proto-shell.c

   1 #define _GNU_SOURCE
   2
   3 #include <string.h>
   4 #include <stdlib.h>
   5 #include <stdio.h>
   6 #include <glob.h>
   7 #include <unistd.h>
   8 #include <fcntl.h>
   9 #include <signal.h>
  10
  11 #include <arpa/inet.h>
  12 #include <netinet/in.h>
  13
  14 #include <libubox/blobmsg_json.h>
  15
  16 #include "netifd.h"
  17 #include "interface.h"
  18 #include "interface-ip.h"
  19 #include "proto.h"
  20
  21 static struct netifd_fd proto_fd;
  22
  23 struct proto_shell_handler {
  24         struct list_head list;
  25         struct proto_handler proto;
  26         struct config_param_list config;
  27         char *config_buf;
  28         char script_name[];
  29 };
  30
  31 struct proto_shell_state {
  32         struct interface_proto_state proto;
  33         struct proto_shell_handler *handler;
  34         struct blob_attr *config;
  35
  36         struct device_user l3_dev;
  37
  38         struct uloop_timeout setup_timeout;
  39         struct netifd_process setup_task;
  40         struct netifd_process teardown_task;
  41         bool teardown_pending;
  42         bool teardown_wait_task;
  43
  44         struct netifd_process proto_task;
  45 };
  46
  47 static int
  48 proto_shell_handler(struct interface_proto_state *proto,
  49                     enum interface_proto_cmd cmd, bool force)
  50 {
  51         struct proto_shell_state *state;
  52         struct proto_shell_handler *handler;
  53         struct netifd_process *proc;
  54         const char *argv[6];
  55         const char *action;
  56         char *config;
  57         int ret, i = 0;
  58
  59         state = container_of(proto, struct proto_shell_state, proto);
  60         handler = state->handler;
  61
  62         if (cmd == PROTO_CMD_SETUP) {
  63                 action = "setup";
  64                 proc = &state->setup_task;
  65         } else {
  66                 action = "teardown";
  67                 proc = &state->teardown_task;
  68                 if (state->setup_task.uloop.pending && !state->teardown_wait_task) {
  69                         uloop_timeout_set(&state->setup_timeout, 1000);
  70                         kill(state->setup_task.uloop.pid, SIGTERM);
  71                         state->teardown_pending = true;
  72                         return 0;
  73                 }
  74         }
  75
  76         config = blobmsg_format_json(state->config, true);
  77         if (!config)
  78                 return -1;
  79
  80         argv[i++] = handler->script_name;
  81         argv[i++] = handler->proto.name;
  82         argv[i++] = action;
  83         argv[i++] = proto->iface->name;
  84         argv[i++] = config;
  85         if (proto->iface->main_dev.dev)
  86                 argv[i++] = proto->iface->main_dev.dev->ifname;
  87         argv[i] = NULL;
  88
  89         ret = netifd_start_process(argv, NULL, proc);
  90         free(config);
  91
  92         return ret;
  93 }
  94
  95 static void
  96 proto_shell_setup_timeout_cb(struct uloop_timeout *timeout)
  97 {
  98         struct proto_shell_state *state;
  99
 100         state = container_of(timeout, struct proto_shell_state, setup_timeout);
 101         kill(state->setup_task.uloop.pid, SIGKILL);
 102 }
 103
 104 static void
 105 proto_shell_setup_cb(struct netifd_process *p, int ret)
 106 {
 107         struct proto_shell_state *state;
 108
 109         state = container_of(p, struct proto_shell_state, setup_task);
 110         uloop_timeout_cancel(&state->setup_timeout);
 111         if (state->teardown_pending) {
 112                 state->teardown_pending = false;
 113                 proto_shell_handler(&state->proto, PROTO_CMD_TEARDOWN, false);
 114         }
 115 }
 116
 117 static void
 118 proto_shell_teardown_cb(struct netifd_process *p, int ret)
 119 {
 120         struct proto_shell_state *state;
 121
 122         state = container_of(p, struct proto_shell_state, teardown_task);
 123
 124         if (state->teardown_wait_task)
