573 lines
20 KiB
C
573 lines
20 KiB
C
/*
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* services/mesh.h - deal with mesh of query states and handle events for that.
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*
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* Copyright (c) 2007, NLnet Labs. All rights reserved.
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*
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* This software is open source.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* Neither the name of the NLNET LABS nor the names of its contributors may
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* be used to endorse or promote products derived from this software without
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* specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
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* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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/**
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* \file
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*
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* This file contains functions to assist in dealing with a mesh of
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* query states. This mesh is supposed to be thread-specific.
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* It consists of query states (per qname, qtype, qclass) and connections
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* between query states and the super and subquery states, and replies to
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* send back to clients.
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*/
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#ifndef SERVICES_MESH_H
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#define SERVICES_MESH_H
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#include "util/rbtree.h"
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#include "util/netevent.h"
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#include "util/data/msgparse.h"
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#include "util/module.h"
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#include "services/modstack.h"
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struct sldns_buffer;
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struct mesh_state;
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struct mesh_reply;
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struct mesh_cb;
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struct query_info;
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struct reply_info;
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struct outbound_entry;
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struct timehist;
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/**
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* Maximum number of mesh state activations. Any more is likely an
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* infinite loop in the module. It is then terminated.
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*/
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#define MESH_MAX_ACTIVATION 3000
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/**
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* Max number of references-to-references-to-references.. search size.
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* Any more is treated like 'too large', and the creation of a new
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* dependency is failed (so that no loops can be created).
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*/
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#define MESH_MAX_SUBSUB 1024
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/**
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* Mesh of query states
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*/
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struct mesh_area {
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/** active module stack */
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struct module_stack mods;
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/** environment for new states */
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struct module_env* env;
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/** set of runnable queries (mesh_state.run_node) */
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rbtree_t run;
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/** rbtree of all current queries (mesh_state.node)*/
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rbtree_t all;
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/** count of the total number of mesh_reply entries */
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size_t num_reply_addrs;
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/** count of the number of mesh_states that have mesh_replies
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* Because a state can send results to multiple reply addresses,
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* this number must be equal or lower than num_reply_addrs. */
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size_t num_reply_states;
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/** number of mesh_states that have no mesh_replies, and also
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* an empty set of super-states, thus are 'toplevel' or detached
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* internal opportunistic queries */
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size_t num_detached_states;
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/** number of reply states in the forever list */
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size_t num_forever_states;
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/** max total number of reply states to have */
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size_t max_reply_states;
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/** max forever number of reply states to have */
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size_t max_forever_states;
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/** stats, cumulative number of reply states jostled out */
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size_t stats_jostled;
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/** stats, cumulative number of incoming client msgs dropped */
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size_t stats_dropped;
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/** number of replies sent */
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size_t replies_sent;
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/** sum of waiting times for the replies */
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struct timeval replies_sum_wait;
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/** histogram of time values */
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struct timehist* histogram;
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/** (extended stats) secure replies */
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size_t ans_secure;
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/** (extended stats) bogus replies */
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size_t ans_bogus;
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/** (extended stats) rcodes in replies */
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size_t ans_rcode[16];
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/** (extended stats) rcode nodata in replies */
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size_t ans_nodata;
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/** backup of query if other operations recurse and need the
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* network buffers */
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struct sldns_buffer* qbuf_bak;
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/** double linked list of the run-to-completion query states.
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* These are query states with a reply */
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struct mesh_state* forever_first;
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/** last entry in run forever list */
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struct mesh_state* forever_last;
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/** double linked list of the query states that can be jostled out
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* by new queries if too old. These are query states with a reply */
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struct mesh_state* jostle_first;
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/** last entry in jostle list - this is the entry that is newest */
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struct mesh_state* jostle_last;
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/** timeout for jostling. if age is lower, it does not get jostled. */
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struct timeval jostle_max;
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};
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/**
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* A mesh query state
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* Unique per qname, qtype, qclass (from the qstate).
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* And RD / CD flag; in case a client turns it off.
