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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 nighbour 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 ajdacency 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 adjacenices 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  /** Broadcasr Adjacency. */
86 
87  /** Multicast Midchain Adjacency. An Adjacency for sending macst 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 delcartion
146  */
147 struct ip_adjacency_t_;
148 
149 /**
150  * @brief A function type for post-rewrite fixups on midchain adjacency
151  */
153  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 bridege 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 } adj_attr_t;
185 
186 #define ADJ_ATTR_NAMES { \
187  [ADJ_ATTR_SYNC_WALK_ACTIVE] = "walk-active", \
188  [ADJ_ATTR_MIDCHAIN_NO_COUNT] = "midchain-no-count", \
189  [ADJ_ATTR_MIDCHAIN_IP_STACK] = "midchain-ip-stack", \
190  [ADJ_ATTR_MIDCHAIN_LOOPED] = "midchain-looped", \
191 }
192 
193 #define FOR_EACH_ADJ_ATTR(_attr) \
194  for (_attr = ADJ_ATTR_SYNC_WALK_ACTIVE; \
195  _attr <= ADJ_ATTR_MIDCHAIN_LOOPED; \
196  _attr++)
197 
198 /**
199  * @brief Flags on an IP adjacency
200  */
201 typedef enum adj_flags_t_
202 {
208 } __attribute__ ((packed)) adj_flags_t;
209 
210 /**
211  * @brief Format adjacency flags
212  */
213 extern u8* format_adj_flags(u8 * s, va_list * args);
214 
215 /**
216  * @brief IP unicast adjacency.
217  * @note cache aligned.
218  *
219  * An adjacency is a represenation of a peer on a particular link.
220  */
221 typedef struct ip_adjacency_t_
222 {
223  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
224 
225  /**
226  * Linkage into the FIB node grpah. First member since this type
227  * has 8 byte alignment requirements.
228  */
230 
231  /**
232  * Next hop after ip4-lookup.
233  * This is not accessed in the rewrite nodes.
234  * 1-bytes
235  */
236  ip_lookup_next_t lookup_next_index;
237 
238  /**
239  * link/ether-type
240  * 1 bytes
241  */
243 
244  /**
245  * The protocol of the neighbor/peer. i.e. the protocol with
246  * which to interpret the 'next-hop' attirbutes of the sub-types.
247  * 1-btyes
248  */
250 
251  /**
252  * Flags on the adjacency
253  * 1-bytes
254  */
256 
257  union
258  {
259  /**
260  * IP_LOOKUP_NEXT_ARP/IP_LOOKUP_NEXT_REWRITE
261  *
262  * neighbour adjacency sub-type;
263  */
264  struct
265  {
266  ip46_address_t next_hop;
267  } nbr;
268  /**
269  * IP_LOOKUP_NEXT_MIDCHAIN
270  *
271  * A nbr adj that is also recursive. Think tunnels.
272  * A nbr adj can transition to be of type MDICHAIN
273  * so be sure to leave the two structs with the next_hop
274  * fields aligned.
275  */
276  struct
277  {
278  /**
279  * The recursive next-hop.
280  * This field MUST be at the same memory location as
281  * sub_type.nbr.next_hop
282  */
283  ip46_address_t next_hop;
284  /**
285  * The next DPO to use
286  */
288  /**
289  * A function to perform the post-rewrite fixup
290  */
292  /**
293  * Fixup data passed back to the client in the fixup function
294  */
295  const void *fixup_data;
296  /**
297  * the FIB entry this midchain resolves through. required for recursive
298  * loop detection.
299  */
301  } midchain;
302  /**
303  * IP_LOOKUP_NEXT_GLEAN
304  *
305  * Glean the address to ARP for from the packet's destination.
306  * Technically these aren't adjacencies, i.e. they are not a
307  * representation of a peer. One day we might untangle this coupling
308  * and use a new Glean DPO.
