git.ozlabs.org Git - ccan/blob - ccan/iscsi/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 General Public License as published by
   6    the Free Software Foundation; either version 3 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 General Public License for more details.
  13
  14    You should have received a copy of the GNU 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 <string.h>
  21 #include <strings.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <unistd.h>
  25 #include <netinet/in.h>
  26 #include <poll.h>
  27 #include <sys/ioctl.h>
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <arpa/inet.h>
  31 #include "iscsi.h"
  32 #include "iscsi-private.h"
  33 #include "dlinklist.h"
  34
  35 static void set_nonblocking(int fd)
  36 {
  37         unsigned v;
  38         v = fcntl(fd, F_GETFL, 0);
  39         fcntl(fd, F_SETFL, v | O_NONBLOCK);
  40 }
  41
  42 int iscsi_connect_async(struct iscsi_context *iscsi, const char *target, iscsi_command_cb cb, void *private_data)
  43 {
  44         int tpgt = -1;
  45         int port = 3260;
  46         char *str;
  47         char *addr;
  48         union {
  49                 struct sockaddr sa;
  50                 struct sockaddr_storage ss;
  51                 struct sockaddr_in sin;
  52         } s;
  53         int socksize;
  54
  55         if (iscsi == NULL) {
  56                 printf("Trying to connect NULL context\n");
  57                 return -1;
  58         }
  59         if (iscsi->fd != -1) {
  60                 printf("Trying to connect but already connected\n");
  61                 return -2;
  62         }
  63
  64         addr = strdup(target);
  65         if (addr == NULL) {
  66                 printf("failed to strdup target address\n");
  67                 return -3;
  68         }
  69
  70         /* check if we have a target portal group tag */
  71         if ((str = rindex(addr, ',')) != NULL) {
  72                 tpgt = atoi(str+1);
  73                 str[0] = 0;
  74         }
  75
  76         /* XXX need handling for {ipv6 addresses} */
  77         /* for now, assume all is ipv4 */
  78         if ((str = rindex(addr, ':')) != NULL) {
  79                 port = atoi(str+1);
  80                 str[0] = 0;
  81         }
  82
  83         s.sin.sin_family = AF_INET;
  84         s.sin.sin_port   = htons(port);
  85         if (inet_pton(AF_INET, addr, &s.sin.sin_addr) != 1) {
  86                 printf("failed to convert to ip address\n");
  87                 free(addr);
  88                 return -4;
  89         }
  90         free(addr);
  91
  92         switch (s.ss.ss_family) {
  93         case AF_INET:
  94                 iscsi->fd = socket(AF_INET, SOCK_STREAM, 0);
  95                 socksize = sizeof(struct sockaddr_in);
  96                 break;
  97         default:
  98                 printf("Unknown family :%d\n", s.ss.ss_family);
  99                 return -5;
 100
 101         }
 102
 103         if (iscsi->fd == -1) {
 104                 printf("Failed to open socket\n");
 105                 return -6;
 106
 107         }
 108
 109         iscsi->connect_cb  = cb;
 110         iscsi->connect_data = private_data;
 111
 112         set_nonblocking(iscsi->fd);
 113
 114         if (connect(iscsi->fd, &s.sa, socksize) != 0 && errno != EINPROGRESS) {
 115                 printf("Connect failed errno : %s (%d)\n", strerror(errno), errno);
 116                 return -7;
 117         }
 118
 119         return 0;
 120 }
 121
 122 int iscsi_disconnect(struct iscsi_context *iscsi)
 123 {
 124         if (iscsi == NULL) {
 125                 printf("Trying to disconnect NULL context\n");
 126                 return -1;
 127         }
 128         if (iscsi->is_loggedin != 0) {
 129                 printf("Trying to disconnect while logged in\n");
 130                 return -2;
 131         }
 132         if (iscsi->fd == -1) {
 133                 printf("Trying to disconnect but not connected\n");
 134                 return -3;
 135         }
 136
 137         close(iscsi->fd);
 138         iscsi->fd  = -1;
 139
 140         iscsi->is_connected = 0;
 141
 142         return 0;
 143 }
 144
 145 int iscsi_get_fd(struct iscsi_context *iscsi)
 146 {
 147         if (iscsi == NULL) {
 148                 printf("Trying to get fd for NULL context\n");
 149                 return -1;
 150         }
 151
 152         return iscsi->fd;
 153 }
 154
 155 int iscsi_which_events(struct iscsi_context *iscsi)
 156 {
 157         int events = POLLIN;
 158
 159         if (iscsi->is_connected == 0) {
 160                 events |= POLLOUT;
 161         }
 162
 163         if (iscsi->outqueue) {
 164                 events |= POLLOUT;
 165         }
 166         return events;
 167 }
 168
 169 static int iscsi_read_from_socket(struct iscsi_context *iscsi)
 170 {
 171         int available;
 172         int size;
 173         unsigned char *buf;
 174         ssize_t count;
 175
 176         if (ioctl(iscsi->fd, FIONREAD, &available) != 0) {
 177                 printf("ioctl FIONREAD returned error : %d\n", errno);
 178                 return -1;
 179         }
 180         if (available == 0) {
 181                 printf("no data readable in socket, socket is closed\n");
 182                 return -2;
 183         }
 184         size = iscsi->insize - iscsi->inpos + available;
 185         buf = malloc(size);
 186         if (buf == NULL) {
 187                 printf("failed to allocate %d bytes for input buffer\n", size);
