2 * Copyright (C) 2004-2007, 2009 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1998-2003 Internet Software Consortium.
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
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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,
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13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
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15 * PERFORMANCE OF THIS SOFTWARE.
18 /* $Id: name.h,v 1.126.332.2 2009/01/18 23:47:41 tbox 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
134 #define DNS_NAMEATTR_NOCOMPRESS 0x0010
136 * Attributes below 0x0100 reserved for name.c usage.
138 #define DNS_NAMEATTR_CACHE 0x0100 /*%< Used by resolver. */
139 #define DNS_NAMEATTR_ANSWER 0x0200 /*%< Used by resolver. */
140 #define DNS_NAMEATTR_NCACHE 0x0400 /*%< Used by resolver. */
141 #define DNS_NAMEATTR_CHAINING 0x0800 /*%< Used by resolver. */
142 #define DNS_NAMEATTR_CHASE 0x1000 /*%< Used by resolver. */
143 #define DNS_NAMEATTR_WILDCARD 0x2000 /*%< Used by server. */
145 #define DNS_NAME_DOWNCASE 0x0001
146 #define DNS_NAME_CHECKNAMES 0x0002 /*%< Used by rdata. */
147 #define DNS_NAME_CHECKNAMESFAIL 0x0004 /*%< Used by rdata. */
148 #define DNS_NAME_CHECKREVERSE 0x0008 /*%< Used by rdata. */
149 #define DNS_NAME_CHECKMX 0x0010 /*%< Used by rdata. */
150 #define DNS_NAME_CHECKMXFAIL 0x0020 /*%< Used by rdata. */
152 LIBDNS_EXTERNAL_DATA extern dns_name_t *dns_rootname;
153 LIBDNS_EXTERNAL_DATA extern dns_name_t *dns_wildcardname;
156 * Standard size of a wire format name
158 #define DNS_NAME_MAXWIRE 255
161 * Text output filter procedure.
162 * 'target' is the buffer to be converted. The region to be converted
163 * is from 'buffer'->base + 'used_org' to the end of the used region.
165 typedef isc_result_t (*dns_name_totextfilter_t)(isc_buffer_t *target,
166 unsigned int used_org,
167 isc_boolean_t absolute);
174 dns_name_init(dns_name_t *name, unsigned char *offsets);
179 * \li 'offsets' is never required to be non-NULL, but specifying a
180 * dns_offsets_t for 'offsets' will improve the performance of most
181 * name operations if the name is used more than once.
184 * \li 'name' is not NULL and points to a struct dns_name.
186 * \li offsets == NULL or offsets is a dns_offsets_t.
189 * \li 'name' is a valid name.
190 * \li dns_name_countlabels(name) == 0
191 * \li dns_name_isabsolute(name) == ISC_FALSE
195 dns_name_reset(dns_name_t *name);
197 * Reinitialize 'name'.
200 * \li This function distinguishes itself from dns_name_init() in two
203 * \li + If any buffer is associated with 'name' (via dns_name_setbuffer()
204 * or by being part of a dns_fixedname_t) the link to the buffer
205 * is retained but the buffer itself is cleared.
207 * \li + Of the attributes associated with 'name', all are retained except
208 * DNS_NAMEATTR_ABSOLUTE.
211 * \li 'name' is a valid name.
214 * \li 'name' is a valid name.
215 * \li dns_name_countlabels(name) == 0
216 * \li dns_name_isabsolute(name) == ISC_FALSE
220 dns_name_invalidate(dns_name_t *name);
222 * Make 'name' invalid.
225 * \li 'name' is a valid name.
228 * \li If assertion checking is enabled, future attempts to use 'name'
229 * without initializing it will cause an assertion failure.
231 * \li If the name had a dedicated buffer, that association is ended.
236 *** Dedicated Buffers
240 dns_name_setbuffer(dns_name_t *name, isc_buffer_t *buffer);
242 * Dedicate a buffer for use with 'name'.
245 * \li Specification of a target buffer in dns_name_fromwire(),
246 * dns_name_fromtext(), and dns_name_concatenate() is optional if
247 * 'name' has a dedicated buffer.
249 * \li The caller must not write to buffer until the name has been
250 * invalidated or is otherwise known not to be in use.
252 * \li If buffer is NULL and the name previously had a dedicated buffer,
253 * than that buffer is no longer dedicated to use with this name.
