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
  26 #include <fcntl.h>
  27 #include <unistd.h>
  28 #include <stdlib.h>
  29 #include <libgen.h>
  30
  31 #include "../procd.h"
  32
  33 #include "hotplug.h"
  34
  35 #define HOTPLUG_WAIT    500
  36
  37 struct cmd_queue {
  38         struct list_head list;
  39
  40         struct blob_attr *msg;
  41         struct blob_attr *data;
  42         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
  43 };
  44
  45 static LIST_HEAD(cmd_queue);
  46 static struct uloop_process queue_proc;
  47 static struct uloop_timeout last_event;
  48 static struct blob_buf b;
  49 static char *rule_file;
  50 static struct blob_buf script;
  51
  52 static char *hotplug_msg_find_var(struct blob_attr *msg, const char *name)
  53 {
  54         struct blob_attr *cur;
  55         int rem;
  56
  57         blobmsg_for_each_attr(cur, msg, rem) {
  58                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
  59                         continue;
  60
  61                 if (strcmp(blobmsg_name(cur), name) != 0)
  62                         continue;
  63
  64                 return blobmsg_data(cur);
  65         }
  66
  67         return NULL;
  68 }
  69
  70 static void mkdir_p(char *dir)
  71 {
  72         char *l = strrchr(dir, '/');
  73
  74         if (l) {
  75                 *l = '\0';
  76                 mkdir_p(dir);
  77                 *l = '/';
  78                 mkdir(dir, 0755);
  79         }
  80 }
  81
  82 static void handle_makedev(struct blob_attr *msg, struct blob_attr *data)
  83 {
  84         unsigned int oldumask = umask(0);
  85         static struct blobmsg_policy mkdev_policy[2] = {
  86                 { .type = BLOBMSG_TYPE_STRING },
  87                 { .type = BLOBMSG_TYPE_STRING },
  88         };
  89         struct blob_attr *tb[2];
  90         char *minor = hotplug_msg_find_var(msg, "MINOR");
  91         char *major = hotplug_msg_find_var(msg, "MAJOR");
  92         char *subsystem = hotplug_msg_find_var(msg, "SUBSYSTEM");
  93
  94         blobmsg_parse_array(mkdev_policy, 2, tb, blobmsg_data(data), blobmsg_data_len(data));
  95         if (tb[0] && tb[1] && minor && major && subsystem) {
  96                 mode_t m = S_IFCHR;
  97                 char *d = strdup(blobmsg_get_string(tb[0]));
  98
  99                 d = dirname(d);
 100                 mkdir_p(d);
 101                 free(d);
 102
 103                 if (!strcmp(subsystem, "block"))
 104                         m = S_IFBLK;
 105                 mknod(blobmsg_get_string(tb[0]),
 106                                 m | strtoul(blobmsg_data(tb[1]), NULL, 8),
 107                                 makedev(atoi(major), atoi(minor)));
 108         }
 109         umask(oldumask);
 110 }
 111
 112 static void handle_rm(struct blob_attr *msg, struct blob_attr *data)
 113 {
 114         static struct blobmsg_policy rm_policy = {
 115                 .type = BLOBMSG_TYPE_STRING,
 116         };
 117         struct blob_attr *tb;
 118
 119         blobmsg_parse_array(&rm_policy, 1, &tb, blobmsg_data(data), blobmsg_data_len(data));
 120         if (tb)
 121                 unlink(blobmsg_data(tb));
 122 }
 123
 124 static void handle_exec(struct blob_attr *msg, struct blob_attr *data)
 125 {
 126         char *argv[8];
 127         struct blob_attr *cur;
 128         int rem, fd;
 129         int i = 0;
 130
 131         blobmsg_for_each_attr(cur, msg, rem)
 132                 setenv(blobmsg_name(cur), blobmsg_data(cur), 1);
 133
 134         blobmsg_for_each_attr(cur, data, rem) {
 135                 argv[i] = blobmsg_data(cur);
 136                 i++;
 137                 if (i == 7)
 138                         break;
 139         }
 140
 141         if (debug < 3) {
 142                 fd = open("/dev/null", O_RDWR);
 143                 if (fd > -1) {
 144                         dup2(fd, STDIN_FILENO);
 145                         dup2(fd, STDOUT_FILENO);
 146                         dup2(fd, STDERR_FILENO);
 147                         if (fd > STDERR_FILENO)
 148                                 close(fd);
 149                 }
 150         }
 151
 152         if (i > 0) {
 153                 argv[i] = NULL;
 154                 execvp(argv[0], &argv[0]);
 155         }
 156         exit(-1);
 157 }
 158
 159 static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
 160 {
 161         char *dir = blobmsg_get_string(blobmsg_data(data));
 162         char *file = hotplug_msg_find_var(msg, "FIRMWARE");
 163         char *dev = hotplug_msg_find_var(msg, "DEVPATH");
 164         void *fw_data;
 165         struct stat s;
 166         char *path, loadpath[256], syspath[256];
 167         int fw, load, sys, len;
 168
 169         DEBUG(2, "Firmware request for %s/%s\n", dir, file);
 170
 171         if (!file || !dir || !dev) {
 172                 ERROR("Request for unknown firmware %s/%s\n", dir, file);
 173                 exit(-1);
 174         }
