local nmap = require "nmap" local stdnse = require "stdnse" local table = require "table" local bin = require "bin" local packet = require "packet" local ipOps = require "ipOps" local target = require "target" local coroutine = require "coroutine" local string = require "string" local io = require "io" description = [[ Discovers targets that have IGMP Multicast memberships and grabs interesting information. The scripts works by sending IGMP Membership Query message to the 224.0.0.1 All Hosts multicast address and listening for IGMP Membership Report messages. The script then extracts all the interesting information from the report messages such as the version, group, mode, source addresses (depending on the version). The script defaults to sending an IGMPv2 Query but this could be changed to another version (version 1 or 3) or to sending queries of all three version. If no interface was specified as a script argument or with the -e option, the script will proceed to sending queries through all the valid ethernet interfaces. ]] --- -- @args broadcast-igmp-discovery.timeout Time to wait for reports in seconds. -- Defaults to 5 seconds. -- -- @args broadcast-igmp-discovery.version IGMP version to use. Could be -- 1, 2, 3 or all. Defaults to 2 -- -- @args broadcast-igmp-discovery.interface Network interface to use. -- -- @args broadcast-igmp-discovery.mgroupnamesdb Database with multicast group names -- --@usage -- nmap --script broadcast-igmp-discovery -- nmap --script broadcast-igmp-discovery -e wlan0 -- nmap --script broadcast-igmp-discovery -- --script-args 'broadcast-igmp-discovery.version=all, broadcast-igmp-discovery.timeout=3' -- --@output --Pre-scan script results: -- | broadcast-igmp-discovery: -- | 192.168.2.2 -- | Interface: tap0 -- | Version: 3 -- | Group: 239.1.1.1 -- | Mode: EXCLUDE -- | Description: Organization-Local Scope (rfc2365) -- | Group: 239.1.1.2 -- | Mode: EXCLUDE -- | Description: Organization-Local Scope (rfc2365) -- | Group: 239.1.1.44 -- | Mode: INCLUDE -- | Description: Organization-Local Scope (rfc2365) -- | Sources: -- | 192.168.31.1 -- | 192.168.1.3 -- | Interface: wlan0 -- | Version: 2 -- | Group: 239.255.255.250 -- | Description: Organization-Local Scope (rfc2365) -- | 192.168.1.3 -- | Interface: wlan0 -- | Version: 2 -- | Group: 239.255.255.253 -- | Description: Organization-Local Scope (rfc2365) -- |_ Use the newtargets script-arg to add the results as targets -- -- -- The Multicast Group names DB can be created by the following script: -- -- #!/usr/bin/awk -f -- BEGIN { FS="<|>"; } -- /.*-.*<\/addr>/ { T=$3; FS="-"; $0=T; addr1=$1; addr2=$2; FS="<|>"; } -- /[^-]*<\/addr>/ { addr1=$3; addr2=$3; } -- // { desc=$3; } -- /nselib/data/mgroupnames.db prerule = function() if nmap.address_family() ~= 'inet' then stdnse.verbose1("is IPv4 only.") return false end if ( not(nmap.is_privileged()) ) then stdnse.verbose1("not running due to lack of privileges.") return false end return true end author = "Hani Benhabiles" license = "Same as Nmap--See https://nmap.org/book/man-legal.html" categories = {"discovery", "safe", "broadcast"} --- Parses a raw igmp packet and return a structured packet. -- @param data string IGMP Raw packet. -- @return response table Structured igmp packet. local igmpParse = function(data) local index local response = {} local group, source -- Report type (0x12 == v1, 0x16 == v2, 0x22 == v3) index, response.type = bin.unpack(">C", data, index) if response.type == 0x12 or response.type == 0x16 then -- Max response time index, response.maxrt = bin.unpack(">C", data, index) -- Checksum index, response.checksum = bin.unpack(">S", data, index) -- Multicast group index, response.group = bin.unpack("= 12 then -- Skip reserved byte index = index + 1 -- Checksum index, response.checksum = bin.unpack(">S", data, index) -- Skip reserved byte index = index + 2 -- Number of groups index, response.ngroups = bin.unpack(">S", data, index) response.groups = {} for i=1,response.ngroups do group = {} -- Mode is either INCLUDE or EXCLUDE index, group.mode = bin.unpack(">C", data, index) -- Auxiliary data length in the group record (in 32bits units) index, group.auxdlen = bin.unpack(">C", data, index) -- Number of source addresses index, group.nsrc = bin.unpack(">S", data, index) index, group.address = bin.unpack(" 0 then for i=1,group.nsrc do index, source = bin.unpack("CCSI", 0x11, -- Membership Query, same for all versions version == 1 and 0 or 0x16, -- Max response time: 10 Seconds, for version 2 and 3 0, -- Checksum, calculated later 0 -- Multicast Address: 0.0.0.0 ) if version == 3 then igmp_raw = bin.pack(">ACCSI", igmp_raw, 0, -- Reserved = 4 bits (Should be zeroed) -- Supress Flag = 1 bit -- QRV (Querier's Robustness Variable) = 3 bits -- all are set to 0 0x10, -- QQIC (Querier's Query Interval Code) in seconds = Set to 0 to get insta replies. 