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Diffstat (limited to 'src/include/dns_resolver.h')
| -rw-r--r-- | src/include/dns_resolver.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/src/include/dns_resolver.h b/src/include/dns_resolver.h new file mode 100644 index 000000000..b04a9764f --- /dev/null +++ b/src/include/dns_resolver.h @@ -0,0 +1,58 @@ +// 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 + |