xref: /freebsd/contrib/libevent/include/event2/dns_compat.h (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*
2  * Copyright (c) 2006-2007 Niels Provos <provos@citi.umich.edu>
3  * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. The name of the author may not be used to endorse or promote products
14  *    derived from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 #ifndef EVENT2_DNS_COMPAT_H_INCLUDED_
28 #define EVENT2_DNS_COMPAT_H_INCLUDED_
29 
30 /** @file event2/dns_compat.h
31 
32   Potentially non-threadsafe versions of the functions in dns.h: provided
33   only for backwards compatibility.
34 
35 
36  */
37 
38 #ifdef __cplusplus
39 extern "C" {
40 #endif
41 
42 #include <event2/event-config.h>
43 #ifdef EVENT__HAVE_SYS_TYPES_H
44 #include <sys/types.h>
45 #endif
46 #ifdef EVENT__HAVE_SYS_TIME_H
47 #include <sys/time.h>
48 #endif
49 
50 /* For int types. */
51 #include <event2/util.h>
52 #include <event2/visibility.h>
53 
54 /**
55   Initialize the asynchronous DNS library.
56 
57   This function initializes support for non-blocking name resolution by
58   calling evdns_resolv_conf_parse() on UNIX and
59   evdns_config_windows_nameservers() on Windows.
60 
61   @deprecated This function is deprecated because it always uses the current
62     event base, and is easily confused by multiple calls to event_init(), and
63     so is not safe for multithreaded use.  Additionally, it allocates a global
64     structure that only one thread can use. The replacement is
65     evdns_base_new().
66 
67   @return 0 if successful, or -1 if an error occurred
68   @see evdns_shutdown()
69  */
70 EVENT2_EXPORT_SYMBOL
71 int evdns_init(void);
72 
73 struct evdns_base;
74 /**
75    Return the global evdns_base created by event_init() and used by the other
76    deprecated functions.
77 
78    @deprecated This function is deprecated because use of the global
79      evdns_base is error-prone.
80  */
81 EVENT2_EXPORT_SYMBOL
82 struct evdns_base *evdns_get_global_base(void);
83 
84 /**
85   Shut down the asynchronous DNS resolver and terminate all active requests.
86 
87   If the 'fail_requests' option is enabled, all active requests will return
88   an empty result with the error flag set to DNS_ERR_SHUTDOWN. Otherwise,
89   the requests will be silently discarded.
90 
91   @deprecated This function is deprecated because it does not allow the
92     caller to specify which evdns_base it applies to.  The recommended
93     function is evdns_base_shutdown().
94 
95   @param fail_requests if zero, active requests will be aborted; if non-zero,
96 		active requests will return DNS_ERR_SHUTDOWN.
97   @see evdns_init()
98  */
99 EVENT2_EXPORT_SYMBOL
100 void evdns_shutdown(int fail_requests);
101 
102 /**
103   Add a nameserver.
104 
105   The address should be an IPv4 address in network byte order.
106   The type of address is chosen so that it matches in_addr.s_addr.
107 
108   @deprecated This function is deprecated because it does not allow the
109     caller to specify which evdns_base it applies to.  The recommended
110     function is evdns_base_nameserver_add().
111 
112   @param address an IP address in network byte order
113   @return 0 if successful, or -1 if an error occurred
114   @see evdns_nameserver_ip_add()
115  */
116 EVENT2_EXPORT_SYMBOL
117 int evdns_nameserver_add(unsigned long int address);
118 
119 /**
120   Get the number of configured nameservers.
121 
122   This returns the number of configured nameservers (not necessarily the
123   number of running nameservers).  This is useful for double-checking
124   whether our calls to the various nameserver configuration functions
125   have been successful.
126 
127   @deprecated This function is deprecated because it does not allow the
128     caller to specify which evdns_base it applies to.  The recommended
129     function is evdns_base_count_nameservers().
