[lttng-tools.git] / src / common / sessiond-comm / inet.c

/*
 * Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
 *
 * SPDX-License-Identifier: GPL-2.0-only
 *
 */

#define _LGPL_SOURCE
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
#include <common/compat/time.h>
#include <poll.h>

#include <common/common.h>
#include <common/time.h>
#include <common/compat/errno.h>

#include "inet.h"

#define RECONNECT_DELAY	200	/* ms */

/*
 * INET protocol operations.
 */
static const struct lttcomm_proto_ops inet_ops = {
	.bind = lttcomm_bind_inet_sock,
	.close = lttcomm_close_inet_sock,
	.connect = lttcomm_connect_inet_sock,
	.accept = lttcomm_accept_inet_sock,
	.listen = lttcomm_listen_inet_sock,
	.recvmsg = lttcomm_recvmsg_inet_sock,
	.sendmsg = lttcomm_sendmsg_inet_sock,
};

unsigned long lttcomm_inet_tcp_timeout;

/*
 * Creates an PF_INET socket.
 */
int lttcomm_create_inet_sock(struct lttcomm_sock *sock, int type, int proto)
{
	int val = 1, ret;
	unsigned long timeout;

	/* Create server socket */
	if ((sock->fd = socket(PF_INET, type, proto)) < 0) {
		PERROR("socket inet");
		goto error;
	}

	sock->ops = &inet_ops;

	/*
	 * Set socket option to reuse the address.
	 */
	ret = setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(int));
	if (ret < 0) {
		PERROR("setsockopt inet");
		goto error;
	}
	timeout = lttcomm_get_network_timeout();
	if (timeout) {
		ret = lttcomm_setsockopt_rcv_timeout(sock->fd, timeout);
		if (ret) {
			goto error;
		}
		ret = lttcomm_setsockopt_snd_timeout(sock->fd, timeout);
		if (ret) {
			goto error;
		}
	}

	return 0;

error:
	return -1;
}

/*
 * Bind socket and return.
 */
int lttcomm_bind_inet_sock(struct lttcomm_sock *sock)
{
	struct sockaddr_in sockaddr = sock->sockaddr.addr.sin;

	return bind(sock->fd, &sockaddr, sizeof(sockaddr));
}

static
int connect_no_timeout(struct lttcomm_sock *sock)
{
	struct sockaddr_in sockaddr = sock->sockaddr.addr.sin;

	return connect(sock->fd, &sockaddr, sizeof(sockaddr));
}

static
int connect_with_timeout(struct lttcomm_sock *sock)
{
	unsigned long timeout = lttcomm_get_network_timeout();
	int ret, flags, connect_ret;
	struct timespec orig_time, cur_time;
	unsigned long diff_ms;
	struct sockaddr_in sockaddr;

	ret = fcntl(sock->fd, F_GETFL, 0);
	if (ret == -1) {
		PERROR("fcntl");
		return -1;
	}
	flags = ret;

	/* Set socket to nonblock */
	ret = fcntl(sock->fd, F_SETFL, flags | O_NONBLOCK);
	if (ret == -1) {
		PERROR("fcntl");
		return -1;
	}

	ret = lttng_clock_gettime(CLOCK_MONOTONIC, &orig_time);
	if (ret == -1) {
		PERROR("clock_gettime");
		return -1;
	}

	sockaddr = sock->sockaddr.addr.sin;
	connect_ret = connect(sock->fd, &sockaddr, sizeof(sockaddr));
	if (connect_ret == -1 && errno != EAGAIN && errno != EWOULDBLOCK &&
			errno != EINPROGRESS) {
		goto error;
	} else if (!connect_ret) {
		/* Connect succeeded */
		goto success;
	}

