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 #include <sys/sysmacros.h>
  19
  20 #include <linux/types.h>
  21 #include <linux/netlink.h>
  22
  23 #include <libubox/blobmsg_json.h>
  24 #include <libubox/json_script.h>
  25 #include <libubox/uloop.h>
  26 #include <libubox/utils.h>
  27 #include <json-c/json.h>
  28
  29 #include <errno.h>
  30 #include <fcntl.h>
  31 #include <unistd.h>
  32 #include <stdlib.h>
  33 #include <libgen.h>
  34 #include <grp.h>
  35
  36 #include "../procd.h"
  37
  38 #include "hotplug.h"
  39
  40 #define HOTPLUG_WAIT    500
  41
  42 struct cmd_handler;
  43 struct cmd_queue {
  44         struct list_head list;
  45
  46         struct blob_attr *msg;
  47         struct blob_attr *data;
  48         int timeout;
  49
  50         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
  51         void (*start)(struct blob_attr *msg, struct blob_attr *data);
  52         void (*complete)(struct blob_attr *msg, struct blob_attr *data, int ret);
  53 };
  54
  55 struct button_timeout {
  56         struct list_head list;
  57         struct uloop_timeout timeout;
  58         char *name;
  59         int seen;
  60         struct blob_attr *data;
  61 };
  62
  63 static LIST_HEAD(cmd_queue);
  64 static LIST_HEAD(button_timer);
  65 static struct uloop_process queue_proc;
  66 static struct uloop_timeout last_event;
  67 static struct blob_buf b, button_buf;
  68 static char *rule_file;
  69 static struct blob_buf script;
  70 static struct cmd_queue *current;
  71
  72 static void queue_add(struct cmd_handler *h, struct blob_attr *msg, struct blob_attr *data);
  73 static void handle_button_complete(struct blob_attr *msg, struct blob_attr *data, int ret);
  74
  75 static void button_free(struct button_timeout *b)
  76 {
  77         uloop_timeout_cancel(&b->timeout);
  78         list_del(&b->list);
  79         free(b->data);
  80         free(b->name);
  81         free(b);
  82 }
  83
  84 static void button_timeout_remove(char *button)
  85 {
  86         struct button_timeout *b, *c;
  87
  88         if (!list_empty(&button_timer)) list_for_each_entry_safe(b, c, &button_timer, list) {
  89                 if (!strcmp(b->name, button))
  90                         button_free(b);
  91         }
  92 }
  93
  94 static char *hotplug_msg_find_var(struct blob_attr *msg, const char *name)
  95 {
  96         struct blob_attr *cur;
  97         int rem;
  98
  99         blobmsg_for_each_attr(cur, msg, rem) {
 100                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
 101                         continue;
 102
 103                 if (strcmp(blobmsg_name(cur), name) != 0)
 104                         continue;
 105
 106                 return blobmsg_data(cur);
 107         }
 108
 109         return NULL;
 110 }
 111
 112 static void chgrp_error(const char *group, const char *target, const char *failed)
 113 {
 114         ERROR("cannot set group %s for %s (%s: %d)\n",
 115                group, target, failed, errno);
 116 }
 117
 118 static void chgrp_target(struct blob_attr *bgroup, struct blob_attr *btarget)
 119 {
 120         int ret = 0;
 121         struct group *g = NULL;
 122         const char *group = blobmsg_get_string(bgroup);
 123         const char *target = blobmsg_get_string(btarget);
 124
 125         errno = 0;
 126
 127         g = getgrnam(group);
 128         if (!g)
 129                 return chgrp_error(group, target, "getgrnam");
 130
 131         ret = chown(target, 0, g->gr_gid);
 132         if (ret < 0)
 133                 return chgrp_error(group, target, "chown");
 134 }
 135
 136 static void handle_makedev(struct blob_attr *msg, struct blob_attr *data)
 137 {
 138         unsigned int oldumask = umask(0);
 139         static struct blobmsg_policy mkdev_policy[3] = {
 140                 { .type = BLOBMSG_TYPE_STRING },
 141                 { .type = BLOBMSG_TYPE_STRING },
 142                 { .type = BLOBMSG_TYPE_STRING },
 143         };
 144         struct blob_attr *tb[3];
 145         char *minor = hotplug_msg_find_var(msg, "MINOR");
 146         char *major = hotplug_msg_find_var(msg, "MAJOR");
