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