1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149
|
/*
* 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;
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, forward_desc_t **ring,
int *await_send, int *insert_idx, uint16_t *next_expected_seq, void *vcur, uint16_t window_size);
void handle_extended_options(void *vcur);
void handle_ack(uint16_t seq_no, icmp_desc_t *ring, int *packets_awaiting_ack,
int one_ack_only, int insert_idx, int *first_ack,
uint16_t *remote_ack, int is_pcap, uint16_t window_size);
#endif
|