dlz.h revision 170223 
1/*
2 * Portions Copyright (C) 2005  Internet Systems Consortium, Inc. ("ISC")
3 * Portions Copyright (C) 1999-2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/*
19 * Copyright (C) 2002 Stichting NLnet, Netherlands, stichting@nlnet.nl.
20 *
21 * Permission to use, copy, modify, and distribute this software for any
22 * purpose with or without fee is hereby granted, provided that the
23 * above copyright notice and this permission notice appear in all
24 * copies.
25 *
26 * THE SOFTWARE IS PROVIDED "AS IS" AND STICHTING NLNET
27 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
29 * STICHTING NLNET BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
30 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
31 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
32 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE
33 * USE OR PERFORMANCE OF THIS SOFTWARE.
34 *
35 * The development of Dynamically Loadable Zones (DLZ) for Bind 9 was
36 * conceived and contributed by Rob Butler.
37 *
38 * Permission to use, copy, modify, and distribute this software for any
39 * purpose with or without fee is hereby granted, provided that the
40 * above copyright notice and this permission notice appear in all
41 * copies.
42 *
43 * THE SOFTWARE IS PROVIDED "AS IS" AND ROB BUTLER
44 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
45 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
46 * ROB BUTLER BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR
47 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
48 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
49 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE
50 * USE OR PERFORMANCE OF THIS SOFTWARE.
51 */
52
53/* $Id: dlz.h,v 1.2.2.2 2005/09/06 03:47:18 marka Exp $ */
54
55/*! \file */
56
57#ifndef DLZ_H
58#define DLZ_H 1
59
60/*****
61 ***** Module Info
62 *****/
63
64/*
65 * DLZ Interface
66 *
67 * The DLZ interface allows zones to be looked up using a driver instead of
68 * Bind's default in memory zone table.
69 *
70 *
71 * Reliability:
72 *	No anticipated impact.
73 *
74 * Resources:
75 *
76 * Security:
77 *	No anticipated impact.
78 *
79 * Standards:
80 *	None.
81 */
82
83/*****
84 ***** Imports
85 *****/
86
87#include <dns/name.h>
88#include <dns/types.h>
89#include <dns/view.h>
90
91#include <isc/lang.h>
92
93ISC_LANG_BEGINDECLS
94
95/***
96 *** Types
97 ***/
98
99#define DNS_DLZ_MAGIC		ISC_MAGIC('D','L','Z','D')
100#define DNS_DLZ_VALID(dlz)	ISC_MAGIC_VALID(dlz, DNS_DLZ_MAGIC)
101
102typedef isc_result_t
103(*dns_dlzallowzonexfr_t)(void *driverarg, void *dbdata, isc_mem_t *mctx,
104			 dns_rdataclass_t rdclass, dns_name_t *name,
105			 isc_sockaddr_t *clientaddr,
106			 dns_db_t **dbp);
107
108/*%<
109 * Method prototype.  Drivers implementing the DLZ interface MUST
110 * supply an allow zone transfer method.  This method is called when
111 * the DNS server is performing a zone transfer query.  The driver's
112 * method should return ISC_R_SUCCESS and a database pointer to the
113 * name server if the zone is supported by the database, and zone
114 * transfer is allowed.  Otherwise it will return ISC_R_NOTFOUND if
115 * the zone is not supported by the database, or ISC_R_NOPERM if zone
116 * transfers are not allowed.  If an error occurs it should return a
117 * result code indicating the type of error.
118 */
119
120typedef isc_result_t
121(*dns_dlzcreate_t)(isc_mem_t *mctx, const char *dlzname, unsigned int argc,
122		   char *argv[], void *driverarg, void **dbdata);
123
124/*%<
125 * Method prototype.  Drivers implementing the DLZ interface MUST
126 * supply a create method.  This method is called when the DNS server
127 * is starting up and creating drivers for use later.
128 */
129
130typedef void
131(*dns_dlzdestroy_t)(void *driverarg, void **dbdata);
132
133/*%<
134 * Method prototype.  Drivers implementing the DLZ interface MUST
135 * supply a destroy method.  This method is called when the DNS server
136 * is shuting down and no longer needs the driver.
137 */
138
139typedef isc_result_t
140(*dns_dlzfindzone_t)(void *driverarg, void *dbdata, isc_mem_t *mctx,
141		     dns_rdataclass_t rdclass, dns_name_t *name,
142		     dns_db_t **dbp);
143
144/*%<
145
146 * Method prototype.  Drivers implementing the DLZ interface MUST
147 * supply a find zone method.  This method is called when the DNS
148 * server is performing a query.  The find zone method will be called
149 * with the longest possible name first, and continue to be called
150 * with successively shorter domain names, until any of the following
151 * occur:
152 *
153 * \li	1) a match is found, and the function returns (ISC_R_SUCCESS)
154 *
155 * \li	2) a problem occurs, and the functions returns anything other
156 *	   than (ISC_R_NOTFOUND)
157 * \li	3) we run out of domain name labels. I.E. we have tried the
158 *	   shortest domain name
159 * \li	4) the number of labels in the domain name is less than
160 *	   min_lables for dns_dlzfindzone
161 *
162 * The driver's find zone method should return ISC_R_SUCCESS and a
163 * database pointer to the name server if the zone is supported by the
164 * database.  Otherwise it will return ISC_R_NOTFOUND, and a null
165 * pointer if the zone is not supported.  If an error occurs it should
166 * return a result code indicating the type of error.
