NAT44: code cleanup and refactor (VPP-1285)

Change-Id: I088163f10ae5515d7a9115781cc13ef563fafed5
Signed-off-by: Matus Fabian <matfabia@cisco.com>

1 files changed, 250 insertions, 0 deletions

diff --git a/src/plugins/nat/nat_inlines.h b/src/plugins/nat/nat_inlines.h
new file mode 100644
index 00000000000..db5b295f938
--- /dev/null
+++ b/src/plugins/nat/nat_inlines.h
@@ -0,0 +1,250 @@
+/*
+ * Copyright (c) 2018 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.
+ */
+/**
+ * @brief The NAT inline functions
+ */
+
+#ifndef __included_nat_inlines_h__
+#define __included_nat_inlines_h__
+
+#include <nat/nat.h>
+
+always_inline u32
+ip_proto_to_snat_proto (u8 ip_proto)
+{
+  u32 snat_proto = ~0;
+
+  snat_proto = (ip_proto == IP_PROTOCOL_UDP) ? SNAT_PROTOCOL_UDP : snat_proto;
+  snat_proto = (ip_proto == IP_PROTOCOL_TCP) ? SNAT_PROTOCOL_TCP : snat_proto;
+  snat_proto =
+    (ip_proto == IP_PROTOCOL_ICMP) ? SNAT_PROTOCOL_ICMP : snat_proto;
+  snat_proto =
+    (ip_proto == IP_PROTOCOL_ICMP6) ? SNAT_PROTOCOL_ICMP : snat_proto;
+
+  return snat_proto;
+}
+
+always_inline u8
+snat_proto_to_ip_proto (snat_protocol_t snat_proto)
+{
+  u8 ip_proto = ~0;
+
+  ip_proto = (snat_proto == SNAT_PROTOCOL_UDP) ? IP_PROTOCOL_UDP : ip_proto;
+  ip_proto = (snat_proto == SNAT_PROTOCOL_TCP) ? IP_PROTOCOL_TCP : ip_proto;
+  ip_proto = (snat_proto == SNAT_PROTOCOL_ICMP) ? IP_PROTOCOL_ICMP : ip_proto;
+
+  return ip_proto;
+}
+
+static_always_inline u8
+icmp_is_error_message (icmp46_header_t * icmp)
+{
+  switch (icmp->type)
+    {
+    case ICMP4_destination_unreachable:
+    case ICMP4_time_exceeded:
+    case ICMP4_parameter_problem:
+    case ICMP4_source_quench:
+    case ICMP4_redirect:
+    case ICMP4_alternate_host_address:
+      return 1;
+    }
+  return 0;
+}
+
+always_inline u8
+is_interface_addr (snat_main_t * sm, vlib_node_runtime_t * node,
+		   u32 sw_if_index0, u32 ip4_addr)
+{
+  snat_runtime_t *rt = (snat_runtime_t *) node->runtime_data;
+  ip4_address_t *first_int_addr;
+
+  if (PREDICT_FALSE (rt->cached_sw_if_index != sw_if_index0))
+    {
+      first_int_addr =
+	ip4_interface_first_address (sm->ip4_main, sw_if_index0,
+				     0 /* just want the address */ );
+      rt->cached_sw_if_index = sw_if_index0;
+      if (first_int_addr)
+	rt->cached_ip4_address = first_int_addr->as_u32;
+      else
+	rt->cached_ip4_address = 0;
+    }
+
+  if (PREDICT_FALSE (ip4_addr == rt->cached_ip4_address))
+    return 1;
+  else
+    return 0;
+}
+
+always_inline u8
+maximum_sessions_exceeded (snat_main_t * sm, u32 thread_index)
+{
+  if (pool_elts (sm->per_thread_data[thread_index].sessions) >=
+      sm->max_translations)
+    return 1;
+
+  return 0;
+}
+
+always_inline void
+nat_send_all_to_node (vlib_main_t * vm, u32 * bi_vector,
+		      vlib_node_runtime_t * node, vlib_error_t * error,
+		      u32 next)
+{
+  u32 n_left_from, *from, next_index, *to_next, n_left_to_next;
+
+  from = bi_vector;
+  n_left_from = vec_len (bi_vector);
+  next_index = node->cached_next_index;
+  while (n_left_from > 0)
+    {
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+      while (n_left_from > 0 && n_left_to_next > 0)
+	{
+	  u32 bi0 = to_next[0] = from[0];
+	  from += 1;
+	  n_left_from -= 1;
+	  to_next += 1;
+	  n_left_to_next -= 1;
+	  vlib_buffer_t *p0 = vlib_get_buffer (vm, bi0);
+	  p0->error = *error;
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					   n_left_to_next, bi0, next);
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+}
