release/src/router/dnsmasq/src/dns_protocol.h

   1 /* dnsmasq is Copyright (c) 2000-2011 Simon Kelley
   2
   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
  17 #define IN6ADDRSZ       16
  18 #define INADDRSZ        4
  19
  20 #define PACKETSZ        512             /* maximum packet size */
  21 #define MAXDNAME        1025            /* maximum presentation domain name */
  22 #define RRFIXEDSZ       10              /* #/bytes of fixed data in r record */
  23 #define MAXLABEL        63              /* maximum length of domain label */
  24
  25 #define NOERROR         0               /* no error */
  26 #define FORMERR         1               /* format error */
  27 #define SERVFAIL        2               /* server failure */
  28 #define NXDOMAIN        3               /* non existent domain */
  29 #define NOTIMP          4               /* not implemented */
  30 #define REFUSED         5               /* query refused */
  31
  32 #define QUERY           0               /* opcode */
  33
  34 #define C_IN            1               /* the arpa internet */
  35 #define C_CHAOS         3               /* for chaos net (MIT) */
  36 #define C_ANY           255             /* wildcard match */
  37
  38 #define T_A             1
  39 #define T_NS            2
  40 #define T_CNAME         5
  41 #define T_SOA           6
  42 #define T_PTR           12
  43 #define T_MX            15
  44 #define T_TXT           16
  45 #define T_SIG           24
  46 #define T_AAAA          28
  47 #define T_SRV           33
  48 #define T_NAPTR         35
  49 #define T_OPT           41
  50 #define T_TKEY          249
  51 #define T_TSIG          250
  52 #define T_MAILB         253
  53 #define T_ANY           255
  54
  55 struct dns_header {
  56   u16 id;
  57   u8  hb3,hb4;
  58   u16 qdcount,ancount,nscount,arcount;
  59 };
  60
  61 #define HB3_QR       0x80
  62 #define HB3_OPCODE   0x78
  63 #define HB3_AA       0x04
  64 #define HB3_TC       0x02
  65 #define HB3_RD       0x01
  66
  67 #define HB4_RA       0x80
  68 #define HB4_AD       0x20
  69 #define HB4_CD       0x10
  70 #define HB4_RCODE    0x0f
  71
  72 #define OPCODE(x)          (((x)->hb3 & HB3_OPCODE) >> 3)
  73 #define RCODE(x)           ((x)->hb4 & HB4_RCODE)
  74 #define SET_RCODE(x, code) (x)->hb4 = ((x)->hb4 & ~HB4_RCODE) | code
  75
  76 #define GETSHORT(s, cp) { \
  77         unsigned char *t_cp = (unsigned char *)(cp); \
  78         (s) = ((u16)t_cp[0] << 8) \
  79             | ((u16)t_cp[1]) \
  80             ; \
  81         (cp) += 2; \
  82 }
  83
  84 #define GETLONG(l, cp) { \
  85         unsigned char *t_cp = (unsigned char *)(cp); \
  86         (l) = ((u32)t_cp[0] << 24) \
  87             | ((u32)t_cp[1] << 16) \
  88             | ((u32)t_cp[2] << 8) \
  89             | ((u32)t_cp[3]) \
  90             ; \
  91         (cp) += 4; \
  92 }
  93
  94 #define PUTSHORT(s, cp) { \
  95         u16 t_s = (u16)(s); \
  96         unsigned char *t_cp = (unsigned char *)(cp); \
  97         *t_cp++ = t_s >> 8; \
  98         *t_cp   = t_s; \
  99         (cp) += 2; \
 100 }
 101
 102 #define PUTLONG(l, cp) { \
 103         u32 t_l = (u32)(l); \
 104         unsigned char *t_cp = (unsigned char *)(cp); \
 105         *t_cp++ = t_l >> 24; \
 106         *t_cp++ = t_l >> 16; \
 107         *t_cp++ = t_l >> 8; \
 108         *t_cp   = t_l; \
 109         (cp) += 4; \
 110 }
 111