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 #ifdef HAVE_SYS_FILIO_H
  38 #include <sys/filio.h>
  39 #endif
  40 #ifdef HAVE_SYS_SOCKIO_H
  41 #include <sys/sockio.h>
  42 #endif
  43 #include <sys/types.h>
  44 #include "libnfs-zdr.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         assert(rpc->magic == RPC_CONTEXT_MAGIC);
  74
  75         return rpc->fd;
  76 }
  77
  78 int rpc_which_events(struct rpc_context *rpc)
  79 {
  80         int events;
  81
  82         assert(rpc->magic == RPC_CONTEXT_MAGIC);
  83
  84         events = rpc->is_connected ? POLLIN : POLLOUT;
  85
  86         if (rpc->is_udp != 0) {
  87                 /* for udp sockets we only wait for pollin */
  88                 return POLLIN;
  89         }
  90
  91         if (rpc->outqueue) {
  92                 events |= POLLOUT;
  93         }
  94         return events;
  95 }
  96
  97 static int rpc_write_to_socket(struct rpc_context *rpc)
  98 {
  99         int32_t count;
 100
 101         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 102
 103         if (rpc->fd == -1) {
 104                 rpc_set_error(rpc, "trying to write but not connected");
 105                 return -1;
 106         }
 107
 108         while (rpc->outqueue != NULL) {
 109                 int64_t total;
 110
 111                 total = rpc->outqueue->outdata.size;
 112
 113 #if defined(WIN32)
 114                 count = send(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written, 0);
 115 #else
 116                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
 117 #endif
 118                 if (count == -1) {
 119                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
 120                                 return 0;
 121                         }
 122                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
 123                         return -1;
 124                 }
 125
 126                 rpc->outqueue->written += count;
 127                 if (rpc->outqueue->written == total) {
 128                         struct rpc_pdu *pdu = rpc->outqueue;
 129
 130                         SLIST_REMOVE(&rpc->outqueue, pdu);
 131                         SLIST_ADD_END(&rpc->waitpdu, pdu);
 132                 }
 133         }
 134         return 0;
 135 }
 136
 137 static int rpc_read_from_socket(struct rpc_context *rpc)
 138 {
 139         int available;
 140         int size;
 141         int pdu_size;
 142         int32_t count;
 143
 144         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 145
 146 #if defined(WIN32)
 147         if (ioctlsocket(rpc->fd, FIONREAD, &available) != 0) {
 148 #else
 149         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 150 #endif
 151                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 152                 return -1;
 153         }
 154
 155         if (available == 0) {
 156                 rpc_set_error(rpc, "Socket has been closed");
 157                 return -1;
 158         }
 159
 160         if (rpc->is_udp) {
 161                 char *buf;
 162                 socklen_t socklen = sizeof(rpc->udp_src);
 163
 164                 buf = malloc(available);
 165                 if (buf == NULL) {
 166                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 167                         return -1;
 168                 }
 169                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 170                 if (count < 0) {
 171                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 172                         free(buf);
 173                 }
 174                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 175                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 176                         free(buf);
 177                         return -1;
 178                 }
 179                 free(buf);
 180                 return 0;
 181         }
 182
 183         /* read record marker, 4 bytes at the beginning of every pdu */
 184         if (rpc->inbuf == NULL) {
 185                 rpc->insize = 4;
 186                 rpc->inbuf = malloc(rpc->insize);
 187                 if (rpc->inbuf == NULL) {
 188                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 189                         return -1;
 190                 }
 191         }
 192         if (rpc->inpos < 4) {
 193                 size = 4 - rpc->inpos;
 194
 195 #if defined(WIN32)
 196                 count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 197 #else
 198                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 199 #endif
 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
 211         if (available == 0) {
 212                 return 0;
 213         }
 214
 215         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 216         if (rpc->insize < pdu_size) {
 217                 unsigned char *buf;
 218
 219                 buf = malloc(pdu_size);
 220                 if (buf == NULL) {
 221                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 222                         return -1;
 223                 }
 224                 memcpy(buf, rpc->inbuf, rpc->insize);
 225                 free(rpc->inbuf);
 226                 rpc->inbuf  = buf;
 227                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 228         }
 229
 230         size = available;
 231         if (size > rpc->insize - rpc->inpos) {
 232                 size = rpc->insize - rpc->inpos;
 233         }
 234
 235 #if defined(WIN32)
