DNS resolver rewritten, moved to proto/dns.c

2 files changed, 81 insertions, 58 deletions

diff --git a/src/include/dns.h b/src/include/dns.h
new file mode 100644
index 000000000..cd26a9611
--- /dev/null
+++ b/src/include/dns.h
@@ -0,0 +1,81 @@
+#ifndef DNS_RESOLVER_H
+#define DNS_RESOLVER_H
+
+#include "stdint.h"
+#include "nic.h"
+#include "in.h"
+
+/*
+ * Constants
+ *
+ */
+
+#define DNS_TYPE_A		1
+#define DNS_TYPE_CNAME		5
+#define DNS_TYPE_ANY		255
+
+#define DNS_CLASS_IN		1
+#define DNS_CLASS_CS		2
+#define DNS_CLASS_CH		3
+#define DNS_CLASS_HS		4
+
+#define DNS_FLAG_QUERY		( 0x00 << 15 )
+#define DNS_FLAG_RESPONSE	( 0x01 << 15 )
+#define DNS_FLAG_QR(flags)	( (flags) & ( 0x01 << 15 ) )
+#define DNS_FLAG_OPCODE_QUERY	( 0x00 << 11 )
+#define DNS_FLAG_OPCODE_IQUERY	( 0x01 << 11 )
+#define DNS_FLAG_OPCODE_STATUS	( 0x02 << 11 )
+#define DNS_FLAG_OPCODE(flags)	( (flags) & ( 0x0f << 11 ) )
+#define DNS_FLAG_RD		( 0x01 << 8 )
+#define DNS_FLAG_RA		( 0x01 << 7 )
+#define DNS_FLAG_RCODE_OK	( 0x00 << 0 )
+#define DNS_FLAG_RCODE_NX	( 0x03 << 0 )
+#define DNS_FLAG_RCODE(flags)	( (flags) & ( 0x0f << 0 ) )
+
+#define	DNS_UDP_PORT		53
+#define	DNS_MAX_RETRIES		3
+#define	DNS_MAX_CNAME_RECURSION	0x30
+
+/*
+ * DNS protocol structures
+ *
+ */
+struct dns_header {
+	uint16_t	id;
+	uint16_t	flags;
+	uint16_t	qdcount;
+	uint16_t	ancount;
+	uint16_t	nscount;
+	uint16_t	arcount;
+} __attribute__ (( packed ));
+
+struct dns_query_info {
+	uint16_t	qtype;
+	uint16_t	qclass;
+} __attribute__ (( packed ));
+
+struct dns_query {
+	struct iphdr	ip;
+	struct udphdr	udp;
+	struct dns_header dns;
+	char		payload[ 256 + sizeof ( struct dns_query_info ) ];
+} __attribute__ (( packed ));
+
+struct dns_rr_info {
+	uint16_t	type;
+	uint16_t	class;
+	uint16_t	ttl;
+	uint16_t	rdlength;
+} __attribute__ (( packed ));
+
+struct dns_rr_info_a {
+	struct dns_rr_info;
+	struct in_addr in_addr;
+} __attribute__ (( packed ));
+
+struct dns_rr_info_cname {
+	struct dns_rr_info;
+	char		cname[0];
+};
+
+#endif /* DNS_RESOLVER_H */
diff --git a/src/include/dns_resolver.h b/src/include/dns_resolver.h
deleted file mode 100644
index b04a9764f..000000000
--- a/src/include/dns_resolver.h
+++ /dev/null
@@ -1,58 +0,0 @@
-// 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
-