（1）OSI 5层模型
OSI中的层 功能 TCP/IP协议族
应用层 文件传输，电子邮件，文件服务，虚拟终端 TFTP，HTTP，SNMP，FTP，SMTP，DNS，Telnet
传输层 提供端对端的接口 TCP，UDP
网络层 为数据包选择路由 IP，ICMP，RIP，OSPF，BGP，IGMP
数据链路层 传输有地址的帧以及错误检测功能 SLIP，CSLIP，PPP，ARP，RARP，MTU
物理层 以二进制数据形式在物理媒体上传输数据 ISO2110，IEEE802，IEEE802.2
常用包的数据结构:
>>> ls(Ether)
dst : DestMACField = (None)
src : SourceMACField = (None)
type : XShortEnumField = (36864)
>>> ls(UDP)
sport : ShortEnumField = (53)
dport : ShortEnumField = (53)
len : ShortField = (None)
chksum : XShortField = (None)
>>> ls(TCP)
sport : ShortEnumField = (20)
dport : ShortEnumField = (80)
seq : IntField = (0)
ack : IntField = (0)
dataofs : BitField (4 bits) = (None)
reserved : BitField (3 bits) = (0)
flags : FlagsField (9 bits) = (<Flag 2 (S)>)
window : ShortField = (8192)
chksum : XShortField = (None)
urgptr : ShortField = (0)
options : TCPOptionsField = ([])
>>> ls(IP)
version : BitField (4 bits) = (4)
ihl : BitField (4 bits) = (None)
tos : XByteField = (0)
len : ShortField = (None)
id : ShortField = (1)
flags : FlagsField (3 bits) = (<Flag 0 ()>)
frag : BitField (13 bits) = (0)
ttl : ByteField = (64)
proto : ByteEnumField = (0)
chksum : XShortField = (None)
src : SourceIPField = (None)
dst : DestIPField = (None)
options : PacketListField = ([])
>>> ls(ARP)
hwtype : XShortField = (1)
ptype : XShortEnumField = (2048)
hwlen : ByteField = (6)
plen : ByteField = (4)
op : ShortEnumField = (1)
hwsrc : ARPSourceMACField = (None)
psrc : SourceIPField = (None)
hwdst : MACField = ('00:00:00:00:00:00')
pdst : IPField = ('0.0.0.0')
>>> ls(ICMP)
type : ByteEnumField = (8)
code : MultiEnumField = (0)
chksum : XShortField = (None)
id : ConditionalField = (0)
seq : ConditionalField = (0)
ts_ori : ConditionalField = (79546771)
ts_rx : ConditionalField = (79546771)
ts_tx : ConditionalField = (79546771)
gw : ConditionalField = ('0.0.0.0')
ptr : ConditionalField = (0)
reserved : ConditionalField = (0)
addr_mask : ConditionalField = ('0.0.0.0')
unused : ConditionalField = (0)
>>> ls(DNS)
id : ShortField = (0)
qr : BitField = (0)
opcode : BitEnumField = (0)
aa : BitField = (0)
tc : BitField = (0)
rd : BitField = (0)
ra : BitField = (0)
z : BitField = (0)
rcode : BitEnumField = (0)
qdcount : DNSRRCountField = (None)
ancount : DNSRRCountField = (None)
nscount : DNSRRCountField = (None)
arcount : DNSRRCountField = (None)
qd : DNSQRField = (None)
an : DNSRRField = (None)
ns : DNSRRField = (None)
ar : DNSRRField = (None)
查看scapy函数
>>> lsc()
IPID_count : Identify IP id values classes in a list of packets
arpcachepoison : Poison target's cache with (your MAC,victim's IP) couple
arping : Send ARP who-has requests to determine which hosts are up
bind_layers : Bind 2 layers on some specific fields' values
bridge_and_sniff : Forward traffic between interfaces if1 and if2, sniff and return
chexdump : Build a per byte hexadecimal representation
computeNIGroupAddr : Compute the NI group Address. Can take a FQDN as input parameter
corrupt_bits : Flip a given percentage or number of bits from a string
corrupt_bytes : Corrupt a given percentage or number of bytes from a string
defrag : defrag(plist) -> ([not fragmented], [defragmented],
defragment : defrag(plist) -> plist defragmented as much as possible
dhcp_request : --
dyndns_add : Send a DNS add message to a nameserver for "name" to have a new "rdata"
dyndns_del : Send a DNS delete message to a nameserver for "name"
etherleak : Exploit Etherleak flaw
fletcher16_checkbytes: Calculates the Fletcher-16 checkbytes returned as 2 byte binary-string.
fletcher16_checksum : Calculates Fletcher-16 checksum of the given buffer.
fragleak : --
fragleak2 : --
fragment : Fragment a big IP datagram
fuzz : Transform a layer into a fuzzy layer by replacing some default values by random objects
getmacbyip : Return MAC address corresponding to a given IP address
getmacbyip6 : Returns the MAC address corresponding to an IPv6 address
hexdiff : Show differences between 2 binary strings
hexdump : Build a tcpdump like hexadecimal view
hexedit : --
hexstr : --
import_hexcap : --
is_promisc : Try to guess if target is in Promisc mode. The target is provided by its ip.
linehexdump : Build an equivalent view of hexdump() on a single line
ls : List available layers, or infos on a given layer class or name
neighsol : Sends an ICMPv6 Neighbor Solicitation message to get the MAC address of the neighbor with specified IPv6 address addr
overlap_frag : Build overlapping fragments to bypass NIPS
promiscping : Send ARP who-has requests to determine which hosts are in promiscuous mode
rdpcap : Read a pcap or pcapng file and return a packet list
report_ports : portscan a target and output a LaTeX table
restart : Restarts scapy
send : Send packets at layer 3
sendp : Send packets at layer 2
sendpfast : Send packets at layer 2 using tcpreplay for performance
sniff :
split_layers : Split 2 layers previously bound
sr : Send and receive packets at layer 3
sr1 : Send packets at layer 3 and return only the first answer
sr1flood : Flood and receive packets at layer 3 and return only the first answer
srbt : send and receive using a bluetooth socket
srbt1 : send and receive 1 packet using a bluetooth socket
srflood : Flood and receive packets at layer 3
srloop : Send a packet at layer 3 in loop and print the answer each time
srp : Send and receive packets at layer 2
srp1 : Send and receive packets at layer 2 and return only the first answer
srp1flood : Flood and receive packets at layer 2 and return only the first answer
srpflood : Flood and receive packets at layer 2
srploop : Send a packet at layer 2 in loop and print the answer each time
tcpdump : Run tcpdump or tshark on a list of packets
traceroute : Instant TCP traceroute
traceroute6 : Instant TCP traceroute using IPv6
traceroute_map : Util function to call traceroute on multiple targets, then
tshark : Sniff packets and print them calling pkt.summary(), a bit like text wireshark
wireshark : Run wireshark on a list of packets
wrpcap : Write a list of packets to a pcap file