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 enum proto_shell_sm {
  24         S_IDLE,
  25         S_SETUP,
  26         S_SETUP_ABORT,
  27         S_TEARDOWN,
  28 };
  29
  30 struct proto_shell_handler {
  31         struct list_head list;
  32         struct proto_handler proto;
  33         struct config_param_list config;
  34         char *config_buf;
  35         bool init_available;
  36         char script_name[];
  37 };
  38
  39 struct proto_shell_state {
  40         struct interface_proto_state proto;
  41         struct proto_shell_handler *handler;
  42         struct blob_attr *config;
  43
  44         struct device_user l3_dev;
  45
  46         struct uloop_timeout teardown_timeout;
  47
  48         struct netifd_process script_task;
  49         struct netifd_process proto_task;
  50
  51         enum proto_shell_sm sm;
  52         bool proto_task_killed;
  53
  54         int last_error;
  55 };
  56
  57 static int
  58 proto_shell_handler(struct interface_proto_state *proto,
  59                     enum interface_proto_cmd cmd, bool force)
  60 {
  61         struct proto_shell_state *state;
  62         struct proto_shell_handler *handler;
  63         struct netifd_process *proc;
  64         static char error_buf[32];
  65         const char *argv[7];
  66         char *envp[2];
  67         const char *action;
  68         char *config;
  69         int ret, i = 0, j = 0;
  70
  71         state = container_of(proto, struct proto_shell_state, proto);
  72         handler = state->handler;
  73         proc = &state->script_task;
  74
  75         if (cmd == PROTO_CMD_SETUP) {
  76                 action = "setup";
  77                 state->last_error = -1;
  78         } else {
  79                 if (state->sm == S_TEARDOWN)
  80                         return 0;
  81
  82                 if (state->script_task.uloop.pending) {
  83                         if (state->sm != S_SETUP_ABORT) {
  84                                 uloop_timeout_set(&state->teardown_timeout, 1000);
  85                                 kill(state->script_task.uloop.pid, SIGTERM);
  86                                 if (state->proto_task.uloop.pending)
  87                                         kill(state->proto_task.uloop.pid, SIGTERM);
  88                                 state->sm = S_SETUP_ABORT;
  89                         }
  90                         return 0;
  91                 }
  92
  93                 action = "teardown";
  94                 state->sm = S_TEARDOWN;
  95                 if (state->last_error >= 0) {
  96                         snprintf(error_buf, sizeof(error_buf), "ERROR=%d", state->last_error);
  97                         envp[j++] = error_buf;
  98                 }
  99                 uloop_timeout_set(&state->teardown_timeout, 5000);
 100         }
 101
 102         config = blobmsg_format_json(state->config, true);
 103         if (!config)
 104                 return -1;
 105
 106         argv[i++] = handler->script_name;
 107         argv[i++] = handler->proto.name;
 108         argv[i++] = action;
 109         argv[i++] = proto->iface->name;
 110         argv[i++] = config;
 111         if (proto->iface->main_dev.dev)
 112                 argv[i++] = proto->iface->main_dev.dev->ifname;
 113         argv[i] = NULL;
 114         envp[j] = NULL;
 115
 116         ret = netifd_start_process(argv, envp, proc);
 117         free(config);
 118
 119         return ret;
 120 }
 121
 122 static void
 123 proto_shell_task_finish(struct proto_shell_state *state,
 124                         struct netifd_process *task)
 125 {
 126         switch (state->sm) {
 127         case S_IDLE:
 128                 if (task == &state->proto_task)
 129                         state->proto.proto_event(&state->proto, IFPEV_LINK_LOST);
 130                 /* fall through */
 131         case S_SETUP:
 132                 if (task == &state->proto_task)
 133                         proto_shell_handler(&state->proto, PROTO_CMD_TEARDOWN,
