diff options
Diffstat (limited to 'contrib/unbound/util/module.h')
| -rw-r--r-- | contrib/unbound/util/module.h | 998 |
1 files changed, 998 insertions, 0 deletions
diff --git a/contrib/unbound/util/module.h b/contrib/unbound/util/module.h new file mode 100644 index 000000000000..edce4a523759 --- /dev/null +++ b/contrib/unbound/util/module.h @@ -0,0 +1,998 @@ +/* + * util/module.h - DNS handling module interface + * + * 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 the interface for DNS handling modules. + * + * The module interface uses the DNS modules as state machines. The + * state machines are activated in sequence to operate on queries. Once + * they are done, the reply is passed back. In the usual setup the mesh + * is the caller of the state machines and once things are done sends replies + * and invokes result callbacks. + * + * The module provides a number of functions, listed in the module_func_block. + * The module is inited and destroyed and memory usage queries, for the + * module as a whole, for entire-module state (such as a cache). And per-query + * functions are called, operate to move the state machine and cleanup of + * the per-query state. + * + * Most per-query state should simply be allocated in the query region. + * This is destroyed at the end of the query. + * + * The module environment contains services and information and caches + * shared by the modules and the rest of the system. It also contains + * function pointers for module-specific tasks (like sending queries). + * + * *** Example module calls for a normal query + * + * In this example, the query does not need recursion, all the other data + * can be found in the cache. This makes the example shorter. + * + * At the start of the program the iterator module is initialised. + * The iterator module sets up its global state, such as donotquery lists + * and private address trees. + * + * A query comes in, and a mesh entry is created for it. The mesh + * starts the resolution process. The validator module is the first + * in the list of modules, and it is started on this new query. The + * operate() function is called. The validator decides it needs not do + * anything yet until there is a result and returns wait_module, that + * causes the next module in the list to be started. + * + * The next module is the iterator. It is started on the passed query and + * decides to perform a lookup. For this simple example, the delegation + * point information is available, and all the iterator wants to do is + * send a UDP query. The iterator uses env.send_query() to send the + * query. Then the iterator suspends (returns from the operate call). + * + * When the UDP reply comes back (and on errors and timeouts), the + * operate function is called for the query, on the iterator module, + * with the event that there is a reply. The iterator decides that this + * is enough, the work is done. It returns the value finished from the + * operate call, which causes the previous module to be started. + * + * The previous module, the validator module, is started with the event + * that the iterator module is done. The validator decides to validate + * the query. Once it is done (which could take recursive lookups, but + * in this example no recursive lookups are needed), it returns from the + * operate function with finished. + * + * There is no previous module from the validator module, and the mesh + * takes this to mean that the query is finally done. The mesh invokes + * callbacks and sends packets to queriers. + * + * If other modules had been waiting (recursively) on the answer to this + * query, then the mesh will tell them about it. It calls the inform_super + * routine on all the waiting modules, and once that is done it calls all of + * them with the operate() call. During inform_super the query that is done + * still exists and information can be copied from it (but the module should + * not really re-entry codepoints and services). During the operate call + * the modules can use stored state to continue operation with the results. + * (network buffers are used to contain the answer packet during the + * inform_super phase, but after that the network buffers will be cleared + * of their contents so that other tasks can be performed). + * + * *** Example module calls for recursion + * + * A module is called in operate, and it decides that it wants to perform + * recursion. That is, it wants the full state-machine-list to operate on + * a different query. It calls env.attach_sub() to create a new query state. + * The routine returns the newly created state, and potentially the module + * can edit the module-states for the newly created query (i.e. pass along + * some information, like delegation points). The module then suspends, + * returns from the operate routine. + * + * The mesh meanwhile will have the newly created query (or queries) on + * a waiting list, and will call operate() on this query (or queries). + * It starts again at the start of the module list for them. The query + * (or queries) continue to operate their state machines, until they are + * done. When they are done the mesh calls inform_super on the module that + * wanted the recursion. After that the mesh calls operate() on the module + * that wanted to do the recursion, and during this phase the module could, + * for example, decide to create more recursions. + * + * If the module decides it no longer wants the recursive information + * it can call detach_subs. Those queries will still run to completion, + * potentially filling the cache with information. Inform_super is not + * called any more. + * + * The iterator module will fetch items from the cache, so a recursion + * attempt may complete very quickly if the item is in cache. The calling + * module has to wait for completion or eventual timeout. A recursive query + * that times out returns a servfail rcode (servfail is also returned for + * other errors during the lookup). + * + * Results are passed in the qstate, the rcode member is used to pass + * errors without requiring memory allocation, so that the code can continue + * in out-of-memory conditions. If the rcode member is 0 (NOERROR) then + * the dns_msg entry contains a filled out message. This message may + * also contain an rcode that is nonzero, but in this case additional + * information (query, additional) can be passed along. + * + * The rcode and dns_msg are used to pass the result from the rightmost + * module towards the leftmost modules and then towards the user. + * + * If you want to avoid recursion-cycles where queries need other queries + * that need the first one, use detect_cycle() to see if that will happen. + * + */ + +#ifndef UTIL_MODULE_H +#define UTIL_MODULE_H +#include "util/storage/lruhash.h" +#include "util/data/msgreply.h" +#include "util/data/msgparse.h" +struct sldns_buffer; +struct alloc_cache; +struct rrset_cache; +struct key_cache; +struct config_file; +struct slabhash; +struct query_info; +struct edns_data; +struct regional; +struct worker; +struct comm_base; +struct auth_zones; +struct outside_network; +struct module_qstate; +struct ub_randstate; +struct mesh_area; +struct mesh_state; +struct val_anchors; +struct val_neg_cache; +struct iter_forwards; +struct iter_hints; +struct views; +struct respip_set; +struct respip_client_info; +struct respip_addr_info; +struct module_stack; + +/** Maximum number of modules in operation */ +#define MAX_MODULE 16 + +/** Maximum number of known edns options */ +#define MAX_KNOWN_EDNS_OPTS 256 + +struct errinf_strlist { + /** next item in list */ + struct errinf_strlist* next; + /** config option string */ + char* str; + /** EDE code companion to the error str */ + int reason_bogus; +}; + +enum inplace_cb_list_type { + /* Inplace callbacks for when a resolved reply is ready to be sent to the + * front.*/ + inplace_cb_reply = 0, + /* Inplace callbacks for when a reply is given from the cache. */ + inplace_cb_reply_cache, + /* Inplace callbacks for when a reply is given with local data + * (or Chaos reply). */ + inplace_cb_reply_local, + /* Inplace callbacks for when the reply is servfail. */ + inplace_cb_reply_servfail, + /* Inplace callbacks for when a query is ready to be sent to the back.*/ + inplace_cb_query, + /* Inplace callback for when a reply is received from the back. */ + inplace_cb_query_response, + /* Inplace callback for when EDNS is parsed on a reply received from the + * back. */ + inplace_cb_edns_back_parsed, + /* Total number of types. Used for array initialization. + * Should always be last. */ + inplace_cb_types_total +}; + + +/** Known edns option. Can be populated during modules' init. */ +struct edns_known_option { + /** type of this edns option */ + uint16_t opt_code; + /** whether the option needs to bypass the cache stage */ + int bypass_cache_stage; + /** whether the option needs mesh aggregation */ + int no_aggregation; +}; + +/** + * Inplace callback list of registered routines to be called. + */ +struct inplace_cb { + /** next in list */ + struct inplace_cb* next; + /** Inplace callback routine */ + void* cb; + void* cb_arg; + /** module id */ + int id; +}; + +/** + * Inplace callback function called before replying. + * Called as func(qinfo, qstate, rep, rcode, edns, opt_list_out, repinfo, + * region, id, python_callback) + * Where: + * qinfo: the query info. + * qstate: the module state. NULL when calling before the query reaches the + * mesh states. + * rep: reply_info. Could be NULL. + * rcode: the return code. + * edns: the edns_data of the reply. When qstate is NULL, it is also used as + * the edns input. + * opt_list_out: the edns options list for the reply. + * repinfo: reply information for a communication point. NULL when calling + * during the mesh states; the same could be found from + * qstate->mesh_info->reply_list. + * region: region to store data. + * id: module id. + * python_callback: only used for registering a python callback function. + */ +typedef int inplace_cb_reply_func_type(struct query_info* qinfo, + struct module_qstate* qstate, struct reply_info* rep, int rcode, + struct edns_data* edns, struct edns_option** opt_list_out, + struct comm_reply* repinfo, struct regional* region, + struct timeval* start_time, int id, void* callback); + +/** + * Inplace callback function called before sending the query to a nameserver. + * Called as func(qinfo, flags, qstate, addr, addrlen, zone, zonelen, region, + * id, python_callback) + * Where: + * qinfo: query info. + * flags: flags of the query. + * qstate: query state. + * addr: to which server to send the query. + * addrlen: length of addr. + * zone: name of the zone of the delegation point. wireformat dname. + * This is the delegation point name for which the server is deemed + * authoritative. + * zonelen: length of zone. + * region: region to store data. + * id: module id. + * python_callback: only used for registering a python callback function. + */ +typedef int inplace_cb_query_func_type(struct query_info* qinfo, uint16_t flags, + struct module_qstate* qstate, struct sockaddr_storage* addr, + socklen_t addrlen, uint8_t* zone, size_t zonelen, struct regional* region, + int id, void* callback); + +/** + * Inplace callback function called after parsing edns on query reply. + * Called as func(qstate, id, cb_args) + * Where: + * qstate: the query state. + * id: module id. + * cb_args: argument passed when registering callback. + */ +typedef int inplace_cb_edns_back_parsed_func_type(struct module_qstate* qstate, + int id, void* cb_args); + +/** + * Inplace callback function called after parsing query response. + * Called as func(qstate, response, id, cb_args) + * Where: + * qstate: the query state. + * response: query response. + * id: module id. + * cb_args: argument passed when registering callback. + */ +typedef int inplace_cb_query_response_func_type(struct module_qstate* qstate, + struct dns_msg* response, int id, void* cb_args); + +/** + * Function called when looking for (expired) cached answers during the serve + * expired logic. + * Called as func(qstate, lookup_qinfo, &is_expired) + * Where: + * qstate: the query state. + * lookup_qinfo: the qinfo to lookup for. + * is_expired: set if the cached answer is expired. + */ +typedef struct dns_msg* serve_expired_lookup_func_type( + struct module_qstate* qstate, struct query_info* lookup_qinfo, + int* is_expired); + +/** + * Module environment. + * Services and data provided to the module. + */ +struct module_env { + /* --- data --- */ + /** config file with config options */ + struct config_file* cfg; + /** shared message cache */ + struct slabhash* msg_cache; + /** shared rrset cache */ + struct rrset_cache* rrset_cache; + /** shared infrastructure cache (edns, lameness) */ + struct infra_cache* infra_cache; + /** shared key cache */ + struct key_cache* key_cache; + + /* --- services --- */ + /** + * Send serviced DNS query to server. UDP/TCP and EDNS is handled. + * operate() should return with wait_reply. Later on a callback + * will cause operate() to be called with event timeout or reply. + * The time until a timeout is calculated from roundtrip timing, + * several UDP retries are attempted. + * @param qinfo: query info. + * @param flags: host order flags word, with opcode and CD bit. + * @param dnssec: if set, EDNS record will have bits set. + * If EDNS_DO bit is set, DO bit is set in EDNS records. + * If BIT_CD is set, CD bit is set in queries with EDNS records. + * @param want_dnssec: if set, the validator wants DNSSEC. Without + * EDNS, the answer is likely to be useless for this domain. + * @param nocaps: do not use caps_for_id, use the qname as given. + * (ignored if caps_for_id is disabled). + * @param check_ratelimit: if set, will check ratelimit before sending out. + * @param addr: where to. + * @param addrlen: length of addr. + * @param zone: delegation point name. + * @param zonelen: length of zone name. + * @param tcp_upstream: use TCP for upstream queries. + * @param ssl_upstream: use SSL for upstream queries. + * @param tls_auth_name: if ssl_upstream, use this name with TLS + * authentication. + * @param q: which query state to reactivate upon return. + * @param was_ratelimited: it will signal back if the query failed to pass the + * ratelimit check. + * @return: false on failure (memory or socket related). no query was + * sent. Or returns an outbound entry with qsent and qstate set. + * This outbound_entry will be used on later module invocations + * that involve this query (timeout, error or reply). + */ + struct outbound_entry* (*send_query)(struct query_info* qinfo, + uint16_t flags, int dnssec, int want_dnssec, int nocaps, + int check_ratelimit, + struct sockaddr_storage* addr, socklen_t addrlen, + uint8_t* zone, size_t zonelen, int tcp_upstream, int ssl_upstream, + char* tls_auth_name, struct module_qstate* q, int* was_ratelimited); + + /** + * 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 (*detach_subs)(struct module_qstate* qstate); + + /** + * Attach subquery. + * Creates it if it does not exist already. + * Keeps sub and super references correct. + * 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: validation lookup recursion, does not need validation + * @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 (*attach_sub)(struct module_qstate* qstate, + struct query_info* qinfo, uint16_t qflags, int prime, + int valrec, struct module_qstate** newq); + + /** + * Add detached query. + * Creates it if it does not exist already. + * Does not make super/sub references. + * Performs a cycle detection - for double check - and fails if there is + * one. + * 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. + * o added subquery, created if it did not exist already. + * + * @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. + * @param sub: The added mesh state, created if it did not exist already. + * @return: false on error, true if success (and init may be needed). + */ + int (*add_sub)(struct module_qstate* qstate, + struct query_info* qinfo, uint16_t qflags, int prime, + int valrec, struct module_qstate** newq, + struct mesh_state** sub); + + /** + * Kill newly attached sub. If attach_sub returns newq for + * initialisation, but that fails, then this routine will cleanup and + * delete the freshly created sub. + * @param newq: the new subquery that is no longer needed. + * It is removed. + */ + void (*kill_sub)(struct module_qstate* newq); + + /** + * Detect if adding a dependency for qstate on name,type,class will + * create a dependency cycle. + * @param qstate: given mesh querystate. + * @param qinfo: query info for dependency. + * @param flags: query flags of dependency, RD/CD flags. + * @param prime: if dependency is a priming query or not. + * @param valrec: validation lookup recursion, does not need validation + * @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. + */ + int (*detect_cycle)(struct module_qstate* qstate, + struct query_info* qinfo, uint16_t flags, int prime, + int valrec); + + /** region for temporary usage. May be cleared after operate() call. */ + struct regional* scratch; + /** buffer for temporary usage. May be cleared after operate() call. */ + struct sldns_buffer* scratch_buffer; + /** internal data for daemon - worker thread. */ + struct worker* worker; + /** the worker event base */ + struct comm_base* worker_base; + /** the outside network */ + struct outside_network* outnet; + /** mesh area with query state dependencies */ + struct mesh_area* mesh; + /** allocation service */ + struct alloc_cache* alloc; + /** random table to generate random numbers */ + struct ub_randstate* rnd; + /** time in seconds, converted to integer */ + time_t* now; + /** time in microseconds. Relatively recent. */ + struct timeval* now_tv; + /** is validation required for messages, controls client-facing + * validation status (AD bits) and servfails */ + int need_to_validate; + /** trusted key storage; these are the configured keys, if not NULL, + * otherwise configured by validator. These are the trust anchors, + * and are not primed and ready for validation, but on the bright + * side, they are read only memory, thus no locks and fast. */ + struct val_anchors* anchors; + /** negative cache, configured by the validator. if not NULL, + * contains NSEC record lookup trees. */ + struct val_neg_cache* neg_cache; + /** the 5011-probe timer (if any) */ + struct comm_timer* probe_timer; + /** auth zones */ + struct auth_zones* auth_zones; + /** Mapping of forwarding zones to targets. + * iterator forwarder information. */ + struct iter_forwards* fwds; + /** + * iterator stub information. + * The hints -- these aren't stored in the cache because they don't + * expire. The hints are always used to "prime" the cache. Note + * that both root hints and stub zone "hints" are stored in this + * data structure. + */ + struct iter_hints* hints; + /** views structure containing view tree */ + struct views* views; + /** response-ip set with associated actions and tags. */ + struct respip_set* respip_set; + /** module specific data. indexed by module id. */ + void* modinfo[MAX_MODULE]; + + /* Shared linked list of inplace callback functions */ + struct inplace_cb* inplace_cb_lists[inplace_cb_types_total]; + + /** + * Shared array of known edns options (size MAX_KNOWN_EDNS_OPTS). + * Filled by edns literate modules during init. + */ + struct edns_known_option* edns_known_options; + /* Number of known edns options */ + size_t edns_known_options_num; + /** EDNS client string information */ + struct edns_strings* edns_strings; + + /** module stack */ + struct module_stack* modstack; +#ifdef USE_CACHEDB + /** the cachedb enabled