2 * Copyright (C) 2004-2006 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1998-2003 Internet Software Consortium.
5 * Permission to use, copy, modify, and distribute this software for any
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18 /* $Id: name.h,v 1.107.18.15 2006/03/02 00:37:21 marka Exp $ */
29 * Provides facilities for manipulating DNS names and labels, including
30 * conversions to and from wire format and text format.
32 * Given the large number of names possible in a nameserver, and because
33 * names occur in rdata, it was important to come up with a very efficient
34 * way of storing name data, but at the same time allow names to be
35 * manipulated. The decision was to store names in uncompressed wire format,
36 * and not to make them fully abstracted objects; i.e. certain parts of the
37 * server know names are stored that way. This saves a lot of memory, and
38 * makes adding names to messages easy. Having much of the server know
39 * the representation would be perilous, and we certainly don't want each
40 * user of names to be manipulating such a low-level structure. This is
41 * where the Names and Labels module comes in. The module allows name or
42 * label handles to be created and attached to uncompressed wire format
43 * regions. All name operations and conversions are done through these
47 *\li Clients of this module must impose any required synchronization.
50 *\li This module deals with low-level byte streams. Errors in any of
51 * the functions are likely to crash the server or corrupt memory.
60 *\li dns_name_fromwire() deals with raw network data. An error in
61 * this routine could result in the failure or hijacking of the server.
66 *\li Draft Binary Labels (2)
76 #include <isc/boolean.h>
78 #include <isc/magic.h>
79 #include <isc/region.h> /* Required for storage size of dns_label_t. */
81 #include <dns/types.h>
88 ***** A 'label' is basically a region. It contains one DNS wire format
89 ***** label of type 00 (ordinary).
95 ***** A 'name' is a handle to a binary region. It contains a sequence of one
96 ***** or more DNS wire format labels of type 00 (ordinary).
97 ***** Note that all names are not required to end with the root label,
98 ***** as they are in the actual DNS wire protocol.
102 *** Compression pointer chaining limit
105 #define DNS_POINTER_MAXHOPS 16
112 * Clients are strongly discouraged from using this type directly, with
113 * the exception of the 'link' and 'list' fields which may be used directly
114 * for whatever purpose the client desires.
118 unsigned char * ndata;
121 unsigned int attributes;
122 unsigned char * offsets;
123 isc_buffer_t * buffer;
124 ISC_LINK(dns_name_t) link;
125 ISC_LIST(dns_rdataset_t) list;
128 #define DNS_NAME_MAGIC ISC_MAGIC('D','N','S','n')
130 #define DNS_NAMEATTR_ABSOLUTE 0x0001
131 #define DNS_NAMEATTR_READONLY 0x0002
132 #define DNS_NAMEATTR_DYNAMIC 0x0004
133 #define DNS_NAMEATTR_DYNOFFSETS 0x0008
135 * Attributes below 0x0100 reserved for name.c usage.
137 #define DNS_NAMEATTR_CACHE 0x0100 /*%< Used by resolver. */
138 #define DNS_NAMEATTR_ANSWER 0x0200 /*%< Used by resolver. */
139 #define DNS_NAMEATTR_NCACHE 0x0400 /*%< Used by resolver. */
140 #define DNS_NAMEATTR_CHAINING 0x0800 /*%< Used by resolver. */
141 #define DNS_NAMEATTR_CHASE 0x1000 /*%< Used by resolver. */
142 #define DNS_NAMEATTR_WILDCARD 0x2000 /*%< Used by server. */
144 #define DNS_NAME_DOWNCASE 0x0001
145 #define DNS_NAME_CHECKNAMES 0x0002 /*%< Used by rdata. */
146 #define DNS_NAME_CHECKNAMESFAIL 0x0004 /*%< Used by rdata. */
147 #define DNS_NAME_CHECKREVERSE 0x0008 /*%< Used by rdata. */
148 #define DNS_NAME_CHECKMX 0x0010 /*%< Used by rdata. */
149 #define DNS_NAME_CHECKMXFAIL 0x0020 /*%< Used by rdata. */
151 LIBDNS_EXTERNAL_DATA extern dns_name_t *dns_rootname;
152 LIBDNS_EXTERNAL_DATA extern dns_name_t *dns_wildcardname;
155 * Standard size of a wire format name
157 #define DNS_NAME_MAXWIRE 255
160 * Text output filter procedure.
