diff options
Diffstat (limited to 'contrib/bind9/lib/dns/rbt.c')
| -rw-r--r-- | contrib/bind9/lib/dns/rbt.c | 2544 |
1 files changed, 0 insertions, 2544 deletions
diff --git a/contrib/bind9/lib/dns/rbt.c b/contrib/bind9/lib/dns/rbt.c deleted file mode 100644 index b8db99a..0000000 --- a/contrib/bind9/lib/dns/rbt.c +++ /dev/null @@ -1,2544 +0,0 @@ -/* - * Copyright (C) 2004, 2005 Internet Systems Consortium, Inc. ("ISC") - * Copyright (C) 1999-2003 Internet Software Consortium. - * - * Permission to use, copy, modify, and distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. - * - * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH - * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY - * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, - * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM - * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE - * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR - * PERFORMANCE OF THIS SOFTWARE. - */ - -/* $Id: rbt.c,v 1.128.18.7 2005/10/13 01:26:06 marka Exp $ */ - -/*! \file */ - -/* Principal Authors: DCL */ - -#include <config.h> - -#include <isc/mem.h> -#include <isc/platform.h> -#include <isc/print.h> -#include <isc/refcount.h> -#include <isc/string.h> -#include <isc/util.h> - -/*% - * This define is so dns/name.h (included by dns/fixedname.h) uses more - * efficient macro calls instead of functions for a few operations. - */ -#define DNS_NAME_USEINLINE 1 - -#include <dns/fixedname.h> -#include <dns/rbt.h> -#include <dns/result.h> - -#define RBT_MAGIC ISC_MAGIC('R', 'B', 'T', '+') -#define VALID_RBT(rbt) ISC_MAGIC_VALID(rbt, RBT_MAGIC) - -/* - * XXXDCL Since parent pointers were added in again, I could remove all of the - * chain junk, and replace with dns_rbt_firstnode, _previousnode, _nextnode, - * _lastnode. This would involve pretty major change to the API. - */ -#define CHAIN_MAGIC ISC_MAGIC('0', '-', '0', '-') -#define VALID_CHAIN(chain) ISC_MAGIC_VALID(chain, CHAIN_MAGIC) - -#define RBT_HASH_SIZE 64 - -#ifdef RBT_MEM_TEST -#undef RBT_HASH_SIZE -#define RBT_HASH_SIZE 2 /*%< To give the reallocation code a workout. */ -#endif - -struct dns_rbt { - unsigned int magic; - isc_mem_t * mctx; - dns_rbtnode_t * root; - void (*data_deleter)(void *, void *); - void * deleter_arg; - unsigned int nodecount; - unsigned int hashsize; - dns_rbtnode_t ** hashtable; -}; - -#define RED 0 -#define BLACK 1 - -/*% - * Elements of the rbtnode structure. - */ -#define PARENT(node) ((node)->parent) -#define LEFT(node) ((node)->left) -#define RIGHT(node) ((node)->right) -#define DOWN(node) ((node)->down) -#define DATA(node) ((node)->data) -#define HASHNEXT(node) ((node)->hashnext) -#define HASHVAL(node) ((node)->hashval) -#define COLOR(node) ((node)->color) -#define NAMELEN(node) ((node)->namelen) -#define OFFSETLEN(node) ((node)->offsetlen) -#define ATTRS(node) ((node)->attributes) -#define PADBYTES(node) ((node)->padbytes) -#define IS_ROOT(node) ISC_TF((node)->is_root == 1) -#define FINDCALLBACK(node) ISC_TF((node)->find_callback == 1) - -/*% - * Structure elements from the rbtdb.c, not - * used as part of the rbt.c algorithms. - */ -#define DIRTY(node) ((node)->dirty) -#define WILD(node) ((node)->wild) -#define LOCKNUM(node) ((node)->locknum) - -/*% - * The variable length stuff stored after the node. - */ -#define NAME(node) ((unsigned char *)((node) + 1)) -#define OFFSETS(node) (NAME(node) + NAMELEN(node)) - -#define NODE_SIZE(node) (sizeof(*node) + \ - NAMELEN(node) + OFFSETLEN(node) + PADBYTES(node)) - -/*% - * Color management. - */ -#define IS_RED(node) ((node) != NULL && (node)->color == RED) -#define IS_BLACK(node) ((node) == NULL || (node)->color == BLACK) -#define MAKE_RED(node) ((node)->color = RED) -#define MAKE_BLACK(node) ((node)->color = BLACK) - -/*% - * Chain management. - * - * The "ancestors" member of chains were removed, with their job now - * being wholy handled by parent pointers (which didn't exist, because - * of memory concerns, when chains were first implemented). - */ -#define ADD_LEVEL(chain, node) \ - (chain)->levels[(chain)->level_count++] = (node) - -/*% - * The following macros directly access normally private name variables. - * These macros are used to avoid a lot of function calls in the critical - * path of the tree traversal code. - */ - -#define NODENAME(node, name) \ -do { \ - (name)->length = NAMELEN(node); \ - (name)->labels = OFFSETLEN(node); \ - (name)->ndata = NAME(node); \ - (name)->offsets = OFFSETS(node); \ - (name)->attributes = ATTRS(node); \ - (name)->attributes |= DNS_NAMEATTR_READONLY; \ -} while (0) - -#ifdef DNS_RBT_USEHASH -static isc_result_t -inithash(dns_rbt_t *rbt); -#endif - -#ifdef DEBUG -#define inline -/* - * A little something to help out in GDB. - */ -dns_name_t Name(dns_rbtnode_t *node); -dns_name_t -Name(dns_rbtnode_t *node) { - dns_name_t name; - - dns_name_init(&name, NULL); - if (node != NULL) - NODENAME(node, &name); - - return (name); -} - -static void dns_rbt_printnodename(dns_rbtnode_t *node); -#endif - -static inline dns_rbtnode_t * -find_up(dns_rbtnode_t *node) { - dns_rbtnode_t *root; - - /* - * Return the node in the level above the argument node that points - * to the level the argument node is in. If the argument node is in - * the top level, the return value is NULL. - */ - for (root = node; ! IS_ROOT(root); root = PARENT(root)) - ; /* Nothing. */ - - return (PARENT(root)); -} - -/* - * Forward declarations. - */ -static isc_result_t -create_node(isc_mem_t *mctx, dns_name_t *name, dns_rbtnode_t **nodep); - -#ifdef DNS_RBT_USEHASH -static inline void -hash_node(dns_rbt_t *rbt, dns_rbtnode_t *node, dns_name_t *name); -static inline void -unhash_node(dns_rbt_t *rbt, dns_rbtnode_t *node); -#else -#define hash_node(rbt, node, name) (ISC_R_SUCCESS) -#define unhash_node(rbt, node) -#endif - -static inline void -rotate_left(dns_rbtnode_t *node, dns_rbtnode_t **rootp); -static inline void -rotate_right(dns_rbtnode_t *node, dns_rbtnode_t **rootp); - -static void -dns_rbt_addonlevel(dns_rbtnode_t *node, dns_rbtnode_t *current, int order, - dns_rbtnode_t **rootp); - -static void -dns_rbt_deletefromlevel(dns_rbtnode_t *delete, dns_rbtnode_t **rootp); - -static isc_result_t -dns_rbt_deletetree(dns_rbt_t *rbt, dns_rbtnode_t *node); - -static void -dns_rbt_deletetreeflat(dns_rbt_t *rbt, unsigned int quantum, - dns_rbtnode_t **nodep); - -/* - * Initialize a red/black tree of trees. - */ -isc_result_t -dns_rbt_create(isc_mem_t *mctx, void (*deleter)(void *, void *), - void *deleter_arg, dns_rbt_t **rbtp) -{ -#ifdef DNS_RBT_USEHASH - isc_result_t result; -#endif - dns_rbt_t *rbt; - - - REQUIRE(mctx != NULL); - REQUIRE(rbtp != NULL && *rbtp == NULL); - REQUIRE(deleter == NULL ? deleter_arg == NULL : 1); - - rbt = (dns_rbt_t *)isc_mem_get(mctx, sizeof(*rbt)); - if (rbt == NULL) - return (ISC_R_NOMEMORY); - - rbt->mctx = mctx; - rbt->data_deleter = deleter; - rbt->deleter_arg = deleter_arg; - rbt->root = NULL; - rbt->nodecount = 0; - rbt->hashtable = NULL; - rbt->hashsize = 0; -#ifdef DNS_RBT_USEHASH - result = inithash(rbt); - if (result != ISC_R_SUCCESS) { - isc_mem_put(mctx, rbt, sizeof(*rbt)); - return (result); - } -#endif - rbt->magic = RBT_MAGIC; - - *rbtp = rbt; - - return (ISC_R_SUCCESS); -} - -/* - * Deallocate a red/black tree of trees. - */ -void -dns_rbt_destroy(dns_rbt_t **rbtp) { - RUNTIME_CHECK(dns_rbt_destroy2(rbtp, 0) == ISC_R_SUCCESS); -} - -isc_result_t -dns_rbt_destroy2(dns_rbt_t **rbtp, unsigned int quantum) { - dns_rbt_t *rbt; - - REQUIRE(rbtp != NULL && VALID_RBT(*rbtp)); - - rbt = *rbtp; - - dns_rbt_deletetreeflat(rbt, quantum, &rbt->root); - if (rbt->root != NULL) - return (ISC_R_QUOTA); - - INSIST(rbt->nodecount == 0); - - if (rbt->hashtable != NULL) - isc_mem_put(rbt->mctx, rbt->hashtable, - rbt->hashsize * sizeof(dns_rbtnode_t *)); - - rbt->magic = 