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
  18 #ifdef HAVE_CONFIG_H
  19 #include "config.h"
  20 #endif
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <poll.h>
  26 #include <string.h>
  27 #include <errno.h>
  28 #include <rpc/rpc.h>
  29 #include <rpc/xdr.h>
  30 #include <arpa/inet.h>
  31 #ifdef HAVE_SYS_FILIO_H
  32 #include <sys/filio.h>
  33 #endif
  34 #include <sys/ioctl.h>
  35 #include <sys/types.h>
  36 #include <sys/socket.h>
  37 #include <netdb.h>
  38 #include "libnfs.h"
  39 #include "libnfs-raw.h"
  40 #include "libnfs-private.h"
  41 #include "slist.h"
  42
  43 static int rpc_disconnect_requeue(struct rpc_context *rpc);
  44
  45 static void set_nonblocking(int fd)
  46 {
  47         unsigned v;
  48         v = fcntl(fd, F_GETFL, 0);
  49         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  50 }
  51
  52 int rpc_get_fd(struct rpc_context *rpc)
  53 {
  54         return rpc->fd;
  55 }
  56
  57 int rpc_which_events(struct rpc_context *rpc)
  58 {
  59         int events = rpc->is_connected ? POLLIN : POLLOUT;
  60
  61         if (rpc->is_udp != 0) {
  62                 /* for udp sockets we only wait for pollin */
  63                 return POLLIN;
  64         }
  65
  66         if (rpc->outqueue) {
  67                 events |= POLLOUT;
  68         }
  69         return events;
  70 }
  71
  72 static int rpc_write_to_socket(struct rpc_context *rpc)
  73 {
  74         ssize_t count;
  75
  76         if (rpc == NULL) {
  77                 return -1;
  78         }
  79         if (rpc->fd == -1) {
  80                 rpc_set_error(rpc, "trying to write but not connected");
  81                 return -1;
  82         }
  83
  84         while (rpc->outqueue != NULL) {
  85                 ssize_t total;
  86
  87                 total = rpc->outqueue->outdata.size;
  88
  89                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
  90                 if (count == -1) {
  91                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
  92                                 return 0;
  93                         }
  94                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
  95                         return -1;
  96                 }
  97
  98                 rpc->outqueue->written += count;
  99                 if (rpc->outqueue->written == total) {
 100                         struct rpc_pdu *pdu = rpc->outqueue;
 101
 102                         SLIST_REMOVE(&rpc->outqueue, pdu);
 103                         SLIST_ADD_END(&rpc->waitpdu, pdu);
 104                 }
 105         }
 106         return 0;
 107 }
 108
 109 static int rpc_read_from_socket(struct rpc_context *rpc)
 110 {
 111         int available;
 112         int size;
 113         int pdu_size;
 114         ssize_t count;
 115
 116         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 117                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 118                 return -1;
 119         }
 120         if (available == 0) {
 121                 rpc_set_error(rpc, "Socket has been closed");
 122                 return -1;
 123         }
 124
 125         if (rpc->is_udp) {
 126                 char *buf;
 127                 socklen_t socklen = sizeof(rpc->udp_src);
 128
 129                 buf = malloc(available);
 130                 if (buf == NULL) {
 131                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 132                         return -1;
 133                 }
 134                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 135                 if (count < 0) {
 136                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 137                         free(buf);
 138                 }
 139                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 140                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 141                         free(buf);
 142                         return -1;
 143                 }
 144                 free(buf);
 145                 return 0;
 146         }
 147
 148         /* read record marker, 4 bytes at the beginning of every pdu */
 149         if (rpc->inbuf == NULL) {
 150                 rpc->insize = 4;
 151                 rpc->inbuf = malloc(rpc->insize);
 152                 if (rpc->inbuf == NULL) {
 153                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 154                         return -1;
 155                 }
 156         }
 157         if (rpc->inpos < 4) {
 158                 size = 4 - rpc->inpos;
 159
 160                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 161                 if (count == -1) {
 162                         if (errno == EINTR) {
 163                                 return 0;
 164                         }
 165                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 166                         return -1;
 167                 }
 168                 available  -= count;
 169                 rpc->inpos += count;
 170         }
 171
 172         if (available == 0) {
 173                 return 0;
 174         }
 175