 175
 176         path = malloc(strlen(dir) + strlen(file) + 2);
 177         if (!path) {
 178                 ERROR("Failed to allocate memory\n");
 179                 exit(-1);
 180         }
 181         sprintf(path, "%s/%s", dir, file);
 182
 183         if (stat(path, &s)) {
 184                 ERROR("Could not find firmware %s\n", path);
 185                 exit(-1);
 186         }
 187
 188         fw_data = malloc(s.st_size);
 189         if (!fw_data) {
 190                 ERROR("Failed to allocate firmware data memory\n");
 191                 exit(-1);
 192         }
 193
 194         fw = open(path, O_RDONLY);
 195         if (!fw) {
 196                 ERROR("Failed to open %s\n", path);
 197                 exit(-1);
 198         }
 199         if (read(fw, fw_data, s.st_size) != s.st_size) {
 200                 ERROR("Failed to read firmware data\n");
 201                 exit(-1);
 202         }
 203         close(fw);
 204
 205         snprintf(loadpath, sizeof(loadpath), "/sys/%s/loading", dev);
 206         load = open(loadpath, O_WRONLY);
 207         if (!load) {
 208                 ERROR("Failed to open %s\n", loadpath);
 209                 exit(-1);
 210         }
 211         write(load, "1", 1);
 212         close(load);
 213
 214         snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
 215         sys = open(syspath, O_WRONLY);
 216         if (!sys) {
 217                 ERROR("Failed to open %s\n", syspath);
 218                 exit(-1);
 219         }
 220
 221         len = s.st_size;
 222         while (len > 4096) {
 223                 write(fw, fw_data, 4096);
 224                 len -= 4096;
 225         }
 226         if (len)
 227                 write(fw, fw_data, len);
 228         close(fw);
 229
 230         load = open(loadpath, O_WRONLY);
 231         write(load, "0", 1);
 232         close(load);
 233
 234         DEBUG(2, "Done loading %s\n", path);
 235
 236         exit(-1);
 237 }
 238
 239 static struct cmd_handler {
 240         char *name;
 241         int atomic;
 242         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
 243 } handlers[] = {
 244         {
 245                 .name = "makedev",
 246                 .atomic = 1,
 247                 .handler = handle_makedev,
 248         }, {
 249                 .name = "rm",
 250                 .atomic = 1,
 251                 .handler = handle_rm,
 252         }, {
 253                 .name = "exec",
 254                 .handler = handle_exec,
 255         }, {
 256                 .name = "load-firmware",
 257                 .handler = handle_firmware,
 258         },
 259 };
 260
 261 static void queue_next(void)
 262 {
 263         struct cmd_queue *c;
 264
 265         if (queue_proc.pending || list_empty(&cmd_queue))
 266                 return;
 267
 268         c = list_first_entry(&cmd_queue, struct cmd_queue, list);
 269
 270         queue_proc.pid = fork();
 271         if (!queue_proc.pid) {
 272                 uloop_done();
 273                 c->handler(c->msg, c->data);
 274                 exit(0);
 275         }
 276
 277         list_del(&c->list);
 278         free(c);
 279
 280         if (queue_proc.pid <= 0) {
 281                 queue_next();
 282                 return;
 283         }
 284
 285         uloop_process_add(&queue_proc);
 286
 287         DEBUG(4, "Launched hotplug exec instance, pid=%d\n", (int) queue_proc.pid);
 288 }
 289
 290 static void queue_proc_cb(struct uloop_process *c, int ret)
 291 {
 292         DEBUG(4, "Finished hotplug exec instance, pid=%d\n", (int) c->pid);
 293
 294         queue_next();
 295 }
 296
 297 static void queue_add(struct cmd_handler *h, struct blob_attr *msg, struct blob_attr *data)
 298 {
 299         struct cmd_queue *c = NULL;
 300         struct blob_attr *_msg, *_data;
 301
 302         c = calloc_a(sizeof(struct cmd_queue),
 303                 &_msg, blob_pad_len(msg),
 304                 &_data, blob_pad_len(data),
 305                 NULL);
 306
 307         c->msg = _msg;
 308         c->data = _data;
 309
 310         if (!c)
 311                 return;
 312
 313         memcpy(c->msg, msg, blob_pad_len(msg));
 314         memcpy(c->data, data, blob_pad_len(data));
 315         c->handler = h->handler;
 316         list_add_tail(&c->list, &cmd_queue);
 317         queue_next();
 318 }
 319
 320 static const char* rule_handle_var(struct json_script_ctx *ctx, const char *name, struct blob_attr *vars)
 321 {
 322         const char *str, *sep;
 323
 324         if (!strcmp(name, "DEVICENAME") || !strcmp(name, "DEVNAME")) {
 325                 str = json_script_find_var(ctx, vars, "DEVPATH");
 326                 if (!str)
 327                         return NULL;
 328
 329                 sep = strrchr(str, '/');
 330                 if (sep)
 331                         return sep + 1;
 332
 333                 return str;
 334         }
 335
 336         return NULL;
 337 }
 338
