Line data Source code
1 : /*
2 : * ip/ip6_neighbor.c: IP6 neighbor handling
3 : *
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:
8 : *
9 : * http://www.apache.org/licenses/LICENSE-2.0
10 : *
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.
16 : */
17 :
18 : #include <vnet/ip-neighbor/ip6_neighbor.h>
19 : #include <vnet/ip-neighbor/ip_neighbor.api_enum.h>
20 : #include <vnet/util/throttle.h>
21 : #include <vnet/fib/fib_sas.h>
22 : #include <vnet/ip/ip_sas.h>
23 :
24 : /** ND throttling */
25 : static throttle_t nd_throttle;
26 :
27 575 : VLIB_REGISTER_LOG_CLASS (ip6_neighbor_log, static) = {
28 : .class_name = "ip6",
29 : .subclass_name = "neighbor",
30 : };
31 :
32 : #define log_debug(fmt, ...) \
33 : vlib_log_debug (ip6_neighbor_log.class, fmt, __VA_ARGS__)
34 : void
35 57 : ip6_neighbor_probe_dst (u32 sw_if_index, u32 thread_index,
36 : const ip6_address_t *dst)
37 : {
38 : ip6_address_t src;
39 :
40 62 : if (fib_sas6_get (sw_if_index, dst, &src) ||
41 5 : ip6_sas_by_sw_if_index (sw_if_index, dst, &src))
42 52 : ip6_neighbor_probe (vlib_get_main (), vnet_get_main (), sw_if_index,
43 : thread_index, &src, dst);
44 57 : }
45 :
46 : void
47 12 : ip6_neighbor_advertise (vlib_main_t *vm, vnet_main_t *vnm, u32 sw_if_index,
48 : u32 thread_index, const ip6_address_t *addr)
49 : {
50 12 : vnet_hw_interface_t *hi = vnet_get_sup_hw_interface (vnm, sw_if_index);
51 12 : ip6_main_t *i6m = &ip6_main;
52 : u8 *rewrite, rewrite_len;
53 : u8 dst_address[6];
54 :
55 12 : if (NULL == addr)
56 0 : addr = ip6_interface_first_address (i6m, sw_if_index);
57 :
58 12 : if (addr)
59 : {
60 12 : log_debug ("Sending unsolicitated NA IP6 address %U on sw_if_idex %d",
61 : format_ip6_address, addr, sw_if_index);
62 :
63 : /* Form unsolicited neighbor advertisement packet from NS pkt template */
64 : int bogus_length;
65 12 : u32 bi = 0;
66 : icmp6_neighbor_solicitation_header_t *h =
67 12 : vlib_packet_template_get_packet (vm,
68 : &ip6_neighbor_packet_template,
69 : &bi);
70 12 : if (!h)
71 0 : return;
72 :
73 12 : ip6_set_reserved_multicast_address (&h->ip.dst_address,
74 : IP6_MULTICAST_SCOPE_link_local,
75 : IP6_MULTICAST_GROUP_ID_all_hosts);
76 12 : h->ip.src_address = addr[0];
77 12 : h->neighbor.icmp.type = ICMP6_neighbor_advertisement;
78 12 : h->neighbor.target_address = addr[0];
79 12 : h->neighbor.advertisement_flags = clib_host_to_net_u32
80 : (ICMP6_NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE);
81 12 : h->link_layer_option.header.type =
82 : ICMP6_NEIGHBOR_DISCOVERY_OPTION_target_link_layer_address;
83 12 : clib_memcpy (h->link_layer_option.ethernet_address,
84 : hi->hw_address, vec_len (hi->hw_address));
85 12 : h->neighbor.icmp.checksum =
86 12 : ip6_tcp_udp_icmp_compute_checksum (vm, 0, &h->ip, &bogus_length);
87 12 : ASSERT (bogus_length == 0);
88 :
