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