161 * 'target' is the buffer to be converted. The region to be converted
162 * is from 'buffer'->base + 'used_org' to the end of the used region.
164 typedef isc_result_t (*dns_name_totextfilter_t)(isc_buffer_t *target,
165 unsigned int used_org,
166 isc_boolean_t absolute);
173 dns_name_init(dns_name_t *name, unsigned char *offsets);
178 * \li 'offsets' is never required to be non-NULL, but specifying a
179 * dns_offsets_t for 'offsets' will improve the performance of most
180 * name operations if the name is used more than once.
183 * \li 'name' is not NULL and points to a struct dns_name.
185 * \li offsets == NULL or offsets is a dns_offsets_t.
188 * \li 'name' is a valid name.
189 * \li dns_name_countlabels(name) == 0
190 * \li dns_name_isabsolute(name) == ISC_FALSE
194 dns_name_reset(dns_name_t *name);
196 * Reinitialize 'name'.
199 * \li This function distinguishes itself from dns_name_init() in two
202 * \li + If any buffer is associated with 'name' (via dns_name_setbuffer()
203 * or by being part of a dns_fixedname_t) the link to the buffer
204 * is retained but the buffer itself is cleared.
206 * \li + Of the attributes associated with 'name', all are retained except
207 * DNS_NAMEATTR_ABSOLUTE.
210 * \li 'name' is a valid name.
213 * \li 'name' is a valid name.
214 * \li dns_name_countlabels(name) == 0
215 * \li dns_name_isabsolute(name) == ISC_FALSE
219 dns_name_invalidate(dns_name_t *name);
221 * Make 'name' invalid.
224 * \li 'name' is a valid name.
227 * \li If assertion checking is enabled, future attempts to use 'name'
228 * without initializing it will cause an assertion failure.
230 * \li If the name had a dedicated buffer, that association is ended.
235 *** Dedicated Buffers
239 dns_name_setbuffer(dns_name_t *name, isc_buffer_t *buffer);
241 * Dedicate a buffer for use with 'name'.
244 * \li Specification of a target buffer in dns_name_fromwire(),
245 * dns_name_fromtext(), and dns_name_concatentate() is optional if
246 * 'name' has a dedicated buffer.
248 * \li The caller must not write to buffer until the name has been
249 * invalidated or is otherwise known not to be in use.
251 * \li If buffer is NULL and the name previously had a dedicated buffer,
252 * than that buffer is no longer dedicated to use with this name.
253 * The caller is responsible for ensuring that the storage used by
254 * the name remains valid.
257 * \li 'name' is a valid name.
259 * \li 'buffer' is a valid binary buffer and 'name' doesn't have a
260 * dedicated buffer already, or 'buffer' is NULL.
264 dns_name_hasbuffer(const dns_name_t *name);
266 * Does 'name' have a dedicated buffer?
269 * \li 'name' is a valid name.
272 * \li ISC_TRUE 'name' has a dedicated buffer.
273 * \li ISC_FALSE 'name' does not have a dedicated buffer.
281 dns_name_isabsolute(const dns_name_t *name);
283 * Does 'name' end in the root label?
286 * \li 'name' is a valid name
289 * \li TRUE The last label in 'name' is the root label.
290 * \li FALSE The last label in 'name' is not the root label.
294 dns_name_iswildcard(const dns_name_t *name);
296 * Is 'name' a wildcard name?
299 * \li 'name' is a valid name
301 * \li dns_name_countlabels(name) > 0
304 * \li TRUE The least significant label of 'name' is '*'.
305 * \li FALSE The least significant label of 'name' is not '*'.
309 dns_name_hash(dns_name_t *name, isc_boolean_t case_sensitive);
311 * Provide a hash value for 'name'.
313 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
314 * case will have the same hash value.
