1 /* -*-  Mode: C++; c-file-style: "gnu"; indent-tabs-mode:nil; -*- */

     2 /*

     3  * Copyright (c) 2010 Lalith Suresh 

     4  *

     5  * This program is free software; you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License version 2 as

     7  * published by the Free Software Foundation;

     8  *

     9  * This program is distributed in the hope that it will be useful,

    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    12  * GNU General Public License for more details.

    13  *

    14  * You should have received a copy of the GNU General Public License

    15  * along with this program; if not, write to the Free Software

    16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    17  *

    18  * Authors: Lalith Suresh <suresh.lalith@gmail.com>

    19  */

    20 

    21 /**

    22 * \ingroup routing

    23 * \defgroup click Click

    24 *

    25 * \section model Model

    26 *

    27 * This model implements the interface to the Click Modular Router and

    28 * provides the Ipv4ClickRouting class to allow a node to use Click 

    29 * for external routing. Unlike normal Ipv4RoutingProtocol sub types,

    30 * Ipv4ClickRouting doesn't use a RouteInput() method, but instead, 

    31 * receives a packet on the appropriate interface and processes it 

    32 * accordingly. Note that you need to have a routing table type element 

    33 * in your Click graph to use Click for external routing. This is needed

    34 * by the RouteOutput() function inherited from Ipv4RoutingProtocol.

    35 * Furthermore, a Click based node uses a different kind of L3 in the

    36 * form of Ipv4L3ClickProtocol, which is a trimmed down version of

    37 * Ipv4L3Protocol. Ipv4L3ClickProtocol passes on packets passing through

    38 * the stack to Ipv4ClickRouting for processing.

    39 *

    40 * \section build Build Instructions

    41 *

    42 * The first step is to build Click. At the top of your Click source directory:

    43 *

    44 *   $: ./configure --enable-userlevel --disable-linuxmodule --enable-nsclick --enable-wifi

    45 *   $: make

    46 * 

    47 * The --enable wifi flag can be skipped in case you don't intend on using

    48 * Click with Wifi.

    49 * *Note: You don't need to do a 'make install'.

    50 *

    51 * Once Click has been built successfully, we proceed to configure ns-3 with 

    52 * Click Integration support:

    53 *

    54 *   $: ./waf configure --with-nsclick=/path/to/click/source

    55 *

    56 * If it says 'enabled' beside 'NS-3 Click Integration Support', then you're 

    57 * good to go.

    58 *

    59 * Next, try running one of the examples:

    60 *

    61 *   $: ./waf --run nsclick-simple-lan

    62 *

    63 * You will find a lot of output being generated. This is because of the 

    64 * IPPrint and Print elements present in the nsclick-simple-lan.click 

    65 * configuration file that the example script uses. 

    66 *

    67 * \section clickgraph Click Graph Instructions

    68 *

    69 * The following should be kept in mind when making your Click graph:

    70 *   - Only userlevel elements can be used.

    71 *   - You will need to replace FromDevice and ToDevice elements 

    72 *     with FromSimDevice and ToSimDevice elements.

    73 *   - Packets to the kernel are sent up using ToSimDevice(tap0,IP).

    74 *   - For any node, the 0th device will be tap0. The remaining devices 

    75 *     should be eth0, eth1 and so forth (even if you're using wifi). 

    76 *     Please note that the device numbering should begin from 0.

    77 *   - A routing table element is a mandatory. The OUTports of the routing 

    78 *     table element should correspond to the interface number of the device 

    79 *     through which the packet will ultimately be sent out. Violating this 

    80 *     rule will lead to really weird packet traces. This routing table element's 

    81 *     name should then be passed to the Ipv4ClickRouting protocol object as 

    82 *     a simulation parameter. See the Click examples for details.

    83 *   - When using Wifi with ns-3-click, do not use wifi specific elements like 

    84 *     WifiEncap, ExtraEncap, MadWifiRate etc. for outgoing packets. Incoming 

    85 *     packets should have their Wifi headers removed using WifiDecap + ExtraDecap 

    86 *     or Strip elements. See the nsclick-raw-wlan.click file for an idea of the same.

    87 *   - The current implementation leaves Click with mainly L3 functionality, 

    88 *     with ns-3 handling L2. We will soon begin working to support the use of 

    89 *     MAC protocols on Click as well.

    90 *

    91 * \section usage Usage

    92 *

    93 * To have a node run Click, the easiest way would be to use the ClickInternetStackHelper 

    94 * class in your simulation script. For instance:

    95 *

    96 *   ClickInternetStackHelper click;

    97 *   click.SetClickFile (myNodeContainer, "nsclick-simple-lan.click");

    98 *   click.SetRoutingTableElement (myNodeContainer, "u/rt");

    99 *   click.Install (myNodeContainer);

   100 * 

   101 * The example scripts inside examples/click/ demonstrate the use of Click based 

   102 * nodes in different scenarios.

   103 *

   104 *

   105 */

   106