89 : /* Setup MAC header with IP6 Etype and mcast DMAC */
90 12 : vlib_buffer_t *b = vlib_get_buffer (vm, bi);
91 12 : ip6_multicast_ethernet_address (dst_address,
92 : IP6_MULTICAST_GROUP_ID_all_hosts);
93 12 : rewrite =
94 12 : ethernet_build_rewrite (vnm, sw_if_index, VNET_LINK_IP6, dst_address);
95 12 : rewrite_len = vec_len (rewrite);
96 12 : vlib_buffer_advance (b, -rewrite_len);
97 12 : ethernet_header_t *e = vlib_buffer_get_current (b);
98 12 : clib_memcpy (e->dst_address, rewrite, rewrite_len);
99 12 : vec_free (rewrite);
100 :
101 : /* Send unsolicited ND advertisement packet out the specified interface */
102 12 : vnet_buffer (b)->sw_if_index[VLIB_RX] =
103 12 : vnet_buffer (b)->sw_if_index[VLIB_TX] = sw_if_index;
104 12 : vlib_frame_t *f = vlib_get_frame_to_node (vm, hi->output_node_index);
105 12 : u32 *to_next = vlib_frame_vector_args (f);
106 12 : to_next[0] = bi;
107 12 : f->n_vectors = 1;
108 12 : vlib_put_frame_to_node (vm, hi->output_node_index, f);
109 :
110 12 : vlib_increment_simple_counter (
111 : &ip_neighbor_counters[AF_IP6].ipnc[VLIB_TX][IP_NEIGHBOR_CTR_GRAT],
112 : thread_index, sw_if_index, 1);
113 : }
114 : }
115 :
116 : typedef enum
117 : {
118 : IP6_NBR_NEXT_DROP,
119 : IP6_NBR_NEXT_REPLY_TX,
120 : IP6_NBR_N_NEXT,
121 : } ip6_discover_neighbor_next_t;
122 :
123 : static uword
124 47 : ip6_discover_neighbor_inline (vlib_main_t * vm,
125 : vlib_node_runtime_t * node,
126 : vlib_frame_t * frame, int is_glean)
127 : {
128 47 : vnet_main_t *vnm = vnet_get_main ();
129 : u32 *from, *to_next_drop;
130 : uword n_left_from, n_left_to_next_drop;
131 : u64 seed;
132 47 : u32 thread_index = vm->thread_index;
133 :
134 47 : if (node->flags & VLIB_NODE_FLAG_TRACE)
135 12 : ip6_forward_next_trace (vm, node, frame, VLIB_TX);
136 :
137 47 : seed = throttle_seed (&nd_throttle, thread_index, vlib_time_now (vm));
138 :
139 47 : from = vlib_frame_vector_args (frame);
140 47 : n_left_from = frame->n_vectors;
141 :
142 94 : while (n_left_from > 0)
143 : {
144 47 : vlib_get_next_frame (vm, node, IP6_NBR_NEXT_DROP,
145 : to_next_drop, n_left_to_next_drop);
146 :
147 349 : while (n_left_from > 0 && n_left_to_next_drop > 0)
148 : {
149 : u32 pi0, adj_index0, sw_if_index0, drop0, r0;
150 : vnet_hw_interface_t *hw_if0;
151 : vlib_buffer_t *p0, *b0;
152 : ip_adjacency_t *adj0;
153 : ip6_address_t src;
154 : ip6_header_t *ip0;
155 :
156 302 : pi0 = from[0];
157 :
158 302 : p0 = vlib_get_buffer (vm, pi0);
159 :
160 302 : adj_index0 = vnet_buffer (p0)->ip.adj_index[VLIB_TX];
161 :
162 302 : ip0 = vlib_buffer_get_current (p0);
163 :
164 302 : adj0 = adj_get (adj_index0);
165 :
166 302 : if (!is_glean)
167 : {
168 264 : ip0->dst_address.as_u64[0] =
169 264 : adj0->sub_type.nbr.next_hop.ip6.as_u64[0];
170 264 : ip0->dst_address.as_u64[1] =
171 264 : adj0->sub_type.nbr.next_hop.ip6.as_u64[1];