	DBG("Asynchronous connect for sock %d, performing polling with"
			" timeout: %lums", sock->fd, timeout);
	/*
	 * Perform poll loop following EINPROGRESS recommendation from
	 * connect(2) man page.
	 */
	do {
		struct pollfd fds;

		fds.fd = sock->fd;
		fds.events = POLLOUT;
		fds.revents = 0;
		ret = poll(&fds, 1, RECONNECT_DELAY);
		if (ret < 0) {
			goto error;
		} else if (ret > 0) {
			int optval;
			socklen_t optval_len = sizeof(optval);

			if (!(fds.revents & POLLOUT)) {
				/* Either hup or error */
				errno = EPIPE;
				goto error;
			}
			/* got something */
			ret = getsockopt(sock->fd, SOL_SOCKET,
				SO_ERROR, &optval, &optval_len);
			if (ret) {
				PERROR("getsockopt");
				goto error;
			}
			if (!optval) {
				connect_ret = 0;
				goto success;
			} else {
				/* Get actual connect() errno from opt_val */
				errno = optval;
				goto error;
			}
		}
		/* ret == 0: timeout */
		ret = lttng_clock_gettime(CLOCK_MONOTONIC, &cur_time);
		if (ret == -1) {
			PERROR("clock_gettime");
			connect_ret = ret;
			goto error;
		}
		if (timespec_to_ms(timespec_abs_diff(cur_time, orig_time), &diff_ms) < 0) {
			ERR("timespec_to_ms input overflows milliseconds output");
			connect_ret = -1;
			goto error;
		}
	} while (diff_ms < timeout);

	/* Timeout */
	errno = ETIMEDOUT;
	connect_ret = -1;

success:
	/* Restore initial flags */
	ret = fcntl(sock->fd, F_SETFL, flags);
	if (ret == -1) {
		PERROR("fcntl");
		/* Continue anyway */
	}
error:
	return connect_ret;
}

/*
 * Connect PF_INET socket.
 */
int lttcomm_connect_inet_sock(struct lttcomm_sock *sock)
{
	int ret, closeret;

	if (lttcomm_get_network_timeout()) {
		ret = connect_with_timeout(sock);
	} else {
		ret = connect_no_timeout(sock);
	}
	if (ret < 0) {
		PERROR("connect");
		goto error_connect;
	}

	return ret;

error_connect:
	closeret = close(sock->fd);
	if (closeret) {
		PERROR("close inet");
	}

	return ret;
}

/*
 * Do an accept(2) on the sock and return the new lttcomm socket. The socket
 * MUST be bind(2) before.
 */
struct lttcomm_sock *lttcomm_accept_inet_sock(struct lttcomm_sock *sock)
{
	int new_fd;
	socklen_t len;
	struct lttcomm_sock *new_sock;
	unsigned long timeout;
	struct sockaddr_in new_addr = {};

	if (sock->proto == LTTCOMM_SOCK_UDP) {
		/*
		 * accept(2) does not exist for UDP so simply return the passed socket.
		 */
		new_sock = sock;
		goto end;
	}

	new_sock = lttcomm_alloc_sock(sock->proto);
	if (new_sock == NULL) {
		goto error;
	}

	len = sizeof(new_addr);

	/* Blocking call */
	new_fd = accept(sock->fd, (struct sockaddr *) &new_addr, &len);
	if (new_fd < 0) {
		PERROR("accept inet");
		goto error;
	}
	new_sock->sockaddr.addr.sin = new_addr;
	timeout = lttcomm_get_network_timeout();
	if (timeout) {
		int ret;

		ret = lttcomm_setsockopt_rcv_timeout(new_fd, timeout);
		if (ret) {
			goto error_close;
		}
		ret = lttcomm_setsockopt_snd_timeout(new_fd, timeout);
		if (ret) {
			goto error_close;
		}
	}

	new_sock->fd = new_fd;
	new_sock->ops = &inet_ops;

end:
	return new_sock;

error_close:
	if (close(new_fd) < 0) {
		PERROR("accept inet close fd");
	}

error:
	free(new_sock);
	return NULL;
}

/*
 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
 */
int lttcomm_listen_inet_sock(struct lttcomm_sock *sock, int backlog)
{
	int ret;

	if (sock->proto == LTTCOMM_SOCK_UDP) {
		/* listen(2) does not exist for UDP so simply return success. */
		ret = 0;
		goto end;
	}

