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
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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 1.126.332.3 2009/12/24 00:34:59 each 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.
106 * Clients are strongly discouraged from using this type directly, with
107 * the exception of the 'link' and 'list' fields which may be used directly
108 * for whatever purpose the client desires.
112 unsigned char * ndata;
115 unsigned int attributes;
116 unsigned char * offsets;
117 isc_buffer_t * buffer;
118 ISC_LINK(dns_name_t) link;
119 ISC_LIST(dns_rdataset_t) list;
122 #define DNS_NAME_MAGIC ISC_MAGIC('D','N','S','n')
124 #define DNS_NAMEATTR_ABSOLUTE 0x0001
125 #define DNS_NAMEATTR_READONLY 0x0002
126 #define DNS_NAMEATTR_DYNAMIC 0x0004
127 #define DNS_NAMEATTR_DYNOFFSETS 0x0008
128 #define DNS_NAMEATTR_NOCOMPRESS 0x0010
130 * Attributes below 0x0100 reserved for name.c usage.
132 #define DNS_NAMEATTR_CACHE 0x0100 /*%< Used by resolver. */
133 #define DNS_NAMEATTR_ANSWER 0x0200 /*%< Used by resolver. */
134 #define DNS_NAMEATTR_NCACHE 0x0400 /*%< Used by resolver. */
135 #define DNS_NAMEATTR_CHAINING 0x0800 /*%< Used by resolver. */
136 #define DNS_NAMEATTR_CHASE 0x1000 /*%< Used by resolver. */
137 #define DNS_NAMEATTR_WILDCARD 0x2000 /*%< Used by server. */
139 #define DNS_NAME_DOWNCASE 0x0001
140 #define DNS_NAME_CHECKNAMES 0x0002 /*%< Used by rdata. */
141 #define DNS_NAME_CHECKNAMESFAIL 0x0004 /*%< Used by rdata. */
142 #define DNS_NAME_CHECKREVERSE 0x0008 /*%< Used by rdata. */
143 #define DNS_NAME_CHECKMX 0x0010 /*%< Used by rdata. */
144 #define DNS_NAME_CHECKMXFAIL 0x0020 /*%< Used by rdata. */
146 LIBDNS_EXTERNAL_DATA extern dns_name_t *dns_rootname;
147 LIBDNS_EXTERNAL_DATA extern dns_name_t *dns_wildcardname;
150 * Standard size of a wire format name
152 #define DNS_NAME_MAXWIRE 255
155 * Text output filter procedure.
156 * 'target' is the buffer to be converted. The region to be converted
157 * is from 'buffer'->base + 'used_org' to the end of the used region.
159 typedef isc_result_t (*dns_name_totextfilter_t)(isc_buffer_t *target,
160 unsigned int used_org,
161 isc_boolean_t absolute);
168 dns_name_init(dns_name_t *name, unsigned char *offsets);
173 * \li 'offsets' is never required to be non-NULL, but specifying a
174 * dns_offsets_t for 'offsets' will improve the performance of most
175 * name operations if the name is used more than once.
178 * \li 'name' is not NULL and points to a struct dns_name.
180 * \li offsets == NULL or offsets is a dns_offsets_t.
183 * \li 'name' is a valid name.
184 * \li dns_name_countlabels(name) == 0
185 * \li dns_name_isabsolute(name) == ISC_FALSE
189 dns_name_reset(dns_name_t *name);
191 * Reinitialize 'name'.
194 * \li This function distinguishes itself from dns_name_init() in two
197 * \li + If any buffer is associated with 'name' (via dns_name_setbuffer()
198 * or by being part of a dns_fixedname_t) the link to the buffer
199 * is retained but the buffer itself is cleared.
201 * \li + Of the attributes associated with 'name', all are retained except
202 * DNS_NAMEATTR_ABSOLUTE.
205 * \li 'name' is a valid name.
208 * \li 'name' is a valid name.
209 * \li dns_name_countlabels(name) == 0
210 * \li dns_name_isabsolute(name) == ISC_FALSE
214 dns_name_invalidate(dns_name_t *name);
216 * Make 'name' invalid.
219 * \li 'name' is a valid name.
222 * \li If assertion checking is enabled, future attempts to use 'name'
223 * without initializing it will cause an assertion failure.
225 * \li If the name had a dedicated buffer, that association is ended.
