[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
#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 sun;
	int fd, ret, closeret;

	if (strlen(pathname) >= sizeof(sun.sun_path)) {
		ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
				pathname, strlen(pathname) + 1,
				sizeof(sun.sun_path));
		ret = -ENAMETOOLONG;
		goto error;
	}

	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;
}

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 sun;
	int fd = -1;
	int ret = -1;

	if (strlen(pathname) >= sizeof(sun.sun_path)) {
		ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
				pathname, strlen(pathname) + 1,
				sizeof(sun.sun_path));
		ret = -ENAMETOOLONG;
		goto error;
	}

	/* 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, MSG_NOSIGNAL);
		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);
	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;
#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);
	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__))
	{
		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
6c1c0768	20	#define _LGPL_SOURCE
0d37f2bc DG	21	#include <assert.h>
	22	#include <limits.h>
	23	#include <stdio.h>
	24	#include <stdlib.h>
	25	#include <string.h>
	26	#include <sys/stat.h>
	27	#include <sys/types.h>
	28	#include <unistd.h>
	29	#include <errno.h>
	30
90e535ef	31	#include <common/common.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)
	40	{
	41	struct sockaddr_un sun;
	42	int fd, ret, closeret;
	43
0a09ade8 JG	44	if (strlen(pathname) >= sizeof(sun.sun_path)) {
	45	ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
	46	pathname, strlen(pathname) + 1,
	47	sizeof(sun.sun_path));
	48	ret = -ENAMETOOLONG;
	49	goto error;
	50	}
	51
0d37f2bc DG	52	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	53	if (fd < 0) {
	54	PERROR("socket");
	55	ret = fd;
	56	goto error;
	57	}
	58
	59	memset(&sun, 0, sizeof(sun));
	60	sun.sun_family = AF_UNIX;
	61	strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
	62	sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
	63
	64	ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
	65	if (ret < 0) {
	66	/*
	67	* Don't print message on connect error, because connect is used in
	68	* normal execution to detect if sessiond is alive.
	69	*/
	70	goto error_connect;
	71	}
	72
	73	return fd;
	74
	75	error_connect:
	76	closeret = close(fd);
	77	if (closeret) {
	78	PERROR("close");
	79	}
	80	error:
	81	return ret;
	82	}
	83
	84	/*
	85	* Do an accept(2) on the sock and return the new file descriptor. The socket
	86	* MUST be bind(2) before.
	87	*/
90e535ef	88	LTTNG_HIDDEN
0d37f2bc DG	89	int lttcomm_accept_unix_sock(int sock)
	90	{
	91	int new_fd;
	92	struct sockaddr_un sun;
	93	socklen_t len = 0;
	94
	95	/* Blocking call */
	96	new_fd = accept(sock, (struct sockaddr *) &sun, &len);
	97	if (new_fd < 0) {
	98	PERROR("accept");
	99	}
	100
	101	return new_fd;
	102	}
	103
0e904f3e MD	104	LTTNG_HIDDEN
	105	int lttcomm_create_anon_unix_socketpair(int *fds)
	106	{
	107	if (socketpair(PF_UNIX, SOCK_STREAM, 0, fds) < 0) {
	108	PERROR("socketpair");
	109	return -1;
	110	}
	111	return 0;
	112	}
	113
0d37f2bc DG	114	/*
	115	* Creates a AF_UNIX local socket using pathname bind the socket upon creation
	116	* and return the fd.
	117	*/
90e535ef	118	LTTNG_HIDDEN
0d37f2bc DG	119	int lttcomm_create_unix_sock(const char *pathname)
	120	{
	121	struct sockaddr_un sun;
0a09ade8	122	int fd = -1;
0d37f2bc DG	123	int ret = -1;
0d37f2bc DG	124
0a09ade8 JG	125	if (strlen(pathname) >= sizeof(sun.sun_path)) {
	126	ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
	127	pathname, strlen(pathname) + 1,
	128	sizeof(sun.sun_path));
	129	ret = -ENAMETOOLONG;
	130	goto error;
	131	}
	132
0d37f2bc DG	133	/* Create server socket */
	134	if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
	135	PERROR("socket");
	136	goto error;
	137	}
	138
	139	memset(&sun, 0, sizeof(sun));
	140	sun.sun_family = AF_UNIX;
	141	strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
	142	sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
	143
	144	/* Unlink the old file if present */
	145	(void) unlink(pathname);
	146	ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
	147	if (ret < 0) {
	148	PERROR("bind");
	149	goto error;
	150	}
	151
	152	return fd;
	153
	154	error:
17e75273 DG	155	if (fd >= 0) {
	156	if (close(fd) < 0) {
	157	PERROR("close create unix sock");
	158	}
	159	}
0d37f2bc DG	160	return ret;
	161	}
	162
	163	/*
	164	* Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
	165	*/
90e535ef	166	LTTNG_HIDDEN
0d37f2bc DG	167	int lttcomm_listen_unix_sock(int sock)
	168	{
	169	int ret;
	170
	171	ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
	172	if (ret < 0) {
	173	PERROR("listen");
	174	}
	175
	176	return ret;
	177	}
	178
	179	/*
	180	* Receive data of size len in put that data into the buf param. Using recvmsg
	181	* API.