	/* Default listen backlog */
	if (backlog <= 0) {
		backlog = LTTNG_SESSIOND_COMM_MAX_LISTEN;
	}

	ret = listen(sock->fd, backlog);
	if (ret < 0) {
		PERROR("listen inet");
	}

end:
	return ret;
}

/*
 * Receive data of size len in put that data into the buf param. Using recvmsg
 * API.
 *
 * Return the size of received data.
 */
ssize_t lttcomm_recvmsg_inet_sock(struct lttcomm_sock *sock, void *buf,
		size_t len, int flags)
{
	struct msghdr msg;
	struct iovec iov[1];
	ssize_t ret = -1;
	size_t len_last;
	struct sockaddr_in addr = sock->sockaddr.addr.sin;

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

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

	msg.msg_name = (struct sockaddr *) &addr;
	msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);

	do {
		len_last = iov[0].iov_len;
		ret = recvmsg(sock->fd, &msg, flags);
		if (ret > 0) {
			if (flags & MSG_DONTWAIT) {
				goto end;
			}
			iov[0].iov_base += ret;
			iov[0].iov_len -= ret;
			LTTNG_ASSERT(ret <= len_last);
		}
	} while ((ret > 0 && ret < len_last) || (ret < 0 && errno == EINTR));

	if (ret < 0) {
		if (errno == EAGAIN && flags & MSG_DONTWAIT) {
			/*
			 * EAGAIN is expected in non-blocking mode and should
			 * not be reported as an error. Moreover, if no data
			 * was read, 0 must not be returned as it would be
			 * interpreted as an orderly shutdown of the socket.
			 */
			goto end;
		}
		PERROR("recvmsg inet");
	} else if (ret > 0) {
		ret = len;
	}
	/* Else ret = 0 meaning an orderly shutdown. */
end:
	return ret;
}

/*
 * Send buf data of size len. Using sendmsg API.
 *
 * Return the size of sent data.
 */
ssize_t lttcomm_sendmsg_inet_sock(struct lttcomm_sock *sock, const void *buf,
		size_t len, int flags)
{
	struct msghdr msg;
	struct iovec iov[1];
	ssize_t ret = -1;

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

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

	switch (sock->proto) {
	case LTTCOMM_SOCK_UDP:
	{
		struct sockaddr_in addr = sock->sockaddr.addr.sin;

		msg.msg_name = (struct sockaddr *) &addr;
		msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
		break;
	}
	default:
		break;
	}

	do {
		ret = sendmsg(sock->fd, &msg, flags);
	} 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 inet");
		}
	}

	return ret;
}

/*
 * Shutdown cleanly and close.
 */
int lttcomm_close_inet_sock(struct lttcomm_sock *sock)
{
	int ret;

	/* Don't try to close an invalid marked socket */
	if (sock->fd == -1) {
		return 0;
	}

	ret = close(sock->fd);
	if (ret) {
		PERROR("close inet");
	}

	/* Mark socket */
	sock->fd = -1;

	return ret;
}

/*
 * Return value read from /proc or else 0 if value is not found.
 */
static unsigned long read_proc_value(const char *path)
{
	int ret, fd;
	ssize_t size_ret;
	long r_val;
	unsigned long val = 0;
	char buf[64];

	fd = open(path, O_RDONLY);
	if (fd < 0) {
		goto error;
	}

	size_ret = lttng_read(fd, buf, sizeof(buf));
	/*
	 * Allow reading a file smaller than buf, but keep space for
	 * final \0.
	 */
	if (size_ret < 0 || size_ret >= sizeof(buf)) {
		PERROR("read proc failed");
		goto error_close;
	}
	buf[size_ret] = '\0';

	errno = 0;
	r_val = strtol(buf, NULL, 10);
	if (errno != 0 || r_val < -1L) {
		val = 0;
		goto error_close;
	} else {
		if (r_val > 0) {
			val = r_val;
		}
	}

error_close:
	ret = close(fd);
	if (ret) {
		PERROR("close /proc value");
	}
error:
	return val;
}

void lttcomm_inet_init(void)
{
	unsigned long syn_retries, fin_timeout, syn_timeout, env;

	env = lttcomm_get_network_timeout();
	if (env) {
		lttcomm_inet_tcp_timeout = env;
		goto end;
	}

