plug/hotplug.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <sys/stat.h>
  16 #include <sys/socket.h>
  17 #include <sys/types.h>
  18
  19 #include <linux/types.h>
  20 #include <linux/netlink.h>
  21
  22 #include <libubox/avl-cmp.h>
  23 #include <libubox/blobmsg_json.h>
  24 #include <libubox/json_script.h>
  25 #include <libubox/uloop.h>
  26 #include <json-c/json.h>
  27
  28 #include <fcntl.h>
  29 #include <unistd.h>
  30 #include <stdlib.h>
  31 #include <libgen.h>
  32
  33 #include "../procd.h"
  34
  35 #include "hotplug.h"
  36
  37 #define HOTPLUG_WAIT    500
  38
  39 struct cmd_queue {
  40         struct list_head list;
  41
  42         struct blob_attr *msg;
  43         struct blob_attr *data;
  44         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
  45 };
  46
  47 struct cmd_interval {
  48         struct avl_node avl;
  49
  50         bool cancelled;
  51         struct timespec start;
  52         struct uloop_timeout timeout;
  53         struct uloop_process process;
  54
  55         struct blob_attr *msg;
  56         struct blob_attr *data;
  57 };
  58
  59 static LIST_HEAD(cmd_queue);
  60 static AVL_TREE(cmd_intervals, avl_strcmp, false, NULL);
  61 static struct uloop_process queue_proc;
  62 static struct uloop_timeout last_event;
  63 static struct blob_buf b;
  64 static char *rule_file;
  65 static struct blob_buf script;
  66
  67 static char *hotplug_msg_find_var(struct blob_attr *msg, const char *name)
  68 {
  69         struct blob_attr *cur;
  70         int rem;
  71
  72         blobmsg_for_each_attr(cur, msg, rem) {
  73                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
  74                         continue;
  75
  76                 if (strcmp(blobmsg_name(cur), name) != 0)
  77                         continue;
  78
  79                 return blobmsg_data(cur);
  80         }
  81
  82         return NULL;
  83 }
  84
  85 static void mkdir_p(char *dir)
  86 {
  87         char *l = strrchr(dir, '/');
  88
  89         if (l) {
  90                 *l = '\0';
  91                 mkdir_p(dir);
  92                 *l = '/';
  93                 mkdir(dir, 0755);
  94         }
  95 }
  96
  97 static void handle_makedev(struct blob_attr *msg, struct blob_attr *data)
  98 {
  99         unsigned int oldumask = umask(0);
 100         static struct blobmsg_policy mkdev_policy[2] = {
 101                 { .type = BLOBMSG_TYPE_STRING },
 102                 { .type = BLOBMSG_TYPE_STRING },
 103         };
 104         struct blob_attr *tb[2];
 105         char *minor = hotplug_msg_find_var(msg, "MINOR");
 106         char *major = hotplug_msg_find_var(msg, "MAJOR");
 107         char *subsystem = hotplug_msg_find_var(msg, "SUBSYSTEM");
 108
 109         blobmsg_parse_array(mkdev_policy, 2, tb, blobmsg_data(data), blobmsg_data_len(data));
 110         if (tb[0] && tb[1] && minor && major && subsystem) {
 111                 mode_t m = S_IFCHR;
 112                 char *d = strdup(blobmsg_get_string(tb[0]));
 113
 114                 d = dirname(d);
 115                 mkdir_p(d);
 116                 free(d);
 117
 118                 if (!strcmp(subsystem, "block"))
 119                         m = S_IFBLK;
 120                 mknod(blobmsg_get_string(tb[0]),
 121                                 m | strtoul(blobmsg_data(tb[1]), NULL, 8),
 122                                 makedev(atoi(major), atoi(minor)));
 123         }
 124         umask(oldumask);
 125 }
 126
 127 static void handle_rm(struct blob_attr *msg, struct blob_attr *data)
 128 {
 129         static struct blobmsg_policy rm_policy = {
 130                 .type = BLOBMSG_TYPE_STRING,
 131         };
 132         struct blob_attr *tb;
 133
 134         blobmsg_parse_array(&rm_policy, 1, &tb, blobmsg_data(data), blobmsg_data_len(data));
 135         if (tb)
 136                 unlink(blobmsg_data(tb));
 137 }
 138
 139 static void handle_exec(struct blob_attr *msg, struct blob_attr *data)
 140 {
 141         char *argv[8];
 142         struct blob_attr *cur;
 143         int rem, fd;
 144         int i = 0;
 145
 146         blobmsg_for_each_attr(cur, msg, rem)
 147                 setenv(blobmsg_name(cur), blobmsg_data(cur), 1);
 148
 149         blobmsg_for_each_attr(cur, data, rem) {
 150                 argv[i] = blobmsg_data(cur);
 151                 i++;