254 * The caller is responsible for ensuring that the storage used by
255 * the name remains valid.
258 * \li 'name' is a valid name.
260 * \li 'buffer' is a valid binary buffer and 'name' doesn't have a
261 * dedicated buffer already, or 'buffer' is NULL.
265 dns_name_hasbuffer(const dns_name_t *name);
267 * Does 'name' have a dedicated buffer?
270 * \li 'name' is a valid name.
273 * \li ISC_TRUE 'name' has a dedicated buffer.
274 * \li ISC_FALSE 'name' does not have a dedicated buffer.
282 dns_name_isabsolute(const dns_name_t *name);
284 * Does 'name' end in the root label?
287 * \li 'name' is a valid name
290 * \li TRUE The last label in 'name' is the root label.
291 * \li FALSE The last label in 'name' is not the root label.
295 dns_name_iswildcard(const dns_name_t *name);
297 * Is 'name' a wildcard name?
300 * \li 'name' is a valid name
302 * \li dns_name_countlabels(name) > 0
305 * \li TRUE The least significant label of 'name' is '*'.
306 * \li FALSE The least significant label of 'name' is not '*'.
310 dns_name_hash(dns_name_t *name, isc_boolean_t case_sensitive);
312 * Provide a hash value for 'name'.
314 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
315 * case will have the same hash value.
318 * \li 'name' is a valid name
325 dns_name_fullhash(dns_name_t *name, isc_boolean_t case_sensitive);
327 * Provide a hash value for 'name'. Unlike dns_name_hash(), this function
328 * always takes into account of the entire name to calculate the hash value.
330 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
331 * case will have the same hash value.
334 *\li 'name' is a valid name
341 dns_name_hashbylabel(dns_name_t *name, isc_boolean_t case_sensitive);
343 * Provide a hash value for 'name', where the hash value is the sum
344 * of the hash values of each label.
346 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
347 * case will have the same hash value.
350 *\li 'name' is a valid name
361 dns_name_fullcompare(const dns_name_t *name1, const dns_name_t *name2,
362 int *orderp, unsigned int *nlabelsp);
364 * Determine the relative ordering under the DNSSEC order relation of
365 * 'name1' and 'name2', and also determine the hierarchical
366 * relationship of the names.
368 * Note: It makes no sense for one of the names to be relative and the
369 * other absolute. If both names are relative, then to be meaningfully
370 * compared the caller must ensure that they are both relative to the
374 *\li 'name1' is a valid name
376 *\li dns_name_countlabels(name1) > 0
378 *\li 'name2' is a valid name
380 *\li dns_name_countlabels(name2) > 0
382 *\li orderp and nlabelsp are valid pointers.
384 *\li Either name1 is absolute and name2 is absolute, or neither is.
388 *\li *orderp is < 0 if name1 < name2, 0 if name1 = name2, > 0 if
391 *\li *nlabelsp is the number of common significant labels.
394 *\li dns_namereln_none There's no hierarchical relationship
395 * between name1 and name2.
396 *\li dns_namereln_contains name1 properly contains name2; i.e.
397 * name2 is a proper subdomain of name1.
398 *\li dns_namereln_subdomain name1 is a proper subdomain of name2.
399 *\li dns_namereln_equal name1 and name2 are equal.
400 *\li dns_namereln_commonancestor name1 and name2 share a common
405 dns_name_compare(const dns_name_t *name1, const dns_name_t *name2);
407 * Determine the relative ordering under the DNSSEC order relation of
408 * 'name1' and 'name2'.
410 * Note: It makes no sense for one of the names to be relative and the
411 * other absolute. If both names are relative, then to be meaningfully
412 * compared the caller must ensure that they are both relative to the
416 * \li 'name1' is a valid name
418 * \li 'name2' is a valid name
420 * \li Either name1 is absolute and name2 is absolute, or neither is.
423 * \li < 0 'name1' is less than 'name2'
424 * \li 0 'name1' is equal to 'name2'
425 * \li > 0 'name1' is greater than 'name2'
429 dns_name_equal(const dns_name_t *name1, const dns_name_t *name2);
431 * Are 'name1' and 'name2' equal?
434 * \li Because it only needs to test for equality, dns_name_equal() can be
435 * significantly faster than dns_name_fullcompare() or dns_name_compare().
