blockd.c

   1 #define _GNU_SOURCE
   2 #include <sys/stat.h>
   3 #include <sys/mount.h>
   4 #include <sys/wait.h>
   5
   6 #include <stdlib.h>
   7 #include <stdio.h>
   8 #include <unistd.h>
   9 #include <fcntl.h>
  10
  11 #include <errno.h>
  12
  13 #include <linux/limits.h>
  14 #include <linux/auto_fs4.h>
  15
  16 #include <libubox/uloop.h>
  17 #include <libubox/vlist.h>
  18 #include <libubox/ulog.h>
  19 #include <libubox/avl-cmp.h>
  20 #include <libubus.h>
  21
  22 #include "libfstools/libfstools.h"
  23
  24 #define AUTOFS_MOUNT_PATH       "/tmp/run/blockd/"
  25 #define AUTOFS_TIMEOUT          30
  26 #define AUTOFS_EXPIRE_TIMER     (5 * 1000)
  27
  28 struct hotplug_context {
  29         struct uloop_process process;
  30         void *priv;
  31 };
  32
  33 struct device {
  34         struct vlist_node node;
  35         struct blob_attr *msg;
  36         char *name;
  37         char *target;
  38         int autofs;
  39         int anon;
  40 };
  41
  42 static struct uloop_fd fd_autofs_read;
  43 static int fd_autofs_write = 0;
  44 static struct ubus_auto_conn conn;
  45 struct blob_buf bb = { 0 };
  46
  47 enum {
  48         MOUNT_UUID,
  49         MOUNT_LABEL,
  50         MOUNT_ENABLE,
  51         MOUNT_TARGET,
  52         MOUNT_DEVICE,
  53         MOUNT_OPTIONS,
  54         MOUNT_AUTOFS,
  55         MOUNT_ANON,
  56         MOUNT_REMOVE,
  57         __MOUNT_MAX
  58 };
  59
  60 static const struct blobmsg_policy mount_policy[__MOUNT_MAX] = {
  61         [MOUNT_UUID] = { .name = "uuid", .type = BLOBMSG_TYPE_STRING },
  62         [MOUNT_LABEL] = { .name = "label", .type = BLOBMSG_TYPE_STRING },
  63         [MOUNT_DEVICE] = { .name = "device", .type = BLOBMSG_TYPE_STRING },
  64         [MOUNT_TARGET] = { .name = "target", .type = BLOBMSG_TYPE_STRING },
  65         [MOUNT_OPTIONS] = { .name = "options", .type = BLOBMSG_TYPE_STRING },
  66         [MOUNT_ENABLE] = { .name = "enabled", .type = BLOBMSG_TYPE_INT32 },
  67         [MOUNT_AUTOFS] = { .name = "autofs", .type = BLOBMSG_TYPE_INT32 },
  68         [MOUNT_ANON] = { .name = "anon", .type = BLOBMSG_TYPE_INT32 },
  69         [MOUNT_REMOVE] = { .name = "remove", .type = BLOBMSG_TYPE_INT32 },
  70 };
  71
  72 enum {
  73         INFO_DEVICE,
  74         __INFO_MAX
  75 };
  76
  77 static const struct blobmsg_policy info_policy[__INFO_MAX] = {
  78         [INFO_DEVICE] = { .name = "device", .type = BLOBMSG_TYPE_STRING },
  79 };
  80
  81 static char*
  82 _find_mount_point(char *device)
  83 {
  84         char *dev, *mp;
  85
  86         if (asprintf(&dev, "/dev/%s", device) == -1)
  87                 exit(ENOMEM);
  88
  89         mp = find_mount_point(dev, 0);
  90         free(dev);
  91
  92         return mp;
  93 }
  94
  95 static int
  96 block(char *cmd, char *action, char *device, int sync, struct uloop_process *process)
  97 {
  98         pid_t pid = fork();
  99         int ret = sync;
 100         int status;
 101         char *argv[5] = { 0 };
 102         int a = 0;
 103
 104         switch (pid) {
 105         case -1:
 106                 ULOG_ERR("failed to fork block process\n");
 107                 break;
 108
 109         case 0:
 110                 uloop_end();
 111
 112                 argv[a++] = "/sbin/block";
 113                 argv[a++] = cmd;
 114                 argv[a++] = action;
 115                 argv[a++] = device;
 116                 execvp(argv[0], argv);
 117                 ULOG_ERR("failed to spawn %s %s %s\n", *argv, action, device);
 118                 exit(EXIT_FAILURE);
 119
 120         default:
 121                 if (!sync && process) {
 122                         process->pid = pid;
 123                         uloop_process_add(process);
 124                 } else if (sync) {
 125                         waitpid(pid, &status, 0);
 126                         ret = WEXITSTATUS(status);
 127                         if (ret)
 128                                 ULOG_ERR("failed to run block. %s/%s\n", action, device);
