from construct3 import Struct, Sequence, int8, Embedded, Padding, Computed, this, anchor, Container
x = Struct(
"a" / int8,
"b" / int8,
Padding(2),
"c" / int8,
Embedded(Struct(
"d" / int8,
"e" / int8,
"x" / Computed(this.d - this.a),
)),
"f" / int8,
# "g" / anchor,
)
#print x.unpack("ABppCDEF")
print repr(x.pack(Container(a=1,b=2,c=3,d=4,e=5,f=6)))
y = Sequence(
int8,
int8,
Padding(2),
int8,
Embedded(Sequence(
int8,
int8,
Computed(this[4] - this[0]),
)),
int8,
from construct3 import Struct, Sequence, int8, Embedded, Padding, Computed, this, anchor, Container
x = Struct(
"a" / int8,
"b" / int8,
Padding(2),
"c" / int8,
Embedded(Struct(
"d" / int8,
"e" / int8,
"x" / Computed(this.d - this.a),
)),
"f" / int8,
# "g" / anchor,
)
#print x.unpack("ABppCDEF")
print repr(x.pack(Container(a=1, b=2, c=3, d=4, e=5, f=6)))
y = Sequence(
int8,
int8,
Padding(2),
int8,
Embedded(Sequence(
int8,
int8,
Computed(this[4] - this[0]),
)),
int8,
anchor,
ipaddr = byte[4]
print ipaddr.unpack("ABCD") # [65, 66, 67, 68]
ipaddr = Adapter(byte[4],
decode=lambda arr, _: ".".join(map(str, arr)),
encode=lambda ipstr, _: map(int, ipstr.split(".")))
print ipaddr.unpack("ABCD") # 65.66.67.68
print repr(ipaddr.pack("127.0.0.1")) # '\x7f\x00\x00\x01'
mac_addr = Adapter(
byte[6],
decode=lambda arr, _: "-".join(map("%02x".__mod__, arr)),
encode=lambda macstr, _: macstr.replace("-", "").decode("hex"))
ethernet_header = Struct("destination" / mac_addr, "source" / mac_addr,
"type" / int16ub)
print ethernet_header.unpack("123456ABCDEF\x86\xDD")
ethernet_header = Struct(
"destination" / mac_addr, "source" / mac_addr, "type" / Enum(
int16ub,
IPv4=0x0800,
ARP=0x0806,
RARP=0x8035,
X25=0x0805,
IPX=0x8137,
IPv6=0x86DD,
))
print ethernet_header.unpack("123456ABCDEF\x86\xDD")
ipv4_header = Struct(
+BitStruct(
"version" / nibble,
"header_length" / Adapter(nibble, decode = lambda obj, _: obj * 4, encode = lambda obj, _: obj / 4),
),
"tos" / BitStruct(
"precedence" / Bits(3),
"minimize_delay" / flag,
"high_throuput" / flag,
"high_reliability" / flag,
"minimize_cost" / flag,
Padding(1),
),
"total_length" / int16ub,
"payload_length" / Computed(this.total_length - this.header_length),
int16ub / "identification",
+BitStruct(
"flags" / Struct(
Padding(1),
"dont_fragment" / flag,
"more_fragments" / flag,
),
"frame_offset" / Bits(13),
),
"ttl" / int8u,
"protocol" / Enum(int8u, ICMP = 1, TCP = 6, UDP = 17),
"checksum" / int16ub,
"source" / ipaddr,
"destination" / ipaddr,
"options" / Raw(this.header_length - 20),
)
ipaddr = Adapter(byte[4],
decode = lambda arr, _: ".".join(map(str, arr)),
encode = lambda ipstr, _: map(int, ipstr.split("."))
)
print ipaddr.unpack("ABCD") # 65.66.67.68
print repr(ipaddr.pack("127.0.0.1")) # '\x7f\x00\x00\x01'
mac_addr = Adapter(byte[6],
decode = lambda arr, _: "-".join(map("%02x".__mod__, arr)),
encode = lambda macstr, _: macstr.replace("-", "").decode("hex")
)
ethernet_header = Struct(
"destination" / mac_addr,
"source" / mac_addr,
"type" / int16ub
)
print ethernet_header.unpack("123456ABCDEF\x86\xDD")
ethernet_header = Struct(
"destination" / mac_addr,
"source" / mac_addr,
"type" / Enum(int16ub,
IPv4 = 0x0800,
ARP = 0x0806,
RARP = 0x8035,
X25 = 0x0805,
IPX = 0x8137,
IPv6 = 0x86DD,
