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74b2466e LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | #pragma once | |
4 | ||
5 | /*** | |
6 | This file is part of systemd. | |
7 | ||
8 | Copyright 2014 Lennart Poettering | |
9 | ||
10 | systemd is free software; you can redistribute it and/or modify it | |
11 | under the terms of the GNU Lesser General Public License as published by | |
12 | the Free Software Foundation; either version 2.1 of the License, or | |
13 | (at your option) any later version. | |
14 | ||
15 | systemd is distributed in the hope that it will be useful, but | |
16 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | Lesser General Public License for more details. | |
19 | ||
20 | You should have received a copy of the GNU Lesser General Public License | |
21 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
22 | ***/ | |
23 | ||
74b2466e LP |
24 | |
25 | #include "macro.h" | |
26 | #include "sparse-endian.h" | |
27 | #include "hashmap.h" | |
7e8e0422 LP |
28 | #include "in-addr-util.h" |
29 | ||
30 | typedef struct DnsPacketHeader DnsPacketHeader; | |
31 | typedef struct DnsPacket DnsPacket; | |
32 | ||
74b2466e | 33 | #include "resolved-dns-rr.h" |
faa133f3 LP |
34 | #include "resolved-dns-question.h" |
35 | #include "resolved-dns-answer.h" | |
51323288 | 36 | #include "resolved-def.h" |
74b2466e | 37 | |
1716f6dc LP |
38 | typedef enum DnsProtocol { |
39 | DNS_PROTOCOL_DNS, | |
40 | DNS_PROTOCOL_MDNS, | |
41 | DNS_PROTOCOL_LLMNR, | |
42 | _DNS_PROTOCOL_MAX, | |
43 | _DNS_PROTOCOL_INVALID = -1 | |
44 | } DnsProtocol; | |
45 | ||
74b2466e LP |
46 | struct DnsPacketHeader { |
47 | uint16_t id; | |
48 | be16_t flags; | |
49 | be16_t qdcount; | |
50 | be16_t ancount; | |
51 | be16_t nscount; | |
52 | be16_t arcount; | |
53 | }; | |
54 | ||
55 | #define DNS_PACKET_HEADER_SIZE sizeof(DnsPacketHeader) | |
c73ce96b LP |
56 | |
57 | /* The various DNS protocols deviate in how large a packet can grow, | |
58 | but the TCP transport has a 16bit size field, hence that appears to | |
e1c95994 | 59 | be the absolute maximum. */ |
c73ce96b | 60 | #define DNS_PACKET_SIZE_MAX 0xFFFF |
e1c95994 LP |
61 | |
62 | /* RFC 1035 say 512 is the maximum, for classic unicast DNS */ | |
63 | #define DNS_PACKET_UNICAST_SIZE_MAX 512 | |
64 | ||
74b2466e LP |
65 | #define DNS_PACKET_SIZE_START 512 |
66 | ||
67 | struct DnsPacket { | |
68 | int n_ref; | |
1716f6dc | 69 | DnsProtocol protocol; |
74b2466e | 70 | size_t size, allocated, rindex; |
faa133f3 | 71 | void *_data; /* don't access directly, use DNS_PACKET_DATA()! */ |
74b2466e | 72 | Hashmap *names; /* For name compression */ |
faa133f3 LP |
73 | |
74 | /* Parsed data */ | |
75 | DnsQuestion *question; | |
76 | DnsAnswer *answer; | |
1716f6dc LP |
77 | |
78 | /* Packet reception meta data */ | |
79 | int ifindex; | |
623a4c97 | 80 | int family, ipproto; |
1716f6dc | 81 | union in_addr_union sender, destination; |
623a4c97 | 82 | uint16_t sender_port, destination_port; |
0dd25fb9 | 83 | uint32_t ttl; |
a4076574 LP |
84 | |
85 | bool extracted; | |
74b2466e LP |
86 | }; |
87 | ||
88 | static inline uint8_t* DNS_PACKET_DATA(DnsPacket *p) { | |
89 | if (_unlikely_(!p)) | |
90 | return NULL; | |
91 | ||
faa133f3 LP |
92 | if (p->_data) |
93 | return p->_data; | |
74b2466e LP |
94 | |
95 | return ((uint8_t*) p) + ALIGN(sizeof(DnsPacket)); | |
96 | } | |
97 | ||
98 | #define DNS_PACKET_HEADER(p) ((DnsPacketHeader*) DNS_PACKET_DATA(p)) | |
3cb10d3a LP |
99 | #define DNS_PACKET_ID(p) DNS_PACKET_HEADER(p)->id |
100 | #define DNS_PACKET_QR(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 15) & 1) | |
101 | #define DNS_PACKET_OPCODE(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 11) & 15) | |
8b757a38 | 102 | #define DNS_PACKET_AA(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 10) & 1) |
ad867662 | 103 | #define DNS_PACKET_TC(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 9) & 1) |
8b757a38 DM |
104 | #define DNS_PACKET_RD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 8) & 1) |
105 | #define DNS_PACKET_RA(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 7) & 1) | |
106 | #define DNS_PACKET_AD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 5) & 1) | |
107 | #define DNS_PACKET_CD(p) ((be16toh(DNS_PACKET_HEADER(p)->flags) >> 4) & 1) | |
108 | #define DNS_PACKET_RCODE(p) (be16toh(DNS_PACKET_HEADER(p)->flags) & 15) | |
109 | ||
110 | /* LLMNR defines some bits differently */ | |
111 | #define DNS_PACKET_LLMNR_C(p) DNS_PACKET_AA(p) | |
112 | #define DNS_PACKET_LLMNR_T(p) DNS_PACKET_RD(p) | |
113 | ||
3cb10d3a LP |
114 | #define DNS_PACKET_QDCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->qdcount) |
115 | #define DNS_PACKET_ANCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->ancount) | |
116 | #define DNS_PACKET_NSCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->nscount) | |
117 | #define DNS_PACKET_ARCOUNT(p) be16toh(DNS_PACKET_HEADER(p)->arcount) | |
118 | ||
119 | #define DNS_PACKET_MAKE_FLAGS(qr, opcode, aa, tc, rd, ra, ad, cd, rcode) \ | |
120 | (((uint16_t) !!qr << 15) | \ | |
121 | ((uint16_t) (opcode & 15) << 11) | \ | |
122 | ((uint16_t) !!aa << 10) | \ | |
123 | ((uint16_t) !!tc << 9) | \ | |
124 | ((uint16_t) !!rd << 8) | \ | |
125 | ((uint16_t) !!ra << 7) | \ | |
126 | ((uint16_t) !!ad << 5) | \ | |
127 | ((uint16_t) !!cd << 4) | \ | |
128 | ((uint16_t) (rcode & 15))) | |
129 | ||
322345fd LP |
130 | static inline unsigned DNS_PACKET_RRCOUNT(DnsPacket *p) { |
131 | return | |
132 | (unsigned) DNS_PACKET_ANCOUNT(p) + | |
133 | (unsigned) DNS_PACKET_NSCOUNT(p) + | |
134 | (unsigned) DNS_PACKET_ARCOUNT(p); | |
135 | } | |
74b2466e | 136 | |
1716f6dc LP |
137 | int dns_packet_new(DnsPacket **p, DnsProtocol protocol, size_t mtu); |
138 | int dns_packet_new_query(DnsPacket **p, DnsProtocol protocol, size_t mtu); | |
74b2466e LP |
139 | |
140 | DnsPacket *dns_packet_ref(DnsPacket *p); | |
141 | DnsPacket *dns_packet_unref(DnsPacket *p); | |
142 | ||
143 | DEFINE_TRIVIAL_CLEANUP_FUNC(DnsPacket*, dns_packet_unref); | |
144 | ||
145 | int dns_packet_validate(DnsPacket *p); | |
146 | int dns_packet_validate_reply(DnsPacket *p); | |
623a4c97 | 147 | int dns_packet_validate_query(DnsPacket *p); |
74b2466e | 148 | |
623a4c97 | 149 | int dns_packet_append_blob(DnsPacket *p, const void *d, size_t sz, size_t *start); |
74b2466e LP |
150 | int dns_packet_append_uint8(DnsPacket *p, uint8_t v, size_t *start); |
151 | int dns_packet_append_uint16(DnsPacket *p, uint16_t v, size_t *start); | |
623a4c97 | 152 | int dns_packet_append_uint32(DnsPacket *p, uint32_t v, size_t *start); |
74b2466e LP |
153 | int dns_packet_append_string(DnsPacket *p, const char *s, size_t *start); |
154 | int dns_packet_append_label(DnsPacket *p, const char *s, size_t l, size_t *start); | |
151226ab ZJS |
155 | int dns_packet_append_name(DnsPacket *p, const char *name, |
156 | bool allow_compression, size_t *start); | |
623a4c97 LP |
157 | int dns_packet_append_key(DnsPacket *p, const DnsResourceKey *key, size_t *start); |
158 | int dns_packet_append_rr(DnsPacket *p, const DnsResourceRecord *rr, size_t *start); | |
74b2466e LP |
159 | |
160 | int dns_packet_read(DnsPacket *p, size_t sz, const void **ret, size_t *start); | |
