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

/*
 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
 * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#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;
}

/*
 * Receive data of size len in put that data into the buf param. Using recvmsg
 * API. Only use with sockets set in non-blocking mode.
 *
 * NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
 * poll set. The poll loop will handle the EPIPE original cause.
 *
 * Return the size of received data.
 */
LTTNG_HIDDEN
ssize_t lttcomm_recv_unix_sock_non_block(int sock, void *buf, size_t len)
{
	struct msghdr msg;
	struct iovec iov[1];
	ssize_t ret;

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

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

retry:
	ret = lttng_recvmsg_nosigpipe(sock, &msg);
	if (ret < 0) {
		if (errno == EINTR) {
			goto retry;
		} else {
			/*
			 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
			 */
			if (errno == EAGAIN || errno == EWOULDBLOCK ||
					errno == EPIPE) {
				/*
				 * Nothing was recv.
				 */
				ret = 0;
				goto end;
			}

			/* Unexpected error */
			PERROR("recvmsg");
			ret = -1;
			goto end;
		}
	}
	ret = len;
end:
	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;
}

/*
 * Send buf data of size len. Using sendmsg API.
 * Only use with non-blocking sockets. The difference with the blocking version
 * of the function is that this one does not retry to send on partial sends,
 * except if the interruption was caused by a signal (EINTR).
 *
 * NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
 * poll set. The poll loop will handle the EPIPE original cause.
 *
 * Return the size of sent data.
 */
LTTNG_HIDDEN
ssize_t lttcomm_send_unix_sock_non_block(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;

retry:
	ret = sendmsg(sock, &msg, 0);
	if (ret < 0) {
		if (errno == EINTR) {
			goto retry;
		} else {
			/*
			 * We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
			 */
			if (errno == EAGAIN || errno == EWOULDBLOCK ||
					errno == EPIPE) {
				/*
				 * This can happen in non blocking mode.
				 * Nothing was sent.
				 */
				ret = 0;
				goto end;
			}

			/* Unexpected error */
			PERROR("sendmsg");
			ret = -1;
			goto end;
		}
	}
	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, const 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, sizeof(tmp));

	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);

#ifdef __linux__
/* Account for the struct ucred cmsg in the buffer size */
#define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
#else
#define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
#endif /* __linux__ */

	char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE];
	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;

	cmsg = (struct cmsghdr *) recv_buf;
	cmsg->cmsg_len = CMSG_LEN(sizeof_fds);
	cmsg->cmsg_level = SOL_SOCKET;
	cmsg->cmsg_type = SCM_RIGHTS;

	msg.msg_control = cmsg;
	msg.msg_controllen = CMSG_LEN(sizeof(recv_buf));
	msg.msg_flags = 0;

