| 1 | /* $Id: ares_dns.h,v 1.3 2001-07-30 12:40:26 ghudson Exp $ */ |
|---|
| 2 | |
|---|
| 3 | /* Copyright 1998 by the Massachusetts Institute of Technology. |
|---|
| 4 | * |
|---|
| 5 | * Permission to use, copy, modify, and distribute this |
|---|
| 6 | * software and its documentation for any purpose and without |
|---|
| 7 | * fee is hereby granted, provided that the above copyright |
|---|
| 8 | * notice appear in all copies and that both that copyright |
|---|
| 9 | * notice and this permission notice appear in supporting |
|---|
| 10 | * documentation, and that the name of M.I.T. not be used in |
|---|
| 11 | * advertising or publicity pertaining to distribution of the |
|---|
| 12 | * software without specific, written prior permission. |
|---|
| 13 | * M.I.T. makes no representations about the suitability of |
|---|
| 14 | * this software for any purpose. It is provided "as is" |
|---|
| 15 | * without express or implied warranty. |
|---|
| 16 | */ |
|---|
| 17 | |
|---|
| 18 | #ifndef ARES__DNS_H |
|---|
| 19 | #define ARES__DNS_H |
|---|
| 20 | |
|---|
| 21 | #define DNS__16BIT(p) (((p)[0] << 8) | (p)[1]) |
|---|
| 22 | #define DNS__32BIT(p) (((p)[0] << 24) | ((p)[1] << 16) | \ |
|---|
| 23 | ((p)[2] << 8) | (p)[3]) |
|---|
| 24 | #define DNS__SET16BIT(p, v) (((p)[0] = ((v) >> 8) & 0xff), \ |
|---|
| 25 | ((p)[1] = (v) & 0xff)) |
|---|
| 26 | #define DNS__SET32BIT(p, v) (((p)[0] = ((v) >> 24) & 0xff), \ |
|---|
| 27 | ((p)[1] = ((v) >> 16) & 0xff), \ |
|---|
| 28 | ((p)[2] = ((v) >> 8) & 0xff), \ |
|---|
| 29 | ((p)[3] = (v) & 0xff)) |
|---|
| 30 | |
|---|
| 31 | /* Macros for parsing a DNS header */ |
|---|
| 32 | #define DNS_HEADER_QID(h) DNS__16BIT(h) |
|---|
| 33 | #define DNS_HEADER_QR(h) (((h)[2] >> 7) & 0x1) |
|---|
| 34 | #define DNS_HEADER_OPCODE(h) (((h)[2] >> 3) & 0xf) |
|---|
| 35 | #define DNS_HEADER_AA(h) (((h)[2] >> 2) & 0x1) |
|---|
| 36 | #define DNS_HEADER_TC(h) (((h)[2] >> 1) & 0x1) |
|---|
| 37 | #define DNS_HEADER_RD(h) ((h)[2] & 0x1) |
|---|
| 38 | #define DNS_HEADER_RA(h) (((h)[3] >> 7) & 0x1) |
|---|
| 39 | #define DNS_HEADER_Z(h) (((h)[3] >> 4) & 0x7) |
|---|
| 40 | #define DNS_HEADER_RCODE(h) ((h)[3] & 0xf) |
|---|
| 41 | #define DNS_HEADER_QDCOUNT(h) DNS__16BIT((h) + 4) |
|---|
| 42 | #define DNS_HEADER_ANCOUNT(h) DNS__16BIT((h) + 6) |
|---|
| 43 | #define DNS_HEADER_NSCOUNT(h) DNS__16BIT((h) + 8) |
|---|
| 44 | #define DNS_HEADER_ARCOUNT(h) DNS__16BIT((h) + 10) |
|---|
| 45 | |
|---|
| 46 | /* Macros for constructing a DNS header */ |
|---|
| 47 | #define DNS_HEADER_SET_QID(h, v) DNS__SET16BIT(h, v) |
|---|
| 48 | #define DNS_HEADER_SET_QR(h, v) ((h)[2] |= (((v) & 0x1) << 7)) |
|---|
| 49 | #define DNS_HEADER_SET_OPCODE(h, v) ((h)[2] |= (((v) & 0xf) << 3)) |
|---|
| 50 | #define DNS_HEADER_SET_AA(h, v) ((h)[2] |= (((v) & 0x1) << 2)) |
|---|
| 51 | #define DNS_HEADER_SET_TC(h, v) ((h)[2] |= (((v) & 0x1) << 1)) |
|---|
| 52 | #define DNS_HEADER_SET_RD(h, v) ((h)[2] |= (((v) & 0x1))) |
|---|
| 53 | #define DNS_HEADER_SET_RA(h, v) ((h)[3] |= (((v) & 0x1) << 7)) |
|---|
| 54 | #define DNS_HEADER_SET_Z(h, v) ((h)[3] |= (((v) & 0x7) << 4)) |
|---|
| 55 | #define DNS_HEADER_SET_RCODE(h, v) ((h)[3] |= (((v) & 0xf))) |
|---|
| 56 | #define DNS_HEADER_SET_QDCOUNT(h, v) DNS__SET16BIT((h) + 4, v) |
|---|
| 57 | #define DNS_HEADER_SET_ANCOUNT(h, v) DNS__SET16BIT((h) + 6, v) |
|---|
| 58 | #define DNS_HEADER_SET_NSCOUNT(h, v) DNS__SET16BIT((h) + 8, v) |
|---|
| 59 | #define DNS_HEADER_SET_ARCOUNT(h, v) DNS__SET16BIT((h) + 10, v) |
|---|
| 60 | |
|---|
| 61 | /* Macros for parsing the fixed part of a DNS question */ |
|---|
| 62 | #define DNS_QUESTION_TYPE(q) DNS__16BIT(q) |
|---|
| 63 | #define DNS_QUESTION_CLASS(q) DNS__16BIT((q) + 2) |
|---|
| 64 | |
|---|
| 65 | /* Macros for constructing the fixed part of a DNS question */ |
|---|
| 66 | #define DNS_QUESTION_SET_TYPE(q, v) DNS__SET16BIT(q, v) |
|---|
| 67 | #define DNS_QUESTION_SET_CLASS(q, v) DNS__SET16BIT((q) + 2, v) |
|---|
| 68 | |
|---|
| 69 | /* Macros for parsing the fixed part of a DNS resource record */ |
|---|
| 70 | #define DNS_RR_TYPE(r) DNS__16BIT(r) |
|---|
| 71 | #define DNS_RR_CLASS(r) DNS__16BIT((r) + 2) |
|---|
| 72 | #define DNS_RR_TTL(r) DNS__32BIT((r) + 4) |
|---|
| 73 | #define DNS_RR_LEN(r) DNS__16BIT((r) + 8) |
|---|
| 74 | |
|---|
| 75 | /* Macros for constructing the fixed part of a DNS resource record */ |
|---|
| 76 | #define DNS_RR_SET_TYPE(r, v) DNS__SET16BIT(r, v) |
|---|
| 77 | #define DNS_RR_SET_CLASS(r, v) DNS__SET16BIT((r) + 2, v) |
|---|
| 78 | #define DNS_RR_SET_TTL(r, v) DNS__SET32BIT((r) + 4, v) |
|---|
| 79 | #define DNS_RR_SET_LEN(r, v) DNS__SET16BIT((r) + 8, v) |
|---|
| 80 | |
|---|
| 81 | #endif /* ARES__DNS_H */ |
|---|
