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 #ifdef HAVE_SYS_SOCKIO_H
  35 #include <sys/sockio.h>
  36 #endif
  37 #include <sys/ioctl.h>
  38 #include <sys/types.h>
  39 #include <sys/socket.h>
  40 #include <netdb.h>
  41 #include "libnfs.h"
  42 #include "libnfs-raw.h"
  43 #include "libnfs-private.h"
  44 #include "slist.h"
  45
  46 static int rpc_disconnect_requeue(struct rpc_context *rpc);
  47
  48 static void set_nonblocking(int fd)
  49 {
  50         unsigned v;
  51         v = fcntl(fd, F_GETFL, 0);
  52         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  53 }
  54
  55 int rpc_get_fd(struct rpc_context *rpc)
  56 {
  57         return rpc->fd;
  58 }
  59
  60 int rpc_which_events(struct rpc_context *rpc)
  61 {
  62         int events = rpc->is_connected ? POLLIN : POLLOUT;
  63
  64         if (rpc->is_udp != 0) {
  65                 /* for udp sockets we only wait for pollin */
  66                 return POLLIN;
  67         }
  68
  69         if (rpc->outqueue) {
  70                 events |= POLLOUT;
  71         }
  72         return events;
  73 }
  74
  75 static int rpc_write_to_socket(struct rpc_context *rpc)
  76 {
  77         ssize_t count;
  78
  79         if (rpc == NULL) {
  80                 return -1;
  81         }
  82         if (rpc->fd == -1) {
  83                 rpc_set_error(rpc, "trying to write but not connected");
  84                 return -1;
  85         }
  86
  87         while (rpc->outqueue != NULL) {
  88                 ssize_t total;
  89
  90                 total = rpc->outqueue->outdata.size;
  91
  92                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
  93                 if (count == -1) {
  94                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
  95                                 return 0;
  96                         }
  97                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
  98                         return -1;
  99                 }
 100
 101                 rpc->outqueue->written += count;
 102                 if (rpc->outqueue->written == total) {
 103                         struct rpc_pdu *pdu = rpc->outqueue;
 104
 105                         SLIST_REMOVE(&rpc->outqueue, pdu);
 106                         SLIST_ADD_END(&rpc->waitpdu, pdu);
 107                 }
 108         }
 109         return 0;
 110 }
 111
 112 static int rpc_read_from_socket(struct rpc_context *rpc)
 113 {
 114         int available;
 115         int size;
 116         int pdu_size;
 117         ssize_t count;
 118
 119         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 120                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 121                 return -1;
 122         }
 123         if (available == 0) {
 124                 rpc_set_error(rpc, "Socket has been closed");
 125                 return -1;
 126         }
 127
 128         if (rpc->is_udp) {
 129                 char *buf;
 130                 socklen_t socklen = sizeof(rpc->udp_src);
 131
 132                 buf = malloc(available);
 133                 if (buf == NULL) {
 134                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 135                         return -1;
 136                 }
 137                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 138                 if (count < 0) {
 139                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 140                         free(buf);
 141                 }
 142                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 143                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 144                         free(buf);
 145                         return -1;
 146                 }
 147                 free(buf);
 148                 return 0;
 149         }
 150
 151         /* read record marker, 4 bytes at the beginning of every pdu */
 152         if (rpc->inbuf == NULL) {
 153                 rpc->insize = 4;
 154                 rpc->inbuf = malloc(rpc->insize);
 155                 if (rpc->inbuf == NULL) {
 156                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 157                         return -1;
 158                 }
 159         }
 160         if (rpc->inpos < 4) {
 161                 size = 4 - rpc->inpos;
 162
 163                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 164                 if (count == -1) {
 165                         if (errno == EINTR) {
 166                                 return 0;
 167                         }
 168                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 169                         return -1;
 170                 }
 171                 available  -= count;
 172                 rpc->inpos += count;
 173         }
 174
 175         if (available == 0) {
 176                 return 0;
 177         }
 178
 179         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 180         if (rpc->insize < pdu_size) {
