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| -rw-r--r-- | external/unbound/iterator/iter_hints.h | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/external/unbound/iterator/iter_hints.h b/external/unbound/iterator/iter_hints.h new file mode 100644 index 000000000..715ec9f41 --- /dev/null +++ b/external/unbound/iterator/iter_hints.h @@ -0,0 +1,161 @@ +/* + * iterator/iter_hints.h - iterative resolver module stub and root hints. + * + * Copyright (c) 2007, NLnet Labs. All rights reserved. + * + * This software is open source. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * + * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * + * Neither the name of the NLNET LABS nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED + * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/** + * \file + * + * This file contains functions to assist the iterator module. + * Keep track of stub and root hints, and read those from config. + */ + +#ifndef ITERATOR_ITER_HINTS_H +#define ITERATOR_ITER_HINTS_H +#include "util/storage/dnstree.h" +struct iter_env; +struct config_file; +struct delegpt; + +/** + * Iterator hints structure + */ +struct iter_hints { + /** + * Hints are stored in this tree. Sort order is specially chosen. + * first sorted on qclass. Then on dname in nsec-like order, so that + * a lookup on class, name will return an exact match or the closest + * match which gives the ancestor needed. + * contents of type iter_hints_stub. The class IN root is in here. + * uses name_tree_node from dnstree.h. + */ + rbtree_t tree; +}; + +/** + * Iterator hints for a particular stub. + */ +struct iter_hints_stub { + /** tree sorted by name, class */ + struct name_tree_node node; + /** delegation point with hint information for this stub. malloced. */ + struct delegpt* dp; + /** does the stub need to forego priming (like on other ports) */ + uint8_t noprime; +}; + +/** + * Create hints + * @return new hints or NULL on error. + */ +struct iter_hints* hints_create(void); + +/** + * Delete hints. + * @param hints: to delete. + */ +void hints_delete(struct iter_hints* hints); + +/** + * Process hints config. Sets default values for root hints if no config. + * @param hints: where to store. + * @param cfg: config options. + * @return 0 on error. + */ +int hints_apply_cfg(struct iter_hints* hints, struct config_file* cfg); + +/** + * Find root hints for the given class. + * @param hints: hint storage. + * @param qclass: class for which root hints are requested. host order. + * @return: NULL if no hints, or a ptr to stored hints. + */ +struct delegpt* hints_lookup_root(struct iter_hints* hints, uint16_t qclass); + +/** + * Find next root hints (to cycle through all root hints). + * @param hints: hint storage + * @param qclass: class for which root hints are sought. + * 0 means give the first available root hints class. + * x means, give class x or a higher class if any. + * returns the found class in this variable. + * @return true if a root hint class is found. + * false if not root hint class is found (qclass may have been changed). + */ +int hints_next_root(struct iter_hints* hints, uint16_t* qclass); + +/** + * Given a qname/qclass combination, and the delegation point from the cache + * for this qname/qclass, determine if this combination indicates that a + * stub hint exists and must be primed. + * + * @param hints: hint storage. + * @param qname: The qname that generated the delegation point. + * @param qclass: The qclass that generated the delegation point. + * @param dp: The cache generated delegation point. + * @return: A priming delegation point if there is a stub hint that must + * be primed, otherwise null. + */ +struct iter_hints_stub* hints_lookup_stub(struct iter_hints* hints, + uint8_t* qname, uint16_t qclass, struct delegpt* dp); + +/** + * Get memory in use by hints + * @param hints: hint storage. + * @return bytes in use + */ +size_t hints_get_mem(struct iter_hints* hints); + +/** + * Add stub to hints structure. For external use since it recalcs + * the tree parents. + * @param hints: the hints data structure + * @param c: class of zone + * @param dp: delegation point with name and target nameservers for new + * hints stub. malloced. + * @param noprime: set noprime option to true or false on new hint stub. + * @return false on failure (out of memory); + */ +int hints_add_stub(struct iter_hints* hints, uint16_t c, struct delegpt* dp, + int noprime); + +/** + * Remove stub from hints structure. For external use since it + * recalcs the tree parents. + * @param hints: the hints data structure + * @param c: class of stub zone + * @param nm: name of stub zone (in uncompressed wireformat). + */ +void hints_delete_stub(struct iter_hints* hints, uint16_t c, uint8_t* nm); + +#endif /* ITERATOR_ITER_HINTS_H */ |