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Vector Packet Processing
adj.h
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3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
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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 } adj_attr_t;
189 
190 #define ADJ_ATTR_NAMES { \
191  [ADJ_ATTR_SYNC_WALK_ACTIVE] = "walk-active", \
192  [ADJ_ATTR_MIDCHAIN_NO_COUNT] = "midchain-no-count", \
193  [ADJ_ATTR_MIDCHAIN_IP_STACK] = "midchain-ip-stack", \
194  [ADJ_ATTR_MIDCHAIN_LOOPED] = "midchain-looped", \
195  [ADJ_ATTR_MIDCHAIN_FIXUP_IP4O4_HDR] = "midchain-ip4o4-hdr-fixup", \
196 }
197 
198 #define FOR_EACH_ADJ_ATTR(_attr) \
199  for (_attr = ADJ_ATTR_SYNC_WALK_ACTIVE; \
200  _attr <= ADJ_ATTR_MIDCHAIN_FIXUP_IP4O4_HDR; \
201  _attr++)
202 
203 /**
204  * @brief Flags on an IP adjacency
205  */
206 typedef enum adj_flags_t_
207 {
214 } __attribute__ ((packed)) adj_flags_t;
215 
216 /**
217  * @brief Format adjacency flags
218  */
219 extern u8* format_adj_flags(u8 * s, va_list * args);
220 
221 /**
222  * @brief IP unicast adjacency.
223  * @note cache aligned.
224  *
225  * An adjacency is a representation of a peer on a particular link.
226  */
227 typedef struct ip_adjacency_t_
228 {
229  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
230 
231  /**
232  * Linkage into the FIB node graph. First member since this type
233  * has 8 byte alignment requirements.
234  */
236  /**
237  * feature [arc] config index
238  */
240 
241  union
242  {
243  /**
244  * IP_LOOKUP_NEXT_ARP/IP_LOOKUP_NEXT_REWRITE
245  *
246  * neighbour adjacency sub-type;
247  */
248  struct
249  {
250  ip46_address_t next_hop;
251  } nbr;
252  /**
253  * IP_LOOKUP_NEXT_MIDCHAIN
254  *
255  * A nbr adj that is also recursive. Think tunnels.
256  * A nbr adj can transition to be of type MIDCHAIN
257  * so be sure to leave the two structs with the next_hop
258  * fields aligned.
259  */
260  struct
261  {
262  /**
263  * The recursive next-hop.
264  * This field MUST be at the same memory location as
265  * sub_type.nbr.next_hop
266  */
267  ip46_address_t next_hop;
268  /**
269  * The next DPO to use
270  */
272  /**
273  * A function to perform the post-rewrite fixup
274  */
276  /**
277  * Fixup data passed back to the client in the fixup function
278  */
279  const void *fixup_data;
280  /**
281  * the FIB entry this midchain resolves through. required for recursive
282  * loop detection.
283  */
285 
286  /** spare space */
287  u8 __ia_midchain_pad[4];
288 
289  } midchain;
290  /**
291  * IP_LOOKUP_NEXT_GLEAN
292  *
293  * Glean the address to ARP for from the packet's destination.
294  * Technically these aren't adjacencies, i.e. they are not a
295  * representation of a peer. One day we might untangle this coupling
296  * and use a new Glean DPO.
297  */
298  struct
299  {
300  ip46_address_t receive_addr;
301  } glean;
302  } sub_type;
303 
304  CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
305 
306  /** Rewrite in second and third cache lines */
308 
309  /**
310  * more control plane members that do not fit on the first cacheline
311  */
312  CLIB_CACHE_LINE_ALIGN_MARK (cacheline3);
313 
314  /**
315  * A sorted vector of delegates
316  */
318 
319  /**
320  * The VLIB node in which this adj is used to forward packets
321  */
323 
324  /**
325  * Next hop after ip4-lookup.
326  * This is not accessed in the rewrite nodes.
327  * 1-bytes
328  */
329  ip_lookup_next_t lookup_next_index;
330 
331  /**
332  * link/ether-type
333  * 1 bytes
334  */
336 
337  /**
338  * The protocol of the neighbor/peer. i.e. the protocol with
339  * which to interpret the 'next-hop' attributes of the sub-types.
340  * 1-bytes
341  */
343 
344  /**
345  * Flags on the adjacency
346  * 1-bytes
347  */
349 
350  /**
351  * Free space on the fourth cacheline (not used in the DP)
352  */
353  u8 __ia_pad[48];
355 
356 STATIC_ASSERT ((STRUCT_OFFSET_OF (ip_adjacency_t, cacheline0) == 0),
357  "IP adjacency cacheline 0 is not offset");
360  "IP adjacency cacheline 1 is more than one cacheline size offset");
361 #if defined __x86_64__
364  "IP adjacency cacheline 3 is more than one cacheline size offset");
365 /* An adj fits into 4 cachelines on your average machine */
367 #endif
368 
369 /**
370  * @brief
371  * Take a reference counting lock on the adjacency
372  */
373 extern void adj_lock(adj_index_t adj_index);
374 /**
375  * @brief
376  * Release a reference counting lock on the adjacency
377  */
378 extern void adj_unlock(adj_index_t adj_index);
379 
380 /**
381  * @brief
382  * Add a child dependent to an adjacency. The child will
383  * thus be informed via its registered back-walk function
384  * when the adjacency state changes.