230 *** Dedicated Buffers
234 dns_name_setbuffer(dns_name_t *name, isc_buffer_t *buffer);
236 * Dedicate a buffer for use with 'name'.
239 * \li Specification of a target buffer in dns_name_fromwire(),
240 * dns_name_fromtext(), and dns_name_concatenate() is optional if
241 * 'name' has a dedicated buffer.
243 * \li The caller must not write to buffer until the name has been
244 * invalidated or is otherwise known not to be in use.
246 * \li If buffer is NULL and the name previously had a dedicated buffer,
247 * than that buffer is no longer dedicated to use with this name.
248 * The caller is responsible for ensuring that the storage used by
249 * the name remains valid.
252 * \li 'name' is a valid name.
254 * \li 'buffer' is a valid binary buffer and 'name' doesn't have a
255 * dedicated buffer already, or 'buffer' is NULL.
259 dns_name_hasbuffer(const dns_name_t *name);
261 * Does 'name' have a dedicated buffer?
264 * \li 'name' is a valid name.
267 * \li ISC_TRUE 'name' has a dedicated buffer.
268 * \li ISC_FALSE 'name' does not have a dedicated buffer.
276 dns_name_isabsolute(const dns_name_t *name);
278 * Does 'name' end in the root label?
281 * \li 'name' is a valid name
284 * \li TRUE The last label in 'name' is the root label.
285 * \li FALSE The last label in 'name' is not the root label.
289 dns_name_iswildcard(const dns_name_t *name);
291 * Is 'name' a wildcard name?
294 * \li 'name' is a valid name
296 * \li dns_name_countlabels(name) > 0
299 * \li TRUE The least significant label of 'name' is '*'.
300 * \li FALSE The least significant label of 'name' is not '*'.
304 dns_name_hash(dns_name_t *name, isc_boolean_t case_sensitive);
306 * Provide a hash value for 'name'.
308 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
309 * case will have the same hash value.
312 * \li 'name' is a valid name
319 dns_name_fullhash(dns_name_t *name, isc_boolean_t case_sensitive);
321 * Provide a hash value for 'name'. Unlike dns_name_hash(), this function
322 * always takes into account of the entire name to calculate the hash value.
324 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
325 * case will have the same hash value.
328 *\li 'name' is a valid name
335 dns_name_hashbylabel(dns_name_t *name, isc_boolean_t case_sensitive);
337 * Provide a hash value for 'name', where the hash value is the sum
338 * of the hash values of each label.
340 * Note: if 'case_sensitive' is ISC_FALSE, then names which differ only in
341 * case will have the same hash value.
344 *\li 'name' is a valid name
355 dns_name_fullcompare(const dns_name_t *name1, const dns_name_t *name2,
356 int *orderp, unsigned int *nlabelsp);
358 * Determine the relative ordering under the DNSSEC order relation of
359 * 'name1' and 'name2', and also determine the hierarchical
360 * relationship of the names.
362 * Note: It makes no sense for one of the names to be relative and the
363 * other absolute. If both names are relative, then to be meaningfully
364 * compared the caller must ensure that they are both relative to the
368 *\li 'name1' is a valid name
370 *\li dns_name_countlabels(name1) > 0
372 *\li 'name2' is a valid name
374 *\li dns_name_countlabels(name2) > 0
376 *\li orderp and nlabelsp are valid pointers.
378 *\li Either name1 is absolute and name2 is absolute, or neither is.
382 *\li *orderp is < 0 if name1 < name2, 0 if name1 = name2, > 0 if
385 *\li *nlabelsp is the number of common significant labels.
388 *\li dns_namereln_none There's no hierarchical relationship
389 * between name1 and name2.
390 *\li dns_namereln_contains name1 properly contains name2; i.e.
391 * name2 is a proper subdomain of name1.
392 *\li dns_namereln_subdomain name1 is a proper subdomain of name2.
393 *\li dns_namereln_equal name1 and name2 are equal.
394 *\li dns_namereln_commonancestor name1 and name2 share a common
399 dns_name_compare(const dns_name_t *name1, const dns_name_t *name2);
401 * Determine the relative ordering under the DNSSEC order relation of
402 * 'name1' and 'name2'.
404 * Note: It makes no sense for one of the names to be relative and the
405 * other absolute. If both names are relative, then to be meaningfully
406 * compared the caller must ensure that they are both relative to the
410 * \li 'name1' is a valid name
412 * \li 'name2' is a valid name
414 * \li Either name1 is absolute and name2 is absolute, or neither is.