	/* Assign default value and see if we can change it. */
	lttcomm_inet_tcp_timeout = DEFAULT_INET_TCP_TIMEOUT;

	syn_retries = read_proc_value(LTTCOMM_INET_PROC_SYN_RETRIES_PATH);
	fin_timeout = read_proc_value(LTTCOMM_INET_PROC_FIN_TIMEOUT_PATH);

	syn_timeout = syn_retries * LTTCOMM_INET_SYN_TIMEOUT_FACTOR;

	/*
	 * Get the maximum between the two possible timeout value and use that to
	 * get the maximum with the default timeout.
	 */
	lttcomm_inet_tcp_timeout = max_t(unsigned long,
			max_t(unsigned long, syn_timeout, fin_timeout),
			lttcomm_inet_tcp_timeout);

end:
	DBG("TCP inet operation timeout set to %lu sec", lttcomm_inet_tcp_timeout);
}
Commit	Line	Data
6364a07a	1	/*
ab5be9fa	2	* Copyright (C) 2012 David Goulet <dgoulet@efficios.com>
6364a07a	3	*
ab5be9fa	4	* SPDX-License-Identifier: GPL-2.0-only
6364a07a	5	*
6364a07a DG	6	*/
6364a07a DG	7
6c1c0768	8	#define _LGPL_SOURCE
6364a07a DG	9	#include <limits.h>
	10	#include <stdio.h>
	11	#include <stdlib.h>
	12	#include <string.h>
	13	#include <sys/stat.h>
	14	#include <sys/types.h>
	15	#include <unistd.h>
a655f4cf	16	#include <fcntl.h>
389fbf04	17	#include <common/compat/time.h>
a655f4cf	18	#include <poll.h>
6364a07a	19
90e535ef	20	#include <common/common.h>
395d6b02	21	#include <common/time.h>
edf4b93e	22	#include <common/compat/errno.h>
6364a07a DG	23
	24	#include "inet.h"
	25
a655f4cf MD	26	#define RECONNECT_DELAY 200 /* ms */
a655f4cf MD	27
6364a07a DG	28	/*
	29	* INET protocol operations.
	30	*/
	31	static const struct lttcomm_proto_ops inet_ops = {
	32	.bind = lttcomm_bind_inet_sock,
	33	.close = lttcomm_close_inet_sock,
	34	.connect = lttcomm_connect_inet_sock,
	35	.accept = lttcomm_accept_inet_sock,
	36	.listen = lttcomm_listen_inet_sock,
	37	.recvmsg = lttcomm_recvmsg_inet_sock,
	38	.sendmsg = lttcomm_sendmsg_inet_sock,
	39	};
	40
d831c249 DG	41	unsigned long lttcomm_inet_tcp_timeout;
d831c249 DG	42
6364a07a DG	43	/*
	44	* Creates an PF_INET socket.
	45	*/
	46	int lttcomm_create_inet_sock(struct lttcomm_sock *sock, int type, int proto)
	47	{
de5e9086	48	int val = 1, ret;
783a3b9a	49	unsigned long timeout;
6364a07a DG	50
	51	/* Create server socket */
	52	if ((sock->fd = socket(PF_INET, type, proto)) < 0) {
	53	PERROR("socket inet");
	54	goto error;
	55	}
	56
	57	sock->ops = &inet_ops;
	58
	59	/*
	60	* Set socket option to reuse the address.
	61	*/
	62	ret = setsockopt(sock->fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(int));
	63	if (ret < 0) {
	64	PERROR("setsockopt inet");
	65	goto error;
	66	}
783a3b9a MD	67	timeout = lttcomm_get_network_timeout();
	68	if (timeout) {
	69	ret = lttcomm_setsockopt_rcv_timeout(sock->fd, timeout);
	70	if (ret) {
	71	goto error;
	72	}
	73	ret = lttcomm_setsockopt_snd_timeout(sock->fd, timeout);
	74	if (ret) {
	75	goto error;
	76	}
	77	}
6364a07a DG	78
	79	return 0;
	80
	81	error:
	82	return -1;
	83	}
	84
	85	/*
	86	* Bind socket and return.
	87	*/
	88	int lttcomm_bind_inet_sock(struct lttcomm_sock *sock)
