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/fib/fib_entry_src.h>
26 #include <vnet/adj/adj_nbr.h>
27 #include <vnet/adj/adj_mcast.h>
28 #include <vnet/mpls/mpls.h>
34 * This file contains code to manage the IPv4 ARP tables (IP Address
35 * to MAC Address lookup).
39 void vl_api_rpc_call_main_thread (void *fp, u8 * data, u32 data_length);
42 * @brief Per-interface ARP configuration and state
44 typedef struct ethernet_arp_interface_t_
47 * Hash table of ARP entries.
48 * Since this hash table is per-interface, the key is only the IPv4 address.
51 } ethernet_arp_interface_t;
58 } ethernet_proxy_arp_t;
66 /* Used for arp event notification only */
69 } pending_resolution_t;
73 /* Hash tables mapping name to opcode. */
74 uword *opcode_by_name;
76 /* lite beer "glean" adjacency handling */
77 uword *pending_resolutions_by_address;
78 pending_resolution_t *pending_resolutions;
80 /* Mac address change notification */
81 uword *mac_changes_by_address;
82 pending_resolution_t *mac_changes;
84 ethernet_arp_ip4_entry_t *ip4_entry_pool;
86 /* ARP attack mitigation */
88 u32 limit_arp_cache_size;
90 /** Per interface state */
91 ethernet_arp_interface_t *ethernet_arp_by_sw_if_index;
93 /* Proxy arp vector */
94 ethernet_proxy_arp_t *proxy_arps;
95 } ethernet_arp_main_t;
97 static ethernet_arp_main_t ethernet_arp_main;
102 ethernet_arp_ip4_over_ethernet_address_t a;
106 #define ETHERNET_ARP_ARGS_REMOVE (1<<0)
107 #define ETHERNET_ARP_ARGS_FLUSH (1<<1)
108 #define ETHERNET_ARP_ARGS_POPULATE (1<<2)
109 } vnet_arp_set_ip4_over_ethernet_rpc_args_t;
111 static const u8 vrrp_prefix[] = { 0x00, 0x00, 0x5E, 0x00, 0x01 };
114 set_ip4_over_ethernet_rpc_callback (vnet_arp_set_ip4_over_ethernet_rpc_args_t
118 format_ethernet_arp_hardware_type (u8 * s, va_list * va)
120 ethernet_arp_hardware_type_t h = va_arg (*va, ethernet_arp_hardware_type_t);
124 #define _(n,f) case n: t = #f; break;
125 foreach_ethernet_arp_hardware_type;
129 return format (s, "unknown 0x%x", h);
132 return format (s, "%s", t);
136 format_ethernet_arp_opcode (u8 * s, va_list * va)
138 ethernet_arp_opcode_t o = va_arg (*va, ethernet_arp_opcode_t);
142 #define _(f) case ETHERNET_ARP_OPCODE_##f: t = #f; break;
143 foreach_ethernet_arp_opcode;
147 return format (s, "unknown 0x%x", o);
150 return format (s, "%s", t);
154 unformat_ethernet_arp_opcode_host_byte_order (unformat_input_t * input,
157 int *result = va_arg (*args, int *);
158 ethernet_arp_main_t *am = ðernet_arp_main;
161 /* Numeric opcode. */
162 if (unformat (input, "0x%x", &x) || unformat (input, "%d", &x))
171 if (unformat_user (input, unformat_vlib_number_by_name,
172 am->opcode_by_name, &i))
182 unformat_ethernet_arp_opcode_net_byte_order (unformat_input_t * input,
185 int *result = va_arg (*args, int *);
187 (input, unformat_ethernet_arp_opcode_host_byte_order, result))
190 *result = clib_host_to_net_u16 ((u16) * result);
195 format_ethernet_arp_header (u8 * s, va_list * va)
197 ethernet_arp_header_t *a = va_arg (*va, ethernet_arp_header_t *);
198 u32 max_header_bytes = va_arg (*va, u32);
200 u16 l2_type, l3_type;
202 if (max_header_bytes != 0 && sizeof (a[0]) > max_header_bytes)
203 return format (s, "ARP header truncated");
205 l2_type = clib_net_to_host_u16 (a->l2_type);
206 l3_type = clib_net_to_host_u16 (a->l3_type);
208 indent = format_get_indent (s);
210 s = format (s, "%U, type %U/%U, address size %d/%d",
211 format_ethernet_arp_opcode, clib_net_to_host_u16 (a->opcode),
212 format_ethernet_arp_hardware_type, l2_type,
213 format_ethernet_type, l3_type,
214 a->n_l2_address_bytes, a->n_l3_address_bytes);
216 if (l2_type == ETHERNET_ARP_HARDWARE_TYPE_ethernet
217 && l3_type == ETHERNET_TYPE_IP4)
219 s = format (s, "\n%U%U/%U -> %U/%U",
220 format_white_space, indent,
221 format_ethernet_address, a->ip4_over_ethernet[0].ethernet,
222 format_ip4_address, &a->ip4_over_ethernet[0].ip4,
223 format_ethernet_address, a->ip4_over_ethernet[1].ethernet,
224 format_ip4_address, &a->ip4_over_ethernet[1].ip4);
228 uword n2 = a->n_l2_address_bytes;
229 uword n3 = a->n_l3_address_bytes;
230 s = format (s, "\n%U%U/%U -> %U/%U",
231 format_white_space, indent,
232 format_hex_bytes, a->data + 0 * n2 + 0 * n3, n2,
233 format_hex_bytes, a->data + 1 * n2 + 0 * n3, n3,
234 format_hex_bytes, a->data + 1 * n2 + 1 * n3, n2,
235 format_hex_bytes, a->data + 2 * n2 + 1 * n3, n3);
242 format_ethernet_arp_ip4_entry (u8 * s, va_list * va)
244 vnet_main_t *vnm = va_arg (*va, vnet_main_t *);
245 ethernet_arp_ip4_entry_t *e = va_arg (*va, ethernet_arp_ip4_entry_t *);
246 vnet_sw_interface_t *si;
250 return format (s, "%=12s%=16s%=6s%=20s%=24s", "Time", "IP4",
251 "Flags", "Ethernet", "Interface");
253 si = vnet_get_sw_interface (vnm, e->sw_if_index);
255 if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC)
256 flags = format (flags, "S");
258 if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC)
259 flags = format (flags, "D");
261 if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_NO_FIB_ENTRY)
262 flags = format (flags, "N");
264 s = format (s, "%=12U%=16U%=6s%=20U%=24U",
265 format_vlib_cpu_time, vnm->vlib_main, e->cpu_time_last_updated,
266 format_ip4_address, &e->ip4_address,
267 flags ? (char *) flags : "",
268 format_ethernet_address, e->ethernet_address,
269 format_vnet_sw_interface_name, vnm, si);
278 } ethernet_arp_input_trace_t;
281 format_ethernet_arp_input_trace (u8 * s, va_list * va)
283 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
284 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
285 ethernet_arp_input_trace_t *t = va_arg (*va, ethernet_arp_input_trace_t *);
288 format_ethernet_arp_header,
289 t->packet_data, sizeof (t->packet_data));
295 format_arp_term_input_trace (u8 * s, va_list * va)
297 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
298 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
299 ethernet_arp_input_trace_t *t = va_arg (*va, ethernet_arp_input_trace_t *);
301 /* arp-term trace data saved is either arp or ip6/icmp6 packet:
302 - for arp, the 1st 16-bit field is hw type of value of 0x0001.
303 - for ip6, the first nibble has value of 6. */
304 s = format (s, "%U", t->packet_data[0] == 0 ?
305 format_ethernet_arp_header : format_ip6_header,
306 t->packet_data, sizeof (t->packet_data));
312 arp_nbr_probe (ip_adjacency_t * adj)
314 vnet_main_t *vnm = vnet_get_main ();
315 ip4_main_t *im = &ip4_main;
316 ip_interface_address_t *ia;
317 ethernet_arp_header_t *h;
318 vnet_hw_interface_t *hi;
319 vnet_sw_interface_t *si;
325 vm = vlib_get_main ();
327 si = vnet_get_sw_interface (vnm, adj->rewrite_header.sw_if_index);
329 if (!(si->flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP))
335 ip4_interface_address_matching_destination (im,
336 &adj->sub_type.nbr.next_hop.
