1 /* $OpenBSD: monitor_fdpass.c,v 1.19 2010/01/12 00:58:25 djm Exp $ */
2 /*
3 * Copyright 2001 Niels Provos <provos@citi.umich.edu>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include "includes.h"
28
29 #include <sys/types.h>
30 #include <sys/socket.h>
31 #include <sys/uio.h>
32 #ifdef HAVE_SYS_UN_H
33 #include <sys/un.h>
34 #endif
35
36 #include <errno.h>
37 #ifdef HAVE_POLL_H
38 #include <poll.h>
39 #endif
40 #include <string.h>
41 #include <stdarg.h>
42
43 #include "log.h"
44 #include "monitor_fdpass.h"
45
46 int
mm_send_fd(int sock,int fd)47 mm_send_fd(int sock, int fd)
48 {
49 #if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR))
50 struct msghdr msg;
51 #ifndef HAVE_ACCRIGHTS_IN_MSGHDR
52 union {
53 struct cmsghdr hdr;
54 char buf[CMSG_SPACE(sizeof(int))];
55 } cmsgbuf;
56 struct cmsghdr *cmsg;
57 #endif
58 struct iovec vec;
59 char ch = '\0';
60 ssize_t n;
61 struct pollfd pfd;
62
63 memset(&msg, 0, sizeof(msg));
64 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR
65 msg.msg_accrights = (caddr_t)&fd;
66 msg.msg_accrightslen = sizeof(fd);
67 #else
68 msg.msg_control = (caddr_t)&cmsgbuf.buf;
69 msg.msg_controllen = sizeof(cmsgbuf.buf);
70 cmsg = CMSG_FIRSTHDR(&msg);
71 cmsg->cmsg_len = CMSG_LEN(sizeof(int));
72 cmsg->cmsg_level = SOL_SOCKET;
73 cmsg->cmsg_type = SCM_RIGHTS;
74 *(int *)CMSG_DATA(cmsg) = fd;
75 #endif
76
77 vec.iov_base = &ch;
78 vec.iov_len = 1;
79 msg.msg_iov = &vec;
80 msg.msg_iovlen = 1;
81
82 pfd.fd = sock;
83 pfd.events = POLLOUT;
84 while ((n = sendmsg(sock, &msg, 0)) == -1 &&
85 (errno == EAGAIN || errno == EINTR)) {
86 debug3("%s: sendmsg(%d): %s", __func__, fd, strerror(errno));
87 (void)poll(&pfd, 1, -1);
88 }
89 if (n == -1) {
90 error("%s: sendmsg(%d): %s", __func__, fd,
91 strerror(errno));
92 return -1;
93 }
94
95 if (n != 1) {
96 error("%s: sendmsg: expected sent 1 got %ld",
97 __func__, (long)n);
98 return -1;
99 }
100 return 0;
101 #else
102 error("%s: file descriptor passing not supported", __func__);
103 return -1;
104 #endif
105 }
106
107 int
mm_receive_fd(int sock)108 mm_receive_fd(int sock)
109 {
110 #if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR))
111 struct msghdr msg;
112 #ifndef HAVE_ACCRIGHTS_IN_MSGHDR
113 union {
114 struct cmsghdr hdr;
115 char buf[CMSG_SPACE(sizeof(int))];
116 } cmsgbuf;
117 struct cmsghdr *cmsg;
118 #endif
119 struct iovec vec;
120 ssize_t n;
121 char ch;
122 int fd;
123 struct pollfd pfd;
124
125 memset(&msg, 0, sizeof(msg));
126 vec.iov_base = &ch;
127 vec.iov_len = 1;
128 msg.msg_iov = &vec;
129 msg.msg_iovlen = 1;
130 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR
131 msg.msg_accrights = (caddr_t)&fd;
132 msg.msg_accrightslen = sizeof(fd);
133 #else
134 msg.msg_control = &cmsgbuf.buf;
135 msg.msg_controllen = sizeof(cmsgbuf.buf);
136 #endif
137
138 pfd.fd = sock;
139 pfd.events = POLLIN;
140 while ((n = recvmsg(sock, &msg, 0)) == -1 &&
141 (errno == EAGAIN || errno == EINTR)) {
142 debug3("%s: recvmsg: %s", __func__, strerror(errno));
143 (void)poll(&pfd, 1, -1);
144 }
145 if (n == -1) {
146 error("%s: recvmsg: %s", __func__, strerror(errno));
147 return -1;
148 }
149
150 if (n != 1) {
151 error("%s: recvmsg: expected received 1 got %ld",
152 __func__, (long)n);
153 return -1;
154 }
155
156 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR
157 if (msg.msg_accrightslen != sizeof(fd)) {
158 error("%s: no fd", __func__);
159 return -1;
160 }
161 #else
162 cmsg = CMSG_FIRSTHDR(&msg);
163 if (cmsg == NULL) {
164 error("%s: no message header", __func__);
165 return -1;
166 }
167
168 #ifndef BROKEN_CMSG_TYPE
169 if (cmsg->cmsg_type != SCM_RIGHTS) {
170 error("%s: expected type %d got %d", __func__,
171 SCM_RIGHTS, cmsg->cmsg_type);
172 return -1;
173 }
174 #endif
175 fd = (*(int *)CMSG_DATA(cmsg));
176 #endif
177 return fd;
178 #else
179 error("%s: file descriptor passing not supported", __func__);
180 return -1;
181 #endif
182 }
183