diff options
Diffstat (limited to 'external/unbound/services/mesh.h')
| -rw-r--r-- | external/unbound/services/mesh.h | 572 |
1 files changed, 572 insertions, 0 deletions
diff --git a/external/unbound/services/mesh.h b/external/unbound/services/mesh.h new file mode 100644 index 000000000..fbfbbcb4a --- /dev/null +++ b/external/unbound/services/mesh.h @@ -0,0 +1,572 @@ +/* + * services/mesh.h - deal with mesh of query states and handle events for that. + * + * 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 in dealing with a mesh of + * query states. This mesh is supposed to be thread-specific. + * It consists of query states (per qname, qtype, qclass) and connections + * between query states and the super and subquery states, and replies to + * send back to clients. + */ + +#ifndef SERVICES_MESH_H +#define SERVICES_MESH_H + +#include "util/rbtree.h" +#include "util/netevent.h" +#include "util/data/msgparse.h" +#include "util/module.h" +#include "services/modstack.h" +struct sldns_buffer; +struct mesh_state; +struct mesh_reply; +struct mesh_cb; +struct query_info; +struct reply_info; +struct outbound_entry; +struct timehist; + +/** + * Maximum number of mesh state activations. Any more is likely an + * infinite loop in the module. It is then terminated. + */ +#define MESH_MAX_ACTIVATION 3000 + +/** + * Max number of references-to-references-to-references.. search size. + * Any more is treated like 'too large', and the creation of a new + * dependency is failed (so that no loops can be created). + */ +#define MESH_MAX_SUBSUB 1024 + +/** + * Mesh of query states + */ +struct mesh_area { + /** active module stack */ + struct module_stack mods; + /** environment for new states */ + struct module_env* env; + + /** set of runnable queries (mesh_state.run_node) */ + rbtree_t run; + /** rbtree of all current queries (mesh_state.node)*/ + rbtree_t all; + + /** count of the total number of mesh_reply entries */ + size_t num_reply_addrs; + /** count of the number of mesh_states that have mesh_replies + * Because a state can send results to multiple reply addresses, + * this number must be equal or lower than num_reply_addrs. */ + size_t num_reply_states; + /** number of mesh_states that have no mesh_replies, and also + * an empty set of super-states, thus are 'toplevel' or detached + * internal opportunistic queries */ + size_t num_detached_states; + /** number of reply states in the forever list */ + size_t num_forever_states; + + /** max total number of reply states to have */ + size_t max_reply_states; + /** max forever number of reply states to have */ + size_t max_forever_states; + + /** stats, cumulative number of reply states jostled out */ + size_t stats_jostled; + /** stats, cumulative number of incoming client msgs dropped */ + size_t stats_dropped; + /** number of replies sent */ + size_t replies_sent; + /** sum of waiting times for the replies */ + struct timeval replies_sum_wait; + /** histogram of time values */ + struct timehist* histogram; + /** (extended stats) secure replies */ + size_t ans_secure; + /** (extended stats) bogus replies */ + size_t ans_bogus; + /** (extended stats) rcodes in replies */ + size_t ans_rcode[16]; + /** (extended stats) rcode nodata in replies */ + size_t ans_nodata; + + /** backup of query if other operations recurse and need the + * network buffers */ + struct sldns_buffer* qbuf_bak; + + /** double linked list of the run-to-completion query states. + * These are query states with a reply */ + struct mesh_state* forever_first; + /** last entry in run forever list */ + struct mesh_state* forever_last; + + /** double linked list of the query states that can be jostled out + * by new queries if too old. These are query states with a reply */ + struct mesh_state* jostle_first; + /** last entry in jostle list - this is the entry that is newest */ + struct mesh_state* jostle_last; + /** timeout for jostling. if age is lower, it does not get jostled. */ + struct timeval jostle_max; +}; + +/** + * A mesh query state + * Unique per qname, qtype, qclass (from the qstate). + * And RD / CD flag; in case a client turns it off. + * And priming queries are different from ordinary queries (because of hints). + * + * The entire structure is allocated in a region, this region is the qstate + * region. All parts (rbtree nodes etc) are also allocated in the region. + */ +struct mesh_state { + /** node in mesh_area all tree, key is this struct. Must be first. */ + rbnode_t node; + /** node in mesh_area runnable tree, key is this struct */ + rbnode_t run_node; + /** the query state. Note that the qinfo and query_flags + * may not change. */ + struct module_qstate s; + /** the list of replies to clients for the results */ + struct mesh_reply* reply_list; + /** the list of callbacks for the results */ + struct mesh_cb* cb_list; + /** set of superstates (that want this state's result) + * contains struct mesh_state_ref* */ + rbtree_t super_set; + /** set of substates (that this state needs to continue) + * contains struct mesh_state_ref* */ + rbtree_t sub_set; + /** number of activations for the mesh state */ + size_t num_activated; + + /** previous in linked list for reply states */ + struct mesh_state* prev; + /** next in linked list for reply states */ + struct mesh_state* next; + /** if this state is in the forever list, jostle list, or neither */ + enum mesh_list_select { mesh_no_list, mesh_forever_list, + mesh_jostle_list } list_select; + + /** true if replies have been sent out (at end for alignment) */ + uint8_t replies_sent; +}; + +/** + * Rbtree reference to a mesh_state. + * Used in super_set and sub_set. + */ +struct mesh_state_ref { + /** node in rbtree for set, key is this structure */ + rbnode_t node; + /** the mesh state */ + struct mesh_state* s; +}; + +/** + * Reply to a client + */ +struct mesh_reply { + /** next in reply list */ + struct mesh_reply* next; + /** the query reply destination, packet buffer and where to send. */ + struct comm_reply query_reply; + /** edns data from query */ + struct edns_data edns; + /** the time when request was entered */ + struct timeval start_time; + /** id of query, in network byteorder. */ + uint16_t qid; + /** flags of query, for reply flags */ + uint16_t qflags; + /** qname from this query. len same as mesh qinfo. */ + uint8_t* qname; +}; + +/** + * Mesh result callback func. + * called as func(cb_arg, rcode, buffer_with_reply, security, why_bogus); + */ +typedef void (*mesh_cb_func_t)(void*, int, struct sldns_buffer*, enum sec_status, + char*); + +/** + * Callback to result routine + */ +struct mesh_cb { + /** next in list */ + struct mesh_cb* next; + /** edns data from query */ + struct edns_data edns; + /** id of query, in network byteorder. */ + uint16_t qid; + /** flags of query, for reply flags */ + uint16_t qflags; + /** buffer for reply */ + struct sldns_buffer* buf; + + /** callback routine for results. if rcode != 0 buf has message. + * called as cb(cb_arg, rcode, buf, sec_state); + */ + mesh_cb_func_t cb; + /** user arg for callback */ + void* cb_arg; +}; + +/* ------------------- Functions for worker -------------------- */ + +/** + * Allocate mesh, to empty. + * @param stack: module stack to activate, copied (as readonly reference). + * @param env: environment for new queries. + * @return mesh: the new mesh or NULL on error. + */ +struct mesh_area* mesh_create(struct module_stack* stack, + struct module_env* env); + +/** + * Delete mesh, and all query states and replies in it. + * @param mesh: the mesh to delete. + */ +void mesh_delete(struct mesh_area* mesh); + +/** + * New query incoming from clients. Create new query state if needed, and + * add mesh_reply to it. Returns error to client on malloc failures. + * Will run the mesh area queries to process if a new query state is created. + * + * @param mesh: the mesh. + * @param qinfo: query from client. + * @param qflags: flags from client query. + * @param edns: edns data from client query. + * @param rep: where to reply to. + * @param qid: query id to reply with. + */ +void mesh_new_client(struct mesh_area* mesh, struct query_info* qinfo, + uint16_t qflags, struct edns_data* edns, struct comm_reply* rep, + uint16_t qid); + +/** + * New query with callback. Create new query state if needed, and + * add mesh_cb to it. + * Will run the mesh area queries to process if a new query state is created. + * + * @param