rbt.h revision 170222
1135446Strhodes/* 2170222Sdougb * Copyright (C) 2004, 2005 Internet Systems Consortium, Inc. ("ISC") 3135446Strhodes * Copyright (C) 1999-2002 Internet Software Consortium. 4135446Strhodes * 5135446Strhodes * Permission to use, copy, modify, and distribute this software for any 6135446Strhodes * purpose with or without fee is hereby granted, provided that the above 7135446Strhodes * copyright notice and this permission notice appear in all copies. 8135446Strhodes * 9135446Strhodes * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 10135446Strhodes * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 11135446Strhodes * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 12135446Strhodes * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 13135446Strhodes * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 14135446Strhodes * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 15135446Strhodes * PERFORMANCE OF THIS SOFTWARE. 16135446Strhodes */ 17135446Strhodes 18170222Sdougb/* $Id: rbt.h,v 1.59.18.5 2005/10/13 01:26:07 marka Exp $ */ 19135446Strhodes 20135446Strhodes#ifndef DNS_RBT_H 21135446Strhodes#define DNS_RBT_H 1 22135446Strhodes 23170222Sdougb/*! \file */ 24170222Sdougb 25135446Strhodes#include <isc/lang.h> 26135446Strhodes#include <isc/magic.h> 27170222Sdougb#include <isc/refcount.h> 28135446Strhodes 29135446Strhodes#include <dns/types.h> 30135446Strhodes 31135446StrhodesISC_LANG_BEGINDECLS 32135446Strhodes 33135446Strhodes#define DNS_RBT_USEHASH 1 34135446Strhodes 35170222Sdougb/*@{*/ 36170222Sdougb/*% 37135446Strhodes * Option values for dns_rbt_findnode() and dns_rbt_findname(). 38135446Strhodes * These are used to form a bitmask. 39135446Strhodes */ 40135446Strhodes#define DNS_RBTFIND_NOOPTIONS 0x00 41135446Strhodes#define DNS_RBTFIND_EMPTYDATA 0x01 42135446Strhodes#define DNS_RBTFIND_NOEXACT 0x02 43135446Strhodes#define DNS_RBTFIND_NOPREDECESSOR 0x04 44170222Sdougb/*@}*/ 45135446Strhodes 46170222Sdougb#ifndef DNS_RBT_USEISCREFCOUNT 47170222Sdougb#ifdef ISC_REFCOUNT_HAVEATOMIC 48170222Sdougb#define DNS_RBT_USEISCREFCOUNT 1 49170222Sdougb#endif 50170222Sdougb#endif 51170222Sdougb 52135446Strhodes/* 53135446Strhodes * These should add up to 30. 54135446Strhodes */ 55135446Strhodes#define DNS_RBT_LOCKLENGTH 10 56135446Strhodes#define DNS_RBT_REFLENGTH 20 57135446Strhodes 58135446Strhodes#define DNS_RBTNODE_MAGIC ISC_MAGIC('R','B','N','O') 59135446Strhodes#if DNS_RBT_USEMAGIC 60135446Strhodes#define DNS_RBTNODE_VALID(n) ISC_MAGIC_VALID(n, DNS_RBTNODE_MAGIC) 61135446Strhodes#else 62135446Strhodes#define DNS_RBTNODE_VALID(n) ISC_TRUE 63135446Strhodes#endif 64135446Strhodes 65170222Sdougb/*% 66135446Strhodes * This is the structure that is used for each node in the red/black 67135446Strhodes * tree of trees. NOTE WELL: the implementation manages this as a variable 68135446Strhodes * length structure, with the actual wire-format name and other data 69135446Strhodes * appended to this structure. Allocating a contiguous block of memory for 70135446Strhodes * multiple dns_rbtnode structures will not work. 71135446Strhodes */ 72135446Strhodestypedef struct dns_rbtnode { 73135446Strhodes#if DNS_RBT_USEMAGIC 74135446Strhodes unsigned int magic; 75135446Strhodes#endif 76135446Strhodes struct dns_rbtnode *parent; 77135446Strhodes struct dns_rbtnode *left; 78135446Strhodes struct dns_rbtnode *right; 79135446Strhodes struct dns_rbtnode *down; 80135446Strhodes#ifdef DNS_RBT_USEHASH 81135446Strhodes struct dns_rbtnode *hashnext; 82135446Strhodes#endif 83170222Sdougb /*@{*/ 84170222Sdougb /*! 85135446Strhodes * The following bitfields add up to a total bitwidth of 32. 86135446Strhodes * The range of values necessary for each item is indicated, 87135446Strhodes * but in the case of "attributes" the field is wider to accomodate 88135446Strhodes * possible future expansion. "offsetlen" could be one bit 89135446Strhodes * narrower by always adjusting its value by 1 to find the real 90135446Strhodes * offsetlen, but doing so does not gain anything (except perhaps 91135446Strhodes * another bit for "attributes", which doesn't yet need any more). 92135446Strhodes * 93135446Strhodes * In each case below the "range" indicated is what's _necessary_ for 94135446Strhodes * the bitfield to hold, not what it actually _can_ hold. 95135446Strhodes */ 96170222Sdougb unsigned int is_root : 1; /*%< range is 0..1 */ 97170222Sdougb unsigned int color : 1; /*%< range is 0..1 */ 98170222Sdougb unsigned int find_callback : 1; /*%< range is 0..1 */ 99170222Sdougb unsigned int attributes : 4; /*%< range is 0..2 */ 100170222Sdougb unsigned int namelen : 8; /*%< range is 1..255 */ 101170222Sdougb unsigned int offsetlen : 8; /*%< range is 1..128 */ 102170222Sdougb unsigned int padbytes : 9; /*%< range is 0..380 */ 103170222Sdougb /*@}*/ 104135446Strhodes 105135446Strhodes#ifdef DNS_RBT_USEHASH 106135446Strhodes unsigned int hashval; 107135446Strhodes#endif 108135446Strhodes 109170222Sdougb /*@{*/ 110170222Sdougb /*! 111135446Strhodes * These values are used in the RBT DB implementation. The appropriate 112135446Strhodes * node lock must be held before accessing them. 113135446Strhodes */ 114135446Strhodes void *data; 115135446Strhodes unsigned int dirty:1; 116135446Strhodes unsigned int wild:1; 117135446Strhodes unsigned int locknum:DNS_RBT_LOCKLENGTH; 118170222Sdougb#ifndef DNS_RBT_USEISCREFCOUNT 119135446Strhodes unsigned int references:DNS_RBT_REFLENGTH; 120170222Sdougb#else 121170222Sdougb isc_refcount_t references; /* note that this is not in the bitfield */ 122170222Sdougb#endif 123170222Sdougb /*@}*/ 124135446Strhodes} dns_rbtnode_t; 125135446Strhodes 126135446Strhodestypedef isc_result_t (*dns_rbtfindcallback_t)(dns_rbtnode_t *node, 127135446Strhodes dns_name_t *name, 128135446Strhodes void *callback_arg); 129135446Strhodes 130135446Strhodes/***** 131135446Strhodes ***** Chain Info 132135446Strhodes *****/ 133135446Strhodes 134170222Sdougb/*! 