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#!/usr/bin/env dnsjit
local clock = require("dnsjit.lib.clock")
local log = require("dnsjit.core.log")
local getopt = require("dnsjit.lib.getopt").new({
{ "v", "verbose", 0, "Enable and increase verbosity for each time given", "?+" },
{ "r", "read-state", "", "File to read state from before processing", "?" },
{ "w", "write-state", "", "File to write state to after processing", "?" },
})
local pcap = unpack(getopt:parse())
if getopt:val("help") then
getopt:usage()
return
end
local v = getopt:val("v")
if v > 0 then
log.enable("warning")
end
if v > 1 then
log.enable("notice")
end
if v > 2 then
log.enable("info")
end
if v > 3 then
log.enable("debug")
end
if pcap == nil then
print("usage: "..arg[1].." <pcap>")
return
end
local object = require("dnsjit.core.objects")
local input = require("dnsjit.input.mmpcap").new()
local layer = require("dnsjit.filter.layer").new()
local dns = require("dnsjit.core.object.dns").new()
local label = require("dnsjit.core.object.dns.label")
local ffi = require("ffi")
local labels = require("dnsjit.core.object.dns.label").new(16)
local q = require("dnsjit.core.object.dns.q").new()
local bit = require("bit")
hash_u32 = ffi.new("uint32_t[2]")
hash_u32p = ffi.cast("uint32_t*", hash_u32)
function hashkey(dns, transport, protocol)
if transport.obj_type == object.IP then
ffi.copy(hash_u32p, transport.src, 4)
hash_u32[1] = hash_u32[0]
ffi.copy(hash_u32p, transport.dst, 4)
hash_u32[1] = bit.bxor(hash_u32[0], hash_u32[1])
else
local srcp = ffi.cast("uint8_t*", transport.src)
ffi.copy(hash_u32p, srcp, 4)
hash_u32[1] = hash_u32[0]
ffi.copy(hash_u32p, srcp+4, 4)
hash_u32[1] = bit.bxor(hash_u32[0], hash_u32[1])
srcp = ffi.cast("uint8_t*", transport.dst)
ffi.copy(hash_u32p, srcp, 4)
hash_u32[1] = bit.bxor(hash_u32[0], hash_u32[1])
ffi.copy(hash_u32p, srcp+4, 4)
hash_u32[1] = bit.bxor(hash_u32[0], hash_u32[1])
end
if dns.qr == 1 then
hash_u32[0] = protocol.dport + bit.lshift(protocol.sport, 16)
else
hash_u32[0] = protocol.sport + bit.lshift(protocol.dport, 16)
end
hash_u32[1] = bit.bxor(hash_u32[0], hash_u32[1])
hash_u32[0] = dns.id + bit.lshift(dns.id, 16)
return bit.bxor(hash_u32[0], hash_u32[1])
end
function dump_inflight(hkey, obj)
return string.format("return %d, { qsec = %d, qnsec = %d, rsec = %d, rnsec = %d, src = %q, sport = %d, dst = %q, dport = %d, id = %d, qname = %q, qtype = %q, rcode = %d }",
hkey,
tonumber(obj.qsec), tonumber(obj.qnsec),
tonumber(obj.rsec), tonumber(obj.rnsec),
obj.src, obj.sport,
obj.dst, obj.dport,
obj.id,
obj.qname, obj.qtype,
obj.rcode
)
end
function qrout(res)
local tsq = tonumber(res.qsec) + (tonumber(res.qnsec)/1000000000)
local tsr = tonumber(res.rsec) + (tonumber(res.rnsec)/1000000000)
print(tsq, tsr, math.floor(((tsr-tsq)*1000000)+0.5),
res.src, res.dst, res.id, res.rcode, res.qname, res.qtype)
end
input:open(pcap)
layer:producer(input)
local producer, ctx = layer:produce()
local inflight = {}
if getopt:val("read-state") > "" then
local f, _ = io.open(getopt:val("read-state"))
local inflights = 0
if f ~= nil then
for chunk in f:lines() do
local hkey, query = assert(loadstring(chunk))()
if hkey and query then
if not inflight[hkey] then
inflight[hkey] = {
queries = {},
size = 0,
}
end
table.insert(inflight[hkey].queries, query)
inflight[hkey].size = inflight[hkey].size + 1
inflights = inflights + 1
end
end
f:close()
print(string.format("== read %d inflight states from %q", inflights, getopt:val("read-state")))
end
end
local stat = {
packets = 0,
queries = 0,
responses = 0,
dropped = 0,
}
local start_sec, start_nsec = clock:monotonic()
