reassembly: prevent long chain attack
[vpp.git] / src / vnet / ip / ip6_reassembly.c
index 5a7c081..45cd2b2 100644 (file)
 #define MSEC_PER_SEC 1000
 #define IP6_REASS_TIMEOUT_DEFAULT_MS 100
 #define IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS 10000        // 10 seconds default
-#define IP6_REASS_MAX_REASSEMBLIES_DEAFULT 1024
+#define IP6_REASS_MAX_REASSEMBLIES_DEFAULT 1024
+#define IP6_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT 3
 #define IP6_REASS_HT_LOAD_FACTOR (0.75)
 
-static vlib_node_registration_t ip6_reass_node;
+typedef enum
+{
+  IP6_REASS_RC_OK,
+  IP6_REASS_RC_INTERNAL_ERROR,
+  IP6_REASS_RC_TOO_MANY_FRAGMENTS,
+  IP6_REASS_RC_NO_BUF,
+} ip6_reass_rc_t;
 
 typedef struct
 {
@@ -42,59 +49,59 @@ typedef struct
     {
       ip6_address_t src;
       ip6_address_t dst;
-      // align by making this 4 octets even though its a 2 octets field
       u32 xx_id;
-      // align by making this 4 octets even though its a 2 octets field
       u32 frag_id;
-      // align by making this 4 octets even though its a 1 octet field
-      u32 proto;
-      u32 unused;
+      u8 unused[7];
+      u8 proto;
     };
     u64 as_u64[6];
   };
 } ip6_reass_key_t;
 
-always_inline u32
-ip6_reass_buffer_get_data_offset_no_check (vlib_buffer_t * b)
+typedef union
 {
-  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
-  return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
-}
+  struct
+  {
+    u32 reass_index;
+    u32 thread_index;
+  };
+  u64 as_u64;
+} ip6_reass_val_t;
+
+typedef union
+{
+  struct
+  {
+    ip6_reass_key_t k;
+    ip6_reass_val_t v;
+  };
+  clib_bihash_kv_48_8_t kv;
+} ip6_reass_kv_t;
+
 
 always_inline u32
 ip6_reass_buffer_get_data_offset (vlib_buffer_t * b)
 {
   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
-  ASSERT (vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first);
-  return ip6_reass_buffer_get_data_offset_no_check (b);
+  return vnb->ip.reass.range_first - vnb->ip.reass.fragment_first;
 }
 
 always_inline u16
-ip6_reass_buffer_get_data_len_no_check (vlib_buffer_t * b)
+ip6_reass_buffer_get_data_len (vlib_buffer_t * b)
 {
   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
   return clib_min (vnb->ip.reass.range_last, vnb->ip.reass.fragment_last) -
     (vnb->ip.reass.fragment_first + ip6_reass_buffer_get_data_offset (b)) + 1;
 }
 
-always_inline u16
-ip6_reass_buffer_get_data_len (vlib_buffer_t * b)
-{
-  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
-  ASSERT (vnb->ip.reass.range_last > vnb->ip.reass.fragment_first);
-  return ip6_reass_buffer_get_data_len_no_check (b);
-}
-
 typedef struct
 {
   // hash table key
   ip6_reass_key_t key;
-  // time when first packet was received
-  f64 first_heard;
   // time when last packet was received
   f64 last_heard;
   // internal id of this reassembly
-  u32 id;
+  u64 id;
   // buffer index of first buffer in this reassembly context
   u32 first_bi;
   // last octet of packet, ~0 until fragment without more_fragments arrives
@@ -103,22 +110,38 @@ typedef struct
   u32 data_len;
   // trace operation counter
   u32 trace_op_counter;
+  // next index - used by non-feature node
+  u8 next_index;
+  // minimum fragment length for this reassembly - used to estimate MTU
+  u16 min_fragment_length;
+  // number of fragments for this reassembly
+  u32 fragments_n;
 } ip6_reass_t;
 
+typedef struct
+{
+  ip6_reass_t *pool;
+  u32 reass_n;
+  u32 id_counter;
+  clib_spinlock_t lock;
+} ip6_reass_per_thread_t;
+
 typedef struct
 {
   // IPv6 config
   u32 timeout_ms;
   f64 timeout;
   u32 expire_walk_interval_ms;
+  // maximum number of fragments in one reassembly
+  u32 max_reass_len;
+  // maximum number of reassemblies
   u32 max_reass_n;
 
   // IPv6 runtime
-  ip6_reass_t *pool;
   clib_bihash_48_8_t hash;
-  u32 reass_n;
-  u32 id_counter;
-  u32 buffers_n;
+
+  // per-thread data
+  ip6_reass_per_thread_t *per_thread_data;
 
   // convenience
   vlib_main_t *vlib_main;
@@ -129,15 +152,24 @@ typedef struct
   u32 ip6_icmp_error_idx;
   u32 ip6_reass_expire_node_idx;
 
+  /** Worker handoff */
+  u32 fq_index;
+  u32 fq_feature_index;
+
 } ip6_reass_main_t;
 
+extern ip6_reass_main_t ip6_reass_main;
+
+#ifndef CLIB_MARCH_VARIANT
 ip6_reass_main_t ip6_reass_main;
+#endif /* CLIB_MARCH_VARIANT */
 
 typedef enum
 {
   IP6_REASSEMBLY_NEXT_INPUT,
   IP6_REASSEMBLY_NEXT_DROP,
   IP6_REASSEMBLY_NEXT_ICMP_ERROR,
+  IP6_REASSEMBLY_NEXT_HANDOFF,
   IP6_REASSEMBLY_N_NEXT,
 } ip6_reass_next_t;
 
@@ -164,7 +196,6 @@ typedef struct
 typedef struct
 {
   ip6_reass_trace_operation_e action;
-  u32 pool_index;
   u32 reass_id;
   ip6_reass_range_trace_t trace_range;
   u32 size_diff;
@@ -182,12 +213,12 @@ ip6_reass_trace_details (vlib_main_t * vm, u32 bi,
   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
   trace->range_first = vnb->ip.reass.range_first;
   trace->range_last = vnb->ip.reass.range_last;
-  trace->data_offset = ip6_reass_buffer_get_data_offset_no_check (b);
-  trace->data_len = ip6_reass_buffer_get_data_len_no_check (b);
+  trace->data_offset = ip6_reass_buffer_get_data_offset (b);
+  trace->data_len = ip6_reass_buffer_get_data_len (b);
   trace->range_bi = bi;
 }
 
-u8 *
+static u8 *
 format_ip6_reass_range_trace (u8 * s, va_list * args)
 {
   ip6_reass_range_trace_t *trace = va_arg (*args, ip6_reass_range_trace_t *);
@@ -197,7 +228,7 @@ format_ip6_reass_range_trace (u8 * s, va_list * args)
   return s;
 }
 
-u8 *
+static u8 *
 format_ip6_reass_trace (u8 * s, va_list * args)
 {
   CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
@@ -247,8 +278,13 @@ ip6_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 {
   vlib_buffer_t *b = vlib_get_buffer (vm, bi);
   vnet_buffer_opaque_t *vnb = vnet_buffer (b);
+  if (pool_is_free_index (vm->trace_main.trace_buffer_pool, b->trace_index))
+    {
+      // this buffer's trace is gone
+      b->flags &= ~VLIB_BUFFER_IS_TRACED;
+      return;
+    }
   ip6_reass_trace_t *t = vlib_add_trace (vm, node, b, sizeof (t[0]));
-  t->pool_index = reass - rm->pool;
   t->reass_id = reass->id;
   t->action = action;
   ip6_reass_trace_details (vm, bi, &t->trace_range);
@@ -268,8 +304,9 @@ ip6_reass_add_trace (vlib_main_t * vm, vlib_node_runtime_t * node,
 #endif
 }
 
-static void
-ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_t * reass)
+always_inline void
+ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
+               ip6_reass_t * reass)
 {
   clib_bihash_kv_48_8_t kv;
   kv.key[0] = reass->key.as_u64[0];
@@ -279,17 +316,18 @@ ip6_reass_free (ip6_reass_main_t * rm, ip6_reass_t * reass)
   kv.key[4] = reass->key.as_u64[4];
   kv.key[5] = reass->key.as_u64[5];
   clib_bihash_add_del_48_8 (&rm->hash, &kv, 0);
-  pool_put (rm->pool, reass);
-  --rm->reass_n;
+  pool_put (rt->pool, reass);
+  --rt->reass_n;
 }
 