417 * \li < 0 'name1' is less than 'name2'
418 * \li 0 'name1' is equal to 'name2'
419 * \li > 0 'name1' is greater than 'name2'
423 dns_name_equal(const dns_name_t *name1, const dns_name_t *name2);
425 * Are 'name1' and 'name2' equal?
428 * \li Because it only needs to test for equality, dns_name_equal() can be
429 * significantly faster than dns_name_fullcompare() or dns_name_compare().
431 * \li Offsets tables are not used in the comparision.
433 * \li It makes no sense for one of the names to be relative and the
434 * other absolute. If both names are relative, then to be meaningfully
435 * compared the caller must ensure that they are both relative to the
439 * \li 'name1' is a valid name
441 * \li 'name2' is a valid name
443 * \li Either name1 is absolute and name2 is absolute, or neither is.
446 * \li ISC_TRUE 'name1' and 'name2' are equal
447 * \li ISC_FALSE 'name1' and 'name2' are not equal
451 dns_name_caseequal(const dns_name_t *name1, const dns_name_t *name2);
453 * Case sensitive version of dns_name_equal().
457 dns_name_rdatacompare(const dns_name_t *name1, const dns_name_t *name2);
459 * Compare two names as if they are part of rdata in DNSSEC canonical
463 * \li 'name1' is a valid absolute name
465 * \li dns_name_countlabels(name1) > 0
467 * \li 'name2' is a valid absolute name
469 * \li dns_name_countlabels(name2) > 0
472 * \li < 0 'name1' is less than 'name2'
473 * \li 0 'name1' is equal to 'name2'
474 * \li > 0 'name1' is greater than 'name2'
478 dns_name_issubdomain(const dns_name_t *name1, const dns_name_t *name2);
480 * Is 'name1' a subdomain of 'name2'?
483 * \li name1 is a subdomain of name2 if name1 is contained in name2, or
484 * name1 equals name2.
486 * \li It makes no sense for one of the names to be relative and the
487 * other absolute. If both names are relative, then to be meaningfully
488 * compared the caller must ensure that they are both relative to the
492 * \li 'name1' is a valid name
494 * \li 'name2' is a valid name
496 * \li Either name1 is absolute and name2 is absolute, or neither is.
499 * \li TRUE 'name1' is a subdomain of 'name2'
500 * \li FALSE 'name1' is not a subdomain of 'name2'
504 dns_name_matcheswildcard(const dns_name_t *name, const dns_name_t *wname);
506 * Does 'name' match the wildcard specified in 'wname'?
509 * \li name matches the wildcard specified in wname if all labels
510 * following the wildcard in wname are identical to the same number
511 * of labels at the end of name.
513 * \li It makes no sense for one of the names to be relative and the
514 * other absolute. If both names are relative, then to be meaningfully
515 * compared the caller must ensure that they are both relative to the
519 * \li 'name' is a valid name
521 * \li dns_name_countlabels(name) > 0
523 * \li 'wname' is a valid name
525 * \li dns_name_countlabels(wname) > 0
527 * \li dns_name_iswildcard(wname) is true
529 * \li Either name is absolute and wname is absolute, or neither is.
532 * \li TRUE 'name' matches the wildcard specified in 'wname'
533 * \li FALSE 'name' does not match the wildcard specified in 'wname'
541 dns_name_countlabels(const dns_name_t *name);
543 * How many labels does 'name' have?
546 * \li In this case, as in other places, a 'label' is an ordinary label.
549 * \li 'name' is a valid name
552 * \li The result is <= 128.
555 * \li The number of labels in 'name'.
559 dns_name_getlabel(const dns_name_t *name, unsigned int n, dns_label_t *label);
561 * Make 'label' refer to the 'n'th least significant label of 'name'.
564 * \li Numbering starts at 0.
566 * \li Given "rc.vix.com.", the label 0 is "rc", and label 3 is the
569 * \li 'label' refers to the same memory as 'name', so 'name' must not
570 * be changed while 'label' is still in use.
573 * \li n < dns_name_countlabels(name)
577 dns_name_getlabelsequence(const dns_name_t *source, unsigned int first,
578 unsigned int n, dns_name_t *target);
580 * Make 'target' refer to the 'n' labels including and following 'first'
584 * \li Numbering starts at 0.