623a4c97 | 161 | int dns_packet_read_blob(DnsPacket *p, void *d, size_t sz, size_t *start); |
74b2466e LP |
162 | int dns_packet_read_uint8(DnsPacket *p, uint8_t *ret, size_t *start); |
163 | int dns_packet_read_uint16(DnsPacket *p, uint16_t *ret, size_t *start); | |
164 | int dns_packet_read_uint32(DnsPacket *p, uint32_t *ret, size_t *start); | |
165 | int dns_packet_read_string(DnsPacket *p, char **ret, size_t *start); | |
151226ab ZJS |
166 | int dns_packet_read_name(DnsPacket *p, char **ret, |
167 | bool allow_compression, size_t *start); | |
faa133f3 | 168 | int dns_packet_read_key(DnsPacket *p, DnsResourceKey **ret, size_t *start); |
74b2466e LP |
169 | int dns_packet_read_rr(DnsPacket *p, DnsResourceRecord **ret, size_t *start); |
170 | ||
8ba9fd9c LP |
171 | void dns_packet_rewind(DnsPacket *p, size_t idx); |
172 | ||
74b2466e | 173 | int dns_packet_skip_question(DnsPacket *p); |
faa133f3 | 174 | int dns_packet_extract(DnsPacket *p); |
74b2466e | 175 | |
74b2466e LP |
176 | enum { |
177 | DNS_RCODE_SUCCESS = 0, | |
178 | DNS_RCODE_FORMERR = 1, | |
179 | DNS_RCODE_SERVFAIL = 2, | |
180 | DNS_RCODE_NXDOMAIN = 3, | |
181 | DNS_RCODE_NOTIMP = 4, | |
182 | DNS_RCODE_REFUSED = 5, | |
183 | DNS_RCODE_YXDOMAIN = 6, | |
184 | DNS_RCODE_YXRRSET = 7, | |
185 | DNS_RCODE_NXRRSET = 8, | |
186 | DNS_RCODE_NOTAUTH = 9, | |
187 | DNS_RCODE_NOTZONE = 10, | |
188 | DNS_RCODE_BADVERS = 16, | |
189 | DNS_RCODE_BADSIG = 16, /* duplicate value! */ | |
190 | DNS_RCODE_BADKEY = 17, | |
191 | DNS_RCODE_BADTIME = 18, | |
192 | DNS_RCODE_BADMODE = 19, | |
193 | DNS_RCODE_BADNAME = 20, | |
194 | DNS_RCODE_BADALG = 21, | |
195 | DNS_RCODE_BADTRUNC = 22, | |
196 | _DNS_RCODE_MAX_DEFINED | |
197 | }; | |
198 | ||
199 | const char* dns_rcode_to_string(int i) _const_; | |
200 | int dns_rcode_from_string(const char *s) _pure_; | |
1716f6dc LP |
201 | |
202 | const char* dns_protocol_to_string(DnsProtocol p) _const_; | |
203 | DnsProtocol dns_protocol_from_string(const char *s) _pure_; | |
204 | ||
205 | #define LLMNR_MULTICAST_IPV4_ADDRESS ((struct in_addr) { .s_addr = htobe32(224U << 24 | 252U) }) | |
206 | #define LLMNR_MULTICAST_IPV6_ADDRESS ((struct in6_addr) { .s6_addr = { 0xFF, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x03 } }) | |
8db0d2f5 ZJS |
207 | |
208 | #define DNSKEY_FLAG_ZONE_KEY (1u << 8) | |
209 | #define DNSKEY_FLAG_SEP (1u << 0) | |
210 | ||
211 | static inline uint16_t dnskey_to_flags(const DnsResourceRecord *rr) { | |
212 | return (rr->dnskey.zone_key_flag * DNSKEY_FLAG_ZONE_KEY | | |
213 | rr->dnskey.sep_flag * DNSKEY_FLAG_SEP); | |
214 | } | |
ff3d6560 ZJS |
215 | |
216 | /* http://tools.ietf.org/html/rfc4034#appendix-A.1 */ | |
217 | enum { | |
218 | DNSSEC_ALGORITHM_RSAMD5 = 1, | |
219 | DNSSEC_ALGORITHM_DH, | |
220 | DNSSEC_ALGORITHM_DSA, | |
221 | DNSSEC_ALGORITHM_ECC, | |
222 | DNSSEC_ALGORITHM_RSASHA1, | |
223 | DNSSEC_ALGORITHM_INDIRECT = 252, | |
224 | DNSSEC_ALGORITHM_PRIVATEDNS, | |
225 | DNSSEC_ALGORITHM_PRIVATEOID, | |
226 | _DNSSEC_ALGORITHM_MAX_DEFINED | |
227 | }; | |
228 | ||
229 | const char* dnssec_algorithm_to_string(int i) _const_; | |
230 | int dnssec_algorithm_from_string(const char *s) _pure_; | |
51323288 LP |
231 | |
232 | static inline uint64_t SD_RESOLVED_FLAGS_MAKE(DnsProtocol protocol, int family) { | |
233 | ||
234 | /* Converts a protocol + family into a flags field as used in queries */ | |
235 | ||
236 | if (protocol == DNS_PROTOCOL_DNS) | |
237 | return SD_RESOLVED_DNS; | |
238 | ||
239 | if (protocol == DNS_PROTOCOL_LLMNR) | |
240 | return family == AF_INET6 ? SD_RESOLVED_LLMNR_IPV6 : SD_RESOLVED_LLMNR_IPV4; | |
241 | ||
242 | return 0; | |
243 | } |