0; - - isc_mem_put(rbt->mctx, rbt, sizeof(*rbt)); - *rbtp = NULL; - return (ISC_R_SUCCESS); -} - -unsigned int -dns_rbt_nodecount(dns_rbt_t *rbt) { - REQUIRE(VALID_RBT(rbt)); - return (rbt->nodecount); -} - -static inline isc_result_t -chain_name(dns_rbtnodechain_t *chain, dns_name_t *name, - isc_boolean_t include_chain_end) -{ - dns_name_t nodename; - isc_result_t result = ISC_R_SUCCESS; - int i; - - dns_name_init(&nodename, NULL); - - if (include_chain_end && chain->end != NULL) { - NODENAME(chain->end, &nodename); - result = dns_name_copy(&nodename, name, NULL); - if (result != ISC_R_SUCCESS) - return (result); - } else - dns_name_reset(name); - - for (i = (int)chain->level_count - 1; i >= 0; i--) { - NODENAME(chain->levels[i], &nodename); - result = dns_name_concatenate(name, &nodename, name, NULL); - - if (result != ISC_R_SUCCESS) - return (result); - } - return (result); -} - -static inline isc_result_t -move_chain_to_last(dns_rbtnodechain_t *chain, dns_rbtnode_t *node) { - do { - /* - * Go as far right and then down as much as possible, - * as long as the rightmost node has a down pointer. - */ - while (RIGHT(node) != NULL) - node = RIGHT(node); - - if (DOWN(node) == NULL) - break; - - ADD_LEVEL(chain, node); - node = DOWN(node); - } while (1); - - chain->end = node; - - return (ISC_R_SUCCESS); -} - -/* - * Add 'name' to tree, initializing its data pointer with 'data'. - */ - -isc_result_t -dns_rbt_addnode(dns_rbt_t *rbt, dns_name_t *name, dns_rbtnode_t **nodep) { - /* - * Does this thing have too many variables or what? - */ - dns_rbtnode_t **root, *parent, *child, *current, *new_current; - dns_name_t *add_name, *new_name, current_name, *prefix, *suffix; - dns_fixedname_t fixedcopy, fixedprefix, fixedsuffix, fnewname; - dns_offsets_t current_offsets; - dns_namereln_t compared; - isc_result_t result = ISC_R_SUCCESS; - dns_rbtnodechain_t chain; - unsigned int common_labels; - unsigned int nlabels, hlabels; - int order; - - REQUIRE(VALID_RBT(rbt)); - REQUIRE(dns_name_isabsolute(name)); - REQUIRE(nodep != NULL && *nodep == NULL); - - /* - * Create a copy of the name so the original name structure is - * not modified. - */ - dns_fixedname_init(&fixedcopy); - add_name = dns_fixedname_name(&fixedcopy); - dns_name_clone(name, add_name); - - if (rbt->root == NULL) { - result = create_node(rbt->mctx, add_name, &new_current); - if (result == ISC_R_SUCCESS) { - rbt->nodecount++; - new_current->is_root = 1; - rbt->root = new_current; - *nodep = new_current; - hash_node(rbt, new_current, name); - } - return (result); - } - - dns_rbtnodechain_init(&chain, rbt->mctx); - - dns_fixedname_init(&fixedprefix); - dns_fixedname_init(&fixedsuffix); - prefix = dns_fixedname_name(&fixedprefix); - suffix = dns_fixedname_name(&fixedsuffix); - - root = &rbt->root; - INSIST(IS_ROOT(*root)); - parent = NULL; - current = NULL; - child = *root; - dns_name_init(¤t_name, current_offsets); - dns_fixedname_init(&fnewname); - new_name = dns_fixedname_name(&fnewname); - nlabels = dns_name_countlabels(name); - hlabels = 0; - - do { - current = child; - - NODENAME(current, ¤t_name); - compared = dns_name_fullcompare(add_name, ¤t_name, - &order, &common_labels); - - if (compared == dns_namereln_equal) { - *nodep = current; - result = ISC_R_EXISTS; - break; - - } - - if (compared == dns_namereln_none) { - - if (order < 0) { - parent = current; - child = LEFT(current); - - } else if (order > 0) { - parent = current; - child = RIGHT(current); - - } - - } else { - /* - * This name has some suffix in common with the - * name at the current node. If the name at - * the current node is shorter, that means the - * new name should be in a subtree. If the - * name at the current node is longer, that means - * the down pointer to this tree should point - * to a new tree that has the common suffix, and - * the non-common parts of these two names should - * start a new tree. - */ - hlabels += common_labels; - if (compared == dns_namereln_subdomain) { - /* - * All of the existing labels are in common, - * so the new name is in a subtree. - * Whack off the common labels for the - * not-in-common part to be searched for - * in the next level. - */ - dns_name_split(add_name, common_labels, - add_name, NULL); - - /* - * Follow the down pointer (possibly NULL). - */ - root = &DOWN(current); - - INSIST(*root == NULL || - (IS_ROOT(*root) && - PARENT(*root) == current)); - - parent = NULL; - child = DOWN(current); - ADD_LEVEL(&chain, current); - - } else { - /* - * The number of labels in common is fewer - * than the number of labels at the current - * node, so the current node must be adjusted - * to have just the common suffix, and a down - * pointer made to a new tree. - */ - - INSIST(compared == dns_namereln_commonancestor - || compared == dns_namereln_contains); - - /* - * Ensure the number of levels in the tree - * does not exceed the number of logical - * levels allowed by DNSSEC. - * - * XXXDCL need a better error result? - * - * XXXDCL Since chain ancestors were removed, - * no longer used by dns_rbt_addonlevel(), - * this is the only real use of chains in the - * function. It could be done instead with - * a simple integer variable, but I am pressed - * for time. - */ - if (chain.level_count == - (sizeof(chain.levels) / - sizeof(*chain.levels))) { - result = ISC_R_NOSPACE; - break; - } - - /* - * Split the name into two parts, a prefix - * which is the not-in-common parts of the - * two names and a suffix that is the common - * parts of them. - */ - dns_name_split(¤t_name, common_labels, - prefix, suffix); - result = create_node(rbt->mctx, suffix, - &new_current); - - if (result != ISC_R_SUCCESS) - break; - - /* - * Reproduce the tree attributes of the - * current node. - */ - new_current->is_root = current->is_root; - PARENT(new_current) = PARENT(current); - LEFT(new_current) = LEFT(current); - RIGHT(new_current) = RIGHT(current); - COLOR(new_current) = COLOR(current); - - /* - * Fix pointers that were to the current node. - */ - if (parent != NULL) { - if (LEFT(parent) == current) - LEFT(parent) = new_current; - else - RIGHT(parent) = new_current; - } - if (LEFT(new_current) != NULL) - PARENT(LEFT(new_current)) = - new_current; - if (RIGHT(new_current) != NULL) - PARENT(RIGHT(new_current)) = - new_current; - if (*root == current) - *root = new_current; - - NAMELEN(current) = prefix->length; - OFFSETLEN(current) = prefix->labels; - memcpy(OFFSETS(current), prefix->offsets, - prefix->labels); - PADBYTES(current) += - (current_name.length - prefix->length) + - (current_name.labels - prefix->labels); - - /* - * Set up the new root of the next level. - * By definition it will not be the top - * level tree, so clear DNS_NAMEATTR_ABSOLUTE. - */ - current->is_root = 1; - PARENT(current) = new_current; - DOWN(new_current) = current; - root = &DOWN(new_current); - - ADD_LEVEL(&chain, new_current); - - LEFT(current) = NULL; - RIGHT(current) = NULL; - - MAKE_BLACK(current); - ATTRS(current) &= ~DNS_NAMEATTR_ABSOLUTE; - - rbt->nodecount++; - dns_name_getlabelsequence(name, - nlabels - hlabels, - hlabels, new_name); - hash_node(rbt, new_current, new_name); - - if (common_labels == - dns_name_countlabels(add_name)) { - /* - * The name has been added by pushing - * the not-in-common parts down to - * a new level. - */ - *nodep = new_current; - return (ISC_R_SUCCESS); - - } else { - /* - * The current node has no data, - * because it is just a placeholder. - * Its data pointer is already NULL - * from create_node()), so there's - * nothing more to do to it. - */ - - /* - * The not-in-common parts of the new - * name will be inserted into the new - * level following this loop (unless - * result != ISC_R_SUCCESS, which - * is tested after the loop ends). - */ - dns_name_split(add_name, common_labels, - add_name, NULL); - - break; - } - - } - - } - - } while (child != NULL); - - if (result == ISC_R_SUCCESS) - result = create_node(rbt->mctx, add_name, &new_current); - - if (result == ISC_R_SUCCESS) { - dns_rbt_addonlevel(new_current, current, order, root); - rbt->nodecount++; - *nodep = new_current; - hash_node(rbt, new_current, name); - } - - return (result); -} - -/* - * Add a name to the tree of trees, associating it with some data. - */ -isc_result_t -dns_rbt_addname(dns_rbt_t *rbt, dns_name_t *name, void *data) { - isc_result_t result; - dns_rbtnode_t *node; - - REQUIRE(VALID_RBT(rbt)); - REQUIRE(dns_name_isabsolute(name)); - - node = NULL; - - result = dns_rbt_addnode(rbt, name, &node); - - /* - * dns_rbt_addnode will report the node exists even when - * it does not have data associated with it, but the - * dns_rbt_*name functions all behave depending on whether - * there is data associated with a node. - */ - if (result == ISC_R_SUCCESS || - (result == ISC_R_EXISTS && DATA(node) == NULL)) { - DATA(node) = data; - result = ISC_R_SUCCESS; - } - - return (result); -} - -/* - * Find the node for "name" in the tree of trees. - */ -isc_result_t -dns_rbt_findnode(dns_rbt_t *rbt, dns_name_t *name, dns_name_t *foundname, - dns_rbtnode_t **node, dns_rbtnodechain_t *chain, - unsigned int options, dns_rbtfindcallback_t callback, - void *callback_arg) -{ - dns_rbtnode_t *current, *last_compared, *current_root; - dns_rbtnodechain_t localchain; - dns_name_t *search_name, current_name, *callback_name; - dns_fixedname_t fixedcallbackname, fixedsearchname; - dns_namereln_t compared; - isc_result_t result, saved_result; - unsigned int common_labels; - unsigned int hlabels = 0; - int order; - - REQUIRE(VALID_RBT(rbt)); - REQUIRE(dns_name_isabsolute(name)); - REQUIRE(node != NULL && *node == NULL); - REQUIRE((options & (DNS_RBTFIND_NOEXACT | DNS_RBTFIND_NOPREDECESSOR)) - != (DNS_RBTFIND_NOEXACT | DNS_RBTFIND_NOPREDECESSOR)); - - /* - * If there is a chain it needs to appear to be in a sane state, - * otherwise a chain is still needed to generate foundname and - * callback_name. - */ - if (chain == NULL) { - options |= DNS_RBTFIND_NOPREDECESSOR; - chain = &localchain; - dns_rbtnodechain_init(chain, rbt->mctx); - } else - dns_rbtnodechain_reset(chain); - - if (rbt->root == NULL) - return (ISC_R_NOTFOUND); - else { - /* - * Appease GCC about variables it incorrectly thinks are - * possibly used uninitialized. - */ - compared = dns_namereln_none; - last_compared = NULL; - } - - dns_fixedname_init(&fixedcallbackname); - callback_name = dns_fixedname_name(&fixedcallbackname); - - /* - * search_name is the name segment being sought in each tree level. - * By using a fixedname, the search_name will definitely have offsets - * for use by any splitting. - * By using dns_name_clone, no name data should be copied thanks to - * the lack of bitstring labels. - */ - dns_fixedname_init(&fixedsearchname); - search_name = dns_fixedname_name(&fixedsearchname); - dns_name_clone(name, search_name); - - dns_name_init(¤t_name, NULL); - - saved_result = ISC_R_SUCCESS; - current = rbt->root; - current_root = rbt->root; - - while (current != NULL) { - NODENAME(current, ¤t_name); - compared = dns_name_fullcompare(search_name, ¤t_name, - &order, &common_labels); - last_compared = current; - - if (compared == dns_namereln_equal) - break; - - if (compared == dns_namereln_none) { -#ifdef DNS_RBT_USEHASH - dns_name_t hash_name; - dns_rbtnode_t *hnode; - dns_rbtnode_t *up_current; - unsigned int nlabels; - unsigned int tlabels = 1; - unsigned int hash; - - /* - * If there is no hash table, hashing can't be done. - */ - if (rbt->hashtable == NULL) - goto nohash; - - /* - * The case of current != current_root, that - * means a left or right pointer was followed, - * only happens when the algorithm fell through to - * the traditional binary search because of a - * bitstring label. Since we dropped the bitstring - * support, this should not happen. - */ - INSIST(current == current_root); - - nlabels = dns_name_countlabels(search_name); - - /* - * current_root is the root of the current level, so - * it's parent is the same as it's "up" pointer. - */ - up_current = PARENT(current_root); - dns_name_init(&hash_name, NULL); - - hashagain: - /* - * Hash includes tail. - */ - dns_name_getlabelsequence(name, - nlabels - tlabels, - hlabels + tlabels, - &hash_name); - hash = dns_name_fullhash(&hash_name, ISC_FALSE); - dns_name_getlabelsequence(search_name, - nlabels - tlabels, - tlabels, &hash_name); - - for (hnode = rbt->hashtable[hash % rbt->hashsize]; - hnode != NULL; - hnode = hnode->hashnext) - { - dns_name_t hnode_name; - - if (hash != HASHVAL(hnode)) - continue; - if (find_up(hnode) != up_current) - continue; - dns_name_init(&hnode_name, NULL); - NODENAME(hnode, &hnode_name); - if (dns_name_equal(&hnode_name, &hash_name)) - break; - } - - if (hnode != NULL) { - current = hnode; - /* - * This is an optimization. If hashing found - * the right node, the next call to - * dns_name_fullcompare() would obviously - * return _equal or _subdomain. Determine - * which of those would be the case by - * checking if the full name was hashed. Then - * make it look like dns_name_fullcompare - * was called and jump to the right place. - */ - if (tlabels == nlabels) { - compared = dns_namereln_equal; - break; - } else { - common_labels = tlabels; - compared = dns_namereln_subdomain; - goto subdomain; - } - } - - if (tlabels++ < nlabels) - goto hashagain; - - /* - * All of the labels have been tried against the hash - * table. Since we dropped the support of bitstring - * labels, the name isn't in the table. - */ - current = NULL; - continue; - - nohash: -#endif /* DNS_RBT_USEHASH */ - /* - * Standard binary search tree movement. - */ - if (order < 0) - current = LEFT(current); - else - current = RIGHT(current); - - } else { - /* - * The names have some common suffix labels. - * - * If the number in common are equal in length to - * the current node's name length, then follow the - * down pointer and search in the new tree. - */ - if (compared == dns_namereln_subdomain) { - subdomain: - /* - * Whack off the current node's common parts - * for the name to search in the next level. - */ - dns_name_split(search_name, common_labels, - search_name, NULL); - hlabels += common_labels; - /* - * This might be the closest enclosing name. - */ - if (DATA(current) != NULL || - (options & DNS_RBTFIND_EMPTYDATA) != 0) - *node = current; - - /* - * Point the chain to the next level. This - * needs to be done before 'current' is pointed - * there because the callback in the next - * block of code needs the current 'current', - * but in the event the callback requests that - * the search be stopped then the - * DNS_R_PARTIALMATCH code at the end of this - * function needs the chain pointed to the - * next level. - */ - ADD_LEVEL(chain, current); - - /* - * The caller may want to interrupt the - * downward search when certain special nodes - * are traversed. If this is a special node, - * the callback is used to learn what the - * caller wants to do. - */ - if (callback != NULL && - FINDCALLBACK(current)) { - result = chain_name(chain, - callback_name, - ISC_FALSE); - if (result != ISC_R_SUCCESS) { - dns_rbtnodechain_reset(chain); - return (result); - } - - result = (callback)(current, - callback_name, - callback_arg); - if (result != DNS_R_CONTINUE) { - saved_result = result; - /* - * Treat this node as if it - * had no down pointer. - */ - current = NULL; - break; - } - } - - /* - * Finally, head to the next tree level. - */ - current = DOWN(current); - current_root = current; - - } else { - /* - * Though there are labels in common, the - * entire name at this node is not common - * with the search name so the search - * name does not exist in the tree. - */ - INSIST(compared == dns_namereln_commonancestor - || compared == dns_namereln_contains); - - current = NULL; - } - } - } - - /* - * If current is not NULL, NOEXACT is not disallowing exact matches, - * and either the node has data or an empty node is ok, return - * ISC_R_SUCCESS to indicate an exact match. - */ - if (current != NULL && (options & DNS_RBTFIND_NOEXACT) == 0 && - (DATA(current) != NULL || - (options & DNS_RBTFIND_EMPTYDATA) != 0)) { - /* - * Found an exact match. - */ - chain->end = current; - chain->level_matches = chain->level_count; - - if (foundname != NULL) - result = chain_name(chain, foundname, ISC_TRUE); - else - result = ISC_R_SUCCESS; - - if (result == ISC_R_SUCCESS) { - *node = current; - result = saved_result; - } else - *node = NULL; - } else { - /* - * Did not find an exact match (or did not want one). - */ - if (*node != NULL) { - /* - * ... but found a partially matching superdomain. - * Unwind the chain to the partial match node - * to set level_matches to the level above the node, - * and then to derive the name. - * - * chain->level_count is guaranteed to be at least 1 - * here because by definition of finding a superdomain, - * the chain is pointed to at least the first subtree. - */ - chain->level_matches = chain->level_count - 1; - - while (chain->levels[chain->level_matches] != *node) { - INSIST(chain->level_matches > 0); - chain->level_matches--; - } - - if (foundname != NULL) { - unsigned int saved_count = chain->level_count; - - chain->level_count = chain->level_matches + 1; - - result = chain_name(chain, foundname, - ISC_FALSE); - - chain->level_count = saved_count; - } else - result = ISC_R_SUCCESS; - - if (result == ISC_R_SUCCESS) - result = DNS_R_PARTIALMATCH; - - } else - result = ISC_R_NOTFOUND; - - if (current != NULL) { - /* - * There was an exact match but either - * DNS_RBTFIND_NOEXACT was set, or - * DNS_RBTFIND_EMPTYDATA was set and the node had no - * data. A policy decision was made to set the - * chain to the exact match, but this is subject - * to change if it becomes apparent that something - * else would be more useful. It is important that - * this case is handled here, because the predecessor - * setting code below assumes the match was not exact. - */ - INSIST(((options & DNS_RBTFIND_NOEXACT) != 0) || - ((options & DNS_RBTFIND_EMPTYDATA) == 0 && - DATA(current) == NULL)); - chain->end = current; - - } else if ((options & DNS_RBTFIND_NOPREDECESSOR) != 0) { - /* - * Ensure the chain points nowhere. - */ - chain->end = NULL; - - } else { - /* - * Since there was no exact match, the chain argument - * needs to be pointed at the DNSSEC predecessor of - * the search name. - */ - if (compared == dns_namereln_subdomain) { - /* - * Attempted to follow a down pointer that was - * NULL, which means the searched for name was - * a subdomain of a terminal name in the tree. - * Since there are no existing subdomains to - * order against, the terminal name is the - * predecessor. - */ - INSIST(chain->level_count > 0); - INSIST(chain->level_matches < - chain->level_count); - chain->end = - chain->levels[--chain->level_count]; - - } else { - isc_result_t result2; - - /* - * Point current to the node that stopped - * the search. - * - * With the hashing modification that has been - * added to the algorithm, the stop node of a - * standard binary search is not known. So it - * has to be found. There is probably a more - * clever way of doing this. - * - * The assignment of current to NULL when - * the relationship is *not* dns_namereln_none, - * even though it later gets set to the same - * last_compared anyway, is simply to not push - * the while loop in one more level of - * indentation. - */ - if (compared == dns_namereln_none) - current = last_compared; - else - current = NULL; - - while (current != NULL) { - NODENAME(current, ¤t_name); - compared = dns_name_fullcompare( - search_name, - ¤t_name, - &order, - &common_labels); - - last_compared = current; - - /* - * Standard binary search movement. - */ - if (order < 0) - current = LEFT(current); - else - current = RIGHT(current); - - } - - current = last_compared; - - /* - * Reached a point within a level tree that - * positively indicates the name is not - * present, but the stop node could be either - * less than the desired name (order > 0) or - * greater than the desired name (order < 0). - * - * If the stop node is less, it is not - * necessarily the predecessor. If the stop - * node has a down pointer, then the real - * predecessor is at the end of a level below - * (not necessarily the next level). - * Move down levels until the rightmost node - * does not have a down pointer. - * - * When the stop node is greater, it is - * the successor. All the logic for finding - * the predecessor is handily encapsulated - * in dns_rbtnodechain_prev. In the event - * that the search name is less than anything - * else in the tree, the chain is reset. - * XXX DCL What is the best way for the caller - * to know that the search name has - * no predecessor? - */ - - - if (order > 0) { - if (DOWN(current) != NULL) { - ADD_LEVEL(chain, current); - - result2 = - move_chain_to_last(chain, - DOWN(current)); - - if (result2 != ISC_R_SUCCESS) - result = result2; - } else - /* - * Ah, the pure and simple - * case. The stop node is the - * predecessor. - */ - chain->end = current; - - } else { - INSIST(order < 0); - - chain->end = current; - - result2 = dns_rbtnodechain_prev(chain, - NULL, - NULL); - if (result2 == ISC_R_SUCCESS || - result2 == DNS_R_NEWORIGIN) - ; /* Nothing. */ - else if (result2 == ISC_R_NOMORE) - /* - * There is no predecessor. - */ - dns_rbtnodechain_reset(chain); - else - result = result2; - } - - } - } - } - - ENSURE(*node == NULL || DNS_RBTNODE_VALID(*node)); - - return (result); -} - -/* - * Get the data pointer associated with 'name'. - */ -isc_result_t -dns_rbt_findname(dns_rbt_t *rbt, dns_name_t *name, unsigned int options, - dns_name_t *foundname, void **data) { - dns_rbtnode_t *node = NULL; - isc_result_t result; - - REQUIRE(data != NULL && *data == NULL); - - result = dns_rbt_findnode(rbt, name, foundname, &node, NULL, - options, NULL, NULL); - - if (node != NULL && - (DATA(node) != NULL || (options & DNS_RBTFIND_EMPTYDATA) != 0)) - *data = DATA(node); - else - result = ISC_R_NOTFOUND; - - return (result); -} - -/* - * Delete a name from the tree of trees. - */ -isc_result_t -dns_rbt_deletename(dns_rbt_t *rbt, dns_name_t *name, isc_boolean_t recurse) { - dns_rbtnode_t *node = NULL; - isc_result_t result; - - REQUIRE(VALID_RBT(rbt)); - REQUIRE(dns_name_isabsolute(name)); - - /* - * First, find the node. - * - * When searching, the name might not have an exact match: - * consider a.b.a.com, b.b.a.com and c.b.a.com as the only - * elements of a tree, which would make layer 1 a single - * node tree of "b.a.com" and layer 2 a three node tree of - * a, b, and c. Deleting a.com would find only a partial depth - * match in the first layer. Should it be a requirement that - * that the name to be deleted have data? For now, it is. - * - * ->dirty, ->locknum and ->references are ignored; they are - * solely the province of rbtdb.c. - */ - result = dns_rbt_findnode(rbt, name, NULL, &node, NULL, - DNS_RBTFIND_NOOPTIONS, NULL, NULL); - - if (result == ISC_R_SUCCESS) { - if (DATA(node) != NULL) - result = dns_rbt_deletenode(rbt, node, recurse); - else - result = ISC_R_NOTFOUND; - - } else if (result == DNS_R_PARTIALMATCH) - result = ISC_R_NOTFOUND; - - return (result); -} - -/* - * Remove a node from the tree of trees. - * - * NOTE WELL: deletion is *not* symmetric with addition; that is, reversing - * a sequence of additions to be deletions will not generally get the - * tree back to the state it started in. For example, if the addition - * of "b.c" caused the node "a.b.c" to be split, pushing "a" to its own level, - * then the subsequent deletion of "b.c" will not cause "a" to be pulled up, - * restoring "a.b.c". The RBT *used* to do this kind of rejoining, but it - * turned out to be a bad idea because it could corrupt an active nodechain - * that had "b.c" as one of its levels -- and the RBT has no idea what - * nodechains are in use by callers, so it can't even *try* to helpfully - * fix them up (which would probably be doomed to failure anyway). - * - * Similarly, it is possible to leave the tree in a state where a supposedly - * deleted node still exists. The first case of this is obvious; take - * the tree which has "b.c" on one level, pointing to "a". Now deleted "b.c". - * It was just established in the previous paragraph why we can't pull "a" - * back up to its parent level. But what happens when "a" then gets deleted? - * "b.c" is left hanging around without data or children. This condition - * is actually pretty easy to detect, but ... should it really be removed? - * Is a chain pointing to it? An iterator? Who knows! (Note that the - * references structure member cannot be looked at because it is private to - * rbtdb.) This is ugly and makes me unhappy, but after hours of trying to - * make it more aesthetically proper and getting nowhere, this is the way it - * is going to stay until such time as it proves to be a *real* problem. - * - * Finally, for reference, note that the original routine that did node - * joining was called join_nodes(). It has been excised, living now only - * in the CVS history, but comments have been left behind that point to it just - * in case someone wants to muck with this some more. - * - * The one positive aspect of all of this is that joining used to have a - * case where it might fail. Without trying to join, now this function always - * succeeds. It still returns isc_result_t, though, so the API wouldn't change. - */ -isc_result_t -dns_rbt_deletenode(dns_rbt_t *rbt, dns_rbtnode_t *node, isc_boolean_t recurse) -{ - dns_rbtnode_t *parent; - - REQUIRE(VALID_RBT(rbt)); - REQUIRE(DNS_RBTNODE_VALID(node)); - - if (DOWN(node) != NULL) { - if (recurse) - RUNTIME_CHECK(dns_rbt_deletetree(rbt, DOWN(node)) - == ISC_R_SUCCESS); - else { - if (DATA(node) != NULL && rbt->data_deleter != NULL) - rbt->data_deleter(DATA(node), - rbt->deleter_arg); - DATA(node) = NULL; - - /* - * Since there is at least one node below this one and - * no recursion was requested, the deletion is - * complete. The down node from this node might be all - * by itself on a single level, so join_nodes() could - * be used to collapse the tree (with all the caveats - * of the comment at the start of this function). - */ - return (ISC_R_SUCCESS); - } - } - - /* - * Note the node that points to the level of the node that is being - * deleted. If the deleted node is the top level, parent will be set - * to NULL. - */ - parent = find_up(node); - - /* - * This node now has no down pointer (either because it didn't - * have one to start, or because it was recursively removed). - * So now the node needs to be removed from this level. - */ - dns_rbt_deletefromlevel(node, parent == NULL ? &rbt->root : - &DOWN(parent)); - - if (DATA(node) != NULL && rbt->data_deleter != NULL) - rbt->data_deleter(DATA(node), rbt->deleter_arg); - - unhash_node(rbt, node); -#if DNS_RBT_USEMAGIC - node->magic = 0; -#endif - dns_rbtnode_refdestroy(node); - isc_mem_put(rbt->mctx, node, NODE_SIZE(node)); - rbt->nodecount--; - - /* - * There are now two special cases that can exist that would - * not have existed if the tree had been created using only - * the names that now exist in it. (This is all related to - * join_nodes() as described in this function's introductory comment.) - * Both cases exist when the deleted node's parent (the node - * that pointed to the deleted node's level) is not null but - * it has no data: parent != NULL && DATA(parent) == NULL. - * - * The first case is that the deleted node was the last on its level: - * DOWN(parent) == NULL. This case can only exist if the parent was - * previously deleted -- and so now, apparently, the parent should go - * away. That can't be done though because there might be external - * references to it, such as through a nodechain. - * - * The other case also involves a parent with no data, but with the - * deleted node being the next-to-last node instead of the last: - * LEFT(DOWN(parent)) == NULL && RIGHT(DOWN(parent)) == NULL. - * Presumably now the remaining node on the level should be joined - * with the parent, but it's already been described why that can't be - * done. - */ - - /* - * This function never fails. - */ - return (ISC_R_SUCCESS); -} - -void -dns_rbt_namefromnode(dns_rbtnode_t *node, dns_name_t *name) { - - REQUIRE(DNS_RBTNODE_VALID(node)); - REQUIRE(name != NULL); - REQUIRE(name->offsets == NULL); - - NODENAME(node, name); -} - -isc_result_t -dns_rbt_fullnamefromnode(dns_rbtnode_t *node, dns_name_t *name) { - dns_name_t current; - isc_result_t result; - - REQUIRE(DNS_RBTNODE_VALID(node)); - REQUIRE(name != NULL); - REQUIRE(name->buffer != NULL); - - dns_name_init(¤t, NULL); - dns_name_reset(name); - - do { - INSIST(node != NULL); - - NODENAME(node, ¤t); - - result = dns_name_concatenate(name, ¤t, name, NULL); - if (result != ISC_R_SUCCESS) - break; - - node = find_up(node); - } while (! dns_name_isabsolute(name)); - - return (result); -} - -char * -dns_rbt_formatnodename(dns_rbtnode_t *node, char *printname, unsigned int size) -{ - dns_fixedname_t fixedname; - dns_name_t *name; - isc_result_t result; - - REQUIRE(DNS_RBTNODE_VALID(node)); - REQUIRE(printname != NULL); - - dns_fixedname_init(&fixedname); - name = dns_fixedname_name(&fixedname); - result = dns_rbt_fullnamefromnode(node, name); - if (result == ISC_R_SUCCESS) - dns_name_format(name, printname, size); - else - snprintf(printname, size, "<error building name: %s>", - dns_result_totext(result)); - - return (printname); -} - -static isc_result_t -create_node(isc_mem_t *mctx, dns_name_t *name, dns_rbtnode_t **nodep) { - dns_rbtnode_t *node; - isc_region_t region; - unsigned int labels; - - REQUIRE(name->offsets != NULL); - - dns_name_toregion(name, ®ion); - labels = dns_name_countlabels(name); - ENSURE(labels > 0); - - /* - * Allocate space for the node structure, the name, and the offsets. - */ - node = (dns_rbtnode_t *)isc_mem_get(mctx, sizeof(*node) + - region.length + labels); - - if (node == NULL) - return (ISC_R_NOMEMORY); - - node->is_root = 0; - PARENT(node) = NULL; - RIGHT(node) = NULL; - LEFT(node) = NULL; - DOWN(node) = NULL; - DATA(node) = NULL; -#ifdef DNS_RBT_USEHASH - HASHNEXT(node) = NULL; - HASHVAL(node) = 0; -#endif - - LOCKNUM(node) = 0; - WILD(node) = 0; - DIRTY(node) = 0; - dns_rbtnode_refinit(node, 0); - node->find_callback = 0; - - MAKE_BLACK(node); - - /* - * The following is stored to make reconstructing a name from the - * stored value in the node easy: the length of the name, the number - * of labels, whether the name is absolute or not, the name itself, - * and the name's offsets table. - * - * XXX RTH - * The offsets table could be made smaller by eliminating the - * first offset, which is always 0. This requires changes to - * lib/dns/name.c. - */ - NAMELEN(node) = region.length; - PADBYTES(node) = 0; - OFFSETLEN(node) = labels; - ATTRS(node) = name->attributes; - - memcpy(NAME(node), region.base, region.length); - memcpy(OFFSETS(node), name->offsets, labels); - -#if DNS_RBT_USEMAGIC - node->magic = DNS_RBTNODE_MAGIC; -#endif - *nodep = node; - - return (ISC_R_SUCCESS); -} - -#ifdef DNS_RBT_USEHASH -static inline void -hash_add_node(dns_rbt_t *rbt, dns_rbtnode_t *node, dns_name_t *name) { - unsigned int hash; - - HASHVAL(node) = dns_name_fullhash(name, ISC_FALSE); - - hash = HASHVAL(node) % rbt->hashsize; - HASHNEXT(node) = rbt->hashtable[hash]; - - rbt->hashtable[hash] = node; -} - -static isc_result_t -inithash(dns_rbt_t *rbt) { - unsigned int bytes; - - rbt->hashsize = RBT_HASH_SIZE; - bytes = rbt->hashsize * sizeof(dns_rbtnode_t *); - rbt->hashtable = isc_mem_get(rbt->mctx, bytes); - - if (rbt->hashtable == NULL) - return (ISC_R_NOMEMORY); - - memset(rbt->hashtable, 0, bytes); - - return (ISC_R_SUCCESS); -} - -static void -rehash(dns_rbt_t *rbt) { - unsigned int oldsize; - dns_rbtnode_t **oldtable; - dns_rbtnode_t *node; - unsigned int hash; - unsigned int i; - - oldsize = rbt->hashsize; - oldtable = rbt->hashtable; - rbt->hashsize *= 2 + 1; - rbt->hashtable = isc_mem_get(rbt->mctx, - rbt->hashsize * sizeof(dns_rbtnode_t *)); - if (rbt->hashtable == NULL) { - rbt->hashtable = oldtable; - rbt->hashsize = oldsize; - return; - } - - for (i = 0; i < rbt->hashsize; i++) - rbt->hashtable[i] = NULL; - - for (i = 0; i < oldsize; i++) { - node = oldtable[i]; - while (node != NULL) { - hash = HASHVAL(node) % rbt->hashsize; - oldtable[i] = HASHNEXT(node); - HASHNEXT(node) = rbt->hashtable[hash]; - rbt->hashtable[hash] = node; - node = oldtable[i]; - } - } - - isc_mem_put(rbt->mctx, oldtable, oldsize * sizeof(dns_rbtnode_t *)); -} - -static inline void -hash_node(dns_rbt_t *rbt, dns_rbtnode_t *node, dns_name_t *name) { - - REQUIRE(DNS_RBTNODE_VALID(node)); - - if (rbt->nodecount >= (rbt->hashsize *3)) - rehash(rbt); - - hash_add_node(rbt, node, name); -} - -static inline void -unhash_node(dns_rbt_t *rbt, dns_rbtnode_t *node) { - unsigned int bucket; - dns_rbtnode_t *bucket_node; - - REQUIRE(DNS_RBTNODE_VALID(node)); - - if (rbt->hashtable != NULL) { - bucket = HASHVAL(node) % rbt->hashsize; - bucket_node = rbt->hashtable[bucket]; - - if (bucket_node == node) - rbt->hashtable[bucket] = HASHNEXT(node); - else { - while (HASHNEXT(bucket_node) != node) { - INSIST(HASHNEXT(bucket_node) != NULL); - bucket_node = HASHNEXT(bucket_node); - } - HASHNEXT(bucket_node) = HASHNEXT(node); - } - } -} -#endif /* DNS_RBT_USEHASH */ - -static inline void -rotate_left(dns_rbtnode_t *node, dns_rbtnode_t **rootp) { - dns_rbtnode_t *child; - - REQUIRE(DNS_RBTNODE_VALID(node)); - REQUIRE(rootp != NULL); - - child = RIGHT(node); - INSIST(child != NULL); - - RIGHT(node) = LEFT(child); - if (LEFT(child) != NULL) - PARENT(LEFT(child)) = node; - LEFT(child) = node; - - if (child != NULL) - PARENT(child) = PARENT(node); - - if (IS_ROOT(node)) { - *rootp = child; - child->is_root = 1; - node->is_root = 0; - - } else { - if (LEFT(PARENT(node)) == node) - LEFT(PARENT(node)) = child; - else - RIGHT(PARENT(node)) = child; - } - - PARENT(node) = child; -} - -static inline void -rotate_right(dns_rbtnode_t *node, dns_rbtnode_t **rootp) { - dns_rbtnode_t *child; - - REQUIRE(DNS_RBTNODE_VALID(node)); - REQUIRE(rootp != NULL); - - child = LEFT(node); - INSIST(child != NULL); - - LEFT(node) = RIGHT(child); - if (RIGHT(child) != NULL) - PARENT(RIGHT(child)) = node; - RIGHT(child) = node; - - if (child != NULL) - PARENT(child) = PARENT(node); - - if (IS_ROOT(node)) { - *rootp = child; - child->is_root = 1; - node->is_root = 0; - - } else { - if (LEFT(PARENT(node)) == node) - LEFT(PARENT(node)) = child; - else - RIGHT(PARENT(node)) = child; - } - - PARENT(node) = child; -} - -/* - * This is the real workhorse of the insertion code, because it does the - * true red/black tree on a single level. - */ -static void -dns_rbt_addonlevel(dns_rbtnode_t *node, dns_rbtnode_t *current, int order, - dns_rbtnode_t **rootp) -{ - dns_rbtnode_t *child, *root, *parent, *grandparent; - dns_name_t add_name, current_name; - dns_offsets_t add_offsets, current_offsets; - - REQUIRE(rootp != NULL); - REQUIRE(DNS_RBTNODE_VALID(node) && LEFT(node) == NULL && - RIGHT(node) == NULL); - REQUIRE(current != NULL); - - root = *rootp; - if (root == NULL) { - /* - * First node of a level. - */ - MAKE_BLACK(node); - node->is_root = 1; - PARENT(node) = current; - *rootp = node; - return; - } - - child = root; - - dns_name_init(&add_name, add_offsets); - NODENAME(node, &add_name); - - dns_name_init(¤t_name, current_offsets); - NODENAME(current, ¤t_name); - - if (order < 0) { - INSIST(LEFT(current) == NULL); - LEFT(current) = node; - } else { - INSIST(RIGHT(current) == NULL); - RIGHT(current) = node; - } - - INSIST(PARENT(node) == NULL); - PARENT(node) = current; - - MAKE_RED(node); - - while (node != root && IS_RED(PARENT(node))) { - /* - * XXXDCL could do away with separate parent and grandparent - * variables. They are vestiges of the days before parent - * pointers. However, they make the code a little clearer. - */ - - parent = PARENT(node); - grandparent = PARENT(parent); - - if (parent == LEFT(grandparent)) { - child = RIGHT(grandparent); - if (child != NULL && IS_RED(child)) { - MAKE_BLACK(parent); - MAKE_BLACK(child); - MAKE_RED(grandparent); - node = grandparent; - } else { - if (node == RIGHT(parent)) { - rotate_left(parent, &root); - node = parent; - parent = PARENT(node); - grandparent = PARENT(parent); - } - MAKE_BLACK(parent); - MAKE_RED(grandparent); - rotate_right(grandparent, &root); - } - } else { - child = LEFT(grandparent); - if (child != NULL && IS_RED(child)) { - MAKE_BLACK(parent); - MAKE_BLACK(child); - MAKE_RED(grandparent); - node = grandparent; - } else { - if (node == LEFT(parent)) { - rotate_right(parent, &root); - node = parent; - parent = PARENT(node); - grandparent = PARENT(parent); - } - MAKE_BLACK(parent); - MAKE_RED(grandparent); - rotate_left(grandparent, &root); - } - } - } - - MAKE_BLACK(root); - ENSURE(IS_ROOT(root)); - *rootp = root; - - return; -} - -/* - * This is the real workhorse of the deletion code, because it does the - * true red/black tree on a single level. - */ -static void -dns_rbt_deletefromlevel(dns_rbtnode_t *delete, dns_rbtnode_t **rootp) { - dns_rbtnode_t *child, *sibling, *parent; - dns_rbtnode_t *successor; - - REQUIRE(delete != NULL); - - /* - * Verify that the parent history is (apparently) correct. - */ - INSIST((IS_ROOT(delete) && *rootp == delete) || - (! IS_ROOT(delete) && - (LEFT(PARENT(delete)) == delete || - RIGHT(PARENT(delete)) == delete))); - - child = NULL; - - if (LEFT(delete) == NULL) { - if (RIGHT(delete) == NULL) { - if (IS_ROOT(delete)) { - /* - * This is the only item in the tree. - */ - *rootp = NULL; - return; - } - } else - /* - * This node has one child, on the right. - */ - child = RIGHT(delete); - - } else if (RIGHT(delete) == NULL) - /* - * This node has one child, on the left. - */ - child = LEFT(delete); - else { - dns_rbtnode_t holder, *tmp = &holder; - - /* - * This node has two children, so it cannot be directly - * deleted. Find its immediate in-order successor and - * move it to this location, then do the deletion at the - * old site of the successor. - */ - successor = RIGHT(delete); - while (LEFT(successor) != NULL) - successor = LEFT(successor); - - /* - * The successor cannot possibly have a left child; - * if there is any child, it is on the right. - */ - if (RIGHT(successor) != NULL) - child = RIGHT(successor); - - /* - * Swap the two nodes; it would be simpler to just replace - * the value being deleted with that of the successor, - * but this rigamarole is done so the caller has complete - * control over the pointers (and memory allocation) of - * all of nodes. If just the key value were removed from - * the tree, the pointer to the node would be unchanged. - */ - - /* - * First, put the successor in the tree location of the - * node to be deleted. Save its existing tree pointer - * information, which will be needed when linking up - * delete to the successor's old location. - */ - memcpy(tmp, successor, sizeof(dns_rbtnode_t)); - - if (IS_ROOT(delete)) { - *rootp = successor; - successor->is_root = ISC_TRUE; - delete->is_root = ISC_FALSE; - - } else - if (LEFT(PARENT(delete)) == delete) - LEFT(PARENT(delete)) = successor; - else - RIGHT(PARENT(delete)) = successor; - - PARENT(successor) = PARENT(delete); - LEFT(successor) = LEFT(delete); - RIGHT(successor) = RIGHT(delete); - COLOR(successor) = COLOR(delete); - - if (LEFT(successor) != NULL) - PARENT(LEFT(successor)) = successor; - if (RIGHT(successor) != successor) - PARENT(RIGHT(successor)) = successor; - - /* - * Now relink the node to be deleted into the - * successor's previous tree location. PARENT(tmp) - * is the successor's original parent. - */ - INSIST(! IS_ROOT(delete)); - - if (PARENT(tmp) == delete) { - /* - * Node being deleted was successor's parent. - */ - RIGHT(successor) = delete; - PARENT(delete) = successor; - - } else { - LEFT(PARENT(tmp)) = delete; - PARENT(delete) = PARENT(tmp); - } - - /* - * Original location of successor node has no left. - */ - LEFT(delete) = NULL; - RIGHT(delete) = RIGHT(tmp); - COLOR(delete) = COLOR(tmp); - } - - /* - * Remove the node by removing the links from its parent. - */ - if (! IS_ROOT(delete)) { - if (LEFT(PARENT(delete)) == delete) - LEFT(PARENT(delete)) = child; - else - RIGHT(PARENT(delete)) = child; - - if (child != NULL) - PARENT(child) = PARENT(delete); - - } else { - /* - * This is the root being deleted, and at this point - * it is known to have just one child. - */ - *rootp = child; - child->is_root = 1; - PARENT(child) = PARENT(delete); - } - - /* - * Fix color violations. - */ - if (IS_BLACK(delete)) { - parent = PARENT(delete); - - while (child != *rootp && IS_BLACK(child)) { - INSIST(child == NULL || ! IS_ROOT(child)); - - if (LEFT(parent) == child) { - sibling = RIGHT(parent); - - if (IS_RED(sibling)) { - MAKE_BLACK(sibling); - MAKE_RED(parent); - rotate_left(parent, rootp); - sibling = RIGHT(parent); - } - - if (IS_BLACK(LEFT(sibling)) && - IS_BLACK(RIGHT(sibling))) { - MAKE_RED(sibling); - child = parent; - - } else { - - if (IS_BLACK(RIGHT(sibling))) { - MAKE_BLACK(LEFT(sibling)); - MAKE_RED(sibling); - rotate_right(sibling, rootp); - sibling = RIGHT(parent); - } - - COLOR(sibling) = COLOR(parent); - MAKE_BLACK(parent); - MAKE_BLACK(RIGHT(sibling)); - rotate_left(parent, rootp); - child = *rootp; - } - - } else { - /* - * Child is parent's right child. - * Everything is doen the same as above, - * except mirrored. - */ - sibling = LEFT(parent); - - if (IS_RED(sibling)) { - MAKE_BLACK(sibling); - MAKE_RED(parent); - rotate_right(parent, rootp); - sibling = LEFT(parent); - } - - if (IS_BLACK(LEFT(sibling)) && - IS_BLACK(RIGHT(sibling))) { - MAKE_RED(sibling); - child = parent; - - } else { - if (IS_BLACK(LEFT(sibling))) { - MAKE_BLACK(RIGHT(sibling)); - MAKE_RED(sibling); - rotate_left(sibling, rootp); - sibling = LEFT(parent); - } - - COLOR(sibling) = COLOR(parent); - MAKE_BLACK(parent); - MAKE_BLACK(LEFT(sibling)); - rotate_right(parent, rootp); - child = *rootp; - } - } - - parent = PARENT(child); - } - - if (IS_RED(child)) - MAKE_BLACK(child); - } -} - -/* - * This should only be used on the root of a tree, because no color fixup - * is done at all. - * - * NOTE: No root pointer maintenance is done, because the function is only - * used for two cases: - * + deleting everything DOWN from a node that is itself being deleted, and - * + deleting the entire tree of trees from dns_rbt_destroy. - * In each case, the root pointer is no longer relevant, so there - * is no need for a root parameter to this function. - * - * If the function is ever intended to be used to delete something where - * a pointer needs to be told that this tree no longer exists, - * this function would need to adjusted accordingly. - */ -static isc_result_t -dns_rbt_deletetree(dns_rbt_t *rbt, dns_rbtnode_t *node) { - isc_result_t result = ISC_R_SUCCESS; - REQUIRE(VALID_RBT(rbt)); - - if (node == NULL) - return (result); - - if (LEFT(node) != NULL) { - result = dns_rbt_deletetree(rbt, LEFT(node)); - if (result != ISC_R_SUCCESS) - goto done; - LEFT(node) = NULL; - } - if (RIGHT(node) != NULL) { - result = dns_rbt_deletetree(rbt, RIGHT(node)); - if (result != ISC_R_SUCCESS) - goto done; - RIGHT(node) = NULL; - } - if (DOWN(node) != NULL) { - result = dns_rbt_deletetree(rbt, DOWN(node)); - if (result != ISC_R_SUCCESS) - goto done; - DOWN(node) = NULL; - } - done: - if (result != ISC_R_SUCCESS) - return (result); - - if (DATA(node) != NULL && rbt->data_deleter != NULL) - rbt->data_deleter(DATA(node), rbt->deleter_arg); - - unhash_node(rbt, node); -#if DNS_RBT_USEMAGIC - node->magic = 0; -#endif - isc_mem_put(rbt->mctx, node, NODE_SIZE(node)); - rbt->nodecount--; - return (result); -} - -static void -dns_rbt_deletetreeflat(dns_rbt_t *rbt, unsigned int quantum, - dns_rbtnode_t **nodep) -{ - dns_rbtnode_t *parent; - dns_rbtnode_t *node = *nodep; - REQUIRE(VALID_RBT(rbt)); - - again: - if (node == NULL) { - *nodep = NULL; - return; - } - - traverse: - if (LEFT(node) != NULL) { - node = LEFT(node); - goto traverse; - } - if (RIGHT(node) != NULL) { - node = RIGHT(node); - goto traverse; - } - if (DOWN(node) != NULL) { - node = DOWN(node); - goto traverse; - } - - if (DATA(node) != NULL && rbt->data_deleter != NULL) - rbt->data_deleter(DATA(node), rbt->deleter_arg); - - /* - * Note: we don't call unhash_node() here as we are destroying - * the complete rbt tree. - */ -#if DNS_RBT_USEMAGIC - node->magic = 0; -#endif - parent = PARENT(node); - if (parent != NULL) { - if (LEFT(parent) == node) - LEFT(parent) = NULL; - else if (DOWN(parent) == node) - DOWN(parent) = NULL; - else if (RIGHT(parent) == node) - RIGHT(parent) = NULL; - } - isc_mem_put(rbt->mctx, node, NODE_SIZE(node)); - rbt->nodecount--; - node = parent; - if (quantum != 0 && --quantum == 0) { - *nodep = node; - return; - } - goto again; -} - -static void -dns_rbt_indent(int depth) { - int i; - - for (i = 0; i < depth; i++) - putchar('\t'); -} - -static void -dns_rbt_printnodename(dns_rbtnode_t *node) { - isc_region_t r; - dns_name_t name; - char buffer[DNS_NAME_FORMATSIZE]; - dns_offsets_t offsets; - - r.length = NAMELEN(node); - r.base = NAME(node); - - dns_name_init(&name, offsets); - dns_name_fromregion(&name, &r); - - dns_name_format(&name, buffer, sizeof(buffer)); - - printf("%s", buffer); -} - -static void -dns_rbt_printtree(dns_rbtnode_t *root, dns_rbtnode_t *parent, int depth) { - dns_rbt_indent(depth); - - if (root != NULL) { - dns_rbt_printnodename(root); - printf(" (%s", IS_RED(root) ? "RED" : "black"); - if (parent) { - printf(" from "); - dns_rbt_printnodename(parent); - } - - if ((! IS_ROOT(root) && PARENT(root) != parent) || - ( IS_ROOT(root) && depth > 0 && - DOWN(PARENT(root)) != root)) { - - printf(" (BAD parent pointer! -> "); - if (PARENT(root) != NULL) - dns_rbt_printnodename(PARENT(root)); - else - printf("NULL"); - printf(")"); - } - - printf(")\n"); - - - depth++; - - if (DOWN(root)) { - dns_rbt_indent(depth); - printf("++ BEG down from "); - dns_rbt_printnodename(root); - printf("\n"); - dns_rbt_printtree(DOWN(root), NULL, depth); - dns_rbt_indent(depth); - printf("-- END down from "); - dns_rbt_printnodename(root); - printf("\n"); - } - - if (IS_RED(root) && IS_RED(LEFT(root))) - printf("** Red/Red color violation on left\n"); - dns_rbt_printtree(LEFT(root), root, depth); - - if (IS_RED(root) && IS_RED(RIGHT(root))) - printf("** Red/Red color violation on right\n"); - dns_rbt_printtree(RIGHT(root), root, depth); - - } else - printf("NULL\n"); -} - -void -dns_rbt_printall(dns_rbt_t *rbt) { - REQUIRE(VALID_RBT(rbt)); - - dns_rbt_printtree(rbt->root, NULL, 0); -} - -/* - * Chain Functions - */ - -void -dns_rbtnodechain_init(dns_rbtnodechain_t *chain, isc_mem_t *mctx) { - /* - * Initialize 'chain'. - */ - - REQUIRE(chain != NULL); - - chain->mctx = mctx; - chain->end = NULL; - chain->level_count = 0; - chain->level_matches = 0; - - chain->magic = CHAIN_MAGIC; -} - -isc_result_t -dns_rbtnodechain_current(dns_rbtnodechain_t *chain, dns_name_t *name, - dns_name_t *origin, dns_rbtnode_t **node) -{ - isc_result_t