/* dnsmasq is Copyright (c) 2000-2022 Simon Kelley
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 dated June, 1991, or
(at your option) version 3 dated 29 June, 2007.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
*/
#define NAMESERVER_PORT 53
#define TFTP_PORT 69
#define MIN_PORT 1024 /* first non-reserved port */
#define MAX_PORT 65535u
#define IN6ADDRSZ 16
#define INADDRSZ 4
#define PACKETSZ 512 /* maximum packet size */
#define MAXDNAME 1025 /* maximum presentation domain name */
#define RRFIXEDSZ 10 /* #/bytes of fixed data in r record */
#define MAXLABEL 63 /* maximum length of domain label */
#define NOERROR 0 /* no error */
#define FORMERR 1 /* format error */
#define SERVFAIL 2 /* server failure */
#define NXDOMAIN 3 /* non existent domain */
#define NOTIMP 4 /* not implemented */
#define REFUSED 5 /* query refused */
#define QUERY 0 /* opcode */
#define C_IN 1 /* the arpa internet */
#define C_CHAOS 3 /* for chaos net (MIT) */
#define C_HESIOD 4 /* hesiod */
#define C_ANY 255 /* wildcard match */
#define T_A 1
#define T_NS 2
#define T_MD 3
#define T_MF 4
#define T_CNAME 5
#define T_SOA 6
#define T_MB 7
#define T_MG 8
#define T_MR 9
#define T_PTR 12
#define T_MINFO 14
#define T_MX 15
#define T_TXT 16
#define T_RP 17
#define T_AFSDB 18
#define T_RT 21
#define T_SIG 24
#define T_PX 26
#define T_AAAA 28
#define T_NXT 30
#define T_SRV 33
#define T_NAPTR 35
#define T_KX 36
#define T_DNAME 39
#define T_OPT 41
#define T_DS 43
#define T_RRSIG 46
#define T_NSEC 47
#define T_DNSKEY 48
#define T_NSEC3 50
#define T_TKEY 249
#define T_TSIG 250
#define T_AXFR 252
#define T_MAILB 253
#define T_ANY 255
#define T_CAA 257
#define EDNS0_OPTION_MAC 65001 /* dyndns.org temporary assignment */
#define EDNS0_OPTION_CLIENT_SUBNET 8 /* IANA */
#define EDNS0_OPTION_EDE 15 /* IANA - RFC 8914 */
#define EDNS0_OPTION_NOMDEVICEID 65073 /* Nominum temporary assignment */
#define EDNS0_OPTION_NOMCPEID 65074 /* Nominum temporary assignment */
#define EDNS0_OPTION_UMBRELLA 20292 /* Cisco Umbrella temporary assignment */
/* RFC-8914 extended errors, negative values are our definitions */
#define EDE_UNSET -1 /* No extended DNS error available */
#define EDE_OTHER 0 /* Other */
#define EDE_USUPDNSKEY 1 /* Unsupported DNSKEY algo */
#define EDE_USUPDS 2 /* Unsupported DS Digest */
#define EDE_STALE 3 /* Stale answer */
#define EDE_FORGED 4 /* Forged answer */
#define EDE_DNSSEC_IND 5 /* DNSSEC Indeterminate */
#define EDE_DNSSEC_BOGUS 6 /* DNSSEC Bogus */
#define EDE_SIG_EXP 7 /* Signature Expired */
#define EDE_SIG_NYV 8 /* Signature Not Yet Valid */
#define EDE_NO_DNSKEY 9 /* DNSKEY missing */
#define EDE_NO_RRSIG 10 /* RRSIGs missing */
#define EDE_NO_ZONEKEY 11 /* No Zone Key Bit Set */
#define EDE_NO_NSEC 12 /* NSEC Missing */
#define EDE_CACHED_ERR 13 /* Cached Error */
#define EDE_NOT_READY 14 /* Not Ready */
#define EDE_BLOCKED 15 /* Blocked */
#define EDE_CENSORED 16 /* Censored */
#define EDE_FILTERED 17 /* Filtered */
#define EDE_PROHIBITED 18 /* Prohibited */
#define EDE_STALE_NXD 19 /* Stale NXDOMAIN */
#define EDE_NOT_AUTH 20 /* Not Authoritative */
#define EDE_NOT_SUP 21 /* Not Supported */
#define EDE_NO_AUTH 22 /* No Reachable Authority */
#define EDE_NETERR 23 /* Network error */
#define EDE_INVALID_DATA 24 /* Invalid Data */
struct dns_header {
u16 id;
u8 hb3,hb4;
u16 qdcount,ancount,nscount,arcount;
};
#define HB3_QR 0x80 /* Query */
#define HB3_OPCODE 0x78
#define HB3_AA 0x04 /* Authoritative Answer */
#define HB3_TC 0x02 /* TrunCated */
#define HB3_RD 0x01 /* Recursion Desired */
#define HB4_RA 0x80 /* Recursion Available */
#define HB4_AD 0x20 /* Authenticated Data */
#define HB4_CD 0x10 /* Checking Disabled */
#define HB4_RCODE 0x0f
#define OPCODE(x) (((x)->hb3 & HB3_OPCODE) >> 3)
#define SET_OPCODE(x, code) (x)->hb3 = ((x)->hb3 & ~HB3_OPCODE) | code
#define RCODE(x) ((x)->hb4 & HB4_RCODE)
#define SET_RCODE(x, code) (x)->hb4 = ((x)->hb4 & ~HB4_RCODE) | code
#define GETSHORT(s, cp) { \
unsigned char *t_cp = (unsigned char *)(cp); \
(s) = ((u16)t_cp[0] << 8) \
| ((u16)t_cp[1]) \
; \
(cp) += 2; \
}
#define GETLONG(l, cp) { \
unsigned char *t_cp = (unsigned char *)(cp); \
(l) = ((u32)t_cp[0] << 24) \
| ((u32)t_cp[1] << 16) \
| ((u32)t_cp[2] << 8) \
| ((u32)t_cp[3]) \
; \
(cp) += 4; \
}
#define PUTSHORT(s, cp) { \
u16 t_s = (u16)(s); \
unsigned char *t_cp = (unsigned char *)(cp); \
*t_cp++ = t_s >> 8; \
*t_cp = t_s; \
(cp) += 2; \
}
#define PUTLONG(l, cp) { \
u32 t_l = (u32)(l); \
unsigned char *t_cp = (unsigned char *)(cp); \
*t_cp++ = t_l >> 24; \
*t_cp++ = t_l >> 16; \
*t_cp++ = t_l >> 8; \
*t_cp = t_l; \
(cp) += 4; \
}
#define CHECK_LEN(header, pp, plen, len) \
((size_t)((pp) - (unsigned char *)(header) + (len)) <= (plen))
#define ADD_RDLEN(header, pp, plen, len) \
(!CHECK_LEN(header, pp, plen, len) ? 0 : (((pp) += (len)), 1))
/* Escape character in our presentation format for names.
Cannot be '.' or /000 and must be !isprint().
Note that escaped chars are stored as
to ensure that the escaped form of /000 doesn't include /000
*/
#define NAME_ESCAPE 1