586 * \li Given "rc.vix.com.", the label 0 is "rc", and label 3 is the
589 * \li 'target' refers to the same memory as 'source', so 'source'
590 * must not be changed while 'target' is still in use.
593 * \li 'source' and 'target' are valid names.
595 * \li first < dns_name_countlabels(name)
597 * \li first + n <= dns_name_countlabels(name)
602 dns_name_clone(const dns_name_t *source, dns_name_t *target);
604 * Make 'target' refer to the same name as 'source'.
608 * \li 'target' refers to the same memory as 'source', so 'source'
609 * must not be changed while 'target' is still in use.
611 * \li This call is functionally equivalent to:
614 * dns_name_getlabelsequence(source, 0,
615 * dns_name_countlabels(source),
619 * but is more efficient. Also, dns_name_clone() works even if 'source'
624 * \li 'source' is a valid name.
626 * \li 'target' is a valid name that is not read-only.
634 dns_name_fromregion(dns_name_t *name, const isc_region_t *r);
636 * Make 'name' refer to region 'r'.
639 * \li If the conversion encounters a root label before the end of the
640 * region the conversion stops and the length is set to the length
641 * so far converted. A maximum of 255 bytes is converted.
644 * \li The data in 'r' is a sequence of one or more type 00 or type 01000001
649 dns_name_toregion(dns_name_t *name, isc_region_t *r);
651 * Make 'r' refer to 'name'.
655 * \li 'name' is a valid name.
657 * \li 'r' is a valid region.
661 dns_name_fromwire(dns_name_t *name, isc_buffer_t *source,
662 dns_decompress_t *dctx, unsigned int options,
663 isc_buffer_t *target);
665 * Copy the possibly-compressed name at source (active region) into target,
669 * \li Decompression policy is controlled by 'dctx'.
671 * \li If DNS_NAME_DOWNCASE is set, any uppercase letters in 'source' will be
672 * downcased when they are copied into 'target'.
676 * \li *** WARNING ***
678 * \li This routine will often be used when 'source' contains raw network
679 * data. A programming error in this routine could result in a denial
680 * of service, or in the hijacking of the server.
684 * \li 'name' is a valid name.
686 * \li 'source' is a valid buffer and the first byte of the active
687 * region should be the first byte of a DNS wire format domain name.
689 * \li 'target' is a valid buffer or 'target' is NULL and 'name' has
690 * a dedicated buffer.
692 * \li 'dctx' is a valid decompression context.
696 * If result is success:
697 * \li If 'target' is not NULL, 'name' is attached to it.
699 * \li Uppercase letters are downcased in the copy iff
700 * DNS_NAME_DOWNCASE is set in options.
702 * \li The current location in source is advanced, and the used space
703 * in target is updated.
707 * \li Bad Form: Label Length
708 * \li Bad Form: Unknown Label Type
709 * \li Bad Form: Name Length
710 * \li Bad Form: Compression type not allowed
711 * \li Bad Form: Bad compression pointer
712 * \li Bad Form: Input too short
713 * \li Resource Limit: Too many compression pointers
714 * \li Resource Limit: Not enough space in buffer
718 dns_name_towire(const dns_name_t *name, dns_compress_t *cctx,
719 isc_buffer_t *target);
721 * Convert 'name' into wire format, compressing it as specified by the
722 * compression context 'cctx', and storing the result in 'target'.
725 * \li If the compression context allows global compression, then the
726 * global compression table may be updated.
729 * \li 'name' is a valid name
731 * \li dns_name_countlabels(name) > 0
733 * \li dns_name_isabsolute(name) == TRUE
735 * \li target is a valid buffer.
737 * \li Any offsets specified in a global compression table are valid
742 * If the result is success:
744 * \li The used space in target is updated.
748 * \li Resource Limit: Not enough space in buffer
752 dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
753 dns_name_t *origin, unsigned int options,
754 isc_buffer_t *target);
756 * Convert the textual representation of a DNS name at source
757 * into uncompressed wire form stored in target.
760 * \li Relative domain names will have 'origin' appended to them
761 * unless 'origin' is NULL, in which case relative domain names
762 * will remain relative.
764 * \li If DNS_NAME_DOWNCASE is set in 'options', any uppercase letters
765 * in 'source' will be downcased when they are copied into 'target'.
769 * \li 'name' is a valid name.
771 * \li 'source' is a valid buffer.
773 * \li 'target' is a valid buffer or 'target' is NULL and 'name' has
774 * a dedicated buffer.
