diff options
author | Toni Uhlig <matzeton@googlemail.com> | 2017-12-18 23:31:09 +0100 |
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committer | Toni Uhlig <matzeton@googlemail.com> | 2017-12-18 23:31:09 +0100 |
commit | 3c491a8bec71606b7af5f1d8c34de8e9710bbe13 (patch) | |
tree | 8d909a5a1fc72138887078c9c54b3b6514253234 /src/pkt.h | |
parent | 9c82c27e6326609150db837f37077774a8a5919c (diff) |
ptunnel-ng:
* this is now an autotools project (added/renamed required files e.g. AUTHORS, COPYING)
* removed user defined ip header (buggy; not useful anymore)
Diffstat (limited to 'src/pkt.h')
-rw-r--r-- | src/pkt.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/src/pkt.h b/src/pkt.h new file mode 100644 index 0000000..22c039d --- /dev/null +++ b/src/pkt.h @@ -0,0 +1,96 @@ +#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; + +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 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); + +#endif |