2 * ethernet/arp.c: IP v4 ARP node
4 * Copyright (c) 2010 Cisco and/or its affiliates.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at:
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
18 #include <vnet/ip/ip.h>
19 #include <vnet/ip/ip6.h>
20 #include <vnet/ethernet/ethernet.h>
21 #include <vnet/ethernet/arp_packet.h>
22 #include <vnet/l2/l2_input.h>
23 #include <vppinfra/mhash.h>
24 #include <vnet/fib/ip4_fib.h>
25 #include <vnet/adj/adj_nbr.h>
26 #include <vnet/adj/adj_mcast.h>
27 #include <vnet/mpls/mpls.h>
33 * This file contains code to manage the IPv4 ARP tables (IP Address
34 * to MAC Address lookup).
38 void vl_api_rpc_call_main_thread (void *fp, u8 * data, u32 data_length);
41 * @brief Per-interface ARP configuration and state
43 typedef struct ethernet_arp_interface_t_
46 * Hash table of ARP entries.
47 * Since this hash table is per-interface, the key is only the IPv4 address.
50 } ethernet_arp_interface_t;
57 } ethernet_proxy_arp_t;
65 /* Used for arp event notification only */
68 } pending_resolution_t;
72 /* Hash tables mapping name to opcode. */
73 uword *opcode_by_name;
75 /* lite beer "glean" adjacency handling */
76 uword *pending_resolutions_by_address;
77 pending_resolution_t *pending_resolutions;
79 /* Mac address change notification */
80 uword *mac_changes_by_address;
81 pending_resolution_t *mac_changes;
83 ethernet_arp_ip4_entry_t *ip4_entry_pool;
85 /* ARP attack mitigation */
87 u32 limit_arp_cache_size;
89 /** Per interface state */
90 ethernet_arp_interface_t *ethernet_arp_by_sw_if_index;
92 /* Proxy arp vector */
93 ethernet_proxy_arp_t *proxy_arps;
94 } ethernet_arp_main_t;
96 static ethernet_arp_main_t ethernet_arp_main;
101 ethernet_arp_ip4_over_ethernet_address_t a;
105 #define ETHERNET_ARP_ARGS_REMOVE (1<<0)
106 #define ETHERNET_ARP_ARGS_FLUSH (1<<1)
107 #define ETHERNET_ARP_ARGS_POPULATE (1<<2)
108 } vnet_arp_set_ip4_over_ethernet_rpc_args_t;
110 static const u8 vrrp_prefix[] = { 0x00, 0x00, 0x5E, 0x00, 0x01 };
113 set_ip4_over_ethernet_rpc_callback (vnet_arp_set_ip4_over_ethernet_rpc_args_t
117 format_ethernet_arp_hardware_type (u8 * s, va_list * va)
119 ethernet_arp_hardware_type_t h = va_arg (*va, ethernet_arp_hardware_type_t);
123 #define _(n,f) case n: t = #f; break;
124 foreach_ethernet_arp_hardware_type;
128 return format (s, "unknown 0x%x", h);
131 return format (s, "%s", t);
135 format_ethernet_arp_opcode (u8 * s, va_list * va)
137 ethernet_arp_opcode_t o = va_arg (*va, ethernet_arp_opcode_t);
141 #define _(f) case ETHERNET_ARP_OPCODE_##f: t = #f; break;
142 foreach_ethernet_arp_opcode;
146 return format (s, "unknown 0x%x", o);
149 return format (s, "%s", t);
153 unformat_ethernet_arp_opcode_host_byte_order (unformat_input_t * input,
156 int *result = va_arg (*args, int *);
157 ethernet_arp_main_t *am = ðernet_arp_main;
160 /* Numeric opcode. */
161 if (unformat (input, "0x%x", &x) || unformat (input, "%d", &x))
170 if (unformat_user (input, unformat_vlib_number_by_name,
171 am->opcode_by_name, &i))
181 unformat_ethernet_arp_opcode_net_byte_order (unformat_input_t * input,
184 int *result = va_arg (*args, int *);
186 (input, unformat_ethernet_arp_opcode_host_byte_order, result))
189 *result = clib_host_to_net_u16 ((u16) * result);
194 format_ethernet_arp_header (u8 * s, va_list * va)
196 ethernet_arp_header_t *a = va_arg (*va, ethernet_arp_header_t *);
197 u32 max_header_bytes = va_arg (*va, u32);
199 u16 l2_type, l3_type;
201 if (max_header_bytes != 0 && sizeof (a[0]) > max_header_bytes)
202 return format (s, "ARP header truncated");
204 l2_type = clib_net_to_host_u16 (a->l2_type);
205 l3_type = clib_net_to_host_u16 (a->l3_type);
207 indent = format_get_indent (s);
209 s = format (s, "%U, type %U/%U, address size %d/%d",
210 format_ethernet_arp_opcode, clib_net_to_host_u16 (a->opcode),
211 format_ethernet_arp_hardware_type, l2_type,
212 format_ethernet_type, l3_type,
213 a->n_l2_address_bytes, a->n_l3_address_bytes);
215 if (l2_type == ETHERNET_ARP_HARDWARE_TYPE_ethernet
216 && l3_type == ETHERNET_TYPE_IP4)
218 s = format (s, "\n%U%U/%U -> %U/%U",
219 format_white_space, indent,
220 format_ethernet_address, a->ip4_over_ethernet[0].ethernet,
221 format_ip4_address, &a->ip4_over_ethernet[0].ip4,
222 format_ethernet_address, a->ip4_over_ethernet[1].ethernet,
223 format_ip4_address, &a->ip4_over_ethernet[1].ip4);
227 uword n2 = a->n_l2_address_bytes;
228 uword n3 = a->n_l3_address_bytes;
229 s = format (s, "\n%U%U/%U -> %U/%U",
230 format_white_space, indent,
231 format_hex_bytes, a->data + 0 * n2 + 0 * n3, n2,
232 format_hex_bytes, a->data + 1 * n2 + 0 * n3, n3,
233 format_hex_bytes, a->data + 1 * n2 + 1 * n3, n2,
234 format_hex_bytes, a->data + 2 * n2 + 1 * n3, n3);
241 format_ethernet_arp_ip4_entry (u8 * s, va_list * va)
243 vnet_main_t *vnm = va_arg (*va, vnet_main_t *);
244 ethernet_arp_ip4_entry_t *e = va_arg (*va, ethernet_arp_ip4_entry_t *);
245 vnet_sw_interface_t *si;
249 return format (s, "%=12s%=16s%=6s%=20s%=24s", "Time", "IP4",
250 "Flags", "Ethernet", "Interface");
252 si = vnet_get_sw_interface (vnm, e->sw_if_index);
254 if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC)
255 flags = format (flags, "S");
257 if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC)
258 flags = format (flags, "D");
260 if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_NO_FIB_ENTRY)
261 flags = format (flags, "N");
263 s = format (s, "%=12U%=16U%=6s%=20U%=24U",
264 format_vlib_cpu_time, vnm->vlib_main, e->cpu_time_last_updated,
265 format_ip4_address, &e->ip4_address,
266 flags ? (char *) flags : "",
267 format_ethernet_address, e->ethernet_address,
268 format_vnet_sw_interface_name, vnm, si);
277 } ethernet_arp_input_trace_t;
280 format_ethernet_arp_input_trace (u8 * s, va_list * va)
282 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
283 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
284 ethernet_arp_input_trace_t *t = va_arg (*va, ethernet_arp_input_trace_t *);
287 format_ethernet_arp_header,
288 t->packet_data, sizeof (t->packet_data));
294 format_arp_term_input_trace (u8 * s, va_list * va)
296 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
297 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
298 ethernet_arp_input_trace_t *t = va_arg (*va, ethernet_arp_input_trace_t *);
300 /* arp-term trace data saved is either arp or ip6/icmp6 packet:
301 - for arp, the 1st 16-bit field is hw type of value of 0x0001.
302 - for ip6, the first nibble has value of 6. */
303 s = format (s, "%U", t->packet_data[0] == 0 ?
304 format_ethernet_arp_header : format_ip6_header,
305 t->packet_data, sizeof (t->packet_data));
311 arp_nbr_probe (ip_adjacency_t * adj)
313 vnet_main_t *vnm = vnet_get_main ();
314 ip4_main_t *im = &ip4_main;
315 ip_interface_address_t *ia;
316 ethernet_arp_header_t *h;
317 vnet_hw_interface_t *hi;
318 vnet_sw_interface_t *si;
324 vm = vlib_get_main ();
326 si = vnet_get_sw_interface (vnm, adj->rewrite_header.sw_if_index);
328 if (!(si->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP))
334 ip4_interface_address_matching_destination (im,
335 &adj->sub_type.nbr.next_hop.
