FD.io VPP  v21.01.1
Vector Packet Processing
adj.h
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2  * Copyright (c) 2016 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:
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12  * See the License for the specific language governing permissions and
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14  */
15 /**
16  * An adjacency is a representation of an attached L3 peer.
17  *
18  * Adjacency Sub-types:
19  * - neighbour: a representation of an attached L3 peer.
20  * Key:{addr,interface,link/ether-type}
21  * SHARED
22  * - glean: used to drive ARP/ND for packets destined to a local sub-net.
23  * 'glean' mean use the packet's destination address as the target
24  * address in the ARP packet.
25  * UNSHARED. Only one per-interface.
26  * - midchain: a neighbour adj on a virtual/tunnel interface.
27  *
28  * The API to create and update the adjacency is very sub-type specific. This
29  * is intentional as it encourages the user to carefully consider which adjacency
30  * sub-type they are really using, and hence assign it data in the appropriate
31  * sub-type space in the union of sub-types. This prevents the adj becoming a
32  * disorganised dumping group for 'my features needs a u16 somewhere' data. It
33  * is important to enforce this approach as space in the adjacency is a premium,
34  * as we need it to fit in 1 cache line.
35  *
36  * the API is also based around an index to an adjacency not a raw pointer. This
37  * is so the user doesn't suffer the same limp inducing firearm injuries that
38  * the author suffered as the adjacencies can realloc.
39  */
40 
41 #ifndef __ADJ_H__
42 #define __ADJ_H__
43 
44 #include <vnet/adj/adj_types.h>
45 #include <vnet/adj/adj_nbr.h>
46 #include <vnet/adj/adj_glean.h>
47 #include <vnet/adj/rewrite.h>
48 
49 /** @brief Common (IP4/IP6) next index stored in adjacency. */
50 typedef enum
51 {
52  /** Adjacency to drop this packet. */
54  /** Adjacency to punt this packet. */
56 
57  /** This packet is for one of our own IP addresses. */
59 
60  /** This packet matches an "incomplete adjacency" and packets
61  need to be passed to ARP to find rewrite string for
62  this destination. */
64 
65  /** This packet matches an "interface route" and packets
66  need to be passed to ARP to find rewrite string for
67  this destination. */
69 
70  /** This packet is to be rewritten and forwarded to the next
71  processing node. This is typically the output interface but
72  might be another node for further output processing. */
74 
75  /** This packets follow a mid-chain adjacency */
77 
78  /** This packets needs to go to ICMP error */
80 
81  /** Multicast Adjacency. */
83 
84  /** Broadcast Adjacency. */
86 
87  /** Multicast Midchain Adjacency. An Adjacency for sending multicast packets
88  * on a tunnel/virtual interface */
90 
92 } __attribute__ ((packed)) ip_lookup_next_t;
93 
94 typedef enum
95 {
98 
99 typedef enum
100 {
101  /* Hop-by-hop header handling */
107 
108 #define IP4_LOOKUP_NEXT_NODES { \
109  [IP_LOOKUP_NEXT_DROP] = "ip4-drop", \
110  [IP_LOOKUP_NEXT_PUNT] = "ip4-punt", \
111  [IP_LOOKUP_NEXT_LOCAL] = "ip4-local", \
112  [IP_LOOKUP_NEXT_ARP] = "ip4-arp", \
113  [IP_LOOKUP_NEXT_GLEAN] = "ip4-glean", \
114  [IP_LOOKUP_NEXT_REWRITE] = "ip4-rewrite", \
115  [IP_LOOKUP_NEXT_MCAST] = "ip4-rewrite-mcast", \