135135446Strhodes * A chain is used to keep track of the sequence of nodes to reach any given 136135446Strhodes * node from the root of the tree. Originally nodes did not have parent 137135446Strhodes * pointers in them (for memory usage reasons) so there was no way to find 138135446Strhodes * the path back to the root from any given node. Now that nodes have parent 139135446Strhodes * pointers, chains might be going away in a future release, though the 140135446Strhodes * movement functionality would remain. 141135446Strhodes * 142135446Strhodes * In any event, parent information, whether via parent pointers or chains, is 143135446Strhodes * necessary information for iterating through the tree or for basic internal 144135446Strhodes * tree maintenance issues (ie, the rotations that are done to rebalance the 145135446Strhodes * tree when a node is added). The obvious implication of this is that for a 146135446Strhodes * chain to remain valid, the tree has to be locked down against writes for the 147135446Strhodes * duration of the useful life of the chain, because additions or removals can 148135446Strhodes * change the path from the root to the node the chain has targetted. 149135446Strhodes * 150135446Strhodes * The dns_rbtnodechain_ functions _first, _last, _prev and _next all take 151135446Strhodes * dns_name_t parameters for the name and the origin, which can be NULL. If 152135446Strhodes * non-NULL, 'name' will end up pointing to the name data and offsets that are 153135446Strhodes * stored at the node (and thus it will be read-only), so it should be a 154135446Strhodes * regular dns_name_t that has been initialized with dns_name_init. When 155135446Strhodes * 'origin' is non-NULL, it will get the name of the origin stored in it, so it 156135446Strhodes * needs to have its own buffer space and offsets, which is most easily 157135446Strhodes * accomplished with a dns_fixedname_t. It is _not_ necessary to reinitialize 158135446Strhodes * either 'name' or 'origin' between calls to the chain functions. 159135446Strhodes * 160135446Strhodes * NOTE WELL: even though the name data at the root of the tree of trees will 161135446Strhodes * be absolute (typically just "."), it will will be made into a relative name 162135446Strhodes * with an origin of "." -- an empty name when the node is ".". This is 163135446Strhodes * because a common on operation on 'name' and 'origin' is to use 164135446Strhodes * dns_name_concatenate() on them to generate the complete name. An empty name 165135446Strhodes * can be detected when dns_name_countlabels == 0, and is printed by 166135446Strhodes * dns_name_totext()/dns_name_format() as "@", consistent with RFC1035's 167135446Strhodes * definition of "@" as the current origin. 168135446Strhodes * 169135446Strhodes * dns_rbtnodechain_current is similar to the _first, _last, _prev and _next 170135446Strhodes * functions but additionally can provide the node to which the chain points. 171135446Strhodes */ 172135446Strhodes 173170222Sdougb/*% 174135446Strhodes * The number of level blocks to allocate at a time. Currently the maximum 175135446Strhodes * number of levels is allocated directly in the structure, but future 176135446Strhodes * revisions of this code might have a static initial block with dynamic 177135446Strhodes * growth. Allocating space for 256 levels when the tree is almost never that 178135446Strhodes * deep is wasteful, but it's not clear that it matters, since the waste is 179135446Strhodes * only 2MB for 1000 concurrently active chains on a system with 64-bit 180135446Strhodes * pointers. 181135446Strhodes */ 182135446Strhodes#define DNS_RBT_LEVELBLOCK 254 183135446Strhodes 184135446Strhodestypedef struct dns_rbtnodechain { 185135446Strhodes unsigned int magic; 186135446Strhodes isc_mem_t * mctx; 187170222Sdougb /*% 188135446Strhodes * The terminal node of the chain. It is not in levels[]. 189135446Strhodes * This is ostensibly private ... but in a pinch it could be 190135446Strhodes * used tell that the chain points nowhere without needing to 191135446Strhodes * call dns_rbtnodechain_current(). 192135446Strhodes */ 193135446Strhodes dns_rbtnode_t * end; 194170222Sdougb /*% 195135446Strhodes * The maximum number of labels in a name is 128; bitstrings mean 196135446Strhodes * a conceptually very large number (which I have not bothered to 197135446Strhodes * compute) of logical levels because splitting can potentially occur 198135446Strhodes * at each bit. However, DNSSEC restricts the number of "logical" 199135446Strhodes * labels in a name to 255, meaning only 254 pointers are needed 200135446Strhodes * in the worst case. 201135446Strhodes */ 202135446Strhodes dns_rbtnode_t * levels[DNS_RBT_LEVELBLOCK]; 203170222Sdougb /*% 204135446Strhodes * level_count indicates how deep the chain points into the 205135446Strhodes * tree of trees, and is the index into the levels[] array. 206135446Strhodes * Thus, levels[level_count - 1] is the last level node stored. 207135446Strhodes * A chain that points to the top level of the tree of trees has 208135446Strhodes * a level_count of 0, the first level has a level_count of 1, and 209135446Strhodes * so on. 210135446Strhodes */ 211135446Strhodes unsigned int level_count; 212170222Sdougb /*% 213135446Strhodes * level_matches tells how many levels matched above the node 214135446Strhodes * returned by dns_rbt_findnode(). A match (partial or exact) found 215135446Strhodes * in the first level thus results in level_matches being set to 1. 216135446Strhodes * This is used by the rbtdb to set the start point for a recursive 217135446Strhodes * search of superdomains until the RR it is looking for is found. 218135446Strhodes */ 219135446Strhodes unsigned int level_matches; 220135446Strhodes} dns_rbtnodechain_t; 221135446Strhodes 222135446Strhodes/***** 223135446Strhodes ***** Public interfaces. 224135446Strhodes *****/ 225135446Strhodesisc_result_t 226135446Strhodesdns_rbt_create(isc_mem_t *mctx, void (*deleter)(void *, void *), 227135446Strhodes void *deleter_arg, dns_rbt_t **rbtp); 228170222Sdougb/*%< 229135446Strhodes * Initialize a red-black tree of trees. 230135446Strhodes * 231135446Strhodes * Notes: 232170222Sdougb *\li The deleter argument, if non-null, points to a function that is 233135446Strhodes * responsible for cleaning up any memory associated with the data 234135446Strhodes * pointer of a node when the node is deleted. It is passed the 235135446Strhodes * deleted node's data pointer as its first argument and deleter_arg 236135446Strhodes * as its second argument. 237135446Strhodes * 238135446Strhodes * Requires: 239170222Sdougb * \li mctx is a pointer to a valid memory context. 240170222Sdougb *\li rbtp != NULL && *rbtp == NULL 241170222Sdougb *\li arg == NULL iff deleter == NULL 242135446Strhodes * 243135446Strhodes * Ensures: 244170222Sdougb *\li If result is ISC_R_SUCCESS: 245135446Strhodes * *rbtp points to a valid red-black tree manager 246135446Strhodes * 247170222Sdougb *\li If result is failure: 248135446Strhodes * *rbtp does not point to a valid red-black tree manager. 249135446Strhodes * 250135446Strhodes * Returns: 251170222Sdougb *\li #ISC_R_SUCCESS Success 252170222Sdougb *\li #ISC_R_NOMEMORY Resource limit: Out of Memory 253135446Strhodes */ 254135446Strhodes 255135446Strhodesisc_result_t 256135446Strhodesdns_rbt_addname(dns_rbt_t *rbt, dns_name_t *name, void *data); 257170222Sdougb/*%< 258135446Strhodes * Add 'name' to the tree of trees, associated with 'data'. 259135446Strhodes * 260135446Strhodes * Notes: 261170222Sdougb *\li 'data' is never required to be non-NULL, but specifying it 262135446Strhodes * when the name is added is faster than searching for 'name' 263135446Strhodes * again and then setting the data pointer. The lack of a data pointer 264135446Strhodes * for a node also has other ramifications regarding whether 265135446Strhodes * dns_rbt_findname considers a node to exist, or dns_rbt_deletename 266135446Strhodes * joins nodes. 267135446Strhodes * 268135446Strhodes * Requires: 269170222Sdougb *\li rbt is a valid rbt manager. 270170222Sdougb *\li dns_name_isabsolute(name) == TRUE 271135446Strhodes * 272135446Strhodes * Ensures: 273170222Sdougb *\li 'name' is not altered in any way. 274135446Strhodes * 275170222Sdougb *\li Any external references to nodes in the tree are unaffected by 276135446Strhodes * node splits that are necessary to insert the new name. 277135446Strhodes * 278170222Sdougb *\li If result is #ISC_R_SUCCESS: 279135446Strhodes * 'name' is findable in the red/black tree of trees in O(log N). 280135446Strhodes * The data pointer of the node for 'name' is set to 'data'. 281135446Strhodes * 282170222Sdougb *\li If result is #ISC_R_EXISTS or #ISC_R_NOSPACE: 283135446Strhodes * The tree of trees is unaltered. 284135446Strhodes * 285170222Sdougb *\li If result is #ISC_R_NOMEMORY: 286135446Strhodes * No guarantees. 287135446Strhodes * 288135446Strhodes * Returns: 289170222Sdougb *\li #ISC_R_SUCCESS Success 290170222Sdougb *\li #ISC_R_EXISTS The name already exists with associated data. 291170222Sdougb *\li #ISC_R_NOSPACE The name had more logical labels than are allowed. 292170222Sdougb *\li #ISC_R_NOMEMORY Resource Limit: Out of Memory 293135446Strhodes */ 294135446Strhodes 295135446Strhodesisc_result_t 296135446Strhodesdns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep); 297135446Strhodes 298170222Sdougb/*%< 299135446Strhodes * Just like dns_rbt_addname, but returns the address of the node. 300135446Strhodes * 301135446Strhodes * Requires: 302170222Sdougb *\li rbt is a valid rbt structure. 303170222Sdougb *\li dns_name_isabsolute(name) == TRUE 304170222Sdougb *\li nodep != NULL && *nodep == NULL 305135446Strhodes * 306135446Strhodes * Ensures: 307170222Sdougb *\li 'name' is not altered in any way. 308135446Strhodes * 309170222Sdougb *\li Any external references to nodes in the tree are unaffected by 310135446Strhodes * node splits that are necessary to insert the new name. 311135446Strhodes * 312170222Sdougb *\li If result is ISC_R_SUCCESS: 313135446Strhodes * 'name' is findable in the red/black tree of trees in O(log N). 314135446Strhodes * *nodep is the node that was added for 'name'. 315135446Strhodes * 316170222Sdougb *\li If result is ISC_R_EXISTS: 317135446Strhodes * The tree of trees is unaltered. 318135446Strhodes * *nodep is the existing node for 'name'. 319135446Strhodes * 320170222Sdougb *\li If result is ISC_R_NOMEMORY: 321135446Strhodes * No guarantees. 322135446Strhodes * 323135446Strhodes * Returns: 324170222Sdougb *\li #ISC_R_SUCCESS Success 325170222Sdougb *\li #ISC_R_EXISTS The name already exists, possibly without data. 326170222Sdougb *\li #ISC_R_NOMEMORY Resource Limit: Out of Memory 327135446Strhodes */ 328135446Strhodes 329135446Strhodesisc_result_t 330135446Strhodesdns_rbt_findname(dns_rbt_t *rbt, dns_name_t *name, unsigned int options, 331135446Strhodes dns_name_t *foundname, void **data); 332170222Sdougb/*%< 333135446Strhodes * Get the data pointer associated with 'name'. 