-static void
+always_inline void
 ip6_reass_drop_all (vlib_main_t * vm, ip6_reass_main_t * rm,
-                   ip6_reass_t * reass, u32 ** vec_drop_bi)
+                   ip6_reass_t * reass)
 {
   u32 range_bi = reass->first_bi;
   vlib_buffer_t *range_b;
   vnet_buffer_opaque_t *range_vnb;
+  u32 *to_free = NULL;
   while (~0 != range_bi)
     {
       range_b = vlib_get_buffer (vm, range_bi);
@@ -297,7 +335,7 @@ ip6_reass_drop_all (vlib_main_t * vm, ip6_reass_main_t * rm,
       u32 bi = range_bi;
       while (~0 != bi)
        {
-         vec_add1 (*vec_drop_bi, bi);
+         vec_add1 (to_free, bi);
          vlib_buffer_t *b = vlib_get_buffer (vm, bi);
          if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
            {
@@ -311,12 +349,14 @@ ip6_reass_drop_all (vlib_main_t * vm, ip6_reass_main_t * rm,
        }
       range_bi = range_vnb->ip.reass.next_range_bi;
     }
+  vlib_buffer_free (vm, to_free, vec_len (to_free));
+  vec_free (to_free);
 }
 
-static void
+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, u32 ** vec_timeout)
+                     u32 * icmp_bi)
 {
   if (~0 == reass->first_bi)
     {
@@ -346,33 +386,31 @@ ip6_reass_on_timeout (vlib_main_t * vm, vlib_node_runtime_t * node,
                                   ICMP6_time_exceeded_fragment_reassembly_time_exceeded,
                                   0);
     }
-  ip6_reass_drop_all (vm, rm, reass, vec_timeout);
+  ip6_reass_drop_all (vm, rm, reass);
 }
 
-static ip6_reass_t *
-ip6_reass_find_or_create (vlib_main_t * vm,
-                         vlib_node_runtime_t * node,
-                         ip6_reass_main_t * rm,
-                         ip6_reass_key_t * k, u32 * icmp_bi,
-                         u32 ** vec_timeout)
+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)
 {
   ip6_reass_t *reass = NULL;
   f64 now = vlib_time_now (rm->vlib_main);
-  clib_bihash_kv_48_8_t kv, value;
-  kv.key[0] = k->as_u64[0];
-  kv.key[1] = k->as_u64[1];
-  kv.key[2] = k->as_u64[2];
-  kv.key[3] = k->as_u64[3];
-  kv.key[4] = k->as_u64[4];
-  kv.key[5] = k->as_u64[5];
-
-  if (!clib_bihash_search_48_8 (&rm->hash, &kv, &value))
+
+  if (!clib_bihash_search_48_8
+      (&rm->hash, (clib_bihash_kv_48_8_t *) kv, (clib_bihash_kv_48_8_t *) kv))
     {
-      reass = pool_elt_at_index (rm->pool, value.value);
+      if (vm->thread_index != kv->v.thread_index)
+       {
+         *do_handoff = 1;
+         return NULL;
+       }
+      reass = pool_elt_at_index (rt->pool, kv->v.reass_index);
+
       if (now > reass->last_heard + rm->timeout)
        {
-         ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi, vec_timeout);
-         ip6_reass_free (rm, reass);
+         ip6_reass_on_timeout (vm, node, rm, reass, icmp_bi);
+         ip6_reass_free (rm, rt, reass);
          reass = NULL;
        }
     }
@@ -383,50 +421,49 @@ ip6_reass_find_or_create (vlib_main_t * vm,
       return reass;
     }
 
-  if (rm->reass_n >= rm->max_reass_n)
+  if (rt->reass_n >= rm->max_reass_n)
     {
       reass = NULL;
       return reass;
     }
   else
     {
-      pool_get (rm->pool, reass);
-      memset (reass, 0, sizeof (*reass));
-      reass->id = rm->id_counter;
-      ++rm->id_counter;
+      pool_get (rt->pool, reass);
+      clib_memset (reass, 0, sizeof (*reass));
+      reass->id = ((u64) vm->thread_index * 1000000000) + rt->id_counter;
+      ++rt->id_counter;
       reass->first_bi = ~0;
       reass->last_packet_octet = ~0;
       reass->data_len = 0;
-      ++rm->reass_n;
+      ++rt->reass_n;
     }
 
-  reass->key.as_u64[0] = kv.key[0] = k->as_u64[0];
-  reass->key.as_u64[1] = kv.key[1] = k->as_u64[1];
-  reass->key.as_u64[2] = kv.key[2] = k->as_u64[2];
-  reass->key.as_u64[3] = kv.key[3] = k->as_u64[3];
-  reass->key.as_u64[4] = kv.key[4] = k->as_u64[4];
-  reass->key.as_u64[5] = kv.key[5] = k->as_u64[5];
-  kv.value = reass - rm->pool;
+  reass->key.as_u64[0] = ((clib_bihash_kv_48_8_t *) kv)->key[0];
+  reass->key.as_u64[1] = ((clib_bihash_kv_48_8_t *) kv)->key[1];
+  reass->key.as_u64[2] = ((clib_bihash_kv_48_8_t *) kv)->key[2];
+  reass->key.as_u64[3] = ((clib_bihash_kv_48_8_t *) kv)->key[3];
+  reass->key.as_u64[4] = ((clib_bihash_kv_48_8_t *) kv)->key[4];
+  reass->key.as_u64[5] = ((clib_bihash_kv_48_8_t *) kv)->key[5];
+  kv->v.reass_index = (reass - rt->pool);
+  kv->v.thread_index = vm->thread_index;
   reass->last_heard = now;
 
-  if (clib_bihash_add_del_48_8 (&rm->hash, &kv, 1))
+  if (clib_bihash_add_del_48_8 (&rm->hash, (clib_bihash_kv_48_8_t *) kv, 1))
     {
-      ip6_reass_free (rm, reass);
+      ip6_reass_free (rm, rt, reass);
       reass = NULL;
     }
 