346 vlib_packet_template_get_packet (vm, &im->ip4_arp_request_packet_template,
349 hi = vnet_get_sup_hw_interface (vnm, adj->rewrite_header.sw_if_index);
351 clib_memcpy (h->ip4_over_ethernet[0].ethernet,
352 hi->hw_address, sizeof (h->ip4_over_ethernet[0].ethernet));
354 h->ip4_over_ethernet[0].ip4 = src[0];
355 h->ip4_over_ethernet[1].ip4 = adj->sub_type.nbr.next_hop.ip4;
357 b = vlib_get_buffer (vm, bi);
358 vnet_buffer (b)->sw_if_index[VLIB_RX] =
359 vnet_buffer (b)->sw_if_index[VLIB_TX] = adj->rewrite_header.sw_if_index;
361 /* Add encapsulation string for software interface (e.g. ethernet header). */
362 vnet_rewrite_one_header (adj[0], h, sizeof (ethernet_header_t));
363 vlib_buffer_advance (b, -adj->rewrite_header.data_bytes);
366 vlib_frame_t *f = vlib_get_frame_to_node (vm, hi->output_node_index);
367 u32 *to_next = vlib_frame_vector_args (f);
370 vlib_put_frame_to_node (vm, hi->output_node_index, f);
375 arp_mk_complete (adj_index_t ai, ethernet_arp_ip4_entry_t * e)
377 adj_nbr_update_rewrite
378 (ai, ADJ_NBR_REWRITE_FLAG_COMPLETE,
379 ethernet_build_rewrite (vnet_get_main (),
381 adj_get_link_type (ai), e->ethernet_address));
385 arp_mk_incomplete (adj_index_t ai)
387 ip_adjacency_t *adj = adj_get (ai);
389 adj_nbr_update_rewrite
391 ADJ_NBR_REWRITE_FLAG_INCOMPLETE,
392 ethernet_build_rewrite (vnet_get_main (),
393 adj->rewrite_header.sw_if_index,
395 VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST));
398 static ethernet_arp_ip4_entry_t *
399 arp_entry_find (ethernet_arp_interface_t * eai, const ip4_address_t * addr)
401 ethernet_arp_main_t *am = ðernet_arp_main;
402 ethernet_arp_ip4_entry_t *e = NULL;
405 if (NULL != eai->arp_entries)
407 p = hash_get (eai->arp_entries, addr->as_u32);
411 e = pool_elt_at_index (am->ip4_entry_pool, p[0]);
418 arp_mk_complete_walk (adj_index_t ai, void *ctx)
420 ethernet_arp_ip4_entry_t *e = ctx;
422 arp_mk_complete (ai, e);
424 return (ADJ_WALK_RC_CONTINUE);
428 arp_mk_incomplete_walk (adj_index_t ai, void *ctx)
430 arp_mk_incomplete (ai);
432 return (ADJ_WALK_RC_CONTINUE);
436 arp_update_adjacency (vnet_main_t * vnm, u32 sw_if_index, u32 ai)
438 ethernet_arp_main_t *am = ðernet_arp_main;
439 ethernet_arp_interface_t *arp_int;
440 ethernet_arp_ip4_entry_t *e;
445 vec_validate (am->ethernet_arp_by_sw_if_index, sw_if_index);
446 arp_int = &am->ethernet_arp_by_sw_if_index[sw_if_index];
447 e = arp_entry_find (arp_int, &adj->sub_type.nbr.next_hop.ip4);
449 switch (adj->lookup_next_index)
451 case IP_LOOKUP_NEXT_ARP:
452 case IP_LOOKUP_NEXT_GLEAN:
455 adj_nbr_walk_nh4 (sw_if_index,
456 &e->ip4_address, arp_mk_complete_walk, e);
461 * no matching ARP entry.
462 * construct the rewrite required to for an ARP packet, and stick
463 * that in the adj's pipe to smoke.
465 adj_nbr_update_rewrite
467 ADJ_NBR_REWRITE_FLAG_INCOMPLETE,
468 ethernet_build_rewrite
472 VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST));
475 * since the FIB has added this adj for a route, it makes sense it
476 * may want to forward traffic sometime soon. Let's send a
477 * speculative ARP. just one. If we were to do periodically that
478 * wouldn't be bad either, but that's more code than i'm prepared to
479 * write at this time for relatively little reward.
484 case IP_LOOKUP_NEXT_MCAST:
487 * Construct a partial rewrite from the known ethernet mcast dest MAC
492 rewrite = ethernet_build_rewrite (vnm,
495 ethernet_ip4_mcast_dst_addr ());
496 offset = vec_len (rewrite) - 2;
499 * Complete the remaining fields of the adj's rewrite to direct the
500 * complete of the rewrite at switch time by copying in the IP
501 * dst address's bytes.
502 * Ofset is 2 bytes into the MAC desintation address. And we copy 23 bits
505 adj_mcast_update_rewrite (ai, rewrite, offset, 0x007fffff);
509 case IP_LOOKUP_NEXT_DROP:
510 case IP_LOOKUP_NEXT_PUNT:
511 case IP_LOOKUP_NEXT_LOCAL:
512 case IP_LOOKUP_NEXT_REWRITE:
513 case IP_LOOKUP_NEXT_MCAST_MIDCHAIN:
514 case IP_LOOKUP_NEXT_MIDCHAIN:
515 case IP_LOOKUP_NEXT_ICMP_ERROR:
516 case IP_LOOKUP_N_NEXT:
523 vnet_arp_set_ip4_over_ethernet_internal (vnet_main_t * vnm,
524 vnet_arp_set_ip4_over_ethernet_rpc_args_t
527 ethernet_arp_ip4_entry_t *e = 0;
528 ethernet_arp_main_t *am = ðernet_arp_main;
529 ethernet_arp_ip4_over_ethernet_address_t *a = &args->a;
530 vlib_main_t *vm = vlib_get_main ();
531 int make_new_arp_cache_entry = 1;
533 pending_resolution_t *pr, *mc;
534 ethernet_arp_interface_t *arp_int;
535 int is_static = args->is_static;
536 u32 sw_if_index = args->sw_if_index;
537 int is_no_fib_entry = args->is_no_fib_entry;
539 vec_validate (am->ethernet_arp_by_sw_if_index, sw_if_index);
541 arp_int = &am->ethernet_arp_by_sw_if_index[sw_if_index];
543 if (NULL != arp_int->arp_entries)
545 p = hash_get (arp_int->arp_entries, a->ip4.as_u32);
548 e = pool_elt_at_index (am->ip4_entry_pool, p[0]);
550 /* Refuse to over-write static arp. */
551 if (!is_static && (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC))
553 make_new_arp_cache_entry = 0;
557 if (make_new_arp_cache_entry)
559 pool_get (am->ip4_entry_pool, e);
561 if (NULL == arp_int->arp_entries)
563 arp_int->arp_entries = hash_create (0, sizeof (u32));
566 hash_set (arp_int->arp_entries, a->ip4.as_u32, e - am->ip4_entry_pool);
568 e->sw_if_index = sw_if_index;
569 e->ip4_address = a->ip4;
570 e->fib_entry_index = FIB_NODE_INDEX_INVALID;
571 clib_memcpy (e->ethernet_address,
572 a->ethernet, sizeof (e->ethernet_address));
574 if (!is_no_fib_entry)
578 .fp_proto = FIB_PROTOCOL_IP4,
579 .fp_addr.ip4 = a->ip4,
584 ip4_fib_table_get_index_for_sw_if_index (e->sw_if_index);
586 fib_table_entry_path_add (fib_index, &pfx, FIB_SOURCE_ADJ,
587 FIB_ENTRY_FLAG_ATTACHED,
588 FIB_PROTOCOL_IP4, &pfx.fp_addr,
589 e->sw_if_index, ~0, 1, NULL,
590 FIB_ROUTE_PATH_FLAG_NONE);
594 e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_NO_FIB_ENTRY;
600 * prevent a DoS attack from the data-plane that
601 * spams us with no-op updates to the MAC address
603 if (0 == memcmp (e->ethernet_address,
604 a->ethernet, sizeof (e->ethernet_address)))
607 /* Update time stamp and ethernet address. */
608 clib_memcpy (e->ethernet_address, a->ethernet,
609 sizeof (e->ethernet_address));
612 e->cpu_time_last_updated = clib_cpu_time_now ();
614 e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_STATIC;
616 e->flags |= ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC;
618 adj_nbr_walk_nh4 (sw_if_index, &e->ip4_address, arp_mk_complete_walk, e);
620 /* Customer(s) waiting for this address to be resolved? */
621 p = hash_get (am->pending_resolutions_by_address, a->ip4.as_u32);
627 while (next_index != (u32) ~ 0)
629 pr = pool_elt_at_index (am->pending_resolutions, next_index);
630 vlib_process_signal_event (vm, pr->node_index,
631 pr->type_opaque, pr->data);
632 next_index = pr->next_index;
633 pool_put (am->pending_resolutions, pr);
636 hash_unset (am->pending_resolutions_by_address, a->ip4.as_u32);
639 /* Customer(s) requesting ARP event for this address? */
640 p = hash_get (am->mac_changes_by_address, a->ip4.as_u32);
646 while (next_index != (u32) ~ 0)
648 int (*fp) (u32, u8 *, u32, u32);