 125                 return;
 126
 127         netifd_kill_process(&state->proto_task);
 128         state->proto.proto_event(&state->proto, IFPEV_DOWN);
 129 }
 130
 131 static void
 132 proto_shell_task_cb(struct netifd_process *p, int ret)
 133 {
 134         struct proto_shell_state *state;
 135         bool teardown_wait_task;
 136
 137         state = container_of(p, struct proto_shell_state, proto_task);
 138
 139         teardown_wait_task = state->teardown_wait_task;
 140         state->teardown_wait_task = false;
 141         if (state->teardown_pending || state->teardown_task.uloop.pending)
 142                 return;
 143
 144         if (teardown_wait_task) {
 145                 proto_shell_teardown_cb(&state->teardown_task, 0);
 146                 return;
 147         }
 148
 149         state->proto.proto_event(&state->proto, IFPEV_LINK_LOST);
 150         proto_shell_handler(&state->proto, PROTO_CMD_TEARDOWN, false);
 151 }
 152
 153 static void
 154 proto_shell_free(struct interface_proto_state *proto)
 155 {
 156         struct proto_shell_state *state;
 157
 158         state = container_of(proto, struct proto_shell_state, proto);
 159         free(state->config);
 160         free(state);
 161 }
 162
 163 static void
 164 proto_shell_parse_addr_list(struct interface *iface, struct blob_attr *attr,
 165                             bool v6, bool external)
 166 {
 167         struct device_addr *addr;
 168         struct blob_attr *cur;
 169         int rem;
 170
 171         blobmsg_for_each_attr(cur, attr, rem) {
 172                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING) {
 173                         DPRINTF("Ignore wrong address type: %d\n", blobmsg_type(cur));
 174                         continue;
 175                 }
 176
 177                 addr = proto_parse_ip_addr_string(blobmsg_data(cur), v6, v6 ? 32 : 128);
 178                 if (!addr) {
 179                         DPRINTF("Failed to parse IP address string: %s\n", (char *) blobmsg_data(cur));
 180                         continue;
 181                 }
 182
 183                 if (external)
 184                         addr->flags |= DEVADDR_EXTERNAL;
 185
 186                 vlist_add(&iface->proto_addr, &addr->node);
 187         }
 188 }
 189
 190 enum {
 191         ROUTE_TARGET,
 192         ROUTE_MASK,
 193         ROUTE_GATEWAY,
 194         ROUTE_DEVICE,
 195         __ROUTE_LAST
 196 };
 197
 198 static const struct blobmsg_policy route_attr[__ROUTE_LAST] = {
 199         [ROUTE_TARGET] = { .name = "target", .type = BLOBMSG_TYPE_STRING },
 200         [ROUTE_MASK] = { .name = "mask", .type = BLOBMSG_TYPE_STRING },
 201         [ROUTE_GATEWAY] = { .name = "gateway", .type = BLOBMSG_TYPE_STRING },
 202         [ROUTE_DEVICE] = { .name = "device", .type = BLOBMSG_TYPE_STRING },
 203 };
 204
 205 static void
 206 parse_route(struct interface *iface, struct blob_attr *attr, bool v6)
 207 {
 208         struct blob_attr *tb[__ROUTE_LAST], *cur;
 209         struct device_route *route;
 210         int af = v6 ? AF_INET6 : AF_INET;
 211
 212         blobmsg_parse(route_attr, __ROUTE_LAST, tb, blobmsg_data(attr), blobmsg_data_len(attr));
 213
 214         if (!tb[ROUTE_GATEWAY] && !tb[ROUTE_DEVICE])
 215                 return;
 216
 217         route = calloc(1, sizeof(*route));
 218         if (!route)
 219                 return;
 220
 221         route->mask = v6 ? 128 : 32;
 222         if ((cur = tb[ROUTE_MASK]) != NULL) {
 223                 route->mask = parse_netmask_string(blobmsg_data(cur), v6);
 224                 if (route->mask > (v6 ? 128 : 32))
 225                         goto error;
 226         }
 227
 228         if ((cur = tb[ROUTE_TARGET]) != NULL) {
 229                 if (!inet_pton(af, blobmsg_data(cur), &route->addr)) {
 230                         DPRINTF("Failed to parse route target: %s\n", (char *) blobmsg_data(cur));
 231                         goto error;
 232                 }
