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1 /* dnsmasq is Copyright (c) 2000-2009 Simon Kelley
2 
3    This program is free software; you can redistribute it and/or modify
4    it under the terms of the GNU General Public License as published by
5    the Free Software Foundation; version 2 dated June, 1991, or
6    (at your option) version 3 dated 29 June, 2007.
7 
8    This program is distributed in the hope that it will be useful,
9    but WITHOUT ANY WARRANTY; without even the implied warranty of
10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11    GNU General Public License for more details.
12 
13    You should have received a copy of the GNU General Public License
14    along with this program.  If not, see <http://www.gnu.org/licenses/>.
15 */
16 
17 #include "dnsmasq.h"
18 
19 #ifdef HAVE_DBUS
20 
21 #include <dbus/dbus.h>
22 
23 const char* introspection_xml =
24 "<!DOCTYPE node PUBLIC \"-//freedesktop//DTD D-BUS Object Introspection 1.0//EN\"\n"
25 "\"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd\">\n"
26 "<node name=\"" DNSMASQ_PATH "\">\n"
27 "  <interface name=\"org.freedesktop.DBus.Introspectable\">\n"
28 "    <method name=\"Introspect\">\n"
29 "      <arg name=\"data\" direction=\"out\" type=\"s\"/>\n"
30 "    </method>\n"
31 "  </interface>\n"
32 "  <interface name=\"" DNSMASQ_SERVICE "\">\n"
33 "    <method name=\"ClearCache\">\n"
34 "    </method>\n"
35 "    <method name=\"GetVersion\">\n"
36 "      <arg name=\"version\" direction=\"out\" type=\"s\"/>\n"
37 "    </method>\n"
38 "    <method name=\"SetServers\">\n"
39 "      <arg name=\"servers\" direction=\"in\" type=\"av\"/>\n"
40 "    </method>\n"
41 "    <signal name=\"DhcpLeaseAdded\">\n"
42 "      <arg name=\"ipaddr\" type=\"s\"/>\n"
43 "      <arg name=\"hwaddr\" type=\"s\"/>\n"
44 "      <arg name=\"hostname\" type=\"s\"/>\n"
45 "    </signal>\n"
46 "    <signal name=\"DhcpLeaseDeleted\">\n"
47 "      <arg name=\"ipaddr\" type=\"s\"/>\n"
48 "      <arg name=\"hwaddr\" type=\"s\"/>\n"
49 "      <arg name=\"hostname\" type=\"s\"/>\n"
50 "    </signal>\n"
51 "    <signal name=\"DhcpLeaseUpdated\">\n"
52 "      <arg name=\"ipaddr\" type=\"s\"/>\n"
53 "      <arg name=\"hwaddr\" type=\"s\"/>\n"
54 "      <arg name=\"hostname\" type=\"s\"/>\n"
55 "    </signal>\n"
56 "  </interface>\n"
57 "</node>\n";
58 
59 struct watch {
60   DBusWatch *watch;
61   struct watch *next;
62 };
63 
64 
add_watch(DBusWatch * watch,void * data)65 static dbus_bool_t add_watch(DBusWatch *watch, void *data)
66 {
67   struct watch *w;
68 
69   for (w = daemon->watches; w; w = w->next)
70     if (w->watch == watch)
71       return TRUE;
72 
73   if (!(w = whine_malloc(sizeof(struct watch))))
74     return FALSE;
75 
76   w->watch = watch;
77   w->next = daemon->watches;
78   daemon->watches = w;
79 
80   w = data; /* no warning */
81   return TRUE;
82 }
83 
remove_watch(DBusWatch * watch,void * data)84 static void remove_watch(DBusWatch *watch, void *data)
85 {
86   struct watch **up, *w;
87 
88   for (up = &(daemon->watches), w = daemon->watches; w; w = w->next)
89     if (w->watch == watch)
90       {
91         *up = w->next;
92         free(w);
93       }
94     else
95       up = &(w->next);
96 
97   w = data; /* no warning */
98 }
99 
dbus_read_servers(DBusMessage * message)100 static void dbus_read_servers(DBusMessage *message)
101 {
102   struct server *serv, *tmp, **up;
103   DBusMessageIter iter;
104   union  mysockaddr addr, source_addr;
