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 <fcntl.h>
  34 #include <string.h>
  35 #include <errno.h>
  36 #include <rpc/rpc.h>
  37 #include <rpc/xdr.h>
  38 #ifdef HAVE_SYS_FILIO_H
  39 #include <sys/filio.h>
  40 #endif
  41 #ifdef HAVE_SYS_SOCKIO_H
  42 #include <sys/sockio.h>
  43 #endif
  44 #include <sys/types.h>
  45 #include "libnfs.h"
  46 #include "libnfs-raw.h"
  47 #include "libnfs-private.h"
  48 #include "slist.h"
  49
  50 #ifdef WIN32
  51 //has to be included after stdlib!!
  52 #include "win32_errnowrapper.h"
  53 #endif
  54
  55
  56 static int rpc_reconnect_requeue(struct rpc_context *rpc);
  57 static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_storage *s);
  58
  59 static void set_nonblocking(int fd)
  60 {
  61         int v = 0;
  62 #if defined(WIN32)
  63         long nonblocking=1;
  64         v = ioctlsocket(fd, FIONBIO,&nonblocking);
  65 #else
  66         v = fcntl(fd, F_GETFL, 0);
  67         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  68 #endif //FIXME
  69 }
  70
  71 int rpc_get_fd(struct rpc_context *rpc)
  72 {
  73         return rpc->fd;
  74 }
  75
  76 int rpc_which_events(struct rpc_context *rpc)
  77 {
  78         int events = rpc->is_connected ? POLLIN : POLLOUT;
  79
  80         if (rpc->is_udp != 0) {
  81                 /* for udp sockets we only wait for pollin */
  82                 return POLLIN;
  83         }
  84
  85         if (rpc->outqueue) {
  86                 events |= POLLOUT;
  87         }
  88         return events;
  89 }
  90
  91 static int rpc_write_to_socket(struct rpc_context *rpc)
  92 {
  93         int64_t count;
  94
  95         if (rpc == NULL) {
  96                 return -1;
  97         }
  98         if (rpc->fd == -1) {
  99                 rpc_set_error(rpc, "trying to write but not connected");
 100                 return -1;
 101         }
 102
 103         while (rpc->outqueue != NULL) {
 104                 int64_t total;
 105
 106                 total = rpc->outqueue->outdata.size;
 107
 108 #if defined(WIN32)
 109                 count = send(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written, 0);
 110 #else
 111                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
 112 #endif
 113                 if (count == -1) {
 114                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
 115                                 return 0;
 116                         }
 117                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
 118                         return -1;
 119                 }
 120
 121                 rpc->outqueue->written += count;
 122                 if (rpc->outqueue->written == total) {
 123                         struct rpc_pdu *pdu = rpc->outqueue;
 124
 125                         SLIST_REMOVE(&rpc->outqueue, pdu);
 126                         SLIST_ADD_END(&rpc->waitpdu, pdu);
 127                 }
 128         }
 129         return 0;
 130 }
 131
 132 static int rpc_read_from_socket(struct rpc_context *rpc)
 133 {
 134         int available;
 135         int size;
 136         int pdu_size;
 137         int64_t count;
 138
 139 #if defined(WIN32)
 140         if (ioctlsocket(rpc->fd, FIONREAD, &available) != 0) {
 141 #else
 142         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 143 #endif
 144                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 145                 return -1;
 146         }
 147
 148         if (available == 0) {
 149                 rpc_set_error(rpc, "Socket has been closed");
 150                 return -1;
 151         }
 152
 153         if (rpc->is_udp) {
 154                 char *buf;
 155                 socklen_t socklen = sizeof(rpc->udp_src);
 156
 157                 buf = malloc(available);
 158                 if (buf == NULL) {
 159                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 160                         return -1;
 161                 }
 162                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 163                 if (count < 0) {
 164                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 165                         free(buf);
 166                 }
 167                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 168                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 169                         free(buf);
 170                         return -1;
 171                 }
 172                 free(buf);
 173                 return 0;
 174         }
 175
 176         /* read record marker, 4 bytes at the beginning of every pdu */
 177         if (rpc->inbuf == NULL) {
 178                 rpc->insize = 4;
 179                 rpc->inbuf = malloc(rpc->insize);
 180                 if (rpc->inbuf == NULL) {
 181                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 182                         return -1;
 183                 }
 184         }
 185         if (rpc->inpos < 4) {
 186                 size = 4 - rpc->inpos;
 187
 188 #if defined(WIN32)
 189                 count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 190 #else
 191                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 192 #endif
 193                 if (count == -1) {
 194                         if (errno == EINTR) {
 195                                 return 0;
 196                         }
 197                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 198                         return -1;
 199                 }
 200                 available  -= count;
 201                 rpc->inpos += count;
 202         }
 203
 204         if (available == 0) {
 205                 return 0;
 206         }
 207
 208         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 209         if (rpc->insize < pdu_size) {
 210                 unsigned char *buf;
 211
 212                 buf = malloc(pdu_size);