 134                                             false);
 135                 break;
 136
 137         case S_SETUP_ABORT:
 138                 if (state->script_task.uloop.pending ||
 139                     state->proto_task.uloop.pending)
 140                         break;
 141
 142                 uloop_timeout_cancel(&state->teardown_timeout);
 143                 state->sm = S_IDLE;
 144                 proto_shell_handler(&state->proto, PROTO_CMD_TEARDOWN, false);
 145                 break;
 146
 147         case S_TEARDOWN:
 148                 if (state->script_task.uloop.pending)
 149                         break;
 150
 151                 if (state->proto_task.uloop.pending) {
 152                         if (!state->proto_task_killed)
 153                                 kill(state->proto_task.uloop.pid, SIGTERM);
 154                         break;
 155                 }
 156
 157                 uloop_timeout_cancel(&state->teardown_timeout);
 158                 state->sm = S_IDLE;
 159                 state->proto.proto_event(&state->proto, IFPEV_DOWN);
 160                 break;
 161         }
 162 }
 163
 164 static void
 165 proto_shell_teardown_timeout_cb(struct uloop_timeout *timeout)
 166 {
 167         struct proto_shell_state *state;
 168
 169         state = container_of(timeout, struct proto_shell_state, teardown_timeout);
 170
 171         netifd_kill_process(&state->script_task);
 172         netifd_kill_process(&state->proto_task);
 173         proto_shell_task_finish(state, NULL);
 174 }
 175
 176 static void
 177 proto_shell_script_cb(struct netifd_process *p, int ret)
 178 {
 179         struct proto_shell_state *state;
 180
 181         state = container_of(p, struct proto_shell_state, script_task);
 182         proto_shell_task_finish(state, p);
 183 }
 184
 185 static void
 186 proto_shell_task_cb(struct netifd_process *p, int ret)
 187 {
 188         struct proto_shell_state *state;
 189
 190         state = container_of(p, struct proto_shell_state, proto_task);
 191
 192         if (state->sm == S_IDLE || state->sm == S_SETUP)
 193                 state->last_error = WEXITSTATUS(ret);
 194
 195         proto_shell_task_finish(state, p);
 196 }
 197
 198 static void
 199 proto_shell_free(struct interface_proto_state *proto)
 200 {
 201         struct proto_shell_state *state;
 202
 203         state = container_of(proto, struct proto_shell_state, proto);
 204         free(state->config);
 205         free(state);
 206 }
 207
 208 static void
 209 proto_shell_parse_route_list(struct interface *iface, struct blob_attr *attr,
 210                              bool v6)
 211 {
 212         struct blob_attr *cur;
 213         int rem;
 214
 215         blobmsg_for_each_attr(cur, attr, rem) {
 216                 if (blobmsg_type(cur) != BLOBMSG_TYPE_TABLE) {
 217                         DPRINTF("Ignore wrong route type: %d\n", blobmsg_type(cur));
 218                         continue;
 219                 }
 220
 221                 interface_ip_add_route(iface, cur, v6);
 222         }
 223 }
 224
 225 static struct device *
 226 proto_shell_create_tunnel(const char *name, struct blob_attr *attr)
 227 {
 228         struct device *dev;
 229         struct blob_buf b;
 230
 231         memset(&b, 0, sizeof(b));
 232         blob_buf_init(&b, 0);
 233         blob_put(&b, 0, blobmsg_data(attr), blobmsg_data_len(attr));
 234         dev = device_create(name, &tunnel_device_type, blob_data(b.head));
 235         blob_buf_free(&b);
 236
 237         return dev;
 238 }
 239
 240 enum {
 241         NOTIFY_ACTION,
 242         NOTIFY_ERROR,
 243         NOTIFY_COMMAND,
 244         NOTIFY_ENV,
 245         NOTIFY_SIGNAL,
 246         NOTIFY_AVAILABLE,
 247         NOTIFY_LINK_UP,
 248         NOTIFY_IFNAME,
 249         NOTIFY_ADDR_EXT,
 250         NOTIFY_ROUTES,
 251         NOTIFY_ROUTES6,
 252         NOTIFY_TUNNEL,
 253         __NOTIFY_LAST
 254 };
 255
 256 static const struct blobmsg_policy notify_attr[__NOTIFY_LAST] = {
