author = "jah"
license = "Same as Nmap--See http://nmap.org/book/man-legal.html"
categories = {"discovery", "intrusive"}
description = [[
Obtains and prints an NTP server's monitor data.
Monitor data is a list of the most recently used (MRU) having NTP associations
with the target. Each record contains information about the most recent NTP
packet sent by a host to the target including the source and destination
addresses and the NTP version and mode of the packet. With this information it
is possible to classify associated hosts as Servers, Peers, and Clients.
A Peers command is also sent to the target and the peers list in the response
allows differentiation between configured Mode 1 Peers and clients which act
like Peers (such as the Windows W32Time service).
Associated hosts are further classified as either public or private.
Private hosts are those
having IP addresses which are not routable on the public Internet and thus can
help to form a picture about the topology of the private network on which the
target resides.
Other information revealed by the monlist and peers commands are the host with
which the target clock is synchronized and hosts which send Control Mode (6)
and Private Mode (7) commands to the target and which may be used by admins for
the NTP service.
It should be noted that the very nature of the NTP monitor data means that the
Mode 7 commands sent by this script are recorded by the target (and will often
appear in these results). Since the monitor data is a MRU list, it is probable
that you can overwrite the record of the Mode 7 command by sending an innoccuous
looking Client Mode request. This can be acheived easily using Nmap:
<code>nmap -sU -pU:123 -Pn -n --max-retries=0 <target></code>
Notes:
* The monitor list in response to the monlist command is limited to 600 associations.
* The monitor capability may not be enabled on the target in which case you may receive an error number 4 (No Data Available).
* There may be a restriction on who can perform Mode 7 commands (e.g. "restrict noquery" in <code>ntp.conf</code>) in which case you may not receive a reply.
* This script does not handle authenticating and targets expecting auth info may respond with error number 3 (Format Error).
]]
---
-- @usage
-- nmap -sU -pU:123 -Pn -n --script=ntp-monlist <target>
--
-- @output
-- PORT STATE SERVICE REASON
-- 123/udp open ntp udp-response
-- | ntp-monlist:
-- | Target is synchronised with 127.127.38.0 (reference clock)
-- | Alternative Target Interfaces:
-- | 10.17.4.20
-- | Private Servers (0)
-- | Public Servers (0)
-- | Private Peers (0)
-- | Public Peers (0)
-- | Private Clients (2)
-- | 10.20.8.69 169.254.138.63
-- | Public Clients (597)
-- | 4.79.17.248 68.70.72.194 74.247.37.194 99.190.119.152
-- | ...
-- | 12.10.160.20 68.80.36.133 75.1.39.42 108.7.58.118
-- | 68.56.205.98
-- | 2001:1400:0:0:0:0:0:1 2001:16d8:dd00:38:0:0:0:2
-- | 2002:db5a:bccd:1:21d:e0ff:feb7:b96f 2002:b6ef:81c4:0:0:1145:59c5:3682
-- | Other Associations (1)
-- |_ 127.0.0.1 seen 1949869 times. last tx was unicast v2 mode 7
-- This script uses the NTP sequence numbers and the 'more' bit found in
-- response packets in order to determine when to stop the reception loop. It
-- would be possible for a malicious target to tie-up this script by sending
-- a continuous stream of UDP datagrams.
-- Therefore MAXIMUM_EVIL has been defined to limit the number of malformed or
-- duplicate packets that will be processed before a target is rejected and
-- MAX_RECORDS simply limits the storage of valid looking NTP data to a sane
-- level.
local MAXIMUM_EVIL = 25
local MAX_RECORDS = 1200
local TIMEOUT = 5000 -- ms
local bin = require 'bin'
local bit = require 'bit'
local nmap = require 'nmap'
local ipOps = require 'ipOps'
local packet = require 'packet'
local stdnse = require 'stdnse'
local short = require 'shortport'
---
-- ntp-monlist will run against the ntp service which only runs on UDP 123
--
portrule = short.port_or_service(123, 'ntp', {'udp'})
---
-- Send an NTPv2 Mode 7 'monlist' command to the target, receive any responses
-- and parse records from those responses. If the target responds favourably
-- then send a 'peers' command and parse the responses. Finally, categorise the
-- discovered NTP associations (hosts) and output the interpreted results.