   return reass;
 }
 
-void
+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_t * reass, u32 * bi0,
-                   u32 * next0, vlib_error_t * error0, u32 next_input,
-                   u32 ** vec_drop_compress)
+                   ip6_reass_main_t * rm, ip6_reass_per_thread_t * rt,
+                   ip6_reass_t * reass, u32 * bi0, u32 * next0, u32 * error0,
+                   bool is_feature)
 {
-  ASSERT (~0 != reass->first_bi);
   *bi0 = reass->first_bi;
-  *next0 = next_input;
   *error0 = IP6_ERROR_NONE;
   ip6_frag_hdr_t *frag_hdr;
   vlib_buffer_t *last_b = NULL;
@@ -434,10 +471,20 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
   u32 total_length = 0;
   u32 buf_cnt = 0;
   u32 dropped_cnt = 0;
+  u32 *vec_drop_compress = NULL;
+  ip6_reass_rc_t rv = IP6_REASS_RC_OK;
   do
     {
       u32 tmp_bi = sub_chain_bi;
       vlib_buffer_t *tmp = vlib_get_buffer (vm, tmp_bi);
+      vnet_buffer_opaque_t *vnb = vnet_buffer (tmp);
+      if (!(vnb->ip.reass.range_first >= vnb->ip.reass.fragment_first) &&
+         !(vnb->ip.reass.range_last > vnb->ip.reass.fragment_first))
+       {
+         rv = IP6_REASS_RC_INTERNAL_ERROR;
+         goto free_buffers_and_return;
+       }
+
       u32 data_len = ip6_reass_buffer_get_data_len (tmp);
       u32 trim_front = vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
        sizeof (*frag_hdr) + ip6_reass_buffer_get_data_offset (tmp);
@@ -446,12 +493,20 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
       if (tmp_bi == reass->first_bi)
        {
          /* first buffer - keep ip6 header */
-         ASSERT (0 == ip6_reass_buffer_get_data_offset (tmp));
+         if (0 != ip6_reass_buffer_get_data_offset (tmp))
+           {
+             rv = IP6_REASS_RC_INTERNAL_ERROR;
+             goto free_buffers_and_return;
+           }
          trim_front = 0;
          trim_end = vlib_buffer_length_in_chain (vm, tmp) - data_len -
            (vnet_buffer (tmp)->ip.reass.ip6_frag_hdr_offset +
             sizeof (*frag_hdr));
-         ASSERT (vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0);
+         if (!(vlib_buffer_length_in_chain (vm, tmp) - trim_end > 0))
+           {
+             rv = IP6_REASS_RC_INTERNAL_ERROR;
+             goto free_buffers_and_return;
+           }
        }
       u32 keep_data =
        vlib_buffer_length_in_chain (vm, tmp) - trim_front - trim_end;
@@ -463,10 +518,13 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
              if (trim_front > tmp->current_length)
                {
                  /* drop whole buffer */
-                 vec_add1 (*vec_drop_compress, tmp_bi);
-                 ++dropped_cnt;
+                 vec_add1 (vec_drop_compress, tmp_bi);
                  trim_front -= tmp->current_length;
-                 ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
+                 if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
+                   {
+                     rv = IP6_REASS_RC_INTERNAL_ERROR;
+                     goto free_buffers_and_return;
+                   }
                  tmp->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
                  tmp_bi = tmp->next_buffer;
                  tmp = vlib_get_buffer (vm, tmp_bi);
@@ -494,14 +552,22 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
              else
                {
                  keep_data -= tmp->current_length;
-                 ASSERT (tmp->flags & VLIB_BUFFER_NEXT_PRESENT);
+                 if (!(tmp->flags & VLIB_BUFFER_NEXT_PRESENT))
+                   {
+                     rv = IP6_REASS_RC_INTERNAL_ERROR;
+                     goto free_buffers_and_return;
+                   }
                }
              total_length += tmp->current_length;
            }
          else
            {
-             vec_add1 (*vec_drop_compress, tmp_bi);
-             ASSERT (reass->first_bi != tmp_bi);
+             vec_add1 (vec_drop_compress, tmp_bi);
+             if (reass->first_bi == tmp_bi)
+               {
+                 rv = IP6_REASS_RC_INTERNAL_ERROR;
+                 goto free_buffers_and_return;
+               }
              ++dropped_cnt;
            }
          if (tmp->flags & VLIB_BUFFER_NEXT_PRESENT)
@@ -519,9 +585,19 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
        reass.next_range_bi;
     }
   while (~0 != sub_chain_bi);
+
+  if (!last_b)
+    {
+      rv = IP6_REASS_RC_INTERNAL_ERROR;
+      goto free_buffers_and_return;
+    }
   last_b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
   vlib_buffer_t *first_b = vlib_get_buffer (vm, reass->first_bi);
-  ASSERT (total_length >= first_b->current_length);
+  if (total_length < first_b->current_length)
+    {
+      rv = IP6_REASS_RC_INTERNAL_ERROR;
+      goto free_buffers_and_return;
+    }
   total_length -= first_b->current_length;
   first_b->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
   first_b->total_length_not_including_first_buffer = total_length;
@@ -540,7 +616,11 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
     {
       ip->protocol = frag_hdr->next_hdr;
     }
-  ASSERT ((u8 *) frag_hdr - (u8 *) ip == ip6_frag_hdr_offset);
+  if (!((u8 *) frag_hdr - (u8 *) ip == ip6_frag_hdr_offset))
+    {
+      rv = IP6_REASS_RC_INTERNAL_ERROR;
+      goto free_buffers_and_return;
+    }
   memmove (frag_hdr, (u8 *) frag_hdr + sizeof (*frag_hdr),
           first_b->current_length - ip6_frag_hdr_offset -
           sizeof (ip6_frag_hdr_t));
@@ -548,8 +628,11 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
   ip->payload_length =
     clib_host_to_net_u16 (total_length + first_b->current_length -
                          sizeof (*ip));
-  ip6_reass_free (rm, reass);
-  vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
+  if (!vlib_buffer_chain_linearize (vm, first_b))
+    {
+      rv = IP6_REASS_RC_NO_BUF;
+      goto free_buffers_and_return;
+    }
   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
     {
       ip6_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
@@ -580,33 +663,28 @@ ip6_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
       while (0);
 #endif
     }
-  reass = NULL;
-}
-
-static u32
-ip6_reass_get_buffer_chain_length (vlib_main_t * vm, vlib_buffer_t * b)
-{
-  u32 len = 0;
-  while (b)
+  if (is_feature)
     {
-      ++len;
-      if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NEXT_PRESENT))
-       {
-         b = vlib_get_buffer (vm, b->next_buffer);
-       }
-      else
-       {
-         break;
-       }
+      *next0 = IP6_REASSEMBLY_NEXT_INPUT;
     }
-  return len;
+  else
+    {
+      *next0 = reass->next_index;
+    }
+  vnet_buffer (first_b)->ip.reass.estimated_mtu = reass->min_fragment_length;
+  ip6_reass_free (rm, rt, reass);
+  reass = NULL;
+free_buffers_and_return:
+  vlib_buffer_free (vm, vec_drop_compress, vec_len (vec_drop_compress));
+  vec_free (vec_drop_compress);
+  return rv;
 }
 
-static void
-ip6_reass_insert_range_in_chain (vlib_main_t * vm,
-                                ip6_reass_main_t * rm,
-                                ip6_reass_t * reass,
-                                u32 prev_range_bi, u32 new_next_bi)
+always_inline void
+ip6_reass_insert_range_in_chain (vlib_main_t * vm, ip6_reass_main_t * rm,
+                                ip6_reass_per_thread_t * rt,
+                                ip6_reass_t * reass, u32 prev_range_bi,
+                                u32 new_next_bi)
 {
 
   vlib_buffer_t *new_next_b = vlib_get_buffer (vm, new_next_bi);
@@ -627,26 +705,28 @@ ip6_reass_insert_range_in_chain (vlib_main_t * vm,
       reass->first_bi = new_next_bi;
     }
   reass->data_len += ip6_reass_buffer_get_data_len (new_next_b);
-  rm->buffers_n += ip6_reass_get_buffer_chain_length (vm, new_next_b);
 }
 