345 vlib_packet_template_get_packet (vm, &im->ip4_arp_request_packet_template,
348 hi = vnet_get_sup_hw_interface (vnm, adj->rewrite_header.sw_if_index);
350 clib_memcpy (h->ip4_over_ethernet[0].ethernet,
351 hi->hw_address, sizeof (h->ip4_over_ethernet[0].ethernet));
353 h->ip4_over_ethernet[0].ip4 = src[0];
354 h->ip4_over_ethernet[1].ip4 = adj->sub_type.nbr.next_hop.ip4;
356 b = vlib_get_buffer (vm, bi);
357 vnet_buffer (b)->sw_if_index[VLIB_RX] =
358 vnet_buffer (b)->sw_if_index[VLIB_TX] = adj->rewrite_header.sw_if_index;
360 /* Add encapsulation string for software interface (e.g. ethernet header). */
361 vnet_rewrite_one_header (adj[0], h, sizeof (ethernet_header_t));
362 vlib_buffer_advance (b, -adj->rewrite_header.data_bytes);
365 vlib_frame_t *f = vlib_get_frame_to_node (vm, hi->output_node_index);
366 u32 *to_next = vlib_frame_vector_args (f);
369 vlib_put_frame_to_node (vm, hi->output_node_index, f);
374 arp_mk_complete (adj_index_t ai, ethernet_arp_ip4_entry_t * e)
376 adj_nbr_update_rewrite
377 (ai, ADJ_NBR_REWRITE_FLAG_COMPLETE,
378 ethernet_build_rewrite (vnet_get_main (),
380 adj_get_link_type (ai), e->ethernet_address));
384 arp_mk_incomplete (adj_index_t ai)
386 ip_adjacency_t *adj = adj_get (ai);
388 adj_nbr_update_rewrite
390 ADJ_NBR_REWRITE_FLAG_INCOMPLETE,
391 ethernet_build_rewrite (vnet_get_main (),
392 adj->rewrite_header.sw_if_index,
394 VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST));
397 static ethernet_arp_ip4_entry_t *
398 arp_entry_find (ethernet_arp_interface_t * eai, const ip4_address_t * addr)
400 ethernet_arp_main_t *am = ðernet_arp_main;
401 ethernet_arp_ip4_entry_t *e = NULL;
404 if (NULL != eai->arp_entries)
406 p = hash_get (eai->arp_entries, addr->as_u32);
410 e = pool_elt_at_index (am->ip4_entry_pool, p[0]);
417 arp_mk_complete_walk (adj_index_t ai, void *ctx)
419 ethernet_arp_ip4_entry_t *e = ctx;
421 arp_mk_complete (ai, e);
423 return (ADJ_WALK_RC_CONTINUE);
427 arp_mk_incomplete_walk (adj_index_t ai, void *ctx)
429 arp_mk_incomplete (ai);
431 return (ADJ_WALK_RC_CONTINUE);
435 arp_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
437 ethernet_arp_main_t *am = ðernet_arp_main;
438 ethernet_arp_interface_t *arp_int;
439 ethernet_arp_ip4_entry_t *e;
444 vec_validate (am->ethernet_arp_by_sw_if_index, sw_if_index);
445 arp_int = &am->ethernet_arp_by_sw_if_index[sw_if_index];
446 e = arp_entry_find (arp_int, &adj->sub_type.nbr.next_hop.ip4);
448 switch (adj->lookup_next_index)
450 case IP_LOOKUP_NEXT_ARP:
451 case IP_LOOKUP_NEXT_GLEAN:
454 adj_nbr_walk_nh4 (sw_if_index,
455 &e->ip4_address, arp_mk_complete_walk, e);
460 * no matching ARP entry.
461 * construct the rewrite required to for an ARP packet, and stick
462 * that in the adj's pipe to smoke.
464 adj_nbr_update_rewrite
466 ADJ_NBR_REWRITE_FLAG_INCOMPLETE,
467 ethernet_build_rewrite
471 VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST));
474 * since the FIB has added this adj for a route, it makes sense it
475 * may want to forward traffic sometime soon. Let's send a
476 * speculative ARP. just one. If we were to do periodically that
477 * wouldn't be bad either, but that's more code than i'm prepared to
478 * write at this time for relatively little reward.
483 case IP_LOOKUP_NEXT_MCAST:
486 * Construct a partial rewrite from the known ethernet mcast dest MAC
491 rewrite = ethernet_build_rewrite (vnm,
494 ethernet_ip4_mcast_dst_addr ());
495 offset = vec_len (rewrite) - 2;
498 * Complete the remaining fields of the adj's rewrite to direct the
499 * complete of the rewrite at switch time by copying in the IP
500 * dst address's bytes.
501 * Ofset is 2 bytes into the MAC desintation address. And we copy 23 bits
504 adj_mcast_update_rewrite (ai, rewrite, offset, 0x007fffff);
508 case IP_LOOKUP_NEXT_DROP:
509 case IP_LOOKUP_NEXT_PUNT:
510 case IP_LOOKUP_NEXT_LOCAL:
511 case IP_LOOKUP_NEXT_REWRITE:
512 case IP_LOOKUP_NEXT_MCAST_MIDCHAIN:
513 case IP_LOOKUP_NEXT_MIDCHAIN:
514 case IP_LOOKUP_NEXT_ICMP_ERROR:
515 case IP_LOOKUP_N_NEXT:
522 vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
523 vnet_arp_set_ip4_over_ethernet_rpc_args_t
526 ethernet_arp_ip4_entry_t *e = 0;
527 ethernet_arp_main_t *am = ðernet_arp_main;
528 ethernet_arp_ip4_over_ethernet_address_t *a = &args->a;
529 vlib_main_t *vm = vlib_get_main ();
530 int make_new_arp_cache_entry = 1;
532 pending_resolution_t *pr, *mc;
533 ethernet_arp_interface_t *arp_int;
534 int is_static = args->is_static;
535 u32 sw_if_index = args->sw_if_index;
536 int is_no_fib_entry = args->is_no_fib_entry;
538 vec_validate (am->ethernet_arp_by_sw_if_index, sw_if_index);
540 arp_int = &am->ethernet_arp_by_sw_if_index[sw_if_index];
542 if (NULL != arp_int->arp_entries)
544 p = hash_get (arp_int->arp_entries, a->ip4.as_u32);
547 e = pool_elt_at_index (am->ip4_entry_pool, p[0]);
549 /* Refuse to over-write static arp. */
550 if (!is_static && (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC))
552 make_new_arp_cache_entry = 0;
556 if (make_new_arp_cache_entry)
558 pool_get (am->ip4_entry_pool, e);
560 if (NULL == arp_int->arp_entries)
562 arp_int->arp_entries = hash_create (0, sizeof (u32));
565 hash_set (arp_int->arp_entries, a->ip4.as_u32, e - am->ip4_entry_pool);
567 e->sw_if_index = sw_if_index;
568 e->ip4_address = a->ip4;
569 e->fib_entry_index = FIB_NODE_INDEX_INVALID;
570 clib_memcpy (e->ethernet_address,
571 a->ethernet, sizeof (e->ethernet_address));
573 if (!is_no_fib_entry)
577 .fp_proto = FIB_PROTOCOL_IP4,
578 .fp_addr.ip4 = a->ip4,
583 ip4_fib_table_get_index_for_sw_if_index (e->sw_if_index);
585 fib_table_entry_path_add (fib_index, &pfx, FIB_SOURCE_ADJ,
586 FIB_ENTRY_FLAG_ATTACHED,
587 FIB_PROTOCOL_IP4, &pfx.fp_addr,
588 e->sw_if_index, ~0, 1, NULL,
589 FIB_ROUTE_PATH_FLAG_NONE);
593 e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_NO_FIB_ENTRY;
599 * prevent a DoS attack from the data-plane that
600 * spams us with no-op updates to the MAC address
602 if (0 == memcmp (e->ethernet_address,
603 a->ethernet, sizeof (e->ethernet_address)))
606 /* Update time stamp and ethernet address. */
607 clib_memcpy (e->ethernet_address, a->ethernet,
608 sizeof (e->ethernet_address));
611 e->cpu_time_last_updated = clib_cpu_time_now ();
613 e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC;
615 e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC;
617 adj_nbr_walk_nh4 (sw_if_index, &e->ip4_address, arp_mk_complete_walk, e);
619 /* Customer(s) waiting for this address to be resolved? */
620 p = hash_get (am->pending_resolutions_by_address, a->ip4.as_u32);
626 while (next_index != (u32) ~ 0)
628 pr = pool_elt_at_index (am->pending_resolutions, next_index);
629 vlib_process_signal_event (vm, pr->node_index,
630 pr->type_opaque, pr->data);
631 next_index = pr->next_index;
632 pool_put (am->pending_resolutions, pr);
635 hash_unset (am->pending_resolutions_by_address, a->ip4.as_u32);
638 /* Customer(s) requesting ARP event for this address? */
639 p = hash_get (am->mac_changes_by_address, a->ip4.as_u32);
645 while (next_index != (u32) ~ 0)