+
+always_inline void
+user_session_increment (snat_main_t * sm, snat_user_t * u, u8 is_static)
+{
+  if (u->nsessions + u->nstaticsessions < sm->max_translations_per_user)
+    {
+      if (is_static)
+	u->nstaticsessions++;
+      else
+	u->nsessions++;
+    }
+}
+
+always_inline void
+nat44_delete_session (snat_main_t * sm, snat_session_t * ses,
+		      u32 thread_index)
+{
+  snat_main_per_thread_data_t *tsm = vec_elt_at_index (sm->per_thread_data,
+						       thread_index);
+  clib_bihash_kv_8_8_t kv, value;
+  snat_user_key_t u_key;
+  snat_user_t *u;
+
+  nat_log_debug ("session deleted %U", format_snat_session, tsm, ses);
+  u_key.addr = ses->in2out.addr;
+  u_key.fib_index = ses->in2out.fib_index;
+  kv.key = u_key.as_u64;
+  if (!clib_bihash_search_8_8 (&tsm->user_hash, &kv, &value))
+    {
+      u = pool_elt_at_index (tsm->users, value.value);
+      if (snat_is_session_static (ses))
+	u->nstaticsessions--;
+      else
+	u->nsessions--;
+    }
+  clib_dlist_remove (tsm->list_pool, ses->per_user_index);
+  pool_put_index (tsm->list_pool, ses->per_user_index);
+  pool_put (tsm->sessions, ses);
+}
+
+/** \brief Set TCP session state.
+    @return 1 if session was closed, otherwise 0
+*/
+always_inline int
+nat44_set_tcp_session_state_i2o (snat_main_t * sm, snat_session_t * ses,
+				 tcp_header_t * tcp, u32 thread_index)
+{
+  if (tcp->flags & TCP_FLAG_FIN)
+    {
+      ses->i2o_fin_seq = clib_net_to_host_u32 (tcp->seq_number);
+      ses->state |= NAT44_SES_I2O_FIN;
+    }
+  if ((tcp->flags & TCP_FLAG_ACK) && (ses->state & NAT44_SES_O2I_FIN))
+    {
+      if (clib_net_to_host_u32 (tcp->ack_number) > ses->o2i_fin_seq)
+	ses->state |= NAT44_SES_O2I_FIN_ACK;
+    }
+  if (nat44_is_ses_closed (ses))
+    {
+      nat_log_debug ("TCP close connection %U", format_snat_session,
+		     &sm->per_thread_data[thread_index], ses);
+      nat_free_session_data (sm, ses, thread_index);
+      nat44_delete_session (sm, ses, thread_index);
+      return 1;
+    }
+  return 0;
+}
+
+always_inline int
+nat44_set_tcp_session_state_o2i (snat_main_t * sm, snat_session_t * ses,
+				 tcp_header_t * tcp, u32 thread_index)
+{
+  if (tcp->flags & TCP_FLAG_FIN)
+    {
+      ses->o2i_fin_seq = clib_net_to_host_u32 (tcp->seq_number);
+      ses->state |= NAT44_SES_O2I_FIN;
+    }
+  if ((tcp->flags & TCP_FLAG_ACK) && (ses->state & NAT44_SES_I2O_FIN))
+    {
+      if (clib_net_to_host_u32 (tcp->ack_number) > ses->i2o_fin_seq)
+	ses->state |= NAT44_SES_I2O_FIN_ACK;
+    }
+  if (nat44_is_ses_closed (ses))
+    {
+      nat_log_debug ("TCP close connection %U", format_snat_session,
+		     &sm->per_thread_data[thread_index], ses);
+      nat_free_session_data (sm, ses, thread_index);
+      nat44_delete_session (sm, ses, thread_index);
+      return 1;
+    }
+  return 0;
+}
+
+always_inline void
+nat44_session_update_counters (snat_session_t * s, f64 now, uword bytes)
+{
+  s->last_heard = now;
+  s->total_pkts++;
+  s->total_bytes += bytes;
+}
+
+/** \brief Per-user LRU list maintenance */
+always_inline void
+nat44_session_update_lru (snat_main_t * sm, snat_session_t * s,
+			  u32 thread_index)
+{
+  clib_dlist_remove (sm->per_thread_data[thread_index].list_pool,
+		     s->per_user_index);
+  clib_dlist_addtail (sm->per_thread_data[thread_index].list_pool,
+		      s->per_user_list_head_index, s->per_user_index);
+}
+
+#endif /* __included_nat_inlines_h__ */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */