[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;

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

	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 = sizeof(s_un);

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

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

	/* 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;

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

	iov[0].iov_base = (void *) buf;
	iov[0].iov_len = len;
	msg.msg_iov = iov;
	msg.msg_iovlen = 1;

	while (iov[0].iov_len) {
		ret = sendmsg(sock, &msg, 0);
		if (ret < 0) {
			if (errno == EINTR) {
				continue;
			} else {
				/*
				 * Only warn about EPIPE when quiet mode is
				 * deactivated.
				 * We consider EPIPE as expected.
				 */
				if (errno != EPIPE || !lttng_opt_quiet) {
					PERROR("sendmsg");
				}
				goto end;
			}
		}
		iov[0].iov_len -= ret;
		iov[0].iov_base += ret;
	}
	ret = len;
end:
	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__) || defined(__APPLE__))
	{
		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__) || defined(__APPLE__))
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;
0d37f2bc DG	43
7f8bf467 JG	44	if (strlen(pathname) >= sizeof(s_un.sun_path)) {
	45	ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
	46	pathname, strlen(pathname) + 1,
	47	sizeof(s_un.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
665886a6 MJ	59	memset(&s_un, 0, sizeof(s_un));
	60	s_un.sun_family = AF_UNIX;
	61	strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
	62	s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
0d37f2bc	63
665886a6	64	ret = connect(fd, (struct sockaddr *) &s_un, sizeof(s_un));
0d37f2bc DG	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;
665886a6	92	struct sockaddr_un s_un;
50786a72	93	socklen_t len = sizeof(s_un);
0d37f2bc DG	94
0d37f2bc DG	95	/* Blocking call */
665886a6	96	new_fd = accept(sock, (struct sockaddr *) &s_un, &len);
0d37f2bc DG	97	if (new_fd < 0) {
	98	PERROR("accept");
	99	}
	100
	101	return new_fd;
	102	}
	103
7567352f 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)
0d37f2bc DG	120	{
665886a6	121	struct sockaddr_un s_un;
7f8bf467	122	int fd = -1;
0d37f2bc DG	123	int ret = -1;
0d37f2bc DG	124
7f8bf467 JG	125	if (strlen(pathname) >= sizeof(s_un.sun_path)) {
	126	ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
	127	pathname, strlen(pathname) + 1,
	128	sizeof(s_un.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
665886a6 MJ	139	memset(&s_un, 0, sizeof(s_un));
	140	s_un.sun_family = AF_UNIX;
	141	strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
	142	s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
0d37f2bc DG	143
	144	/* Unlink the old file if present */
	145	(void) unlink(pathname);
665886a6	146	ret = bind(fd, (struct sockaddr *) &s_un, sizeof(s_un));
0d37f2bc DG	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;
fbb1fd3a	202	ret = lttng_recvmsg_nosigpipe(sock, &msg);
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
c2d69327	225	ssize_t lttcomm_send_unix_sock(int sock, const void *buf, size_t len)
0d37f2bc DG	226	{
	227	struct msghdr msg;
	228	struct iovec iov[1];
56f36fe5	229	ssize_t ret;
0d37f2bc DG	230
	231	memset(&msg, 0, sizeof(msg));
	232
c2d69327	233	iov[0].iov_base = (void *) buf;
0d37f2bc DG	234	iov[0].iov_len = len;
	235	msg.msg_iov = iov;
	236	msg.msg_iovlen = 1;
	237
56f36fe5 JG	238	while (iov[0].iov_len) {
	239	ret = sendmsg(sock, &msg, 0);
	240	if (ret < 0) {
	241	if (errno == EINTR) {
	242	continue;
	243	} else {
	244	/*
	245	* Only warn about EPIPE when quiet mode is
	246	* deactivated.
	247	* We consider EPIPE as expected.
	248	*/
	249	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	250	PERROR("sendmsg");
	251	}
	252	goto end;
	253	}
0d37f2bc	254	}
56f36fe5 JG	255	iov[0].iov_len -= ret;
56f36fe5 JG	256	iov[0].iov_base += ret;
0d37f2bc	257	}
56f36fe5 JG	258	ret = len;
56f36fe5 JG	259	end:
0d37f2bc DG	260	return ret;
	261	}
	262
	263	/*
	264	* Shutdown cleanly a unix socket.
	265	*/
90e535ef	266	LTTNG_HIDDEN
0d37f2bc DG	267	int lttcomm_close_unix_sock(int sock)
	268	{
	269	int ret, closeret;
	270
	271	/* Shutdown receptions and transmissions */
	272	ret = shutdown(sock, SHUT_RDWR);
	273	if (ret < 0) {
	274	PERROR("shutdown");
	275	}
	276
	277	closeret = close(sock);
	278	if (closeret) {
	279	PERROR("close");
	280	}
	281
	282	return ret;
	283	}
	284
	285	/*
	286	* Send a message accompanied by fd(s) over a unix socket.
	287	*
	288	* Returns the size of data sent, or negative error value.
	289	*/
90e535ef	290	LTTNG_HIDDEN
0d37f2bc DG	291	ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	292	{
	293	struct msghdr msg;
	294	struct cmsghdr *cmptr;
	295	struct iovec iov[1];
	296	ssize_t ret = -1;
	297	unsigned int sizeof_fds = nb_fd * sizeof(int);
	298	char tmp[CMSG_SPACE(sizeof_fds)];
	299	char dummy = 0;
	300
	301	memset(&msg, 0, sizeof(msg));
c617c0c6	302	memset(tmp, 0, CMSG_SPACE(sizeof_fds) * sizeof(char));
0d37f2bc DG	303
	304	if (nb_fd > LTTCOMM_MAX_SEND_FDS)
	305	return -EINVAL;
	306
	307	msg.msg_control = (caddr_t)tmp;
	308	msg.msg_controllen = CMSG_LEN(sizeof_fds);
	309
	310	cmptr = CMSG_FIRSTHDR(&msg);
1d8d0328 MJ	311	if (!cmptr) {
	312	return -1;
	313	}
0d37f2bc DG	314	cmptr->cmsg_level = SOL_SOCKET;
	315	cmptr->cmsg_type = SCM_RIGHTS;
	316	cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
	317	memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
	318	/* Sum of the length of all control messages in the buffer: */
	319	msg.msg_controllen = cmptr->cmsg_len;
	320
	321	iov[0].iov_base = &dummy;
	322	iov[0].iov_len = 1;
	323	msg.msg_iov = iov;
	324	msg.msg_iovlen = 1;
	325
	326	do {
	327	ret = sendmsg(sock, &msg, 0);
	328	} while (ret < 0 && errno == EINTR);
	329	if (ret < 0) {
	330	/*
	331	* Only warn about EPIPE when quiet mode is deactivated.
	332	* We consider EPIPE as expected.
	333	*/
	334	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	335	PERROR("sendmsg");
	336	}
	337	}
	338	return ret;
	339	}
	340
	341	/*
	342	* Recv a message accompanied by fd(s) from a unix socket.
	343	*
	344	* Returns the size of received data, or negative error value.
	345	*
	346	* Expect at most "nb_fd" file descriptors. Returns the number of fd
	347	* actually received in nb_fd.
	348	*/
90e535ef	349	LTTNG_HIDDEN
0d37f2bc DG	350	ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	351	{
	352	struct iovec iov[1];
	353	ssize_t ret = 0;
	354	struct cmsghdr *cmsg;
	355	size_t sizeof_fds = nb_fd * sizeof(int);
	356	char recv_fd[CMSG_SPACE(sizeof_fds)];