 236         count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 237 #else
 238         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 239 #endif
 240         if (count == -1) {
 241                 if (errno == EINTR) {
 242                         return 0;
 243                 }
 244                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 245                 return -1;
 246         }
 247         available  -= count;
 248         rpc->inpos += count;
 249
 250         if (rpc->inpos == rpc->insize) {
 251                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 252                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 253                         return -1;
 254                 }
 255                 free(rpc->inbuf);
 256                 rpc->inbuf  = NULL;
 257                 rpc->insize = 0;
 258                 rpc->inpos  = 0;
 259         }
 260
 261         return 0;
 262 }
 263
 264
 265
 266 int rpc_service(struct rpc_context *rpc, int revents)
 267 {
 268         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 269
 270         if (revents & POLLERR) {
 271 #ifdef WIN32
 272                 char err = 0;
 273 #else
 274                 int err = 0;
 275 #endif
 276                 socklen_t err_size = sizeof(err);
 277
 278                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 279                                 (char *)&err, &err_size) != 0 || err != 0) {
 280                         if (err == 0) {
 281                                 err = errno;
 282                         }
 283                         rpc_set_error(rpc, "rpc_service: socket error "
 284                                                "%s(%d).",
 285                                                strerror(err), err);
 286                 } else {
 287                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 288                                                 "Unknown socket error.");
 289                 }
 290                 if (rpc->connect_cb != NULL) {
 291                         rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 292                 }
 293                 return -1;
 294         }
 295         if (revents & POLLHUP) {
 296                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 297                 if (rpc->connect_cb != NULL) {
 298                         rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 299                 }
 300                 return -1;
 301         }
 302
 303         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 304                 int err = 0;
 305                 socklen_t err_size = sizeof(err);
 306
 307                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 308                                 (char *)&err, &err_size) != 0 || err != 0) {
 309                         if (err == 0) {
 310                                 err = errno;
 311                         }
 312                         rpc_set_error(rpc, "rpc_service: socket error "
 313                                         "%s(%d) while connecting.",
 314                                         strerror(err), err);
 315                         if (rpc->connect_cb != NULL) {
 316                                 rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 317                                         NULL, rpc->connect_data);
 318                         }
 319                         return -1;
 320                 }
 321
 322                 rpc->is_connected = 1;
 323                 if (rpc->connect_cb != NULL) {
 324                         rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 325                 }
 326                 return 0;
 327         }
 328
 329         if (revents & POLLIN) {
 330                 if (rpc_read_from_socket(rpc) != 0) {
 331                         rpc_reconnect_requeue(rpc);
 332                         return 0;
 333                 }
 334         }
 335
 336         if (revents & POLLOUT && rpc->outqueue != NULL) {
 337                 if (rpc_write_to_socket(rpc) != 0) {
 338                         rpc_set_error(rpc, "write to socket failed");
 339                         return -1;
 340                 }
 341         }
 342
 343         return 0;
 344 }
 345
 346 void rpc_set_autoreconnect(struct rpc_context *rpc)
 347 {
 348         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 349
 350         rpc->auto_reconnect = 1;
 351 }
 352
 353 void rpc_unset_autoreconnect(struct rpc_context *rpc)
 354 {
 355         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 356
 357         rpc->auto_reconnect = 0;
 358 }
 359
 360 static int rpc_connect_sockaddr_async(struct rpc_context *rpc, struct sockaddr_storage *s)
 361 {
 362         int socksize;
 363
 364         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 365
 366         switch (s->ss_family) {
 367         case AF_INET:
 368                 socksize = sizeof(struct sockaddr_in);
 369                 rpc->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 370                 break;
 371         default:
 372                 rpc_set_error(rpc, "Can not handle AF_FAMILY:%d", s->ss_family);
 373                 return -1;
 374         }
 375
 376         if (rpc->fd == -1) {
 377                 rpc_set_error(rpc, "Failed to open socket");
 378                 return -1;
 379         }
 380
 381         /* Some systems allow you to set capabilities on an executable
 382          * to allow the file to be executed with privilege to bind to
 383          * privileged system ports, even if the user is not root.
