sbin/udevd/udevd_monitor.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 #include <assert.h>
  44
  45 #include <ctype.h>
  46 #include <err.h>
  47 #include <errno.h>
  48 #include <fcntl.h>
  49 #include <libgen.h>
  50 #include <regex.h>
  51 #include <signal.h>
  52 #include <stdarg.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <string.h>
  56 #include <syslog.h>
  57 #include <unistd.h>
  58 #include <pthread.h>
  59
  60 #include <libprop/proplib.h>
  61 #include <sys/udev.h>
  62 #include "udevd.h"
  63
  64 #define MONITOR_LOCK()          pthread_mutex_lock(&monitor_lock)
  65 #define MONITOR_UNLOCK()        pthread_mutex_unlock(&monitor_lock)
  66
  67 static int _parse_filter_prop(struct udev_monitor *udm, prop_array_t pa);
  68 static int match_filter(struct event_filter *evf, prop_dictionary_t dict);
  69
  70 static int WildCaseCmp(const char *w, const char *s);
  71 static int wildCaseCmp(const char **mary, int d, const char *w, const char *s);
  72
  73 TAILQ_HEAD(udev_monitor_list_head, udev_monitor)        udev_monitor_list;
  74 pthread_mutex_t monitor_lock;
  75
  76
  77 void
  78 monitor_queue_event(prop_dictionary_t ev_dict)
  79 {
  80         struct udev_monitor             *udm;
  81         struct udev_monitor_event       *udm_ev;
  82
  83         MONITOR_LOCK();
  84
  85         TAILQ_FOREACH(udm, &udev_monitor_list, link) {
  86                 udm_ev = malloc(sizeof(struct udev_monitor_event));
  87                 if (udm_ev == NULL)
  88                         continue;
  89
  90                 prop_object_retain(ev_dict);
  91                 udm_ev->ev_dict = ev_dict;
  92
  93                 if (match_event_filter(udm,
  94                     prop_dictionary_get(udm_ev->ev_dict, "evdict")) == 0) {
  95                         prop_object_release(ev_dict);
  96                         free(udm_ev);
  97                         continue;
  98                 }
  99
 100                 pthread_mutex_lock(&udm->q_lock);
 101                 TAILQ_INSERT_TAIL(&udm->ev_queue, udm_ev, link);
 102                 pthread_cond_signal(&udm->cond);
 103                 pthread_mutex_unlock(&udm->q_lock);
 104         }
 105
 106         MONITOR_UNLOCK();
 107 }
 108
 109 struct udev_monitor *
 110 udev_monitor_init(struct client_info *cli, prop_array_t filters)
 111 {
 112         struct udev_monitor *udm;
 113         int error;
 114
 115         udm = malloc(sizeof(struct udev_monitor));
 116         if (udm == NULL)
 117                 return NULL;
 118
 119         TAILQ_INIT(&udm->ev_queue);
 120         TAILQ_INIT(&udm->ev_filt);
 121
 122         pthread_mutex_init(&udm->q_lock, NULL);
 123         pthread_cond_init(&udm->cond, NULL);
 124         udm->cli = cli;
 125
 126         if (filters != NULL) {
 127                 error = _parse_filter_prop(udm, filters);
 128                 /* XXX: ignore error for now */
 129         }
 130
 131         return udm;
 132 }
 133
 134 void
 135 udev_monitor_free(struct udev_monitor *udm)
 136 {
 137         struct event_filter     *evf;
 138         struct udev_monitor_event       *udm_ev;
 139
 140         pthread_mutex_lock(&udm->q_lock);
 141
 142         while ((udm_ev = TAILQ_FIRST(&udm->ev_queue)) != NULL) {
 143                 prop_object_release(udm_ev->ev_dict);
 144                 udm_ev->ev_dict = NULL;
 145                 TAILQ_REMOVE(&udm->ev_queue, udm_ev, link);
 146                 free(udm_ev);
 147         }
 148
 149         while ((evf = TAILQ_FIRST(&udm->ev_filt)) != NULL) {
 150                 TAILQ_REMOVE(&udm->ev_filt, evf, link);
 151                 free(evf->key);
 152                 if (evf->type == EVENT_FILTER_TYPE_WILDCARD)
 153                         free(evf->wildcard_match);
