subnet-whitelist.c revision 356345 
1/*
2 * edns-subnet/subnet-whitelist.c - Hosts we actively try to send subnet option
3 * to.
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 *
39 * Keep track of the white listed servers for subnet option. Based
40 * on acl_list.c|h
41 */
42
43#include "config.h"
44
45#ifdef CLIENT_SUBNET /* keeps splint happy */
46#include "edns-subnet/edns-subnet.h"
47#include "edns-subnet/subnet-whitelist.h"
48#include "util/regional.h"
49#include "util/log.h"
50#include "util/config_file.h"
51#include "util/net_help.h"
52#include "util/storage/dnstree.h"
53#include "sldns/str2wire.h"
54#include "util/data/dname.h"
55
56struct ecs_whitelist*
57ecs_whitelist_create(void)
58{
59	struct ecs_whitelist* whitelist =
60		(struct ecs_whitelist*)calloc(1,
61		sizeof(struct ecs_whitelist));
62	if(!whitelist)
63		return NULL;
64	whitelist->region = regional_create();
65	if(!whitelist->region) {
66		ecs_whitelist_delete(whitelist);
67		return NULL;
68	}
69	return whitelist;
70}
71
72void
73ecs_whitelist_delete(struct ecs_whitelist* whitelist)
74{
75	if(!whitelist)
76		return;
77	regional_destroy(whitelist->region);
78	free(whitelist);
79}
80
81/** insert new address into whitelist structure */
82static int
83upstream_insert(struct ecs_whitelist* whitelist,
84	struct sockaddr_storage* addr, socklen_t addrlen, int net)
85{
86	struct addr_tree_node* node = (struct addr_tree_node*)regional_alloc(
87		whitelist->region, sizeof(*node));
88	if(!node)
89		return 0;
90	if(!addr_tree_insert(&whitelist->upstream, node, addr, addrlen, net)) {
91		verbose(VERB_QUERY,
92			"duplicate send-client-subnet address ignored.");
93	}
94	return 1;
95}
96
97/** apply edns-subnet string */
98static int
99upstream_str_cfg(struct ecs_whitelist* whitelist, const char* str)
100{
101	struct sockaddr_storage addr;
102	int net;
103	socklen_t addrlen;
104	verbose(VERB_ALGO, "send-client-subnet: %s", str);
105	if(!netblockstrtoaddr(str, UNBOUND_DNS_PORT, &addr, &addrlen, &net)) {
106		log_err("cannot parse send-client-subnet netblock: %s", str);
107		return 0;
108	}
109	if(!upstream_insert(whitelist, &addr, addrlen, net)) {
110		log_err("out of memory");
111		return 0;
112	}
113	return 1;
114}
115
116/** read client_subnet config */
117static int
118read_upstream(struct ecs_whitelist* whitelist, struct config_file* cfg)
119{
120	struct config_strlist* p;
121	for(p = cfg->client_subnet; p; p = p->next) {
122		log_assert(p->str);
123		if(!upstream_str_cfg(whitelist, p->str))
124			return 0;
125	}
126	return 1;
127}
128
129/** read client_subnet_zone config */
130static int
131read_names(struct ecs_whitelist* whitelist, struct config_file* cfg)
132{
133	/* parse names, report errors, insert into tree */
134	struct config_strlist* p;
135	struct name_tree_node* n;
136	uint8_t* nm, *nmr;
137	size_t nm_len;
138	int nm_labs;
139
140	for(p = cfg->client_subnet_zone; p; p = p->next) {
141		log_assert(p->str);
142		nm = sldns_str2wire_dname(p->str, &nm_len);
143		if(!nm) {
144			log_err("cannot parse client-subnet-zone: %s", p->str);
145			return 0;
146		}
147		nm_labs = dname_count_size_labels(nm, &nm_len);
148		nmr = (uint8_t*)regional_alloc_init(whitelist->region, nm,
149			nm_len);
150		free(nm);
151		if(!nmr) {
152			log_err("out of memory");
153			return 0;
154		}
155		n = (struct name_tree_node*)regional_alloc(whitelist->region,
156			sizeof(*n));
157		if(!n) {
158			log_err("out of memory");
159			return 0;
160		}
161		if(!name_tree_insert(&whitelist->dname, n, nmr, nm_len, nm_labs,
162			LDNS_RR_CLASS_IN)) {
163			verbose(VERB_QUERY, "ignoring duplicate "
164				"client-subnet-zone: %s", p->str);
165		}
166	}
167	return 1;
168}
169
170int
171ecs_whitelist_apply_cfg(struct ecs_whitelist* whitelist,
172	struct config_file* cfg)
173{
174	regional_free_all(whitelist->region);
175	addr_tree_init(&whitelist->upstream);
176	name_tree_init(&whitelist->dname);
177	if(!read_upstream(whitelist, cfg))
178		return 0;
179	if(!read_names(whitelist, cfg))
180		return 0;
181	addr_tree_init_parents(&whitelist->upstream);
182	name_tree_init_parents(&whitelist->dname);
183	return 1;
184}
185
186int
187ecs_is_whitelisted(struct ecs_whitelist* whitelist,
188	struct sockaddr_storage* addr, socklen_t addrlen, uint8_t* qname,
189	size_t qname_len, uint16_t qclass)
190{
191	int labs;
192	if(addr_tree_lookup(&whitelist->upstream, addr, addrlen))
193		return 1;
194	/* Not in upstream whitelist, check dname whitelist. */
195	labs = dname_count_labels(qname);
196	return name_tree_lookup(&whitelist->dname, qname, qname_len, labs,
197		qclass) != NULL;
198}
199
200size_t
201ecs_whitelist_get_mem(struct ecs_whitelist* whitelist)
202{
203	if(!whitelist) return 0;
204	return sizeof(*whitelist) + regional_get_mem(whitelist->region);
205}
206
207#endif /* CLIENT_SUBNET */
208