116  [IP_LOOKUP_NEXT_BCAST] = "ip4-rewrite-bcast", \
117  [IP_LOOKUP_NEXT_MIDCHAIN] = "ip4-midchain", \
118  [IP_LOOKUP_NEXT_MCAST_MIDCHAIN] = "ip4-mcast-midchain", \
119  [IP_LOOKUP_NEXT_ICMP_ERROR] = "ip4-icmp-error", \
120 }
121 
122 #define IP6_LOOKUP_NEXT_NODES { \
123  [IP_LOOKUP_NEXT_DROP] = "ip6-drop", \
124  [IP_LOOKUP_NEXT_PUNT] = "ip6-punt", \
125  [IP_LOOKUP_NEXT_LOCAL] = "ip6-local", \
126  [IP_LOOKUP_NEXT_ARP] = "ip6-discover-neighbor", \
127  [IP_LOOKUP_NEXT_GLEAN] = "ip6-glean", \
128  [IP_LOOKUP_NEXT_REWRITE] = "ip6-rewrite", \
129  [IP_LOOKUP_NEXT_BCAST] = "ip6-rewrite-bcast", \
130  [IP_LOOKUP_NEXT_MCAST] = "ip6-rewrite-mcast", \
131  [IP_LOOKUP_NEXT_MIDCHAIN] = "ip6-midchain", \
132  [IP_LOOKUP_NEXT_MCAST_MIDCHAIN] = "ip6-mcast-midchain", \
133  [IP_LOOKUP_NEXT_ICMP_ERROR] = "ip6-icmp-error", \
134  [IP6_LOOKUP_NEXT_HOP_BY_HOP] = "ip6-hop-by-hop", \
135  [IP6_LOOKUP_NEXT_ADD_HOP_BY_HOP] = "ip6-add-hop-by-hop", \
136  [IP6_LOOKUP_NEXT_POP_HOP_BY_HOP] = "ip6-pop-hop-by-hop", \
137 }
138 
139 /**
140  * The special broadcast address (to construct a broadcast adjacency
141  */
142 extern const ip46_address_t ADJ_BCAST_ADDR;
143 
144 /**
145  * Forward declaration
146  */
147 struct ip_adjacency_t_;
148 
149 /**
150  * @brief A function type for post-rewrite fixups on midchain adjacency
151  */
153  const struct ip_adjacency_t_ * adj,
154  vlib_buffer_t * b0,
155  const void *data);
156 
157 /**
158  * @brief Flags on an IP adjacency
159  */
160 typedef enum adj_attr_t_
161 {
162  /**
163  * Currently a sync walk is active. Used to prevent re-entrant walking
164  */
166 
167  /**
168  * Packets TX through the midchain do not increment the interface
169  * counters. This should be used when the adj is associated with an L2
170  * interface and that L2 interface is in a bridge domain. In that case
171  * the packet will have traversed the interface's TX node, and hence have
172  * been counted, before it traverses ths midchain
173  */
175  /**
176  * When stacking midchains on a fib-entry extract the choice from the
177  * load-balance returned based on an IP hash of the adj's rewrite
178  */
180  /**
181  * If the midchain were to stack on its FIB entry a loop would form.
182  */
184  /**
185  * the fixup function is standard IP4o4 header
186  */
188  /**
189  * the fixup function performs the flow hash
190  * this means the flow hash is performed on the inner
191  * header, where the entropy is higher.
192  */
194 } adj_attr_t;
195 
196 #define ADJ_ATTR_NAMES { \
197  [ADJ_ATTR_SYNC_WALK_ACTIVE] = "walk-active", \
198  [ADJ_ATTR_MIDCHAIN_NO_COUNT] = "midchain-no-count", \
199  [ADJ_ATTR_MIDCHAIN_IP_STACK] = "midchain-ip-stack", \
200  [ADJ_ATTR_MIDCHAIN_LOOPED] = "midchain-looped", \
201  [ADJ_ATTR_MIDCHAIN_FIXUP_IP4O4_HDR] = "midchain-ip4o4-hdr-fixup", \
202  [ADJ_ATTR_MIDCHAIN_FIXUP_FLOW_HASH] = "midchain-flow-hash", \
203 }
204 
205 #define FOR_EACH_ADJ_ATTR(_attr) \
206  for (_attr = ADJ_ATTR_SYNC_WALK_ACTIVE; \
207  _attr <= ADJ_ATTR_MIDCHAIN_FIXUP_FLOW_HASH; \
208  _attr++)
209 
210 /**
211  * @brief Flags on an IP adjacency
212  */
213 typedef enum adj_flags_t_
214 {
222 } __attribute__ ((packed)) adj_flags_t;
223 
224 /**
225  * @brief Format adjacency flags
226  */
227 extern u8* format_adj_flags(u8 * s, va_list * args);
228 
229 /**
230  * @brief IP unicast adjacency.
