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Message-Id: <20190104131705.9550-2-fw@strlen.de>
Date: Fri, 4 Jan 2019 14:16:59 +0100
From: Florian Westphal <fw@...len.de>
To: steffen.klassert@...unet.com
Cc: xiyou.wangcong@...il.com, <netdev@...r.kernel.org>,
Florian Westphal <fw@...len.de>
Subject: [PATCH ipsec 1/7] selftests: xfrm: add block rules with adjacent/overlapping subnets
The existing script lacks a policy pattern that triggers 'tree node
merges' in the kernel.
Consider adding policy affecting following subnet:
pol1: dst 10.0.0.0/22
pol2: dst 10.0.0.0/23 # adds to existing 10.0.0.0/22 node
-> no problems here. But now, lets consider reverse order:
pol1: dst 10.0.0.0/24
pol2: dst 10.0.0.0/23 # CANNOT add to existing node
When second policy gets added, the kernel must check that the new node
("10.0.0.0/23") doesn't overlap with any existing subnet.
Example:
dst 10.0.0.0/24
dst 10.0.0.1/24
dst 10.0.0.0/23
When the third policy gets added, the kernel must replace the nodes for
the 10.0.0.0/24 and 10.0.0.1/24 policies with a single one and must merge
all the subtrees/lists stored in those nodes into the new node.
The existing test cases only have overlaps with a single node, so no
merging takes place (we can always remove the 'old' node and replace
it with the new subnet prefix).
Add a few 'block policies' in a pattern that triggers this, with a priority
that will make kernel prefer the 'esp' rules.
Make sure the 'tunnel ping' tests still pass after they have been added.
Signed-off-by: Florian Westphal <fw@...len.de>
---
tools/testing/selftests/net/xfrm_policy.sh | 109 +++++++++++++++++----
1 file changed, 91 insertions(+), 18 deletions(-)
diff --git a/tools/testing/selftests/net/xfrm_policy.sh b/tools/testing/selftests/net/xfrm_policy.sh
index 8db35b99457c..b5a1b565a7e6 100755
--- a/tools/testing/selftests/net/xfrm_policy.sh
+++ b/tools/testing/selftests/net/xfrm_policy.sh
@@ -46,6 +46,58 @@ do_esp() {
ip -net $ns xfrm policy add src $rnet dst $lnet dir fwd tmpl src $remote dst $me proto esp mode tunnel priority 100 action allow
}
+# add policies with different netmasks, to make sure kernel carries
+# the policies contained within new netmask over when search tree is
+# re-built.
+# peer netns that are supposed to be encapsulated via esp have addresses
+# in the 10.0.1.0/24 and 10.0.2.0/24 subnets, respectively.
+#
+# Adding a policy for '10.0.1.0/23' will make it necessary to
+# alter the prefix of 10.0.1.0 subnet.
+# In case new prefix overlaps with existing node, the node and all
+# policies it carries need to be merged with the existing one(s).
+#
+# Do that here.
+do_overlap()
+{
+ local ns=$1
+
+ # adds new nodes to tree (neither network exists yet in policy database).
+ ip -net $ns xfrm policy add src 10.1.0.0/24 dst 10.0.0.0/24 dir fwd priority 200 action block
+
+ # adds a new node in the 10.0.0.0/24 tree (dst node exists).
+ ip -net $ns xfrm policy add src 10.2.0.0/24 dst 10.0.0.0/24 dir fwd priority 200 action block
+
+ # adds a 10.2.0.0/24 node, but for different dst.
+ ip -net $ns xfrm policy add src 10.2.0.0/24 dst 10.0.1.0/24 dir fwd priority 200 action block
+
+ # dst now overlaps with the 10.0.1.0/24 ESP policy in fwd.
+ # kernel must 'promote' existing one (10.0.0.0/24) to 10.0.0.0/23.
+ # But 10.0.0.0/23 also includes existing 10.0.1.0/24, so that node
+ # also has to be merged too, including source-sorted subtrees.
