update code

Makefile

@@ -1,9 +1,9 @@
 
 BIN=smartdns 
-OBJS=smartdns.o fast_ping.o lib/bitops.o dns_client.o dns_server.o
-CFLAGS=-g -O0 -Wall
+OBJS=smartdns.o fast_ping.o lib/bitops.o dns_client.o dns_server.o dns.o
+CFLAGS=-g -O0 -Wall 
 CFLAGS +=-Iinclude
-CXXFLAGS=-g -O0 -Wall -std=c++11
+CXXFLAGS=-g -O0 -Wall -std=c++11 
 CXXFLAGS +=-Iinclude
 
 .PHONY: all
@@ -11,7 +11,7 @@ CXXFLAGS +=-Iinclude
 all: $(BIN)
 
 $(BIN) : $(OBJS)
-	$(CC) $(OBJS) -o $@ -lpthread
+	$(CC) $(OBJS) -o $@ -lpthread 
 
 clean:
 	$(RM) $(OBJS) $(BIN)

dns.c

@@ -0,0 +1,102 @@
+#include "dns.h"
+
+#define DNS_MAX_CNAME_LEN 128
+
+int dns_decode_head(struct dns_head *head, struct idns_head *ihead)
+{
+	head->id = ntohs(ihead->id);
+	head->opcode = (ihead->opcode >> 3) & 0x0F;
+	head->query = (ihead->opcode & 0x80) != 0x80;
+	head->aa = (ihead->opcode & 0x04) == 0x04;
+	head->tc = (ihead->opcode & 0x02) == 0x02;
+	head->rd = (ihead->opcode & 0x01) == 0x01;
+	head->ra = (ihead->rcode & 0x80) == 0x80;
+	head->z = (ihead->rcode & 0x40) == 0x40;
+	head->ad = (ihead->rcode & 0x20) == 0x20;
+	head->cd = (ihead->rcode & 0x10) == 0x10;
+	head->rcode = (ihead->rcode & 0x0F);
+	head->qdcount = ntohs(ihead->qdcount);
+	head->ancount = ntohs(ihead->ancount);
+	head->nscount = ntohs(ihead->nscount);
+	head->nrcount = ntohs(ihead->arcount);
+
+	return 0;
+}
+
+int dns_decode_rr(char *data, int size)
+{
+	int ret;
+	int len = 0;
+
+	return len;
+}
+
+int dns_get_domain(char *data, int size, char *output)
+{
+    int i = 0;
+
+    while (data[i]) {
+        int len = data[i];
+		*output = '.';
+		output++;
+		i++;
+		memcpy(output, data + i, len);
+		i += len;
+		output += len;
+	}
+
+    int qtype = (unsigned short) data[i+1];
+    int qclass = (unsigned short) data[i+3];
+
+	return 0;
+}
+
+int dns_decode_qd(char *data, int size)
+{
+	int ret;
+	int len = 0;
+	char name[DNS_MAX_CNAME_LEN];
+	len = dns_get_domain(data, size, name);
+	printf("%s\n", name);
+
+	return len;
+}
+
+int dns_decode_body(struct dns_packet *packet, char *data, int size)
+{
+	struct dns_head *head = &packet->head;
+	int i = 0;
+	int len = 0;
+	int decode_len = 0;
+
+	for (i = 0; i < head->qdcount; i++) {
+		len = dns_decode_qd(data, size - decode_len);
+
+		decode_len += len;
+		data += len;
+	}
+
+	for (i = 0; i < head->qdcount; i++) {
+	}
+
+	for (i = 0; i < head->qdcount; i++) {
+	}
+
+	for (i = 0; i < head->qdcount; i++) {
+	}
+
+	return 0;
+}
+
+int dns_decode(struct dns_packet *packet, char *data, int size)
+{
+	struct idns_head *ihead = (struct idns_head *)data;
+	struct dns_head *head = &packet->head;
+	int decode_len = 0;
+
+	dns_decode_head(head, ihead);
+	decode_len += sizeof(struct idns_head);
+	data += sizeof(struct idns_head);
+	dns_decode_body(packet, data, size - decode_len);
+	return -1;
+}

