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, fd;
 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                 fd = open("/dev/null", O_RDWR);
 142                 if (fd > -1) {
 143                         dup2(fd, STDIN_FILENO);
 144                         dup2(fd, STDOUT_FILENO);
 145                         dup2(fd, STDERR_FILENO);
 146                         if (fd > STDERR_FILENO)
 147                                 close(fd);
 148                 }
 149         }
 150
 151         if (i > 0) {
 152                 argv[i] = NULL;
 153                 execvp(argv[0], &argv[0]);
 154         }
 155         exit(-1);
 156 }
 157
 158 static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
 159 {
 160         char *dir = blobmsg_get_string(blobmsg_data(data));
 161         char *file = hotplug_msg_find_var(msg, "FIRMWARE");
 162         char *dev = hotplug_msg_find_var(msg, "DEVPATH");
 163         void *fw_data;
 164         struct stat s;
 165         char *path, loadpath[256], syspath[256];
 166         int fw, load, sys, len;
 167
 168         DEBUG(1, "Firmware request for %s/%s\n", dir, file);
 169
 170         if (!file || !dir || !dev) {
 171                 ERROR("Request for unknown firmware %s/%s\n", dir, file);
 172                 exit(-1);
 173         }
 174
 175         path = malloc(strlen(dir) + strlen(file) + 2);
 176         if (!path) {
 177                 ERROR("Failed to allocate memory\n");
 178                 exit(-1);
 179         }
 180         sprintf(path, "%s/%s", dir, file);
 181
 182         if (stat(path, &s)) {
 183                 ERROR("Could not find firmware %s\n", path);
 184                 exit(-1);
 185         }
 186
 187         fw_data = malloc(s.st_size);
 188         if (!fw_data) {
 189                 ERROR("Failed to allocate firmware data memory\n");
 190                 exit(-1);
 191         }
 192
 193         fw = open(path, O_RDONLY);
 194         if (!fw) {
 195                 ERROR("Failed to open %s\n", path);
 196                 exit(-1);
 197         }
 198         if (read(fw, fw_data, s.st_size) != s.st_size) {
 199                 ERROR("Failed to read firmware data\n");
 200                 exit(-1);
 201         }
 202         close(fw);
 203
 204         snprintf(loadpath, sizeof(loadpath), "/sys/%s/loading", dev);
 205         load = open(loadpath, O_WRONLY);
 206         if (!load) {
 207                 ERROR("Failed to open %s\n", loadpath);
 208                 exit(-1);
 209         }
 210         write(load, "1", 1);
 211         close(load);
 212
 213         snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
 214         sys = open(syspath, O_WRONLY);
 215         if (!sys) {
 216                 ERROR("Failed to open %s\n", syspath);
 217                 exit(-1);
 218         }
 219
 220         len = s.st_size;
 221         while (len > 4096) {
 222                 write(fw, fw_data, 4096);
 223                 len -= 4096;
 224         }
 225         if (len)
 226                 write(fw, fw_data, len);
 227         close(fw);
 228
 229         load = open(loadpath, O_WRONLY);
 230         write(load, "0", 1);
 231         close(load);
 232
 233         DEBUG(1, "Done loading %s\n", path);
 234
 235         exit(-1);
 236 }
 237
 238 static struct cmd_handler {
 239         char *name;
 240         int atomic;
 241         void (*handler)(struct blob_attr *msg, struct blob_attr *data);
 242 } handlers[] = {
 243         {
 244                 .name = "makedev",
 245                 .atomic = 1,
 246                 .handler = handle_makedev,
 247         }, {
 248                 .name = "rm",
 249                 .atomic = 1,
 250                 .handler = handle_rm,
 251         }, {
 252                 .name = "exec",
 253                 .handler = handle_exec,
 254         }, {
 255                 .name = "load-firmware",
 256                 .handler = handle_firmware,
 257         },
 258 };
 259
 260 static void queue_next(void)
 261 {
 262         struct cmd_queue *c;
 263
 264         if (queue_proc.pending || list_empty(&cmd_queue))
 265                 return;
 266
 267         c = list_first_entry(&cmd_queue, struct cmd_queue, list);
 268
 269         queue_proc.pid = fork();
 270         if (!queue_proc.pid) {
 271                 uloop_done();
 272                 c->handler(c->msg, c->data);
 273                 exit(0);
 274         }
 275
 276         list_del(&c->list);
 277         free(c);
 278
 279         if (queue_proc.pid <= 0) {
 280                 queue_next();
 281                 return;
 282         }
 283
 284         uloop_process_add(&queue_proc);
 285
 286         DEBUG(2, "Launched hotplug exec instance, pid=%d\n", (int) queue_proc.pid);
 287 }
 288
 289 static void queue_proc_cb(struct uloop_process *c, int ret)
 290 {
 291         DEBUG(2, "Finished hotplug exec instance, pid=%d\n", (int) c->pid);
 292
 293         queue_next();
 294 }
 295
 296 static void queue_add(struct cmd_handler *h, struct blob_attr *msg, struct blob_attr *data)
 297 {
 298         struct cmd_queue *c = NULL;
 299         struct blob_attr *_msg, *_data;
 300
 301         c = calloc_a(sizeof(struct cmd_queue),
 302                 &_msg, blob_pad_len(msg),
 303                 &_data, blob_pad_len(data),
 304                 NULL);
 305
 306         c->msg = _msg;
 307         c->data = _data;
 308
 309         if (!c)
