147	/*
	148	* Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
	149	*/
90e535ef	150	LTTNG_HIDDEN
0d37f2bc DG	151	int lttcomm_listen_unix_sock(int sock)
	152	{
	153	int ret;
	154
	155	ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
	156	if (ret < 0) {
	157	PERROR("listen");
	158	}
	159
	160	return ret;
	161	}
	162
	163	/*
	164	* Receive data of size len in put that data into the buf param. Using recvmsg
	165	* API.
	166	*
	167	* Return the size of received data.
	168	*/
90e535ef	169	LTTNG_HIDDEN
0d37f2bc DG	170	ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
	171	{
	172	struct msghdr msg;
	173	struct iovec iov[1];
	174	ssize_t ret = -1;
7c5aef62	175	size_t len_last;
0d37f2bc DG	176
	177	memset(&msg, 0, sizeof(msg));
	178
	179	iov[0].iov_base = buf;
	180	iov[0].iov_len = len;
	181	msg.msg_iov = iov;
	182	msg.msg_iovlen = 1;
	183
	184	do {
7c5aef62	185	len_last = iov[0].iov_len;
fbb1fd3a	186	ret = lttng_recvmsg_nosigpipe(sock, &msg);
7c5aef62 DG	187	if (ret > 0) {
	188	iov[0].iov_base += ret;
	189	iov[0].iov_len -= ret;
	190	assert(ret <= len_last);
	191	}
	192	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
0d37f2bc DG	193	if (ret < 0) {
0d37f2bc DG	194	PERROR("recvmsg");
7c5aef62 DG	195	} else if (ret > 0) {
7c5aef62 DG	196	ret = len;
0d37f2bc	197	}
7c5aef62	198	/* Else ret = 0 meaning an orderly shutdown. */
0d37f2bc DG	199
	200	return ret;
	201	}
	202
	203	/*
	204	* Send buf data of size len. Using sendmsg API.
	205	*
	206	* Return the size of sent data.
	207	*/
90e535ef	208	LTTNG_HIDDEN
c2d69327	209	ssize_t lttcomm_send_unix_sock(int sock, const void *buf, size_t len)
0d37f2bc DG	210	{
	211	struct msghdr msg;
	212	struct iovec iov[1];
	213	ssize_t ret = -1;
	214
	215	memset(&msg, 0, sizeof(msg));
	216
c2d69327	217	iov[0].iov_base = (void *) buf;
0d37f2bc DG	218	iov[0].iov_len = len;
	219	msg.msg_iov = iov;
	220	msg.msg_iovlen = 1;
	221
	222	ret = sendmsg(sock, &msg, 0);
	223	if (ret < 0) {
	224	/*
	225	* Only warn about EPIPE when quiet mode is deactivated.
	226	* We consider EPIPE as expected.
	227	*/
	228	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	229	PERROR("sendmsg");
	230	}
	231	}
	232
	233	return ret;
	234	}
	235
	236	/*
	237	* Shutdown cleanly a unix socket.
	238	*/
90e535ef	239	LTTNG_HIDDEN
0d37f2bc DG	240	int lttcomm_close_unix_sock(int sock)
	241	{
	242	int ret, closeret;
	243
	244	/* Shutdown receptions and transmissions */
	245	ret = shutdown(sock, SHUT_RDWR);
	246	if (ret < 0) {
	247	PERROR("shutdown");
	248	}
	249
	250	closeret = close(sock);
	251	if (closeret) {
	252	PERROR("close");
	253	}
	254
	255	return ret;
	256	}
	257
	258	/*
	259	* Send a message accompanied by fd(s) over a unix socket.
	260	*
	261	* Returns the size of data sent, or negative error value.
	262	*/
90e535ef	263	LTTNG_HIDDEN
0d37f2bc DG	264	ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	265	{
	266	struct msghdr msg;
	267	struct cmsghdr *cmptr;
	268	struct iovec iov[1];
	269	ssize_t ret = -1;
	270	unsigned int sizeof_fds = nb_fd * sizeof(int);
	271	char tmp[CMSG_SPACE(sizeof_fds)];
	272	char dummy = 0;
	273
	274	memset(&msg, 0, sizeof(msg));
c617c0c6	275	memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
0d37f2bc DG	276
	277	if (nb_fd > LTTCOMM_MAX_SEND_FDS)
	278	return -EINVAL;
	279
	280	msg.msg_control = (caddr_t)tmp;
	281	msg.msg_controllen = CMSG_LEN(sizeof_fds);
	282
	283	cmptr = CMSG_FIRSTHDR(&msg);
1d8d0328 MJ	284	if (!cmptr) {
	285	return -1;
	286	}
0d37f2bc DG	287	cmptr->cmsg_level = SOL_SOCKET;
	288	cmptr->cmsg_type = SCM_RIGHTS;
	289	cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
	290	memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
	291	/* Sum of the length of all control messages in the buffer: */
	292	msg.msg_controllen = cmptr->cmsg_len;
	293
	294	iov[0].iov_base = &dummy;
	295	iov[0].iov_len = 1;
	296	msg.msg_iov = iov;
	297	msg.msg_iovlen = 1;
	298
	299	do {
	300	ret = sendmsg(sock, &msg, 0);
	301	} while (ret < 0 && errno == EINTR);
	302	if (ret < 0) {
	303	/*
	304	* Only warn about EPIPE when quiet mode is deactivated.
