sbin/udevd/udevd.c

   1 /*
   2  * Copyright (c) 2010 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Alex Hornung <ahornung@gmail.com>
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34 #include <sys/types.h>
  35 #include <sys/device.h>
  36 #include <sys/wait.h>
  37 #include <sys/socket.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/poll.h>
  40 #include <sys/queue.h>
  41 #include <sys/un.h>
  42 #include <cpu/inttypes.h>
  43
  44 #include <err.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <libgen.h>
  48 #include <regex.h>
  49 #include <signal.h>
  50 #include <stdarg.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <syslog.h>
  55 #include <unistd.h>
  56 #include <pthread.h>
  57
  58 #include <libprop/proplib.h>
  59 #include <sys/udev.h>
  60 #include "udevd.h"
  61
  62 int debugopt = 0;
  63
  64 static int udevfd;
  65 static int hangup_ongoing = 0;
  66 static struct pollfd fds[NFDS];
  67
  68 extern pthread_mutex_t  monitor_lock;
  69 extern TAILQ_HEAD(udev_monitor_list_head, udev_monitor) udev_monitor_list;
  70 extern TAILQ_HEAD(pdev_array_list_head, pdev_array_entry)       pdev_array_list;
  71
  72 static void usage(void);
  73
  74 int match_dev_dict(prop_dictionary_t, prop_dictionary_t);
  75 prop_dictionary_t find_dev_dict(int64_t, prop_dictionary_t, int *);
  76
  77 void udev_read_event(int);
  78 prop_array_t udev_getdevs(int);
  79
  80 static
  81 void
  82 usage(void)
  83 {
  84         fprintf(stderr, "usage: udevd [-d]\n");
  85         exit(1);
  86 }
  87
  88 int
  89 match_dev_dict(prop_dictionary_t dict, prop_dictionary_t match_dict)
  90 {
  91         prop_number_t   pn, pn2;
  92         prop_string_t   ps, ps2;
  93
  94         if (dict == NULL)
  95                 return 0;
  96
  97         if ((ps = prop_dictionary_get(dict, "name")) == NULL)
  98                 return 0;
  99         if ((ps2 = prop_dictionary_get(match_dict, "name")) == NULL)
 100                 return 0;
 101         if (!prop_string_equals(ps, ps2))
 102                 return 0;
 103
 104         if ((pn = prop_dictionary_get(dict, "devnum")) == NULL)
 105                 return 0;
 106         if ((pn2 = prop_dictionary_get(match_dict, "devnum")) == NULL)
 107                 return 0;
 108         if (!prop_number_equals(pn, pn2))
 109                 return 0;
 110
 111         if ((pn = prop_dictionary_get(dict, "kptr")) == NULL)
 112                 return 0;
 113         if ((pn2 = prop_dictionary_get(match_dict, "kptr")) == NULL)
 114                 return 0;
 115         if (!prop_number_equals(pn, pn2))
 116                 return 0;
 117
 118         return 1;
 119 }
 120
 121 prop_dictionary_t
 122 find_dev_dict(int64_t generation, prop_dictionary_t match_dict, int *idx)
 123 {
 124         struct pdev_array_entry *pae;
 125         prop_array_t            pa;
 126         prop_object_iterator_t  iter;
 127         prop_dictionary_t       dict;
 128         int i = 0;
 129
 130         if (generation == -1)
 131                 pae = pdev_array_entry_get_last();
 132         else
 133                 pae = pdev_array_entry_get(generation);
 134
 135         if (pae == NULL)
 136                 return NULL;
 137
 138         pa = pae->pdev_array;
 139
 140         iter = prop_array_iterator(pa);
 141         if (iter == NULL) {
 142                 pdev_array_entry_unref(pae);
 143                 return NULL;
 144         }
 145
 146         while ((dict = prop_object_iterator_next(iter)) != NULL) {
 147                 if (match_dev_dict(dict, match_dict))
 148                         break;
 149                 ++i;
 150         }
 151
 152         prop_object_iterator_release(iter);
 153
 154         if (idx != NULL)
 155                 *idx = i;
 156
 157         pdev_array_entry_unref(pae);
 158         return dict;
 159 }
 160
 161 void
 162 udev_read_event(int fd)
 163 {
 164         struct pdev_array_entry *pae;
 165         prop_dictionary_t       dict, evdict, devdict;
 166         prop_number_t           pn;
 167         prop_string_t           ps;
 168         prop_object_t           po;
 169         prop_array_t            pa;
 170         char    *xml;
 171         int     n, idx, evtype;
 172         size_t  sz;
 173
 174         sz = 4096 * 1024;
 175
 176         xml = malloc(sz); /* 4 MB */
 177 again:
 178         if ((n = read(fd, xml, sz)) <= 0) {
 179                 if (errno == ENOMEM) {
 180                         sz <<= 2;
 181                         if ((xml = realloc(xml, sz)) == NULL) {
 182                                 syslog(LOG_ERR, "could not realloc xml memory");
 183                                 return;
 184                         }
 185                         goto again;
 186                 }
 187                 free(xml);