	182	*
	183	* Return the size of received data.
	184	*/
90e535ef	185	LTTNG_HIDDEN
0d37f2bc DG	186	ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
	187	{
	188	struct msghdr msg;
	189	struct iovec iov[1];
	190	ssize_t ret = -1;
7c5aef62	191	size_t len_last;
0d37f2bc DG	192
	193	memset(&msg, 0, sizeof(msg));
	194
	195	iov[0].iov_base = buf;
	196	iov[0].iov_len = len;
	197	msg.msg_iov = iov;
	198	msg.msg_iovlen = 1;
	199
	200	do {
7c5aef62	201	len_last = iov[0].iov_len;
b51ae080	202	ret = recvmsg(sock, &msg, MSG_NOSIGNAL);
7c5aef62 DG	203	if (ret > 0) {
	204	iov[0].iov_base += ret;
	205	iov[0].iov_len -= ret;
	206	assert(ret <= len_last);
	207	}
	208	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
0d37f2bc DG	209	if (ret < 0) {
0d37f2bc DG	210	PERROR("recvmsg");
7c5aef62 DG	211	} else if (ret > 0) {
7c5aef62 DG	212	ret = len;
0d37f2bc	213	}
7c5aef62	214	/* Else ret = 0 meaning an orderly shutdown. */
0d37f2bc DG	215
	216	return ret;
	217	}
	218
	219	/*
	220	* Send buf data of size len. Using sendmsg API.
	221	*
	222	* Return the size of sent data.
	223	*/
90e535ef	224	LTTNG_HIDDEN
0d37f2bc DG	225	ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
	226	{
	227	struct msghdr msg;
	228	struct iovec iov[1];
	229	ssize_t ret = -1;
	230
	231	memset(&msg, 0, sizeof(msg));
	232
	233	iov[0].iov_base = buf;
	234	iov[0].iov_len = len;
	235	msg.msg_iov = iov;
	236	msg.msg_iovlen = 1;
	237
	238	ret = sendmsg(sock, &msg, 0);
	239	if (ret < 0) {
	240	/*
	241	* Only warn about EPIPE when quiet mode is deactivated.
	242	* We consider EPIPE as expected.
	243	*/
	244	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	245	PERROR("sendmsg");
	246	}
	247	}
	248
	249	return ret;
	250	}
	251
	252	/*
	253	* Shutdown cleanly a unix socket.
	254	*/
90e535ef	255	LTTNG_HIDDEN
0d37f2bc DG	256	int lttcomm_close_unix_sock(int sock)
	257	{
	258	int ret, closeret;
	259
	260	/* Shutdown receptions and transmissions */
	261	ret = shutdown(sock, SHUT_RDWR);
	262	if (ret < 0) {
	263	PERROR("shutdown");
	264	}
	265
	266	closeret = close(sock);
	267	if (closeret) {
	268	PERROR("close");
	269	}
	270
	271	return ret;
	272	}
	273
	274	/*
	275	* Send a message accompanied by fd(s) over a unix socket.
	276	*
	277	* Returns the size of data sent, or negative error value.
	278	*/
90e535ef	279	LTTNG_HIDDEN
0d37f2bc DG	280	ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	281	{
	282	struct msghdr msg;
	283	struct cmsghdr *cmptr;
	284	struct iovec iov[1];
	285	ssize_t ret = -1;
	286	unsigned int sizeof_fds = nb_fd * sizeof(int);
	287	char tmp[CMSG_SPACE(sizeof_fds)];
	288	char dummy = 0;
	289
	290	memset(&msg, 0, sizeof(msg));
c617c0c6	291	memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
0d37f2bc DG	292
	293	if (nb_fd > LTTCOMM_MAX_SEND_FDS)
	294	return -EINVAL;
	295
	296	msg.msg_control = (caddr_t)tmp;
	297	msg.msg_controllen = CMSG_LEN(sizeof_fds);
	298
	299	cmptr = CMSG_FIRSTHDR(&msg);
ce0fc06f MJ	300	if (!cmptr) {
	301	return -1;
	302	}
0d37f2bc DG	303	cmptr->cmsg_level = SOL_SOCKET;
	304	cmptr->cmsg_type = SCM_RIGHTS;
	305	cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
	306	memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
	307	/* Sum of the length of all control messages in the buffer: */
	308	msg.msg_controllen = cmptr->cmsg_len;
	309
	310	iov[0].iov_base = &dummy;
	311	iov[0].iov_len = 1;
	312	msg.msg_iov = iov;
	313	msg.msg_iovlen = 1;
	314
	315	do {
	316	ret = sendmsg(sock, &msg, 0);
	317	} while (ret < 0 && errno == EINTR);
	318	if (ret < 0) {
	319	/*
	320	* Only warn about EPIPE when quiet mode is deactivated.