231  * @note cache aligned.
232  *
233  * An adjacency is a representation of a peer on a particular link.
234  */
235 typedef struct ip_adjacency_t_
236 {
237  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
238 
239  /**
240  * Linkage into the FIB node graph. First member since this type
241  * has 8 byte alignment requirements.
242  */
244  /**
245  * feature [arc] config index
246  */
248 
249  union
250  {
251  /**
252  * IP_LOOKUP_NEXT_ARP/IP_LOOKUP_NEXT_REWRITE
253  *
254  * neighbour adjacency sub-type;
255  */
256  struct
257  {
258  ip46_address_t next_hop;
259  } nbr;
260  /**
261  * IP_LOOKUP_NEXT_MIDCHAIN
262  *
263  * A nbr adj that is also recursive. Think tunnels.
264  * A nbr adj can transition to be of type MIDCHAIN
265  * so be sure to leave the two structs with the next_hop
266  * fields aligned.
267  */
268  struct
269  {
270  /**
271  * The recursive next-hop.
272  * This field MUST be at the same memory location as
273  * sub_type.nbr.next_hop
274  */
275  ip46_address_t next_hop;
276  /**
277  * The next DPO to use
278  */
280  /**
281  * A function to perform the post-rewrite fixup
282  */
284  /**
285  * Fixup data passed back to the client in the fixup function
286  */
287  const void *fixup_data;
288  /**
289  * the FIB entry this midchain resolves through. required for recursive
290  * loop detection.
291  */
293 
294  /** spare space */
295  u8 __ia_midchain_pad[4];
296 
297  } midchain;
298  /**
299  * IP_LOOKUP_NEXT_GLEAN
300  *
301  * Glean the address to ARP for from the packet's destination.
302  * Technically these aren't adjacencies, i.e. they are not a
303  * representation of a peer. One day we might untangle this coupling
304  * and use a new Glean DPO.
305  */
306  struct
307  {
309  } glean;
310  } sub_type;
311 
312  CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
313 
314  /** Rewrite in second and third cache lines */
316 
317  /**
318  * more control plane members that do not fit on the first cacheline
319  */
320  CLIB_CACHE_LINE_ALIGN_MARK (cacheline3);
321 
322  /**
323  * A sorted vector of delegates
324  */
326 
327  /**
328  * The VLIB node in which this adj is used to forward packets
329  */
331 
332  /**
333  * Next hop after ip4-lookup.
334  * This is not accessed in the rewrite nodes.
335  * 1-bytes
336  */
337  ip_lookup_next_t lookup_next_index;
338 
339  /**
340  * link/ether-type
341  * 1 bytes
342  */
344 
345  /**
346  * The protocol of the neighbor/peer. i.e. the protocol with
347  * which to interpret the 'next-hop' attributes of the sub-types.
