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 #ifdef HAVE_SYS_FILIO_H
  37 #include <sys/filio.h>
  38 #endif
  39 #ifdef HAVE_SYS_SOCKIO_H
  40 #include <sys/sockio.h>
  41 #endif
  42 #include <sys/types.h>
  43 #include "libnfs-zdr.h"
  44 #include "libnfs.h"
  45 #include "libnfs-raw.h"
  46 #include "libnfs-private.h"
  47 #include "slist.h"
  48
  49 #ifdef WIN32
  50 //has to be included after stdlib!!
  51 #include "win32_errnowrapper.h"
  52 #endif
  53
  54
  55 static int rpc_reconnect_requeue(struct rpc_context *rpc);
  56 static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_storage *s);
  57
  58 static void set_nonblocking(int fd)
  59 {
  60         int v = 0;
  61 #if defined(WIN32)
  62         long nonblocking=1;
  63         v = ioctlsocket(fd, FIONBIO,&nonblocking);
  64 #else
  65         v = fcntl(fd, F_GETFL, 0);
  66         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  67 #endif //FIXME
  68 }
  69
  70 int rpc_get_fd(struct rpc_context *rpc)
  71 {
  72         return rpc->fd;
  73 }
  74
  75 int rpc_which_events(struct rpc_context *rpc)
  76 {
  77         int events = rpc->is_connected ? POLLIN : POLLOUT;
  78
  79         if (rpc->is_udp != 0) {
  80                 /* for udp sockets we only wait for pollin */
  81                 return POLLIN;
  82         }
  83
  84         if (rpc->outqueue) {
  85                 events |= POLLOUT;
  86         }
  87         return events;
  88 }
  89
  90 static int rpc_write_to_socket(struct rpc_context *rpc)
  91 {
  92         int32_t count;
  93
  94         if (rpc == NULL) {
  95                 return -1;
  96         }
  97         if (rpc->fd == -1) {
  98                 rpc_set_error(rpc, "trying to write but not connected");
  99                 return -1;
 100         }
 101
 102         while (rpc->outqueue != NULL) {
 103                 int64_t total;
 104
 105                 total = rpc->outqueue->outdata.size;
 106
 107 #if defined(WIN32)
 108                 count = send(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written, 0);
 109 #else
 110                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
 111 #endif
 112                 if (count == -1) {
 113                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
 114                                 return 0;
 115                         }
 116                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
 117                         return -1;
 118                 }
 119
 120                 rpc->outqueue->written += count;
 121                 if (rpc->outqueue->written == total) {
 122                         struct rpc_pdu *pdu = rpc->outqueue;
 123
 124                         SLIST_REMOVE(&rpc->outqueue, pdu);
 125                         SLIST_ADD_END(&rpc->waitpdu, pdu);
 126                 }
 127         }
 128         return 0;
 129 }
 130
 131 static int rpc_read_from_socket(struct rpc_context *rpc)
 132 {
 133         int available;
 134         int size;
 135         int pdu_size;
 136         int32_t count;
 137
 138 #if defined(WIN32)
 139         if (ioctlsocket(rpc->fd, FIONREAD, &available) != 0) {
 140 #else
 141         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 142 #endif
 143                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 144                 return -1;
 145         }
 146
 147         if (available == 0) {
 148                 rpc_set_error(rpc, "Socket has been closed");
 149                 return -1;
 150         }
 151
 152         if (rpc->is_udp) {
 153                 char *buf;
 154                 socklen_t socklen = sizeof(rpc->udp_src);
 155
 156                 buf = malloc(available);
 157                 if (buf == NULL) {
 158                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 159                         return -1;
 160                 }
 161                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 162                 if (count < 0) {
 163                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 164                         free(buf);
 165                 }
 166                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 167                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 168                         free(buf);
 169                         return -1;
 170                 }
 171                 free(buf);
 172                 return 0;
 173         }
 174
 175         /* read record marker, 4 bytes at the beginning of every pdu */
 176         if (rpc->inbuf == NULL) {
 177                 rpc->insize = 4;
 178                 rpc->inbuf = malloc(rpc->insize);
 179                 if (rpc->inbuf == NULL) {
 180                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 181                         return -1;
 182                 }
 183         }
 184         if (rpc->inpos < 4) {
 185                 size = 4 - rpc->inpos;
 186
 187 #if defined(WIN32)
 188                 count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 189 #else
 190                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 191 #endif
 192                 if (count == -1) {
 193                         if (errno == EINTR) {
 194                                 return 0;
 195                         }
 196                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 197                         return -1;
 198                 }
 199                 available  -= count;
 200                 rpc->inpos += count;
 201         }
 202
 203         if (available == 0) {
 204                 return 0;
 205         }
 206
 207         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 208         if (rpc->insize < pdu_size) {
 209                 unsigned char *buf;
 210
 211                 buf = malloc(pdu_size);
 212                 if (buf == NULL) {