778 * If result is success:
779 * \li If 'target' is not NULL, 'name' is attached to it.
781 * \li Uppercase letters are downcased in the copy iff
782 * DNS_NAME_DOWNCASE is set in 'options'.
784 * \li The current location in source is advanced, and the used space
785 * in target is updated.
789 *\li #DNS_R_EMPTYLABEL
790 *\li #DNS_R_LABELTOOLONG
791 *\li #DNS_R_BADESCAPE
792 *\li (#DNS_R_BADBITSTRING: should not be returned)
793 *\li (#DNS_R_BITSTRINGTOOLONG: should not be returned)
794 *\li #DNS_R_BADDOTTEDQUAD
796 *\li #ISC_R_UNEXPECTEDEND
800 dns_name_totext(dns_name_t *name, isc_boolean_t omit_final_dot,
801 isc_buffer_t *target);
803 * Convert 'name' into text format, storing the result in 'target'.
806 *\li If 'omit_final_dot' is true, then the final '.' in absolute
807 * names other than the root name will be omitted.
809 *\li If dns_name_countlabels == 0, the name will be "@", representing the
810 * current origin as described by RFC1035.
812 *\li The name is not NUL terminated.
816 *\li 'name' is a valid name
818 *\li 'target' is a valid buffer.
820 *\li if dns_name_isabsolute == FALSE, then omit_final_dot == FALSE
824 *\li If the result is success:
825 * the used space in target is updated.
832 #define DNS_NAME_MAXTEXT 1023
834 * The maximum length of the text representation of a domain
835 * name as generated by dns_name_totext(). This does not
836 * include space for a terminating NULL.
838 * This definition is conservative - the actual maximum
839 * is 1004, derived as follows:
841 * A backslash-decimal escaped character takes 4 bytes.
842 * A wire-encoded name can be up to 255 bytes and each
843 * label is one length byte + at most 63 bytes of data.
844 * Maximizing the label lengths gives us a name of
845 * three 63-octet labels, one 61-octet label, and the
848 * 1 + 63 + 1 + 63 + 1 + 63 + 1 + 61 + 1 = 255
850 * When printed, this is (3 * 63 + 61) * 4
851 * bytes for the escaped label data + 4 bytes for the
852 * dot terminating each label = 1004 bytes total.
856 dns_name_tofilenametext(dns_name_t *name, isc_boolean_t omit_final_dot,
857 isc_buffer_t *target);
859 * Convert 'name' into an alternate text format appropriate for filenames,
860 * storing the result in 'target'. The name data is downcased, guaranteeing
861 * that the filename does not depend on the case of the converted name.
864 *\li If 'omit_final_dot' is true, then the final '.' in absolute
865 * names other than the root name will be omitted.
867 *\li The name is not NUL terminated.
871 *\li 'name' is a valid absolute name
873 *\li 'target' is a valid buffer.
877 *\li If the result is success:
878 * the used space in target is updated.
886 dns_name_downcase(dns_name_t *source, dns_name_t *name,
887 isc_buffer_t *target);
893 *\li 'source' and 'name' are valid names.
895 *\li If source == name, then
896 * 'source' must not be read-only
899 * 'target' is a valid buffer or 'target' is NULL and
900 * 'name' has a dedicated buffer.
906 * Note: if source == name, then the result will always be ISC_R_SUCCESS.
910 dns_name_concatenate(dns_name_t *prefix, dns_name_t *suffix,
911 dns_name_t *name, isc_buffer_t *target);
913 * Concatenate 'prefix' and 'suffix'.
917 *\li 'prefix' is a valid name or NULL.
919 *\li 'suffix' is a valid name or NULL.
921 *\li 'name' is a valid name or NULL.
923 *\li 'target' is a valid buffer or 'target' is NULL and 'name' has
924 * a dedicated buffer.
926 *\li If 'prefix' is absolute, 'suffix' must be NULL or the empty name.
931 * If 'target' is not NULL and 'name' is not NULL, then 'name'
933 * The used space in target is updated.
938 *\li #DNS_R_NAMETOOLONG
942 dns_name_split(dns_name_t *name, unsigned int suffixlabels,
943 dns_name_t *prefix, dns_name_t *suffix);
946 * Split 'name' into two pieces on a label boundary.
949 * \li 'name' is split such that 'suffix' holds the most significant
950 * 'suffixlabels' labels. All other labels are stored in 'prefix'.
