xref: /freebsd/contrib/unbound/util/data/packed_rrset.h (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*
2  * util/data/packed_rrset.h - data storage for a set of resource records.
3  *
4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * This file contains the data storage for RRsets.
40  */
41 
42 #ifndef UTIL_DATA_PACKED_RRSET_H
43 #define UTIL_DATA_PACKED_RRSET_H
44 #include "util/storage/lruhash.h"
45 struct alloc_cache;
46 struct regional;
47 
48 /** type used to uniquely identify rrsets. Cannot be reused without
49  * clearing the cache. */
50 typedef uint64_t rrset_id_t;
51 
52 /** this rrset is NSEC and is at zone apex (at child side of zonecut) */
53 #define PACKED_RRSET_NSEC_AT_APEX 0x1
54 /** this rrset is A/AAAA and is in-zone-glue (from parent side of zonecut) */
55 #define PACKED_RRSET_PARENT_SIDE 0x2
56 /** this rrset is SOA and has the negative ttl (from nxdomain or nodata),
57  * this is set on SOA rrsets in the authority section, to keep its TTL separate
58  * from the SOA in the answer section from a direct SOA query or ANY query. */
59 #define PACKED_RRSET_SOA_NEG 0x4
60 
61 /** number of rrs and rrsets for integer overflow protection.  More than
62  * this is not really possible (64K packet has much less RRs and RRsets) in
63  * a message.  And this is small enough that also multiplied there is no
64  * integer overflow. */
65 #define RR_COUNT_MAX 0xffffff
66 
67 /**
68  * The identifying information for an RRset.
69  */
70 struct packed_rrset_key {
71 	/**
72 	 * The domain name. If not null (for id=0) it is allocated, and
73 	 * contains the wireformat domain name.
74 	 * This dname is not canonicalized.
75 	 */
76 	uint8_t* dname;
77 	/**
78 	 * Length of the domain name, including last 0 root octet.
79 	 */
80 	size_t dname_len;
81 	/**
82 	 * Flags. 32bit to be easy for hashing:
83 	 * 	o PACKED_RRSET_NSEC_AT_APEX
84 	 * 	o PACKED_RRSET_PARENT_SIDE
85 	 * 	o PACKED_RRSET_SOA_NEG
86 	 */
87 	uint32_t flags;
88 	/** the rrset type in network format */
89 	uint16_t type;
90 	/** the rrset class in network format */
91 	uint16_t rrset_class;
92 };
93 
94 /**
95  * This structure contains an RRset. A set of resource records that
96  * share the same domain name, type and class.
97  *
98  * Due to memory management and threading, the key structure cannot be
99  * deleted, although the data can be. The id can be set to 0 to store and the
100  * structure can be recycled with a new id.
101  */
102 struct ub_packed_rrset_key {
103 	/**
104 	 * entry into hashtable. Note the lock is never destroyed,
105 	 *  even when this key is retired to the cache.
106 	 * the data pointer (if not null) points to a struct packed_rrset.
107 	 */
108 	struct lruhash_entry entry;
109 	/**
110 	 * the ID of this rrset. unique, based on threadid + sequenceno.
111 	 * ids are not reused, except after flushing the cache.
112 	 * zero is an unused entry, and never a valid id.
113 	 * Check this value after getting entry.lock.
114 	 * The other values in this struct may only be altered after changing
115 	 * the id (which needs a writelock on entry.lock).
116 	 */
117 	rrset_id_t id;
118 	/** key data: dname, type and class */
119 	struct packed_rrset_key rk;
120 };
121 
122 /**
123  * RRset trustworthiness. Bigger value is more trust. RFC 2181.
124  * The rrset_trust_add_noAA, rrset_trust_auth_noAA, rrset_trust_add_AA,
125  * are mentioned as the same trustworthiness in 2181, but split up here
126  * for ease of processing.
127  *
128  * rrset_trust_nonauth_ans_AA, rrset_trust_ans_noAA
129  * are also mentioned as the same trustworthiness in 2181, but split up here
130  * for ease of processing.
131  *
132  * Added trust_none for a sane initial value, smaller than anything else.