317 * \li 'name' is a valid name
324 dns_name_fullhash(dns_name_t *name, isc_boolean_t case_sensitive);
326 * Provide a hash value for 'name'. Unlike dns_name_hash(), this function
327 * always takes into account of the entire name to calculate the hash value.
329 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
330 * case will have the same hash value.
333 *\li 'name' is a valid name
340 dns_name_hashbylabel(dns_name_t *name, isc_boolean_t case_sensitive);
342 * Provide a hash value for 'name', where the hash value is the sum
343 * of the hash values of each label.
345 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
346 * case will have the same hash value.
349 *\li 'name' is a valid name
360 dns_name_fullcompare(const dns_name_t *name1, const dns_name_t *name2,
361 int *orderp, unsigned int *nlabelsp);
363 * Determine the relative ordering under the DNSSEC order relation of
364 * 'name1' and 'name2', and also determine the hierarchical
365 * relationship of the names.
367 * Note: It makes no sense for one of the names to be relative and the
368 * other absolute. If both names are relative, then to be meaningfully
369 * compared the caller must ensure that they are both relative to the
373 *\li 'name1' is a valid name
375 *\li dns_name_countlabels(name1) > 0
377 *\li 'name2' is a valid name
379 *\li dns_name_countlabels(name2) > 0
381 *\li orderp and nlabelsp are valid pointers.
383 *\li Either name1 is absolute and name2 is absolute, or neither is.
387 *\li *orderp is < 0 if name1 < name2, 0 if name1 = name2, > 0 if
390 *\li *nlabelsp is the number of common significant labels.
393 *\li dns_namereln_none There's no hierarchical relationship
394 * between name1 and name2.
395 *\li dns_namereln_contains name1 properly contains name2; i.e.
396 * name2 is a proper subdomain of name1.
397 *\li dns_namereln_subdomain name1 is a proper subdomain of name2.
398 *\li dns_namereln_equal name1 and name2 are equal.
399 *\li dns_namereln_commonancestor name1 and name2 share a common
404 dns_name_compare(const dns_name_t *name1, const dns_name_t *name2);
406 * Determine the relative ordering under the DNSSEC order relation of
407 * 'name1' and 'name2'.
409 * Note: It makes no sense for one of the names to be relative and the
410 * other absolute. If both names are relative, then to be meaningfully
411 * compared the caller must ensure that they are both relative to the
415 * \li 'name1' is a valid name
417 * \li 'name2' is a valid name
419 * \li Either name1 is absolute and name2 is absolute, or neither is.
422 * \li < 0 'name1' is less than 'name2'
423 * \li 0 'name1' is equal to 'name2'
424 * \li > 0 'name1' is greater than 'name2'
428 dns_name_equal(const dns_name_t *name1, const dns_name_t *name2);
430 * Are 'name1' and 'name2' equal?
433 * \li Because it only needs to test for equality, dns_name_equal() can be
434 * significantly faster than dns_name_fullcompare() or dns_name_compare().
436 * \li Offsets tables are not used in the comparision.
438 * \li It makes no sense for one of the names to be relative and the
439 * other absolute. If both names are relative, then to be meaningfully
440 * compared the caller must ensure that they are both relative to the
444 * \li 'name1' is a valid name
446 * \li 'name2' is a valid name
448 * \li Either name1 is absolute and name2 is absolute, or neither is.
451 * \li ISC_TRUE 'name1' and 'name2' are equal
452 * \li ISC_FALSE 'name1' and 'name2' are not equal
456 dns_name_caseequal(const dns_name_t *name1, const dns_name_t *name2);
458 * Case sensitive version of dns_name_equal().
462 dns_name_rdatacompare(const dns_name_t *name1, const dns_name_t *name2);
464 * Compare two names as if they are part of rdata in DNSSEC canonical
468 * \li 'name1' is a valid absolute name
470 * \li dns_name_countlabels(name1) > 0
472 * \li 'name2' is a valid absolute name
474 * \li dns_name_countlabels(name2) > 0
477 * \li < 0 'name1' is less than 'name2'
478 * \li 0 'name1' is equal to 'name2'
479 * \li > 0 'name1' is greater than 'name2'
483 dns_name_issubdomain(const dns_name_t *name1, const dns_name_t *name2);
485 * Is 'name1' a subdomain of 'name2'?
488 * \li name1 is a subdomain of name2 if name1 is contained in name2, or
489 * name1 equals name2.
491 * \li It makes no sense for one of the names to be relative and the
492 * other absolute. If both names are relative, then to be meaningfully
493 * compared the caller must ensure that they are both relative to the
497 * \li 'name1' is a valid name
499 * \li 'name2' is a valid name
501 * \li Either name1 is absolute and name2 is absolute, or neither is.
504 * \li TRUE 'name1' is a subdomain of 'name2'
505 * \li FALSE 'name1' is not a subdomain of 'name2'
509 dns_name_matcheswildcard(const dns_name_t *name, const dns_name_t *wname);
511 * Does 'name' match the wildcard specified in 'wname'?
514 * \li name matches the wildcard specified in wname if all labels
515 * following the wildcard in wname are identical to the same number
516 * of labels at the end of name.
518 * \li It makes no sense for one of the names to be relative and the
519 * other absolute. If both names are relative, then to be meaningfully
520 * compared the caller must ensure that they are both relative to the
524 * \li 'name' is a valid name
526 * \li dns_name_countlabels(name) > 0
528 * \li 'wname' is a valid name
530 * \li dns_name_countlabels(wname) > 0
532 * \li dns_name_iswildcard(wname) is true
534 * \li Either name is absolute and wname is absolute, or neither is.
537 * \li TRUE 'name' matches the wildcard specified in 'wname'
538 * \li FALSE 'name' does not match the wildcard specified in 'wname'
546 dns_name_countlabels(const dns_name_t *name);
548 * How many labels does 'name' have?
551 * \li In this case, as in other places, a 'label' is an ordinary label.
554 * \li 'name' is a valid name
557 * \li The result is <= 128.
560 * \li The number of labels in 'name'.
564 dns_name_getlabel(const dns_name_t *name, unsigned int n, dns_label_t *label);
566 * Make 'label' refer to the 'n'th least significant label of 'name'.
569 * \li Numbering starts at 0.
571 * \li Given "rc.vix.com.", the label 0 is "rc", and label 3 is the
574 * \li 'label' refers to the same memory as 'name', so 'name' must not
575 * be changed while 'label' is still in use.
578 * \li n < dns_name_countlabels(name)
582 dns_name_getlabelsequence(const dns_name_t *source, unsigned int first,
583 unsigned int n, dns_name_t *target);
585 * Make 'target' refer to the 'n' labels including and following 'first'
589 * \li Numbering starts at 0.
591 * \li Given "rc.vix.com.", the label 0 is "rc", and label 3 is the
594 * \li 'target' refers to the same memory as 'source', so 'source'
595 * must not be changed while 'target' is still in use.
598 * \li 'source' and 'target' are valid names.
600 * \li first < dns_name_countlabels(name)
602 * \li first + n <= dns_name_countlabels(name)
607 dns_name_clone(const dns_name_t *source, dns_name_t *target);
609 * Make 'target' refer to the same name as 'source'.
613 * \li 'target' refers to the same memory as 'source', so 'source'
614 * must not be changed while 'target' is still in use.
616 * \li This call is functionally equivalent to:
619 * dns_name_getlabelsequence(source, 0,
620 * dns_name_countlabels(source),
624 * but is more efficient. Also, dns_name_clone() works even if 'source'
629 * \li 'source' is a valid name.
631 * \li 'target' is a valid name that is not read-only.
639 dns_name_fromregion(dns_name_t *name, const isc_region_t *r);
641 * Make 'name' refer to region 'r'.
644 * \li If the conversion encounters a root label before the end of the
645 * region the conversion stops and the length is set to the length
646 * so far converted. A maximum of 255 bytes is converted.
649 * \li The data in 'r' is a sequence of one or more type 00 or type 01000001
654 dns_name_toregion(dns_name_t *name, isc_region_t *r);
656 * Make 'r' refer to 'name'.
660 * \li 'name' is a valid name.
662 * \li 'r' is a valid region.
666 dns_name_fromwire(dns_name_t *name, isc_buffer_t *source,
667 dns_decompress_t *dctx, unsigned int options,
668 isc_buffer_t *target);
670 * Copy the possibly-compressed name at source (active region) into target,
674 * \li Decompression policy is controlled by 'dctx'.
676 * \li If DNS_NAME_DOWNCASE is set, any uppercase letters in 'source' will be
677 * downcased when they are copied into 'target'.
681 * \li *** WARNING ***
683 * \li This routine will often be used when 'source' contains raw network
684 * data. A programming error in this routine could result in a denial
685 * of service, or in the hijacking of the server.
689 * \li 'name' is a valid name.
691 * \li 'source' is a valid buffer and the first byte of the active
692 * region should be the first byte of a DNS wire format domain name.
694 * \li 'target' is a valid buffer or 'target' is NULL and 'name' has
695 * a dedicated buffer.
697 * \li 'dctx' is a valid decompression context.
701 * If result is success:
702 * \li If 'target' is not NULL, 'name' is attached to it.
704 * \li Uppercase letters are downcased in the copy iff
705 * DNS_NAME_DOWNCASE is set in options.
707 * \li The current location in source is advanced, and the used space
708 * in target is updated.
712 * \li Bad Form: Label Length
713 * \li Bad Form: Unknown Label Type
714 * \li Bad Form: Name Length
715 * \li Bad Form: Compression type not allowed
716 * \li Bad Form: Bad compression pointer
717 * \li Bad Form: Input too short
718 * \li Resource Limit: Too many compression pointers
719 * \li Resource Limit: Not enough space in buffer
723 dns_name_towire(const dns_name_t *name, dns_compress_t *cctx,
724 isc_buffer_t *target);
726 * Convert 'name' into wire format, compressing it as specified by the
727 * compression context 'cctx', and storing the result in 'target'.
730 * \li If the compression context allows global compression, then the
731 * global compression table may be updated.
734 * \li 'name' is a valid name
736 * \li dns_name_countlabels(name) > 0
738 * \li dns_name_isabsolute(name) == TRUE
740 * \li target is a valid buffer.
742 * \li Any offsets specified in a global compression table are valid
747 * If the result is success:
749 * \li The used space in target is updated.
753 * \li Resource Limit: Not enough space in buffer
757 dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
758 dns_name_t *origin, unsigned int options,
759 isc_buffer_t *target);
761 * Convert the textual representation of a DNS name at source
762 * into uncompressed wire form stored in target.
765 * \li Relative domain names will have 'origin' appended to them
766 * unless 'origin' is NULL, in which case relative domain names
767 * will remain relative.
769 * \li If DNS_NAME_DOWNCASE is set in 'options', any uppercase letters
770 * in 'source' will be downcased when they are copied into 'target'.
774 * \li 'name' is a valid name.
776 * \li 'source' is a valid buffer.
778 * \li 'target' is a valid buffer or 'target' is NULL and 'name' has
779 * a dedicated buffer.
783 * If result is success:
784 * \li If 'target' is not NULL, 'name' is attached to it.
786 * \li Uppercase letters are downcased in the copy iff
787 * DNS_NAME_DOWNCASE is set in 'options'.
789 * \li The current location in source is advanced, and the used space
790 * in target is updated.
794 *\li #DNS_R_EMPTYLABEL
795 *\li #DNS_R_LABELTOOLONG
796 *\li #DNS_R_BADESCAPE
797 *\li (#DNS_R_BADBITSTRING: should not be returned)
798 *\li (#DNS_R_BITSTRINGTOOLONG: should not be returned)
799 *\li #DNS_R_BADDOTTEDQUAD
801 *\li #ISC_R_UNEXPECTEDEND
805 dns_name_totext(dns_name_t *name, isc_boolean_t omit_final_dot,
806 isc_buffer_t *target);
808 * Convert 'name' into text format, storing the result in 'target'.
