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