VPP-1523: harden reassembly

[vpp.git] / src / vnet / ip / ip4_reassembly.c

diff --git a/src/vnet/ip/ip4_reassembly.c b/src/vnet/ip/ip4_reassembly.c
index a88ee2f..3e9d22f 100644 (file)
--- a/src/vnet/ip/ip4_reassembly.c
+++ b/src/vnet/ip/ip4_reassembly.c
@@ -368,7 +368,7 @@ ip4_reass_find_or_create (vlib_main_t * vm, ip4_reass_main_t * rm,
   else
     {
       pool_get (rt->pool, reass);
-      memset (reass, 0, sizeof (*reass));
+      clib_memset (reass, 0, sizeof (*reass));
       reass->id =
        ((u64) os_get_thread_index () * 1000000000) + rt->id_counter;
       ++rt->id_counter;
@@ -504,7 +504,10 @@ ip4_reass_finalize (vlib_main_t * vm, vlib_node_runtime_t * node,
   ip->flags_and_fragment_offset = 0;
   ip->length = clib_host_to_net_u16 (first_b->current_length + total_length);
   ip->checksum = ip4_header_checksum (ip);
+  u32 before = vec_len (*vec_drop_compress);
   vlib_buffer_chain_compress (vm, first_b, vec_drop_compress);
+  rt->buffers_n += vec_len (*vec_drop_compress) - before;
+
   if (PREDICT_FALSE (first_b->flags & VLIB_BUFFER_IS_TRACED))
     {
       ip4_reass_add_trace (vm, node, rm, reass, reass->first_bi, FINALIZE, 0);
@@ -654,12 +657,12 @@ ip4_reass_update (vlib_main_t * vm, vlib_node_runtime_t * node,
   ASSERT (fb->current_length >= sizeof (*fip));
   vnet_buffer_opaque_t *fvnb = vnet_buffer (fb);
   reass->next_index = fvnb->ip.reass.next_index;       // store next_index before it's overwritten
-  u32 fragment_first = fvnb->ip.reass.fragment_first =
-    ip4_get_fragment_offset_bytes (fip);
-  u32 fragment_length =
+  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);
-  u32 fragment_last = fvnb->ip.reass.fragment_last =
-    fragment_first + fragment_length - 1;
+  const u32 fragment_last = fragment_first + fragment_length - 1;
+  fvnb->ip.reass.fragment_first = fragment_first;
+  fvnb->ip.reass.fragment_last = fragment_last;
   int more_fragments = ip4_get_fragment_more (fip);
   u32 candidate_range_bi = reass->first_bi;
   u32 prev_range_bi = ~0;
@@ -927,28 +930,41 @@ ip4_reassembly_inline (vlib_main_t * vm,
            }
          else
            {
-             ip4_reass_key_t k;
-             k.as_u64[0] =
-               (u64) vnet_buffer (b0)->sw_if_index[VLIB_RX] << 32 | (u64)
-               ip0->src_address.as_u32;
-             k.as_u64[1] =
-               (u64) ip0->dst_address.
-               as_u32 << 32 | (u64) ip0->fragment_id << 16 | (u64) ip0->
-               protocol << 8;
-
-             ip4_reass_t *reass =
-               ip4_reass_find_or_create (vm, rm, rt, &k, &vec_drop_timeout);
-
-             if (reass)
+             const u32 fragment_first = ip4_get_fragment_offset_bytes (ip0);
+             const u32 fragment_length =
+               clib_net_to_host_u16 (ip0->length) - ip4_header_bytes (ip0);
+             const u32 fragment_last = fragment_first + fragment_length - 1;
+             if (fragment_first > fragment_last || fragment_first + fragment_length > UINT16_MAX - 20 || (fragment_length < 8 && ip4_get_fragment_more (ip0))) // 8 is minimum frag length per RFC 791
                {
-                 ip4_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
-                                   &error0, &vec_drop_overlap,
-                                   &vec_drop_compress, is_feature);
+                 next0 = IP4_REASSEMBLY_NEXT_DROP;
+                 error0 = IP4_ERROR_REASS_MALFORMED_PACKET;
                }
              else
                {
-                 next0 = IP4_REASSEMBLY_NEXT_DROP;
-                 error0 = IP4_ERROR_REASS_LIMIT_REACHED;
+                 ip4_reass_key_t k;
+                 k.as_u64[0] =
+                   (u64) vnet_buffer (b0)->sw_if_index[VLIB_RX] << 32 | (u64)
+                   ip0->src_address.as_u32;
+                 k.as_u64[1] =
+                   (u64) ip0->dst_address.
+                   as_u32 << 32 | (u64) ip0->fragment_id << 16 | (u64) ip0->
+                   protocol << 8;
+
+                 ip4_reass_t *reass =
+                   ip4_reass_find_or_create (vm, rm, rt, &k,
+                                             &vec_drop_timeout);
+
+                 if (reass)
+                   {
+                     ip4_reass_update (vm, node, rm, rt, reass, &bi0, &next0,
+                                       &error0, &vec_drop_overlap,
+                                       &vec_drop_compress, is_feature);
+                   }
+                 else
+                   {
+                     next0 = IP4_REASSEMBLY_NEXT_DROP;
+                     error0 = IP4_ERROR_REASS_LIMIT_REACHED;
+                   }
                }
 
