[PATCH 22/27] tasst: IP address allocation helpers

[David Gibson <david@gibson.dropbear.id.au>]

A bunch of our test scenarious will require us to allocate IPv4 and IPv6
addresses in example networks.  Make helpers to do this easily.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
 test/tasst/address.py   | 80 +++++++++++++++++++++++++++++++++++++++++
 test/tasst/meta/veth.py | 20 +++++++++++
 test/tasst/transfer.py  |  5 ++-
 3 files changed, 102 insertions(+), 3 deletions(-)
 create mode 100644 test/tasst/address.py

diff --git a/test/tasst/address.py b/test/tasst/address.py
new file mode 100644
index 00000000..24f118c3
--- /dev/null
+++ b/test/tasst/address.py
@@ -0,0 +1,80 @@
+#! /usr/bin/env avocado-runner-avocado-classless
+
+# SPDX-License-Identifier: GPL-2.0-or-later
+#
+# Copyright Red Hat
+# Author: David Gibson <david@gibson.dropbear.id.au>
+
+"""
+Test A Simple Socket Transport
+
+address.py - Address allocation helpers
+"""
+
+import ipaddress
+
+from avocado_classless.test import assert_eq, test
+
+
+# Loopback addresses, for convenience
+LOOPBACK4 = ipaddress.ip_address('127.0.0.1')
+LOOPBACK6 = ipaddress.ip_address('::1')
+
+# Documentation test networks defined by RFC 5737
+TEST_NET_1 = ipaddress.ip_network('192.0.2.0/24')
+TEST_NET_2 = ipaddress.ip_network('198.51.100.0/24')
+TEST_NET_3 = ipaddress.ip_network('203.0.113.0/24')
+
+# Documentation test network defined by RFC 3849
+TEST_NET6 = ipaddress.ip_network('2001:db8::/32')
+# Some subnets of that for our usage
+TEST_NET6_TASST_A = ipaddress.ip_network('2001:db8:9a55:aaaa::/64')
+TEST_NET6_TASST_B = ipaddress.ip_network('2001:db8:9a55:bbbb::/64')
+TEST_NET6_TASST_C = ipaddress.ip_network('2001:db8:9a55:cccc::/64')
+
+
+class IpiAllocator:  # pylint: disable=R0903
+    """IP address allocator"""
+
+    DEFAULT_NETS = [TEST_NET_1, TEST_NET6_TASST_A]
+
+    def __init__(self, *nets):
+        if not nets:
+            nets = self.DEFAULT_NETS
+
+        self.nets = [ipaddress.ip_network(n) for n in nets]
+        self.hostses = [n.hosts() for n in self.nets]
+
+    def next_ipis(self):
+        addrs = [next(h) for h in self.hostses]
+        return [ipaddress.ip_interface(f'{a}/{n.prefixlen}')
+                for a, n in zip(addrs, self.nets)]
+
+
+@test
+def ipa_test(nets=None, count=12):
+    if nets is None:
+        ipa = IpiAllocator()
+        nets = IpiAllocator.DEFAULT_NETS
+    else:
+        ipa = IpiAllocator(*nets)
+
+    addrsets = [set() for i in range(len(nets))]
+    for i in range(count):
+        addrs = ipa.next_ipis()
+        # Check we got as many addresses as expected
+        assert_eq(len(addrs), len(nets))
+        for s, a, n in zip(addrsets, addrs, nets):
+            # Check the addresses belong to the right network
+            assert_eq(a.network, ipaddress.ip_network(n))
+            s.add(a)
+
+    print(addrsets)
+    # Check the addresses are unique
+    for s in addrsets:
+        assert_eq(len(s), count)
+
+
+@test
+def ipa_test_custom():
+    ipa_test(nets=['10.55.0.0/16', '192.168.55.0/24', 'fd00:9a57:a000::/48'])
diff --git a/test/tasst/meta/veth.py b/test/tasst/meta/veth.py
index cedcf059..b2aafc2c 100644
--- a/test/tasst/meta/veth.py
+++ b/test/tasst/meta/veth.py
@@ -17,6 +17,8 @@ import ipaddress
 from avocado_classless.test import assert_eq, assert_eq_unordered, test
 
 from tasst.nstool import unshare_site
+from tasst.transfer import test_transfers
+from tasst.address import IpiAllocator
 
 
 @contextlib.contextmanager
@@ -64,3 +66,21 @@ def test_optimistic_dad():
 @test
 def test_no_dad():
     test_slaac(dad='disable')
+
+
+ipa = IpiAllocator()
+NS1_IP4, NS1_IP6 = ipa.next_ipis()
+NS2_IP4, NS2_IP6 = ipa.next_ipis()
+
+
+@test_transfers(ip4=NS2_IP4.ip, ip6=NS2_IP6.ip, port=10000)
+@contextlib.contextmanager
+def configured_veth():
+    with unconfigured_veth() as (ns1, ns2):
+        ns1.ifup('lo')
+        ns1.ifup('veth1', NS1_IP4, NS1_IP6, dad='disable')
+
+        ns2.ifup('lo')
+        ns2.ifup('veth2', NS2_IP4, NS2_IP6, dad='disable')
+
+        yield (ns1, ns2)
diff --git a/test/tasst/transfer.py b/test/tasst/transfer.py
index 788c1d52..5399bb54 100644
--- a/test/tasst/transfer.py
+++ b/test/tasst/transfer.py
@@ -17,6 +17,7 @@ import time
 
 from avocado_classless.test import assert_eq, test_output
 
+from tasst.address import LOOPBACK4, LOOPBACK6
 from tasst.nstool import unshare_site
 
 
@@ -165,9 +166,7 @@ def test_transfers(ip4, ip6, port, **kwargs):
     return dec
 
 
-@test_transfers(ip4=ipaddress.ip_address('127.0.0.1'),
-                ip6=ipaddress.ip_address('::1'),
-                port=10000)
+@test_transfers(ip4=LOOPBACK4, ip6=LOOPBACK6, port=10000)
 @contextlib.contextmanager
 def local_only():
     with unshare_site('ns', '-Un') as ns:
-- 
@@ -17,6 +17,7 @@ import time
 
 from avocado_classless.test import assert_eq, test_output
 
+from tasst.address import LOOPBACK4, LOOPBACK6
 from tasst.nstool import unshare_site
 
 
@@ -165,9 +166,7 @@ def test_transfers(ip4, ip6, port, **kwargs):
     return dec
 
 
-@test_transfers(ip4=ipaddress.ip_address('127.0.0.1'),
-                ip6=ipaddress.ip_address('::1'),
-                port=10000)
+@test_transfers(ip4=LOOPBACK4, ip6=LOOPBACK6, port=10000)
 @contextlib.contextmanager
 def local_only():
     with unshare_site('ns', '-Un') as ns:
-- 
2.41.0