 339 static struct json_script_file *
 340 rule_handle_file(struct json_script_ctx *ctx, const char *name)
 341 {
 342         json_object *obj;
 343
 344         obj = json_object_from_file((char*)name);
 345         if (is_error(obj))
 346                 return NULL;
 347
 348         blob_buf_init(&script, 0);
 349         blobmsg_add_json_element(&script, "", obj);
 350
 351         return json_script_file_from_blobmsg(name, blob_data(script.head), blob_len(script.head));
 352 }
 353
 354 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 355                                 struct blob_attr *data, struct blob_attr *vars)
 356 {
 357         struct blob_attr *cur;
 358         int rem, i;
 359
 360         if (debug > 3) {
 361                 DEBUG(4, "Command: %s", name);
 362                 blobmsg_for_each_attr(cur, data, rem)
 363                         DEBUG(4, " %s", (char *) blobmsg_data(cur));
 364                 DEBUG(4, "\n");
 365
 366                 DEBUG(4, "Message:");
 367                 blobmsg_for_each_attr(cur, vars, rem)
 368                         DEBUG(4, " %s=%s", blobmsg_name(cur), (char *) blobmsg_data(cur));
 369                 DEBUG(4, "\n");
 370         }
 371
 372         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 373                 if (!strcmp(handlers[i].name, name)) {
 374                         if (handlers[i].atomic)
 375                                 handlers[i].handler(vars, data);
 376                         else
 377                                 queue_add(&handlers[i], vars, data);
 378                         break;
 379                 }
 380
 381         if (last_event.cb)
 382                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 383 }
 384
 385 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 386                                 struct blob_attr *context)
 387 {
 388         char *s;
 389
 390         s = blobmsg_format_json(context, false);
 391         ERROR("ERROR: %s in block: %s\n", msg, s);
 392         free(s);
 393 }
 394
 395 static struct json_script_ctx jctx = {
 396         .handle_var = rule_handle_var,
 397         .handle_error = rule_handle_error,
 398         .handle_command = rule_handle_command,
 399         .handle_file = rule_handle_file,
 400 };
 401
 402 static void hotplug_handler_debug(struct blob_attr *data)
 403 {
 404         char *str;
 405
 406         if (debug < 3)
 407                 return;
 408
 409         str = blobmsg_format_json(data, true);
 410         DEBUG(3, "%s\n", str);
 411         free(str);
 412 }
 413
 414 static void hotplug_handler(struct uloop_fd *u, unsigned int ev)
 415 {
 416         int i = 0;
 417         static char buf[4096];
 418         int len = recv(u->fd, buf, sizeof(buf), MSG_DONTWAIT);
 419         void *index;
 420         if (len < 1)
 421                 return;
 422
 423         blob_buf_init(&b, 0);
 424         index = blobmsg_open_table(&b, NULL);
 425         while (i < len) {
 426                 int l = strlen(buf + i) + 1;
 427                 char *e = strstr(&buf[i], "=");
 428
 429                 if (e) {
 430                         *e = '\0';
 431                         blobmsg_add_string(&b, &buf[i], &e[1]);
 432                 }
 433                 i += l;
 434         }
 435         blobmsg_close_table(&b, index);
 436         hotplug_handler_debug(b.head);
 437         json_script_run(&jctx, rule_file, blob_data(b.head));
 438 }
 439
 440 static struct uloop_fd hotplug_fd = {
 441         .cb = hotplug_handler,
 442 };
 443
 444 void hotplug_last_event(uloop_timeout_handler handler)
 445 {
 446         last_event.cb = handler;
 447         if (handler)
 448                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 449         else
 450                 uloop_timeout_cancel(&last_event);
 451 }
 452
 453 void hotplug(char *rules)
 454 {
 455         struct sockaddr_nl nls;
 456
 457         rule_file = strdup(rules);
 458         memset(&nls,0,sizeof(struct sockaddr_nl));
 459         nls.nl_family = AF_NETLINK;
 460         nls.nl_pid = getpid();
 461         nls.nl_groups = -1;
 462
 463         if ((hotplug_fd.fd = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT)) == -1) {
 464                 ERROR("Failed to open hotplug socket: %s\n", strerror(errno));
 465                 exit(1);
 466         }
 467         if (bind(hotplug_fd.fd, (void *)&nls, sizeof(struct sockaddr_nl))) {
 468                 ERROR("Failed to bind hotplug socket: %s\n", strerror(errno));
 469                 exit(1);
 470         }
 471
 472         json_script_init(&jctx);
 473         queue_proc.cb = queue_proc_cb;
 474         uloop_fd_add(&hotplug_fd, ULOOP_READ);
 475 }
 476
 477 int hotplug_run(char *rules)
 478 {
 479         uloop_init();
 480         hotplug(rules);
 481         uloop_run();
 482
 483         return 0;
 484 }
 485
 486 void hotplug_shutdown(void)
 487 {
 488         uloop_fd_delete(&hotplug_fd);
 489         close(hotplug_fd.fd);
 490 }