ip: reassembly-separate feature and custom code

This change is made fix a crash, because is_feature flag semantics turn
out to be different from "custom app code" semantics. Introduce a flag
which custom plugins/apps can use to instead of tying that code to
is_feature flag.

Change-Id: Ief5898711e68529f9306cfac54c4dc9b3650f9e3
Ticket: N/A
Type: fix
Fixes: 21aa8f1022590b8b5caf819b4bbd485de0f1dfe5
Signed-off-by: Klement Sekera <ksekera@cisco.com>
Signed-off-by: Ole Troan <ot@cisco.com>

3 files changed, 67 insertions, 64 deletions

diff --git a/src/vnet/buffer.h b/src/vnet/buffer.h
index 7065bd745d0..6738f3cdca8 100644
--- a/src/vnet/buffer.h
+++ b/src/vnet/buffer.h
@@ -188,8 +188,8 @@ typedef struct
 	  /* in/out variables */
 	  struct
 	  {
-	    u32 next_index;	/* index of next node - ignored if "feature" node */
-	    u32 error_next_index;	/* index of next node if error - ignored if 'feature' node */
+	    u32 next_index;	/* index of next node - used by custom apps */
+	    u32 error_next_index;	/* index of next node if error - used by custom apps */
 	    u16 estimated_mtu;	/* estimated MTU calculated during reassembly */
 	    u16 owner_thread_index;
 	  };
diff --git a/src/vnet/ip/ip4_reassembly.c b/src/vnet/ip/ip4_reassembly.c
index 73a83a9a632..85861025b2d 100644
--- a/src/vnet/ip/ip4_reassembly.c
+++ b/src/vnet/ip/ip4_reassembly.c
@@ -133,10 +133,8 @@ typedef struct
   u32 trace_op_counter;
   // next index - used by non-feature node
   u32 next_index;
-  // error next index - used by non-feature node
+  // error next index - used by custom apps (~0 if not used)
   u32 error_next_index;
-  // is_feature flag stored for non-inline code use
-  bool is_feature;
   // minimum fragment length for this reassembly - used to estimate MTU
   u16 min_fragment_length;
   // number of fragments in this reassembly
@@ -337,8 +335,7 @@ ip4_reass_free (ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 
 always_inline void
 ip4_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
-		    ip4_reass_main_t * rm, ip4_reass_t * reass,
-		    bool is_feature)
+		    ip4_reass_main_t * rm, ip4_reass_t * reass)
 {
   u32 range_bi = reass->first_bi;
   vlib_buffer_t *range_b;
@@ -366,7 +363,7 @@ ip4_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
       range_bi = range_vnb->ip.reass.next_range_bi;
     }
   /* send to next_error_index */
-  if (!(is_feature))
+  if (~0 != reass->error_next_index)
     {
       u32 n_left_to_next, *to_next, next_index;
 
@@ -403,8 +400,7 @@ ip4_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
 static ip4_reass_t *
 ip4_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 			  ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
-			  ip4_reass_kv_t * kv, u8 * do_handoff,
-			  bool is_feature)
+			  ip4_reass_kv_t * kv, u8 * do_handoff)
 {
   ip4_reass_t *reass = NULL;
   f64 now = vlib_time_now (rm->vlib_main);
@@ -421,7 +417,7 @@ ip4_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 
       if (now > reass->last_heard + rm->timeout)
 	{
-	  ip4_reass_drop_all (vm, node, rm, reass, is_feature);
+	  ip4_reass_drop_all (vm, node, rm, reass);
 	  ip4_reass_free (rm, rt, reass);
 	  reass = NULL;
 	}
@@ -447,7 +443,8 @@ ip4_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
       reass->first_bi = ~0;
       reass->last_packet_octet = ~0;
       reass->data_len = 0;
-      reass->is_feature = is_feature;
+      reass->next_index = ~0;
+      reass->error_next_index = ~0;
       ++rt->reass_n;
     }
 
