2 * Copyright (c) 2017 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 * This file implements caching of ioam header and reattaching
17 * it in response message by performing request-response matching.
18 * Works for TCP SYN/SYN-ACK.
19 * This feature is used for anycast server selection.
20 * ioam data thus cached is used to measure and get complete round trip
21 * network path to help in server selection.
22 * There are 2 graph nodes defined to :
23 * 1. process packets that contain iOAM header and cache it
24 * 2. process TCP SYN-ACKs and reattach ioam header from the
25 * cache corresponding to TCP-SYN
26 * These graph nodes are attached to the vnet graph based on
27 * ioam cache and classifier configs.
29 * If db06::06 is the anycast service IP6 address:
33 * Apply this classifier on interface where requests for anycast service are received:
34 * classify session acl-hit-next ip6-node ip6-lookup table-index 0 match l3 ip6 dst db06::06
35 * ioam-decap anycast <<< ioam-decap is hooked to cache when set ioam ip6 cache is enabled
37 * Apply this classifier on interface where responses from anycast service are received:
38 * classify session acl-hit-next ip6-node ip6-add-from-cache-hop-by-hop table-index 0 match l3
39 * ip6 src db06::06 ioam-encap anycast-response
42 #include <vlib/vlib.h>
43 #include <vnet/vnet.h>
44 #include <vppinfra/error.h>
45 #include <vnet/ip/ip.h>
46 #include <ioam/ip6/ioam_cache.h>
47 #include <vnet/ip/ip6_hop_by_hop.h>
48 #include <vnet/ip/ip6_hop_by_hop_packet.h>
49 #include <vnet/ip/ip6_inlines.h>
57 /* packet trace format function */
59 format_cache_trace (u8 * s, va_list * args)
61 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
62 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
63 cache_trace_t *t = va_arg (*args, cache_trace_t *);
65 s = format (s, "CACHE: flow_label %d, next index %d",
66 t->flow_label, t->next_index);
70 #define foreach_cache_error \
71 _(RECORDED, "ip6 iOAM headers cached")
75 #define _(sym,str) CACHE_ERROR_##sym,
81 static char *cache_error_strings[] = {
82 #define _(sym,string) string,
89 IOAM_CACHE_NEXT_POP_HBYH,
94 ip6_ioam_cache_node_fn (vlib_main_t * vm,
95 vlib_node_runtime_t * node, vlib_frame_t * frame)
97 u32 n_left_from, *from, *to_next;
98 cache_next_t next_index;
101 from = vlib_frame_vector_args (frame);
102 n_left_from = frame->n_vectors;
103 next_index = node->cached_next_index;
105 while (n_left_from > 0)
109 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
111 while (n_left_from > 0 && n_left_to_next > 0)
115 u32 next0 = IOAM_CACHE_NEXT_POP_HBYH;
117 ip6_hop_by_hop_header_t *hbh0;
121 /* speculatively enqueue p0 to the current next frame */
129 p0 = vlib_get_buffer (vm, bi0);
130 ip0 = vlib_buffer_get_current (p0);
131 if (IP_PROTOCOL_TCP ==
132 ip6_locate_header (p0, ip0, IP_PROTOCOL_TCP, &tcp_offset0))
134 tcp0 = (tcp_header_t *) ((u8 *) ip0 + tcp_offset0);
135 if ((tcp0->flags & TCP_FLAG_SYN) == TCP_FLAG_SYN &&
136 (tcp0->flags & TCP_FLAG_ACK) == 0)
138 /* Cache the ioam hbh header */
139 hbh0 = (ip6_hop_by_hop_header_t *) (ip0 + 1);
140 if (0 == ioam_cache_add (p0,
145 (tcp0->dst_port), hbh0,
147 (tcp0->seq_number) + 1))
153 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)))
155 if (p0->flags & VLIB_BUFFER_IS_TRACED)
158 vlib_add_trace (vm, node, p0, sizeof (*t));
161 (ip0->ip_version_traffic_class_and_flow_label);
162 t->next_index = next0;
165 /* verify speculative enqueue, maybe switch current next frame */
166 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
167 to_next, n_left_to_next,
171 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
174 vlib_node_increment_counter (vm, ioam_cache_node.index,
175 CACHE_ERROR_RECORDED, recorded);
176 return frame->n_vectors;
180 * Node for IP6 iOAM header cache
183 VLIB_REGISTER_NODE (ioam_cache_node) =
185 .function = ip6_ioam_cache_node_fn,
186 .name = "ip6-ioam-cache",
187 .vector_size = sizeof (u32),
188 .format_trace = format_cache_trace,
189 .type = VLIB_NODE_TYPE_INTERNAL,
190 .n_errors = ARRAY_LEN (cache_error_strings),
191 .error_strings = cache_error_strings,
192 .n_next_nodes = IOAM_CACHE_N_NEXT,
193 /* edit / add dispositions here */
196 [IOAM_CACHE_NEXT_POP_HBYH] = "ip6-pop-hop-by-hop"
204 } ip6_add_from_cache_hbh_trace_t;
206 /* packet trace format function */
208 format_ip6_add_from_cache_hbh_trace (u8 * s, va_list * args)
210 CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
211 CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
212 ip6_add_from_cache_hbh_trace_t *t = va_arg (*args,
213 ip6_add_from_cache_hbh_trace_t
216 s = format (s, "IP6_ADD_FROM_CACHE_HBH: next index %d", t->next_index);
220 #define foreach_ip6_add_from_cache_hbh_error \
221 _(PROCESSED, "Pkts w/ added ip6 hop-by-hop options")
225 #define _(sym,str) IP6_ADD_FROM_CACHE_HBH_ERROR_##sym,
226 foreach_ip6_add_from_cache_hbh_error
228 IP6_ADD_FROM_CACHE_HBH_N_ERROR,
229 } ip6_add_from_cache_hbh_error_t;
231 static char *ip6_add_from_cache_hbh_error_strings[] = {
232 #define _(sym,string) string,
233 foreach_ip6_add_from_cache_hbh_error
237 #define foreach_ip6_ioam_cache_input_next \
238 _(IP6_LOOKUP, "ip6-lookup") \
239 _(DROP, "error-drop")
243 #define _(s,n) IP6_IOAM_CACHE_INPUT_NEXT_##s,
244 foreach_ip6_ioam_cache_input_next
246 IP6_IOAM_CACHE_INPUT_N_NEXT,
247 } ip6_ioam_cache_input_next_t;
250 VLIB_NODE_FN (ip6_add_from_cache_hbh_node) (vlib_main_t * vm,
251 vlib_node_runtime_t * node,
252 vlib_frame_t * frame)
254 ioam_cache_main_t *cm = &ioam_cache_main;
255 u32 n_left_from, *from, *to_next;
256 ip_lookup_next_t next_index;
260 u32 sr_rewrite_len = vec_len (cm->sr_rewrite_template);
262 from = vlib_frame_vector_args (frame);
263 n_left_from = frame->n_vectors;
264 next_index = node->cached_next_index;
266 while (n_left_from > 0)
270 vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
272 while (n_left_from > 0 && n_left_to_next > 0)
278 ip6_hop_by_hop_header_t *hbh0;
279 ip6_sr_header_t *srh0 = 0;
280 u64 *copy_src0, *copy_dst0;
284 ioam_cache_entry_t *entry = 0;
286 next0 = IP6_IOAM_CACHE_INPUT_NEXT_IP6_LOOKUP;
287 /* speculatively enqueue b0 to the current next frame */
295 b0 = vlib_get_buffer (vm, bi0);
297 ip0 = vlib_buffer_get_current (b0);
298 if (IP_PROTOCOL_TCP !=