130 
131   @return the number of configured nameservers
132   @see evdns_nameserver_add()
133  */
134 EVENT2_EXPORT_SYMBOL
135 int evdns_count_nameservers(void);
136 
137 /**
138   Remove all configured nameservers, and suspend all pending resolves.
139 
140   Resolves will not necessarily be re-attempted until evdns_resume() is called.
141 
142   @deprecated This function is deprecated because it does not allow the
143     caller to specify which evdns_base it applies to.  The recommended
144     function is evdns_base_clear_nameservers_and_suspend().
145 
146   @return 0 if successful, or -1 if an error occurred
147   @see evdns_resume()
148  */
149 EVENT2_EXPORT_SYMBOL
150 int evdns_clear_nameservers_and_suspend(void);
151 
152 /**
153   Resume normal operation and continue any suspended resolve requests.
154 
155   Re-attempt resolves left in limbo after an earlier call to
156   evdns_clear_nameservers_and_suspend().
157 
158   @deprecated This function is deprecated because it does not allow the
159     caller to specify which evdns_base it applies to.  The recommended
160     function is evdns_base_resume().
161 
162   @return 0 if successful, or -1 if an error occurred
163   @see evdns_clear_nameservers_and_suspend()
164  */
165 EVENT2_EXPORT_SYMBOL
166 int evdns_resume(void);
167 
168 /**
169   Add a nameserver.
170 
171   This wraps the evdns_nameserver_add() function by parsing a string as an IP
172   address and adds it as a nameserver.
173 
174   @deprecated This function is deprecated because it does not allow the
175     caller to specify which evdns_base it applies to.  The recommended
176     function is evdns_base_nameserver_ip_add().
177 
178   @return 0 if successful, or -1 if an error occurred
179   @see evdns_nameserver_add()
180  */
181 EVENT2_EXPORT_SYMBOL
182 int evdns_nameserver_ip_add(const char *ip_as_string);
183 
184 /**
185   Lookup an A record for a given name.
186 
187   @deprecated This function is deprecated because it does not allow the
188     caller to specify which evdns_base it applies to.  The recommended
189     function is evdns_base_resolve_ipv4().
190 
191   @param name a DNS hostname
192   @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
193   @param callback a callback function to invoke when the request is completed
194   @param ptr an argument to pass to the callback function
195   @return 0 if successful, or -1 if an error occurred
196   @see evdns_resolve_ipv6(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6()
197  */
198 EVENT2_EXPORT_SYMBOL
199 int evdns_resolve_ipv4(const char *name, int flags, evdns_callback_type callback, void *ptr);
200 
201 /**
202   Lookup an AAAA record for a given name.
203 
204   @param name a DNS hostname
205   @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
206   @param callback a callback function to invoke when the request is completed
207   @param ptr an argument to pass to the callback function
208   @return 0 if successful, or -1 if an error occurred
209   @see evdns_resolve_ipv4(), evdns_resolve_reverse(), evdns_resolve_reverse_ipv6()
210  */
211 EVENT2_EXPORT_SYMBOL
212 int evdns_resolve_ipv6(const char *name, int flags, evdns_callback_type callback, void *ptr);
213 
214 struct in_addr;
215 struct in6_addr;
216 
217 /**
218   Lookup a PTR record for a given IP address.
219 
220   @deprecated This function is deprecated because it does not allow the
221     caller to specify which evdns_base it applies to.  The recommended
222     function is evdns_base_resolve_reverse().
223 
224   @param in an IPv4 address
225   @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
226   @param callback a callback function to invoke when the request is completed
227   @param ptr an argument to pass to the callback function
228   @return 0 if successful, or -1 if an error occurred
229   @see evdns_resolve_reverse_ipv6()
230  */
231 EVENT2_EXPORT_SYMBOL
232 int evdns_resolve_reverse(const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr);
233 
234 /**
235   Lookup a PTR record for a given IPv6 address.
236 
237   @deprecated This function is deprecated because it does not allow the
238     caller to specify which evdns_base it applies to.  The recommended
239     function is evdns_base_resolve_reverse_ipv6().
240 
241   @param in an IPv6 address
242   @param flags either 0, or DNS_QUERY_NO_SEARCH to disable searching for this query.