437 * \li Offsets tables are not used in the comparision.
439 * \li It makes no sense for one of the names to be relative and the
440 * other absolute. If both names are relative, then to be meaningfully
441 * compared the caller must ensure that they are both relative to the
445 * \li 'name1' is a valid name
447 * \li 'name2' is a valid name
449 * \li Either name1 is absolute and name2 is absolute, or neither is.
452 * \li ISC_TRUE 'name1' and 'name2' are equal
453 * \li ISC_FALSE 'name1' and 'name2' are not equal
457 dns_name_caseequal(const dns_name_t *name1, const dns_name_t *name2);
459 * Case sensitive version of dns_name_equal().
463 dns_name_rdatacompare(const dns_name_t *name1, const dns_name_t *name2);
465 * Compare two names as if they are part of rdata in DNSSEC canonical
469 * \li 'name1' is a valid absolute name
471 * \li dns_name_countlabels(name1) > 0
473 * \li 'name2' is a valid absolute name
475 * \li dns_name_countlabels(name2) > 0
478 * \li < 0 'name1' is less than 'name2'
479 * \li 0 'name1' is equal to 'name2'
480 * \li > 0 'name1' is greater than 'name2'
484 dns_name_issubdomain(const dns_name_t *name1, const dns_name_t *name2);
486 * Is 'name1' a subdomain of 'name2'?
489 * \li name1 is a subdomain of name2 if name1 is contained in name2, or
490 * name1 equals name2.
492 * \li It makes no sense for one of the names to be relative and the
493 * other absolute. If both names are relative, then to be meaningfully
494 * compared the caller must ensure that they are both relative to the
498 * \li 'name1' is a valid name
500 * \li 'name2' is a valid name
502 * \li Either name1 is absolute and name2 is absolute, or neither is.
505 * \li TRUE 'name1' is a subdomain of 'name2'
506 * \li FALSE 'name1' is not a subdomain of 'name2'
510 dns_name_matcheswildcard(const dns_name_t *name, const dns_name_t *wname);
512 * Does 'name' match the wildcard specified in 'wname'?
515 * \li name matches the wildcard specified in wname if all labels
516 * following the wildcard in wname are identical to the same number
517 * of labels at the end of name.
519 * \li It makes no sense for one of the names to be relative and the
520 * other absolute. If both names are relative, then to be meaningfully
521 * compared the caller must ensure that they are both relative to the
525 * \li 'name' is a valid name
527 * \li dns_name_countlabels(name) > 0
529 * \li 'wname' is a valid name
531 * \li dns_name_countlabels(wname) > 0
533 * \li dns_name_iswildcard(wname) is true
535 * \li Either name is absolute and wname is absolute, or neither is.
538 * \li TRUE 'name' matches the wildcard specified in 'wname'
539 * \li FALSE 'name' does not match the wildcard specified in 'wname'
547 dns_name_countlabels(const dns_name_t *name);
549 * How many labels does 'name' have?
552 * \li In this case, as in other places, a 'label' is an ordinary label.
555 * \li 'name' is a valid name
558 * \li The result is <= 128.
561 * \li The number of labels in 'name'.
565 dns_name_getlabel(const dns_name_t *name, unsigned int n, dns_label_t *label);
567 * Make 'label' refer to the 'n'th least significant label of 'name'.
570 * \li Numbering starts at 0.
572 * \li Given "rc.vix.com.", the label 0 is "rc", and label 3 is the
575 * \li 'label' refers to the same memory as 'name', so 'name' must not
576 * be changed while 'label' is still in use.
579 * \li n < dns_name_countlabels(name)
583 dns_name_getlabelsequence(const dns_name_t *source, unsigned int first,
584 unsigned int n, dns_name_t *target);
586 * Make 'target' refer to the 'n' labels including and following 'first'
590 * \li Numbering starts at 0.
592 * \li Given "rc.vix.com.", the label 0 is "rc", and label 3 is the
595 * \li 'target' refers to the same memory as 'source', so 'source'
596 * must not be changed while 'target' is still in use.
599 * \li 'source' and 'target' are valid names.
601 * \li first < dns_name_countlabels(name)
603 * \li first + n <= dns_name_countlabels(name)
608 dns_name_clone(const dns_name_t *source, dns_name_t *target);
610 * Make 'target' refer to the same name as 'source'.