650 mc = pool_elt_at_index (am->mac_changes, next_index);
651 fp = mc->data_callback;
653 /* Call the user's data callback, return 1 to suppress dup events */
655 rv = (*fp) (mc->data, a->ethernet, sw_if_index, 0);
658 * Signal the resolver process, as long as the user
659 * says they want to be notified
662 vlib_process_signal_event (vm, mc->node_index,
663 mc->type_opaque, mc->data);
664 next_index = mc->next_index;
672 vnet_register_ip4_arp_resolution_event (vnet_main_t * vnm,
675 uword type_opaque, uword data)
677 ethernet_arp_main_t *am = ðernet_arp_main;
678 ip4_address_t *address = address_arg;
680 pending_resolution_t *pr;
682 pool_get (am->pending_resolutions, pr);
685 pr->node_index = node_index;
686 pr->type_opaque = type_opaque;
688 pr->data_callback = 0;
690 p = hash_get (am->pending_resolutions_by_address, address->as_u32);
693 /* Insert new resolution at the head of the list */
694 pr->next_index = p[0];
695 hash_unset (am->pending_resolutions_by_address, address->as_u32);
698 hash_set (am->pending_resolutions_by_address, address->as_u32,
699 pr - am->pending_resolutions);
703 vnet_add_del_ip4_arp_change_event (vnet_main_t * vnm,
708 uword type_opaque, uword data, int is_add)
710 ethernet_arp_main_t *am = ðernet_arp_main;
711 ip4_address_t *address = address_arg;
713 /* Try to find an existing entry */
714 u32 *first = (u32 *) hash_get (am->mac_changes_by_address, address->as_u32);
716 pending_resolution_t *mc;
717 while (p && *p != ~0)
719 mc = pool_elt_at_index (am->mac_changes, *p);
720 if (mc->node_index == node_index && mc->type_opaque == type_opaque
726 int found = p && *p != ~0;
730 return VNET_API_ERROR_ENTRY_ALREADY_EXISTS;
732 pool_get (am->mac_changes, mc);
733 *mc = (pending_resolution_t)
735 .next_index = ~0,.node_index = node_index,.type_opaque =
736 type_opaque,.data = data,.data_callback = data_callback,.pid =
739 /* Insert new resolution at the end of the list */
740 u32 new_idx = mc - am->mac_changes;
744 hash_set (am->mac_changes_by_address, address->as_u32, new_idx);
749 return VNET_API_ERROR_NO_SUCH_ENTRY;
751 /* Clients may need to clean up pool entries, too */
752 void (*fp) (u32, u8 *) = data_callback;
754 (*fp) (mc->data, 0 /* no new mac addrs */ );
756 /* Remove the entry from the list and delete the entry */
758 pool_put (am->mac_changes, mc);
760 /* Remove from hash if we deleted the last entry */
761 if (*p == ~0 && p == first)
762 hash_unset (am->mac_changes_by_address, address->as_u32);
767 /* Either we drop the packet or we send a reply to the sender. */
771 ARP_INPUT_NEXT_REPLY_TX,
775 #define foreach_ethernet_arp_error \
776 _ (replies_sent, "ARP replies sent") \
777 _ (l2_type_not_ethernet, "L2 type not ethernet") \
778 _ (l3_type_not_ip4, "L3 type not IP4") \
779 _ (l3_src_address_not_local, "IP4 source address not local to subnet") \
780 _ (l3_dst_address_not_local, "IP4 destination address not local to subnet") \
781 _ (l3_src_address_is_local, "IP4 source address matches local interface") \
782 _ (l3_src_address_learned, "ARP request IP4 source address learned") \
783 _ (replies_received, "ARP replies received") \
784 _ (opcode_not_request, "ARP opcode not request") \
785 _ (proxy_arp_replies_sent, "Proxy ARP replies sent") \
786 _ (l2_address_mismatch, "ARP hw addr does not match L2 frame src addr") \
787 _ (missing_interface_address, "ARP missing interface address") \
788 _ (gratuitous_arp, "ARP probe or announcement dropped") \
789 _ (interface_no_table, "Interface is not mapped to an IP table") \
790 _ (interface_not_ip_enabled, "Interface is not IP enabled") \
794 #define _(sym,string) ETHERNET_ARP_ERROR_##sym,
795 foreach_ethernet_arp_error
797 ETHERNET_ARP_N_ERROR,
798 } ethernet_arp_input_error_t;
802 unset_random_arp_entry (void)
804 ethernet_arp_main_t *am = ðernet_arp_main;
805 ethernet_arp_ip4_entry_t *e;
806 vnet_main_t *vnm = vnet_get_main ();
807 ethernet_arp_ip4_over_ethernet_address_t delme;
810 index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
811 am->arp_delete_rotor = index;
813 /* Try again from elt 0, could happen if an intfc goes down */
816 index = pool_next_index (am->ip4_entry_pool, am->arp_delete_rotor);
817 am->arp_delete_rotor = index;
820 /* Nothing left in the pool */
824 e = pool_elt_at_index (am->ip4_entry_pool, index);
826 clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
827 delme.ip4.as_u32 = e->ip4_address.as_u32;
829 vnet_arp_unset_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
833 arp_unnumbered (vlib_buffer_t * p0,
834 u32 input_sw_if_index, u32 conn_sw_if_index)
836 vnet_main_t *vnm = vnet_get_main ();
837 vnet_interface_main_t *vim = &vnm->interface_main;
838 vnet_sw_interface_t *si;
840 /* verify that the input interface is unnumbered to the connected.
841 * the connected interface is the interface on which the subnet is
843 si = &vim->sw_interfaces[input_sw_if_index];
845 if (!(si->flags & VNET_SW_INTERFACE_FLAG_UNNUMBERED &&
846 (si->unnumbered_sw_if_index == conn_sw_if_index)))
848 /* the input interface is not unnumbered to the interface on which
849 * the sub-net is configured that covers the ARP request.
850 * So this is not the case for unnumbered.. */
858 arp_learn (vnet_main_t * vnm,
859 ethernet_arp_main_t * am, u32 sw_if_index, void *addr)
861 if (am->limit_arp_cache_size &&
862 pool_elts (am->ip4_entry_pool) >= am->limit_arp_cache_size)
863 unset_random_arp_entry ();
865 vnet_arp_set_ip4_over_ethernet (vnm, sw_if_index, addr, 0, 0);
866 return (ETHERNET_ARP_ERROR_l3_src_address_learned);
870 arp_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
872 ethernet_arp_main_t *am = ðernet_arp_main;
873 vnet_main_t *vnm = vnet_get_main ();
874 ip4_main_t *im4 = &ip4_main;
875 u32 n_left_from, next_index, *from, *to_next;
876 u32 n_replies_sent = 0, n_proxy_arp_replies_sent = 0;
878 from = vlib_frame_vector_args (frame);
879 n_left_from = frame->n_vectors;
880 next_index = node->cached_next_index;
882 if (node->flags & VLIB_NODE_FLAG_TRACE)
883 vlib_trace_frame_buffers_only (vm, node, from, frame->n_vectors,
885 sizeof (ethernet_arp_input_trace_t));
887 while (n_left_from > 0)
891 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
893 while (n_left_from > 0 && n_left_to_next > 0)
896 vnet_hw_interface_t *hw_if0;
897 ethernet_arp_header_t *arp0;
898 ethernet_header_t *eth_rx, *eth_tx;
899 ip4_address_t *if_addr0, proxy_src;
900 u32 pi0, error0, next0, sw_if_index0, conn_sw_if_index0, fib_index0;
901 u8 is_request0, dst_is_local0, is_unnum0, is_vrrp_reply0;
902 ethernet_proxy_arp_t *pa;
903 fib_node_index_t dst_fei, src_fei;
905 fib_entry_flag_t src_flags, dst_flags;
906 ip_adjacency_t *adj0 = NULL;
917 p0 = vlib_get_buffer (vm, pi0);
918 arp0 = vlib_buffer_get_current (p0);
919 /* Fill in ethernet header. */
920 eth_rx = ethernet_buffer_get_header (p0);
922 is_request0 = arp0->opcode
923 == clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request);
925 error0 = ETHERNET_ARP_ERROR_replies_sent;
929 clib_net_to_host_u16 (ETHERNET_ARP_HARDWARE_TYPE_ethernet) ?
930 ETHERNET_ARP_ERROR_l2_type_not_ethernet : error0);
933 clib_net_to_host_u16 (ETHERNET_TYPE_IP4) ?
