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 if (!state->l3_dev.dev) {
 322                 device_add_user(&state->l3_dev,
 323                         device_get(blobmsg_data(tb[NOTIFY_IFNAME]), true));
 324                 device_claim(&state->l3_dev);
 325                 state->proto.iface->l3_dev = &state->l3_dev;
 326         }
 327
 328         interface_ip_update_start(state->proto.iface);
 329
 330         if ((cur = tb[NOTIFY_ADDR_EXT]) != NULL)
 331                 addr_ext = blobmsg_get_bool(cur);
 332
 333         if ((cur = tb[NOTIFY_IPADDR]) != NULL)
 334                 proto_shell_parse_addr_list(state->proto.iface, cur, false, addr_ext);
 335
 336         if ((cur = tb[NOTIFY_IP6ADDR]) != NULL)
 337                 proto_shell_parse_addr_list(state->proto.iface, cur, true, addr_ext);
 338
 339         if ((cur = tb[NOTIFY_ROUTES]) != NULL)
 340                 proto_shell_parse_route_list(state->proto.iface, cur, false);
 341
 342         if ((cur = tb[NOTIFY_ROUTES6]) != NULL)
 343                 proto_shell_parse_route_list(state->proto.iface, cur, true);
 344
 345         if ((cur = tb[NOTIFY_DNS]) != NULL)
 346                 interface_add_dns_server_list(state->proto.iface, cur);
 347
 348         if ((cur = tb[NOTIFY_DNS_SEARCH]) != NULL)
 349                 interface_add_dns_search_list(state->proto.iface, cur);
 350
 351         interface_ip_update_complete(state->proto.iface);
 352
 353         state->proto.proto_event(&state->proto, IFPEV_UP);
 354
 355         return 0;
 356 }
 357
 358 static bool
 359 fill_string_list(struct blob_attr *attr, char **argv, int max)
 360 {
 361         struct blob_attr *cur;
 362         int argc = 0;
 363         int rem;
 364
 365         if (!attr)
 366                 goto out;
 367
 368         blobmsg_for_each_attr(cur, attr, rem) {
 369                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
 370                         return false;
 371
 372                 if (!blobmsg_check_attr(cur, NULL))
 373                         return false;
 374
 375                 argv[argc++] = blobmsg_data(cur);
 376                 if (argc == max - 1)
 377                         return false;
 378         }
 379
 380 out:
 381         argv[argc] = NULL;
 382         return true;
 383 }
 384
 385 static int
 386 proto_shell_run_command(struct proto_shell_state *state, struct blob_attr **tb)
 387 {
 388         char *argv[64];
 389         char *env[32];
 390
 391         if (!tb[NOTIFY_COMMAND])
 392                 goto error;
 393
 394         if (!fill_string_list(tb[NOTIFY_COMMAND], argv, ARRAY_SIZE(argv)))
 395                 goto error;
 396
 397         if (!fill_string_list(tb[NOTIFY_ENV], env, ARRAY_SIZE(env)))
 398                 goto error;
 399
 400         netifd_start_process((const char **) argv, (char **) env, &state->proto_task);
 401
 402         return 0;
 403
 404 error:
 405         return UBUS_STATUS_INVALID_ARGUMENT;
 406 }
 407
 408 static int
 409 proto_shell_kill_command(struct proto_shell_state *state, struct blob_attr **tb)
 410 {
 411         unsigned int signal = ~0;
 412
 413         if (tb[NOTIFY_SIGNAL])
 414                 signal = blobmsg_get_u32(tb[NOTIFY_SIGNAL]);
 415
 416         if (signal > 31)
 417                 signal = SIGTERM;
 418
 419         if (state->proto_task.uloop.pending) {
 420                 kill(state->proto_task.uloop.pid, signal);
 421                 state->teardown_wait_task = true;
 422         }
 423
 424         return 0;
 425 }
 426
 427 static int
 428 proto_shell_notify(struct interface_proto_state *proto, struct blob_attr *attr)
 429 {
 430         struct proto_shell_state *state;
 431         struct blob_attr *tb[__NOTIFY_LAST];
 432
 433         state = container_of(proto, struct proto_shell_state, proto);
 434
 435         blobmsg_parse(notify_attr, __NOTIFY_LAST, tb, blob_data(attr), blob_len(attr));
 436         if (!tb[NOTIFY_ACTION])
 437                 return UBUS_STATUS_INVALID_ARGUMENT;
 438
 439         switch(blobmsg_get_u32(tb[NOTIFY_ACTION])) {
 440         case 0:
 441                 return proto_shell_update_link(state, tb);
 442         case 1:
 443                 return proto_shell_run_command(state, tb);
 444         case 2:
 445                 return proto_shell_kill_command(state, tb);
 446         default:
 447                 return UBUS_STATUS_INVALID_ARGUMENT;
 448         }
 449 }
 450
 451 struct interface_proto_state *
 452 proto_shell_attach(const struct proto_handler *h, struct interface *iface,
 453                    struct blob_attr *attr)
 454 {
 455         struct proto_shell_state *state;
 456
 457         state = calloc(1, sizeof(*state));
 458         state->config = malloc(blob_pad_len(attr));
 459         if (!state->config)
 460                 goto error;
 461
 462         memcpy(state->config, attr, blob_pad_len(attr));
 463         state->proto.free = proto_shell_free;
 464         state->proto.notify = proto_shell_notify;
 465         state->proto.cb = proto_shell_handler;
 466         state->setup_timeout.cb = proto_shell_setup_timeout_cb;
 467         state->setup_task.cb = proto_shell_setup_cb;
 468         state->setup_task.dir_fd = proto_fd.fd;
 469         state->setup_task.log_prefix = iface->name;
 470         state->teardown_task.cb = proto_shell_teardown_cb;
 471         state->teardown_task.dir_fd = proto_fd.fd;
 472         state->teardown_task.log_prefix = iface->name;
 473         state->proto_task.cb = proto_shell_task_cb;
 474         state->proto_task.dir_fd = proto_fd.fd;
 475         state->proto_task.log_prefix = iface->name;
 476         state->handler = container_of(h, struct proto_shell_handler, proto);
 477
 478         return &state->proto;
 479
 480 error:
 481         free(state);
 482         return NULL;
 483 }
 484
 485 static json_object *
 486 check_type(json_object *obj, json_type type)
 487 {
 488         if (!obj)
 489                 return NULL;
 490
 491         if (json_object_get_type(obj) != type)
 492                 return NULL;
 493
 494         return obj;
 495 }
 496
 497 static inline json_object *
 498 get_field(json_object *obj, const char *name, json_type type)
 499 {
 500         return check_type(json_object_object_get(obj, name), type);
 501 }
 502
 503 static char *
 504 proto_shell_parse_config(struct config_param_list *config, json_object *obj)
 505 {
 506         struct blobmsg_policy *attrs;
 507         char *str_buf, *str_cur;
 508         int str_len = 0;
 509         int i;
 510
 511         config->n_params = json_object_array_length(obj);
 512         attrs = calloc(1, sizeof(*attrs) * config->n_params);
 513         if (!attrs)
 514                 return NULL;
 515
 516         config->params = attrs;
 517         for (i = 0; i < config->n_params; i++) {
 518                 json_object *cur, *name, *type;
 519
 520                 cur = check_type(json_object_array_get_idx(obj, i), json_type_array);
 521                 if (!cur)
 522                         goto error;
 523
 524                 name = check_type(json_object_array_get_idx(cur, 0), json_type_string);
 525                 if (!name)
 526                         goto error;
 527
 528                 type = check_type(json_object_array_get_idx(cur, 1), json_type_int);
 529                 if (!type)
 530                         goto error;
 531
 532                 attrs[i].name = json_object_get_string(name);
 533                 attrs[i].type = json_object_get_int(type);
 534                 if (attrs[i].type > BLOBMSG_TYPE_LAST)
 535                         goto error;
 536
 537                 str_len += strlen(attrs[i].name) + 1;
 538         }
 539
 540         str_buf = malloc(str_len);
 541         if (!str_buf)
 542                 goto error;
 543
 544         str_cur = str_buf;
 545         for (i = 0; i < config->n_params; i++) {
 546                 const char *name = attrs[i].name;
 547
 548                 attrs[i].name = str_cur;
 549                 str_cur += sprintf(str_cur, "%s", name) + 1;
 550         }
 551
 552         return str_buf;
 553
 554 error:
 555         free(attrs);
 556         config->n_params = 0;
 557         return NULL;
 558 }
 559
 560 static void
 561 proto_shell_add_handler(const char *script, json_object *obj)
 562 {
 563         struct proto_shell_handler *handler;