647 int (*fp) (u32, u8 *, u32, u32);
649 mc = pool_elt_at_index (am->mac_changes, next_index);
650 fp = mc->data_callback;
652 /* Call the user's data callback, return 1 to suppress dup events */
654 rv = (*fp) (mc->data, a->ethernet, sw_if_index, 0);
657 * Signal the resolver process, as long as the user
658 * says they want to be notified
661 vlib_process_signal_event (vm, mc->node_index,
662 mc->type_opaque, mc->data);
663 next_index = mc->next_index;
671 vnet_register_ip4_arp_resolution_event (vnet_main_t * vnm,
674 uword type_opaque, uword data)
676 ethernet_arp_main_t *am = ðernet_arp_main;
677 ip4_address_t *address = address_arg;
679 pending_resolution_t *pr;
681 pool_get (am->pending_resolutions, pr);
684 pr->node_index = node_index;
685 pr->type_opaque = type_opaque;
687 pr->data_callback = 0;
689 p = hash_get (am->pending_resolutions_by_address, address->as_u32);
692 /* Insert new resolution at the head of the list */
693 pr->next_index = p[0];
694 hash_unset (am->pending_resolutions_by_address, address->as_u32);
697 hash_set (am->pending_resolutions_by_address, address->as_u32,
698 pr - am->pending_resolutions);
702 vnet_add_del_ip4_arp_change_event (vnet_main_t * vnm,
707 uword type_opaque, uword data, int is_add)
709 ethernet_arp_main_t *am = ðernet_arp_main;
710 ip4_address_t *address = address_arg;
712 /* Try to find an existing entry */
713 u32 *first = (u32 *) hash_get (am->mac_changes_by_address, address->as_u32);
715 pending_resolution_t *mc;
716 while (p && *p != ~0)
718 mc = pool_elt_at_index (am->mac_changes, *p);
719 if (mc->node_index == node_index && mc->type_opaque == type_opaque
725 int found = p && *p != ~0;
729 return VNET_API_ERROR_ENTRY_ALREADY_EXISTS;
731 pool_get (am->mac_changes, mc);
732 *mc = (pending_resolution_t)
734 .next_index = ~0,.node_index = node_index,.type_opaque =
735 type_opaque,.data = data,.data_callback = data_callback,.pid =
738 /* Insert new resolution at the end of the list */
739 u32 new_idx = mc - am->mac_changes;
743 hash_set (am->mac_changes_by_address, address->as_u32, new_idx);
748 return VNET_API_ERROR_NO_SUCH_ENTRY;
750 /* Clients may need to clean up pool entries, too */
751 void (*fp) (u32, u8 *) = data_callback;
753 (*fp) (mc->data, 0 /* no new mac addrs */ );
755 /* Remove the entry from the list and delete the entry */
757 pool_put (am->mac_changes, mc);
759 /* Remove from hash if we deleted the last entry */
760 if (*p == ~0 && p == first)
761 hash_unset (am->mac_changes_by_address, address->as_u32);
766 /* Either we drop the packet or we send a reply to the sender. */
770 ARP_INPUT_NEXT_REPLY_TX,
774 #define foreach_ethernet_arp_error \
775 _ (replies_sent, "ARP replies sent") \
776 _ (l2_type_not_ethernet, "L2 type not ethernet") \
777 _ (l3_type_not_ip4, "L3 type not IP4") \
778 _ (l3_src_address_not_local, "IP4 source address not local to subnet") \
779 _ (l3_dst_address_not_local, "IP4 destination address not local to subnet") \
780 _ (l3_src_address_is_local, "IP4 source address matches local interface") \
781 _ (l3_src_address_learned, "ARP request IP4 source address learned") \
782 _ (replies_received, "ARP replies received") \
783 _ (opcode_not_request, "ARP opcode not request") \
784 _ (proxy_arp_replies_sent, "Proxy ARP replies sent") \
785 _ (l2_address_mismatch, "ARP hw addr does not match L2 frame src addr") \
786 _ (missing_interface_address, "ARP missing interface address") \
787 _ (gratuitous_arp, "ARP probe or announcement dropped") \
788 _ (interface_no_table, "Interface is not mapped to an IP table") \
789 _ (interface_not_ip_enabled, "Interface is not IP enabled") \
793 #define _(sym,string) ETHERNET_ARP_ERROR_##sym,
794 foreach_ethernet_arp_error
796 ETHERNET_ARP_N_ERROR,
797 } ethernet_arp_input_error_t;
801 unset_random_arp_entry (void)
803 ethernet_arp_main_t *am = ðernet_arp_main;
804 ethernet_arp_ip4_entry_t *e;
805 vnet_main_t *vnm = vnet_get_main ();
806 ethernet_arp_ip4_over_ethernet_address_t delme;
809 index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
810 am->arp_delete_rotor = index;
812 /* Try again from elt 0, could happen if an intfc goes down */
815 index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
816 am->arp_delete_rotor = index;
819 /* Nothing left in the pool */
823 e = pool_elt_at_index (am->ip4_entry_pool, index);
825 clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
826 delme.ip4.as_u32 = e->ip4_address.as_u32;
828 vnet_arp_unset_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
832 arp_unnumbered (vlib_buffer_t * p0,
833 u32 input_sw_if_index, u32 conn_sw_if_index)
835 vnet_main_t *vnm = vnet_get_main ();
836 vnet_interface_main_t *vim = &vnm->interface_main;
837 vnet_sw_interface_t *si;
839 /* verify that the input interface is unnumbered to the connected.
840 * the connected interface is the interface on which the subnet is
842 si = &vim->sw_interfaces[input_sw_if_index];
844 if (!(si->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED &&
845 (si->unnumbered_sw_if_index == conn_sw_if_index)))
847 /* the input interface is not unnumbered to the interface on which
848 * the sub-net is configured that covers the ARP request.
849 * So this is not the case for unnumbered.. */
857 arp_learn (vnet_main_t * vnm,
858 ethernet_arp_main_t * am, u32 sw_if_index, void *addr)
860 if (am->limit_arp_cache_size &&
861 pool_elts (am->ip4_entry_pool) >= am->limit_arp_cache_size)
862 unset_random_arp_entry ();
864 vnet_arp_set_ip4_over_ethernet (vnm, sw_if_index, addr, 0, 0);
865 return (ETHERNET_ARP_ERROR_l3_src_address_learned);
869 arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
871 ethernet_arp_main_t *am = ðernet_arp_main;
872 vnet_main_t *vnm = vnet_get_main ();
873 ip4_main_t *im4 = &ip4_main;
874 u32 n_left_from, next_index, *from, *to_next;
875 u32 n_replies_sent = 0, n_proxy_arp_replies_sent = 0;
877 from = vlib_frame_vector_args (frame);
878 n_left_from = frame->n_vectors;
879 next_index = node->cached_next_index;
881 if (node->flags & VLIB_NODE_FLAG_TRACE)
882 vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
884 sizeof (ethernet_arp_input_trace_t));
886 while (n_left_from > 0)
890 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
892 while (n_left_from > 0 && n_left_to_next > 0)
895 vnet_hw_interface_t *hw_if0;
896 ethernet_arp_header_t *arp0;
897 ethernet_header_t *eth_rx, *eth_tx;
898 ip4_address_t *if_addr0, proxy_src;
899 u32 pi0, error0, next0, sw_if_index0, conn_sw_if_index0, fib_index0;
900 u8 is_request0, dst_is_local0, is_unnum0, is_vrrp_reply0;
901 ethernet_proxy_arp_t *pa;
902 fib_node_index_t dst_fei, src_fei;
904 fib_entry_flag_t src_flags, dst_flags;
905 ip_adjacency_t *adj0 = NULL;
916 p0 = vlib_get_buffer (vm, pi0);
917 arp0 = vlib_buffer_get_current (p0);
918 /* Fill in ethernet header. */
919 eth_rx = ethernet_buffer_get_header (p0);
921 is_request0 = arp0->opcode
922 == clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request);
924 error0 = ETHERNET_ARP_ERROR_replies_sent;
928 clib_net_to_host_u16 (ETHERNET_ARP_HARDWARE_TYPE_ethernet) ?