	321	* We consider EPIPE as expected.
	322	*/
	323	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	324	PERROR("sendmsg");
	325	}
	326	}
	327	return ret;
	328	}
	329
	330	/*
	331	* Recv a message accompanied by fd(s) from a unix socket.
	332	*
	333	* Returns the size of received data, or negative error value.
	334	*
	335	* Expect at most "nb_fd" file descriptors. Returns the number of fd
	336	* actually received in nb_fd.
	337	*/
90e535ef	338	LTTNG_HIDDEN
0d37f2bc DG	339	ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	340	{
	341	struct iovec iov[1];
	342	ssize_t ret = 0;
	343	struct cmsghdr *cmsg;
	344	size_t sizeof_fds = nb_fd * sizeof(int);
	345	char recv_fd[CMSG_SPACE(sizeof_fds)];
	346	struct msghdr msg;
	347	char dummy;
	348
	349	memset(&msg, 0, sizeof(msg));
	350
	351	/* Prepare to receive the structures */
	352	iov[0].iov_base = &dummy;
	353	iov[0].iov_len = 1;
	354	msg.msg_iov = iov;
	355	msg.msg_iovlen = 1;
	356	msg.msg_control = recv_fd;
	357	msg.msg_controllen = sizeof(recv_fd);
	358
	359	do {
	360	ret = recvmsg(sock, &msg, 0);
	361	} while (ret < 0 && errno == EINTR);
	362	if (ret < 0) {
	363	PERROR("recvmsg fds");
	364	goto end;
	365	}
	366	if (ret != 1) {
	367	fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
	368	ret, 1);
	369	goto end;
	370	}
	371	if (msg.msg_flags & MSG_CTRUNC) {
	372	fprintf(stderr, "Error: Control message truncated.\n");
	373	ret = -1;
	374	goto end;
	375	}
	376	cmsg = CMSG_FIRSTHDR(&msg);
	377	if (!cmsg) {
	378	fprintf(stderr, "Error: Invalid control message header\n");
	379	ret = -1;
	380	goto end;
	381	}
	382	if (cmsg->cmsg_level != SOL_SOCKET \|\| cmsg->cmsg_type != SCM_RIGHTS) {
	383	fprintf(stderr, "Didn't received any fd\n");
	384	ret = -1;
	385	goto end;
	386	}
	387	if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
	388	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	389	(size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
	390	ret = -1;
	391	goto end;
	392	}
	393	memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
	394	ret = sizeof_fds;
	395	end:
	396	return ret;
	397	}
	398
	399	/*
	400	* Send a message with credentials over a unix socket.
	401	*
	402	* Returns the size of data sent, or negative error value.
403	*/
90e535ef	404	LTTNG_HIDDEN
0d37f2bc DG	405	ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
	406	{
	407	struct msghdr msg;
	408	struct iovec iov[1];
	409	ssize_t ret = -1;
	410	#ifdef __linux__
	411	struct cmsghdr *cmptr;
	412	size_t sizeof_cred = sizeof(lttng_sock_cred);
	413	char anc_buf[CMSG_SPACE(sizeof_cred)];
	414	lttng_sock_cred *creds;
	415	#endif /* __linux__ */
	416
	417	memset(&msg, 0, sizeof(msg));
c617c0c6	418	memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));
0d37f2bc DG	419
	420	iov[0].iov_base = buf;
	421	iov[0].iov_len = len;
	422	msg.msg_iov = iov;
	423	msg.msg_iovlen = 1;
	424
	425	#ifdef __linux__
	426	msg.msg_control = (caddr_t) anc_buf;
	427	msg.msg_controllen = CMSG_LEN(sizeof_cred);
	428
	429	cmptr = CMSG_FIRSTHDR(&msg);
ce0fc06f MJ	430	if (!cmptr) {
	431	return -1;
	432	}
0d37f2bc DG	433	cmptr->cmsg_level = SOL_SOCKET;
	434	cmptr->cmsg_type = LTTNG_SOCK_CREDS;
	435	cmptr->cmsg_len = CMSG_LEN(sizeof_cred);
	436
	437	creds = (lttng_sock_cred*) CMSG_DATA(cmptr);
	438
	439	LTTNG_SOCK_SET_UID_CRED(creds, geteuid());
	440	LTTNG_SOCK_SET_GID_CRED(creds, getegid());
	441	LTTNG_SOCK_SET_PID_CRED(creds, getpid());
	442	#endif /* __linux__ */
	443
	444	do {
	445	ret = sendmsg(sock, &msg, 0);
	446	} while (ret < 0 && errno == EINTR);
	447	if (ret < 0) {
	448	/*
	449	* Only warn about EPIPE when quiet mode is deactivated.
