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