update code

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;
+}