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