929 ETHERNET_ARP_ERROR_l2_type_not_ethernet : error0);
932 clib_net_to_host_u16 (ETHERNET_TYPE_IP4) ?
933 ETHERNET_ARP_ERROR_l3_type_not_ip4 : error0);
935 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
937 /* not playing the ARP game if the interface is not IPv4 enabled */
939 (im4->ip_enabled_by_sw_if_index[sw_if_index0] == 0 ?
940 ETHERNET_ARP_ERROR_interface_not_ip_enabled : error0);
945 /* Check that IP address is local and matches incoming interface. */
946 fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
947 if (~0 == fib_index0)
949 error0 = ETHERNET_ARP_ERROR_interface_no_table;
953 dst_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0),
954 &arp0->ip4_over_ethernet[1].ip4,
956 dst_flags = fib_entry_get_flags (dst_fei);
958 src_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0),
959 &arp0->ip4_over_ethernet[0].ip4,
961 src_flags = fib_entry_get_flags (src_fei);
963 conn_sw_if_index0 = fib_entry_get_resolving_interface (dst_fei);
965 if (!(FIB_ENTRY_FLAG_CONNECTED & dst_flags))
967 error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local;
971 /* Honor unnumbered interface, if any */
972 is_unnum0 = sw_if_index0 != conn_sw_if_index0;
974 /* Source must also be local to subnet of matching interface address. */
975 if (!((FIB_ENTRY_FLAG_ATTACHED & src_flags) ||
976 (FIB_ENTRY_FLAG_CONNECTED & src_flags)))
979 * The packet was sent from an address that is not connected nor attached
980 * i.e. it is not from an address that is covered by a link's sub-net,
981 * nor is it a already learned host resp.
983 error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local;
987 if (sw_if_index0 != fib_entry_get_resolving_interface (src_fei))
990 * The interface the ARP was received on is not the interface
991 * on which the covering prefix is configured. Maybe this is a case
997 /* Reject requests/replies with our local interface address. */
998 if (FIB_ENTRY_FLAG_LOCAL & src_flags)
1000 error0 = ETHERNET_ARP_ERROR_l3_src_address_is_local;
1004 dst_is_local0 = (FIB_ENTRY_FLAG_LOCAL & dst_flags);
1005 fib_entry_get_prefix (dst_fei, &pfx0);
1006 if_addr0 = &pfx0.fp_addr.ip4;
1010 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply))
1013 (arp0->ip4_over_ethernet[0].ethernet, vrrp_prefix,
1014 sizeof (vrrp_prefix))));
1016 /* Trash ARP packets whose ARP-level source addresses do not
1017 match their L2-frame-level source addresses, unless it's
1018 a reply from a VRRP virtual router */
1020 (eth_rx->src_address, arp0->ip4_over_ethernet[0].ethernet,
1021 sizeof (eth_rx->src_address)) && !is_vrrp_reply0)
1023 error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
1027 /* Learn or update sender's mapping only for replies to addresses
1028 * that are local to the subnet */
1030 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply) &&
1033 error0 = arp_learn (vnm, am, sw_if_index0,
1034 &arp0->ip4_over_ethernet[0]);
1040 ai = fib_entry_get_adj (src_fei);
1041 if (ADJ_INDEX_INVALID != ai)
1043 adj0 = adj_get (ai);
1047 error0 = ETHERNET_ARP_ERROR_missing_interface_address;
1050 /* Figure out how much to rewind current data from adjacency. */
1051 vlib_buffer_advance (p0, -adj0->rewrite_header.data_bytes);
1052 eth_tx = vlib_buffer_get_current (p0);
1054 vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
1055 hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
1057 /* Send reply back through input interface */
1058 vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
1059 next0 = ARP_INPUT_NEXT_REPLY_TX;
1061 arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
1063 arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
1065 clib_memcpy (arp0->ip4_over_ethernet[0].ethernet,
1066 hw_if0->hw_address, 6);
1067 clib_mem_unaligned (&arp0->ip4_over_ethernet[0].ip4.data_u32, u32) =
1070 /* Hardware must be ethernet-like. */
1071 ASSERT (vec_len (hw_if0->hw_address) == 6);
1073 /* the rx nd tx ethernet headers wil overlap in the case
1074 * when we received a tagged VLAN=0 packet, but we are sending
1076 memmove (eth_tx->dst_address, eth_rx->src_address, 6);
1077 clib_memcpy (eth_tx->src_address, hw_if0->hw_address, 6);
1083 if (!arp_unnumbered (p0, sw_if_index0, conn_sw_if_index0))
1088 /* We are going to reply to this request, so learn the sender */
1089 error0 = arp_learn (vnm, am, sw_if_index0,
1090 &arp0->ip4_over_ethernet[1]);
1092 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1093 n_left_to_next, pi0, next0);
1095 n_replies_sent += 1;
1099 if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ||
1100 (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
1101 arp0->ip4_over_ethernet[1].ip4.as_u32))
1103 error0 = ETHERNET_ARP_ERROR_gratuitous_arp;
1106 /* See if proxy arp is configured for the address */
1109 vnet_sw_interface_t *si;
1110 u32 this_addr = clib_net_to_host_u32
1111 (arp0->ip4_over_ethernet[1].ip4.as_u32);
1114 si = vnet_get_sw_interface (vnm, sw_if_index0);
1116 if (!(si->flags & VNET_SW_INTERFACE_FLAG_PROXY_ARP))
1119 fib_index0 = vec_elt (im4->fib_index_by_sw_if_index,
1122 vec_foreach (pa, am->proxy_arps)
1124 u32 lo_addr = clib_net_to_host_u32 (pa->lo_addr);
1125 u32 hi_addr = clib_net_to_host_u32 (pa->hi_addr);
1127 /* an ARP request hit in the proxy-arp table? */
1128 if ((this_addr >= lo_addr && this_addr <= hi_addr) &&
1129 (fib_index0 == pa->fib_index))
1132 arp0->ip4_over_ethernet[1].ip4.data_u32;
1135 * change the interface address to the proxied
1137 if_addr0 = &proxy_src;
1139 n_proxy_arp_replies_sent++;
1147 next0 = ARP_INPUT_NEXT_DROP;
1148 p0->error = node->errors[error0];
1150 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1151 n_left_to_next, pi0, next0);
1154 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1157 vlib_error_count (vm, node->node_index,
1158 ETHERNET_ARP_ERROR_replies_sent,
1159 n_replies_sent - n_proxy_arp_replies_sent);
1161 vlib_error_count (vm, node->node_index,
1162 ETHERNET_ARP_ERROR_proxy_arp_replies_sent,
1163 n_proxy_arp_replies_sent);
1164 return frame->n_vectors;
1167 static char *ethernet_arp_error_strings[] = {
1168 #define _(sym,string) string,
1169 foreach_ethernet_arp_error
1174 VLIB_REGISTER_NODE (arp_input_node, static) =
1176 .function = arp_input,
1177 .name = "arp-input",
1178 .vector_size = sizeof (u32),
1179 .n_errors = ETHERNET_ARP_N_ERROR,
1180 .error_strings = ethernet_arp_error_strings,
1181 .n_next_nodes = ARP_INPUT_N_NEXT,
1183 [ARP_INPUT_NEXT_DROP] = "error-drop",
1184 [ARP_INPUT_NEXT_REPLY_TX] = "interface-output",
1186 .format_buffer = format_ethernet_arp_header,
1187 .format_trace = format_ethernet_arp_input_trace,
1192 ip4_arp_entry_sort (void *a1, void *a2)
1194 ethernet_arp_ip4_entry_t *e1 = a1;
1195 ethernet_arp_ip4_entry_t *e2 = a2;
1198 vnet_main_t *vnm = vnet_get_main ();
1200 cmp = vnet_sw_interface_compare (vnm, e1->sw_if_index, e2->sw_if_index);
1202 cmp = ip4_address_compare (&e1->ip4_address, &e2->ip4_address);
1206 ethernet_arp_ip4_entry_t *
1207 ip4_neighbor_entries (u32 sw_if_index)
1209 ethernet_arp_main_t *am = ðernet_arp_main;
1210 ethernet_arp_ip4_entry_t *n, *ns = 0;
1213 pool_foreach (n, am->ip4_entry_pool, ({
1214 if (sw_if_index != ~0 && n->sw_if_index != sw_if_index)
1216 vec_add1 (ns, n[0]);
1221 vec_sort_with_function (ns, ip4_arp_entry_sort);
1225 static clib_error_t *
1226 show_ip4_arp (vlib_main_t * vm,
1227 unformat_input_t * input, vlib_cli_command_t * cmd)
1229 vnet_main_t *vnm = vnet_get_main ();
1230 ethernet_arp_main_t *am = ðernet_arp_main;
1231 ethernet_arp_ip4_entry_t *e, *es;
1232 ethernet_proxy_arp_t *pa;
1233 clib_error_t *error = 0;
1236 /* Filter entries by interface if given. */
1238 (void) unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index);
1240 es = ip4_neighbor_entries (sw_if_index);
1243 vlib_cli_output (vm, "%U", format_ethernet_arp_ip4_entry, vnm, 0);
1246 vlib_cli_output (vm, "%U", format_ethernet_arp_ip4_entry, vnm, e);
1251 if (vec_len (am->proxy_arps))
1253 vlib_cli_output (vm, "Proxy arps enabled for:");
1254 vec_foreach (pa, am->proxy_arps)
1256 vlib_cli_output (vm, "Fib_index %d %U - %U ",
1258 format_ip4_address, &pa->lo_addr,
1259 format_ip4_address, &pa->hi_addr);
1267 * Display all the IPv4 ARP entries.
1270 * Example of how to display the IPv4 ARP table:
1271 * @cliexstart{show ip arp}
1272 * Time FIB IP4 Flags Ethernet Interface
1273 * 346.3028 0 6.1.1.3 de:ad:be:ef:ba:be GigabitEthernet2/0/0
1274 * 3077.4271 0 6.1.1.4 S de:ad:be:ef:ff:ff GigabitEthernet2/0/0
1275 * 2998.6409 1 6.2.2.3 de:ad:be:ef:00:01 GigabitEthernet2/0/0
1276 * Proxy arps enabled for:
1277 * Fib_index 0 6.0.0.1 - 6.0.0.11
1281 VLIB_CLI_COMMAND (show_ip4_arp_command, static) = {
1282 .path = "show ip arp",
1283 .function = show_ip4_arp,
1284 .short_help = "show ip arp",
1290 pg_edit_t l2_type, l3_type;
1291 pg_edit_t n_l2_address_bytes, n_l3_address_bytes;
1297 } ip4_over_ethernet[2];
1298 } pg_ethernet_arp_header_t;
1301 pg_ethernet_arp_header_init (pg_ethernet_arp_header_t * p)
1303 /* Initialize fields that are not bit fields in the IP header. */
1304 #define _(f) pg_edit_init (&p->f, ethernet_arp_header_t, f);
1307 _(n_l2_address_bytes);
1308 _(n_l3_address_bytes);
1310 _(ip4_over_ethernet[0].ethernet);
1311 _(ip4_over_ethernet[0].ip4);
1312 _(ip4_over_ethernet[1].ethernet);
1313 _(ip4_over_ethernet[1].ip4);
1318 unformat_pg_arp_header (unformat_input_t * input, va_list * args)
1320 pg_stream_t *s = va_arg (*args, pg_stream_t *);
1321 pg_ethernet_arp_header_t *p;
1324 p = pg_create_edit_group (s, sizeof (p[0]), sizeof (ethernet_arp_header_t),
1326 pg_ethernet_arp_header_init (p);
1329 pg_edit_set_fixed (&p->l2_type, ETHERNET_ARP_HARDWARE_TYPE_ethernet);
1330 pg_edit_set_fixed (&p->l3_type, ETHERNET_TYPE_IP4);
1331 pg_edit_set_fixed (&p->n_l2_address_bytes, 6);
1332 pg_edit_set_fixed (&p->n_l3_address_bytes, 4);
1334 if (!unformat (input, "%U: %U/%U -> %U/%U",
1336 unformat_ethernet_arp_opcode_net_byte_order, &p->opcode,
1338 unformat_ethernet_address, &p->ip4_over_ethernet[0].ethernet,
1340 unformat_ip4_address, &p->ip4_over_ethernet[0].ip4,
1342 unformat_ethernet_address, &p->ip4_over_ethernet[1].ethernet,
1344 unformat_ip4_address, &p->ip4_over_ethernet[1].ip4))
1346 /* Free up any edits we may have added. */
1347 pg_free_edit_group (s);
1354 ip4_set_arp_limit (u32 arp_limit)
1356 ethernet_arp_main_t *am = ðernet_arp_main;
1358 am->limit_arp_cache_size = arp_limit;
1363 * @brief Control Plane hook to remove an ARP entry
1366 vnet_arp_unset_ip4_over_ethernet (vnet_main_t * vnm,
1367 u32 sw_if_index, void *a_arg)
1369 ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
1370 vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1372 args.sw_if_index = sw_if_index;
1373 args.flags = ETHERNET_ARP_ARGS_REMOVE;
1374 clib_memcpy (&args.a, a, sizeof (*a));
1376 vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1377 (u8 *) & args, sizeof (args));
1382 * @brief Internally generated event to flush the ARP cache on an
1383 * interface state change event.
1384 * A flush will remove dynamic ARP entries, and for statics remove the MAC
1385 * address from the corresponding adjacencies.
1388 vnet_arp_flush_ip4_over_ethernet (vnet_main_t * vnm,
1389 u32 sw_if_index, void *a_arg)
1391 ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
1392 vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1394 args.sw_if_index = sw_if_index;
1395 args.flags = ETHERNET_ARP_ARGS_FLUSH;
1396 clib_memcpy (&args.a, a, sizeof (*a));
1398 vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1399 (u8 *) & args, sizeof (args));
1404 * @brief Internally generated event to populate the ARP cache on an
1405 * interface state change event.
1406 * For static entries this will re-source the adjacencies.
1408 * @param sw_if_index The interface on which the ARP entires are acted
1411 vnet_arp_populate_ip4_over_ethernet (vnet_main_t * vnm,
1412 u32 sw_if_index, void *a_arg)
1414 ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
1415 vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1417 args.sw_if_index = sw_if_index;
1418 args.flags = ETHERNET_ARP_ARGS_POPULATE;
1419 clib_memcpy (&args.a, a, sizeof (*a));
1421 vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1422 (u8 *) & args, sizeof (args));
1427 * arp_add_del_interface_address
1429 * callback when an interface address is added or deleted
1432 arp_add_del_interface_address (ip4_main_t * im,
1435 ip4_address_t * address,
1437 u32 if_address_index, u32 is_del)
1440 * Flush the ARP cache of all entries covered by the address
1441 * that is being removed.
