2 * l2/l2_arp_term.c: IP v4 ARP L2 BD termination
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 <vlibmemory/api.h>
20 #include <vnet/l2/l2_arp_term.h>
21 #include <vnet/l2/l2_input.h>
22 #include <vnet/l2/feat_bitmap.h>
24 #include <vnet/ip/ip4_packet.h>
25 #include <vnet/ethernet/arp_packet.h>
27 static const u8 vrrp_prefix[] = { 0x00, 0x00, 0x5E, 0x00, 0x01 };
29 l2_arp_term_main_t l2_arp_term_main;
32 * ARP/ND Termination in a L2 Bridge Domain based on IP4/IP6 to MAC
33 * hash tables mac_by_ip4 and mac_by_ip6 for each BD.
37 ARP_TERM_NEXT_L2_OUTPUT,
42 u32 arp_term_next_node_index[32];
47 } ethernet_arp_input_trace_t;
49 #define foreach_ethernet_arp_error \
50 _ (replies_sent, "ARP replies sent") \
51 _ (l2_type_not_ethernet, "L2 type not ethernet") \
52 _ (l3_type_not_ip4, "L3 type not IP4") \
53 _ (l3_src_address_not_local, "IP4 source address not local to subnet") \
54 _ (l3_dst_address_not_local, "IP4 destination address not local to subnet") \
55 _ (l3_dst_address_unset, "IP4 destination address is unset") \
56 _ (l3_src_address_is_local, "IP4 source address matches local interface") \
57 _ (l3_src_address_learned, "ARP request IP4 source address learned") \
58 _ (replies_received, "ARP replies received") \
59 _ (opcode_not_request, "ARP opcode not request") \
60 _ (proxy_arp_replies_sent, "Proxy ARP replies sent") \
61 _ (l2_address_mismatch, "ARP hw addr does not match L2 frame src addr") \
62 _ (gratuitous_arp, "ARP probe or announcement dropped") \
63 _ (interface_no_table, "Interface is not mapped to an IP table") \
64 _ (interface_not_ip_enabled, "Interface is not IP enabled") \
65 _ (unnumbered_mismatch, "RX interface is unnumbered to different subnet") \
69 #define _(sym,string) ETHERNET_ARP_ERROR_##sym,
70 foreach_ethernet_arp_error
73 } ethernet_arp_reply_error_t;
75 static char *ethernet_arp_error_strings[] = {
76 #define _(sym,string) string,
77 foreach_ethernet_arp_error
82 format_arp_term_input_trace (u8 * s, va_list * va)
84 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*va, vlib_main_t *);
85 CLIB_UNUSED (vlib_node_t * node) = va_arg (*va, vlib_node_t *);
86 ethernet_arp_input_trace_t *t = va_arg (*va, ethernet_arp_input_trace_t *);
88 /* arp-term trace data saved is either arp or ip6/icmp6 packet:
89 - for arp, the 1st 16-bit field is hw type of value of 0x0001.
90 - for ip6, the first nibble has value of 6. */
91 s = format (s, "%U", t->packet_data[0] == 0 ?