	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;
	}

	/*
	 * If the socket was configured with SO_PASSCRED, the kernel will add a
	 * control message (cmsg) to the ancillary data of the unix socket. We
	 * need to expect a cmsg of the SCM_CREDENTIALS as the first control
	 * message.
	 */
	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
		if (cmsg->cmsg_level != SOL_SOCKET) {
			fprintf(stderr, "Error: The socket needs to be of type SOL_SOCKET\n");
			ret = -1;
			goto end;
		}
		if (cmsg->cmsg_type == SCM_RIGHTS) {
			/*
			 * We found the controle message for file descriptors,
			 * now copy the fds to the fds ptr and return success.
			 */
			if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
				fprintf(stderr, "Error: Received %zu bytes of"
					"ancillary data for FDs, 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;
			goto end;
		}
#ifdef __linux__
		if (cmsg->cmsg_type == SCM_CREDENTIALS) {
			/*
			 * Expect credentials to be sent when expecting fds even
			 * if no credential were include in the send(). The
			 * kernel adds them...
			 */
			ret = -1;
		}
#endif /* __linux__ */
	}
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	1	/*
ab5be9fa MJ	2	* Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
ab5be9fa MJ	3	* Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
0d37f2bc	4	*
ab5be9fa	5	* SPDX-License-Identifier: GPL-2.0-only
0d37f2bc	6	*
0d37f2bc DG	7	*/
0d37f2bc DG	8
6c1c0768	9	#define _LGPL_SOURCE
0d37f2bc DG	10	#include <assert.h>
	11	#include <limits.h>
	12	#include <stdio.h>
	13	#include <stdlib.h>
	14	#include <string.h>
	15	#include <sys/stat.h>
	16	#include <sys/types.h>
	17	#include <unistd.h>
	18	#include <errno.h>
	19
90e535ef	20	#include <common/common.h>
2038dd6c	21	#include <common/sessiond-comm/sessiond-comm.h>
0d37f2bc DG	22
	23	#include "unix.h"
	24
	25	/*
	26	* Connect to unix socket using the path name.
	27	*/
90e535ef	28	LTTNG_HIDDEN
0d37f2bc DG	29	int lttcomm_connect_unix_sock(const char *pathname)
0d37f2bc DG	30	{
665886a6	31	struct sockaddr_un s_un;
0d37f2bc DG	32	int fd, ret, closeret;
0d37f2bc DG	33
7f8bf467 JG	34	if (strlen(pathname) >= sizeof(s_un.sun_path)) {
	35	ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
	36	pathname, strlen(pathname) + 1,
	37	sizeof(s_un.sun_path));
	38	ret = -ENAMETOOLONG;
	39	goto error;
	40	}
	41
0d37f2bc DG	42	fd = socket(PF_UNIX, SOCK_STREAM, 0);
	43	if (fd < 0) {
	44	PERROR("socket");
	45	ret = fd;
	46	goto error;
	47	}
	48
665886a6 MJ	49	memset(&s_un, 0, sizeof(s_un));
	50	s_un.sun_family = AF_UNIX;
	51	strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
	52	s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
0d37f2bc	53
665886a6	54	ret = connect(fd, (struct sockaddr *) &s_un, sizeof(s_un));
0d37f2bc DG	55	if (ret < 0) {
	56	/*
	57	* Don't print message on connect error, because connect is used in
	58	* normal execution to detect if sessiond is alive.
	59	*/
	60	goto error_connect;
	61	}
	62
	63	return fd;
	64
	65	error_connect:
	66	closeret = close(fd);
	67	if (closeret) {
	68	PERROR("close");
	69	}
	70	error:
	71	return ret;
	72	}
	73
	74	/*
	75	* Do an accept(2) on the sock and return the new file descriptor. The socket
	76	* MUST be bind(2) before.
	77	*/
90e535ef	78	LTTNG_HIDDEN
0d37f2bc DG	79	int lttcomm_accept_unix_sock(int sock)
	80	{
	81	int new_fd;
665886a6	82	struct sockaddr_un s_un;
50786a72	83	socklen_t len = sizeof(s_un);
0d37f2bc DG	84
0d37f2bc DG	85	/* Blocking call */
665886a6	86	new_fd = accept(sock, (struct sockaddr *) &s_un, &len);