	89	{
7966af57 SM	90	struct sockaddr_in sockaddr = sock->sockaddr.addr.sin;
	91
	92	return bind(sock->fd, &sockaddr, sizeof(sockaddr));
6364a07a DG	93	}
6364a07a DG	94
a655f4cf MD	95	static
	96	int connect_no_timeout(struct lttcomm_sock *sock)
	97	{
7966af57 SM	98	struct sockaddr_in sockaddr = sock->sockaddr.addr.sin;
	99
	100	return connect(sock->fd, &sockaddr, sizeof(sockaddr));
a655f4cf MD	101	}
a655f4cf MD	102
a655f4cf MD	103	static
	104	int connect_with_timeout(struct lttcomm_sock *sock)
	105	{
	106	unsigned long timeout = lttcomm_get_network_timeout();
	107	int ret, flags, connect_ret;
	108	struct timespec orig_time, cur_time;
2daf6502	109	unsigned long diff_ms;
7966af57	110	struct sockaddr_in sockaddr;
a655f4cf MD	111
	112	ret = fcntl(sock->fd, F_GETFL, 0);
	113	if (ret == -1) {
	114	PERROR("fcntl");
	115	return -1;
	116	}
	117	flags = ret;
	118
	119	/* Set socket to nonblock */
	120	ret = fcntl(sock->fd, F_SETFL, flags \| O_NONBLOCK);
	121	if (ret == -1) {
	122	PERROR("fcntl");
	123	return -1;
	124	}
	125
389fbf04	126	ret = lttng_clock_gettime(CLOCK_MONOTONIC, &orig_time);
a655f4cf MD	127	if (ret == -1) {
	128	PERROR("clock_gettime");
	129	return -1;
	130	}
	131
7966af57 SM	132	sockaddr = sock->sockaddr.addr.sin;
7966af57 SM	133	connect_ret = connect(sock->fd, &sockaddr, sizeof(sockaddr));
1a65bbb8 JG	134	if (connect_ret == -1 && errno != EAGAIN && errno != EWOULDBLOCK &&
1a65bbb8 JG	135	errno != EINPROGRESS) {
a655f4cf MD	136	goto error;
	137	} else if (!connect_ret) {
	138	/* Connect succeeded */
	139	goto success;
	140	}
	141
48ac9596 JR	142	DBG("Asynchronous connect for sock %d, performing polling with"
48ac9596 JR	143	" timeout: %lums", sock->fd, timeout);
a655f4cf MD	144	/*
	145	* Perform poll loop following EINPROGRESS recommendation from
	146	* connect(2) man page.
	147	*/
	148	do {
	149	struct pollfd fds;
	150
	151	fds.fd = sock->fd;
	152	fds.events = POLLOUT;
	153	fds.revents = 0;
	154	ret = poll(&fds, 1, RECONNECT_DELAY);
	155	if (ret < 0) {
	156	goto error;
	157	} else if (ret > 0) {
	158	int optval;
	159	socklen_t optval_len = sizeof(optval);
	160
	161	if (!(fds.revents & POLLOUT)) {
	162	/* Either hup or error */
	163	errno = EPIPE;
	164	goto error;
	165	}
	166	/* got something */
	167	ret = getsockopt(sock->fd, SOL_SOCKET,
	168	SO_ERROR, &optval, &optval_len);
	169	if (ret) {
48ac9596	170	PERROR("getsockopt");
a655f4cf MD	171	goto error;
	172	}
	173	if (!optval) {
	174	connect_ret = 0;
	175	goto success;
	176	} else {
48ac9596 JR	177	/* Get actual connect() errno from opt_val */
48ac9596 JR	178	errno = optval;
a655f4cf MD	179	goto error;
	180	}
	181	}
	182	/* ret == 0: timeout */
389fbf04	183	ret = lttng_clock_gettime(CLOCK_MONOTONIC, &cur_time);
a655f4cf MD	184	if (ret == -1) {
	185	PERROR("clock_gettime");
	186	connect_ret = ret;
	187	goto error;
	188	}
2daf6502 MD	189	if (timespec_to_ms(timespec_abs_diff(cur_time, orig_time), &diff_ms) < 0) {