 129                 }
 130                 break;
 131         }
 132
 133         return ret;
 134 }
 135
 136 static int send_block_notification(struct ubus_context *ctx, const char *action,
 137                             const char *devname, const char *target);
 138 static int hotplug_call_mount(struct ubus_context *ctx, const char *action,
 139                               const char *devname, uloop_process_handler cb, void *priv)
 140 {
 141         char * const argv[] = { "hotplug-call", "mount", NULL };
 142         struct hotplug_context *c = NULL;
 143         pid_t pid;
 144         int err;
 145
 146         if (cb) {
 147                 c = calloc(1, sizeof(*c));
 148                 if (!c)
 149                         return -ENOMEM;
 150         }
 151
 152         pid = fork();
 153         switch (pid) {
 154         case -1:
 155                 if (c)
 156                         free(c);
 157
 158                 err = -errno;
 159                 ULOG_ERR("fork() failed\n");
 160                 return err;
 161         case 0:
 162                 uloop_end();
 163
 164                 setenv("ACTION", action, 1);
 165                 setenv("DEVICE", devname, 1);
 166
 167                 execv("/sbin/hotplug-call", argv);
 168                 exit(-1);
 169                 break;
 170         default:
 171                 if (c) {
 172                         c->process.pid = pid;
 173                         c->process.cb = cb;
 174                         c->priv = priv;
 175                         uloop_process_add(&c->process);
 176                 }
 177                 break;
 178         }
 179
 180         return 0;
 181 }
 182
 183 static void device_mount_remove_hotplug_cb(struct uloop_process *p, int stat)
 184 {
 185         struct hotplug_context *hctx = container_of(p, struct hotplug_context, process);
 186         struct device *device = hctx->priv;
 187         char *mp;
 188
 189         if (device->target)
 190                 unlink(device->target);
 191
 192         mp = _find_mount_point(device->name);
 193         if (mp) {
 194                 block("autofs", "remove", device->name, 0, NULL);
 195                 free(mp);
 196         }
 197
 198         free(device);
 199         free(hctx);
 200 }
 201
 202 static void device_mount_remove(struct ubus_context *ctx, struct device *device)
 203 {
 204         static const char *action = "remove";
 205
 206         hotplug_call_mount(ctx, action, device->name,
 207                            device_mount_remove_hotplug_cb, device);
 208
 209         send_block_notification(ctx, action, device->name, device->target);
 210 }
 211
 212 static void device_mount_add(struct ubus_context *ctx, struct device *device)
 213 {
 214         struct stat st;
 215         char *path, *tmp;
 216
 217         if (asprintf(&path, "/tmp/run/blockd/%s", device->name) == -1)
 218                 exit(ENOMEM);
 219
 220         if (!lstat(device->target, &st)) {
 221                 if (S_ISLNK(st.st_mode))
 222                         unlink(device->target);
 223                 else if (S_ISDIR(st.st_mode))
 224                         rmdir(device->target);
 225         }
 226
 227         tmp = strrchr(device->target, '/');
 228         if (tmp && tmp != device->target && tmp != &device->target[strlen(path)-1]) {
 229                 *tmp = '\0';
 230                 mkdir_p(device->target, 0755);
 231                 *tmp = '/';
 232         }
 233
 234         if (symlink(path, device->target)) {
 235                 ULOG_ERR("failed to symlink %s->%s (%d) - %m\n", device->target, path, errno);
 236         } else {
 237                 static const char *action = "add";
 238                 hotplug_call_mount(ctx, action, device->name, NULL, NULL);
 239                 send_block_notification(ctx, action, device->name, device->target);
 240         }
 241         free(path);
 242 }
 243
 244 static int
 245 device_move(struct device *device_o, struct device *device_n)