105   char *domain;
106 
107   dbus_message_iter_init(message, &iter);
108 
109   /* mark everything from DBUS */
110   for (serv = daemon->servers; serv; serv = serv->next)
111     if (serv->flags & SERV_FROM_DBUS)
112       serv->flags |= SERV_MARK;
113 
114   while (1)
115     {
116       int skip = 0;
117 
118       if (dbus_message_iter_get_arg_type(&iter) == DBUS_TYPE_UINT32)
119 	{
120 	  u32 a;
121 
122 	  dbus_message_iter_get_basic(&iter, &a);
123 	  dbus_message_iter_next (&iter);
124 
125 #ifdef HAVE_SOCKADDR_SA_LEN
126 	  source_addr.in.sin_len = addr.in.sin_len = sizeof(struct sockaddr_in);
127 #endif
128 	  addr.in.sin_addr.s_addr = ntohl(a);
129 	  source_addr.in.sin_family = addr.in.sin_family = AF_INET;
130 	  addr.in.sin_port = htons(NAMESERVER_PORT);
131 	  source_addr.in.sin_addr.s_addr = INADDR_ANY;
132 	  source_addr.in.sin_port = htons(daemon->query_port);
133 	}
134       else if (dbus_message_iter_get_arg_type(&iter) == DBUS_TYPE_BYTE)
135 	{
136 	  unsigned char p[sizeof(struct in6_addr)];
137 	  unsigned int i;
138 
139 	  skip = 1;
140 
141 	  for(i = 0; i < sizeof(struct in6_addr); i++)
142 	    {
143 	      dbus_message_iter_get_basic(&iter, &p[i]);
144 	      dbus_message_iter_next (&iter);
145 	      if (dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_BYTE)
146 		break;
147 	    }
148 
149 #ifndef HAVE_IPV6
150 	  my_syslog(LOG_WARNING, _("attempt to set an IPv6 server address via DBus - no IPv6 support"));
151 #else
152 	  if (i == sizeof(struct in6_addr)-1)
153 	    {
154 	      memcpy(&addr.in6.sin6_addr, p, sizeof(struct in6_addr));
155 #ifdef HAVE_SOCKADDR_SA_LEN
156               source_addr.in6.sin6_len = addr.in6.sin6_len = sizeof(struct sockaddr_in6);
157 #endif
158               source_addr.in6.sin6_family = addr.in6.sin6_family = AF_INET6;
159               addr.in6.sin6_port = htons(NAMESERVER_PORT);
160               source_addr.in6.sin6_flowinfo = addr.in6.sin6_flowinfo = 0;
161 	      source_addr.in6.sin6_scope_id = addr.in6.sin6_scope_id = 0;
162               source_addr.in6.sin6_addr = in6addr_any;
163               source_addr.in6.sin6_port = htons(daemon->query_port);
164 	      skip = 0;
165 	    }
166 #endif
167 	}
168       else
169 	/* At the end */
170 	break;
171 
172       do {
173 	if (dbus_message_iter_get_arg_type(&iter) == DBUS_TYPE_STRING)
174 	  {
175 	    dbus_message_iter_get_basic(&iter, &domain);
176 	    dbus_message_iter_next (&iter);
177 	  }
178 	else
179 	  domain = NULL;
180 
181 	if (!skip)
182 	  {
183 	    /* See if this is already there, and unmark */
184 	    for (serv = daemon->servers; serv; serv = serv->next)
185 	      if ((serv->flags & SERV_FROM_DBUS) &&
186 		  (serv->flags & SERV_MARK))
187 		{
188 		  if (!(serv->flags & SERV_HAS_DOMAIN) && !domain)
189 		    {
190 		      serv->flags &= ~SERV_MARK;
191 		      break;
192 		    }
193 		  if ((serv->flags & SERV_HAS_DOMAIN) &&
194 		      domain &&
195 		      hostname_isequal(domain, serv->domain))
196 		    {
197 		      serv->flags &= ~SERV_MARK;
198 		      break;
199 		    }
200 		}
201 
202 	    if (!serv && (serv = whine_malloc(sizeof (struct server))))
203 	      {
204 		/* Not found, create a new one. */
205 		memset(serv, 0, sizeof(struct server));
206 
207 		if (domain)
208 		  serv->domain = whine_malloc(strlen(domain)+1);
209 
210 		if (domain && !serv->domain)
211 		  {
212 		    free(serv);
213 		    serv = NULL;
214 		  }
215 		else
