lib/socket.c

   1 /*
   2    Copyright (C) 2010 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as published by
   6    the Free Software Foundation; either version 2.1 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program; if not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <poll.h>
  26 #include <string.h>
  27 #include <errno.h>
  28 #include <rpc/rpc.h>
  29 #include <rpc/xdr.h>
  30 #include <arpa/inet.h>
  31 #ifdef HAVE_SYS_FILIO_H
  32 #include <sys/filio.h>
  33 #endif
  34 #include <sys/ioctl.h>
  35 #include <sys/types.h>
  36 #include <sys/socket.h>
  37 #include <netdb.h>
  38 #include "libnfs.h"
  39 #include "libnfs-raw.h"
  40 #include "libnfs-private.h"
  41 #include "slist.h"
  42
  43 static void set_nonblocking(int fd)
  44 {
  45         unsigned v;
  46         v = fcntl(fd, F_GETFL, 0);
  47         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  48 }
  49
  50 int rpc_get_fd(struct rpc_context *rpc)
  51 {
  52         return rpc->fd;
  53 }
  54
  55 int rpc_which_events(struct rpc_context *rpc)
  56 {
  57         int events = rpc->is_connected ? POLLIN : POLLOUT;
  58
  59         if (rpc->is_udp != 0) {
  60                 /* for udp sockets we only wait for pollin */
  61                 return POLLIN;
  62         }
  63
  64         if (rpc->outqueue) {
  65                 events |= POLLOUT;
  66         }
  67         return events;
  68 }
  69
  70 static int rpc_write_to_socket(struct rpc_context *rpc)
  71 {
  72         ssize_t count;
  73
  74         if (rpc == NULL) {
  75                 return -1;
  76         }
  77         if (rpc->fd == -1) {
  78                 rpc_set_error(rpc, "trying to write but not connected");
  79                 return -1;
  80         }
  81
  82         while (rpc->outqueue != NULL) {
  83                 ssize_t total;
  84
  85                 total = rpc->outqueue->outdata.size;
  86
  87                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
  88                 if (count == -1) {
  89                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
  90                                 return 0;
  91                         }
  92                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
  93                         return -1;
  94                 }
  95
  96                 rpc->outqueue->written += count;
  97                 if (rpc->outqueue->written == total) {
  98                         struct rpc_pdu *pdu = rpc->outqueue;
  99
 100                         SLIST_REMOVE(&rpc->outqueue, pdu);
 101                         SLIST_ADD_END(&rpc->waitpdu, pdu);
 102                 }
 103         }
 104         return 0;
 105 }
 106
 107 static int rpc_read_from_socket(struct rpc_context *rpc)
 108 {
 109         int available;
 110         int size;
 111         int pdu_size;
 112         ssize_t count;
 113
 114         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 115                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 116                 return -1;
 117         }
 118         if (available == 0) {
 119                 rpc_set_error(rpc, "Socket has been closed");
 120                 return -1;
 121         }
 122
 123         if (rpc->is_udp) {
 124                 char *buf;
 125                 socklen_t socklen = sizeof(rpc->udp_src);
 126
 127                 buf = malloc(available);
 128                 if (buf == NULL) {
 129                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 130                         return -1;
 131                 }
 132                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 133                 if (count < 0) {
 134                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 135                         free(buf);
 136                 }
 137                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 138                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 139                         free(buf);
 140                         return -1;
 141                 }
 142                 free(buf);
 143                 return 0;
 144         }
 145
 146         /* read record marker, 4 bytes at the beginning of every pdu */
 147         if (rpc->inbuf == NULL) {
 148                 rpc->insize = 4;
 149                 rpc->inbuf = malloc(rpc->insize);
 150                 if (rpc->inbuf == NULL) {
 151                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 152                         return -1;
 153                 }
 154         }
 155         if (rpc->inpos < 4) {
 156                 size = 4 - rpc->inpos;
 157
 158                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 159                 if (count == -1) {
 160                         if (errno == EINTR) {
 161                                 return 0;
 162                         }
 163                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 164                         return -1;
 165                 }
 166                 available  -= count;
 167                 rpc->inpos += count;
 168         }
 169
 170         if (available == 0) {
 171                 return 0;
 172         }
 173
 174         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 175         if (rpc->insize < pdu_size) {
 176                 unsigned char *buf;
 177
 178                 buf = malloc(pdu_size);
 179                 if (buf == NULL) {
 180                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 181                         return -1;
 182                 }
 183                 memcpy(buf, rpc->inbuf, rpc->insize);
 184                 free(rpc->inbuf);
 185                 rpc->inbuf  = buf;
 186                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 187         }
 188
 189         size = available;
 190         if (size > rpc->insize - rpc->inpos) {
 191                 size = rpc->insize - rpc->inpos;
 192         }
 193
 194         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 195         if (count == -1) {
 196                 if (errno == EINTR) {
 197                         return 0;
 198                 }
 199                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 200                 return -1;
 201         }
 202         available  -= count;
 203         rpc->inpos += count;
 204
 205         if (rpc->inpos == rpc->insize) {
 206                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 207                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 208                         return -1;
 209                 }
 210                 free(rpc->inbuf);
 211                 rpc->inbuf  = NULL;
 212                 rpc->insize = 0;
 213                 rpc->inpos  = 0;
 214         }
 215
 216         return 0;
 217 }
 218
 219
 220
 221 int rpc_service(struct rpc_context *rpc, int revents)
 222 {
 223         if (revents & POLLERR) {
 224                 int err = 0;
 225                 socklen_t err_size = sizeof(err);
 226
 227                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 228                                 &err, &err_size) != 0 || err != 0) {
 229                         if (err == 0) {
 230                                 err = errno;
