ethereal文件格式libpcap

libpcap 的数组表示:低位在前
文件头 24字节
1 32-bit magic number   D4C3B2A1
2 16-bit major version number 0200
3 16-bit minor version number 0400
4 32-bit time zone offset 未使用 全零
5 32-bit time stamp accuracy 未使用 全零
6 32-bit snapshot length
7 32-bit link layer type

0		BSD loopback devices, except for later OpenBSD
	1		Ethernet, and Linux loopback devices
	6		802.5 Token Ring
	7		ARCnet
	8		SLIP
	9		PPP
	10		FDDI
	100		LLC/SNAP-encapsulated ATM
	101		"raw IP", with no link
	102		BSD/OS SLIP
	103		BSD/OS PPP
	104		Cisco HDLC
	105		802.11
	108		later OpenBSD loopback devices (with the AF_value in network byte order)
	113		special Linux "cooked" capture
	114		LocalTalk

帧头 16字节
1 32-bit time zone offset  秒
2 32-bit time stamp accuracy 毫秒
3 32-bit captured length
4 32-bit packet length
[用户数据]


对于Ethernet, and Linux loopback devices
以太网包头
1 48-bit  目标 Physical Address
2 48-bit  源 Physical Address
3 16-bit 类型
             0x0800 IP包
             0x0805 ARP包
[以太网数据]


对于IP包可参照TCP/IP中的说明