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 #if defined(WIN32)
  29 #include <winsock2.h>
  30 #include <ws2tcpip.h>
  31 #include <basetsd.h>
  32 #define ssize_t SSIZE_T
  33 #define MSG_DONTWAIT 0
  34 #else
  35 #include <unistd.h>
  36 #include <poll.h>
  37 #include <arpa/inet.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/socket.h>
  40 #include <netdb.h>
  41 #endif
  42
  43 #ifdef HAVE_CONFIG_H
  44 #include "config.h"
  45 #endif
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <fcntl.h>
  49 #include <string.h>
  50 #include <errno.h>
  51 #include <rpc/rpc.h>
  52 #include <rpc/xdr.h>
  53 #ifdef HAVE_SYS_FILIO_H
  54 #include <sys/filio.h>
  55 #endif
  56 #ifdef HAVE_SYS_SOCKIO_H
  57 #include <sys/sockio.h>
  58 #endif
  59 #include <sys/types.h>
  60 #include "libnfs.h"
  61 #include "libnfs-raw.h"
  62 #include "libnfs-private.h"
  63 #include "slist.h"
  64
  65 static int rpc_disconnect_requeue(struct rpc_context *rpc);
  66
  67 static void set_nonblocking(int fd)
  68 {
  69         int v = 0;
  70 #if defined(WIN32)
  71         long nonblocking=1;
  72         v = ioctlsocket(fd, FIONBIO,&nonblocking);
  73 #else
  74         v = fcntl(fd, F_GETFL, 0);
  75         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  76 #endif //FIXME
  77 }
  78
  79 int rpc_get_fd(struct rpc_context *rpc)
  80 {
  81         return rpc->fd;
  82 }
  83
  84 int rpc_which_events(struct rpc_context *rpc)
  85 {
  86         int events = rpc->is_connected ? POLLIN : POLLOUT;
  87
  88         if (rpc->is_udp != 0) {
  89                 /* for udp sockets we only wait for pollin */
  90                 return POLLIN;
  91         }
  92
  93         if (rpc->outqueue) {
  94                 events |= POLLOUT;
  95         }
  96         return events;
  97 }
  98
  99 static int rpc_write_to_socket(struct rpc_context *rpc)
 100 {
 101         ssize_t count;
 102
 103         if (rpc == NULL) {
 104                 return -1;
 105         }
 106         if (rpc->fd == -1) {
 107                 rpc_set_error(rpc, "trying to write but not connected");
 108                 return -1;
 109         }
 110
 111         while (rpc->outqueue != NULL) {
 112                 ssize_t total;
 113
 114                 total = rpc->outqueue->outdata.size;
 115
 116 #if defined(WIN32)
 117                 count = send(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written, 0);
 118 #else
 119                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
 120 #endif
 121                 if (count == -1) {
 122                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
 123                                 return 0;
 124                         }
 125                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
 126                         return -1;
 127                 }
 128
 129                 rpc->outqueue->written += count;
 130                 if (rpc->outqueue->written == total) {
 131                         struct rpc_pdu *pdu = rpc->outqueue;
 132
 133                         SLIST_REMOVE(&rpc->outqueue, pdu);
 134                         SLIST_ADD_END(&rpc->waitpdu, pdu);
 135                 }
 136         }
 137         return 0;
 138 }
 139
 140 static int rpc_read_from_socket(struct rpc_context *rpc)
 141 {
 142         int available;
 143         int size;
 144         int pdu_size;
 145         ssize_t count;
 146
 147 #if defined(WIN32)
 148         if (ioctlsocket(rpc->fd, FIONREAD, &available) != 0) {
 149 #else
 150         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 151 #endif
 152                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 153                 return -1;
 154         }
 155
 156         if (available == 0) {
 157                 rpc_set_error(rpc, "Socket has been closed");
 158                 return -1;
 159         }
 160
 161         if (rpc->is_udp) {
 162                 char *buf;
 163                 socklen_t socklen = sizeof(rpc->udp_src);
 164
 165                 buf = malloc(available);
 166                 if (buf == NULL) {
 167                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 168                         return -1;
 169                 }
 170                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 171                 if (count < 0) {
 172                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 173                         free(buf);
 174                 }
 175                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 176                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 177                         free(buf);
 178                         return -1;
 179                 }
 180                 free(buf);
 181                 return 0;
 182         }
 183
 184         /* read record marker, 4 bytes at the beginning of every pdu */
 185         if (rpc->inbuf == NULL) {
 186                 rpc->insize = 4;
 187                 rpc->inbuf = malloc(rpc->insize);
 188                 if (rpc->inbuf == NULL) {
 189                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 190                         return -1;
 191                 }
 192         }
 193         if (rpc->inpos < 4) {
 194                 size = 4 - rpc->inpos;
 195
 196 #if defined(WIN32)
 197                 count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 198 #else
 199                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 200 #endif
 201                 if (count == -1) {
 202                         if (errno == EINTR) {
 203                                 return 0;
 204                         }
 205                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 206                         return -1;
 207                 }
 208                 available  -= count;
 209                 rpc->inpos += count;
 210         }
 211
 212         if (available == 0) {
 213                 return 0;
 214         }
 215
 216         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 217         if (rpc->insize < pdu_size) {
 218                 unsigned char *buf;
 219
 220                 buf = malloc(pdu_size);
 221                 if (buf == NULL) {
 222                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 223                         return -1;
 224                 }
 225                 memcpy(buf, rpc->inbuf, rpc->insize);
 226                 free(rpc->inbuf);
 227                 rpc->inbuf  = buf;
 228                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 229         }
 230
 231         size = available;
 232         if (size > rpc->insize - rpc->inpos) {
 233                 size = rpc->insize - rpc->inpos;
 234         }
 235
 236 #if defined(WIN32)
 237         count = recv(rpc->fd, rpc->inbuf + rpc->inpos, size, 0);
 238 #else
 239         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 240 #endif
 241         if (count == -1) {
 242                 if (errno == EINTR) {
 243                         return 0;
 244                 }
 245                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 246                 return -1;
 247         }
 248         available  -= count;
 249         rpc->inpos += count;
 250
 251         if (rpc->inpos == rpc->insize) {
 252                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 253                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 254                         return -1;
 255                 }
 256                 free(rpc->inbuf);
 257                 rpc->inbuf  = NULL;
 258                 rpc->insize = 0;
 259                 rpc->inpos  = 0;
 260         }
 261
 262         return 0;
 263 }
 264
 265
 266
 267 int rpc_service(struct rpc_context *rpc, int revents)
 268 {
 269         if (revents & POLLERR) {
 270                 char err = 0;
 271                 socklen_t err_size = sizeof(err);
 272
 273                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 274                                 (char *)&err, &err_size) != 0 || err != 0) {
 275                         if (err == 0) {
 276                                 err = errno;
 277                         }
 278                         rpc_set_error(rpc, "rpc_service: socket error "
 279                                                "%s(%d).",
 280                                                strerror(err), err);
 281                 } else {
 282                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 283                                                 "Unknown socket error.");
 284                 }
 285                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 286                 return -1;
 287         }
 288         if (revents & POLLHUP) {
 289                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 290                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 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                         rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 307                                         NULL, rpc->connect_data);
 308                         return -1;
 309                 }
 310
 311                 rpc->is_connected = 1;
 312                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 313                 return 0;
 314         }
 315
 316         if (revents & POLLIN) {
 317                 if (rpc_read_from_socket(rpc) != 0) {
 318                         rpc_disconnect_requeue(rpc);
 319                         return 0;
 320                 }
 321         }
 322
 323         if (revents & POLLOUT && rpc->outqueue != NULL) {
 324                 if (rpc_write_to_socket(rpc) != 0) {
 325                         rpc_set_error(rpc, "write to socket failed");
 326                         return -1;
 327                 }
 328         }
 329
 330         return 0;
 331 }
 332
 333 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 334 {
 335         struct sockaddr_storage s;
 336         struct sockaddr_in *sin = (struct sockaddr_in *)&s;
 337         int socksize;
 338
 339         if (rpc->fd != -1) {
 340                 rpc_set_error(rpc, "Trying to connect while already connected");
 341                 return -1;
 342         }
 343
 344         if (rpc->is_udp != 0) {
 345                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 346                 return -1;
 347         }
 348
 349         sin->sin_family = AF_INET;
 350         sin->sin_port   = htons(port);
 351         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 352                 rpc_set_error(rpc, "Not a valid server ip address");
 353                 return -1;
 354         }
 355
 356         switch (s.ss_family) {
 357         case AF_INET:
 358                 socksize = sizeof(struct sockaddr_in);
 359 #ifdef HAVE_SOCKADDR_LEN
 360                 sin->sin_len = socksize;
 361 #endif
 362                 rpc->fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
 363                 break;
 364         }
 365
 366         if (rpc->fd == -1) {
 367                 rpc_set_error(rpc, "Failed to open socket");
 368                 return -1;
 369         }
 370
 371         rpc->connect_cb  = cb;
 372         rpc->connect_data = private_data;
 373
 374
 375 #if !defined(WIN32)
 376         /* Some systems allow you to set capabilities on an executable
 377          * to allow the file to be executed with privilege to bind to
 378          * privileged system ports, even if the user is not root.
 379          *
 380          * Opportunistically try to bind the socket to a low numbered
 381          * system port in the hope that the user is either root or the
 382          * executable has the CAP_NET_BIND_SERVICE.
 383          *
 384          * As soon as we fail the bind() with EACCES we know we will never
 385          * be able to bind to a system port so we terminate the loop.
 386          *
 387          * On linux, use
 388          *    sudo setcap 'cap_net_bind_service=+ep' /path/executable
 389          * to make the executable able to bind to a system port.
