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