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