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Commit 8c93b479 authored by Pierre LALET's avatar Pierre LALET
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Add & test DNS over TCP, update dnstypes

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scapy/layers/dns.py
+ 55
− 30
View file @ 8c93b479
......@@ -14,7 +14,7 @@ from scapy.packet import *
from scapy.fields import *
from scapy.ansmachine import *
from scapy.sendrecv import sr1
from scapy.layers.inet import IP, DestIPField, UDP
from scapy.layers.inet import IP, DestIPField, UDP, TCP
from scapy.layers.inet6 import DestIP6Field
class DNSStrField(StrField):
......@@ -233,36 +233,43 @@ class RDLenField(Field):
rdataf = pkt.get_field("rdata")
x = len(rdataf.i2m(pkt, pkt.rdata))
return x
class DNS(Packet):
name = "DNS"
fields_desc = [ ShortField("id", 0),
BitField("qr", 0, 1),
BitEnumField("opcode", 0, 4, {0:"QUERY",1:"IQUERY",2:"STATUS"}),
BitField("aa", 0, 1),
BitField("tc", 0, 1),
BitField("rd", 1, 1),
BitField("ra", 0, 1),
BitField("z", 0, 1),
# AD and CD bits are defined in RFC 2535
BitField("ad", 0, 1), # Authentic Data
BitField("cd", 0, 1), # Checking Disabled
BitEnumField("rcode", 0, 4, {0:"ok", 1:"format-error", 2:"server-failure", 3:"name-error", 4:"not-implemented", 5:"refused"}),
DNSRRCountField("qdcount", None, "qd"),
DNSRRCountField("ancount", None, "an"),
DNSRRCountField("nscount", None, "ns"),
DNSRRCountField("arcount", None, "ar"),
DNSQRField("qd", "qdcount"),
DNSRRField("an", "ancount"),
DNSRRField("ns", "nscount"),
DNSRRField("ar", "arcount",0) ]
fields_desc = [
ConditionalField(ShortField("length", None),
lambda p: isinstance(p.underlayer, TCP)),
ShortField("id", 0),
BitField("qr", 0, 1),
BitEnumField("opcode", 0, 4, {0: "QUERY", 1: "IQUERY", 2: "STATUS"}),
BitField("aa", 0, 1),
BitField("tc", 0, 1),
BitField("rd", 1, 1),
BitField("ra", 0, 1),
BitField("z", 0, 1),
# AD and CD bits are defined in RFC 2535
BitField("ad", 0, 1), # Authentic Data
BitField("cd", 0, 1), # Checking Disabled
BitEnumField("rcode", 0, 4, {0: "ok", 1: "format-error",
2: "server-failure", 3: "name-error",
4: "not-implemented", 5: "refused"}),
DNSRRCountField("qdcount", None, "qd"),
DNSRRCountField("ancount", None, "an"),
DNSRRCountField("nscount", None, "ns"),
DNSRRCountField("arcount", None, "ar"),
DNSQRField("qd", "qdcount"),
DNSRRField("an", "ancount"),
DNSRRField("ns", "nscount"),
DNSRRField("ar", "arcount", 0),
]
def answers(self, other):
return (isinstance(other, DNS)
and self.id == other.id
and self.qr == 1
and other.qr == 0)
def mysummary(self):
type = ["Qry","Ans"][self.qr]
name = ""
......@@ -276,14 +283,30 @@ class DNS(Packet):
name = ' "%s"' % self.qd.qname
return 'DNS %s%s ' % (type, name)
dnstypes = { 0:"ANY", 255:"ALL",
1:"A", 2:"NS", 3:"MD", 4:"MF", 5:"CNAME", 6:"SOA", 7: "MB", 8:"MG",