while true do
local obj = producer(ctx)
if obj == nil then break end
stat.packets = stat.packets + 1
local pl = obj:cast()
if obj:type() == "payload" and pl.len > 0 then
local protocol = obj.obj_prev
while protocol ~= nil do
if protocol.obj_type == object.UDP or protocol.obj_type == object.TCP then
break
end
protocol = protocol.obj_prev
end
local transport = protocol.obj_prev
while transport ~= nil do
if transport.obj_type == object.IP or transport.obj_type == object.IP6 then
break
end
transport = transport.obj_prev
end
local pcap = transport.obj_prev
while pcap ~= nil do
if pcap.obj_type == object.PCAP then
break
end
pcap = pcap.obj_prev
end
dns.obj_prev = obj
if pcap ~= nil and transport ~= nil and protocol ~= nil and dns:parse_header() == 0 then
transport = transport:cast()
protocol = protocol:cast()
pcap = pcap:cast()
local hkey = hashkey(dns, transport, protocol)
if dns.qr == 1 then
stat.responses = stat.responses + 1
if inflight[hkey] then
for k, n in pairs(inflight[hkey].queries) do
if n.id == dns.id
and n.sport == protocol.dport
and n.dport == protocol.sport
and n.src == transport:destination()
and n.dst == transport:source()
then
n.rsec = pcap.ts.sec
n.rnsec = pcap.ts.nsec
n.rcode = dns.rcode
qrout(n)
inflight[hkey].queries[k] = nil
inflight[hkey].size = inflight[hkey].size - 1
if inflight[hkey].size < 1 then
inflight[hkey] = nil
end
break
end
end
else
print("== dropped",
tonumber(pcap.ts.sec) + (tonumber(pcap.ts.nsec) / 1000000000),
transport:source(),
transport:destination(),
dns.id,
label.tooffstr(dns, labels, 16),
dns.type_tostring(q.type)
)
stat.dropped = stat.dropped + 1
end
else
stat.queries = stat.queries + 1
if dns.qdcount > 0 and dns:parse_q(q, labels, 16) == 0 then
if not inflight[hkey] then
inflight[hkey] = {
queries = {},
size = 0,
}
end
table.insert(inflight[hkey].queries, {
qsec = pcap.ts.sec,
qnsec = pcap.ts.nsec,
rsec = -1,
rnsec = -1,
src = transport:source(),
sport = protocol.sport,
dst = transport:destination(),
dport = protocol.dport,
id = dns.id,
qname = label.tooffstr(dns, labels, 16),
qtype = dns.type_tostring(q.type),
rcode = -1,
})
inflight[hkey].size = inflight[hkey].size + 1
end
end
end
end
end
local end_sec, end_nsec = clock:monotonic()
local runtime = 0
if end_sec > start_sec then
runtime = ((end_sec - start_sec) - 1) + ((1000000000 - start_nsec + end_nsec)/1000000000)
elseif end_sec == start_sec and end_nsec > start_nsec then
runtime = (end_nsec - start_nsec) / 1000000000
end
print("== runtime", runtime)
print("== packets", stat.packets, stat.packets/runtime)
print("== queries", stat.queries, stat.queries/runtime)
print("== responses", stat.responses, stat.responses/runtime)
print("== dropped", stat.dropped, stat.dropped/runtime)
if getopt:val("write-state") > "" then
local f, _ = io.open(getopt:val("write-state"), "w+")
local inflights = 0
if f ~= nil then
for hkey, unanswered in pairs(inflight) do
for _, query in pairs(unanswered.queries) do
f:write(dump_inflight(hkey, query), "\n")
inflights = inflights + 1
end
end
f:close()
print(string.format("== wrote %d inflight states to %q", inflights, getopt:val("write-state")))
end
else
inflights = 0
for hkey, unanswered in pairs(inflight) do
inflights = inflights + unanswered.size
end
if inflights > 0 then
print("== inflight queries (tsq, src, dst, id, qname, qtype)")
for hkey, unanswered in pairs(inflight) do
for _, query in pairs(unanswered.queries) do
print(tonumber(query.qsec) + (tonumber(query.qnsec)/1000000000), query.src, query.dst, query.id, query.qname, query.qtype)
end
end
end
end
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