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 <unistd.h>
  20 #include <fcntl.h>
  21 #include <poll.h>
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <rpc/xdr.h>
  25 #include <arpa/inet.h>
  26 #include <sys/ioctl.h>
  27 #include "libnfs.h"
  28 #include "libnfs-raw.h"
  29 #include "libnfs-private.h"
  30 #include "slist.h"
  31
  32 static void set_nonblocking(int fd)
  33 {
  34         unsigned v;
  35         v = fcntl(fd, F_GETFL, 0);
  36         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  37 }
  38
  39 int rpc_get_fd(struct rpc_context *rpc)
  40 {
  41         return rpc->fd;
  42 }
  43
  44 int rpc_which_events(struct rpc_context *rpc)
  45 {
  46         int events = rpc->is_connected ? POLLIN : POLLOUT;
  47
  48         if (rpc->outqueue) {
  49                 events |= POLLOUT;
  50         }
  51         return events;
  52 }
  53
  54 static int rpc_write_to_socket(struct rpc_context *rpc)
  55 {
  56         ssize_t count;
  57
  58         if (rpc == NULL) {
  59                 printf("trying to write to socket for NULL context\n");
  60                 return -1;
  61         }
  62         if (rpc->fd == -1) {
  63                 printf("trying to write but not connected\n");
  64                 return -2;
  65         }
  66
  67         while (rpc->outqueue != NULL) {
  68                 ssize_t total;
  69
  70                 total = rpc->outqueue->outdata.size;
  71
  72                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
  73                 if (count == -1) {
  74                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
  75                                 printf("socket would block, return from write to socket\n");
  76                                 return 0;
  77                         }
  78                         printf("Error when writing to socket :%s(%d)\n", strerror(errno), errno);
  79                         return -3;
  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         unsigned char *buf;
  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 -2;
 107         }
 108         size = rpc->insize - rpc->inpos + available;
 109         buf = malloc(size);
 110         if (buf == NULL) {
 111                 rpc_set_error(rpc, "Out of memory: failed to allocate %d bytes for input buffer. Closing socket.", size);
 112                 return -3;
 113         }
 114         if (rpc->insize > rpc->inpos) {
 115                 memcpy(buf, rpc->inbuf + rpc->inpos, rpc->insize - rpc->inpos);
 116                 rpc->insize -= rpc->inpos;
 117                 rpc->inpos   = 0;
 118         }
 119
 120         count = read(rpc->fd, buf + rpc->insize, available);
 121         if (count == -1) {
 122                 if (errno == EINTR) {
 123                         free(buf);
 124                         buf = NULL;
 125                         return 0;
 126                 }
 127                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 128                 free(buf);
 129                 buf = NULL;
 130                 return -4;
 131         }
 132
 133         if (rpc->inbuf != NULL) {
 134                 free(rpc->inbuf);
 135         }
 136         rpc->inbuf   = (char *)buf;
 137         rpc->insize += count;
 138
 139         while (1) {
 140                 if (rpc->insize - rpc->inpos < 4) {
 141                         return 0;
 142                 }
 143                 count = rpc_get_pdu_size(rpc->inbuf + rpc->inpos);
 144                 if (rpc->insize + rpc->inpos < count) {
 145                         return 0;
 146                 }
 147                 if (rpc_process_pdu(rpc, rpc->inbuf + rpc->inpos, count) != 0) {
 148                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 149                         return -5;
 150                 }
 151                 rpc->inpos += count;
 152                 if (rpc->inpos == rpc->insize) {
 153                         free(rpc->inbuf);
 154                         rpc->inbuf = NULL;
 155                         rpc->insize = 0;
 156                         rpc->inpos = 0;
 157                 }
 158         }
 159         return 0;
 160 }
 161
 162
 163
 164 int rpc_service(struct rpc_context *rpc, int revents)
 165 {
 166         if (revents & POLLERR) {
 167                 int err = 0;
 168                 socklen_t err_size = sizeof(err);
 169
 170                 if (getsockopt(rpc->fd, SOL_SOCKET, SO_ERROR,
 171                                 &err, &err_size) != 0 || err != 0) {
 172                         if (err == 0) {
 173                                 err = errno;
 174                         }
 175                         rpc_set_error(rpc, "rpc_service: socket error "
 176                                                "%s(%d).",
 177                                                strerror(err), err);
 178                 } else {
 179                         rpc_set_error(rpc, "rpc_service: POLLERR, "
 180                                                 "Unknown socket error.");
 181                 }
 182                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 183                 return -1;
 184         }
 185         if (revents & POLLHUP) {
 186                 printf("rpc_service: POLLHUP, socket error\n");
 187                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 188                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 189                 return -2;
 190         }
 191
 192         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 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) while connecting.",
 203                                         strerror(err), err);
 204                         rpc->connect_cb(rpc, RPC_STATUS_ERROR,
 205                                         NULL, rpc->connect_data);
 206                         return -1;
 207                 }
 208
 209                 rpc->is_connected = 1;
 210                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 211                 return 0;
 212         }
 213
 214         if (revents & POLLOUT && rpc->outqueue != NULL) {
 215                 if (rpc_write_to_socket(rpc) != 0) {
 216                         printf("write to socket failed\n");
 217                         return -3;
 218                 }
 219         }
 220
 221         if (revents & POLLIN) {
 222                 if (rpc_read_from_socket(rpc) != 0) {
 223                         rpc_disconnect(rpc, rpc_get_error(rpc));
 224                         return -4;
 225                 }
 226         }
 227
 228         return 0;
 229 }
 230
 231
 232 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 233 {
 234         struct sockaddr_storage s;
 235         struct sockaddr_in *sin = (struct sockaddr_in *)&s;
 236         int socksize;
 237
 238         if (rpc->fd != -1) {
 239                 rpc_set_error(rpc, "Trying to connect while already connected");
 240                 printf("%s\n", rpc->error_string);
 241                 return -1;
 242         }
 243
 244         sin->sin_family = AF_INET;
 245         sin->sin_port   = htons(port);
 246         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 247                 rpc_set_error(rpc, "Not a valid server ip address");
 248                 printf("%s\n", rpc->error_string);
 249                 return -2;
 250         }
 251
 252         switch (s.ss_family) {
 253         case AF_INET:
 254                 socksize = sizeof(struct sockaddr_in);
 255 #ifdef HAVE_SOCK_SIN_LEN
 256                 sin->sin_len = socksize;
 257 #endif
 258                 rpc->fd = socket(AF_INET, SOCK_STREAM, 0);
 259                 break;
 260         }
 261
 262         if (rpc->fd == -1) {
 263                 rpc_set_error(rpc, "Failed to open socket");
 264                 printf("%s\n", rpc->error_string);
 265                 return -3;
 266         }
 267
 268         rpc->connect_cb  = cb;
 269         rpc->connect_data = private_data;
 270
 271         set_nonblocking(rpc->fd);
 272
 273         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) != 0 && errno != EINPROGRESS) {
 274                 rpc_set_error(rpc, "connect() to server failed");
 275                 printf("%s\n", rpc->error_string);
 276                 return -4;
 277         }
 278
 279         return 0;
 280 }
 281
 282 int rpc_disconnect(struct rpc_context *rpc, char *error)
 283 {
 284         if (rpc->fd != -1) {
 285                 close(rpc->fd);
 286         }
 287         rpc->fd  = -1;
 288
 289         rpc->is_connected = 0;
 290
 291         rpc_error_all_pdus(rpc, error);
 292
 293         return 0;
 294 }