 154                 else if (evf->type == EVENT_FILTER_TYPE_REGEX)
 155                         regfree(&evf->regex_match);
 156                 free(evf);
 157         }
 158
 159         pthread_mutex_unlock(&udm->q_lock);
 160         free(udm);
 161 }
 162
 163 int
 164 client_cmd_monitor(struct client_info *cli, prop_dictionary_t dict)
 165 {
 166         prop_array_t    pa;
 167         prop_object_t   po;
 168         struct udev_monitor     *udm;
 169         struct udev_monitor_event       *udm_ev;
 170         struct timespec abstime;
 171         struct pollfd fds[1];
 172         char *xml;
 173         ssize_t r;
 174         int ret, ok, dummy;
 175
 176         pa = NULL;
 177         po = prop_dictionary_get(dict, "filters");
 178         if ((po != NULL) && prop_object_type(po) == PROP_TYPE_ARRAY) {
 179                 pa = po;
 180         }
 181
 182         udm = udev_monitor_init(cli, pa);
 183         if (udm == NULL)
 184                 return 1;
 185
 186         ok = 1;
 187         fds[0].fd = cli->fd;
 188         fds[0].events = POLLRDNORM;
 189
 190         MONITOR_LOCK();
 191         TAILQ_INSERT_TAIL(&udev_monitor_list, udm, link);
 192         MONITOR_UNLOCK();
 193
 194         pthread_mutex_lock(&udm->q_lock);
 195         while (ok) {
 196                 clock_gettime(CLOCK_REALTIME,&abstime);
 197                 abstime.tv_sec += 2;
 198                 ret = pthread_cond_timedwait(&udm->cond, &udm->q_lock, &abstime);
 199
 200                 if (ret == EINVAL) {
 201                         syslog(LOG_ERR, "pthread_cond_timedwait error: EINVAL");
 202                         goto end_nofree;
 203                 }
 204
 205                 if ((ret = poll(fds, 1, 0)) > 0) {
 206                         ret = recv(fds[0].fd, &dummy, sizeof(dummy), MSG_DONTWAIT);
 207                         if ((ret == 0) || ((ret < 0) && (errno != EAGAIN)))
 208                                 goto end_nofree;
 209                 }
 210
 211                 udm_ev = TAILQ_FIRST(&udm->ev_queue);
 212                 if (udm_ev == NULL)
 213                         continue;
 214
 215                 assert(udm_ev->ev_dict != NULL);
 216                 xml = prop_dictionary_externalize(udm_ev->ev_dict);
 217                 if (xml == NULL)
 218                         continue;
 219
 220                 prop_object_release(udm_ev->ev_dict);
 221                 udm_ev->ev_dict = NULL;
 222                 TAILQ_REMOVE(&udm->ev_queue, udm_ev, link);
 223                 free(udm_ev);
 224
 225                 r = send_xml(cli->fd, xml);
 226                 if (r <= 0)
 227                         goto end;
 228
 229                 free(xml);
 230                 continue;
 231 end:
 232                 free(xml);
 233 end_nofree:
 234                 pthread_mutex_unlock(&udm->q_lock);
 235                 close(cli->fd);
 236                 ok = 0;
 237
 238         }
 239
 240         MONITOR_LOCK();
 241         TAILQ_REMOVE(&udev_monitor_list, udm, link);
 242         MONITOR_UNLOCK();
 243
 244         udev_monitor_free(udm);
 245
 246         return 1;
 247 }
 248
 249 static int
 250 _parse_filter_prop(struct udev_monitor *udm, prop_array_t pa)
 251 {
 252         prop_string_t   ps;
 253         prop_number_t   pn;
 254         prop_object_iterator_t  iter;
 255         prop_dictionary_t       dict;
 256         struct event_filter *evf;
 257         int error;
 258
 259         iter = prop_array_iterator(pa);
 260         if (iter == NULL)
 261                 return -1;
 262
 263         while ((dict = prop_object_iterator_next(iter)) != NULL) {
 264                 evf = malloc(sizeof(struct event_filter));
 265                 bzero(evf, sizeof(struct event_filter));
 266                 if (evf == NULL)
 267                         goto error_alloc;
 268
 269                 ps = prop_dictionary_get(dict, "key");
 270                 if (ps == NULL)
 271                         goto error_out;
 272                 evf->key = prop_string_cstring(ps);
 273                 if (evf->key == NULL)
 274                         goto error_out;
 275
 276                 pn = prop_dictionary_get(dict, "type");
 277                 if (pn == NULL)
 278                         goto error_out_ps;
 279
 280                 ps = prop_dictionary_get(dict, "expr");
 281                 if (ps == NULL)
 282                         goto error_out_ps;
 283
 284                 if (prop_dictionary_get(dict, "negative"))
 285                         evf->neg = 1;
 286                 else
 287                         evf->neg = 0;
 288
 289                 evf->type = prop_number_integer_value(pn);
 290                 switch (evf->type) {
 291                 case EVENT_FILTER_TYPE_WILDCARD:
 292                         evf->wildcard_match = prop_string_cstring(ps);
 293                         if (evf->wildcard_match == NULL)
 294                                 goto error_out_ps;
 295                         break;
 296
 297                 case EVENT_FILTER_TYPE_REGEX:
 298                         error = regcomp(&evf->regex_match, prop_string_cstring_nocopy(ps), REG_ICASE | REG_NOSUB);
 299                         if (error)
 300                                 goto error_out_ps;
 301                         break;
 302
 303                 default:
 304                         goto error_out_ps;
 305                 }
 306
 307                 pthread_mutex_lock(&udm->q_lock);
 308                 TAILQ_INSERT_TAIL(&udm->ev_filt, evf, link);
 309                 pthread_mutex_unlock(&udm->q_lock);
 310
 311         }
 312
 313         prop_object_iterator_release(iter);
 314         return 0;
 315
 316 error_out_ps:
 317         free(evf->key);
 318 error_out:
 319         free(evf);
 320 error_alloc:
 321         prop_object_iterator_release(iter);
 322         return -1;
 323 }
 324
 325 /*
 326 Event filter format:
 327 <array>
 328 <dictionary>
 329 <key>key</key>
 330 <value>(e.g. kptr, devnum, ...)</value>
 331 <key>type</key>
 332 <value>(e.g. wildcard or regex)</value>
 333 <key>expr</key>
 334 <value>(regex)</value>
 335 </dictionary>
 336 ... repeat ...
 337 </array>
 338 */
 339
 340 static int
 341 match_filter(struct event_filter *evf, prop_dictionary_t ev_dict)
 342 {
 343         prop_object_t           po;
 344         prop_string_t           ps;
 345         prop_number_t           pn;
 346         char *str;
 347         char buf[128];
 348         int ret;
 349
 350         if (ev_dict == NULL)
 351                 return 0;
 352
 353         prop_object_retain(ev_dict);
 354
 355         if ((po = prop_dictionary_get(ev_dict, evf->key)) == NULL)
 356                 goto no_match;
 357
 358         if (prop_object_type(po) == PROP_TYPE_STRING) {
 359                 ps = po;
 360                 str = __DECONST(char *, prop_string_cstring_nocopy(ps));
 361         } else if (prop_object_type(po) == PROP_TYPE_NUMBER) {
 362                 pn = po;
 363                 if (prop_number_unsigned(pn)) {
 364                         snprintf(buf, sizeof(buf), "%" PRIu64, prop_number_unsigned_integer_value(pn));
 365                 } else {
 366                         snprintf(buf, sizeof(buf), "%" PRIi64, prop_number_integer_value(pn));
 367                 }
 368                 str = buf;
 369         } else {
 370                 syslog(LOG_DEBUG, "Unexpected type in match_filter: %d\n", prop_object_type(po));
 371                 /* Unexpected type */
 372                 goto no_match;
 373         }
 374
 375         switch (evf->type) {