 213                 if (buf == NULL) {
 214                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 215                         return -1;
 216                 }
 217                 memcpy(buf, rpc->inbuf, rpc->insize);
 218                 free(rpc->inbuf);
 219                 rpc->inbuf  = buf;
 220                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 221         }
 222
 223         size = available;
 224         if (size > rpc->insize - rpc->inpos) {
 225                 size = rpc->insize - rpc->inpos;
 226         }
 227
 228 #if defined(WIN32)
 229         count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 230 #else
 231         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 232 #endif
 233         if (count == -1) {
 234                 if (errno == EINTR) {
 235                         return 0;
 236                 }
 237                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 238                 return -1;
 239         }
 240         available  -= count;
 241         rpc->inpos += count;
 242
 243         if (rpc->inpos == rpc->insize) {
 244                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 245                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 246                         return -1;
 247                 }
 248                 free(rpc->inbuf);
 249                 rpc->inbuf  = NULL;
 250                 rpc->insize = 0;
 251                 rpc->inpos  = 0;
 252         }
 253
 254         return 0;
 255 }
 256
 257
 258
 259 int rpc_service(struct rpc_context *rpc, int revents)
 260 {
 261         if (revents & POLLERR) {
 262 #ifdef WIN32
 263                 char err = 0;
 264 #else
 265                 int err = 0;
 266 #endif
 267                 socklen_t err_size = sizeof(err);
 268
 269                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 270                                 (char *)&err, &err_size) != 0 || err != 0) {
 271                         if (err == 0) {
 272                                 err = errno;
 273                         }
 274                         rpc_set_error(rpc, "rpc_service: socket error "
 275                                                "%s(%d).",
 276                                                strerror(err), err);
 277                 } else {
 278                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 279                                                 "Unknown socket error.");
 280                 }
 281                 if (rpc->connect_cb != NULL) {
 282                         rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 283                 }
 284                 return -1;
 285         }
 286         if (revents & POLLHUP) {
 287                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 288                 if (rpc->connect_cb != NULL) {
 289                         rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 290                 }
 291                 return -1;
 292         }
 293
 294         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 295                 int err = 0;
 296                 socklen_t err_size = sizeof(err);
 297
 298                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 299                                 (char *)&err, &err_size) != 0 || err != 0) {
 300                         if (err == 0) {
 301                                 err = errno;
 302                         }
 303                         rpc_set_error(rpc, "rpc_service: socket error "
 304                                         "%s(%d) while connecting.",
 305                                         strerror(err), err);
 306                         if (rpc->connect_cb != NULL) {
 307                                 rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 308                                         NULL, rpc->connect_data);
 309                         }
 310                         return -1;
 311                 }
 312
 313                 rpc->is_connected = 1;
 314                 if (rpc->connect_cb != NULL) {
 315                         rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 316                 }
 317                 return 0;
 318         }
 319
 320         if (revents & POLLIN) {
 321                 if (rpc_read_from_socket(rpc) != 0) {
 322                         rpc_reconnect_requeue(rpc);
 323                         return 0;
 324                 }
 325         }
 326
 327         if (revents & POLLOUT && rpc->outqueue != NULL) {
 328                 if (rpc_write_to_socket(rpc) != 0) {
 329                         rpc_set_error(rpc, "write to socket failed");
 330                         return -1;
 331                 }
 332         }
 333
 334         return 0;
 335 }
 336
 337 void rpc_set_autoreconnect(struct rpc_context *rpc)
 338 {
 339         rpc->auto_reconnect = 1;
 340 }
 341
 342 void rpc_unset_autoreconnect(struct rpc_context *rpc)
 343 {
 344         rpc->auto_reconnect = 0;
 345 }
 346
 347 static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_storage *s)
 348 {
 349         int socksize;
 350
 351         switch (s->ss_family) {
 352         case AF_INET:
 353                 socksize = sizeof(struct sockaddr_in);
 354                 rpc->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 355                 break;
 356         default:
 357                 rpc_set_error(rpc, "Can not handle AF_FAMILY:%d", s->ss_family);
 358                 return -1;
 359         }
 360
 361         if (rpc->fd == -1) {
 362                 rpc_set_error(rpc, "Failed to open socket");
 363                 return -1;
 364         }
 365
 366
 367 #if !defined(WIN32)
 368         /* Some systems allow you to set capabilities on an executable
 369          * to allow the file to be executed with privilege to bind to
 370          * privileged system ports, even if the user is not root.