 188                 return;
 189         }
 190
 191         dict = prop_dictionary_internalize(xml);
 192         free(xml);
 193         if (dict == NULL) {
 194                 syslog(LOG_ERR, "internalization of xml failed");
 195                 return;
 196         }
 197
 198         pn = prop_dictionary_get(dict, "evtype");
 199         if (pn == NULL) {
 200                 syslog(LOG_ERR, "read_event: no key evtype");
 201                 goto out;
 202         }
 203
 204         evtype = prop_number_integer_value(pn);
 205
 206         evdict = prop_dictionary_get(dict, "evdict");
 207         if (evdict == NULL) {
 208                 syslog(LOG_ERR, "read_event: no key evdict");
 209                 goto out;
 210         }
 211
 212         switch (evtype) {
 213         case UDEV_EVENT_ATTACH:
 214                 monitor_queue_event(dict);
 215                 pae = pdev_array_entry_get_last();
 216                 pa = prop_array_copy(pae->pdev_array);
 217                 pdev_array_entry_unref(pae);
 218                 if (pa == NULL)
 219                         goto out;
 220                 prop_array_add(pa, evdict);
 221                 pdev_array_entry_insert(pa);
 222                 break;
 223
 224         case UDEV_EVENT_DETACH:
 225                 monitor_queue_event(dict);
 226                 if ((devdict = find_dev_dict(-1, evdict, &idx)) == NULL)
 227                         goto out;
 228                 pae = pdev_array_entry_get_last();
 229                 pa = prop_array_copy(pae->pdev_array);
 230                 pdev_array_entry_unref(pae);
 231                 if (pa == NULL)
 232                         goto out;
 233                 prop_array_remove(pa, idx);
 234                 pdev_array_entry_insert(pa);
 235                 break;
 236
 237         case UDEV_EV_KEY_UPDATE:
 238                 if ((devdict = find_dev_dict(-1, evdict, NULL)) == NULL)
 239                         goto out;
 240                 if ((ps = prop_dictionary_get(evdict, "key")) == NULL)
 241                         goto out;
 242                 if ((po = prop_dictionary_get(evdict, "value")) == NULL)
 243                         goto out;
 244                 /* prop_object_retain(po); */ /* not necessary afaik */
 245                 prop_dictionary_set(devdict, prop_string_cstring_nocopy(ps), po);
 246                 break;
 247
 248         case UDEV_EV_KEY_REMOVE:
 249                 if ((devdict = find_dev_dict(-1, evdict, NULL)) == NULL)
 250                         goto out;
 251                 if ((ps = prop_dictionary_get(evdict, "key")) == NULL)
 252                         goto out;
 253                 prop_dictionary_remove(devdict, prop_string_cstring_nocopy(ps));
 254                 break;
 255
 256         default:
 257                 syslog(LOG_ERR, "read_event: unknown evtype %d", evtype);
 258         }
 259
 260 out:
 261         prop_object_release(dict);
 262         return;
 263 }
 264
 265 prop_array_t
 266 udev_getdevs(int devfd)
 267 {
 268         prop_dictionary_t       pd, rpd;
 269         prop_string_t           ps;
 270         prop_array_t            pa;
 271
 272         pd = prop_dictionary_create();
 273         if (pd == NULL) {
 274                 err(1, "prop_dictionary_create()");
 275         }
 276
 277         ps = prop_string_create_cstring("getdevs");
 278         if (ps == NULL) {
 279                 prop_object_release(pd);
 280                 err(1, "prop_string_create_cstring()");
 281         }
 282
 283         if (prop_dictionary_set(pd, "command", ps) == false) {
 284                 prop_object_release(ps);
 285                 prop_object_release(pd);
 286                 err(1, "prop_dictionary_set()");
 287         }
 288
 289         prop_object_release(ps);
 290
 291         /* Send dictionary to kernel space */
 292         if (prop_dictionary_sendrecv_ioctl(pd, devfd, UDEVPROP, &rpd) != 0)
 293                 err(1, "prop_array_recv_ioctl()");
 294
 295         prop_object_release(pd);
 296
 297         pa = prop_dictionary_get(rpd, "array");
 298         if (pa == NULL)
 299                 goto out;
 300         prop_object_retain(pa);
 301
 302 out:
 303         prop_object_release(rpd);
 304         return pa;
 305 }
 306
 307 static void
 308 killed(int sig __unused)
 309 {
 310         syslog(LOG_ERR, "udevd stopped");
 311         unlink("/var/run/udevd.pid");
 312         pdev_array_clean();
 313         exit(0);
 314 }
 315
 316 static void
 317 hangup(int sig __unused)
 318 {
 319         FILE *pidf;
 320         int s;
 321
 322         syslog(LOG_ERR, "udevd hangup+resume");
 323
 324         pidf = fopen("/var/run/udevd.pid", "w");
 325         if (pidf != NULL) {
 326                 fprintf(pidf, "%ld\n", (long)getpid());