216 		  {
217 		    serv->next = daemon->servers;
218 		    daemon->servers = serv;
219 		    serv->flags = SERV_FROM_DBUS;
220 		    if (domain)
221 		      {
222 			strcpy(serv->domain, domain);
223 			serv->flags |= SERV_HAS_DOMAIN;
224 		      }
225 		  }
226 	      }
227 
228 	    if (serv)
229 	      {
230 		if (source_addr.in.sin_family == AF_INET &&
231 		    addr.in.sin_addr.s_addr == 0 &&
232 		    serv->domain)
233 		  serv->flags |= SERV_NO_ADDR;
234 		else
235 		  {
236 		    serv->flags &= ~SERV_NO_ADDR;
237 		    serv->addr = addr;
238 		    serv->source_addr = source_addr;
239 		  }
240 	      }
241 	  }
242 	} while (dbus_message_iter_get_arg_type(&iter) == DBUS_TYPE_STRING);
243     }
244 
245   /* unlink and free anything still marked. */
246   for (serv = daemon->servers, up = &daemon->servers; serv; serv = tmp)
247     {
248       tmp = serv->next;
249       if (serv->flags & SERV_MARK)
250 	{
251 	  server_gone(serv);
252 	  *up = serv->next;
253 	  free(serv);
254 	}
255       else
256 	up = &serv->next;
257     }
258 
259 }
260 
message_handler(DBusConnection * connection,DBusMessage * message,void * user_data)261 DBusHandlerResult message_handler(DBusConnection *connection,
262 				  DBusMessage *message,
263 				  void *user_data)
264 {
265   char *method = (char *)dbus_message_get_member(message);
266 
267   if (dbus_message_is_method_call(message, DBUS_INTERFACE_INTROSPECTABLE, "Introspect"))
268     {
269       DBusMessage *reply = dbus_message_new_method_return(message);
270 
271       dbus_message_append_args(reply, DBUS_TYPE_STRING, &introspection_xml, DBUS_TYPE_INVALID);
272       dbus_connection_send (connection, reply, NULL);
273       dbus_message_unref (reply);
274     }
275   else if (strcmp(method, "GetVersion") == 0)
276     {
277       char *v = VERSION;
278       DBusMessage *reply = dbus_message_new_method_return(message);
279 
280       dbus_message_append_args(reply, DBUS_TYPE_STRING, &v, DBUS_TYPE_INVALID);
281       dbus_connection_send (connection, reply, NULL);
282       dbus_message_unref (reply);
283     }
284   else if (strcmp(method, "SetServers") == 0)
285     {
286       my_syslog(LOG_INFO, _("setting upstream servers from DBus"));
287       dbus_read_servers(message);
288       check_servers();
289     }
290   else if (strcmp(method, "ClearCache") == 0)
291     clear_cache_and_reload(dnsmasq_time());
292   else
293     return (DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
294 
295   method = user_data; /* no warning */
296 
297   return (DBUS_HANDLER_RESULT_HANDLED);
298 
299 }
300 
301 
302 /* returns NULL or error message, may fail silently if dbus daemon not yet up. */
dbus_init(void)303 char *dbus_init(void)
304 {
305   DBusConnection *connection = NULL;
306   DBusObjectPathVTable dnsmasq_vtable = {NULL, &message_handler, NULL, NULL, NULL, NULL };
307   DBusError dbus_error;
308   DBusMessage *message;
309 
310   dbus_error_init (&dbus_error);
311   if (!(connection = dbus_bus_get (DBUS_BUS_SYSTEM, &dbus_error)))
312     return NULL;
313 
314   dbus_connection_set_exit_on_disconnect(connection, FALSE);
315   dbus_connection_set_watch_functions(connection, add_watch, remove_watch,
316 				      NULL, NULL, NULL);
317   dbus_error_init (&dbus_error);
318   dbus_bus_request_name (connection, DNSMASQ_SERVICE, 0, &dbus_error);
319   if (dbus_error_is_set (&dbus_error))
320     return (char *)dbus_error.message;
321 