952 *\li Copying name data is avoided as much as possible, so 'prefix'
953 * and 'suffix' will end up pointing at the data for 'name'.
955 *\li It is legitimate to pass a 'prefix' or 'suffix' that has
956 * its name data stored someplace other than the dedicated buffer.
957 * This is useful to avoid name copying in the calling function.
959 *\li It is also legitimate to pass a 'prefix' or 'suffix' that is
960 * the same dns_name_t as 'name'.
963 *\li 'name' is a valid name.
965 *\li 'suffixlabels' cannot exceed the number of labels in 'name'.
967 * \li 'prefix' is a valid name or NULL, and cannot be read-only.
969 *\li 'suffix' is a valid name or NULL, and cannot be read-only.
971 *\li If non-NULL, 'prefix' and 'suffix' must have dedicated buffers.
973 *\li 'prefix' and 'suffix' cannot point to the same buffer.
978 * If 'prefix' is not NULL it will contain the least significant
980 * If 'suffix' is not NULL it will contain the most significant
981 * labels. dns_name_countlabels(suffix) will be equal to
985 * Either 'prefix' or 'suffix' is invalidated (depending
986 * on which one the problem was encountered with).
989 *\li #ISC_R_SUCCESS No worries. (This function should always success).
993 dns_name_dup(const dns_name_t *source, isc_mem_t *mctx,
996 * Make 'target' a dynamically allocated copy of 'source'.
1000 *\li 'source' is a valid non-empty name.
1002 *\li 'target' is a valid name that is not read-only.
1004 *\li 'mctx' is a valid memory context.
1008 dns_name_dupwithoffsets(dns_name_t *source, isc_mem_t *mctx,
1009 dns_name_t *target);
1011 * Make 'target' a read-only dynamically allocated copy of 'source'.
1012 * 'target' will also have a dynamically allocated offsets table.
1016 *\li 'source' is a valid non-empty name.
1018 *\li 'target' is a valid name that is not read-only.
1020 *\li 'target' has no offsets table.
1022 *\li 'mctx' is a valid memory context.
1026 dns_name_free(dns_name_t *name, isc_mem_t *mctx);
1032 *\li 'name' is a valid name created previously in 'mctx' by dns_name_dup().
1034 *\li 'mctx' is a valid memory context.
1038 *\li All dynamic resources used by 'name' are freed and the name is
1043 dns_name_digest(dns_name_t *name, dns_digestfunc_t digest, void *arg);
1045 * Send 'name' in DNSSEC canonical form to 'digest'.
1049 *\li 'name' is a valid name.
1051 *\li 'digest' is a valid dns_digestfunc_t.
1055 *\li If successful, the DNSSEC canonical form of 'name' will have been
1058 *\li If digest() returns something other than ISC_R_SUCCESS, that result
1059 * will be returned as the result of dns_name_digest().
1065 *\li Many other results are possible if not successful.
1070 dns_name_dynamic(dns_name_t *name);
1072 * Returns whether there is dynamic memory associated with this name.
1076 *\li 'name' is a valid name.
1080 *\li 'ISC_TRUE' if the name is dynamic otherwise 'ISC_FALSE'.
1084 dns_name_print(dns_name_t *name, FILE *stream);
1086 * Print 'name' on 'stream'.
1090 *\li 'name' is a valid name.
1092 *\li 'stream' is a valid stream.
1098 *\li Any error that dns_name_totext() can return.
1102 dns_name_format(dns_name_t *name, char *cp, unsigned int size);
1104 * Format 'name' as text appropriate for use in log messages.
1106 * Store the formatted name at 'cp', writing no more than
1107 * 'size' bytes. The resulting string is guaranteed to be
1110 * The formatted name will have a terminating dot only if it is
1113 * This function cannot fail, instead any errors are indicated
1114 * in the returned text.
1118 *\li 'name' is a valid name.
1120 *\li 'cp' points a valid character array of size 'size'.
1127 dns_name_settotextfilter(dns_name_totextfilter_t proc);
1129 * Set / clear a thread specific function 'proc' to be called at the
1130 * end of dns_name_totext().
1132 * Note: Under Windows you need to call "dns_name_settotextfilter(NULL);"
1133 * prior to exiting the thread otherwise memory will be leaked.
1134 * For other platforms, which are pthreads based, this is still a good
1135 * idea but not required.
