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 = POLLIN;
  47
  48         if (rpc->is_connected == 0) {
  49                 events |= POLLOUT;
  50         }
  51
  52         if (rpc->outqueue) {
  53                 events |= POLLOUT;
  54         }
  55         return events;
  56 }
  57
  58 static int rpc_write_to_socket(struct rpc_context *rpc)
  59 {
  60         ssize_t count;
  61
  62         if (rpc == NULL) {
  63                 printf("trying to write to socket for NULL context\n");
  64                 return -1;
  65         }
  66         if (rpc->fd == -1) {
  67                 printf("trying to write but not connected\n");
  68                 return -2;
  69         }
  70
  71         while (rpc->outqueue != NULL) {
  72                 ssize_t total;
  73
  74                 total = rpc->outqueue->outdata.size;
  75
  76                 count = write(rpc->fd, rpc->outqueue->outdata.data + rpc->outqueue->written, total - rpc->outqueue->written);
  77                 if (count == -1) {
  78                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
  79                                 printf("socket would block, return from write to socket\n");
  80                                 return 0;
  81                         }
  82                         printf("Error when writing to socket :%s(%d)\n", strerror(errno), errno);
  83                         return -3;
  84                 }
  85
  86                 rpc->outqueue->written += count;
  87                 if (rpc->outqueue->written == total) {
  88                         struct rpc_pdu *pdu = rpc->outqueue;
  89
  90                         SLIST_REMOVE(&rpc->outqueue, pdu);
  91                         SLIST_ADD_END(&rpc->waitpdu, pdu);
  92                 }
  93         }
  94         return 0;
  95 }
  96
  97 static int rpc_read_from_socket(struct rpc_context *rpc)
  98 {
  99         int available;
 100         int size;
 101         unsigned char *buf;
 102         ssize_t count;
 103
 104         if (ioctl(rpc->fd, FIONREAD, &available) != 0) {
 105                 rpc_set_error(rpc, "Ioctl FIONREAD returned error : %d. Closing socket.", errno);
 106                 return -1;
 107         }
 108         if (available == 0) {
 109                 rpc_set_error(rpc, "Socket has been closed");
 110                 return -2;
 111         }
 112         size = rpc->insize - rpc->inpos + available;
 113         buf = malloc(size);
 114         if (buf == NULL) {
 115                 rpc_set_error(rpc, "Out of memory: failed to allocate %d bytes for input buffer. Closing socket.", size);
 116                 return -3;
 117         }
 118         if (rpc->insize > rpc->inpos) {
 119                 memcpy(buf, rpc->inbuf + rpc->inpos, rpc->insize - rpc->inpos);
 120                 rpc->insize -= rpc->inpos;
 121                 rpc->inpos   = 0;
 122         }
 123
 124         count = read(rpc->fd, buf + rpc->insize, available);
 125         if (count == -1) {
 126                 if (errno == EINTR) {
 127                         free(buf);
 128                         buf = NULL;
 129                         return 0;
 130                 }
 131                 rpc_set_error(rpc, "Read from socket failed, errno:%d. Closing socket.", errno);
 132                 free(buf);
 133                 buf = NULL;
 134                 return -4;
 135         }
 136
 137         if (rpc->inbuf != NULL) {
 138                 free(rpc->inbuf);
 139         }
 140         rpc->inbuf   = (char *)buf;
 141         rpc->insize += count;
 142
 143         while (1) {
 144                 if (rpc->insize - rpc->inpos < 4) {
 145                         return 0;
 146                 }
 147                 count = rpc_get_pdu_size(rpc->inbuf + rpc->inpos);
 148                 if (rpc->insize + rpc->inpos < count) {
 149                         return 0;
 150                 }
 151                 if (rpc_process_pdu(rpc, rpc->inbuf + rpc->inpos, count) != 0) {
 152                         rpc_set_error(rpc, "Invalid/garbage pdu received from server. Closing socket");