934 ETHERNET_ARP_ERROR_l3_type_not_ip4 : error0);
936 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
938 /* not playing the ARP game if the interface is not IPv4 enabled */
940 (im4->ip_enabled_by_sw_if_index[sw_if_index0] == 0 ?
941 ETHERNET_ARP_ERROR_interface_not_ip_enabled : error0);
946 /* Check that IP address is local and matches incoming interface. */
947 fib_index0 = ip4_fib_table_get_index_for_sw_if_index (sw_if_index0);
948 if (~0 == fib_index0)
950 error0 = ETHERNET_ARP_ERROR_interface_no_table;
954 dst_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0),
955 &arp0->ip4_over_ethernet[1].ip4,
957 dst_flags = fib_entry_get_flags (dst_fei);
959 conn_sw_if_index0 = fib_entry_get_resolving_interface (dst_fei);
961 /* Honor unnumbered interface, if any */
962 is_unnum0 = sw_if_index0 != conn_sw_if_index0;
966 * we're looking for FIB entries that indicate the source
967 * is attached. There may be more specific non-attached
968 * routes tht match the source, but these do not influence
969 * whether we respond to an ARP request, i.e. they do not
970 * influence whether we are the correct way for the sender
971 * to reach us, they only affect how we reach the sender.
973 fib_entry_t *src_fib_entry;
974 fib_entry_src_t *src;
985 src_fei = ip4_fib_table_lookup (ip4_fib_get (fib_index0),
987 ip4_over_ethernet[0].ip4,
989 src_fib_entry = fib_entry_get (src_fei);
992 * It's possible that the source that provides the
993 * flags we need, or the flags we must not have,
994 * is not the best source, so check then all.
997 FOR_EACH_SRC_ADDED(src_fib_entry, src, source,
999 src_flags = fib_entry_get_flags_for_source (src_fei, source);
1001 /* Reject requests/replies with our local interface
1003 if (FIB_ENTRY_FLAG_LOCAL & src_flags)
1005 error0 = ETHERNET_ARP_ERROR_l3_src_address_is_local;
1008 /* A Source must also be local to subnet of matching
1009 * interface address. */
1010 if ((FIB_ENTRY_FLAG_ATTACHED & src_flags) ||
1011 (FIB_ENTRY_FLAG_CONNECTED & src_flags))
1018 * The packet was sent from an address that is not
1019 * connected nor attached i.e. it is not from an
1020 * address that is covered by a link's sub-net,
1021 * nor is it a already learned host resp.
1027 * shorter mask lookup for the next iteration.
1029 fib_entry_get_prefix (src_fei, &pfx);
1030 mask = pfx.fp_len - 1;
1033 * continue until we hit the default route or we find
1034 * the attached we are looking for. The most likely
1035 * outcome is we find the attached with the first source
1036 * on the first lookup.
1040 !fib_entry_is_sourced (src_fei, FIB_SOURCE_DEFAULT_ROUTE));
1045 * the matching route is a not attached, i.e. it was
1046 * added as a result of routing, rather than interface/ARP
1047 * configuration. If the matching route is not a host route
1050 error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local;
1055 if (!(FIB_ENTRY_FLAG_CONNECTED & dst_flags))
1057 error0 = ETHERNET_ARP_ERROR_l3_dst_address_not_local;
1061 if (sw_if_index0 != fib_entry_get_resolving_interface (src_fei))
1064 * The interface the ARP was received on is not the interface
1065 * on which the covering prefix is configured. Maybe this is a
1066 * case for unnumbered.
1071 dst_is_local0 = (FIB_ENTRY_FLAG_LOCAL & dst_flags);
1072 fib_entry_get_prefix (dst_fei, &pfx0);
1073 if_addr0 = &pfx0.fp_addr.ip4;
1077 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply))
1080 (arp0->ip4_over_ethernet[0].ethernet, vrrp_prefix,
1081 sizeof (vrrp_prefix))));
1083 /* Trash ARP packets whose ARP-level source addresses do not
1084 match their L2-frame-level source addresses, unless it's
1085 a reply from a VRRP virtual router */
1087 (eth_rx->src_address, arp0->ip4_over_ethernet[0].ethernet,
1088 sizeof (eth_rx->src_address)) && !is_vrrp_reply0)
1090 error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
1094 /* Learn or update sender's mapping only for replies to addresses
1095 * that are local to the subnet */
1097 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply) &&
1100 error0 = arp_learn (vnm, am, sw_if_index0,
1101 &arp0->ip4_over_ethernet[0]);
1107 ai = fib_entry_get_adj (src_fei);
1108 if (ADJ_INDEX_INVALID != ai)
1110 adj0 = adj_get (ai);
1114 error0 = ETHERNET_ARP_ERROR_missing_interface_address;
1117 /* Figure out how much to rewind current data from adjacency. */
1118 vlib_buffer_advance (p0, -adj0->rewrite_header.data_bytes);
1119 eth_tx = vlib_buffer_get_current (p0);
1121 vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
1122 hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
1124 /* Send reply back through input interface */
1125 vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
1126 next0 = ARP_INPUT_NEXT_REPLY_TX;
1128 arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
1130 arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
1132 clib_memcpy (arp0->ip4_over_ethernet[0].ethernet,
1133 hw_if0->hw_address, 6);
1134 clib_mem_unaligned (&arp0->ip4_over_ethernet[0].ip4.data_u32, u32) =
1137 /* Hardware must be ethernet-like. */
1138 ASSERT (vec_len (hw_if0->hw_address) == 6);
1140 /* the rx nd tx ethernet headers wil overlap in the case
1141 * when we received a tagged VLAN=0 packet, but we are sending
1143 memmove (eth_tx->dst_address, eth_rx->src_address, 6);
1144 clib_memcpy (eth_tx->src_address, hw_if0->hw_address, 6);
1150 if (!arp_unnumbered (p0, sw_if_index0, conn_sw_if_index0))
1155 /* We are going to reply to this request, so learn the sender */
1156 error0 = arp_learn (vnm, am, sw_if_index0,
1157 &arp0->ip4_over_ethernet[1]);
1159 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1160 n_left_to_next, pi0, next0);
1162 n_replies_sent += 1;
1166 if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ||
1167 (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
1168 arp0->ip4_over_ethernet[1].ip4.as_u32))
1170 error0 = ETHERNET_ARP_ERROR_gratuitous_arp;
1173 /* See if proxy arp is configured for the address */
1176 vnet_sw_interface_t *si;
1177 u32 this_addr = clib_net_to_host_u32
1178 (arp0->ip4_over_ethernet[1].ip4.as_u32);
1181 si = vnet_get_sw_interface (vnm, sw_if_index0);
1183 if (!(si->flags & VNET_SW_INTERFACE_FLAG_PROXY_ARP))
1186 fib_index0 = vec_elt (im4->fib_index_by_sw_if_index,
1189 vec_foreach (pa, am->proxy_arps)
1191 u32 lo_addr = clib_net_to_host_u32 (pa->lo_addr);
1192 u32 hi_addr = clib_net_to_host_u32 (pa->hi_addr);
1194 /* an ARP request hit in the proxy-arp table? */
1195 if ((this_addr >= lo_addr && this_addr <= hi_addr) &&
1196 (fib_index0 == pa->fib_index))
1199 arp0->ip4_over_ethernet[1].ip4.data_u32;
1202 * change the interface address to the proxied
1204 if_addr0 = &proxy_src;
1206 n_proxy_arp_replies_sent++;
1214 next0 = ARP_INPUT_NEXT_DROP;
1215 p0->error = node->errors[error0];
1217 vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
1218 n_left_to_next, pi0, next0);
1221 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
1224 vlib_error_count (vm, node->node_index,
1225 ETHERNET_ARP_ERROR_replies_sent,
1226 n_replies_sent - n_proxy_arp_replies_sent);
1228 vlib_error_count (vm, node->node_index,
1229 ETHERNET_ARP_ERROR_proxy_arp_replies_sent,
1230 n_proxy_arp_replies_sent);
1231 return frame->n_vectors;
1234 static char *ethernet_arp_error_strings[] = {
1235 #define _(sym,string) string,
1236 foreach_ethernet_arp_error
1241 VLIB_REGISTER_NODE (arp_input_node, static) =
1243 .function = arp_input,
1244 .name = "arp-input",
1245 .vector_size = sizeof (u32),
1246 .n_errors = ETHERNET_ARP_N_ERROR,
1247 .error_strings = ethernet_arp_error_strings,
1248 .n_next_nodes = ARP_INPUT_N_NEXT,
1250 [ARP_INPUT_NEXT_DROP] = "error-drop",
1251 [ARP_INPUT_NEXT_REPLY_TX] = "interface-output",
1253 .format_buffer = format_ethernet_arp_header,
1254 .format_trace = format_ethernet_arp_input_trace,
1259 ip4_arp_entry_sort (void *a1, void *a2)
1261 ethernet_arp_ip4_entry_t *e1 = a1;
1262 ethernet_arp_ip4_entry_t *e2 = a2;
1265 vnet_main_t *vnm = vnet_get_main ();
1267 cmp = vnet_sw_interface_compare (vnm, e1->sw_if_index, e2->sw_if_index);
1269 cmp = ip4_address_compare (&e1->ip4_address, &e2->ip4_address);
1273 ethernet_arp_ip4_entry_t *
1274 ip4_neighbor_entries (u32 sw_if_index)
1276 ethernet_arp_main_t *am = ðernet_arp_main;
1277 ethernet_arp_ip4_entry_t *n, *ns = 0;
1280 pool_foreach (n, am->ip4_entry_pool, ({
1281 if (sw_if_index != ~0 && n->sw_if_index != sw_if_index)
1283 vec_add1 (ns, n[0]);
1288 vec_sort_with_function (ns, ip4_arp_entry_sort);
1292 static clib_error_t *
1293 show_ip4_arp (vlib_main_t * vm,
1294 unformat_input_t * input, vlib_cli_command_t * cmd)
1296 vnet_main_t *vnm = vnet_get_main ();
1297 ethernet_arp_main_t *am = ðernet_arp_main;
1298 ethernet_arp_ip4_entry_t *e, *es;
1299 ethernet_proxy_arp_t *pa;
1300 clib_error_t *error = 0;
1303 /* Filter entries by interface if given. */
1305 (void) unformat_user (input, unformat_vnet_sw_interface, vnm, &sw_if_index);
1307 es = ip4_neighbor_entries (sw_if_index);
1310 vlib_cli_output (vm, "%U", format_ethernet_arp_ip4_entry, vnm, 0);
1313 vlib_cli_output (vm, "%U", format_ethernet_arp_ip4_entry, vnm, e);
1318 if (vec_len (am->proxy_arps))
1320 vlib_cli_output (vm, "Proxy arps enabled for:");
1321 vec_foreach (pa, am->proxy_arps)
1323 vlib_cli_output (vm, "Fib_index %d %U - %U ",
1325 format_ip4_address, &pa->lo_addr,
1326 format_ip4_address, &pa->hi_addr);
1334 * Display all the IPv4 ARP entries.
