unbound/libunbound/libworker.h

   1 /*
   2  * libunbound/worker.h - worker thread or process that resolves
   3  *
   4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
   5  *
   6  * This software is open source.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  *
  12  * Redistributions of source code must retain the above copyright notice,
  13  * this list of conditions and the following disclaimer.
  14  *
  15  * Redistributions in binary form must reproduce the above copyright notice,
  16  * this list of conditions and the following disclaimer in the documentation
  17  * and/or other materials provided with the distribution.
  18  *
  19  * Neither the name of the NLNET LABS nor the names of its contributors may
  20  * be used to endorse or promote products derived from this software without
  21  * specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
  29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 /**
  37  * \file
  38  *
  39  * This file contains the worker process or thread that performs
  40  * the DNS resolving and validation. The worker is called by a procedure
  41  * and if in the background continues until exit, if in the foreground
  42  * returns from the procedure when done.
  43  */
  44 #ifndef LIBUNBOUND_LIBWORKER_H
  45 #define LIBUNBOUND_LIBWORKER_H
  46 #include "util/data/packed_rrset.h"
  47 struct ub_ctx;
  48 struct ub_result;
  49 struct module_env;
  50 struct comm_base;
  51 struct outside_network;
  52 struct ub_randstate;
  53 struct ctx_query;
  54 struct outbound_entry;
  55 struct module_qstate;
  56 struct comm_point;
  57 struct comm_reply;
  58 struct regional;
  59 struct tube;
  60 struct sldns_buffer;
  61 struct event_base;
  62
  63 /**
  64  * The library-worker status structure
  65  * Internal to the worker.
  66  */
  67 struct libworker {
  68         /** every worker has a unique thread_num. (first in struct) */
  69         int thread_num;
  70         /** context we are operating under */
  71         struct ub_ctx* ctx;
  72
  73         /** is this the bg worker? */
  74         int is_bg;
  75         /** is this a bg worker that is threaded (not forked)? */
  76         int is_bg_thread;
  77
  78         /** copy of the module environment with worker local entries. */
  79         struct module_env* env;
  80         /** the event base this worker works with */
  81         struct comm_base* base;
  82         /** the backside outside network interface to the auth servers */
  83         struct outside_network* back;
  84         /** random() table for this worker. */
  85         struct ub_randstate* rndstate;
  86         /** sslcontext for SSL wrapped DNS over TCP queries */
  87         void* sslctx;
  88 };
  89
  90 /**
  91  * Create a background worker
  92  * @param ctx: is updated with pid/tid of the background worker.
  93  *      a new allocation cache is obtained from ctx. It contains the
  94  *      threadnumber and unique id for further (shared) cache insertions.
  95  * @return 0 if OK, else error.
  96  *      Further communication is done via the pipes in ctx.
  97  */
  98 int libworker_bg(struct ub_ctx* ctx);
  99
 100 /**
 101  * Create a foreground worker.
 102  * This worker will join the threadpool of resolver threads.
 103  * It exits when the query answer has been obtained (or error).
 104  * This routine blocks until the worker is finished.
 105  * @param ctx: new allocation cache obtained and returned to it.
 106  * @param q: query (result is stored in here).
 107  * @return 0 if finished OK, else error.
 108  */
 109 int libworker_fg(struct ub_ctx* ctx, struct ctx_query* q);
 110
 111 /**
 112  * create worker for event-based interface.
 113  * @param ctx: context with config.
 114  * @param eb: event base.
 115  * @return new worker or NULL.
 116  */
 117 struct libworker* libworker_create_event(struct ub_ctx* ctx,
 118         struct event_base* eb);
 119
 120 /**
 121  * Attach context_query to mesh for callback in event-driven setup.
 122  * @param ctx: context
 123  * @param q: context query entry
 124  * @param async_id: store query num if query takes long.
 125  * @return 0 if finished OK, else error.
 126  */
 127 int libworker_attach_mesh(struct ub_ctx* ctx, struct ctx_query* q,
 128         int* async_id);
 129
 130 /**
 131  * delete worker for event-based interface.  does not free the event_base.
 132  * @param w: event-based worker to delete.
 133  */
 134 void libworker_delete_event(struct libworker* w);
 135
 136 /** cleanup the cache to remove all rrset IDs from it, arg is libworker */
 137 void libworker_alloc_cleanup(void* arg);
 138
 139 /**
 140  * fill result from parsed message, on error fills servfail
 141  * @param res: is clear at start, filled in at end.
 142  * @param buf: contains DNS message.
 143  * @param temp: temporary buffer for parse.
 144  * @param msg_security: security status of the DNS message.
 145  *   On error, the res may contain a different status
 146  *   (out of memory is not secure, not bogus).
 147  */
 148 void libworker_enter_result(struct ub_result* res, struct sldns_buffer* buf,
 149         struct regional* temp, enum sec_status msg_security);
 150
 151 #endif /* LIBUNBOUND_LIBWORKER_H */