0d37f2bc DG	87	if (new_fd < 0) {
	88	PERROR("accept");
	89	}
	90
	91	return new_fd;
	92	}
	93
7567352f MD	94	LTTNG_HIDDEN
	95	int lttcomm_create_anon_unix_socketpair(int *fds)
	96	{
	97	if (socketpair(PF_UNIX, SOCK_STREAM, 0, fds) < 0) {
	98	PERROR("socketpair");
	99	return -1;
	100	}
	101	return 0;
	102	}
	103
0d37f2bc DG	104	/*
	105	* Creates a AF_UNIX local socket using pathname bind the socket upon creation
	106	* and return the fd.
	107	*/
90e535ef	108	LTTNG_HIDDEN
0d37f2bc DG	109	int lttcomm_create_unix_sock(const char *pathname)
0d37f2bc DG	110	{
665886a6	111	struct sockaddr_un s_un;
7f8bf467	112	int fd = -1;
0d37f2bc DG	113	int ret = -1;
0d37f2bc DG	114
7f8bf467 JG	115	if (strlen(pathname) >= sizeof(s_un.sun_path)) {
	116	ERR("unix socket address (\"%s\") is longer than the platform's limit (%zu > %zu).",
	117	pathname, strlen(pathname) + 1,
	118	sizeof(s_un.sun_path));
	119	ret = -ENAMETOOLONG;
	120	goto error;
	121	}
	122
0d37f2bc DG	123	/* Create server socket */
	124	if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
	125	PERROR("socket");
	126	goto error;
	127	}
	128
665886a6 MJ	129	memset(&s_un, 0, sizeof(s_un));
	130	s_un.sun_family = AF_UNIX;
	131	strncpy(s_un.sun_path, pathname, sizeof(s_un.sun_path));
	132	s_un.sun_path[sizeof(s_un.sun_path) - 1] = '\0';
0d37f2bc DG	133
	134	/* Unlink the old file if present */
	135	(void) unlink(pathname);
665886a6	136	ret = bind(fd, (struct sockaddr *) &s_un, sizeof(s_un));
0d37f2bc DG	137	if (ret < 0) {
	138	PERROR("bind");
	139	goto error;
	140	}
	141
	142	return fd;
	143
	144	error:
17e75273 DG	145	if (fd >= 0) {
	146	if (close(fd) < 0) {
	147	PERROR("close create unix sock");
	148	}
	149	}
0d37f2bc DG	150	return ret;
	151	}
	152
	153	/*
	154	* Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
	155	*/
90e535ef	156	LTTNG_HIDDEN
0d37f2bc DG	157	int lttcomm_listen_unix_sock(int sock)
	158	{
	159	int ret;
	160
	161	ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
	162	if (ret < 0) {
	163	PERROR("listen");
	164	}
	165
	166	return ret;
	167	}
	168
	169	/*
	170	* Receive data of size len in put that data into the buf param. Using recvmsg
	171	* API.
	172	*
	173	* Return the size of received data.
	174	*/
90e535ef	175	LTTNG_HIDDEN
0d37f2bc DG	176	ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
	177	{
	178	struct msghdr msg;
	179	struct iovec iov[1];
	180	ssize_t ret = -1;
7c5aef62	181	size_t len_last;
0d37f2bc DG	182
	183	memset(&msg, 0, sizeof(msg));
	184
	185	iov[0].iov_base = buf;
	186	iov[0].iov_len = len;
	187	msg.msg_iov = iov;
	188	msg.msg_iovlen = 1;
	189
	190	do {
7c5aef62	191	len_last = iov[0].iov_len;
fbb1fd3a	192	ret = lttng_recvmsg_nosigpipe(sock, &msg);
7c5aef62 DG	193	if (ret > 0) {
	194	iov[0].iov_base += ret;
	195	iov[0].iov_len -= ret;
	196	assert(ret <= len_last);
	197	}
	198	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
0d37f2bc DG	199	if (ret < 0) {
0d37f2bc DG	200	PERROR("recvmsg");
7c5aef62 DG	201	} else if (ret > 0) {
7c5aef62 DG	202	ret = len;
0d37f2bc	203	}
7c5aef62	204	/* Else ret = 0 meaning an orderly shutdown. */
0d37f2bc DG	205
	206	return ret;
	207	}
	208
c72435ad JG	209	/*
	210	* Receive data of size len in put that data into the buf param. Using recvmsg
	211	* API. Only use with sockets set in non-blocking mode.
	212	*
44c180ca JR	213	* NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
	214	* poll set. The poll loop will handle the EPIPE original cause.
	215	*
c72435ad JG	216	* Return the size of received data.
