101 lines
2.6 KiB
C
101 lines
2.6 KiB
C
#include "../src/hammer.h"
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#include "dns_common.h"
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#include "dns.h"
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#define false 0
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#define true 1
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bool is_zero(parse_result_t *p) {
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if (TT_UINT != p->ast->token_type)
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return false;
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return (0 == p->ast->uint);
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}
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/**
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* Every DNS message should have QDCOUNT entries in the question
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* section, and ANCOUNT+NSCOUNT+ARCOUNT resource records.
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*/
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bool validate_dns(parse_result_t *p) {
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if (TT_SEQUENCE != p->ast->token_type)
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return false;
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// The header holds the counts as its last 4 elements.
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parsed_token_t **elems = p->ast->seq->elements[0]->seq->elements;
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size_t qd = elems[8]->uint;
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size_t an = elems[9]->uint;
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size_t ns = elems[10]->uint;
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size_t ar = elems[11]->uint;
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parsed_token_t *questions = p->ast->seq->elements[1];
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if (questions->seq->used != qd)
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return false;
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parsed_token_t *rrs = p->ast->seq->elements[2];
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if (an+ns+ar != rrs->seq->used)
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return false;
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return true;
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}
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const parsed_token_t* pack_dns_struct(const parse_result_t *p);
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const parser_t* init_parser() {
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static parser_t *dns_message = NULL;
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if (dns_message)
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return dns_message;
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const parser_t *domain = init_domain();
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const parser_t *dns_header = sequence(bits(16, false), // ID
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bits(1, false), // QR
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bits(4, false), // opcode
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bits(1, false), // AA
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bits(1, false), // TC
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bits(1, false), // RD
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bits(1, false), // RA
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ignore(attr_bool(bits(3, false), is_zero)), // Z
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bits(4, false), // RCODE
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uint16(), // QDCOUNT
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uint16(), // ANCOUNT
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uint16(), // NSCOUNT
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uint16(), // ARCOUNT
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NULL);
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const parser_t *type = int_range(uint16(), 1, 16);
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const parser_t *qtype = choice(type,
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int_range(uint16(), 252, 255),
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NULL);
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const parser_t *class = int_range(uint16(), 1, 4);
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const parser_t *qclass = choice(class,
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int_range(uint16(), 255, 255),
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NULL);
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const parser_t *dns_question = sequence(sequence(many1(length_value(uint8(),
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uint8())),
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ch('\x00'),
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NULL), // QNAME
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qtype, // QTYPE
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qclass, // QCLASS
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NULL);
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const parser_t *dns_rr = sequence(domain, // NAME
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type, // TYPE
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class, // CLASS
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uint32(), // TTL
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length_value(uint16(), uint8()), // RDLENGTH+RDATA
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NULL);
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dns_message = (parser_t*)attr_bool(sequence(dns_header,
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many(dns_question),
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many(dns_rr),
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end_p(),
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NULL),
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validate_dns);
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return dns_message;
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}
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int main(int argc, char** argv) {
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return 0;
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}
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