	190	ERR("timespec_to_ms input overflows milliseconds output");
	191	connect_ret = -1;
	192	goto error;
	193	}
	194	} while (diff_ms < timeout);
a655f4cf MD	195
	196	/* Timeout */
	197	errno = ETIMEDOUT;
	198	connect_ret = -1;
	199
	200	success:
	201	/* Restore initial flags */
	202	ret = fcntl(sock->fd, F_SETFL, flags);
	203	if (ret == -1) {
	204	PERROR("fcntl");
	205	/* Continue anyway */
	206	}
	207	error:
	208	return connect_ret;
	209	}
	210
6364a07a DG	211	/*
	212	* Connect PF_INET socket.
	213	*/
	214	int lttcomm_connect_inet_sock(struct lttcomm_sock *sock)
	215	{
	216	int ret, closeret;
	217
a655f4cf MD	218	if (lttcomm_get_network_timeout()) {
	219	ret = connect_with_timeout(sock);
	220	} else {
	221	ret = connect_no_timeout(sock);
	222	}
6364a07a	223	if (ret < 0) {
82c05d47	224	PERROR("connect");
6364a07a DG	225	goto error_connect;
	226	}
	227
	228	return ret;
	229
	230	error_connect:
	231	closeret = close(sock->fd);
	232	if (closeret) {
	233	PERROR("close inet");
	234	}
	235
	236	return ret;
	237	}
	238
	239	/*
	240	* Do an accept(2) on the sock and return the new lttcomm socket. The socket
	241	* MUST be bind(2) before.
	242	*/
	243	struct lttcomm_sock lttcomm_accept_inet_sock(struct lttcomm_sock sock)
	244	{
	245	int new_fd;
88a5db70	246	socklen_t len;
6364a07a	247	struct lttcomm_sock *new_sock;
71c648d8	248	unsigned long timeout;
1a65bbb8	249	struct sockaddr_in new_addr = {};
6364a07a DG	250
	251	if (sock->proto == LTTCOMM_SOCK_UDP) {
	252	/*
	253	* accept(2) does not exist for UDP so simply return the passed socket.
	254	*/
	255	new_sock = sock;
	256	goto end;
	257	}
	258
de5e9086	259	new_sock = lttcomm_alloc_sock(sock->proto);
6364a07a DG	260	if (new_sock == NULL) {
	261	goto error;
	262	}
	263
1a65bbb8	264	len = sizeof(new_addr);
88a5db70	265
6364a07a	266	/* Blocking call */
1a65bbb8	267	new_fd = accept(sock->fd, (struct sockaddr *) &new_addr, &len);
6364a07a DG	268	if (new_fd < 0) {
	269	PERROR("accept inet");
	270	goto error;
	271	}
1a65bbb8	272	new_sock->sockaddr.addr.sin = new_addr;
71c648d8 JG	273	timeout = lttcomm_get_network_timeout();
	274	if (timeout) {
	275	int ret;
	276
	277	ret = lttcomm_setsockopt_rcv_timeout(new_fd, timeout);
	278	if (ret) {
475cd9fa	279	goto error_close;
71c648d8 JG	280	}
	281	ret = lttcomm_setsockopt_snd_timeout(new_fd, timeout);
	282	if (ret) {
475cd9fa	283	goto error_close;
71c648d8 JG	284	}
71c648d8 JG	285	}
6364a07a DG	286
6364a07a DG	287	new_sock->fd = new_fd;
de5e9086	288	new_sock->ops = &inet_ops;
6364a07a DG	289
	290	end:
	291	return new_sock;
	292
475cd9fa DG	293	error_close:
	294	if (close(new_fd) < 0) {
	295	PERROR("accept inet close fd");
	296	}
	297
6364a07a DG	298	error:
	299	free(new_sock);
	300	return NULL;
	301	}
	302
	303	/*
	304	* Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
	305	*/
	306	int lttcomm_listen_inet_sock(struct lttcomm_sock *sock, int backlog)
	307	{
	308	int ret;
	309
	310	if (sock->proto == LTTCOMM_SOCK_UDP) {
