403 lines
14 KiB
C
403 lines
14 KiB
C
/*
|
|
* 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 REGENTS 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.
|
|
*/
|
|
|
|
#ifndef UTIL_MODULE_H
|
|
#define UTIL_MODULE_H
|
|
#include "util/storage/lruhash.h"
|
|
#include "util/data/msgreply.h"
|
|
#include "util/data/msgparse.h"
|
|
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 module_qstate;
|
|
struct ub_randstate;
|
|
struct mesh_area;
|
|
struct mesh_state;
|
|
struct val_anchors;
|
|
struct val_neg_cache;
|
|
struct iter_forwards;
|
|
struct iter_hints;
|
|
|
|
/** Maximum number of modules in operation */
|
|
#define MAX_MODULE 5
|
|
|
|
/**
|
|
* 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 qname: query name. (host order)
|
|
* @param qnamelen: length in bytes of qname, including trailing 0.
|
|
* @param qtype: query type. (host order)
|
|
* @param qclass: query class. (host order)
|
|
* @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 addr: where to.
|
|
* @param addrlen: length of addr.
|
|
* @param zone: delegation point name.
|
|
* @param zonelen: length of zone name.
|
|
* @param q: wich query state to reactivate upon return.
|
|
* @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)(uint8_t* qname, size_t qnamelen,
|
|
uint16_t qtype, uint16_t qclass, uint16_t flags, int dnssec,
|
|
int want_dnssec, struct sockaddr_storage* addr,
|
|
socklen_t addrlen, uint8_t* zone, size_t zonelen,
|
|
struct module_qstate* q);
|
|
|
|
/**
|
|
* 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 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,
|
|
struct module_qstate** newq);
|
|
|
|
/**
|
|
* Kill newly attached sub. If attach_sub returns newq for
|
|
* initialisation, but that fails, then this routine will cleanup and
|
|
* delete the fresly 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.
|
|
* @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);
|
|
|
|
/** region for temporary usage. May be cleared after operate() call. */
|
|
struct regional* scratch;
|
|
/** buffer for temporary usage. May be cleared after operate() call. */
|
|
ldns_buffer* scratch_buffer;
|
|
/** internal data for daemon - worker thread. */
|
|
struct worker* worker;
|
|
/** 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 */
|
|
uint32_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;
|
|
/** Mapping of forwarding zones to targets.
|
|
* iterator forwarder information. per-thread, created by worker */
|
|
struct iter_forwards* fwds;
|
|
/**
|
|
* iterator forwarder information. per-thread, created by worker.
|
|
* 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;
|
|
/** module specific data. indexed by module id. */
|
|
void* modinfo[MAX_MODULE];
|
|
};
|
|
|
|
/**
|
|
* 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;
|
|
};
|
|
|
|
/**
|
|
* 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;
|
|
|
|
/** 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 config_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) */
|
|
uint32_t prefetch_leeway;
|
|
};
|
|
|
|
/**
|
|
* Module functionality block
|
|
*/
|
|
struct module_func_block {
|
|
/** text string name of module */
|
|
const char* name;
|
|
|
|
/**
|
|
* init the module. Called once for the global state.
|
|
* 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);
|
|
|
|
/**
|
|
* de-init, delete, the module. Called once for the global state.
|
|
* @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);
|
|
|
|
#endif /* UTIL_MODULE_H */
|