385  */
386 extern u32 adj_child_add(adj_index_t adj_index,
388  fib_node_index_t child_index);
389 /**
390  * @brief
391  * Remove a child dependent
392  */
393 extern void adj_child_remove(adj_index_t adj_index,
394  u32 sibling_index);
395 
396 /**
397  * @brief Walk the Adjacencies on a given interface
398  */
399 extern void adj_walk (u32 sw_if_index,
400  adj_walk_cb_t cb,
401  void *ctx);
402 
403 /**
404  * @brief Return the link type of the adjacency
405  */
407 
408 /**
409  * @brief Return the sw interface index of the adjacency.
410  */
412 
413 /**
414  * @brief Return true if the adjacency is 'UP', i.e. can be used for forwarding.
415  * 0 is down, !0 is up.
416  */
417 extern int adj_is_up (adj_index_t ai);
418 
419 /**
420  * @brief Return the link type of the adjacency
421  */
422 extern const u8* adj_get_rewrite (adj_index_t ai);
423 
424 /**
425  * @brief descend the FIB graph looking for loops
426  *
427  * @param ai
428  * The adj index to traverse
429  *
430  * @param entry_indicies)
431  * A pointer to a vector of FIB entries already visited.
432  */
434  fib_node_index_t **entry_indicies);
435 
436 /**
437  * @brief
438  * The global adjacency pool. Exposed for fast/inline data-plane access
439  */
440 extern ip_adjacency_t *adj_pool;
441 
442 /**
443  * @brief
444  * Adjacency packet counters
445  */
447 
448 /**
449  * @brief Global Config for enabling per-adjacency counters
450  * This is configurable because it comes with a non-negligible
451  * performance cost. */
452 extern int adj_per_adj_counters;
453 
454 /**
455  * @brief
456  * Get a pointer to an adjacency object from its index
457  */
458 static inline ip_adjacency_t *
459 adj_get (adj_index_t adj_index)
460 {
461  return (pool_elt_at_index(adj_pool, adj_index));
462 }
463 
464 static inline int
466 {
467  return !(pool_is_free_index(adj_pool, adj_index));
468 }
469 
470 /**
471  * @brief Get the global configuration option for enabling per-adj counters
472  */
473 static inline int
475 {
476  return (adj_per_adj_counters);
477 }
478 
479 #endif
struct ip_adjacency_t_::@149::@152 glean
IP_LOOKUP_NEXT_GLEAN.
int adj_is_up(adj_index_t ai)
Return true if the adjacency is &#39;UP&#39;, i.e.
Definition: adj.c:534
adj_flags_t ia_flags
Flags on the adjacency 1-bytes.
Definition: adj.h:348
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:367
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:227
adj_flags_t_
Flags on an IP adjacency.
Definition: adj.h:206
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:70
const ip46_address_t ADJ_BCAST_ADDR
The special broadcast address (to construct a broadcast adjacency.
Definition: adj.c:41
vlib_main_t * vm
Definition: in2out_ed.c:1582
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:275
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:89
void adj_walk(u32 sw_if_index, adj_walk_cb_t cb, void *ctx)
Walk the Adjacencies on a given interface.
Definition: adj.c:487
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:335
Adjacency to punt this packet.
Definition: adj.h:55
ip46_address_t receive_addr
Definition: adj.h:300
static ip_adjacency_t * adj_get(adj_index_t adj_index)
Get a pointer to an adjacency object from its index.
Definition: adj.h:459
ip6_lookup_next_t
Definition: adj.h:99
ip46_address_t next_hop
The recursive next-hop.
Definition: adj.h:250
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
struct ip_adjacency_t_::@149::@151 midchain
IP_LOOKUP_NEXT_MIDCHAIN.
union ip_adjacency_t_::@149 sub_type
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:271
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:534
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:322
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:331
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:235
const u8 * adj_get_rewrite(adj_index_t ai)
Return the link type of the adjacency.
Definition: adj.c:543
fib_node_index_t fei
the FIB entry this midchain resolves through.
Definition: adj.h:284
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: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
#define pool_is_free_index(P, I)
Use free bitmap to query whether given index is free.
Definition: pool.h:299
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
struct ip_adjacency_t_::@149::@150 nbr
IP_LOOKUP_NEXT_ARP/IP_LOOKUP_NEXT_REWRITE.
vnet_link_t adj_get_link_type(adj_index_t ai)
Return the link type of the adjacency.
Definition: adj.c:507
u32 ia_cfg_index
feature [arc] config index
Definition: adj.h:239
const void * fixup_data
Fixup data passed back to the client in the fixup function.
Definition: adj.h:279
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:342
ip4_lookup_next_t
Definition: adj.h:94
ip_lookup_next_t lookup_next_index
Next hop after ip4-lookup.
Definition: adj.h:329
void adj_child_remove(adj_index_t adj_index, u32 sibling_index)
Remove a child dependent.
Definition: adj.c:384
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:520
A collection of combined counters.
Definition: counter.h:188
static int adj_is_valid(adj_index_t adj_index)
Definition: adj.h:465
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:348
VNET_DECLARE_REWRITE
Rewrite in second and third cache lines.
Definition: adj.h:307
static int adj_are_counters_enabled(void)
Get the global configuration option for enabling per-adj counters.
Definition: adj.h:474
vl_api_interface_index_t sw_if_index
Definition: wireguard.api:33
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:317