133  * Added validated and ultimate trust for keys and rrsig validated content.
134  */
135 enum rrset_trust {
136 	/** initial value for trust */
137 	rrset_trust_none = 0,
138 	/** Additional information from non-authoritative answers */
139 	rrset_trust_add_noAA,
140 	/** Data from the authority section of a non-authoritative answer */
141 	rrset_trust_auth_noAA,
142 	/** Additional information from an authoritative answer */
143 	rrset_trust_add_AA,
144 	/** non-authoritative data from the answer section of authoritative
145 	 * answers */
146 	rrset_trust_nonauth_ans_AA,
147 	/** Data from the answer section of a non-authoritative answer */
148 	rrset_trust_ans_noAA,
149 	/** Glue from a primary zone, or glue from a zone transfer */
150 	rrset_trust_glue,
151 	/** Data from the authority section of an authoritative answer */
152 	rrset_trust_auth_AA,
153 	/** The authoritative data included in the answer section of an
154 	 *  authoritative reply */
155 	rrset_trust_ans_AA,
156 	/** Data from a zone transfer, other than glue */
157 	rrset_trust_sec_noglue,
158 	/** Data from a primary zone file, other than glue data */
159 	rrset_trust_prim_noglue,
160 	/** DNSSEC(rfc4034) validated with trusted keys */
161 	rrset_trust_validated,
162 	/** ultimately trusted, no more trust is possible;
163 	 * trusted keys from the unbound configuration setup. */
164 	rrset_trust_ultimate
165 };
166 
167 /**
168  * Security status from validation for data.
169  * The order is significant; more secure, more proven later.
170  */
171 enum sec_status {
172 	/** UNCHECKED means that object has yet to be validated. */
173 	sec_status_unchecked = 0,
174 	/** BOGUS means that the object (RRset or message) failed to validate
175 	 *  (according to local policy), but should have validated. */
176 	sec_status_bogus,
177 	/** INDETERMINATE means that the object is insecure, but not
178 	 * authoritatively so. Generally this means that the RRset is not
179 	 * below a configured trust anchor. */
180 	sec_status_indeterminate,
181 	/** INSECURE means that the object is authoritatively known to be
182 	 * insecure. Generally this means that this RRset is below a trust
183 	 * anchor, but also below a verified, insecure delegation. */
184 	sec_status_insecure,
185 	/** SECURE means that the object (RRset or message) validated
186 	 * according to local policy. */
187 	sec_status_secure
188 };
189 
190 /**
191  * RRset data.
192  *
193  * The data is packed, stored contiguously in memory.
194  * memory layout:
195  *	o base struct
196  *	o rr_len size_t array
197  *	o rr_data uint8_t* array
198  *	o rr_ttl time_t array (after size_t and ptrs because those may be
199  *		64bit and this array before those would make them unaligned).
200  *		Since the stuff before is 32/64bit, rr_ttl is 32 bit aligned.
201  *	o rr_data rdata wireformats
202  *	o rrsig_data rdata wireformat(s)
203  *
204  * Rdata is stored in wireformat. The dname is stored in wireformat.
205  * TTLs are stored as absolute values (and could be expired).
206  *
207  * RRSIGs are stored in the arrays after the regular rrs.
208  *
209  * You need the packed_rrset_key to know dname, type, class of the
210  * resource records in this RRset. (if signed the rrsig gives the type too).
211  *
212  * On the wire an RR is:
213  *	name, type, class, ttl, rdlength, rdata.
214  * So we need to send the following per RR:
215  *	key.dname, ttl, rr_data[i].
216  *	since key.dname ends with type and class.
217  *	and rr_data starts with the rdlength.
218  *	the ttl value to send changes due to time.
219  */
220 struct packed_rrset_data {
221 	/** TTL (in seconds like time()) of the rrset.