322   if (!dbus_connection_register_object_path(connection,  DNSMASQ_PATH,
323 					    &dnsmasq_vtable, NULL))
324     return _("could not register a DBus message handler");
325 
326   daemon->dbus = connection;
327 
328   if ((message = dbus_message_new_signal(DNSMASQ_PATH, DNSMASQ_SERVICE, "Up")))
329     {
330       dbus_connection_send(connection, message, NULL);
331       dbus_message_unref(message);
332     }
333 
334   return NULL;
335 }
336 
337 
set_dbus_listeners(int * maxfdp,fd_set * rset,fd_set * wset,fd_set * eset)338 void set_dbus_listeners(int *maxfdp,
339 			fd_set *rset, fd_set *wset, fd_set *eset)
340 {
341   struct watch *w;
342 
343   for (w = daemon->watches; w; w = w->next)
344     if (dbus_watch_get_enabled(w->watch))
345       {
346 	unsigned int flags = dbus_watch_get_flags(w->watch);
347 	int fd = dbus_watch_get_unix_fd(w->watch);
348 
349 	bump_maxfd(fd, maxfdp);
350 
351 	if (flags & DBUS_WATCH_READABLE)
352 	  FD_SET(fd, rset);
353 
354 	if (flags & DBUS_WATCH_WRITABLE)
355 	  FD_SET(fd, wset);
356 
357 	FD_SET(fd, eset);
358       }
359 }
360 
check_dbus_listeners(fd_set * rset,fd_set * wset,fd_set * eset)361 void check_dbus_listeners(fd_set *rset, fd_set *wset, fd_set *eset)
362 {
363   DBusConnection *connection = (DBusConnection *)daemon->dbus;
364   struct watch *w;
365 
366   for (w = daemon->watches; w; w = w->next)
367     if (dbus_watch_get_enabled(w->watch))
368       {
369 	unsigned int flags = 0;
370 	int fd = dbus_watch_get_unix_fd(w->watch);
371 
372 	if (FD_ISSET(fd, rset))
373 	  flags |= DBUS_WATCH_READABLE;
374 
375 	if (FD_ISSET(fd, wset))
376 	  flags |= DBUS_WATCH_WRITABLE;
377 
378 	if (FD_ISSET(fd, eset))
379 	  flags |= DBUS_WATCH_ERROR;
380 
381 	if (flags != 0)
382 	  dbus_watch_handle(w->watch, flags);
383       }
384 
385   if (connection)
386     {
387       dbus_connection_ref (connection);
388       while (dbus_connection_dispatch (connection) == DBUS_DISPATCH_DATA_REMAINS);
389       dbus_connection_unref (connection);
390     }
391 }
392 
emit_dbus_signal(int action,struct dhcp_lease * lease,char * hostname)393 void emit_dbus_signal(int action, struct dhcp_lease *lease, char *hostname)
394 {
395   DBusConnection *connection = (DBusConnection *)daemon->dbus;
396   DBusMessage* message = NULL;
397   DBusMessageIter args;
398   char *action_str, *addr, *mac = daemon->namebuff;
399   unsigned char *p;
400   int i;
401 
402   if (!connection)
403     return;
404 
405   if (!hostname)
406     hostname = "";
407 
408   p = extended_hwaddr(lease->hwaddr_type, lease->hwaddr_len,
409 		      lease->hwaddr, lease->clid_len, lease->clid, &i);
410   print_mac(mac, p, i);
411 
412   if (action == ACTION_DEL)
413     action_str = "DhcpLeaseDeleted";
414   else if (action == ACTION_ADD)
415     action_str = "DhcpLeaseAdded";
416   else if (action == ACTION_OLD)
417     action_str = "DhcpLeaseUpdated";
418   else
419     return;
420 
421   addr = inet_ntoa(lease->addr);
422 
423   if (!(message = dbus_message_new_signal(DNSMASQ_PATH, DNSMASQ_SERVICE, action_str)))
424     return;
425 
426   dbus_message_iter_init_append(message, &args);
427 
428   if (dbus_message_iter_append_basic(&args, DBUS_TYPE_STRING, &addr) &&
429       dbus_message_iter_append_basic(&args, DBUS_TYPE_STRING, &mac) &&
430       dbus_message_iter_append_basic(&args, DBUS_TYPE_STRING, &hostname))
431     dbus_connection_send(connection, message, NULL);
432 
433   dbus_message_unref(message);
434 }
435 
436 #endif
437