 246 {
 247         char *path;
 248
 249         if (device_o->autofs != device_n->autofs)
 250                 return -1;
 251
 252         if (device_o->anon || device_n->anon)
 253                 return -1;
 254
 255         if (device_o->autofs) {
 256                 unlink(device_o->target);
 257                 if (asprintf(&path, "/tmp/run/blockd/%s", device_n->name) == -1)
 258                         exit(ENOMEM);
 259
 260                 if (symlink(path, device_n->target))
 261                         ULOG_ERR("failed to symlink %s->%s (%d) - %m\n", device_n->target, path, errno);
 262
 263                 free(path);
 264         } else {
 265                 mkdir(device_n->target, 0755);
 266                 if (mount(device_o->target, device_n->target, NULL, MS_MOVE, NULL))
 267                         rmdir(device_n->target);
 268                 else
 269                         rmdir(device_o->target);
 270         }
 271
 272         return 0;
 273 }
 274
 275 static void vlist_nop_update(struct vlist_tree *tree,
 276                              struct vlist_node *node_new,
 277                              struct vlist_node *node_old)
 278 {
 279 }
 280
 281 VLIST_TREE(devices, avl_strcmp, vlist_nop_update, false, false);
 282
 283 static int
 284 block_hotplug(struct ubus_context *ctx, struct ubus_object *obj,
 285               struct ubus_request_data *req, const char *method,
 286               struct blob_attr *msg)
 287 {
 288         struct blob_attr *data[__MOUNT_MAX];
 289         struct device *device;
 290         struct blob_attr *_msg;
 291         char *devname, *_name;
 292         char *target = NULL, *__target;
 293         char *_target = NULL;
 294
 295         blobmsg_parse(mount_policy, __MOUNT_MAX, data, blob_data(msg), blob_len(msg));
 296
 297         if (!data[MOUNT_DEVICE])
 298                 return UBUS_STATUS_INVALID_ARGUMENT;
 299
 300         devname = blobmsg_get_string(data[MOUNT_DEVICE]);
 301
 302         if (data[MOUNT_TARGET]) {
 303                 target = blobmsg_get_string(data[MOUNT_TARGET]);
 304         } else {
 305                 if (asprintf(&_target, "/mnt/%s",
 306                              blobmsg_get_string(data[MOUNT_DEVICE])) == -1)
 307                         exit(ENOMEM);
 308
 309                 target = _target;
 310         }
 311
 312         if (data[MOUNT_REMOVE])
 313                 device = vlist_find(&devices, devname, device, node);
 314         else
 315                 device = calloc_a(sizeof(*device), &_msg, blob_raw_len(msg),
 316                                   &_name, strlen(devname) + 1, &__target, strlen(target) + 1);
 317
 318         if (!device) {
 319                 if (_target)
 320                         free(_target);
 321
 322                 return UBUS_STATUS_UNKNOWN_ERROR;
 323         }
 324
 325         if (data[MOUNT_REMOVE]) {
 326                 vlist_delete(&devices, &device->node);
 327
 328                 if (device->autofs)
 329                         device_mount_remove(ctx, device);
 330                 else
 331                         free(device);
 332
 333                 if (_target)
 334                         free(_target);
 335         } else {
 336                 struct device *old = vlist_find(&devices, devname, device, node);
 337
 338                 device->autofs = data[MOUNT_AUTOFS] ? blobmsg_get_u32(data[MOUNT_AUTOFS]) : 0;
 339                 device->anon = data[MOUNT_ANON] ? blobmsg_get_u32(data[MOUNT_ANON]) : 0;
 340                 device->msg = _msg;
 341                 memcpy(_msg, msg, blob_raw_len(msg));
 342                 device->name = _name;
 343                 strcpy(_name, devname);
 344                 device->target = __target;
 345                 strcpy(__target, target);
 346                 if (_target)
 347                         free(_target);
 348
 349                 vlist_add(&devices, &device->node, device->name);
 350
 351                 if (old && !device_move(old, device)) {
