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