 213                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 214                         return -1;
 215                 }
 216                 memcpy(buf, rpc->inbuf, rpc->insize);
 217                 free(rpc->inbuf);
 218                 rpc->inbuf  = buf;
 219                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 220         }
 221
 222         size = available;
 223         if (size > rpc->insize - rpc->inpos) {
 224                 size = rpc->insize - rpc->inpos;
 225         }
 226
 227 #if defined(WIN32)
 228         count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 229 #else
 230         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 231 #endif
 232         if (count == -1) {
 233                 if (errno == EINTR) {
 234                         return 0;
 235                 }
 236                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 237                 return -1;
 238         }
 239         available  -= count;
 240         rpc->inpos += count;
 241
 242         if (rpc->inpos == rpc->insize) {
 243                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 244                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 245                         return -1;
 246                 }
 247                 free(rpc->inbuf);
 248                 rpc->inbuf  = NULL;
 249                 rpc->insize = 0;
 250                 rpc->inpos  = 0;
 251         }
 252
 253         return 0;
 254 }
 255
 256
 257
 258 int rpc_service(struct rpc_context *rpc, int revents)
 259 {
 260         if (revents & POLLERR) {
 261 #ifdef WIN32
 262                 char err = 0;
 263 #else
 264                 int err = 0;
 265 #endif
 266                 socklen_t err_size = sizeof(err);
 267
 268                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 269                                 (char *)&err, &err_size) != 0 || err != 0) {
 270                         if (err == 0) {
 271                                 err = errno;
 272                         }
 273                         rpc_set_error(rpc, "rpc_service: socket error "
 274                                                "%s(%d).",
 275                                                strerror(err), err);
 276                 } else {
 277                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 278                                                 "Unknown socket error.");
 279                 }
 280                 if (rpc->connect_cb != NULL) {
 281                         rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 282                 }
 283                 return -1;
 284         }
 285         if (revents & POLLHUP) {
 286                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 287                 if (rpc->connect_cb != NULL) {
 288                         rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 289                 }
 290                 return -1;
 291         }
 292
 293         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 294                 int err = 0;
 295                 socklen_t err_size = sizeof(err);
 296
 297                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 298                                 (char *)&err, &err_size) != 0 || err != 0) {
 299                         if (err == 0) {
 300                                 err = errno;
 301                         }
 302                         rpc_set_error(rpc, "rpc_service: socket error "
 303                                         "%s(%d) while connecting.",
 304                                         strerror(err), err);
 305                         if (rpc->connect_cb != NULL) {
 306                                 rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 307                                         NULL, rpc->connect_data);
 308                         }
 309                         return -1;
 310                 }
 311
 312                 rpc->is_connected = 1;
 313                 if (rpc->connect_cb != NULL) {
 314                         rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 315                 }
 316                 return 0;
 317         }
 318
 319         if (revents & POLLIN) {
 320                 if (rpc_read_from_socket(rpc) != 0) {
 321                         rpc_reconnect_requeue(rpc);
 322                         return 0;
 323                 }
 324         }
 325
 326         if (revents & POLLOUT && rpc->outqueue != NULL) {
 327                 if (rpc_write_to_socket(rpc) != 0) {
 328                         rpc_set_error(rpc, "write to socket failed");
 329                         return -1;
 330                 }
 331         }
 332
 333         return 0;
 334 }
 335
 336 void rpc_set_autoreconnect(struct rpc_context *rpc)
 337 {
 338         rpc->auto_reconnect = 1;
 339 }
 340
 341 void rpc_unset_autoreconnect(struct rpc_context *rpc)
 342 {
 343         rpc->auto_reconnect = 0;
 344 }
 345
 346 static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_storage *s)
 347 {
 348         int socksize;
 349
 350         switch (s->ss_family) {
 351         case AF_INET:
 352                 socksize = sizeof(struct sockaddr_in);
 353                 rpc->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 354                 break;
 355         default:
 356                 rpc_set_error(rpc, "Can not handle AF_FAMILY:%d", s->ss_family);
 357                 return -1;
 358         }
 359
 360         if (rpc->fd == -1) {
 361                 rpc_set_error(rpc, "Failed to open socket");
 362                 return -1;
 363         }
 364
 365         /* Some systems allow you to set capabilities on an executable
 366          * to allow the file to be executed with privilege to bind to
 367          * privileged system ports, even if the user is not root.