 352                         if (device->autofs) {
 353                                 device_mount_remove(ctx, old);
 354                                 device_mount_add(ctx, device);
 355                         } else {
 356                                 block("mount", NULL, NULL, 0, NULL);
 357                         }
 358                 } else if (device->autofs) {
 359                         device_mount_add(ctx, device);
 360                 }
 361         }
 362
 363         return 0;
 364 }
 365
 366 static int blockd_mount(struct ubus_context *ctx, struct ubus_object *obj,
 367                         struct ubus_request_data *req, const char *method,
 368                         struct blob_attr *msg)
 369 {
 370         static const char *action = "add";
 371         struct blob_attr *data[__MOUNT_MAX];
 372         struct device *device;
 373         char *devname;
 374
 375         blobmsg_parse(mount_policy, __MOUNT_MAX, data, blob_data(msg), blob_len(msg));
 376
 377         if (!data[MOUNT_DEVICE])
 378                 return UBUS_STATUS_INVALID_ARGUMENT;
 379
 380         devname = blobmsg_get_string(data[MOUNT_DEVICE]);
 381
 382         device = vlist_find(&devices, devname, device, node);
 383         if (!device)
 384                 return UBUS_STATUS_UNKNOWN_ERROR;
 385
 386         hotplug_call_mount(ctx, action, device->name, NULL, NULL);
 387         send_block_notification(ctx, action, device->name, device->target);
 388
 389         return 0;
 390 }
 391
 392 struct blockd_umount_context {
 393         struct ubus_context *ctx;
 394         struct ubus_request_data req;
 395 };
 396
 397 static void blockd_umount_hotplug_cb(struct uloop_process *p, int stat)
 398 {
 399         struct hotplug_context *hctx = container_of(p, struct hotplug_context, process);
 400         struct blockd_umount_context *c = hctx->priv;
 401
 402         ubus_complete_deferred_request(c->ctx, &c->req, 0);
 403
 404         free(c);
 405         free(hctx);
 406 }
 407
 408 static int blockd_umount(struct ubus_context *ctx, struct ubus_object *obj,
 409                          struct ubus_request_data *req, const char *method,
 410                          struct blob_attr *msg)
 411 {
 412         struct blob_attr *data[__MOUNT_MAX];
 413         struct blockd_umount_context *c;
 414         static const char *action = "remove";
 415         char *devname;
 416         static char oldtarget[PATH_MAX];
 417         struct device *device;
 418         int err;
 419
 420         blobmsg_parse(mount_policy, __MOUNT_MAX, data, blob_data(msg), blob_len(msg));
 421
 422         if (!data[MOUNT_DEVICE])
 423                 return UBUS_STATUS_INVALID_ARGUMENT;
 424
 425         devname = blobmsg_get_string(data[MOUNT_DEVICE]);
 426         device = vlist_find(&devices, devname, device, node);
 427         if (device) {
 428                 strncpy(oldtarget, device->target, sizeof(oldtarget)-1);
 429                 oldtarget[PATH_MAX - 1] = '\0';
 430         }
 431
 432         c = calloc(1, sizeof(*c));
 433         if (!c)
 434                 return UBUS_STATUS_UNKNOWN_ERROR;
 435
 436         c->ctx = ctx;
 437         ubus_defer_request(ctx, req, &c->req);
 438
 439         err = hotplug_call_mount(ctx, action, devname, blockd_umount_hotplug_cb, c);
 440         if (err) {
 441                 free(c);
 442                 return UBUS_STATUS_UNKNOWN_ERROR;
 443         }
 444
 445         send_block_notification(ctx, action, devname, oldtarget);
 446
 447         return 0;
 448 }
 449
 450 static void block_info_dump(struct blob_buf *b, struct device *device)
 451 {
 452         struct blob_attr *v;
 453         char *mp;
 454         int rem;
 455
 456         blob_for_each_attr(v, device->msg, rem)
 457                 blobmsg_add_blob(b, v);
 458
 459         mp = _find_mount_point(device->name);
 460         if (mp) {
 461                 blobmsg_add_string(b, "mount", mp);
 462                 free(mp);
 463         } else if (device->autofs && device->target) {