 233         }
 234
 235         if ((cur = tb[ROUTE_GATEWAY]) != NULL) {
 236                 if (!inet_pton(af, blobmsg_data(cur), &route->nexthop)) {
 237                         DPRINTF("Failed to parse route gateway: %s\n", (char *) blobmsg_data(cur));
 238                         goto error;
 239                 }
 240         }
 241
 242         if ((cur = tb[ROUTE_DEVICE]) != NULL)
 243                 route->device = device_get(blobmsg_data(cur), true);
 244
 245         vlist_add(&iface->proto_route, &route->node);
 246         return;
 247
 248 error:
 249         free(route);
 250 }
 251
 252 static void
 253 proto_shell_parse_route_list(struct interface *iface, struct blob_attr *attr,
 254                              bool v6)
 255 {
 256         struct blob_attr *cur;
 257         int rem;
 258
 259         blobmsg_for_each_attr(cur, attr, rem) {
 260                 if (blobmsg_type(cur) != BLOBMSG_TYPE_TABLE) {
 261                         DPRINTF("Ignore wrong route type: %d\n", blobmsg_type(cur));
 262                         continue;
 263                 }
 264
 265                 parse_route(iface, cur, v6);
 266         }
 267 }
 268
 269 enum {
 270         NOTIFY_ACTION,
 271         NOTIFY_COMMAND,
 272         NOTIFY_ENV,
 273         NOTIFY_SIGNAL,
 274         NOTIFY_LINK_UP,
 275         NOTIFY_IFNAME,
 276         NOTIFY_ADDR_EXT,
 277         NOTIFY_IPADDR,
 278         NOTIFY_IP6ADDR,
 279         NOTIFY_ROUTES,
 280         NOTIFY_ROUTES6,
 281         NOTIFY_DNS,
 282         NOTIFY_DNS_SEARCH,
 283         __NOTIFY_LAST
 284 };
 285
 286 static const struct blobmsg_policy notify_attr[__NOTIFY_LAST] = {
 287         [NOTIFY_ACTION] = { .name = "action", .type = BLOBMSG_TYPE_INT32 },
 288         [NOTIFY_COMMAND] = { .name = "command", .type = BLOBMSG_TYPE_ARRAY },
 289         [NOTIFY_ENV] = { .name = "env", .type = BLOBMSG_TYPE_ARRAY },
 290         [NOTIFY_SIGNAL] = { .name = "signal", .type = BLOBMSG_TYPE_INT32 },
 291         [NOTIFY_LINK_UP] = { .name = "link-up", .type = BLOBMSG_TYPE_BOOL },
 292         [NOTIFY_IFNAME] = { .name = "ifname", .type = BLOBMSG_TYPE_STRING },
 293         [NOTIFY_ADDR_EXT] = { .name = "address-external", .type = BLOBMSG_TYPE_BOOL },
 294         [NOTIFY_IPADDR] = { .name = "ipaddr", .type = BLOBMSG_TYPE_ARRAY },
 295         [NOTIFY_IP6ADDR] = { .name = "ip6addr", .type = BLOBMSG_TYPE_ARRAY },
 296         [NOTIFY_ROUTES] = { .name = "routes", .type = BLOBMSG_TYPE_ARRAY },
 297         [NOTIFY_ROUTES6] = { .name = "routes6", .type = BLOBMSG_TYPE_ARRAY },
 298         [NOTIFY_DNS] = { .name = "dns", .type = BLOBMSG_TYPE_ARRAY },
 299         [NOTIFY_DNS_SEARCH] = { .name = "dns_search", .type = BLOBMSG_TYPE_ARRAY },
 300 };
 301
 302 static int
 303 proto_shell_update_link(struct proto_shell_state *state, struct blob_attr **tb)
 304 {
 305         struct blob_attr *cur;
 306         bool addr_ext = false;
 307         bool up;
 308
 309         if (!tb[NOTIFY_LINK_UP])
 310                 return UBUS_STATUS_INVALID_ARGUMENT;
 311
 312         up = blobmsg_get_bool(tb[NOTIFY_LINK_UP]);
 313         if (!up) {
 314                 state->proto.proto_event(&state->proto, IFPEV_LINK_LOST);
 315                 return 0;
 316         }
 317
 318         if (!tb[NOTIFY_IFNAME]) {
 319                 if (!state->proto.iface->main_dev.dev)
 320                         return UBUS_STATUS_INVALID_ARGUMENT;
 321         } else {
 322                 if (state->l3_dev.dev)
 323                         device_remove_user(&state->l3_dev);
 324
 325                 device_add_user(&state->l3_dev,
 326                         device_get(blobmsg_data(tb[NOTIFY_IFNAME]), true));
 327                 state->proto.iface->l3_dev = &state->l3_dev;
 328                 device_claim(&state->l3_dev);
 329         }
 330
 331         interface_ip_update_start(state->proto.iface);
 332
 333         if ((cur = tb[NOTIFY_ADDR_EXT]) != NULL)
 334                 addr_ext = blobmsg_get_bool(cur);
 335
