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 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <unistd.h>
  21 #include <fcntl.h>
  22 #include <poll.h>
  23 #include <string.h>
  24 #include <errno.h>
  25 #include <rpc/rpc.h>
  26 #include <rpc/xdr.h>
  27 #include <arpa/inet.h>
  28 #include <sys/ioctl.h>
  29 #include "libnfs.h"
  30 #include "libnfs-raw.h"
  31 #include "libnfs-private.h"
  32 #include "slist.h"
  33
  34 static void set_nonblocking(int fd)
  35 {
  36         unsigned v;
  37         v = fcntl(fd, F_GETFL, 0);
  38         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  39 }
  40
  41 int rpc_get_fd(struct rpc_context *rpc)
  42 {
  43         return rpc->fd;
  44 }
  45
  46 int rpc_which_events(struct rpc_context *rpc)
  47 {
  48         int events = rpc->is_connected ? POLLIN : POLLOUT;
  49
  50         if (rpc->is_udp != 0) {
  51                 /* for udp sockets we only wait for pollin */
  52                 return POLLIN;
  53         }
  54
  55         if (rpc->outqueue) {
  56                 events |= POLLOUT;
  57         }
  58         return events;
  59 }
  60
  61 static int rpc_write_to_socket(struct rpc_context *rpc)
  62 {
  63         ssize_t count;
  64
  65         if (rpc == NULL) {
  66                 return -1;
  67         }
  68         if (rpc->fd == -1) {
  69                 rpc_set_error(rpc, "trying to write but not connected");
  70                 return -1;
  71         }
  72
  73         while (rpc->outqueue != NULL) {
  74                 ssize_t total;
  75
  76                 total = rpc->outqueue->outdata.size;
  77
  78                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
  79                 if (count == -1) {
  80                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
  81                                 return 0;
  82                         }
  83                         rpc_set_error(rpc, "Error when writing to socket :%s(%d)", strerror(errno), errno);
  84                         return -1;
  85                 }
  86
  87                 rpc->outqueue->written += count;
  88                 if (rpc->outqueue->written == total) {
  89                         struct rpc_pdu *pdu = rpc->outqueue;
  90
  91                         SLIST_REMOVE(&rpc->outqueue, pdu);
  92                         SLIST_ADD_END(&rpc->waitpdu, pdu);
  93                 }
  94         }
  95         return 0;
  96 }
  97
  98 static int rpc_read_from_socket(struct rpc_context *rpc)
  99 {
 100         int available;
 101         int size;
 102         int pdu_size;
 103         ssize_t count;
 104
 105         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 106                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 107                 return -1;
 108         }
 109         if (available == 0) {
 110                 rpc_set_error(rpc, "Socket has been closed");
 111                 return -1;
 112         }
 113
 114         if (rpc->is_udp) {
 115                 char *buf;
 116                 socklen_t socklen = sizeof(rpc->udp_src);
 117
 118                 buf = malloc(available);
 119                 if (buf == NULL) {
 120                         rpc_set_error(rpc, "Failed to malloc buffer for recvfrom");
 121                         return -1;
 122                 }
 123                 count = recvfrom(rpc->fd, buf, available, MSG_DONTWAIT, (struct sockaddr *)&rpc->udp_src, &socklen);
 124                 if (count < 0) {
 125                         rpc_set_error(rpc, "Failed recvfrom: %s", strerror(errno));
 126                         free(buf);
 127                 }
 128                 if (rpc_process_pdu(rpc, buf, count) != 0) {
 129                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Ignoring PDU");
 130                         free(buf);
 131                         return -1;
 132                 }
 133                 free(buf);
 134                 return 0;
 135         }
 136
 137         /* read record marker, 4 bytes at the beginning of every pdu */
 138         if (rpc->inbuf == NULL) {
 139                 rpc->insize = 4;
 140                 rpc->inbuf = malloc(rpc->insize);
 141                 if (rpc->inbuf == NULL) {
 142                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 143                         return -1;
 144                 }
 145         }
 146         if (rpc->inpos < 4) {
 147                 size = 4 - rpc->inpos;
 148
 149                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 150                 if (count == -1) {
 151                         if (errno == EINTR) {
 152                                 return 0;
 153                         }
 154                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 155                         return -1;
 156                 }
 157                 available  -= count;
 158                 rpc->inpos += count;
 159         }
 160
 161         if (available == 0) {
 162                 return 0;
 163         }
 164
 165         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 166         if (rpc->insize < pdu_size) {
 167                 unsigned char *buf;
 168
 169                 buf = malloc(pdu_size);
 170                 if (buf == NULL) {
 171                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 172                         return -1;
 173                 }
 174                 memcpy(buf, rpc->inbuf, rpc->insize);
 175                 free(rpc->inbuf);
 176                 rpc->inbuf  = buf;
 177                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 178         }
 179
 180         size = available;
 181         if (size > rpc->insize - rpc->inpos) {
