[PATCH lnst 13/13] recipes: switchdev: Test a conflicting tunnel

[Petr Machata]

Several GRE tunnels can share the same local address, provided that
they differ by a tunnel key (or lack thereof) or a remote address (or
lack thereof). Linux handles such situations in a well-defined manner.
Test that the driver deals with such configurations gracefully.

Signed-off-by: Petr Machata <petrm(a)mellanox.com&gt;
---

Notes:
    Changes from v1 to v2:
    
    - Split out this code to patch of its own.
    - Replace manual route handling with add_nhs_route() call

 recipes/switchdev/ipip-008-gre-conflict.py  | 82 +++++++++++++++++++++++++++++
 recipes/switchdev/ipip-008-gre-conflict.xml | 12 +++++
 2 files changed, 94 insertions(+)
 create mode 100644 recipes/switchdev/ipip-008-gre-conflict.py
 create mode 100644 recipes/switchdev/ipip-008-gre-conflict.xml

diff --git a/recipes/switchdev/ipip-008-gre-conflict.py
b/recipes/switchdev/ipip-008-gre-conflict.py
new file mode 100644
index 0000000..78d7de8
--- /dev/null
+++ b/recipes/switchdev/ipip-008-gre-conflict.py
@@ -0,0 +1,82 @@
+"""
+Copyright 2017 Mellanox Technologies. All rights reserved.
+Licensed under the GNU General Public License, version 2 as
+published by the Free Software Foundation; see COPYING for details.
+"""
+
+__author__ = """
+petrm(a)mellanox.com (Petr Machata)
+"""
+
+from lnst.Controller.Task import ctl
+from TestLib import TestLib, vrf, dummy, gre
+from ipip_common import ping_test, encap_route, \
+                        add_forward_route, connect_host_ifaces, \
+                        test_ip, ipv4, ipv6
+from time import sleep
+import logging
+
+def do_task(ctl, hosts, ifaces, aliases):
+    m1, m2, sw = hosts
+    m1_if1, m2_if1, sw_if1, sw_if2 = ifaces
+
+    m1_if1.add_nhs_route(ipv4(test_ip(2, 0)), [ipv4(test_ip(1, 1, []))])
+    m1_if1.add_nhs_route(ipv6(test_ip(2, 0)), [ipv6(test_ip(1, 1, []))])
+    m2_if1.add_nhs_route("1.2.3.4/32", [ipv4(test_ip(99, 1, []))])
+
+    vrf_None = None
+    tl = TestLib(ctl, aliases)
+    sw_if1.reset(ip=test_ip(1, 1))
+    sw_if2.reset(ip=test_ip(99,1))
+
+    # Check the behavior when two tunnels with conflicting local addresses are
+    # used.
+    logging.info("=== Conflict in GRE local endpoint")
+    with encap_route(m2, vrf_None, 1, "gre1", ip=ipv4), \
+         encap_route(m2, vrf_None, 1, "gre1", ip=ipv6), \
+         vrf(sw) as vrf1, \
+         dummy(sw, vrf1, ip=["1.2.3.4/32"]) as d, \
+         gre(sw, None, vrf1,
+             tos="inherit",
+             local_ip="1.2.3.4",
+             remote_ip="1.2.3.5") as g, \
+         encap_route(sw, vrf1, 2, g, ip=ipv4), \
+         encap_route(sw, vrf1, 2, g, ip=ipv6):
+
+        connect_host_ifaces(sw, sw_if1, vrf1, sw_if2, vrf1)
+        sw_if1.reset()
+        sw_if2.reset()
+        add_forward_route(sw, vrf1, "1.2.3.5")
+
+        # Now create another tunnel whose local address conflicts with this one.
+        # The original tunnel should keep working, even if it has to be
+        # temporarily brought to slow path.
+        with gre(sw, None, vrf1,
+                 tos="inherit",
+                 local_ip="1.2.3.4",
+                 remote_ip="1.2.3.5",
+                 key=3333) as g2, \
+             encap_route(sw, vrf1, 4, g2, ip=ipv4), \
+             encap_route(sw, vrf1, 4, g2, ip=ipv6):
+
+            sleep(15)
+            ping_test(tl, m1, sw, ipv6(test_ip(2, 33, [])), m1_if1, g,
+                      ipv6=True, require_fastpath=False)
+            ping_test(tl, m1, sw, ipv4(test_ip(2, 33, [])), m1_if1, g,
+                      require_fastpath=False)
+
+        # After the conflicting tunnel is gone, the traffic should again go
+        # through fast path.
+        sleep(15)
+        ping_test(tl, m1, sw, ipv6(test_ip(2, 33, [])), m1_if1, g,
+                  ipv6=True)
+        ping_test(tl, m1, sw, ipv4(test_ip(2, 33, [])), m1_if1, g)
+
+do_task(ctl, [ctl.get_host("machine1"),
+              ctl.get_host("machine2"),
+              ctl.get_host("switch")],
+        [ctl.get_host("machine1").get_interface("if1"),
+         ctl.get_host("machine2").get_interface("if1"),
+         ctl.get_host("switch").get_interface("if1"),
+         ctl.get_host("switch").get_interface("if2")],
+        ctl.get_aliases())
diff --git a/recipes/switchdev/ipip-008-gre-conflict.xml
b/recipes/switchdev/ipip-008-gre-conflict.xml
new file mode 100644
index 0000000..5c95a28
--- /dev/null
+++ b/recipes/switchdev/ipip-008-gre-conflict.xml
@@ -0,0 +1,12 @@
+<lnstrecipe xmlns:xi="http://www.w3.org/2003/XInclude">
+    <xi:include href="default_aliases.xml" />
+    <define>
+        <alias name="onet1" value="192.168.1"/>
+        <alias name="onet2" value="192.168.2"/>
+        <alias name="o6net1" value="2002:1"/>
+        <alias name="o6net2" value="2002:2"/>
+        <alias name="unet" value="192.168.99"/>
+    </define>
+    <xi:include href="ipip_common_topology.xml" />
+    <task python="ipip-008-gre-conflict.py" />
+</lnstrecipe>
-- 
2.4.11