added decpcap.c and decpcap.h code

decpcap.h

@@ -0,0 +1,51 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <pcap.h>
+
+/* definitions */
+
+enum dp_packet_type {
+	dp_packet_ethernet,
+	dp_packet_ppp,
+	dp_packet_ip,
+	dp_packet_ip6,
+	dp_packet_tcp,
+	dp_packet_udp,
+	dp_n_packet_types
+};
+
+enum dp_link_type {
+	dp_link_ethernet,
+	dp_link_ppp,
+	dp_n_link_types
+};
+
+/*struct dp_header {
+};*/
+typedef struct pcap_pkthdr dp_header;
+
+typedef int (*dp_callback)(u_char *, const dp_header *, const u_char *);
+
+struct dp_handle {
+	pcap_t * pcap_handle;
+	dp_callback callback [dp_n_packet_types];
+	enum dp_link_type linktype;
+	u_char * userdata;
+	int userdata_size;
+};
+
+/* functions to set up a handle (which is basically just a pcap handle) */
+
+struct dp_handle * dp_open_live(char * device, enum dp_link_type link, int snaplen, int promisc, int to_ms, char * ebuf);
+
+/* functions to add callbacks */
+
+void dp_addcb (struct dp_handle * handle, enum dp_packet_type type, dp_callback callback);
+
+/* functions to parse payloads */
+
+void dp_parse (enum dp_packet_type type, void * packet);
+
+/* functions to start monitoring */
+
+int dp_dispatch (struct dp_handle * handler, int count, u_char *user, int size);