222 	 * Same for all RRs see rfc2181(5.2).  */
223 	time_t ttl;
224 	/** number of rrs. */
225 	size_t count;
226 	/** number of rrsigs, if 0 no rrsigs */
227 	size_t rrsig_count;
228 	/** the trustworthiness of the rrset data */
229 	enum rrset_trust trust;
230 	/** security status of the rrset data */
231 	enum sec_status security;
232 	/** length of every rr's rdata, rr_len[i] is size of rr_data[i]. */
233 	size_t* rr_len;
234 	/** ttl of every rr. rr_ttl[i] ttl of rr i. */
235 	time_t *rr_ttl;
236 	/**
237 	 * Array of pointers to every rr's rdata.
238 	 * The rr_data[i] rdata is stored in uncompressed wireformat.
239 	 * The first uint16_t of rr_data[i] is network format rdlength.
240 	 *
241 	 * rr_data[count] to rr_data[count+rrsig_count] contain the rrsig data.
242 	 */
243 	uint8_t** rr_data;
244 };
245 
246 /**
247  * An RRset can be represented using both key and data together.
248  * Split into key and data structures to simplify implementation of
249  * caching schemes.
250  */
251 struct packed_rrset {
252 	/** domain name, type and class */
253 	struct packed_rrset_key* k;
254 	/** ttl, count and rdatas (and rrsig) */
255 	struct packed_rrset_data* d;
256 };
257 
258 /**
259  * list of packed rrsets
260  */
261 struct packed_rrset_list {
262 	/** next in list */
263 	struct packed_rrset_list* next;
264 	/** rrset key and data */
265 	struct packed_rrset rrset;
266 };
267 
268 /**
269  * Delete packed rrset key and data, not entered in hashtables yet.
270  * Used during parsing.
271  * @param pkey: rrset key structure with locks, key and data pointers.
272  * @param alloc: where to return the unfree-able key structure.
273  */
274 void ub_packed_rrset_parsedelete(struct ub_packed_rrset_key* pkey,
275 	struct alloc_cache* alloc);
276 
277 /**
278  * Memory size of rrset data. RRset data must be filled in correctly.
279  * @param data: data to examine.
280  * @return size in bytes.
281  */
282 size_t packed_rrset_sizeof(struct packed_rrset_data* data);
283 
284 /**
285  * Get TTL of rrset. RRset data must be filled in correctly.
286  * @param key: rrset key, with data to examine.
287  * @return ttl value.
288  */
289 time_t ub_packed_rrset_ttl(struct ub_packed_rrset_key* key);
290 
291 /**
292  * Calculate memory size of rrset entry. For hash table usage.
293  * @param key: struct ub_packed_rrset_key*.
294  * @param data: struct packed_rrset_data*.
295  * @return size in bytes.
296  */
297 size_t ub_rrset_sizefunc(void* key, void* data);
298 
299 /**
300  * compares two rrset keys.
301  * @param k1: struct ub_packed_rrset_key*.
302  * @param k2: struct ub_packed_rrset_key*.
303  * @return 0 if equal.
304  */
305 int ub_rrset_compare(void* k1, void* k2);
306 
307 /**
308  * compare two rrset data structures.
309  * Compared rdata and rrsigdata, not the trust or ttl value.
310  * @param d1: data to compare.
311  * @param d2: data to compare.
312  * @return 1 if equal.
313  */
314 int rrsetdata_equal(struct packed_rrset_data* d1, struct packed_rrset_data* d2);
315 
316 /**
317  * Old key to be deleted. RRset keys are recycled via alloc.
318  * The id is set to 0. So that other threads, after acquiring a lock always
319  * get the correct value, in this case the 0 deleted-special value.
320  * @param key: struct ub_packed_rrset_key*.
321  * @param userdata: alloc structure to use for recycling.
322  */
323 void ub_rrset_key_delete(void* key, void* userdata);
324 
325 /**
326  * Old data to be deleted.
327  * @param data: what to delete.
328  * @param userdata: user data ptr.
329  */
330 void rrset_data_delete(void* data, void* userdata);
331 
332 /**
333  * Calculate hash value for a packed rrset key.
334  * @param key: the rrset key with name, type, class, flags.
335  * @return hash value.
336  */
337 hashvalue_t rrset_key_hash(struct packed_rrset_key* key);
338 
339 /**
340  * Fixup pointers in fixed data packed_rrset_data blob.