              b0->error = node->errors[error0];
@@ -961,6 +977,7 @@ ip4_reassembly_inline (vlib_main_t * vm,
              n_left_to_next -= 1;
              if (is_feature && IP4_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,
@@ -1108,7 +1125,7 @@ ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
   if (ip4_reass_main.max_reass_n > 0 && new_nbuckets > old_nbuckets)
     {
       clib_bihash_16_8_t new_hash;
-      memset (&new_hash, 0, sizeof (new_hash));
+      clib_memset (&new_hash, 0, sizeof (new_hash));
       ip4_rehash_cb_ctx ctx;
       ctx.failure = 0;
       ctx.new_hash = &new_hash;
@@ -1124,8 +1141,8 @@ ip4_reass_set (u32 timeout_ms, u32 max_reassemblies,
       else
        {
          clib_bihash_free_16_8 (&ip4_reass_main.hash);
-         clib_memcpy (&ip4_reass_main.hash, &new_hash,
-                      sizeof (ip4_reass_main.hash));
+         clib_memcpy_fast (&ip4_reass_main.hash, &new_hash,
+                           sizeof (ip4_reass_main.hash));
        }
     }
   return 0;
@@ -1152,7 +1169,7 @@ ip4_reass_init_function (vlib_main_t * vm)
   rm->vlib_main = vm;
   rm->vnet_main = vnet_get_main ();
 
-  vec_validate (rm->per_thread_data, vlib_num_workers () + 1);
+  vec_validate (rm->per_thread_data, vlib_num_workers ());
   ip4_reass_per_thread_t *rt;
   vec_foreach (rt, rm->per_thread_data)
   {
@@ -1213,7 +1230,7 @@ ip4_reass_walk_expired (vlib_main_t * vm,
 
       uword thread_index = 0;
       int index;
-      const uword nthreads = os_get_nthreads ();
+      const uword nthreads = vlib_num_workers () + 1;
       for (thread_index = 0; thread_index < nthreads; ++thread_index)
        {
          ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];
@@ -1286,7 +1303,7 @@ ip4_reass_walk_expired (vlib_main_t * vm,
              n_left_to_next -= 1;
              IP4_REASS_DEBUG_BUFFER (bi, enqueue_drop_timeout_walk);
            }
-         f->flags |= (trace_frame * VLIB_FRAME_TRACE);
+         f->frame_flags |= (trace_frame * VLIB_FRAME_TRACE);
          vlib_put_frame_to_node (vm, rm->ip4_drop_idx, f);
        }
 
@@ -1380,7 +1397,7 @@ show_ip4_reass (vlib_main_t * vm, unformat_input_t * input,
   u64 sum_buffers_n = 0;
   ip4_reass_t *reass;
   uword thread_index;
-  const uword nthreads = os_get_nthreads ();
+  const uword nthreads = vlib_num_workers () + 1;
   for (thread_index = 0; thread_index < nthreads; ++thread_index)
     {
       ip4_reass_per_thread_t *rt = &rm->per_thread_data[thread_index];