| /* |
| * Copyright (c) 2015 Cisco and/or its affiliates. |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at: |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #ifndef included_dns_packet_h |
| #define included_dns_packet_h |
| |
| /** |
| * DNS packet header format |
| */ |
| |
| /* *INDENT-OFF* */ |
| typedef CLIB_PACKED (struct { |
| u16 id; /**< transaction ID */ |
| u16 flags; /**< flags */ |
| u16 qdcount; /**< number of questions */ |
| u16 anscount; /**< number of answers */ |
| u16 nscount; /**< number of name servers */ |
| u16 arcount; /**< number of additional records */ |
| }) dns_header_t; |
| /* *INDENT-ON* */ |
| |
| #define DNS_RCODE_MASK (0xf) |
| #define DNS_RCODE_NO_ERROR 0 |
| #define DNS_RCODE_FORMAT_ERROR 1 |
| #define DNS_RCODE_SERVER_FAILURE 2 |
| #define DNS_RCODE_NAME_ERROR 3 |
| #define DNS_RCODE_NOT_IMPLEMENTED 4 |
| #define DNS_RCODE_REFUSED 5 |
| |
| #define DNS_RA (1<<7) /**< recursion available */ |
| #define DNS_RD (1<<8) /**< recursion desired */ |
| #define DNS_TC (1<<9) /**< truncation */ |
| #define DNS_AA (1<<10) /**< authoritative answer */ |
| #define DNS_OPCODE_MASK (0xf<<11) /**< opcode mask */ |
| #define DNS_OPCODE_QUERY (0<<11) /**< standard query */ |
| #define DNS_OPCODE_IQUERY (1<<11) /**< inverse query (deprecated) */ |
| #define DNS_OPCODE_STATUS (2<<11) /**< server status */ |
| #define DNS_QR (1<<15) /**< query=0, response=1 */ |
| |
| |
| /* |
| * Note: in DNS-land, www.foobar.com is encoded as three "labels," |
| * each of which amount to a 1 octet length followed by up to 63 |
| * octets of name. Don't forget to add a "null root label" after the last |
| * real one, or the poor slob trying to parse the name will have |
| * no chance whatsoever. |
| * |
| * All RRs have the same top level format shown below: |
| * |
| * 1 1 1 1 1 1 |
| * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * | | |
| * / / |
| * / NAME / |
| * | | |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * | TYPE | |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * | CLASS | |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * | TTL | |
| * | | |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * | RDLENGTH | |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--| |
| * / RDATA / |
| * / / |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * |
| * |
| * DNS "questions" have the following format: |
| * |
| * 1 1 1 1 1 1 |
| * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * | | |
| * / QNAME / |
| * / / |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * | QTYPE | |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| * | QCLASS | |
| * +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ |
| */ |
| |
| /** |
| * DNS "question" fixed header. |
| */ |
| /* *INDENT-OFF* */ |
| typedef CLIB_PACKED (struct { |
| u16 type; /**< record type requested */ |
| u16 class; /**< class, 1 = internet */ |
| }) dns_query_t; |
| /* *INDENT-ON* */ |
| |
| /** |
| * DNS RR fixed header. |
| */ |
| /* *INDENT-OFF* */ |
| typedef CLIB_PACKED (struct { |
| u16 type; /**< record type */ |
| u16 class; /**< class, 1 = internet */ |
| u32 ttl; /**< time to live, in seconds */ |
| u16 rdlength; |
| /**< length of r */ |
| u8 rdata[0]; |
| }) dns_rr_t; |
| /* *INDENT-ON* */ |
| |
| /* |
| * There are quite a number of DNS record types |
| * Feel free to add as needed |
| */ |
| #define foreach_dns_type \ |
| _(A, 1) /**< ip4 host address */ \ |
| _(AAAA, 28) /**< ip6 host address */ \ |
| _(ALL, 255) /**< all available data */ \ |
| _(TEXT, 16) /**< a text string */ \ |
| _(NAMESERVER, 2) /**< a nameserver */ \ |
| _(CNAME, 5) /**< a CNAME (alias) */ \ |
| _(MAIL_EXCHANGE, 15) /**< a mail exchange */ \ |
| _(PTR, 12) /**< a PTR (pointer) record */ \ |
| _(HINFO, 13) /**< Host info */ |
| |
| typedef enum |
| { |
| #define _(name,value) DNS_TYPE_##name = value, |
| foreach_dns_type |
| #undef _ |
| } dns_type_t; |
| |
| #define DNS_CLASS_IN 1 /**< The Internet */ |
| |
| |
| #endif /* included_dns_packet_h */ |
| |
| /* |
| * fd.io coding-style-patch-verification: ON |
| * |
| * Local Variables: |
| * eval: (c-set-style "gnu") |
| * End: |
| */ |