	357	struct msghdr msg;
	358	char dummy;
	359
	360	memset(&msg, 0, sizeof(msg));
	361
	362	/* Prepare to receive the structures */
	363	iov[0].iov_base = &dummy;
	364	iov[0].iov_len = 1;
	365	msg.msg_iov = iov;
	366	msg.msg_iovlen = 1;
	367	msg.msg_control = recv_fd;
	368	msg.msg_controllen = sizeof(recv_fd);
	369
	370	do {
	371	ret = recvmsg(sock, &msg, 0);
	372	} while (ret < 0 && errno == EINTR);
	373	if (ret < 0) {
	374	PERROR("recvmsg fds");
	375	goto end;
	376	}
	377	if (ret != 1) {
	378	fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
	379	ret, 1);
	380	goto end;
	381	}
	382	if (msg.msg_flags & MSG_CTRUNC) {
	383	fprintf(stderr, "Error: Control message truncated.\n");
	384	ret = -1;
	385	goto end;
	386	}
	387	cmsg = CMSG_FIRSTHDR(&msg);
	388	if (!cmsg) {
	389	fprintf(stderr, "Error: Invalid control message header\n");
	390	ret = -1;
	391	goto end;
	392	}
	393	if (cmsg->cmsg_level != SOL_SOCKET \|\| cmsg->cmsg_type != SCM_RIGHTS) {
	394	fprintf(stderr, "Didn't received any fd\n");
	395	ret = -1;
	396	goto end;
	397	}
	398	if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
	399	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	400	(size_t) cmsg->cmsg_len, (size_t) CMSG_LEN(sizeof_fds));
	401	ret = -1;
	402	goto end;
	403	}
	404	memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
	405	ret = sizeof_fds;
	406	end:
	407	return ret;
	408	}
	409
	410	/*
	411	* Send a message with credentials over a unix socket.
	412	*
	413	* Returns the size of data sent, or negative error value.
414	*/
90e535ef	415	LTTNG_HIDDEN
0d37f2bc DG	416	ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
	417	{
	418	struct msghdr msg;
	419	struct iovec iov[1];
	420	ssize_t ret = -1;
	421	#ifdef __linux__
	422	struct cmsghdr *cmptr;
	423	size_t sizeof_cred = sizeof(lttng_sock_cred);
	424	char anc_buf[CMSG_SPACE(sizeof_cred)];
	425	lttng_sock_cred *creds;
8bbffd54 MJ	426
8bbffd54 MJ	427	memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));
0d37f2bc DG	428	#endif /* __linux__ */
	429
	430	memset(&msg, 0, sizeof(msg));
	431
	432	iov[0].iov_base = buf;
	433	iov[0].iov_len = len;
	434	msg.msg_iov = iov;
	435	msg.msg_iovlen = 1;
	436
	437	#ifdef __linux__
	438	msg.msg_control = (caddr_t) anc_buf;
	439	msg.msg_controllen = CMSG_LEN(sizeof_cred);
	440
	441	cmptr = CMSG_FIRSTHDR(&msg);
1d8d0328 MJ	442	if (!cmptr) {
	443	return -1;
	444	}
0d37f2bc DG	445	cmptr->cmsg_level = SOL_SOCKET;
	446	cmptr->cmsg_type = LTTNG_SOCK_CREDS;
	447	cmptr->cmsg_len = CMSG_LEN(sizeof_cred);
	448
	449	creds = (lttng_sock_cred*) CMSG_DATA(cmptr);
	450
	451	LTTNG_SOCK_SET_UID_CRED(creds, geteuid());
	452	LTTNG_SOCK_SET_GID_CRED(creds, getegid());
	453	LTTNG_SOCK_SET_PID_CRED(creds, getpid());
	454	#endif /* __linux__ */
	455
	456	do {
	457	ret = sendmsg(sock, &msg, 0);
	458	} while (ret < 0 && errno == EINTR);
	459	if (ret < 0) {
	460	/*
	461	* Only warn about EPIPE when quiet mode is deactivated.
	462	* We consider EPIPE as expected.
	463	*/
	464	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	465	PERROR("sendmsg");
	466	}
	467	}
	468	return ret;
	469	}
	470
	471	/*
	472	* Recv a message accompanied with credentials from a unix socket.
	473	*
	474	* Returns the size of received data, or negative error value.
	475	*/
90e535ef	476	LTTNG_HIDDEN
