tcpopt: bogus assertion on undefined options

 # nft add rule x y tcp option 6 exists
 # nft list ruleset
 nft: tcpopt.c:208: tcpopt_init_raw: Assertion `expr->exthdr.desc != NULL' failed.
 Aborted

Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1557
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

3 files changed, 23 insertions, 0 deletions

diff --git a/tests/py/any/tcpopt.t b/tests/py/any/tcpopt.t
index f17a20b5..bcc64eac 100644
--- a/tests/py/any/tcpopt.t
+++ b/tests/py/any/tcpopt.t
@@ -31,6 +31,7 @@ tcp option timestamp length 1;ok
 tcp option timestamp tsval 1;ok
 tcp option timestamp tsecr 1;ok
 tcp option 255 missing;ok
+tcp option 6 exists;ok
 tcp option @255,8,8 255;ok
 
 tcp option foobar;fail
diff --git a/tests/py/any/tcpopt.t.json b/tests/py/any/tcpopt.t.json
index 139e97d8..a45b4c8b 100644
--- a/tests/py/any/tcpopt.t.json
+++ b/tests/py/any/tcpopt.t.json
@@ -414,6 +414,23 @@
     }
 ]
 
+# tcp option 6 exists
+[
+    {
+        "match": {
+            "left": {
+                "tcp option": {
+                    "base": 6,
+                    "len": 8,
+                    "offset": 0
+                }
+            },
+            "op": "==",
+            "right": true
+        }
+    }
+]
+
 # tcp option 255 missing
 [
     {
diff --git a/tests/py/any/tcpopt.t.payload b/tests/py/any/tcpopt.t.payload
index 1005df32..51f3a752 100644
--- a/tests/py/any/tcpopt.t.payload
+++ b/tests/py/any/tcpopt.t.payload
@@ -133,6 +133,11 @@ inet
   [ exthdr load tcpopt 1b @ 255 + 0 present => reg 1 ]
   [ cmp eq reg 1 0x00000000 ]
 
+# tcp option 6 exists
+inet
+  [ exthdr load tcpopt 1b @ 6 + 0 present => reg 1 ]
+  [ cmp eq reg 1 0x00000001 ]
+
 # tcp option @255,8,8 255
 inet
   [ exthdr load tcpopt 1b @ 255 + 1 => reg 1 ]