614 * \li 'target' refers to the same memory as 'source', so 'source'
615 * must not be changed while 'target' is still in use.
617 * \li This call is functionally equivalent to:
620 * dns_name_getlabelsequence(source, 0,
621 * dns_name_countlabels(source),
625 * but is more efficient. Also, dns_name_clone() works even if 'source'
630 * \li 'source' is a valid name.
632 * \li 'target' is a valid name that is not read-only.
640 dns_name_fromregion(dns_name_t *name, const isc_region_t *r);
642 * Make 'name' refer to region 'r'.
645 * \li If the conversion encounters a root label before the end of the
646 * region the conversion stops and the length is set to the length
647 * so far converted. A maximum of 255 bytes is converted.
650 * \li The data in 'r' is a sequence of one or more type 00 or type 01000001
655 dns_name_toregion(dns_name_t *name, isc_region_t *r);
657 * Make 'r' refer to 'name'.
661 * \li 'name' is a valid name.
663 * \li 'r' is a valid region.
667 dns_name_fromwire(dns_name_t *name, isc_buffer_t *source,
668 dns_decompress_t *dctx, unsigned int options,
669 isc_buffer_t *target);
671 * Copy the possibly-compressed name at source (active region) into target,
675 * \li Decompression policy is controlled by 'dctx'.
677 * \li If DNS_NAME_DOWNCASE is set, any uppercase letters in 'source' will be
678 * downcased when they are copied into 'target'.
682 * \li *** WARNING ***
684 * \li This routine will often be used when 'source' contains raw network
685 * data. A programming error in this routine could result in a denial
686 * of service, or in the hijacking of the server.
690 * \li 'name' is a valid name.
692 * \li 'source' is a valid buffer and the first byte of the active
693 * region should be the first byte of a DNS wire format domain name.
695 * \li 'target' is a valid buffer or 'target' is NULL and 'name' has
696 * a dedicated buffer.
698 * \li 'dctx' is a valid decompression context.
702 * If result is success:
703 * \li If 'target' is not NULL, 'name' is attached to it.
705 * \li Uppercase letters are downcased in the copy iff
706 * DNS_NAME_DOWNCASE is set in options.
708 * \li The current location in source is advanced, and the used space
709 * in target is updated.
713 * \li Bad Form: Label Length
714 * \li Bad Form: Unknown Label Type
715 * \li Bad Form: Name Length
716 * \li Bad Form: Compression type not allowed
717 * \li Bad Form: Bad compression pointer
718 * \li Bad Form: Input too short
719 * \li Resource Limit: Too many compression pointers
720 * \li Resource Limit: Not enough space in buffer
724 dns_name_towire(const dns_name_t *name, dns_compress_t *cctx,
725 isc_buffer_t *target);
727 * Convert 'name' into wire format, compressing it as specified by the
728 * compression context 'cctx', and storing the result in 'target'.
731 * \li If the compression context allows global compression, then the
732 * global compression table may be updated.
735 * \li 'name' is a valid name
737 * \li dns_name_countlabels(name) > 0
739 * \li dns_name_isabsolute(name) == TRUE
741 * \li target is a valid buffer.
743 * \li Any offsets specified in a global compression table are valid
748 * If the result is success:
750 * \li The used space in target is updated.
754 * \li Resource Limit: Not enough space in buffer
758 dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
759 dns_name_t *origin, unsigned int options,
760 isc_buffer_t *target);
762 * Convert the textual representation of a DNS name at source
763 * into uncompressed wire form stored in target.
766 * \li Relative domain names will have 'origin' appended to them
767 * unless 'origin' is NULL, in which case relative domain names
768 * will remain relative.
770 * \li If DNS_NAME_DOWNCASE is set in 'options', any uppercase letters
771 * in 'source' will be downcased when they are copied into 'target'.
775 * \li 'name' is a valid name.
777 * \li 'source' is a valid buffer.
779 * \li 'target' is a valid buffer or 'target' is NULL and 'name' has
780 * a dedicated buffer.
784 * If result is success:
785 * \li If 'target' is not NULL, 'name' is attached to it.
787 * \li Uppercase letters are downcased in the copy iff
788 * DNS_NAME_DOWNCASE is set in 'options'.
790 * \li The current location in source is advanced, and the used space
791 * in target is updated.