9:"MR",10:"NULL",11:"WKS",12:"PTR",13:"HINFO",14:"MINFO",15:"MX",16:"TXT",
17:"RP",18:"AFSDB",28:"AAAA", 33:"SRV",38:"A6",39:"DNAME",
41:"OPT", 43:"DS", 46:"RRSIG", 47:"NSEC", 48:"DNSKEY",
50: "NSEC3", 51: "NSEC3PARAM", 32769:"DLV" }
def post_build(self, pkt, pay):
if isinstance(self.underlayer, TCP) and self.length is None:
pkt = struct.pack("!H", len(pkt) - 2) + pkt[2:]
return pkt + pay
# http://www.iana.org/assignments/dns-parameters/dns-parameters.xhtml
dnstypes = {
0:"ANY",
1: "A", 2: "NS", 3: "MD", 4: "MF", 5: "CNAME", 6: "SOA", 7: "MB", 8: "MG",
9: "MR", 10: "NULL", 11: "WKS", 12: "PTR", 13: "HINFO", 14: "MINFO",
15: "MX", 16: "TXT", 17: "RP", 18: "AFSDB", 19: "X25", 20: "ISDN", 21: "RT",
22: "NSAP", 23: "NSAP-PTR", 24: "SIG", 25: "KEY", 26: "PX", 27: "GPOS",
28: "AAAA", 29: "LOC", 30: "NXT", 31: "EID", 32: "NIMLOC", 33: "SRV",
34: "ATMA", 35: "NAPTR", 36: "KX", 37: "CERT", 38: "A6", 39: "DNAME",
40: "SINK", 41: "OPT", 42: "APL", 43: "DS", 44: "SSHFP", 45: "IPSECKEY",
46: "RRSIG", 47: "NSEC", 48: "DNSKEY", 49: "DHCID", 50: "NSEC3",
51: "NSEC3PARAM", 55: "HIP", 56: "NINFO", 57: "RKEY", 58: "TALINK",
99: "SPF", 100: "UINFO", 101: "UID", 102: "GID", 103: "UNSPEC", 249: "TKEY",
250: "TSIG",
32768: "TA", 32769:"DLV",
}
dnsqtypes = {251:"IXFR",252:"AXFR",253:"MAILB",254:"MAILA",255:"ALL"}
dnsqtypes = {251: "IXFR", 252: "AXFR", 253: "MAILB", 254: "MAILA", 255: "ALL"}
dnsqtypes.update(dnstypes)
dnsclasses = {1: 'IN', 2: 'CS', 3: 'CH', 4: 'HS', 255: 'ANY'}
......@@ -627,6 +650,8 @@ bind_layers(UDP, DNS, dport=53)
bind_layers(UDP, DNS, sport=53)
DestIPField.bind_addr(UDP, "224.0.0.251", dport=5353)
DestIP6Field.bind_addr(UDP, "ff02::fb", dport=5353)
bind_layers(TCP, DNS, dport=53)
bind_layers(TCP, DNS, sport=53)
@conf.commands.register
......
test/regression.uts
+ 14
− 0
View file @ 8c93b479
......@@ -4822,6 +4822,20 @@ pkt = IP(len=42, ihl=6, options=[IPOption_RR()]) / UDP() / ("A" * 10)
bpkt = IP(str(pkt))
assert bpkt.chksum == 0x70bd and bpkt.payload.chksum == 0xbb17
= DNS
* DNS over UDP
pkt = IP(str(IP(src="10.0.0.1", dst="8.8.8.8")/UDP(sport=RandShort(), dport=53)/DNS(qd=DNSQR(qname="secdev.org."))))
assert UDP in pkt and isinstance(pkt[UDP].payload, DNS)
assert pkt[UDP].dport == 53 and pkt[UDP].length is None
assert pkt[DNS].qdcount == 1 and pkt[DNS].qd.qname == "secdev.org."
* DNS over TCP
pkt = IP(str(IP(src="10.0.0.1", dst="8.8.8.8")/TCP(sport=RandShort(), dport=53, flags="P")/DNS(qd=DNSQR(qname="secdev.org."))))
assert TCP in pkt and isinstance(pkt[TCP].payload, DNS)
assert pkt[TCP].dport == 53 and pkt[DNS].length is not None
assert pkt[DNS].qdcount == 1 and pkt[DNS].qd.qname == "secdev.org."
= Layer binding
* Test DestMACField & DestIPField
......
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