	311	/* listen(2) does not exist for UDP so simply return success. */
	312	ret = 0;
	313	goto end;
	314	}
	315
	316	/* Default listen backlog */
	317	if (backlog <= 0) {
	318	backlog = LTTNG_SESSIOND_COMM_MAX_LISTEN;
	319	}
	320
	321	ret = listen(sock->fd, backlog);
	322	if (ret < 0) {
	323	PERROR("listen inet");
	324	}
	325
	326	end:
	327	return ret;
	328	}
	329
	330	/*
	331	* Receive data of size len in put that data into the buf param. Using recvmsg
	332	* API.
	333	*
	334	* Return the size of received data.
	335	*/
	336	ssize_t lttcomm_recvmsg_inet_sock(struct lttcomm_sock sock, void buf,
	337	size_t len, int flags)
	338	{
	339	struct msghdr msg;
	340	struct iovec iov[1];
	341	ssize_t ret = -1;
7c5aef62	342	size_t len_last;
1a65bbb8	343	struct sockaddr_in addr = sock->sockaddr.addr.sin;
6364a07a DG	344
	345	memset(&msg, 0, sizeof(msg));
	346
	347	iov[0].iov_base = buf;
	348	iov[0].iov_len = len;
	349	msg.msg_iov = iov;
	350	msg.msg_iovlen = 1;
	351
1a65bbb8	352	msg.msg_name = (struct sockaddr *) &addr;
6364a07a DG	353	msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
6364a07a DG	354
6364a07a	355	do {
7c5aef62	356	len_last = iov[0].iov_len;
6364a07a	357	ret = recvmsg(sock->fd, &msg, flags);
7c5aef62	358	if (ret > 0) {
5312a3ed JG	359	if (flags & MSG_DONTWAIT) {
	360	goto end;
	361	}
7c5aef62 DG	362	iov[0].iov_base += ret;
7c5aef62 DG	363	iov[0].iov_len -= ret;
a0377dfe	364	LTTNG_ASSERT(ret <= len_last);
7c5aef62 DG	365	}
7c5aef62 DG	366	} while ((ret > 0 && ret < len_last) \|\| (ret < 0 && errno == EINTR));
5312a3ed	367
6364a07a	368	if (ret < 0) {
c2e8c366 JG	369	if (errno == EAGAIN && flags & MSG_DONTWAIT) {
	370	/*
	371	* EAGAIN is expected in non-blocking mode and should
	372	* not be reported as an error. Moreover, if no data
	373	* was read, 0 must not be returned as it would be
	374	* interpreted as an orderly shutdown of the socket.
	375	*/
	376	goto end;
	377	}
6364a07a	378	PERROR("recvmsg inet");
7c5aef62 DG	379	} else if (ret > 0) {
7c5aef62 DG	380	ret = len;
6364a07a	381	}
7c5aef62	382	/* Else ret = 0 meaning an orderly shutdown. */
5312a3ed	383	end:
6364a07a DG	384	return ret;
	385	}
	386
	387	/*
	388	* Send buf data of size len. Using sendmsg API.
	389	*
	390	* Return the size of sent data.
	391	*/
c2d69327	392	ssize_t lttcomm_sendmsg_inet_sock(struct lttcomm_sock sock, const void buf,
6364a07a DG	393	size_t len, int flags)
	394	{
	395	struct msghdr msg;
	396	struct iovec iov[1];
	397	ssize_t ret = -1;
	398
	399	memset(&msg, 0, sizeof(msg));
	400
c2d69327	401	iov[0].iov_base = (void *) buf;
6364a07a DG	402	iov[0].iov_len = len;
	403	msg.msg_iov = iov;
	404	msg.msg_iovlen = 1;
	405
	406	switch (sock->proto) {
	407	case LTTCOMM_SOCK_UDP:
1a65bbb8 JG	408	{
	409	struct sockaddr_in addr = sock->sockaddr.addr.sin;
	410
	411	msg.msg_name = (struct sockaddr *) &addr;
6364a07a DG	412	msg.msg_namelen = sizeof(sock->sockaddr.addr.sin);
6364a07a DG	413	break;
1a65bbb8	414	}
6364a07a DG	415	default:
	416	break;
	417	}
	418
	419	do {
	420	ret = sendmsg(sock->fd, &msg, flags);
	421	} while (ret < 0 && errno == EINTR);
	422	if (ret < 0) {
	423	/*
	424	* Only warn about EPIPE when quiet mode is deactivated.
	425	* We consider EPIPE as expected.
	426	*/
	427	if (errno != EPIPE \|\| !lttng_opt_quiet) {
	428	PERROR("sendmsg inet");
	429	}
	430	}
	431
	432	return ret;
	433	}
	434
	435	/*
	436	* Shutdown cleanly and close.
	437	*/
	438	int lttcomm_close_inet_sock(struct lttcomm_sock *sock)
	439	{
6e742359	440	int ret;
6364a07a	441
de5e9086	442	/* Don't try to close an invalid marked socket */
6364a07a DG	443	if (sock->fd == -1) {
	444	return 0;
	445	}
	446
6e742359 DG	447	ret = close(sock->fd);
6e742359 DG	448	if (ret) {
6364a07a DG	449	PERROR("close inet");
	450	}
	451
	452	/* Mark socket */
	453	sock->fd = -1;
	454
	455	return ret;
	456	}
d831c249 DG	457
	458	/*
	459	* Return value read from /proc or else 0 if value is not found.
	460	*/
	461	static unsigned long read_proc_value(const char *path)
	462	{
	463	int ret, fd;
6cd525e8	464	ssize_t size_ret;
d831c249 DG	465	long r_val;
	466	unsigned long val = 0;
	467	char buf[64];
	468
	469	fd = open(path, O_RDONLY);
	470	if (fd < 0) {
	471	goto error;
	472	}
	473
6cd525e8 MD	474	size_ret = lttng_read(fd, buf, sizeof(buf));
	475	/*
	476	* Allow reading a file smaller than buf, but keep space for
	477	* final \0.
	478	*/
	479	if (size_ret < 0 \|\| size_ret >= sizeof(buf)) {
d831c249 DG	480	PERROR("read proc failed");
	481	goto error_close;
	482	}
6cd525e8	483	buf[size_ret] = '\0';
d831c249 DG	484
	485	errno = 0;
	486	r_val = strtol(buf, NULL, 10);
	487	if (errno != 0 \|\| r_val < -1L) {
	488	val = 0;
	489	goto error_close;
	490	} else {
	491	if (r_val > 0) {
	492	val = r_val;
	493	}
	494	}
	495
	496	error_close:
	497	ret = close(fd);
	498	if (ret) {
	499	PERROR("close /proc value");
	500	}
	501	error:
	502	return val;
	503	}
	504
d831c249 DG	505	void lttcomm_inet_init(void)
d831c249 DG	506	{
18eed43f DG	507	unsigned long syn_retries, fin_timeout, syn_timeout, env;
	508
	509	env = lttcomm_get_network_timeout();
	510	if (env) {
	511	lttcomm_inet_tcp_timeout = env;
	512	goto end;
	513	}
d831c249 DG	514
	515	/* Assign default value and see if we can change it. */
	516	lttcomm_inet_tcp_timeout = DEFAULT_INET_TCP_TIMEOUT;
	517
	518	syn_retries = read_proc_value(LTTCOMM_INET_PROC_SYN_RETRIES_PATH);
	519	fin_timeout = read_proc_value(LTTCOMM_INET_PROC_FIN_TIMEOUT_PATH);
	520
	521	syn_timeout = syn_retries * LTTCOMM_INET_SYN_TIMEOUT_FACTOR;
	522
	523	/*
	524	* Get the maximum between the two possible timeout value and use that to
	525	* get the maximum with the default timeout.
	526	*/
	527	lttcomm_inet_tcp_timeout = max_t(unsigned long,
	528	max_t(unsigned long, syn_timeout, fin_timeout),
	529	lttcomm_inet_tcp_timeout);
	530
18eed43f	531	end:
d831c249 DG	532	DBG("TCP inet operation timeout set to %lu sec", lttcomm_inet_tcp_timeout);
d831c249 DG	533	}