334135446Strhodes * 335135446Strhodes * Notes: 336170222Sdougb *\li When #DNS_RBTFIND_NOEXACT is set, the closest matching superdomain is 337170222Sdougb * returned (also subject to #DNS_RBTFIND_EMPTYDATA), even when there is 338135446Strhodes * an exact match in the tree. 339135446Strhodes * 340170222Sdougb *\li A node that has no data is considered not to exist for this function, 341170222Sdougb * unless the #DNS_RBTFIND_EMPTYDATA option is set. 342135446Strhodes * 343135446Strhodes * Requires: 344170222Sdougb *\li rbt is a valid rbt manager. 345170222Sdougb *\li dns_name_isabsolute(name) == TRUE 346170222Sdougb *\li data != NULL && *data == NULL 347135446Strhodes * 348135446Strhodes * Ensures: 349170222Sdougb *\li 'name' and the tree are not altered in any way. 350135446Strhodes * 351170222Sdougb *\li If result is ISC_R_SUCCESS: 352135446Strhodes * *data is the data associated with 'name'. 353135446Strhodes * 354170222Sdougb *\li If result is DNS_R_PARTIALMATCH: 355135446Strhodes * *data is the data associated with the deepest superdomain 356135446Strhodes * of 'name' which has data. 357135446Strhodes * 358170222Sdougb *\li If result is ISC_R_NOTFOUND: 359135446Strhodes * Neither the name nor a superdomain was found with data. 360135446Strhodes * 361135446Strhodes * Returns: 362170222Sdougb *\li #ISC_R_SUCCESS Success 363170222Sdougb *\li #DNS_R_PARTIALMATCH Superdomain found with data 364170222Sdougb *\li #ISC_R_NOTFOUND No match 365170222Sdougb *\li #ISC_R_NOSPACE Concatenating nodes to form foundname failed 366135446Strhodes */ 367135446Strhodes 368135446Strhodesisc_result_t 369135446Strhodesdns_rbt_findnode(dns_rbt_t *rbt, dns_name_t *name, dns_name_t *foundname, 370135446Strhodes dns_rbtnode_t **node, dns_rbtnodechain_t *chain, 371135446Strhodes unsigned int options, dns_rbtfindcallback_t callback, 372135446Strhodes void *callback_arg); 373170222Sdougb/*%< 374135446Strhodes * Find the node for 'name'. 375135446Strhodes * 376135446Strhodes * Notes: 377170222Sdougb *\li A node that has no data is considered not to exist for this function, 378135446Strhodes * unless the DNS_RBTFIND_EMPTYDATA option is set. This applies to both 379135446Strhodes * exact matches and partial matches. 380135446Strhodes * 381170222Sdougb *\li If the chain parameter is non-NULL, then the path through the tree 382135446Strhodes * to the DNSSEC predecessor of the searched for name is maintained, 383135446Strhodes * unless the DNS_RBTFIND_NOPREDECESSOR or DNS_RBTFIND_NOEXACT option 384135446Strhodes * is used. (For more details on those options, see below.) 385135446Strhodes * 386170222Sdougb *\li If there is no predecessor, then the chain will point to nowhere, as 387135446Strhodes * indicated by chain->end being NULL or dns_rbtnodechain_current 388135446Strhodes * returning ISC_R_NOTFOUND. Note that in a normal Internet DNS RBT 389135446Strhodes * there will always be a predecessor for all names except the root 390135446Strhodes * name, because '.' will exist and '.' is the predecessor of 391135446Strhodes * everything. But you can certainly construct a trivial tree and a 392135446Strhodes * search for it that has no predecessor. 393135446Strhodes * 394170222Sdougb *\li Within the chain structure, the 'levels' member of the structure holds 395135446Strhodes * the root node of each level except the first. 396135446Strhodes * 397170222Sdougb *\li The 'level_count' of the chain indicates how deep the chain to the 398135446Strhodes * predecessor name is, as an index into the 'levels[]' array. It does 399135446Strhodes * not count name elements, per se, but only levels of the tree of trees, 400135446Strhodes * the distinction arrising because multiple labels from a name can be 401135446Strhodes * stored on only one level. It is also does not include the level 402135446Strhodes * that has the node, since that level is not stored in levels[]. 403135446Strhodes * 404170222Sdougb *\li The chain's 'level_matches' is not directly related to the predecessor. 405135446Strhodes * It is the number of levels above the level of the found 'node', 406135446Strhodes * regardless of whether it was a partial match or exact match. When 407135446Strhodes * the node is found in the top level tree, or no node is found at all, 408135446Strhodes * level_matches is 0. 409135446Strhodes * 410170222Sdougb *\li When DNS_RBTFIND_NOEXACT is set, the closest matching superdomain is 411135446Strhodes * returned (also subject to DNS_RBTFIND_EMPTYDATA), even when 412135446Strhodes * there is an exact match in the tree. In this case, the chain 413135446Strhodes * will not point to the DNSSEC predecessor, but will instead point 414135446Strhodes * to the exact match, if there was any. Thus the preceding paragraphs 415135446Strhodes * should have "exact match" substituted for "predecessor" to describe 416135446Strhodes * how the various elements of the chain are set. This was done to 417135446Strhodes * ensure that the chain's state was sane, and to prevent problems that 418135446Strhodes * occurred when running the predecessor location code under conditions 419135446Strhodes * it was not designed for. It is not clear *where* the chain should 420135446Strhodes * point when DNS_RBTFIND_NOEXACT is set, so if you end up using a chain 421135446Strhodes * with this option because you want a particular node, let us know 422135446Strhodes * where you want the chain pointed, so this can be made more firm. 423135446Strhodes * 424135446Strhodes * Requires: 425170222Sdougb *\li rbt is a valid rbt manager. 426170222Sdougb *\li dns_name_isabsolute(name) == TRUE. 427170222Sdougb *\li node != NULL && *node == NULL. 428170222Sdougb *\li #DNS_RBTFIND_NOEXACT and DNS_RBTFIND_NOPREDECESSOR are mutally 429135446Strhodes * exclusive. 