	217	*/
	218	LTTNG_HIDDEN
	219	ssize_t lttcomm_recv_unix_sock_non_block(int sock, void *buf, size_t len)
	220	{
	221	struct msghdr msg;
	222	struct iovec iov[1];
	223	ssize_t ret;
	224
	225	memset(&msg, 0, sizeof(msg));
	226
	227	iov[0].iov_base = buf;
	228	iov[0].iov_len = len;
	229	msg.msg_iov = iov;
	230	msg.msg_iovlen = 1;
	231
	232	retry:
	233	ret = lttng_recvmsg_nosigpipe(sock, &msg);
	234	if (ret < 0) {
	235	if (errno == EINTR) {
	236	goto retry;
	237	} else {
44c180ca JR	238	/*
	239	* We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
	240	*/
	241	if (errno == EAGAIN \|\| errno == EWOULDBLOCK \|\|
	242	errno == EPIPE) {
	243	/*
	244	* Nothing was recv.
	245	*/
	246	ret = 0;
	247	goto end;
c72435ad	248	}
44c180ca JR	249
	250	/* Unexpected error */
	251	PERROR("recvmsg");
	252	ret = -1;
c72435ad JG	253	goto end;
	254	}
	255	}
	256	ret = len;
	257	end:
	258	return ret;
	259	}
	260
0d37f2bc DG	261	/*
	262	* Send buf data of size len. Using sendmsg API.
	263	*
	264	* Return the size of sent data.
	265	*/
90e535ef	266	LTTNG_HIDDEN
c2d69327	267	ssize_t lttcomm_send_unix_sock(int sock, const void *buf, size_t len)
0d37f2bc DG	268	{
	269	struct msghdr msg;
	270	struct iovec iov[1];
c72435ad	271	ssize_t ret;
0d37f2bc DG	272
	273	memset(&msg, 0, sizeof(msg));
	274
c2d69327	275	iov[0].iov_base = (void *) buf;
0d37f2bc DG	276	iov[0].iov_len = len;
	277	msg.msg_iov = iov;
	278	msg.msg_iovlen = 1;
	279
c72435ad JG	280	while (iov[0].iov_len) {
	281	ret = sendmsg(sock, &msg, 0);
	282	if (ret < 0) {
	283	if (errno == EINTR) {
	284	continue;
	285	} else {
	286	/*
	287	* Only warn about EPIPE when quiet mode is
	288	* deactivated.
	289	* We consider EPIPE as expected.
	290	*/
	291	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	292	PERROR("sendmsg");
	293	}
	294	goto end;
	295	}
	296	}
	297	iov[0].iov_len -= ret;
	298	iov[0].iov_base += ret;
	299	}
	300	ret = len;
	301	end:
	302	return ret;
	303	}
	304
	305	/*
	306	* Send buf data of size len. Using sendmsg API.
	307	* Only use with non-blocking sockets. The difference with the blocking version
	308	* of the function is that this one does not retry to send on partial sends,
	309	* except if the interruption was caused by a signal (EINTR).
	310	*
44c180ca JR	311	* NOTE: EPIPE errors are NOT reported. This call expects the socket to be in a
	312	* poll set. The poll loop will handle the EPIPE original cause.
	313	*
c72435ad JG	314	* Return the size of sent data.
	315	*/
	316	LTTNG_HIDDEN
	317	ssize_t lttcomm_send_unix_sock_non_block(int sock, const void *buf, size_t len)
	318	{
	319	struct msghdr msg;
	320	struct iovec iov[1];
	321	ssize_t ret;
	322
	323	memset(&msg, 0, sizeof(msg));
	324
	325	iov[0].iov_base = (void *) buf;
	326	iov[0].iov_len = len;
	327	msg.msg_iov = iov;
	328	msg.msg_iovlen = 1;
	329
	330	retry:
0d37f2bc DG	331	ret = sendmsg(sock, &msg, 0);
0d37f2bc DG	332	if (ret < 0) {
c72435ad JG	333	if (errno == EINTR) {
	334	goto retry;
	335	} else {
44c180ca JR	336	/*
	337	* We consider EPIPE and EAGAIN/EWOULDBLOCK as expected.
	338	*/
	339	if (errno == EAGAIN \|\| errno == EWOULDBLOCK \|\|
	340	errno == EPIPE) {
	341	/*
	342	* This can happen in non blocking mode.
	343	* Nothing was sent.
	344	*/
	345	ret = 0;
	346	goto end;
c72435ad	347	}
44c180ca JR	348
	349	/* Unexpected error */
	350	PERROR("sendmsg");
	351	ret = -1;
c72435ad	352	goto end;
0d37f2bc DG	353	}
0d37f2bc DG	354	}
c72435ad JG	355	ret = len;
c72435ad JG	356	end:
0d37f2bc DG	357	return ret;
	358	}
	359
	360	/*