 390          */
 391         if (1) {
 392                 int port;
 393                 int one = 1;
 394
 395                 setsockopt(rpc->fd, SOL_SOCKET, SO_REUSEADDR, (char *)&one, sizeof(one));
 396
 397                 for (port = 200; port < 500; port++) {
 398                         struct sockaddr_in sin;
 399
 400                         printf("try port %d\n", port);
 401                         memset(&sin, 0, sizeof(sin));
 402                         sin.sin_port        = htons(port);
 403                         sin.sin_family      = AF_INET;
 404                         sin.sin_addr.s_addr = 0;
 405
 406                         if (bind(rpc->fd, (struct sockaddr *)&sin, sizeof(struct sockaddr_in)) != 0 && errno != EACCES) {
 407                                 /* we didnt get EACCES, so try again */
 408                                 continue;
 409                         }
 410                         break;
 411                 }
 412         }
 413 #endif
 414
 415         set_nonblocking(rpc->fd);
 416
 417 #if defined(WIN32)
 418         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) == 0 && GetLastError() != WSAEINPROGRESS   )
 419 #else
 420         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) != 0 && errno != EINPROGRESS)
 421 #endif
 422         {
 423                 rpc_set_error(rpc, "connect() to server failed");
 424                 return -1;
 425         }
 426
 427         return 0;
 428 }
 429
 430 int rpc_disconnect(struct rpc_context *rpc, char *error)
 431 {
 432         if (rpc->fd != -1) {
 433 #if defined(WIN32)
 434                 closesocket(rpc->fd);
 435 #else
 436                 close(rpc->fd);
 437 #endif
 438         }
 439         rpc->fd  = -1;
 440
 441         rpc->is_connected = 0;
 442
 443         rpc_error_all_pdus(rpc, error);
 444
 445         return 0;
 446 }
 447
 448 /* disconnect but do not error all PDUs, just move pdus in-flight back to the outqueue */
 449 static int rpc_disconnect_requeue(struct rpc_context *rpc)
 450 {
 451         struct rpc_pdu *pdu;
 452
 453         if (rpc->fd != -1) {
 454 #if defined(WIN32)
 455                 closesocket(rpc->fd);
 456 #else
 457                 close(rpc->fd);
 458 #endif
 459         }
 460         rpc->fd  = -1;
 461
 462         rpc->is_connected = 0;
 463
 464         /* socket is closed so we will not get any replies to any commands
 465          * in flight. Move them all over from the waitpdu queue back to the out queue
 466          */
 467         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 468                 SLIST_REMOVE(&rpc->waitpdu, pdu);
 469                 SLIST_ADD(&rpc->outqueue, pdu);
 470         }
 471
 472         return 0;
 473 }
 474
 475
 476 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 477 {
 478         struct addrinfo *ai = NULL;
 479         char service[6];
 480
 481         if (rpc->is_udp == 0) {
 482                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 483                 return -1;
 484         }
 485
 486         sprintf(service, "%d", port);
 487         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 488                 rpc_set_error(rpc, "Invalid address:%s. "
 489                         "Can not resolv into IPv4/v6 structure.");
 490                 return -1;
 491         }
 492
 493         switch(ai->ai_family) {
 494         case AF_INET:
 495                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 496                 if (rpc->fd == -1) {
 497                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 498                         freeaddrinfo(ai);
 499                         return -1;
 500                 }
 501
 502                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 503                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 504                         freeaddrinfo(ai);
 505                         return -1;
 506                 }
 507                 break;
 508         default:
 509                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 510                 freeaddrinfo(ai);
 511                 return -1;
 512         }
 513
 514         freeaddrinfo(ai);
 515
 516         return 0;
 517 }
 518
 519 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 520 {
 521         struct addrinfo *ai = NULL;
 522         char service[6];
 523
 524         if (rpc->is_udp == 0) {
 525                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 526                 return -1;
 527         }
 528
 529         sprintf(service, "%d", port);
 530         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 531                 rpc_set_error(rpc, "Invalid address:%s. "
 532                         "Can not resolv into IPv4/v6 structure.");
 533                 return -1;
 534         }
 535
 536         if (rpc->udp_dest) {
 537                 free(rpc->udp_dest);
 538                 rpc->udp_dest = NULL;
 539         }
 540         rpc->udp_dest = malloc(ai->ai_addrlen);
 541         if (rpc->udp_dest == NULL) {
 542                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 543                 return -1;
 544         }
 545         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 546         freeaddrinfo(ai);
 547
 548         rpc->is_broadcast = is_broadcast;
 549         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, (char *)&is_broadcast, sizeof(is_broadcast));
 550
 551         return 0;
 552 }
 553
 554 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 555 {
 556         return (struct sockaddr *)&rpc->udp_src;
 557 }
 558
 559 int rpc_queue_length(struct rpc_context *rpc)
 560 {
 561         int i=0;
 562         struct rpc_pdu *pdu;
 563
 564         for(pdu = rpc->outqueue; pdu; pdu = pdu->next) {
 565                 i++;
 566         }
 567         for(pdu = rpc->waitpdu; pdu; pdu = pdu->next) {
 568                 i++;
 569         }
 570         return i;
 571 }