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         struct stat s = { 0 };
 165         char *path, loadpath[256], syspath[256];
 166         int fw, src, load, len;
 167         static char buf[4096];
 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 = alloca(strlen(dir) + strlen(file) + 2);
 177         sprintf(path, "%s/%s", dir, file);
 178
 179         if (stat(path, &s)) {
 180                 ERROR("Could not find firmware %s\n", path);
 181                 src = -1;
 182                 s.st_size = 0;
 183                 goto send_to_kernel;
 184         }
 185
 186         src = open(path, O_RDONLY);
 187         if (src < 0) {
 188                 ERROR("Failed to open %s\n", path);
 189                 s.st_size = 0;
 190                 goto send_to_kernel;
 191         }
 192
 193 send_to_kernel:
 194         snprintf(loadpath, sizeof(loadpath), "/sys/%s/loading", dev);
 195         load = open(loadpath, O_WRONLY);
 196         if (!load) {
 197                 ERROR("Failed to open %s\n", loadpath);
 198                 exit(-1);
 199         }
 200         write(load, "1", 1);
 201         close(load);
 202
 203         snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
 204         fw = open(syspath, O_WRONLY);
 205         if (fw < 0) {
 206                 ERROR("Failed to open %s\n", syspath);
 207                 exit(-1);
 208         }
 209
 210         len = s.st_size;
 211         while (len) {
 212                 len = read(src, buf, sizeof(buf));
 213                 if (len <= 0)
 214                         break;
 215
 216                 write(fw, buf, len);
 217         }
 218
 219         if (src >= 0)
 220                 close(src);
 221         close(fw);
 222
 223         load = open(loadpath, O_WRONLY);
 224         write(load, "0", 1);
 225         close(load);
 226
 227         DEBUG(2, "Done loading %s\n", path);
 228
 229         exit(-1);
 230 }
 231
 232 static struct cmd_handler {
 233         char *name;
 234         int atomic;
 235         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
 236 } handlers[] = {
 237         {
 238                 .name = "makedev",
 239                 .atomic = 1,
 240                 .handler = handle_makedev,
 241         }, {
 242                 .name = "rm",
 243                 .atomic = 1,
 244                 .handler = handle_rm,
 245         }, {
 246                 .name = "exec",
 247                 .handler = handle_exec,
 248         }, {
 249                 .name = "load-firmware",
 250                 .handler = handle_firmware,
 251         },
 252 };
 253
 254 static void queue_next(void)
 255 {
 256         struct cmd_queue *c;
 257
 258         if (queue_proc.pending || list_empty(&cmd_queue))
 259                 return;
 260
 261         c = list_first_entry(&cmd_queue, struct cmd_queue, list);
 262
 263         queue_proc.pid = fork();
 264         if (!queue_proc.pid) {
 265                 uloop_done();
 266                 c->handler(c->msg, c->data);
 267                 exit(0);
 268         }
 269
 270         list_del(&c->list);
 271         free(c);
 272
 273         if (queue_proc.pid <= 0) {
 274                 queue_next();
 275                 return;
 276         }
 277
 278         uloop_process_add(&queue_proc);
 279
 280         DEBUG(4, "Launched hotplug exec instance, pid=%d\n", (int) queue_proc.pid);
 281 }
 282
 283 static void queue_proc_cb(struct uloop_process *c, int ret)
 284 {
 285         DEBUG(4, "Finished hotplug exec instance, pid=%d\n", (int) c->pid);
 286
 287         queue_next();
 288 }
 289
 290 static void queue_add(struct cmd_handler *h, struct blob_attr *msg, struct blob_attr *data)
 291 {
 292         struct cmd_queue *c = NULL;
 293         struct blob_attr *_msg, *_data;
 294
 295         c = calloc_a(sizeof(struct cmd_queue),
 296                 &_msg, blob_pad_len(msg),
 297                 &_data, blob_pad_len(data),
 298                 NULL);
 299
 300         c->msg = _msg;
 301         c->data = _data;
 302
 303         if (!c)
 304                 return;
 305
 306         memcpy(c->msg, msg, blob_pad_len(msg));
 307         memcpy(c->data, data, blob_pad_len(data));
 308         c->handler = h->handler;
 309         list_add_tail(&c->list, &cmd_queue);
 310         queue_next();
 311 }
 312
 313 static const char* rule_handle_var(struct json_script_ctx *ctx, const char *name, struct blob_attr *vars)
 314 {
 315         const char *str, *sep;
 316
 317         if (!strcmp(name, "DEVICENAME") || !strcmp(name, "DEVNAME")) {
 318                 str = json_script_find_var(ctx, vars, "DEVPATH");
 319                 if (!str)
 320                         return NULL;
 321
 322                 sep = strrchr(str, '/');
 323                 if (sep)
 324                         return sep + 1;
 325
 326                 return str;
 327         }
 328
 329         return NULL;
 330 }
 331
 332 static struct json_script_file *
 333 rule_handle_file(struct json_script_ctx *ctx, const char *name)
 334 {
 335         json_object *obj;
 336
 337         obj = json_object_from_file((char*)name);