 152                 if (i == 7)
 153                         break;
 154         }
 155
 156         if (debug < 3) {
 157                 fd = open("/dev/null", O_RDWR);
 158                 if (fd > -1) {
 159                         dup2(fd, STDIN_FILENO);
 160                         dup2(fd, STDOUT_FILENO);
 161                         dup2(fd, STDERR_FILENO);
 162                         if (fd > STDERR_FILENO)
 163                                 close(fd);
 164                 }
 165         }
 166
 167         if (i > 0) {
 168                 argv[i] = NULL;
 169                 execvp(argv[0], &argv[0]);
 170         }
 171         exit(-1);
 172 }
 173
 174 static void handle_set_interval_timeout(struct uloop_timeout *timeout)
 175 {
 176         struct cmd_interval *interval = container_of(timeout, struct cmd_interval, timeout);
 177         struct blob_attr *cur;
 178         char *argv[8];
 179         int rem, fd;
 180         int msecs = 0;
 181         int i = 0;
 182
 183         blobmsg_for_each_attr(cur, interval->data, rem) {
 184                 switch (i) {
 185                 case 0:
 186                         break;
 187                 case 1:
 188                         msecs = strtol(blobmsg_get_string(cur), NULL, 0);
 189                         break;
 190                 default:
 191                         argv[i - 2] = blobmsg_data(cur);
 192                 }
 193                 i++;
 194                 if (i - 2 == 7)
 195                         break;
 196         }
 197
 198         if (interval->process.pending) {
 199                 uloop_timeout_set(&interval->timeout, msecs);
 200                 return;
 201         }
 202
 203         interval->process.pid = fork();
 204         if (interval->process.pid < 0) {
 205                 perror("fork");
 206         } else if (interval->process.pid == 0) {
 207                 struct timespec now;
 208                 char elapsed[6];
 209
 210                 if (i - 2 <= 0)
 211                         return;
 212
 213                 clock_gettime(CLOCK_MONOTONIC, &now);
 214                 snprintf(elapsed, sizeof(elapsed), "%ld", now.tv_sec - interval->start.tv_sec);
 215
 216                 blobmsg_for_each_attr(cur, interval->msg, rem)
 217                         setenv(blobmsg_name(cur), blobmsg_data(cur), 1);
 218                 setenv("ACTION", "interval", 1);
 219                 setenv("ELAPSED", elapsed, 1);
 220                 unsetenv("SEEN");
 221
 222                 if (debug < 3) {
 223                         fd = open("/dev/null", O_RDWR);
 224                         if (fd > -1) {
 225                                 dup2(fd, STDIN_FILENO);
 226                                 dup2(fd, STDOUT_FILENO);
 227                                 dup2(fd, STDERR_FILENO);
 228                                 if (fd > STDERR_FILENO)
 229                                         close(fd);
 230                         }
 231                 }
 232
 233                 argv[i - 2] = NULL;
 234                 execvp(argv[0], &argv[0]);
 235                 exit(-1);
 236         } else {
 237                 uloop_process_add(&interval->process);
 238                 uloop_timeout_set(&interval->timeout, msecs);
 239         }
 240 }
 241
 242 static void handle_set_interval_process_cb(struct uloop_process *process, int ret)
 243 {
 244         struct cmd_interval *interval = container_of(process, struct cmd_interval, process);
 245
 246         if (interval->cancelled)
 247                 free(interval);
 248 }
 249
 250 static void handle_set_interval(struct blob_attr *msg, struct blob_attr *data)
 251 {
 252         static struct blobmsg_policy set_interval_policy[2] = {
 253                 { .type = BLOBMSG_TYPE_STRING },
 254                 { .type = BLOBMSG_TYPE_STRING },
 255         };
 256         struct blob_attr *tb[2];
 257         struct cmd_interval *interval;
 258         struct blob_attr *_msg, *_data;
 259         char *_key;
 260         char *name;
 261         int msecs;
 262
 263         blobmsg_parse_array(set_interval_policy, 2, tb, blobmsg_data(data), blobmsg_data_len(data));
 264         if (!tb[0] || !tb[1])
 265                 return;
 266         name = blobmsg_get_string(tb[0]);
 267         msecs = strtol(blobmsg_get_string(tb[1]), NULL, 0);
 268