811 *\li If 'omit_final_dot' is true, then the final '.' in absolute
812 * names other than the root name will be omitted.
814 *\li If dns_name_countlabels == 0, the name will be "@", representing the
815 * current origin as described by RFC1035.
817 *\li The name is not NUL terminated.
821 *\li 'name' is a valid name
823 *\li 'target' is a valid buffer.
825 *\li if dns_name_isabsolute == FALSE, then omit_final_dot == FALSE
829 *\li If the result is success:
830 * the used space in target is updated.
837 #define DNS_NAME_MAXTEXT 1023
839 * The maximum length of the text representation of a domain
840 * name as generated by dns_name_totext(). This does not
841 * include space for a terminating NULL.
843 * This definition is conservative - the actual maximum
844 * is 1004, derived as follows:
846 * A backslash-decimal escaped character takes 4 bytes.
847 * A wire-encoded name can be up to 255 bytes and each
848 * label is one length byte + at most 63 bytes of data.
849 * Maximizing the label lengths gives us a name of
850 * three 63-octet labels, one 61-octet label, and the
853 * 1 + 63 + 1 + 63 + 1 + 63 + 1 + 61 + 1 = 255
855 * When printed, this is (3 * 63 + 61) * 4
856 * bytes for the escaped label data + 4 bytes for the
857 * dot terminating each label = 1004 bytes total.
861 dns_name_tofilenametext(dns_name_t *name, isc_boolean_t omit_final_dot,
862 isc_buffer_t *target);
864 * Convert 'name' into an alternate text format appropriate for filenames,
865 * storing the result in 'target'. The name data is downcased, guaranteeing
866 * that the filename does not depend on the case of the converted name.
869 *\li If 'omit_final_dot' is true, then the final '.' in absolute
870 * names other than the root name will be omitted.
872 *\li The name is not NUL terminated.
876 *\li 'name' is a valid absolute name
878 *\li 'target' is a valid buffer.
882 *\li If the result is success:
883 * the used space in target is updated.
891 dns_name_downcase(dns_name_t *source, dns_name_t *name,
892 isc_buffer_t *target);
898 *\li 'source' and 'name' are valid names.
900 *\li If source == name, then
901 * 'source' must not be read-only
904 * 'target' is a valid buffer or 'target' is NULL and
905 * 'name' has a dedicated buffer.
911 * Note: if source == name, then the result will always be ISC_R_SUCCESS.
915 dns_name_concatenate(dns_name_t *prefix, dns_name_t *suffix,
916 dns_name_t *name, isc_buffer_t *target);
918 * Concatenate 'prefix' and 'suffix'.
922 *\li 'prefix' is a valid name or NULL.
924 *\li 'suffix' is a valid name or NULL.
926 *\li 'name' is a valid name or NULL.
928 *\li 'target' is a valid buffer or 'target' is NULL and 'name' has
929 * a dedicated buffer.
931 *\li If 'prefix' is absolute, 'suffix' must be NULL or the empty name.
936 * If 'target' is not NULL and 'name' is not NULL, then 'name'
938 * The used space in target is updated.
943 *\li #DNS_R_NAMETOOLONG
947 dns_name_split(dns_name_t *name, unsigned int suffixlabels,
948 dns_name_t *prefix, dns_name_t *suffix);
951 * Split 'name' into two pieces on a label boundary.
954 * \li 'name' is split such that 'suffix' holds the most significant
955 * 'suffixlabels' labels. All other labels are stored in 'prefix'.
957 *\li Copying name data is avoided as much as possible, so 'prefix'
958 * and 'suffix' will end up pointing at the data for 'name'.
960 *\li It is legitimate to pass a 'prefix' or 'suffix' that has
961 * its name data stored someplace other than the dedicated buffer.
962 * This is useful to avoid name copying in the calling function.
964 *\li It is also legitimate to pass a 'prefix' or 'suffix' that is
965 * the same dns_name_t as 'name'.
968 *\li 'name' is a valid name.
970 *\li 'suffixlabels' cannot exceed the number of labels in 'name'.
972 * \li 'prefix' is a valid name or NULL, and cannot be read-only.
