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 #ifdef WIN32
  18 #include "win32_compat.h"
  19 #else
  20 #include <unistd.h>
  21 #include <poll.h>
  22 #include <arpa/inet.h>
  23 #include <sys/ioctl.h>
  24 #include <sys/socket.h>
  25 #include <netdb.h>
  26 #endif/*WIN32*/
  27
  28 #ifdef HAVE_CONFIG_H
  29 #include "config.h"
  30 #endif
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <assert.h>
  34 #include <fcntl.h>
  35 #include <string.h>
  36 #include <errno.h>
  37 #include <rpc/rpc.h>
  38 #include <rpc/xdr.h>
  39 #ifdef HAVE_SYS_FILIO_H
  40 #include <sys/filio.h>
  41 #endif
  42 #ifdef HAVE_SYS_SOCKIO_H
  43 #include <sys/sockio.h>
  44 #endif
  45 #include <sys/types.h>
  46 #include "libnfs.h"
  47 #include "libnfs-raw.h"
  48 #include "libnfs-private.h"
  49 #include "slist.h"
  50
  51 #ifdef WIN32
  52 //has to be included after stdlib!!
  53 #include "win32_errnowrapper.h"
  54 #endif
  55
  56
  57 static int rpc_reconnect_requeue(struct rpc_context *rpc);
  58 static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_storage *s);
  59
  60 static void set_nonblocking(int fd)
  61 {
  62         int v = 0;
  63 #if defined(WIN32)
  64         long nonblocking=1;
  65         v = ioctlsocket(fd, FIONBIO,&nonblocking);
  66 #else
  67         v = fcntl(fd, F_GETFL, 0);
  68         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  69 #endif //FIXME
  70 }
  71
  72 int rpc_get_fd(struct rpc_context *rpc)
  73 {
  74         assert(rpc->magic == RPC_CONTEXT_MAGIC);
  75
  76         return rpc->fd;
  77 }
  78
  79 int rpc_which_events(struct rpc_context *rpc)
  80 {
  81         int events;
  82
  83         assert(rpc->magic == RPC_CONTEXT_MAGIC);
  84
  85         events = rpc->is_connected ? POLLIN : POLLOUT;
  86
  87         if (rpc->is_udp != 0) {
  88                 /* for udp sockets we only wait for pollin */
  89                 return POLLIN;
  90         }
  91
  92         if (rpc->outqueue) {
  93                 events |= POLLOUT;
  94         }
  95         return events;
  96 }
  97
  98 static int rpc_write_to_socket(struct rpc_context *rpc)
  99 {
 100         int64_t count;
 101
 102         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 103
 104         if (rpc->fd == -1) {
 105                 rpc_set_error(rpc, "trying to write but not connected");
 106                 return -1;
 107         }
 108
 109         while (rpc->outqueue != NULL) {
 110                 int64_t total;
 111
 112                 total = rpc->outqueue->outdata.size;
 113
 114 #if defined(WIN32)
 115                 count = send(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written, 0);
 116 #else
 117                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
 118 #endif
 119                 if (count == -1) {
 120                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
 121                                 return 0;
 122                         }
 123                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
 124                         return -1;
 125                 }
 126
 127                 rpc->outqueue->written += count;
 128                 if (rpc->outqueue->written == total) {
 129                         struct rpc_pdu *pdu = rpc->outqueue;
 130
 131                         SLIST_REMOVE(&rpc->outqueue, pdu);
 132                         SLIST_ADD_END(&rpc->waitpdu, pdu);
 133                 }
 134         }
 135         return 0;
 136 }
 137
 138 static int rpc_read_from_socket(struct rpc_context *rpc)
 139 {
 140         int available;
 141         int size;
 142         int pdu_size;
 143         int64_t count;
 144
 145         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 146
 147 #if defined(WIN32)
 148         if (ioctlsocket(rpc->fd, FIONREAD, &available) != 0) {
 149 #else
 150         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 151 #endif
 152                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 153                 return -1;
 154         }
 155
 156         if (available == 0) {
 157                 rpc_set_error(rpc, "Socket has been closed");
 158                 return -1;
 159         }
 160
 161         if (rpc->is_udp) {
 162                 char *buf;
 163                 socklen_t socklen = sizeof(rpc->udp_src);
 164
 165                 buf = malloc(available);
 166                 if (buf == NULL) {
 167                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 168                         return -1;
 169                 }
 170                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 171                 if (count < 0) {
 172                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 173                         free(buf);
 174                 }
 175                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 176                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 177                         free(buf);
 178                         return -1;
 179                 }
 180                 free(buf);
 181                 return 0;
 182         }
 183
 184         /* read record marker, 4 bytes at the beginning of every pdu */
 185         if (rpc->inbuf == NULL) {
 186                 rpc->insize = 4;
 187                 rpc->inbuf = malloc(rpc->insize);
 188                 if (rpc->inbuf == NULL) {
 189                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 190                         return -1;
 191                 }
 192         }
 193         if (rpc->inpos < 4) {
 194                 size = 4 - rpc->inpos;
 195
 196 #if defined(WIN32)
 197                 count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 198 #else
 199                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 200 #endif
 201                 if (count == -1) {
 202                         if (errno == EINTR) {
 203                                 return 0;
 204                         }
 205                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 206                         return -1;
 207                 }
 208                 available  -= count;
 209                 rpc->inpos += count;
 210         }
 211
 212         if (available == 0) {
 213                 return 0;
 214         }
 215