1443 ethernet_arp_main_t *am = ðernet_arp_main;
1444 ethernet_arp_ip4_entry_t *e;
1446 if (vec_len (am->ethernet_arp_by_sw_if_index) <= sw_if_index)
1451 ethernet_arp_interface_t *eai;
1452 u32 i, *to_delete = 0;
1455 eai = &am->ethernet_arp_by_sw_if_index[sw_if_index];
1458 hash_foreach_pair (pair, eai->arp_entries,
1460 e = pool_elt_at_index(am->ip4_entry_pool,
1462 if (ip4_destination_matches_route (im, &e->ip4_address,
1463 address, address_length))
1465 vec_add1 (to_delete, e - am->ip4_entry_pool);
1470 for (i = 0; i < vec_len (to_delete); i++)
1472 ethernet_arp_ip4_over_ethernet_address_t delme;
1473 e = pool_elt_at_index (am->ip4_entry_pool, to_delete[i]);
1475 clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
1476 delme.ip4.as_u32 = e->ip4_address.as_u32;
1478 vnet_arp_flush_ip4_over_ethernet (vnet_get_main (),
1479 e->sw_if_index, &delme);
1482 vec_free (to_delete);
1486 static clib_error_t *
1487 ethernet_arp_init (vlib_main_t * vm)
1489 ethernet_arp_main_t *am = ðernet_arp_main;
1490 ip4_main_t *im = &ip4_main;
1491 clib_error_t *error;
1494 if ((error = vlib_call_init_function (vm, ethernet_init)))
1497 ethernet_register_input_type (vm, ETHERNET_TYPE_ARP, arp_input_node.index);
1499 pn = pg_get_node (arp_input_node.index);
1500 pn->unformat_edit = unformat_pg_arp_header;
1502 am->opcode_by_name = hash_create_string (0, sizeof (uword));
1503 #define _(o) hash_set_mem (am->opcode_by_name, #o, ETHERNET_ARP_OPCODE_##o);
1504 foreach_ethernet_arp_opcode;
1507 /* $$$ configurable */
1508 am->limit_arp_cache_size = 50000;
1510 am->pending_resolutions_by_address = hash_create (0, sizeof (uword));
1511 am->mac_changes_by_address = hash_create (0, sizeof (uword));
1513 /* don't trace ARP error packets */
1515 vlib_node_runtime_t *rt =
1516 vlib_node_get_runtime (vm, arp_input_node.index);
1519 vnet_pcap_drop_trace_filter_add_del \
1520 (rt->errors[ETHERNET_ARP_ERROR_##a], \
1522 foreach_ethernet_arp_error
1526 ip4_add_del_interface_address_callback_t cb;
1527 cb.function = arp_add_del_interface_address;
1528 cb.function_opaque = 0;
1529 vec_add1 (im->add_del_interface_address_callbacks, cb);
1534 VLIB_INIT_FUNCTION (ethernet_arp_init);
1537 arp_entry_free (ethernet_arp_interface_t * eai, ethernet_arp_ip4_entry_t * e)
1539 ethernet_arp_main_t *am = ðernet_arp_main;
1541 if (FIB_NODE_INDEX_INVALID != e->fib_entry_index)
1543 fib_prefix_t pfx = {
1545 .fp_proto = FIB_PROTOCOL_IP4,
1546 .fp_addr.ip4 = e->ip4_address,
1550 fib_index = ip4_fib_table_get_index_for_sw_if_index (e->sw_if_index);
1552 fib_table_entry_path_remove (fib_index, &pfx,
1556 e->sw_if_index, ~0, 1,
1557 FIB_ROUTE_PATH_FLAG_NONE);
1559 hash_unset (eai->arp_entries, e->ip4_address.as_u32);
1560 pool_put (am->ip4_entry_pool, e);
1564 vnet_arp_unset_ip4_over_ethernet_internal (vnet_main_t * vnm,
1565 vnet_arp_set_ip4_over_ethernet_rpc_args_t
1568 ethernet_arp_main_t *am = ðernet_arp_main;
1569 ethernet_arp_ip4_entry_t *e;
1570 ethernet_arp_interface_t *eai;
1572 eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
1574 e = arp_entry_find (eai, &args->a.ip4);
1578 arp_entry_free (eai, e);
1580 adj_nbr_walk_nh4 (e->sw_if_index,
1581 &e->ip4_address, arp_mk_incomplete_walk, NULL);
1588 vnet_arp_flush_ip4_over_ethernet_internal (vnet_main_t * vnm,
1589 vnet_arp_set_ip4_over_ethernet_rpc_args_t
1592 ethernet_arp_main_t *am = ðernet_arp_main;
1593 ethernet_arp_ip4_entry_t *e;
1594 ethernet_arp_interface_t *eai;
1596 eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
1598 e = arp_entry_find (eai, &args->a.ip4);
1602 adj_nbr_walk_nh4 (e->sw_if_index,
1603 &e->ip4_address, arp_mk_incomplete_walk, e);
1606 * The difference between flush and unset, is that an unset
1607 * means delete for static and dynamic entries. A flush
1608 * means delete only for dynamic. Flushing is what the DP
1609 * does in response to interface events. unset is only done
1610 * by the control plane.
1612 if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC)
1614 arp_entry_free (eai, e);
1621 vnet_arp_populate_ip4_over_ethernet_internal (vnet_main_t * vnm,
1622 vnet_arp_set_ip4_over_ethernet_rpc_args_t
1625 ethernet_arp_main_t *am = ðernet_arp_main;
1626 ethernet_arp_ip4_entry_t *e;
1627 ethernet_arp_interface_t *eai;
1629 eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
1631 e = arp_entry_find (eai, &args->a.ip4);
1635 adj_nbr_walk_nh4 (e->sw_if_index,
1636 &e->ip4_address, arp_mk_complete_walk, e);
1642 set_ip4_over_ethernet_rpc_callback (vnet_arp_set_ip4_over_ethernet_rpc_args_t
1645 vnet_main_t *vm = vnet_get_main ();
1646 ASSERT (vlib_get_thread_index () == 0);
1648 if (a->flags & ETHERNET_ARP_ARGS_REMOVE)
1649 vnet_arp_unset_ip4_over_ethernet_internal (vm, a);
1650 else if (a->flags & ETHERNET_ARP_ARGS_FLUSH)
1651 vnet_arp_flush_ip4_over_ethernet_internal (vm, a);
1652 else if (a->flags & ETHERNET_ARP_ARGS_POPULATE)
1653 vnet_arp_populate_ip4_over_ethernet_internal (vm, a);
1655 vnet_arp_set_ip4_over_ethernet_internal (vm, a);
1659 * @brief Invoked when the interface's admin state changes
1661 static clib_error_t *
1662 ethernet_arp_sw_interface_up_down (vnet_main_t * vnm,
1663 u32 sw_if_index, u32 flags)
1665 ethernet_arp_main_t *am = ðernet_arp_main;
1666 ethernet_arp_ip4_entry_t *e;
1667 u32 i, *to_delete = 0;
1670 pool_foreach (e, am->ip4_entry_pool,
1672 if (e->sw_if_index == sw_if_index)
1673 vec_add1 (to_delete,
1674 e - am->ip4_entry_pool);
1678 for (i = 0; i < vec_len (to_delete); i++)
1680 ethernet_arp_ip4_over_ethernet_address_t delme;
1681 e = pool_elt_at_index (am->ip4_entry_pool, to_delete[i]);
1683 clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
1684 delme.ip4.as_u32 = e->ip4_address.as_u32;
1686 if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
1688 vnet_arp_populate_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
1692 vnet_arp_flush_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
1696 vec_free (to_delete);
1701 VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION (ethernet_arp_sw_interface_up_down);
1704 increment_ip4_and_mac_address (ethernet_arp_ip4_over_ethernet_address_t * a)
1709 for (i = 3; i >= 0; i--)
1711 old = a->ip4.as_u8[i];
1712 a->ip4.as_u8[i] += 1;
1713 if (old < a->ip4.as_u8[i])
1717 for (i = 5; i >= 0; i--)
1719 old = a->ethernet[i];
1720 a->ethernet[i] += 1;
1721 if (old < a->ethernet[i])
1727 vnet_arp_set_ip4_over_ethernet (vnet_main_t * vnm,
1728 u32 sw_if_index, void *a_arg,
1729 int is_static, int is_no_fib_entry)
1731 ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
1732 vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1734 args.sw_if_index = sw_if_index;
1735 args.is_static = is_static;
1736 args.is_no_fib_entry = is_no_fib_entry;
1738 clib_memcpy (&args.a, a, sizeof (*a));
1740 vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1741 (u8 *) & args, sizeof (args));
1746 vnet_proxy_arp_add_del (ip4_address_t * lo_addr,