 327                 fclose(pidf);
 328         }
 329
 330         hangup_ongoing = 1;
 331         close(fds[UDEV_SOCKET_FD_IDX].fd);
 332         pdev_array_clean();
 333         s = init_local_server(LISTEN_SOCKET_FILE, SOCK_STREAM, 0);
 334         if (s < 0)
 335                 err(1, "init_local_server");
 336
 337         fds[UDEV_SOCKET_FD_IDX].fd = s;
 338         pdev_array_entry_insert(udev_getdevs(udevfd));
 339         hangup_ongoing = 0;
 340 }
 341
 342 int
 343 ignore_signal(int signum)
 344 {
 345         struct sigaction act;
 346         int ret;
 347
 348         act.sa_handler = SIG_IGN;
 349         sigemptyset(&act.sa_mask);
 350         act.sa_flags = 0;
 351
 352         ret = sigaction(signum, &act, NULL);
 353         return ret;
 354 }
 355
 356 static int
 357 set_signal(int signum, sig_t sig_func)
 358 {
 359         struct sigaction act;
 360         int ret;
 361
 362         act.sa_handler = sig_func;
 363         sigemptyset(&act.sa_mask);
 364         act.sa_flags = 0;
 365
 366         ret = sigaction(signum, &act, NULL);
 367         return ret;
 368 }
 369
 370 int main(int argc, char *argv[])
 371 {
 372         int error __unused, i, r, s;
 373         FILE *pidf;
 374         int ch = 0;
 375
 376         while ((ch = getopt(argc, argv, "d")) != -1) {
 377                 switch(ch) {
 378                 case 'd':
 379                         debugopt = 1;
 380                         break;
 381                 default:
 382                         usage();
 383                         /* NOT REACHED */
 384                 }
 385         }
 386         argc -= optind;
 387         argv += optind;
 388
 389         TAILQ_INIT(&pdev_array_list);
 390         TAILQ_INIT(&udev_monitor_list);
 391
 392         r = ignore_signal(SIGPIPE);
 393         if (r != 0)
 394                 err(1, "could not ignore_signal SIGPIPE");
 395
 396         r = pthread_mutex_init(&(monitor_lock), NULL);
 397         if (r != 0)
 398                 err(1, "could not allocate a pthread_mutex");
 399
 400         if ((udevfd = open(UDEV_DEVICE_PATH, O_RDWR | O_NONBLOCK)) == -1)
 401                 err(1, "%s", UDEV_DEVICE_PATH);
 402         unblock_descriptor(udevfd);
 403
 404         s = init_local_server(LISTEN_SOCKET_FILE, SOCK_STREAM, 0);
 405         if (s < 0)
 406                 err(1, "init_local_server");
 407
 408         pidf = fopen("/var/run/udevd.pid", "w");
 409 #if 0
 410         if (pidf == NULL)
 411                 err(1, "pidfile");
 412 #endif
 413
 414         set_signal(SIGTERM, killed);
 415         set_signal(SIGHUP, hangup);
 416
 417         if (debugopt == 0)
 418                 if (daemon(0, 0) == -1)
 419                         err(1, "daemon");
 420
 421         if (pidf != NULL) {
 422                 fprintf(pidf, "%ld\n", (long)getpid());
 423                 fclose(pidf);
 424         }
 425
 426         syslog(LOG_ERR, "udevd started");
 427
 428         pdev_array_entry_insert(udev_getdevs(udevfd));
 429
 430         memset(fds, 0 , sizeof(fds));
 431         fds[UDEV_DEVICE_FD_IDX].fd = udevfd;
 432         fds[UDEV_DEVICE_FD_IDX].events = POLLIN;
 433         fds[UDEV_SOCKET_FD_IDX].fd = s;
 434         fds[UDEV_SOCKET_FD_IDX].events = POLLIN | POLLPRI;
 435
 436         for (;;) {
 437                 r = poll(fds, NFDS, -1);
 438                 if (r < 0) {
 439                         if (hangup_ongoing == 0) {
 440                                 if (errno == EINTR) {
 441                                         usleep(5000);
 442                                         continue;
 443                                 } else {
 444                                         err(1, "polling...");
 445                                 }
 446                         } else {
 447                                 usleep(20000); /* 20 ms */
 448                                 continue;
 449                         }
 450                 }
 451
 452                 for (i = 0; (i < NFDS) && (r > 0); i++) {
 453                         if (fds[i].revents == 0)
 454                                 continue;
 455
 456                         --r;
 457                         switch (i) {
 458                         case UDEV_DEVICE_FD_IDX:
 459                                 udev_read_event(udevfd);
 460                                 break;
 461                         case UDEV_SOCKET_FD_IDX:
 462                                 handle_new_connection(s);
 463                                 break;
 464                         default:
 465                                 break;
 466                         }
 467                 }
 468         }
 469
 470         syslog(LOG_ERR, "udevd is exiting normally");
 471         return 0;
 472 }