795 *\li #DNS_R_EMPTYLABEL
796 *\li #DNS_R_LABELTOOLONG
797 *\li #DNS_R_BADESCAPE
798 *\li (#DNS_R_BADBITSTRING: should not be returned)
799 *\li (#DNS_R_BITSTRINGTOOLONG: should not be returned)
800 *\li #DNS_R_BADDOTTEDQUAD
802 *\li #ISC_R_UNEXPECTEDEND
806 dns_name_totext(dns_name_t *name, isc_boolean_t omit_final_dot,
807 isc_buffer_t *target);
809 * Convert 'name' into text format, storing the result in 'target'.
812 *\li If 'omit_final_dot' is true, then the final '.' in absolute
813 * names other than the root name will be omitted.
815 *\li If dns_name_countlabels == 0, the name will be "@", representing the
816 * current origin as described by RFC1035.
818 *\li The name is not NUL terminated.
822 *\li 'name' is a valid name
824 *\li 'target' is a valid buffer.
826 *\li if dns_name_isabsolute == FALSE, then omit_final_dot == FALSE
830 *\li If the result is success:
831 * the used space in target is updated.
838 #define DNS_NAME_MAXTEXT 1023
840 * The maximum length of the text representation of a domain
841 * name as generated by dns_name_totext(). This does not
842 * include space for a terminating NULL.
844 * This definition is conservative - the actual maximum
845 * is 1004, derived as follows:
847 * A backslash-decimal escaped character takes 4 bytes.
848 * A wire-encoded name can be up to 255 bytes and each
849 * label is one length byte + at most 63 bytes of data.
850 * Maximizing the label lengths gives us a name of
851 * three 63-octet labels, one 61-octet label, and the
854 * 1 + 63 + 1 + 63 + 1 + 63 + 1 + 61 + 1 = 255
856 * When printed, this is (3 * 63 + 61) * 4
857 * bytes for the escaped label data + 4 bytes for the
858 * dot terminating each label = 1004 bytes total.
862 dns_name_tofilenametext(dns_name_t *name, isc_boolean_t omit_final_dot,
863 isc_buffer_t *target);
865 * Convert 'name' into an alternate text format appropriate for filenames,
866 * storing the result in 'target'. The name data is downcased, guaranteeing
867 * that the filename does not depend on the case of the converted name.
870 *\li If 'omit_final_dot' is true, then the final '.' in absolute
871 * names other than the root name will be omitted.
873 *\li The name is not NUL terminated.
877 *\li 'name' is a valid absolute name
879 *\li 'target' is a valid buffer.
883 *\li If the result is success:
884 * the used space in target is updated.
892 dns_name_downcase(dns_name_t *source, dns_name_t *name,
893 isc_buffer_t *target);
899 *\li 'source' and 'name' are valid names.
901 *\li If source == name, then
902 * 'source' must not be read-only
905 * 'target' is a valid buffer or 'target' is NULL and
906 * 'name' has a dedicated buffer.
912 * Note: if source == name, then the result will always be ISC_R_SUCCESS.
916 dns_name_concatenate(dns_name_t *prefix, dns_name_t *suffix,
917 dns_name_t *name, isc_buffer_t *target);
919 * Concatenate 'prefix' and 'suffix'.
923 *\li 'prefix' is a valid name or NULL.
925 *\li 'suffix' is a valid name or NULL.
927 *\li 'name' is a valid name or NULL.
929 *\li 'target' is a valid buffer or 'target' is NULL and 'name' has
930 * a dedicated buffer.
932 *\li If 'prefix' is absolute, 'suffix' must be NULL or the empty name.
937 * If 'target' is not NULL and 'name' is not NULL, then 'name'
939 * The used space in target is updated.
944 *\li #DNS_R_NAMETOOLONG
948 dns_name_split(dns_name_t *name, unsigned int suffixlabels,
949 dns_name_t *prefix, dns_name_t *suffix);
952 * Split 'name' into two pieces on a label boundary.
955 * \li 'name' is split such that 'suffix' holds the most significant
956 * 'suffixlabels' labels. All other labels are stored in 'prefix'.
958 *\li Copying name data is avoided as much as possible, so 'prefix'
959 * and 'suffix' will end up pointing at the data for 'name'.
961 *\li It is legitimate to pass a 'prefix' or 'suffix' that has
962 * its name data stored someplace other than the dedicated buffer.
