/[gxemul]/trunk/doc/networking.html
This is repository of my old source code which isn't updated any more. Go to git.rot13.org for current projects!
ViewVC logotype

Contents of /trunk/doc/networking.html

Parent Directory Parent Directory | Revision Log Revision Log

Revision 44 - (show annotations)
Mon Oct 8 16:22:56 2007 UTC (16 years, 6 months ago) by dpavlin
File MIME type: text/html
File size: 9761 byte(s) 
++ trunk/HISTORY	(local)
$Id: HISTORY,v 1.1632 2007/09/11 21:46:35 debug Exp $
20070616	Implementing the MIPS32/64 revision 2 "ror" instruction.
20070617	Adding a struct for each physpage which keeps track of which
		ranges within that page (base offset, length) that are
		continuously translatable. When running with native code
		generation enabled (-b), a range is added after each read-
		ahead loop.
		Experimenting with using the physical program counter sample
		data (implemented 20070608) together with the "translatable
		range" information, to figure out which physical address ranges
		would be worth translating to native code (if the number of
		samples falling within a range is above a certain threshold).
20070618	Adding automagic building of .index comment files for
		src/file/, src/promemul/, src src/useremul/ as well.
		Adding a "has been translated" bit to the ranges, so that only
		not-yet-translated ranges will be sampled.
20070619	Moving src/cpu.c and src/memory_rw.c into src/cpus/,
		src/device.c into src/devices/, and src/machine.c into
		src/machines/.
		Creating a skeleton cc/ld native backend module; beginning on
		the function which will detect cc command line, etc.
20070620	Continuing on the native code generation infrastructure.
20070621	Moving src/x11.c and src/console.c into a new src/console/
		subdir (for everything that is console or framebuffer related).
		Moving src/symbol*.c into a new src/symbol/, which should
		contain anything that is symbol handling related.
20070624	Making the program counter sampling threshold a "settings
		variable" (sampling_threshold), i.e. it can now be changed
		during runtime.
		Switching the RELEASE notes format from plain text to HTML.
		If the TMPDIR environment variable is set, it is used instead
		of "/tmp" for temporary files.
		Continuing on the cc/ld backend: simple .c code is generated,
		the compiler and linker are called, etc.
		Adding detection of host architecture to the configure script
		(again), and adding icache invalidation support (only
		implemented for Alpha hosts so far).
20070625	Simplifying the program counter sampling mechanism.
20070626	Removing the cc/ld native code generation stuff, program
		counter sampling, etc; it would not have worked well in the
		general case.
20070627	Removing everything related to native code generation.
20070629	Removing the (practically unusable) support for multiple
		emulations. (The single emulation allowed now still supports
		multiple simultaneous machines, as before.)
		Beginning on PCCTWO and M88K interrupts.
20070723	Adding a dummy skeleton for emulation of M32R processors.
20070901	Fixing a warning found by "gcc version 4.3.0 20070817
		(experimental)" on amd64.
20070905	Removing some more traces of the old "multiple emulations"
		code.
		Also looking in /usr/local/include and /usr/local/lib for
		X11 libs, when running configure.
20070909	Minor updates to the guest OS install instructions, in
		preparation for the NetBSD 4.0 release.
20070918	More testing of NetBSD 4.0 RC1.
1 <html><head><title>Gavare's eXperimental Emulator:&nbsp;&nbsp;&nbsp;Networking</title>
2 <meta name="robots" content="noarchive,nofollow,noindex"></head>
3 <body bgcolor="#f8f8f8" text="#000000" link="#4040f0" vlink="#404040" alink="#ff0000">
4 <table border=0 width=100% bgcolor="#d0d0d0"><tr>
5 <td width=100% align=center valign=center><table border=0 width=100%><tr>
6 <td align="left" valign=center bgcolor="#d0efff"><font color="#6060e0" size="6">
7 <b>GXemul:</b></font>&nbsp;&nbsp;
8 <font color="#000000" size="6"><b>Networking</b>
9 </font></td></tr></table></td></tr></table><p>
10
11 <!--
12
13 $Id: networking.html,v 1.7 2007/06/23 16:59:35 debug Exp $
14
15 Copyright (C) 2003-2007 Anders Gavare. All rights reserved.
16
17 Redistribution and use in source and binary forms, with or without
18 modification, are permitted provided that the following conditions are met:
19
20 1. Redistributions of source code must retain the above copyright
21 notice, this list of conditions and the following disclaimer.
22 2. Redistributions in binary form must reproduce the above copyright
23 notice, this list of conditions and the following disclaimer in the
24 documentation and/or other materials provided with the distribution.
25 3. The name of the author may not be used to endorse or promote products
26 derived from this software without specific prior written permission.
27
28 THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
29 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
32 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 SUCH DAMAGE.
39
40 -->
41
42
43 <a href="./">Back to the index</a>
44
45 <p><br>
46 <h2>Networking</h2>
47
48 <p>
49 <ul>
50 <li><a href="#intro">Introduction</a>
51 <li><a href="#multihost">Network across multiple hosts</a>
52 <li><a href="#direct_example_1">Direct-access example 1: udp_snoop</a>
53 </ul>
54
55
56
57
58
59
60
61 <p><br>
62 <a name="intro"></a>
63 <h3>Introduction:</h3>
64
65 GXemul's current networking layer supports two modes:
66
67 <p><ol>
68 <li>A NAT-like layer, which allows guest OSes to access the outside
69 internet world (IPv4 only, so far). When only one machine is being
70 emulated, the following default values apply to the guest OS:<pre>
71 IPv4 address: 10.0.0.1
72 Netmask: 255.0.0.0
73 Gateway / default route: 10.0.0.254
74 Nameserver: 10.0.0.254
75 </pre>To the outside world, it will seem as if the host is doing all the
76 networking, since the emulator is just a normal user process
77 on the host.
78 <p>
79 <li>A direct-access layer, allowing external tools to read/write raw
80 ethernet packages from/to the emulator.
81 </ol>
82
83 <p><i>NOTE:</i> Both these modes have problems. The NAT-like layer is very
84 "hackish" and was only meant as a proof-of-concept, to see if networking
85 like this would work with e.g. NetBSD as a guest OS. (If you are
86 interested in the technical details, and the reasons why NAT networking is
87 implemented this way, you might want to read the <a
88 href="technical.html#net"> networking section in the technical
89 documentation</a>.) Because of the obvious limitations with the NAT
90 approach, I have also included support for direct packet access, but this
91 is not designed for security or anything like that.
92
93 <p><font color="#ff0000">Use the networking features at your own risk.
94 </font>
95
96
97 <p>The emulated machine must have a NIC (network interface card). Not all
98 machines have this. At the moment, the following NICs are more or less
99 working:
100
101 <ul>
102 <li><tt><b>dec21143</b></tt>, Digital's 21143 PCI NIC (known as <tt>dc</tt>
103 in OpenBSD, or <tt>tlp</tt> in NetBSD)
104 <li><tt><b>ether</b></tt>, the "fake" experimental ethernet device
105 (documented <a href="experiments.html#expdevices_ether">here</a>)
106 <li><tt><b>le</b></tt>, <a href="http://en.wikipedia.org/wiki/TURBOchannel">Turbochannel</a>
107 Lance Ethernet, as used in DECstation 5000/200 ("3max")
108 <li><tt><b>mec</b></tt>, the SGI O2's ethernet controller
109 </ul>
110
111 <p>It is not possible to simply attach any of the supported NICs into any
112 of the supported emulated machines. Some machines, for example, have a
113 specific NIC in them, others may have a PCI bus where a PCI NIC can be
114 used. This is very much machine-dependent.
115
116 <p>If you are impatient, and simply want to try out networking in GXemul,
117 I would recommend trying out an ftp install of <a
118 href="guestoses.html#netbsdpmaxinstall">NetBSD/pmax</a>.
119
120
121
122
123
124
125
126 <p><br>
127 <a name="multihost"></a>
128 <h3>Network across multiple hosts:</h3>
129
130 <p>The way to emulate a network of multiple emulated machines, whether
131 they are actually running on the same physical host, or on multiple hosts,
132 is to use <a href="configfiles.html">configuration files</a>, and the
133 "direct-access" method of networking.
134
135 <p>Although it <i>is</i> possible to have more than one machine per
136 configuration file, I strongly recommend against it. Please use one
137 configuration file for one emulated machine.