299 ip6_locate_header (b0, ip0, IP_PROTOCOL_TCP, &tcp_offset0))
303 tcp0 = (tcp_header_t *) ((u8 *) ip0 + tcp_offset0);
304 if (((tcp0->flags & TCP_FLAG_SYN) == TCP_FLAG_SYN &&
305 (tcp0->flags & TCP_FLAG_ACK) == TCP_FLAG_ACK) ||
306 (tcp0->flags & TCP_FLAG_RST) == TCP_FLAG_RST)
308 if (0 != (entry = ioam_cache_lookup (ip0,
314 (tcp0->ack_number))))
316 rewrite = entry->ioam_rewrite_string;
317 rewrite_len = vec_len (rewrite);
321 next0 = IP6_IOAM_CACHE_INPUT_NEXT_DROP;
329 /* Copy the ip header left by the required amount */
330 copy_dst0 = (u64 *) (((u8 *) ip0) - (rewrite_len + sr_rewrite_len));
331 copy_src0 = (u64 *) ip0;
333 copy_dst0[0] = copy_src0[0];
334 copy_dst0[1] = copy_src0[1];
335 copy_dst0[2] = copy_src0[2];
336 copy_dst0[3] = copy_src0[3];
337 copy_dst0[4] = copy_src0[4];
338 vlib_buffer_advance (b0, -(word) (rewrite_len + sr_rewrite_len));
339 ip0 = vlib_buffer_get_current (b0);
341 hbh0 = (ip6_hop_by_hop_header_t *) (ip0 + 1);
342 srh0 = (ip6_sr_header_t *) ((u8 *) hbh0 + rewrite_len);
343 /* $$$ tune, rewrite_len is a multiple of 8 */
344 clib_memcpy_fast (hbh0, rewrite, rewrite_len);
345 clib_memcpy_fast (srh0, cm->sr_rewrite_template, sr_rewrite_len);
346 /* Copy dst address into the DA slot in the segment list */
347 clib_memcpy_fast (srh0->segments, ip0->dst_address.as_u64,
348 sizeof (ip6_address_t));
349 /* Rewrite the ip6 dst address with the first hop */
350 clib_memcpy_fast (ip0->dst_address.as_u64, entry->next_hop.as_u64,
351 sizeof (ip6_address_t));
352 clib_memcpy_fast (&srh0->segments[1],
353 (u8 *) hbh0 + entry->my_address_offset,
354 sizeof (ip6_address_t));
355 ioam_cache_entry_free (entry);
357 /* Patch the protocol chain, insert the h-b-h (type 0) header */
358 srh0->protocol = ip0->protocol;
359 hbh0->protocol = IPPROTO_IPV6_ROUTE;
362 clib_net_to_host_u16 (ip0->payload_length) + rewrite_len +
364 ip0->payload_length = clib_host_to_net_u16 (new_l0);
367 if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
368 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
370 ip6_add_from_cache_hbh_trace_t *t =
371 vlib_add_trace (vm, node, b0, sizeof (*t));
372 t->next_index = next0;
375 /* verify speculative enqueue, maybe switch current next frame */
376 vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
377 to_next, n_left_to_next,
381 vlib_put_next_frame (vm, node, next_index, n_left_to_next);
384 vlib_node_increment_counter (vm, cm->ip6_add_from_cache_hbh_node_index,
385 IP6_ADD_FROM_CACHE_HBH_ERROR_PROCESSED,
387 return frame->n_vectors;
390 VLIB_REGISTER_NODE (ip6_add_from_cache_hbh_node) =
392 .name = "ip6-add-from-cache-hop-by-hop",
393 .vector_size = sizeof (u32),
394 .format_trace = format_ip6_add_from_cache_hbh_trace,
395 .type = VLIB_NODE_TYPE_INTERNAL,
396 .n_errors = ARRAY_LEN (ip6_add_from_cache_hbh_error_strings),
397 .error_strings = ip6_add_from_cache_hbh_error_strings,
398 /* See ip/lookup.h */
399 .n_next_nodes = IP6_IOAM_CACHE_INPUT_N_NEXT,
402 #define _(s,n) [IP6_IOAM_CACHE_INPUT_NEXT_##s] = n,
403 foreach_ip6_ioam_cache_input_next
410 * fd.io coding-style-patch-verification: ON
413 * eval: (c-set-style "gnu")