 257         [NOTIFY_ACTION] = { .name = "action", .type = BLOBMSG_TYPE_INT32 },
 258         [NOTIFY_ERROR] = { .name = "error", .type = BLOBMSG_TYPE_ARRAY },
 259         [NOTIFY_COMMAND] = { .name = "command", .type = BLOBMSG_TYPE_ARRAY },
 260         [NOTIFY_ENV] = { .name = "env", .type = BLOBMSG_TYPE_ARRAY },
 261         [NOTIFY_SIGNAL] = { .name = "signal", .type = BLOBMSG_TYPE_INT32 },
 262         [NOTIFY_AVAILABLE] = { .name = "available", .type = BLOBMSG_TYPE_BOOL },
 263         [NOTIFY_LINK_UP] = { .name = "link-up", .type = BLOBMSG_TYPE_BOOL },
 264         [NOTIFY_IFNAME] = { .name = "ifname", .type = BLOBMSG_TYPE_STRING },
 265         [NOTIFY_ADDR_EXT] = { .name = "address-external", .type = BLOBMSG_TYPE_BOOL },
 266         [NOTIFY_ROUTES] = { .name = "routes", .type = BLOBMSG_TYPE_ARRAY },
 267         [NOTIFY_ROUTES6] = { .name = "routes6", .type = BLOBMSG_TYPE_ARRAY },
 268         [NOTIFY_TUNNEL] = { .name = "tunnel", .type = BLOBMSG_TYPE_TABLE },
 269 };
 270
 271 static int
 272 proto_shell_update_link(struct proto_shell_state *state, struct blob_attr *data, struct blob_attr **tb)
 273 {
 274         struct interface *iface = state->proto.iface;
 275         struct blob_attr *cur;
 276         struct device *dev;
 277         const char *devname;
 278         int dev_create = 1;
 279         bool addr_ext = false;
 280         bool up;
 281
 282         if (!tb[NOTIFY_LINK_UP])
 283                 return UBUS_STATUS_INVALID_ARGUMENT;
 284
 285         up = blobmsg_get_bool(tb[NOTIFY_LINK_UP]);
 286         if (!up) {
 287                 state->proto.proto_event(&state->proto, IFPEV_LINK_LOST);
 288                 return 0;
 289         }
 290
 291         if ((cur = tb[NOTIFY_ADDR_EXT]) != NULL) {
 292                 addr_ext = blobmsg_get_bool(cur);
 293                 if (addr_ext)
 294                         dev_create = 2;
 295         }
 296
 297         if (!tb[NOTIFY_IFNAME]) {
 298                 if (!iface->main_dev.dev)
 299                         return UBUS_STATUS_INVALID_ARGUMENT;
 300         } else {
 301                 if (state->l3_dev.dev)
 302                         device_remove_user(&state->l3_dev);
 303
 304                 devname = blobmsg_data(tb[NOTIFY_IFNAME]);
 305                 if (tb[NOTIFY_TUNNEL]) {
 306                         dev = proto_shell_create_tunnel(devname,
 307                                 tb[NOTIFY_TUNNEL]);
 308                         if (!dev)
 309                                 return UBUS_STATUS_INVALID_ARGUMENT;
 310                 } else {
 311                         dev = device_get(devname, dev_create);
 312                         if (!dev)
 313                                 return UBUS_STATUS_NOT_FOUND;
 314                 }
 315
 316                 device_add_user(&state->l3_dev, dev);
 317                 iface->l3_dev = &state->l3_dev;
 318                 device_claim(&state->l3_dev);
 319         }
 320
 321         interface_update_start(iface);
 322         proto_apply_ip_settings(iface, data, addr_ext);
 323
 324         if ((cur = tb[NOTIFY_ROUTES]) != NULL)
 325                 proto_shell_parse_route_list(state->proto.iface, cur, false);
 326
 327         if ((cur = tb[NOTIFY_ROUTES6]) != NULL)
 328                 proto_shell_parse_route_list(state->proto.iface, cur, true);
 329
 330         interface_update_complete(state->proto.iface);
 331
 332         state->proto.proto_event(&state->proto, IFPEV_UP);
 333
 334         return 0;
 335 }
 336
 337 static bool
 338 fill_string_list(struct blob_attr *attr, char **argv, int max)
 339 {
 340         struct blob_attr *cur;
 341         int argc = 0;
 342         int rem;
 343
 344         if (!attr)
 345                 goto out;
 346
 347         blobmsg_for_each_attr(cur, attr, rem) {
 348                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
 349                         return false;
 350
 351                 if (!blobmsg_check_attr(cur, NULL))
 352                         return false;
