diff options
Diffstat (limited to 'src/vnet/ethernet')
| -rw-r--r-- | src/vnet/ethernet/arp.c | 127 |
1 files changed, 97 insertions, 30 deletions
diff --git a/src/vnet/ethernet/arp.c b/src/vnet/ethernet/arp.c index 619628b37ca..d5dc9cceb39 100644 --- a/src/vnet/ethernet/arp.c +++ b/src/vnet/ethernet/arp.c @@ -22,6 +22,7 @@ #include <vnet/l2/l2_input.h> #include <vppinfra/mhash.h> #include <vnet/fib/ip4_fib.h> +#include <vnet/fib/fib_entry_src.h> #include <vnet/adj/adj_nbr.h> #include <vnet/adj/adj_mcast.h> #include <vnet/mpls/mpls.h> @@ -955,52 +956,118 @@ arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame) 32); dst_flags = fib_entry_get_flags (dst_fei); - src_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0), - &arp0->ip4_over_ethernet[0].ip4, - 32); - src_flags = fib_entry_get_flags (src_fei); - conn_sw_if_index0 = fib_entry_get_resolving_interface (dst_fei); - if (!(FIB_ENTRY_FLAG_CONNECTED & dst_flags)) - { - error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local; - goto drop1; - } - /* Honor unnumbered interface, if any */ is_unnum0 = sw_if_index0 != conn_sw_if_index0; - /* Source must also be local to subnet of matching interface address. */ - if (!((FIB_ENTRY_FLAG_ATTACHED & src_flags) || - (FIB_ENTRY_FLAG_CONNECTED & src_flags))) + { + /* + * we're looking for FIB entries that indicate the source + * is attached. There may be more specific non-attached + * routes tht match the source, but these do not influence + * whether we respond to an ARP request, i.e. they do not + * influence whether we are the correct way for the sender + * to reach us, they only affect how we reach the sender. + */ + fib_entry_t *src_fib_entry; + fib_entry_src_t *src; + fib_source_t source; + fib_prefix_t pfx; + int attached; + int mask; + + mask = 32; + attached = 0; + + do + { + src_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0), + &arp0-> + ip4_over_ethernet[0].ip4, + mask); + src_fib_entry = fib_entry_get (src_fei); + + /* + * It's possible that the source that provides the + * flags we need, or the flags we must not have, + * is not the best source, so check then all. + */ + /* *INDENT-OFF* */ + FOR_EACH_SRC_ADDED(src_fib_entry, src, source, + ({ + src_flags = fib_entry_get_flags_for_source (src_fei, source); + + /* Reject requests/replies with our local interface + address. */ + if (FIB_ENTRY_FLAG_LOCAL & src_flags) + { + error0 = ETHERNET_ARP_ERROR_l3_src_address_is_local; + goto drop2; + } + /* A Source must also be local to subnet of matching + * interface address. */ + if ((FIB_ENTRY_FLAG_ATTACHED & src_flags) || + (FIB_ENTRY_FLAG_CONNECTED & src_flags)) + { + attached = 1; + break; + } + /* + * else + * The packet was sent from an address that is not + * connected nor attached i.e. it is not from an + * address that is covered by a link's sub-net, + * nor is it a already learned host resp. + */ + })); + /* *INDENT-ON* */ + + /* + * shorter mask lookup for the next iteration. + */ + fib_entry_get_prefix (src_fei, &pfx); + mask = pfx.fp_len - 1; + + /* + * continue until we hit the default route or we find + * the attached we are looking for. The most likely + * outcome is we find the attached with the first source + * on the first lookup. + */ + } + while (!attached && + !fib_entry_is_sourced (src_fei, FIB_SOURCE_DEFAULT_ROUTE)); + + if (!attached) + { + /* + * the matching route is a not attached, i.e. it was + * added as a result of routing, rather than interface/ARP + * configuration. If the matching route is not a host route + * (i.e. a /32) + */ + error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local; + goto drop2; + } + } + + if (!(FIB_ENTRY_FLAG_CONNECTED & dst_flags)) { - /* - * The packet was sent from an address that is not connected nor attached - * i.e. it is not from an address that is covered by a link's sub-net, - * nor is it a already learned host resp. - */ - error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local; - goto drop2; + error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local; + goto drop1; } if (sw_if_index0 != fib_entry_get_resolving_interface (src_fei)) { /* * The interface the ARP was received on is not the interface - * on which the covering prefix is configured. Maybe this is a case - * for unnumbered. + * on which the covering prefix is configured. Maybe this is a + * case for unnumbered. */ is_unnum0 = 1; } - /* Reject requests/replies with our local interface address. */ - if (FIB_ENTRY_FLAG_LOCAL & src_flags) - { - error0 = ETHERNET_ARP_ERROR_l3_src_address_is_local; - goto drop2; - } - dst_is_local0 = (FIB_ENTRY_FLAG_LOCAL & dst_flags); fib_entry_get_prefix (dst_fei, &pfx0); if_addr0 = &pfx0.fp_addr.ip4; |