--
action = function(host, port)
-- Define the request code and implementation numbers of the NTP request to
-- send to the target.
local REQ_MON_GETLIST_1 = 42
local REQ_PEER_LIST = 0
local IMPL_XNTPD = 3
-- parsed records will be stored in this table.
local records = {['peerlist'] = {}}
-- send monlist command and fill the records table with the responses.
local inum, rcode = IMPL_XNTPD, REQ_MON_GETLIST_1
local sock = doquery(nil, host, port, inum, rcode, records)
-- end here if there are zero records.
if #records == 0 then
if sock then sock:close() end
return nil
end
-- send peers command and add the responses to records.peerlist.
rcode = REQ_PEER_LIST
sock = doquery(sock, host, port, inum, rcode, records)
if sock then sock:close() end
-- now we can interpret the collected records.
local interpreted = interpret(records, host.ip)
-- output.
return summary(interpreted)
end
---
-- Sends NTPv2 Mode 7 requests to the target, receives any responses and parses
-- records from those responses.
--
-- @param sock Socket object which must be supplied in a connected state.
-- nil may be supplied instead and a socket will be created.
-- @param host Nmap host table for the target.
-- @param port Nmap port table for the target.
-- @param inum NTP implementation number (i.e. 0, 2 or 3).
-- @param rcode NTP Mode 7 request code (e.g. 42 for 'monlist').
-- @param records Table in which to store records parsed from responses.
-- @return sock Socket object connected to the target.
--
function doquery(sock, host, port, inum, rcode, records)
local target = ('%s%s%d'):format(
host.ip, host.ip:match(':') and '.' or ':', port.number
)
records.badpkts = records.badpkts or 0
records.peerlist = records.peerlist or {}
if #records + #records.peerlist >= MAX_RECORDS then
stdnse.print_debug(1,
'MAX_RECORDS has been reached for target %s - only processing what we have already!',
target
)
if sock then sock:close() end
return nil
end
-- connect a new socket if one wasn't supplied
if not sock then
sock = nmap.new_socket()
sock:set_timeout(TIMEOUT)
local constatus, conerr = sock:connect(host, port)
if not constatus then
stdnse.print_debug(1,
'Error establishing a UDP connection for %s - %s', target, conerr
)
return nil
end
end
-- send
stdnse.print_debug(2,
'Sending NTPv2 Mode 7 Request %d Implementation %d to %s.',
rcode, inum, target
)
local ntpData = getPrivateMode(inum, rcode)
local sendstatus, senderr = sock:send(ntpData)
if not sendstatus then
stdnse.print_debug(1,
'Error sending NTP request to %s:%d - %s',
host.ip, port.number, senderr
)
sock:close()
return nil
end
local track = {
['evil_pkts'] = records.badpkts, -- a count of bad packets
['hseq'] = -1, -- highest received seq number
['mseq'] = '|', -- missing seq numbers
['errcond'] = false, -- true if sock, ntp or sane response error exists
['rcv_again'] = false, -- true if we should receive_bytes again (more bit is set or missing seq).
['target'] = target, -- target ip and port
['v'] = 2, -- ntp version
['m'] = 7, -- ntp mode
['c'] = rcode, -- ntp request code
['i'] = inum -- ntp request implementation number
}
-- receive and parse
repeat
-- receive any response
local rcvstatus, response = sock:receive_bytes(1)
-- check the response
local packet_to_parse = check(rcvstatus, response, track)
-- parse the response
if not track.errcond then
local remain = parse_v2m7(packet_to_parse, records)
if remain > 0 then
stdnse.print_debug(1,
'MAX_RECORDS has been reached while parsing NTPv2 Mode 7 Code %d responses from the target %s.',
rcode, target
)
track.rcv_again = false
elseif remain == -1 then
stdnse.print_debug(1,
'Parsing of NTPv2 Mode 7 implementation number %d request code %d response from %s has not been implemented.',
inum, rcode, target
)
track.rcv_again = false
end
end
records.badpkts = records.badpkts + track.evil_pkts
if records.badpkts >= MAXIMUM_EVIL then
stdnse.print_debug(1,
'Had %d bad packets from %s - Not continuing with this host!',
target, records.badpkts
)
sock:close()
return nil
end
until not track.rcv_again
return sock
end
---
-- Generates an NTP Private Mode (7) request with the supplied implementation
-- number and request code.