 464                 blobmsg_add_string(b, "mount", device->target);
 465         }
 466 }
 467
 468 static int
 469 block_info(struct ubus_context *ctx, struct ubus_object *obj,
 470            struct ubus_request_data *req, const char *method,
 471            struct blob_attr *msg)
 472 {
 473         struct blob_attr *data[__INFO_MAX];
 474         struct device *device = NULL;
 475
 476         blobmsg_parse(info_policy, __INFO_MAX, data, blob_data(msg), blob_len(msg));
 477
 478         if (data[INFO_DEVICE]) {
 479                 device = vlist_find(&devices, blobmsg_get_string(data[INFO_DEVICE]), device, node);
 480                 if (!device)
 481                         return UBUS_STATUS_INVALID_ARGUMENT;
 482         }
 483
 484         blob_buf_init(&bb, 0);
 485         if (device) {
 486                 block_info_dump(&bb, device);
 487         } else {
 488                 void *a;
 489
 490                 a = blobmsg_open_array(&bb, "devices");
 491                 vlist_for_each_element(&devices, device, node) {
 492                         void *t;
 493
 494                         t = blobmsg_open_table(&bb, "");
 495                         block_info_dump(&bb, device);
 496                         blobmsg_close_table(&bb, t);
 497                 }
 498                 blobmsg_close_array(&bb, a);
 499         }
 500         ubus_send_reply(ctx, req, bb.head);
 501
 502         return 0;
 503 }
 504
 505 static const struct ubus_method block_methods[] = {
 506         UBUS_METHOD("hotplug", block_hotplug, mount_policy),
 507         UBUS_METHOD("mount", blockd_mount, mount_policy),
 508         UBUS_METHOD("umount", blockd_umount, mount_policy),
 509         UBUS_METHOD("info", block_info, info_policy),
 510 };
 511
 512 static struct ubus_object_type block_object_type =
 513         UBUS_OBJECT_TYPE("block", block_methods);
 514
 515 static struct ubus_object block_object = {
 516         .name = "block",
 517         .type = &block_object_type,
 518         .methods = block_methods,
 519         .n_methods = ARRAY_SIZE(block_methods),
 520 };
 521
 522 /* send ubus event for successful mounts, useful for procd triggers */
 523 static int send_block_notification(struct ubus_context *ctx, const char *action,
 524                             const char *devname, const char *target)
 525 {
 526         struct blob_buf buf = { 0 };
 527         char evname[16] = "mount.";
 528         int err;
 529
 530         if (!ctx)
 531                 return -ENXIO;
 532
 533         strncat(evname, action, sizeof(evname) - 1);
 534
 535         blob_buf_init(&buf, 0);
 536
 537         if (devname)
 538                 blobmsg_add_string(&buf, "device", devname);
 539
 540         if (target)
 541                 blobmsg_add_string(&buf, "target", target);
 542
 543         err = ubus_notify(ctx, &block_object, evname, buf.head, -1);
 544
 545         return err;
 546 }
 547
 548 static void
 549 ubus_connect_handler(struct ubus_context *ctx)
 550 {
 551         int ret;
 552
 553         ret = ubus_add_object(ctx, &block_object);
 554         if (ret)
 555                 fprintf(stderr, "Failed to add object: %s\n", ubus_strerror(ret));
 556 }
 557
 558 static int autofs_umount(void)
 559 {
 560         umount2(AUTOFS_MOUNT_PATH, MNT_DETACH);
 561         return 0;
 562 }
 563
 564 static void autofs_read_handler(struct uloop_fd *u, unsigned int events)
 565 {
 566         union autofs_v5_packet_union pktu;
 567         const struct autofs_v5_packet *pkt;
 568         int cmd = AUTOFS_IOC_READY;
 569         struct stat st;
 570
 571         while (read(u->fd, &pktu, sizeof(pktu)) == -1) {
 572                 if (errno != EINTR)
 573                         return;
 574                 continue;
 575         }
 576
 577         if (pktu.hdr.type != autofs_ptype_missing_indirect) {
 578                 ULOG_ERR("unknown packet type %d\n", pktu.hdr.type);
 579                 return;
 580         }
 581
 582         pkt = &pktu.missing_indirect;