 147         char *subsystem = hotplug_msg_find_var(msg, "SUBSYSTEM");
 148
 149         blobmsg_parse_array(mkdev_policy, 3, tb, blobmsg_data(data), blobmsg_data_len(data));
 150         if (tb[0] && tb[1] && minor && major && subsystem) {
 151                 mode_t m = S_IFCHR;
 152                 char *d = strdup(blobmsg_get_string(tb[0]));
 153
 154                 d = dirname(d);
 155                 mkdir_p(d, 0755);
 156                 free(d);
 157
 158                 if (!strcmp(subsystem, "block"))
 159                         m = S_IFBLK;
 160                 mknod(blobmsg_get_string(tb[0]),
 161                                 m | strtoul(blobmsg_data(tb[1]), NULL, 8),
 162                                 makedev(atoi(major), atoi(minor)));
 163                 if (tb[2])
 164                         chgrp_target(tb[2], tb[0]);
 165         }
 166         umask(oldumask);
 167 }
 168
 169 static void handle_rm(struct blob_attr *msg, struct blob_attr *data)
 170 {
 171         static struct blobmsg_policy rm_policy = {
 172                 .type = BLOBMSG_TYPE_STRING,
 173         };
 174         struct blob_attr *tb;
 175
 176         blobmsg_parse_array(&rm_policy, 1, &tb, blobmsg_data(data), blobmsg_data_len(data));
 177         if (tb)
 178                 unlink(blobmsg_data(tb));
 179 }
 180
 181 static void handle_exec(struct blob_attr *msg, struct blob_attr *data)
 182 {
 183         char *argv[8];
 184         struct blob_attr *cur;
 185         int rem, fd;
 186         int i = 0;
 187
 188         blobmsg_for_each_attr(cur, msg, rem)
 189                 setenv(blobmsg_name(cur), blobmsg_data(cur), 1);
 190
 191         blobmsg_for_each_attr(cur, data, rem) {
 192                 argv[i] = blobmsg_data(cur);
 193                 i++;
 194                 if (i == 7)
 195                         break;
 196         }
 197
 198         if (debug < 3) {
 199                 fd = open("/dev/null", O_RDWR);
 200                 if (fd > -1) {
 201                         dup2(fd, STDIN_FILENO);
 202                         dup2(fd, STDOUT_FILENO);
 203                         dup2(fd, STDERR_FILENO);
 204                         if (fd > STDERR_FILENO)
 205                                 close(fd);
 206                 }
 207         }
 208
 209         if (i > 0) {
 210                 argv[i] = NULL;
 211                 execvp(argv[0], &argv[0]);
 212         }
 213         exit(EXIT_FAILURE);
 214 }
 215
 216 static void handle_button_start(struct blob_attr *msg, struct blob_attr *data)
 217 {
 218         char *button = hotplug_msg_find_var(msg, "BUTTON");
 219
 220         if (button)
 221                 button_timeout_remove(button);
 222 }
 223
 224 static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
 225 {
 226         char *dir = blobmsg_get_string(blobmsg_data(data));
 227         char *file = hotplug_msg_find_var(msg, "FIRMWARE");
 228         char *dev = hotplug_msg_find_var(msg, "DEVPATH");
 229         struct stat s = { 0 };
 230         char *path, loadpath[256], syspath[256];
 231         int fw, src, load, len;
 232         static char buf[4096];
 233
 234         P_DEBUG(2, "Firmware request for %s/%s\n", dir, file);
 235
 236         if (!file || !dir || !dev) {
 237                 ERROR("Request for unknown firmware %s/%s\n", dir, file);
 238                 exit(EXIT_FAILURE);
 239         }
 240
 241         path = alloca(strlen(dir) + strlen(file) + 2);
 242         sprintf(path, "%s/%s", dir, file);
 243
 244         if (stat(path, &s)) {
 245                 ERROR("Could not find firmware %s: %m\n", path);
 246                 src = -1;
 247                 s.st_size = 0;
 248                 goto send_to_kernel;
 249         }
 250
 251         src = open(path, O_RDONLY);
 252         if (src < 0) {
 253                 ERROR("Failed to open %s: %m\n", path);
 254                 s.st_size = 0;
 255                 goto send_to_kernel;
 256         }
 257
 258 send_to_kernel:
 259         snprintf(loadpath, sizeof(loadpath), "/sys/%s/loading", dev);
 260         load = open(loadpath, O_WRONLY);
 261         if (!load) {
 262                 ERROR("Failed to open %s: %m\n", loadpath);