 336         if ((cur = tb[NOTIFY_IPADDR]) != NULL)
 337                 proto_shell_parse_addr_list(state->proto.iface, cur, false, addr_ext);
 338
 339         if ((cur = tb[NOTIFY_IP6ADDR]) != NULL)
 340                 proto_shell_parse_addr_list(state->proto.iface, cur, true, addr_ext);
 341
 342         if ((cur = tb[NOTIFY_ROUTES]) != NULL)
 343                 proto_shell_parse_route_list(state->proto.iface, cur, false);
 344
 345         if ((cur = tb[NOTIFY_ROUTES6]) != NULL)
 346                 proto_shell_parse_route_list(state->proto.iface, cur, true);
 347
 348         if ((cur = tb[NOTIFY_DNS]) != NULL)
 349                 interface_add_dns_server_list(state->proto.iface, cur);
 350
 351         if ((cur = tb[NOTIFY_DNS_SEARCH]) != NULL)
 352                 interface_add_dns_search_list(state->proto.iface, cur);
 353
 354         interface_ip_update_complete(state->proto.iface);
 355
 356         state->proto.proto_event(&state->proto, IFPEV_UP);
 357
 358         return 0;
 359 }
 360
 361 static bool
 362 fill_string_list(struct blob_attr *attr, char **argv, int max)
 363 {
 364         struct blob_attr *cur;
 365         int argc = 0;
 366         int rem;
 367
 368         if (!attr)
 369                 goto out;
 370
 371         blobmsg_for_each_attr(cur, attr, rem) {
 372                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
 373                         return false;
 374
 375                 if (!blobmsg_check_attr(cur, NULL))
 376                         return false;
 377
 378                 argv[argc++] = blobmsg_data(cur);
 379                 if (argc == max - 1)
 380                         return false;
 381         }
 382
 383 out:
 384         argv[argc] = NULL;
 385         return true;
 386 }
 387
 388 static int
 389 proto_shell_run_command(struct proto_shell_state *state, struct blob_attr **tb)
 390 {
 391         char *argv[64];
 392         char *env[32];
 393
 394         if (!tb[NOTIFY_COMMAND])
 395                 goto error;
 396
 397         if (!fill_string_list(tb[NOTIFY_COMMAND], argv, ARRAY_SIZE(argv)))
 398                 goto error;
 399
 400         if (!fill_string_list(tb[NOTIFY_ENV], env, ARRAY_SIZE(env)))
 401                 goto error;
 402
 403         netifd_start_process((const char **) argv, (char **) env, &state->proto_task);
 404
 405         return 0;
 406
 407 error:
 408         return UBUS_STATUS_INVALID_ARGUMENT;
 409 }
 410
 411 static int
 412 proto_shell_kill_command(struct proto_shell_state *state, struct blob_attr **tb)
 413 {
 414         unsigned int signal = ~0;
 415
 416         if (tb[NOTIFY_SIGNAL])
 417                 signal = blobmsg_get_u32(tb[NOTIFY_SIGNAL]);
 418
 419         if (signal > 31)
 420                 signal = SIGTERM;
 421
 422         if (state->proto_task.uloop.pending) {
 423                 kill(state->proto_task.uloop.pid, signal);
 424                 state->teardown_wait_task = true;
 425         }
 426
 427         return 0;
 428 }
 429
 430 static int
 431 proto_shell_notify(struct interface_proto_state *proto, struct blob_attr *attr)
 432 {
 433         struct proto_shell_state *state;
 434         struct blob_attr *tb[__NOTIFY_LAST];
 435
 436         state = container_of(proto, struct proto_shell_state, proto);
 437
 438         blobmsg_parse(notify_attr, __NOTIFY_LAST, tb, blob_data(attr), blob_len(attr));
 439         if (!tb[NOTIFY_ACTION])
 440                 return UBUS_STATUS_INVALID_ARGUMENT;
 441
 442         switch(blobmsg_get_u32(tb[NOTIFY_ACTION])) {
 443         case 0:
 444                 return proto_shell_update_link(state, tb);
 445         case 1:
 446                 return proto_shell_run_command(state, tb);
 447         case 2:
 448                 return proto_shell_kill_command(state, tb);
 449         default:
 450                 return UBUS_STATUS_INVALID_ARGUMENT;
 451         }
 452 }
 453
 454 struct interface_proto_state *
 455 proto_shell_attach(const struct proto_handler *h, struct interface *iface,