 231                         }
 232                         rpc_set_error(rpc, "rpc_service: socket error "
 233                                                "%s(%d).",
 234                                                strerror(err), err);
 235                 } else {
 236                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 237                                                 "Unknown socket error.");
 238                 }
 239                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 240                 return -1;
 241         }
 242         if (revents & POLLHUP) {
 243                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 244                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 245                 return -1;
 246         }
 247
 248         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 249                 int err = 0;
 250                 socklen_t err_size = sizeof(err);
 251
 252                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 253                                 &err, &err_size) != 0 || err != 0) {
 254                         if (err == 0) {
 255                                 err = errno;
 256                         }
 257                         rpc_set_error(rpc, "rpc_service: socket error "
 258                                         "%s(%d) while connecting.",
 259                                         strerror(err), err);
 260                         rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 261                                         NULL, rpc->connect_data);
 262                         return -1;
 263                 }
 264
 265                 rpc->is_connected = 1;
 266                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 267                 return 0;
 268         }
 269
 270         if (revents & POLLOUT && rpc->outqueue != NULL) {
 271                 if (rpc_write_to_socket(rpc) != 0) {
 272                         rpc_set_error(rpc, "write to socket failed");
 273                         return -1;
 274                 }
 275         }
 276
 277         if (revents & POLLIN) {
 278                 if (rpc_read_from_socket(rpc) != 0) {
 279                         rpc_disconnect(rpc, rpc_get_error(rpc));
 280                         return -1;
 281                 }
 282         }
 283
 284         return 0;
 285 }
 286
 287
 288 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 289 {
 290         struct sockaddr_storage s;
 291         struct sockaddr_in *sin = (struct sockaddr_in *)&s;
 292         int socksize;
 293
 294         if (rpc->fd != -1) {
 295                 rpc_set_error(rpc, "Trying to connect while already connected");
 296                 return -1;
 297         }
 298
 299         if (rpc->is_udp != 0) {
 300                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 301                 return -1;
 302         }
 303
 304         sin->sin_family = AF_INET;
 305         sin->sin_port   = htons(port);
 306         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 307                 rpc_set_error(rpc, "Not a valid server ip address");
 308                 return -1;
 309         }
 310
 311         switch (s.ss_family) {
 312         case AF_INET:
 313                 socksize = sizeof(struct sockaddr_in);
 314 #ifdef HAVE_SOCKADDR_LEN
 315                 sin->sin_len = socksize;
 316 #endif
 317                 rpc->fd = socket(AF_INET, SOCK_STREAM, 0);
 318                 break;
 319         }
 320
 321         if (rpc->fd == -1) {
 322                 rpc_set_error(rpc, "Failed to open socket");
 323                 return -1;
 324         }
 325
 326         rpc->connect_cb  = cb;
 327         rpc->connect_data = private_data;
 328
 329         set_nonblocking(rpc->fd);
 330
 331         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) != 0 && errno != EINPROGRESS) {
 332                 rpc_set_error(rpc, "connect() to server failed");
 333                 return -1;
 334         }
 335
 336         return 0;
 337 }
 338
 339 int rpc_disconnect(struct rpc_context *rpc, char *error)
 340 {
 341         if (rpc->fd != -1) {
 342                 close(rpc->fd);
 343         }
 344         rpc->fd  = -1;
 345
 346         rpc->is_connected = 0;
 347
 348         rpc_error_all_pdus(rpc, error);
 349
 350         return 0;
 351 }
 352
 353
 354 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 355 {
 356         struct addrinfo *ai = NULL;
 357         char service[6];
 358
 359         if (rpc->is_udp == 0) {
 360                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 361                 return -1;
 362         }
 363
 364         snprintf(service, 6, "%d", port);
 365         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 366                 rpc_set_error(rpc, "Invalid address:%s. "
 367                         "Can not resolv into IPv4/v6 structure.");
 368                 return -1;
 369         }
 370
 371         switch(ai->ai_family) {
 372         case AF_INET:
 373                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 374                 if (rpc->fd == -1) {
 375                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 376                         freeaddrinfo(ai);
 377                         return -1;
 378                 }
 379
 380                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 381                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 382                         freeaddrinfo(ai);
 383                         return -1;
 384                 }
 385                 break;
 386         default:
 387                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 388                 freeaddrinfo(ai);
 389                 return -1;
 390         }
 391
 392         freeaddrinfo(ai);
 393
 394         return 0;
 395 }
 396
 397 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 398 {
 399         struct addrinfo *ai = NULL;
 400         char service[6];
 401
 402         if (rpc->is_udp == 0) {
 403                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 404                 return -1;
 405         }
 406
 407         snprintf(service, 6, "%d", port);
 408         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 409                 rpc_set_error(rpc, "Invalid address:%s. "
 410                         "Can not resolv into IPv4/v6 structure.");
 411                 return -1;
 412         }
 413
 414         if (rpc->udp_dest) {
 415                 free(rpc->udp_dest);
 416                 rpc->udp_dest = NULL;
 417         }
 418         rpc->udp_dest = malloc(ai->ai_addrlen);
 419         if (rpc->udp_dest == NULL) {
 420                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 421                 return -1;
 422         }
 423         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 424         freeaddrinfo(ai);
 425
 426         rpc->is_broadcast = is_broadcast;
 427         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, &is_broadcast, sizeof(is_broadcast));
 428
 429         return 0;
 430 }
 431
 432 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 433 {
 434         return (struct sockaddr *)&rpc->udp_src;
 435 }