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Diffstat (limited to 'scripts/external_libs/scapy-2.3.1/python3/scapy/contrib/igmp.py')
| -rw-r--r-- | scripts/external_libs/scapy-2.3.1/python3/scapy/contrib/igmp.py | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/scripts/external_libs/scapy-2.3.1/python3/scapy/contrib/igmp.py b/scripts/external_libs/scapy-2.3.1/python3/scapy/contrib/igmp.py new file mode 100644 index 00000000..b3505810 --- /dev/null +++ b/scripts/external_libs/scapy-2.3.1/python3/scapy/contrib/igmp.py @@ -0,0 +1,171 @@ +#! /usr/bin/env python + +# scapy.contrib.description = IGMP/IGMPv2 +# scapy.contrib.status = loads + + +# TODO: scapy 2 has function getmacbyip, maybe it can replace igmpize +# at least from the MAC layer + +from scapy.all import * + +#-------------------------------------------------------------------------- +def isValidMCAddr(ip): + """convert dotted quad string to long and check the first octet""" + FirstOct=atol(ip)>>24 & 0xFF + return (FirstOct >= 224) and (FirstOct <= 239) + +#-------------------------------------------------------------------------- + +class IGMP(Packet): + """IGMP Message Class for v1 and v2. + +This class is derived from class Packet. You need to "igmpize" +the IP and Ethernet layers before a full packet is sent. +a=Ether(src="00:01:02:03:04:05") +b=IP(src="1.2.3.4") +c=IGMP(type=0x12, gaddr="224.2.3.4") +c.igmpize(b, a) +print("Joining IP " + c.gaddr + " MAC " + a.dst) +sendp(a/b/c, iface="en0") + + Parameters: + type IGMP type field, 0x11, 0x12, 0x16 or 0x17 + mrtime Maximum Response time (zero for v1) + gaddr Multicast Group Address 224.x.x.x/4 + +See RFC2236, Section 2. Introduction for definitions of proper +IGMPv2 message format http://www.faqs.org/rfcs/rfc2236.html + + """ + name = "IGMP" + + igmptypes = { 0x11 : "Group Membership Query", + 0x12 : "Version 1 - Membership Report", + 0x16 : "Version 2 - Membership Report", + 0x17 : "Leave Group"} + + fields_desc = [ ByteEnumField("type", 0x11, igmptypes), + ByteField("mrtime",20), + XShortField("chksum", None), + IPField("gaddr", "0.0.0.0")] + +#-------------------------------------------------------------------------- + def post_build(self, p, pay): + """Called implicitly before a packet is sent to compute and place IGMP checksum. + + Parameters: + self The instantiation of an IGMP class + p The IGMP message in hex in network byte order + pay Additional payload for the IGMP message + """ + p += pay + if self.chksum is None: + ck = checksum(p) + p = p[:2]+chr(ck>>8)+chr(ck&0xff)+p[4:] + return p + +#-------------------------------------------------------------------------- + def mysummary(self): + """Display a summary of the IGMP object.""" + + if isinstance(self.underlayer, IP): + return self.underlayer.sprintf("IGMP: %IP.src% > %IP.dst% %IGMP.type% %IGMP.gaddr%") + else: + return self.sprintf("IGMP %IGMP.type% %IGMP.gaddr%") + +#-------------------------------------------------------------------------- + def igmpize(self, ip=None, ether=None): + """Called to explicitely fixup associated IP and Ethernet headers + + Parameters: + self The instantiation of an IGMP class. + ip The instantiation of the associated IP class. + ether The instantiation of the associated Ethernet. + + Returns: + True The tuple ether/ip/self passed all check and represents + a proper IGMP packet. + False One of more validation checks failed and no fields + were adjusted. + + The function will examine the IGMP message to assure proper format. + Corrections will be attempted if possible. The IP header is then properly + adjusted to ensure correct formatting and assignment. The Ethernet header + is then adjusted to the proper IGMP packet format. + """ + +# The rules are: +# 1. the Max Response time is meaningful only in Membership Queries and should be zero +# otherwise (RFC 2236, section 2.2) + + if (self.type != 0x11): #rule 1 + self.mrtime = 0 + + if (self.adjust_ip(ip) == True): + if (self.adjust_ether(ip, ether) == True): return True + return False + +#-------------------------------------------------------------------------- + def adjust_ether (self, ip=None, ether=None): + """Called to explicitely fixup an associated Ethernet header + + The function adjusts the ethernet header destination MAC address based on + the destination IP address. + """ +# The rules are: +# 1. send to the group mac address address corresponding to the IP.dst + if ip != None and ip.haslayer(IP) and ether != None and ether.haslayer(Ether): + iplong = atol(ip.dst) + ether.dst = "01:00:5e:%02x:%02x:%02x" % ( (iplong>>16)&0x7F, (iplong>>8)&0xFF, (iplong)&0xFF ) + # print "igmpize ip " + ip.dst + " as mac " + ether.dst + return True + else: + return False + +#-------------------------------------------------------------------------- + def adjust_ip (self, ip=None): + """Called to explicitely fixup an associated IP header + + The function adjusts the IP header based on conformance rules + and the group address encoded in the IGMP message. + The rules are: + 1. Send General Group Query to 224.0.0.1 (all systems) + 2. Send Leave Group to 224.0.0.2 (all routers) + 3a.Otherwise send the packet to the group address + 3b.Send reports/joins to the group address + 4. ttl = 1 (RFC 2236, section 2) + 5. send the packet with the router alert IP option (RFC 2236, section 2) + """ + if ip != None and ip.haslayer(IP): + if (self.type == 0x11): + if (self.gaddr == "0.0.0.0"): + ip.dst = "224.0.0.1" # IP rule 1 + retCode = True + elif isValidMCAddr(self.gaddr): + ip.dst = self.gaddr # IP rule 3a + retCode = True + else: + print("Warning: Using invalid Group Address") + retCode = False + elif ((self.type == 0x17) and isValidMCAddr(self.gaddr)): + ip.dst = "224.0.0.2" # IP rule 2 + retCode = True + elif ((self.type == 0x12) or (self.type == 0x16)) and (isValidMCAddr(self.gaddr)): + ip.dst = self.gaddr # IP rule 3b + retCode = True + else: + print("Warning: Using invalid IGMP Type") + retCode = False + else: + print("Warning: No IGMP Group Address set") + retCode = False + if retCode == True: + ip.ttl=1 # IP Rule 4 + ip.options=[IPOption_Router_Alert()] # IP rule 5 + return retCode + + +bind_layers( IP, IGMP, frag=0, proto=2) + + |