-void
+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_t * reass, u32 * bi0,
-                 u32 * next0, vlib_error_t * error0,
-                 ip6_frag_hdr_t * frag_hdr, u32 ** vec_drop_overlap,
-                 u32 ** vec_drop_compress, u32 next_input, u32 next_drop,
-                 u32 next_icmp_error)
+                 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)
 {
   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
   fvnb->ip.reass.ip6_frag_hdr_offset =
     (u8 *) frag_hdr - (u8 *) vlib_buffer_get_current (fb);
   ip6_header_t *fip = vlib_buffer_get_current (fb);
-  ASSERT (fb->current_length > sizeof (*fip));
-  ASSERT (fvnb->ip.reass.ip6_frag_hdr_offset > 0 &&
-         fvnb->ip.reass.ip6_frag_hdr_offset < fb->current_length);
+  if (fb->current_length < sizeof (*fip) ||
+      fvnb->ip.reass.ip6_frag_hdr_offset == 0 ||
+      fvnb->ip.reass.ip6_frag_hdr_offset >= fb->current_length)
+    {
+      return IP6_REASS_RC_INTERNAL_ERROR;
+    }
+
   u32 fragment_first = fvnb->ip.reass.fragment_first =
     ip6_frag_hdr_offset_bytes (frag_hdr);
   u32 fragment_length =
@@ -660,34 +740,6 @@ ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
   fvnb->ip.reass.range_first = fragment_first;
   fvnb->ip.reass.range_last = fragment_last;
   fvnb->ip.reass.next_range_bi = ~0;
-  if (more_fragments && 0 != fragment_length % 8)
-    {
-      if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
-       {
-         ip6_reass_add_trace (vm, node, rm, reass, *bi0,
-                              ICMP_ERROR_FL_NOT_MULT_8, 0);
-       }
-      *next0 = next_icmp_error;
-      icmp6_error_set_vnet_buffer (fb, ICMP6_parameter_problem,
-                                  ICMP6_parameter_problem_erroneous_header_field,
-                                  (u8 *) & fip->payload_length - (u8 *) fip);
-      return;
-    }
-  if (fragment_first + fragment_length > 65535)
-    {
-      if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
-       {
-         ip6_reass_add_trace (vm, node, rm, reass, *bi0,
-                              ICMP_ERROR_FL_TOO_BIG, 0);
-       }
-      *next0 = next_icmp_error;
-      ip6_header_t *ip0 = vlib_buffer_get_current (fb);
-      icmp6_error_set_vnet_buffer (fb, ICMP6_parameter_problem,
-                                  ICMP6_parameter_problem_erroneous_header_field,
-                                  (u8 *) & frag_hdr->fragment_offset_and_more
-                                  - (u8 *) ip0);
-      return;
-    }
   if (!more_fragments)
     {
       reass->last_packet_octet = fragment_last;
@@ -695,15 +747,14 @@ ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
   if (~0 == reass->first_bi)
     {
       // starting a new reassembly
-      ip6_reass_insert_range_in_chain (vm, rm, reass, prev_range_bi, *bi0);
-      if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
-       {
-         ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_NEW, 0);
-       }
-      *bi0 = ~0;
-      return;
+      ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
+                                      *bi0);
+      reass->min_fragment_length = clib_net_to_host_u16 (fip->payload_length);
+      consumed = 1;
+      reass->fragments_n = 1;
+      goto check_if_done_maybe;
     }
-  fvnb->ip.reass.estimated_mtu =
+  reass->min_fragment_length =
     clib_min (clib_net_to_host_u16 (fip->payload_length),
              fvnb->ip.reass.estimated_mtu);
   while (~0 != candidate_range_bi)
@@ -719,8 +770,8 @@ ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
              ~0 == candidate_range_bi)
            {
              // special case - this fragment falls beyond all known ranges
-             ip6_reass_insert_range_in_chain (vm, rm, reass, prev_range_bi,
-                                              *bi0);
+             ip6_reass_insert_range_in_chain (vm, rm, rt, reass,
+                                              prev_range_bi, *bi0);
              consumed = 1;
              break;
            }
@@ -729,7 +780,7 @@ ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
       if (fragment_last < candidate_vnb->ip.reass.range_first)
        {
          // this fragment ends before candidate range without any overlap
-         ip6_reass_insert_range_in_chain (vm, rm, reass, prev_range_bi,
+         ip6_reass_insert_range_in_chain (vm, rm, rt, reass, prev_range_bi,
                                           *bi0);
          consumed = 1;
        }
@@ -741,18 +792,21 @@ 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, rm, reass, vec_drop_overlap);
-         ip6_reass_free (rm, reass);
+         ip6_reass_drop_all (vm, rm, reass);
+         ip6_reass_free (rm, rt, reass);
          if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
            {
              ip6_reass_add_trace (vm, node, rm, reass, *bi0, RANGE_OVERLAP,
                                   0);
            }
-         *next0 = next_drop;
+         *next0 = IP6_REASSEMBLY_NEXT_DROP;
          *error0 = IP6_ERROR_REASS_OVERLAPPING_FRAGMENT;
+         return IP6_REASS_RC_OK;
        }
       break;
     }
+  ++reass->fragments_n;
+check_if_done_maybe:
   if (consumed)
     {
       if (PREDICT_FALSE (fb->flags & VLIB_BUFFER_IS_TRACED))
@@ -763,150 +817,215 @@ ip6_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
   if (~0 != reass->last_packet_octet &&
       reass->data_len == reass->last_packet_octet + 1)
     {
-      ip6_reass_finalize (vm, node, rm, reass, bi0, next0, error0, next_input,
-                         vec_drop_compress);
+      return ip6_reass_finalize (vm, node, rm, rt, reass, bi0, next0, error0,
+                                is_feature);
     }
   else
     {
       if (consumed)
        {
          *bi0 = ~0;
+         if (reass->fragments_n > rm->max_reass_len)
+           {
+             return IP6_REASS_RC_TOO_MANY_FRAGMENTS;
+           }
        }
       else
        {
-         *next0 = next_drop;
+         *next0 = IP6_REASSEMBLY_NEXT_DROP;
          *error0 = IP6_ERROR_REASS_DUPLICATE_FRAGMENT;
        }
     }
+  return IP6_REASS_RC_OK;
+}
+
+always_inline bool
+ip6_reass_verify_upper_layer_present (vlib_node_runtime_t * node,
+                                     vlib_buffer_t * b,
+                                     ip6_frag_hdr_t * frag_hdr)
+{
+  ip6_ext_header_t *tmp = (ip6_ext_header_t *) frag_hdr;
+  while (ip6_ext_hdr (tmp->next_hdr))
+    {
+      tmp = ip6_ext_next_header (tmp);
+    }
+  if (IP_PROTOCOL_IP6_NONXT == tmp->next_hdr)
+    {
+      icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
+                                  ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain,
+                                  0);
+      b->error = node->errors[IP6_ERROR_REASS_MISSING_UPPER];
+
+      return false;
+    }
+  return true;
+}
+
+always_inline bool
+ip6_reass_verify_fragment_multiple_8 (vlib_main_t * vm,
+                                     vlib_node_runtime_t * node,
+                                     vlib_buffer_t * b,
+                                     ip6_frag_hdr_t * frag_hdr)
+{
+  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
+  ip6_header_t *ip = vlib_buffer_get_current (b);
+  int more_fragments = ip6_frag_hdr_more (frag_hdr);
+  u32 fragment_length =
+    vlib_buffer_length_in_chain (vm, b) -
+    (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
+  if (more_fragments && 0 != fragment_length % 8)
+    {
+      icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
+                                  ICMP6_parameter_problem_erroneous_header_field,
+                                  (u8 *) & ip->payload_length - (u8 *) ip);
+      return false;
+    }
+  return true;
+}
+
+always_inline bool
+ip6_reass_verify_packet_size_lt_64k (vlib_main_t * vm,
+                                    vlib_node_runtime_t * node,
+                                    vlib_buffer_t * b,
+                                    ip6_frag_hdr_t * frag_hdr)
+{
+  vnet_buffer_opaque_t *vnb = vnet_buffer (b);
+  u32 fragment_first = ip6_frag_hdr_offset_bytes (frag_hdr);
+  u32 fragment_length =
+    vlib_buffer_length_in_chain (vm, b) -
+    (vnb->ip.reass.ip6_frag_hdr_offset + sizeof (*frag_hdr));
+  if (fragment_first + fragment_length > 65535)
+    {
+      ip6_header_t *ip0 = vlib_buffer_get_current (b);
+      icmp6_error_set_vnet_buffer (b, ICMP6_parameter_problem,
+                                  ICMP6_parameter_problem_erroneous_header_field,
+                                  (u8 *) & frag_hdr->fragment_offset_and_more
+                                  - (u8 *) ip0);
+      return false;
+    }
+  return true;
 }
 
 always_inline uword
-ip6_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
-               vlib_frame_t * frame)
+ip6_reassembly_inline (vlib_main_t * vm,
+                      vlib_node_runtime_t * node,
+                      vlib_frame_t * frame, bool is_feature)
 {
   u32 *from = vlib_frame_vector_args (frame);
   u32 n_left_from, n_left_to_next, *to_next, next_index;
   ip6_reass_main_t *rm = &ip6_reass_main;
+  ip6_reass_per_thread_t *rt = &rm->per_thread_data[vm->thread_index];
+  clib_spinlock_lock (&rt->lock);
 
   n_left_from = frame->n_vectors;
   next_index = node->cached_next_index;
-  static u32 *vec_timeout = NULL;      // indexes of buffers which timed out
-  static u32 *vec_drop_overlap = NULL; // indexes of buffers dropped due to overlap
-  static u32 *vec_drop_compress = NULL;        // indexes of buffers dropped due to buffer compression
-  while (n_left_from > 0 || vec_len (vec_timeout) > 0 ||
-        vec_len (vec_drop_overlap) > 0)
+  while (n_left_from > 0)
     {
       vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
 
