[thirdparty/lldpd.git] / src / privsep_fdpass.c

/*
 * Copyright 2001 Niels Provos <provos@citi.umich.edu>
 * All rights reserved.
 *
 * Copyright (c) 2002 Matthieu Herrb
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *    - Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *    - Redistributions in binary form must reproduce the above
 *      copyright notice, this list of conditions and the following
 *      disclaimer in the documentation and/or other materials provided
 *      with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "lldpd.h"

#include <sys/param.h>
#include <sys/uio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

void
send_fd(int sock, int fd)
{
	struct msghdr msg;
	union {
		struct cmsghdr hdr;
		char buf[CMSG_SPACE(sizeof(int))];
	} cmsgbuf;
	struct cmsghdr *cmsg;
	struct iovec vec;
	int result = 0;
	ssize_t n;

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

	if (fd >= 0) {
		msg.msg_control = (caddr_t)&cmsgbuf.buf;
		msg.msg_controllen = sizeof(cmsgbuf.buf);
		cmsg = CMSG_FIRSTHDR(&msg);
		cmsg->cmsg_len = CMSG_LEN(sizeof(int));
		cmsg->cmsg_level = SOL_SOCKET;
		cmsg->cmsg_type = SCM_RIGHTS;
		memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
	} else {
		result = errno;
	}

	vec.iov_base = &result;
	vec.iov_len = sizeof(int);
	msg.msg_iov = &vec;
	msg.msg_iovlen = 1;

	if ((n = sendmsg(sock, &msg, 0)) == -1)
		LLOG_WARN("sendmsg(%d)", sock);
	if (n != sizeof(int))
		LLOG_WARNX("sendmsg: expected sent 1 got %ld",
		    (long)n);
}

int
receive_fd(int sock)
{
	struct msghdr msg;
	union {
		struct cmsghdr hdr;
		char buf[CMSG_SPACE(sizeof(int))];
	} cmsgbuf;
	struct cmsghdr *cmsg;
	struct iovec vec;
	ssize_t n;
	int result;
	int fd;

	memset(&msg, 0, sizeof(msg));
	vec.iov_base = &result;
	vec.iov_len = sizeof(int);
	msg.msg_iov = &vec;
	msg.msg_iovlen = 1;
	msg.msg_control = &cmsgbuf.buf;
	msg.msg_controllen = sizeof(cmsgbuf.buf);

	if ((n = recvmsg(sock, &msg, 0)) == -1)
		LLOG_WARN("recvmsg");
	if (n != sizeof(int))
		LLOG_WARNX("recvmsg: expected received 1 got %ld",
		    (long)n);
	if (result == 0) {
		cmsg = CMSG_FIRSTHDR(&msg);
		if (cmsg == NULL) {
			LLOG_WARNX("no message header");
			return -1;
		}
		if (cmsg->cmsg_type != SCM_RIGHTS)
			LLOG_WARNX("expected type %d got %d",
			    SCM_RIGHTS, cmsg->cmsg_type);
		memcpy(&fd, CMSG_DATA(cmsg), sizeof(int));
		return fd;
	} else {
		errno = result;
		return -1;
	}
}
Commit	Line	Data
4afe659e VB	1	/*
	2	* Copyright 2001 Niels Provos <provos@citi.umich.edu>
	3	* All rights reserved.
	4	*
	5	* Copyright (c) 2002 Matthieu Herrb
	6	* All rights reserved.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	*
	12	* - Redistributions of source code must retain the above copyright
	13	* notice, this list of conditions and the following disclaimer.
	14	* - Redistributions in binary form must reproduce the above
	15	* copyright notice, this list of conditions and the following
	16	* disclaimer in the documentation and/or other materials provided
	17	* with the distribution.
	18	*
	19	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	20	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	21	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
	22	* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
	23	* COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
	24	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
	25	* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	26	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
	27	* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
	29	* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	30	* POSSIBILITY OF SUCH DAMAGE.
	31	*/
	32
	33	#include "lldpd.h"
	34
	35	#include <sys/param.h>
	36	#include <sys/uio.h>
	37	#include <sys/types.h>
	38	#include <sys/socket.h>
	39	#include <sys/stat.h>
	40	#include <err.h>
	41	#include <errno.h>
	42	#include <fcntl.h>
	43	#include <signal.h>
	44	#include <stdio.h>
	45	#include <stdlib.h>
	46	#include <string.h>
	47	#include <unistd.h>
	48
	49	void
	50	send_fd(int sock, int fd)
	51	{
	52	struct msghdr msg;
	53	union {
	54	struct cmsghdr hdr;
	55	char buf[CMSG_SPACE(sizeof(int))];
	56	} cmsgbuf;
	57	struct cmsghdr *cmsg;
	58	struct iovec vec;
	59	int result = 0;
	60	ssize_t n;
	61
	62	memset(&msg, 0, sizeof(msg));
	63
	64	if (fd >= 0) {
65	msg.msg_control = (caddr_t)&cmsgbuf.buf;
66	msg.msg_controllen = sizeof(cmsgbuf.buf);
67	cmsg = CMSG_FIRSTHDR(&msg);
68	cmsg->cmsg_len = CMSG_LEN(sizeof(int));
69	cmsg->cmsg_level = SOL_SOCKET;
70	cmsg->cmsg_type = SCM_RIGHTS;
72c00381	71	memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));
4afe659e VB	72	} else {
	73	result = errno;
	74	}
	75
	76	vec.iov_base = &result;
	77	vec.iov_len = sizeof(int);
	78	msg.msg_iov = &vec;
	79	msg.msg_iovlen = 1;
	80
	81	if ((n = sendmsg(sock, &msg, 0)) == -1)
	82	LLOG_WARN("sendmsg(%d)", sock);
	83	if (n != sizeof(int))
	84	LLOG_WARNX("sendmsg: expected sent 1 got %ld",
	85	(long)n);
	86	}
	87
	88	int
	89	receive_fd(int sock)
	90	{
	91	struct msghdr msg;
	92	union {
	93	struct cmsghdr hdr;
	94	char buf[CMSG_SPACE(sizeof(int))];
	95	} cmsgbuf;
	96	struct cmsghdr *cmsg;
	97	struct iovec vec;
	98	ssize_t n;
	99	int result;
	100	int fd;
	101
	102	memset(&msg, 0, sizeof(msg));
	103	vec.iov_base = &result;
	104	vec.iov_len = sizeof(int);
	105	msg.msg_iov = &vec;
	106	msg.msg_iovlen = 1;
	107	msg.msg_control = &cmsgbuf.buf;
	108	msg.msg_controllen = sizeof(cmsgbuf.buf);
	109
	110	if ((n = recvmsg(sock, &msg, 0)) == -1)
	111	LLOG_WARN("recvmsg");
	112	if (n != sizeof(int))
	113	LLOG_WARNX("recvmsg: expected received 1 got %ld",
	114	(long)n);
	115	if (result == 0) {
	116	cmsg = CMSG_FIRSTHDR(&msg);
	117	if (cmsg == NULL) {
	118	LLOG_WARNX("no message header");
	119	return -1;
	120	}
	121	if (cmsg->cmsg_type != SCM_RIGHTS)
	122	LLOG_WARNX("expected type %d got %d",
	123	SCM_RIGHTS, cmsg->cmsg_type);
72c00381	124	memcpy(&fd, CMSG_DATA(cmsg), sizeof(int));
4afe659e VB	125	return fd;
	126	} else {
	127	errno = result;
	128	return -1;
	129	}
	130	}