nat: harden ICMP handling

[vpp.git] / src / plugins / nat / nat44-ed / nat44_ed_in2out.c

diff --git a/src/plugins/nat/nat44-ed/nat44_ed_in2out.c b/src/plugins/nat/nat44-ed/nat44_ed_in2out.c
index 85cda76..ead5685 100644 (file)
--- a/src/plugins/nat/nat44-ed/nat44_ed_in2out.c
+++ b/src/plugins/nat/nat44-ed/nat44_ed_in2out.c
@@ -342,7 +342,7 @@ slow_path_ed (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
   ip4_address_t outside_addr;
   u16 outside_port;
   u32 outside_fib_index;
-  u8 is_identity_nat;
+  u8 is_identity_nat = 0;
 
   u32 nat_proto = ip_proto_to_nat_proto (proto);
   snat_session_t *s = NULL;
@@ -350,17 +350,6 @@ slow_path_ed (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
   ip4_address_t daddr = r_addr;
   u16 dport = r_port;
 
-  if (PREDICT_TRUE (nat_proto == NAT_PROTOCOL_TCP))
-    {
-      if (PREDICT_FALSE
-         (!tcp_flags_is_init
-          (vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
-       {
-         b->error = node->errors[NAT_IN2OUT_ED_ERROR_NON_SYN];
-         return NAT_NEXT_DROP;
-       }
-    }
-
   if (PREDICT_FALSE
       (nat44_ed_maximum_sessions_exceeded (sm, rx_fib_index, thread_index)))
     {
@@ -402,13 +391,22 @@ slow_path_ed (vlib_main_t *vm, snat_main_t *sm, vlib_buffer_t *b,
     }
   else
     {
+      if (PREDICT_FALSE (is_identity_nat))
+       {
+         *sessionp = NULL;
+         return next;
+       }
       is_sm = 1;
     }
 
-  if (PREDICT_FALSE (is_sm && is_identity_nat))
+  if (PREDICT_TRUE (nat_proto == NAT_PROTOCOL_TCP))
     {
-      *sessionp = NULL;
-      return next;
+      if (PREDICT_FALSE (!tcp_flags_is_init (
+           vnet_buffer (b)->ip.reass.icmp_type_or_tcp_flags)))
+       {
+         b->error = node->errors[NAT_IN2OUT_ED_ERROR_NON_SYN];
+         return NAT_NEXT_DROP;
+       }
     }
 
   s = nat_ed_session_alloc (sm, thread_index, now, proto);
@@ -1012,7 +1010,7 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t *vm,
 
          vlib_prefetch_buffer_header (p2, LOAD);
 
-         CLIB_PREFETCH (p2->data, CLIB_CACHE_LINE_BYTES, LOAD);
+         clib_prefetch_load (p2->data);
        }
 
       if (is_output_feature)
@@ -1030,7 +1028,7 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t *vm,
        fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
       lookup.fib_index = rx_fib_index0;
 
-      if (PREDICT_FALSE (ip0->ttl == 1))
+      if (PREDICT_FALSE (!is_output_feature && ip0->ttl == 1))
        {
          vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
          icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
@@ -1179,16 +1177,18 @@ nat44_ed_in2out_fast_path_node_fn_inline (vlib_main_t *vm,
          nat_free_session_data (sm, s0, thread_index, 0);
          nat_ed_session_delete (sm, s0, thread_index, 1);
          next[0] = NAT_NEXT_DROP;
+         b0->error = node->errors[NAT_IN2OUT_ED_ERROR_TRNSL_FAILED];
          goto trace0;
        }
 
       if (NAT_ED_TRNSL_ERR_SUCCESS !=
-         (translation_error = nat_6t_flow_buf_translate (
-            sm, b0, ip0, f, proto0, is_output_feature)))
+         (translation_error = nat_6t_flow_buf_translate_i2o (
+            vm, sm, b0, ip0, f, proto0, is_output_feature)))
        {
          nat_free_session_data (sm, s0, thread_index, 0);
          nat_ed_session_delete (sm, s0, thread_index, 1);
          next[0] = NAT_NEXT_DROP;
+         b0->error = node->errors[NAT_IN2OUT_ED_ERROR_TRNSL_FAILED];
          goto trace0;
        }
 
@@ -1308,7 +1308,7 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t *vm,
       rx_fib_index0 =
        fib_table_get_index_for_sw_if_index (FIB_PROTOCOL_IP4, sw_if_index0);
 
-      if (PREDICT_FALSE (ip0->ttl == 1))
+      if (PREDICT_FALSE (!is_output_feature && ip0->ttl == 1))
        {
          vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
          icmp4_error_set_vnet_buffer (b0, ICMP4_time_exceeded,
@@ -1329,10 +1329,15 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t *vm,
          if (!s0)
            next[0] = NAT_NEXT_DROP;
 
-         if (NAT_ED_TRNSL_ERR_SUCCESS !=
-             (translation_error = nat_6t_flow_buf_translate (
-                sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
+         if (NAT_NEXT_DROP != next[0] && s0 &&
+             NAT_ED_TRNSL_ERR_SUCCESS !=
+               (translation_error = nat_6t_flow_buf_translate_i2o (
+                  vm, sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
            {
+             nat_free_session_data (sm, s0, thread_index, 0);
+             nat_ed_session_delete (sm, s0, thread_index, 1);
+             next[0] = NAT_NEXT_DROP;
+             b0->error = node->errors[NAT_IN2OUT_ED_ERROR_TRNSL_FAILED];
              goto trace0;
            }
 
@@ -1348,9 +1353,13 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t *vm,
            now, thread_index, proto0, &s0, is_multi_worker);
          if (NAT_NEXT_DROP != next[0] && s0 &&
              NAT_ED_TRNSL_ERR_SUCCESS !=
-               (translation_error = nat_6t_flow_buf_translate (
-                  sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
+               (translation_error = nat_6t_flow_buf_translate_i2o (
+                  vm, sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
            {
+             nat_free_session_data (sm, s0, thread_index, 0);
+             nat_ed_session_delete (sm, s0, thread_index, 1);
+             next[0] = NAT_NEXT_DROP;
+             b0->error = node->errors[NAT_IN2OUT_ED_ERROR_TRNSL_FAILED];
              goto trace0;
            }
 
@@ -1425,12 +1434,13 @@ nat44_ed_in2out_slow_path_node_fn_inline (vlib_main_t *vm,
       b0->flags |= VNET_BUFFER_F_IS_NATED;
 
       if (NAT_ED_TRNSL_ERR_SUCCESS !=
-         (translation_error = nat_6t_flow_buf_translate (
-            sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
+         (translation_error = nat_6t_flow_buf_translate_i2o (
+            vm, sm, b0, ip0, &s0->i2o, proto0, is_output_feature)))
        {
          nat_free_session_data (sm, s0, thread_index, 0);
          nat_ed_session_delete (sm, s0, thread_index, 1);
-         s0 = NULL;
+         next[0] = NAT_NEXT_DROP;
+         b0->error = node->errors[NAT_IN2OUT_ED_ERROR_TRNSL_FAILED];
          goto trace0;
        }