 376         case EVENT_FILTER_TYPE_WILDCARD:
 377                 ret = WildCaseCmp(evf->wildcard_match, str);
 378
 379                 if (ret != 0)
 380                         goto no_match;
 381
 382                 break;
 383         case EVENT_FILTER_TYPE_REGEX:
 384                 ret = regexec(&evf->regex_match, str, 0, NULL, 0);
 385
 386                 if (ret != 0)
 387                         goto no_match;
 388                 break;
 389         default:
 390                 goto no_match;
 391         }
 392
 393         prop_object_release(ev_dict);
 394         return 1;
 395
 396 no_match:
 397         prop_object_release(ev_dict);
 398         return 0;
 399 }
 400
 401 int
 402 match_event_filter(struct udev_monitor *udm, prop_dictionary_t ev_dict)
 403 {
 404         struct event_filter *evf;
 405
 406         pthread_mutex_lock(&udm->q_lock);
 407
 408         if (TAILQ_EMPTY(&udm->ev_filt))
 409                 return 1;
 410
 411         TAILQ_FOREACH(evf, &udm->ev_filt, link) {
 412                 if ((evf->neg == 0 && !match_filter(evf, ev_dict)) ||
 413                    (evf->neg == 1 && match_filter(evf, ev_dict))) {
 414                         pthread_mutex_unlock(&udm->q_lock);
 415                         return 0;
 416                 }
 417         }
 418
 419         pthread_mutex_unlock(&udm->q_lock);
 420         return 1;
 421 }
 422
 423 static int
 424 WildCaseCmp(const char *w, const char *s)
 425 {
 426     int i;
 427     int c;
 428     int slen = strlen(s);
 429     const char **mary;
 430
 431     for (i = c = 0; w[i]; ++i) {
 432         if (w[i] == '*')
 433             ++c;
 434     }
 435     mary = malloc(sizeof(char *) * (c + 1));
 436     if (mary == NULL)
 437              return -1;
 438
 439     for (i = 0; i < c; ++i)
 440         mary[i] = s + slen;
 441     i = wildCaseCmp(mary, 0, w, s);
 442     free(mary);
 443     return(i);
 444 }
 445
 446 /*
 447  * WildCaseCmp() - compare wild string to sane string, case insensitive
 448  *
 449  *      Returns 0 on success, -1 on failure.
 450  */
 451 static int
 452 wildCaseCmp(const char **mary, int d, const char *w, const char *s)
 453 {
 454     int i;
 455
 456     /*
 457      * skip fixed portion
 458      */
 459     for (;;) {
 460         switch(*w) {
 461         case '*':
 462             /*
 463              * optimize terminator
 464              */
 465             if (w[1] == 0)
 466                 return(0);
 467             if (w[1] != '?' && w[1] != '*') {
 468                 /*
 469                  * optimize * followed by non-wild
 470                  */
 471                 for (i = 0; s + i < mary[d]; ++i) {
 472                     if (s[i] == w[1] && wildCaseCmp(mary, d + 1, w + 1, s + i) == 0)
 473                         return(0);
 474                 }
 475             } else {
 476                 /*
 477                  * less-optimal
 478                  */
 479                 for (i = 0; s + i < mary[d]; ++i) {
 480                     if (wildCaseCmp(mary, d + 1, w + 1, s + i) == 0)
 481                         return(0);
 482                 }
 483             }
 484             mary[d] = s;
 485             return(-1);
 486         case '?':
 487             if (*s == 0)
 488                 return(-1);
 489             ++w;
 490             ++s;
 491             break;
 492         default:
 493             if (*w != *s) {
 494                 if (tolower(*w) != tolower(*s))
 495                     return(-1);
 496             }
 497             if (*w == 0)        /* terminator */
 498                 return(0);
 499             ++w;
 500             ++s;
 501             break;
 502         }
 503     }
 504     /* not reached */
 505     return(-1);
 506 }