[lttng-tools.git] / src / common / compat / socket.h

/*
 * Copyright (C) 2011 - David Goulet <dgoulet@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.
 */

#ifndef _COMPAT_SOCKET_H
#define _COMPAT_SOCKET_H

#include <sys/socket.h>
#include <sys/un.h>

#include <common/macros.h>

#ifndef MSG_NOSIGNAL
# ifdef SO_NOSIGPIPE
#   define MSG_NOSIGNAL SO_NOSIGPIPE
# endif
#endif

#if defined(MSG_NOSIGNAL)
static inline
ssize_t lttng_recvmsg_nosigpipe(int sockfd, struct msghdr *msg)
{
	return recvmsg(sockfd, msg, MSG_NOSIGNAL);
}
#else

#include <signal.h>
#include <errno.h>

static inline
ssize_t lttng_recvmsg_nosigpipe(int sockfd, struct msghdr *msg)
{
	ssize_t received;
	int saved_err;
	sigset_t sigpipe_set, pending_set, old_set;
	int sigpipe_was_pending;

	/*
	 * Discard the SIGPIPE from send(), not disturbing any SIGPIPE
	 * that might be already pending. If a bogus SIGPIPE is sent to
	 * the entire process concurrently by a malicious user, it may
	 * be simply discarded.
	 */
	if (sigemptyset(&pending_set)) {
		return -1;
	}
	/*
	 * sigpending returns the mask of signals that are _both_
	 * blocked for the thread _and_ pending for either the thread or
	 * the entire process.
	 */
	if (sigpending(&pending_set)) {
		return -1;
	}
	sigpipe_was_pending = sigismember(&pending_set, SIGPIPE);
	/*
	 * If sigpipe was pending, it means it was already blocked, so
	 * no need to block it.
	 */
	if (!sigpipe_was_pending) {
		if (sigemptyset(&sigpipe_set)) {
			return -1;
		}
		if (sigaddset(&sigpipe_set, SIGPIPE)) {
			return -1;
		}
		if (pthread_sigmask(SIG_BLOCK, &sigpipe_set, &old_set)) {
			return -1;
		}
	}

	/* Send and save errno. */
	received = recvmsg(sockfd, msg, 0);
	saved_err = errno;

	if (received == -1 && errno == EPIPE && !sigpipe_was_pending) {
		struct timespec timeout = { 0, 0 };
		int ret;

		do {
			ret = sigtimedwait(&sigpipe_set, NULL,
				&timeout);
		} while (ret == -1 && errno == EINTR);
	}
	if (!sigpipe_was_pending) {
		if (pthread_sigmask(SIG_SETMASK, &old_set, NULL)) {
			return -1;
		}
	}
	/* Restore send() errno */
	errno = saved_err;

	return received;
}
#endif


#ifdef __linux__

#define LTTNG_SOCK_CREDS SCM_CREDENTIALS

typedef struct ucred lttng_sock_cred;

#define LTTNG_SOCK_SET_UID_CRED(c, u) LTTNG_REF(c)->uid = u
#define LTTNG_SOCK_SET_GID_CRED(c, g) LTTNG_REF(c)->gid = g
#define LTTNG_SOCK_SET_PID_CRED(c, p) LTTNG_REF(c)->pid = p

#define LTTNG_SOCK_GET_UID_CRED(c) LTTNG_REF(c)->uid
#define LTTNG_SOCK_GET_GID_CRED(c) LTTNG_REF(c)->gid
#define LTTNG_SOCK_GET_PID_CRED(c) LTTNG_REF(c)->pid

#elif (defined(__FreeBSD__) || defined(__CYGWIN__) || defined(__sun__) || defined(__APPLE__))

struct lttng_sock_cred {
	uid_t uid;
	gid_t gid;
};

typedef struct lttng_sock_cred lttng_sock_cred;

#define LTTNG_SOCK_GET_UID_CRED(c) LTTNG_REF(c)->uid
#define LTTNG_SOCK_GET_GID_CRED(c) LTTNG_REF(c)->gid
#define LTTNG_SOCK_GET_PID_CRED(c) -1

#else
#error "Please add support for your OS."
#endif /* __linux__ , __FreeBSD__ */


