nat: static mappings in flow hash

Put static mappings in flow hash, drop existing hash tables used for
static mappings. Drop refcount variables and use hash table as a single
point of truth. Allow creating a static mapping conflicting with dynamic
mapping, which will take precedence after dynamic mapping is freed, so
that the existing flow can finish transferring data.

Type: fix
Signed-off-by: Klement Sekera <ksekera@cisco.com>
Change-Id: Ieeba691d83a83887d0a0baccd5f3832f66126096

1 files changed, 75 insertions, 0 deletions

diff --git a/src/plugins/nat/lib/nat_proto.h b/src/plugins/nat/lib/nat_proto.h
new file mode 100644
index 00000000000..9b20d9a71d1
--- /dev/null
+++ b/src/plugins/nat/lib/nat_proto.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2021 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#ifndef included_nat_proto_h__
+#define included_nat_proto_h__
+
+#include <vnet/ip/ip.h>
+
+#define foreach_nat_protocol                                                  \
+  _ (OTHER, 0, other, "other")                                                \
+  _ (UDP, 1, udp, "udp")                                                      \
+  _ (TCP, 2, tcp, "tcp")                                                      \
+  _ (ICMP, 3, icmp, "icmp")
+
+typedef enum
+{
+#define _(N, i, n, s) NAT_PROTOCOL_##N = i,
+  foreach_nat_protocol
+#undef _
+} nat_protocol_t;
+
+always_inline nat_protocol_t
+ip_proto_to_nat_proto (ip_protocol_t ip_proto)
+{
+  static const nat_protocol_t lookup_table[256] = {
+    [IP_PROTOCOL_TCP] = NAT_PROTOCOL_TCP,
+    [IP_PROTOCOL_UDP] = NAT_PROTOCOL_UDP,
+    [IP_PROTOCOL_ICMP] = NAT_PROTOCOL_ICMP,
+    [IP_PROTOCOL_ICMP6] = NAT_PROTOCOL_ICMP,
+  };
+
+  return lookup_table[ip_proto];
+}
+
+static_always_inline ip_protocol_t
+nat_proto_to_ip_proto (nat_protocol_t nat_proto)
+{
+  ASSERT (nat_proto <= NAT_PROTOCOL_ICMP);
+
+  static const u8 lookup_table[256] = {
+    [NAT_PROTOCOL_OTHER] = ~0,
+    [NAT_PROTOCOL_TCP] = IP_PROTOCOL_TCP,
+    [NAT_PROTOCOL_UDP] = IP_PROTOCOL_UDP,
+    [NAT_PROTOCOL_ICMP] = IP_PROTOCOL_ICMP,
+  };
+
+  ASSERT (NAT_PROTOCOL_OTHER == nat_proto || NAT_PROTOCOL_TCP == nat_proto ||
+	  NAT_PROTOCOL_UDP == nat_proto || NAT_PROTOCOL_ICMP == nat_proto);
+
+  return lookup_table[nat_proto];
+}
+
+u8 *format_nat_protocol (u8 *s, va_list *args);
+
+uword unformat_nat_protocol (unformat_input_t *input, va_list *args);
+
+#endif /* included_nat_proto_h__ */
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */