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      1 /*
      2  * daemon/worker.h - worker that handles a pending list of requests.
      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 describes the worker structure that holds a list of
     40  * pending requests and handles them.
     41  */
     42 
     43 #ifndef DAEMON_WORKER_H
     44 #define DAEMON_WORKER_H
     45 
     46 #include "libunbound/worker.h"
     47 #include "util/netevent.h"
     48 #include "util/locks.h"
     49 #include "util/alloc.h"
     50 #include "util/data/msgreply.h"
     51 #include "util/data/msgparse.h"
     52 #include "daemon/stats.h"
     53 #include "util/module.h"
     54 #include "dnstap/dnstap.h"
     55 struct listen_dnsport;
     56 struct outside_network;
     57 struct config_file;
     58 struct daemon;
     59 struct listen_port;
     60 struct ub_randstate;
     61 struct regional;
     62 struct tube;
     63 struct daemon_remote;
     64 struct query_info;
     65 
     66 /** worker commands */
     67 enum worker_commands {
     68 	/** make the worker quit */
     69 	worker_cmd_quit,
     70 	/** obtain statistics */
     71 	worker_cmd_stats,
     72 	/** obtain statistics without statsclear */
     73 	worker_cmd_stats_noreset,
     74 	/** execute remote control command */
     75 	worker_cmd_remote,
     76 	/** for fast-reload, perform stop */
     77 	worker_cmd_reload_stop,
     78 	/** for fast-reload, start again */
     79 	worker_cmd_reload_start,
     80 	/** for fast-reload, poll to make sure worker has released data */
     81 	worker_cmd_reload_poll
     82 };
     83 
     84 /**
     85  * Structure holding working information for unbound.
     86  * Holds globally visible information.
     87  */
     88 struct worker {
     89 	/** the thread number (in daemon array). First in struct for debug. */
     90 	int thread_num;
     91 	/** global shared daemon structure */
     92 	struct daemon* daemon;
     93 	/** thread id */
     94 	ub_thread_type thr_id;
     95 #ifdef HAVE_GETTID
     96 	/** thread tid, the LWP id. */
     97 	pid_t thread_tid;
     98 #endif
     99 	/** pipe, for commands for this worker */
    100 	struct tube* cmd;
    101 	/** the event base this worker works with */
    102 	struct comm_base* base;
    103 	/** the frontside listening interface where request events come in */
    104 	struct listen_dnsport* front;
    105 	/** the backside outside network interface to the auth servers */
    106 	struct outside_network* back;
    107 	/** ports to be used by this worker. */
    108 	int* ports;
    109 	/** number of ports for this worker */
    110 	int numports;
    111 	/** the signal handler */
    112 	struct comm_signal* comsig;
    113 	/** commpoint to listen to commands. */
    114 	struct comm_point* cmd_com;
    115 	/** timer for statistics */
    116 	struct comm_timer* stat_timer;
    117 	/** ratelimit for errors, time value */
    118 	time_t err_limit_time;
    119 	/** ratelimit for errors, packet count */
    120 	unsigned int err_limit_count;
    121 
    122 	/** random() table for this worker. */
    123 	struct ub_randstate* rndstate;
    124 	/** do we need to restart or quit (on signal) */
    125 	int need_to_exit;
    126 	/** allocation cache for this thread */
    127 	struct alloc_cache *alloc;
    128 	/** per thread statistics */
    129 	struct ub_server_stats stats;
    130 	/** thread scratch regional */
    131 	struct regional* scratchpad;
    132 
    133 	/** module environment passed to modules, changed for this thread */
    134 	struct module_env env;
    135 
    136 #ifdef USE_DNSTAP
    137 	/** dnstap environment, changed for this thread */
    138 	struct dt_env dtenv;
    139 #endif
    140 	/** reuse existing cache on reload if other conditions allow it. */
    141 	int reuse_cache;
    142 };
    143 
    144 /**
    145  * Create the worker structure. Bare bones version, zeroed struct,
    146  * with backpointers only. Use worker_init on it later.
    147  * @param daemon: the daemon that this worker thread is part of.
    148  * @param id: the thread number from 0.. numthreads-1.
    149  * @param ports: the ports it is allowed to use, array.
    150  * @param n: the number of ports.
    151  * @return: the new worker or NULL on alloc failure.
    152  */
    153 struct worker* worker_create(struct daemon* daemon, int id, int* ports, int n);
    154 
    155 /**
    156  * Initialize worker.
    157  * Allocates event base, listens to ports
    158  * @param worker: worker to initialize, created with worker_create.
    159  * @param cfg: configuration settings.
    160  * @param ports: list of shared query ports.
    161  * @param do_sigs: if true, worker installs signal handlers.
    162  * @return: false on error.
    163  */
    164 int worker_init(struct worker* worker, struct config_file *cfg,
    165 	struct listen_port* ports, int do_sigs);
    166 
    167 /**
    168  * Make worker work.
    169  */
    170 void worker_work(struct worker* worker);
    171 
    172 /**
    173  * Delete worker.
    174  */
    175 void worker_delete(struct worker* worker);
    176 
    177 /**
    178  * Send a command to a worker. Uses blocking writes.
    179  * @param worker: worker to send command to.
    180  * @param cmd: command to send.
    181  */
    182 void worker_send_cmd(struct worker* worker, enum worker_commands cmd);
    183 
    184 /**
    185  * Init worker stats - includes server_stats_init, outside network and mesh.
    186  * @param worker: the worker to init
    187  */
    188 void worker_stats_clear(struct worker* worker);
    189 
    190 #endif /* DAEMON_WORKER_H */
    191