	450	* We consider EPIPE as expected.
	451	*/
	452	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	453	PERROR("sendmsg");
	454	}
	455	}
	456	return ret;
	457	}
	458
	459	/*
	460	* Recv a message accompanied with credentials from a unix socket.
	461	*
	462	* Returns the size of received data, or negative error value.
	463	*/
90e535ef	464	LTTNG_HIDDEN
0d37f2bc DG	465	ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
	466	lttng_sock_cred *creds)
	467	{
	468	struct msghdr msg;
	469	struct iovec iov[1];
	470	ssize_t ret;
4100e49a	471	size_t len_last;
0d37f2bc DG	472	#ifdef __linux__
	473	struct cmsghdr *cmptr;
	474	size_t sizeof_cred = sizeof(lttng_sock_cred);
	475	char anc_buf[CMSG_SPACE(sizeof_cred)];
	476	#endif /* __linux__ */
	477
	478	memset(&msg, 0, sizeof(msg));
	479
	480	/* Not allowed */
	481	if (creds == NULL) {
	482	ret = -1;
	483	goto end;
	484	}
	485
	486	/* Prepare to receive the structures */
	487	iov[0].iov_base = buf;
	488	iov[0].iov_len = len;
	489	msg.msg_iov = iov;
	490	msg.msg_iovlen = 1;
	491
	492	#ifdef __linux__
	493	msg.msg_control = anc_buf;
	494	msg.msg_controllen = sizeof(anc_buf);
	495	#endif /* __linux__ */
	496
	497	do {
4100e49a	498	len_last = iov[0].iov_len;
0d37f2bc	499	ret = recvmsg(sock, &msg, 0);
4100e49a DG	500	if (ret > 0) {
	501	iov[0].iov_base += ret;
	502	iov[0].iov_len -= ret;
	503	assert(ret <= len_last);
	504	}
	505	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
0d37f2bc DG	506	if (ret < 0) {
	507	PERROR("recvmsg fds");
	508	goto end;
4100e49a DG	509	} else if (ret > 0) {
4100e49a DG	510	ret = len;
0d37f2bc	511	}
4100e49a	512	/* Else ret = 0 meaning an orderly shutdown. */
0d37f2bc DG	513
	514	#ifdef __linux__
	515	if (msg.msg_flags & MSG_CTRUNC) {
	516	fprintf(stderr, "Error: Control message truncated.\n");
	517	ret = -1;
	518	goto end;
	519	}
	520
	521	cmptr = CMSG_FIRSTHDR(&msg);
	522	if (cmptr == NULL) {
	523	fprintf(stderr, "Error: Invalid control message header\n");
	524	ret = -1;
	525	goto end;
	526	}
	527
	528	if (cmptr->cmsg_level != SOL_SOCKET \|\|
	529	cmptr->cmsg_type != LTTNG_SOCK_CREDS) {
	530	fprintf(stderr, "Didn't received any credentials\n");
	531	ret = -1;
	532	goto end;
	533	}
	534
	535	if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) {
	536	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	537	(size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred));
	538	ret = -1;
	539	goto end;
	540	}
	541
	542	memcpy(creds, CMSG_DATA(cmptr), sizeof_cred);
	543	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__))
	544	{
	545	int peer_ret;
	546
	547	peer_ret = getpeereid(sock, &creds->uid, &creds->gid);
	548	if (peer_ret != 0) {
	549	return peer_ret;
	550	}
	551	}
	552	#else
	553	#error "Please implement credential support for your OS."
	554	#endif /* __linux__ */
	555
	556	end:
	557	return ret;
	558	}
	559
	560	/*
	561	* Set socket option to use credentials passing.
	562	*/
	563	#ifdef __linux__
90e535ef	564	LTTNG_HIDDEN
0d37f2bc DG	565	int lttcomm_setsockopt_creds_unix_sock(int sock)
	566	{
	567	int ret, on = 1;
	568
	569	/* Set socket for credentials retrieval */
	570	ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
	571	if (ret < 0) {
	572	PERROR("setsockopt creds unix sock");
	573	}
	574	return ret;
	575	}
	576	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__))
90e535ef	577	LTTNG_HIDDEN
0d37f2bc DG	578	int lttcomm_setsockopt_creds_unix_sock(int sock)
	579	{
	580	return 0;
	581	}
	582	#else
	583	#error "Please implement credential support for your OS."
	584	#endif /* __linux__ */