430135446Strhodes * 431135446Strhodes * Ensures: 432170222Sdougb *\li 'name' and the tree are not altered in any way. 433135446Strhodes * 434170222Sdougb *\li If result is ISC_R_SUCCESS: 435170222Sdougb *\verbatim 436135446Strhodes * *node is the terminal node for 'name'. 437170222Sdougb 438135446Strhodes * 'foundname' and 'name' represent the same name (though not 439135446Strhodes * the same memory). 440170222Sdougb 441135446Strhodes * 'chain' points to the DNSSEC predecessor, if any, of 'name'. 442135446Strhodes * 443135446Strhodes * chain->level_matches and chain->level_count are equal. 444170222Sdougb *\endverbatim 445135446Strhodes * 446135446Strhodes * If result is DNS_R_PARTIALMATCH: 447170222Sdougb *\verbatim 448135446Strhodes * *node is the data associated with the deepest superdomain 449135446Strhodes * of 'name' which has data. 450135446Strhodes * 451135446Strhodes * 'foundname' is the name of deepest superdomain (which has 452135446Strhodes * data, unless the DNS_RBTFIND_EMPTYDATA option is set). 453135446Strhodes * 454135446Strhodes * 'chain' points to the DNSSEC predecessor, if any, of 'name'. 455170222Sdougb *\endverbatim 456135446Strhodes * 457170222Sdougb *\li If result is ISC_R_NOTFOUND: 458170222Sdougb *\verbatim 459135446Strhodes * Neither the name nor a superdomain was found. *node is NULL. 460135446Strhodes * 461135446Strhodes * 'chain' points to the DNSSEC predecessor, if any, of 'name'. 462135446Strhodes * 463135446Strhodes * chain->level_matches is 0. 464170222Sdougb *\endverbatim 465135446Strhodes * 466135446Strhodes * Returns: 467170222Sdougb *\li #ISC_R_SUCCESS Success 468170222Sdougb *\li #DNS_R_PARTIALMATCH Superdomain found with data 469170222Sdougb *\li #ISC_R_NOTFOUND No match, or superdomain with no data 470170222Sdougb *\li #ISC_R_NOSPACE Concatenating nodes to form foundname failed 471135446Strhodes */ 472135446Strhodes 473135446Strhodesisc_result_t 474135446Strhodesdns_rbt_deletename(dns_rbt_t *rbt, dns_name_t *name, isc_boolean_t recurse); 475170222Sdougb/*%< 476135446Strhodes * Delete 'name' from the tree of trees. 477135446Strhodes * 478135446Strhodes * Notes: 479170222Sdougb *\li When 'name' is removed, if recurse is ISC_TRUE then all of its 480135446Strhodes * subnames are removed too. 481135446Strhodes * 482135446Strhodes * Requires: 483170222Sdougb *\li rbt is a valid rbt manager. 484170222Sdougb *\li dns_name_isabsolute(name) == TRUE 485135446Strhodes * 486135446Strhodes * Ensures: 487170222Sdougb *\li 'name' is not altered in any way. 488135446Strhodes * 489170222Sdougb *\li Does NOT ensure that any external references to nodes in the tree 490135446Strhodes * are unaffected by node joins. 491135446Strhodes * 492170222Sdougb *\li If result is ISC_R_SUCCESS: 493135446Strhodes * 'name' does not appear in the tree with data; however, 494135446Strhodes * the node for the name might still exist which can be 495135446Strhodes * found with dns_rbt_findnode (but not dns_rbt_findname). 496135446Strhodes * 497170222Sdougb *\li If result is ISC_R_NOTFOUND: 498135446Strhodes * 'name' does not appear in the tree with data, because 499135446Strhodes * it did not appear in the tree before the function was called. 500135446Strhodes * 501170222Sdougb *\li If result is something else: 502135446Strhodes * See result codes for dns_rbt_findnode (if it fails, the 503135446Strhodes * node is not deleted) or dns_rbt_deletenode (if it fails, 504135446Strhodes * the node is deleted, but the tree is not optimized when 505135446Strhodes * it could have been). 506135446Strhodes * 507135446Strhodes * Returns: 508170222Sdougb *\li #ISC_R_SUCCESS Success 509170222Sdougb *\li #ISC_R_NOTFOUND No match 510170222Sdougb *\li something_else Any return code from dns_rbt_findnode except 511135446Strhodes * DNS_R_PARTIALMATCH (which causes ISC_R_NOTFOUND 512135446Strhodes * to be returned instead), and any code from 513135446Strhodes * dns_rbt_deletenode. 514135446Strhodes */ 515135446Strhodes 516135446Strhodesisc_result_t 517135446Strhodesdns_rbt_deletenode(dns_rbt_t *rbt, dns_rbtnode_t *node, isc_boolean_t recurse); 518170222Sdougb/*%< 519135446Strhodes * Delete 'node' from the tree of trees. 520135446Strhodes * 521135446Strhodes * Notes: 522170222Sdougb *\li When 'node' is removed, if recurse is ISC_TRUE then all nodes 523135446Strhodes * in levels down from it are removed too. 524135446Strhodes * 525135446Strhodes * Requires: 526170222Sdougb *\li rbt is a valid rbt manager. 527170222Sdougb *\li node != NULL. 528135446Strhodes * 529135446Strhodes * Ensures: 530170222Sdougb *\li Does NOT ensure that any external references to nodes in the tree 531135446Strhodes * are unaffected by node joins. 532135446Strhodes * 533170222Sdougb *\li If result is ISC_R_SUCCESS: 534135446Strhodes * 'node' does not appear in the tree with data; however, 535135446Strhodes * the node might still exist if it serves as a pointer to 536135446Strhodes * a lower tree level as long as 'recurse' was false, hence 537135446Strhodes * the node could can be found with dns_rbt_findnode whem 538135446Strhodes * that function's empty_data_ok parameter is true. 539135446Strhodes * 540170222Sdougb *\li If result is ISC_R_NOMEMORY or ISC_R_NOSPACE: 541135446Strhodes * The node was deleted, but the tree structure was not 542135446Strhodes * optimized. 543135446Strhodes * 544135446Strhodes * Returns: 545170222Sdougb *\li #ISC_R_SUCCESS Success 546170222Sdougb *\li #ISC_R_NOMEMORY Resource Limit: Out of Memory when joining nodes. 547170222Sdougb *\li #ISC_R_NOSPACE dns_name_concatenate failed when joining nodes. 548135446Strhodes */ 549135446Strhodes 550135446Strhodesvoid 551135446Strhodesdns_rbt_namefromnode(dns_rbtnode_t *node, dns_name_t *name); 552170222Sdougb/*%< 553135446Strhodes * Convert the sequence of labels stored at 'node' into a 'name'. 