1139 *\li #ISC_R_UNEXPECTED
1142 #define DNS_NAME_FORMATSIZE (DNS_NAME_MAXTEXT + 1)
1144 * Suggested size of buffer passed to dns_name_format().
1145 * Includes space for the terminating NULL.
1149 dns_name_copy(dns_name_t *source, dns_name_t *dest, isc_buffer_t *target);
1151 * Makes 'dest' refer to a copy of the name in 'source'. The data are
1152 * either copied to 'target' or the dedicated buffer in 'dest'.
1155 * \li 'source' is a valid name.
1157 * \li 'dest' is an initialized name with a dedicated buffer.
1159 * \li 'target' is NULL or an initialized buffer.
1161 * \li Either dest has a dedicated buffer or target != NULL.
1165 *\li On success, the used space in target is updated.
1173 dns_name_ishostname(const dns_name_t *name, isc_boolean_t wildcard);
1175 * Return if 'name' is a valid hostname. RFC 952 / RFC 1123.
1176 * If 'wildcard' is ISC_TRUE then allow the first label of name to
1178 * The root is also accepted.
1181 * 'name' to be valid.
1186 dns_name_ismailbox(const dns_name_t *name);
1188 * Return if 'name' is a valid mailbox. RFC 821.
1191 * \li 'name' to be valid.
1195 dns_name_internalwildcard(const dns_name_t *name);
1197 * Return if 'name' contains a internal wildcard name.
1200 * \li 'name' to be valid.
1204 dns_name_destroy(void);
1206 * Cleanup dns_name_settotextfilter() / dns_name_totext() state.
1208 * This should be called as part of the final cleanup process.
1210 * Note: dns_name_settotextfilter(NULL); should be called for all
1211 * threads which have called dns_name_settotextfilter() with a
1212 * non-NULL argument prior to calling dns_name_destroy();
1218 *** High Performance Macros
1222 * WARNING: Use of these macros by applications may require recompilation
1223 * of the application in some situations where calling the function
1226 * WARNING: No assertion checking is done for these macros.
1229 #define DNS_NAME_INIT(n, o) \
1231 (n)->magic = DNS_NAME_MAGIC; \
1232 (n)->ndata = NULL; \
1235 (n)->attributes = 0; \
1236 (n)->offsets = (o); \
1237 (n)->buffer = NULL; \
1238 ISC_LINK_INIT((n), link); \
1239 ISC_LIST_INIT((n)->list); \
1242 #define DNS_NAME_RESET(n) \
1244 (n)->ndata = NULL; \
1247 (n)->attributes &= ~DNS_NAMEATTR_ABSOLUTE; \
1248 if ((n)->buffer != NULL) \
1249 isc_buffer_clear((n)->buffer); \
1252 #define DNS_NAME_SETBUFFER(n, b) \
1255 #define DNS_NAME_ISABSOLUTE(n) \
1256 (((n)->attributes & DNS_NAMEATTR_ABSOLUTE) != 0 ? ISC_TRUE : ISC_FALSE)
1258 #define DNS_NAME_COUNTLABELS(n) \
1261 #define DNS_NAME_TOREGION(n, r) \
1263 (r)->base = (n)->ndata; \
1264 (r)->length = (n)->length; \
1267 #define DNS_NAME_SPLIT(n, l, p, s) \
1269 dns_name_t *_n = (n); \
1270 dns_name_t *_p = (p); \
1271 dns_name_t *_s = (s); \
1272 unsigned int _l = (l); \
1274 dns_name_getlabelsequence(_n, 0, _n->labels - _l, _p); \
1276 dns_name_getlabelsequence(_n, _n->labels - _l, _l, _s); \
1279 #ifdef DNS_NAME_USEINLINE
1281 #define dns_name_init(n, o) DNS_NAME_INIT(n, o)
1282 #define dns_name_reset(n) DNS_NAME_RESET(n)
1283 #define dns_name_setbuffer(n, b) DNS_NAME_SETBUFFER(n, b)
1284 #define dns_name_countlabels(n) DNS_NAME_COUNTLABELS(n)
1285 #define dns_name_isabsolute(n) DNS_NAME_ISABSOLUTE(n)
1286 #define dns_name_toregion(n, r) DNS_NAME_TOREGION(n, r)
1287 #define dns_name_split(n, l, p, s) DNS_NAME_SPLIT(n, l, p, s)
1289 #endif /* DNS_NAME_USEINLINE */
1291 #endif /* DNS_NAME_H */