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