-      while (vec_len (vec_timeout) > 0 && n_left_to_next > 0)
-       {
-         u32 bi = vec_pop (vec_timeout);
-         vlib_buffer_t *b = vlib_get_buffer (vm, bi);
-         b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
-         to_next[0] = bi;
-         to_next += 1;
-         n_left_to_next -= 1;
-         vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
-                                          n_left_to_next, bi,
-                                          IP6_REASSEMBLY_NEXT_DROP);
-         ASSERT (rm->buffers_n > 0);
-         --rm->buffers_n;
-       }
-
-      while (vec_len (vec_drop_overlap) > 0 && n_left_to_next > 0)
-       {
-         u32 bi = vec_pop (vec_drop_overlap);
-         vlib_buffer_t *b = vlib_get_buffer (vm, bi);
-         b->error = node->errors[IP6_ERROR_REASS_OVERLAPPING_FRAGMENT];
-         to_next[0] = bi;
-         to_next += 1;
-         n_left_to_next -= 1;
-         vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
-                                          n_left_to_next, bi,
-                                          IP6_REASSEMBLY_NEXT_DROP);
-         ASSERT (rm->buffers_n > 0);
-         --rm->buffers_n;
-       }
-
-      while (vec_len (vec_drop_compress) > 0 && n_left_to_next > 0)
-       {
-         u32 bi = vec_pop (vec_drop_compress);
-         vlib_buffer_t *b = vlib_get_buffer (vm, bi);
-         b->error = node->errors[IP6_ERROR_NONE];
-         to_next[0] = bi;
-         to_next += 1;
-         n_left_to_next -= 1;
-         vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
-                                          n_left_to_next, bi,
-                                          IP6_REASSEMBLY_NEXT_DROP);
-         ASSERT (rm->buffers_n > 0);
-         --rm->buffers_n;
-       }
-
       while (n_left_from > 0 && n_left_to_next > 0)
        {
          u32 bi0;
          vlib_buffer_t *b0;
-         u32 next0;            //, error0;
+         u32 next0 = IP6_REASSEMBLY_NEXT_DROP;
+         u32 error0 = IP6_ERROR_NONE;
+         u32 icmp_bi = ~0;
 
          bi0 = from[0];
          b0 = vlib_get_buffer (vm, bi0);
 
          ip6_header_t *ip0 = vlib_buffer_get_current (b0);
-         ip6_frag_hdr_t *frag_hdr;
+         ip6_frag_hdr_t *frag_hdr = NULL;
          ip6_ext_header_t *prev_hdr;
-         ip6_ext_header_find_t (ip0, prev_hdr, frag_hdr,
-                                IP_PROTOCOL_IPV6_FRAGMENTATION);
+         if (ip6_ext_hdr (ip0->protocol))
+           {
+             ip6_ext_header_find_t (ip0, prev_hdr, frag_hdr,
+                                    IP_PROTOCOL_IPV6_FRAGMENTATION);
+           }
+         if (!frag_hdr)
+           {
+             // this is a regular packet - no fragmentation
+             next0 = IP6_REASSEMBLY_NEXT_INPUT;
+             goto skip_reass;
+           }
          if (0 == ip6_frag_hdr_offset (frag_hdr))
            {
              // first fragment - verify upper-layer is present
-             ip6_ext_header_t *tmp = (ip6_ext_header_t *) frag_hdr;
-             while (ip6_ext_hdr (tmp->next_hdr))
+             if (!ip6_reass_verify_upper_layer_present (node, b0, frag_hdr))
                {
-                 tmp = ip6_ext_next_header (tmp);
-               }
-             if (IP_PROTOCOL_IP6_NONXT == tmp->next_hdr)
-               {
-                 icmp6_error_set_vnet_buffer (b0, ICMP6_parameter_problem,
-                                              ICMP6_parameter_problem_first_fragment_has_incomplete_header_chain,
-                                              0);
-                 b0->error = node->errors[IP6_ERROR_REASS_MISSING_UPPER];
-
-                 to_next[0] = bi0;
-                 to_next += 1;
-                 n_left_to_next -= 1;
-                 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
-                                                  to_next, n_left_to_next,
-                                                  bi0,
-                                                  IP6_REASSEMBLY_NEXT_ICMP_ERROR);
-                 goto next;
+                 next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
+                 goto skip_reass;
                }
            }
+         if (!ip6_reass_verify_fragment_multiple_8 (vm, node, b0, frag_hdr)
+             || !ip6_reass_verify_packet_size_lt_64k (vm, node, b0,
+                                                      frag_hdr))
+           {
+             next0 = IP6_REASSEMBLY_NEXT_ICMP_ERROR;
+             goto skip_reass;
+           }
          vnet_buffer (b0)->ip.reass.ip6_frag_hdr_offset =
            (u8 *) frag_hdr - (u8 *) ip0;
 
-         ip6_reass_key_t k;
-         k.src.as_u64[0] = ip0->src_address.as_u64[0];
-         k.src.as_u64[1] = ip0->src_address.as_u64[1];
-         k.dst.as_u64[0] = ip0->dst_address.as_u64[0];
-         k.dst.as_u64[1] = ip0->dst_address.as_u64[1];
-         k.xx_id = vnet_buffer (b0)->sw_if_index[VLIB_RX];
-         k.frag_id = frag_hdr->identification;
-         k.proto = ip0->protocol;
-         k.unused = 0;
-         u32 icmp_bi = ~0;
+         ip6_reass_kv_t kv;
+         u8 do_handoff = 0;
+
+         kv.k.as_u64[0] = ip0->src_address.as_u64[0];
+         kv.k.as_u64[1] = ip0->src_address.as_u64[1];
+         kv.k.as_u64[2] = ip0->dst_address.as_u64[0];
+         kv.k.as_u64[3] = ip0->dst_address.as_u64[1];
+         kv.k.as_u64[4] =
+           ((u64) vec_elt (ip6_main.fib_index_by_sw_if_index,
+                           vnet_buffer (b0)->sw_if_index[VLIB_RX])) << 32 |
+           (u64) frag_hdr->identification;
+         kv.k.as_u64[5] = ip0->protocol;
+
          ip6_reass_t *reass =
-           ip6_reass_find_or_create (vm, node, rm, &k, &icmp_bi,
-                                     &vec_timeout);
+           ip6_reass_find_or_create (vm, node, rm, rt, &kv, &icmp_bi,
+                                     &do_handoff);
 
-         u32 error0 = IP6_ERROR_NONE;
-         if (reass)
+         if (PREDICT_FALSE (do_handoff))
+           {
+             next0 = IP6_REASSEMBLY_NEXT_HANDOFF;
+             if (is_feature)
+               vnet_buffer (b0)->ip.reass.owner_feature_thread_index =
+                 kv.v.thread_index;
+             else
+               vnet_buffer (b0)->ip.reass.owner_thread_index =
+                 kv.v.thread_index;
+           }
+         else if (reass)
            {
-             ip6_reass_update (vm, node, rm, reass, &bi0, &next0, &error0,
-                               frag_hdr, &vec_drop_overlap,
-                               &vec_drop_compress, IP6_REASSEMBLY_NEXT_INPUT,
-                               IP6_REASSEMBLY_NEXT_DROP,
-                               IP6_REASSEMBLY_NEXT_ICMP_ERROR);
+             switch (ip6_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
+                                       &error0, frag_hdr, is_feature))
+               {
+               case IP6_REASS_RC_OK:
+                 /* nothing to do here */
+                 break;
+               case IP6_REASS_RC_TOO_MANY_FRAGMENTS:
+                 vlib_node_increment_counter (vm, node->node_index,
+                                              IP6_ERROR_REASS_FRAGMENT_CHAIN_TOO_LONG,
+                                              1);
+                 ip6_reass_drop_all (vm, 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, rm, reass);
+                 ip6_reass_free (rm, rt, reass);
+                 goto next_packet;
+                 break;
+               case IP6_REASS_RC_INTERNAL_ERROR:
+                 vlib_node_increment_counter (vm, node->node_index,
+                                              IP6_ERROR_REASS_INTERNAL_ERROR,
+                                              1);
+                 ip6_reass_drop_all (vm, rm, reass);
+                 ip6_reass_free (rm, rt, reass);
+                 goto next_packet;
+                 break;
+               }
            }
          else
            {
@@ -918,9 +1037,15 @@ ip6_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
 
          if (~0 != bi0)
            {
+           skip_reass:
              to_next[0] = bi0;
              to_next += 1;
              n_left_to_next -= 1;
+             if (is_feature && IP6_ERROR_NONE == error0)
+               {
+                 b0 = vlib_get_buffer (vm, bi0);
+                 vnet_feature_next (&next0, b0);
+               }
              vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
                                               n_left_to_next, bi0, next0);
            }
@@ -935,7 +1060,7 @@ ip6_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
                                               n_left_to_next, icmp_bi,
                                               next0);
            }
-       next:
+       next_packet:
          from += 1;
          n_left_from -= 1;
        }
@@ -943,6 +1068,7 @@ ip6_reassembly (vlib_main_t * vm, vlib_node_runtime_t * node,
       vlib_put_next_frame (vm, node, next_index, n_left_to_next);
     }
 