--
-- @param impl number - valid values are 0, 2 and 3 - defaults to 3
-- @param requestCode number - defaults to 42
-- @return String request.
--
function getPrivateMode(impl, requestCode)
local pay
-- udp payload is 48 bytes.
-- For a description of Mode 7 packets see NTP source file:
-- include/ntp_request.h
--
-- Flags 8bits: 0x17
-- (Response Bit: 0, More Bit: 0, Version Number 3bits: 2, Mode 3bits: 7)
-- Authenticated Bit: 0, Sequence Number 7bits: 0
-- Implementation Number 8bits: e.g. 0x03 (IMPL_XNTPD)
-- Request Code 8bits: e.g. 0x2a (MON_GETLIST_1)
-- Err 4bits: 0, Number of Data Items 12bits: 0
-- MBZ 4bits: 0, Size of Data Items 12bits: 0
pay = string.char(
0x17, 0x00, impl or 0x03, requestCode or 0x2a,
0x00, 0x00, 0x00, 0x00
)
-- Data 40 Octets: 0
pay = pay .. string.char(0x00):rep(40)
-- The following are optional if the Authenticated bit is set:
-- Encryption Keyid 4 Octets: 0
-- Message Authentication Code 16 Octets (MD5): 0
return pay
end
---
-- Checks that the response from the target is a valid NTP response.
--
-- Starts by checking that the socket read was successful and then creates a
-- packet object from the response (with dummy IP and UDP headers). Then
-- perform checks that ensure that the response is of the expected type and
-- length, that the records in the response are of the correct size and that
-- the response is part of a sequence of 1 or more responses and is not a
-- duplicate.
--
-- @param status boolean returned from a socket read operation.
-- @param response string response returned from a socket operation.
-- @param track table used for tracking a sequence of NTP responses.
-- @return A Packet object ready for parsing or
-- nil if the response does not pass all checks.
--
function check(status, response, track)
-- check for socket error
if not status then
track.errcond = true
track.rcv_again = false
if track.rcv_again then -- we were expecting more responses
stdnse.print_debug(1,
'Socket error while reading from %s - %s', track.target, response
)
end
return nil
end
-- reset flags
track.errcond = false
track.rcv_again = false
-- create a packet object
local pkt = make_udp_packet(response)
if pkt == nil then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Failed to create a Packet object with response from %s', track.target
)
return nil
end
-- off is the start of udp payload i.e. NTP
local off = 28
-- NTP sanity checks
local val
-- NTP data must be at least 8 bytes
val = response:len()
if val < 8 then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Expected a response of at least 8 bytes from %s, got %d bytes.',
track.target, val
)
return nil
end
-- response bit set
if bit.rshift(pkt:u8(off), 7) ~= 1 then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Bad response from %s - did not have response bit set.', track.target
)
return nil
end
-- version is as expected
val = bit.band(bit.rshift(pkt:u8(off), 3), 0x07)
if val ~= track.v then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Bad response from %s - expected NTP version %d, got %d', track.target,
track.v, val
)
return nil
end
-- mode is as expected
val = bit.band(pkt:u8(off), 0x07)
if val ~= track.m then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Bad response from %s - expected NTP mode %d, got %d', track.target,
track.m, val
)
return nil
end
-- implementation number is as expected
val = pkt:u8(off+2)
if val ~= track.i then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Bad response from %s - expected NTP implementation number %d, got %d',
track.target, track.i, val
)
return nil
end
-- request code is as expected
val = pkt:u8(off+3)
if val ~= track.c then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Bad response from %s - expected NTP request code %d got %d.', track.target,
track.c, val
)
return nil
end
-- NTP error conditions - defined codes are not evil (bogus codes are).