 216         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 217         if (rpc->insize < pdu_size) {
 218                 unsigned char *buf;
 219
 220                 buf = malloc(pdu_size);
 221                 if (buf == NULL) {
 222                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 223                         return -1;
 224                 }
 225                 memcpy(buf, rpc->inbuf, rpc->insize);
 226                 free(rpc->inbuf);
 227                 rpc->inbuf  = buf;
 228                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 229         }
 230
 231         size = available;
 232         if (size > rpc->insize - rpc->inpos) {
 233                 size = rpc->insize - rpc->inpos;
 234         }
 235
 236 #if defined(WIN32)
 237         count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 238 #else
 239         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 240 #endif
 241         if (count == -1) {
 242                 if (errno == EINTR) {
 243                         return 0;
 244                 }
 245                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 246                 return -1;
 247         }
 248         available  -= count;
 249         rpc->inpos += count;
 250
 251         if (rpc->inpos == rpc->insize) {
 252                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 253                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 254                         return -1;
 255                 }
 256                 free(rpc->inbuf);
 257                 rpc->inbuf  = NULL;
 258                 rpc->insize = 0;
 259                 rpc->inpos  = 0;
 260         }
 261
 262         return 0;
 263 }
 264
 265
 266
 267 int rpc_service(struct rpc_context *rpc, int revents)
 268 {
 269         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 270
 271         if (revents & POLLERR) {
 272 #ifdef WIN32
 273                 char err = 0;
 274 #else
 275                 int err = 0;
 276 #endif
 277                 socklen_t err_size = sizeof(err);
 278
 279                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 280                                 (char *)&err, &err_size) != 0 || err != 0) {
 281                         if (err == 0) {
 282                                 err = errno;
 283                         }
 284                         rpc_set_error(rpc, "rpc_service: socket error "
 285                                                "%s(%d).",
 286                                                strerror(err), err);
 287                 } else {
 288                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 289                                                 "Unknown socket error.");
 290                 }
 291                 if (rpc->connect_cb != NULL) {
 292                         rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 293                 }
 294                 return -1;
 295         }
 296         if (revents & POLLHUP) {
 297                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 298                 if (rpc->connect_cb != NULL) {
 299                         rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 300                 }
 301                 return -1;
 302         }
 303
 304         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 305                 int err = 0;
 306                 socklen_t err_size = sizeof(err);
 307
 308                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 309                                 (char *)&err, &err_size) != 0 || err != 0) {
 310                         if (err == 0) {
 311                                 err = errno;
 312                         }
 313                         rpc_set_error(rpc, "rpc_service: socket error "
 314                                         "%s(%d) while connecting.",
 315                                         strerror(err), err);
 316                         if (rpc->connect_cb != NULL) {
 317                                 rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 318                                         NULL, rpc->connect_data);
 319                         }
 320                         return -1;
 321                 }
 322
 323                 rpc->is_connected = 1;
 324                 if (rpc->connect_cb != NULL) {
 325                         rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 326                 }
 327                 return 0;
 328         }
 329
 330         if (revents & POLLIN) {
 331                 if (rpc_read_from_socket(rpc) != 0) {
 332                         rpc_reconnect_requeue(rpc);
 333                         return 0;
 334                 }
 335         }
 336
 337         if (revents & POLLOUT && rpc->outqueue != NULL) {
 338                 if (rpc_write_to_socket(rpc) != 0) {
 339                         rpc_set_error(rpc, "write to socket failed");
 340                         return -1;
 341                 }
 342         }
 343
 344         return 0;
 345 }
 346
 347 void rpc_set_autoreconnect(struct rpc_context *rpc)
 348 {
 349         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 350
 351         rpc->auto_reconnect = 1;
 352 }
 353
 354 void rpc_unset_autoreconnect(struct rpc_context *rpc)
 355 {
 356         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 357
 358         rpc->auto_reconnect = 0;
 359 }
 360
 361 static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_storage *s)
 362 {
 363         int socksize;
 364
 365         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 366
 367         switch (s->ss_family) {
 368         case AF_INET:
 369                 socksize = sizeof(struct sockaddr_in);
 370                 rpc->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 371                 break;
 372         default:
 373                 rpc_set_error(rpc, "Can not handle AF_FAMILY:%d", s->ss_family);
 374                 return -1;
 375         }
 376
 377         if (rpc->fd == -1) {
 378                 rpc_set_error(rpc, "Failed to open socket");
 379                 return -1;
 380         }
 381
 382         /* Some systems allow you to set capabilities on an executable
 383          * to allow the file to be executed with privilege to bind to
 384          * privileged system ports, even if the user is not root.
