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Simon Kelleyd1ced3a2018-01-01 22:18:03 +00001/* dnsmasq is Copyright (c) 2000-2018 Simon Kelley
Simon Kelley572b41e2011-02-18 18:11:18 +00002
3 This program is free software; you can redistribute it and/or modify
4 it under the terms of the GNU General Public License as published by
5 the Free Software Foundation; version 2 dated June, 1991, or
6 (at your option) version 3 dated 29 June, 2007.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with this program. If not, see <http://www.gnu.org/licenses/>.
15*/
16
Simon Kelleyc72daea2012-01-05 21:33:27 +000017#define NAMESERVER_PORT 53
18#define TFTP_PORT 69
Simon Kelleybaf553d2018-01-29 22:49:27 +000019#define MIN_PORT 1024 /* first non-reserved port */
Hans Dedecker926332a2016-01-23 10:48:12 +000020#define MAX_PORT 65535u
Simon Kelleyc72daea2012-01-05 21:33:27 +000021
Simon Kelley572b41e2011-02-18 18:11:18 +000022#define IN6ADDRSZ 16
23#define INADDRSZ 4
24
25#define PACKETSZ 512 /* maximum packet size */
26#define MAXDNAME 1025 /* maximum presentation domain name */
27#define RRFIXEDSZ 10 /* #/bytes of fixed data in r record */
28#define MAXLABEL 63 /* maximum length of domain label */
29
30#define NOERROR 0 /* no error */
31#define FORMERR 1 /* format error */
32#define SERVFAIL 2 /* server failure */
33#define NXDOMAIN 3 /* non existent domain */
34#define NOTIMP 4 /* not implemented */
35#define REFUSED 5 /* query refused */
36
37#define QUERY 0 /* opcode */
38
39#define C_IN 1 /* the arpa internet */
40#define C_CHAOS 3 /* for chaos net (MIT) */
Simon Kelleycbf13a22014-01-25 17:59:14 +000041#define C_HESIOD 4 /* hesiod */
Simon Kelley572b41e2011-02-18 18:11:18 +000042#define C_ANY 255 /* wildcard match */
43
44#define T_A 1
Simon Kelley5f8e58f2014-01-09 17:31:19 +000045#define T_NS 2
46#define T_MD 3
47#define T_MF 4
Simon Kelley572b41e2011-02-18 18:11:18 +000048#define T_CNAME 5
49#define T_SOA 6
Simon Kelley5f8e58f2014-01-09 17:31:19 +000050#define T_MB 7
51#define T_MG 8
52#define T_MR 9
Simon Kelley572b41e2011-02-18 18:11:18 +000053#define T_PTR 12
Simon Kelley5f8e58f2014-01-09 17:31:19 +000054#define T_MINFO 14
Simon Kelley572b41e2011-02-18 18:11:18 +000055#define T_MX 15
56#define T_TXT 16
Simon Kelley5f8e58f2014-01-09 17:31:19 +000057#define T_RP 17
58#define T_AFSDB 18
59#define T_RT 21
Simon Kelley572b41e2011-02-18 18:11:18 +000060#define T_SIG 24
Simon Kelley5f8e58f2014-01-09 17:31:19 +000061#define T_PX 26
Simon Kelley572b41e2011-02-18 18:11:18 +000062#define T_AAAA 28
Simon Kelley5f8e58f2014-01-09 17:31:19 +000063#define T_NXT 30
Simon Kelley572b41e2011-02-18 18:11:18 +000064#define T_SRV 33
65#define T_NAPTR 35
Simon Kelley5f8e58f2014-01-09 17:31:19 +000066#define T_KX 36
67#define T_DNAME 39
Simon Kelley572b41e2011-02-18 18:11:18 +000068#define T_OPT 41
Giovanni Bajoa669f012012-04-05 02:47:28 +020069#define T_DS 43
70#define T_RRSIG 46
71#define T_NSEC 47
72#define T_DNSKEY 48
Simon Kelley5107ace2014-02-23 10:48:32 +000073#define T_NSEC3 50
Simon Kelley572b41e2011-02-18 18:11:18 +000074#define T_TKEY 249
75#define T_TSIG 250
Simon Kelleyb75e9362012-12-07 11:50:41 +000076#define T_AXFR 252