local fail, msg = false
local err = bit.band(bit.rshift(pkt:u8(off+4), 4), 0x0f)
if err == 0 then
-- NoOp
elseif err == 1 then
fail = true
msg = 'Incompatable Implementation Number'
elseif err == 2 then
fail = true
msg = 'Unimplemented Request Code'
elseif err == 3 then
fail = true
msg = 'Format Error' -- could be that auth is required - we didn't provide it.
elseif err == 4 then
fail = true
msg = 'No Data Available' -- monitor not enabled or nothing in mru list.
elseif err == 5 or err == 6 then
fail = true
msg = 'I don\'t know'
elseif err == 7 then
fail = true
msg = 'Authentication Failure'
elseif err > 7 then
fail = true
track.evil_pkts = track.evil_pkts+1
msg = 'Bogus Error Code!' -- should not happen...
end
if fail then
track.errcond = true
stdnse.print_debug(1,
'Response from %s was NTP Error Code %d - "%s"', track.target, err, msg
)
return nil
end
-- length checks - the data (number of items * size of an item) should be
-- 8 <= data <= 500 and each data item should be of correct length for the
-- implementation and request type.
-- Err 4 bits, Number of Data Items 12 bits
local icount = bit.band(pkt:u16(off+4), 0xFFF)
-- MBZ 4 bits, Size of Data Items: 12 bits
local isize = bit.band(pkt:u16(off+6), 0xFFF)
if icount < 1 then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Expected at least one record from %s.', track.target
)
return nil
elseif icount*isize + 8 > response:len() then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'NTP Mode 7 response from %s has invalid count (%d) and/or size (%d) values.',
track.target, icount, isize
)
return nil
elseif icount*isize > 500 then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'NTP Mode 7 data section is larger than 500 bytes (%d) in response from %s.',
icount*isize, track.target
)
return nil
end
if track.c == 42 and track.i == 3 and isize ~= 72 then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Expected item size of 72 bytes (got %d) for request code 42 implementation number 3 in response from %s.',
isize, track.target
)
return nil
elseif track.c == 0 and track.i == 3 and isize ~= 32 then
track.errcond = true
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Expected item size of 32 bytes (got %d) for request code 0 implementation number 3 in response from %s.',
isize, track.target
)
return nil
end
-- is the response out of sequence, a duplicate or is it peachy
local seq = bit.band(pkt:u8(off+1), 0x7f)
if seq == track.hseq+1 then -- all good
track.hseq = track.hseq+1
elseif track.mseq:match(('|%d|'):format(seq)) then -- one of our missing seq#
track.mseq:gsub(('|%d|'):format(seq), '|', 1)
stdnse.print_debug(3,
'Response from %s with sequence number %s was previously missing.', -- this never seems to happen!
track.target, seq
)
elseif seq > track.hseq then -- some seq# have gone missing
for i=track.hseq+1, seq-1 do
track.mseq = ('%s%d|'):format(track.mseq, i)
end
stdnse.print_debug(3,
'Response from %s was out of sequence - expected #%d but got #%d (missing:%s)',
track.target, track.hseq+1, seq, track.mseq
)
track.hseq = seq
else -- seq <= hseq !duplicate!
track.evil_pkts = track.evil_pkts+1
stdnse.print_debug(1,
'Response from %s had a duplcate sequence number - dropping it.',
track.target
)
return nil
end
-- if the more bit is set or if we have missing sequence numbers then we'll
-- want to receive more packets after parsing this one.
local more = bit.band(bit.rshift(pkt:u8(off), 6), 0x01)
if more == 1 then
track.rcv_again = true
elseif track.mseq:len() > 1 then
track.rcv_again = true
end
return pkt
end
---
-- Returns a Packet Object generated with dummy IP and UDP headers and the
-- supplied UDP payload so that the payload may be conveniently parsed using
-- packet library methods. The dummy headers contain the barest information
-- needed to appear valid to packet.lua
--
-- @param response String UDP payload.