value, copied and stored here. */ + int cachedb_enabled; +#endif + /* Make every mesh state unique, do not aggregate mesh states. */ + int unique_mesh; +}; + +/** + * External visible states of the module state machine + * Modules may also have an internal state. + * Modules are supposed to run to completion or until blocked. + */ +enum module_ext_state { + /** initial state - new query */ + module_state_initial = 0, + /** waiting for reply to outgoing network query */ + module_wait_reply, + /** module is waiting for another module */ + module_wait_module, + /** module is waiting for another module; that other is restarted */ + module_restart_next, + /** module is waiting for sub-query */ + module_wait_subquery, + /** module could not finish the query */ + module_error, + /** module is finished with query */ + module_finished +}; + +/** + * Events that happen to modules, that start or wakeup modules. + */ +enum module_ev { + /** new query */ + module_event_new = 0, + /** query passed by other module */ + module_event_pass, + /** reply inbound from server */ + module_event_reply, + /** no reply, timeout or other error */ + module_event_noreply, + /** reply is there, but capitalisation check failed */ + module_event_capsfail, + /** next module is done, and its reply is awaiting you */ + module_event_moddone, + /** error */ + module_event_error +}; + +/** + * Linked list of sockaddrs + * May be allocated such that only 'len' bytes of addr exist for the structure. + */ +struct sock_list { + /** next in list */ + struct sock_list* next; + /** length of addr */ + socklen_t len; + /** sockaddr */ + struct sockaddr_storage addr; +}; + +struct respip_action_info; + +/** + * Struct to hold relevant data for serve expired + */ +struct serve_expired_data { + struct comm_timer* timer; + serve_expired_lookup_func_type* get_cached_answer; +}; + +/** + * Module state, per query. + */ +struct module_qstate { + /** which query is being answered: name, type, class */ + struct query_info qinfo; + /** flags uint16 from query */ + uint16_t query_flags; + /** if this is a (stub or root) priming query (with hints) */ + int is_priming; + /** if this is a validation recursion query that does not get + * validation itself */ + int is_valrec; +#ifdef CLIENT_SUBNET + /** the client network address is needed for the client-subnet option + * when prefetching, but we can't use reply_list in mesh_info, because + * we don't want to send a reply for the internal query. */ + struct sockaddr_storage client_addr; +#endif + + /** comm_reply contains server replies */ + struct comm_reply* reply; + /** the reply message, with message for client and calling module */ + struct dns_msg* return_msg; + /** the rcode, in case of error, instead of a reply message */ + int return_rcode; + /** origin of the reply (can be NULL from cache, list for cnames) */ + struct sock_list* reply_origin; + /** IP blacklist for queries */ + struct sock_list* blacklist; + /** region for this query. Cleared when query process finishes. */ + struct regional* region; + /** failure reason information if val-log-level is high */ + struct errinf_strlist* errinf; + /** which module is executing */ + int curmod; + /** module states */ + enum module_ext_state ext_state[MAX_MODULE]; + /** module specific data for query. indexed by module id. */ + void* minfo[MAX_MODULE]; + /** environment for this query */ + struct module_env* env; + /** mesh related information for this query */ + struct mesh_state* mesh_info; + /** how many seconds before expiry is this prefetched (0 if not) */ + time_t prefetch_leeway; + /** serve expired data */ + struct serve_expired_data* serve_expired_data; + + /** incoming edns options from the front end */ + struct edns_option* edns_opts_front_in; + /** outgoing edns options to the back end */ + struct edns_option* edns_opts_back_out; + /** incoming edns options from the back end */ + struct edns_option* edns_opts_back_in; + /** outgoing edns options to the front end */ + struct edns_option* edns_opts_front_out; + /** whether modules should answer from the cache */ + int no_cache_lookup; + /** whether modules should store answer in the cache */ + int no_cache_store; + /** whether to refetch a fresh answer on finishing this state*/ + int need_refetch; + /** whether the query (or a subquery) was ratelimited */ + int was_ratelimited; + /** time when query was started. This is when the qstate is created. + * This is used so that type NS data cannot be overwritten by them + * expiring while the lookup is in progress, using data fetched from + * those servers. By comparing expiry time with qstarttime for type NS. + */ + time_t qstarttime; + /** whether a message from cachedb will be used for the reply */ + int is_cachedb_answer; + + /** + * Attributes of clients that share the qstate that may affect IP-based + * actions. + */ + struct respip_client_info* client_info; + + /** Extended result