0x0001, -- Number of sources (in the next arrays) = 1 ( Our IP only) ipOps.todword(interface.address) -- Source = Our IP address ) end igmp_raw = igmp_raw:sub(1,2) .. bin.pack(">S", packet.in_cksum(igmp_raw)) .. igmp_raw:sub(5) return igmp_raw end local igmpQuery; --- Sends an IGMP Membership query. -- @param interface Network interface to send on. -- @param version IGMP version. Could be 1, 2, 3 or all. igmpQuery = function(interface, version) local srcip = interface.address local dstip = "224.0.0.1" if version == 'all' then -- Small pause to let listener begin and not miss reports. stdnse.sleep(0.5) igmpQuery(interface, 3) igmpQuery(interface, 2) igmpQuery(interface, 1) else local igmp_raw = igmpRaw(interface, version) local ip_raw = bin.pack("H", "45c00040ed780000010218bc0a00c8750a00c86b") .. igmp_raw local igmp_packet = packet.Packet:new(ip_raw, ip_raw:len()) igmp_packet:ip_set_bin_src(ipOps.ip_to_str(srcip)) igmp_packet:ip_set_bin_dst(ipOps.ip_to_str(dstip)) igmp_packet:ip_set_len(#igmp_packet.buf) igmp_packet:ip_count_checksum() local sock = nmap.new_dnet() sock:ethernet_open(interface.device) -- Ethernet IPv4 multicast, our ethernet address and type IP local eth_hdr = bin.pack("HAH", "01 00 5e 00 00 01", interface.mac, "08 00") sock:ethernet_send(eth_hdr .. igmp_packet.buf) sock:ethernet_close() end end -- Function to compare weight of an IGMP response message. -- Used to sort elements in responses table. local respCompare = function(a,b) return ipOps.todword(a.src) + a.type + (a.ngroups or ipOps.todword(a.group)) < ipOps.todword(b.src) + b.type + (b.ngroups or ipOps.todword(b.group)) end local mgroup_names_fetch = function(filename) local groupnames_db = {} local file = io.open(filename, "r") if not file then return false end for l in file:lines() do groupnames_db[#groupnames_db + 1] = stdnse.strsplit("\t", l) end file:close() return groupnames_db end local mgroup_name_identify = function(db, ip) --stdnse.debug1("'%s'", ip) for _, mg in ipairs(db) do local ip1 = mg[1] local ip2 = mg[2] local desc = mg[3] --stdnse.debug1("try: %s <= %s <= %s (%s)", ip1, ip, ip2, desc) if (not ipOps.compare_ip(ip, "lt", ip1) and not ipOps.compare_ip(ip2, "lt", ip)) then --stdnse.debug1("found! %s <= %s <= %s (%s)", ip1, ip, ip2, desc) return desc end end return false end action = function(host, port) local timeout = stdnse.parse_timespec(stdnse.get_script_args(SCRIPT_NAME .. ".timeout")) local version = stdnse.get_script_args(SCRIPT_NAME .. ".version") or 2 local interface = stdnse.get_script_args(SCRIPT_NAME .. ".interface") timeout = (timeout or 7) * 1000 if version ~= 'all' then version = tonumber(version) end local responses, results, interfaces, lthreads = {}, {}, {}, {} local result, grouptable, sourcetable local group_names_fname = stdnse.get_script_args(SCRIPT_NAME .. ".mgroupnamesdb") or nmap.fetchfile("nselib/data/mgroupnames.db") local mg_names_db = group_names_fname and mgroup_names_fetch(group_names_fname) -- Check the interface interface = interface or nmap.get_interface() if interface then -- Get the interface information interface = nmap.get_interface_info(interface) if not interface then return stdnse.format_output(false, ("Failed to retrieve %s interface information."):format(interface)) end interfaces = {interface} stdnse.debug1("Will use %s interface.", interface.shortname) else local ifacelist = nmap.list_interfaces() for _, iface in ipairs(ifacelist) do -- Match all ethernet interfaces if iface.address and iface.link=="ethernet" and iface.address:match("%d+%.%d+%.%d+%.%d+") then stdnse.debug1("Will use %s interface.", iface.shortname) table.insert(interfaces, iface) end end end -- We should iterate over interfaces for _, interface in pairs(interfaces) do local co = stdnse.new_thread(igmpListener, interface, timeout, responses) igmpQuery(interface, version) lthreads[co] = true end local condvar = nmap.condvar(responses) -- Wait for the listening threads to finish repeat for thread in pairs(lthreads) do if coroutine.status(thread) == "dead" then lthreads[thread] = nil end end if ( next(lthreads) ) then condvar("wait") end until next(lthreads) == nil; -- Output useful info from the responses if #responses > 0 then -- We should sort our list here. -- This is useful to have consistent results for tools such as Ndiff. table.sort(responses, respCompare) for _, response in pairs(responses) do result = {} result.name = response.src table.insert(result, "Interface: " .. response.interface) -- Add to new targets if newtargets script arg provided if target.ALLOW_NEW_TARGETS then target.add(response.src) end if response.type == 0x12 then table.insert(result, "Version: 1") table.insert(result, "Multicast group: ".. response.group) elseif response.type == 0x16 then table.insert(result, "Version: 2") table.insert(result, "Group: ".. response.group) local mg_desc = mgroup_name_identify(mg_names_db, response.group) if mg_desc then table.insert(result, "Description: ".. mg_desc) end elseif response.type == 0x22 then table.insert(result, "Version: 3") for _, group in pairs(response.groups) do grouptable = {} grouptable.name = "Group: " .. group.address if group.mode == 0x01 then table.insert(grouptable, "Mode: INCLUDE") elseif group.mode == 0x02 then table.insert(grouptable, "Mode: EXCLUDE") end local mg_desc = mgroup_name_identify(mg_names_db, group.address) if mg_desc then table.insert(grouptable, "Description: ".. mg_desc) end if group.nsrc > 0 then sourcetable = {} sourcetable.name = "Sources:" table.insert(sourcetable, group.src) table.insert(grouptable, sourcetable) end table.insert(result, grouptable) end end table.insert(results, result) end if #results>0 and not target.ALLOW_NEW_TARGETS then table.insert(results,"Use the newtargets script-arg to add the results as targets") end return stdnse.format_output(true, results) end end