1 /* $NetBSD: monitor_fdpass.c,v 1.2 2009/06/07 22:38:46 christos Exp $ */ 2 /* $OpenBSD: monitor_fdpass.c,v 1.18 2008/11/30 11:59:26 dtucker Exp $ */ 3 /* 4 * Copyright 2001 Niels Provos <provos@citi.umich.edu> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include "includes.h" 29 __RCSID("$NetBSD: monitor_fdpass.c,v 1.2 2009/06/07 22:38:46 christos Exp $"); 30 #include <sys/types.h> 31 #include <sys/socket.h> 32 #include <sys/uio.h> 33 34 #include <errno.h> 35 #include <string.h> 36 #include <stdarg.h> 37 38 #include "log.h" 39 #include "monitor_fdpass.h" 40 41 int 42 mm_send_fd(int sock, int fd) 43 { 44 struct msghdr msg; 45 union { 46 struct cmsghdr hdr; 47 char buf[1024]; 48 } cmsgbuf; 49 struct cmsghdr *cmsg; 50 struct iovec vec; 51 char ch = '\0'; 52 ssize_t n; 53 54 if (sizeof(cmsgbuf.buf) < CMSG_SPACE(sizeof(int))) { 55 error("%s: %zu < %zu, recompile", __func__, 56 sizeof(cmsgbuf.buf), CMSG_SPACE(sizeof(int))); 57 return -1; 58 } 59 60 memset(&msg, 0, sizeof(msg)); 61 msg.msg_control = &cmsgbuf.buf; 62 msg.msg_controllen = CMSG_SPACE(sizeof(int)); 63 cmsg = CMSG_FIRSTHDR(&msg); 64 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 65 cmsg->cmsg_level = SOL_SOCKET; 66 cmsg->cmsg_type = SCM_RIGHTS; 67 *(int *)CMSG_DATA(cmsg) = fd; 68 msg.msg_controllen = cmsg->cmsg_len; 69 70 vec.iov_base = &ch; 71 vec.iov_len = 1; 72 msg.msg_iov = &vec; 73 msg.msg_iovlen = 1; 74 75 while ((n = sendmsg(sock, &msg, 0)) == -1 && (errno == EAGAIN || 76 errno == EINTR)) 77 debug3("%s: sendmsg(%d): %s", __func__, fd, strerror(errno)); 78 if (n == -1) { 79 error("%s: sendmsg(%d): %s", __func__, fd, 80 strerror(errno)); 81 return -1; 82 } 83 84 if (n != 1) { 85 error("%s: sendmsg: expected sent 1 got %ld", 86 __func__, (long)n); 87 return -1; 88 } 89 return 0; 90 } 91 92 int 93 mm_receive_fd(int sock) 94 { 95 struct msghdr msg; 96 union { 97 struct cmsghdr hdr; 98 char buf[1024]; 99 } cmsgbuf; 100 struct cmsghdr *cmsg; 101 struct iovec vec; 102 ssize_t n; 103 char ch; 104 int fd; 105 106 if (sizeof(cmsgbuf.buf) < CMSG_SPACE(sizeof(int))) { 107 error("%s: %zu < %zu, recompile", __func__, 108 sizeof(cmsgbuf.buf), CMSG_SPACE(sizeof(int))); 109 return -1; 110 } 111 112 memset(&msg, 0, sizeof(msg)); 113 vec.iov_base = &ch; 114 vec.iov_len = 1; 115 msg.msg_iov = &vec; 116 msg.msg_iovlen = 1; 117 msg.msg_control = &cmsgbuf.buf; 118 msg.msg_controllen = CMSG_SPACE(sizeof(int)); 119 120 while ((n = recvmsg(sock, &msg, 0)) == -1 && (errno == EAGAIN || 121 errno == EINTR)) 122 debug3("%s: recvmsg: %s", __func__, strerror(errno)); 123 if (n == -1) { 124 error("%s: recvmsg: %s", __func__, strerror(errno)); 125 return -1; 126 } 127 128 if (n != 1) { 129 error("%s: recvmsg: expected received 1 got %ld", 130 __func__, (long)n); 131 return -1; 132 } 133 134 cmsg = CMSG_FIRSTHDR(&msg); 135 if (cmsg == NULL) { 136 error("%s: no message header", __func__); 137 return -1; 138 } 139 140 if (cmsg->cmsg_type != SCM_RIGHTS) { 141 error("%s: expected type %d got %d", __func__, 142 SCM_RIGHTS, cmsg->cmsg_type); 143 return -1; 144 } 145 fd = (*(int *)CMSG_DATA(cmsg)); 146 return fd; 147 } 148