348  * 1-bytes
349  */
351 
352  /**
353  * Flags on the adjacency
354  * 1-bytes
355  */
357 
358  /**
359  * Free space on the fourth cacheline (not used in the DP)
360  */
361  u8 __ia_pad[48];
363 
364 STATIC_ASSERT ((STRUCT_OFFSET_OF (ip_adjacency_t, cacheline0) == 0),
365  "IP adjacency cacheline 0 is not offset");
368  "IP adjacency cacheline 1 is more than one cacheline size offset");
369 #if defined __x86_64__
372  "IP adjacency cacheline 3 is more than one cacheline size offset");
373 /* An adj fits into 4 cachelines on your average machine */
375 #endif
376 
377 /**
378  * @brief
379  * Take a reference counting lock on the adjacency
380  */
381 extern void adj_lock(adj_index_t adj_index);
382 /**
383  * @brief
384  * Release a reference counting lock on the adjacency
385  */
386 extern void adj_unlock(adj_index_t adj_index);
387 
388 /**
389  * @brief
390  * Add a child dependent to an adjacency. The child will
391  * thus be informed via its registered back-walk function
392  * when the adjacency state changes.
393  */
394 extern u32 adj_child_add(adj_index_t adj_index,
396  fib_node_index_t child_index);
397 /**
398  * @brief
399  * Remove a child dependent
400  */
401 extern void adj_child_remove(adj_index_t adj_index,
402  u32 sibling_index);
403 
404 /**
405  * @brief Walk the Adjacencies on a given interface
406  */
407 extern void adj_walk (u32 sw_if_index,
408  adj_walk_cb_t cb,
409  void *ctx);
410 
411 /**
412  * @brief Return the link type of the adjacency
413  */
415 
416 /**
417  * @brief Return the sw interface index of the adjacency.
418  */
420 
421 /**
422  * @brief Return true if the adjacency is 'UP', i.e. can be used for forwarding.
423  * 0 is down, !0 is up.
424  */
425 extern int adj_is_up (adj_index_t ai);
426 
427 /**
428  * @brief Return the link type of the adjacency
429  */
430 extern const u8* adj_get_rewrite (adj_index_t ai);
431 
432 /**
433  * @brief descend the FIB graph looking for loops
434  *
435  * @param ai
436  * The adj index to traverse
437  *
438  * @param entry_indicies)
439  * A pointer to a vector of FIB entries already visited.
440  */
442  fib_node_index_t **entry_indicies);
443 
444 /**
445  * @brief
446  * The global adjacency pool. Exposed for fast/inline data-plane access
447  */
448 extern ip_adjacency_t *adj_pool;
449 
450 /**
451  * @brief
452  * Adjacency packet counters
453  */
455 
456 /**
457  * @brief Global Config for enabling per-adjacency counters
458  * This is configurable because it comes with a non-negligible
459  * performance cost. */
460 extern int adj_per_adj_counters;
461 
462 /**
463  * @brief
464  * Get a pointer to an adjacency object from its index
465  */
466 static inline ip_adjacency_t *
467 adj_get (adj_index_t adj_index)
468 {
469  return (pool_elt_at_index(adj_pool, adj_index));
470 }
471 
472 static inline int
474 {
475  return !(pool_is_free_index(adj_pool, adj_index));
476 }
477 
478 /**
479  * @brief Get the global configuration option for enabling per-adj counters
480  */
481 static inline int
483 {
484  return (adj_per_adj_counters);
485 }
486 
487 #endif
int adj_is_up(adj_index_t ai)
Return true if the adjacency is &#39;UP&#39;, i.e.
Definition: adj.c:533
adj_flags_t ia_flags
Flags on the adjacency 1-bytes.
Definition: adj.h:356
Packets TX through the midchain do not increment the interface counters.
Definition: adj.h:174
u32 adj_child_add(adj_index_t adj_index, fib_node_type_t type, fib_node_index_t child_index)
Add a child dependent to an adjacency.
Definition: adj.c:366
enum adj_attr_t_ adj_attr_t
Flags on an IP adjacency.
Multicast Adjacency.
Definition: adj.h:82
Broadcast Adjacency.
Definition: adj.h:85
IP unicast adjacency.
Definition: adj.h:235
adj_flags_t_
Flags on an IP adjacency.