of response-ip action processing, mainly + * for logging purposes. */ + struct respip_action_info* respip_action_info; + /** if the query has been modified by rpz processing. */ + int rpz_applied; + /** if the query is rpz passthru, no further rpz processing for it */ + int rpz_passthru; + /* Flag tcp required. */ + int tcp_required; + + /** whether the reply should be dropped */ + int is_drop; +}; + +/** + * Module functionality block + */ +struct module_func_block { + /** text string name of module */ + const char* name; + + /** + * Set up the module for start. This is called only once at startup. + * Privileged operations like opening device files may be done here. + * The function ptr can be NULL, if it is not used. + * @param env: module environment. + * @param id: module id number. + * return: 0 on error + */ + int (*startup)(struct module_env* env, int id); + + /** + * Close down the module for stop. This is called only once before + * shutdown to free resources allocated during startup(). + * Closing privileged ports or files must be done here. + * The function ptr can be NULL, if it is not used. + * @param env: module environment. + * @param id: module id number. + */ + void (*destartup)(struct module_env* env, int id); + + /** + * Initialise the module. Called when restarting or reloading the + * daemon. + * This is the place to apply settings from the config file. + * @param env: module environment. + * @param id: module id number. + * return: 0 on error + */ + int (*init)(struct module_env* env, int id); + + /** + * Deinitialise the module, undo stuff done during init(). + * Called before reloading the daemon. + * @param env: module environment. + * @param id: module id number. + */ + void (*deinit)(struct module_env* env, int id); + + /** + * accept a new query, or work further on existing query. + * Changes the qstate->ext_state to be correct on exit. + * @param ev: event that causes the module state machine to + * (re-)activate. + * @param qstate: the query state. + * Note that this method is not allowed to change the + * query state 'identity', that is query info, qflags, + * and priming status. + * Attach a subquery to get results to a different query. + * @param id: module id number that operate() is called on. + * @param outbound: if not NULL this event is due to the reply/timeout + * or error on this outbound query. + * @return: if at exit the ext_state is: + * o wait_module: next module is started. (with pass event). + * o error or finished: previous module is resumed. + * o otherwise it waits until that event happens (assumes + * the service routine to make subrequest or send message + * have been called. + */ + void (*operate)(struct module_qstate* qstate, enum module_ev event, + int id, struct outbound_entry* outbound); + + /** + * inform super querystate about the results from this subquerystate. + * Is called when the querystate is finished. The method invoked is + * the one from the current module active in the super querystate. + * @param qstate: the query state that is finished. + * Examine return_rcode and return_reply in the qstate. + * @param id: module id for this module. + * This coincides with the current module for the super qstate. + * @param super: the super querystate that needs to be informed. + */ + void (*inform_super)(struct module_qstate* qstate, int id, + struct module_qstate* super); + + /** + * clear module specific data + */ + void (*clear)(struct module_qstate* qstate, int id); + + /** + * How much memory is the module specific data using. + * @param env: module environment. + * @param id: the module id. + * @return the number of bytes that are alloced. + */ + size_t (*get_mem)(struct module_env* env, int id); +}; + +/** + * Debug utility: module external qstate to string + * @param s: the state value. + * @return descriptive string. + */ +const char* strextstate(enum module_ext_state s); + +/** + * Debug utility: module event to string + * @param e: the module event value. + * @return descriptive string. + */ +const char* strmodulevent(enum module_ev e); + +/** + * Append text to the error info for validation. + * @param qstate: query state. + * @param str: copied into query region and appended. + * Failures to allocate are logged. + */ +void errinf(struct module_qstate* qstate, const char* str); +void errinf_ede(struct module_qstate* qstate, const char* str, + sldns_ede_code reason_bogus); + +/** + * Append text to error info: from 1.2.3.4 + * @param qstate: query state. + * @param origin: sock list with origin of trouble. + * Every element added. + * If NULL: nothing is added. + * if 0len element: 'from cache' is added. + */ +void errinf_origin(struct module_qstate* qstate, struct sock_list *origin); + +/** + * Append text to error info: for RRset name type class + * @param qstate: query state. + * @param rr: rrset_key. + */ +void errinf_rrset(struct module_qstate* qstate, struct