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                         realloc(xml, sz);
 182                         goto again;
 183                 }
 184                 free(xml);
 185                 return;
 186         }
 187
 188         dict = prop_dictionary_internalize(xml);
 189         free(xml);
 190         if (dict == NULL) {
 191                 syslog(LOG_ERR, "internalization of xml failed");
 192                 return;
 193         }
 194
 195         pn = prop_dictionary_get(dict, "evtype");
 196         if (pn == NULL) {
 197                 syslog(LOG_ERR, "read_event: no key evtype");
 198                 goto out;
 199         }
 200
 201         evtype = prop_number_integer_value(pn);
 202
 203         evdict = prop_dictionary_get(dict, "evdict");
 204         if (evdict == NULL) {
 205                 syslog(LOG_ERR, "read_event: no key evdict");
 206                 goto out;
 207         }
 208
 209         switch (evtype) {
 210         case UDEV_EVENT_ATTACH:
 211                 monitor_queue_event(dict);
 212                 pae = pdev_array_entry_get_last();
 213                 pa = prop_array_copy(pae->pdev_array);
 214                 pdev_array_entry_unref(pae);
 215                 if (pa == NULL)
 216                         goto out;
 217                 prop_array_add(pa, evdict);
 218                 pdev_array_entry_insert(pa);
 219                 break;
 220
 221         case UDEV_EVENT_DETACH:
 222                 monitor_queue_event(dict);
 223                 if ((devdict = find_dev_dict(-1, evdict, &idx)) == NULL)
 224                         goto out;
 225                 pae = pdev_array_entry_get_last();
 226                 pa = prop_array_copy(pae->pdev_array);
 227                 pdev_array_entry_unref(pae);
 228                 if (pa == NULL)
 229                         goto out;
 230                 prop_array_remove(pa, idx);
 231                 pdev_array_entry_insert(pa);
 232                 break;
 233
 234         case UDEV_EV_KEY_UPDATE:
 235                 if ((devdict = find_dev_dict(-1, evdict, NULL)) == NULL)
 236                         goto out;
 237                 if ((ps = prop_dictionary_get(evdict, "key")) == NULL)
 238                         goto out;
 239                 if ((po = prop_dictionary_get(evdict, "value")) == NULL)
 240                         goto out;
 241                 /* prop_object_retain(po); */ /* not necessary afaik */
 242                 prop_dictionary_set(devdict, prop_string_cstring_nocopy(ps), po);
 243                 break;
 244
 245         case UDEV_EV_KEY_REMOVE:
 246                 if ((devdict = find_dev_dict(-1, evdict, NULL)) == NULL)
 247                         goto out;
 248                 if ((ps = prop_dictionary_get(evdict, "key")) == NULL)
 249                         goto out;
 250                 prop_dictionary_remove(devdict, prop_string_cstring_nocopy(ps));
 251                 break;
 252
 253         default:
 254                 syslog(LOG_ERR, "read_event: unknown evtype %d", evtype);
 255         }
 256
 257 out:
 258         prop_object_release(dict);
 259         return;
 260 }
 261
 262 prop_array_t
 263 udev_getdevs(int devfd)
 264 {
 265         prop_dictionary_t       pd, rpd;
 266         prop_string_t           ps;
 267         prop_array_t            pa;
 268
 269         pd = prop_dictionary_create();
 270         if (pd == NULL) {
 271                 err(1, "prop_dictionary_create()");
 272         }
 273
 274         ps = prop_string_create_cstring("getdevs");
 275         if (ps == NULL) {
 276                 prop_object_release(pd);
 277                 err(1, "prop_string_create_cstring()");
 278         }
 279
 280         if (prop_dictionary_set(pd, "command", ps) == false) {
 281                 prop_object_release(ps);
 282                 prop_object_release(pd);
 283                 err(1, "prop_dictionary_set()");
 284         }
 285
 286         prop_object_release(ps);
 287
 288         /* Send dictionary to kernel space */
 289         if (prop_dictionary_sendrecv_ioctl(pd, devfd, UDEVPROP, &rpd) != 0)
 290                 err(1, "prop_array_recv_ioctl()");
 291
 292         prop_object_release(pd);
 293
 294         pa = prop_dictionary_get(rpd, "array");
 295         if (pa == NULL)
 296                 goto out;
 297         prop_object_retain(pa);
 298
 299 out:
 300         prop_object_release(rpd);
 301         return pa;
 302 }
 303
 304 static void
 305 killed(int sig __unused)
 306 {
 307         syslog(LOG_ERR, "udevd stopped");
 308         unlink("/var/run/udevd.pid");
 309         pdev_array_clean();
 310         exit(0);
 311 }
 312
 313 static void
 314 hangup(int sig __unused)
 315 {
 316         FILE *pidf;
 317         int s;
 318
 319         syslog(LOG_ERR, "udevd hangup+resume");
 320
 321         pidf = fopen("/var/run/udevd.pid", "w");