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* And priming queries are different from ordinary queries (because of hints).
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*
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* The entire structure is allocated in a region, this region is the qstate
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* region. All parts (rbtree nodes etc) are also allocated in the region.
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*/
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struct mesh_state {
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/** node in mesh_area all tree, key is this struct. Must be first. */
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rbnode_t node;
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/** node in mesh_area runnable tree, key is this struct */
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rbnode_t run_node;
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/** the query state. Note that the qinfo and query_flags
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* may not change. */
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struct module_qstate s;
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/** the list of replies to clients for the results */
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struct mesh_reply* reply_list;
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/** the list of callbacks for the results */
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struct mesh_cb* cb_list;
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/** set of superstates (that want this state's result)
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* contains struct mesh_state_ref* */
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rbtree_t super_set;
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/** set of substates (that this state needs to continue)
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* contains struct mesh_state_ref* */
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rbtree_t sub_set;
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/** number of activations for the mesh state */
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size_t num_activated;
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/** previous in linked list for reply states */
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struct mesh_state* prev;
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/** next in linked list for reply states */
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struct mesh_state* next;
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/** if this state is in the forever list, jostle list, or neither */
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enum mesh_list_select { mesh_no_list, mesh_forever_list,
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mesh_jostle_list } list_select;
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/** true if replies have been sent out (at end for alignment) */
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uint8_t replies_sent;
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};
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/**
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* Rbtree reference to a mesh_state.
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* Used in super_set and sub_set.
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*/
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struct mesh_state_ref {
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/** node in rbtree for set, key is this structure */
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rbnode_t node;
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/** the mesh state */
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struct mesh_state* s;
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};
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/**
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* Reply to a client
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*/
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struct mesh_reply {
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/** next in reply list */
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struct mesh_reply* next;
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/** the query reply destination, packet buffer and where to send. */
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struct comm_reply query_reply;
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/** edns data from query */
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struct edns_data edns;
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/** the time when request was entered */
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struct timeval start_time;
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/** id of query, in network byteorder. */
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uint16_t qid;
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/** flags of query, for reply flags */
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uint16_t qflags;
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/** qname from this query. len same as mesh qinfo. */
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uint8_t* qname;
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};
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/**
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* Mesh result callback func.
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* called as func(cb_arg, rcode, buffer_with_reply, security, why_bogus);
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*/
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typedef void (*mesh_cb_func_t)(void*, int, struct sldns_buffer*, enum sec_status,
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char*);
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/**
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* Callback to result routine
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*/
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struct mesh_cb {
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/** next in list */
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struct mesh_cb* next;
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/** edns data from query */
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struct edns_data edns;
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/** id of query, in network byteorder. */
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uint16_t qid;
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/** flags of query, for reply flags */
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uint16_t qflags;
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/** buffer for reply */
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struct sldns_buffer* buf;
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/** callback routine for results. if rcode != 0 buf has message.
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* called as cb(cb_arg, rcode, buf, sec_state);
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*/
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mesh_cb_func_t cb;
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/** user arg for callback */
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void* cb_arg;
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};
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/* ------------------- Functions for worker -------------------- */
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/**
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* Allocate mesh, to empty.
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* @param stack: module stack to activate, copied (as readonly reference).
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* @param env: environment for new queries.
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* @return mesh: the new mesh or NULL on error.
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*/
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struct mesh_area* mesh_create(struct module_stack* stack,
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struct module_env* env);
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/**
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* Delete mesh, and all query states and replies in it.
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* @param mesh: the mesh to delete.
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*/
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void mesh_delete(struct mesh_area* mesh);
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/**
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* New query incoming from clients. Create new query state if needed, and
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* add mesh_reply to it. Returns error to client on malloc failures.
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* Will run the mesh area queries to process if a new query state is created.
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*
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* @param mesh: the mesh.
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* @param qinfo: query from client.
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* @param qflags: flags from client query.
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* @param edns: edns data from client query.
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* @param rep: where to reply to.