341  * After a memcpy of the data for example. Will set internal pointers right.
342  * @param data: rrset data structure. Otherwise correctly filled in.
343  */
344 void packed_rrset_ptr_fixup(struct packed_rrset_data* data);
345 
346 /**
347  * Fixup TTLs in fixed data packed_rrset_data blob.
348  * @param data: rrset data structure. Otherwise correctly filled in.
349  * @param add: how many seconds to add, pass time(0) for example.
350  */
351 void packed_rrset_ttl_add(struct packed_rrset_data* data, time_t add);
352 
353 /**
354  * Utility procedure to extract CNAME target name from its rdata.
355  * Failsafes; it will change passed dname to a valid dname or do nothing.
356  * @param rrset: the rrset structure. Must be a CNAME.
357  *	Only first RR is used (multiple RRs are technically illegal anyway).
358  * 	Also works on type DNAME. Returns target name.
359  * @param dname: this pointer is updated to point into the cname rdata.
360  *	If a failsafe fails, nothing happens to the pointer (such as the
361  *	rdata was not a valid dname, not a CNAME, ...).
362  * @param dname_len: length of dname is returned.
363  */
364 void get_cname_target(struct ub_packed_rrset_key* rrset, uint8_t** dname,
365 	size_t* dname_len);
366 
367 /**
368  * Get a printable string for a rrset trust value
369  * @param s: rrset trust value
370  * @return printable string.
371  */
372 const char* rrset_trust_to_string(enum rrset_trust s);
373 
374 /**
375  * Get a printable string for a security status value
376  * @param s: security status
377  * @return printable string.
378  */
379 const char* sec_status_to_string(enum sec_status s);
380 
381 /**
382  * Print string with neat domain name, type, class from rrset.
383  * @param v: at what verbosity level to print this.
384  * @param str: string of message.
385  * @param rrset: structure with name, type and class.
386  */
387 void log_rrset_key(enum verbosity_value v, const char* str,
388 	struct ub_packed_rrset_key* rrset);
389 
390 /**
391  * Convert RR from RRset to string.
392  * @param rrset: structure with data.
393  * @param i: index of rr or RRSIG.
394  * @param now: time that is subtracted from ttl before printout. Can be 0.
395  * @param dest: destination string buffer. Must be nonNULL.
396  * @param dest_len: length of dest buffer (>0).
397  * @return false on failure.
398  */
399 int packed_rr_to_string(struct ub_packed_rrset_key* rrset, size_t i,
400 	time_t now, char* dest, size_t dest_len);
401 
402 /**
403  * Print the string with prefix, one rr per line.
404  * @param v: at what verbosity level to print this.
405  * @param str: string of message.
406  * @param rrset: with name, and rdata, and rrsigs.
407  */
408 void log_packed_rrset(enum verbosity_value v, const char* str,
409 	struct ub_packed_rrset_key* rrset);
410 
411 /**
412  * Allocate rrset in region - no more locks needed
413  * @param key: a (just from rrset cache looked up) rrset key + valid,
414  * 	packed data record.
415  * @param region: where to alloc the copy
416  * @param now: adjust the TTLs to be relative (subtract from all TTLs).
417  * @return new region-alloced rrset key or NULL on alloc failure.
418  */
419 struct ub_packed_rrset_key* packed_rrset_copy_region(
420 	struct ub_packed_rrset_key* key, struct regional* region,
421 	time_t now);
422 
423 /**
424  * Allocate rrset with malloc (from region or you are holding the lock).
425  * @param key: key with data entry.
426  * @param alloc: alloc_cache to create rrset_keys
427  * @param now: adjust the TTLs to be absolute (add to all TTLs).
428  * @return new region-alloced rrset key or NULL on alloc failure.
429  */
430 struct ub_packed_rrset_key* packed_rrset_copy_alloc(
431 	struct ub_packed_rrset_key* key, struct alloc_cache* alloc,
432 	time_t now);
433 
434 #endif /* UTIL_DATA_PACKED_RRSET_H */
435