-- @return Packet object or nil in case of an error.
--
function make_udp_packet(response)
-- udp len
local udplen = 8 + response:len()
-- ip len
local iplen = 20 + udplen
-- dummy headers
-- ip
local dh = string.char(0x45, 0x00)
dh = dh .. bin.pack('S', iplen)
dh = dh .. string.char(
0x00, 0x00, 0x40, 0x00, 0x40, 0x11, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
-- udp
0x00, 0x00, 0x00, 0x00
)
dh = dh .. bin.pack('S', udplen)
dh = dh .. string.char(0x00, 0x00)
return packet.Packet:new(dh .. response, iplen)
end
---
-- Invokes parsing routines for NTPv2 Mode 7 response packets based on the
-- implementation number and request code defined in the response.
--
-- @param pkt Packet Object to be parsed.
-- @param recs Table to hold the accumulated records parsed from supplied
-- packet objects.
-- @return Number of records not parsed from the packet (usually zero) or
-- -1 if the response does not have an associated parsing routine.
--
function parse_v2m7(pkt, recs)
local off = pkt.udp_offset + 8
local impl = pkt:u8(off+2)
local code = pkt:u8(off+3)
if (impl == 3 or impl == 2) and code == 42 then
return parse_monlist_1(pkt, recs)
elseif (impl == 3 or impl == 2) and code == 0 then
return parse_peerlist(pkt, recs)
else
return -1
end
end
---
-- Parsed records from the supplied monitor list packet into the supplied table
-- of accumulated records.
--
-- The supplied response packets should be NTPv2 Mode 7 implementation number 2
-- or 3 and request code 42.
-- The fields parsed are the source and destination IP addresses, the count of
-- times the target has seen the host, the method of transmission (uni|broad|
-- multicast), NTP Version and Mode of the last packet received by the target
-- from the host.
--
-- @param pkt Packet object to extract monitor records from.
-- @param recs A table of accumulated monitor records for storage of parsed
-- records.
-- @return Number of records not parsed from the packet which will be zero
-- except when MAX_RECORDS is reached.
--
function parse_monlist_1(pkt, recs)
local off = pkt.udp_offset + 8 -- beginning of NTP
local icount = bit.band(pkt:u16(off+4), 0xFFF)
local isize = bit.band(pkt:u16(off+6), 0xFFF)
local remaining = icount
off = off+8 -- beginning of data section
for i=1, icount, 1 do
if #recs + #recs.peerlist >= MAX_RECORDS then
return remaining
end
pos = off + isize * (i-1) -- beginning of item
local t = {}
-- src and dst addresses
-- IPv4 if impl == 2 or v6 flag is not set
if isize == 32 or pkt:u8(pos+32) ~= 1 then -- IPv4
local saddr = packet.toip(pkt:raw(pos+16, 4))
local daddr = packet.toip(pkt:raw(pos+20, 4))
t.saddr = saddr
t.daddr = daddr
else -- IPv6
local saddr = {}
for j=40, 54, 2 do
saddr[#saddr+1] = stdnse.tohex(pkt:u16(pos+j))
end
t.saddr = table.concat(saddr, ':')
local daddr = {}
for j=56, 70, 2 do
daddr[#daddr+1] = stdnse.tohex(pkt:u16(pos+j))
end
t.daddr = table.concat(daddr, ':')
end
t.count = pkt:u32(pos+12)
t.flags = pkt:u32(pos+24)
-- I've seen flags be wrong-endian just once. why? I really don't know.
-- Some implementations are not doing htonl for this field?
if t.flags > 0xFFFFFF then
-- only concerned with the high order byte
t.flags = bit.rshift(t.flags, 24)
end
t.mode = pkt:u8(pos+30)
t.version = pkt:u8(pos+31)
recs[#recs+1] = t
remaining = remaining -1
end
return remaining
end
---
-- Parsed records from the supplied peer list packet into the supplied table of
-- accumulated records.
