def compose_options(options):
tcpsoption = ""
avail_opt_len = 40
for opt in options:
if opt[0] == 'NOP':
if avail_opt_len < 1:
break
nop = tcplib.create_nop()
tcpsoption += nop
avail_opt_len -= 1
continue
if opt[0] == 'MSS':
if avail_opt_len < 4:
break
mssoption = tcplib.create_mss(opt[1])
tcpsoption += mssoption
avail_opt_len -= 4
continue
if opt[0] == 'WSCALE':
if avail_opt_len < 3:
break
wsoption = tcplib.create_winscale(opt[1])
tcpsoption += wsoption
avail_opt_len -= 3
continue
if opt[0] == 'SACKOK':
if avail_opt_len < 2:
break
sackok_option = tcplib.create_sackok()
tcpsoption += sackok_option
avail_opt_len -= 2
continue
if opt[0] == 'TIMESTAMP':
if avail_opt_len < 10:
break
tsoption = tcplib.create_timestamp(opt[1], opt[2])
tcpsoption += tsoption
avail_opt_len -= 10
continue
if opt[0] == 'MP_CAPABLE':
length = 20 if opt[3] is not None else 12
if avail_opt_len < length:
break
mpcap_option = tcplib.create_mpcapable(opt[1], opt[2], opt[3])
tcpsoption += mpcap_option
avail_opt_len -= length
continue
if opt[0] == 'MP_DSS':
length = (14 if opt[6] is not None else 0) + (4 if opt[4] is not None else 0) + \
(4 if opt[4] is not None and opt[3] else 0) + (4 if opt[5] else 0)
if avail_opt_len < length:
break
dss_option = tcplib.create_mpdss(opt[1], opt[2], opt[3], opt[4], \
opt[5], opt[6], opt[7])
tcpsoption += dss_option
avail_opt_len -= length
continue
if opt[0] == 'MP_ACK':
if avail_opt_len < 10:
break
dataack_option = tcplib.create_mpack(opt[1])
tcpsoption += dataack_option
avail_opt_len -= 10
continue
tcpsoption += tcplib.check_padding(tcpsoption)
return tcpsoption
def compose_options(options):
tcpsoption = ""
avail_opt_len = 40
for opt in options:
if opt[0] == 'NOP':
if avail_opt_len < 1:
break
nop = tcplib.create_nop()
tcpsoption += nop
avail_opt_len -= 1
continue
if opt[0] == 'MSS':
if avail_opt_len < 4:
break
mssoption = tcplib.create_mss(opt[1])
tcpsoption += mssoption
avail_opt_len -= 4
continue
if opt[0] == 'WSCALE':
if avail_opt_len < 3:
break
wsoption = tcplib.create_winscale(opt[1])
tcpsoption += wsoption
avail_opt_len -= 3
continue
if opt[0] == 'SACKOK':
if avail_opt_len < 2:
break
sackok_option = tcplib.create_sackok()
tcpsoption += sackok_option
avail_opt_len -= 2
continue
if opt[0] == 'TIMESTAMP':
if avail_opt_len < 10:
break
tsoption = tcplib.create_timestamp(opt[1], opt[2])
tcpsoption += tsoption
avail_opt_len -= 10
continue
if opt[0] == 'MP_CAPABLE':
if avail_opt_len < 12:
break
mpcap_option = tcplib.create_mpcapable(opt[1], opt[2])
tcpsoption += mpcap_option
avail_opt_len -= 12
continue
if opt[0] == 'MP_DATA':
if avail_opt_len < 16:
break
# (Dsn (8 Byte), Dlen (2 Byte), Ssn(4 Byte))
dsn_option = tcplib.create_mpdata(opt[1], opt[2], opt[3])
tcpsoption += dsn_option
avail_opt_len -= 16
continue
if opt[0] == 'MP_ACK':
if avail_opt_len < 10:
break
dataack_option = tcplib.create_mpack(opt[1])
tcpsoption += dataack_option
avail_opt_len -= 10
continue
tcpsoption += tcplib.check_padding(tcpsoption)
return tcpsoption
dest = struct.unpack('!L',socket.inet_aton(deststr))[0]
return (src, dest)
#
# tcp options
#
MSSval = 512
WSval = 6
TSval = 12345678
SynTsEcr = 0xffff0000 # Initiator's value
mssoption = tcplib.create_mss(MSSval)
wsoption = tcplib.create_winscale(WSval)
tsoption = tcplib.create_timestamp(TSval,0)
sackokoption = tcplib.create_sackok()
#
# mpcapable option
#
mptcp_token = 0x0D0C0B0A
mptcp_isn = 0x0102030405060000
mpcap_option = tcplib.create_mpcapable(mptcp_token, mptcp_isn)
#
# constants for ip and tcp header
#
ipid = 0x4321
ipttl = 255
otcpseqno = 0xabcdef
tcpseqno = 0xabcdef