mesh: the mesh. + * @param qinfo: query from client. + * @param qflags: flags from client query. + * @param edns: edns data from client query. + * @param buf: buffer for reply contents. + * @param qid: query id to reply with. + * @param cb: callback function. + * @param cb_arg: callback user arg. + * @return 0 on error. + */ +int mesh_new_callback(struct mesh_area* mesh, struct query_info* qinfo, + uint16_t qflags, struct edns_data* edns, struct sldns_buffer* buf, + uint16_t qid, mesh_cb_func_t cb, void* cb_arg); + +/** + * New prefetch message. Create new query state if needed. + * Will run the mesh area queries to process if a new query state is created. + * + * @param mesh: the mesh. + * @param qinfo: query from client. + * @param qflags: flags from client query. + * @param leeway: TTL leeway what to expire earlier for this update. + */ +void mesh_new_prefetch(struct mesh_area* mesh, struct query_info* qinfo, + uint16_t qflags, time_t leeway); + +/** + * Handle new event from the wire. A serviced query has returned. + * The query state will be made runnable, and the mesh_area will process + * query states until processing is complete. + * + * @param mesh: the query mesh. + * @param e: outbound entry, with query state to run and reply pointer. + * @param reply: the comm point reply info. + * @param what: NETEVENT_* error code (if not 0, what is wrong, TIMEOUT). + */ +void mesh_report_reply(struct mesh_area* mesh, struct outbound_entry* e, + struct comm_reply* reply, int what); + +/* ------------------- Functions for module environment --------------- */ + +/** + * Detach-subqueries. + * Remove all sub-query references from this query state. + * Keeps super-references of those sub-queries correct. + * Updates stat items in mesh_area structure. + * @param qstate: used to find mesh state. + */ +void mesh_detach_subs(struct module_qstate* qstate); + +/** + * Attach subquery. + * Creates it if it does not exist already. + * Keeps sub and super references correct. + * Performs a cycle detection - for double check - and fails if there is one. + * Also fails if the sub-sub-references become too large. + * Updates stat items in mesh_area structure. + * Pass if it is priming query or not. + * return: + * o if error (malloc) happened. + * o need to initialise the new state (module init; it is a new state). + * so that the next run of the query with this module is successful. + * o no init needed, attachment successful. + * + * @param qstate: the state to find mesh state, and that wants to receive + * the results from the new subquery. + * @param qinfo: what to query for (copied). + * @param qflags: what flags to use (RD / CD flag or not). + * @param prime: if it is a (stub) priming query. + * @param newq: If the new subquery needs initialisation, it is returned, + * otherwise NULL is returned. + * @return: false on error, true if success (and init may be needed). + */ +int mesh_attach_sub(struct module_qstate* qstate, struct query_info* qinfo, + uint16_t qflags, int prime, struct module_qstate** newq); + +/** + * Query state is done, send messages to reply entries. + * Encode messages using reply entry values and the querystate (with original + * qinfo), using given reply_info. + * Pass errcode != 0 if an error reply is needed. + * If no reply entries, nothing is done. + * Must be called before a module can module_finished or return module_error. + * The module must handle the super query states itself as well. + * + * @param mstate: mesh state that is done. return_rcode and return_msg + * are used for replies. + * return_rcode: if not 0 (NOERROR) an error is sent back (and + * return_msg is ignored). + * return_msg: reply to encode and send back to clients. + */ +void mesh_query_done(struct mesh_state* mstate); + +/** + * Call inform_super for the super query states that are interested in the + * results from this query state. These can then be changed for error + * or results. + * Called when a module is module_finished or returns module_error. + * The super query states become runnable with event module_event_pass, + * it calls the current module for the super with the inform_super event. + * + * @param mesh: mesh area to add newly