@@ -470,7 +467,7 @@ always_inline ip4_reass_rc_t
 ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 		    ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 		    ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
-		    bool is_feature)
+		    bool is_custom_app)
 {
   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
   vlib_buffer_t *last_b = NULL;
@@ -653,7 +650,7 @@ ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 #endif
     }
   *bi0 = reass->first_bi;
-  if (is_feature)
+  if (!is_custom_app)
     {
       *next0 = IP4_REASSEMBLY_NEXT_INPUT;
     }
@@ -762,14 +759,19 @@ always_inline ip4_reass_rc_t
 ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 		  ip4_reass_main_t * rm, ip4_reass_per_thread_t * rt,
 		  ip4_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
-		  bool is_feature)
+		  bool is_custom_app)
 {
   ip4_reass_rc_t rc = IP4_REASS_RC_OK;
   int consumed = 0;
   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
   ip4_header_t *fip = vlib_buffer_get_current (fb);
   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
-  reass->next_index = fvnb->ip.reass.next_index;	// store next_index before it's overwritten
+  if (is_custom_app)
+    {
+      // store (error_)next_index before it's overwritten
+      reass->next_index = fvnb->ip.reass.next_index;
+      reass->error_next_index = fvnb->ip.reass.error_next_index;
+    }
   const u32 fragment_first = ip4_get_fragment_offset_bytes (fip);
   const u32 fragment_length =
     clib_net_to_host_u16 (fip->length) - ip4_header_bytes (fip);
@@ -972,7 +974,7 @@ ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
       reass->data_len == reass->last_packet_octet + 1)
     {
       return ip4_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
-				 is_feature);
+				 is_custom_app);
     }
   else
     {
@@ -994,9 +996,9 @@ ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 }
 
 always_inline uword
-ip4_reassembly_inline (vlib_main_t * vm,
-		       vlib_node_runtime_t * node,
-		       vlib_frame_t * frame, bool is_feature)
+ip4_reassembly_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+		       vlib_frame_t * frame, bool is_feature,
+		       bool is_custom_app)
 {
   u32 *from = vlib_frame_vector_args (frame);
   u32 n_left_from, n_left_to_next, *to_next, next_index;
@@ -1024,7 +1026,7 @@ ip4_reassembly_inline (vlib_main_t * vm,
 	  if (!ip4_get_fragment_more (ip0) && !ip4_get_fragment_offset (ip0))
 	    {
 	      // this is a whole packet - no fragmentation
-	      if (is_feature)
+	      if (!is_custom_app)
 		{
 		  next0 = IP4_REASSEMBLY_NEXT_INPUT;
 		}
@@ -1059,7 +1061,7 @@ ip4_reassembly_inline (vlib_main_t * vm,
 
 		  ip4_reass_t *reass =
 		    ip4_reass_find_or_create (vm, node, rm, rt, &kv,
-					      &do_handoff, is_feature);
+					      &do_handoff);
 