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* @param qid: query id to reply with.
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*/
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void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo,
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uint16_t qflags, struct edns_data* edns, struct comm_reply* rep,
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uint16_t qid);
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/**
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* New query with callback. Create new query state if needed, and
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* add mesh_cb to it.
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* Will run the mesh area queries to process if a new query state is created.
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*
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* @param mesh: the mesh.
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* @param qinfo: query from client.
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* @param qflags: flags from client query.
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* @param edns: edns data from client query.
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* @param buf: buffer for reply contents.
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* @param qid: query id to reply with.
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* @param cb: callback function.
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* @param cb_arg: callback user arg.
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* @return 0 on error.
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*/
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int mesh_new_callback(struct mesh_area* mesh, struct query_info* qinfo,
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uint16_t qflags, struct edns_data* edns, struct sldns_buffer* buf,
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uint16_t qid, mesh_cb_func_t cb, void* cb_arg);
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/**
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* New prefetch message. Create new query state if needed.
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* Will run the mesh area queries to process if a new query state is created.
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*
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* @param mesh: the mesh.
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* @param qinfo: query from client.
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* @param qflags: flags from client query.
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* @param leeway: TTL leeway what to expire earlier for this update.
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*/
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void mesh_new_prefetch(struct mesh_area* mesh, struct query_info* qinfo,
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uint16_t qflags, time_t leeway);
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/**
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* Handle new event from the wire. A serviced query has returned.
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* The query state will be made runnable, and the mesh_area will process
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* query states until processing is complete.
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*
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* @param mesh: the query mesh.
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* @param e: outbound entry, with query state to run and reply pointer.
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* @param reply: the comm point reply info.
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* @param what: NETEVENT_* error code (if not 0, what is wrong, TIMEOUT).
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*/
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void mesh_report_reply(struct mesh_area* mesh, struct outbound_entry* e,
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struct comm_reply* reply, int what);
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/* ------------------- Functions for module environment --------------- */
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/**
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* Detach-subqueries.
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* Remove all sub-query references from this query state.
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* Keeps super-references of those sub-queries correct.
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* Updates stat items in mesh_area structure.
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* @param qstate: used to find mesh state.
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*/
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void mesh_detach_subs(struct module_qstate* qstate);
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/**
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* Attach subquery.
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* Creates it if it does not exist already.
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* Keeps sub and super references correct.
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* Performs a cycle detection - for double check - and fails if there is one.
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* Also fails if the sub-sub-references become too large.
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* Updates stat items in mesh_area structure.
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* Pass if it is priming query or not.
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* return:
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* o if error (malloc) happened.
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* o need to initialise the new state (module init; it is a new state).
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* so that the next run of the query with this module is successful.
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* o no init needed, attachment successful.
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*
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* @param qstate: the state to find mesh state, and that wants to receive
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* the results from the new subquery.
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* @param qinfo: what to query for (copied).
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* @param qflags: what flags to use (RD / CD flag or not).
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* @param prime: if it is a (stub) priming query.
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* @param newq: If the new subquery needs initialisation, it is returned,
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* otherwise NULL is returned.
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* @return: false on error, true if success (and init may be needed).
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*/
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int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo,
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uint16_t qflags, int prime, struct module_qstate** newq);
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/**
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* Query state is done, send messages to reply entries.
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* Encode messages using reply entry values and the querystate (with original
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* qinfo), using given reply_info.
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* Pass errcode != 0 if an error reply is needed.
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* If no reply entries, nothing is done.
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* Must be called before a module can module_finished or return module_error.
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* The module must handle the super query states itself as well.
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*
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* @param mstate: mesh state that is done. return_rcode and return_msg
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* are used for replies.
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* return_rcode: if not 0 (NOERROR) an error is sent back (and
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* return_msg is ignored).
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* return_msg: reply to encode and send back to clients.
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*/
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void mesh_query_done(struct mesh_state* mstate);
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/**
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* Call inform_super for the super query states that are interested in the
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* results from this query state. These can then be changed for error
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* or results.
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* Called when a module is module_finished or returns module_error.
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* The super query states become runnable with event module_event_pass,
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* it calls the current module for the super with the inform_super event.
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*
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* @param mesh: mesh area to add newly runnable modules to.
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* @param mstate: the state that has results, used to find mesh state.
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*/
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void mesh_walk_supers(struct mesh_area* mesh, struct mesh_state* mstate);
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/**
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* Delete mesh state, cleanup and also rbtrees and so on.
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* Will detach from all super/subnodes.
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* @param qstate: to remove.
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*/
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void mesh_state_delete(struct module_qstate* qstate);
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/* ------------------- Functions for mesh -------------------- */
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/**
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* Create and initialize a new mesh state and its query state
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* Does not put the mesh state into rbtrees and so on.
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* @param env: module environment to set.
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* @param qinfo: query info that the mesh is for.
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* @param qflags: flags for query (RD / CD flag).
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* @param prime: if true, it is a priming query, set is_priming on mesh state.
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* @return: new mesh state or NULL on allocation error.
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*/
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struct mesh_state* mesh_state_create(struct module_env* env,
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struct query_info* qinfo, uint16_t qflags, int prime);
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/**
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* Cleanup a mesh state and its query state. Does not do rbtree or
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* reference cleanup.
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* @param mstate: mesh state to cleanup. Its pointer may no longer be used
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* afterwards. Cleanup rbtrees before calling this function.
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*/
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void mesh_state_cleanup(struct mesh_state* mstate);
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/**
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* Delete all mesh states from the mesh.
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* @param mesh: the mesh area to clear
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*/
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void mesh_delete_all(struct mesh_area* mesh);
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/**
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* Find a mesh state in the mesh area. Pass relevant flags.
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*
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* @param mesh: the mesh area to look in.
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* @param qinfo: what query
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* @param qflags: if RD / CD bit is set or not.
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* @param prime: if it is a priming query.
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* @return: mesh state or NULL if not found.
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*/
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struct mesh_state* mesh_area_find(struct mesh_area* mesh,
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struct query_info* qinfo, uint16_t qflags, int prime);
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/**
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* Setup attachment super/sub relation between super and sub mesh state.
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* The relation must not be present when calling the function.
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* Does not update stat items in mesh_area.
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* @param super: super state.
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* @param sub: sub state.
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* @return: 0 on alloc error.
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*/
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int mesh_state_attachment(struct mesh_state* super, struct mesh_state* sub);
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/**
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* Create new reply structure and attach it to a mesh state.
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* Does not update stat items in mesh area.
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* @param s: the mesh state.
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* @param edns: edns data for reply (bufsize).
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* @param rep: comm point reply info.
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* @param qid: ID of reply.
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* @param qflags: original query flags.
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* @param qname: original query name.
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* @return: 0 on alloc error.
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*/
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int mesh_state_add_reply(struct mesh_state* s, struct edns_data* edns,
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struct comm_reply* rep, uint16_t qid, uint16_t qflags, uint8_t* qname);
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/**
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* Create new callback structure and attach it to a mesh state.
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* Does not update stat items in mesh area.
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* @param s: the mesh state.
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* @param edns: edns data for reply (bufsize).
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* @param buf: buffer for reply
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* @param cb: callback to call with results.
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* @param cb_arg: callback user arg.
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* @param qid: ID of reply.
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* @param qflags: original query flags.
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* @return: 0 on alloc error.
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*/
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int mesh_state_add_cb(struct mesh_state* s, struct edns_data* edns,
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struct sldns_buffer* buf, mesh_cb_func_t cb, void* cb_arg, uint16_t qid,
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uint16_t qflags);
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/**
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* Run the mesh. Run all runnable mesh states. Which can create new
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* runnable mesh states. Until completion. Automatically called by
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* mesh_report_reply and mesh_new_client as needed.
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* @param mesh: mesh area.
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* @param mstate: first mesh state to run.
