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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 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  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 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 representation 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 graph. 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' attributes 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 
329  /**
330  * The VLIB node in which this adj is used to forward packets
331  */
334 
335 STATIC_ASSERT ((STRUCT_OFFSET_OF (ip_adjacency_t, cacheline0) == 0),
336  "IP adjacency cacheline 0 is not offset");
339  "IP adjacency cacheline 1 is more than one cacheline size offset");
340 
341 /**
342  * @brief
343  * Take a reference counting lock on the adjacency
344  */
345 extern void adj_lock(adj_index_t adj_index);
346 /**
347  * @brief
348  * Release a reference counting lock on the adjacency
349  */
350 extern void adj_unlock(adj_index_t adj_index);
351 
352 /**
353  * @brief
354  * Add a child dependent to an adjacency. The child will
355  * thus be informed via its registerd back-walk function
356  * when the adjacency state changes.
357  */
358 extern u32 adj_child_add(adj_index_t adj_index,
360  fib_node_index_t child_index);
361 /**
362  * @brief
363  * Remove a child dependent
364  */
365 extern void adj_child_remove(adj_index_t adj_index,
366  u32 sibling_index);
367 
368 /**
369  * @brief Walk the Adjacencies on a given interface
370  */
371 extern void adj_walk (u32 sw_if_index,
372  adj_walk_cb_t cb,
373  void *ctx);
374 
375 /**
376  * @brief Return the link type of the adjacency
377  */
379 
380 /**
381  * @brief Return the sw interface index of the adjacency.
382  */
384 
385 /**
386  * @brief Return true if the adjacency is 'UP', i.e. can be used for forwarding.
387  * 0 is down, !0 is up.
388  */
389 extern int adj_is_up (adj_index_t ai);
390 
391 /**
392  * @brief Return the link type of the adjacency
393  */
394 extern const u8* adj_get_rewrite (adj_index_t ai);
395 
396 /**
397  * @brief descend the FIB graph looking for loops
398  *
399  * @param ai
400  * The adj index to traverse
401  *
402  * @param entry_indicies)
403  * A pointer to a vector of FIB entries already visited.
404  */
406  fib_node_index_t **entry_indicies);
407 
408 /**
409  * @brief
410  * The global adjacency pool. Exposed for fast/inline data-plane access
411  */
412 extern ip_adjacency_t *adj_pool;
413 
414 /**
415  * @brief
416  * Adjacency packet counters
417  */
419 
420 /**
421  * @brief Global Config for enabling per-adjacency counters
422  * This is configurable because it comes with a non-negligible
423  * performance cost. */
424 extern int adj_per_adj_counters;
425 
426 /**
427  * @brief
428  * Get a pointer to an adjacency object from its index
429  */
430 static inline ip_adjacency_t *
431 adj_get (adj_index_t adj_index)
432 {
433  return (pool_elt_at_index(adj_pool, adj_index));
434 }
435 
436 static inline int
438 {
439  return !(pool_is_free_index(adj_pool, adj_index));
440 }
441 
442 /**
443  * @brief Get the global configuration option for enabling per-adj counters
444  */
445 static inline int
447 {
448  return (adj_per_adj_counters);
449 }
450 
451 #endif
int adj_is_up(adj_index_t ai)
Return true if the adjacency is &#39;UP&#39;, i.e.
Definition: adj.c:502
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:343
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
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
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: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:455
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:431
vl_api_interface_index_t sw_if_index
Definition: gre.api:59
struct ip_adjacency_t_::@119::@120 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: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:200
union ip_adjacency_t_::@119 sub_type
Adj delegate.
Definition: adj_delegate.h:50
unsigned int u32
Definition: types.h:88
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
struct ip_adjacency_t_::@119::@122 glean
IP_LOOKUP_NEXT_GLEAN.
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:287
#define pool_elt_at_index(p, i)
Returns pointer to element at given index.
Definition: pool.h:519
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:332
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:307
An node in the FIB graph.
Definition: fib_node.h:295
vlib_main_t * vm
Definition: in2out_ed.c:1810
fib_node_t ia_node
Linkage into the FIB node graph.
Definition: adj.h:229
const u8 * adj_get_rewrite(adj_index_t ai)
Return the link type of the adjacency.
Definition: adj.c:511
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
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:284
u32 adj_index_t
An index for adjacencies.
Definition: adj_types.h:30
This packets follow a mid-chain adjacency.
Definition: adj.h:76
u8 data[128]
Definition: ipsec_types.api:87
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:475
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
void adj_child_remove(adj_index_t adj_index, u32 sibling_index)
Remove a child dependent.
Definition: adj.c:360
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:488
A collection of combined counters.
Definition: counter.h:188
static int adj_is_valid(adj_index_t adj_index)
Definition: adj.h:437
enum fib_node_type_t_ fib_node_type_t
The types of nodes in a FIB graph.
struct ip_adjacency_t_::@119::@121 midchain
IP_LOOKUP_NEXT_MIDCHAIN.
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
void adj_unlock(adj_index_t adj_index)
Release a reference counting lock on the adjacency.
Definition: adj.c:324
VNET_DECLARE_REWRITE
Definition: adj.h:319
static int adj_are_counters_enabled(void)
Get the global configuration option for enabling per-adj counters.
Definition: adj.h:446
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