92 format_ethernet_arp_header : format_ip6_header,
93 t->packet_data, sizeof (t->packet_data));
99 l2_arp_term_set_publisher_node (bool on)
101 l2_arp_term_main_t *l2am = &l2_arp_term_main;
107 l2_arp_term_publish (l2_arp_term_publish_event_t * ctx)
109 l2_arp_term_main_t *l2am = &l2_arp_term_main;
111 vec_add1 (l2am->publish_events, *ctx);
113 vlib_process_signal_event (vlib_get_main (),
114 l2_arp_term_process_node.index,
115 L2_ARP_TERM_EVENT_PUBLISH, 0);
121 l2_arp_term_publish_v4_dp (u32 sw_if_index,
122 const ethernet_arp_ip4_over_ethernet_address_t * a)
124 l2_arp_term_main_t *l2am = &l2_arp_term_main;
129 l2_arp_term_publish_event_t args = {
130 .sw_if_index = sw_if_index,
131 .type = IP46_TYPE_IP4,
136 vl_api_rpc_call_main_thread (l2_arp_term_publish, (u8 *) & args,
141 l2_arp_term_publish_v6_dp (u32 sw_if_index,
142 const ip6_address_t * addr,
143 const mac_address_t * mac)
145 l2_arp_term_main_t *l2am = &l2_arp_term_main;
150 l2_arp_term_publish_event_t args = {
151 .sw_if_index = sw_if_index,
152 .type = IP46_TYPE_IP6,
157 vl_api_rpc_call_main_thread (l2_arp_term_publish, (u8 *) & args,
162 vnet_ip6_nd_term (vlib_main_t * vm,
163 vlib_node_runtime_t * node,
165 ethernet_header_t * eth,
166 ip6_header_t * ip, u32 sw_if_index, u16 bd_index)
168 icmp6_neighbor_solicitation_or_advertisement_header_t *ndh;
171 mac_address_from_bytes (&mac, eth->src_address);
172 ndh = ip6_next_header (ip);
173 if (ndh->icmp.type != ICMP6_neighbor_solicitation &&
174 ndh->icmp.type != ICMP6_neighbor_advertisement)
177 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
178 (p0->flags & VLIB_BUFFER_IS_TRACED)))
180 u8 *t0 = vlib_add_trace (vm, node, p0,
181 sizeof (icmp6_input_trace_t));
182 clib_memcpy (t0, ip, sizeof (icmp6_input_trace_t));
185 /* Check if anyone want ND events for L2 BDs */
186 if (PREDICT_FALSE (!ip6_address_is_link_local_unicast (&ip->src_address)))
188 l2_arp_term_publish_v6_dp (sw_if_index, &ip->src_address, &mac);
191 /* Check if MAC entry exsist for solicited target IP */
192 if (ndh->icmp.type == ICMP6_neighbor_solicitation)
194 icmp6_neighbor_discovery_ethernet_link_layer_address_option_t *opt;
195 l2_bridge_domain_t *bd_config;
198 opt = (void *) (ndh + 1);
199 if ((opt->header.type !=
200 ICMP6_NEIGHBOR_DISCOVERY_OPTION_source_link_layer_address) ||
201 (opt->header.n_data_u64s != 1))
202 return 0; /* source link layer address option not present */
204 bd_config = vec_elt_at_index (l2input_main.bd_configs, bd_index);
206 (u8 *) hash_get_mem (bd_config->mac_by_ip6, &ndh->target_address);
208 { /* found ip-mac entry, generate eighbor advertisement response */
210 vlib_node_runtime_t *error_node =
211 vlib_node_get_runtime (vm, ip6_icmp_input_node.index);
212 ip->dst_address = ip->src_address;
213 ip->src_address = ndh->target_address;
216 ICMP6_NEIGHBOR_DISCOVERY_OPTION_target_link_layer_address;
217 clib_memcpy (opt->ethernet_address, macp, 6);
218 ndh->icmp.type = ICMP6_neighbor_advertisement;
219 ndh->advertisement_flags = clib_host_to_net_u32
220 (ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_SOLICITED |
221 ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE);
222 ndh->icmp.checksum = 0;
224 ip6_tcp_udp_icmp_compute_checksum (vm, p0, ip, &bogus_length);