#ifdef __sun__

# ifndef CMSG_ALIGN
#  ifdef _CMSG_DATA_ALIGN
#   define CMSG_ALIGN(len) _CMSG_DATA_ALIGN(len)
#  else
    /* aligning to sizeof (long) is assumed to be portable (fd.o#40235) */
#   define CMSG_ALIGN(len) (((len) + sizeof (long) - 1) & ~(sizeof (long) - 1))
#  endif
#  ifndef CMSG_SPACE
#    define CMSG_SPACE(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + CMSG_ALIGN (len))
#  endif
#  ifndef CMSG_LEN
#    define CMSG_LEN(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + (len))
#  endif
# endif


#include <ucred.h>

static inline
int getpeereid(int s, uid_t *euid, gid_t *gid)
{
	int ret = 0;
	ucred_t *ucred = NULL;

	ret = getpeerucred(s, &ucred);
	if (ret == -1) {
		goto end;
	}

	ret = ucred_geteuid(ucred);
	if (ret == -1) {
		goto free;
	}
	*euid = ret;

	ret = ucred_getrgid(ucred);
	if (ret == -1) {
		goto free;
	}
	*gid = ret;
	ret = 0;
free:
	ucred_free(ucred);
end:
	return ret;
}

#endif /* __sun__ */

#endif /* _COMPAT_SOCKET_H */
Commit	Line	Data
b17231c6 DG	1	/*
	2	* Copyright (C) 2011 - David Goulet <dgoulet@efficios.com>
	3	*
d14d33bf AM	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License, version 2 only,
	6	* as published by the Free Software Foundation.
b17231c6 DG	7	*
	8	* This program is distributed in the hope that it will be useful, but WITHOUT
	9	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	10	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	11	* more details.
	12	*
d14d33bf AM	13	* You should have received a copy of the GNU General Public License along
	14	* with this program; if not, write to the Free Software Foundation, Inc.,
	15	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
b17231c6 DG	16	*/
	17
	18	#ifndef _COMPAT_SOCKET_H
	19	#define _COMPAT_SOCKET_H
	20
	21	#include <sys/socket.h>
	22	#include <sys/un.h>
	23
	24	#include <common/macros.h>
	25
fbb1fd3a MJ	26	#ifndef MSG_NOSIGNAL
	27	# ifdef SO_NOSIGPIPE
	28	# define MSG_NOSIGNAL SO_NOSIGPIPE
	29	# endif
	30	#endif
	31
	32	#if defined(MSG_NOSIGNAL)
	33	static inline
	34	ssize_t lttng_recvmsg_nosigpipe(int sockfd, struct msghdr *msg)
	35	{
	36	return recvmsg(sockfd, msg, MSG_NOSIGNAL);
	37	}
	38	#else
	39
	40	#include <signal.h>
	41	#include <errno.h>
	42
	43	static inline
	44	ssize_t lttng_recvmsg_nosigpipe(int sockfd, struct msghdr *msg)
	45	{
	46	ssize_t received;
	47	int saved_err;
	48	sigset_t sigpipe_set, pending_set, old_set;
	49	int sigpipe_was_pending;
	50
	51	/*
	52	* Discard the SIGPIPE from send(), not disturbing any SIGPIPE
	53	* that might be already pending. If a bogus SIGPIPE is sent to
	54	* the entire process concurrently by a malicious user, it may
	55	* be simply discarded.
	56	*/
	57	if (sigemptyset(&pending_set)) {
	58	return -1;
	59	}
	60	/*
	61	* sigpending returns the mask of signals that are _both_
	62	* blocked for the thread _and_ pending for either the thread or
	63	* the entire process.
	64	*/
	65	if (sigpending(&pending_set)) {
	66	return -1;
	67	}
	68	sigpipe_was_pending = sigismember(&pending_set, SIGPIPE);
	69	/*
	70	* If sigpipe was pending, it means it was already blocked, so
	71	* no need to block it.
	72	*/
	73	if (!sigpipe_was_pending) {