	305	* We consider EPIPE as expected.
	306	*/
	307	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	308	PERROR("sendmsg");
	309	}
	310	}
	311	return ret;
	312	}
	313
	314	/*
	315	* Recv a message accompanied by fd(s) from a unix socket.
	316	*
	317	* Returns the size of received data, or negative error value.
	318	*
	319	* Expect at most "nb_fd" file descriptors. Returns the number of fd
	320	* actually received in nb_fd.
	321	*/
90e535ef	322	LTTNG_HIDDEN
0d37f2bc DG	323	ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	324	{
	325	struct iovec iov[1];
	326	ssize_t ret = 0;
	327	struct cmsghdr *cmsg;
	328	size_t sizeof_fds = nb_fd * sizeof(int);
	329	char recv_fd[CMSG_SPACE(sizeof_fds)];
	330	struct msghdr msg;
	331	char dummy;
	332
	333	memset(&msg, 0, sizeof(msg));
	334
	335	/* Prepare to receive the structures */
	336	iov[0].iov_base = &dummy;
	337	iov[0].iov_len = 1;
	338	msg.msg_iov = iov;
	339	msg.msg_iovlen = 1;
	340	msg.msg_control = recv_fd;
	341	msg.msg_controllen = sizeof(recv_fd);
	342
	343	do {
	344	ret = recvmsg(sock, &msg, 0);
	345	} while (ret < 0 && errno == EINTR);
	346	if (ret < 0) {
	347	PERROR("recvmsg fds");
	348	goto end;
	349	}
	350	if (ret != 1) {
	351	fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
	352	ret, 1);
	353	goto end;
	354	}
	355	if (msg.msg_flags & MSG_CTRUNC) {
	356	fprintf(stderr, "Error: Control message truncated.\n");
	357	ret = -1;
	358	goto end;
	359	}
	360	cmsg = CMSG_FIRSTHDR(&msg);
	361	if (!cmsg) {
	362	fprintf(stderr, "Error: Invalid control message header\n");
	363	ret = -1;
	364	goto end;
	365	}
	366	if (cmsg->cmsg_level != SOL_SOCKET \|\| cmsg->cmsg_type != SCM_RIGHTS) {
	367	fprintf(stderr, "Didn't received any fd\n");
	368	ret = -1;
	369	goto end;
	370	}
	371	if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
	372	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	373	(size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
	374	ret = -1;
	375	goto end;
	376	}
	377	memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
	378	ret = sizeof_fds;
	379	end:
	380	return ret;
	381	}
	382
	383	/*
	384	* Send a message with credentials over a unix socket.
	385	*
	386	* Returns the size of data sent, or negative error value.
387	*/
90e535ef	388	LTTNG_HIDDEN
0d37f2bc DG	389	ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
	390	{
	391	struct msghdr msg;
	392	struct iovec iov[1];
	393	ssize_t ret = -1;
	394	#ifdef __linux__
	395	struct cmsghdr *cmptr;
	396	size_t sizeof_cred = sizeof(lttng_sock_cred);
	397	char anc_buf[CMSG_SPACE(sizeof_cred)];
	398	lttng_sock_cred *creds;
8bbffd54 MJ	399
8bbffd54 MJ	400	memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));
0d37f2bc DG	401	#endif /* __linux__ */
	402
	403	memset(&msg, 0, sizeof(msg));
	404
	405	iov[0].iov_base = buf;
	406	iov[0].iov_len = len;
	407	msg.msg_iov = iov;
	408	msg.msg_iovlen = 1;
	409
	410	#ifdef __linux__
	411	msg.msg_control = (caddr_t) anc_buf;
	412	msg.msg_controllen = CMSG_LEN(sizeof_cred);
	413
	414	cmptr = CMSG_FIRSTHDR(&msg);
1d8d0328 MJ	415	if (!cmptr) {
	416	return -1;
	417	}
0d37f2bc DG	418	cmptr->cmsg_level = SOL_SOCKET;
	419	cmptr->cmsg_type = LTTNG_SOCK_CREDS;
	420	cmptr->cmsg_len = CMSG_LEN(sizeof_cred);
	421
	422	creds = (lttng_sock_cred*) CMSG_DATA(cmptr);
	423
	424	LTTNG_SOCK_SET_UID_CRED(creds, geteuid());
	425	LTTNG_SOCK_SET_GID_CRED(creds, getegid());
	426	LTTNG_SOCK_SET_PID_CRED(creds, getpid());
	427	#endif /* __linux__ */
	428
	429	do {
	430	ret = sendmsg(sock, &msg, 0);
	431	} while (ret < 0 && errno == EINTR);
	432	if (ret < 0) {
	433	/*
	434	* Only warn about EPIPE when quiet mode is deactivated.