 368          *
 369          * Opportunistically try to bind the socket to a low numbered
 370          * system port in the hope that the user is either root or the
 371          * executable has the CAP_NET_BIND_SERVICE.
 372          *
 373          * As soon as we fail the bind() with EACCES we know we will never
 374          * be able to bind to a system port so we terminate the loop.
 375          *
 376          * On linux, use
 377          *    sudo setcap 'cap_net_bind_service=+ep' /path/executable
 378          * to make the executable able to bind to a system port.
 379          *
 380          * On Windows, there is no concept of privileged ports. Thus
 381          * binding will usually succeed.
 382          */
 383         {
 384                 struct sockaddr_in sin;
 385                 static int portOfs = 0;
 386                 const int firstPort = 512;      /* >= 512 according to Sun docs */
 387                 const int portCount = IPPORT_RESERVED - firstPort;
 388                 int startOfs = portOfs, port, rc;
 389
 390                 do {
 391                         rc = -1;
 392                         port = htons(firstPort + portOfs);
 393                         portOfs = (portOfs + 1) % portCount;
 394
 395                         /* skip well-known ports */
 396                         if (!getservbyport(port, "tcp")) {
 397                                 memset(&sin, 0, sizeof(sin));
 398                                 sin.sin_port        = port;
 399                                 sin.sin_family      = AF_INET;
 400                                 sin.sin_addr.s_addr = 0;
 401
 402                                 rc = bind(rpc->fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in));
 403 #if !defined(WIN32)
 404                                 /* we got EACCES, so don't try again */
 405                                 if (rc != 0 && errno == EACCES)
 406                                         break;
 407 #endif
 408                         }
 409                 } while (rc != 0 && portOfs != startOfs);
 410         }
 411
 412         set_nonblocking(rpc->fd);
 413
 414         if (connect(rpc->fd, (struct sockaddr *)s, socksize) != 0 && errno != EINPROGRESS) {
 415                 rpc_set_error(rpc, "connect() to server failed. %s(%d)", strerror(errno), errno);
 416                 return -1;
 417         }
 418
 419         return 0;
 420 }
 421
 422 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 423 {
 424         struct sockaddr_in *sin = (struct sockaddr_in *)&rpc->s;
 425
 426         if (rpc->fd != -1) {
 427                 rpc_set_error(rpc, "Trying to connect while already connected");
 428                 return -1;
 429         }
 430
 431         if (rpc->is_udp != 0) {
 432                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 433                 return -1;
 434         }
 435
 436         rpc->auto_reconnect = 0;
 437
 438         sin->sin_family = AF_INET;
 439         sin->sin_port   = htons(port);
 440         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 441                 rpc_set_error(rpc, "Not a valid server ip address");
 442                 return -1;
 443         }
 444
 445
 446         switch (rpc->s.ss_family) {
 447         case AF_INET:
 448 #ifdef HAVE_SOCKADDR_LEN
 449                 sin->sin_len = sizeof(struct sockaddr_in);
 450 #endif
 451                 break;
 452         }
 453
 454         rpc->connect_cb  = cb;
 455         rpc->connect_data = private_data;
 456
 457         if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 458                 return -1;
 459         }
 460
 461         return 0;
 462 }
 463
 464 int rpc_disconnect(struct rpc_context *rpc, char *error)
 465 {
 466         rpc_unset_autoreconnect(rpc);
 467
 468         if (rpc->fd != -1) {
 469 #if defined(WIN32)
 470                 closesocket(rpc->fd);
 471 #else
 472                 close(rpc->fd);
 473 #endif
 474         }
 475         rpc->fd  = -1;
 476
 477         rpc->is_connected = 0;
 478
 479         rpc_error_all_pdus(rpc, error);
 480
 481         return 0;
 482 }
 483
 484 static void reconnect_cb(struct rpc_context *rpc, int status, void *data _U_, void *private_data)
 485 {
 486         if (status != RPC_STATUS_SUCCESS) {
 487                 rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 488                 return;
 489         }
 490
 491         rpc->is_connected = 1;
 492         rpc->connect_cb   = NULL;
 493 }
 494