 		  if (PREDICT_FALSE (do_handoff))
 		    {
@@ -1076,7 +1078,7 @@ ip4_reassembly_inline (vlib_main_t * vm,
 		    {
 		      switch (ip4_reass_update
 			      (vm, node, rm, rt, reass, &bi0, &next0,
-			       &error0, is_feature))
+			       &error0, is_custom_app))
 			{
 			case IP4_REASS_RC_OK:
 			  /* nothing to do here */
@@ -1085,8 +1087,7 @@ ip4_reassembly_inline (vlib_main_t * vm,
 			  vlib_node_increment_counter (vm, node->node_index,
 						       IP4_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
 						       1);
-			  ip4_reass_drop_all (vm, node, rm, reass,
-					      is_feature);
+			  ip4_reass_drop_all (vm, node, rm, reass);
 			  ip4_reass_free (rm, rt, reass);
 			  goto next_packet;
 			  break;
@@ -1094,8 +1095,7 @@ ip4_reassembly_inline (vlib_main_t * vm,
 			  vlib_node_increment_counter (vm, node->node_index,
 						       IP4_ERROR_REASS_NO_BUF,
 						       1);
-			  ip4_reass_drop_all (vm, node, rm, reass,
-					      is_feature);
+			  ip4_reass_drop_all (vm, node, rm, reass);
 			  ip4_reass_free (rm, rt, reass);
 			  goto next_packet;
 			  break;
@@ -1104,8 +1104,7 @@ ip4_reassembly_inline (vlib_main_t * vm,
 			  vlib_node_increment_counter (vm, node->node_index,
 						       IP4_ERROR_REASS_INTERNAL_ERROR,
 						       1);
-			  ip4_reass_drop_all (vm, node, rm, reass,
-					      is_feature);
+			  ip4_reass_drop_all (vm, node, rm, reass);
 			  ip4_reass_free (rm, rt, reass);
 			  goto next_packet;
 			  break;
@@ -1158,7 +1157,8 @@ static char *ip4_reassembly_error_strings[] = {
 VLIB_NODE_FN (ip4_reass_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
 			       vlib_frame_t * frame)
 {
-  return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ );
+  return ip4_reassembly_inline (vm, node, frame, false /* is_feature */ ,
+				false /* is_custom_app */ );
 }
 
 /* *INDENT-OFF* */
@@ -1183,7 +1183,8 @@ VLIB_NODE_FN (ip4_reass_node_feature) (vlib_main_t * vm,
 				       vlib_node_runtime_t * node,
 				       vlib_frame_t * frame)
 {
-  return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ );
+  return ip4_reassembly_inline (vm, node, frame, true /* is_feature */ ,
+				false /* is_custom_app */ );
 }
 
 /* *INDENT-OFF* */
@@ -1412,7 +1413,7 @@ ip4_reass_walk_expired (vlib_main_t * vm,
           vec_foreach (i, pool_indexes_to_free)
           {
             ip4_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
-            ip4_reass_drop_all (vm, node, rm, reass, reass->is_feature);
+            ip4_reass_drop_all (vm, node, rm, reass);
             ip4_reass_free (rm, rt, reass);
           }
           /* *INDENT-ON* */
diff --git a/src/vnet/ip/ip6_reassembly.c b/src/vnet/ip/ip6_reassembly.c
index 01f76aa1f0e..10fc6f1f559 100644
--- a/src/vnet/ip/ip6_reassembly.c
+++ b/src/vnet/ip/ip6_reassembly.c
@@ -110,12 +110,10 @@ typedef struct
   u32 data_len;
   // trace operation counter
   u32 trace_op_counter;
-  // next index - used by non-feature node
+  // next index - used by custom apps (~0 if not set)
   u32 next_index;
-  // error next index - used by non-feature node
+  // error next index - used by custom apps (~0 if not set)
   u32 error_next_index;
-  // is_feature flag stored for non-inline code use
-  bool is_feature;
   // minimum fragment length for this reassembly - used to estimate MTU
   u16 min_fragment_length;
   // number of fragments for this reassembly
@@ -326,8 +324,7 @@ ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 
 always_inline void
 ip6_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
-		    ip6_reass_main_t * rm, ip6_reass_t * reass,
-		    bool is_feature)
+		    ip6_reass_main_t * rm, ip6_reass_t * reass)
 {
   u32 range_bi = reass->first_bi;
   vlib_buffer_t *range_b;
@@ -355,7 +352,7 @@ ip6_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
       range_bi = range_vnb->ip.reass.next_range_bi;
     }
   /* send to next_error_index */
-  if (!(is_feature))
+  if (~0 != reass->error_next_index)
     {
       u32 n_left_to_next, *to_next, next_index;
 