 384          *
 385          * Opportunistically try to bind the socket to a low numbered
 386          * system port in the hope that the user is either root or the
 387          * executable has the CAP_NET_BIND_SERVICE.
 388          *
 389          * As soon as we fail the bind() with EACCES we know we will never
 390          * be able to bind to a system port so we terminate the loop.
 391          *
 392          * On linux, use
 393          *    sudo setcap 'cap_net_bind_service=+ep' /path/executable
 394          * to make the executable able to bind to a system port.
 395          *
 396          * On Windows, there is no concept of privileged ports. Thus
 397          * binding will usually succeed.
 398          */
 399         {
 400                 struct sockaddr_in sin;
 401                 static int portOfs = 0;
 402                 const int firstPort = 512;      /* >= 512 according to Sun docs */
 403                 const int portCount = IPPORT_RESERVED - firstPort;
 404                 int startOfs = portOfs, port, rc;
 405
 406                 do {
 407                         rc = -1;
 408                         port = htons(firstPort + portOfs);
 409                         portOfs = (portOfs + 1) % portCount;
 410
 411                         /* skip well-known ports */
 412                         if (!getservbyport(port, "tcp")) {
 413                                 memset(&sin, 0, sizeof(sin));
 414                                 sin.sin_port        = port;
 415                                 sin.sin_family      = AF_INET;
 416                                 sin.sin_addr.s_addr = 0;
 417
 418                                 rc = bind(rpc->fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in));
 419 #if !defined(WIN32)
 420                                 /* we got EACCES, so don't try again */
 421                                 if (rc != 0 && errno == EACCES)
 422                                         break;
 423 #endif
 424                         }
 425                 } while (rc != 0 && portOfs != startOfs);
 426         }
 427
 428         set_nonblocking(rpc->fd);
 429
 430         if (connect(rpc->fd, (struct sockaddr *)s, socksize) != 0 && errno != EINPROGRESS) {
 431                 rpc_set_error(rpc, "connect() to server failed. %s(%d)", strerror(errno), errno);
 432                 return -1;
 433         }
 434
 435         return 0;
 436 }
 437
 438 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 439 {
 440         struct sockaddr_in *sin = (struct sockaddr_in *)&rpc->s;
 441
 442         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 443
 444         if (rpc->fd != -1) {
 445                 rpc_set_error(rpc, "Trying to connect while already connected");
 446                 return -1;
 447         }
 448
 449         if (rpc->is_udp != 0) {
 450                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 451                 return -1;
 452         }
 453
 454         rpc->auto_reconnect = 0;
 455
 456         sin->sin_family = AF_INET;
 457         sin->sin_port   = htons(port);
 458         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 459                 rpc_set_error(rpc, "Not a valid server ip address");
 460                 return -1;
 461         }
 462
 463
 464         switch (rpc->s.ss_family) {
 465         case AF_INET:
 466 #ifdef HAVE_SOCKADDR_LEN
 467                 sin->sin_len = sizeof(struct sockaddr_in);
 468 #endif
 469                 break;
 470         }
 471
 472         rpc->connect_cb  = cb;
 473         rpc->connect_data = private_data;
 474
 475         if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 476                 return -1;
 477         }
 478
 479         return 0;
 480 }
 481
 482 int rpc_disconnect(struct rpc_context *rpc, char *error)
 483 {
 484         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 485
 486         rpc_unset_autoreconnect(rpc);
 487
 488         if (rpc->fd != -1) {
 489 #if defined(WIN32)
 490                 closesocket(rpc->fd);
 491 #else
 492                 close(rpc->fd);
 493 #endif
 494         }
 495         rpc->fd  = -1;
 496
 497         rpc->is_connected = 0;
 498
 499         rpc_error_all_pdus(rpc, error);
 500
 501         return 0;
 502 }
 503
 504 static void reconnect_cb(struct rpc_context *rpc, int status, void *data _U_, void *private_data)
 505 {
 506         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 507
 508         if (status != RPC_STATUS_SUCCESS) {
 509                 rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 510                 return;
 511         }
 512
 513         rpc->is_connected = 1;
 514         rpc->connect_cb   = NULL;
 515 }
 516
 517 /* disconnect but do not error all PDUs, just move pdus in-flight back to the outqueue and reconnect */
