1 /* $OpenBSD: privsep_fdpass.c,v 1.5 2008/03/24 16:11:08 deraadt Exp $ */ 2 3 /* 4 * Copyright 2001 Niels Provos <provos@citi.umich.edu> 5 * All rights reserved. 6 * 7 * Copyright (c) 2002 Matthieu Herrb 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 14 * - Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * - Redistributions in binary form must reproduce the above 17 * copyright notice, this list of conditions and the following 18 * disclaimer in the documentation and/or other materials provided 19 * with the distribution. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 29 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 31 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 32 * POSSIBILITY OF SUCH DAMAGE. 33 */ 34 #include <sys/param.h> 35 #include <sys/uio.h> 36 #include <sys/types.h> 37 #include <sys/socket.h> 38 #include <sys/stat.h> 39 #include <err.h> 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <signal.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 #include "pflogd.h" 48 49 void 50 send_fd(int sock, int fd) 51 { 52 struct msghdr msg; 53 union { 54 struct cmsghdr hdr; 55 char buf[CMSG_SPACE(sizeof(int))]; 56 } cmsgbuf; 57 struct cmsghdr *cmsg; 58 struct iovec vec; 59 int result = 0; 60 ssize_t n; 61 62 memset(&msg, 0, sizeof(msg)); 63 64 if (fd >= 0) { 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 } else { 73 result = errno; 74 } 75 76 vec.iov_base = &result; 77 vec.iov_len = sizeof(int); 78 msg.msg_iov = &vec; 79 msg.msg_iovlen = 1; 80 81 if ((n = sendmsg(sock, &msg, 0)) == -1) 82 warn("%s: sendmsg(%d)", __func__, sock); 83 if (n != sizeof(int)) 84 warnx("%s: sendmsg: expected sent 1 got %ld", 85 __func__, (long)n); 86 } 87 88 int 89 receive_fd(int sock) 90 { 91 struct msghdr msg; 92 union { 93 struct cmsghdr hdr; 94 char buf[CMSG_SPACE(sizeof(int))]; 95 } cmsgbuf; 96 struct cmsghdr *cmsg; 97 struct iovec vec; 98 ssize_t n; 99 int result; 100 int fd; 101 102 memset(&msg, 0, sizeof(msg)); 103 vec.iov_base = &result; 104 vec.iov_len = sizeof(int); 105 msg.msg_iov = &vec; 106 msg.msg_iovlen = 1; 107 msg.msg_control = &cmsgbuf.buf; 108 msg.msg_controllen = sizeof(cmsgbuf.buf); 109 110 if ((n = recvmsg(sock, &msg, 0)) == -1) 111 warn("%s: recvmsg", __func__); 112 if (n != sizeof(int)) 113 warnx("%s: recvmsg: expected received 1 got %ld", 114 __func__, (long)n); 115 if (result == 0) { 116 cmsg = CMSG_FIRSTHDR(&msg); 117 if (cmsg == NULL) { 118 warnx("%s: no message header", __func__); 119 return -1; 120 } 121 if (cmsg->cmsg_type != SCM_RIGHTS) 122 warnx("%s: expected type %d got %d", __func__, 123 SCM_RIGHTS, cmsg->cmsg_type); 124 fd = (*(int *)CMSG_DATA(cmsg)); 125 return fd; 126 } else { 127 errno = result; 128 return -1; 129 } 130 } 131