172 : }
173 :
174 302 : sw_if_index0 = adj0->rewrite_header.sw_if_index;
175 302 : vnet_buffer (p0)->sw_if_index[VLIB_TX] = sw_if_index0;
176 :
177 : /* combine the address and interface for a hash */
178 302 : r0 = ip6_address_hash_to_u64 (&ip0->dst_address) ^ sw_if_index0;
179 :
180 302 : drop0 = throttle_check (&nd_throttle, thread_index, r0, seed);
181 :
182 302 : from += 1;
183 302 : n_left_from -= 1;
184 302 : to_next_drop[0] = pi0;
185 302 : to_next_drop += 1;
186 302 : n_left_to_next_drop -= 1;
187 :
188 302 : if (drop0)
189 : {
190 255 : p0->error = node->errors[IP6_NEIGHBOR_ERROR_THROTTLED];
191 255 : continue;
192 : }
193 :
194 47 : hw_if0 = vnet_get_sup_hw_interface (vnm, sw_if_index0);
195 :
196 : /* If the interface is link-down, drop the pkt */
197 47 : if (!(hw_if0->flags & VNET_HW_INTERFACE_FLAG_LINK_UP))
198 0 : drop0 = 1;
199 :
200 47 : if (!ip6_link_is_enabled (sw_if_index0))
201 0 : drop0 = 1;
202 :
203 : /*
204 : * the adj has been updated to a rewrite but the node the DPO that got
205 : * us here hasn't - yet. no big deal. we'll drop while we wait.
206 : */
207 47 : if (IP_LOOKUP_NEXT_REWRITE == adj0->lookup_next_index)
208 0 : drop0 = 1;
209 :
210 47 : if (drop0)
211 : {
212 0 : p0->error = node->errors[IP6_NEIGHBOR_ERROR_DROP];
213 0 : continue;
214 : }
215 :
216 : /*
217 : * Choose source address based on destination lookup
218 : * adjacency.
219 : */
220 47 : const ip6_address_t *ll = ip6_get_link_local_address (sw_if_index0);
221 47 : if (!ll)
222 : {
223 : /* There is no address on the interface */
224 0 : p0->error = node->errors[IP6_NEIGHBOR_ERROR_NO_SOURCE_ADDRESS];
225 0 : continue;
226 : }
227 47 : ip6_address_copy (&src, ll);
228 :
229 47 : b0 = ip6_neighbor_probe (vm, vnm, sw_if_index0, thread_index, &src,
230 47 : &ip0->dst_address);
231 :
232 47 : if (PREDICT_TRUE (NULL != b0))
233 : {
234 47 : clib_memcpy_fast (b0->opaque2, p0->opaque2,
235 : sizeof (p0->opaque2));
236 47 : b0->flags |= p0->flags & VLIB_BUFFER_IS_TRACED;
237 47 : b0->trace_handle = p0->trace_handle;
238 47 : p0->error = node->errors[IP6_NEIGHBOR_ERROR_REQUEST_SENT];
239 : }
240 : else
241 : {
242 : /* There is no address on the interface */
243 0 : p0->error = node->errors[IP6_NEIGHBOR_ERROR_NO_BUFFERS];
244 0 : continue;
245 : }
246 : }
247 :
248 47 : vlib_put_next_frame (vm, node, IP6_NBR_NEXT_DROP, n_left_to_next_drop);
249 : }
250 :
251 47 : return frame->n_vectors;
252 : }
253 :
254 : static uword
255 9 : ip6_discover_neighbor (vlib_main_t * vm,
256 : vlib_node_runtime_t * node, vlib_frame_t * frame)
257 : {
258 9 : return (ip6_discover_neighbor_inline (vm, node, frame, 0));
259 : }
260 :
261 : static uword
262 38 : ip6_glean (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * frame)
263 : {
264 38 : return (ip6_discover_neighbor_inline (vm, node, frame, 1));