 353
 354                 argv[argc++] = blobmsg_data(cur);
 355                 if (argc == max - 1)
 356                         return false;
 357         }
 358
 359 out:
 360         argv[argc] = NULL;
 361         return true;
 362 }
 363
 364 static int
 365 proto_shell_run_command(struct proto_shell_state *state, struct blob_attr **tb)
 366 {
 367         static char *argv[64];
 368         static char *env[32];
 369
 370         if (!tb[NOTIFY_COMMAND])
 371                 goto error;
 372
 373         if (!fill_string_list(tb[NOTIFY_COMMAND], argv, ARRAY_SIZE(argv)))
 374                 goto error;
 375
 376         if (!fill_string_list(tb[NOTIFY_ENV], env, ARRAY_SIZE(env)))
 377                 goto error;
 378
 379         netifd_start_process((const char **) argv, (char **) env, &state->proto_task);
 380
 381         return 0;
 382
 383 error:
 384         return UBUS_STATUS_INVALID_ARGUMENT;
 385 }
 386
 387 static int
 388 proto_shell_kill_command(struct proto_shell_state *state, struct blob_attr **tb)
 389 {
 390         unsigned int signal = ~0;
 391
 392         if (tb[NOTIFY_SIGNAL])
 393                 signal = blobmsg_get_u32(tb[NOTIFY_SIGNAL]);
 394
 395         if (signal > 31)
 396                 signal = SIGTERM;
 397
 398         if (state->proto_task.uloop.pending) {
 399                 state->proto_task_killed = true;
 400                 kill(state->proto_task.uloop.pid, signal);
 401         }
 402
 403         return 0;
 404 }
 405
 406 static int
 407 proto_shell_notify_error(struct proto_shell_state *state, struct blob_attr **tb)
 408 {
 409         struct blob_attr *cur;
 410         char *data[16];
 411         int n_data = 0;
 412         int rem;
 413
 414         if (!tb[NOTIFY_ERROR])
 415                 return UBUS_STATUS_INVALID_ARGUMENT;
 416
 417         blobmsg_for_each_attr(cur, tb[NOTIFY_ERROR], rem) {
 418                 if (n_data + 1 == ARRAY_SIZE(data))
 419                         goto error;
 420
 421                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
 422                         goto error;
 423
 424                 if (!blobmsg_check_attr(cur, NULL))
 425                         goto error;
 426
 427                 data[n_data++] = blobmsg_data(cur);
 428         }
 429
 430         if (!n_data)
 431                 goto error;
 432
 433         interface_add_error(state->proto.iface, state->handler->proto.name,
 434                         data[0], (const char **) &data[1], n_data - 1);
 435
 436         return 0;
 437
 438 error:
 439         return UBUS_STATUS_INVALID_ARGUMENT;
 440 }
 441
 442 static int
 443 proto_shell_block_restart(struct proto_shell_state *state, struct blob_attr **tb)
 444 {
 445         state->proto.iface->autostart = false;
 446         return 0;
 447 }
 448
 449 static int
 450 proto_shell_set_available(struct proto_shell_state *state, struct blob_attr **tb)
 451 {
 452         if (!tb[NOTIFY_AVAILABLE])
 453                 return UBUS_STATUS_INVALID_ARGUMENT;
 454
 455         interface_set_available(state->proto.iface, blobmsg_get_bool(tb[NOTIFY_AVAILABLE]));
 456         return 0;
 457 }
 458
 459 static int
 460 proto_shell_notify(struct interface_proto_state *proto, struct blob_attr *attr)
 461 {
 462         struct proto_shell_state *state;
 463         struct blob_attr *tb[__NOTIFY_LAST];
 464
 465         state = container_of(proto, struct proto_shell_state, proto);
 466
 467         blobmsg_parse(notify_attr, __NOTIFY_LAST, tb, blob_data(attr), blob_len(attr));
 468         if (!tb[NOTIFY_ACTION])
 469                 return UBUS_STATUS_INVALID_ARGUMENT;
 470
 471         switch(blobmsg_get_u32(tb[NOTIFY_ACTION])) {
 472         case 0:
 473                 return proto_shell_update_link(state, attr, tb);
 474         case 1:
 475                 return proto_shell_run_command(state, tb);
 476         case 2:
 477                 return proto_shell_kill_command(state, tb);
 478         case 3:
 479                 return proto_shell_notify_error(state, tb);
