dns_resolver.h revision 677833bc953b6cb418c701facbdcf4aa18d6c44e
// dns_resolver.h - #define statements for the DNS resolver
// We only need A and CNAME queries (later possibly AAAA/A6?)
#define QUERYTYPE_A 1
#define QUERYTYPE_CNAME 5
// We only query with INTERNET class (not CHAOS or whatever)
#define QUERYCLASS_INET 1
// Our first query will have the identifier <1> (arbitrary -
// remember however that (256 - QUERYIDENTIFIER)/2 > MAX_CNAME_RECURSION !!!
#define QUERYIDENTIFIER 1
// Query flags are standard values here
#define QUERYFLAGS 0x0100
#define QUERYFLAGS_MASK 0xf8
#define QUERYFLAGS_WANT 0x80
// Indices inside the byte array that holds DNS queries/answers
#define QINDEX_ID 0
#define QINDEX_FLAGS 2
#define QINDEX_NUMQUEST 4
#define QINDEX_NUMANSW 6
#define QINDEX_NUMAUTH 8
#define QINDEX_NUMADDIT 10
#define QINDEX_QUESTION 12
#define QINDEX_QTYPE 14
#define QINDEX_QCLASS 16
#define QINDEX_STORE_A 256
// Constant UDP port number for DNS traffic
#define UDP_PORT_DNS 53
// Return values that the package parser may give
// This packet was not for us (broadcast or whatever)
#define RET_PACK_GARBAG 0
// Retrieved an address - query finishes
#define RET_GOT_ADDR 1
// No A record for that hostname - try running a CNAME query
#define RET_RUN_CNAME_Q 2
// The CNAME query returned a valid hostname - run A query on that
#define RET_RUN_NEXT_A 3
// The CNAME query failed - stop resolving
#define RET_CNAME_FAIL 4
// We have a reliable input that claims that the hostname does not exist
#define RET_NOSUCHNAME 5
// The name server response is somehow bogus/can not be parsed -> Abort
#define RET_DNSERROR 6
// Return values that the query engine may give
// DNS query succeeded, IP address delivered
#define RET_DNS_OK 0
// DNS query failed
#define RET_DNS_FAIL 1
// Error codes the DNS server can send to us
#define ERR_NOSUCHNAME 3