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         /* read record marker, 4 bytes at the beginning of every pdu */
 115         if (rpc->inbuf == NULL) {
 116                 rpc->insize = 4;
 117                 rpc->inbuf = malloc(rpc->insize);
 118                 if (rpc->inbuf == NULL) {
 119                         rpc_set_error(rpc, "Failed to allocate buffer for record marker, errno:%d. Closing socket.", errno);
 120                         return -1;
 121                 }
 122         }
 123         if (rpc->inpos < 4) {
 124                 size = 4 - rpc->inpos;
 125
 126                 count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 127                 if (count == -1) {
 128                         if (errno == EINTR) {
 129                                 return 0;
 130                         }
 131                         rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 132                         return -1;
 133                 }
 134                 available  -= count;
 135                 rpc->inpos += count;
 136         }
 137
 138         if (available == 0) {
 139                 return 0;
 140         }
 141
 142         pdu_size = rpc_get_pdu_size(rpc->inbuf);
 143         if (rpc->insize < pdu_size) {
 144                 unsigned char *buf;
 145
 146                 buf = malloc(pdu_size);
 147                 if (buf == NULL) {
 148                         rpc_set_error(rpc, "Failed to allocate buffer of %d bytes for pdu, errno:%d. Closing socket.", pdu_size, errno);
 149                         return -1;
 150                 }
 151                 memcpy(buf, rpc->inbuf, rpc->insize);
 152                 free(rpc->inbuf);
 153                 rpc->inbuf  = buf;
 154                 rpc->insize = rpc_get_pdu_size(rpc->inbuf);
 155         }
 156
 157         size = available;
 158         if (size > rpc->insize - rpc->inpos) {
 159                 size = rpc->insize - rpc->inpos;
 160         }
 161
 162         count = read(rpc->fd, rpc->inbuf + rpc->inpos, size);
 163         if (count == -1) {
 164                 if (errno == EINTR) {
 165                         return 0;
 166                 }
 167                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 168                 return -1;
 169         }
 170         available  -= count;
 171         rpc->inpos += count;
 172
 173         if (rpc->inpos == rpc->insize) {
 174                 if (rpc_process_pdu(rpc, rpc->inbuf, pdu_size) != 0) {
 175                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 176                         return -1;
 177                 }
 178                 free(rpc->inbuf);
 179                 rpc->inbuf  = NULL;
 180                 rpc->insize = 0;
 181                 rpc->inpos  = 0;
 182         }
 183
 184         return 0;
 185 }
 186
 187
 188
 189 int rpc_service(struct rpc_context *rpc, int revents)
 190 {
 191         if (revents & POLLERR) {
 192                 int err = 0;
 193                 socklen_t err_size = sizeof(err);
 194
 195                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 196                                 &err, &err_size) != 0 || err != 0) {
 197                         if (err == 0) {
 198                                 err = errno;
 199                         }
 200                         rpc_set_error(rpc, "rpc_service: socket error "
 201                                                "%s(%d).",
 202                                                strerror(err), err);
 203                 } else {
 204                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 205                                                 "Unknown socket error.");
 206                 }
 207                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 208                 return -1;
 209         }
 210         if (revents & POLLHUP) {
 211                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 212                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 213                 return -1;
 214         }
 215
 216         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 217                 int err = 0;
 218                 socklen_t err_size = sizeof(err);
 219
 220                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 221                                 &err, &err_size) != 0 || err != 0) {
 222                         if (err == 0) {
 223                                 err = errno;
 224                         }
 225                         rpc_set_error(rpc, "rpc_service: socket error "
 226                                         "%s(%d) while connecting.",
 227                                         strerror(err), err);
 228                         rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 229                                         NULL, rpc->connect_data);
 230                         return -1;
 231                 }
 232
 233                 rpc->is_connected = 1;
 234                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 235                 return 0;
 236         }
 237
 238         if (revents & POLLOUT && rpc->outqueue != NULL) {
 239                 if (rpc_write_to_socket(rpc) != 0) {
 240                         rpc_set_error(rpc, "write to socket failed");
 241                         return -1;
 242                 }
 243         }
 244
 245         if (revents & POLLIN) {
 246                 if (rpc_read_from_socket(rpc) != 0) {
 247                         rpc_disconnect(rpc, rpc_get_error(rpc));
 248                         return -1;
 249                 }
 250         }
 251
 252         return 0;
 253 }
 254
 255
 256 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 257 {
 258         struct sockaddr_storage s;
 259         struct sockaddr_in *sin = (struct sockaddr_in *)&s;
 260         int socksize;
 261
 262         if (rpc->fd != -1) {
 263                 rpc_set_error(rpc, "Trying to connect while already connected");
 264                 return -1;
 265         }
 266
 267         sin->sin_family = AF_INET;
 268         sin->sin_port   = htons(port);
 269         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 270                 rpc_set_error(rpc, "Not a valid server ip address");
 271                 return -1;
 272         }
 273
 274         switch (s.ss_family) {
 275         case AF_INET:
 276                 socksize = sizeof(struct sockaddr_in);
 277 #ifdef HAVE_SOCK_SIN_LEN
 278                 sin->sin_len = socksize;
 279 #endif
 280                 rpc->fd = socket(AF_INET, SOCK_STREAM, 0);
 281                 break;
 282         }
 283
 284         if (rpc->fd == -1) {
 285                 rpc_set_error(rpc, "Failed to open socket");
 286                 return -1;
 287         }
 288
 289         rpc->connect_cb  = cb;
 290         rpc->connect_data = private_data;
 291
 292         set_nonblocking(rpc->fd);
 293
 294         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) != 0 && errno != EINPROGRESS) {
 295                 rpc_set_error(rpc, "connect() to server failed");
 296                 return -1;
 297         }
 298
 299         return 0;
 300 }
 301
 302 int rpc_disconnect(struct rpc_context *rpc, char *error)
 303 {
 304         if (rpc->fd != -1) {
 305                 close(rpc->fd);
 306         }
 307         rpc->fd  = -1;
 308
 309         rpc->is_connected = 0;
 310
 311         rpc_error_all_pdus(rpc, error);
 312
 313         return 0;
 314 }