+  clib_spinlock_unlock (&rt->lock);
   return frame->n_vectors;
 }
 
@@ -952,9 +1078,14 @@ static char *ip6_reassembly_error_strings[] = {
 #undef _
 };
 
+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 */ );
+}
+
 /* *INDENT-OFF* */
-VLIB_REGISTER_NODE (ip6_reass_node, static) = {
-    .function = ip6_reassembly,
+VLIB_REGISTER_NODE (ip6_reass_node) = {
     .name = "ip6-reassembly",
     .vector_size = sizeof (u32),
     .format_trace = format_ip6_reass_trace,
@@ -966,12 +1097,48 @@ VLIB_REGISTER_NODE (ip6_reass_node, static) = {
                 [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
                 [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
                 [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
+                [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reassembly-handoff",
+        },
+};
+/* *INDENT-ON* */
+
+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 */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ip6_reass_node_feature) = {
+    .name = "ip6-reassembly-feature",
+    .vector_size = sizeof (u32),
+    .format_trace = format_ip6_reass_trace,
+    .n_errors = ARRAY_LEN (ip6_reassembly_error_strings),
+    .error_strings = ip6_reassembly_error_strings,
+    .n_next_nodes = IP6_REASSEMBLY_N_NEXT,
+    .next_nodes =
+        {
+                [IP6_REASSEMBLY_NEXT_INPUT] = "ip6-input",
+                [IP6_REASSEMBLY_NEXT_DROP] = "ip6-drop",
+                [IP6_REASSEMBLY_NEXT_ICMP_ERROR] = "ip6-icmp-error",
+                [IP6_REASSEMBLY_NEXT_HANDOFF] = "ip6-reass-feature-hoff",
         },
 };
 /* *INDENT-ON* */
 
-VLIB_NODE_FUNCTION_MULTIARCH (ip6_reass_node, ip6_reassembly)
-     static u32 ip6_reass_get_nbuckets ()
+/* *INDENT-OFF* */
+VNET_FEATURE_INIT (ip6_reassembly_feature, static) = {
+    .arc_name = "ip6-unicast",
+    .node_name = "ip6-reassembly-feature",
+    .runs_before = VNET_FEATURES ("ip6-lookup"),
+    .runs_after = 0,
+};
+/* *INDENT-ON* */
+
+#ifndef CLIB_MARCH_VARIANT
+static u32
+ip6_reass_get_nbuckets ()
 {
   ip6_reass_main_t *rm = &ip6_reass_main;
   u32 nbuckets;
@@ -986,19 +1153,21 @@ VLIB_NODE_FUNCTION_MULTIARCH (ip6_reass_node, ip6_reassembly)
 
   return nbuckets;
 }
+#endif /* CLIB_MARCH_VARIANT */
 
 typedef enum
 {
   IP6_EVENT_CONFIG_CHANGED = 1,
 } ip6_reass_event_t;
 
+#ifndef CLIB_MARCH_VARIANT
 typedef struct
 {
   int failure;
   clib_bihash_48_8_t *new_hash;
 } ip6_rehash_cb_ctx;
 
-void
+static void
 ip6_rehash_cb (clib_bihash_kv_48_8_t * kv, void *_ctx)
 {
   ip6_rehash_cb_ctx *ctx = _ctx;
@@ -1008,24 +1177,32 @@ ip6_rehash_cb (clib_bihash_kv_48_8_t * kv, void *_ctx)
     }
 }
 
-vnet_api_error_t
-ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
-              u32 expire_walk_interval_ms)
+static void
+ip6_reass_set_params (u32 timeout_ms, u32 max_reassemblies,
+                     u32 max_reassembly_length, u32 expire_walk_interval_ms)
 {
-  u32 old_nbuckets = ip6_reass_get_nbuckets ();
   ip6_reass_main.timeout_ms = timeout_ms;
   ip6_reass_main.timeout = (f64) timeout_ms / (f64) MSEC_PER_SEC;
   ip6_reass_main.max_reass_n = max_reassemblies;
+  ip6_reass_main.max_reass_len = max_reassembly_length;
   ip6_reass_main.expire_walk_interval_ms = expire_walk_interval_ms;
+}
+
+vnet_api_error_t
+ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
+              u32 max_reassembly_length, u32 expire_walk_interval_ms)
+{
+  u32 old_nbuckets = ip6_reass_get_nbuckets ();
+  ip6_reass_set_params (timeout_ms, max_reassemblies, max_reassembly_length,
+                       expire_walk_interval_ms);
   vlib_process_signal_event (ip6_reass_main.vlib_main,
                             ip6_reass_main.ip6_reass_expire_node_idx,
                             IP6_EVENT_CONFIG_CHANGED, 0);
   u32 new_nbuckets = ip6_reass_get_nbuckets ();
-  if (ip6_reass_main.max_reass_n > 0 && new_nbuckets > 1 &&
-      new_nbuckets != old_nbuckets)
+  if (ip6_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
     {
       clib_bihash_48_8_t new_hash;
-      memset (&new_hash, 0, sizeof (new_hash));
+      clib_memset (&new_hash, 0, sizeof (new_hash));
       ip6_rehash_cb_ctx ctx;
       ctx.failure = 0;
       ctx.new_hash = &new_hash;
@@ -1041,8 +1218,8 @@ ip6_reass_set (u32 timeout_ms, u32 max_reassemblies,
       else
        {
          clib_bihash_free_48_8 (&ip6_reass_main.hash);
-         clib_memcpy (&ip6_reass_main.hash, &new_hash,
-                      sizeof (ip6_reass_main.hash));
+         clib_memcpy_fast (&ip6_reass_main.hash, &new_hash,
+                           sizeof (ip6_reass_main.hash));
        }
     }
   return 0;
@@ -1058,31 +1235,40 @@ ip6_reass_get (u32 * timeout_ms, u32 * max_reassemblies,
   return 0;
 }
 
-clib_error_t *
+static clib_error_t *
 ip6_reass_init_function (vlib_main_t * vm)
 {
   ip6_reass_main_t *rm = &ip6_reass_main;
   clib_error_t *error = 0;
   u32 nbuckets;
+  vlib_node_t *node;
 
   rm->vlib_main = vm;
   rm->vnet_main = vnet_get_main ();
 
-  rm->reass_n = 0;
-  pool_alloc (rm->pool, rm->max_reass_n);
-  ip6_reass_set (IP6_REASS_TIMEOUT_DEFAULT_MS,
-                IP6_REASS_MAX_REASSEMBLIES_DEAFULT,
-                IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
+  vec_validate (rm->per_thread_data, vlib_num_workers ());
+  ip6_reass_per_thread_t *rt;
+  vec_foreach (rt, rm->per_thread_data)
+  {
+    clib_spinlock_init (&rt->lock);
+    pool_alloc (rt->pool, rm->max_reass_n);
+  }
+
+  node = vlib_get_node_by_name (vm, (u8 *) "ip6-reassembly-expire-walk");
+  ASSERT (node);
+  rm->ip6_reass_expire_node_idx = node->index;
+
+  ip6_reass_set_params (IP6_REASS_TIMEOUT_DEFAULT_MS,
+                       IP6_REASS_MAX_REASSEMBLIES_DEFAULT,
+                       IP6_REASS_MAX_REASSEMBLY_LENGTH_DEFAULT,
+                       IP6_REASS_EXPIRE_WALK_INTERVAL_DEFAULT_MS);
 
   nbuckets = ip6_reass_get_nbuckets ();
   clib_bihash_init_48_8 (&rm->hash, "ip6-reass", nbuckets, nbuckets * 1024);
 