243   @param callback a callback function to invoke when the request is completed
244   @param ptr an argument to pass to the callback function
245   @return 0 if successful, or -1 if an error occurred
246   @see evdns_resolve_reverse_ipv6()
247  */
248 EVENT2_EXPORT_SYMBOL
249 int evdns_resolve_reverse_ipv6(const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr);
250 
251 /**
252   Set the value of a configuration option.
253 
254   The currently available configuration options are:
255 
256     ndots, timeout, max-timeouts, max-inflight, and attempts
257 
258   @deprecated This function is deprecated because it does not allow the
259     caller to specify which evdns_base it applies to.  The recommended
260     function is evdns_base_set_option().
261 
262   @param option the name of the configuration option to be modified
263   @param val the value to be set
264   @param flags Ignored.
265   @return 0 if successful, or -1 if an error occurred
266  */
267 EVENT2_EXPORT_SYMBOL
268 int evdns_set_option(const char *option, const char *val, int flags);
269 
270 /**
271   Parse a resolv.conf file.
272 
273   The 'flags' parameter determines what information is parsed from the
274   resolv.conf file. See the man page for resolv.conf for the format of this
275   file.
276 
277   The following directives are not parsed from the file: sortlist, rotate,
278   no-check-names, inet6, debug.
279 
280   If this function encounters an error, the possible return values are: 1 =
281   failed to open file, 2 = failed to stat file, 3 = file too large, 4 = out of
282   memory, 5 = short read from file, 6 = no nameservers listed in the file
283 
284   @deprecated This function is deprecated because it does not allow the
285     caller to specify which evdns_base it applies to.  The recommended
286     function is evdns_base_resolv_conf_parse().
287 
288   @param flags any of DNS_OPTION_NAMESERVERS|DNS_OPTION_SEARCH|DNS_OPTION_MISC|
289     DNS_OPTIONS_ALL
290   @param filename the path to the resolv.conf file
291   @return 0 if successful, or various positive error codes if an error
292     occurred (see above)
293   @see resolv.conf(3), evdns_config_windows_nameservers()
294  */
295 EVENT2_EXPORT_SYMBOL
296 int evdns_resolv_conf_parse(int flags, const char *const filename);
297 
298 /**
299   Clear the list of search domains.
300 
301   @deprecated This function is deprecated because it does not allow the
302     caller to specify which evdns_base it applies to.  The recommended
303     function is evdns_base_search_clear().
304  */
305 EVENT2_EXPORT_SYMBOL
306 void evdns_search_clear(void);
307 
308 /**
309   Add a domain to the list of search domains
310 
311   @deprecated This function is deprecated because it does not allow the
312     caller to specify which evdns_base it applies to.  The recommended
313     function is evdns_base_search_add().
314 
315   @param domain the domain to be added to the search list
316  */
317 EVENT2_EXPORT_SYMBOL
318 void evdns_search_add(const char *domain);
319 
320 /**
321   Set the 'ndots' parameter for searches.
322 
323   Sets the number of dots which, when found in a name, causes
324   the first query to be without any search domain.
325 
326   @deprecated This function is deprecated because it does not allow the
327     caller to specify which evdns_base it applies to.  The recommended
328     function is evdns_base_search_ndots_set().
329 
330   @param ndots the new ndots parameter
331  */
332 EVENT2_EXPORT_SYMBOL
333 void evdns_search_ndots_set(const int ndots);
334 
335 /**
336    As evdns_server_new_with_base.
337 
338   @deprecated This function is deprecated because it does not allow the
339     caller to specify which even_base it uses.  The recommended
340     function is evdns_add_server_port_with_base().
341 
342 */
343 EVENT2_EXPORT_SYMBOL
344 struct evdns_server_port *
345 evdns_add_server_port(evutil_socket_t socket, int flags,
346 	evdns_request_callback_fn_type callback, void *user_data);
347 
348 #ifdef _WIN32
349 EVENT2_EXPORT_SYMBOL
350 int evdns_config_windows_nameservers(void);
351 #define EVDNS_CONFIG_WINDOWS_NAMESERVERS_IMPLEMENTED
352 #endif
353 
354 #ifdef __cplusplus
355 }
356 #endif
357 
358 #endif /* EVENT2_EVENT_COMPAT_H_INCLUDED_ */
359