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