TCPIP常用协议头格式

李国帅于2008.6编辑

包含TCP,UDP，IP,IPv6,Ethernet frame,FDDI 802等常见帧结构

TCP Header Format

/*RFC-793*/

typedef

struct _tcphdr

{

unsigned short source; //原端口地址

unsigned short dest; //目的端口地址

unsigned long seq; //序号

unsigned long ack_seq; //确认号

unsigned short doff:4; //首部长度

unsigned short resl:4; //保留

unsigned short cwr:1; //控制

unsigned short ece:1;

unsigned short urg:1;

unsigned short ack:1;

unsigned short psh:1;

unsigned short rst:1;

unsigned short syn:1;

unsigned short fin:1;

unsigned short window;

unsigned short check;

unsigned short urg_ptr;

}tcphdr;

IP Header Format

/*RFC-791*/



typedef

struct _iphdr

{

unsigned char version:4; //版本

unsigned char ihl:4; //首部长度

unsigned char tos; //服务类型

unsigned short tot_len; //总长度

unsigned short id; //标志

unsigned short frag_off; //分片偏移

unsigned char ttl; //生存时间

unsigned char protocol; //协议

unsigned char check; //检验和

unsigned long saddr; //源IP地址

unsigned long daaddr; //目的IP地址

}iphdr;

UDP Header Format

/*RFC-768--*/

typedef

struct _udphdr

{

unsigned short source;

unsigned short dest;

unsigned short len;

unsigned short

ICMP Header Format

/*

RFC-792

--*/

typedef

struct _icmphdr

{

unsigned char type; //类型

unsigned char code; //代码

unsigned short checksum; //校验和

union {

struct {

unsigned short id; //标识符

unsigned short sequence; //序号

} echo;

unsigned long gateway; //目标路由器的IP地址

struct {

unsigned short unused; //

unsigned short mtu;

} frag;

} un;

} icmphdr;

IGMP Header Format

/*

RFC-988

--*/

typedef

struct _igmphdr

{

unsigned char type;

unsigned char code; /* For newer IGMP */

unsigned short csum;

unsigned long group;

} igmphdr;

IPv6 Header Format

/*

RFC-1365

--*/

typedef

struct _ipv6hdr

{

unsigned char version:4;

unsigned char priority:4;

unsigned char flow_lbl[3];

unsigned short payload_len;

unsigned char nexthdr;

unsigned char hop_limit;

struct in6_addr saddr;

struct in6_addr daddr;

} ipv6hdr;

Ethernet frame header

/*

* This is an Ethernet frame header.

*/

typedef

struct _ethhdr

{

unsigned char h_dest[ETH_ALEN]; // destination eth addr

unsigned char h_source[ETH_ALEN]; // source ether addr

unsigned short h_proto; // packet type ID field

} ethhdr;

FDDI 802.2

/* 

Define 802.2 Type 1 header */

struct fddi_8022_1_hdr

{

__u8 dsap; /* destination service access point */

__u8 ssap; /* source service access point */

__u8 ctrl; /* control byte #1 */

} __attribute__ ((packed));

/* Define 802.2 Type 2 header */

struct fddi_8022_2_hdr

{

__u8 dsap; /* destination service access point */

__u8 ssap; /* source service access point */

__u8 ctrl_1; /* control byte #1 */

__u8 ctrl_2; /* control byte #2 */

} __attribute__ ((packed));

/* Define 802.2 SNAP header */

#define FDDI_K_OUI_LEN 3

struct fddi_snap_hdr

{

__u8 dsap; /* always 0xAA */

__u8 ssap; /* always 0xAA */

__u8 ctrl; /* always 0x03 */

__u8 oui[FDDI_K_OUI_LEN]; /* organizational universal id */

__u16 ethertype; /* packet type ID field */

} __attribute__ ((packed));

/* Define FDDI LLC frame header */

struct fddihdr

{

__u8 fc; /* frame control */

__u8 daddr[FDDI_K_ALEN]; /* destination address */

__u8 saddr[FDDI_K_ALEN]; /* source address */

union

{

struct fddi_8022_1_hdr llc_8022_1;

struct fddi_8022_2_hdr llc_8022_2;

struct fddi_snap_hdr llc_snap;

} hdr;

} __attribute__ ((packed));