--
-- The supplied response packets should be NTPv2 Mode 7 implementation number 2
-- or 3 and request code 0.
-- The fields parsed are the source IP address and the peer information flag.
--
-- @param pkt Packet object to extract peer records from.
-- @param recs A table of accumulated monitor and peer records for storage of
-- parsed records.
-- @return Number of records not parsed from the packet which will be zero
-- except when MAX_RECORDS is reached.
--
function parse_peerlist(pkt, recs)
local off = pkt.udp_offset + 8 -- beginning of NTP
local icount = bit.band(pkt:u16(off+4), 0xFFF)
local isize = bit.band(pkt:u16(off+6), 0xFFF)
local remaining = icount
off = off+8 -- beginning of data section
for i=0, icount-1, 1 do
if #recs + #recs.peerlist >= MAX_RECORDS then
return remaining
end
pos = off + (i * isize) -- beginning of item
local t = {}
-- src address
-- IPv4 if impl == 2 or v6 flag is not set
if isize == 8 or pkt:u8(pos+8) ~= 1 then
local saddr = packet.toip(pkt:raw(pos, 4))
t.saddr = saddr
else -- IPv6
local saddr = {}
for j=16, 30, 2 do
saddr[#saddr+1] = stdnse.tohex(pkt:u16(pos+j))
end
t.saddr = table.concat(saddr, ':')
end
t.flags = pkt:u8(pos+7)
table.insert(recs.peerlist, t)
remaining = remaining -1
end
return remaining
end
---
-- Interprets the supplied records to discover information about the target
-- NTP associations.
--
-- Associations are categorised as NTP Servers, Peers and Clients based on the
-- Mode of packets sent to the target. Alternative target interfaces are
-- recorded as well as the transmission mode of packets sent to the target (i.e.
-- unicast, broadcast or multicast).
--
-- @param recs A table of accumulated monitor and peer records for storage
-- of parsed records.
-- @param targetip String target IP address (e.g. host.ip)
-- @return Table of interpreted results with fields such as servs, clients,
-- peers, ifaces etc.
--
function interpret(recs, targetip)
local txtyp = {
['1'] = 'unicast',
['2'] = 'broadcast',
['4'] = 'multicast'
}
local t = {}
t.servs = {['pub']={['4']={},['6']={}}, ['prv']={['4']={},['6']={}}}
t.peers = {['pub']={['4']={},['6']={}}, ['prv']={['4']={},['6']={}}}
t.porc = {['pub']={['4']={},['6']={}}, ['prv']={['4']={},['6']={}}}
t.clients = {['pub']={['4']={},['6']={}}, ['prv']={['4']={},['6']={}}}
t.casts = {['b']={['4']={},['6']={}}, ['m']={['4']={},['6']={}}}
t.ifaces = {['4']={},['6']={}}
t.other = {}
t.sync = ''
if #recs.peerlist > 0 then
t.have_peerlist = true
recs.peerhash = {}
for _, peer in ipairs(recs.peerlist) do
recs.peerhash[peer.saddr] = peer
end
else
t.have_peerlist = false
end
for _, r in ipairs(recs) do
local vis = ipOps.isPrivate(r.saddr) and 'prv' or 'pub'
local af = r.saddr:match(':') and '6' or '4'
-- is the host a client, peer, server or other?
if r.mode == 3 then
table.insert(t.clients[vis][af], r.saddr)
elseif r.mode == 4 then
table.insert(t.servs[vis][af], r.saddr)
elseif r.mode == 2 then
table.insert(t.peers[vis][af], r.saddr)
elseif r.mode == 1 then
-- if we have a list of peers we can distinguish between mode 1 peers and
-- mode 1 peers that are really clients (i.e. not configured as peers).
