/*
* libunbound/worker.h - worker thread or process that resolves
*
* 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 worker process or thread that performs
* the DNS resolving and validation. The worker is called by a procedure
* and if in the background continues until exit, if in the foreground
* returns from the procedure when done.
*/
#ifndef LIBUNBOUND_LIBWORKER_H
#define LIBUNBOUND_LIBWORKER_H
#include "util/data/packed_rrset.h"
struct ub_ctx;
struct ub_result;
struct module_env;
struct comm_base;
struct outside_network;
struct ub_randstate;
struct ctx_query;
struct outbound_entry;
struct module_qstate;
struct comm_point;
struct comm_reply;
struct regional;
struct tube;
struct sldns_buffer;
struct event_base;
/**
* The library-worker status structure
* Internal to the worker.
*/
struct libworker {
/** every worker has a unique thread_num. (first in struct) */
int thread_num;
/** context we are operating under */
struct ub_ctx* ctx;
/** is this the bg worker? */
int is_bg;
/** is this a bg worker that is threaded (not forked)? */
int is_bg_thread;
/** copy of the module environment with worker local entries. */
struct module_env* env;
/** the event base this worker works with */
struct comm_base* base;
/** the backside outside network interface to the auth servers */
struct outside_network* back;
/** random() table for this worker. */
struct ub_randstate* rndstate;
/** sslcontext for SSL wrapped DNS over TCP queries */
void* sslctx;
};
/**
* Create a background worker
* @param ctx: is updated with pid/tid of the background worker.
* a new allocation cache is obtained from ctx. It contains the
* threadnumber and unique id for further (shared) cache insertions.
* @return 0 if OK, else error.
* Further communication is done via the pipes in ctx.
*/
int libworker_bg(struct ub_ctx* ctx);
/**
* Create a foreground worker.
* This worker will join the threadpool of resolver threads.
* It exits when the query answer has been obtained (or error).
* This routine blocks until the worker is finished.
* @param ctx: new allocation cache obtained and returned to it.
* @param q: query (result is stored in here).
* @return 0 if finished OK, else error.
*/
int libworker_fg(struct ub_ctx* ctx, struct ctx_query* q);
/**
* create worker for event-based interface.
* @param ctx: context with config.
* @param eb: event base.
* @return new worker or NULL.
*/
struct libworker* libworker_create_event(struct ub_ctx* ctx,
struct event_base* eb);
/**
* Attach context_query to mesh for callback in event-driven setup.
* @param ctx: context
* @param q: context query entry
* @param async_id: store query num if query takes long.
* @return 0 if finished OK, else error.
*/
int libworker_attach_mesh(struct ub_ctx* ctx, struct ctx_query* q,
int* async_id);
/**
* delete worker for event-based interface. does not free the event_base.
* @param w: event-based worker to delete.
*/
void libworker_delete_event(struct libworker* w);
/** cleanup the cache to remove all rrset IDs from it, arg is libworker */
void libworker_alloc_cleanup(void* arg);
/**
* fill result from parsed message, on error fills servfail
* @param res: is clear at start, filled in at end.
* @param buf: contains DNS message.
* @param temp: temporary buffer for parse.
* @param msg_security: security status of the DNS message.
* On error, the res may contain a different status
* (out of memory is not secure, not bogus).
*/
void libworker_enter_result(struct ub_result* res, struct sldns_buffer* buf,
struct regional* temp, enum sec_status msg_security);
#endif /* LIBUNBOUND_LIBWORKER_H */