309  */
310  struct
311  {
312  ip46_address_t receive_addr;
313  } glean;
314  } sub_type;
315 
316  CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
317 
318  /* Rewrite in second/third cache lines */
320 
321  /**
322  * more control plane members that do not fit on the first cacheline
323  */
324  /**
325  * A sorted vector of delegates
326  */
328 
330 
331 STATIC_ASSERT ((STRUCT_OFFSET_OF (ip_adjacency_t, cacheline0) == 0),
332  "IP adjacency cachline 0 is not offset");
335  "IP adjacency cachline 1 is more than one cachline size offset");
336 
337 /**
338  * @brief
339  * Take a reference counting lock on the adjacency
340  */
341 extern void adj_lock(adj_index_t adj_index);
342 /**
343  * @brief
344  * Release a reference counting lock on the adjacency
345  */
346 extern void adj_unlock(adj_index_t adj_index);
347 
348 /**
349  * @brief
350  * Add a child dependent to an adjacency. The child will
351  * thus be informed via its registerd back-walk function
352  * when the adjacency state changes.
353  */
354 extern u32 adj_child_add(adj_index_t adj_index,
355  fib_node_type_t type,
356  fib_node_index_t child_index);
357 /**
358  * @brief
359  * Remove a child dependent
360  */
361 extern void adj_child_remove(adj_index_t adj_index,
362  u32 sibling_index);
363 
364 /**
365  * @brief Walk the Adjacencies on a given interface
366  */
367 extern void adj_walk (u32 sw_if_index,
368  adj_walk_cb_t cb,
369  void *ctx);
370 
371 /**
372  * @brief Return the link type of the adjacency
373  */
375 
376 /**
377  * @brief Return the sw interface index of the adjacency.
378  */
380 
381 /**
382  * @brief Return true if the adjacency is 'UP', i.e. can be used for forwarding.
383  * 0 is down, !0 is up.
384  */
385 extern int adj_is_up (adj_index_t ai);
386 
387 /**
388  * @brief Return the link type of the adjacency
389  */
390 extern const u8* adj_get_rewrite (adj_index_t ai);
391 
392 /**
393  * @brief Notify the adjacency subsystem that the features settings for
394  * an interface have changed
395  */
396 extern void adj_feature_update (u32 sw_if_index, u8 arc_index, u8 is_enable);
397 
398 /**
399  * @brief descend the FIB graph looking for loops
400  *
401  * @param ai
402  * The adj index to traverse
403  *
404  * @param entry_indicies)
405  * A pointer to a vector of FIB entries already visited.
406  */
408  fib_node_index_t **entry_indicies);
409 
410 /**
411  * @brief
412  * The global adjacnecy pool. Exposed for fast/inline data-plane access
413  */
414 extern ip_adjacency_t *adj_pool;
415 
416 /**
417  * @brief
418  * Adjacency packet counters
419  */
421 
422 /**
423  * @brief Global Config for enabling per-adjacency counters
424  * This is configurable because it comes with a non-negligible
425  * performance cost. */
426 extern int adj_per_adj_counters;
427 
428 /**
429  * @brief
430  * Get a pointer to an adjacency object from its index
431  */
432 static inline ip_adjacency_t *
433 adj_get (adj_index_t adj_index)
434 {
435  return (vec_elt_at_index(adj_pool, adj_index));
436 }
437 
438 /**
439  * @brief Get the global configuration option for enabling per-adj counters
440  */
441 static inline int
443 {
444  return (adj_per_adj_counters);
445 }
446 
447 #endif
int adj_is_up(adj_index_t ai)
Return true if the adjacency is &#39;UP&#39;, i.e.
Definition: adj.c:495
adj_flags_t ia_flags
Flags on the adjacency 1-bytes.
Definition: adj.h:255
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:337
enum adj_attr_t_ adj_attr_t
Flags on an IP adjacency.
Multicast Adjacency.
Definition: adj.h:82
Broadcasr Adjacency.
Definition: adj.h:85
IP unicast adjacency.
Definition: adj.h:221
#define VLIB_BUFFER_PRE_DATA_SIZE
Definition: buffer.h:52
adj_flags_t_
Flags on an IP adjacency.
Definition: adj.h:201
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
#define STRUCT_OFFSET_OF(t, f)
Definition: clib.h:65
const ip46_address_t ADJ_BCAST_ADDR
The special broadcast address (to construct a broadcast adjacency.
Definition: adj.c:41
adj_midchain_fixup_t fixup_func
A function to perform the post-rewrite fixup.
