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 <sys/types.h> 27 #include <sys/uio.h> 28 #include <errno.h> 29 #include <string.h> 30 31 #include "log.h" 32 #include "monitor.h" 33 34 int 35 mm_send_fd (int socket, int fd) 36 { 37 struct msghdr msg; 38 char tmp[CMSG_SPACE (sizeof (int))]; 39 struct cmsghdr *cmsg; 40 struct iovec vec; 41 char ch = '\0'; 42 ssize_t n; 43 44 memset(&msg, 0, sizeof msg); 45 msg.msg_control = (caddr_t)tmp; 46 msg.msg_controllen = CMSG_LEN (sizeof (int)); 47 cmsg = CMSG_FIRSTHDR (&msg); 48 cmsg->cmsg_len = CMSG_LEN (sizeof (int)); 49 cmsg->cmsg_level = SOL_SOCKET; 50 cmsg->cmsg_type = SCM_RIGHTS; 51 *(int *)CMSG_DATA (cmsg) = fd; 52 53 vec.iov_base = &ch; 54 vec.iov_len = 1; 55 msg.msg_iov = &vec; 56 msg.msg_iovlen = 1; 57 58 if ((n = sendmsg (socket, &msg, 0)) == -1) 59 { 60 log_error ("%s: sendmsg(%d)", __func__, fd); 61 return -1; 62 } 63 if (n != 1) 64 { 65 log_error ("%s: sendmsg: expected sent 1 got %ld", __func__, (long)n); 66 return -1; 67 } 68 return 0; 69 } 70 71 int 72 mm_receive_fd (int socket) 73 { 74 struct msghdr msg; 75 char tmp[CMSG_SPACE (sizeof (int))]; 76 struct cmsghdr *cmsg; 77 struct iovec vec; 78 ssize_t n; 79 char ch; 80 int fd; 81 82 memset (&msg, 0, sizeof msg); 83 vec.iov_base = &ch; 84 vec.iov_len = 1; 85 msg.msg_iov = &vec; 86 msg.msg_iovlen = 1; 87 msg.msg_control = tmp; 88 msg.msg_controllen = sizeof tmp; 89 90 if ((n = recvmsg(socket, &msg, 0)) == -1) 91 { 92 log_error ("%s: recvmsg", __func__); 93 return -1; 94 } 95 if (n != 1) 96 { 97 log_error ("%s: recvmsg: expected received 1 got %ld", __func__, 98 (long)n); 99 return -1; 100 } 101 102 cmsg = CMSG_FIRSTHDR (&msg); 103 if (cmsg->cmsg_type != SCM_RIGHTS) 104 { 105 log_error ("%s: expected type %d got %d", __func__, SCM_RIGHTS, 106 cmsg->cmsg_type); 107 return -1; 108 } 109 fd = (*(int *)CMSG_DATA (cmsg)); 110 111 return fd; 112 } 113