1337 * Example of how to display the IPv4 ARP table:
1338 * @cliexstart{show ip arp}
1339 * Time FIB IP4 Flags Ethernet Interface
1340 * 346.3028 0 6.1.1.3 de:ad:be:ef:ba:be GigabitEthernet2/0/0
1341 * 3077.4271 0 6.1.1.4 S de:ad:be:ef:ff:ff GigabitEthernet2/0/0
1342 * 2998.6409 1 6.2.2.3 de:ad:be:ef:00:01 GigabitEthernet2/0/0
1343 * Proxy arps enabled for:
1344 * Fib_index 0 6.0.0.1 - 6.0.0.11
1348 VLIB_CLI_COMMAND (show_ip4_arp_command, static) = {
1349 .path = "show ip arp",
1350 .function = show_ip4_arp,
1351 .short_help = "show ip arp",
1357 pg_edit_t l2_type, l3_type;
1358 pg_edit_t n_l2_address_bytes, n_l3_address_bytes;
1364 } ip4_over_ethernet[2];
1365 } pg_ethernet_arp_header_t;
1368 pg_ethernet_arp_header_init (pg_ethernet_arp_header_t * p)
1370 /* Initialize fields that are not bit fields in the IP header. */
1371 #define _(f) pg_edit_init (&p->f, ethernet_arp_header_t, f);
1374 _(n_l2_address_bytes);
1375 _(n_l3_address_bytes);
1377 _(ip4_over_ethernet[0].ethernet);
1378 _(ip4_over_ethernet[0].ip4);
1379 _(ip4_over_ethernet[1].ethernet);
1380 _(ip4_over_ethernet[1].ip4);
1385 unformat_pg_arp_header (unformat_input_t * input, va_list * args)
1387 pg_stream_t *s = va_arg (*args, pg_stream_t *);
1388 pg_ethernet_arp_header_t *p;
1391 p = pg_create_edit_group (s, sizeof (p[0]), sizeof (ethernet_arp_header_t),
1393 pg_ethernet_arp_header_init (p);
1396 pg_edit_set_fixed (&p->l2_type, ETHERNET_ARP_HARDWARE_TYPE_ethernet);
1397 pg_edit_set_fixed (&p->l3_type, ETHERNET_TYPE_IP4);
1398 pg_edit_set_fixed (&p->n_l2_address_bytes, 6);
1399 pg_edit_set_fixed (&p->n_l3_address_bytes, 4);
1401 if (!unformat (input, "%U: %U/%U -> %U/%U",
1403 unformat_ethernet_arp_opcode_net_byte_order, &p->opcode,
1405 unformat_ethernet_address, &p->ip4_over_ethernet[0].ethernet,
1407 unformat_ip4_address, &p->ip4_over_ethernet[0].ip4,
1409 unformat_ethernet_address, &p->ip4_over_ethernet[1].ethernet,
1411 unformat_ip4_address, &p->ip4_over_ethernet[1].ip4))
1413 /* Free up any edits we may have added. */
1414 pg_free_edit_group (s);
1421 ip4_set_arp_limit (u32 arp_limit)
1423 ethernet_arp_main_t *am = ðernet_arp_main;
1425 am->limit_arp_cache_size = arp_limit;
1430 * @brief Control Plane hook to remove an ARP entry
1433 vnet_arp_unset_ip4_over_ethernet (vnet_main_t * vnm,
1434 u32 sw_if_index, void *a_arg)
1436 ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
1437 vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1439 args.sw_if_index = sw_if_index;
1440 args.flags = ETHERNET_ARP_ARGS_REMOVE;
1441 clib_memcpy (&args.a, a, sizeof (*a));
1443 vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1444 (u8 *) & args, sizeof (args));
1449 * @brief Internally generated event to flush the ARP cache on an
1450 * interface state change event.
1451 * A flush will remove dynamic ARP entries, and for statics remove the MAC
1452 * address from the corresponding adjacencies.
1455 vnet_arp_flush_ip4_over_ethernet (vnet_main_t * vnm,
1456 u32 sw_if_index, void *a_arg)
1458 ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
1459 vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1461 args.sw_if_index = sw_if_index;
1462 args.flags = ETHERNET_ARP_ARGS_FLUSH;
1463 clib_memcpy (&args.a, a, sizeof (*a));
1465 vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1466 (u8 *) & args, sizeof (args));
1471 * @brief Internally generated event to populate the ARP cache on an
1472 * interface state change event.
1473 * For static entries this will re-source the adjacencies.
1475 * @param sw_if_index The interface on which the ARP entires are acted
1478 vnet_arp_populate_ip4_over_ethernet (vnet_main_t * vnm,
1479 u32 sw_if_index, void *a_arg)
1481 ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
1482 vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1484 args.sw_if_index = sw_if_index;
1485 args.flags = ETHERNET_ARP_ARGS_POPULATE;
1486 clib_memcpy (&args.a, a, sizeof (*a));
1488 vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1489 (u8 *) & args, sizeof (args));
1494 * arp_add_del_interface_address
1496 * callback when an interface address is added or deleted
1499 arp_add_del_interface_address (ip4_main_t * im,
1502 ip4_address_t * address,
1504 u32 if_address_index, u32 is_del)
1507 * Flush the ARP cache of all entries covered by the address
1508 * that is being removed.