 338         if (is_error(obj))
 339                 return NULL;
 340
 341         blob_buf_init(&script, 0);
 342         blobmsg_add_json_element(&script, "", obj);
 343
 344         return json_script_file_from_blobmsg(name, blob_data(script.head), blob_len(script.head));
 345 }
 346
 347 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 348                                 struct blob_attr *data, struct blob_attr *vars)
 349 {
 350         struct blob_attr *cur;
 351         int rem, i;
 352
 353         if (debug > 3) {
 354                 DEBUG(4, "Command: %s", name);
 355                 blobmsg_for_each_attr(cur, data, rem)
 356                         DEBUG(4, " %s", (char *) blobmsg_data(cur));
 357                 DEBUG(4, "\n");
 358
 359                 DEBUG(4, "Message:");
 360                 blobmsg_for_each_attr(cur, vars, rem)
 361                         DEBUG(4, " %s=%s", blobmsg_name(cur), (char *) blobmsg_data(cur));
 362                 DEBUG(4, "\n");
 363         }
 364
 365         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 366                 if (!strcmp(handlers[i].name, name)) {
 367                         if (handlers[i].atomic)
 368                                 handlers[i].handler(vars, data);
 369                         else
 370                                 queue_add(&handlers[i], vars, data);
 371                         break;
 372                 }
 373
 374         if (last_event.cb)
 375                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 376 }
 377
 378 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 379                                 struct blob_attr *context)
 380 {
 381         char *s;
 382
 383         s = blobmsg_format_json(context, false);
 384         ERROR("ERROR: %s in block: %s\n", msg, s);
 385         free(s);
 386 }
 387
 388 static struct json_script_ctx jctx = {
 389         .handle_var = rule_handle_var,
 390         .handle_error = rule_handle_error,
 391         .handle_command = rule_handle_command,
 392         .handle_file = rule_handle_file,
 393 };
 394
 395 static void hotplug_handler_debug(struct blob_attr *data)
 396 {
 397         char *str;
 398
 399         if (debug < 3)
 400                 return;
 401
 402         str = blobmsg_format_json(data, true);
 403         DEBUG(3, "%s\n", str);
 404         free(str);
 405 }
 406
 407 static void hotplug_handler(struct uloop_fd *u, unsigned int ev)
 408 {
 409         int i = 0;
 410         static char buf[4096];
 411         int len = recv(u->fd, buf, sizeof(buf), MSG_DONTWAIT);
 412         void *index;
 413         if (len < 1)
 414                 return;
 415
 416         blob_buf_init(&b, 0);
 417         index = blobmsg_open_table(&b, NULL);
 418         while (i < len) {
 419                 int l = strlen(buf + i) + 1;
 420                 char *e = strstr(&buf[i], "=");
 421
 422                 if (e) {
 423                         *e = '\0';
 424                         blobmsg_add_string(&b, &buf[i], &e[1]);
 425                 }
 426                 i += l;
 427         }
 428         blobmsg_close_table(&b, index);
 429         hotplug_handler_debug(b.head);
 430         json_script_run(&jctx, rule_file, blob_data(b.head));
 431 }
 432
 433 static struct uloop_fd hotplug_fd = {
 434         .cb = hotplug_handler,
 435 };
 436
 437 void hotplug_last_event(uloop_timeout_handler handler)
 438 {
 439         last_event.cb = handler;
 440         if (handler)
 441                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 442         else
 443                 uloop_timeout_cancel(&last_event);
 444 }
 445
 446 void hotplug(char *rules)
 447 {
 448         struct sockaddr_nl nls;
 449         int nlbufsize = 512 * 1024;
 450
 451         rule_file = strdup(rules);
 452         memset(&nls,0,sizeof(struct sockaddr_nl));
 453         nls.nl_family = AF_NETLINK;
 454         nls.nl_pid = getpid();
 455         nls.nl_groups = -1;
 456
 457         if ((hotplug_fd.fd = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT)) == -1) {
 458                 ERROR("Failed to open hotplug socket: %s\n", strerror(errno));
 459                 exit(1);
 460         }
 461         if (bind(hotplug_fd.fd, (void *)&nls, sizeof(struct sockaddr_nl))) {
 462                 ERROR("Failed to bind hotplug socket: %s\n", strerror(errno));
 463                 exit(1);
 464         }
 465
 466         if (setsockopt(hotplug_fd.fd, SOL_SOCKET, SO_RCVBUFFORCE, &nlbufsize, sizeof(nlbufsize))) {
 467                 ERROR("Failed to resize receive buffer: %s\n", strerror(errno));
 468                 exit(1);
 469         }
 470
 471         json_script_init(&jctx);
 472         queue_proc.cb = queue_proc_cb;
 473         uloop_fd_add(&hotplug_fd, ULOOP_READ);
 474 }
 475
 476 int hotplug_run(char *rules)
 477 {
 478         uloop_init();
 479         hotplug(rules);
 480         uloop_run();
 481
 482         return 0;
 483 }
 484
 485 void hotplug_shutdown(void)
 486 {
 487         uloop_fd_delete(&hotplug_fd);
 488         close(hotplug_fd.fd);
 489 }