 181                 unsigned char *buf;
 182
 183                 buf = malloc(pdu_size);
 184                 if (buf == NULL) {
 185                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 186                         return -1;
 187                 }
 188                 memcpy(buf, rpc->inbuf, rpc->insize);
 189                 free(rpc->inbuf);
 190                 rpc->inbuf  = buf;
 191                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 192         }
 193
 194         size = available;
 195         if (size > rpc->insize - rpc->inpos) {
 196                 size = rpc->insize - rpc->inpos;
 197         }
 198
 199         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 200         if (count == -1) {
 201                 if (errno == EINTR) {
 202                         return 0;
 203                 }
 204                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 205                 return -1;
 206         }
 207         available  -= count;
 208         rpc->inpos += count;
 209
 210         if (rpc->inpos == rpc->insize) {
 211                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 212                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 213                         return -1;
 214                 }
 215                 free(rpc->inbuf);
 216                 rpc->inbuf  = NULL;
 217                 rpc->insize = 0;
 218                 rpc->inpos  = 0;
 219         }
 220
 221         return 0;
 222 }
 223
 224
 225
 226 int rpc_service(struct rpc_context *rpc, int revents)
 227 {
 228         if (revents & POLLERR) {
 229                 int err = 0;
 230                 socklen_t err_size = sizeof(err);
 231
 232                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 233                                 &err, &err_size) != 0 || err != 0) {
 234                         if (err == 0) {
 235                                 err = errno;
 236                         }
 237                         rpc_set_error(rpc, "rpc_service: socket error "
 238                                                "%s(%d).",
 239                                                strerror(err), err);
 240                 } else {
 241                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 242                                                 "Unknown socket error.");
 243                 }
 244                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 245                 return -1;
 246         }
 247         if (revents & POLLHUP) {
 248                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 249                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 250                 return -1;
 251         }
 252
 253         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 254                 int err = 0;
 255                 socklen_t err_size = sizeof(err);
 256
 257                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 258                                 &err, &err_size) != 0 || err != 0) {
 259                         if (err == 0) {
 260                                 err = errno;
 261                         }
 262                         rpc_set_error(rpc, "rpc_service: socket error "
 263                                         "%s(%d) while connecting.",
 264                                         strerror(err), err);
 265                         rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 266                                         NULL, rpc->connect_data);
 267                         return -1;
 268                 }
 269
 270                 rpc->is_connected = 1;
 271                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 272                 return 0;
 273         }
 274
 275         if (revents & POLLIN) {
 276                 if (rpc_read_from_socket(rpc) != 0) {
 277                         rpc_disconnect_requeue(rpc);
 278                         return 0;
 279                 }
 280         }
 281
 282         if (revents & POLLOUT && rpc->outqueue != NULL) {
 283                 if (rpc_write_to_socket(rpc) != 0) {
 284                         rpc_set_error(rpc, "write to socket failed");
 285                         return -1;
 286                 }
 287         }
 288
 289         return 0;
 290 }
 291
 292
 293 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 294 {
 295         struct sockaddr_storage s;
 296         struct sockaddr_in *sin = (struct sockaddr_in *)&s;
 297         int socksize;
 298
 299         if (rpc->fd != -1) {
 300                 rpc_set_error(rpc, "Trying to connect while already connected");
 301                 return -1;
 302         }
 303
 304         if (rpc->is_udp != 0) {
 305                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 306                 return -1;
 307         }
 308
 309         sin->sin_family = AF_INET;
 310         sin->sin_port   = htons(port);