167 */
168
169/*% the methods supplied by a DLZ driver */
170typedef struct dns_dlzmethods {
171	dns_dlzcreate_t		create;
172	dns_dlzdestroy_t	destroy;
173	dns_dlzfindzone_t	findzone;
174	dns_dlzallowzonexfr_t	allowzonexfr;
175} dns_dlzmethods_t;
176
177/*% information about a DLZ driver */
178struct dns_dlzimplementation {
179	const char				*name;
180	const dns_dlzmethods_t			*methods;
181	isc_mem_t				*mctx;
182	void					*driverarg;
183	ISC_LINK(dns_dlzimplementation_t)	link;
184};
185
186/*% an instance of a DLZ driver */
187struct dns_dlzdb {
188	unsigned int		magic;
189	isc_mem_t		*mctx;
190	dns_dlzimplementation_t	*implementation;
191	void			*dbdata;
192};
193
194
195/***
196 *** Method declarations
197 ***/
198
199isc_result_t
200dns_dlzallowzonexfr(dns_view_t *view, dns_name_t *name,
201		    isc_sockaddr_t *clientaddr, dns_db_t **dbp);
202
203/*%<
204 * This method is called when the DNS server is performing a zone
205 * transfer query.  It will call the DLZ driver's allow zone tranfer
206 * method.
207 */
208
209isc_result_t
210dns_dlzcreate(isc_mem_t *mctx, const char *dlzname,
211	      const char *drivername, unsigned int argc,
212	      char *argv[], dns_dlzdb_t **dbp);
213
214/*%<
215 * This method is called when the DNS server is starting up and
216 * creating drivers for use later.  It will search the DLZ driver list
217 * for 'drivername' and return a DLZ driver via dbp if a match is
218 * found.  If the DLZ driver supplies a create method, this function
219 * will call it.
220 */
221
222void
223dns_dlzdestroy(dns_dlzdb_t **dbp);
224
225/*%<
226 * This method is called when the DNS server is shuting down and no
227 * longer needs the driver.  If the DLZ driver supplies a destroy
228 * methods, this function will call it.
229 */
230
231isc_result_t
232dns_dlzfindzone(dns_view_t *view, dns_name_t *name,
233		unsigned int minlabels, dns_db_t **dbp);
234
235/*%<
236 * This method is called when the DNS server is performing a query.
237 * It will call the DLZ driver's find zone method.
238 */
239
240isc_result_t
241dns_dlzregister(const char *drivername, const dns_dlzmethods_t *methods,
242		 void *driverarg, isc_mem_t *mctx,
243		dns_dlzimplementation_t **dlzimp);
244
245/*%<
246 * Register a dynamically loadable zones (DLZ) driver for the database
247 * type 'drivername', implemented by the functions in '*methods'.
248 *
249 * dlzimp must point to a NULL dlz_implementation_t pointer.  That is,
250 * dlzimp != NULL && *dlzimp == NULL.  It will be assigned a value that
251 * will later be used to identify the driver when deregistering it.
252 */
253
254isc_result_t
255dns_dlzstrtoargv(isc_mem_t *mctx, char *s, unsigned int *argcp, char ***argvp);
256
257/*%<
258 * This method is called when the name server is starting up to parse
259 * the DLZ driver command line from named.conf.  Basically it splits
260 * up a string into and argc / argv.  The primary difference of this
261 * method is items between braces { } are considered only 1 word.  for
262 * example the command line "this is { one grouped phrase } and this
263 * isn't" would be parsed into:
264 *
265 * \li	argv[0]: "this"
266 * \li	argv[1]: "is"
267 * \li	argv{2]: " one grouped phrase "
268 * \li	argv[3]: "and"
269 * \li	argv[4]: "this"
270 * \li	argv{5}: "isn't"
271 *
272 * braces should NOT be nested, more than one grouping in the command
273 * line is allowed.  Notice, argv[2] has an extra space at the
274 * beginning and end.  Extra spaces are not stripped between a
275 * grouping.  You can do so in your driver if needed, or be sure not
276 * to put extra spaces before / after the braces.
277 */
278
279void
280dns_dlzunregister(dns_dlzimplementation_t **dlzimp);
281
282/*%<
283 * Removes the dlz driver from the list of registered dlz drivers.
284 * There must be no active dlz drivers of this type when this function
285 * is called.
286 */
287
288ISC_LANG_ENDDECLS
289
290#endif /* DLZ_H */
291