 480         case 4:
 481                 return proto_shell_block_restart(state, tb);
 482         case 5:
 483                 return proto_shell_set_available(state, tb);
 484         default:
 485                 return UBUS_STATUS_INVALID_ARGUMENT;
 486         }
 487 }
 488
 489 static struct interface_proto_state *
 490 proto_shell_attach(const struct proto_handler *h, struct interface *iface,
 491                    struct blob_attr *attr)
 492 {
 493         struct proto_shell_state *state;
 494
 495         state = calloc(1, sizeof(*state));
 496         state->config = malloc(blob_pad_len(attr));
 497         if (!state->config)
 498                 goto error;
 499
 500         memcpy(state->config, attr, blob_pad_len(attr));
 501         state->proto.free = proto_shell_free;
 502         state->proto.notify = proto_shell_notify;
 503         state->proto.cb = proto_shell_handler;
 504         state->teardown_timeout.cb = proto_shell_teardown_timeout_cb;
 505         state->script_task.cb = proto_shell_script_cb;
 506         state->script_task.dir_fd = proto_fd.fd;
 507         state->script_task.log_prefix = iface->name;
 508         state->proto_task.cb = proto_shell_task_cb;
 509         state->proto_task.dir_fd = proto_fd.fd;
 510         state->proto_task.log_prefix = iface->name;
 511         state->handler = container_of(h, struct proto_shell_handler, proto);
 512
 513         return &state->proto;
 514
 515 error:
 516         free(state);
 517         return NULL;
 518 }
 519
 520 static json_object *
 521 check_type(json_object *obj, json_type type)
 522 {
 523         if (!obj)
 524                 return NULL;
 525
 526         if (json_object_get_type(obj) != type)
 527                 return NULL;
 528
 529         return obj;
 530 }
 531
 532 static inline json_object *
 533 get_field(json_object *obj, const char *name, json_type type)
 534 {
 535         return check_type(json_object_object_get(obj, name), type);
 536 }
 537
 538 static char *
 539 proto_shell_parse_config(struct config_param_list *config, json_object *obj)
 540 {
 541         struct blobmsg_policy *attrs;
 542         char *str_buf, *str_cur;
 543         int str_len = 0;
 544         int i;
 545
 546         config->n_params = json_object_array_length(obj);
 547         attrs = calloc(1, sizeof(*attrs) * config->n_params);
 548         if (!attrs)
 549                 return NULL;
 550
 551         config->params = attrs;
 552         for (i = 0; i < config->n_params; i++) {
 553                 json_object *cur, *name, *type;
 554
 555                 cur = check_type(json_object_array_get_idx(obj, i), json_type_array);
 556                 if (!cur)
 557                         goto error;
 558
 559                 name = check_type(json_object_array_get_idx(cur, 0), json_type_string);
 560                 if (!name)
 561                         goto error;
 562
 563                 type = check_type(json_object_array_get_idx(cur, 1), json_type_int);
 564                 if (!type)
 565                         goto error;
 566
 567                 attrs[i].name = json_object_get_string(name);
 568                 attrs[i].type = json_object_get_int(type);
 569                 if (attrs[i].type > BLOBMSG_TYPE_LAST)
 570                         goto error;
 571
 572                 str_len += strlen(attrs[i].name) + 1;
 573         }
 574
 575         str_buf = malloc(str_len);
 576         if (!str_buf)
 577                 goto error;
 578
 579         str_cur = str_buf;
 580         for (i = 0; i < config->n_params; i++) {
 581                 const char *name = attrs[i].name;
 582
 583                 attrs[i].name = str_cur;
 584                 str_cur += sprintf(str_cur, "%s", name) + 1;
 585         }
 586
 587         return str_buf;
 588
 589 error:
 590         free(attrs);
 591         config->n_params = 0;
 592         return NULL;
 593 }
 594
 595 static void
 596 proto_shell_add_handler(const char *script, json_object *obj)
 597 {