 188                 return -3;
 189         }
 190         if (iscsi->insize > iscsi->inpos) {
 191                 memcpy(buf, iscsi->inbuf + iscsi->inpos, iscsi->insize - iscsi->inpos);
 192                 iscsi->insize -= iscsi->inpos;
 193                 iscsi->inpos   = 0;
 194         }
 195
 196         count = read(iscsi->fd, buf + iscsi->insize, available);
 197         if (count == -1) {
 198                 if (errno == EINTR) {
 199                         free(buf);
 200                         buf = NULL;
 201                         return 0;
 202                 }
 203                 printf("read from socket failed, errno:%d\n", errno);
 204                 free(buf);
 205                 buf = NULL;
 206                 return -4;
 207         }
 208
 209         if (iscsi->inbuf != NULL) {
 210                 free(iscsi->inbuf);
 211         }
 212         iscsi->inbuf   = buf;
 213         iscsi->insize += count;
 214
 215         while (1) {
 216                 if (iscsi->insize - iscsi->inpos < 48) {
 217                         return 0;
 218                 }
 219                 count = iscsi_get_pdu_size(iscsi->inbuf + iscsi->inpos);
 220                 if (iscsi->insize + iscsi->inpos < count) {
 221                         return 0;
 222                 }
 223                 if (iscsi_process_pdu(iscsi, iscsi->inbuf + iscsi->inpos, count) != 0) {
 224                         printf("failed to process pdu\n");
 225                         return -5;
 226                 }
 227                 iscsi->inpos += count;
 228                 if (iscsi->inpos == iscsi->insize) {
 229                         free(iscsi->inbuf);
 230                         iscsi->inbuf = NULL;
 231                         iscsi->insize = 0;
 232                         iscsi->inpos = 0;
 233                 }
 234                 if (iscsi->inpos > iscsi->insize) {
 235                         printf("inpos > insize. bug!\n");
 236                         return -6;
 237                 }
 238         }
 239
 240         return 0;
 241 }
 242
 243 static int iscsi_write_to_socket(struct iscsi_context *iscsi)
 244 {
 245         ssize_t count;
 246
 247         if (iscsi == NULL) {
 248                 printf("trying to write to socket for NULL context\n");
 249                 return -1;
 250         }
 251         if (iscsi->fd == -1) {
 252                 printf("trying to write but not connected\n");
 253                 return -2;
 254         }
 255
 256         while (iscsi->outqueue != NULL) {
 257                 ssize_t total;
 258
 259                 total = iscsi->outqueue->outdata.size;
 260                 total = (total +3) & 0xfffffffc;
 261
 262                 count = write(iscsi->fd, iscsi->outqueue->outdata.data + iscsi->outqueue->written, total - iscsi->outqueue->written);
 263                 if (count == -1) {
 264                         if (errno == EAGAIN || errno == EWOULDBLOCK) {
 265                                 printf("socket would block, return from write to socket\n");
 266                                 return 0;
 267                         }
 268                         printf("Error when writing to socket :%d\n", errno);
 269                         return -3;
 270                 }
 271
 272                 iscsi->outqueue->written += count;
 273                 if (iscsi->outqueue->written == total) {
 274                         struct iscsi_pdu *pdu = iscsi->outqueue;
 275
 276                         DLIST_REMOVE(iscsi->outqueue, pdu);
 277                         DLIST_ADD_END(iscsi->waitpdu, pdu, NULL);
 278                 }
 279         }
 280         return 0;
 281 }
 282
 283 int iscsi_service(struct iscsi_context *iscsi, int revents)
 284 {
 285         if (revents & POLLERR) {
 286                 printf("iscsi_service: POLLERR, socket error\n");
 287                 iscsi->connect_cb(iscsi, ISCSI_STATUS_ERROR, NULL, iscsi->connect_data);
 288                 return -1;
 289         }
 290         if (revents & POLLHUP) {
 291                 printf("iscsi_service: POLLHUP, socket error\n");
 292                 iscsi->connect_cb(iscsi, ISCSI_STATUS_ERROR, NULL, iscsi->connect_data);
 293                 return -2;
 294         }
 295
 296         if (iscsi->is_connected == 0 && iscsi->fd != -1 && revents&POLLOUT) {
 297                 iscsi->is_connected = 1;
 298                 iscsi->connect_cb(iscsi, ISCSI_STATUS_GOOD, NULL, iscsi->connect_data);
 299                 return 0;
 300         }
 301
 302         if (revents & POLLOUT && iscsi->outqueue != NULL) {
 303                 if (iscsi_write_to_socket(iscsi) != 0) {
 304                         printf("write to socket failed\n");
 305                         return -3;
 306                 }
 307         }
 308         if (revents & POLLIN) {
 309                 if (iscsi_read_from_socket(iscsi) != 0) {
 310                         printf("read from socket failed\n");
 311                         return -4;
 312                 }
 313         }
 314
 315         return 0;
 316 }
 317
 318 int iscsi_queue_pdu(struct iscsi_context *iscsi, struct iscsi_pdu *pdu)
 319 {
 320         if (iscsi == NULL) {
 321                 printf("trying to queue to NULL context\n");
 322                 return -1;
 323         }
 324         if (pdu == NULL) {
 325                 printf("trying to queue NULL pdu\n");
 326                 return -2;
 327         }
 328         DLIST_ADD_END(iscsi->outqueue, pdu, NULL);
 329
 330         return 0;
 331 }
 332
 333
 334