0d37f2bc DG	477	ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
	478	lttng_sock_cred *creds)
	479	{
	480	struct msghdr msg;
	481	struct iovec iov[1];
	482	ssize_t ret;
4100e49a	483	size_t len_last;
0d37f2bc DG	484	#ifdef __linux__
	485	struct cmsghdr *cmptr;
	486	size_t sizeof_cred = sizeof(lttng_sock_cred);
	487	char anc_buf[CMSG_SPACE(sizeof_cred)];
	488	#endif /* __linux__ */
	489
	490	memset(&msg, 0, sizeof(msg));
	491
	492	/* Not allowed */
	493	if (creds == NULL) {
	494	ret = -1;
	495	goto end;
	496	}
	497
	498	/* Prepare to receive the structures */
	499	iov[0].iov_base = buf;
	500	iov[0].iov_len = len;
	501	msg.msg_iov = iov;
	502	msg.msg_iovlen = 1;
	503
	504	#ifdef __linux__
	505	msg.msg_control = anc_buf;
	506	msg.msg_controllen = sizeof(anc_buf);
	507	#endif /* __linux__ */
	508
	509	do {
4100e49a	510	len_last = iov[0].iov_len;
0d37f2bc	511	ret = recvmsg(sock, &msg, 0);
4100e49a DG	512	if (ret > 0) {
	513	iov[0].iov_base += ret;
	514	iov[0].iov_len -= ret;
	515	assert(ret <= len_last);
	516	}
	517	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
0d37f2bc DG	518	if (ret < 0) {
	519	PERROR("recvmsg fds");
	520	goto end;
4100e49a DG	521	} else if (ret > 0) {
4100e49a DG	522	ret = len;
0d37f2bc	523	}
4100e49a	524	/* Else ret = 0 meaning an orderly shutdown. */
0d37f2bc DG	525
	526	#ifdef __linux__
	527	if (msg.msg_flags & MSG_CTRUNC) {
	528	fprintf(stderr, "Error: Control message truncated.\n");
	529	ret = -1;
	530	goto end;
	531	}
	532
	533	cmptr = CMSG_FIRSTHDR(&msg);
	534	if (cmptr == NULL) {
	535	fprintf(stderr, "Error: Invalid control message header\n");
	536	ret = -1;
	537	goto end;
	538	}
	539
	540	if (cmptr->cmsg_level != SOL_SOCKET \|\|
	541	cmptr->cmsg_type != LTTNG_SOCK_CREDS) {
	542	fprintf(stderr, "Didn't received any credentials\n");
	543	ret = -1;
	544	goto end;
	545	}
	546
	547	if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) {
	548	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	549	(size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred));
	550	ret = -1;
	551	goto end;
	552	}
	553
	554	memcpy(creds, CMSG_DATA(cmptr), sizeof_cred);
bfa419e4	555	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__) \|\| defined(__APPLE__))
0d37f2bc DG	556	{
	557	int peer_ret;
	558
	559	peer_ret = getpeereid(sock, &creds->uid, &creds->gid);
	560	if (peer_ret != 0) {
	561	return peer_ret;
	562	}
	563	}
	564	#else
	565	#error "Please implement credential support for your OS."
	566	#endif /* __linux__ */
	567
	568	end:
	569	return ret;
	570	}
	571
	572	/*
	573	* Set socket option to use credentials passing.
	574	*/
	575	#ifdef __linux__
90e535ef	576	LTTNG_HIDDEN
0d37f2bc DG	577	int lttcomm_setsockopt_creds_unix_sock(int sock)
	578	{
	579	int ret, on = 1;
	580
	581	/* Set socket for credentials retrieval */
	582	ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
	583	if (ret < 0) {
	584	PERROR("setsockopt creds unix sock");
	585	}
	586	return ret;
	587	}
bfa419e4	588	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__) \|\| defined(__APPLE__))
90e535ef	589	LTTNG_HIDDEN
0d37f2bc DG	590	int lttcomm_setsockopt_creds_unix_sock(int sock)
	591	{
	592	return 0;
	593	}
	594	#else
	595	#error "Please implement credential support for your OS."
	596	#endif /* __linux__ */