Definition: adj.h:213
This packet is to be rewritten and forwarded to the next processing node.
Definition: adj.h:73
When stacking midchains on a fib-entry extract the choice from the load-balance returned based on an ...
Definition: adj.h:179
fib_prefix_t rx_pfx
Definition: adj.h:308
#define STRUCT_OFFSET_OF(t, f)
Definition: clib.h:70
const ip46_address_t ADJ_BCAST_ADDR
The special broadcast address (to construct a broadcast adjacency.
Definition: adj.c:41
struct ip_adjacency_t_::@161::@163 midchain
IP_LOOKUP_NEXT_MIDCHAIN.
vlib_main_t * vm
Definition: in2out_ed.c:1580
void(* adj_midchain_fixup_t)(vlib_main_t *vm, const struct ip_adjacency_t_ *adj, vlib_buffer_t *b0, const void *data)
A function type for post-rewrite fixups on midchain adjacency.
Definition: adj.h:152
adj_midchain_fixup_t fixup_func
A function to perform the post-rewrite fixup.
Definition: adj.h:283
unsigned char u8
Definition: types.h:56
ip_lookup_next_t
An adjacency is a representation of an attached L3 peer.
Definition: adj.h:50
u8 data[128]
Definition: ipsec_types.api:90
void adj_walk(u32 sw_if_index, adj_walk_cb_t cb, void *ctx)
Walk the Adjacencies on a given interface.
Definition: adj.c:486
enum fib_protocol_t_ fib_protocol_t
Protocol Type.
struct ip_adjacency_t_ ip_adjacency_t
IP unicast adjacency.
vnet_link_t ia_link
link/ether-type 1 bytes
Definition: adj.h:343
Adjacency to punt this packet.
Definition: adj.h:55
static ip_adjacency_t * adj_get(adj_index_t adj_index)
Get a pointer to an adjacency object from its index.
Definition: adj.h:467
struct ip_adjacency_t_::@161::@162 nbr
IP_LOOKUP_NEXT_ARP/IP_LOOKUP_NEXT_REWRITE.
ip6_lookup_next_t
Definition: adj.h:99
ip46_address_t next_hop
The recursive next-hop.
Definition: adj.h:258
Aggregate type for a prefix.
Definition: fib_types.h:202
int adj_recursive_loop_detect(adj_index_t ai, fib_node_index_t **entry_indicies)
descend the FIB graph looking for loops
Definition: adj.c:224
Adj delegate.
Definition: adj_delegate.h:50
unsigned int u32
Definition: types.h:88
STATIC_ASSERT_SIZEOF(ip_adjacency_t, 4 *64)
vl_api_fib_path_type_t type
Definition: fib_types.api:123
The identity of a DPO is a combination of its type and its instance number/index of objects of that t...
Definition: dpo.h:170
STATIC_ASSERT((STRUCT_OFFSET_OF(ip_adjacency_t, cacheline0)==0), "IP adjacency cacheline 0 is not offset")
dpo_id_t next_dpo
The next DPO to use.
Definition: adj.h:279
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:546
CLIB_CACHE_LINE_ALIGN_MARK(cacheline0)
long ctx[MAX_CONNS]
Definition: main.c:144
ip_adjacency_t * adj_pool
The global adjacency pool.
Definition: adj.c:33
u32 ia_node_index
The VLIB node in which this adj is used to forward packets.
Definition: adj.h:330
This packet matches an "interface route" and packets need to be passed to ARP to find rewrite string ...
Definition: adj.h:68
void adj_lock(adj_index_t adj_index)
Take a reference counting lock on the adjacency.
Definition: adj.c:330
An node in the FIB graph.
Definition: fib_node.h:295
fib_node_t ia_node
Linkage into the FIB node graph.
Definition: adj.h:243
const u8 * adj_get_rewrite(adj_index_t ai)
Return the link type of the adjacency.