-  vlib_node_t *node = vlib_get_node_by_name (vm, (u8 *) "ip6-drop");
+  node = vlib_get_node_by_name (vm, (u8 *) "ip6-drop");
   ASSERT (node);
   rm->ip6_drop_idx = node->index;
-  node = vlib_get_node_by_name (vm, (u8 *) "ip6-reassembly-expire-walk");
-  ASSERT (node);
-  rm->ip6_reass_expire_node_idx = node->index;
   node = vlib_get_node_by_name (vm, (u8 *) "ip6-icmp-error");
   ASSERT (node);
   rm->ip6_icmp_error_idx = node->index;
@@ -1091,10 +1277,16 @@ ip6_reass_init_function (vlib_main_t * vm)
     return error;
   ip6_register_protocol (IP_PROTOCOL_IPV6_FRAGMENTATION,
                         ip6_reass_node.index);
+
+  rm->fq_index = vlib_frame_queue_main_init (ip6_reass_node.index, 0);
+  rm->fq_feature_index =
+    vlib_frame_queue_main_init (ip6_reass_node_feature.index, 0);
+
   return error;
 }
 
 VLIB_INIT_FUNCTION (ip6_reass_init_function);
+#endif /* CLIB_MARCH_VARIANT */
 
 static uword
 ip6_reass_walk_expired (vlib_main_t * vm,
@@ -1124,71 +1316,53 @@ ip6_reass_walk_expired (vlib_main_t * vm,
       f64 now = vlib_time_now (vm);
 
       ip6_reass_t *reass;
-      u32 *vec_timeout = NULL;
       int *pool_indexes_to_free = NULL;
 
+      uword thread_index = 0;
       int index;
-      /* *INDENT-OFF* */
-      pool_foreach_index (index, rm->pool, ({
-                            reass = pool_elt_at_index (rm->pool, index);
-                            if (now > reass->last_heard + rm->timeout)
-                              {
-                                vec_add1 (pool_indexes_to_free, index);
-                              }
-                          }));
-      /* *INDENT-ON* */
-      int *i;
+      const uword nthreads = vlib_num_workers () + 1;
       u32 *vec_icmp_bi = NULL;
-      /* *INDENT-OFF* */
-      vec_foreach (i, pool_indexes_to_free)
-      {
-        ip6_reass_t *reass = pool_elt_at_index (rm->pool, i[0]);
-        u32 icmp_bi = ~0;
-        ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi, &vec_timeout);
-        if (~0 != icmp_bi)
+      for (thread_index = 0; thread_index < nthreads; ++thread_index)
+       {
+         ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
+         clib_spinlock_lock (&rt->lock);
+
+         vec_reset_length (pool_indexes_to_free);
+          /* *INDENT-OFF* */
+          pool_foreach_index (index, rt->pool, ({
+                                reass = pool_elt_at_index (rt->pool, index);
+                                if (now > reass->last_heard + rm->timeout)
+                                  {
+                                    vec_add1 (pool_indexes_to_free, index);
+                                  }
+                              }));
+          /* *INDENT-ON* */
+         int *i;
+          /* *INDENT-OFF* */
+          vec_foreach (i, pool_indexes_to_free)
           {
-            vec_add1 (vec_icmp_bi, icmp_bi);
+            ip6_reass_t *reass = pool_elt_at_index (rt->pool, i[0]);
+            u32 icmp_bi = ~0;
+            vlib_buffer_t *b = vlib_get_buffer (vm, reass->first_bi);
+            if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
+              {
+                if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
+                                        b->trace_index))
+                  {
+                    /* the trace is gone, don't trace this buffer anymore */
+                    b->flags &= ~VLIB_BUFFER_IS_TRACED;
+                  }
+              }
+            ip6_reass_on_timeout (vm, node, rm, reass, &icmp_bi);
+            if (~0 != icmp_bi)
+              {
+                vec_add1 (vec_icmp_bi, icmp_bi);
+              }
+            ip6_reass_free (rm, rt, reass);
           }
-        ip6_reass_free (rm, reass);
-      }
-      /* *INDENT-ON* */
+          /* *INDENT-ON* */
 
-      while (vec_len (vec_timeout) > 0)
-       {
-         vlib_frame_t *f = vlib_get_frame_to_node (vm, rm->ip6_drop_idx);
-         u32 *to_next = vlib_frame_vector_args (f);
-         u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
-         u32 n_trace = 0;
-         while (vec_len (vec_timeout) > 0 && n_left_to_next > 0)
-           {
-             u32 bi = vec_pop (vec_timeout);
-             vlib_buffer_t *b = vlib_get_buffer (vm, bi);
-             if (PREDICT_FALSE (b->flags & VLIB_BUFFER_IS_TRACED))
-               {
-                 if (pool_is_free_index (vm->trace_main.trace_buffer_pool,
-                                         b->trace_index))
-                   {
-                     /* the trace is gone, don't trace this buffer anymore */
-                     b->flags &= ~VLIB_BUFFER_IS_TRACED;
-                   }
-                 else
-                   {
-                     ++n_trace;
-                   }
-               }
-             b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
-             to_next[0] = bi;
-             ++f->n_vectors;
-             to_next += 1;
-             n_left_to_next -= 1;
-             ASSERT (rm->buffers_n > 0);
-             --rm->buffers_n;
-           }
-         if (PREDICT_FALSE (n_trace > 0))
-           {
-             f->flags |= VLIB_FRAME_TRACE;
-           }
-         vlib_put_frame_to_node (vm, rm->ip6_drop_idx, f);
+         clib_spinlock_unlock (&rt->lock);
        }
 
       while (vec_len (vec_icmp_bi) > 0)
@@ -1197,7 +1371,7 @@ ip6_reass_walk_expired (vlib_main_t * vm,
            vlib_get_frame_to_node (vm, rm->ip6_icmp_error_idx);
          u32 *to_next = vlib_frame_vector_args (f);
          u32 n_left_to_next = VLIB_FRAME_SIZE - f->n_vectors;
-         u32 n_trace = 0;
+         int trace_frame = 0;
          while (vec_len (vec_icmp_bi) > 0 && n_left_to_next > 0)
            {
              u32 bi = vec_pop (vec_icmp_bi);
@@ -1212,7 +1386,7 @@ ip6_reass_walk_expired (vlib_main_t * vm,
                    }
                  else
                    {
-                     ++n_trace;
+                     trace_frame = 1;
                    }
                }
              b->error = node->errors[IP6_ERROR_REASS_TIMEOUT];
@@ -1220,18 +1394,12 @@ ip6_reass_walk_expired (vlib_main_t * vm,
              ++f->n_vectors;
              to_next += 1;
              n_left_to_next -= 1;
-             ASSERT (rm->buffers_n > 0);
-             --rm->buffers_n;
-           }
-         if (PREDICT_FALSE (n_trace > 0))
-           {
-             f->flags |= VLIB_FRAME_TRACE;
            }
+         f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
          vlib_put_frame_to_node (vm, rm->ip6_icmp_error_idx, f);
        }
 
       vec_free (pool_indexes_to_free);
-      vec_free (vec_timeout);
       vec_free (vec_icmp_bi);
       if (event_data)
        {
@@ -1242,8 +1410,6 @@ ip6_reass_walk_expired (vlib_main_t * vm,
   return 0;
 }
 
-static vlib_node_registration_t ip6_reass_expire_node;
-
 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (ip6_reass_expire_node, static) = {
     .function = ip6_reass_walk_expired,
@@ -1273,7 +1439,7 @@ format_ip6_reass (u8 * s, va_list * args)
   vlib_main_t *vm = va_arg (*args, vlib_main_t *);
   ip6_reass_t *reass = va_arg (*args, ip6_reass_t *);
 
