1 /* $OpenBSD: monitor_fdpass.c,v 1.18 2008/11/30 11:59:26 dtucker 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 #ifndef HAVE_ACCRIGHTS_IN_MSGHDR 49 union { 50 struct cmsghdr hdr; 51 char buf[CMSG_SPACE(sizeof(int))]; 52 } cmsgbuf; 53 struct cmsghdr *cmsg; 54 #endif 55 struct iovec vec; 56 char ch = '\0'; 57 ssize_t n; 58 59 memset(&msg, 0, sizeof(msg)); 60 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR 61 msg.msg_accrights = (caddr_t)&fd; 62 msg.msg_accrightslen = sizeof(fd); 63 #else 64 msg.msg_control = (caddr_t)&cmsgbuf.buf; 65 msg.msg_controllen = sizeof(cmsgbuf.buf); 66 cmsg = CMSG_FIRSTHDR(&msg); 67 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 68 cmsg->cmsg_level = SOL_SOCKET; 69 cmsg->cmsg_type = SCM_RIGHTS; 70 *(int *)CMSG_DATA(cmsg) = fd; 71 #endif 72 73 vec.iov_base = &ch; 74 vec.iov_len = 1; 75 msg.msg_iov = &vec; 76 msg.msg_iovlen = 1; 77 78 while ((n = sendmsg(sock, &msg, 0)) == -1 && (errno == EAGAIN || 79 errno == EINTR)) 80 debug3("%s: sendmsg(%d): %s", __func__, fd, strerror(errno)); 81 if (n == -1) { 82 error("%s: sendmsg(%d): %s", __func__, fd, 83 strerror(errno)); 84 return -1; 85 } 86 87 if (n != 1) { 88 error("%s: sendmsg: expected sent 1 got %ld", 89 __func__, (long)n); 90 return -1; 91 } 92 return 0; 93 #else 94 error("%s: file descriptor passing not supported", __func__); 95 return -1; 96 #endif 97 } 98 99 int 100 mm_receive_fd(int sock) 101 { 102 #if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) 103 struct msghdr msg; 104 #ifndef HAVE_ACCRIGHTS_IN_MSGHDR 105 union { 106 struct cmsghdr hdr; 107 char buf[CMSG_SPACE(sizeof(int))]; 108 } cmsgbuf; 109 struct cmsghdr *cmsg; 110 #endif 111 struct iovec vec; 112 ssize_t n; 113 char ch; 114 int fd; 115 116 memset(&msg, 0, sizeof(msg)); 117 vec.iov_base = &ch; 118 vec.iov_len = 1; 119 msg.msg_iov = &vec; 120 msg.msg_iovlen = 1; 121 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR 122 msg.msg_accrights = (caddr_t)&fd; 123 msg.msg_accrightslen = sizeof(fd); 124 #else 125 msg.msg_control = &cmsgbuf.buf; 126 msg.msg_controllen = sizeof(cmsgbuf.buf); 127 #endif 128 129 while ((n = recvmsg(sock, &msg, 0)) == -1 && (errno == EAGAIN || 130 errno == EINTR)) 131 debug3("%s: recvmsg: %s", __func__, strerror(errno)); 132 if (n == -1) { 133 error("%s: recvmsg: %s", __func__, strerror(errno)); 134 return -1; 135 } 136 137 if (n != 1) { 138 error("%s: recvmsg: expected received 1 got %ld", 139 __func__, (long)n); 140 return -1; 141 } 142 143 #ifdef HAVE_ACCRIGHTS_IN_MSGHDR 144 if (msg.msg_accrightslen != sizeof(fd)) { 145 error("%s: no fd", __func__); 146 return -1; 147 } 148 #else 149 cmsg = CMSG_FIRSTHDR(&msg); 150 if (cmsg == NULL) { 151 error("%s: no message header", __func__); 152 return -1; 153 } 154 155 #ifndef BROKEN_CMSG_TYPE 156 if (cmsg->cmsg_type != SCM_RIGHTS) { 157 error("%s: expected type %d got %d", __func__, 158 SCM_RIGHTS, cmsg->cmsg_type); 159 return -1; 160 } 161 #endif 162 fd = (*(int *)CMSG_DATA(cmsg)); 163 #endif 164 return fd; 165 #else 166 error("%s: file descriptor passing not supported", __func__); 167 return -1; 168 #endif 169 } 170