Simon Kelley572b41e2011-02-18 18:11:18 +000077#define T_MAILB 253
78#define T_ANY 255
79
Simon Kelleyed4c0762013-10-08 20:46:34 +010080#define EDNS0_OPTION_MAC 65001 /* dyndns.org temporary assignment */
Simon Kelleyc3edf382013-10-10 21:09:15 +010081#define EDNS0_OPTION_CLIENT_SUBNET 8 /* IANA */
Simon Kelley33702ab2015-12-28 23:17:15 +000082#define EDNS0_OPTION_NOMDEVICEID 65073 /* Nominum temporary assignment */
83#define EDNS0_OPTION_NOMCPEID 65074 /* Nominum temporary assignment */
Simon Kelleyed4c0762013-10-08 20:46:34 +010084
Simon Kelley572b41e2011-02-18 18:11:18 +000085struct dns_header {
86 u16 id;
87 u8 hb3,hb4;
88 u16 qdcount,ancount,nscount,arcount;
Simon Kelley7de060b2011-08-26 17:24:52 +010089};
Simon Kelley572b41e2011-02-18 18:11:18 +000090
swiggerbd7bfa22015-06-01 20:54:59 +010091#define HB3_QR 0x80 /* Query */
Simon Kelley572b41e2011-02-18 18:11:18 +000092#define HB3_OPCODE 0x78
swiggerbd7bfa22015-06-01 20:54:59 +010093#define HB3_AA 0x04 /* Authoritative Answer */
94#define HB3_TC 0x02 /* TrunCated */
95#define HB3_RD 0x01 /* Recursion Desired */
Simon Kelley572b41e2011-02-18 18:11:18 +000096
swiggerbd7bfa22015-06-01 20:54:59 +010097#define HB4_RA 0x80 /* Recursion Available */
98#define HB4_AD 0x20 /* Authenticated Data */
99#define HB4_CD 0x10 /* Checking Disabled */
Simon Kelley572b41e2011-02-18 18:11:18 +0000100#define HB4_RCODE 0x0f
101
102#define OPCODE(x) (((x)->hb3 & HB3_OPCODE) >> 3)
Simon Kelley9d633042013-12-13 15:36:55 +0000103#define SET_OPCODE(x, code) (x)->hb3 = ((x)->hb3 & ~HB3_OPCODE) | code
104
Simon Kelley572b41e2011-02-18 18:11:18 +0000105#define RCODE(x) ((x)->hb4 & HB4_RCODE)
106#define SET_RCODE(x, code) (x)->hb4 = ((x)->hb4 & ~HB4_RCODE) | code
107
108#define GETSHORT(s, cp) { \
109 unsigned char *t_cp = (unsigned char *)(cp); \
110 (s) = ((u16)t_cp[0] << 8) \
111 | ((u16)t_cp[1]) \
112 ; \
113 (cp) += 2; \
114}
115
116#define GETLONG(l, cp) { \
117 unsigned char *t_cp = (unsigned char *)(cp); \
118 (l) = ((u32)t_cp[0] << 24) \
119 | ((u32)t_cp[1] << 16) \
120 | ((u32)t_cp[2] << 8) \
121 | ((u32)t_cp[3]) \
122 ; \
123 (cp) += 4; \
124}
125
126#define PUTSHORT(s, cp) { \
127 u16 t_s = (u16)(s); \
128 unsigned char *t_cp = (unsigned char *)(cp); \
129 *t_cp++ = t_s >> 8; \
130 *t_cp = t_s; \
131 (cp) += 2; \
132}
133
134#define PUTLONG(l, cp) { \
135 u32 t_l = (u32)(l); \
136 unsigned char *t_cp = (unsigned char *)(cp); \
137 *t_cp++ = t_l >> 24; \
138 *t_cp++ = t_l >> 16; \
139 *t_cp++ = t_l >> 8; \
140 *t_cp = t_l; \
141 (cp) += 4; \
142}
143
Simon Kelleyc3e0b9b2013-12-31 13:50:39 +0000144#define CHECK_LEN(header, pp, plen, len) \
145 ((size_t)((pp) - (unsigned char *)(header) + (len)) <= (plen))
146
147#define ADD_RDLEN(header, pp, plen, len) \
148 (!CHECK_LEN(header, pp, plen, len) ? 0 : (((pp) += (len)), 1))
Simon Kelleycbe379a2015-04-21 22:57:06 +0100149
150/* Escape character in our presentation format for names.
Simon Kelleyb8f16552015-04-22 21:14:31 +0100151 Cannot be '.' or /000 and must be !isprint().
152 Note that escaped chars are stored as
153 <NAME_ESCAPE> <orig-char+1>
154 to ensure that the escaped form of /000 doesn't include /000
155*/
Simon Kelleycbe379a2015-04-21 22:57:06 +0100156#define NAME_ESCAPE 1