 564         struct proto_handler *proto;
 565         json_object *config, *tmp;
 566         const char *name;
 567         char *str;
 568
 569         if (!check_type(obj, json_type_object))
 570                 return;
 571
 572         tmp = get_field(obj, "name", json_type_string);
 573         if (!tmp)
 574                 return;
 575
 576         name = json_object_get_string(tmp);
 577
 578         handler = calloc(1, sizeof(*handler) +
 579                          strlen(script) + 1 +
 580                          strlen(name) + 1);
 581         if (!handler)
 582                 return;
 583
 584         strcpy(handler->script_name, script);
 585
 586         str = handler->script_name + strlen(handler->script_name) + 1;
 587         strcpy(str, name);
 588
 589         proto = &handler->proto;
 590         proto->name = str;
 591         proto->config_params = &handler->config;
 592         proto->attach = proto_shell_attach;
 593
 594         tmp = get_field(obj, "no-device", json_type_boolean);
 595         if (tmp && json_object_get_boolean(tmp))
 596                 handler->proto.flags |= PROTO_FLAG_NODEV;
 597
 598         config = get_field(obj, "config", json_type_array);
 599         if (config)
 600                 handler->config_buf = proto_shell_parse_config(&handler->config, config);
 601
 602         DPRINTF("Add handler for script %s: %s\n", script, proto->name);
 603         add_proto_handler(proto);
 604 }
 605
 606 static void proto_shell_add_script(const char *name)
 607 {
 608         struct json_tokener *tok = NULL;
 609         json_object *obj;
 610         static char buf[512];
 611         char *start, *end, *cmd;
 612         FILE *f;
 613         int buflen, len;
 614
 615 #define DUMP_SUFFIX     " '' dump"
 616
 617         cmd = alloca(strlen(name) + 1 + sizeof(DUMP_SUFFIX));
 618         sprintf(cmd, "%s" DUMP_SUFFIX, name);
 619
 620         f = popen(cmd, "r");
 621         if (!f)
 622                 return;
 623
 624         do {
 625                 buflen = fread(buf, 1, sizeof(buf) - 1, f);
 626                 if (buflen <= 0)
 627                         continue;
 628
 629                 start = buf;
 630                 len = buflen;
 631                 do {
 632                         end = memchr(start, '\n', len);
 633                         if (end)
 634                                 len = end - start;
 635
 636                         if (!tok)
 637                                 tok = json_tokener_new();
 638
 639                         obj = json_tokener_parse_ex(tok, start, len);
 640                         if (!is_error(obj)) {
 641                                 proto_shell_add_handler(name, obj);
 642                                 json_object_put(obj);
 643                                 json_tokener_free(tok);
 644                                 tok = NULL;
 645                         }
 646
 647                         if (end) {
 648                                 start = end + 1;
 649                                 len = buflen - (start - buf);
 650                         }
 651                 } while (len > 0);
 652         } while (!feof(f) && !ferror(f));
 653
 654         if (tok)
 655                 json_tokener_free(tok);
 656
 657         pclose(f);
 658 }
 659
 660 void __init proto_shell_init(void)
 661 {
 662         glob_t g;
 663         int main_fd;
 664         int i;
 665
 666         main_fd = open(".", O_RDONLY | O_DIRECTORY);
 667         if (main_fd < 0)
 668                 return;
 669
 670         if (chdir(main_path)) {
 671                 perror("chdir(main path)");
 672                 goto close_cur;
 673         }
 674
 675         if (chdir("./proto"))
 676                 goto close_cur;
 677
 678         proto_fd.fd = open(".", O_RDONLY | O_DIRECTORY);
 679         if (proto_fd.fd < 0)
 680                 goto close_cur;
 681
 682         netifd_fd_add(&proto_fd);
 683         glob("./*.sh", 0, NULL, &g);
 684         for (i = 0; i < g.gl_pathc; i++)
 685                 proto_shell_add_script(g.gl_pathv[i]);
 686
 687 close_cur:
 688         fchdir(main_fd);
 689         close(main_fd);
 690 }