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 #include "hotplug.h"
  33
  34 #define HOTPLUG_WAIT    500
  35
  36 struct cmd_queue {
  37         struct list_head list;
  38
  39         struct blob_attr *msg;
  40         struct blob_attr *data;
  41         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
  42 };
  43
  44 static LIST_HEAD(cmd_queue);
  45 static struct uloop_process queue_proc;
  46 static struct uloop_timeout last_event;
  47 static struct blob_buf b;
  48 static char *rule_file;
  49 static struct blob_buf script;
  50
  51 static char *hotplug_msg_find_var(struct blob_attr *msg, const char *name)
  52 {
  53         struct blob_attr *cur;
  54         int rem;
  55
  56         blobmsg_for_each_attr(cur, msg, rem) {
  57                 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
  58                         continue;
  59
  60                 if (strcmp(blobmsg_name(cur), name) != 0)
  61                         continue;
  62
  63                 return blobmsg_data(cur);
  64         }
  65
  66         return NULL;
  67 }
  68
  69 static void mkdir_p(char *dir)
  70 {
  71         char *l = strrchr(dir, '/');
  72
  73         if (l) {
  74                 *l = '\0';
  75                 mkdir_p(dir);
  76                 *l = '/';
  77                 mkdir(dir, 0755);
  78         }
  79 }
  80
  81 static void handle_makedev(struct blob_attr *msg, struct blob_attr *data)
  82 {
  83         unsigned int oldumask = umask(0);
  84         static struct blobmsg_policy mkdev_policy[2] = {
  85                 { .type = BLOBMSG_TYPE_STRING },
  86                 { .type = BLOBMSG_TYPE_STRING },
  87         };
  88         struct blob_attr *tb[2];
  89         char *minor = hotplug_msg_find_var(msg, "MINOR");
  90         char *major = hotplug_msg_find_var(msg, "MAJOR");
  91         char *subsystem = hotplug_msg_find_var(msg, "SUBSYSTEM");
  92
  93         blobmsg_parse_array(mkdev_policy, 2, tb, blobmsg_data(data), blobmsg_data_len(data));
  94         if (tb[0] && tb[1] && minor && major && subsystem) {
  95                 mode_t m = S_IFCHR;
  96                 char *d = strdup(blobmsg_get_string(tb[0]));
  97
  98                 d = dirname(d);
  99                 mkdir_p(d);
 100                 free(d);
 101
 102                 if (!strcmp(subsystem, "block"))
 103                         m = S_IFBLK;
 104                 mknod(blobmsg_get_string(tb[0]),
 105                                 m | strtoul(blobmsg_data(tb[1]), NULL, 8),
 106                                 makedev(atoi(major), atoi(minor)));
 107         }
 108         umask(oldumask);
 109 }
 110
 111 static void handle_rm(struct blob_attr *msg, struct blob_attr *data)
 112 {
 113         static struct blobmsg_policy rm_policy = {
 114                 .type = BLOBMSG_TYPE_STRING,
 115         };
 116         struct blob_attr *tb;
 117
 118         blobmsg_parse_array(&rm_policy, 1, &tb, blobmsg_data(data), blobmsg_data_len(data));
 119         if (tb)
 120                 unlink(blobmsg_data(tb));
 121 }
 122
 123 static void handle_exec(struct blob_attr *msg, struct blob_attr *data)
 124 {
 125         char *argv[8];
 126         struct blob_attr *cur;
 127         int rem;
 128         int i = 0;
 129
 130         blobmsg_for_each_attr(cur, msg, rem)
 131                 setenv(blobmsg_name(cur), blobmsg_data(cur), 1);
 132
 133         blobmsg_for_each_attr(cur, data, rem) {
 134                 argv[i] = blobmsg_data(cur);
 135                 i++;
 136                 if (i == 7)
 137                         break;
 138         }
 139
 140         if (debug < 2) {
 141                 close(STDIN_FILENO);
 142                 close(STDOUT_FILENO);
 143                 close(STDERR_FILENO);
 144         }
 145
 146         if (i > 0) {
 147                 argv[i] = NULL;
 148                 execvp(argv[0], &argv[0]);
 149         }
 150         exit(-1);
 151 }
 152
 153 static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
 154 {
 155         char *dir = blobmsg_get_string(blobmsg_data(data));
 156         char *file = hotplug_msg_find_var(msg, "FIRMWARE");
 157         char *dev = hotplug_msg_find_var(msg, "DEVPATH");
 158         void *fw_data;
 159         struct stat s;
 160         char *path, loadpath[256], syspath[256];
 161         int fw, load, sys, len;
 162
 163         DEBUG(1, "Firmware request for %s/%s\n", dir, file);
 164
 165         if (!file || !dir || !dev) {
 166                 ERROR("Request for unknown firmware %s/%s\n", dir, file);
 167                 exit(-1);
 168         }
 169
 170         path = malloc(strlen(dir) + strlen(file) + 2);
 171         if (!path) {
 172                 ERROR("Failed to allocate memory\n");
 173                 exit(-1);
 174         }
 175         sprintf(path, "%s/%s", dir, file);
 176
 177         if (stat(path, &s)) {
 178                 ERROR("Could not find firmware %s\n", path);
 179                 exit(-1);
 180         }
 181
 182         fw_data = malloc(s.st_size);
 183         if (!fw_data) {
 184                 ERROR("Failed to allocate firmware data memory\n");
 185                 exit(-1);
 186         }
 187
 188         fw = open(path, O_RDONLY);
 189         if (!fw) {