 583         ULOG_ERR("kernel is requesting a mount -> %s\n", pkt->name);
 584         if (lstat(pkt->name, &st) == -1)
 585                 if (block("autofs", "add", (char *)pkt->name, 1, NULL))
 586                         cmd = AUTOFS_IOC_FAIL;
 587
 588         if (ioctl(fd_autofs_write, cmd, pkt->wait_queue_token) < 0)
 589                 ULOG_ERR("failed to report back to kernel\n");
 590 }
 591
 592 static void autofs_expire(struct uloop_timeout *t)
 593 {
 594         struct autofs_packet_expire pkt;
 595
 596         while (ioctl(fd_autofs_write, AUTOFS_IOC_EXPIRE, &pkt) == 0)
 597                 block("autofs", "remove", pkt.name, 1, NULL);
 598
 599         uloop_timeout_set(t, AUTOFS_EXPIRE_TIMER);
 600 }
 601
 602 struct uloop_timeout autofs_expire_timer = {
 603         .cb = autofs_expire,
 604 };
 605
 606 static int autofs_mount(void)
 607 {
 608         unsigned long autofs_timeout = AUTOFS_TIMEOUT;
 609         int kproto_version;
 610         int pipefd[2];
 611         char source[64];
 612         char opts[64];
 613
 614         if (pipe(pipefd) < 0) {
 615                 ULOG_ERR("failed to get kernel pipe\n");
 616                 return -1;
 617         }
 618
 619         snprintf(source, sizeof(source), "mountd(pid%u)", getpid());
 620         snprintf(opts, sizeof(opts), "fd=%d,pgrp=%u,minproto=5,maxproto=5", pipefd[1], (unsigned) getpgrp());
 621         mkdir(AUTOFS_MOUNT_PATH, 0555);
 622         if (mount(source, AUTOFS_MOUNT_PATH, "autofs", 0, opts)) {
 623                 ULOG_ERR("unable to mount autofs on %s\n", AUTOFS_MOUNT_PATH);
 624                 close(pipefd[0]);
 625                 close(pipefd[1]);
 626                 return -1;
 627         }
 628         close(pipefd[1]);
 629         fd_autofs_read.fd = pipefd[0];
 630         fd_autofs_read.cb = autofs_read_handler;
 631         uloop_fd_add(&fd_autofs_read, ULOOP_READ);
 632
 633         fd_autofs_write = open(AUTOFS_MOUNT_PATH, O_RDONLY);
 634         if(fd_autofs_write < 0) {
 635                 autofs_umount();
 636                 ULOG_ERR("failed to open direcory\n");
 637                 return -1;
 638         }
 639
 640         ioctl(fd_autofs_write, AUTOFS_IOC_PROTOVER, &kproto_version);
 641         if (kproto_version != 5) {
 642                 ULOG_ERR("only kernel protocol version 5 is tested. You have %d.\n",
 643                         kproto_version);
 644                 exit(EXIT_FAILURE);
 645         }
 646         if (ioctl(fd_autofs_write, AUTOFS_IOC_SETTIMEOUT, &autofs_timeout))
 647                 ULOG_ERR("failed to set autofs timeout\n");
 648
 649         uloop_timeout_set(&autofs_expire_timer, AUTOFS_EXPIRE_TIMER);
 650
 651         fcntl(fd_autofs_write, F_SETFD, fcntl(fd_autofs_write, F_GETFD) | FD_CLOEXEC);
 652         fcntl(fd_autofs_read.fd, F_SETFD, fcntl(fd_autofs_read.fd, F_GETFD) | FD_CLOEXEC);
 653
 654         return 0;
 655 }
 656
 657 static void blockd_startup_cb(struct uloop_process *p, int stat)
 658 {
 659         send_block_notification(&conn.ctx, "ready", NULL, NULL);
 660 }
 661
 662 static struct uloop_process startup_process = {
 663         .cb = blockd_startup_cb,
 664 };
 665
 666 static void blockd_startup(struct uloop_timeout *t)
 667 {
 668         block("autofs", "start", NULL, 0, &startup_process);
 669 }
 670
 671 struct uloop_timeout startup = {
 672         .cb = blockd_startup,
 673 };
 674
 675 int main(int argc, char **argv)
 676 {
 677         /* make sure blockd is in it's own POSIX process group */
 678         setpgrp();
 679
 680         ulog_open(ULOG_SYSLOG | ULOG_STDIO, LOG_DAEMON, "blockd");
 681         uloop_init();
 682
 683         autofs_mount();
 684
 685         conn.cb = ubus_connect_handler;
 686         ubus_auto_connect(&conn);
 687
 688         uloop_timeout_set(&startup, 1000);
 689
 690         uloop_run();
 691         uloop_done();
 692
 693         autofs_umount();
 694
 695         vlist_flush_all(&devices);
 696
 697         return 0;
 698 }