1/*
2 * edns-subnet/subnetmod.h - edns subnet module. Must be called before validator
3 * and iterator.
4 *
5 * Copyright (c) 2013, NLnet Labs. All rights reserved.
6 *
7 * This software is open source.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * Redistributions of source code must retain the above copyright notice,
14 * this list of conditions and the following disclaimer.
15 *
16 * Redistributions in binary form must reproduce the above copyright notice,
17 * this list of conditions and the following disclaimer in the documentation
18 * and/or other materials provided with the distribution.
19 *
20 * Neither the name of the NLNET LABS nor the names of its contributors may
21 * be used to endorse or promote products derived from this software without
22 * specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
25 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
26 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
27 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
28 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
29 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
30 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
31 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35 */
36/**
37 * \file
38 * subnet module for unbound.
39 */
40
41#ifndef SUBNETMOD_H
42#define SUBNETMOD_H
43#include "util/module.h"
44#include "services/outbound_list.h"
45#include "util/alloc.h"
46#include "util/net_help.h"
47#include "util/storage/slabhash.h"
48#include "util/data/dname.h"
49#include "edns-subnet/addrtree.h"
50#include "edns-subnet/edns-subnet.h"
51
52/**
53 * Global state for the subnet module.
54 */
55struct subnet_env {
56	/** shared message cache
57	 * key: struct query_info*
58	 * data: struct subnet_msg_cache_data* */
59	struct slabhash* subnet_msg_cache;
60	/** access control, which upstream servers we send client address */
61	struct ecs_whitelist* whitelist;
62	/** allocation service */
63	struct alloc_cache alloc;
64	lock_rw_type biglock;
65	/** number of messages from cache */
66	size_t num_msg_cache;
67	/** number of messages not from cache */
68	size_t num_msg_nocache;
69};
70
71struct subnet_msg_cache_data {
72	struct addrtree* tree4;
73	struct addrtree* tree6;
74};
75
76struct subnet_qstate {
77	/** We need the hash for both cache lookup and insert */
78	hashvalue_type qinfo_hash;
79	int qinfo_hash_calculated;
80	/** ecs_data for client communication */
81	struct ecs_data	ecs_client_in;
82	struct ecs_data	ecs_client_out;
83	/** ecss data for server communication */
84	struct ecs_data	ecs_server_in;
85	struct ecs_data	ecs_server_out;
86	int subnet_downstream;
87	int subnet_sent;
88	/**
89	 * If there was no subnet sent because the client used source prefix
90	 * length 0 for omitting the information. Then the answer is cached
91	 * like subnet was a /0 scope. Like the subnet_sent flag, but when
92	 * the EDNS subnet option is omitted because the client asked.
93	 */
94	int subnet_sent_no_subnet;
95	/** keep track of longest received scope, set after receiving CNAME for
96	 * incoming QNAME. */
97	int track_max_scope;
98	/** longest received scope mask since track_max_scope is set. This value
99	 * is used for caching and answereing to client. */
100	uint8_t max_scope;
101	/** has the subnet module been started with no_cache_store? */
102	int started_no_cache_store;
103	/** has the subnet module been started with no_cache_lookup? */
104	int started_no_cache_lookup;
105};
106
107void subnet_data_delete(void* d, void* ATTR_UNUSED(arg));
108size_t msg_cache_sizefunc(void* k, void* d);
109
110/**
111 * Get the module function block.
112 * @return: function block with function pointers to module methods.
113 */
114struct module_func_block* subnetmod_get_funcblock(void);
115
116/** subnet module init */
117int subnetmod_init(struct module_env* env, int id);
118
119/** subnet module deinit */
120void subnetmod_deinit(struct module_env* env, int id);
121
122/** subnet module operate on a query */
123void subnetmod_operate(struct module_qstate* qstate, enum module_ev event,
124	int id, struct outbound_entry* outbound);
125
126/** subnet module  */
127void subnetmod_inform_super(struct module_qstate* qstate, int id,
128	struct module_qstate* super);
129
130/** subnet module cleanup query state */
131void subnetmod_clear(struct module_qstate* qstate, int id);
132
133/** subnet module alloc size routine */
134size_t subnetmod_get_mem(struct module_env* env, int id);
135
136/** Wrappers for static functions to unit test */
137size_t unittest_wrapper_subnetmod_sizefunc(void *elemptr);
138
139/** Whitelist check, called just before query is sent upstream. */
140int ecs_whitelist_check(struct query_info* qinfo, uint16_t flags,
141	struct module_qstate* qstate, struct sockaddr_storage* addr,
142	socklen_t addrlen, uint8_t* zone, size_t zonelen,
143	struct regional* region, int id, void* cbargs);
144
145/** Check whether response from server contains ECS record, if so, skip cache
146 * store. Called just after parsing EDNS data from server. */
147int ecs_edns_back_parsed(struct module_qstate* qstate, int id, void* cbargs);
148
149/** Remove ECS record from back_out when query resulted in REFUSED response. */
150int ecs_query_response(struct module_qstate* qstate, struct dns_msg* response,
151	int id, void* cbargs);
152
153/** mark subnet msg to be deleted */
154void subnet_markdel(void* key);
155
156/** Add ecs struct to edns list, after parsing it to wire format. */
157void subnet_ecs_opt_list_append(struct ecs_data* ecs, struct edns_option** list,
158	struct module_qstate *qstate, struct regional *region);
159
160/** Create ecs_data from the sockaddr_storage information. */
161void subnet_option_from_ss(struct sockaddr_storage *ss, struct ecs_data* ecs,
162	struct config_file* cfg);
163#endif /* SUBNETMOD_H */
164