1 /*- 2 * Copyright (c) 2012 The FreeBSD Foundation 3 * All rights reserved. 4 * 5 * This software was developed by Pawel Jakub Dawidek under sponsorship from 6 * the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/types.h> 31 #include <sys/select.h> 32 #include <sys/socket.h> 33 34 #include <assert.h> 35 #include <errno.h> 36 #include <stdlib.h> 37 #include <strings.h> 38 39 #include "misc.h" 40 41 int 42 pdwait(int pfd) 43 { 44 fd_set fdset; 45 46 FD_ZERO(&fdset); 47 FD_SET(pfd, &fdset); 48 49 return (select(pfd + 1, NULL, &fdset, NULL, NULL) == -1 ? -1 : 0); 50 } 51 52 int 53 descriptor_send(int sock, int fd) 54 { 55 unsigned char ctrl[CMSG_SPACE(sizeof(fd))]; 56 struct msghdr msg; 57 struct cmsghdr *cmsg; 58 59 assert(sock >= 0); 60 assert(fd >= 0); 61 62 bzero(&msg, sizeof(msg)); 63 bzero(&ctrl, sizeof(ctrl)); 64 65 msg.msg_iov = NULL; 66 msg.msg_iovlen = 0; 67 msg.msg_control = ctrl; 68 msg.msg_controllen = sizeof(ctrl); 69 70 cmsg = CMSG_FIRSTHDR(&msg); 71 cmsg->cmsg_level = SOL_SOCKET; 72 cmsg->cmsg_type = SCM_RIGHTS; 73 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 74 bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 75 76 if (sendmsg(sock, &msg, 0) == -1) 77 return (errno); 78 79 return (0); 80 } 81 82 int 83 descriptor_recv(int sock, int *fdp) 84 { 85 unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))]; 86 struct msghdr msg; 87 struct cmsghdr *cmsg; 88 struct iovec iov; 89 int val; 90 91 assert(sock >= 0); 92 assert(fdp != NULL); 93 94 bzero(&msg, sizeof(msg)); 95 bzero(&ctrl, sizeof(ctrl)); 96 97 #if 1 98 /* 99 * This doesn't really make sense, as we don't plan to receive any 100 * data, but if no buffer is provided and recv(2) returns 0 without 101 * control message. Must be kernel bug. 102 */ 103 iov.iov_base = &val; 104 iov.iov_len = sizeof(val); 105 msg.msg_iov = &iov; 106 msg.msg_iovlen = 1; 107 #else 108 msg.msg_iov = NULL; 109 msg.msg_iovlen = 0; 110 #endif 111 msg.msg_control = ctrl; 112 msg.msg_controllen = sizeof(ctrl); 113 114 if (recvmsg(sock, &msg, 0) == -1) 115 return (errno); 116 117 cmsg = CMSG_FIRSTHDR(&msg); 118 if (cmsg == NULL || cmsg->cmsg_level != SOL_SOCKET || 119 cmsg->cmsg_type != SCM_RIGHTS) { 120 return (EINVAL); 121 } 122 bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp)); 123 124 return (0); 125 } 126