 269         interval = calloc_a(sizeof(struct cmd_interval),
 270                 &_key, strlen(name) + 1,
 271                 &_msg, blob_pad_len(msg),
 272                 &_data, blob_pad_len(data),
 273                 NULL);
 274         if (!interval)
 275                 return;
 276
 277         strcpy(_key, name);
 278         interval->avl.key = _key;
 279         interval->msg = _msg;
 280         interval->data = _data;
 281         clock_gettime(CLOCK_MONOTONIC, &interval->start);
 282         interval->timeout.cb = handle_set_interval_timeout;
 283         interval->process.cb = handle_set_interval_process_cb;
 284
 285         memcpy(interval->msg, msg, blob_pad_len(msg));
 286         memcpy(interval->data, data, blob_pad_len(data));
 287
 288         avl_insert(&cmd_intervals, &interval->avl);
 289
 290         uloop_timeout_set(&interval->timeout, msecs);
 291 }
 292
 293 static void handle_clear_interval(struct blob_attr *msg, struct blob_attr *data)
 294 {
 295         static struct blobmsg_policy clear_interval_policy = {
 296                 .type = BLOBMSG_TYPE_STRING,
 297         };
 298         struct blob_attr *tb;
 299         struct cmd_interval *interval;
 300         char *name;
 301
 302         blobmsg_parse_array(&clear_interval_policy, 1, &tb, blobmsg_data(data), blobmsg_data_len(data));
 303         if (!tb)
 304                 return;
 305         name = blobmsg_get_string(tb);
 306
 307         interval = avl_find_element(&cmd_intervals, name, interval, avl);
 308         if (interval) {
 309                 uloop_timeout_cancel(&interval->timeout);
 310                 avl_delete(&cmd_intervals, &interval->avl);
 311                 if (interval->process.pending)
 312                         interval->cancelled = true;
 313                 else
 314                         free(interval);
 315         }
 316 }
 317
 318 static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
 319 {
 320         char *dir = blobmsg_get_string(blobmsg_data(data));
 321         char *file = hotplug_msg_find_var(msg, "FIRMWARE");
 322         char *dev = hotplug_msg_find_var(msg, "DEVPATH");
 323         struct stat s = { 0 };
 324         char *path, loadpath[256], syspath[256];
 325         int fw, src, load, len;
 326         static char buf[4096];
 327
 328         DEBUG(2, "Firmware request for %s/%s\n", dir, file);
 329
 330         if (!file || !dir || !dev) {
 331                 ERROR("Request for unknown firmware %s/%s\n", dir, file);
 332                 exit(-1);
 333         }
 334
 335         path = alloca(strlen(dir) + strlen(file) + 2);
 336         sprintf(path, "%s/%s", dir, file);
 337
 338         if (stat(path, &s)) {
 339                 ERROR("Could not find firmware %s\n", path);
 340                 src = -1;
 341                 s.st_size = 0;
 342                 goto send_to_kernel;
 343         }
 344
 345         src = open(path, O_RDONLY);
 346         if (src < 0) {
 347                 ERROR("Failed to open %s\n", path);
 348                 s.st_size = 0;
 349                 goto send_to_kernel;
 350         }
 351
 352 send_to_kernel:
 353         snprintf(loadpath, sizeof(loadpath), "/sys/%s/loading", dev);
 354         load = open(loadpath, O_WRONLY);
 355         if (!load) {
 356                 ERROR("Failed to open %s\n", loadpath);
 357                 exit(-1);
 358         }
 359         if (write(load, "1", 1) == -1) {
 360                 ERROR("Failed to write to %s\n", loadpath);
 361                 exit(-1);
 362         }
 363         close(load);
 364
 365         snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
 366         fw = open(syspath, O_WRONLY);
 367         if (fw < 0) {
 368                 ERROR("Failed to open %s\n", syspath);
 369                 exit(-1);
 370         }
 371
 372         len = s.st_size;
 373         while (len) {
 374                 len = read(src, buf, sizeof(buf));
 375                 if (len <= 0)
 376                         break;
 377
 378                 if (write(fw, buf, len) == -1) {
 379                         ERROR("failed to write firmware file %s/%s to %s\n", dir, file, dev);
 380                         break;
 381                 }
 382         }
 383
 384         if (src >= 0)
 385                 close(src);
 386         close(fw);
 387
 388         load = open(loadpath, O_WRONLY);