1747 ip4_address_t * hi_addr, u32 fib_index, int is_del)
1749 ethernet_arp_main_t *am = ðernet_arp_main;
1750 ethernet_proxy_arp_t *pa;
1751 u32 found_at_index = ~0;
1753 vec_foreach (pa, am->proxy_arps)
1755 if (pa->lo_addr == lo_addr->as_u32
1756 && pa->hi_addr == hi_addr->as_u32 && pa->fib_index == fib_index)
1758 found_at_index = pa - am->proxy_arps;
1763 if (found_at_index != ~0)
1765 /* Delete, otherwise it's already in the table */
1767 vec_delete (am->proxy_arps, 1, found_at_index);
1770 /* delete, no such entry */
1772 return VNET_API_ERROR_NO_SUCH_ENTRY;
1774 /* add, not in table */
1775 vec_add2 (am->proxy_arps, pa, 1);
1776 pa->lo_addr = lo_addr->as_u32;
1777 pa->hi_addr = hi_addr->as_u32;
1778 pa->fib_index = fib_index;
1783 * Remove any proxy arp entries asdociated with the
1787 vnet_proxy_arp_fib_reset (u32 fib_id)
1789 ethernet_arp_main_t *am = ðernet_arp_main;
1790 ethernet_proxy_arp_t *pa;
1791 u32 *entries_to_delete = 0;
1795 fib_index = fib_table_find (FIB_PROTOCOL_IP4, fib_id);
1796 if (~0 == fib_index)
1797 return VNET_API_ERROR_NO_SUCH_ENTRY;
1799 vec_foreach (pa, am->proxy_arps)
1801 if (pa->fib_index == fib_index)
1803 vec_add1 (entries_to_delete, pa - am->proxy_arps);
1807 for (i = 0; i < vec_len (entries_to_delete); i++)
1809 vec_delete (am->proxy_arps, 1, entries_to_delete[i]);
1812 vec_free (entries_to_delete);
1817 static clib_error_t *
1818 ip_arp_add_del_command_fn (vlib_main_t * vm,
1819 unformat_input_t * input, vlib_cli_command_t * cmd)
1821 vnet_main_t *vnm = vnet_get_main ();
1823 ethernet_arp_ip4_over_ethernet_address_t lo_addr, hi_addr, addr;
1830 int is_no_fib_entry = 0;
1833 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1835 /* set ip arp TenGigE1/1/0/1 1.2.3.4 aa:bb:... or aabb.ccdd... */
1836 if (unformat (input, "%U %U %U",
1837 unformat_vnet_sw_interface, vnm, &sw_if_index,
1838 unformat_ip4_address, &addr.ip4,
1839 unformat_ethernet_address, &addr.ethernet))
1842 else if (unformat (input, "delete") || unformat (input, "del"))
1845 else if (unformat (input, "static"))
1848 else if (unformat (input, "no-fib-entry"))
1849 is_no_fib_entry = 1;
1851 else if (unformat (input, "count %d", &count))
1854 else if (unformat (input, "fib-id %d", &fib_id))
1856 fib_index = fib_table_find (FIB_PROTOCOL_IP4, fib_id);
1858 if (~0 == fib_index)
1859 return clib_error_return (0, "fib ID %d doesn't exist\n", fib_id);
1862 else if (unformat (input, "proxy %U - %U",
1863 unformat_ip4_address, &lo_addr.ip4,
1864 unformat_ip4_address, &hi_addr.ip4))
1872 (void) vnet_proxy_arp_add_del (&lo_addr.ip4, &hi_addr.ip4,
1881 for (i = 0; i < count; i++)
1885 uword event_type, *event_data = 0;
1887 /* Park the debug CLI until the arp entry is installed */
1888 vnet_register_ip4_arp_resolution_event
1889 (vnm, &addr.ip4, vlib_current_process (vm),
1890 1 /* type */ , 0 /* data */ );
1892 vnet_arp_set_ip4_over_ethernet
1893 (vnm, sw_if_index, &addr, is_static, is_no_fib_entry);
1895 vlib_process_wait_for_event (vm);
1896 event_type = vlib_process_get_events (vm, &event_data);
1897 vec_reset_length (event_data);
1898 if (event_type != 1)
1899 clib_warning ("event type %d unexpected", event_type);
1902 vnet_arp_unset_ip4_over_ethernet (vnm, sw_if_index, &addr);
1904 increment_ip4_and_mac_address (&addr);
1909 return clib_error_return (0, "unknown input `%U'",
1910 format_unformat_error, input);
1918 * Add or delete IPv4 ARP cache entries.
1920 * @note 'set ip arp' options (e.g. delete, static, 'fib-id <id>',
1921 * 'count <number>', 'interface ip4_addr mac_addr') can be added in
1922 * any order and combination.
1926 * Add or delete IPv4 ARP cache entries as follows. MAC Address can be in
1927 * either aa:bb:cc:dd:ee:ff format or aabb.ccdd.eeff format.
1928 * @cliexcmd{set ip arp GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
1929 * @cliexcmd{set ip arp delete GigabitEthernet2/0/0 6.0.0.3 de:ad:be:ef:ba:be}
1931 * To add or delete an IPv4 ARP cache entry to or from a specific fib
1933 * @cliexcmd{set ip arp fib-id 1 GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
1934 * @cliexcmd{set ip arp fib-id 1 delete GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
1936 * Add or delete IPv4 static ARP cache entries as follows:
1937 * @cliexcmd{set ip arp static GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
1938 * @cliexcmd{set ip arp static delete GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
1940 * For testing / debugging purposes, the 'set ip arp' command can add or
1941 * delete multiple entries. Supply the 'count N' parameter:
1942 * @cliexcmd{set ip arp count 10 GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
1945 VLIB_CLI_COMMAND (ip_arp_add_del_command, static) = {
1946 .path = "set ip arp",
1948 "set ip arp [del] <intfc> <ip-address> <mac-address> [static] [no-fib-entry] [count <count>] [fib-id <fib-id>] [proxy <lo-addr> - <hi-addr>]",
1949 .function = ip_arp_add_del_command_fn,
1953 static clib_error_t *
1954 set_int_proxy_arp_command_fn (vlib_main_t * vm,
1956 input, vlib_cli_command_t * cmd)
1958 vnet_main_t *vnm = vnet_get_main ();
1960 vnet_sw_interface_t *si;
1964 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1966 if (unformat (input, "%U", unformat_vnet_sw_interface,
1969 else if (unformat (input, "enable") || unformat (input, "on"))
1971 else if (unformat (input, "disable") || unformat (input, "off"))
1978 return clib_error_return (0, "unknown input '%U'",
1979 format_unformat_error, input);
1981 si = vnet_get_sw_interface (vnm, sw_if_index);
1984 si->flags |= VNET_SW_INTERFACE_FLAG_PROXY_ARP;
1986 si->flags &= ~VNET_SW_INTERFACE_FLAG_PROXY_ARP;
1993 * Enable proxy-arp on an interface. The vpp stack will answer ARP
1994 * requests for the indicated address range. Multiple proxy-arp
1995 * ranges may be provisioned.
1997 * @note Proxy ARP as a technology is infamous for blackholing traffic.
1998 * Also, the underlying implementation has not been performance-tuned.
1999 * Avoid creating an unnecessarily large set of ranges.
2002 * To enable proxy arp on a range of addresses, use:
2003 * @cliexcmd{set ip arp proxy 6.0.0.1 - 6.0.0.11}
2004 * Append 'del' to delete a range of proxy ARP addresses:
2005 * @cliexcmd{set ip arp proxy 6.0.0.1 - 6.0.0.11 del}
2006 * You must then specifically enable proxy arp on individual interfaces:
2007 * @cliexcmd{set interface proxy-arp GigabitEthernet0/8/0 enable}
2008 * To disable proxy arp on an individual interface:
2009 * @cliexcmd{set interface proxy-arp GigabitEthernet0/8/0 disable}
2011 VLIB_CLI_COMMAND (set_int_proxy_enable_command, static) = {
2012 .path = "set interface proxy-arp",
2014 "set interface proxy-arp <intfc> [enable|disable]",
2015 .function = set_int_proxy_arp_command_fn,
2021 * ARP/ND Termination in a L2 Bridge Domain based on IP4/IP6 to MAC
2022 * hash tables mac_by_ip4 and mac_by_ip6 for each BD.
