tests: shell: add test case for reset tcp warning

tcp reset rule + nftrace 1 triggers (harmless) splat from flow dissector:

 WARNING: CPU: 2 PID: 145809 at net/core/flow_dissector.c:1104 __skb_flow_dissect+0x19d4/0x5cc0
  __skb_get_hash+0xa8/0x220
  nft_trace_init+0x2ff/0x3b0
  nft_do_chain+0xb04/0x1370
  nft_do_chain_inet+0xc5/0x2e0
  nf_hook_slow+0xa0/0x1d0
  ip_local_out+0x14/0x90
  nf_send_reset+0x94e/0xbd0
  nft_reject_inet_eval+0x45e/0x690
  nft_do_chain+0x220/0x1370
  nf_hook_slow+0xa0/0x1d0
  ip_local_deliver+0x23f/0x2d0

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

3 files changed, 212 insertions, 0 deletions

diff --git a/tests/shell/testcases/packetpath/dumps/tcp_reset.json-nft b/tests/shell/testcases/packetpath/dumps/tcp_reset.json-nft
new file mode 100644
index 00000000..e1367cc1
--- /dev/null
+++ b/tests/shell/testcases/packetpath/dumps/tcp_reset.json-nft
@@ -0,0 +1,168 @@
+{
+  "nftables": [
+    {
+      "metainfo": {
+        "version": "VERSION",
+        "release_name": "RELEASE_NAME",
+        "json_schema_version": 1
+      }
+    },
+    {
+      "table": {
+        "family": "inet",
+        "name": "filter",
+        "handle": 0
+      }
+    },
+    {
+      "chain": {
+        "family": "inet",
+        "table": "filter",
+        "name": "input",
+        "handle": 0,
+        "type": "filter",
+        "hook": "input",
+        "prio": 0,
+        "policy": "accept"
+      }
+    },
+    {
+      "chain": {
+        "family": "inet",
+        "table": "filter",
+        "name": "output",
+        "handle": 0,
+        "type": "filter",
+        "hook": "output",
+        "prio": 0,
+        "policy": "accept"
+      }
+    },
+    {
+      "rule": {
+        "family": "inet",
+        "table": "filter",
+        "chain": "input",
+        "handle": 0,
+        "expr": [
+          {
+            "mangle": {
+              "key": {
+                "meta": {
+                  "key": "nftrace"
+                }
+              },
+              "value": 1
+            }
+          }
+        ]
+      }
+    },
+    {
+      "rule": {
+        "family": "inet",
+        "table": "filter",
+        "chain": "input",
+        "handle": 0,
+        "expr": [
+          {
+            "match": {
+              "op": "==",
+              "left": {
+                "payload": {
+                  "protocol": "ip",
+                  "field": "daddr"
+                }
+              },
+              "right": "127.0.0.1"
+            }
+          },
+          {
+            "match": {
+              "op": "==",
+              "left": {
+                "payload": {
+                  "protocol": "tcp",
+                  "field": "dport"
+                }
+              },
+              "right": 5555
+            }
+          },
+          {
+            "reject": {
+              "type": "tcp reset"
+            }
+          }
+        ]
+      }
+    },
+    {
+      "rule": {
+        "family": "inet",
+        "table": "filter",
+        "chain": "input",
+        "handle": 0,
+        "expr": [
+          {
+            "match": {
+              "op": "==",
+              "left": {
+                "payload": {
+                  "protocol": "ip6",
+                  "field": "daddr"
+                }
+              },
+              "right": "::1"
+            }
+          },
+          {
+            "match": {
+              "op": "==",
+              "left": {
+                "payload": {
+                  "protocol": "tcp",
+                  "field": "dport"
+                }
+              },
+              "right": 5555
+            }
+          },
+          {
+            "reject": {
+              "type": "tcp reset"
+            }
+          }
+        ]
+      }
+    },
+    {
+      "rule": {
+        "family": "inet",
+        "table": "filter",
+        "chain": "input",
+        "handle": 0,
+        "expr": [
+          {
+            "match": {
+              "op": "==",
+              "left": {
+                "payload": {
+                  "protocol": "tcp",
+                  "field": "dport"
+                }
+              },
+              "right": 5555
+            }
+          },
+          {
+            "counter": {
+              "packets": 0,
+              "bytes": 0
+            }
+          }
+        ]
+      }
+    }
+  ]
+}
diff --git a/tests/shell/testcases/packetpath/dumps/tcp_reset.nft b/tests/shell/testcases/packetpath/dumps/tcp_reset.nft
new file mode 100644
index 00000000..fb3df1af
--- /dev/null
+++ b/tests/shell/testcases/packetpath/dumps/tcp_reset.nft
@@ -0,0 +1,13 @@
+table inet filter {
+	chain input {
+		type filter hook input priority filter; policy accept;
+		meta nftrace set 1
+		ip daddr 127.0.0.1 tcp dport 5555 reject with tcp reset
+		ip6 daddr ::1 tcp dport 5555 reject with tcp reset
+		tcp dport 5555 counter packets 0 bytes 0
+	}
+
+	chain output {
+		type filter hook output priority filter; policy accept;
+	}
+}
diff --git a/tests/shell/testcases/packetpath/tcp_reset b/tests/shell/testcases/packetpath/tcp_reset
new file mode 100755
index 00000000..3dfcdde4
--- /dev/null
+++ b/tests/shell/testcases/packetpath/tcp_reset
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# regression check for kernel commit
+# netfilter: nf_reject: init skb->dev for reset packet
+
+socat -h > /dev/null || exit 77
+
+ip link set lo up
+
+$NFT -f - <<EOF
+table inet filter {
+  chain input {
+    type filter hook input priority filter; policy accept;
+    meta nftrace set 1
+    ip daddr 127.0.0.1 tcp dport 5555 reject with tcp reset
+    ip6 daddr ::1 tcp dport 5555 reject with tcp reset
+    tcp dport 5555 counter
+   }
+   chain output {
+    type filter hook output priority filter; policy accept;
+    # empty chain, so nf_hook_slow is called from ip_local_out.
+   }
+}
+EOF
+[ $? -ne 0 ] && exit 1
+
+socat -u STDIN TCP:127.0.0.1:5555,connect-timeout=2 < /dev/null > /dev/null
+socat -u STDIN TCP:[::1]:5555,connect-timeout=2 < /dev/null > /dev/null
+
+$NFT list ruleset |grep -q 'counter packets 0 bytes 0' || exit 1
+exit 0