dns.h

@@ -1,39 +1,178 @@
 #ifndef _DNS_HEAD_H
 #define _DNS_HEAD_H
 
-#pragma pack(push, 1)
+#include <stdint.h>
+#include <arpa/inet.h>
+#include <linux/filter.h>
+#include <netdb.h>
+
+typedef enum dns_section { 
+    DNS_S_QD = 0x01, 
+    DNS_S_AN = 0x02, 
+    DNS_S_NS = 0x04, 
+    DNS_S_AR = 0x08, 
+    DNS_S_ALL = 0x0f 
+} dns_section_t;
+
+typedef enum dns_class { 
+    DNS_C_IN = 1, 
+    DNS_C_ANY = 255 
+} dns_class_t;
+
+typedef enum dns_type {
+	DNS_T_A = 1,
+	DNS_T_NS = 2,
+	DNS_T_CNAME = 5,
+	DNS_T_SOA = 6,
+	DNS_T_PTR = 12,
+	DNS_T_MX = 15,
+	DNS_T_TXT = 16,
+	DNS_T_AAAA = 28,
+	DNS_T_SRV = 33,
+	DNS_T_OPT = 41,
+	DNS_T_SSHFP = 44,
+	DNS_T_SPF = 99,
+	DNS_T_AXFR = 252,
+	DNS_T_ALL = 255
+} dns_type_t;
+
+typedef enum dns_opcode {
+	DNS_OP_QUERY = 0,
+	DNS_OP_IQUERY = 1,
+	DNS_OP_STATUS = 2,
+	DNS_OP_NOTIFY = 4,
+	DNS_OP_UPDATE = 5,
+} dns_opcode_t; /* dns_opcode */
+
+typedef enum dns_rtcode {
+	DNS_RC_NOERROR = 0,
+	DNS_RC_FORMERR = 1,
+	DNS_RC_SERVFAIL = 2,
+	DNS_RC_NXDOMAIN = 3,
+	DNS_RC_NOTIMP = 4,
+	DNS_RC_REFUSED = 5,
+	DNS_RC_YXDOMAIN = 6,
+	DNS_RC_YXRRSET = 7,
+	DNS_RC_NXRRSET = 8,
+	DNS_RC_NOTAUTH = 9,
+	DNS_RC_NOTZONE = 10,
+	/* EDNS(0) extended RCODEs */
+	DNS_RC_BADVERS = 16,
+} dns_rtcode_t ; /* dns_rcode */
+
+struct idns_head
+{
+  unsigned short id;
+  unsigned char  opcode;
+  unsigned char  rcode;
+  unsigned short qdcount;
+  unsigned short ancount;
+  unsigned short nscount;
+  unsigned short arcount;
+} __attribute__ ((packed));
 
 struct dns_head {
-    unsigned short id; // identification number
-    unsigned char rd : 1; // recursion desired
-    unsigned char tc : 1; // truncated message
-    unsigned char aa : 1; // authoritive answer
-    unsigned char opcode : 4; // purpose of message
-    unsigned char qr : 1; // query/response flag
-    unsigned char rcode : 4; // response code
-    unsigned char cd : 1; // checking disabled
-    unsigned char ad : 1; // authenticated data
-    unsigned char z : 1; // its z! reserved
-    unsigned char ra : 1; // recursion available
-    unsigned short qd_count; // number of question entries
-    unsigned short an_count; // number of answer entries
-    unsigned short ns_count; // number of authority entries
-    unsigned short nr_count; // number of resource entries
-};
+	unsigned short id;        // identification number
+	unsigned char rd : 1;     // recursion desired
+	unsigned char tc : 1;     // truncated message
+	unsigned char aa : 1;     // authoritive answer
+	unsigned char opcode : 4; // purpose of message
+	unsigned char query : 1;     // query/response flag
+	unsigned char rcode : 4;  // response code
+	unsigned char cd : 1;     // checking disabled
+	unsigned char ad : 1;     // authenticated data
+	unsigned char z : 1;      // its z! reserved
+	unsigned char ra : 1;     // recursion available
+	unsigned short qdcount;  // number of question entries
+	unsigned short ancount;  // number of answer entries
+	unsigned short nscount;  // number of authority entries
+	unsigned short nrcount;  // number of resource entries
+} __attribute__ ((packed));
 
 struct dns_qds {
-    unsigned short type;
-    unsigned short classes;
+	unsigned short type;
+	unsigned short classes;
 };
 
 struct dns_rrs {
-    unsigned short type;
-    unsigned short classes;
-    unsigned int ttl;
-    unsigned short rd_length;
-    char rd_data[0];
+	unsigned short type;
+	unsigned short classes;
+	unsigned int ttl;
+	unsigned short rd_length;
+	char rd_data[0];
+};
+
+typedef uint32_t TTL;
+
+typedef struct dns_question_t	/* RFC-1035 */
+{
+  const char  *name;
+  dns_type_t   type;
+  dns_class_t  class;
+} dns_question_t;
+
+typedef struct dns_generic_t	/* RFC-1035 */
+{
+  const char  *name;
+  dns_type_t   type;
+  dns_class_t  class;
+  TTL          ttl;
+} dns_generic_t;
+
+typedef struct dns_a_t		/* RFC-1035 */
+{
+  const char  *name;
+  dns_type_t   type;
+  dns_class_t  class;
+  TTL          ttl;
+  in_addr_t    address;
+} dns_a_t;
+
+typedef struct dns_aaaa_t	/* RFC-1886 */
+{
+  const char      *name;
+  dns_type_t       type;
+  dns_class_t      class;
+  TTL              ttl;
+  struct in6_addr  address;
+} dns_aaaa_t;
+
+typedef struct dns_cname_t	/* RFC-1035 */
+{
+  const char  *name;
+  dns_type_t   type;
+  dns_class_t  class;
+  TTL          ttl;
+  const char  *cname;
+} dns_cname_t;
+
+typedef struct dns_ptr_t	/* RFC-1035 */
+{
+  const char  *name;
+  dns_type_t   type;
+  dns_class_t  class;
+  TTL          ttl;
+  const char  *ptr;
+} dns_ptr_t;
+
+
+typedef union dns_answer_t
+{
+  dns_generic_t  generic;
+  dns_a_t        a;
+  dns_cname_t    cname;
+  dns_ptr_t      ptr;
+  dns_aaaa_t     aaaa;
+} dns_answer_t;
+
+struct dns_packet {
+	struct dns_head head;
+	dns_question_t *questions;
+    dns_answer_t   *answers;
+    dns_answer_t   *nameservers;
+    dns_answer_t   *additional;
 };
 
-#pragma pack(pop)
+int dns_decode(struct dns_packet *packet, char *data, int size);
 
 #endif