 190                 ERROR("Failed to open %s\n", path);
 191                 exit(-1);
 192         }
 193         if (read(fw, fw_data, s.st_size) != s.st_size) {
 194                 ERROR("Failed to read firmware data\n");
 195                 exit(-1);
 196         }
 197         close(fw);
 198
 199         snprintf(loadpath, sizeof(loadpath), "/sys/%s/loading", dev);
 200         load = open(loadpath, O_WRONLY);
 201         if (!load) {
 202                 ERROR("Failed to open %s\n", loadpath);
 203                 exit(-1);
 204         }
 205         write(load, "1", 1);
 206         close(load);
 207
 208         snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
 209         sys = open(syspath, O_WRONLY);
 210         if (!sys) {
 211                 ERROR("Failed to open %s\n", syspath);
 212                 exit(-1);
 213         }
 214
 215         len = s.st_size;
 216         while (len > 4096) {
 217                 write(fw, fw_data, 4096);
 218                 len -= 4096;
 219         }
 220         if (len)
 221                 write(fw, fw_data, len);
 222         close(fw);
 223
 224         load = open(loadpath, O_WRONLY);
 225         write(load, "0", 1);
 226         close(load);
 227
 228         DEBUG(1, "Done loading %s\n", path);
 229
 230         exit(-1);
 231 }
 232
 233 static struct cmd_handler {
 234         char *name;
 235         int atomic;
 236         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
 237 } handlers[] = {
 238         {
 239                 .name = "makedev",
 240                 .atomic = 1,
 241                 .handler = handle_makedev,
 242         }, {
 243                 .name = "rm",
 244                 .atomic = 1,
 245                 .handler = handle_rm,
 246         }, {
 247                 .name = "exec",
 248                 .handler = handle_exec,
 249         }, {
 250                 .name = "load-firmware",
 251                 .handler = handle_firmware,
 252         },
 253 };
 254
 255 static void queue_next(void)
 256 {
 257         struct cmd_queue *c;
 258
 259         if (queue_proc.pending || list_empty(&cmd_queue))
 260                 return;
 261
 262         c = list_first_entry(&cmd_queue, struct cmd_queue, list);
 263
 264         queue_proc.pid = fork();
 265         if (!queue_proc.pid) {
 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(2, "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(2, "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 > 1) {
 354                 DEBUG(2, "Command: %s", name);
 355                 blobmsg_for_each_attr(cur, data, rem)
 356                         DEBUG(2, " %s", (char *) blobmsg_data(cur));
 357                 DEBUG(2, "\n");
 358
 359                 DEBUG(2, "Message:");
 360                 blobmsg_for_each_attr(cur, vars, rem)
 361                         DEBUG(2, " %s=%s", blobmsg_name(cur), (char *) blobmsg_data(cur));
 362                 DEBUG(2, "\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(struct uloop_fd *u, unsigned int ev)
 396 {
 397         int i = 0;
 398         static char buf[4096];
 399         int len = recv(u->fd, buf, sizeof(buf), MSG_DONTWAIT);
 400         void *index;
 401         if (len < 1)
 402                 return;
 403
 404         blob_buf_init(&b, 0);
 405         index = blobmsg_open_table(&b, NULL);
 406         while (i < len) {
 407                 int l = strlen(buf + i) + 1;
 408                 char *e = strstr(&buf[i], "=");
 409
 410                 if (e) {
 411                         *e = '\0';
 412                         blobmsg_add_string(&b, &buf[i], &e[1]);
 413                 }
 414                 i += l;
 415         }
 416         blobmsg_close_table(&b, index);
 417         DEBUG(3, "%s\n", blobmsg_format_json(b.head, true));
 418         json_script_run(&jctx, rule_file, blob_data(b.head));
 419 }
 420
 421 static struct uloop_fd hotplug_fd = {
 422         .cb = hotplug_handler,
 423 };
 424
 425 void hotplug_last_event(uloop_timeout_handler handler)
 426 {
 427         last_event.cb = handler;
 428         if (handler)
 429                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 430         else
 431                 uloop_timeout_cancel(&last_event);
 432 }
 433
 434 void hotplug(char *rules)
 435 {
 436         struct sockaddr_nl nls;
 437
 438         rule_file = strdup(rules);
 439         memset(&nls,0,sizeof(struct sockaddr_nl));
 440         nls.nl_family = AF_NETLINK;
 441         nls.nl_pid = getpid();
 442         nls.nl_groups = -1;
 443
 444         if ((hotplug_fd.fd = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT)) == -1) {
 445                 ERROR("Failed to open hotplug socket: %s\n", strerror(errno));
 446                 exit(1);
 447         }
 448         if (bind(hotplug_fd.fd, (void *)&nls, sizeof(struct sockaddr_nl))) {
 449                 ERROR("Failed to bind hotplug socket: %s\n", strerror(errno));
 450                 exit(1);
 451         }
 452
 453         json_script_init(&jctx);
 454         queue_proc.cb = queue_proc_cb;
 455         uloop_fd_add(&hotplug_fd, ULOOP_READ);
 456 }
 457
 458 void hotplug_shutdown(void)
 459 {
 460         uloop_fd_delete(&hotplug_fd);
 461         close(hotplug_fd.fd);
 462 }