554135446Strhodes * 555135446Strhodes * Notes: 556170222Sdougb *\li This function does not return the full name, from the root, but 557135446Strhodes * just the labels at the indicated node. 558135446Strhodes * 559170222Sdougb *\li The name data pointed to by 'name' is the information stored 560135446Strhodes * in the node, not a copy. Altering the data at this pointer 561135446Strhodes * will likely cause grief. 562135446Strhodes * 563135446Strhodes * Requires: 564170222Sdougb * \li name->offsets == NULL 565135446Strhodes * 566135446Strhodes * Ensures: 567170222Sdougb * \li 'name' is DNS_NAMEATTR_READONLY. 568135446Strhodes * 569170222Sdougb * \li 'name' will point directly to the labels stored after the 570135446Strhodes * dns_rbtnode_t struct. 571135446Strhodes * 572170222Sdougb * \li 'name' will have offsets that also point to the information stored 573135446Strhodes * as part of the node. 574135446Strhodes */ 575135446Strhodes 576135446Strhodesisc_result_t 577135446Strhodesdns_rbt_fullnamefromnode(dns_rbtnode_t *node, dns_name_t *name); 578170222Sdougb/*%< 579135446Strhodes * Like dns_rbt_namefromnode, but returns the full name from the root. 580135446Strhodes * 581135446Strhodes * Notes: 582170222Sdougb * \li Unlike dns_rbt_namefromnode, the name will not point directly 583135446Strhodes * to node data. Rather, dns_name_concatenate will be used to copy 584135446Strhodes * the name data from each node into the 'name' argument. 585135446Strhodes * 586135446Strhodes * Requires: 587170222Sdougb * \li name != NULL 588170222Sdougb * \li name has a dedicated buffer. 589135446Strhodes * 590135446Strhodes * Returns: 591170222Sdougb * \li ISC_R_SUCCESS 592170222Sdougb * \li ISC_R_NOSPACE (possible via dns_name_concatenate) 593170222Sdougb * \li DNS_R_NAMETOOLONG (possible via dns_name_concatenate) 594135446Strhodes */ 595135446Strhodes 596135446Strhodeschar * 597135446Strhodesdns_rbt_formatnodename(dns_rbtnode_t *node, char *printname, 598135446Strhodes unsigned int size); 599170222Sdougb/*%< 600135446Strhodes * Format the full name of a node for printing, using dns_name_format(). 601135446Strhodes * 602135446Strhodes * Notes: 603170222Sdougb * \li 'size' is the length of the printname buffer. This should be 604135446Strhodes * DNS_NAME_FORMATSIZE or larger. 605135446Strhodes * 606135446Strhodes * Requires: 607170222Sdougb * \li node and printname are not NULL. 608135446Strhodes * 609135446Strhodes * Returns: 610170222Sdougb * \li The 'printname' pointer. 611135446Strhodes */ 612135446Strhodes 613135446Strhodesunsigned int 614135446Strhodesdns_rbt_nodecount(dns_rbt_t *rbt); 615170222Sdougb/*%< 616135446Strhodes * Obtain the number of nodes in the tree of trees. 617135446Strhodes * 618135446Strhodes * Requires: 619170222Sdougb * \li rbt is a valid rbt manager. 620135446Strhodes */ 621135446Strhodes 622135446Strhodesvoid 623135446Strhodesdns_rbt_destroy(dns_rbt_t **rbtp); 624135446Strhodesisc_result_t 625135446Strhodesdns_rbt_destroy2(dns_rbt_t **rbtp, unsigned int quantum); 626170222Sdougb/*%< 627143731Sdougb * Stop working with a red-black tree of trees. 628143731Sdougb * If 'quantum' is zero then the entire tree will be destroyed. 629143731Sdougb * If 'quantum' is non zero then up to 'quantum' nodes will be destroyed 630143731Sdougb * allowing the rbt to be incrementally destroyed by repeated calls to 631143731Sdougb * dns_rbt_destroy2(). Once dns_rbt_destroy2() has been called no other 632143731Sdougb * operations than dns_rbt_destroy()/dns_rbt_destroy2() should be 633143731Sdougb * performed on the tree of trees. 634143731Sdougb * 635135446Strhodes * Requires: 636170222Sdougb * \li *rbt is a valid rbt manager. 637135446Strhodes * 638143731Sdougb * Ensures on ISC_R_SUCCESS: 639170222Sdougb * \li All space allocated by the RBT library has been returned. 640135446Strhodes * 641170222Sdougb * \li *rbt is invalidated as an rbt manager. 642135446Strhodes * 643135446Strhodes * Returns: 644170222Sdougb * \li ISC_R_SUCCESS 645170222Sdougb * \li ISC_R_QUOTA if 'quantum' nodes have been destroyed. 646135446Strhodes */ 647135446Strhodes 648135446Strhodesvoid 649135446Strhodesdns_rbt_printall(dns_rbt_t *rbt); 650170222Sdougb/*%< 651135446Strhodes * Print an ASCII representation of the internal structure of the red-black 652135446Strhodes * tree of trees. 653135446Strhodes * 654135446Strhodes * Notes: 655170222Sdougb * \li The name stored at each node, along with the node's color, is printed. 656135446Strhodes * Then the down pointer, left and right pointers are displayed 657135446Strhodes * recursively in turn. NULL down pointers are silently omitted; 658135446Strhodes * NULL left and right pointers are printed. 659135446Strhodes */ 660135446Strhodes 661135446Strhodes/***** 662135446Strhodes ***** Chain Functions 663135446Strhodes *****/ 664135446Strhodes 665135446Strhodesvoid 666135446Strhodesdns_rbtnodechain_init(dns_rbtnodechain_t *chain, isc_mem_t *mctx); 667170222Sdougb/*%< 668135446Strhodes * Initialize 'chain'. 669135446Strhodes * 670135446Strhodes * Requires: 671170222Sdougb *\li 'chain' is a valid pointer. 672135446Strhodes * 673170222Sdougb *\li 'mctx' is a valid memory context. 674135446Strhodes * 675135446Strhodes * Ensures: 676170222Sdougb *\li 'chain' is suitable for use. 677135446Strhodes */ 678135446Strhodes 679135446Strhodesvoid 680135446Strhodesdns_rbtnodechain_reset(dns_rbtnodechain_t *chain); 681170222Sdougb/*%< 682135446Strhodes * Free any dynamic storage associated with 'chain', and then reinitialize 683135446Strhodes * 'chain'. 684135446Strhodes * 685135446Strhodes * Requires: 686170222Sdougb *\li 'chain' is a valid pointer. 687135446Strhodes * 688135446Strhodes * Ensures: 689170222Sdougb *\li 'chain' is suitable for use, and uses no dynamic storage. 