Shulou(Shulou.com)06/01 Report--

/ * /

# define ETHER_ADDR_LEN 6 / / NIC physical address occupies 6 bytes

# define MAXDATA 10240

/ *

TCP header, IP header, UDP header, ARP packet, Ethernet packet, etc.

And all kinds of watches. Routing address table, address resolution protocol table, DNS table, etc.

, /

# define ETHERTYPE_IP 0x0800 / / IP Protocal

# define ETHERTYPE_ARP 0x0806 / / Address Resolution Protocal

# define ETHERTYPE_REVARP 0x0835 / / Reverse Address Resolution Protocal inverse address Resolution Protocol

/ * /

/ / ethernet

Typedef struct ether_header

{

U_char ether_ dhost[ETHER _ ADDR_LEN]

U_char ether_ shost[ETHER _ ADDR_LEN]

U_short ether_type

} ETH_HEADER

/ / arp

Typedef struct arphdr

{

U_short ar_hrd

U_short ar_pro

U_char ar_hln

U_char ar_pln

U_short ar_op

} ARP_HEADER

/ / IP header

Typedef struct ip

{

U_int ip_v:4; / / version (version)

U_int ip_hl:4; / / header length (header length)

U_char ip_tos

U_short ip_len

U_short ip_id

U_short ip_off

U_char ip_ttl

U_char ip_p

U_short ip_sum

Struct in_addr ip_src

Struct in_addr ip_dst

} IP_HEADER

/ / TCP header structure

Typedef struct tcphdr

{

U_short th_sport

U_short th_dport

U_int th_seq

U_int th_ack

U_int th_off:4

U_int th_x2:4

U_char th_flags

U_short th_win

U_short th_sum

U_short th_urp

} TCP_HEADER

# define TH_FIN 0x01

# define TH_SYN 0x02

# define TH_RST 0x04

# define TH_PUSH 0x08

# define TH_ACK 0x10

# define TH_URG 0x20

/ / UDP header structure * /

Typedef struct udphdr

{

U_short uh_sport

U_short uh_dport

U_short uh_ulen

U_short uh_sum

} UDP_HEADER

/ * header generated by ARP and ETHERNET * /

Typedef struct ether_arp

{

Struct arphdr ea_hdr

U_char arp_ sha[ETHER _ ADDR_LEN]

U_char arp_spa [4]

U_char arp_ tha[ETHER _ ADDR_LEN]

U_char arp_tpa [4]

} ETH_ARP

# define arp_hrd ea_hdr.ar_hrd

# define arp_pro ea_hdr.ar_pro

# define arp_hln ea_hdr.ar_hln

# define arp_pln ea_hdr.ar_pln

# define arp_op ea_hdr.ar_op

# define ARPHRD 1

/ / headers generated by tcp and ip

Typedef struct packet_tcp

{

Struct ip ip

Struct tcphdr tcp

U_char data [MAXDATA]

} TCP_IP

/ / headers generated by udp and ip

Typedef struct packet_udp

{

Struct ip ip

Struct udphdr udp

} UDP_IP

/ / various forms of ICMP

/ / icmpx,x==icmp_type

/ / icmp message (can reach the destination, response-request packet)

Struct icmp8

{

U_char icmp_type; / / type of message (message type)

U_char icmp_code; / / type sub code (message type subcode)

U_short icmp_cksum

U_short icmp_id

U_short icmp_seq

Char icmp_data [1]

}

/ / icmp message (can return to destination, response-response packet)

Struct icmp0

{

U_char icmp_type; / / type of message (message type)

U_char icmp_code; / / type sub code (message type subcode)

U_short icmp_cksum

U_short icmp_id

U_short icmp_seq

Char icmp_data [1]

}

/ / icmp message (destination unreachable)

Struct icmp3

{

U_char icmp_type; / / type of message (message type)

U_char icmp_code; / / type sub code (message type subcode), for example: 0 network reason can not reach, 1 host reason can not reach.

U_short icmp_cksum

U_short icmp_pmvoid

U_short icmp_nextmtu

Char icmp_data [1]

}

/ / icmp message (retransmission structure)

Struct icmp5

{

U_char icmp_type; / / type of message (message type)

U_char icmp_code; / / type sub code (message type subcode)

U_short icmp_cksum

Struct in_addr icmp_gwaddr

Char icmp_data [1]

}

Struct icmp11

{

U_char icmp_type; / / type of message (message type)

U_char icmp_code; / / type sub code (message type subcode)

U_short icmp_cksum

U_int icmp_void

Char icmp_data [1]

}

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