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-- (C) 2019 - ntop.org and contributors
n2n = Proto("n2n", "n2n Protocol")
-- #############################################
PKT_TYPE_PING = 0
PKT_TYPE_REGISTER = 1
PKT_TYPE_DEREGISTER = 2
PKT_TYPE_PACKET = 3
PKT_TYPE_REGISTER_ACK = 4
PKT_TYPE_REGISTER_SUPER = 5
PKT_TYPE_REGISTER_SUPER_ACK = 6
PKT_TYPE_REGISTER_SUPER_NAK = 7
PKT_TYPE_FEDERATION = 8
PKT_TYPE_PEER_INFO = 9
PKT_TYPE_QUERY_PEER = 10
PKT_TRANSFORM_NULL = 1
PKT_TRANSFORM_TWOFISH = 2
PKT_TRANSFORM_AESCBC = 3
FLAG_FROM_SUPERNODE = 0x0020
FLAG_SOCKET = 0x0040
FLAG_OPTIONS = 0x0080
SOCKET_FAMILY_AF_INET = 0x0000
SOCKET_FAMILY_AF_INET6 = 0x8000
-- #############################################
version = ProtoField.uint8("n2n.version", "version", base.DEC)
ttl = ProtoField.uint8("n2n.ttl", "ttl", base.DEC)
packet_type_mask = 0x001f
pkt_type_2_str = {
[PKT_TYPE_PING] = "ping",
[PKT_TYPE_REGISTER] = "register",
[PKT_TYPE_DEREGISTER] = "deregister",
[PKT_TYPE_PACKET] = "packet",
[PKT_TYPE_REGISTER_ACK] = "register_ack",
[PKT_TYPE_REGISTER_SUPER] = "register_super",
[PKT_TYPE_REGISTER_SUPER_ACK] = "register_super_ack",
[PKT_TYPE_REGISTER_SUPER_NAK] = "register_super_nak",
[PKT_TYPE_FEDERATION] = "federation",
[PKT_TYPE_PEER_INFO] = "peer_info",
[PKT_TYPE_QUERY_PEER] = "query_peer",
}
packet_type = ProtoField.uint8("n2n.packet_type", "packetType", base.HEX, pkt_type_2_str, packet_type_mask)
flags_mask = 0xffe0
flags = ProtoField.uint16("n2n.flags", "Flags", base.HEX, nil, flags_mask)
from_supernode_flag = ProtoField.uint16("n2n.flags.from_supernode", "from_supernode", base.BOOLEAN, nil, FLAG_FROM_SUPERNODE)
socket_flag = ProtoField.uint16("n2n.flags.socket", "socket", base.BOOLEAN, nil, FLAG_SOCKET)
options_flag = ProtoField.uint16("n2n.flags.options", "options", base.BOOLEAN, nil, FLAG_OPTIONS)
community = ProtoField.string("n2n.community", "Community", base.ASCII)
-- #############################################
src_mac = ProtoField.ether("n2n.src_mac", "Source")
dst_mac = ProtoField.ether("n2n.dst_mac", "Destination")
socket_info = ProtoField.none("n2n.socket", "Socket Info")
socket_family = ProtoField.uint16("n2n.socket.family", "Family", base.HEX, {
[0] = "AF_INET",
})
socket_port = ProtoField.uint16("n2n.socket.port", "Port")
socket_ipv4 = ProtoField.ipv4("n2n.socket.ipv4", "IPv4")
socket_ipv6 = ProtoField.ipv6("n2n.socket.ipv6", "IPv6")
-- #############################################
peer_info_field = ProtoField.none("n2n.peer_info", "PeerInfo")
peer_info_flags = ProtoField.uint16("n2n.peer_info.flags", "Flags")
peer_info_mac = ProtoField.ether("n2n.peer_info.query_mac", "Query")
query_peer_field = ProtoField.none("n2n.query_peer", "QueryPeer")
-- #############################################
packet_field = ProtoField.none("n2n.packet", "Packet")
packet_transform = ProtoField.uint16("n2n.packet.transform", "Transform", base.HEX, {
[PKT_TRANSFORM_NULL] = "Plaintext",
[PKT_TRANSFORM_TWOFISH] = "TwoFish",
[PKT_TRANSFORM_AESCBC] = "AES CBC",
})
packet_payload = ProtoField.bytes("n2n.packet.payload", "Payload")
-- #############################################
register_field = ProtoField.none("n2n.register", "Register")
register_cookie = ProtoField.uint32("n2n.register.cookie", "Cookie", base.HEX)
register_ack_field = ProtoField.none("n2n.register_ack", "RegisterACK")