 371          *
 372          * Opportunistically try to bind the socket to a low numbered
 373          * system port in the hope that the user is either root or the
 374          * executable has the CAP_NET_BIND_SERVICE.
 375          *
 376          * As soon as we fail the bind() with EACCES we know we will never
 377          * be able to bind to a system port so we terminate the loop.
 378          *
 379          * On linux, use
 380          *    sudo setcap 'cap_net_bind_service=+ep' /path/executable
 381          * to make the executable able to bind to a system port.
 382          */
 383         if (1) {
 384                 static int port = 200;
 385                 int i;
 386                 int one = 1;
 387
 388                 setsockopt(rpc->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one));
 389
 390                 for (i = 0; i < 500; i++) {
 391                         struct sockaddr_in sin;
 392
 393                         if(++port > 700) port = 200;
 394
 395                         memset(&sin, 0, sizeof(sin));
 396                         sin.sin_port        = htons(port);
 397                         sin.sin_family      = AF_INET;
 398                         sin.sin_addr.s_addr = 0;
 399
 400                         if (bind(rpc->fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in)) != 0 && errno != EACCES) {
 401                                 /* we didnt get EACCES, so try again */
 402                                 continue;
 403                         }
 404                         break;
 405                 }
 406         }
 407 #endif
 408
 409         set_nonblocking(rpc->fd);
 410
 411 #if defined(WIN32)
 412         if (connect(rpc->fd, (struct sockaddr *)s, socksize) == 0 && errno != EINPROGRESS   )
 413 #else
 414         if (connect(rpc->fd, (struct sockaddr *)s, socksize) != 0 && errno != EINPROGRESS)
 415 #endif
 416         {
 417           rpc_set_error(rpc, "connect() to server failed. %s(%d)", strerror(errno), errno);
 418                 return -1;
 419         }
 420
 421         return 0;
 422 }
 423
 424 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 425 {
 426         struct sockaddr_in *sin = (struct sockaddr_in *)&rpc->s;
 427
 428         if (rpc->fd != -1) {
 429                 rpc_set_error(rpc, "Trying to connect while already connected");
 430                 return -1;
 431         }
 432
 433         if (rpc->is_udp != 0) {
 434                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 435                 return -1;
 436         }
 437
 438         rpc->auto_reconnect = 0;
 439
 440         sin->sin_family = AF_INET;
 441         sin->sin_port   = htons(port);
 442         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 443                 rpc_set_error(rpc, "Not a valid server ip address");
 444                 return -1;
 445         }
 446
 447
 448         switch (rpc->s.ss_family) {
 449         case AF_INET:
 450 #ifdef HAVE_SOCKADDR_LEN
 451                 sin->sin_len = sizeof(struct sockaddr_in);
 452 #endif
 453                 break;
 454         }
 455
 456         rpc->connect_cb  = cb;
 457         rpc->connect_data = private_data;
 458
 459         if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 460                 return -1;
 461         }
 462
 463         return 0;
 464 }
 465
 466 int rpc_disconnect(struct rpc_context *rpc, char *error)
 467 {
 468         rpc_unset_autoreconnect(rpc);
 469
 470         if (rpc->fd != -1) {
 471 #if defined(WIN32)
 472                 closesocket(rpc->fd);
 473 #else
 474                 close(rpc->fd);
 475 #endif
 476         }
 477         rpc->fd  = -1;
 478
 479         rpc->is_connected = 0;
 480
 481         rpc_error_all_pdus(rpc, error);
 482
 483         return 0;
 484 }
 485
 486 static void reconnect_cb(struct rpc_context *rpc, int status, void *data _U_, void *private_data)
 487 {
 488         if (status != RPC_STATUS_SUCCESS) {
 489                 rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 490                 return;
 491         }
 492
 493         rpc->is_connected = 1;
 494         rpc->connect_cb   = NULL;
 495 }
 496
 497 /* disconnect but do not error all PDUs, just move pdus in-flight back to the outqueue and reconnect */
 498 static int rpc_reconnect_requeue(struct rpc_context *rpc)
 499 {