@@ -393,13 +390,13 @@ ip6_reass_drop_all (vlib_main_t * vm, vlib_node_runtime_t * node,
 always_inline void
 ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
 		      ip6_reass_main_t * rm, ip6_reass_t * reass,
-		      u32 * icmp_bi, bool is_feature)
+		      u32 * icmp_bi)
 {
   if (~0 == reass->first_bi)
     {
       return;
     }
-  if (is_feature)
+  if (~0 == reass->next_index)	// custom apps don't want icmp
     {
       vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
       if (0 == vnet_buffer (b)->ip.reass.fragment_first)
@@ -426,14 +423,13 @@ ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
 				       0);
 	}
     }
-  ip6_reass_drop_all (vm, node, rm, reass, is_feature);
+  ip6_reass_drop_all (vm, node, rm, reass);
 }
 
 always_inline ip6_reass_t *
 ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 			  ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
-			  ip6_reass_kv_t * kv, u32 * icmp_bi, u8 * do_handoff,
-			  bool is_feature)
+			  ip6_reass_kv_t * kv, u32 * icmp_bi, u8 * do_handoff)
 {
   ip6_reass_t *reass = NULL;
   f64 now = vlib_time_now (rm->vlib_main);
@@ -450,7 +446,7 @@ ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
 
       if (now > reass->last_heard + rm->timeout)
 	{
-	  ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi, is_feature);
+	  ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi);
 	  ip6_reass_free (rm, rt, reass);
 	  reass = NULL;
 	}
@@ -476,7 +472,8 @@ ip6_reass_find_or_create (vlib_main_t * vm, vlib_node_runtime_t * node,
       reass->first_bi = ~0;
       reass->last_packet_octet = ~0;
       reass->data_len = 0;
-      reass->is_feature = is_feature;
+      reass->next_index = ~0;
+      reass->error_next_index = ~0;
       ++rt->reass_n;
     }
 
@@ -503,7 +500,7 @@ always_inline ip6_reass_rc_t
 ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
 		    ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 		    ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
-		    bool is_feature)
+		    bool is_custom_app)
 {
   *bi0 = reass->first_bi;
   *error0 = IP6_ERROR_NONE;
@@ -706,7 +703,7 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
       while (0);
 #endif
     }
-  if (is_feature)
+  if (!is_custom_app)
     {
       *next0 = IP6_REASSEMBLY_NEXT_INPUT;
     }
@@ -754,13 +751,16 @@ always_inline ip6_reass_rc_t
 ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
 		  ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
 		  ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
-		  ip6_frag_hdr_t * frag_hdr, bool is_feature)
+		  ip6_frag_hdr_t * frag_hdr, bool is_custom_app)
 {
   int consumed = 0;
   vlib_buffer_t *fb = vlib_get_buffer (vm, *bi0);
   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
-  reass->next_index = fvnb->ip.reass.next_index;	// store next_index before it's overwritten
-  reass->error_next_index = fvnb->ip.reass.error_next_index;	// store error_next_index before it is overwritten
+  if (is_custom_app)
+    {
+      reass->next_index = fvnb->ip.reass.next_index;	// store next_index before it's overwritten
+      reass->error_next_index = fvnb->ip.reass.error_next_index;	// store error_next_index before it is overwritten
+    }
 
   fvnb->ip.reass.ip6_frag_hdr_offset =
     (u8 *) frag_hdr - (u8 *) vlib_buffer_get_current (fb);
@@ -837,7 +837,7 @@ ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
       else
 	{
 	  // overlapping fragment - not allowed by RFC 8200
-	  ip6_reass_drop_all (vm, node, rm, reass, is_feature);
+	  ip6_reass_drop_all (vm, node, rm, reass);
 	  ip6_reass_free (rm, rt, reass);
 	  if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
 	    {
@@ -863,7 +863,7 @@ check_if_done_maybe:
       reass->data_len == reass->last_packet_octet + 1)
     {
       return ip6_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
-				 is_feature);
+				 is_custom_app);
     }
   else
     {
@@ -952,9 +952,9 @@ ip6_reass_verify_packet_size_lt_64k (vlib_main_t * vm,
 }
 