 385          *
 386          * Opportunistically try to bind the socket to a low numbered
 387          * system port in the hope that the user is either root or the
 388          * executable has the CAP_NET_BIND_SERVICE.
 389          *
 390          * As soon as we fail the bind() with EACCES we know we will never
 391          * be able to bind to a system port so we terminate the loop.
 392          *
 393          * On linux, use
 394          *    sudo setcap 'cap_net_bind_service=+ep' /path/executable
 395          * to make the executable able to bind to a system port.
 396          *
 397          * On Windows, there is no concept of privileged ports. Thus
 398          * binding will usually succeed.
 399          */
 400         {
 401                 struct sockaddr_in sin;
 402                 static int portOfs = 0;
 403                 const int firstPort = 512;      /* >= 512 according to Sun docs */
 404                 const int portCount = IPPORT_RESERVED - firstPort;
 405                 int startOfs = portOfs, port, rc;
 406
 407                 do {
 408                         rc = -1;
 409                         port = htons(firstPort + portOfs);
 410                         portOfs = (portOfs + 1) % portCount;
 411
 412                         /* skip well-known ports */
 413                         if (!getservbyport(port, "tcp")) {
 414                                 memset(&sin, 0, sizeof(sin));
 415                                 sin.sin_port        = port;
 416                                 sin.sin_family      = AF_INET;
 417                                 sin.sin_addr.s_addr = 0;
 418
 419                                 rc = bind(rpc->fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in));
 420 #if !defined(WIN32)
 421                                 /* we got EACCES, so don't try again */
 422                                 if (rc != 0 && errno == EACCES)
 423                                         break;
 424 #endif
 425                         }
 426                 } while (rc != 0 && portOfs != startOfs);
 427         }
 428
 429         set_nonblocking(rpc->fd);
 430
 431         if (connect(rpc->fd, (struct sockaddr *)s, socksize) != 0 && errno != EINPROGRESS) {
 432                 rpc_set_error(rpc, "connect() to server failed. %s(%d)", strerror(errno), errno);
 433                 return -1;
 434         }
 435
 436         return 0;
 437 }
 438
 439 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 440 {
 441         struct sockaddr_in *sin = (struct sockaddr_in *)&rpc->s;
 442
 443         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 444
 445         if (rpc->fd != -1) {
 446                 rpc_set_error(rpc, "Trying to connect while already connected");
 447                 return -1;
 448         }
 449
 450         if (rpc->is_udp != 0) {
 451                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 452                 return -1;
 453         }
 454
 455         rpc->auto_reconnect = 0;
 456
 457         sin->sin_family = AF_INET;
 458         sin->sin_port   = htons(port);
 459         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 460                 rpc_set_error(rpc, "Not a valid server ip address");
 461                 return -1;
 462         }
 463
 464
 465         switch (rpc->s.ss_family) {
 466         case AF_INET:
 467 #ifdef HAVE_SOCKADDR_LEN
 468                 sin->sin_len = sizeof(struct sockaddr_in);
 469 #endif
 470                 break;
 471         }
 472
 473         rpc->connect_cb  = cb;
 474         rpc->connect_data = private_data;
 475
 476         if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 477                 return -1;
 478         }
 479
 480         return 0;
 481 }
 482
 483 int rpc_disconnect(struct rpc_context *rpc, char *error)
 484 {
 485         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 486
 487         rpc_unset_autoreconnect(rpc);
 488
 489         if (rpc->fd != -1) {
 490 #if defined(WIN32)
 491                 closesocket(rpc->fd);
 492 #else
 493                 close(rpc->fd);
 494 #endif
 495         }
 496         rpc->fd  = -1;
 497
 498         rpc->is_connected = 0;
 499
 500         rpc_error_all_pdus(rpc, error);
 501
 502         return 0;
 503 }
 504
 505 static void reconnect_cb(struct rpc_context *rpc, int status, void *data _U_, void *private_data)
 506 {
 507         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 508
 509         if (status != RPC_STATUS_SUCCESS) {
 510                 rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 511                 return;
 512         }
 513
 514         rpc->is_connected = 1;
 515         rpc->connect_cb   = NULL;
 516 }
 517
 518 /* disconnect but do not error all PDUs, just move pdus in-flight back to the outqueue and reconnect */