 263                 exit(EXIT_FAILURE);
 264         }
 265         if (write(load, "1", 1) == -1) {
 266                 ERROR("Failed to write to %s: %m\n", loadpath);
 267                 exit(EXIT_FAILURE);
 268         }
 269         close(load);
 270
 271         snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
 272         fw = open(syspath, O_WRONLY);
 273         if (fw < 0) {
 274                 ERROR("Failed to open %s: %m\n", syspath);
 275                 exit(EXIT_FAILURE);
 276         }
 277
 278         len = s.st_size;
 279         while (len) {
 280                 len = read(src, buf, sizeof(buf));
 281                 if (len <= 0)
 282                         break;
 283
 284                 if (write(fw, buf, len) == -1) {
 285                         ERROR("failed to write firmware file %s/%s to %s: %m\n", dir, file, dev);
 286                         break;
 287                 }
 288         }
 289
 290         if (src >= 0)
 291                 close(src);
 292         close(fw);
 293
 294         load = open(loadpath, O_WRONLY);
 295         if (write(load, "0", 1) == -1)
 296                 ERROR("failed to write to %s: %m\n", loadpath);
 297         close(load);
 298
 299         P_DEBUG(2, "Done loading %s\n", path);
 300
 301         exit(EXIT_FAILURE);
 302 }
 303
 304 static void handle_start_console(struct blob_attr *msg, struct blob_attr *data)
 305 {
 306         char *dev = blobmsg_get_string(blobmsg_data(data));
 307
 308         P_DEBUG(2, "Start console request for %s\n", dev);
 309
 310         procd_inittab_run("respawn");
 311         procd_inittab_run("askfirst");
 312
 313         P_DEBUG(2, "Done starting console for %s\n", dev);
 314
 315         exit(EXIT_FAILURE);
 316 }
 317
 318 enum {
 319         HANDLER_MKDEV = 0,
 320         HANDLER_RM,
 321         HANDLER_EXEC,
 322         HANDLER_BUTTON,
 323         HANDLER_FW,
 324         HANDLER_START_CONSOLE,
 325 };
 326
 327 static struct cmd_handler {
 328         char *name;
 329         int atomic;
 330         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
 331         void (*start)(struct blob_attr *msg, struct blob_attr *data);
 332         void (*complete)(struct blob_attr *msg, struct blob_attr *data, int ret);
 333 } handlers[] = {
 334         [HANDLER_MKDEV] = {
 335                 .name = "makedev",
 336                 .atomic = 1,
 337                 .handler = handle_makedev,
 338         },
 339         [HANDLER_RM] = {
 340                 .name = "rm",
 341                 .atomic = 1,
 342                 .handler = handle_rm,
 343         },
 344         [HANDLER_EXEC] = {
 345                 .name = "exec",
 346                 .handler = handle_exec,
 347         },
 348         [HANDLER_BUTTON] = {
 349                 .name = "button",
 350                 .handler = handle_exec,
 351                 .start = handle_button_start,
 352                 .complete = handle_button_complete,
 353         },
 354         [HANDLER_FW] = {
 355                 .name = "load-firmware",
 356                 .handler = handle_firmware,
 357         },
 358         [HANDLER_START_CONSOLE] = {
 359                 .name = "start-console",
 360                 .handler = handle_start_console,
 361         },
 362 };
 363
 364 static void queue_next(void)
 365 {
 366         struct cmd_queue *c;
 367
 368         if (queue_proc.pending || list_empty(&cmd_queue))
 369                 return;
 370
 371         c = list_first_entry(&cmd_queue, struct cmd_queue, list);
 372
 373         queue_proc.pid = fork();
 374         if (!queue_proc.pid) {
 375                 uloop_done();
 376                 c->handler(c->msg, c->data);
 377                 exit(0);
 378         }
 379         if (c->start)
 380                 c->start(c->msg, c->data);
 381         list_del(&c->list);
 382         if (c->complete)
 383                 current = c;
 384         else
 385                 free(c);
 386         if (queue_proc.pid <= 0) {
 387                 queue_next();
 388                 return;
 389         }
 390
 391         uloop_process_add(&queue_proc);
 392
 393         P_DEBUG(4, "Launched hotplug exec instance, pid=%d\n", (int) queue_proc.pid);
 394 }
 395
 396 static void queue_proc_cb(struct uloop_process *c, int ret)
 397 {
 398         P_DEBUG(4, "Finished hotplug exec instance, pid=%d\n", (int) c->pid);
 399
 400         if (current) {
 401                 current->complete(current->msg, current->data, ret);
 402                 free(current);
 403                 current = NULL;
 404         }
 405         queue_next();
 406 }
 407
 408 static void queue_add(struct cmd_handler *h, struct blob_attr *msg, struct blob_attr *data)
 409 {
 410         struct cmd_queue *c = NULL;
 411         struct blob_attr *_msg, *_data;
 412
 413         c = calloc_a(sizeof(struct cmd_queue),
 414                 &_msg, blob_pad_len(msg),
 415                 &_data, blob_pad_len(data),
 416                 NULL);
 417
 418         if (!c)
 419                 return;
 420
 421         c->msg = _msg;
 422         c->data = _data;
 423
 424         memcpy(c->msg, msg, blob_pad_len(msg));
 425         memcpy(c->data, data, blob_pad_len(data));
 426         c->handler = h->handler;
 427         c->complete = h->complete;
 428         c->start = h->start;
 429         list_add_tail(&c->list, &cmd_queue);
 430         queue_next();
 431 }
 432
 433 static void handle_button_timeout(struct uloop_timeout *t)
 434 {
 435         struct button_timeout *b;
 436         char seen[16];
 437
 438         b = container_of(t, struct button_timeout, timeout);
 439         blob_buf_init(&button_buf, 0);
 440         blobmsg_add_string(&button_buf, "BUTTON", b->name);
 441         blobmsg_add_string(&button_buf, "ACTION", "timeout");
 442         snprintf(seen, sizeof(seen), "%d", b->seen);
 443         blobmsg_add_string(&button_buf, "SEEN", seen);
 444         queue_add(&handlers[HANDLER_EXEC], button_buf.head, b->data);
 445         button_free(b);
 446 }
 447
 448 static void handle_button_complete(struct blob_attr *msg, struct blob_attr *data, int ret)
 449 {
 450         char *name = hotplug_msg_find_var(msg, "BUTTON");
 451         struct button_timeout *b;
 452         int timeout = ret >> 8;
 453
 454         if (!timeout)
 455                 return;
 456
 457         if (!name)
 458                 return;
 459
 460         b = calloc(1, sizeof(*b));
 461         if (!b)
 462                 return;
 463
 464         b->data = malloc(blob_pad_len(data));
 465         b->name = strdup(name);
 466         b->seen = timeout;
 467
 468         memcpy(b->data, data, blob_pad_len(data));
 469         b->timeout.cb = handle_button_timeout;
 470
 471         uloop_timeout_set(&b->timeout, timeout * 1000);
 472         list_add(&b->list, &button_timer);
 473 }
 474
 475 static const char* rule_handle_var(struct json_script_ctx *ctx, const char *name, struct blob_attr *vars)
 476 {
 477         const char *str, *sep;
 478
 479         if (!strcmp(name, "DEVICENAME") || !strcmp(name, "DEVNAME")) {
 480                 str = json_script_find_var(ctx, vars, "DEVPATH");
 481                 if (!str)
 482                         return NULL;
 483
 484                 sep = strrchr(str, '/');
 485                 if (sep)
 486                         return sep + 1;
 487
 488                 return str;
 489         }
 490
 491         return NULL;
 492 }
 493
 494 static struct json_script_file *
 495 rule_handle_file(struct json_script_ctx *ctx, const char *name)
 496 {
 497         json_object *obj;
 498
 499         obj = json_object_from_file((char*)name);
 500         if (!obj)
 501                 return NULL;
 502
 503         blob_buf_init(&script, 0);
 504         blobmsg_add_json_element(&script, "", obj);
 505
 506         return json_script_file_from_blobmsg(name, blob_data(script.head), blob_len(script.head));
 507 }
 508
 509 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 510                                 struct blob_attr *data, struct blob_attr *vars)
 511 {
 512         struct blob_attr *cur;
 513         int rem, i;
 514
 515         if (debug > 3) {
 516                 P_DEBUG(4, "Command: %s\n", name);
 517                 blobmsg_for_each_attr(cur, data, rem)
 518                         P_DEBUG(4, " %s\n", (char *) blobmsg_data(cur));
 519
