2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
7 * http://www.apache.org/licenses/LICENSE-2.0
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
16 * ip/ip4_forward.c: IP v4 forwarding
18 * Copyright (c) 2008 Eliot Dresselhaus
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
40 #include <vnet/ip-neighbor/ip4_neighbor.h>
41 #include <vnet/ethernet/ethernet.h>
42 #include <vnet/util/throttle.h>
43 #include <vnet/fib/fib_sas.h>
44 #include <vnet/ip/ip_sas.h>
47 static throttle_t arp_throttle;
49 VLIB_REGISTER_LOG_CLASS (ip4_neighbor_log, static) = {
51 .subclass_name = "neighbor",
54 #define log_debug(fmt, ...) \
55 vlib_log_debug (ip4_neighbor_log.class, fmt, __VA_ARGS__)
58 ip4_neighbor_probe_dst (u32 sw_if_index, const ip4_address_t * dst)
63 /* any glean will do, it's just for the rewrite */
64 ai = adj_glean_get (FIB_PROTOCOL_IP4, sw_if_index, NULL);
66 if (ADJ_INDEX_INVALID != ai &&
67 (fib_sas4_get (sw_if_index, dst, &src) ||
68 ip4_sas_by_sw_if_index (sw_if_index, dst, &src)))
69 ip4_neighbor_probe (vlib_get_main (),
70 vnet_get_main (), adj_get (ai), &src, dst);
74 ip4_neighbor_advertise (vlib_main_t * vm,
76 u32 sw_if_index, const ip4_address_t * addr)
78 vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
79 ip4_main_t *i4m = &ip4_main;
80 u8 *rewrite, rewrite_len;
85 if (fib_sas4_get (sw_if_index, NULL, &tmp) ||
86 ip4_sas_by_sw_if_index (sw_if_index, NULL, &tmp))
92 log_debug ("Sending GARP for IP4 address %U on sw_if_idex %d",
93 format_ip4_address, addr, sw_if_index);
95 /* Form GARP packet for output - Gratuitous ARP is an ARP request packet
96 where the interface IP/MAC pair is used for both source and request
97 MAC/IP pairs in the request */
99 ethernet_arp_header_t *h = vlib_packet_template_get_packet
100 (vm, &i4m->ip4_arp_request_packet_template, &bi);
105 mac_address_from_bytes (&h->ip4_over_ethernet[0].mac, hi->hw_address);
106 mac_address_from_bytes (&h->ip4_over_ethernet[1].mac, hi->hw_address);
107 h->ip4_over_ethernet[0].ip4 = addr[0];
108 h->ip4_over_ethernet[1].ip4 = addr[0];
110 /* Setup MAC header with ARP Etype and broadcast DMAC */
111 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
113 ethernet_build_rewrite (vnm, sw_if_index, VNET_LINK_ARP,
114 VNET_REWRITE_FOR_SW_INTERFACE_ADDRESS_BROADCAST);
115 rewrite_len = vec_len (rewrite);
116 vlib_buffer_advance (b, -rewrite_len);
117 ethernet_header_t *e = vlib_buffer_get_current (b);
118 clib_memcpy_fast (e->dst_address, rewrite, rewrite_len);
121 /* Send GARP packet out the specified interface */
122 vnet_buffer (b)->sw_if_index[VLIB_RX] =
123 vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index;
124 vlib_frame_t *f = vlib_get_frame_to_node (vm, hi->output_node_index);
125 u32 *to_next = vlib_frame_vector_args (f);
128 vlib_put_frame_to_node (vm, hi->output_node_index, f);
133 ip4_arp_inline (vlib_main_t * vm,
134 vlib_node_runtime_t * node,
135 vlib_frame_t * frame, int is_glean)
137 vnet_main_t *vnm = vnet_get_main ();
138 u32 *from, *to_next_drop;
139 uword n_left_from, n_left_to_next_drop, next_index;
140 u32 thread_index = vm->thread_index;
143 if (node->flags & VLIB_NODE_FLAG_TRACE)
144 ip4_forward_next_trace (vm, node, frame, VLIB_TX);
146 seed = throttle_seed (&arp_throttle, thread_index, vlib_time_now (vm));
148 from = vlib_frame_vector_args (frame);
149 n_left_from = frame->n_vectors;
150 next_index = node->cached_next_index;
151 if (next_index == IP4_ARP_NEXT_DROP)
152 next_index = IP4_ARP_N_NEXT; /* point to first interface */
154 while (n_left_from > 0)
156 vlib_get_next_frame (vm, node, IP4_ARP_NEXT_DROP,
157 to_next_drop, n_left_to_next_drop);
159 while (n_left_from > 0 && n_left_to_next_drop > 0)
161 u32 pi0, adj_index0, sw_if_index0;
162 ip4_address_t resolve0, src0;
163 vlib_buffer_t *p0, *b0;
164 ip_adjacency_t *adj0;
168 p0 = vlib_get_buffer (vm, pi0);
172 to_next_drop[0] = pi0;
174 n_left_to_next_drop -= 1;
176 adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
177 adj0 = adj_get (adj_index0);
178 sw_if_index0 = adj0->rewrite_header.sw_if_index;
182 /* resolve the packet's destination */
183 ip4_header_t *ip0 = vlib_buffer_get_current (p0);
184 resolve0 = ip0->dst_address;
185 src0 = adj0->sub_type.glean.rx_pfx.fp_addr.ip4;
189 /* resolve the incomplete adj */
190 resolve0 = adj0->sub_type.nbr.next_hop.ip4;
191 /* Src IP address in ARP header. */
192 if (!fib_sas4_get (sw_if_index0, &resolve0, &src0) &&
193 !ip4_sas_by_sw_if_index (sw_if_index0, &resolve0, &src0))
195 /* No source address available */
196 p0->error = node->errors[IP4_ARP_ERROR_NO_SOURCE_ADDRESS];
201 /* combine the address and interface for the hash key */
202 r0 = (u64) resolve0.data_u32 << 32;
205 if (throttle_check (&arp_throttle, thread_index, r0, seed))
207 p0->error = node->errors[IP4_ARP_ERROR_THROTTLED];
212 * the adj has been updated to a rewrite but the node the DPO that got
213 * us here hasn't - yet. no big deal. we'll drop while we wait.