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* @param ev: event the mstate. Others get event_pass.
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* @param e: if a reply, its outbound entry.
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*/
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void mesh_run(struct mesh_area* mesh, struct mesh_state* mstate,
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enum module_ev ev, struct outbound_entry* e);
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|
|
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/**
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* Print some stats about the mesh to the log.
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* @param mesh: the mesh to print it for.
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* @param str: descriptive string to go with it.
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|
*/
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void mesh_stats(struct mesh_area* mesh, const char* str);
|
|
|
|
/**
|
|
* Clear the stats that the mesh keeps (number of queries serviced)
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|
* @param mesh: the mesh
|
|
*/
|
|
void mesh_stats_clear(struct mesh_area* mesh);
|
|
|
|
/**
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|
* Print all the states in the mesh to the log.
|
|
* @param mesh: the mesh to print all states of.
|
|
*/
|
|
void mesh_log_list(struct mesh_area* mesh);
|
|
|
|
/**
|
|
* Calculate memory size in use by mesh and all queries inside it.
|
|
* @param mesh: the mesh to examine.
|
|
* @return size in bytes.
|
|
*/
|
|
size_t mesh_get_mem(struct mesh_area* mesh);
|
|
|
|
/**
|
|
* Find cycle; see if the given mesh is in the targets sub, or sub-sub, ...
|
|
* trees.
|
|
* If the sub-sub structure is too large, it returns 'a cycle'=2.
|
|
* @param qstate: given mesh querystate.
|
|
* @param qinfo: query info for dependency.
|
|
* @param flags: query flags of dependency.
|
|
* @param prime: if dependency is a priming query or not.
|
|
* @return true if the name,type,class exists and the given qstate mesh exists
|
|
* as a dependency of that name. Thus if qstate becomes dependent on
|
|
* name,type,class then a cycle is created, this is return value 1.
|
|
* Too large to search is value 2 (also true).
|
|
*/
|
|
int mesh_detect_cycle(struct module_qstate* qstate, struct query_info* qinfo,
|
|
uint16_t flags, int prime);
|
|
|
|
/** compare two mesh_states */
|
|
int mesh_state_compare(const void* ap, const void* bp);
|
|
|
|
/** compare two mesh references */
|
|
int mesh_state_ref_compare(const void* ap, const void* bp);
|
|
|
|
/**
|
|
* Make space for another recursion state for a reply in the mesh
|
|
* @param mesh: mesh area
|
|
* @param qbuf: query buffer to save if recursion is invoked to make space.
|
|
* This buffer is necessary, because the following sequence in calls
|
|
* can result in an overwrite of the incoming query:
|
|
* delete_other_mesh_query - iter_clean - serviced_delete - waiting
|
|
* udp query is sent - on error callback - callback sends SERVFAIL reply
|
|
* over the same network channel, and shared UDP buffer is overwritten.
|
|
* You can pass NULL if there is no buffer that must be backed up.
|
|
* @return false if no space is available.
|
|
*/
|
|
int mesh_make_new_space(struct mesh_area* mesh, struct sldns_buffer* qbuf);
|
|
|
|
/**
|
|
* Insert mesh state into a double linked list. Inserted at end.
|
|
* @param m: mesh state.
|
|
* @param fp: pointer to the first-elem-pointer of the list.
|
|
* @param lp: pointer to the last-elem-pointer of the list.
|
|
*/
|
|
void mesh_list_insert(struct mesh_state* m, struct mesh_state** fp,
|
|
struct mesh_state** lp);
|
|
|
|
/**
|
|
* Remove mesh state from a double linked list. Remove from any position.
|
|
* @param m: mesh state.
|
|
* @param fp: pointer to the first-elem-pointer of the list.
|
|
* @param lp: pointer to the last-elem-pointer of the list.
|
|
*/
|
|
void mesh_list_remove(struct mesh_state* m, struct mesh_state** fp,
|
|
struct mesh_state** lp);
|
|
|
|
#endif /* SERVICES_MESH_H */
|