 500         struct rpc_pdu *pdu;
 501
 502         if (rpc->fd != -1) {
 503 #if defined(WIN32)
 504                 closesocket(rpc->fd);
 505 #else
 506                 close(rpc->fd);
 507 #endif
 508         }
 509         rpc->fd  = -1;
 510
 511         rpc->is_connected = 0;
 512
 513         /* socket is closed so we will not get any replies to any commands
 514          * in flight. Move them all over from the waitpdu queue back to the out queue
 515          */
 516         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 517                 SLIST_REMOVE(&rpc->waitpdu, pdu);
 518                 SLIST_ADD(&rpc->outqueue, pdu);
 519                 /* we have to re-send the whole pdu again */
 520                 pdu->written = 0;
 521         }
 522
 523         if (rpc->auto_reconnect != 0) {
 524                 rpc->connect_cb  = reconnect_cb;
 525
 526                 if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 527                         rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 528                         return -1;
 529                 }
 530         }
 531
 532         return 0;
 533 }
 534
 535
 536 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 537 {
 538         struct addrinfo *ai = NULL;
 539         char service[6];
 540
 541         if (rpc->is_udp == 0) {
 542                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 543                 return -1;
 544         }
 545
 546         sprintf(service, "%d", port);
 547         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 548                 rpc_set_error(rpc, "Invalid address:%s. "
 549                         "Can not resolv into IPv4/v6 structure.");
 550                 return -1;
 551         }
 552
 553         switch(ai->ai_family) {
 554         case AF_INET:
 555                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 556                 if (rpc->fd == -1) {
 557                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 558                         freeaddrinfo(ai);
 559                         return -1;
 560                 }
 561
 562                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 563                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 564                         freeaddrinfo(ai);
 565                         return -1;
 566                 }
 567                 break;
 568         default:
 569                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 570                 freeaddrinfo(ai);
 571                 return -1;
 572         }
 573
 574         freeaddrinfo(ai);
 575
 576         return 0;
 577 }
 578
 579 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 580 {
 581         struct addrinfo *ai = NULL;
 582         char service[6];
 583
 584         if (rpc->is_udp == 0) {
 585                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 586                 return -1;
 587         }
 588
 589         sprintf(service, "%d", port);
 590         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 591                 rpc_set_error(rpc, "Invalid address:%s. "
 592                         "Can not resolv into IPv4/v6 structure.");
 593                 return -1;
 594         }
 595
 596         if (rpc->udp_dest) {
 597                 free(rpc->udp_dest);
 598                 rpc->udp_dest = NULL;
 599         }
 600         rpc->udp_dest = malloc(ai->ai_addrlen);
 601         if (rpc->udp_dest == NULL) {
 602                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 603                 return -1;
 604         }
 605         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 606         freeaddrinfo(ai);
 607
 608         rpc->is_broadcast = is_broadcast;
 609         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, (char *)&is_broadcast, sizeof(is_broadcast));
 610
 611         return 0;
 612 }
 613
 614 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 615 {
 616         return (struct sockaddr *)&rpc->udp_src;
 617 }
 618
 619 int rpc_queue_length(struct rpc_context *rpc)
 620 {
 621         int i=0;
 622         struct rpc_pdu *pdu;
 623
 624         for(pdu = rpc->outqueue; pdu; pdu = pdu->next) {
 625                 i++;
 626         }
 627         for(pdu = rpc->waitpdu; pdu; pdu = pdu->next) {
 628                 i++;
 629         }
 630         return i;
 631 }