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         ssize_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                 ssize_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         ssize_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                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 282                 return -1;
 283         }
 284         if (revents & POLLHUP) {
 285                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 286                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 287                 return -1;
 288         }
 289
 290         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 291                 int err = 0;
 292                 socklen_t err_size = sizeof(err);
 293
 294                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 295                                 (char *)&err, &err_size) != 0 || err != 0) {
 296                         if (err == 0) {
 297                                 err = errno;
 298                         }
 299                         rpc_set_error(rpc, "rpc_service: socket error "
 300                                         "%s(%d) while connecting.",
 301                                         strerror(err), err);
 302                         rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 303                                         NULL, rpc->connect_data);
 304                         return -1;
 305                 }
 306
 307                 rpc->is_connected = 1;
 308                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 309                 return 0;
 310         }
 311
 312         if (revents & POLLIN) {
 313                 if (rpc_read_from_socket(rpc) != 0) {
 314                         rpc_reconnect_requeue(rpc);
 315                         return 0;
 316                 }
 317         }
 318
 319         if (revents & POLLOUT && rpc->outqueue != NULL) {
 320                 if (rpc_write_to_socket(rpc) != 0) {
 321                         rpc_set_error(rpc, "write to socket failed");
 322                         return -1;
 323                 }
 324         }
 325
 326         return 0;
 327 }
 328
 329 void rpc_set_autoreconnect(struct rpc_context *rpc)
 330 {
 331         rpc->auto_reconnect = 1;
 332 }
 333
 334 void rpc_unset_autoreconnect(struct rpc_context *rpc)
 335 {
 336         rpc->auto_reconnect = 0;
 337 }
 338
 339 static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_storage *s)
 340 {
 341         int socksize;
 342
 343         switch (s->ss_family) {
 344         case AF_INET:
 345                 socksize = sizeof(struct sockaddr_in);
 346                 rpc->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 347                 break;
 348         default:
 349                 rpc_set_error(rpc, "Can not handle AF_FAMILY:%d", s->ss_family);
 350                 return -1;
 351         }
 352
 353         if (rpc->fd == -1) {
 354                 rpc_set_error(rpc, "Failed to open socket");
 355                 return -1;
 356         }
 357
 358
 359 #if !defined(WIN32)
 360         /* Some systems allow you to set capabilities on an executable
 361          * to allow the file to be executed with privilege to bind to
 362          * privileged system ports, even if the user is not root.
 363          *
 364          * Opportunistically try to bind the socket to a low numbered
 365          * system port in the hope that the user is either root or the
 366          * executable has the CAP_NET_BIND_SERVICE.
 367          *
 368          * As soon as we fail the bind() with EACCES we know we will never
 369          * be able to bind to a system port so we terminate the loop.
 370          *
 371          * On linux, use
 372          *    sudo setcap 'cap_net_bind_service=+ep' /path/executable
 373          * to make the executable able to bind to a system port.
 374          */
 375         if (1) {
 376                 int port;
 377                 int one = 1;
 378
 379                 setsockopt(rpc->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one));
 380
 381                 for (port = 200; port < 500; port++) {
 382                         struct sockaddr_in sin;
 383
 384                         memset(&sin, 0, sizeof(sin));
 385                         sin.sin_port        = htons(port);
 386                         sin.sin_family      = AF_INET;
 387                         sin.sin_addr.s_addr = 0;
 388
 389                         if (bind(rpc->fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in)) != 0 && errno != EACCES) {
 390                                 /* we didnt get EACCES, so try again */
 391                                 continue;
 392                         }
 393                         break;
 394                 }
 395         }
 396 #endif
 397
 398         set_nonblocking(rpc->fd);
 399
 400 #if defined(WIN32)
 401         if (connect(rpc->fd, (struct sockaddr *)s, socksize) == 0 && errno != EINPROGRESS   )
 402 #else
 403         if (connect(rpc->fd, (struct sockaddr *)s, socksize) != 0 && errno != EINPROGRESS)
 404 #endif
 405         {
 406                 rpc_set_error(rpc, "connect() to server failed");
 407                 return -1;
 408         }
 409
 410         return 0;
 411 }
 412
 413 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 414 {
 415         struct sockaddr_in *sin = (struct sockaddr_in *)&rpc->s;
 416
 417         if (rpc->fd != -1) {
 418                 rpc_set_error(rpc, "Trying to connect while already connected");
 419                 return -1;
 420         }
 421
 422         if (rpc->is_udp != 0) {
 423                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 424                 return -1;
 425         }
 426
 427         rpc->auto_reconnect = 0;
 428
 429         sin->sin_family = AF_INET;
 430         sin->sin_port   = htons(port);