2026 ARP_TERM_NEXT_L2_OUTPUT,
2031 u32 arp_term_next_node_index[32];
2034 arp_term_l2bd (vlib_main_t * vm,
2035 vlib_node_runtime_t * node, vlib_frame_t * frame)
2037 l2input_main_t *l2im = &l2input_main;
2038 u32 n_left_from, next_index, *from, *to_next;
2039 u32 n_replies_sent = 0;
2040 u16 last_bd_index = ~0;
2041 l2_bridge_domain_t *last_bd_config = 0;
2042 l2_input_config_t *cfg0;
2044 from = vlib_frame_vector_args (frame);
2045 n_left_from = frame->n_vectors;
2046 next_index = node->cached_next_index;
2048 while (n_left_from > 0)
2052 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2054 while (n_left_from > 0 && n_left_to_next > 0)
2057 ethernet_header_t *eth0;
2058 ethernet_arp_header_t *arp0;
2061 u32 pi0, error0, next0, sw_if_index0;
2073 n_left_to_next -= 1;
2075 p0 = vlib_get_buffer (vm, pi0);
2076 // Terminate only local (SHG == 0) ARP
2077 if (vnet_buffer (p0)->l2.shg != 0)
2078 goto next_l2_feature;
2080 eth0 = vlib_buffer_get_current (p0);
2081 l3h0 = (u8 *) eth0 + vnet_buffer (p0)->l2.l2_len;
2082 ethertype0 = clib_net_to_host_u16 (*(u16 *) (l3h0 - 2));
2083 arp0 = (ethernet_arp_header_t *) l3h0;
2085 if (PREDICT_FALSE ((ethertype0 != ETHERNET_TYPE_ARP) ||
2087 clib_host_to_net_u16
2088 (ETHERNET_ARP_OPCODE_request))))
2091 /* Must be ARP request packet here */
2092 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
2093 (p0->flags & VLIB_BUFFER_IS_TRACED)))
2095 u8 *t0 = vlib_add_trace (vm, node, p0,
2096 sizeof (ethernet_arp_input_trace_t));
2097 clib_memcpy (t0, l3h0, sizeof (ethernet_arp_input_trace_t));
2100 error0 = ETHERNET_ARP_ERROR_replies_sent;
2103 clib_net_to_host_u16 (ETHERNET_ARP_HARDWARE_TYPE_ethernet)
2104 ? ETHERNET_ARP_ERROR_l2_type_not_ethernet : error0);
2107 clib_net_to_host_u16 (ETHERNET_TYPE_IP4) ?
2108 ETHERNET_ARP_ERROR_l3_type_not_ip4 : error0);
2110 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
2117 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply))
2120 (arp0->ip4_over_ethernet[0].ethernet, vrrp_prefix,
2121 sizeof (vrrp_prefix))));
2123 /* Trash ARP packets whose ARP-level source addresses do not
2124 match their L2-frame-level source addresses, unless it's
2125 a reply from a VRRP virtual router */
2127 (memcmp (eth0->src_address, arp0->ip4_over_ethernet[0].ethernet,
2128 sizeof (eth0->src_address)) && !is_vrrp_reply0))
2130 error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
2134 /* Check if anyone want ARP request events for L2 BDs */
2136 pending_resolution_t *mc;
2137 ethernet_arp_main_t *am = ðernet_arp_main;
2138 uword *p = hash_get (am->mac_changes_by_address, 0);
2141 u32 next_index = p[0];
2142 while (next_index != (u32) ~ 0)
2144 int (*fp) (u32, u8 *, u32, u32);
2146 mc = pool_elt_at_index (am->mac_changes, next_index);
2147 fp = mc->data_callback;
2148 /* Call the callback, return 1 to suppress dup events */
2150 rv = (*fp) (mc->data,
2151 arp0->ip4_over_ethernet[0].ethernet,
2153 arp0->ip4_over_ethernet[0].ip4.as_u32);
2154 /* Signal the resolver process */
2156 vlib_process_signal_event (vm, mc->node_index,
2157 mc->type_opaque, mc->data);
2158 next_index = mc->next_index;
2163 /* lookup BD mac_by_ip4 hash table for MAC entry */
2164 ip0 = arp0->ip4_over_ethernet[1].ip4.as_u32;
2165 bd_index0 = vnet_buffer (p0)->l2.bd_index;
2166 if (PREDICT_FALSE ((bd_index0 != last_bd_index)
2167 || (last_bd_index == (u16) ~ 0)))
2169 last_bd_index = bd_index0;
2170 last_bd_config = vec_elt_at_index (l2im->bd_configs, bd_index0);
2172 macp0 = (u8 *) hash_get (last_bd_config->mac_by_ip4, ip0);
2174 if (PREDICT_FALSE (!macp0))
2175 goto next_l2_feature; /* MAC not found */
2177 /* MAC found, send ARP reply -
2178 Convert ARP request packet to ARP reply */
2179 arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
2180 arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
2181 arp0->ip4_over_ethernet[0].ip4.as_u32 = ip0;
2182 clib_memcpy (arp0->ip4_over_ethernet[0].ethernet, macp0, 6);
2183 clib_memcpy (eth0->dst_address, eth0->src_address, 6);
2184 clib_memcpy (eth0->src_address, macp0, 6);
2185 n_replies_sent += 1;
2188 /* For BVI, need to use l2-fwd node to send ARP reply as
2189 l2-output node cannot output packet to BVI properly */
2190 cfg0 = vec_elt_at_index (l2im->configs, sw_if_index0);
2191 if (PREDICT_FALSE (cfg0->bvi))
2193 vnet_buffer (p0)->l2.feature_bitmap |= L2INPUT_FEAT_FWD;
2194 vnet_buffer (p0)->sw_if_index[VLIB_RX] = 0;
2195 goto next_l2_feature;
2198 /* Send ARP/ND reply back out input interface through l2-output */
2199 vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
2200 next0 = ARP_TERM_NEXT_L2_OUTPUT;
2201 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2202 to_next, n_left_to_next, pi0,
2207 /* IP6 ND event notification or solicitation handling to generate
2208 local response instead of flooding */
2209 iph0 = (ip6_header_t *) l3h0;
2210 if (PREDICT_FALSE (ethertype0 == ETHERNET_TYPE_IP6 &&
2211 iph0->protocol == IP_PROTOCOL_ICMP6 &&
2212 !ip6_address_is_unspecified
2213 (&iph0->src_address)))
2215 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
2216 if (vnet_ip6_nd_term
2217 (vm, node, p0, eth0, iph0, sw_if_index0,
2218 vnet_buffer (p0)->l2.bd_index))
2219 goto output_response;
2224 u32 feature_bitmap0 =
2225 vnet_buffer (p0)->l2.feature_bitmap & ~L2INPUT_FEAT_ARP_TERM;
2226 vnet_buffer (p0)->l2.feature_bitmap = feature_bitmap0;
2228 feat_bitmap_get_next_node_index (arp_term_next_node_index,
2230 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2231 to_next, n_left_to_next,
2237 if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ||
2238 (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
2239 arp0->ip4_over_ethernet[1].ip4.as_u32))
2241 error0 = ETHERNET_ARP_ERROR_gratuitous_arp;
2243 next0 = ARP_TERM_NEXT_DROP;
2244 p0->error = node->errors[error0];
2246 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2247 to_next, n_left_to_next, pi0,
2251 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2254 vlib_error_count (vm, node->node_index,
2255 ETHERNET_ARP_ERROR_replies_sent, n_replies_sent);
2256 return frame->n_vectors;
2260 VLIB_REGISTER_NODE (arp_term_l2bd_node, static) = {
2261 .function = arp_term_l2bd,
2262 .name = "arp-term-l2bd",
2263 .vector_size = sizeof (u32),
2264 .n_errors = ETHERNET_ARP_N_ERROR,
2265 .error_strings = ethernet_arp_error_strings,
2266 .n_next_nodes = ARP_TERM_N_NEXT,
2268 [ARP_TERM_NEXT_L2_OUTPUT] = "l2-output",
2269 [ARP_TERM_NEXT_DROP] = "error-drop",
2271 .format_buffer = format_ethernet_arp_header,
2272 .format_trace = format_arp_term_input_trace,
2277 arp_term_init (vlib_main_t * vm)
2279 // Initialize the feature next-node indexes
2280 feat_bitmap_init_next_nodes (vm,
2281 arp_term_l2bd_node.index,
2283 l2input_get_feat_names (),
2284 arp_term_next_node_index);
2288 VLIB_INIT_FUNCTION (arp_term_init);
2291 change_arp_mac (u32 sw_if_index, ethernet_arp_ip4_entry_t * e)
2293 if (e->sw_if_index == sw_if_index)
2295 adj_nbr_walk_nh4 (e->sw_if_index,
2296 &e->ip4_address, arp_mk_complete_walk, e);
2301 ethernet_arp_change_mac (u32 sw_if_index)
2303 ethernet_arp_main_t *am = ðernet_arp_main;
2304 ethernet_arp_ip4_entry_t *e;
2307 pool_foreach (e, am->ip4_entry_pool,
2309 change_arp_mac (sw_if_index, e);
2315 * fd.io coding-style-patch-verification: ON
2318 * eval: (c-set-style "gnu")