ub_packed_rrset_key *rr); + +/** + * Append text to error info: str dname + * @param qstate: query state. + * @param str: explanation string + * @param dname: the dname. + */ +void errinf_dname(struct module_qstate* qstate, const char* str, + uint8_t* dname); + +/** + * Create error info in string. For validation failures. + * @param qstate: query state. + * @param region: the region for the result or NULL for malloced result. + * @return string or NULL on malloc failure (already logged). + * This string is malloced if region is NULL and has to be freed by caller. + */ +char* errinf_to_str_bogus(struct module_qstate* qstate, struct regional* region); + +/** + * Check the sldns_ede_code of the qstate->errinf. + * @param qstate: query state. + * @return the latest explicitly set sldns_ede_code or LDNS_EDE_NONE. + */ +sldns_ede_code errinf_to_reason_bogus(struct module_qstate* qstate); + +/** + * Create error info in string. For other servfails. + * @param qstate: query state. + * @return string or NULL on malloc failure (already logged). + */ +char* errinf_to_str_servfail(struct module_qstate* qstate); + +/** + * Create error info in string. For misc failures that are not servfail. + * @param qstate: query state. + * @return string or NULL on malloc failure (already logged). + */ +char* errinf_to_str_misc(struct module_qstate* qstate); + +/** + * Initialize the edns known options by allocating the required space. + * @param env: the module environment. + * @return false on failure (no memory). + */ +int edns_known_options_init(struct module_env* env); + +/** + * Free the allocated space for the known edns options. + * @param env: the module environment. + */ +void edns_known_options_delete(struct module_env* env); + +/** + * Register a known edns option. Overwrite the flags if it is already + * registered. Used before creating workers to register known edns options. + * @param opt_code: the edns option code. + * @param bypass_cache_stage: whether the option interacts with the cache. + * @param no_aggregation: whether the option implies more specific + * aggregation. + * @param env: the module environment. + * @return true on success, false on failure (registering more options than + * allowed or trying to register after the environment is copied to the + * threads.) + */ +int edns_register_option(uint16_t opt_code, int bypass_cache_stage, + int no_aggregation, struct module_env* env); + +/** + * Register an inplace callback function. + * @param cb: pointer to the callback function. + * @param type: inplace callback type. + * @param cbarg: argument for the callback function, or NULL. + * @param env: the module environment. + * @param id: module id. + * @return true on success, false on failure (out of memory or trying to + * register after the environment is copied to the threads.) + */ +int +inplace_cb_register(void* cb, enum inplace_cb_list_type type, void* cbarg, + struct module_env* env, int id); + +/** + * Delete callback for specified type and module id. + * @param env: the module environment. + * @param type: inplace callback type. + * @param id: module id. + */ +void +inplace_cb_delete(struct module_env* env, enum inplace_cb_list_type type, + int id); + +/** + * Delete all the inplace callback linked lists. + * @param env: the module environment. + */ +void inplace_cb_lists_delete(struct module_env* env); + +/** + * Check if an edns option is known. + * @param opt_code: the edns option code. + * @param env: the module environment. + * @return pointer to registered option if the edns option is known, + * NULL otherwise. + */ +struct edns_known_option* edns_option_is_known(uint16_t opt_code, + struct module_env* env); + +/** + * Check if an edns option needs to bypass the reply from cache stage. + * @param list: the edns options. + * @param env: the module environment. + * @return true if an edns option needs to bypass the cache stage, + * false otherwise. + */ +int edns_bypass_cache_stage(struct edns_option* list, + struct module_env* env); + +/** + * Check if an unique mesh state is required. Might be triggered by EDNS option + * or set for the complete env. + * @param list: the edns options. + * @param env: the module environment. + * @return true if an edns option needs a unique mesh state, + * false otherwise. + */ +int unique_mesh_state(struct edns_option* list, struct module_env* env); + +/** + * Log the known edns options. + * @param level: the desired verbosity level. + * @param env: the module environment. + */ +void log_edns_known_options(enum verbosity_value level, + struct module_env* env); + +/** + * Copy state that may have happened in the subquery and is always relevant to + * the super. + * @param qstate: query state that finished. + * @param id: module id. + * @param super: the qstate to inform. + */ +void copy_state_to_super(struct module_qstate* qstate, int id, + struct module_qstate* super); + +#endif /* UTIL_MODULE_H */ |