 153                         return -5;
 154                 }
 155                 rpc->inpos += count;
 156                 if (rpc->inpos == rpc->insize) {
 157                         free(rpc->inbuf);
 158                         rpc->inbuf = NULL;
 159                         rpc->insize = 0;
 160                         rpc->inpos = 0;
 161                 }
 162         }
 163         return 0;
 164 }
 165
 166
 167
 168 int rpc_service(struct rpc_context *rpc, int revents)
 169 {
 170         if (revents & POLLERR) {
 171                 printf("rpc_service: POLLERR, socket error\n");
 172                 if (rpc->is_connected == 0) {
 173                         rpc_set_error(rpc, "Failed to connect to server socket.");
 174                 } else {
 175                         rpc_set_error(rpc, "Socket closed with POLLERR");
 176                 }
 177                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 178                 return -1;
 179         }
 180         if (revents & POLLHUP) {
 181                 printf("rpc_service: POLLHUP, socket error\n");
 182                 rpc_set_error(rpc, "Socket failed with POLLHUP");
 183                 rpc->connect_cb(rpc, RPC_STATUS_ERROR, rpc->error_string, rpc->connect_data);
 184                 return -2;
 185         }
 186
 187         if (rpc->is_connected == 0 && rpc->fd != -1 && revents&POLLOUT) {
 188                 rpc->is_connected = 1;
 189                 rpc->connect_cb(rpc, RPC_STATUS_SUCCESS, NULL, rpc->connect_data);
 190                 return 0;
 191         }
 192
 193         if (revents & POLLOUT && rpc->outqueue != NULL) {
 194                 if (rpc_write_to_socket(rpc) != 0) {
 195                         printf("write to socket failed\n");
 196                         return -3;
 197                 }
 198         }
 199
 200         if (revents & POLLIN) {
 201                 if (rpc_read_from_socket(rpc) != 0) {
 202                         rpc_disconnect(rpc, rpc_get_error(rpc));
 203                         return -4;
 204                 }
 205         }
 206
 207         return 0;
 208 }
 209
 210
 211 int rpc_connect_async(struct rpc_context *rpc, const char *server, int port, rpc_cb cb, void *private_data)
 212 {
 213         struct sockaddr_storage s;
 214         struct sockaddr_in *sin = (struct sockaddr_in *)&s;
 215         int socksize;
 216
 217         if (rpc->fd != -1) {
 218                 rpc_set_error(rpc, "Trying to connect while already connected");
 219                 printf("%s\n", rpc->error_string);
 220                 return -1;
 221         }
 222
 223         sin->sin_family = AF_INET;
 224         sin->sin_port   = htons(port);
 225         if (inet_pton(AF_INET, server, &sin->sin_addr) != 1) {
 226                 rpc_set_error(rpc, "Not a valid server ip address");
 227                 printf("%s\n", rpc->error_string);
 228                 return -2;
 229         }
 230
 231         switch (s.ss_family) {
 232         case AF_INET:
 233                 rpc->fd = socket(AF_INET, SOCK_STREAM, 0);
 234                 socksize = sizeof(struct sockaddr_in);
 235                 break;
 236         }
 237
 238         if (rpc->fd == -1) {
 239                 rpc_set_error(rpc, "Failed to open socket");
 240                 printf("%s\n", rpc->error_string);
 241                 return -3;
 242         }
 243
 244         rpc->connect_cb  = cb;
 245         rpc->connect_data = private_data;
 246
 247         set_nonblocking(rpc->fd);
 248
 249         if (connect(rpc->fd, (struct sockaddr *)&s, socksize) != 0 && errno != EINPROGRESS) {
 250                 rpc_set_error(rpc, "connect() to server failed");
 251                 printf("%s\n", rpc->error_string);
 252                 return -4;
 253         }
 254
 255         return 0;
 256 }
 257
 258 int rpc_disconnect(struct rpc_context *rpc, char *error)
 259 {
 260         if (rpc->fd != -1) {
 261                 close(rpc->fd);
 262         }
 263         rpc->fd  = -1;
 264
 265         rpc->is_connected = 0;
 266
 267         rpc_error_all_pdus(rpc, error);
 268
 269         return 0;
 270 }