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 int errcount = 0; 98 99 PJDLOG_ASSERT(sock >= 0); 100 101 if (data == NULL) { 102 /* The caller is just trying to decide about direction. */ 103 104 PJDLOG_ASSERT(size == 0); 105 106 if (shutdown(sock, SHUT_RD) == -1) 107 return (errno); 108 return (0); 109 } 110 111 PJDLOG_ASSERT(data != NULL); 112 PJDLOG_ASSERT(size > 0); 113 114 do { 115 sendsize = size < MAX_SEND_SIZE ? size : MAX_SEND_SIZE; 116 done = send(sock, data, sendsize, MSG_NOSIGNAL); 117 if (done == 0) { 118 return (ENOTCONN); 119 } else if (done < 0) { 120 if (errno == EINTR) 121 continue; 122 if (errno == ENOBUFS) { 123 /* 124 * If there are no buffers we retry. 125 * After each try we increase delay before the 126 * next one and we give up after fifteen times. 127 * This gives 11s of total wait time. 128 */ 129 if (errcount == 15) { 130 pjdlog_warning("Getting ENOBUFS errors for 11s on send(), giving up."); 131 } else { 132 if (errcount == 0) 133 pjdlog_warning("Got ENOBUFS error on send(), retrying for a bit."); 134 errcount++; 135 usleep(100000 * errcount); 136 continue; 137 } 138 } 139 /* 140 * If this is blocking socket and we got EAGAIN, this 141 * means the request timed out. Translate errno to 142 * ETIMEDOUT, to give administrator a hint to 143 * eventually increase timeout. 144 */ 145 if (errno == EAGAIN && blocking_socket(sock)) 146 errno = ETIMEDOUT; 147 return (errno); 148 } 149 data += done; 150 size -= done; 151 } while (size > 0); 152 if (errcount > 0) { 153 pjdlog_info("Data sent successfully after %d ENOBUFS error%s.", 154 errcount, errcount == 1 ? "" : "s"); 155 } 156 157 if (fd == -1) 158 return (0); 159 return (proto_descriptor_send(sock, fd)); 160 } 161 162 static int 163 proto_descriptor_recv(int sock, int *fdp) 164 { 165 unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))]; 166 struct msghdr msg; 167 struct cmsghdr *cmsg; 168 169 PJDLOG_ASSERT(sock >= 0); 170 PJDLOG_ASSERT(fdp != NULL); 171 172 bzero(&msg, sizeof(msg)); 173 bzero(&ctrl, sizeof(ctrl)); 174 175 msg.msg_iov = NULL; 176 msg.msg_iovlen = 0; 177 msg.msg_control = ctrl; 178 msg.msg_controllen = sizeof(ctrl); 179 180 if (recvmsg(sock, &msg, 0) == -1) 181 return (errno); 182 183 cmsg = CMSG_FIRSTHDR(&msg); 184 if (cmsg->cmsg_level != SOL_SOCKET || 185 cmsg->cmsg_type != SCM_RIGHTS) { 186 return (EINVAL); 187 } 188 bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp)); 189 190 return (0); 191 } 192 193 int 194 proto_common_recv(int sock, unsigned char *data, size_t size, int *fdp) 195 { 196 ssize_t done; 197 size_t total_done, recvsize; 198 unsigned char *dp; 199 200 PJDLOG_ASSERT(sock >= 0); 201 202 if (data == NULL) { 203 /* The caller is just trying to decide about direction. */ 204 205 PJDLOG_ASSERT(size == 0); 206 207 if (shutdown(sock, SHUT_WR) == -1) 208 return (errno); 209 return (0); 210 } 211 212 PJDLOG_ASSERT(data != NULL); 213 PJDLOG_ASSERT(size > 0); 214 215 total_done = 0; 216 dp = data; 217 do { 218 recvsize = size - total_done; 219 recvsize = recvsize < MAX_SEND_SIZE ? recvsize : MAX_SEND_SIZE; 220 done = recv(sock, dp, recvsize, MSG_WAITALL); 221 if (done == -1 && errno == EINTR) 222 continue; 223 if (done <= 0) 224 break; 225 total_done += done; 226 dp += done; 227 } while (total_done < size); 228 if (done == 0) { 229 return (ENOTCONN); 230 } else if (done < 0) { 231 /* 232 * If this is blocking socket and we got EAGAIN, this 233 * means the request timed out. Translate errno to 234 * ETIMEDOUT, to give administrator a hint to 235 * eventually increase timeout. 236 */ 237 if (errno == EAGAIN && blocking_socket(sock)) 238 errno = ETIMEDOUT; 239 return (errno); 240 } 241 if (fdp == NULL) 242 return (0); 243 return (proto_descriptor_recv(sock, fdp)); 244 } 245