	361	* Shutdown cleanly a unix socket.
	362	*/
90e535ef	363	LTTNG_HIDDEN
0d37f2bc DG	364	int lttcomm_close_unix_sock(int sock)
	365	{
	366	int ret, closeret;
	367
	368	/* Shutdown receptions and transmissions */
	369	ret = shutdown(sock, SHUT_RDWR);
	370	if (ret < 0) {
	371	PERROR("shutdown");
	372	}
	373
	374	closeret = close(sock);
	375	if (closeret) {
	376	PERROR("close");
	377	}
	378
	379	return ret;
	380	}
	381
	382	/*
	383	* Send a message accompanied by fd(s) over a unix socket.
	384	*
	385	* Returns the size of data sent, or negative error value.
	386	*/
90e535ef	387	LTTNG_HIDDEN
ac2f30af	388	ssize_t lttcomm_send_fds_unix_sock(int sock, const int *fds, size_t nb_fd)
0d37f2bc DG	389	{
	390	struct msghdr msg;
	391	struct cmsghdr *cmptr;
	392	struct iovec iov[1];
	393	ssize_t ret = -1;
	394	unsigned int sizeof_fds = nb_fd * sizeof(int);
	395	char tmp[CMSG_SPACE(sizeof_fds)];
	396	char dummy = 0;
	397
	398	memset(&msg, 0, sizeof(msg));
b3f35e02	399	memset(tmp, 0, sizeof(tmp));
0d37f2bc DG	400
	401	if (nb_fd > LTTCOMM_MAX_SEND_FDS)
	402	return -EINVAL;
	403
	404	msg.msg_control = (caddr_t)tmp;
	405	msg.msg_controllen = CMSG_LEN(sizeof_fds);
	406
	407	cmptr = CMSG_FIRSTHDR(&msg);
1d8d0328 MJ	408	if (!cmptr) {
	409	return -1;
	410	}
b3f35e02	411
0d37f2bc DG	412	cmptr->cmsg_level = SOL_SOCKET;
	413	cmptr->cmsg_type = SCM_RIGHTS;
	414	cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
	415	memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
	416	/* Sum of the length of all control messages in the buffer: */
	417	msg.msg_controllen = cmptr->cmsg_len;
	418
	419	iov[0].iov_base = &dummy;
	420	iov[0].iov_len = 1;
	421	msg.msg_iov = iov;
	422	msg.msg_iovlen = 1;
	423
	424	do {
	425	ret = sendmsg(sock, &msg, 0);
	426	} while (ret < 0 && errno == EINTR);
	427	if (ret < 0) {
	428	/*
	429	* Only warn about EPIPE when quiet mode is deactivated.
	430	* We consider EPIPE as expected.
	431	*/
	432	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	433	PERROR("sendmsg");
	434	}
	435	}
	436	return ret;
	437	}
	438
	439	/*
	440	* Recv a message accompanied by fd(s) from a unix socket.
	441	*
	442	* Returns the size of received data, or negative error value.
	443	*
	444	* Expect at most "nb_fd" file descriptors. Returns the number of fd
	445	* actually received in nb_fd.
	446	*/
90e535ef	447	LTTNG_HIDDEN
0d37f2bc DG	448	ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
	449	{
	450	struct iovec iov[1];
	451	ssize_t ret = 0;
	452	struct cmsghdr *cmsg;
	453	size_t sizeof_fds = nb_fd * sizeof(int);
b3f35e02	454
ba49ae8c MJ	455	#ifdef __linux__
	456	/* Account for the struct ucred cmsg in the buffer size */
	457	#define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds) + CMSG_SPACE(sizeof(struct ucred))
	458	#else
	459	#define LTTNG_SOCK_RECV_FDS_BUF_SIZE CMSG_SPACE(sizeof_fds)
	460	#endif /* __linux__ */
	461
	462	char recv_buf[LTTNG_SOCK_RECV_FDS_BUF_SIZE];
0d37f2bc DG	463	struct msghdr msg;
	464	char dummy;
	465
	466	memset(&msg, 0, sizeof(msg));
	467
	468	/* Prepare to receive the structures */
	469	iov[0].iov_base = &dummy;
	470	iov[0].iov_len = 1;
	471	msg.msg_iov = iov;
	472	msg.msg_iovlen = 1;
b3f35e02 FD	473
	474	cmsg = (struct cmsghdr *) recv_buf;
	475	cmsg->cmsg_len = CMSG_LEN(sizeof_fds);
	476	cmsg->cmsg_level = SOL_SOCKET;
	477	cmsg->cmsg_type = SCM_RIGHTS;
	478
	479	msg.msg_control = cmsg;
	480	msg.msg_controllen = CMSG_LEN(sizeof(recv_buf));
	481	msg.msg_flags = 0;
0d37f2bc DG	482
	483	do {
	484	ret = recvmsg(sock, &msg, 0);
	485	} while (ret < 0 && errno == EINTR);
	486	if (ret < 0) {
	487	PERROR("recvmsg fds");
	488	goto end;
	489	}
b3f35e02	490
0d37f2bc DG	491	if (ret != 1) {
	492	fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
	493	ret, 1);
	494	goto end;
	495	}
b3f35e02	496
0d37f2bc DG	497	if (msg.msg_flags & MSG_CTRUNC) {
	498	fprintf(stderr, "Error: Control message truncated.\n");
	499	ret = -1;
	500	goto end;
	501	}
b3f35e02 FD	502
	503	/*
	504	* If the socket was configured with SO_PASSCRED, the kernel will add a
	505	* control message (cmsg) to the ancillary data of the unix socket. We
	506	* need to expect a cmsg of the SCM_CREDENTIALS as the first control
	507	* message.
	508	*/
	509	for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
b3f35e02 FD	510	if (cmsg->cmsg_level != SOL_SOCKET) {
	511	fprintf(stderr, "Error: The socket needs to be of type SOL_SOCKET\n");
	512	ret = -1;
	513	goto end;
	514	}
	515	if (cmsg->cmsg_type == SCM_RIGHTS) {
	516	/*
	517	* We found the controle message for file descriptors,
	518	* now copy the fds to the fds ptr and return success.
	519	*/
	520	if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
	521	fprintf(stderr, "Error: Received %zu bytes of"
	522	"ancillary data for FDs, expected %zu\n",
	523	(size_t) cmsg->cmsg_len,
	524	(size_t) CMSG_LEN(sizeof_fds));
	525	ret = -1;
	526	goto end;
	527	}
	528	memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
	529	ret = sizeof_fds;
	530	goto end;
	531	}
ba49ae8c	532	#ifdef __linux__
b3f35e02 FD	533	if (cmsg->cmsg_type == SCM_CREDENTIALS) {
	534	/*
	535	* Expect credentials to be sent when expecting fds even
	536	* if no credential were include in the send(). The
	537	* kernel adds them...
	538	*/
b3f35e02 FD	539	ret = -1;
b3f35e02 FD	540	}
ba49ae8c	541	#endif /* __linux__ */
0d37f2bc	542	}
0d37f2bc DG	543	end:
	544	return ret;
	545	}
	546
	547	/*
	548	* Send a message with credentials over a unix socket.
	549	*
	550	* Returns the size of data sent, or negative error value.
	551	*/
90e535ef	552	LTTNG_HIDDEN
0d37f2bc DG	553	ssize_t lttcomm_send_creds_unix_sock(int sock, void *buf, size_t len)
	554	{
	555	struct msghdr msg;
	556	struct iovec iov[1];
	557	ssize_t ret = -1;
	558	#ifdef __linux__
	559	struct cmsghdr *cmptr;
	560	size_t sizeof_cred = sizeof(lttng_sock_cred);
	561	char anc_buf[CMSG_SPACE(sizeof_cred)];
	562	lttng_sock_cred *creds;
8bbffd54 MJ	563
8bbffd54 MJ	564	memset(anc_buf, 0, CMSG_SPACE(sizeof_cred) * sizeof(char));
0d37f2bc DG	565	#endif /* __linux__ */
	566
	567	memset(&msg, 0, sizeof(msg));
	568
	569	iov[0].iov_base = buf;
	570	iov[0].iov_len = len;
	571	msg.msg_iov = iov;
	572	msg.msg_iovlen = 1;
	573
	574	#ifdef __linux__
	575	msg.msg_control = (caddr_t) anc_buf;
	576	msg.msg_controllen = CMSG_LEN(sizeof_cred);
	577
	578	cmptr = CMSG_FIRSTHDR(&msg);
1d8d0328 MJ	579	if (!cmptr) {
	580	return -1;
	581	}
0d37f2bc DG	582	cmptr->cmsg_level = SOL_SOCKET;
	583	cmptr->cmsg_type = LTTNG_SOCK_CREDS;
	584	cmptr->cmsg_len = CMSG_LEN(sizeof_cred);
	585
	586	creds = (lttng_sock_cred*) CMSG_DATA(cmptr);
	587
	588	LTTNG_SOCK_SET_UID_CRED(creds, geteuid());
	589	LTTNG_SOCK_SET_GID_CRED(creds, getegid());
	590	LTTNG_SOCK_SET_PID_CRED(creds, getpid());
	591	#endif /* __linux__ */
	592
	593	do {
	594	ret = sendmsg(sock, &msg, 0);
	595	} while (ret < 0 && errno == EINTR);
	596	if (ret < 0) {
	597	/*
	598	* Only warn about EPIPE when quiet mode is deactivated.
	599	* We consider EPIPE as expected.
	600	*/
	601	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	602	PERROR("sendmsg");
	603	}
	604	}
	605	return ret;
	606	}
	607
	608	/*
	609	* Recv a message accompanied with credentials from a unix socket.
	610	*
	611	* Returns the size of received data, or negative error value.
	612	*/
90e535ef	613	LTTNG_HIDDEN
0d37f2bc DG	614	ssize_t lttcomm_recv_creds_unix_sock(int sock, void *buf, size_t len,
	615	lttng_sock_cred *creds)
	616	{
	617	struct msghdr msg;
	618	struct iovec iov[1];
	619	ssize_t ret;
4100e49a	620	size_t len_last;
0d37f2bc DG	621	#ifdef __linux__
	622	struct cmsghdr *cmptr;
	623	size_t sizeof_cred = sizeof(lttng_sock_cred);
	624	char anc_buf[CMSG_SPACE(sizeof_cred)];
	625	#endif /* __linux__ */
	626
	627	memset(&msg, 0, sizeof(msg));
	628
	629	/* Not allowed */
	630	if (creds == NULL) {
	631	ret = -1;
	632	goto end;
	633	}
	634
	635	/* Prepare to receive the structures */
	636	iov[0].iov_base = buf;
	637	iov[0].iov_len = len;
	638	msg.msg_iov = iov;
	639	msg.msg_iovlen = 1;
	640
	641	#ifdef __linux__
	642	msg.msg_control = anc_buf;
	643	msg.msg_controllen = sizeof(anc_buf);
	644	#endif /* __linux__ */
	645
	646	do {
4100e49a	647	len_last = iov[0].iov_len;
0d37f2bc	648	ret = recvmsg(sock, &msg, 0);
4100e49a DG	649	if (ret > 0) {
	650	iov[0].iov_base += ret;
	651	iov[0].iov_len -= ret;
	652	assert(ret <= len_last);
	653	}
	654	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
0d37f2bc DG	655	if (ret < 0) {
	656	PERROR("recvmsg fds");
	657	goto end;
4100e49a DG	658	} else if (ret > 0) {
4100e49a DG	659	ret = len;
0d37f2bc	660	}
4100e49a	661	/* Else ret = 0 meaning an orderly shutdown. */
0d37f2bc DG	662
	663	#ifdef __linux__
	664	if (msg.msg_flags & MSG_CTRUNC) {
	665	fprintf(stderr, "Error: Control message truncated.\n");
	666	ret = -1;
	667	goto end;
	668	}
	669
	670	cmptr = CMSG_FIRSTHDR(&msg);
	671	if (cmptr == NULL) {
	672	fprintf(stderr, "Error: Invalid control message header\n");
	673	ret = -1;
	674	goto end;
	675	}
	676
	677	if (cmptr->cmsg_level != SOL_SOCKET \|\|
	678	cmptr->cmsg_type != LTTNG_SOCK_CREDS) {
	679	fprintf(stderr, "Didn't received any credentials\n");
	680	ret = -1;
	681	goto end;
	682	}
	683
	684	if (cmptr->cmsg_len != CMSG_LEN(sizeof_cred)) {
	685	fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
	686	(size_t) cmptr->cmsg_len, (size_t) CMSG_LEN(sizeof_cred));
	687	ret = -1;
	688	goto end;
	689	}
	690
	691	memcpy(creds, CMSG_DATA(cmptr), sizeof_cred);
bfa419e4	692	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__) \|\| defined(__APPLE__))
0d37f2bc DG	693	{
	694	int peer_ret;
	695
	696	peer_ret = getpeereid(sock, &creds->uid, &creds->gid);
	697	if (peer_ret != 0) {
	698	return peer_ret;
	699	}
	700	}
	701	#else
	702	#error "Please implement credential support for your OS."
	703	#endif /* __linux__ */
	704
	705	end:
	706	return ret;
	707	}
	708
	709	/*
	710	* Set socket option to use credentials passing.
	711	*/
	712	#ifdef __linux__
90e535ef	713	LTTNG_HIDDEN
0d37f2bc DG	714	int lttcomm_setsockopt_creds_unix_sock(int sock)
	715	{
	716	int ret, on = 1;
	717
	718	/* Set socket for credentials retrieval */
	719	ret = setsockopt(sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
	720	if (ret < 0) {
	721	PERROR("setsockopt creds unix sock");
	722	}
	723	return ret;
	724	}
bfa419e4	725	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__) \|\| defined(__APPLE__))
90e535ef	726	LTTNG_HIDDEN
0d37f2bc DG	727	int lttcomm_setsockopt_creds_unix_sock(int sock)
	728	{
	729	return 0;
	730	}
	731	#else
	732	#error "Please implement credential support for your OS."
	733	#endif /* __linux__ */