1 /* $OpenBSD: monitor_fdpass.c,v 1.12 2006/08/03 03:34:42 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 <sys/types.h> 28 #include <sys/socket.h> 29 #include <sys/uio.h> 30 31 #include <errno.h> 32 #include <string.h> 33 #include <stdarg.h> 34 35 #include "log.h" 36 #include "monitor_fdpass.h" 37 38 void 39 mm_send_fd(int sock, int fd) 40 { 41 struct msghdr msg; 42 char tmp[CMSG_SPACE(sizeof(int))]; 43 struct cmsghdr *cmsg; 44 struct iovec vec; 45 char ch = '\0'; 46 ssize_t n; 47 48 memset(&msg, 0, sizeof(msg)); 49 msg.msg_control = (caddr_t)tmp; 50 msg.msg_controllen = CMSG_LEN(sizeof(int)); 51 cmsg = CMSG_FIRSTHDR(&msg); 52 cmsg->cmsg_len = CMSG_LEN(sizeof(int)); 53 cmsg->cmsg_level = SOL_SOCKET; 54 cmsg->cmsg_type = SCM_RIGHTS; 55 *(int *)CMSG_DATA(cmsg) = fd; 56 57 vec.iov_base = &ch; 58 vec.iov_len = 1; 59 msg.msg_iov = &vec; 60 msg.msg_iovlen = 1; 61 62 if ((n = sendmsg(sock, &msg, 0)) == -1) 63 fatal("%s: sendmsg(%d): %s", __func__, fd, 64 strerror(errno)); 65 if (n != 1) 66 fatal("%s: sendmsg: expected sent 1 got %ld", 67 __func__, (long)n); 68 } 69 70 int 71 mm_receive_fd(int sock) 72 { 73 struct msghdr msg; 74 char tmp[CMSG_SPACE(sizeof(int))]; 75 struct cmsghdr *cmsg; 76 struct iovec vec; 77 ssize_t n; 78 char ch; 79 int fd; 80 81 memset(&msg, 0, sizeof(msg)); 82 vec.iov_base = &ch; 83 vec.iov_len = 1; 84 msg.msg_iov = &vec; 85 msg.msg_iovlen = 1; 86 msg.msg_control = tmp; 87 msg.msg_controllen = sizeof(tmp); 88 89 if ((n = recvmsg(sock, &msg, 0)) == -1) 90 fatal("%s: recvmsg: %s", __func__, strerror(errno)); 91 if (n != 1) 92 fatal("%s: recvmsg: expected received 1 got %ld", 93 __func__, (long)n); 94 95 cmsg = CMSG_FIRSTHDR(&msg); 96 if (cmsg == NULL) 97 fatal("%s: no message header", __func__); 98 if (cmsg->cmsg_type != SCM_RIGHTS) 99 fatal("%s: expected type %d got %d", __func__, 100 SCM_RIGHTS, cmsg->cmsg_type); 101 fd = (*(int *)CMSG_DATA(cmsg)); 102 return fd; 103 } 104