225 clib_memcpy (eth->dst_address, eth->src_address, 6);
226 clib_memcpy (eth->src_address, macp, 6);
227 vlib_error_count (vm, error_node->node_index,
228 ICMP6_ERROR_NEIGHBOR_ADVERTISEMENTS_TX, 1);
238 arp_term_l2bd (vlib_main_t * vm,
239 vlib_node_runtime_t * node, vlib_frame_t * frame)
241 l2input_main_t *l2im = &l2input_main;
242 u32 n_left_from, next_index, *from, *to_next;
243 u32 n_replies_sent = 0;
244 u16 last_bd_index = ~0;
245 l2_bridge_domain_t *last_bd_config = 0;
246 l2_input_config_t *cfg0;
248 from = vlib_frame_vector_args (frame);
249 n_left_from = frame->n_vectors;
250 next_index = node->cached_next_index;
252 while (n_left_from > 0)
256 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
258 while (n_left_from > 0 && n_left_to_next > 0)
261 ethernet_header_t *eth0;
262 ethernet_arp_header_t *arp0;
265 u32 pi0, error0, next0, sw_if_index0;
278 p0 = vlib_get_buffer (vm, pi0);
279 // Terminate only local (SHG == 0) ARP
280 if (vnet_buffer (p0)->l2.shg != 0)
281 goto next_l2_feature;
283 eth0 = vlib_buffer_get_current (p0);
284 l3h0 = (u8 *) eth0 + vnet_buffer (p0)->l2.l2_len;
285 ethertype0 = clib_net_to_host_u16 (*(u16 *) (l3h0 - 2));
286 arp0 = (ethernet_arp_header_t *) l3h0;
288 if (ethertype0 != ETHERNET_TYPE_ARP)
292 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_request)) &&
294 clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply)))
297 /* Must be ARP request/reply packet here */
298 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE) &&
299 (p0->flags & VLIB_BUFFER_IS_TRACED)))
301 u8 *t0 = vlib_add_trace (vm, node, p0,
302 sizeof (ethernet_arp_input_trace_t));
303 clib_memcpy_fast (t0, l3h0,
304 sizeof (ethernet_arp_input_trace_t));
310 clib_net_to_host_u16 (ETHERNET_ARP_HARDWARE_TYPE_ethernet)
311 ? ETHERNET_ARP_ERROR_l2_type_not_ethernet : error0);
314 clib_net_to_host_u16 (ETHERNET_TYPE_IP4) ?
315 ETHERNET_ARP_ERROR_l3_type_not_ip4 : error0);
317 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
322 /* Trash ARP packets whose ARP-level source addresses do not
323 match, or if requester address is mcast */
325 (!ethernet_mac_address_equal (eth0->src_address,
326 arp0->ip4_over_ethernet[0].
328 || ethernet_address_cast (arp0->ip4_over_ethernet[0].mac.bytes))
330 /* VRRP virtual MAC may be different to SMAC in ARP reply */
331 if (!ethernet_mac_address_equal
332 (arp0->ip4_over_ethernet[0].mac.bytes, vrrp_prefix))
334 error0 = ETHERNET_ARP_ERROR_l2_address_mismatch;
339 (ip4_address_is_multicast (&arp0->ip4_over_ethernet[0].ip4)))
341 error0 = ETHERNET_ARP_ERROR_l3_src_address_not_local;
345 /* Check if anyone want ARP request events for L2 BDs */
346 l2_arp_term_publish_v4_dp (sw_if_index0,
347 &arp0->ip4_over_ethernet[0]);
349 /* lookup BD mac_by_ip4 hash table for MAC entry */
350 ip0 = arp0->ip4_over_ethernet[1].ip4.as_u32;
351 bd_index0 = vnet_buffer (p0)->l2.bd_index;
352 if (PREDICT_FALSE ((bd_index0 != last_bd_index)
353 || (last_bd_index == (u16) ~ 0)))
355 last_bd_index = bd_index0;
356 last_bd_config = vec_elt_at_index (l2im->bd_configs, bd_index0);
358 macp0 = (u8 *) hash_get (last_bd_config->mac_by_ip4, ip0);
360 if (PREDICT_FALSE (!macp0))
361 goto next_l2_feature; /* MAC not found */
