1 /* $OpenBSD: monitor_fdpass.c,v 1.17 2008/03/24 16:11:07 deraadt 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 #include <string.h> 38 #include <stdarg.h> 39 40 #include "log.h" 41 #include "monitor_fdpass.h" 42 43 int 44 mm_send_fd(int sock, int fd) 45 { 46 #if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) 47 struct msghdr msg; 48 struct iovec vec; 49 char ch = '\0'; 50 ssize_t n; 51 #ifndef HAVE_ACCRIGHTS_IN_MSGHDR 52 union { 53 struct cmsghdr hdr; 54 char tmp[CMSG_SPACE(sizeof(int))]; 55 char buf[CMSG_SPACE(sizeof(int))]; 56 } cmsgbuf; 57 struct cmsghdr *cmsg; 58 #endif 59 60 memset(&msg, 0, sizeof(msg)); 61 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR 62 msg.msg_accrights = (caddr_t)&fd; 63 msg.msg_accrightslen = sizeof(fd); 64 #else 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 #endif 73 74 vec.iov_base = &ch; 75 vec.iov_len = 1; 76 msg.msg_iov = &vec; 77 msg.msg_iovlen = 1; 78 79 if ((n = sendmsg(sock, &msg, 0)) == -1) { 80 error("%s: sendmsg(%d): %s", __func__, fd, 81 strerror(errno)); 82 return -1; 83 } 84 85 if (n != 1) { 86 error("%s: sendmsg: expected sent 1 got %ld", 87 __func__, (long)n); 88 return -1; 89 } 90 return 0; 91 #else 92 error("%s: file descriptor passing not supported", __func__); 93 return -1; 94 #endif 95 } 96 97 int 98 mm_receive_fd(int sock) 99 { 100 #if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) 101 struct msghdr msg; 102 struct iovec vec; 103 ssize_t n; 104 char ch; 105 int fd; 106 #ifndef HAVE_ACCRIGHTS_IN_MSGHDR 107 union { 108 struct cmsghdr hdr; 109 char buf[CMSG_SPACE(sizeof(int))]; 110 } cmsgbuf; 111 struct cmsghdr *cmsg; 112 #endif 113 114 memset(&msg, 0, sizeof(msg)); 115 vec.iov_base = &ch; 116 vec.iov_len = 1; 117 msg.msg_iov = &vec; 118 msg.msg_iovlen = 1; 119 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR 120 msg.msg_accrights = (caddr_t)&fd; 121 msg.msg_accrightslen = sizeof(fd); 122 #else 123 msg.msg_control = &cmsgbuf.buf; 124 msg.msg_controllen = sizeof(cmsgbuf.buf); 125 #endif 126 127 if ((n = recvmsg(sock, &msg, 0)) == -1) { 128 error("%s: recvmsg: %s", __func__, strerror(errno)); 129 return -1; 130 } 131 if (n != 1) { 132 error("%s: recvmsg: expected received 1 got %ld", 133 __func__, (long)n); 134 return -1; 135 } 136 137 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR 138 if (msg.msg_accrightslen != sizeof(fd)) { 139 error("%s: no fd", __func__); 140 return -1; 141 } 142 #else 143 cmsg = CMSG_FIRSTHDR(&msg); 144 if (cmsg == NULL) { 145 error("%s: no message header", __func__); 146 return -1; 147 } 148 #ifndef BROKEN_CMSG_TYPE 149 if (cmsg->cmsg_type != SCM_RIGHTS) { 150 error("%s: expected type %d got %d", __func__, 151 SCM_RIGHTS, cmsg->cmsg_type); 152 return -1; 153 } 154 #endif 155 fd = (*(int *)CMSG_DATA(cmsg)); 156 #endif 157 return fd; 158 #else 159 error("%s: file descriptor passing not supported", __func__); 160 return -1; 161 #endif 162 } 163