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 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 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