tools/docs: Fix example and default IP addresses.

In various places in documentation and code, IP addresses are provided
as examples, defaults, or dummy configuration.  In general the
specific IP addresses used in Xen are not always appropriate.  (For
example, 1.2.3.4 is used in a few places!)

The following addresses should be used:
 * For examples and documentation, 192.0.2.0/24.  (See RFC3330.)
 * For defaults for private networks, a random network from RFC1918.
   I have randomly selected 172.30.206.0/24 for this purpose and
   documented this in at the only registry I know of,
   www.ucam.org/cam-grin.  This network should henceforth be used for
   default configurations of local bridges, test networks, etc. in
   Xen tools.

The following addresses should NOT be used:
 * 10.0.*.*, 10.1.*.*, 192.168.0.*, 192.168.1.*, etc.  Using these
   addresses gives greatly increased likelihood of collision, as
   ignorant network administrators and reckless middlebox vendors
   often pick networks from the bottom of 10/8 and 192.168/16.
 * 169.254.*.*.  These are reserved for zeroconf (ad-hoc networking)
   and should not be used for Xen private networks, bridges, etc.,
   etc.  Use of these addresses by Xen scripts causes trouble on hosts
   (eg laptops) which find themselves in ad-hoc networking
   environments.  I think this is not hypothetical (!) since at least
   one Linux distribution have specific code to detect this case and
   cause Xen startup to fail iff the host already has an external
   zeroconf address.
 * 1.2.3.4.  WTF !?

I have also used 127.0.255.255 in one place where apparently a dummy
address is needed (some Linux kernels won't accept a lack of an NFS
server address).  If 127.0.255.255 is mistakenly used it is unlikely
to do any damage to real traffic even if it does escape into the
network at large.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

5 files changed, 24 insertions, 31 deletions

diff --git a/tools/xm-test/Writing_Tests_HOWTO b/tools/xm-test/Writing_Tests_HOWTO
index 84cc90e2c6..379b0b145c 100644
--- a/tools/xm-test/Writing_Tests_HOWTO
+++ b/tools/xm-test/Writing_Tests_HOWTO
@@ -104,12 +104,14 @@ routing environments in the future, the current xm-test only supports
 a bridging environment. Xm-test currently only supports a range of
 IPs, the dhcp feature will be added soon.
 
-The network tests will need to know what IPs to use. IPs are configured
-when you build xm-test. Xm-test uses the zeroconf address range by
-default, 169.254.0.1-169.254.255.255. If you'd like to set a new range,
-do so at configure time, a netmask and network address must also be defined:
-
-    # ./configure --with-net-ip-range=192.168.1.1-192.168.1.100 --with-network-address=192.168.1.0 --with-netmask=255.255.255.0
+The network tests will need to know what IPs to use. IPs are
+configured when you build xm-test. Xm-test by default a range chosen
+at random from the RFC1918 private use space, and published at
+www.ucam.org/cam-grin, 172.30.206.1-172.30.206.254 from
+172.30.206.0/24. If you'd like to set a new range, do so at configure
+time, a netmask and network address must also be defined:
+
+    # ./configure --with-net-ip-range=192.0.2.1-192.0.2.100 --with-network-address=192.0.2.0 --with-netmask=255.255.255.0
 
 The tests will not need to set network information, this is done by 
 the library once it's configured.
diff --git a/tools/xm-test/configure.ac b/tools/xm-test/configure.ac
index bbc639bdb0..a92b6daa6b 100644
--- a/tools/xm-test/configure.ac
+++ b/tools/xm-test/configure.ac
@@ -56,24 +56,24 @@ else
 fi
 
 # Network needs to know ips to use: dhcp or a range of IPs in the form
-# of: 192.168.1.1-192.168.1.100
+# of: 192.0.2.1-192.0.2.100
 # If not dhcp, a netmask and network address must be supplied. Defaults to
-# zeroconf range.
-NET_IP_RANGE="169.254.0.1-169.254.255.255"
+# range allocated in www.ucam.org/cam-grin.
+NET_IP_RANGE="172.30.206.1-172.30.206.254"
 AC_ARG_WITH(net-ip-range,
-	[  --with-net-ip-range=ip-range	Set a range of ip addresses to use for xm-test guest domain networks. Can specify dhcp or a range of IPs: 192.168.1.1-192.168.1.100 [[default="169.254.0.1-169.254.255.255"]]],
+	[  --with-net-ip-range=ip-range	Set a range of ip addresses to use for xm-test guest domain networks. Can specify dhcp or a range of IPs: 192.0.2.1-192.0.2.100 [[default="172.30.206.1-172.30.206.254"]]],
 	[ NET_IP_RANGE="$withval" ])
 
 iprange=`echo $NET_IP_RANGE | perl -e 'while(<>) { print if /\d+\.\d+\.\d+\.\d+-\d+\.\d+\.\d+\.\d+/ }'`
 
-NETWORK_ADDRESS="169.254.0.0"
+NETWORK_ADDRESS="172.30.206.0"
 AC_ARG_WITH(network-address,
-	[ --with-network-address=ip Set network address to use with ip range [[default="169.254.0.0"]]],
+	[ --with-network-address=ip Set network address to use with ip range [[default="172.30.206.0"]]],
 	[ NETWORK_ADDRESS="$withval" ])
 
