/* * 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 valrec: if it is a validation recursion query (lookup of key, DS). * @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, int valrec, 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. * @param valrec: if true, it is a validation recursion query, and sets * is_valrec on the 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, int valrec); /** * 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. * @param valrec: if it is a validation-recursion 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, int valrec); /** * 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. * @param valrec: if it is a validation recursion query (lookup of key, DS). * @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, int valrec); /** 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 */