Definition: adj.c:542
fib_node_index_t fei
the FIB entry this midchain resolves through.
Definition: adj.h:292
This packet matches an "incomplete adjacency" and packets need to be passed to ARP to find rewrite st...
Definition: adj.h:63
Adjacency to drop this packet.
Definition: adj.h:53
Multicast Midchain Adjacency.
Definition: adj.h:89
u32 fib_node_index_t
A typedef of a node index.
Definition: fib_types.h:29
adj_walk_rc_t(* adj_walk_cb_t)(adj_index_t ai, void *ctx)
Call back function when walking adjacencies.
Definition: adj_types.h:50
#define pool_is_free_index(P, I)
Use free bitmap to query whether given index is free.
Definition: pool.h:298
u32 adj_index_t
An index for adjacencies.
Definition: adj_types.h:30
This packets follow a mid-chain adjacency.
Definition: adj.h:76
enum vnet_link_t_ vnet_link_t
Link Type: A description of the protocol of packets on the link.
Currently a sync walk is active.
Definition: adj.h:165
vnet_link_t adj_get_link_type(adj_index_t ai)
Return the link type of the adjacency.
Definition: adj.c:506
u32 ia_cfg_index
feature [arc] config index
Definition: adj.h:247
const void * fixup_data
Fixup data passed back to the client in the fixup function.
Definition: adj.h:287
vlib_combined_counter_main_t adjacency_counters
Adjacency packet counters.
Definition: adj.c:25
struct ip_adjacency_t_::@161::@164 glean
IP_LOOKUP_NEXT_GLEAN.
enum adj_flags_t_ adj_flags_t
Flags on an IP adjacency.
union ip_adjacency_t_::@161 sub_type
the fixup function performs the flow hash this means the flow hash is performed on the inner header...
Definition: adj.h:193
This packets needs to go to ICMP error.
Definition: adj.h:79
This packet is for one of our own IP addresses.
Definition: adj.h:58
fib_protocol_t ia_nh_proto
The protocol of the neighbor/peer.
Definition: adj.h:350
ip4_lookup_next_t
Definition: adj.h:94
ip_lookup_next_t lookup_next_index
Next hop after ip4-lookup.
Definition: adj.h:337
void adj_child_remove(adj_index_t adj_index, u32 sibling_index)
Remove a child dependent.
Definition: adj.c:383
VLIB buffer representation.
Definition: buffer.h:102
adj_attr_t_
Flags on an IP adjacency.
Definition: adj.h:160
u32 adj_get_sw_if_index(adj_index_t ai)
Return the sw interface index of the adjacency.
Definition: adj.c:519
A collection of combined counters.
Definition: counter.h:207
static int adj_is_valid(adj_index_t adj_index)
Definition: adj.h:473
enum fib_node_type_t_ fib_node_type_t
The types of nodes in a FIB graph.
int adj_per_adj_counters
Global Config for enabling per-adjacency counters This is configurable because it comes with a non-ne...
Definition: adj.c:39
#define CLIB_CACHE_LINE_BYTES
Definition: cache.h:59
u8 * format_adj_flags(u8 *s, va_list *args)
Format adjacency flags.
Definition: adj.c:128
void adj_unlock(adj_index_t adj_index)
Release a reference counting lock on the adjacency.
Definition: adj.c:347
VNET_DECLARE_REWRITE
Rewrite in second and third cache lines.
Definition: adj.h:315
static int adj_are_counters_enabled(void)
Get the global configuration option for enabling per-adj counters.
Definition: adj.h:482
vl_api_interface_index_t sw_if_index
Definition: wireguard.api:34
If the midchain were to stack on its FIB entry a loop would form.
Definition: adj.h:183
the fixup function is standard IP4o4 header
Definition: adj.h:187
struct adj_delegate_t_ * ia_delegates
A sorted vector of delegates.
Definition: adj.h:325