963 * This is useful to avoid name copying in the calling function.
965 *\li It is also legitimate to pass a 'prefix' or 'suffix' that is
966 * the same dns_name_t as 'name'.
969 *\li 'name' is a valid name.
971 *\li 'suffixlabels' cannot exceed the number of labels in 'name'.
973 * \li 'prefix' is a valid name or NULL, and cannot be read-only.
975 *\li 'suffix' is a valid name or NULL, and cannot be read-only.
977 *\li If non-NULL, 'prefix' and 'suffix' must have dedicated buffers.
979 *\li 'prefix' and 'suffix' cannot point to the same buffer.
984 * If 'prefix' is not NULL it will contain the least significant
986 * If 'suffix' is not NULL it will contain the most significant
987 * labels. dns_name_countlabels(suffix) will be equal to
991 * Either 'prefix' or 'suffix' is invalidated (depending
992 * on which one the problem was encountered with).
995 *\li #ISC_R_SUCCESS No worries. (This function should always success).
999 dns_name_dup(const dns_name_t *source, isc_mem_t *mctx,
1000 dns_name_t *target);
1002 * Make 'target' a dynamically allocated copy of 'source'.
1006 *\li 'source' is a valid non-empty name.
1008 *\li 'target' is a valid name that is not read-only.
1010 *\li 'mctx' is a valid memory context.
1014 dns_name_dupwithoffsets(dns_name_t *source, isc_mem_t *mctx,
1015 dns_name_t *target);
1017 * Make 'target' a read-only dynamically allocated copy of 'source'.
1018 * 'target' will also have a dynamically allocated offsets table.
1022 *\li 'source' is a valid non-empty name.
1024 *\li 'target' is a valid name that is not read-only.
1026 *\li 'target' has no offsets table.
1028 *\li 'mctx' is a valid memory context.
1032 dns_name_free(dns_name_t *name, isc_mem_t *mctx);
1038 *\li 'name' is a valid name created previously in 'mctx' by dns_name_dup().
1040 *\li 'mctx' is a valid memory context.
1044 *\li All dynamic resources used by 'name' are freed and the name is
1049 dns_name_digest(dns_name_t *name, dns_digestfunc_t digest, void *arg);
1051 * Send 'name' in DNSSEC canonical form to 'digest'.
1055 *\li 'name' is a valid name.
1057 *\li 'digest' is a valid dns_digestfunc_t.
1061 *\li If successful, the DNSSEC canonical form of 'name' will have been
1064 *\li If digest() returns something other than ISC_R_SUCCESS, that result
1065 * will be returned as the result of dns_name_digest().
1071 *\li Many other results are possible if not successful.
1076 dns_name_dynamic(dns_name_t *name);
1078 * Returns whether there is dynamic memory associated with this name.
1082 *\li 'name' is a valid name.
1086 *\li 'ISC_TRUE' if the name is dynamic otherwise 'ISC_FALSE'.
1090 dns_name_print(dns_name_t *name, FILE *stream);
1092 * Print 'name' on 'stream'.
1096 *\li 'name' is a valid name.
1098 *\li 'stream' is a valid stream.
1104 *\li Any error that dns_name_totext() can return.
1108 dns_name_format(dns_name_t *name, char *cp, unsigned int size);
1110 * Format 'name' as text appropriate for use in log messages.
1112 * Store the formatted name at 'cp', writing no more than
1113 * 'size' bytes. The resulting string is guaranteed to be
1116 * The formatted name will have a terminating dot only if it is
1119 * This function cannot fail, instead any errors are indicated
1120 * in the returned text.
1124 *\li 'name' is a valid name.
1126 *\li 'cp' points a valid character array of size 'size'.
1133 dns_name_settotextfilter(dns_name_totextfilter_t proc);
1135 * Set / clear a thread specific function 'proc' to be called at the
1136 * end of dns_name_totext().
1138 * Note: Under Windows you need to call "dns_name_settotextfilter(NULL);"
1139 * prior to exiting the thread otherwise memory will be leaked.
1140 * For other platforms, which are pthreads based, this is still a good
1141 * idea but not required.
1145 *\li #ISC_R_UNEXPECTED
1148 #define DNS_NAME_FORMATSIZE (DNS_NAME_MAXTEXT + 1)
1150 * Suggested size of buffer passed to dns_name_format().