-  s = format (s, "ID: %u, key: %U\n  first_bi: %u, data_len: %u, "
+  s = format (s, "ID: %lu, key: %U\n  first_bi: %u, data_len: %u, "
              "last_packet_octet: %u, trace_op_counter: %u\n",
              reass->id, format_ip6_reass_key, &reass->key, reass->first_bi,
              reass->data_len, reass->last_packet_octet,
@@ -1288,8 +1454,8 @@ format_ip6_reass (u8 * s, va_list * args)
                  "fragment[%u, %u]\n",
                  counter, vnb->ip.reass.range_first,
                  vnb->ip.reass.range_last, bi,
-                 ip6_reass_buffer_get_data_offset_no_check (b),
-                 ip6_reass_buffer_get_data_len_no_check (b),
+                 ip6_reass_buffer_get_data_offset (b),
+                 ip6_reass_buffer_get_data_len (b),
                  vnb->ip.reass.fragment_first, vnb->ip.reass.fragment_last);
       if (b->flags & VLIB_BUFFER_NEXT_PRESENT)
        {
@@ -1312,22 +1478,39 @@ show_ip6_reass (vlib_main_t * vm, unformat_input_t * input,
   vlib_cli_output (vm, "---------------------");
   vlib_cli_output (vm, "IP6 reassembly status");
   vlib_cli_output (vm, "---------------------");
+  bool details = false;
   if (unformat (input, "details"))
     {
-      ip6_reass_t *reass;
-      /* *INDENT-OFF* */
-      pool_foreach (reass, rm->pool, {
-        vlib_cli_output (vm, "%U", format_ip6_reass, vm, reass);
-      });
-      /* *INDENT-ON* */
+      details = true;
+    }
+
+  u32 sum_reass_n = 0;
+  u64 sum_buffers_n = 0;
+  ip6_reass_t *reass;
+  uword thread_index;
+  const uword nthreads = vlib_num_workers () + 1;
+  for (thread_index = 0; thread_index < nthreads; ++thread_index)
+    {
+      ip6_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
+      clib_spinlock_lock (&rt->lock);
+      if (details)
+       {
+          /* *INDENT-OFF* */
+          pool_foreach (reass, rt->pool, {
+            vlib_cli_output (vm, "%U", format_ip6_reass, vm, reass);
+          });
+          /* *INDENT-ON* */
+       }
+      sum_reass_n += rt->reass_n;
+      clib_spinlock_unlock (&rt->lock);
     }
   vlib_cli_output (vm, "---------------------");
-  vlib_cli_output (vm, "Current IP6 reassemblies count: %lu\n", rm->reass_n);
-  vlib_cli_output (vm,
-                  "Maximum configured concurrent IP6 reassemblies: %lu\n",
-                  (long unsigned) rm->max_reass_n);
+  vlib_cli_output (vm, "Current IP6 reassemblies count: %lu\n",
+                  (long unsigned) sum_reass_n);
+  vlib_cli_output (vm, "Maximum configured concurrent IP6 reassemblies per "
+                  "worker-thread: %lu\n", (long unsigned) rm->max_reass_n);
   vlib_cli_output (vm, "Buffers in use: %lu\n",
-                  (long unsigned) rm->buffers_n);
+                  (long unsigned) sum_buffers_n);
   return 0;
 }
 
@@ -1339,6 +1522,151 @@ VLIB_CLI_COMMAND (show_ip6_reassembly_cmd, static) = {
 };
 /* *INDENT-ON* */
 
+#ifndef CLIB_MARCH_VARIANT
+vnet_api_error_t
+ip6_reass_enable_disable (u32 sw_if_index, u8 enable_disable)
+{
+  return vnet_feature_enable_disable ("ip6-unicast", "ip6-reassembly-feature",
+                                     sw_if_index, enable_disable, 0, 0);
+}
+#endif /* CLIB_MARCH_VARIANT */
+
+#define foreach_ip6_reassembly_handoff_error                       \
+_(CONGESTION_DROP, "congestion drop")
+
+
+typedef enum
+{
+#define _(sym,str) IP6_REASSEMBLY_HANDOFF_ERROR_##sym,
+  foreach_ip6_reassembly_handoff_error
+#undef _
+    IP6_REASSEMBLY_HANDOFF_N_ERROR,
+} ip6_reassembly_handoff_error_t;
+
+static char *ip6_reassembly_handoff_error_strings[] = {
+#define _(sym,string) string,
+  foreach_ip6_reassembly_handoff_error
+#undef _
+};
+
+typedef struct
+{
+  u32 next_worker_index;
+} ip6_reassembly_handoff_trace_t;
+
+static u8 *
+format_ip6_reassembly_handoff_trace (u8 * s, va_list * args)
+{
+  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
+  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
+  ip6_reassembly_handoff_trace_t *t =
+    va_arg (*args, ip6_reassembly_handoff_trace_t *);
+
+  s =
+    format (s, "ip6-reassembly-handoff: next-worker %d",
+           t->next_worker_index);
+
+  return s;
+}
+
+always_inline uword
+ip6_reassembly_handoff_inline (vlib_main_t * vm, vlib_node_runtime_t * node,
+                              vlib_frame_t * frame, bool is_feature)
+{
+  ip6_reass_main_t *rm = &ip6_reass_main;
+
+  vlib_buffer_t *bufs[VLIB_FRAME_SIZE], **b;
+  u32 n_enq, n_left_from, *from;
+  u16 thread_indices[VLIB_FRAME_SIZE], *ti;
+  u32 fq_index;
+
+  from = vlib_frame_vector_args (frame);
+  n_left_from = frame->n_vectors;
+  vlib_get_buffers (vm, from, bufs, n_left_from);
+
+  b = bufs;
+  ti = thread_indices;
+
+  fq_index = (is_feature) ? rm->fq_feature_index : rm->fq_index;
+
+  while (n_left_from > 0)
+    {
+      ti[0] =
+       (is_feature) ? vnet_buffer (b[0])->ip.
+       reass.owner_feature_thread_index : vnet_buffer (b[0])->ip.
+       reass.owner_thread_index;
+
+      if (PREDICT_FALSE
+         ((node->flags & VLIB_NODE_FLAG_TRACE)
+          && (b[0]->flags & VLIB_BUFFER_IS_TRACED)))
+       {
+         ip6_reassembly_handoff_trace_t *t =
+           vlib_add_trace (vm, node, b[0], sizeof (*t));
+         t->next_worker_index = ti[0];
+       }
+
+      n_left_from -= 1;
+      ti += 1;
+      b += 1;
+    }
+  n_enq =
+    vlib_buffer_enqueue_to_thread (vm, fq_index, from, thread_indices,
+                                  frame->n_vectors, 1);
+
+  if (n_enq < frame->n_vectors)
+    vlib_node_increment_counter (vm, node->node_index,
+                                IP6_REASSEMBLY_HANDOFF_ERROR_CONGESTION_DROP,
+                                frame->n_vectors - n_enq);
+  return frame->n_vectors;
+}
+
+VLIB_NODE_FN (ip6_reassembly_handoff_node) (vlib_main_t * vm,
+                                           vlib_node_runtime_t * node,
+                                           vlib_frame_t * frame)
+{
+  return ip6_reassembly_handoff_inline (vm, node, frame,
+                                       false /* is_feature */ );
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ip6_reassembly_handoff_node) = {
+  .name = "ip6-reassembly-handoff",
+  .vector_size = sizeof (u32),
+  .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
+  .error_strings = ip6_reassembly_handoff_error_strings,
+  .format_trace = format_ip6_reassembly_handoff_trace,
+
+  .n_next_nodes = 1,
+
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+
+
+VLIB_NODE_FN (ip6_reassembly_feature_handoff_node) (vlib_main_t * vm,
+                               vlib_node_runtime_t * node, vlib_frame_t * frame)
+{
+  return ip6_reassembly_handoff_inline (vm, node, frame, true /* is_feature */ );
+}
+
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (ip6_reassembly_feature_handoff_node) = {
+  .name = "ip6-reass-feature-hoff",
+  .vector_size = sizeof (u32),
+  .n_errors = ARRAY_LEN(ip6_reassembly_handoff_error_strings),
+  .error_strings = ip6_reassembly_handoff_error_strings,
+  .format_trace = format_ip6_reassembly_handoff_trace,
+
+  .n_next_nodes = 1,
+
+  .next_nodes = {
+    [0] = "error-drop",
+  },
+};
+/* *INDENT-ON* */
+
 /*
  * fd.io coding-style-patch-verification: ON
  *