 389         if (write(load, "0", 1) == -1)
 390                 ERROR("failed to write to %s\n", loadpath);
 391         close(load);
 392
 393         DEBUG(2, "Done loading %s\n", path);
 394
 395         exit(-1);
 396 }
 397
 398 static struct cmd_handler {
 399         char *name;
 400         int atomic;
 401         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
 402 } handlers[] = {
 403         {
 404                 .name = "makedev",
 405                 .atomic = 1,
 406                 .handler = handle_makedev,
 407         }, {
 408                 .name = "rm",
 409                 .atomic = 1,
 410                 .handler = handle_rm,
 411         }, {
 412                 .name = "exec",
 413                 .handler = handle_exec,
 414         }, {
 415                 .name = "set-interval",
 416                 .atomic = 1,
 417                 .handler = handle_set_interval,
 418         }, {
 419                 .name = "clear-interval",
 420                 .atomic = 1,
 421                 .handler = handle_clear_interval,
 422         }, {
 423                 .name = "load-firmware",
 424                 .handler = handle_firmware,
 425         },
 426 };
 427
 428 static void queue_next(void)
 429 {
 430         struct cmd_queue *c;
 431
 432         if (queue_proc.pending || list_empty(&cmd_queue))
 433                 return;
 434
 435         c = list_first_entry(&cmd_queue, struct cmd_queue, list);
 436
 437         queue_proc.pid = fork();
 438         if (!queue_proc.pid) {
 439                 uloop_done();
 440                 c->handler(c->msg, c->data);
 441                 exit(0);
 442         }
 443
 444         list_del(&c->list);
 445         free(c);
 446
 447         if (queue_proc.pid <= 0) {
 448                 queue_next();
 449                 return;
 450         }
 451
 452         uloop_process_add(&queue_proc);
 453
 454         DEBUG(4, "Launched hotplug exec instance, pid=%d\n", (int) queue_proc.pid);
 455 }
 456
 457 static void queue_proc_cb(struct uloop_process *c, int ret)
 458 {
 459         DEBUG(4, "Finished hotplug exec instance, pid=%d\n", (int) c->pid);
 460
 461         queue_next();
 462 }
 463
 464 static void queue_add(struct cmd_handler *h, struct blob_attr *msg, struct blob_attr *data)
 465 {
 466         struct cmd_queue *c = NULL;
 467         struct blob_attr *_msg, *_data;
 468
 469         c = calloc_a(sizeof(struct cmd_queue),
 470                 &_msg, blob_pad_len(msg),
 471                 &_data, blob_pad_len(data),
 472                 NULL);
 473
 474         c->msg = _msg;
 475         c->data = _data;
 476
 477         if (!c)
 478                 return;
 479
 480         memcpy(c->msg, msg, blob_pad_len(msg));
 481         memcpy(c->data, data, blob_pad_len(data));
 482         c->handler = h->handler;
 483         list_add_tail(&c->list, &cmd_queue);
 484         queue_next();
 485 }
 486
 487 static const char* rule_handle_var(struct json_script_ctx *ctx, const char *name, struct blob_attr *vars)
 488 {
 489         const char *str, *sep;
 490
 491         if (!strcmp(name, "DEVICENAME") || !strcmp(name, "DEVNAME")) {
 492                 str = json_script_find_var(ctx, vars, "DEVPATH");
 493                 if (!str)
 494                         return NULL;
 495
 496                 sep = strrchr(str, '/');
 497                 if (sep)
 498                         return sep + 1;
 499
 500                 return str;
 501         }
 502
 503         return NULL;
 504 }
 505
 506 static struct json_script_file *
 507 rule_handle_file(struct json_script_ctx *ctx, const char *name)
 508 {
 509         json_object *obj;
 510
 511         obj = json_object_from_file((char*)name);
 512         if (!obj)
 513                 return NULL;
 514
 515         blob_buf_init(&script, 0);
 516         blobmsg_add_json_element(&script, "", obj);
 517
 518         return json_script_file_from_blobmsg(name, blob_data(script.head), blob_len(script.head));
 519 }
 520
 521 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 522                                 struct blob_attr *data, struct blob_attr *vars)
 523 {
 524         struct blob_attr *cur;
 525         int rem, i;
 526
 527         if (debug > 3) {
 528                 DEBUG(4, "Command: %s", name);
 529                 blobmsg_for_each_attr(cur, data, rem)
