typedef struct ip_hdr { unsigned char ip_header_len:4; // 4-bit header length (in 32-bit words) normally=5 (Means 20 Bytes may be 24 also) unsigned char ip_version :4; // 4-bit IPv4 version unsigned char ip_tos; // IP type of service unsigned short ip_total_length; // Total length unsigned short ip_id; // Unique identifier
unsigned char ip_frag_offset :5; // Fragment offset field
unsigned char ip_ttl; // Time to live unsigned char ip_protocol; // Protocol(TCP,UDP etc) unsigned short ip_checksum; // IP checksum unsigned int ip_srcaddr; // Source address unsigned int ip_destaddr; // Source address } IPV4_HDR, *PIPV4_HDR, FAR * LPIPV4_HDR; // TCP header typedef struct tcp_header { unsigned short source_port; // source port unsigned short dest_port; // destination port unsigned int sequence; // sequence number - 32 bits unsigned int acknowledge; // acknowledgement number - 32 bits
unsigned char ns :1; //Nonce Sum Flag Added in RFC 3540. unsigned char reserved_part1:3; //according to rfc unsigned char data_offset:4; /*The number of 32-bit words in the TCP header. This indicates where the data begins. The length of the TCP header is always a multiple of 32 bits.*/
unsigned char fin :1; //Finish Flag unsigned char syn :1; //Synchronise Flag unsigned char rst :1; //Reset Flag unsigned char psh :1; //Push Flag unsigned char ack :1; //Acknowledgement Flag unsigned char urg :1; //Urgent Flag
unsigned char ecn :1; //ECN-Echo Flag unsigned char cwr :1; //Congestion Window Reduced Flag
////////////////////////////////
unsigned short window; // window unsigned short checksum; // checksum unsigned short urgent_pointer; // urgent pointer } TCP_HDR , *PTCP_HDR , FAR * LPTCP_HDR , TCPHeader , TCP_HEADER;
{
unsigned char ip_header_len:4; // 4-bit header length (in 32-bit words) normally=5 (Means 20 Bytes may be 24 also)
unsigned char ip_version :4; // 4-bit IPv4 version
unsigned char ip_tos; // IP type of service
unsigned short ip_total_length; // Total length
unsigned short ip_id; // Unique identifier
unsigned char ip_frag_offset :5; // Fragment offset field
unsigned char ip_more_fragment :1;
unsigned char ip_dont_fragment :1;
unsigned char ip_reserved_zero :1;
unsigned char ip_frag_offset1; //fragment offset
unsigned char ip_ttl; // Time to live
unsigned char ip_protocol; // Protocol(TCP,UDP etc)
unsigned short ip_checksum; // IP checksum
unsigned int ip_srcaddr; // Source address
unsigned int ip_destaddr; // Source address
} IPV4_HDR, *PIPV4_HDR, FAR * LPIPV4_HDR;
// TCP header
typedef struct tcp_header
{
unsigned short source_port; // source port
unsigned short dest_port; // destination port
unsigned int sequence; // sequence number - 32 bits
unsigned int acknowledge; // acknowledgement number - 32 bits
unsigned char ns :1; //Nonce Sum Flag Added in RFC 3540.
unsigned char reserved_part1:3; //according to rfc
unsigned char data_offset:4; /*The number of 32-bit words in the TCP header.
This indicates where the data begins.
The length of the TCP header is always a multiple
of 32 bits.*/
unsigned char fin :1; //Finish Flag
unsigned char syn :1; //Synchronise Flag
unsigned char rst :1; //Reset Flag
unsigned char psh :1; //Push Flag
unsigned char ack :1; //Acknowledgement Flag
unsigned char urg :1; //Urgent Flag
unsigned char ecn :1; //ECN-Echo Flag
unsigned char cwr :1; //Congestion Window Reduced Flag
////////////////////////////////
unsigned short window; // window
unsigned short checksum; // checksum
unsigned short urgent_pointer; // urgent pointer
} TCP_HDR , *PTCP_HDR , FAR * LPTCP_HDR , TCPHeader , TCP_HEADER;