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