 518 static int rpc_reconnect_requeue(struct rpc_context *rpc)
 519 {
 520         struct rpc_pdu *pdu;
 521
 522         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 523
 524         if (rpc->fd != -1) {
 525 #if defined(WIN32)
 526                 closesocket(rpc->fd);
 527 #else
 528                 close(rpc->fd);
 529 #endif
 530         }
 531         rpc->fd  = -1;
 532
 533         rpc->is_connected = 0;
 534
 535         /* socket is closed so we will not get any replies to any commands
 536          * in flight. Move them all over from the waitpdu queue back to the out queue
 537          */
 538         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 539                 SLIST_REMOVE(&rpc->waitpdu, pdu);
 540                 SLIST_ADD(&rpc->outqueue, pdu);
 541                 /* we have to re-send the whole pdu again */
 542                 pdu->written = 0;
 543         }
 544
 545         if (rpc->auto_reconnect != 0) {
 546                 rpc->connect_cb  = reconnect_cb;
 547
 548                 if (rpc_connect_sockaddr_async(rpc, &rpc->s) != 0) {
 549                         rpc_error_all_pdus(rpc, "RPC ERROR: Failed to reconnect async");
 550                         return -1;
 551                 }
 552         }
 553
 554         return 0;
 555 }
 556
 557
 558 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 559 {
 560         struct addrinfo *ai = NULL;
 561         char service[6];
 562
 563         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 564
 565         if (rpc->is_udp == 0) {
 566                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 567                 return -1;
 568         }
 569
 570         sprintf(service, "%d", port);
 571         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 572                 rpc_set_error(rpc, "Invalid address:%s. "
 573                         "Can not resolv into IPv4/v6 structure.");
 574                 return -1;
 575         }
 576
 577         switch(ai->ai_family) {
 578         case AF_INET:
 579                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 580                 if (rpc->fd == -1) {
 581                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 582                         freeaddrinfo(ai);
 583                         return -1;
 584                 }
 585
 586                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 587                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 588                         freeaddrinfo(ai);
 589                         return -1;
 590                 }
 591                 break;
 592         default:
 593                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 594                 freeaddrinfo(ai);
 595                 return -1;
 596         }
 597
 598         freeaddrinfo(ai);
 599
 600         return 0;
 601 }
 602
 603 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 604 {
 605         struct addrinfo *ai = NULL;
 606         char service[6];
 607
 608         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 609
 610         if (rpc->is_udp == 0) {
 611                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 612                 return -1;
 613         }
 614
 615         sprintf(service, "%d", port);
 616         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 617                 rpc_set_error(rpc, "Invalid address:%s. "
 618                         "Can not resolv into IPv4/v6 structure.");
 619                 return -1;
 620         }
 621
 622         if (rpc->udp_dest) {
 623                 free(rpc->udp_dest);
 624                 rpc->udp_dest = NULL;
 625         }
 626         rpc->udp_dest = malloc(ai->ai_addrlen);
 627         if (rpc->udp_dest == NULL) {
 628                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 629                 freeaddrinfo(ai);
 630                 return -1;
 631         }
 632         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 633         freeaddrinfo(ai);
 634
 635         rpc->is_broadcast = is_broadcast;
 636         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, (char *)&is_broadcast, sizeof(is_broadcast));
 637
 638         return 0;
 639 }
 640
 641 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 642 {
 643         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 644
 645         return (struct sockaddr *)&rpc->udp_src;
 646 }
 647
 648 int rpc_queue_length(struct rpc_context *rpc)
 649 {
 650         int i=0;
 651         struct rpc_pdu *pdu;
 652
 653         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 654
 655         for(pdu = rpc->outqueue; pdu; pdu = pdu->next) {
 656                 i++;
 657         }
 658         for(pdu = rpc->waitpdu; pdu; pdu = pdu->next) {
 659                 i++;
 660         }
 661         return i;
 662 }