	74	if (sigemptyset(&sigpipe_set)) {
	75	return -1;
	76	}
	77	if (sigaddset(&sigpipe_set, SIGPIPE)) {
	78	return -1;
	79	}
	80	if (pthread_sigmask(SIG_BLOCK, &sigpipe_set, &old_set)) {
	81	return -1;
	82	}
	83	}
	84
	85	/* Send and save errno. */
	86	received = recvmsg(sockfd, msg, 0);
	87	saved_err = errno;
	88
	89	if (received == -1 && errno == EPIPE && !sigpipe_was_pending) {
90	struct timespec timeout = { 0, 0 };
91	int ret;
92
93	do {
94	ret = sigtimedwait(&sigpipe_set, NULL,
95	&timeout);
96	} while (ret == -1 && errno == EINTR);
97	}
98	if (!sigpipe_was_pending) {
99	if (pthread_sigmask(SIG_SETMASK, &old_set, NULL)) {
100	return -1;
101	}
102	}
103	/* Restore send() errno */
104	errno = saved_err;
105
106	return received;
107	}
108	#endif
109
110
b17231c6 DG	111	#ifdef __linux__
	112
	113	#define LTTNG_SOCK_CREDS SCM_CREDENTIALS
b17231c6 DG	114
	115	typedef struct ucred lttng_sock_cred;
	116
1268b9d6 DG	117	#define LTTNG_SOCK_SET_UID_CRED(c, u) LTTNG_REF(c)->uid = u
	118	#define LTTNG_SOCK_SET_GID_CRED(c, g) LTTNG_REF(c)->gid = g
	119	#define LTTNG_SOCK_SET_PID_CRED(c, p) LTTNG_REF(c)->pid = p
	120
	121	#define LTTNG_SOCK_GET_UID_CRED(c) LTTNG_REF(c)->uid
	122	#define LTTNG_SOCK_GET_GID_CRED(c) LTTNG_REF(c)->gid
	123	#define LTTNG_SOCK_GET_PID_CRED(c) LTTNG_REF(c)->pid
b17231c6	124
d05d6fe1	125	#elif (defined(__FreeBSD__) \|\| defined(__CYGWIN__) \|\| defined(__sun__) \|\| defined(__APPLE__))
b17231c6	126
d27c42b8 MD	127	struct lttng_sock_cred {
	128	uid_t uid;
	129	gid_t gid;
	130	};
b17231c6	131
d27c42b8	132	typedef struct lttng_sock_cred lttng_sock_cred;
b17231c6	133
d27c42b8 MD	134	#define LTTNG_SOCK_GET_UID_CRED(c) LTTNG_REF(c)->uid
	135	#define LTTNG_SOCK_GET_GID_CRED(c) LTTNG_REF(c)->gid
	136	#define LTTNG_SOCK_GET_PID_CRED(c) -1
b17231c6 DG	137
b17231c6 DG	138	#else
7657ae75	139	#error "Please add support for your OS."
b17231c6 DG	140	#endif /* __linux__ , __FreeBSD__ */
b17231c6 DG	141
28105b32 MJ	142
	143	#ifdef __sun__
	144
	145	# ifndef CMSG_ALIGN
	146	# ifdef _CMSG_DATA_ALIGN
	147	# define CMSG_ALIGN(len) _CMSG_DATA_ALIGN(len)
	148	# else
	149	/* aligning to sizeof (long) is assumed to be portable (fd.o#40235) */
	150	# define CMSG_ALIGN(len) (((len) + sizeof (long) - 1) & ~(sizeof (long) - 1))
	151	# endif
	152	# ifndef CMSG_SPACE
	153	# define CMSG_SPACE(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + CMSG_ALIGN (len))
	154	# endif
	155	# ifndef CMSG_LEN
	156	# define CMSG_LEN(len) (CMSG_ALIGN (sizeof (struct cmsghdr)) + (len))
	157	# endif
	158	# endif
	159
	160
	161	#include <ucred.h>
11a2fd46 MJ	162
	163	static inline
	164	int getpeereid(int s, uid_t euid, gid_t gid)
28105b32 MJ	165	{
	166	int ret = 0;
	167	ucred_t *ucred = NULL;
	168
	169	ret = getpeerucred(s, &ucred);
	170	if (ret == -1) {
	171	goto end;
	172	}
	173
	174	ret = ucred_geteuid(ucred);
	175	if (ret == -1) {
	176	goto free;
	177	}
	178	*euid = ret;
	179
	180	ret = ucred_getrgid(ucred);
	181	if (ret == -1) {
	182	goto free;
	183	}
	184	*gid = ret;
	185	ret = 0;
	186	free:
	187	ucred_free(ucred);
	188	end:
	189	return ret;
	190	}
	191
	192	#endif /* __sun__ */
	193
b17231c6	194	#endif /* _COMPAT_SOCKET_H */