lib/libdevattr/devattr_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
  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 #define LIBDEVATTR_INTERNAL
  61 #include "devattr.h"
  62
  63 struct udev_monitor {
  64         struct udev     *udev_ctx;
  65         prop_array_t    ev_filt;
  66         int     socket;
  67         int     user_socket; /* maybe... one day... */
  68         int     refs;
  69 };
  70
  71 struct udev_monitor *
  72 udev_monitor_new(struct udev *udev_ctx)
  73 {
  74         struct udev_monitor *udev_monitor;
  75         int ret, s;
  76
  77         ret = conn_local_server(LISTEN_SOCKET_FILE, SOCK_STREAM, 0, &s);
  78         if (ret < 0)
  79                 return NULL;
  80
  81         udev_monitor = malloc(sizeof(struct udev_monitor));
  82         if (udev_monitor == NULL)
  83                 return NULL;
  84
  85         udev_monitor->refs = 1;
  86         udev_monitor->ev_filt = NULL;
  87         udev_monitor->socket = s;
  88         udev_monitor->user_socket = 1;
  89         udev_monitor->udev_ctx = udev_ref(udev_ctx);
  90
  91         return udev_monitor;
  92 }
  93
  94
  95 struct udev_monitor *
  96 udev_monitor_ref(struct udev_monitor *udev_monitor)
  97 {
  98         atomic_add_int(&udev_monitor->refs, 1);
  99
 100         return udev_monitor;
 101 }
 102
 103 void
 104 udev_monitor_unref(struct udev_monitor *udev_monitor)
 105 {
 106         int refcount;
 107
 108         refcount = atomic_fetchadd_int(&udev_monitor->refs, -1);
 109
 110         if (refcount == 1) {
 111                 atomic_subtract_int(&udev_monitor->refs, 0x400); /* in destruction */
 112                 if (udev_monitor->ev_filt != NULL)
 113                         prop_object_release(udev_monitor->ev_filt);
 114
 115                 if (udev_monitor->socket != -1)
 116                         close(udev_monitor->socket);
 117                 if (udev_monitor->user_socket != -1)
 118                         close(udev_monitor->user_socket);
 119
 120                 udev_unref(udev_monitor->udev_ctx);
 121                 free(udev_monitor);
 122         }
 123 }
 124
 125 struct udev *
 126 udev_monitor_get_udev(struct udev_monitor *udev_monitor)
 127 {
 128         return udev_monitor->udev_ctx;
 129 }
 130
 131 int
 132 udev_monitor_get_fd(struct udev_monitor *udev_monitor)
 133 {
 134         return udev_monitor->socket;
 135 }
 136
 137 struct udev_device *
 138 udev_monitor_receive_device(struct udev_monitor *udev_monitor)
 139 {
 140         struct udev_device *udev_dev;
 141         prop_dictionary_t dict, evdict;
 142         prop_number_t   pn;
 143         char *xml;
 144         int n;
 145
 146         if ((n = read_xml(udev_monitor->socket, &xml)) <= 0)
 147                 return NULL;
 148
 149         xml[n+1] = '\0';
 150         dict = prop_dictionary_internalize(xml);
 151         free(xml);
 152         if (dict == NULL)
 153                 return NULL;
 154
 155         pn = prop_dictionary_get(dict, "evtype");
 156         if (pn == NULL) {
 157                 prop_object_release(dict);
 158                 return NULL;
 159         }
 160
 161         evdict = prop_dictionary_get(dict, "evdict");
 162         if (evdict == NULL) {
 163                 prop_object_release(dict);
 164                 return NULL;
 165         }
 166
 167         udev_dev = udev_device_new_from_dictionary(udev_monitor->udev_ctx, evdict);
 168         if (udev_dev == NULL) {
 169                 prop_object_release(dict);
 170                 return NULL;
 171         }
 172
 173         udev_device_set_action(udev_dev, prop_number_integer_value(pn));
 174
 175         prop_object_release(dict);
 176         return udev_dev;
 177 }
 178
 179 int
 180 udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
 181 {
 182         prop_dictionary_t       dict;
 183         char *xml;
 184         int n;
 185         /* ->socket, ->user_socket, ->ev_filt */
 186
 187         dict = udevd_get_command_dict(__DECONST(char *, "monitor"));
 188         if (dict == NULL)
 189                 return -1;
 190
 191         /* Add event filters to message, if available */
 192         if (udev_monitor->ev_filt != NULL) {
 193                 if (prop_dictionary_set(dict, "filters",
 194                     udev_monitor->ev_filt) == false) {
 195                         prop_object_release(dict);
 196                         return -1;
 197                 }
 198         }
 199
 200         xml = prop_dictionary_externalize(dict);
 201         prop_object_release(dict);
 202         if (xml == NULL)
 203                 return -1;
 204
 205         n = send_xml(udev_monitor->socket, xml);
 206         free(xml);
 207         if (n <= 0)
 208                 return -1;
 209
 210         return 0;
 211 }
 212
 213 int
 214 udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor,
 215                                                 const char *subsystem,
 216                                                 const char *devtype __unused)
 217 {
 218         int ret;
 219
 220         ret = _udev_monitor_filter_add_match_gen(udev_monitor,
 221                                                  EVENT_FILTER_TYPE_WILDCARD,
 222                                                  0,
 223                                                  "subsystem",
 224                                                  __DECONST(char *, subsystem));
 225
 226         return ret;
 227 }
 228
 229 int
 230 udev_monitor_filter_add_match_expr(struct udev_monitor *udev_monitor,
 231                                    const char *key,
 232                                    char *expr)
 233 {
 234         int ret;
 235
 236         ret = _udev_monitor_filter_add_match_gen(udev_monitor,
 237                                                  EVENT_FILTER_TYPE_WILDCARD,
 238                                                  0,
 239                                                  key,
 240                                                  expr);
 241
 242         return ret;
 243 }
 244
 245 int
 246 udev_monitor_filter_add_nomatch_expr(struct udev_monitor *udev_monitor,
 247                                      const char *key,
 248                                      char *expr)
 249 {
 250         int ret;
 251
 252         ret = _udev_monitor_filter_add_match_gen(udev_monitor,
 253                                                  EVENT_FILTER_TYPE_WILDCARD,
 254                                                  1,
 255                                                  key,
 256                                                  expr);
 257
 258         return ret;
 259 }
 260
 261 int
 262 udev_monitor_filter_add_match_regex(struct udev_monitor *udev_monitor,
 263                                    const char *key,
 264                                    char *expr)
 265 {
 266         int ret;
 267
 268         ret = _udev_monitor_filter_add_match_gen(udev_monitor,
 269                                                  EVENT_FILTER_TYPE_REGEX,
 270                                                  0,
 271                                                  key,
 272                                                  expr);
 273
 274         return ret;
 275 }
 276
 277 int
 278 udev_monitor_filter_add_nomatch_regex(struct udev_monitor *udev_monitor,
 279                                      const char *key,
 280                                      char *expr)
 281 {
 282         int ret;
 283
 284         ret = _udev_monitor_filter_add_match_gen(udev_monitor,
 285                                                  EVENT_FILTER_TYPE_REGEX,
 286                                                  1,
 287                                                  key,
 288                                                  expr);
 289
 290         return ret;
 291 }
 292
 293 int
 294 _udev_filter_add_match_gen(prop_array_t filters,
 295                                    int type,
 296                                    int neg,
 297                                    const char *key,
 298                                    char *expr)
 299 {
 300         prop_dictionary_t       dict;
 301         int error;
 302
 303         if (key == NULL)
 304                 return -1;
 305         if (expr == NULL)
 306                 return -1;
 307
 308         dict = prop_dictionary_create();
 309         if (dict == NULL)
 310                 return -1;
 311
 312         error = _udev_dict_set_cstr(dict, "key", __DECONST(char *, key));
 313         if (error != 0)
 314                 goto error_out;
 315         error = _udev_dict_set_int(dict, "type", type);
 316         if (error != 0)
 317                 goto error_out;
 318         error = _udev_dict_set_cstr(dict, "expr", expr);
 319         if (error != 0)
 320                 goto error_out;
 321
 322         if (neg) {
 323                 error = _udev_dict_set_int(dict, "negative", 1);
 324                 if (error != 0)
 325                         goto error_out;
 326         }
 327
 328         if (prop_array_add(filters, dict) == false)
 329                 goto error_out;
 330
 331         return 0;
 332
 333 error_out:
 334         prop_object_release(dict);
 335         return -1;
 336 }
 337
 338 int
 339 _udev_monitor_filter_add_match_gen(struct udev_monitor *udev_monitor,
 340                                    int type,
 341                                    int neg,
 342                                    const char *key,
 343                                    char *expr)
 344 {
 345         prop_array_t            pa;
 346         int error;
 347
 348         if (udev_monitor->ev_filt == NULL) {
 349                 pa = prop_array_create_with_capacity(5);
 350                 if (pa == NULL)
 351                         return -1;
 352
 353                 udev_monitor->ev_filt = pa;
 354         }
 355
 356         error = _udev_filter_add_match_gen(udev_monitor->ev_filt, type, neg, key, expr);
 357
 358         return error;
 359 }
 360