 495 /* disconnect but do not error all PDUs, just move pdus in-flight back to the outqueue and reconnect */
 496 static int rpc_reconnect_requeue(struct rpc_context *rpc)
 497 {
 498         struct rpc_pdu *pdu;
 499
 500         if (rpc->fd != -1) {
 501 #if defined(WIN32)
 502                 closesocket(rpc->fd);
 503 #else
 504                 close(rpc->fd);
 505 #endif
 506         }
 507         rpc->fd  = -1;
 508
 509         rpc->is_connected = 0;
 510
 511         /* socket is closed so we will not get any replies to any commands
 512          * in flight. Move them all over from the waitpdu queue back to the out queue
 513          */
 514         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 515                 SLIST_REMOVE(&rpc->waitpdu, pdu);
 516                 SLIST_ADD(&rpc->outqueue, pdu);
 517                 /* we have to re-send the whole pdu again */
 518                 pdu->written = 0;
 519         }
 520
 521         if (rpc->auto_reconnect != 0) {
 522                 rpc->connect_cb  = reconnect_cb;
 523
 524                 if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 525                         rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 526                         return -1;
 527                 }
 528         }
 529
 530         return 0;
 531 }
 532
 533
 534 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 535 {
 536         struct addrinfo *ai = NULL;
 537         char service[6];
 538
 539         if (rpc->is_udp == 0) {
 540                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 541                 return -1;
 542         }
 543
 544         sprintf(service, "%d", port);
 545         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 546                 rpc_set_error(rpc, "Invalid address:%s. "
 547                         "Can not resolv into IPv4/v6 structure.");
 548                 return -1;
 549         }
 550
 551         switch(ai->ai_family) {
 552         case AF_INET:
 553                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 554                 if (rpc->fd == -1) {
 555                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 556                         freeaddrinfo(ai);
 557                         return -1;
 558                 }
 559
 560                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 561                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 562                         freeaddrinfo(ai);
 563                         return -1;
 564                 }
 565                 break;
 566         default:
 567                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 568                 freeaddrinfo(ai);
 569                 return -1;
 570         }
 571
 572         freeaddrinfo(ai);
 573
 574         return 0;
 575 }
 576
 577 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 578 {
 579         struct addrinfo *ai = NULL;
 580         char service[6];
 581
 582         if (rpc->is_udp == 0) {
 583                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 584                 return -1;
 585         }
 586
 587         sprintf(service, "%d", port);
 588         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 589                 rpc_set_error(rpc, "Invalid address:%s. "
 590                         "Can not resolv into IPv4/v6 structure.");
 591                 return -1;
 592         }
 593
 594         if (rpc->udp_dest) {
 595                 free(rpc->udp_dest);
 596                 rpc->udp_dest = NULL;
 597         }
 598         rpc->udp_dest = malloc(ai->ai_addrlen);
 599         if (rpc->udp_dest == NULL) {
 600                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 601                 return -1;
 602         }
 603         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 604         freeaddrinfo(ai);
 605
 606         rpc->is_broadcast = is_broadcast;
 607         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, (char *)&is_broadcast, sizeof(is_broadcast));
 608
 609         return 0;
 610 }
 611
 612 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 613 {
 614         return (struct sockaddr *)&rpc->udp_src;
 615 }
 616
 617 int rpc_queue_length(struct rpc_context *rpc)
 618 {
 619         int i=0;
 620         struct rpc_pdu *pdu;
 621
 622         for(pdu = rpc->outqueue; pdu; pdu = pdu->next) {
 623                 i++;
 624         }
 625         for(pdu = rpc->waitpdu; pdu; pdu = pdu->next) {
 626                 i++;
 627         }
 628         return i;
 629 }