 always_inline uword
-ip6_reassembly_inline (vlib_main_t * vm,
-		       vlib_node_runtime_t * node,
-		       vlib_frame_t * frame, bool is_feature)
+ip6_reassembly_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+		       vlib_frame_t * frame, bool is_feature,
+		       bool is_custom_app)
 {
   u32 *from = vlib_frame_vector_args (frame);
   u32 n_left_from, n_left_to_next, *to_next, next_index;
@@ -1027,7 +1027,7 @@ ip6_reassembly_inline (vlib_main_t * vm,
 
 	  ip6_reass_t *reass =
 	    ip6_reass_find_or_create (vm, node, rm, rt, &kv, &icmp_bi,
-				      &do_handoff, is_feature);
+				      &do_handoff);
 
 	  if (PREDICT_FALSE (do_handoff))
 	    {
@@ -1042,7 +1042,7 @@ ip6_reassembly_inline (vlib_main_t * vm,
 	  else if (reass)
 	    {
 	      switch (ip6_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
-					&error0, frag_hdr, is_feature))
+					&error0, frag_hdr, is_custom_app))
 		{
 		case IP6_REASS_RC_OK:
 		  /* nothing to do here */
@@ -1051,14 +1051,14 @@ ip6_reassembly_inline (vlib_main_t * vm,
 		  vlib_node_increment_counter (vm, node->node_index,
 					       IP6_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
 					       1);
-		  ip6_reass_drop_all (vm, node, rm, reass, is_feature);
+		  ip6_reass_drop_all (vm, node, rm, reass);
 		  ip6_reass_free (rm, rt, reass);
 		  goto next_packet;
 		  break;
 		case IP6_REASS_RC_NO_BUF:
 		  vlib_node_increment_counter (vm, node->node_index,
 					       IP6_ERROR_REASS_NO_BUF, 1);
-		  ip6_reass_drop_all (vm, node, rm, reass, is_feature);
+		  ip6_reass_drop_all (vm, node, rm, reass);
 		  ip6_reass_free (rm, rt, reass);
 		  goto next_packet;
 		  break;
@@ -1067,7 +1067,7 @@ ip6_reassembly_inline (vlib_main_t * vm,
 		  vlib_node_increment_counter (vm, node->node_index,
 					       IP6_ERROR_REASS_INTERNAL_ERROR,
 					       1);
-		  ip6_reass_drop_all (vm, node, rm, reass, is_feature);
+		  ip6_reass_drop_all (vm, node, rm, reass);
 		  ip6_reass_free (rm, rt, reass);
 		  goto next_packet;
 		  break;
@@ -1135,7 +1135,8 @@ static char *ip6_reassembly_error_strings[] = {
 VLIB_NODE_FN (ip6_reass_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
 			       vlib_frame_t * frame)
 {
-  return ip6_reassembly_inline (vm, node, frame, false /* is_feature */ );
+  return ip6_reassembly_inline (vm, node, frame, false /* is_feature */ ,
+				false /* is_custom_app */ );
 }
 
 /* *INDENT-OFF* */
@@ -1160,7 +1161,8 @@ VLIB_NODE_FN (ip6_reass_node_feature) (vlib_main_t * vm,
 				       vlib_node_runtime_t * node,
 				       vlib_frame_t * frame)
 {
-  return ip6_reassembly_inline (vm, node, frame, true /* is_feature */ );
+  return ip6_reassembly_inline (vm, node, frame, true /* is_feature */ ,
+				false /* is_custom_app */ );
 }
 
 /* *INDENT-OFF* */
@@ -1407,7 +1409,7 @@ ip6_reass_walk_expired (vlib_main_t * vm,
                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
                   }
               }
-            ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi, reass->is_feature);
+            ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi);
             if (~0 != icmp_bi)
               {
                 vec_add1 (vec_icmp_bi, icmp_bi);