 176         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 177         if (rpc->insize < pdu_size) {
 178                 unsigned char *buf;
 179
 180                 buf = malloc(pdu_size);
 181                 if (buf == NULL) {
 182                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 183                         return -1;
 184                 }
 185                 memcpy(buf, rpc->inbuf, rpc->insize);
 186                 free(rpc->inbuf);
 187                 rpc->inbuf  = buf;
 188                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 189         }
 190
 191         size = available;
 192         if (size > rpc->insize - rpc->inpos) {
 193                 size = rpc->insize - rpc->inpos;
 194         }
 195
 196         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 197         if (count == -1) {
 198                 if (errno == EINTR) {
 199                         return 0;
 200                 }
 201                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 202                 return -1;
 203         }
 204         available  -= count;
 205         rpc->inpos += count;
 206
 207         if (rpc->inpos == rpc->insize) {
 208                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 209                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 210                         return -1;
 211                 }
 212                 free(rpc->inbuf);
 213                 rpc->inbuf  = NULL;
 214                 rpc->insize = 0;
 215                 rpc->inpos  = 0;
 216         }
 217
 218         return 0;
 219 }
 220
 221
 222
 223 int rpc_service(struct rpc_context *rpc, int revents)
 224 {
 225         if (revents & POLLERR) {
 226                 int err = 0;
 227                 socklen_t err_size = sizeof(err);
 228
 229                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 230                                 &err, &err_size) != 0 || err != 0) {
 231                         if (err == 0) {
 232                                 err = errno;
 233                         }
 234                         rpc_set_error(rpc, "rpc_service: socket error "
 235                                                "%s(%d).",
 236                                                strerror(err), err);
 237                 } else {
 238                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 239                                                 "Unknown socket error.");
 240                 }
 241                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 242                 return -1;
 243         }
 244         if (revents & POLLHUP) {
 245                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 246                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 247                 return -1;
 248         }
 249
 250         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 251                 int err = 0;
 252                 socklen_t err_size = sizeof(err);
 253
 254                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 255                                 &err, &err_size) != 0 || err != 0) {
 256                         if (err == 0) {
 257                                 err = errno;
 258                         }
 259                         rpc_set_error(rpc, "rpc_service: socket error "
 260                                         "%s(%d) while connecting.",
 261                                         strerror(err), err);
 262                         rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 263                                         NULL, rpc->connect_data);
 264                         return -1;
 265                 }
 266
 267                 rpc->is_connected = 1;
 268                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 269                 return 0;
 270         }
 271
 272         if (revents & POLLIN) {
 273                 if (rpc_read_from_socket(rpc) != 0) {
 274                         rpc_disconnect_requeue(rpc);
 275                         return 0;
 276                 }
 277         }
 278
 279         if (revents & POLLOUT && rpc->outqueue != NULL) {
 280                 if (rpc_write_to_socket(rpc) != 0) {
 281                         rpc_set_error(rpc, "write to socket failed");
 282                         return -1;
 283                 }
 284         }
 285
 286         return 0;
 287 }
 288
 289
 290 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 291 {
 292         struct sockaddr_storage s;
 293         struct sockaddr_in *sin = (struct sockaddr_in *)&s;
 294         int socksize;
 295
 296         if (rpc->fd != -1) {
 297                 rpc_set_error(rpc, "Trying to connect while already connected");
 298                 return -1;
 299         }
 300
 301         if (rpc->is_udp != 0) {
 302                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 303                 return -1;
 304         }
 305
 306         sin->sin_family = AF_INET;
 307         sin->sin_port   = htons(port);
 308         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 309                 rpc_set_error(rpc, "Not a valid server ip address");