 311         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 312                 rpc_set_error(rpc, "Not a valid server ip address");
 313                 return -1;
 314         }
 315
 316         switch (s.ss_family) {
 317         case AF_INET:
 318                 socksize = sizeof(struct sockaddr_in);
 319 #ifdef HAVE_SOCKADDR_LEN
 320                 sin->sin_len = socksize;
 321 #endif
 322                 rpc->fd = socket(AF_INET, SOCK_STREAM, 0);
 323                 break;
 324         }
 325
 326         if (rpc->fd == -1) {
 327                 rpc_set_error(rpc, "Failed to open socket");
 328                 return -1;
 329         }
 330
 331         rpc->connect_cb  = cb;
 332         rpc->connect_data = private_data;
 333
 334         set_nonblocking(rpc->fd);
 335
 336         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) != 0 && errno != EINPROGRESS) {
 337                 rpc_set_error(rpc, "connect() to server failed");
 338                 return -1;
 339         }
 340
 341         return 0;
 342 }
 343
 344 int rpc_disconnect(struct rpc_context *rpc, char *error)
 345 {
 346         if (rpc->fd != -1) {
 347                 close(rpc->fd);
 348         }
 349         rpc->fd  = -1;
 350
 351         rpc->is_connected = 0;
 352
 353         rpc_error_all_pdus(rpc, error);
 354
 355         return 0;
 356 }
 357
 358 /* disconnect but do not error all PDUs, just move pdus in-flight back to the outqueue */
 359 static int rpc_disconnect_requeue(struct rpc_context *rpc)
 360 {
 361         struct rpc_pdu *pdu;
 362
 363         if (rpc->fd != -1) {
 364                 close(rpc->fd);
 365         }
 366         rpc->fd  = -1;
 367
 368         rpc->is_connected = 0;
 369
 370         /* socket is closed so we will not get any replies to any commands
 371          * in flight. Move them all over from the waitpdu queue back to the out queue
 372          */
 373         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 374                 SLIST_REMOVE(&rpc->waitpdu, pdu);
 375                 SLIST_ADD(&rpc->outqueue, pdu);
 376         }
 377
 378         return 0;
 379 }
 380
 381
 382 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 383 {
 384         struct addrinfo *ai = NULL;
 385         char service[6];
 386
 387         if (rpc->is_udp == 0) {
 388                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 389                 return -1;
 390         }
 391
 392         snprintf(service, 6, "%d", port);
 393         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 394                 rpc_set_error(rpc, "Invalid address:%s. "
 395                         "Can not resolv into IPv4/v6 structure.");
 396                 return -1;
 397         }
 398
 399         switch(ai->ai_family) {
 400         case AF_INET:
 401                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 402                 if (rpc->fd == -1) {
 403                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 404                         freeaddrinfo(ai);
 405                         return -1;
 406                 }
 407
 408                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 409                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 410                         freeaddrinfo(ai);
 411                         return -1;
 412                 }
 413                 break;
 414         default:
 415                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 416                 freeaddrinfo(ai);
 417                 return -1;
 418         }
 419
 420         freeaddrinfo(ai);
 421
 422         return 0;
 423 }
 424
 425 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 426 {
 427         struct addrinfo *ai = NULL;
 428         char service[6];
 429
 430         if (rpc->is_udp == 0) {
 431                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 432                 return -1;
 433         }
 434
 435         snprintf(service, 6, "%d", port);
 436         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 437                 rpc_set_error(rpc, "Invalid address:%s. "
 438                         "Can not resolv into IPv4/v6 structure.");
 439                 return -1;
 440         }
 441
 442         if (rpc->udp_dest) {
 443                 free(rpc->udp_dest);
 444                 rpc->udp_dest = NULL;
 445         }
 446         rpc->udp_dest = malloc(ai->ai_addrlen);
 447         if (rpc->udp_dest == NULL) {
 448                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 449                 return -1;
 450         }
 451         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 452         freeaddrinfo(ai);
 453
 454         rpc->is_broadcast = is_broadcast;
 455         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, &is_broadcast, sizeof(is_broadcast));
 456
 457         return 0;
 458 }
 459
 460 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 461 {
 462         return (struct sockaddr *)&rpc->udp_src;
 463 }