1 /* $OpenBSD: privsep_fdpass.c,v 1.5 2008/03/24 16:11:08 deraadt Exp $ */
2
3 /*
4 * Copyright 2001 Niels Provos <provos@citi.umich.edu>
5 * All rights reserved.
6 *
7 * Copyright (c) 2002 Matthieu Herrb
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 * - Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * - Redistributions in binary form must reproduce the above
17 * copyright notice, this list of conditions and the following
18 * disclaimer in the documentation and/or other materials provided
19 * with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
29 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
31 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
32 * POSSIBILITY OF SUCH DAMAGE.
33 */
34 #include <sys/param.h>
35 #include <sys/uio.h>
36 #include <sys/types.h>
37 #include <sys/socket.h>
38 #include <sys/stat.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <signal.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include "pflogd.h"
48
49 void
send_fd(int sock,int fd)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;
71 *(int *)CMSG_DATA(cmsg) = fd;
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 warn("%s: sendmsg(%d)", __func__, sock);
83 if (n != sizeof(int))
84 warnx("%s: sendmsg: expected sent 1 got %ld",
85 __func__, (long)n);
86 }
87
88 int
receive_fd(int sock)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 warn("%s: recvmsg", __func__);
112 if (n != sizeof(int))
113 warnx("%s: recvmsg: expected received 1 got %ld",
114 __func__, (long)n);
115 if (result == 0) {
116 cmsg = CMSG_FIRSTHDR(&msg);
117 if (cmsg == NULL) {
118 warnx("%s: no message header", __func__);
119 return -1;
120 }
121 if (cmsg->cmsg_type != SCM_RIGHTS)
122 warnx("%s: expected type %d got %d", __func__,
123 SCM_RIGHTS, cmsg->cmsg_type);
124 fd = (*(int *)CMSG_DATA(cmsg));
125 return fd;
126 } else {
127 errno = result;
128 return -1;
129 }
130 }
131