265 : }
266 :
267 : /* *INDENT-OFF* */
268 183788 : VLIB_REGISTER_NODE (ip6_glean_node) =
269 : {
270 : .function = ip6_glean,
271 : .name = "ip6-glean",
272 : .vector_size = sizeof (u32),
273 : .format_trace = format_ip6_forward_next_trace,
274 : .n_errors = IP6_NEIGHBOR_N_ERROR,
275 : .error_counters = ip6_neighbor_error_counters,
276 : .n_next_nodes = IP6_NBR_N_NEXT,
277 : .next_nodes =
278 : {
279 : [IP6_NBR_NEXT_DROP] = "ip6-drop",
280 : [IP6_NBR_NEXT_REPLY_TX] = "ip6-rewrite-mcast",
281 : },
282 : };
283 183788 : VLIB_REGISTER_NODE (ip6_discover_neighbor_node) =
284 : {
285 : .function = ip6_discover_neighbor,
286 : .name = "ip6-discover-neighbor",
287 : .vector_size = sizeof (u32),
288 : .format_trace = format_ip6_forward_next_trace,
289 : .n_errors = IP6_NEIGHBOR_N_ERROR,
290 : .error_counters = ip6_neighbor_error_counters,
291 : .n_next_nodes = IP6_NBR_N_NEXT,
292 : .next_nodes =
293 : {
294 : [IP6_NBR_NEXT_DROP] = "ip6-drop",
295 : [IP6_NBR_NEXT_REPLY_TX] = "ip6-rewrite-mcast",
296 : },
297 : };
298 : /* *INDENT-ON* */
299 :
300 : /* Template used to generate IP6 neighbor solicitation packets. */
301 : vlib_packet_template_t ip6_neighbor_packet_template;
302 :
303 : static clib_error_t *
304 575 : ip6_neighbor_init (vlib_main_t * vm)
305 : {
306 : icmp6_neighbor_solicitation_header_t p;
307 :
308 575 : clib_memset (&p, 0, sizeof (p));
309 :
310 575 : p.ip.ip_version_traffic_class_and_flow_label =
311 575 : clib_host_to_net_u32 (0x6 << 28);
312 575 : p.ip.payload_length =
313 575 : clib_host_to_net_u16 (sizeof (p) -
314 : STRUCT_OFFSET_OF
315 : (icmp6_neighbor_solicitation_header_t, neighbor));
316 575 : p.ip.protocol = IP_PROTOCOL_ICMP6;
317 575 : p.ip.hop_limit = 255;
318 575 : ip6_set_solicited_node_multicast_address (&p.ip.dst_address, 0);
319 :
320 575 : p.neighbor.icmp.type = ICMP6_neighbor_solicitation;
321 :
322 575 : p.link_layer_option.header.type =
323 : ICMP6_NEIGHBOR_DISCOVERY_OPTION_source_link_layer_address;
324 575 : p.link_layer_option.header.n_data_u64s =
325 : sizeof (p.link_layer_option) / sizeof (u64);
326 :
327 575 : vlib_packet_template_init (vm,
328 : &ip6_neighbor_packet_template, &p, sizeof (p),
329 : /* alloc chunk size */ 8,
330 : "ip6 neighbor discovery");
331 :
332 575 : return NULL;
333 : }
334 :
335 49535 : VLIB_INIT_FUNCTION (ip6_neighbor_init);
336 :
337 : static clib_error_t *
338 575 : ip6_nd_main_loop_enter (vlib_main_t * vm)
339 : {
340 575 : vlib_thread_main_t *tm = &vlib_thread_main;
341 :
342 575 : throttle_init (&nd_throttle, tm->n_vlib_mains, THROTTLE_BITS, 1e-3);
343 :
344 575 : return 0;
345 : }
346 :
347 1727 : VLIB_MAIN_LOOP_ENTER_FUNCTION (ip6_nd_main_loop_enter);
348 :
349 : /*
350 : * fd.io coding-style-patch-verification: ON
351 : *
352 : * Local Variables:
353 : * eval: (c-set-style "gnu")
354 : * End:
355 : */
|
