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Diffstat (limited to 'external/unbound/iterator/iter_fwd.h')
-rw-r--r-- | external/unbound/iterator/iter_fwd.h | 199 |
1 files changed, 199 insertions, 0 deletions
diff --git a/external/unbound/iterator/iter_fwd.h b/external/unbound/iterator/iter_fwd.h new file mode 100644 index 000000000..20113a395 --- /dev/null +++ b/external/unbound/iterator/iter_fwd.h @@ -0,0 +1,199 @@ +/* + * iterator/iter_fwd.h - iterative resolver module forward zones. + * + * 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 forward zones, and read those from config. + */ + +#ifndef ITERATOR_ITER_FWD_H +#define ITERATOR_ITER_FWD_H +#include "util/rbtree.h" +struct config_file; +struct delegpt; + +/** + * Iterator forward zones structure + */ +struct iter_forwards { + /** + * Zones 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_forward_zone. + */ + rbtree_t* tree; +}; + +/** + * Iterator forward servers for a particular zone. + */ +struct iter_forward_zone { + /** redblacktree node, key is this structure: class and name */ + rbnode_t node; + /** name */ + uint8_t* name; + /** length of name */ + size_t namelen; + /** number of labels in name */ + int namelabs; + /** delegation point with forward server information for this zone. + * If NULL then this forward entry is used to indicate that a + * stub-zone with the same name exists, and should be used. + * This delegation point is malloced. + */ + struct delegpt* dp; + /** pointer to parent in tree (or NULL if none) */ + struct iter_forward_zone* parent; + /** class. host order. */ + uint16_t dclass; +}; + +/** + * Create forwards + * @return new forwards or NULL on error. + */ +struct iter_forwards* forwards_create(void); + +/** + * Delete forwards. + * @param fwd: to delete. + */ +void forwards_delete(struct iter_forwards* fwd); + +/** + * Process forwards config. + * @param fwd: where to store. + * @param cfg: config options. + * @return 0 on error. + */ +int forwards_apply_cfg(struct iter_forwards* fwd, struct config_file* cfg); + +/** + * Find forward zone exactly by name + * @param fwd: forward storage. + * @param qname: The qname of the query. + * @param qclass: The qclass of the query. + * @return: A delegation point or null. + */ +struct delegpt* forwards_find(struct iter_forwards* fwd, uint8_t* qname, + uint16_t qclass); + +/** + * Find forward zone information + * For this qname/qclass find forward zone information, returns delegation + * point with server names and addresses, or NULL if no forwarding is needed. + * + * @param fwd: forward storage. + * @param qname: The qname of the query. + * @param qclass: The qclass of the query. + * @return: A delegation point if the query has to be forwarded to that list, + * otherwise null. + */ +struct delegpt* forwards_lookup(struct iter_forwards* fwd, + uint8_t* qname, uint16_t qclass); + +/** + * Same as forwards_lookup, but for the root only + * @param fwd: forward storage. + * @param qclass: The qclass of the query. + * @return: A delegation point if root forward exists, otherwise null. + */ +struct delegpt* forwards_lookup_root(struct iter_forwards* fwd, + uint16_t qclass); + +/** + * Find next root item in forwards lookup tree. + * @param fwd: the forward storage + * @param qclass: class to look at next, or higher. + * @return false if none found, or if true stored in qclass. + */ +int forwards_next_root(struct iter_forwards* fwd, uint16_t* qclass); + +/** + * Get memory in use by forward storage + * @param fwd: forward storage. + * @return bytes in use + */ +size_t forwards_get_mem(struct iter_forwards* fwd); + +/** compare two fwd entries */ +int fwd_cmp(const void* k1, const void* k2); + +/** + * Add zone to forward structure. For external use since it recalcs + * the tree parents. + * @param fwd: the forward data structure + * @param c: class of zone + * @param dp: delegation point with name and target nameservers for new + * forward zone. malloced. + * @return false on failure (out of memory); + */ +int forwards_add_zone(struct iter_forwards* fwd, uint16_t c, + struct delegpt* dp); + +/** + * Remove zone from forward structure. For external use since it + * recalcs the tree parents. + * @param fwd: the forward data structure + * @param c: class of zone + * @param nm: name of zone (in uncompressed wireformat). + */ +void forwards_delete_zone(struct iter_forwards* fwd, uint16_t c, uint8_t* nm); + +/** + * Add stub hole (empty entry in forward table, that makes resolution skip + * a forward-zone because the stub zone should override the forward zone). + * Does not add one if not necessary. + * @param fwd: the forward data structure + * @param c: class of zone + * @param nm: name of zone (in uncompressed wireformat). + * @return false on failure (out of memory); + */ +int forwards_add_stub_hole(struct iter_forwards* fwd, uint16_t c, uint8_t* nm); + +/** + * Remove stub hole, if one exists. + * @param fwd: the forward data structure + * @param c: class of zone + * @param nm: name of zone (in uncompressed wireformat). + */ +void forwards_delete_stub_hole(struct iter_forwards* fwd, uint16_t c, + uint8_t* nm); + +#endif /* ITERATOR_ITER_FWD_H */ |