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