	435	* We consider EPIPE as expected.
	436	*/
	437	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	438	PERROR("sendmsg");
	439	}
	440	}
	441	return ret;
	442	}
	443
	444	/*
	445	* Recv a message accompanied with credentials from a unix socket.
	446	*
	447	* Returns the size of received data, or negative error value.
	448	*/
90e535ef	449	LTTNG_HIDDEN
0d37f2bc DG	450	ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
	451	lttng_sock_cred *creds)
	452	{
	453	struct msghdr msg;
	454	struct iovec iov[1];
	455	ssize_t ret;
4100e49a	456	size_t len_last;
0d37f2bc DG	457	#ifdef __linux__
	458	struct cmsghdr *cmptr;
	459	size_t sizeof_cred = sizeof(lttng_sock_cred);
	460	char anc_buf[CMSG_SPACE(sizeof_cred)];
	461	#endif /* __linux__ */
	462
	463	memset(&msg, 0, sizeof(msg));
	464
	465	/* Not allowed */
	466	if (creds == NULL) {
	467	ret = -1;
	468	goto end;
	469	}
	470
	471	/* Prepare to receive the structures */
	472	iov[0].iov_base = buf;
	473	iov[0].iov_len = len;
	474	msg.msg_iov = iov;
	475	msg.msg_iovlen = 1;
	476
	477	#ifdef __linux__
	478	msg.msg_control = anc_buf;
	479	msg.msg_controllen = sizeof(anc_buf);
	480	#endif /* __linux__ */
	481
	482	do {
4100e49a	483	len_last = iov[0].iov_len;
0d37f2bc	484	ret = recvmsg(sock, &msg, 0);
4100e49a DG	485	if (ret > 0) {
	486	iov[0].iov_base += ret;
	487	iov[0].iov_len -= ret;
	488	assert(ret <= len_last);
	489	}
	490	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
0d37f2bc DG	491	if (ret < 0) {
	492	PERROR("recvmsg fds");
	493	goto end;
4100e49a DG	494	} else if (ret > 0) {
4100e49a DG	495	ret = len;
0d37f2bc	496	}
4100e49a	497	/* Else ret = 0 meaning an orderly shutdown. */
0d37f2bc DG	498
	499	#ifdef __linux__
	500	if (msg.msg_flags & MSG_CTRUNC) {
	501	fprintf(stderr, "Error: Control message truncated.\n");
	502	ret = -1;
	503	goto end;
	504	}
	505
	506	cmptr = CMSG_FIRSTHDR(&msg);
	507	if (cmptr == NULL) {
	508	fprintf(stderr, "Error: Invalid control message header\n");
	509	ret = -1;
	510	goto end;
	511	}
	512
	513	if (cmptr->cmsg_level != SOL_SOCKET \|\|
	514	cmptr->cmsg_type != LTTNG_SOCK_CREDS) {
	515	fprintf(stderr, "Didn't received any credentials\n");
	516	ret = -1;
	517	goto end;
	518	}
	519
	520	if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) {
	521	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	522	(size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred));
	523	ret = -1;
	524	goto end;
	525	}
	526
	527	memcpy(creds, CMSG_DATA(cmptr), sizeof_cred);
06414417	528	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__))
0d37f2bc DG	529	{
	530	int peer_ret;
	531
	532	peer_ret = getpeereid(sock, &creds->uid, &creds->gid);
	533	if (peer_ret != 0) {
	534	return peer_ret;
	535	}
	536	}
	537	#else
	538	#error "Please implement credential support for your OS."
	539	#endif /* __linux__ */
	540
	541	end:
	542	return ret;
	543	}
	544
	545	/*
	546	* Set socket option to use credentials passing.
	547	*/
	548	#ifdef __linux__
90e535ef	549	LTTNG_HIDDEN
0d37f2bc DG	550	int lttcomm_setsockopt_creds_unix_sock(int sock)
	551	{
	552	int ret, on = 1;
	553
	554	/* Set socket for credentials retrieval */
	555	ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
	556	if (ret < 0) {
	557	PERROR("setsockopt creds unix sock");
	558	}
	559	return ret;
	560	}
06414417	561	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__))
90e535ef	562	LTTNG_HIDDEN
0d37f2bc DG	563	int lttcomm_setsockopt_creds_unix_sock(int sock)
	564	{
	565	return 0;
	566	}
	567	#else
	568	#error "Please implement credential support for your OS."
	569	#endif /* __linux__ */