215 if (IP_LOOKUP_NEXT_REWRITE == adj0->lookup_next_index)
217 p0->error = node->errors[IP4_ARP_ERROR_RESOLVED];
222 * Can happen if the control-plane is programming tables
223 * with traffic flowing; at least that's today's lame excuse.
225 if ((is_glean && adj0->lookup_next_index != IP_LOOKUP_NEXT_GLEAN)
226 || (!is_glean && adj0->lookup_next_index != IP_LOOKUP_NEXT_ARP))
228 p0->error = node->errors[IP4_ARP_ERROR_NON_ARP_ADJ];
232 /* Send ARP request. */
233 b0 = ip4_neighbor_probe (vm, vnm, adj0, &src0, &resolve0);
235 if (PREDICT_TRUE (NULL != b0))
237 /* copy the persistent fields from the original */
238 clib_memcpy_fast (b0->opaque2, p0->opaque2,
239 sizeof (p0->opaque2));
240 p0->error = node->errors[IP4_ARP_ERROR_REQUEST_SENT];
244 p0->error = node->errors[IP4_ARP_ERROR_NO_BUFFERS];
249 vlib_put_next_frame (vm, node, IP4_ARP_NEXT_DROP, n_left_to_next_drop);
252 return frame->n_vectors;
255 VLIB_NODE_FN (ip4_arp_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
256 vlib_frame_t * frame)
258 return (ip4_arp_inline (vm, node, frame, 0));
261 VLIB_NODE_FN (ip4_glean_node) (vlib_main_t * vm, vlib_node_runtime_t * node,
262 vlib_frame_t * frame)
264 return (ip4_arp_inline (vm, node, frame, 1));
267 static char *ip4_arp_error_strings[] = {
268 [IP4_ARP_ERROR_THROTTLED] = "ARP requests throttled",
269 [IP4_ARP_ERROR_RESOLVED] = "ARP requests resolved",
270 [IP4_ARP_ERROR_NO_BUFFERS] = "ARP requests out of buffer",
271 [IP4_ARP_ERROR_REQUEST_SENT] = "ARP requests sent",
272 [IP4_ARP_ERROR_NON_ARP_ADJ] = "ARPs to non-ARP adjacencies",
273 [IP4_ARP_ERROR_NO_SOURCE_ADDRESS] = "no source address for ARP request",
277 VLIB_REGISTER_NODE (ip4_arp_node) =
280 .vector_size = sizeof (u32),
281 .format_trace = format_ip4_forward_next_trace,
282 .n_errors = ARRAY_LEN (ip4_arp_error_strings),
283 .error_strings = ip4_arp_error_strings,
284 .n_next_nodes = IP4_ARP_N_NEXT,
286 [IP4_ARP_NEXT_DROP] = "ip4-drop",
290 VLIB_REGISTER_NODE (ip4_glean_node) =
293 .vector_size = sizeof (u32),
294 .format_trace = format_ip4_forward_next_trace,
295 .n_errors = ARRAY_LEN (ip4_arp_error_strings),
296 .error_strings = ip4_arp_error_strings,
297 .n_next_nodes = IP4_ARP_N_NEXT,
299 [IP4_ARP_NEXT_DROP] = "ip4-drop",
304 #define foreach_notrace_ip4_arp_error \
312 static clib_error_t *
313 arp_notrace_init (vlib_main_t * vm)
315 vlib_node_runtime_t *rt = vlib_node_get_runtime (vm, ip4_arp_node.index);
317 /* don't trace ARP request packets */
319 vnet_pcap_drop_trace_filter_add_del \
320 (rt->errors[IP4_ARP_ERROR_##a], \
322 foreach_notrace_ip4_arp_error;
327 VLIB_INIT_FUNCTION (arp_notrace_init);
329 static clib_error_t *
330 ip4_neighbor_main_loop_enter (vlib_main_t * vm)
332 vlib_thread_main_t *tm = &vlib_thread_main;
333 u32 n_vlib_mains = tm->n_vlib_mains;
335 throttle_init (&arp_throttle, n_vlib_mains, 1e-3);
340 VLIB_MAIN_LOOP_ENTER_FUNCTION (ip4_neighbor_main_loop_enter);
344 * fd.io coding-style-patch-verification: ON
347 * eval: (c-set-style "gnu")