138
139 <p>Here is a simple example:
140
141 <p><table border="0" width="100%"><tr><td width="40">&nbsp;</td>
142 <td><pre>
143 <font color="#2020cf">! Configuration file for a
144 ! "client" machine, netbooting
145 ! of another machine.</font>
146
147 <b>net(</b>
148 <b>local_port(15000)</b>
149 <b>add_remote(<font color="#ff003f">"localhost:15001"</font>)</b>
150 <b>)</b>
151 <b>machine(</b>
152 <b>name(<font color="#ff003f">"client machine"</font>)</b>
153 <b>serial_nr(1)</b> <font color="#2020cf">! 10.0.0.1</font>
154
155 <b>type(<font color="#ff003f">"sgi"</font>)</b>
156 <b>subtype(<font color="#ff003f">"o2"</font>)</b>
157 <b>load(<font color="#ff003f">"netbsd-GENERIC32_IP3x.gz"</font>)</b>
158 <b>)</b>
159 </pre></td><td width="20">&nbsp;</td><td><pre>
160 <font color="#2020cf">! Configuration file for the
161 ! "server" machine.</font>
162
163 <b>net(</b>
164 <b>local_port(15001)</b>
165 <b>add_remote(<font color="#ff003f">"localhost:15000"</font>)</b>
166 <b>)</b>
167 <b>machine(</b>
168 <b>name(<font color="#ff003f">"nfs server"</font>)</b>
169 <b>serial_nr(2)</b> <font color="#2020cf">! 10.0.0.2</font>
170
171 <b>type(<font color="#ff003f">"dec"</font>)</b>
172 <b>subtype(<font color="#ff003f">"3max"</font>)</b>
173 <b>disk(<font color="#ff003f">"nbsd_pmax.img"</font>)</b>
174 <b>)</b>
175 </pre></td><td width="20">&nbsp;</td></tr></table>
176
177 <p>This example creates a network using the default settings (10.0.0.0/8),
178 but it also uses the direct-access networking mode to allow the network
179 to be connected to other emulator instances. <tt>local_port(15000)</tt>
180 means that anything coming in to UDP port 15000 on the host is added to
181 the network. All ethernet packets on the network are also sent out to all
182 other connected machines (those added with <tt>add_remote()</tt>).
183
184 <p>As you can see in the example, this is a configuration file for
185 netbooting a NetBSD/sgimips diskless machine, with a NetBSD/pmax machine
186 acting as the nfs server. Note that the nfs server has ports 15000 and
187 15001 reversed, compared to the client!
188
189 <p>"<tt>localhost</tt>" can be changed to the Internet hostname of a
190 remote machine, to run the simulation across a physical network.
191
192 <p><font color="#ff0000"><b>NOTE:</b> There is no error checking or
193 security checking of any kind. All UDP packets arriving at the input port
194 are added to the emulated ethernet. This is not very good of course; use
195 this feature at your own risk.</font>
196
197
198
199
200
201 <p><br>
202 <a name="direct_example_1"></a>
203 <h3>Direct-access example 1: udp_snoop:</h3>
204
205 The most basic example of how the simple direct-access system works is a small
206 program in the <tt>experiments/</tt> directory, <tt>udp_snoop</tt>, which simply
207 dumps incoming UDP packets to the terminal, in hex and ASCII.
208
209 <p>The easiest way to test the example is to download a <a href="ftp://ftp.netbsd.org/pub/NetBSD/NetBSD-3.1/pmax/binary/kernel/netbsd-INSTALL.gz">
210 NetBSD/pmax INSTALL kernel</a>, and start the emulator with a configuration file
211 looking something like this:
212
213 <pre>
214 net(
215 add_remote("localhost:12300")
216 )
217
218 machine(
219 subtype(3max)
220 load("netbsd-INSTALL.gz")
221 )
222 </pre>
223
224 <p>In addition to the machine section, you can see that there is also a
225 <tt>net()</tt> section. It defaults to emulating a 10.0.0.0/8 IPv4 NATed
226 network, but there is also an additional "raw output", to UDP port 12300.
227
228 <p>Now, do the following:
229 <ul>
230 <li>Start the emulator with the configuration file, i.e.
231 <tt><b>gxemul @testconfig</b></tt>.
232 <li>Start <tt><b>udp_snoop 12300</b></tt> in another terminal.
233 <li>Inside emulated NetBSD/pmax, type <tt><b>ifconfig le0 10.0.0.1</b></tt>.
234 </ul>
235
236 <p>This should be enough to see broadcast messages from the guest OS which
237 are not directed to the gateway. It might look like this:
238
239 <pre>
240 $ ./udp_snoop 12300
241 ff ff ff ff ff ff 10 20 30 00 00 10 08 06 00 01 ....... 0.......
242 08 00 06 04 00 01 10 20 30 00 00 10 0a 00 00 02 ....... 0.......
243 00 00 00 00 00 00 0a 00 00 02 00 00 00 00 00 00 ................
244 00 00 00 00 00 00 00 00 00 00 00 00 ............
245
246 33 33 ff 00 00 10 10 20 30 00 00 10 86 dd 60 00 33..... 0.....`.
247 00 00 00 20 00 01 00 00 00 00 00 00 00 00 00 00 ... ............
248 00 00 00 00 00 00 ff 02 00 00 00 00 00 00 00 00 ................
249 00 01 ff 00 00 10 3a 00 01 00 05 02 00 00 83 00 ......:.........
250 80 83 00 00 00 00 ff 02 00 00 00 00 00 00 00 00 ................
251 00 01 ff 00 00 10 ......
252 ...
253 </pre>
254
255
256
257
258 </p>
259
260 </body>
261 </html>
262
263
  ViewVC Help
Powered by ViewVC 1.1.26