if t.have_peerlist then
if recs.peerhash[r.saddr] then
table.insert(t.peers[vis][af], r.saddr)
else
table.insert(t.clients[vis][af], r.saddr)
end
else
table.insert(t.porc[vis][af], r.saddr)
end
elseif r.mode == 5 then
table.insert(t.servs[vis][af], r.saddr)
else
local tx = tostring(r.flags)
table.insert(
t.other,
('%s%s seen %d time%s. last tx was %s v%d mode %d'):format(
r.saddr, _ == 1 and ' (You?)' or '', r.count,
r.count > 1 and 's' or '',
txtyp[tx] or tx, r.version, r.mode
)
)
end
local function isLoopback(addr)
if addr:match(':') then
if ipOps.compare_ip(addr, 'eq', '::1') then return true end
elseif addr:match('^127') then
return true
end
return false
end
-- destination addresses are target interfaces or broad/multicast addresses.
if not isLoopback(r.daddr) then
if r.flags == 1 then
t.ifaces[af][r.daddr] = r.daddr
elseif r.flags == 2 then
t.casts.b[af][r.daddr] = r.daddr
elseif r.flags == 4 then
t.casts.m[af][r.daddr] = r.daddr
else -- shouldn't happen
stdnse.print_debug(1,
'Host associated with %s had transmission flag value %d - Strange!',
targetip, r.flags
)
end
end
end -- for
local function isTarget(addr, target)
local targ_af = target:match(':') and 6 or 4
local test_af = addr:match(':') and 6 or 4
if test_af ~= targ_af then return false end
if targ_af == 4 and addr == target then return true end
if targ_af == 6
and (ipOps.compare_ip(addr, 'eq', target)) then return true end
return false
end
-- reorganise ifaces and casts tables
local _ = {}
for k, v in pairs(t.ifaces['4']) do
if not isTarget(v, targetip) then
_[#_+1] = v
end
end
t.ifaces['4'] = _
_ = {}
for k, v in pairs(t.ifaces['6']) do
if not isTarget(v, targetip) then
_[#_+1] = v
end
end
t.ifaces['6'] = _
_ = {}
for k, v in pairs(t.casts.b['4']) do
_[#_+1] = v
end
t.casts.b['4'] = _
_ = {}
for k, v in pairs(t.casts.b['6']) do
_[#_+1] = v
end
t.casts.b['6'] = _
_ = {}
for k, v in pairs(t.casts.m['4']) do
_[#_+1] = v
end
t.casts.m['4'] = _
_ = {}
for k, v in pairs(t.casts.m['6']) do
_[#_+1] = v
end
t.casts.m['6'] = _
-- Single out the server to which the target is synched.
-- Note that this server may not even appear in the monlist - it depends how
-- busy the server is.
if t.have_peerlist then
for _, peer in ipairs(recs.peerlist) do
if bit.band(peer.flags, 0x2) == 0x2 then
t.sync = peer.saddr
if peer.saddr:match('^127') then -- always IPv4, never IPv6!
t.sync = t.sync .. ' (reference clock)'
end
break
end
end
end
return t
end
---
-- Outputs the supplied table of interpreted records.
--
-- @param t Table of interpreted records as returned from interpret().
-- @return String script output.