974 *\li 'suffix' is a valid name or NULL, and cannot be read-only.
976 *\li If non-NULL, 'prefix' and 'suffix' must have dedicated buffers.
978 *\li 'prefix' and 'suffix' cannot point to the same buffer.
983 * If 'prefix' is not NULL it will contain the least significant
985 * If 'suffix' is not NULL it will contain the most significant
986 * labels. dns_name_countlabels(suffix) will be equal to
990 * Either 'prefix' or 'suffix' is invalidated (depending
991 * on which one the problem was encountered with).
994 *\li #ISC_R_SUCCESS No worries. (This function should always success).
998 dns_name_dup(const dns_name_t *source, isc_mem_t *mctx,
1001 * Make 'target' a dynamically allocated copy of 'source'.
1005 *\li 'source' is a valid non-empty name.
1007 *\li 'target' is a valid name that is not read-only.
1009 *\li 'mctx' is a valid memory context.
1013 dns_name_dupwithoffsets(dns_name_t *source, isc_mem_t *mctx,
1014 dns_name_t *target);
1016 * Make 'target' a read-only dynamically allocated copy of 'source'.
1017 * 'target' will also have a dynamically allocated offsets table.
1021 *\li 'source' is a valid non-empty name.
1023 *\li 'target' is a valid name that is not read-only.
1025 *\li 'target' has no offsets table.
1027 *\li 'mctx' is a valid memory context.
1031 dns_name_free(dns_name_t *name, isc_mem_t *mctx);
1037 *\li 'name' is a valid name created previously in 'mctx' by dns_name_dup().
1039 *\li 'mctx' is a valid memory context.
1043 *\li All dynamic resources used by 'name' are freed and the name is
1048 dns_name_digest(dns_name_t *name, dns_digestfunc_t digest, void *arg);
1050 * Send 'name' in DNSSEC canonical form to 'digest'.
1054 *\li 'name' is a valid name.
1056 *\li 'digest' is a valid dns_digestfunc_t.
1060 *\li If successful, the DNSSEC canonical form of 'name' will have been
1063 *\li If digest() returns something other than ISC_R_SUCCESS, that result
1064 * will be returned as the result of dns_name_digest().
1070 *\li Many other results are possible if not successful.
1075 dns_name_dynamic(dns_name_t *name);
1077 * Returns whether there is dynamic memory associated with this name.
1081 *\li 'name' is a valid name.
1085 *\li 'ISC_TRUE' if the name is dynamic othewise 'ISC_FALSE'.
1089 dns_name_print(dns_name_t *name, FILE *stream);
1091 * Print 'name' on 'stream'.
1095 *\li 'name' is a valid name.
1097 *\li 'stream' is a valid stream.
1103 *\li Any error that dns_name_totext() can return.
1107 dns_name_format(dns_name_t *name, char *cp, unsigned int size);
1109 * Format 'name' as text appropriate for use in log messages.
1111 * Store the formatted name at 'cp', writing no more than
1112 * 'size' bytes. The resulting string is guaranteed to be
1115 * The formatted name will have a terminating dot only if it is
1118 * This function cannot fail, instead any errors are indicated
1119 * in the returned text.
1123 *\li 'name' is a valid name.
1125 *\li 'cp' points a valid character array of size 'size'.
1132 dns_name_settotextfilter(dns_name_totextfilter_t proc);
1134 * Set / clear a thread specific function 'proc' to be called at the
1135 * end of dns_name_totext().
1137 * Note: Under Windows you need to call "dns_name_settotextfilter(NULL);"
1138 * prior to exiting the thread otherwise memory will be leaked.
1139 * For other platforms, which are pthreads based, this is still a good
1140 * idea but not required.
1144 *\li #ISC_R_UNEXPECTED
1147 #define DNS_NAME_FORMATSIZE (DNS_NAME_MAXTEXT + 1)
1149 * Suggested size of buffer passed to dns_name_format().
1150 * Includes space for the terminating NULL.
1154 dns_name_copy(dns_name_t *source, dns_name_t *dest, isc_buffer_t *target);
1156 * Makes 'dest' refer to a copy of the name in 'source'. The data are
1157 * either copied to 'target' or the dedicated buffer in 'dest'.
