monitor_fdpass.c revision 124208
1/* 2 * Copyright 2001 Niels Provos <provos@citi.umich.edu> 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include "includes.h" 27RCSID("$OpenBSD: monitor_fdpass.c,v 1.4 2002/06/26 14:50:04 deraadt Exp $"); 28 29#include <sys/uio.h> 30 31#include "log.h" 32#include "monitor_fdpass.h" 33 34void 35mm_send_fd(int socket, int fd) 36{ 37#if defined(HAVE_SENDMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) 38 struct msghdr msg; 39 struct iovec vec; 40 char ch = '\0'; 41 ssize_t n; 42#ifndef HAVE_ACCRIGHTS_IN_MSGHDR 43 char tmp[CMSG_SPACE(sizeof(int))]; 44 struct cmsghdr *cmsg; 45#endif 46 47 memset(&msg, 0, sizeof(msg)); 48#ifdef HAVE_ACCRIGHTS_IN_MSGHDR 49 msg.msg_accrights = (caddr_t)&fd; 50 msg.msg_accrightslen = sizeof(fd); 51#else 52 msg.msg_control = (caddr_t)tmp; 53 msg.msg_controllen = CMSG_LEN(sizeof(int)); 54 cmsg = CMSG_FIRSTHDR(&msg); 55 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 56 cmsg->cmsg_level = SOL_SOCKET; 57 cmsg->cmsg_type = SCM_RIGHTS; 58 *(int *)CMSG_DATA(cmsg) = fd; 59#endif 60 61 vec.iov_base = &ch; 62 vec.iov_len = 1; 63 msg.msg_iov = &vec; 64 msg.msg_iovlen = 1; 65 66 if ((n = sendmsg(socket, &msg, 0)) == -1) 67 fatal("%s: sendmsg(%d): %s", __func__, fd, 68 strerror(errno)); 69 if (n != 1) 70 fatal("%s: sendmsg: expected sent 1 got %ld", 71 __func__, (long)n); 72#else 73 fatal("%s: UsePrivilegeSeparation=yes not supported", 74 __func__); 75#endif 76} 77 78int 79mm_receive_fd(int socket) 80{ 81#if defined(HAVE_RECVMSG) && (defined(HAVE_ACCRIGHTS_IN_MSGHDR) || defined(HAVE_CONTROL_IN_MSGHDR)) 82 struct msghdr msg; 83 struct iovec vec; 84 ssize_t n; 85 char ch; 86 int fd; 87#ifndef HAVE_ACCRIGHTS_IN_MSGHDR 88 char tmp[CMSG_SPACE(sizeof(int))]; 89 struct cmsghdr *cmsg; 90#endif 91 92 memset(&msg, 0, sizeof(msg)); 93 vec.iov_base = &ch; 94 vec.iov_len = 1; 95 msg.msg_iov = &vec; 96 msg.msg_iovlen = 1; 97#ifdef HAVE_ACCRIGHTS_IN_MSGHDR 98 msg.msg_accrights = (caddr_t)&fd; 99 msg.msg_accrightslen = sizeof(fd); 100#else 101 msg.msg_control = tmp; 102 msg.msg_controllen = sizeof(tmp); 103#endif 104 105 if ((n = recvmsg(socket, &msg, 0)) == -1) 106 fatal("%s: recvmsg: %s", __func__, strerror(errno)); 107 if (n != 1) 108 fatal("%s: recvmsg: expected received 1 got %ld", 109 __func__, (long)n); 110 111#ifdef HAVE_ACCRIGHTS_IN_MSGHDR 112 if (msg.msg_accrightslen != sizeof(fd)) 113 fatal("%s: no fd", __func__); 114#else 115 cmsg = CMSG_FIRSTHDR(&msg); 116#ifndef BROKEN_CMSG_TYPE 117 if (cmsg->cmsg_type != SCM_RIGHTS) 118 fatal("%s: expected type %d got %d", __func__, 119 SCM_RIGHTS, cmsg->cmsg_type); 120#endif 121 fd = (*(int *)CMSG_DATA(cmsg)); 122#endif 123 return fd; 124#else 125 fatal("%s: UsePrivilegeSeparation=yes not supported", 126 __func__); 127#endif 128} 129