- u32 pi0, adj_index0, r0, w0, sw_if_index0, drop0;
- uword m0;
- ip_adjacency_t *adj0;
- vlib_buffer_t *p0;
- ip4_header_t *ip0;
-
- pi0 = from[0];
-
- p0 = vlib_get_buffer (vm, pi0);
-
- adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
- adj0 = adj_get (adj_index0);
- ip0 = vlib_buffer_get_current (p0);
-
- sw_if_index0 = adj0->rewrite_header.sw_if_index;
- vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
-
- if (PREDICT_TRUE (is_glean))
- {
- /*
- * this is the Glean case, so we are ARPing for the
- * packet's destination
- */
- r0 = ip0->dst_address.data_u32;
- }
- else
- {
- r0 = adj0->sub_type.nbr.next_hop.ip4.data_u32;
- }
-
- r0 ^= seed;
- /* Select bit number */
- r0 &= ARP_THROTTLE_BITS - 1;
- w0 = r0 / BITS (uword);
- m0 = (uword) 1 << (r0 % BITS (uword));
-
- drop0 = (im->arp_throttle_bitmaps[thread_index][w0] & m0) != 0;
- im->arp_throttle_bitmaps[thread_index][w0] |= m0;
-
- from += 1;
- n_left_from -= 1;
- to_next_drop[0] = pi0;
- to_next_drop += 1;
- n_left_to_next_drop -= 1;
-
- p0->error =
- node->errors[drop0 ? IP4_ARP_ERROR_DROP :
- IP4_ARP_ERROR_REQUEST_SENT];
-
- /*
- * the adj has been updated to a rewrite but the node the DPO that got
- * us here hasn't - yet. no big deal. we'll drop while we wait.
- */
- if (IP_LOOKUP_NEXT_REWRITE == adj0->lookup_next_index)
- continue;
-
- if (drop0)
- continue;
-
- /*
- * Can happen if the control-plane is programming tables
- * with traffic flowing; at least that's today's lame excuse.
- */
- if ((is_glean && adj0->lookup_next_index != IP_LOOKUP_NEXT_GLEAN)
- || (!is_glean && adj0->lookup_next_index != IP_LOOKUP_NEXT_ARP))
- {
- p0->error = node->errors[IP4_ARP_ERROR_NON_ARP_ADJ];
- }
- else
- /* Send ARP request. */
- {
- u32 bi0 = 0;
- vlib_buffer_t *b0;
- ethernet_arp_header_t *h0;
- vnet_hw_interface_t *hw_if0;
-
- h0 =
- vlib_packet_template_get_packet (vm,
- &im->ip4_arp_request_packet_template,
- &bi0);
-
- /* Seems we're out of buffers */
- if (PREDICT_FALSE (!h0))
- continue;
-
- /* Add rewrite/encap string for ARP packet. */
- vnet_rewrite_one_header (adj0[0], h0,
- sizeof (ethernet_header_t));
-
- hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
-
- /* Src ethernet address in ARP header. */
- clib_memcpy (h0->ip4_over_ethernet[0].ethernet,
- hw_if0->hw_address,
- sizeof (h0->ip4_over_ethernet[0].ethernet));
-
- if (is_glean)
- {
- /* The interface's source address is stashed in the Glean Adj */
- h0->ip4_over_ethernet[0].ip4 =
- adj0->sub_type.glean.receive_addr.ip4;
-
- /* Copy in destination address we are requesting. This is the
- * glean case, so it's the packet's destination.*/
- h0->ip4_over_ethernet[1].ip4.data_u32 =
- ip0->dst_address.data_u32;
- }
- else
- {
- /* Src IP address in ARP header. */
- if (ip4_src_address_for_packet (lm, sw_if_index0,
- &h0->
- ip4_over_ethernet[0].ip4))
- {
- /* No source address available */
- p0->error =
- node->errors[IP4_ARP_ERROR_NO_SOURCE_ADDRESS];
- vlib_buffer_free (vm, &bi0, 1);
- continue;
- }
-
- /* Copy in destination address we are requesting from the
- incomplete adj */
- h0->ip4_over_ethernet[1].ip4.data_u32 =
- adj0->sub_type.nbr.next_hop.ip4.as_u32;
- }
-
- vlib_buffer_copy_trace_flag (vm, p0, bi0);
- b0 = vlib_get_buffer (vm, bi0);
- VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
- vnet_buffer (b0)->sw_if_index[VLIB_TX] = sw_if_index0;
-
- vlib_buffer_advance (b0, -adj0->rewrite_header.data_bytes);
-
- vlib_set_next_frame_buffer (vm, node,
- adj0->rewrite_header.next_index,
- bi0);
- }