diff options
Diffstat (limited to 'src/vnet/ethernet/arp.c')
| -rw-r--r-- | src/vnet/ethernet/arp.c | 41 |
1 files changed, 33 insertions, 8 deletions
diff --git a/src/vnet/ethernet/arp.c b/src/vnet/ethernet/arp.c index 682bc2a2c92..37e3e88c2f2 100644 --- a/src/vnet/ethernet/arp.c +++ b/src/vnet/ethernet/arp.c @@ -864,6 +864,7 @@ typedef enum _ (l3_type_not_ip4, "L3 type not IP4") \ _ (l3_src_address_not_local, "IP4 source address not local to subnet") \ _ (l3_dst_address_not_local, "IP4 destination address not local to subnet") \ + _ (l3_dst_address_unset, "IP4 destination address is unset") \ _ (l3_src_address_is_local, "IP4 source address matches local interface") \ _ (l3_src_address_learned, "ARP request IP4 source address learned") \ _ (replies_received, "ARP replies received") \ @@ -980,6 +981,9 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) (arp0->l3_type != clib_net_to_host_u16 (ETHERNET_TYPE_IP4) ? ETHERNET_ARP_ERROR_l3_type_not_ip4 : error0); + error0 = + (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ? + ETHERNET_ARP_ERROR_l3_dst_address_unset : error0); sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX]; @@ -1110,7 +1114,23 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) } } - if (!(FIB_ENTRY_FLAG_CONNECTED & dst_flags)) + if (fib_entry_is_sourced (dst_fei, FIB_SOURCE_ADJ)) + { + /* + * We matched an adj-fib on ths source subnet (a /32 previously + * added as a result of ARP). If this request is a gratuitous + * ARP, then learn from it. + * The check for matching an adj-fib, is to prevent hosts + * from spamming us with gratuitous ARPS that might otherwise + * blow our ARP cache + */ + if (arp0->ip4_over_ethernet[0].ip4.as_u32 == + arp0->ip4_over_ethernet[1].ip4.as_u32) + error0 = arp_learn (vnm, am, sw_if_index0, + &arp0->ip4_over_ethernet[0]); + goto drop2; + } + else if (!(FIB_ENTRY_FLAG_CONNECTED & dst_flags)) { error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local; goto drop1; @@ -1152,11 +1172,17 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) /* Learn or update sender's mapping only for replies to addresses * that are local to the subnet */ if (arp0->opcode == - clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply) && - dst_is_local0) + clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply)) { - error0 = arp_learn (vnm, am, sw_if_index0, - &arp0->ip4_over_ethernet[0]); + if (dst_is_local0) + error0 = arp_learn (vnm, am, sw_if_index0, + &arp0->ip4_over_ethernet[0]); + else + /* a reply for a non-local destination could be a GARP. + * GARPs for hosts we know were handled above, so this one + * we drop */ + error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local; + goto drop1; } else if (arp0->opcode == @@ -1227,9 +1253,8 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) continue; drop1: - if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 || - (arp0->ip4_over_ethernet[0].ip4.as_u32 == - arp0->ip4_over_ethernet[1].ip4.as_u32)) + if (arp0->ip4_over_ethernet[0].ip4.as_u32 == + arp0->ip4_over_ethernet[1].ip4.as_u32) { error0 = ETHERNET_ARP_ERROR_gratuitous_arp; goto drop2; |