 322         if (pidf != NULL) {
 323                 fprintf(pidf, "%ld\n", (long)getpid());
 324                 fclose(pidf);
 325         }
 326
 327         hangup_ongoing = 1;
 328         close(fds[UDEV_SOCKET_FD_IDX].fd);
 329         pdev_array_clean();
 330         s = init_local_server(LISTEN_SOCKET_FILE, SOCK_STREAM, 0);
 331         if (s < 0)
 332                 err(1, "init_local_server");
 333
 334         fds[UDEV_SOCKET_FD_IDX].fd = s;
 335         pdev_array_entry_insert(udev_getdevs(udevfd));
 336         hangup_ongoing = 0;
 337 }
 338
 339 int
 340 ignore_signal(int signum)
 341 {
 342         struct sigaction act;
 343         int ret;
 344
 345         act.sa_handler = SIG_IGN;
 346         sigemptyset(&act.sa_mask);
 347         act.sa_flags = 0;
 348
 349         ret = sigaction(signum, &act, NULL);
 350         return ret;
 351 }
 352
 353 static int
 354 set_signal(int signum, sig_t sig_func)
 355 {
 356         struct sigaction act;
 357         int ret;
 358
 359         act.sa_handler = sig_func;
 360         sigemptyset(&act.sa_mask);
 361         act.sa_flags = 0;
 362
 363         ret = sigaction(signum, &act, NULL);
 364         return ret;
 365 }
 366
 367 int main(int argc, char *argv[])
 368 {
 369         int error __unused, i, r, s;
 370         FILE *pidf;
 371         int ch = 0;
 372
 373         while ((ch = getopt(argc, argv, "d")) != -1) {
 374                 switch(ch) {
 375                 case 'd':
 376                         debugopt = 1;
 377                         break;
 378                 default:
 379                         usage();
 380                         /* NOT REACHED */
 381                 }
 382         }
 383         argc -= optind;
 384         argv += optind;
 385
 386         TAILQ_INIT(&pdev_array_list);
 387         TAILQ_INIT(&udev_monitor_list);
 388
 389         r = ignore_signal(SIGPIPE);
 390         if (r != 0)
 391                 err(1, "could not ignore_signal SIGPIPE");
 392
 393         r = pthread_mutex_init(&(monitor_lock), NULL);
 394         if (r != 0)
 395                 err(1, "could not allocate a pthread_mutex");
 396
 397         if ((udevfd = open(UDEV_DEVICE_PATH, O_RDWR | O_NONBLOCK)) == -1)
 398                 err(1, "%s", UDEV_DEVICE_PATH);
 399         unblock_descriptor(udevfd);
 400
 401         s = init_local_server(LISTEN_SOCKET_FILE, SOCK_STREAM, 0);
 402         if (s < 0)
 403                 err(1, "init_local_server");
 404
 405         pidf = fopen("/var/run/udevd.pid", "w");
 406 #if 0
 407         if (pidf == NULL)
 408                 err(1, "pidfile");
 409 #endif
 410
 411         set_signal(SIGTERM, killed);
 412         set_signal(SIGHUP, hangup);
 413
 414         if (debugopt == 0)
 415                 if (daemon(0, 0) == -1)
 416                         err(1, "daemon");
 417
 418         if (pidf != NULL) {
 419                 fprintf(pidf, "%ld\n", (long)getpid());
 420                 fclose(pidf);
 421         }
 422
 423         syslog(LOG_ERR, "udevd started");
 424
 425         pdev_array_entry_insert(udev_getdevs(udevfd));
 426
 427         memset(fds, 0 , sizeof(fds));
 428         fds[UDEV_DEVICE_FD_IDX].fd = udevfd;
 429         fds[UDEV_DEVICE_FD_IDX].events = POLLIN;
 430         fds[UDEV_SOCKET_FD_IDX].fd = s;
 431         fds[UDEV_SOCKET_FD_IDX].events = POLLIN | POLLPRI;
 432
 433         for (;;) {
 434                 r = poll(fds, NFDS, -1);
 435                 if (r < 0) {
 436                         if (hangup_ongoing == 0) {
 437                                 if (errno == EINTR) {
 438                                         usleep(5000);
 439                                         continue;
 440                                 } else {
 441                                         err(1, "polling...");
 442                                 }
 443                         } else {
 444                                 usleep(20000); /* 20 ms */
 445                                 continue;
 446                         }
 447                 }
 448
 449                 for (i = 0; (i < NFDS) && (r > 0); i++) {
 450                         if (fds[i].revents == 0)
 451                                 continue;
 452
 453                         --r;
 454                         switch (i) {
 455                         case UDEV_DEVICE_FD_IDX:
 456                                 udev_read_event(udevfd);
 457                                 break;
 458                         case UDEV_SOCKET_FD_IDX:
 459                                 handle_new_connection(s);
 460                                 break;
 461                         default:
 462                                 break;
 463                         }
 464                 }
 465         }
 466
 467         syslog(LOG_ERR, "udevd is exiting normally");
 468         return 0;
 469 }