Definition: adj.h:291
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
void adj_walk(u32 sw_if_index, adj_walk_cb_t cb, void *ctx)
Walk the Adjacencies on a given interface.
Definition: adj.c:448
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:242
Adjacency to punt this packet.
Definition: adj.h:55
ip46_address_t receive_addr
Definition: adj.h:312
static ip_adjacency_t * adj_get(adj_index_t adj_index)
Get a pointer to an adjacency object from its index.
Definition: adj.h:433
union ip_adjacency_t_::@42 sub_type
u32 sw_if_index
Definition: vxlan_gbp.api:37
ip6_lookup_next_t
Definition: adj.h:99
#define vec_elt_at_index(v, i)
Get vector value at index i checking that i is in bounds.
ip46_address_t next_hop
The recursive next-hop.
Definition: adj.h:266
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:196
Adj delegate.
Definition: adj_delegate.h:44
unsigned int u32
Definition: types.h:88
The identity of a DPO is a combination of its type and its instance number/index of objects of that t...
Definition: dpo.h:168
dpo_id_t next_dpo
The next DPO to use.
Definition: adj.h:287
CLIB_CACHE_LINE_ALIGN_MARK(cacheline0)
long ctx[MAX_CONNS]
Definition: main.c:144
ip_adjacency_t * adj_pool
The global adjacnecy pool.
Definition: adj.c:33
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:301
An node in the FIB graph.
Definition: fib_node.h:291
fib_node_t ia_node
Linkage into the FIB node grpah.
Definition: adj.h:229
const u8 * adj_get_rewrite(adj_index_t ai)
Return the link type of the adjacency.
Definition: adj.c:504
fib_node_index_t fei
the FIB entry this midchain resolves through.
Definition: adj.h:300
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
vlib_main_t * vm
Definition: buffer.c:301
Multicast Midchain Adjacency.
Definition: adj.h:89
u32 fib_node_index_t
A typedef of a node index.
Definition: fib_types.h:30
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
void(* adj_midchain_fixup_t)(vlib_main_t *vm, 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
u32 adj_index_t
An index for adjacencies.
Definition: adj_types.h:30
void adj_feature_update(u32 sw_if_index, u8 arc_index, u8 is_enable)
Notify the adjacency subsystem that the features settings for an interface have changed.
Definition: adj.c:405
This packets follow a mid-chain adjacency.
Definition: adj.h:76
STATIC_ASSERT((STRUCT_OFFSET_OF(ip_adjacency_t, cacheline0)==0), "IP adjacency cachline 0 is not offset")
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:468
const void * fixup_data
Fixup data passed back to the client in the fixup function.
Definition: adj.h:295
vlib_combined_counter_main_t adjacency_counters
Adjacency packet counters.
Definition: adj.c:25
enum adj_flags_t_ adj_flags_t
Flags on an IP adjacency.
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:249
ip4_lookup_next_t
Definition: adj.h:94
ip_lookup_next_t lookup_next_index
Next hop after ip4-lookup.
Definition: adj.h:236
struct ip_adjacency_t_::@42::@44 midchain
IP_LOOKUP_NEXT_MIDCHAIN.
void adj_child_remove(adj_index_t adj_index, u32 sibling_index)
Remove a child dependent.
Definition: adj.c:354
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:481
A collection of combined counters.
Definition: counter.h:188
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:104
vnet_declare_rewrite(VLIB_BUFFER_PRE_DATA_SIZE)
void adj_unlock(adj_index_t adj_index)
Release a reference counting lock on the adjacency.
Definition: adj.c:318
struct ip_adjacency_t_::@42::@43 nbr
IP_LOOKUP_NEXT_ARP/IP_LOOKUP_NEXT_REWRITE.
static int adj_are_counters_enabled(void)
Get the global configuration option for enabling per-adj counters.
Definition: adj.h:442
If the midchain were to stack on its FIB entry a loop would form.
Definition: adj.h:183
struct adj_delegate_t_ * ia_delegates
more control plane members that do not fit on the first cacheline
Definition: adj.h:327
struct ip_adjacency_t_::@42::@45 glean
IP_LOOKUP_NEXT_GLEAN.