 310                 return -1;
 311         }
 312
 313         switch (s.ss_family) {
 314         case AF_INET:
 315                 socksize = sizeof(struct sockaddr_in);
 316 #ifdef HAVE_SOCKADDR_LEN
 317                 sin->sin_len = socksize;
 318 #endif
 319                 rpc->fd = socket(AF_INET, SOCK_STREAM, 0);
 320                 break;
 321         }
 322
 323         if (rpc->fd == -1) {
 324                 rpc_set_error(rpc, "Failed to open socket");
 325                 return -1;
 326         }
 327
 328         rpc->connect_cb  = cb;
 329         rpc->connect_data = private_data;
 330
 331         set_nonblocking(rpc->fd);
 332
 333         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) != 0 && errno != EINPROGRESS) {
 334                 rpc_set_error(rpc, "connect() to server failed");
 335                 return -1;
 336         }
 337
 338         return 0;
 339 }
 340
 341 int rpc_disconnect(struct rpc_context *rpc, char *error)
 342 {
 343         if (rpc->fd != -1) {
 344                 close(rpc->fd);
 345         }
 346         rpc->fd  = -1;
 347
 348         rpc->is_connected = 0;
 349
 350         rpc_error_all_pdus(rpc, error);
 351
 352         return 0;
 353 }
 354
 355 /* disconnect but do not error all PDUs, just move pdus in-flight back to the outqueue */
 356 static int rpc_disconnect_requeue(struct rpc_context *rpc)
 357 {
 358         struct rpc_pdu *pdu;
 359
 360         if (rpc->fd != -1) {
 361                 close(rpc->fd);
 362         }
 363         rpc->fd  = -1;
 364
 365         rpc->is_connected = 0;
 366
 367         /* socket is closed so we will not get any replies to any commands
 368          * in flight. Move them all over from the waitpdu queue back to the out queue
 369          */
 370         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 371                 SLIST_REMOVE(&rpc->waitpdu, pdu);
 372                 SLIST_ADD(&rpc->outqueue, pdu);
 373         }
 374
 375         return 0;
 376 }
 377
 378
 379 int rpc_bind_udp(struct rpc_context *rpc, char *addr, int port)
 380 {
 381         struct addrinfo *ai = NULL;
 382         char service[6];
 383
 384         if (rpc->is_udp == 0) {
 385                 rpc_set_error(rpc, "Cant not bind UDP. Not UDP context");
 386                 return -1;
 387         }
 388
 389         snprintf(service, 6, "%d", port);
 390         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 391                 rpc_set_error(rpc, "Invalid address:%s. "
 392                         "Can not resolv into IPv4/v6 structure.");
 393                 return -1;
 394         }
 395
 396         switch(ai->ai_family) {
 397         case AF_INET:
 398                 rpc->fd = socket(ai->ai_family, SOCK_DGRAM, 0);
 399                 if (rpc->fd == -1) {
 400                         rpc_set_error(rpc, "Failed to create UDP socket: %s", strerror(errno));
 401                         freeaddrinfo(ai);
 402                         return -1;
 403                 }
 404
 405                 if (bind(rpc->fd, (struct sockaddr *)ai->ai_addr, sizeof(struct sockaddr_in)) != 0) {
 406                         rpc_set_error(rpc, "Failed to bind to UDP socket: %s",strerror(errno));
 407                         freeaddrinfo(ai);
 408                         return -1;
 409                 }
 410                 break;
 411         default:
 412                 rpc_set_error(rpc, "Can not handle UPD sockets of family %d yet", ai->ai_family);
 413                 freeaddrinfo(ai);
 414                 return -1;
 415         }
 416
 417         freeaddrinfo(ai);
 418
 419         return 0;
 420 }
 421
 422 int rpc_set_udp_destination(struct rpc_context *rpc, char *addr, int port, int is_broadcast)
 423 {
 424         struct addrinfo *ai = NULL;
 425         char service[6];
 426
 427         if (rpc->is_udp == 0) {
 428                 rpc_set_error(rpc, "Can not set destination sockaddr. Not UDP context");
 429                 return -1;
 430         }
 431
 432         snprintf(service, 6, "%d", port);
 433         if (getaddrinfo(addr, service, NULL, &ai) != 0) {
 434                 rpc_set_error(rpc, "Invalid address:%s. "
 435                         "Can not resolv into IPv4/v6 structure.");
 436                 return -1;
 437         }
 438
 439         if (rpc->udp_dest) {
 440                 free(rpc->udp_dest);
 441                 rpc->udp_dest = NULL;
 442         }
 443         rpc->udp_dest = malloc(ai->ai_addrlen);
 444         if (rpc->udp_dest == NULL) {
 445                 rpc_set_error(rpc, "Out of memory. Failed to allocate sockaddr structure");
 446                 return -1;
 447         }
 448         memcpy(rpc->udp_dest, ai->ai_addr, ai->ai_addrlen);
 449         freeaddrinfo(ai);
 450
 451         rpc->is_broadcast = is_broadcast;
 452         setsockopt(rpc->fd, SOL_SOCKET, SO_BROADCAST, &is_broadcast, sizeof(is_broadcast));
 453
 454         return 0;
 455 }
 456
 457 struct sockaddr *rpc_get_recv_sockaddr(struct rpc_context *rpc)
 458 {
 459         return (struct sockaddr *)&rpc->udp_src;
 460 }