result = ISC_R_SUCCESS; - - REQUIRE(VALID_CHAIN(chain)); - - if (node != NULL) - *node = chain->end; - - if (chain->end == NULL) - return (ISC_R_NOTFOUND); - - if (name != NULL) { - NODENAME(chain->end, name); - - if (chain->level_count == 0) { - /* - * Names in the top level tree are all absolute. - * Always make 'name' relative. - */ - INSIST(dns_name_isabsolute(name)); - - /* - * This is cheaper than dns_name_getlabelsequence(). - */ - name->labels--; - name->length--; - name->attributes &= ~DNS_NAMEATTR_ABSOLUTE; - } - } - - if (origin != NULL) { - if (chain->level_count > 0) - result = chain_name(chain, origin, ISC_FALSE); - else - result = dns_name_copy(dns_rootname, origin, NULL); - } - - return (result); -} - -isc_result_t -dns_rbtnodechain_prev(dns_rbtnodechain_t *chain, dns_name_t *name, - dns_name_t *origin) -{ - dns_rbtnode_t *current, *previous, *predecessor; - isc_result_t result = ISC_R_SUCCESS; - isc_boolean_t new_origin = ISC_FALSE; - - REQUIRE(VALID_CHAIN(chain) && chain->end != NULL); - - predecessor = NULL; - - current = chain->end; - - if (LEFT(current) != NULL) { - /* - * Moving left one then right as far as possible is the - * previous node, at least for this level. - */ - current = LEFT(current); - - while (RIGHT(current) != NULL) - current = RIGHT(current); - - predecessor = current; - - } else { - /* - * No left links, so move toward the root. If at any point on - * the way there the link from parent to child is a right - * link, then the parent is the previous node, at least - * for this level. - */ - while (! IS_ROOT(current)) { - previous = current; - current = PARENT(current); - - if (RIGHT(current) == previous) { - predecessor = current; - break; - } - } - } - - if (predecessor != NULL) { - /* - * Found a predecessor node in this level. It might not - * really be the predecessor, however. - */ - if (DOWN(predecessor) != NULL) { - /* - * The predecessor is really down at least one level. - * Go down and as far right as possible, and repeat - * as long as the rightmost node has a down pointer. - */ - do { - /* - * XXX DCL Need to do something about origins - * here. See whether to go down, and if so - * whether it is truly what Bob calls a - * new origin. - */ - ADD_LEVEL(chain, predecessor); - predecessor = DOWN(predecessor); - - /* XXX DCL duplicated from above; clever - * way to unduplicate? */ - - while (RIGHT(predecessor) != NULL) - predecessor = RIGHT(predecessor); - } while (DOWN(predecessor) != NULL); - - /* XXX DCL probably needs work on the concept */ - if (origin != NULL) - new_origin = ISC_TRUE; - } - - } else if (chain->level_count > 0) { - /* - * Dang, didn't find a predecessor in this level. - * Got to the root of this level without having traversed - * any right links. Ascend the tree one level; the - * node that points to this tree is the predecessor. - */ - INSIST(chain->level_count > 0 && IS_ROOT(current)); - predecessor = chain->levels[--chain->level_count]; - - /* XXX DCL probably needs work on the concept */ - /* - * Don't declare an origin change when the new origin is "." - * at the top level tree, because "." is declared as the origin - * for the second level tree. - */ - if (origin != NULL && - (chain->level_count > 0 || OFFSETLEN(predecessor) > 1)) - new_origin = ISC_TRUE; - } - - if (predecessor != NULL) { - chain->end = predecessor; - - if (new_origin) { - result = dns_rbtnodechain_current(chain, name, origin, - NULL); - if (result == ISC_R_SUCCESS) - result = DNS_R_NEWORIGIN; - - } else - result = dns_rbtnodechain_current(chain, name, NULL, - NULL); - - } else - result = ISC_R_NOMORE; - - return (result); -} - -isc_result_t -dns_rbtnodechain_next(dns_rbtnodechain_t *chain, dns_name_t *name, - dns_name_t *origin) -{ - dns_rbtnode_t *current, *previous, *successor; - isc_result_t result = ISC_R_SUCCESS; - isc_boolean_t new_origin = ISC_FALSE; - - REQUIRE(VALID_CHAIN(chain) && chain->end != NULL); - - successor = NULL; - - current = chain->end; - - /* - * If there is a level below this node, the next node is the leftmost - * node of the next level. - */ - if (DOWN(current) != NULL) { - /* - * Don't declare an origin change when the new origin is "." - * at the second level tree, because "." is already declared - * as the origin for the top level tree. - */ - if (chain->level_count > 0 || - OFFSETLEN(current) > 1) - new_origin = ISC_TRUE; - - ADD_LEVEL(chain, current); - current = DOWN(current); - - while (LEFT(current) != NULL) - current = LEFT(current); - - successor = current; - - } else if (RIGHT(current) == NULL) { - /* - * The successor is up, either in this level or a previous one. - * Head back toward the root of the tree, looking for any path - * that was via a left link; the successor is the node that has - * that left link. In the event the root of the level is - * reached without having traversed any left links, ascend one - * level and look for either a right link off the point of - * ascent, or search for a left link upward again, repeating - * ascents until either case is true. - */ - do { - while (! IS_ROOT(current)) { - previous = current; - current = PARENT(current); - - if (LEFT(current) == previous) { - successor = current; - break; - } - } - - if (successor == NULL) { - /* - * Reached the root without having traversed - * any left pointers, so this level is done. - */ - if (chain->level_count == 0) - break; - - current = chain->levels[--chain->level_count]; - new_origin = ISC_TRUE; - - if (RIGHT(current) != NULL) - break; - } - } while (successor == NULL); - } - - if (successor == NULL && RIGHT(current) != NULL) { - current = RIGHT(current); - - while (LEFT(current) != NULL) - current = LEFT(current); - - successor = current; - } - - if (successor != NULL) { - chain->end = successor; - - /* - * It is not necessary to use dns_rbtnodechain_current like - * the other functions because this function will never - * find a node in the topmost level. This is because the - * root level will never be more than one name, and everything - * in the megatree is a successor to that node, down at - * the second level or below. - */ - - if (name != NULL) - NODENAME(chain->end, name); - - if (new_origin) { - if (origin != NULL) - result = chain_name(chain, origin, ISC_FALSE); - - if (result == ISC_R_SUCCESS) - result = DNS_R_NEWORIGIN; - - } else - result = ISC_R_SUCCESS; - - } else - result = ISC_R_NOMORE; - - return (result); -} - -isc_result_t -dns_rbtnodechain_first(dns_rbtnodechain_t *chain, dns_rbt_t *rbt, - dns_name_t *name, dns_name_t *origin) - -{ - isc_result_t result; - - REQUIRE(VALID_RBT(rbt)); - REQUIRE(VALID_CHAIN(chain)); - - dns_rbtnodechain_reset(chain); - - chain->end = rbt->root; - - result = dns_rbtnodechain_current(chain, name, origin, NULL); - - if (result == ISC_R_SUCCESS) - result = DNS_R_NEWORIGIN; - - return (result); -} - -isc_result_t -dns_rbtnodechain_last(dns_rbtnodechain_t *chain, dns_rbt_t *rbt, - dns_name_t *name, dns_name_t *origin) - -{ - isc_result_t result; - - REQUIRE(VALID_RBT(rbt)); - REQUIRE(VALID_CHAIN(chain)); - - dns_rbtnodechain_reset(chain); - - result = move_chain_to_last(chain, rbt->root); - if (result != ISC_R_SUCCESS) - return (result); - - result = dns_rbtnodechain_current(chain, name, origin, NULL); - - if (result == ISC_R_SUCCESS) - result = DNS_R_NEWORIGIN; - - return (result); -} - - -void -dns_rbtnodechain_reset(dns_rbtnodechain_t *chain) { - /* - * Free any dynamic storage associated with 'chain', and then - * reinitialize 'chain'. - */ - - REQUIRE(VALID_CHAIN(chain)); - - chain->end = NULL; - chain->level_count = 0; - chain->level_matches = 0; -} - -void -dns_rbtnodechain_invalidate(dns_rbtnodechain_t *chain) { - /* - * Free any dynamic storage associated with 'chain', and then - * invalidate 'chain'. - */ - - dns_rbtnodechain_reset(chain); - - chain->magic = 0; -} |