690135446Strhodes */ 691135446Strhodes 692135446Strhodesvoid 693135446Strhodesdns_rbtnodechain_invalidate(dns_rbtnodechain_t *chain); 694170222Sdougb/*%< 695135446Strhodes * Free any dynamic storage associated with 'chain', and then invalidates it. 696135446Strhodes * 697135446Strhodes * Notes: 698170222Sdougb *\li Future calls to any dns_rbtnodechain_ function will need to call 699135446Strhodes * dns_rbtnodechain_init on the chain first (except, of course, 700135446Strhodes * dns_rbtnodechain_init itself). 701135446Strhodes * 702135446Strhodes * Requires: 703170222Sdougb *\li 'chain' is a valid chain. 704135446Strhodes * 705135446Strhodes * Ensures: 706170222Sdougb *\li 'chain' is no longer suitable for use, and uses no dynamic storage. 707135446Strhodes */ 708135446Strhodes 709135446Strhodesisc_result_t 710135446Strhodesdns_rbtnodechain_current(dns_rbtnodechain_t *chain, dns_name_t *name, 711135446Strhodes dns_name_t *origin, dns_rbtnode_t **node); 712170222Sdougb/*%< 713135446Strhodes * Provide the name, origin and node to which the chain is currently pointed. 714135446Strhodes * 715135446Strhodes * Notes: 716170222Sdougb *\li The tree need not have be locked against additions for the chain 717135446Strhodes * to remain valid, however there are no guarantees if any deletion 718135446Strhodes * has been made since the chain was established. 719135446Strhodes * 720135446Strhodes * Requires: 721170222Sdougb *\li 'chain' is a valid chain. 722135446Strhodes * 723135446Strhodes * Ensures: 724170222Sdougb *\li 'node', if non-NULL, is the node to which the chain was pointed 725135446Strhodes * by dns_rbt_findnode, dns_rbtnodechain_first or dns_rbtnodechain_last. 726135446Strhodes * If none were called for the chain since it was initialized or reset, 727135446Strhodes * or if the was no predecessor to the name searched for with 728135446Strhodes * dns_rbt_findnode, then '*node' is NULL and ISC_R_NOTFOUND is returned. 729135446Strhodes * 730170222Sdougb *\li 'name', if non-NULL, is the name stored at the terminal level of 731135446Strhodes * the chain. This is typically a single label, like the "www" of 732135446Strhodes * "www.isc.org", but need not be so. At the root of the tree of trees, 733135446Strhodes * if the node is "." then 'name' is ".", otherwise it is relative to ".". 734135446Strhodes * (Minimalist and atypical case: if the tree has just the name 735135446Strhodes * "isc.org." then the root node's stored name is "isc.org." but 'name' 736135446Strhodes * will be "isc.org".) 737135446Strhodes * 738170222Sdougb *\li 'origin', if non-NULL, is the sequence of labels in the levels 739135446Strhodes * above the terminal level, such as "isc.org." in the above example. 740135446Strhodes * 'origin' is always "." for the root node. 741135446Strhodes * 742135446Strhodes * 743135446Strhodes * Returns: 744170222Sdougb *\li #ISC_R_SUCCESS name, origin & node were successfully set. 745170222Sdougb *\li #ISC_R_NOTFOUND The chain does not point to any node. 746170222Sdougb *\li <something_else> Any error return from dns_name_concatenate. 747135446Strhodes */ 748135446Strhodes 749135446Strhodesisc_result_t 750135446Strhodesdns_rbtnodechain_first(dns_rbtnodechain_t *chain, dns_rbt_t *rbt, 751135446Strhodes dns_name_t *name, dns_name_t *origin); 752170222Sdougb/*%< 753135446Strhodes * Set the chain to the lexically first node in the tree of trees. 754135446Strhodes * 755135446Strhodes * Notes: 756170222Sdougb *\li By the definition of ordering for DNS names, the root of the tree of 757135446Strhodes * trees is the very first node, since everything else in the megatree 758135446Strhodes * uses it as a common suffix. 759135446Strhodes * 760135446Strhodes * Requires: 761170222Sdougb *\li 'chain' is a valid chain. 762170222Sdougb *\li 'rbt' is a valid rbt manager. 763135446Strhodes * 764135446Strhodes * Ensures: 765170222Sdougb *\li The chain points to the very first node of the tree. 766135446Strhodes * 767170222Sdougb *\li 'name' and 'origin', if non-NULL, are set as described for 768135446Strhodes * dns_rbtnodechain_current. Thus 'origin' will always be ".". 769135446Strhodes * 770135446Strhodes * Returns: 771170222Sdougb *\li #DNS_R_NEWORIGIN The name & origin were successfully set. 772170222Sdougb *\li <something_else> Any error result from dns_rbtnodechain_current. 773135446Strhodes */ 774135446Strhodes 775135446Strhodesisc_result_t 776135446Strhodesdns_rbtnodechain_last(dns_rbtnodechain_t *chain, dns_rbt_t *rbt, 777135446Strhodes dns_name_t *name, dns_name_t *origin); 778170222Sdougb/*%< 779135446Strhodes * Set the chain to the lexically last node in the tree of trees. 780135446Strhodes * 781135446Strhodes * Requires: 782170222Sdougb *\li 'chain' is a valid chain. 783170222Sdougb *\li 'rbt' is a valid rbt manager. 784135446Strhodes * 785135446Strhodes * Ensures: 786170222Sdougb *\li The chain points to the very last node of the tree. 787135446Strhodes * 788170222Sdougb *\li 'name' and 'origin', if non-NULL, are set as described for 789135446Strhodes * dns_rbtnodechain_current. 790135446Strhodes * 791135446Strhodes * Returns: 792170222Sdougb *\li #DNS_R_NEWORIGIN The name & origin were successfully set. 793170222Sdougb *\li #ISC_R_NOMEMORY Resource Limit: Out of Memory building chain. 794170222Sdougb *\li <something_else> Any error result from dns_name_concatenate. 795135446Strhodes */ 796135446Strhodes 797135446Strhodesisc_result_t 798135446Strhodesdns_rbtnodechain_prev(dns_rbtnodechain_t *chain, dns_name_t *name, 799135446Strhodes dns_name_t *origin); 800170222Sdougb/*%< 801135446Strhodes * Adjusts chain to point the DNSSEC predecessor of the name to which it 802135446Strhodes * is currently pointed. 