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