ptunnel-ng:

	* fixed opt type for `-p`
	* `-l` argument is required
	* exported packet structs from ptunnel.h to pkt.h

1 files changed, 83 insertions, 0 deletions

diff --git a/pkt.h b/pkt.h
new file mode 100644
index 0000000..22cd289
--- /dev/null
+++ b/pkt.h
@@ -0,0 +1,83 @@
+#ifndef PKT_H
+#define PKT_H 1
+
+#include <stdint.h>
+
+#ifdef WIN32
+#include <winsock2.h>
+typedef int socklen_t;
+typedef uint32_t in_addr_t;
+#define ETH_ALEN 6 /* Octets in one ethernet addr   */
+struct ether_header {
+	u_int8_t  ether_dhost[ETH_ALEN]; /* destination eth addr */
+	u_int8_t  ether_shost[ETH_ALEN]; /* source ether addr    */
+	u_int16_t ether_type;            /* packet type ID field */
+};
+#endif /* WIN32 */
+
+/** Resend packets after this interval (in seconds) */
+#define kResend_interval 1.5
+
+/** ping_tunnel_pkt_t: This data structure represents the header of a ptunnel
+ * packet, consisting of a magic number, the tunnel's destination IP and port,
+ * as well as some other fields. Note that the dest IP and port is only valid
+ * in packets from the client to the proxy.
+ */
+typedef struct {
+	/** magic number, used to identify ptunnel packets. */
+	uint32_t magic;
+	/** destination IP and port (used by proxy to figure */
+	uint32_t dst_ip;
+	/** out where to tunnel to) */
+	uint32_t dst_port;
+	/** current connection state; see constants above. */
+	uint32_t state;
+	/** sequence number of last packet received from other end */
+	uint32_t ack;
+	/** length of data buffer */
+	uint32_t data_len;
+	/** sequence number of this packet */
+	uint16_t seq_no;
+	/** id number, used to separate different tunnels from each other */
+	uint16_t id_no;
+	/** optional data buffer */
+	char data[0];
+} __attribute__ ((packed)) ping_tunnel_pkt_t;
+
+/** ip_packet_t: This is basically my own definition of the IP packet, which
+ * of course complies with the official definition ;) See any good book on IP
+ * (or even the RFC) for info on the contents of this packet.
+ */
+typedef struct {
+	uint8_t vers_ihl;
+	uint8_t tos;
+	uint16_t pkt_len;
+	uint16_t id;
+	uint16_t flags_frag_offset;
+	uint8_t ttl;
+	uint8_t proto; // 1 for ICMP
+	uint16_t checksum;
+	uint32_t src_ip;
+	uint32_t dst_ip;
+	char data[0];
+} __attribute__ ((packed)) ip_packet_t;
+
+/** icmp_echo_packet_t: This is the definition of a standard ICMP header. The
+ * ptunnel packets are constructed as follows:
+ * [    ip header (20 bytes)   ]
+ * [   icmp header (8 bytes)   ]
+ * [ ptunnel header (28 bytes) ]
+ *
+ * We actually only create the ICMP and ptunnel headers, the IP header is
+ * taken care of by the OS.
+ */
+typedef struct {
+	uint8_t type;
+	uint8_t code;
+	uint16_t checksum;
+	uint16_t identifier;
+	uint16_t seq;
+	char data[0];
+} __attribute__ ((packed)) icmp_echo_packet_t;
+
+#endif