 530                         DEBUG(4, " %s", (char *) blobmsg_data(cur));
 531                 DEBUG(4, "\n");
 532
 533                 DEBUG(4, "Message:");
 534                 blobmsg_for_each_attr(cur, vars, rem)
 535                         DEBUG(4, " %s=%s", blobmsg_name(cur), (char *) blobmsg_data(cur));
 536                 DEBUG(4, "\n");
 537         }
 538
 539         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 540                 if (!strcmp(handlers[i].name, name)) {
 541                         if (handlers[i].atomic)
 542                                 handlers[i].handler(vars, data);
 543                         else
 544                                 queue_add(&handlers[i], vars, data);
 545                         break;
 546                 }
 547
 548         if (last_event.cb)
 549                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 550 }
 551
 552 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 553                                 struct blob_attr *context)
 554 {
 555         char *s;
 556
 557         s = blobmsg_format_json(context, false);
 558         ERROR("ERROR: %s in block: %s\n", msg, s);
 559         free(s);
 560 }
 561
 562 static struct json_script_ctx jctx = {
 563         .handle_var = rule_handle_var,
 564         .handle_error = rule_handle_error,
 565         .handle_command = rule_handle_command,
 566         .handle_file = rule_handle_file,
 567 };
 568
 569 static void hotplug_handler_debug(struct blob_attr *data)
 570 {
 571         char *str;
 572
 573         if (debug < 3)
 574                 return;
 575
 576         str = blobmsg_format_json(data, true);
 577         DEBUG(3, "%s\n", str);
 578         free(str);
 579 }
 580
 581 static void hotplug_handler(struct uloop_fd *u, unsigned int ev)
 582 {
 583         int i = 0;
 584         static char buf[4096];
 585         int len = recv(u->fd, buf, sizeof(buf), MSG_DONTWAIT);
 586         void *index;
 587         if (len < 1)
 588                 return;
 589
 590         blob_buf_init(&b, 0);
 591         index = blobmsg_open_table(&b, NULL);
 592         while (i < len) {
 593                 int l = strlen(buf + i) + 1;
 594                 char *e = strstr(&buf[i], "=");
 595
 596                 if (e) {
 597                         *e = '\0';
 598                         blobmsg_add_string(&b, &buf[i], &e[1]);
 599                 }
 600                 i += l;
 601         }
 602         blobmsg_close_table(&b, index);
 603         hotplug_handler_debug(b.head);
 604         json_script_run(&jctx, rule_file, blob_data(b.head));
 605 }
 606
 607 static struct uloop_fd hotplug_fd = {
 608         .cb = hotplug_handler,
 609 };
 610
 611 void hotplug_last_event(uloop_timeout_handler handler)
 612 {
 613         last_event.cb = handler;
 614         if (handler)
 615                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 616         else
 617                 uloop_timeout_cancel(&last_event);
 618 }
 619
 620 void hotplug(char *rules)
 621 {
 622         struct sockaddr_nl nls;
 623         int nlbufsize = 512 * 1024;
 624
 625         rule_file = strdup(rules);
 626         memset(&nls,0,sizeof(struct sockaddr_nl));
 627         nls.nl_family = AF_NETLINK;
 628         nls.nl_pid = getpid();
 629         nls.nl_groups = -1;
 630
 631         if ((hotplug_fd.fd = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT)) == -1) {
 632                 ERROR("Failed to open hotplug socket: %s\n", strerror(errno));
 633                 exit(1);
 634         }
 635         if (bind(hotplug_fd.fd, (void *)&nls, sizeof(struct sockaddr_nl))) {
 636                 ERROR("Failed to bind hotplug socket: %s\n", strerror(errno));
 637                 exit(1);
 638         }
 639
 640         if (setsockopt(hotplug_fd.fd, SOL_SOCKET, SO_RCVBUFFORCE, &nlbufsize, sizeof(nlbufsize)))
 641                 ERROR("Failed to resize receive buffer: %s\n", strerror(errno));
 642
 643         json_script_init(&jctx);
 644         queue_proc.cb = queue_proc_cb;
 645         uloop_fd_add(&hotplug_fd, ULOOP_READ);
 646 }
 647
 648 int hotplug_run(char *rules)
 649 {
 650         uloop_init();
 651         hotplug(rules);
 652         uloop_run();
 653
 654         return 0;
 655 }
 656
 657 void hotplug_shutdown(void)
 658 {
 659         uloop_fd_delete(&hotplug_fd);
 660         close(hotplug_fd.fd);
 661 }