ip: rate-limit the sending of ICMP error messages

[vpp.git] / src / vnet / ip / icmp6.c

diff --git a/src/vnet/ip/icmp6.c b/src/vnet/ip/icmp6.c
index 3c8300f..f92f31c 100644 (file)
--- a/src/vnet/ip/icmp6.c
+++ b/src/vnet/ip/icmp6.c
@@ -41,6 +41,10 @@
 #include <vnet/ip/ip.h>
 #include <vnet/pg/pg.h>
 #include <vnet/ip/ip_sas.h>
+#include <vnet/util/throttle.h>
+
+/** ICMP throttling */
+static throttle_t icmp_throttle;
 
 static u8 *
 format_ip6_icmp_type_and_code (u8 * s, va_list * args)
@@ -296,11 +300,14 @@ ip6_icmp_error (vlib_main_t * vm,
   u32 *from, *to_next;
   uword n_left_from, n_left_to_next;
   ip6_icmp_error_next_t next_index;
+  u32 thread_index = vm->thread_index;
 
   from = vlib_frame_vector_args (frame);
   n_left_from = frame->n_vectors;
   next_index = node->cached_next_index;
 
+  u64 seed = throttle_seed (&icmp_throttle, thread_index, vlib_time_now (vm));
+
   if (node->flags & VLIB_NODE_FLAG_TRACE)
     vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
                                   /* stride */ 1,
@@ -330,6 +337,21 @@ ip6_icmp_error (vlib_main_t * vm,
          int bogus_length;
 
          org_p0 = vlib_get_buffer (vm, org_pi0);
+         ip0 = vlib_buffer_get_current (org_p0);
+
+         /* Rate limit based on the src,dst addresses in the original packet
+          */
+         u64 r0 = (ip6_address_hash_to_u64 (&ip0->dst_address) ^
+                   ip6_address_hash_to_u64 (&ip0->src_address));
+
+         if (throttle_check (&icmp_throttle, thread_index, r0, seed))
+           {
+             vlib_error_count (vm, node->node_index, ICMP4_ERROR_DROP, 1);
+             from += 1;
+             n_left_from -= 1;
+             continue;
+           }
+
          p0 = vlib_buffer_copy_no_chain (vm, org_p0, &pi0);
          if (!p0 || pi0 == ~0) /* Out of buffers */
            continue;
@@ -341,9 +363,10 @@ ip6_icmp_error (vlib_main_t * vm,
          n_left_from -= 1;
          n_left_to_next -= 1;
 
-         ip0 = vlib_buffer_get_current (p0);
          sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
 
+         vlib_buffer_copy_trace_flag (vm, p0, pi0);
+
          /* Add IP header and ICMPv6 header including a 4 byte data field */
          vlib_buffer_advance (p0,
                               -(sizeof (ip6_header_t) +
@@ -624,6 +647,11 @@ icmp6_init (vlib_main_t * vm)
   cm->min_valid_length_by_type[ICMP6_redirect] =
     sizeof (icmp6_redirect_header_t);
 
+  vlib_thread_main_t *tm = &vlib_thread_main;
+  u32 n_vlib_mains = tm->n_vlib_mains;
+
+  throttle_init (&icmp_throttle, n_vlib_mains, 1e-3);
+
   return (NULL);
 }