 598         struct proto_shell_handler *handler;
 599         struct proto_handler *proto;
 600         json_object *config, *tmp;
 601         const char *name;
 602         char *str;
 603
 604         if (!check_type(obj, json_type_object))
 605                 return;
 606
 607         tmp = get_field(obj, "name", json_type_string);
 608         if (!tmp)
 609                 return;
 610
 611         name = json_object_get_string(tmp);
 612
 613         handler = calloc(1, sizeof(*handler) +
 614                          strlen(script) + 1 +
 615                          strlen(name) + 1);
 616         if (!handler)
 617                 return;
 618
 619         strcpy(handler->script_name, script);
 620
 621         str = handler->script_name + strlen(handler->script_name) + 1;
 622         strcpy(str, name);
 623
 624         proto = &handler->proto;
 625         proto->name = str;
 626         proto->config_params = &handler->config;
 627         proto->attach = proto_shell_attach;
 628
 629         tmp = get_field(obj, "no-device", json_type_boolean);
 630         if (tmp && json_object_get_boolean(tmp))
 631                 handler->proto.flags |= PROTO_FLAG_NODEV;
 632
 633         tmp = get_field(obj, "available", json_type_boolean);
 634         if (tmp && json_object_get_boolean(tmp))
 635                 handler->proto.flags |= PROTO_FLAG_INIT_AVAILABLE;
 636
 637         config = get_field(obj, "config", json_type_array);
 638         if (config)
 639                 handler->config_buf = proto_shell_parse_config(&handler->config, config);
 640
 641         DPRINTF("Add handler for script %s: %s\n", script, proto->name);
 642         add_proto_handler(proto);
 643 }
 644
 645 static void proto_shell_add_script(const char *name)
 646 {
 647         struct json_tokener *tok = NULL;
 648         json_object *obj;
 649         static char buf[512];
 650         char *start, *cmd;
 651         FILE *f;
 652         int len;
 653
 654 #define DUMP_SUFFIX     " '' dump"
 655
 656         cmd = alloca(strlen(name) + 1 + sizeof(DUMP_SUFFIX));
 657         sprintf(cmd, "%s" DUMP_SUFFIX, name);
 658
 659         f = popen(cmd, "r");
 660         if (!f)
 661                 return;
 662
 663         do {
 664                 start = fgets(buf, sizeof(buf), f);
 665                 if (!start)
 666                         continue;
 667
 668                 len = strlen(start);
 669
 670                 if (!tok)
 671                         tok = json_tokener_new();
 672
 673                 obj = json_tokener_parse_ex(tok, start, len);
 674                 if (!is_error(obj)) {
 675                         proto_shell_add_handler(name, obj);
 676                         json_object_put(obj);
 677                         json_tokener_free(tok);
 678                         tok = NULL;
 679                 } else if (start[len - 1] == '\n') {
 680                         json_tokener_free(tok);
 681                         tok = NULL;
 682                 }
 683         } while (!feof(f) && !ferror(f));
 684
 685         if (tok)
 686                 json_tokener_free(tok);
 687
 688         pclose(f);
 689 }
 690
 691 static void __init proto_shell_init(void)
 692 {
 693         glob_t g;
 694         int main_fd;
 695         int i;
 696
 697         main_fd = open(".", O_RDONLY | O_DIRECTORY);
 698         if (main_fd < 0)
 699                 return;
 700
 701         if (chdir(main_path)) {
 702                 perror("chdir(main path)");
 703                 goto close_cur;
 704         }
 705
 706         if (chdir("./proto"))
 707                 goto close_cur;
 708
 709         proto_fd.fd = open(".", O_RDONLY | O_DIRECTORY);
 710         if (proto_fd.fd < 0)
 711                 goto close_cur;
 712
 713         netifd_fd_add(&proto_fd);
 714         glob("./*.sh", 0, NULL, &g);
 715         for (i = 0; i < g.gl_pathc; i++)
 716                 proto_shell_add_script(g.gl_pathv[i]);
 717
 718 close_cur:
 719         fchdir(main_fd);
 720         close(main_fd);
 721 }