1160 * \li 'source' is a valid name.
1162 * \li 'dest' is an initialized name with a dedicated buffer.
1164 * \li 'target' is NULL or an initialized buffer.
1166 * \li Either dest has a dedicated buffer or target != NULL.
1170 *\li On success, the used space in target is updated.
1178 dns_name_ishostname(const dns_name_t *name, isc_boolean_t wildcard);
1180 * Return if 'name' is a valid hostname. RFC 952 / RFC 1123.
1181 * If 'wildcard' is ISC_TRUE then allow the first label of name to
1183 * The root is also accepted.
1186 * 'name' to be valid.
1191 dns_name_ismailbox(const dns_name_t *name);
1193 * Return if 'name' is a valid mailbox. RFC 821.
1196 * \li 'name' to be valid.
1200 dns_name_internalwildcard(const dns_name_t *name);
1202 * Return if 'name' contains a internal wildcard name.
1205 * \li 'name' to be valid.
1209 dns_name_destroy(void);
1211 * Cleanup dns_name_settotextfilter() / dns_name_totext() state.
1213 * This should be called as part of the final cleanup process.
1215 * Note: dns_name_settotextfilter(NULL); should be called for all
1216 * threads which have called dns_name_settotextfilter() with a
1217 * non-NULL argument prior to calling dns_name_destroy();
1223 *** High Peformance Macros
1227 * WARNING: Use of these macros by applications may require recompilation
1228 * of the application in some situations where calling the function
1231 * WARNING: No assertion checking is done for these macros.
1234 #define DNS_NAME_INIT(n, o) \
1236 (n)->magic = DNS_NAME_MAGIC; \
1237 (n)->ndata = NULL; \
1240 (n)->attributes = 0; \
1241 (n)->offsets = (o); \
1242 (n)->buffer = NULL; \
1243 ISC_LINK_INIT((n), link); \
1244 ISC_LIST_INIT((n)->list); \
1247 #define DNS_NAME_RESET(n) \
1249 (n)->ndata = NULL; \
1252 (n)->attributes &= ~DNS_NAMEATTR_ABSOLUTE; \
1253 if ((n)->buffer != NULL) \
1254 isc_buffer_clear((n)->buffer); \
1257 #define DNS_NAME_SETBUFFER(n, b) \
1260 #define DNS_NAME_ISABSOLUTE(n) \
1261 (((n)->attributes & DNS_NAMEATTR_ABSOLUTE) != 0 ? ISC_TRUE : ISC_FALSE)
1263 #define DNS_NAME_COUNTLABELS(n) \
1266 #define DNS_NAME_TOREGION(n, r) \
1268 (r)->base = (n)->ndata; \
1269 (r)->length = (n)->length; \
1272 #define DNS_NAME_SPLIT(n, l, p, s) \
1274 dns_name_t *_n = (n); \
1275 dns_name_t *_p = (p); \
1276 dns_name_t *_s = (s); \
1277 unsigned int _l = (l); \
1279 dns_name_getlabelsequence(_n, 0, _n->labels - _l, _p); \
1281 dns_name_getlabelsequence(_n, _n->labels - _l, _l, _s); \
1284 #ifdef DNS_NAME_USEINLINE
1286 #define dns_name_init(n, o) DNS_NAME_INIT(n, o)
1287 #define dns_name_reset(n) DNS_NAME_RESET(n)
1288 #define dns_name_setbuffer(n, b) DNS_NAME_SETBUFFER(n, b)
1289 #define dns_name_countlabels(n) DNS_NAME_COUNTLABELS(n)
1290 #define dns_name_isabsolute(n) DNS_NAME_ISABSOLUTE(n)
1291 #define dns_name_toregion(n, r) DNS_NAME_TOREGION(n, r)
1292 #define dns_name_split(n, l, p, s) DNS_NAME_SPLIT(n, l, p, s)
1294 #endif /* DNS_NAME_USEINLINE */
1296 #endif /* DNS_NAME_H */