 519 static int rpc_reconnect_requeue(struct rpc_context *rpc)
 520 {
 521         struct rpc_pdu *pdu;
 522
 523         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 524
 525         if (rpc->fd != -1) {
 526 #if defined(WIN32)
 527                 closesocket(rpc->fd);
 528 #else
 529                 close(rpc->fd);
 530 #endif
 531         }
 532         rpc->fd  = -1;
 533
 534         rpc->is_connected = 0;
 535
 536         /* socket is closed so we will not get any replies to any commands
 537          * in flight. Move them all over from the waitpdu queue back to the out queue
 538          */
 539         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 540                 SLIST_REMOVE(&rpc->waitpdu, pdu);
 541                 SLIST_ADD(&rpc->outqueue, pdu);
 542                 /* we have to re-send the whole pdu again */
 543                 pdu->written = 0;
 544         }
 545
 546         if (rpc->auto_reconnect != 0) {
 547                 rpc->connect_cb  = reconnect_cb;
 548
 549                 if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 550                         rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 551                         return -1;
 552                 }
 553         }
 554
 555         return 0;
 556 }
 557
 558
 559 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 560 {
 561         struct addrinfo *ai = NULL;
 562         char service[6];
 563
 564         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 565
 566         if (rpc->is_udp == 0) {
 567                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 568                 return -1;
 569         }
 570
 571         sprintf(service, "%d", port);
 572         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 573                 rpc_set_error(rpc, "Invalid address:%s. "
 574                         "Can not resolv into IPv4/v6 structure.");
 575                 return -1;
 576         }
 577
 578         switch(ai->ai_family) {
 579         case AF_INET:
 580                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 581                 if (rpc->fd == -1) {
 582                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 583                         freeaddrinfo(ai);
 584                         return -1;
 585                 }
 586
 587                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 588                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 589                         freeaddrinfo(ai);
 590                         return -1;
 591                 }
 592                 break;
 593         default:
 594                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 595                 freeaddrinfo(ai);
 596                 return -1;
 597         }
 598
 599         freeaddrinfo(ai);
 600
 601         return 0;
 602 }
 603
 604 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 605 {
 606         struct addrinfo *ai = NULL;
 607         char service[6];
 608
 609         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 610
 611         if (rpc->is_udp == 0) {
 612                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 613                 return -1;
 614         }
 615
 616         sprintf(service, "%d", port);
 617         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 618                 rpc_set_error(rpc, "Invalid address:%s. "
 619                         "Can not resolv into IPv4/v6 structure.");
 620                 return -1;
 621         }
 622
 623         if (rpc->udp_dest) {
 624                 free(rpc->udp_dest);
 625                 rpc->udp_dest = NULL;
 626         }
 627         rpc->udp_dest = malloc(ai->ai_addrlen);
 628         if (rpc->udp_dest == NULL) {
 629                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 630                 freeaddrinfo(ai);
 631                 return -1;
 632         }
 633         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 634         freeaddrinfo(ai);
 635
 636         rpc->is_broadcast = is_broadcast;
 637         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, (char *)&is_broadcast, sizeof(is_broadcast));
 638
 639         return 0;
 640 }
 641
 642 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 643 {
 644         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 645
 646         return (struct sockaddr *)&rpc->udp_src;
 647 }
 648
 649 int rpc_queue_length(struct rpc_context *rpc)
 650 {
 651         int i=0;
 652         struct rpc_pdu *pdu;
 653
 654         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 655
 656         for(pdu = rpc->outqueue; pdu; pdu = pdu->next) {
 657                 i++;
 658         }
 659         for(pdu = rpc->waitpdu; pdu; pdu = pdu->next) {
 660                 i++;
 661         }
 662         return i;
 663 }