+ # old:
+ # 10.0.0.0/24 (node 1 in dst tree of the bin)
+ # 10.1.0.0/24 (node in src tree of dst node 1)
+ # 10.2.0.0/24 (node in src tree of dst node 1)
+ # 10.0.1.0/24 (node 2 in dst tree of the bin)
+ # 10.0.2.0/24 (node in src tree of dst node 2)
+ # 10.2.0.0/24 (node in src tree of dst node 2)
+ #
+ # The next 'policy add' adds dst '10.0.0.0/23', which means
+ # that dst node 1 and dst node 2 have to be merged including
+ # the sub-tree. As no duplicates are allowed, policies in
+ # the two '10.0.2.0/24' are also merged.
+ #
+ # after the 'add', internal search tree should look like this:
+ # 10.0.0.0/23 (node in dst tree of bin)
+ # 10.0.2.0/24 (node in src tree of dst node)
+ # 10.1.0.0/24 (node in src tree of dst node)
+ # 10.2.0.0/24 (node in src tree of dst node)
+ #
+ # 10.0.0.0/24 and 10.0.1.0/24 nodes have been merged as 10.0.0.0/23.
+ ip -net $ns xfrm policy add src 10.1.0.0/24 dst 10.0.0.0/23 dir fwd priority 200 action block
+}
+
do_esp_policy_get_check() {
local ns=$1
local lnet=$2
@@ -160,6 +212,41 @@ check_xfrm() {
return $lret
}
+check_exceptions()
+{
+ logpostfix="$1"
+ local lret=0
+
+ # ping to .254 should be excluded from the tunnel (exception is in place).
+ check_xfrm 0 254
+ if [ $? -ne 0 ]; then
+ echo "FAIL: expected ping to .254 to fail ($logpostfix)"
+ lret=1
+ else
+ echo "PASS: ping to .254 bypassed ipsec tunnel ($logpostfix)"
+ fi
+
+ # ping to .253 should use use ipsec due to direct policy exception.
+ check_xfrm 1 253
+ if [ $? -ne 0 ]; then
+ echo "FAIL: expected ping to .253 to use ipsec tunnel ($logpostfix)"
+ lret=1
+ else
+ echo "PASS: direct policy matches ($logpostfix)"
+ fi
+
+ # ping to .2 should use ipsec.
+ check_xfrm 1 2
+ if [ $? -ne 0 ]; then
+ echo "FAIL: expected ping to .2 to use ipsec tunnel ($logpostfix)"
+ lret=1
+ else
+ echo "PASS: policy matches ($logpostfix)"
+ fi
+
+ return $lret
+}
+
#check for needed privileges
if [ "$(id -u)" -ne 0 ];then
echo "SKIP: Need root privileges"
@@ -270,31 +357,17 @@ do_exception ns4 10.0.3.10 10.0.3.1 10.0.1.253 10.0.1.240/28
do_exception ns3 dead:3::1 dead:3::10 dead:2::fd dead:2:f0::/96
do_exception ns4 dead:3::10 dead:3::1 dead:1::fd dead:1:f0::/96
-# ping to .254 should now be excluded from the tunnel
-check_xfrm 0 254
+check_exceptions "exceptions"
if [ $? -ne 0 ]; then
- echo "FAIL: expected ping to .254 to fail"
ret=1
-else
- echo "PASS: ping to .254 bypassed ipsec tunnel"
fi
-# ping to .253 should use use ipsec due to direct policy exception.
-check_xfrm 1 253
-if [ $? -ne 0 ]; then
- echo "FAIL: expected ping to .253 to use ipsec tunnel"
- ret=1
-else
- echo "PASS: direct policy matches"
-fi
+# insert block policies with adjacent/overlapping netmasks
+do_overlap ns3
-# ping to .2 should use ipsec.
-check_xfrm 1 2
+check_exceptions "exceptions and block policies"
if [ $? -ne 0 ]; then
- echo "FAIL: expected ping to .2 to use ipsec tunnel"
ret=1
-else
- echo "PASS: policy matches"
fi
for i in 1 2 3 4;do ip netns del ns$i;done
--
2.19.2
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