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/cdefs.h> 31 __FBSDID("$FreeBSD$"); 32 33 #include <sys/types.h> 34 #include <sys/select.h> 35 #include <sys/socket.h> 36 37 #include <assert.h> 38 #include <errno.h> 39 #include <stdlib.h> 40 #include <strings.h> 41 42 #include "misc.h" 43 44 int 45 pdwait(int pfd) 46 { 47 fd_set fdset; 48 49 FD_ZERO(&fdset); 50 FD_SET(pfd, &fdset); 51 52 return (select(pfd + 1, NULL, &fdset, NULL, NULL) == -1 ? -1 : 0); 53 } 54 55 int 56 descriptor_send(int sock, int fd) 57 { 58 unsigned char ctrl[CMSG_SPACE(sizeof(fd))]; 59 struct msghdr msg; 60 struct cmsghdr *cmsg; 61 62 assert(sock >= 0); 63 assert(fd >= 0); 64 65 bzero(&msg, sizeof(msg)); 66 bzero(&ctrl, sizeof(ctrl)); 67 68 msg.msg_iov = NULL; 69 msg.msg_iovlen = 0; 70 msg.msg_control = ctrl; 71 msg.msg_controllen = sizeof(ctrl); 72 73 cmsg = CMSG_FIRSTHDR(&msg); 74 cmsg->cmsg_level = SOL_SOCKET; 75 cmsg->cmsg_type = SCM_RIGHTS; 76 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 77 bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 78 79 if (sendmsg(sock, &msg, 0) == -1) 80 return (errno); 81 82 return (0); 83 } 84 85 int 86 descriptor_recv(int sock, int *fdp) 87 { 88 unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))]; 89 struct msghdr msg; 90 struct cmsghdr *cmsg; 91 struct iovec iov; 92 int val; 93 94 assert(sock >= 0); 95 assert(fdp != NULL); 96 97 bzero(&msg, sizeof(msg)); 98 bzero(&ctrl, sizeof(ctrl)); 99 100 #if 1 101 /* 102 * This doesn't really make sense, as we don't plan to receive any 103 * data, but if no buffer is provided and recv(2) returns 0 without 104 * control message. Must be kernel bug. 105 */ 106 iov.iov_base = &val; 107 iov.iov_len = sizeof(val); 108 msg.msg_iov = &iov; 109 msg.msg_iovlen = 1; 110 #else 111 msg.msg_iov = NULL; 112 msg.msg_iovlen = 0; 113 #endif 114 msg.msg_control = ctrl; 115 msg.msg_controllen = sizeof(ctrl); 116 117 if (recvmsg(sock, &msg, 0) == -1) 118 return (errno); 119 120 cmsg = CMSG_FIRSTHDR(&msg); 121 if (cmsg == NULL || cmsg->cmsg_level != SOL_SOCKET || 122 cmsg->cmsg_type != SCM_RIGHTS) { 123 return (EINVAL); 124 } 125 bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp)); 126 127 return (0); 128 } 129