--
function summary(t)
local o = {}
local count = 0
local vbs = nmap.verbosity()
-- Target is Synchronised with:
if t.sync ~= '' then
table.insert(o, ('Target is synchronised with %s'):format(t.sync))
end
-- Alternative Target Interfaces
if #t.ifaces['4'] > 0 or #t.ifaces['6'] > 0 then
table.insert(o,
{
['name'] = 'Alternative Target Interfaces:',
output_ips(t.ifaces)
}
)
end
-- Target listens to Broadcast Addresses
if #t.casts.b['4'] > 0 or #t.casts.b['6'] > 0 then
table.insert(o,
{
['name'] = 'Target listens to Broadcast Addresses:',
output_ips(t.casts.b)
}
)
end
-- Target listens to Multicast Addresses
if #t.casts.m['4'] > 0 or #t.casts.m['6'] > 0 then
table.insert(o,
{
['name'] = 'Target listens to Multicast Addresses:',
output_ips(t.casts.m)
}
)
end
-- Private Servers
count = #t.servs.prv['4']+#t.servs.prv['6']
if count > 0 or vbs > 1 then
table.insert(o,
{
['name'] = ('Private Servers (%d)'):format(count),
output_ips(t.servs.prv)
}
)
end
-- Public Servers
count = #t.servs.pub['4']+#t.servs.pub['6']
if count > 0 or vbs > 1 then
table.insert(o,
{
['name'] = ('Public Servers (%d)'):format(count),
output_ips(t.servs.pub)
}
)
end
-- Private Peers
count = #t.peers.prv['4']+#t.peers.prv['6']
if count > 0 or vbs > 1 then
table.insert(o,
{
['name'] = ('Private Peers (%d)'):format(count),
output_ips(t.peers.prv)
}
)
end
-- Public Peers
count = #t.peers.pub['4']+#t.peers.pub['6']
if count > 0 or vbs > 1 then
table.insert(o,
{
['name'] = ('Public Peers (%d)'):format(count),
output_ips(t.peers.pub)
}
)
end
-- Private Peers or Clients
count = #t.porc.prv['4']+#t.porc.prv['6']
if not t.have_peerlist and (count > 0 or vbs > 1) then
table.insert(o,
{
['name'] = ('Private Peers or Clients (%d)'):format(count),
output_ips(t.porc.prv)
}
)
end
-- Public Peers or Clients
count = #t.porc.pub['4']+#t.porc.pub['6']
if not t.have_peerlist and (count > 0 or vbs > 1) then
table.insert(o,
{
['name'] = ('Public Peers or Clients (%d)'):format(count),
output_ips(t.porc.pub)
}
)
end
-- Private Clients
count = #t.clients.prv['4']+#t.clients.prv['6']
if count > 0 or vbs > 1 then
table.insert(o,
{
['name'] = ('Private Clients (%d)'):format(count),
output_ips(t.clients.prv)
}
)
end
-- Public Clients
count = #t.clients.pub['4']+#t.clients.pub['6']
if count > 0 or vbs > 1 then
table.insert(o,
{
['name'] = ('Public Clients (%d)'):format(count),
output_ips(t.clients.pub)
}
)
end
-- Other
count = #t.other
if count > 0 then
table.insert(o,
{
['name'] = ('Other Associations (%d)'):format(count),
t.other
}
)
end
return stdnse.format_output(true, o)
end
---
-- Sorts and combines a set of IPv4 and IPv6 addresses into a table of rows.
-- IPv4 addresses are ascending-sorted numerically and arranged in four columns
-- and IPv6 appear in subsequent rows, sorted and arranged to fit as many
-- addresses into a row as possible without the need for wrapping.
--
-- @param t Table containing two subtables indexed as '4' and '6' containing
-- a list of IPv4 and IPv6 addresses respectively.
-- @return Table where each entry is a row of sorted and arranged IP addresses.
--
function output_ips(t)
if #t['4'] < 1 and #t['6'] < 1 then return nil end
local o = {}
-- sort and tabulate IPv4 addresses
table.sort(t['4'], function(a,b) return ipOps.compare_ip(a, "lt", b) end)
local limit = #t['4']
local cols = 4
local rows = math.ceil(limit/cols)
local numlast = limit - cols*rows + cols
local pad4 = (' '):rep(15)
local index = 0
for c=1, cols, 1 do
for r=1, rows, 1 do
if r == rows and c > numlast then break end
index = index+1
o[r] = o[r] or ''
local padlen = pad4:len() - t['4'][index]:len()
o[r] = ('%s%s%s '):format(o[r], t['4'][index], pad4:sub(1, padlen))
end
end
-- IPv6 - for now, no sorting.
-- Rows are allowed to be 71 chars wide
local i = 1
local limit = #t['6']
while i <= limit do
work = {}
local len = 0
local j = i
repeat
if not t['6'][j] then j = j-1; break end
len = len + t['6'][j]:len() + 1
if len > 71 then
j = j-1
else
j = j+1
end
until len > 71
for n = i, j, 1 do
work[#work+1] = t['6'][n]
end
o[#o+1] = table.concat(work, ' ')
i = j+1
end
return o
end
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