 182                 size = rpc->insize - rpc->inpos;
 183         }
 184
 185         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 186         if (count == -1) {
 187                 if (errno == EINTR) {
 188                         return 0;
 189                 }
 190                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 191                 return -1;
 192         }
 193         available  -= count;
 194         rpc->inpos += count;
 195
 196         if (rpc->inpos == rpc->insize) {
 197                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 198                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 199                         return -1;
 200                 }
 201                 free(rpc->inbuf);
 202                 rpc->inbuf  = NULL;
 203                 rpc->insize = 0;
 204                 rpc->inpos  = 0;
 205         }
 206
 207         return 0;
 208 }
 209
 210
 211
 212 int rpc_service(struct rpc_context *rpc, int revents)
 213 {
 214         if (revents & POLLERR) {
 215                 int err = 0;
 216                 socklen_t err_size = sizeof(err);
 217
 218                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 219                                 &err, &err_size) != 0 || err != 0) {
 220                         if (err == 0) {
 221                                 err = errno;
 222                         }
 223                         rpc_set_error(rpc, "rpc_service: socket error "
 224                                                "%s(%d).",
 225                                                strerror(err), err);
 226                 } else {
 227                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 228                                                 "Unknown socket error.");
 229                 }
 230                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 231                 return -1;
 232         }
 233         if (revents & POLLHUP) {
 234                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 235                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 236                 return -1;
 237         }
 238
 239         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 240                 int err = 0;
 241                 socklen_t err_size = sizeof(err);
 242
 243                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 244                                 &err, &err_size) != 0 || err != 0) {
 245                         if (err == 0) {
 246                                 err = errno;
 247                         }
 248                         rpc_set_error(rpc, "rpc_service: socket error "
 249                                         "%s(%d) while connecting.",
 250                                         strerror(err), err);
 251                         rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 252                                         NULL, rpc->connect_data);
 253                         return -1;
 254                 }
 255
 256                 rpc->is_connected = 1;
 257                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 258                 return 0;
 259         }
 260
 261         if (revents & POLLOUT && rpc->outqueue != NULL) {
 262                 if (rpc_write_to_socket(rpc) != 0) {
 263                         rpc_set_error(rpc, "write to socket failed");
 264                         return -1;
 265                 }
 266         }
 267
 268         if (revents & POLLIN) {
 269                 if (rpc_read_from_socket(rpc) != 0) {
 270                         rpc_disconnect(rpc, rpc_get_error(rpc));
 271                         return -1;
 272                 }
 273         }
 274
 275         return 0;
 276 }
 277
 278
 279 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 280 {
 281         struct sockaddr_storage s;
 282         struct sockaddr_in *sin = (struct sockaddr_in *)&s;
 283         int socksize;
 284
 285         if (rpc->fd != -1) {
 286                 rpc_set_error(rpc, "Trying to connect while already connected");
 287                 return -1;
 288         }
 289
 290         if (rpc->is_udp != 0) {
 291                 rpc_set_error(rpc, "Trying to connect on UDP socket");
 292                 return -1;
 293         }
 294
 295         sin->sin_family = AF_INET;
 296         sin->sin_port   = htons(port);
 297         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 298                 rpc_set_error(rpc, "Not a valid server ip address");
 299                 return -1;
 300         }
 301
 302         switch (s.ss_family) {
 303         case AF_INET:
 304                 socksize = sizeof(struct sockaddr_in);
 305 #ifdef HAVE_SOCK_SIN_LEN
 306                 sin->sin_len = socksize;
 307 #endif
 308                 rpc->fd = socket(AF_INET, SOCK_STREAM, 0);
 309                 break;
 310         }
 311
 312         if (rpc->fd == -1) {
 313                 rpc_set_error(rpc, "Failed to open socket");
 314                 return -1;
 315         }
 316
 317         rpc->connect_cb  = cb;
 318         rpc->connect_data = private_data;
 319
 320         set_nonblocking(rpc->fd);
 321
 322         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) != 0 && errno != EINPROGRESS) {
 323                 rpc_set_error(rpc, "connect() to server failed");
 324                 return -1;
 325         }
 326
 327         return 0;
 328 }
 329
 330 int rpc_disconnect(struct rpc_context *rpc, char *error)
 331 {
 332         if (rpc->fd != -1) {
 333                 close(rpc->fd);
 334         }
 335         rpc->fd  = -1;
 336
 337         rpc->is_connected = 0;
 338
 339         rpc_error_all_pdus(rpc, error);
 340
 341         return 0;
 342 }