803135446Strhodes * 804135446Strhodes * Requires: 805170222Sdougb *\li 'chain' is a valid chain. 806170222Sdougb *\li 'chain' has been pointed somewhere in the tree with dns_rbt_findnode, 807135446Strhodes * dns_rbtnodechain_first or dns_rbtnodechain_last -- and remember that 808135446Strhodes * dns_rbt_findnode is not guaranteed to point the chain somewhere, 809135446Strhodes * since there may have been no predecessor to the searched for name. 810135446Strhodes * 811135446Strhodes * Ensures: 812170222Sdougb *\li The chain is pointed to the predecessor of its current target. 813135446Strhodes * 814170222Sdougb *\li 'name' and 'origin', if non-NULL, are set as described for 815135446Strhodes * dns_rbtnodechain_current. 816135446Strhodes * 817170222Sdougb *\li 'origin' is only if a new origin was found. 818135446Strhodes * 819135446Strhodes * Returns: 820170222Sdougb *\li #ISC_R_SUCCESS The predecessor was found and 'name' was set. 821170222Sdougb *\li #DNS_R_NEWORIGIN The predecessor was found with a different 822135446Strhodes * origin and 'name' and 'origin' were set. 823170222Sdougb *\li #ISC_R_NOMORE There was no predecessor. 824170222Sdougb *\li <something_else> Any error result from dns_rbtnodechain_current. 825135446Strhodes */ 826135446Strhodes 827135446Strhodesisc_result_t 828135446Strhodesdns_rbtnodechain_next(dns_rbtnodechain_t *chain, dns_name_t *name, 829135446Strhodes dns_name_t *origin); 830170222Sdougb/*%< 831135446Strhodes * Adjusts chain to point the DNSSEC successor of the name to which it 832135446Strhodes * is currently pointed. 833135446Strhodes * 834135446Strhodes * Requires: 835170222Sdougb *\li 'chain' is a valid chain. 836170222Sdougb *\li 'chain' has been pointed somewhere in the tree with dns_rbt_findnode, 837135446Strhodes * dns_rbtnodechain_first or dns_rbtnodechain_last -- and remember that 838135446Strhodes * dns_rbt_findnode is not guaranteed to point the chain somewhere, 839135446Strhodes * since there may have been no predecessor to the searched for name. 840135446Strhodes * 841135446Strhodes * Ensures: 842170222Sdougb *\li The chain is pointed to the successor of its current target. 843135446Strhodes * 844170222Sdougb *\li 'name' and 'origin', if non-NULL, are set as described for 845135446Strhodes * dns_rbtnodechain_current. 846135446Strhodes * 847170222Sdougb *\li 'origin' is only if a new origin was found. 848135446Strhodes * 849135446Strhodes * Returns: 850170222Sdougb *\li #ISC_R_SUCCESS The successor was found and 'name' was set. 851170222Sdougb *\li #DNS_R_NEWORIGIN The successor was found with a different 852135446Strhodes * origin and 'name' and 'origin' were set. 853170222Sdougb *\li #ISC_R_NOMORE There was no successor. 854170222Sdougb *\li <something_else> Any error result from dns_name_concatenate. 855135446Strhodes */ 856135446Strhodes 857170222Sdougb/* 858170222Sdougb * Wrapper macros for manipulating the rbtnode reference counter: 859170222Sdougb * Since we selectively use isc_refcount_t for the reference counter of 860170222Sdougb * a rbtnode, operations on the counter depend on the actual type of it. 861170222Sdougb * The following macros provide a common interface to these operations, 862170222Sdougb * hiding the back-end. The usage is the same as that of isc_refcount_xxx(). 863170222Sdougb */ 864170222Sdougb#ifdef DNS_RBT_USEISCREFCOUNT 865170222Sdougb#define dns_rbtnode_refinit(node, n) \ 866170222Sdougb do { \ 867170222Sdougb isc_refcount_init(&(node)->references, (n)); \ 868170222Sdougb } while (0) 869170222Sdougb#define dns_rbtnode_refdestroy(node) \ 870170222Sdougb do { \ 871170222Sdougb isc_refcount_destroy(&(node)->references); \ 872170222Sdougb } while (0) 873170222Sdougb#define dns_rbtnode_refcurrent(node) \ 874170222Sdougb isc_refcount_current(&(node)->references) 875170222Sdougb#define dns_rbtnode_refincrement0(node, refs) \ 876170222Sdougb do { \ 877170222Sdougb isc_refcount_increment0(&(node)->references, (refs)); \ 878170222Sdougb } while (0) 879170222Sdougb#define dns_rbtnode_refincrement(node, refs) \ 880170222Sdougb do { \ 881170222Sdougb isc_refcount_increment(&(node)->references, (refs)); \ 882170222Sdougb } while (0) 883170222Sdougb#define dns_rbtnode_refdecrement(node, refs) \ 884170222Sdougb do { \ 885170222Sdougb isc_refcount_decrement(&(node)->references, (refs)); \ 886170222Sdougb } while (0) 887170222Sdougb#else /* DNS_RBT_USEISCREFCOUNT */ 888170222Sdougb#define dns_rbtnode_refinit(node, n) ((node)->references = (n)) 889170222Sdougb#define dns_rbtnode_refdestroy(node) (REQUIRE((node)->references == 0)) 890170222Sdougb#define dns_rbtnode_refcurrent(node) ((node)->references) 891170222Sdougb#define dns_rbtnode_refincrement0(node, refs) \ 892170222Sdougb do { \ 893170222Sdougb unsigned int *_tmp = (unsigned int *)(refs); \ 894170222Sdougb (node)->references++; \ 895170222Sdougb if ((_tmp) != NULL) \ 896170222Sdougb (*_tmp) = (node)->references; \ 897170222Sdougb } while (0) 898170222Sdougb#define dns_rbtnode_refincrement(node, refs) \ 899170222Sdougb do { \ 900170222Sdougb REQUIRE((node)->references > 0); \ 901170222Sdougb (node)->references++; \ 902170222Sdougb if ((refs) != NULL) \ 903170222Sdougb (*refs) = (node)->references; \ 904170222Sdougb } while (0) 905170222Sdougb#define dns_rbtnode_refdecrement(node, refs) \ 906170222Sdougb do { \ 907170222Sdougb REQUIRE((node)->references > 0); \ 908170222Sdougb (node)->references--; \ 909170222Sdougb if ((refs) != NULL) \ 910170222Sdougb (*refs) = (node)->references; \ 911170222Sdougb } while (0) 912170222Sdougb#endif /* DNS_RBT_USEISCREFCOUNT */ 913170222Sdougb 914135446StrhodesISC_LANG_ENDDECLS 915135446Strhodes 916135446Strhodes#endif /* DNS_RBT_H */ 917