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