register_ack_cookie = ProtoField.uint32("n2n.register_ack.cookie", "Cookie", base.HEX)
register_super_field = ProtoField.none("n2n.register_super", "RegisterSuper")
register_super_cookie = ProtoField.uint32("n2n.register_super.cookie", "Cookie", base.HEX)
register_super_auth_schema = ProtoField.uint16("n2n.register_super.auth.schema", "AuthSchema", base.HEX)
register_super_auth_data = ProtoField.uint16("n2n.register_super.auth.data", "AuthData", base.HEX)
register_super_ack_field = ProtoField.none("n2n.register_super_ack", "RegisterSuperACK")
register_super_ack_cookie = ProtoField.uint32("n2n.register_super_ack.cookie", "Cookie", base.HEX)
register_super_ack_lifetime = ProtoField.uint16("n2n.register_super_ack.lifetime", "Registration Lifetime", base.DEC)
register_super_ack_num_sn = ProtoField.uint8("n2n.register_super_ack.num_sn", "Num Supernodes", base.DEC)
-- #############################################
n2n.fields = {
version, ttl, packet_type,
flags, from_supernode_flag, socket_flag, options_flag,
community,
-- Generic
src_mac, dst_mac,
socket_info, socket_family, socket_port, socket_ipv4, socket_ipv6,
-- PKT_TYPE_REGISTER
register_field, register_cookie,
-- PKT_TYPE_PACKET
packet_field, packet_transform, packet_payload,
-- PKT_TYPE_REGISTER_ACK
register_ack_field, register_ack_cookie,
-- PKT_TYPE_REGISTER_SUPER
register_super_field, register_super_cookie, register_super_auth_schema, register_super_auth_data,
-- PKT_TYPE_REGISTER_SUPER_ACK
register_super_ack_field, register_super_ack_cookie, register_super_ack_lifetime, register_super_ack_num_sn,
-- PKT_TYPE_PEER_INFO
peer_info_field, peer_info_flags, peer_info_mac,
-- PKT_TYPE_QUERY_PEER
query_peer_field,
}
-- #############################################
function dissect_socket(subtree, buffer, offset)
local sock_baselen = 4
local sock_protolen = 0
buffer = buffer(offset)
local sock_family = bit.band(buffer(0,4):uint(), 0xFFFF0000)
if(sock_family == SOCKET_FAMILY_AF_INET) then
sock_protolen = 4
elseif(sock_family == SOCKET_FAMILY_AF_INET6) then
sock_protolen = 16
end
local totlen = sock_baselen + sock_protolen
local socktree = subtree:add(socket_info, buffer(0, totlen))
socktree:add(socket_family, buffer(0, 2))
socktree:add(socket_port, buffer(2, 2))
if(sock_family == SOCKET_FAMILY_AF_INET) then
socktree:add(socket_ipv4, buffer(4, sock_protolen))
elseif(sock_family == SOCKET_FAMILY_AF_INET6) then
socktree:add(socket_ipv6, buffer(4, sock_protolen))
end
return offset+totlen, socktree
end
-- #############################################
function dissect_register(subtree, buffer, flags)
local regtree = subtree:add(register_field, buffer)
regtree:add(register_cookie, buffer(0,4))
regtree:add(src_mac, buffer(4,6))
regtree:add(dst_mac, buffer(10,6))
if(bit.band(flags, FLAG_SOCKET) == FLAG_SOCKET) then
dissect_socket(regtree, buffer, 16)
end
return regtree
end
-- #############################################
function dissect_register_ack(subtree, buffer, flags)
local regtree = subtree:add(register_ack_field, buffer)
regtree:add(register_ack_cookie, buffer(0,4))
regtree:add(src_mac, buffer(4,6))
regtree:add(dst_mac, buffer(10,6))
return regtree
end
-- #############################################
function dissect_packet(subtree, buffer, flags, pinfo)
local pktree = subtree:add(packet_field, buffer)
pktree:add(src_mac, buffer(0,6))
pktree:add(dst_mac, buffer(6,6))