 431         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 432                 rpc_set_error(rpc, "Not a valid server ip address");
 433                 return -1;
 434         }
 435
 436
 437         switch (rpc->s.ss_family) {
 438         case AF_INET:
 439 #ifdef HAVE_SOCKADDR_LEN
 440                 sin->sin_len = sizeof(struct sockaddr_in);
 441 #endif
 442                 break;
 443         }
 444
 445         rpc->connect_cb  = cb;
 446         rpc->connect_data = private_data;
 447
 448         if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 449                 return -1;
 450         }
 451
 452         return 0;
 453 }
 454
 455 int rpc_disconnect(struct rpc_context *rpc, char *error)
 456 {
 457         rpc_unset_autoreconnect(rpc);
 458
 459         if (rpc->fd != -1) {
 460 #if defined(WIN32)
 461                 closesocket(rpc->fd);
 462 #else
 463                 close(rpc->fd);
 464 #endif
 465         }
 466         rpc->fd  = -1;
 467
 468         rpc->is_connected = 0;
 469
 470         rpc_error_all_pdus(rpc, error);
 471
 472         return 0;
 473 }
 474
 475 static void reconnect_cb(struct rpc_context *rpc, int status, void *data _U_, void *private_data)
 476 {
 477         if (status != RPC_STATUS_SUCCESS) {
 478                 rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 479                 return;
 480         }
 481
 482         rpc->is_connected = 1;
 483 }
 484
 485 /* disconnect but do not error all PDUs, just move pdus in-flight back to the outqueue and reconnect */
 486 static int rpc_reconnect_requeue(struct rpc_context *rpc)
 487 {
 488         struct rpc_pdu *pdu;
 489
 490         if (rpc->fd != -1) {
 491 #if defined(WIN32)
 492                 closesocket(rpc->fd);
 493 #else
 494                 close(rpc->fd);
 495 #endif
 496         }
 497         rpc->fd  = -1;
 498
 499         rpc->is_connected = 0;
 500
 501         /* socket is closed so we will not get any replies to any commands
 502          * in flight. Move them all over from the waitpdu queue back to the out queue
 503          */
 504         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 505                 SLIST_REMOVE(&rpc->waitpdu, pdu);
 506                 SLIST_ADD(&rpc->outqueue, pdu);
 507                 /* we have to re-send the whole pdu again */
 508                 pdu->written = 0;
 509         }
 510
 511         if (rpc->auto_reconnect != 0) {
 512                 rpc->connect_cb  = reconnect_cb;
 513
 514                 if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 515                         rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 516                         return -1;
 517                 }
 518         }
 519
 520         return 0;
 521 }
 522
 523
 524 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 525 {
 526         struct addrinfo *ai = NULL;
 527         char service[6];
 528
 529         if (rpc->is_udp == 0) {
 530                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 531                 return -1;
 532         }
 533
 534         sprintf(service, "%d", port);
 535         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 536                 rpc_set_error(rpc, "Invalid address:%s. "
 537                         "Can not resolv into IPv4/v6 structure.");
 538                 return -1;
 539         }
 540
 541         switch(ai->ai_family) {
 542         case AF_INET:
 543                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 544                 if (rpc->fd == -1) {
 545                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 546                         freeaddrinfo(ai);
 547                         return -1;
 548                 }
 549
 550                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 551                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 552                         freeaddrinfo(ai);
 553                         return -1;
 554                 }
 555                 break;
 556         default:
 557                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 558                 freeaddrinfo(ai);
 559                 return -1;
 560         }
 561
 562         freeaddrinfo(ai);
 563
 564         return 0;
 565 }
 566
 567 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 568 {
 569         struct addrinfo *ai = NULL;
 570         char service[6];
 571
 572         if (rpc->is_udp == 0) {
 573                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 574                 return -1;
 575         }
 576
 577         sprintf(service, "%d", port);
 578         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 579                 rpc_set_error(rpc, "Invalid address:%s. "
 580                         "Can not resolv into IPv4/v6 structure.");
 581                 return -1;
 582         }
 583
 584         if (rpc->udp_dest) {
 585                 free(rpc->udp_dest);
 586                 rpc->udp_dest = NULL;
 587         }
 588         rpc->udp_dest = malloc(ai->ai_addrlen);
 589         if (rpc->udp_dest == NULL) {
 590                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 591                 return -1;
 592         }
 593         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 594         freeaddrinfo(ai);
 595
 596         rpc->is_broadcast = is_broadcast;
 597         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, (char *)&is_broadcast, sizeof(is_broadcast));
 598
 599         return 0;
 600 }
 601
 602 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 603 {
 604         return (struct sockaddr *)&rpc->udp_src;
 605 }
 606
 607 int rpc_queue_length(struct rpc_context *rpc)
 608 {
 609         int i=0;
 610         struct rpc_pdu *pdu;
 611
 612         for(pdu = rpc->outqueue; pdu; pdu = pdu->next) {
 613                 i++;
 614         }
 615         for(pdu = rpc->waitpdu; pdu; pdu = pdu->next) {
 616                 i++;
 617         }
 618         return i;
 619 }