-/*

- * pkt.h

- * ptunnel is licensed under the BSD license:

- *

- * Copyright (c) 2004-2011, Daniel Stoedle <daniels@cs.uit.no>,

- * Yellow Lemon Software. All rights reserved.

- *

- * Copyright (c) 2017-2019, Toni Uhlig <matzeton@googlemail.com>

- *

- * Redistribution and use in source and binary forms, with or without

- * modification, are permitted provided that the following conditions are met:

- *

- * - Redistributions of source code must retain the above copyright notice,

- * this list of conditions and the following disclaimer.

- *

- * - Redistributions in binary form must reproduce the above copyright notice,

- * this list of conditions and the following disclaimer in the documentation

- * and/or other materials provided with the distribution.

- *

- * - Neither the name of the Yellow Lemon Software nor the names of its

- * contributors may be used to endorse or promote products derived from this

- * software without specific prior written permission.

- *

- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE

- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

- * POSSIBILITY OF SUCH DAMAGE.

- *

- * Contacting the author:

- * You can get in touch with me, Daniel Stødle (that's the Norwegian letter oe,

- * in case your text editor didn't realize), here: <daniels@cs.uit.no>

- *

- * The official ptunnel website is here:

- * <http://www.cs.uit.no/~daniels/PingTunnel/>

- *

- * Note that the source code is best viewed with tabs set to 4 spaces.

- */

-

-#ifndef PKT_H

-#define PKT_H 1

-

-#include <stdint.h>

-

-#ifndef __MINGW32__

-#define __PTATTR__ __attribute__((packed))

-#else

-#define __PTATTR__ __attribute__((packed, gcc_struct))

-#endif

-

-#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 {

- uint8_t ether_dhost[ETH_ALEN]; /* destination eth addr */

- uint8_t ether_shost[ETH_ALEN]; /* source ether addr */

- uint16_t ether_type; /* packet type ID field */

-} __PTATTR__;

-#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];

-} __PTATTR__ 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];

-} __PTATTR__ 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];

-} __PTATTR__ icmp_echo_packet_t;

-

-typedef struct forward_desc_t forward_desc_t;

-typedef struct icmp_desc_t icmp_desc_t;

-typedef struct proxy_desc_t proxy_desc_t;

-

-void handle_packet(char * buf, unsigned bytes, int is_pcap, struct sockaddr_in * addr, int icmp_sock);

-

-void handle_data(icmp_echo_packet_t * pkt, int total_len, proxy_desc_t * cur);

-

-void handle_ack(uint32_t seq_no, proxy_desc_t * cur);

-

-#endif