if(bit.band(flags, FLAG_SOCKET) == FLAG_SOCKET) then
idx = dissect_socket(pktree, buffer, 12)
else
idx = 12
end
pktree:add(packet_transform, buffer(idx,2))
local payload = pktree:add(packet_payload, buffer(idx+2))
local transform = buffer(idx,2):uint()
-- Can only dissect unencrypted data
if(transform == PKT_TRANSFORM_NULL) then
Dissector.get("eth_withoutfcs"):call(buffer(idx+2):tvb(), pinfo, payload)
end
return pktree
end
-- #############################################
function dissect_register_super(subtree, buffer, flags)
local regtree = subtree:add(register_super_field, buffer)
regtree:add(register_super_cookie, buffer(0,4))
regtree:add(src_mac, buffer(4,6))
regtree:add(register_super_auth_schema, buffer(10,2))
regtree:add(register_super_auth_data, buffer(12,2))
return regtree
end
-- #############################################
function dissect_register_super_ack(subtree, buffer, flags)
local regtree = subtree:add(register_super_ack_field, buffer)
regtree:add(register_super_ack_cookie, buffer(0,4))
regtree:add(dst_mac, buffer(4,6))
regtree:add(register_super_ack_lifetime, buffer(10,2))
local idx = dissect_socket(regtree, buffer, 12)
regtree:add(register_super_ack_num_sn, buffer(idx, 1))
return regtree
end
-- #############################################
function dissect_peer_info(subtree, buffer, flags)
local peertree = subtree:add(peer_info_field, buffer)
peertree:add(peer_info_flags, buffer(0,2))
peertree:add(peer_info_mac, buffer(2,6))
dissect_socket(peertree, buffer, 8)
return peertree
end
-- #############################################
function dissect_query_peer(subtree, buffer, flags)
local peertree = subtree:add(query_peer_field, buffer)
peertree:add(src_mac, buffer(0,6))
peertree:add(dst_mac, buffer(6,6))
return peertree
end
-- #############################################
function n2n.dissector(buffer, pinfo, tree)
local length = buffer:len()
if length < 20 then return end
pinfo.cols.protocol = n2n.name
local pkt_type = bit.band(buffer(2,2):uint(), packet_type_mask)
local subtree = tree:add(n2n, buffer(), string.format("n2n Protocol, Type: %s", pkt_type_2_str[pkt_type] or "Unknown"))
-- Common
subtree:add(version, buffer(0,1))
subtree:add(ttl, buffer(1,1))
subtree:add(packet_type, buffer(2,2))
local flags_buffer = buffer(2,2)
local flags_tree = subtree:add(flags, flags_buffer)
subtree:add(community, buffer(4,16))
-- Flags
flags_tree:add(from_supernode_flag, flags_buffer)
flags_tree:add(socket_flag, flags_buffer)
flags_tree:add(options_flag, flags_buffer)
-- Packet specific
local flags = bit.band(buffer(2,2):uint(), flags_mask)
local typebuf = buffer(20)
if(pkt_type == PKT_TYPE_REGISTER) then
dissect_register(subtree, typebuf, flags)
elseif(pkt_type == PKT_TYPE_REGISTER) then
dissect_register_ack(subtree, typebuf, flags)
elseif(pkt_type == PKT_TYPE_PACKET) then
dissect_packet(subtree, typebuf, flags, pinfo)
elseif(pkt_type == PKT_TYPE_REGISTER_SUPER) then
dissect_register_super(subtree, typebuf, flags)
elseif(pkt_type == PKT_TYPE_REGISTER_SUPER_ACK) then
dissect_register_super_ack(subtree, typebuf, flags)
elseif(pkt_type == PKT_TYPE_PEER_INFO) then
dissect_peer_info(subtree, typebuf, flags)
elseif(pkt_type == PKT_TYPE_QUERY_PEER) then
dissect_query_peer(subtree, typebuf, flags)
end
end
-- #############################################
local udp_port = DissectorTable.get("udp.port")
udp_port:add(50001, n2n)