runnable modules to. + * @param mstate: the state that has results, used to find mesh state. + */ +void mesh_walk_supers(struct mesh_area* mesh, struct mesh_state* mstate); + +/** + * Delete mesh state, cleanup and also rbtrees and so on. + * Will detach from all super/subnodes. + * @param qstate: to remove. + */ +void mesh_state_delete(struct module_qstate* qstate); + +/* ------------------- Functions for mesh -------------------- */ + +/** + * Create and initialize a new mesh state and its query state + * Does not put the mesh state into rbtrees and so on. + * @param env: module environment to set. + * @param qinfo: query info that the mesh is for. + * @param qflags: flags for query (RD / CD flag). + * @param prime: if true, it is a priming query, set is_priming on mesh state. + * @return: new mesh state or NULL on allocation error. + */ +struct mesh_state* mesh_state_create(struct module_env* env, + struct query_info* qinfo, uint16_t qflags, int prime); + +/** + * Cleanup a mesh state and its query state. Does not do rbtree or + * reference cleanup. + * @param mstate: mesh state to cleanup. Its pointer may no longer be used + * afterwards. Cleanup rbtrees before calling this function. + */ +void mesh_state_cleanup(struct mesh_state* mstate); + +/** + * Delete all mesh states from the mesh. + * @param mesh: the mesh area to clear + */ +void mesh_delete_all(struct mesh_area* mesh); + +/** + * Find a mesh state in the mesh area. Pass relevant flags. + * + * @param mesh: the mesh area to look in. + * @param qinfo: what query + * @param qflags: if RD / CD bit is set or not. + * @param prime: if it is a priming query. + * @return: mesh state or NULL if not found. + */ +struct mesh_state* mesh_area_find(struct mesh_area* mesh, + struct query_info* qinfo, uint16_t qflags, int prime); + +/** + * Setup attachment super/sub relation between super and sub mesh state. + * The relation must not be present when calling the function. + * Does not update stat items in mesh_area. + * @param super: super state. + * @param sub: sub state. + * @return: 0 on alloc error. + */ +int mesh_state_attachment(struct mesh_state* super, struct mesh_state* sub); + +/** + * Create new reply structure and attach it to a mesh state. + * Does not update stat items in mesh area. + * @param s: the mesh state. + * @param edns: edns data for reply (bufsize). + * @param rep: comm point reply info. + * @param qid: ID of reply. + * @param qflags: original query flags. + * @param qname: original query name. + * @return: 0 on alloc error. + */ +int mesh_state_add_reply(struct mesh_state* s, struct edns_data* edns, + struct comm_reply* rep, uint16_t qid, uint16_t qflags, uint8_t* qname); + +/** + * Create new callback structure and attach it to a mesh state. + * Does not update stat items in mesh area. + * @param s: the mesh state. + * @param edns: edns data for reply (bufsize). + * @param buf: buffer for reply + * @param cb: callback to call with results. + * @param cb_arg: callback user arg. + * @param qid: ID of reply. + * @param qflags: original query flags. + * @return: 0 on alloc error. + */ +int mesh_state_add_cb(struct mesh_state* s, struct edns_data* edns, + struct sldns_buffer* buf, mesh_cb_func_t cb, void* cb_arg, uint16_t qid, + uint16_t qflags); + +/** + * Run the mesh. Run all runnable mesh states. Which can create new + * runnable mesh states. Until completion. Automatically called by + * mesh_report_reply and mesh_new_client as needed. + * @param mesh: mesh area. + * @param mstate: first mesh state to run. + * @param ev: event the mstate. Others get event_pass. + * @param e: if a reply, its outbound entry. + */ +void mesh_run(struct mesh_area* mesh, struct mesh_state* mstate, + enum module_ev ev, struct outbound_entry* e); + +/** + * Print some stats about the mesh to the log. + * @param mesh: the mesh to print it for. + * @param str: descriptive string to go with it. + */ +void mesh_stats(struct mesh_area* mesh, const char* str); + +/** + * Clear the stats that the mesh keeps (number of queries serviced) + * @param mesh: the mesh + */ +void mesh_stats_clear(struct mesh_area* mesh); + +/** + * 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 */ |