1510 ethernet_arp_main_t *am = ðernet_arp_main;
1511 ethernet_arp_ip4_entry_t *e;
1513 if (vec_len (am->ethernet_arp_by_sw_if_index) <= sw_if_index)
1518 ethernet_arp_interface_t *eai;
1519 u32 i, *to_delete = 0;
1522 eai = &am->ethernet_arp_by_sw_if_index[sw_if_index];
1525 hash_foreach_pair (pair, eai->arp_entries,
1527 e = pool_elt_at_index(am->ip4_entry_pool,
1529 if (ip4_destination_matches_route (im, &e->ip4_address,
1530 address, address_length))
1532 vec_add1 (to_delete, e - am->ip4_entry_pool);
1537 for (i = 0; i < vec_len (to_delete); i++)
1539 ethernet_arp_ip4_over_ethernet_address_t delme;
1540 e = pool_elt_at_index (am->ip4_entry_pool, to_delete[i]);
1542 clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
1543 delme.ip4.as_u32 = e->ip4_address.as_u32;
1545 vnet_arp_flush_ip4_over_ethernet (vnet_get_main (),
1546 e->sw_if_index, &delme);
1549 vec_free (to_delete);
1553 static clib_error_t *
1554 ethernet_arp_init (vlib_main_t * vm)
1556 ethernet_arp_main_t *am = ðernet_arp_main;
1557 ip4_main_t *im = &ip4_main;
1558 clib_error_t *error;
1561 if ((error = vlib_call_init_function (vm, ethernet_init)))
1564 ethernet_register_input_type (vm, ETHERNET_TYPE_ARP, arp_input_node.index);
1566 pn = pg_get_node (arp_input_node.index);
1567 pn->unformat_edit = unformat_pg_arp_header;
1569 am->opcode_by_name = hash_create_string (0, sizeof (uword));
1570 #define _(o) hash_set_mem (am->opcode_by_name, #o, ETHERNET_ARP_OPCODE_##o);
1571 foreach_ethernet_arp_opcode;
1574 /* $$$ configurable */
1575 am->limit_arp_cache_size = 50000;
1577 am->pending_resolutions_by_address = hash_create (0, sizeof (uword));
1578 am->mac_changes_by_address = hash_create (0, sizeof (uword));
1580 /* don't trace ARP error packets */
1582 vlib_node_runtime_t *rt =
1583 vlib_node_get_runtime (vm, arp_input_node.index);
1586 vnet_pcap_drop_trace_filter_add_del \
1587 (rt->errors[ETHERNET_ARP_ERROR_##a], \
1589 foreach_ethernet_arp_error
1593 ip4_add_del_interface_address_callback_t cb;
1594 cb.function = arp_add_del_interface_address;
1595 cb.function_opaque = 0;
1596 vec_add1 (im->add_del_interface_address_callbacks, cb);
1601 VLIB_INIT_FUNCTION (ethernet_arp_init);
1604 arp_entry_free (ethernet_arp_interface_t * eai, ethernet_arp_ip4_entry_t * e)
1606 ethernet_arp_main_t *am = ðernet_arp_main;
1608 if (FIB_NODE_INDEX_INVALID != e->fib_entry_index)
1610 fib_prefix_t pfx = {
1612 .fp_proto = FIB_PROTOCOL_IP4,
1613 .fp_addr.ip4 = e->ip4_address,
1617 fib_index = ip4_fib_table_get_index_for_sw_if_index (e->sw_if_index);
1619 fib_table_entry_path_remove (fib_index, &pfx,
1623 e->sw_if_index, ~0, 1,
1624 FIB_ROUTE_PATH_FLAG_NONE);
1626 hash_unset (eai->arp_entries, e->ip4_address.as_u32);
1627 pool_put (am->ip4_entry_pool, e);
1631 vnet_arp_unset_ip4_over_ethernet_internal (vnet_main_t * vnm,
1632 vnet_arp_set_ip4_over_ethernet_rpc_args_t
1635 ethernet_arp_main_t *am = ðernet_arp_main;
1636 ethernet_arp_ip4_entry_t *e;
1637 ethernet_arp_interface_t *eai;
1639 eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
1641 e = arp_entry_find (eai, &args->a.ip4);
1645 arp_entry_free (eai, e);
1647 adj_nbr_walk_nh4 (e->sw_if_index,
1648 &e->ip4_address, arp_mk_incomplete_walk, NULL);
1655 vnet_arp_flush_ip4_over_ethernet_internal (vnet_main_t * vnm,
1656 vnet_arp_set_ip4_over_ethernet_rpc_args_t
1659 ethernet_arp_main_t *am = ðernet_arp_main;
1660 ethernet_arp_ip4_entry_t *e;
1661 ethernet_arp_interface_t *eai;
1663 eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
1665 e = arp_entry_find (eai, &args->a.ip4);
1669 adj_nbr_walk_nh4 (e->sw_if_index,
1670 &e->ip4_address, arp_mk_incomplete_walk, e);
1673 * The difference between flush and unset, is that an unset
1674 * means delete for static and dynamic entries. A flush
1675 * means delete only for dynamic. Flushing is what the DP
1676 * does in response to interface events. unset is only done
1677 * by the control plane.
1679 if (e->flags & ETHERNET_ARP_IP4_ENTRY_FLAG_DYNAMIC)
1681 arp_entry_free (eai, e);
1688 vnet_arp_populate_ip4_over_ethernet_internal (vnet_main_t * vnm,
1689 vnet_arp_set_ip4_over_ethernet_rpc_args_t
1692 ethernet_arp_main_t *am = ðernet_arp_main;
1693 ethernet_arp_ip4_entry_t *e;
1694 ethernet_arp_interface_t *eai;
1696 eai = &am->ethernet_arp_by_sw_if_index[args->sw_if_index];
1698 e = arp_entry_find (eai, &args->a.ip4);
1702 adj_nbr_walk_nh4 (e->sw_if_index,
1703 &e->ip4_address, arp_mk_complete_walk, e);
1709 set_ip4_over_ethernet_rpc_callback (vnet_arp_set_ip4_over_ethernet_rpc_args_t
1712 vnet_main_t *vm = vnet_get_main ();
1713 ASSERT (vlib_get_thread_index () == 0);
1715 if (a->flags & ETHERNET_ARP_ARGS_REMOVE)
1716 vnet_arp_unset_ip4_over_ethernet_internal (vm, a);
1717 else if (a->flags & ETHERNET_ARP_ARGS_FLUSH)
1718 vnet_arp_flush_ip4_over_ethernet_internal (vm, a);
1719 else if (a->flags & ETHERNET_ARP_ARGS_POPULATE)
1720 vnet_arp_populate_ip4_over_ethernet_internal (vm, a);
1722 vnet_arp_set_ip4_over_ethernet_internal (vm, a);
1726 * @brief Invoked when the interface's admin state changes
1728 static clib_error_t *
1729 ethernet_arp_sw_interface_up_down (vnet_main_t * vnm,
1730 u32 sw_if_index, u32 flags)
1732 ethernet_arp_main_t *am = ðernet_arp_main;
1733 ethernet_arp_ip4_entry_t *e;
1734 u32 i, *to_delete = 0;
1737 pool_foreach (e, am->ip4_entry_pool,
1739 if (e->sw_if_index == sw_if_index)
1740 vec_add1 (to_delete,
1741 e - am->ip4_entry_pool);
1745 for (i = 0; i < vec_len (to_delete); i++)
1747 ethernet_arp_ip4_over_ethernet_address_t delme;
1748 e = pool_elt_at_index (am->ip4_entry_pool, to_delete[i]);
1750 clib_memcpy (&delme.ethernet, e->ethernet_address, 6);
1751 delme.ip4.as_u32 = e->ip4_address.as_u32;
1753 if (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP)
1755 vnet_arp_populate_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
1759 vnet_arp_flush_ip4_over_ethernet (vnm, e->sw_if_index, &delme);
1763 vec_free (to_delete);
1768 VNET_SW_INTERFACE_ADMIN_UP_DOWN_FUNCTION (ethernet_arp_sw_interface_up_down);
1771 increment_ip4_and_mac_address (ethernet_arp_ip4_over_ethernet_address_t * a)
1776 for (i = 3; i >= 0; i--)
1778 old = a->ip4.as_u8[i];
1779 a->ip4.as_u8[i] += 1;
1780 if (old < a->ip4.as_u8[i])
1784 for (i = 5; i >= 0; i--)
1786 old = a->ethernet[i];
1787 a->ethernet[i] += 1;
1788 if (old < a->ethernet[i])
1794 vnet_arp_set_ip4_over_ethernet (vnet_main_t * vnm,
1795 u32 sw_if_index, void *a_arg,
1796 int is_static, int is_no_fib_entry)
1798 ethernet_arp_ip4_over_ethernet_address_t *a = a_arg;
1799 vnet_arp_set_ip4_over_ethernet_rpc_args_t args;
1801 args.sw_if_index = sw_if_index;
1802 args.is_static = is_static;
1803 args.is_no_fib_entry = is_no_fib_entry;
1805 clib_memcpy (&args.a, a, sizeof (*a));
1807 vl_api_rpc_call_main_thread (set_ip4_over_ethernet_rpc_callback,
1808 (u8 *) & args, sizeof (args));
1813 vnet_proxy_arp_add_del (ip4_address_t * lo_addr,
