libworker.h revision 356345 
1/*
2 * libunbound/libworker.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"
47struct ub_ctx;
48struct ub_result;
49struct module_env;
50struct comm_base;
51struct outside_network;
52struct ub_randstate;
53struct ctx_query;
54struct outbound_entry;
55struct module_qstate;
56struct comm_point;
57struct comm_reply;
58struct regional;
59struct tube;
60struct sldns_buffer;
61struct ub_event_base;
62struct query_info;
63
64/**
65 * The library-worker status structure
66 * Internal to the worker.
67 */
68struct libworker {
69	/** every worker has a unique thread_num. (first in struct) */
70	int thread_num;
71	/** context we are operating under */
72	struct ub_ctx* ctx;
73
74	/** is this the bg worker? */
75	int is_bg;
76	/** is this a bg worker that is threaded (not forked)? */
77	int is_bg_thread;
78	/** want to quit, stop handling new content */
79	int want_quit;
80
81	/** copy of the module environment with worker local entries. */
82	struct module_env* env;
83	/** the event base this worker works with */
84	struct comm_base* base;
85	/** the backside outside network interface to the auth servers */
86	struct outside_network* back;
87	/** random() table for this worker. */
88	struct ub_randstate* rndstate;
89	/** sslcontext for SSL wrapped DNS over TCP queries */
90	void* sslctx;
91};
92
93/**
94 * Create a background worker
95 * @param ctx: is updated with pid/tid of the background worker.
96 *	a new allocation cache is obtained from ctx. It contains the
97 *	threadnumber and unique id for further (shared) cache insertions.
98 * @return 0 if OK, else error.
99 *	Further communication is done via the pipes in ctx.
100 */
101int libworker_bg(struct ub_ctx* ctx);
102
103/**
104 * Create a foreground worker.
105 * This worker will join the threadpool of resolver threads.
106 * It exits when the query answer has been obtained (or error).
107 * This routine blocks until the worker is finished.
108 * @param ctx: new allocation cache obtained and returned to it.
109 * @param q: query (result is stored in here).
110 * @return 0 if finished OK, else error.
111 */
112int libworker_fg(struct ub_ctx* ctx, struct ctx_query* q);
113
114/**
115 * create worker for event-based interface.
116 * @param ctx: context with config.
117 * @param eb: event base.
118 * @return new worker or NULL.
119 */
120struct libworker* libworker_create_event(struct ub_ctx* ctx,
121	struct ub_event_base* eb);
122
123/**
124 * Attach context_query to mesh for callback in event-driven setup.
125 * @param ctx: context
126 * @param q: context query entry
127 * @param async_id: store query num if query takes long.
128 * @return 0 if finished OK, else error.
129 */
130int libworker_attach_mesh(struct ub_ctx* ctx, struct ctx_query* q,
131	int* async_id);
132
133/**
134 * delete worker for event-based interface.  does not free the event_base.
135 * @param w: event-based worker to delete.
136 */
137void libworker_delete_event(struct libworker* w);
138
139/** cleanup the cache to remove all rrset IDs from it, arg is libworker */
140void libworker_alloc_cleanup(void* arg);
141
142/**
143 * fill result from parsed message, on error fills servfail
144 * @param res: is clear at start, filled in at end.
145 * @param buf: contains DNS message.
146 * @param temp: temporary buffer for parse.
147 * @param msg_security: security status of the DNS message.
148 *   On error, the res may contain a different status
149 *   (out of memory is not secure, not bogus).
150 */
151void libworker_enter_result(struct ub_result* res, struct sldns_buffer* buf,
152	struct regional* temp, enum sec_status msg_security);
153
154#endif /* LIBUNBOUND_LIBWORKER_H */
155