 520                 P_DEBUG(4, "Message:\n");
 521                 blobmsg_for_each_attr(cur, vars, rem)
 522                         P_DEBUG(4, " %s=%s\n", blobmsg_name(cur), (char *) blobmsg_data(cur));
 523         }
 524
 525         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 526                 if (!strcmp(handlers[i].name, name)) {
 527                         if (handlers[i].atomic)
 528                                 handlers[i].handler(vars, data);
 529                         else
 530                                 queue_add(&handlers[i], vars, data);
 531                         break;
 532                 }
 533
 534         if (last_event.cb)
 535                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 536 }
 537
 538 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 539                                 struct blob_attr *context)
 540 {
 541         char *s;
 542
 543         s = blobmsg_format_json(context, false);
 544         ERROR("ERROR: %s in block: %s\n", msg, s);
 545         free(s);
 546 }
 547
 548 static struct json_script_ctx jctx = {
 549         .handle_var = rule_handle_var,
 550         .handle_error = rule_handle_error,
 551         .handle_command = rule_handle_command,
 552         .handle_file = rule_handle_file,
 553 };
 554
 555 static void hotplug_handler_debug(struct blob_attr *data)
 556 {
 557         char *str;
 558
 559         if (debug < 3)
 560                 return;
 561
 562         str = blobmsg_format_json(data, true);
 563         P_DEBUG(3, "%s\n", str);
 564         free(str);
 565 }
 566
 567 static void hotplug_handler(struct uloop_fd *u, unsigned int ev)
 568 {
 569         int i = 0;
 570         static char buf[4096];
 571         int len = recv(u->fd, buf, sizeof(buf) - 1, MSG_DONTWAIT);
 572         void *index;
 573         if (len < 1)
 574                 return;
 575
 576         buf[len] = '\0';
 577
 578         blob_buf_init(&b, 0);
 579         index = blobmsg_open_table(&b, NULL);
 580         while (i < len) {
 581                 int l = strlen(buf + i) + 1;
 582                 char *e = strstr(&buf[i], "=");
 583
 584                 if (e) {
 585                         *e = '\0';
 586                         blobmsg_add_string(&b, &buf[i], &e[1]);
 587                 }
 588                 i += l;
 589         }
 590         blobmsg_close_table(&b, index);
 591         hotplug_handler_debug(b.head);
 592         json_script_run(&jctx, rule_file, blob_data(b.head));
 593 }
 594
 595 static struct uloop_fd hotplug_fd = {
 596         .cb = hotplug_handler,
 597 };
 598
 599 void hotplug_last_event(uloop_timeout_handler handler)
 600 {
 601         last_event.cb = handler;
 602         if (handler)
 603                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 604         else
 605                 uloop_timeout_cancel(&last_event);
 606 }
 607
 608 void hotplug(char *rules)
 609 {
 610         struct sockaddr_nl nls = {};
 611         int nlbufsize = 512 * 1024;
 612
 613         rule_file = strdup(rules);
 614         nls.nl_family = AF_NETLINK;
 615         nls.nl_pid = 0;
 616         nls.nl_groups = -1;
 617
 618         if ((hotplug_fd.fd = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT)) == -1) {
 619                 ERROR("Failed to open hotplug socket: %m\n");
 620                 exit(1);
 621         }
 622         if (bind(hotplug_fd.fd, (void *)&nls, sizeof(struct sockaddr_nl))) {
 623                 ERROR("Failed to bind hotplug socket: %m\n");
 624                 exit(1);
 625         }
 626
 627         if (setsockopt(hotplug_fd.fd, SOL_SOCKET, SO_RCVBUFFORCE, &nlbufsize, sizeof(nlbufsize)))
 628                 ERROR("Failed to resize receive buffer: %m\n");
 629
 630         json_script_init(&jctx);
 631         queue_proc.cb = queue_proc_cb;
 632         uloop_fd_add(&hotplug_fd, ULOOP_READ);
 633 }
 634
 635 int hotplug_run(char *rules)
 636 {
 637         uloop_init();
 638         hotplug(rules);
 639         uloop_run();
 640
 641         return 0;
 642 }
 643
 644 void hotplug_shutdown(void)
 645 {
 646         uloop_fd_delete(&hotplug_fd);
 647         close(hotplug_fd.fd);
 648 }