1814 ip4_address_t * hi_addr, u32 fib_index, int is_del)
1816 ethernet_arp_main_t *am = ðernet_arp_main;
1817 ethernet_proxy_arp_t *pa;
1818 u32 found_at_index = ~0;
1820 vec_foreach (pa, am->proxy_arps)
1822 if (pa->lo_addr == lo_addr->as_u32
1823 && pa->hi_addr == hi_addr->as_u32 && pa->fib_index == fib_index)
1825 found_at_index = pa - am->proxy_arps;
1830 if (found_at_index != ~0)
1832 /* Delete, otherwise it's already in the table */
1834 vec_delete (am->proxy_arps, 1, found_at_index);
1837 /* delete, no such entry */
1839 return VNET_API_ERROR_NO_SUCH_ENTRY;
1841 /* add, not in table */
1842 vec_add2 (am->proxy_arps, pa, 1);
1843 pa->lo_addr = lo_addr->as_u32;
1844 pa->hi_addr = hi_addr->as_u32;
1845 pa->fib_index = fib_index;
1850 * Remove any proxy arp entries asdociated with the
1854 vnet_proxy_arp_fib_reset (u32 fib_id)
1856 ethernet_arp_main_t *am = ðernet_arp_main;
1857 ethernet_proxy_arp_t *pa;
1858 u32 *entries_to_delete = 0;
1862 fib_index = fib_table_find (FIB_PROTOCOL_IP4, fib_id);
1863 if (~0 == fib_index)
1864 return VNET_API_ERROR_NO_SUCH_ENTRY;
1866 vec_foreach (pa, am->proxy_arps)
1868 if (pa->fib_index == fib_index)
1870 vec_add1 (entries_to_delete, pa - am->proxy_arps);
1874 for (i = 0; i < vec_len (entries_to_delete); i++)
1876 vec_delete (am->proxy_arps, 1, entries_to_delete[i]);
1879 vec_free (entries_to_delete);
1884 static clib_error_t *
1885 ip_arp_add_del_command_fn (vlib_main_t * vm,
1886 unformat_input_t * input, vlib_cli_command_t * cmd)
1888 vnet_main_t *vnm = vnet_get_main ();
1890 ethernet_arp_ip4_over_ethernet_address_t lo_addr, hi_addr, addr;
1897 int is_no_fib_entry = 0;
1900 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
1902 /* set ip arp TenGigE1/1/0/1 1.2.3.4 aa:bb:... or aabb.ccdd... */
1903 if (unformat (input, "%U %U %U",
1904 unformat_vnet_sw_interface, vnm, &sw_if_index,
1905 unformat_ip4_address, &addr.ip4,
1906 unformat_ethernet_address, &addr.ethernet))
1909 else if (unformat (input, "delete") || unformat (input, "del"))
1912 else if (unformat (input, "static"))
1915 else if (unformat (input, "no-fib-entry"))
1916 is_no_fib_entry = 1;
1918 else if (unformat (input, "count %d", &count))
1921 else if (unformat (input, "fib-id %d", &fib_id))
1923 fib_index = fib_table_find (FIB_PROTOCOL_IP4, fib_id);
1925 if (~0 == fib_index)
1926 return clib_error_return (0, "fib ID %d doesn't exist\n", fib_id);
1929 else if (unformat (input, "proxy %U - %U",
1930 unformat_ip4_address, &lo_addr.ip4,
1931 unformat_ip4_address, &hi_addr.ip4))
1939 (void) vnet_proxy_arp_add_del (&lo_addr.ip4, &hi_addr.ip4,
1948 for (i = 0; i < count; i++)
1952 uword event_type, *event_data = 0;
1954 /* Park the debug CLI until the arp entry is installed */
1955 vnet_register_ip4_arp_resolution_event
1956 (vnm, &addr.ip4, vlib_current_process (vm),
1957 1 /* type */ , 0 /* data */ );
1959 vnet_arp_set_ip4_over_ethernet
1960 (vnm, sw_if_index, &addr, is_static, is_no_fib_entry);
1962 vlib_process_wait_for_event (vm);
1963 event_type = vlib_process_get_events (vm, &event_data);
1964 vec_reset_length (event_data);
1965 if (event_type != 1)
1966 clib_warning ("event type %d unexpected", event_type);
1969 vnet_arp_unset_ip4_over_ethernet (vnm, sw_if_index, &addr);
1971 increment_ip4_and_mac_address (&addr);
1976 return clib_error_return (0, "unknown input `%U'",
1977 format_unformat_error, input);
1985 * Add or delete IPv4 ARP cache entries.
1987 * @note 'set ip arp' options (e.g. delete, static, 'fib-id <id>',
1988 * 'count <number>', 'interface ip4_addr mac_addr') can be added in
1989 * any order and combination.
1993 * Add or delete IPv4 ARP cache entries as follows. MAC Address can be in
1994 * either aa:bb:cc:dd:ee:ff format or aabb.ccdd.eeff format.
1995 * @cliexcmd{set ip arp GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
1996 * @cliexcmd{set ip arp delete GigabitEthernet2/0/0 6.0.0.3 de:ad:be:ef:ba:be}
1998 * To add or delete an IPv4 ARP cache entry to or from a specific fib
2000 * @cliexcmd{set ip arp fib-id 1 GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
2001 * @cliexcmd{set ip arp fib-id 1 delete GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
2003 * Add or delete IPv4 static ARP cache entries as follows:
2004 * @cliexcmd{set ip arp static GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
2005 * @cliexcmd{set ip arp static delete GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
2007 * For testing / debugging purposes, the 'set ip arp' command can add or
2008 * delete multiple entries. Supply the 'count N' parameter:
2009 * @cliexcmd{set ip arp count 10 GigabitEthernet2/0/0 6.0.0.3 dead.beef.babe}
2012 VLIB_CLI_COMMAND (ip_arp_add_del_command, static) = {
2013 .path = "set ip arp",
2015 "set ip arp [del] <intfc> <ip-address> <mac-address> [static] [no-fib-entry] [count <count>] [fib-id <fib-id>] [proxy <lo-addr> - <hi-addr>]",
2016 .function = ip_arp_add_del_command_fn,
2020 static clib_error_t *
2021 set_int_proxy_arp_command_fn (vlib_main_t * vm,
2023 input, vlib_cli_command_t * cmd)
2025 vnet_main_t *vnm = vnet_get_main ();
2027 vnet_sw_interface_t *si;
2031 while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
2033 if (unformat (input, "%U", unformat_vnet_sw_interface,
2036 else if (unformat (input, "enable") || unformat (input, "on"))
2038 else if (unformat (input, "disable") || unformat (input, "off"))
2045 return clib_error_return (0, "unknown input '%U'",
2046 format_unformat_error, input);
2048 si = vnet_get_sw_interface (vnm, sw_if_index);
2051 si->flags |= VNET_SW_INTERFACE_FLAG_PROXY_ARP;
2053 si->flags &= ~VNET_SW_INTERFACE_FLAG_PROXY_ARP;
2060 * Enable proxy-arp on an interface. The vpp stack will answer ARP
2061 * requests for the indicated address range. Multiple proxy-arp
2062 * ranges may be provisioned.
2064 * @note Proxy ARP as a technology is infamous for blackholing traffic.
2065 * Also, the underlying implementation has not been performance-tuned.
2066 * Avoid creating an unnecessarily large set of ranges.
2069 * To enable proxy arp on a range of addresses, use:
2070 * @cliexcmd{set ip arp proxy 6.0.0.1 - 6.0.0.11}
2071 * Append 'del' to delete a range of proxy ARP addresses:
2072 * @cliexcmd{set ip arp proxy 6.0.0.1 - 6.0.0.11 del}
2073 * You must then specifically enable proxy arp on individual interfaces:
2074 * @cliexcmd{set interface proxy-arp GigabitEthernet0/8/0 enable}
2075 * To disable proxy arp on an individual interface:
2076 * @cliexcmd{set interface proxy-arp GigabitEthernet0/8/0 disable}
2078 VLIB_CLI_COMMAND (set_int_proxy_enable_command, static) = {
2079 .path = "set interface proxy-arp",
2081 "set interface proxy-arp <intfc> [enable|disable]",
2082 .function = set_int_proxy_arp_command_fn,
2088 * ARP/ND Termination in a L2 Bridge Domain based on IP4/IP6 to MAC
2089 * hash tables mac_by_ip4 and mac_by_ip6 for each BD.