362 if (PREDICT_FALSE (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
363 arp0->ip4_over_ethernet[1].ip4.as_u32))
364 goto next_l2_feature; /* GARP */
366 /* MAC found, send ARP reply -
367 Convert ARP request packet to ARP reply */
368 arp0->opcode = clib_host_to_net_u16 (ETHERNET_ARP_OPCODE_reply);
369 arp0->ip4_over_ethernet[1] = arp0->ip4_over_ethernet[0];
370 arp0->ip4_over_ethernet[0].ip4.as_u32 = ip0;
371 mac_address_from_bytes (&arp0->ip4_over_ethernet[0].mac, macp0);
372 clib_memcpy_fast (eth0->dst_address, eth0->src_address, 6);
373 clib_memcpy_fast (eth0->src_address, macp0, 6);
377 /* For BVI, need to use l2-fwd node to send ARP reply as
378 l2-output node cannot output packet to BVI properly */
379 cfg0 = vec_elt_at_index (l2im->configs, sw_if_index0);
380 if (PREDICT_FALSE (cfg0->bvi))
382 vnet_buffer (p0)->l2.feature_bitmap |= L2INPUT_FEAT_FWD;
383 vnet_buffer (p0)->sw_if_index[VLIB_RX] = 0;
384 goto next_l2_feature;
387 /* Send ARP/ND reply back out input interface through l2-output */
388 vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
389 next0 = ARP_TERM_NEXT_L2_OUTPUT;
390 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
391 to_next, n_left_to_next, pi0,
396 /* IP6 ND event notification or solicitation handling to generate
397 local response instead of flooding */
398 iph0 = (ip6_header_t *) l3h0;
399 if (PREDICT_FALSE (ethertype0 == ETHERNET_TYPE_IP6 &&
400 iph0->protocol == IP_PROTOCOL_ICMP6 &&
401 !ip6_address_is_unspecified
402 (&iph0->src_address)))
404 sw_if_index0 = vnet_buffer (p0)->sw_if_index[VLIB_RX];
406 (vm, node, p0, eth0, iph0, sw_if_index0,
407 vnet_buffer (p0)->l2.bd_index))
408 goto output_response;
413 next0 = vnet_l2_feature_next (p0, arp_term_next_node_index,
414 L2INPUT_FEAT_ARP_TERM);
415 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
416 to_next, n_left_to_next,
422 if (0 == arp0->ip4_over_ethernet[0].ip4.as_u32 ||
423 (arp0->ip4_over_ethernet[0].ip4.as_u32 ==
424 arp0->ip4_over_ethernet[1].ip4.as_u32))
426 error0 = ETHERNET_ARP_ERROR_gratuitous_arp;
428 next0 = ARP_TERM_NEXT_DROP;
429 p0->error = node->errors[error0];
431 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
432 to_next, n_left_to_next, pi0,
436 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
439 vlib_error_count (vm, node->node_index,
440 ETHERNET_ARP_ERROR_replies_sent, n_replies_sent);
441 return frame->n_vectors;
445 VLIB_REGISTER_NODE (arp_term_l2bd_node, static) = {
446 .function = arp_term_l2bd,
447 .name = "arp-term-l2bd",
448 .vector_size = sizeof (u32),
449 .n_errors = ETHERNET_ARP_N_ERROR,
450 .error_strings = ethernet_arp_error_strings,
451 .n_next_nodes = ARP_TERM_N_NEXT,
453 [ARP_TERM_NEXT_L2_OUTPUT] = "l2-output",
454 [ARP_TERM_NEXT_DROP] = "error-drop",
456 .format_buffer = format_ethernet_arp_header,
457 .format_trace = format_arp_term_input_trace,
462 arp_term_init (vlib_main_t * vm)
464 // Initialize the feature next-node indexes
465 feat_bitmap_init_next_nodes (vm,
466 arp_term_l2bd_node.index,
468 l2input_get_feat_names (),
469 arp_term_next_node_index);
473 VLIB_INIT_FUNCTION (arp_term_init);
476 * fd.io coding-style-patch-verification: ON
479 * eval: (c-set-style "gnu")