1 /*- 2 * Copyright (c) 2009-2010 The FreeBSD Foundation 3 * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net> 4 * All rights reserved. 5 * 6 * This software was developed by Pawel Jakub Dawidek under sponsorship from 7 * the FreeBSD Foundation. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/types.h> 35 #include <sys/socket.h> 36 37 #include <errno.h> 38 #include <fcntl.h> 39 #include <stdbool.h> 40 #include <stdlib.h> 41 #include <strings.h> 42 #include <unistd.h> 43 44 #include "pjdlog.h" 45 #include "proto_impl.h" 46 47 /* Maximum size of packet we want to use when sending data. */ 48 #ifndef MAX_SEND_SIZE 49 #define MAX_SEND_SIZE 32768 50 #endif 51 52 static bool 53 blocking_socket(int sock) 54 { 55 int flags; 56 57 flags = fcntl(sock, F_GETFL); 58 PJDLOG_ASSERT(flags >= 0); 59 return ((flags & O_NONBLOCK) == 0); 60 } 61 62 static int 63 proto_descriptor_send(int sock, int fd) 64 { 65 unsigned char ctrl[CMSG_SPACE(sizeof(fd))]; 66 struct msghdr msg; 67 struct cmsghdr *cmsg; 68 69 PJDLOG_ASSERT(sock >= 0); 70 PJDLOG_ASSERT(fd >= 0); 71 72 bzero(&msg, sizeof(msg)); 73 bzero(&ctrl, sizeof(ctrl)); 74 75 msg.msg_iov = NULL; 76 msg.msg_iovlen = 0; 77 msg.msg_control = ctrl; 78 msg.msg_controllen = sizeof(ctrl); 79 80 cmsg = CMSG_FIRSTHDR(&msg); 81 cmsg->cmsg_level = SOL_SOCKET; 82 cmsg->cmsg_type = SCM_RIGHTS; 83 cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); 84 bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd)); 85 86 if (sendmsg(sock, &msg, 0) == -1) 87 return (errno); 88 89 return (0); 90 } 91 92 int 93 proto_common_send(int sock, const unsigned char *data, size_t size, int fd) 94 { 95 ssize_t done; 96 size_t sendsize; 97 98 PJDLOG_ASSERT(sock >= 0); 99 100 if (data == NULL) { 101 /* The caller is just trying to decide about direction. */ 102 103 PJDLOG_ASSERT(size == 0); 104 105 if (shutdown(sock, SHUT_RD) == -1) 106 return (errno); 107 return (0); 108 } 109 110 PJDLOG_ASSERT(data != NULL); 111 PJDLOG_ASSERT(size > 0); 112 113 do { 114 sendsize = size < MAX_SEND_SIZE ? size : MAX_SEND_SIZE; 115 done = send(sock, data, sendsize, MSG_NOSIGNAL); 116 if (done == 0) { 117 return (ENOTCONN); 118 } else if (done < 0) { 119 if (errno == EINTR) 120 continue; 121 /* 122 * If this is blocking socket and we got EAGAIN, this 123 * means the request timed out. Translate errno to 124 * ETIMEDOUT, to give administrator a hint to 125 * eventually increase timeout. 126 */ 127 if (errno == EAGAIN && blocking_socket(sock)) 128 errno = ETIMEDOUT; 129 return (errno); 130 } 131 data += done; 132 size -= done; 133 } while (size > 0); 134 135 if (fd == -1) 136 return (0); 137 return (proto_descriptor_send(sock, fd)); 138 } 139 140 static int 141 proto_descriptor_recv(int sock, int *fdp) 142 { 143 unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))]; 144 struct msghdr msg; 145 struct cmsghdr *cmsg; 146 147 PJDLOG_ASSERT(sock >= 0); 148 PJDLOG_ASSERT(fdp != NULL); 149 150 bzero(&msg, sizeof(msg)); 151 bzero(&ctrl, sizeof(ctrl)); 152 153 msg.msg_iov = NULL; 154 msg.msg_iovlen = 0; 155 msg.msg_control = ctrl; 156 msg.msg_controllen = sizeof(ctrl); 157 158 if (recvmsg(sock, &msg, 0) == -1) 159 return (errno); 160 161 cmsg = CMSG_FIRSTHDR(&msg); 162 if (cmsg->cmsg_level != SOL_SOCKET || 163 cmsg->cmsg_type != SCM_RIGHTS) { 164 return (EINVAL); 165 } 166 bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp)); 167 168 return (0); 169 } 170 171 int 172 proto_common_recv(int sock, unsigned char *data, size_t size, int *fdp) 173 { 174 ssize_t done; 175 176 PJDLOG_ASSERT(sock >= 0); 177 178 if (data == NULL) { 179 /* The caller is just trying to decide about direction. */ 180 181 PJDLOG_ASSERT(size == 0); 182 183 if (shutdown(sock, SHUT_WR) == -1) 184 return (errno); 185 return (0); 186 } 187 188 PJDLOG_ASSERT(data != NULL); 189 PJDLOG_ASSERT(size > 0); 190 191 do { 192 done = recv(sock, data, size, MSG_WAITALL); 193 } while (done == -1 && errno == EINTR); 194 if (done == 0) { 195 return (ENOTCONN); 196 } else if (done < 0) { 197 /* 198 * If this is blocking socket and we got EAGAIN, this 199 * means the request timed out. Translate errno to 200 * ETIMEDOUT, to give administrator a hint to 201 * eventually increase timeout. 202 */ 203 if (errno == EAGAIN && blocking_socket(sock)) 204 errno = ETIMEDOUT; 205 return (errno); 206 } 207 if (fdp == NULL) 208 return (0); 209 return (proto_descriptor_recv(sock, fdp)); 210 } 211