2093 ARP_TERM_NEXT_L2_OUTPUT,
2098 u32 arp_term_next_node_index[32];
2101 arp_term_l2bd (vlib_main_t * vm,
2102 vlib_node_runtime_t * node, vlib_frame_t * frame)
2104 l2input_main_t *l2im = &l2input_main;
2105 u32 n_left_from, next_index, *from, *to_next;
2106 u32 n_replies_sent = 0;
2107 u16 last_bd_index = ~0;
2108 l2_bridge_domain_t *last_bd_config = 0;
2109 l2_input_config_t *cfg0;
2111 from = vlib_frame_vector_args (frame);
2112 n_left_from = frame->n_vectors;
2113 next_index = node->cached_next_index;
2115 while (n_left_from > 0)
2119 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
2121 while (n_left_from > 0 && n_left_to_next > 0)
2124 ethernet_header_t *eth0;
2125 ethernet_arp_header_t *arp0;
2128 u32 pi0, error0, next0, sw_if_index0;
2140 n_left_to_next -= 1;
2142 p0 = vlib_get_buffer (vm, pi0);
2143 // Terminate only local (SHG == 0) ARP
2144 if (vnet_buffer (p0)->l2.shg != 0)
2145 goto next_l2_feature;
2147 eth0 = vlib_buffer_get_current (p0);
2148 l3h0 = (u8 *) eth0 + vnet_buffer (p0)->l2.l2_len;
2149 ethertype0 = clib_net_to_host_u16 (*(u16 *) (l3h0 - 2));
2150 arp0 = (ethernet_arp_header_t *) l3h0;
2152 if (PREDICT_FALSE ((ethertype0 != ETHERNET_TYPE_ARP) ||
2154 clib_host_to_net_u16
2155 (ETHERNET_ARP_OPCODE_request))))
2158 /* Must be ARP request packet here */
2159 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
2160 (p0->flags & VLIB_BUFFER_IS_TRACED)))
2162 u8 *t0 = vlib_add_trace (vm, node, p0,
2163 sizeof (ethernet_arp_input_trace_t));
2164 clib_memcpy (t0, l3h0, sizeof (ethernet_arp_input_trace_t));
2167 error0 = ETHERNET_ARP_ERROR_replies_sent;
2170 clib_net_to_host_u16 (ETHERNET_ARP_HARDWARE_TYPE_ethernet)
2171 ? ETHERNET_ARP_ERROR_l2_type_not_ethernet : error0);
2174 clib_net_to_host_u16 (ETHERNET_TYPE_IP4) ?
2175 ETHERNET_ARP_ERROR_l3_type_not_ip4 : error0);
2177 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
2184 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply))
2187 (arp0->ip4_over_ethernet[0].ethernet, vrrp_prefix,
2188 sizeof (vrrp_prefix))));
2190 /* Trash ARP packets whose ARP-level source addresses do not
2191 match their L2-frame-level source addresses, unless it's
2192 a reply from a VRRP virtual router */
2194 (memcmp (eth0->src_address, arp0->ip4_over_ethernet[0].ethernet,
2195 sizeof (eth0->src_address)) && !is_vrrp_reply0))
2197 error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
2201 /* Check if anyone want ARP request events for L2 BDs */
2203 pending_resolution_t *mc;
2204 ethernet_arp_main_t *am = ðernet_arp_main;
2205 uword *p = hash_get (am->mac_changes_by_address, 0);
2208 u32 next_index = p[0];
2209 while (next_index != (u32) ~ 0)
2211 int (*fp) (u32, u8 *, u32, u32);
2213 mc = pool_elt_at_index (am->mac_changes, next_index);
2214 fp = mc->data_callback;
2215 /* Call the callback, return 1 to suppress dup events */
2217 rv = (*fp) (mc->data,
2218 arp0->ip4_over_ethernet[0].ethernet,
2220 arp0->ip4_over_ethernet[0].ip4.as_u32);
2221 /* Signal the resolver process */
2223 vlib_process_signal_event (vm, mc->node_index,
2224 mc->type_opaque, mc->data);
2225 next_index = mc->next_index;
2230 /* lookup BD mac_by_ip4 hash table for MAC entry */
2231 ip0 = arp0->ip4_over_ethernet[1].ip4.as_u32;
2232 bd_index0 = vnet_buffer (p0)->l2.bd_index;
2233 if (PREDICT_FALSE ((bd_index0 != last_bd_index)
2234 || (last_bd_index == (u16) ~ 0)))
2236 last_bd_index = bd_index0;
2237 last_bd_config = vec_elt_at_index (l2im->bd_configs, bd_index0);
2239 macp0 = (u8 *) hash_get (last_bd_config->mac_by_ip4, ip0);
2241 if (PREDICT_FALSE (!macp0))
2242 goto next_l2_feature; /* MAC not found */
2244 /* MAC found, send ARP reply -
2245 Convert ARP request packet to ARP reply */
2246 arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
2247 arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
2248 arp0->ip4_over_ethernet[0].ip4.as_u32 = ip0;
2249 clib_memcpy (arp0->ip4_over_ethernet[0].ethernet, macp0, 6);
2250 clib_memcpy (eth0->dst_address, eth0->src_address, 6);
2251 clib_memcpy (eth0->src_address, macp0, 6);
2252 n_replies_sent += 1;
2255 /* For BVI, need to use l2-fwd node to send ARP reply as
2256 l2-output node cannot output packet to BVI properly */
2257 cfg0 = vec_elt_at_index (l2im->configs, sw_if_index0);
2258 if (PREDICT_FALSE (cfg0->bvi))
2260 vnet_buffer (p0)->l2.feature_bitmap |= L2INPUT_FEAT_FWD;
2261 vnet_buffer (p0)->sw_if_index[VLIB_RX] = 0;
2262 goto next_l2_feature;
2265 /* Send ARP/ND reply back out input interface through l2-output */
2266 vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
2267 next0 = ARP_TERM_NEXT_L2_OUTPUT;
2268 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2269 to_next, n_left_to_next, pi0,
2274 /* IP6 ND event notification or solicitation handling to generate
2275 local response instead of flooding */
2276 iph0 = (ip6_header_t *) l3h0;
2277 if (PREDICT_FALSE (ethertype0 == ETHERNET_TYPE_IP6 &&
2278 iph0->protocol == IP_PROTOCOL_ICMP6 &&
2279 !ip6_address_is_unspecified
2280 (&iph0->src_address)))
2282 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
2283 if (vnet_ip6_nd_term
2284 (vm, node, p0, eth0, iph0, sw_if_index0,
2285 vnet_buffer (p0)->l2.bd_index))
2286 goto output_response;
2291 u32 feature_bitmap0 =
2292 vnet_buffer (p0)->l2.feature_bitmap & ~L2INPUT_FEAT_ARP_TERM;
2293 vnet_buffer (p0)->l2.feature_bitmap = feature_bitmap0;
2295 feat_bitmap_get_next_node_index (arp_term_next_node_index,
2297 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2298 to_next, n_left_to_next,
2304 if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ||
2305 (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
2306 arp0->ip4_over_ethernet[1].ip4.as_u32))
2308 error0 = ETHERNET_ARP_ERROR_gratuitous_arp;
2310 next0 = ARP_TERM_NEXT_DROP;
2311 p0->error = node->errors[error0];
2313 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
2314 to_next, n_left_to_next, pi0,
2318 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
2321 vlib_error_count (vm, node->node_index,
2322 ETHERNET_ARP_ERROR_replies_sent, n_replies_sent);
2323 return frame->n_vectors;
2327 VLIB_REGISTER_NODE (arp_term_l2bd_node, static) = {
2328 .function = arp_term_l2bd,
2329 .name = "arp-term-l2bd",
2330 .vector_size = sizeof (u32),
2331 .n_errors = ETHERNET_ARP_N_ERROR,
2332 .error_strings = ethernet_arp_error_strings,
2333 .n_next_nodes = ARP_TERM_N_NEXT,
2335 [ARP_TERM_NEXT_L2_OUTPUT] = "l2-output",
2336 [ARP_TERM_NEXT_DROP] = "error-drop",
2338 .format_buffer = format_ethernet_arp_header,
2339 .format_trace = format_arp_term_input_trace,
2344 arp_term_init (vlib_main_t * vm)
2346 // Initialize the feature next-node indexes
2347 feat_bitmap_init_next_nodes (vm,
2348 arp_term_l2bd_node.index,
2350 l2input_get_feat_names (),
2351 arp_term_next_node_index);
2355 VLIB_INIT_FUNCTION (arp_term_init);
2358 change_arp_mac (u32 sw_if_index, ethernet_arp_ip4_entry_t * e)
2360 if (e->sw_if_index == sw_if_index)
2362 adj_nbr_walk_nh4 (e->sw_if_index,
2363 &e->ip4_address, arp_mk_complete_walk, e);
2368 ethernet_arp_change_mac (u32 sw_if_index)
2370 ethernet_arp_main_t *am = ðernet_arp_main;
2371 ethernet_arp_ip4_entry_t *e;
2374 pool_foreach (e, am->ip4_entry_pool,
2376 change_arp_mac (sw_if_index, e);
2382 * fd.io coding-style-patch-verification: ON
2385 * eval: (c-set-style "gnu")