 310                 return;
 311
 312         memcpy(c->msg, msg, blob_pad_len(msg));
 313         memcpy(c->data, data, blob_pad_len(data));
 314         c->handler = h->handler;
 315         list_add_tail(&c->list, &cmd_queue);
 316         queue_next();
 317 }
 318
 319 static const char* rule_handle_var(struct json_script_ctx *ctx, const char *name, struct blob_attr *vars)
 320 {
 321         const char *str, *sep;
 322
 323         if (!strcmp(name, "DEVICENAME") || !strcmp(name, "DEVNAME")) {
 324                 str = json_script_find_var(ctx, vars, "DEVPATH");
 325                 if (!str)
 326                         return NULL;
 327
 328                 sep = strrchr(str, '/');
 329                 if (sep)
 330                         return sep + 1;
 331
 332                 return str;
 333         }
 334
 335         return NULL;
 336 }
 337
 338 static struct json_script_file *
 339 rule_handle_file(struct json_script_ctx *ctx, const char *name)
 340 {
 341         json_object *obj;
 342
 343         obj = json_object_from_file((char*)name);
 344         if (is_error(obj))
 345                 return NULL;
 346
 347         blob_buf_init(&script, 0);
 348         blobmsg_add_json_element(&script, "", obj);
 349
 350         return json_script_file_from_blobmsg(name, blob_data(script.head), blob_len(script.head));
 351 }
 352
 353 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
 354                                 struct blob_attr *data, struct blob_attr *vars)
 355 {
 356         struct blob_attr *cur;
 357         int rem, i;
 358
 359         if (debug > 1) {
 360                 DEBUG(2, "Command: %s", name);
 361                 blobmsg_for_each_attr(cur, data, rem)
 362                         DEBUG(2, " %s", (char *) blobmsg_data(cur));
 363                 DEBUG(2, "\n");
 364
 365                 DEBUG(2, "Message:");
 366                 blobmsg_for_each_attr(cur, vars, rem)
 367                         DEBUG(2, " %s=%s", blobmsg_name(cur), (char *) blobmsg_data(cur));
 368                 DEBUG(2, "\n");
 369         }
 370
 371         for (i = 0; i < ARRAY_SIZE(handlers); i++)
 372                 if (!strcmp(handlers[i].name, name)) {
 373                         if (handlers[i].atomic)
 374                                 handlers[i].handler(vars, data);
 375                         else
 376                                 queue_add(&handlers[i], vars, data);
 377                         break;
 378                 }
 379
 380         if (last_event.cb)
 381                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 382 }
 383
 384 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
 385                                 struct blob_attr *context)
 386 {
 387         char *s;
 388
 389         s = blobmsg_format_json(context, false);
 390         ERROR("ERROR: %s in block: %s\n", msg, s);
 391         free(s);
 392 }
 393
 394 static struct json_script_ctx jctx = {
 395         .handle_var = rule_handle_var,
 396         .handle_error = rule_handle_error,
 397         .handle_command = rule_handle_command,
 398         .handle_file = rule_handle_file,
 399 };
 400
 401 static void hotplug_handler(struct uloop_fd *u, unsigned int ev)
 402 {
 403         int i = 0;
 404         static char buf[4096];
 405         int len = recv(u->fd, buf, sizeof(buf), MSG_DONTWAIT);
 406         void *index;
 407         if (len < 1)
 408                 return;
 409
 410         blob_buf_init(&b, 0);
 411         index = blobmsg_open_table(&b, NULL);
 412         while (i < len) {
 413                 int l = strlen(buf + i) + 1;
 414                 char *e = strstr(&buf[i], "=");
 415
 416                 if (e) {
 417                         *e = '\0';
 418                         blobmsg_add_string(&b, &buf[i], &e[1]);
 419                 }
 420                 i += l;
 421         }
 422         blobmsg_close_table(&b, index);
 423         DEBUG(3, "%s\n", blobmsg_format_json(b.head, true));
 424         json_script_run(&jctx, rule_file, blob_data(b.head));
 425 }
 426
 427 static struct uloop_fd hotplug_fd = {
 428         .cb = hotplug_handler,
 429 };
 430
 431 void hotplug_last_event(uloop_timeout_handler handler)
 432 {
 433         last_event.cb = handler;
 434         if (handler)
 435                 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
 436         else
 437                 uloop_timeout_cancel(&last_event);
 438 }
 439
 440 void hotplug(char *rules)
 441 {
 442         struct sockaddr_nl nls;
 443
 444         rule_file = strdup(rules);
 445         memset(&nls,0,sizeof(struct sockaddr_nl));
 446         nls.nl_family = AF_NETLINK;
 447         nls.nl_pid = getpid();
 448         nls.nl_groups = -1;
 449
 450         if ((hotplug_fd.fd = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT)) == -1) {
 451                 ERROR("Failed to open hotplug socket: %s\n", strerror(errno));
 452                 exit(1);
 453         }
 454         if (bind(hotplug_fd.fd, (void *)&nls, sizeof(struct sockaddr_nl))) {
 455                 ERROR("Failed to bind hotplug socket: %s\n", strerror(errno));
 456                 exit(1);
 457         }
 458
 459         json_script_init(&jctx);
 460         queue_proc.cb = queue_proc_cb;
 461         uloop_fd_add(&hotplug_fd, ULOOP_READ);
 462 }
 463
 464 void hotplug_shutdown(void)
 465 {
 466         uloop_fd_delete(&hotplug_fd);
 467         close(hotplug_fd.fd);
 468 }