1151 * Includes space for the terminating NULL.
1155 dns_name_copy(dns_name_t *source, dns_name_t *dest, isc_buffer_t *target);
1157 * Makes 'dest' refer to a copy of the name in 'source'. The data are
1158 * either copied to 'target' or the dedicated buffer in 'dest'.
1161 * \li 'source' is a valid name.
1163 * \li 'dest' is an initialized name with a dedicated buffer.
1165 * \li 'target' is NULL or an initialized buffer.
1167 * \li Either dest has a dedicated buffer or target != NULL.
1171 *\li On success, the used space in target is updated.
1179 dns_name_ishostname(const dns_name_t *name, isc_boolean_t wildcard);
1181 * Return if 'name' is a valid hostname. RFC 952 / RFC 1123.
1182 * If 'wildcard' is ISC_TRUE then allow the first label of name to
1184 * The root is also accepted.
1187 * 'name' to be valid.
1192 dns_name_ismailbox(const dns_name_t *name);
1194 * Return if 'name' is a valid mailbox. RFC 821.
1197 * \li 'name' to be valid.
1201 dns_name_internalwildcard(const dns_name_t *name);
1203 * Return if 'name' contains a internal wildcard name.
1206 * \li 'name' to be valid.
1210 dns_name_destroy(void);
1212 * Cleanup dns_name_settotextfilter() / dns_name_totext() state.
1214 * This should be called as part of the final cleanup process.
1216 * Note: dns_name_settotextfilter(NULL); should be called for all
1217 * threads which have called dns_name_settotextfilter() with a
1218 * non-NULL argument prior to calling dns_name_destroy();
1224 *** High Performance Macros
1228 * WARNING: Use of these macros by applications may require recompilation
1229 * of the application in some situations where calling the function
1232 * WARNING: No assertion checking is done for these macros.
1235 #define DNS_NAME_INIT(n, o) \
1237 (n)->magic = DNS_NAME_MAGIC; \
1238 (n)->ndata = NULL; \
1241 (n)->attributes = 0; \
1242 (n)->offsets = (o); \
1243 (n)->buffer = NULL; \
1244 ISC_LINK_INIT((n), link); \
1245 ISC_LIST_INIT((n)->list); \
1248 #define DNS_NAME_RESET(n) \
1250 (n)->ndata = NULL; \
1253 (n)->attributes &= ~DNS_NAMEATTR_ABSOLUTE; \
1254 if ((n)->buffer != NULL) \
1255 isc_buffer_clear((n)->buffer); \
1258 #define DNS_NAME_SETBUFFER(n, b) \
1261 #define DNS_NAME_ISABSOLUTE(n) \
1262 (((n)->attributes & DNS_NAMEATTR_ABSOLUTE) != 0 ? ISC_TRUE : ISC_FALSE)
1264 #define DNS_NAME_COUNTLABELS(n) \
1267 #define DNS_NAME_TOREGION(n, r) \
1269 (r)->base = (n)->ndata; \
1270 (r)->length = (n)->length; \
1273 #define DNS_NAME_SPLIT(n, l, p, s) \
1275 dns_name_t *_n = (n); \
1276 dns_name_t *_p = (p); \
1277 dns_name_t *_s = (s); \
1278 unsigned int _l = (l); \
1280 dns_name_getlabelsequence(_n, 0, _n->labels - _l, _p); \
1282 dns_name_getlabelsequence(_n, _n->labels - _l, _l, _s); \
1285 #ifdef DNS_NAME_USEINLINE
1287 #define dns_name_init(n, o) DNS_NAME_INIT(n, o)
1288 #define dns_name_reset(n) DNS_NAME_RESET(n)
1289 #define dns_name_setbuffer(n, b) DNS_NAME_SETBUFFER(n, b)
1290 #define dns_name_countlabels(n) DNS_NAME_COUNTLABELS(n)
1291 #define dns_name_isabsolute(n) DNS_NAME_ISABSOLUTE(n)
1292 #define dns_name_toregion(n, r) DNS_NAME_TOREGION(n, r)
1293 #define dns_name_split(n, l, p, s) DNS_NAME_SPLIT(n, l, p, s)
1295 #endif /* DNS_NAME_USEINLINE */
1297 #endif /* DNS_NAME_H */