 456                    struct blob_attr *attr)
 457 {
 458         struct proto_shell_state *state;
 459
 460         state = calloc(1, sizeof(*state));
 461         state->config = malloc(blob_pad_len(attr));
 462         if (!state->config)
 463                 goto error;
 464
 465         memcpy(state->config, attr, blob_pad_len(attr));
 466         state->proto.free = proto_shell_free;
 467         state->proto.notify = proto_shell_notify;
 468         state->proto.cb = proto_shell_handler;
 469         state->setup_timeout.cb = proto_shell_setup_timeout_cb;
 470         state->setup_task.cb = proto_shell_setup_cb;
 471         state->setup_task.dir_fd = proto_fd.fd;
 472         state->setup_task.log_prefix = iface->name;
 473         state->teardown_task.cb = proto_shell_teardown_cb;
 474         state->teardown_task.dir_fd = proto_fd.fd;
 475         state->teardown_task.log_prefix = iface->name;
 476         state->proto_task.cb = proto_shell_task_cb;
 477         state->proto_task.dir_fd = proto_fd.fd;
 478         state->proto_task.log_prefix = iface->name;
 479         state->handler = container_of(h, struct proto_shell_handler, proto);
 480
 481         return &state->proto;
 482
 483 error:
 484         free(state);
 485         return NULL;
 486 }
 487
 488 static json_object *
 489 check_type(json_object *obj, json_type type)
 490 {
 491         if (!obj)
 492                 return NULL;
 493
 494         if (json_object_get_type(obj) != type)
 495                 return NULL;
 496
 497         return obj;
 498 }
 499
 500 static inline json_object *
 501 get_field(json_object *obj, const char *name, json_type type)
 502 {
 503         return check_type(json_object_object_get(obj, name), type);
 504 }
 505
 506 static char *
 507 proto_shell_parse_config(struct config_param_list *config, json_object *obj)
 508 {
 509         struct blobmsg_policy *attrs;
 510         char *str_buf, *str_cur;
 511         int str_len = 0;
 512         int i;
 513
 514         config->n_params = json_object_array_length(obj);
 515         attrs = calloc(1, sizeof(*attrs) * config->n_params);
 516         if (!attrs)
 517                 return NULL;
 518
 519         config->params = attrs;
 520         for (i = 0; i < config->n_params; i++) {
 521                 json_object *cur, *name, *type;
 522
 523                 cur = check_type(json_object_array_get_idx(obj, i), json_type_array);
 524                 if (!cur)
 525                         goto error;
 526
 527                 name = check_type(json_object_array_get_idx(cur, 0), json_type_string);
 528                 if (!name)
 529                         goto error;
 530
 531                 type = check_type(json_object_array_get_idx(cur, 1), json_type_int);
 532                 if (!type)
 533                         goto error;
 534
 535                 attrs[i].name = json_object_get_string(name);
 536                 attrs[i].type = json_object_get_int(type);
 537                 if (attrs[i].type > BLOBMSG_TYPE_LAST)
 538                         goto error;
 539
 540                 str_len += strlen(attrs[i].name) + 1;
 541         }
 542
 543         str_buf = malloc(str_len);
 544         if (!str_buf)
 545                 goto error;
 546
 547         str_cur = str_buf;
 548         for (i = 0; i < config->n_params; i++) {
 549                 const char *name = attrs[i].name;
 550
 551                 attrs[i].name = str_cur;
 552                 str_cur += sprintf(str_cur, "%s", name) + 1;
 553         }
 554
 555         return str_buf;
 556
 557 error:
 558         free(attrs);
 559         config->n_params = 0;
 560         return NULL;
 561 }
 562
 563 static void
 564 proto_shell_add_handler(const char *script, json_object *obj)
 565 {
 566         struct proto_shell_handler *handler;
 567         struct proto_handler *proto;
 568         json_object *config, *tmp;
 569         const char *name;
 570         char *str;
 571
 572         if (!check_type(obj, json_type_object))
 573                 return;
 574
 575         tmp = get_field(obj, "name", json_type_string);
 576         if (!tmp)
 577                 return;
 578
 579         name = json_object_get_string(tmp);
 580
 581         handler = calloc(1, sizeof(*handler) +
 582                          strlen(script) + 1 +
 583                          strlen(name) + 1);
 584         if (!handler)
 585                 return;
 586
 587         strcpy(handler->script_name, script);
 588
 589         str = handler->script_name + strlen(handler->script_name) + 1;
 590         strcpy(str, name);
 591
 592         proto = &handler->proto;
 593         proto->name = str;
 594         proto->config_params = &handler->config;
 595         proto->attach = proto_shell_attach;
 596
 597         tmp = get_field(obj, "no-device", json_type_boolean);
 598         if (tmp && json_object_get_boolean(tmp))
 599                 handler->proto.flags |= PROTO_FLAG_NODEV;
 600
 601         config = get_field(obj, "config", json_type_array);
 602         if (config)
 603                 handler->config_buf = proto_shell_parse_config(&handler->config, config);
 604
 605         DPRINTF("Add handler for script %s: %s\n", script, proto->name);
 606         add_proto_handler(proto);
 607 }
 608
 609 static void proto_shell_add_script(const char *name)
 610 {
 611         struct json_tokener *tok = NULL;
 612         json_object *obj;
 613         static char buf[512];
 614         char *start, *end, *cmd;
 615         FILE *f;
 616         int buflen, len;
 617
 618 #define DUMP_SUFFIX     " '' dump"
 619
 620         cmd = alloca(strlen(name) + 1 + sizeof(DUMP_SUFFIX));
 621         sprintf(cmd, "%s" DUMP_SUFFIX, name);
 622
 623         f = popen(cmd, "r");
 624         if (!f)
 625                 return;
 626
 627         do {
 628                 buflen = fread(buf, 1, sizeof(buf) - 1, f);
 629                 if (buflen <= 0)
 630                         continue;
 631
 632                 start = buf;
 633                 len = buflen;
 634                 do {
 635                         end = memchr(start, '\n', len);
 636                         if (end)
 637                                 len = end - start;
 638
 639                         if (!tok)
 640                                 tok = json_tokener_new();
 641
 642                         obj = json_tokener_parse_ex(tok, start, len);
 643                         if (!is_error(obj)) {
 644                                 proto_shell_add_handler(name, obj);
 645                                 json_object_put(obj);
 646                                 json_tokener_free(tok);
 647                                 tok = NULL;
 648                         }
 649
 650                         if (end) {
 651                                 start = end + 1;
 652                                 len = buflen - (start - buf);
 653                         }
 654                 } while (len > 0);
 655         } while (!feof(f) && !ferror(f));
 656
 657         if (tok)
 658                 json_tokener_free(tok);
 659
 660         pclose(f);
 661 }
 662
 663 void __init proto_shell_init(void)
 664 {
 665         glob_t g;
 666         int main_fd;
 667         int i;
 668
 669         main_fd = open(".", O_RDONLY | O_DIRECTORY);
 670         if (main_fd < 0)
 671                 return;
 672
 673         if (chdir(main_path)) {
 674                 perror("chdir(main path)");
 675                 goto close_cur;
 676         }
 677
 678         if (chdir("./proto"))
 679                 goto close_cur;
 680
 681         proto_fd.fd = open(".", O_RDONLY | O_DIRECTORY);
 682         if (proto_fd.fd < 0)
 683                 goto close_cur;
 684
 685         netifd_fd_add(&proto_fd);
 686         glob("./*.sh", 0, NULL, &g);
 687         for (i = 0; i < g.gl_pathc; i++)
 688                 proto_shell_add_script(g.gl_pathv[i]);
 689
 690 close_cur:
 691         fchdir(main_fd);
 692         close(main_fd);
 693 }