-NETMASK="255.255.0.0"
+NETMASK="255.255.255.0"
 AC_ARG_WITH(netmask,
-	[ --with-netmask=mask Set netmask to use with ip range [[default="255.255.0.0"]]],
+	[ --with-netmask=mask Set netmask to use with ip range [[default="255.255.255.0"]]],
 	[ NETMASK="$withval" ])
 
 if test "x$NET_IP_RANGE" != "xdhcp" && test -z "$iprange"
diff --git a/tools/xm-test/lib/XmTestLib/NetConfig.py b/tools/xm-test/lib/XmTestLib/NetConfig.py
index 919af65fdb..0c39969806 100644
--- a/tools/xm-test/lib/XmTestLib/NetConfig.py
+++ b/tools/xm-test/lib/XmTestLib/NetConfig.py
@@ -69,12 +69,6 @@ def getXendNetConfig():
     configfile.close()
     return netenv
 
-def checkZeroconfAddresses():
-    # Make sure there aren't existing zeroconf addresses.
-    rc, out = traceCommand("ip addr show |grep \"inet 169.254\" | grep eth0")
-    if rc == 0:
-        raise NetworkError("Zeroconf addresses already used: %s" % out)
-
 class NetConfig:
 
     def __init__(self):
@@ -101,9 +95,6 @@ class NetConfig:
 
             self.__setMaxNumberIPs()
 
-            if self.network == "169.254.0.0":
-                checkZeroconfAddresses()
-
             # Clean out any aliases in the network range for dom0's interface.
             # If an alias exists, a test xendevice add command could fail.
             if NETWORK_IP_RANGE != "dhcp":
diff --git a/tools/xm-test/tests/restore/04_restore_withdevices_pos.py b/tools/xm-test/tests/restore/04_restore_withdevices_pos.py
index 63b716da62..a7a67f7c93 100644
--- a/tools/xm-test/tests/restore/04_restore_withdevices_pos.py
+++ b/tools/xm-test/tests/restore/04_restore_withdevices_pos.py
@@ -48,11 +48,11 @@ try:
     if run["return"] != 0:
         FAIL("Unable to write to block device hdb2!")
 
-    run = console.runCmd("ifconfig eth0 169.254.0.1 netmask 255.255.255.0")
+    run = console.runCmd("ifconfig eth0 172.30.206.1 netmask 255.255.255.240")
     if run["return"] != 0:
         FAIL("Unable to configure DomU's eth0")
 
-    run = console.runCmd("ifconfig eth1 169.254.1.1 netmask 255.255.255.0")
+    run = console.runCmd("ifconfig eth1 172.30.206.17 netmask 255.255.255.240")
     if run["return"] != 0:
         FAIL("Unable to configure DomU's eth1")
 
@@ -114,11 +114,11 @@ try:
     run = console.runCmd("ifconfig")
     if not re.search("eth0", run["output"]):
         FAIL("DomU's eth0 disappeared")
-    if not re.search("169.254.0.1", run["output"]):
+    if not re.search("172.30.206.1", run["output"]):
         FAIL("DomU's eth0 lost its IP")
     if not re.search("eth1", run["output"]):
         FAIL("DomU's eth1 disappeared")
-    if not re.search("169.254.1.1", run["output"]):
+    if not re.search("172.30.206.17", run["output"]):
         FAIL("DomU's eth1 lost its IP")
     if not re.search("Loopback", run["output"]):
         FAIL("DomU's lo disappeared")
diff --git a/tools/xm-test/tests/xapi/03_xapi-network_pos.py b/tools/xm-test/tests/xapi/03_xapi-network_pos.py
index 43ea82691d..9ae2daea1b 100644
--- a/tools/xm-test/tests/xapi/03_xapi-network_pos.py
+++ b/tools/xm-test/tests/xapi/03_xapi-network_pos.py
@@ -39,18 +39,18 @@ if status:
 # Configure IP addresses on two domains
 try:
     # Run 'ls'
-    run = console1.runCmd("ifconfig eth0 192.168.0.1 netmask 255.255.255.0 up")
-    run = console2.runCmd("ifconfig eth0 192.168.0.2 netmask 255.255.255.0 up")
+    run = console1.runCmd("ifconfig eth0 172.30.206.1 netmask 255.255.255.0 up")
+    run = console2.runCmd("ifconfig eth0 172.30.206.2 netmask 255.255.255.0 up")
 except ConsoleError, e:
     saveLog(console.getHistory())
     FAIL(str(e))
 
 # Now ping...
 try:
-    run = console1.runCmd("ping -c 4 192.168.0.2")
+    run = console1.runCmd("ping -c 4 172.30.206.2")
     if run['return'] > 0:
         FAIL("Could not ping other host")
-    run = console2.runCmd("ping -c 4 192.168.0.1")
+    run = console2.runCmd("ping -c 4 172.30.206.1")
     if run['return'] > 0:
         FAIL("Could not pint other host")
 except ConsoleError, e: