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Vector Packet Processing
bier_lookup.c
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1 /*
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:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
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.
14  */
15 
16 #include <vnet/buffer.h>
17 #include <vnet/vnet.h>
18 
19 #include <vnet/bier/bier_fmask.h>
21 #include <vnet/bier/bier_table.h>
22 #include <vnet/bier/bier_fmask.h>
23 
24 /**
25  * Struct maintining the per-worker thread data for BIER lookups
26  */
27 typedef struct bier_lookup_main_t_
28 {
29  /* per-cpu vector of cloned packets */
31  /* per-cpu vector of BIER fmasks */
34 
35 /**
36  * Single instance of the lookup main
37  */
39 
40 static char * bier_lookup_error_strings[] = {
41 #define bier_error(n,s) s,
43 #undef bier_error
44 };
45 
46 /*
47  * Keep these values sematically the same as BIER lookup
48  */
49 #define foreach_bier_lookup_next \
50  _(DROP, "bier-drop") \
51  _(OUTPUT, "bier-output")
52 
53 typedef enum {
54 #define _(s,n) BIER_LOOKUP_NEXT_##s,
56 #undef _
59 
60 typedef enum {
61 #define bier_error(n,s) BIER_LOOKUP_ERROR_##n,
63 #undef bier_error
66 
68 
69 /**
70  * @brief Packet trace recoed for a BIER lookup
71  */
72 typedef struct bier_lookup_trace_t_
73 {
78 
79 static uword
81  vlib_node_runtime_t * node,
82  vlib_frame_t * from_frame)
83 {
84  u32 n_left_from, next_index, * from, * to_next;
86  u32 thread_index = vlib_get_thread_index();
88 
89  from = vlib_frame_vector_args (from_frame);
90  n_left_from = from_frame->n_vectors;
91  next_index = BIER_LOOKUP_NEXT_DROP;
92 
93  while (n_left_from > 0)
94  {
95  u32 n_left_to_next;
96 
97  vlib_get_next_frame (vm, node, next_index,
98  to_next, n_left_to_next);
99 
100  while (n_left_from > 0 && n_left_to_next > 0)
101  {
102  u32 next0, bi0, n_bytes, bti0, bfmi0;
103  const bier_fmask_t *bfm0;
104  const bier_table_t *bt0;
105  u16 index, num_buckets;
106  const bier_hdr_t *bh0;
107  bier_bit_string_t bbs;
108  vlib_buffer_t *b0;
109  bier_bp_t fbs;
110  int bucket;
111 
112  bi0 = from[0];
113  from += 1;
114  n_left_from -= 1;
115 
116  b0 = vlib_get_buffer (vm, bi0);
117  bh0 = vlib_buffer_get_current (b0);
118  bti0 = vnet_buffer(b0)->ip.adj_index[VLIB_TX];
119 
120  /*
121  * default to drop so that if no bits are matched then
122  * that is where we go - DROP.
123  */
124  next0 = BIER_LOOKUP_NEXT_DROP;
125 
126  /*
127  * At the imposition or input node,
128  * we stored the BIER Table index in the TX adjacency
129  */
130  bt0 = bier_table_get(vnet_buffer(b0)->ip.adj_index[VLIB_TX]);
131 
132  /*
133  * we should only forward via one for the ECMP tables
134  */
135  ASSERT(!bier_table_is_main(bt0));
136 
137  /*
138  * number of integer sized buckets
139  */
141  vnet_buffer(b0)->mpls.bier.n_bytes = n_bytes;
142  vnet_buffer(b0)->sw_if_index[VLIB_TX] = ~0;
143  num_buckets = n_bytes / sizeof(int);
145  bt0->bt_id.bti_hdr_len,
146  buckets_copy);
147  memcpy(bbs.bbs_buckets, bh0->bh_bit_string, bbs.bbs_len);
148 
149  /*
150  * reset the fmask and clone storage vectors
151  */
152  vec_reset_length (blm->blm_fmasks[thread_index]);
153  vec_reset_length (blm->blm_clones[thread_index]);
154 
155  /*
156  * Loop through the buckets in the header
157  */
158  for (index = 0; index < num_buckets; index++) {
159  /*
160  * loop through each bit in the bucket
161  */
162  bucket = ((int*)bbs.bbs_buckets)[index];
163 
164  while (bucket) {
165  fbs = bier_find_first_bit_string_set(bucket);
166  fbs += (((num_buckets - 1) - index) *
168 
169  bfmi0 = bier_table_fwd_lookup(bt0, fbs);
170 
171  /*
172  * whatever happens, the bit we just looked for
173  * MUST be cleared from the packet
174  * otherwise we could be in this loop a while ...
175  */
176  bier_bit_string_clear_bit(&bbs, fbs);
177 
178  if (PREDICT_TRUE(INDEX_INVALID != bfmi0))
179  {
180  bfm0 = bier_fmask_get(bfmi0);
181 
182  /*
183  * use the bit-string on the fmask to reset
184  * the bits in the header we are walking
185  */
188  &bbs);
189  bucket = ((int*)bbs.bbs_buckets)[index];
190 
191  /*
192  * the fmask is resolved so replicate a
193  * packet its way
194  */
195  next0 = BIER_LOOKUP_NEXT_OUTPUT;
196 
197  vec_add1 (blm->blm_fmasks[thread_index], bfmi0);
198  } else {
199  /*
200  * go to the next bit-position set
201  */
203  vm, node->node_index,
204  BIER_LOOKUP_ERROR_FMASK_UNRES, 1);
205  bucket = ((int*)bbs.bbs_buckets)[index];
206  continue;
207  }
208  }
209  }
210 
211  /*
212  * Full mask now processed.
213  * Create the number of clones we need based on the number
214  * of fmasks we are sending to.
215  */
216  u16 num_cloned, clone;
217  u32 n_clones;
218 
219  n_clones = vec_len(blm->blm_fmasks[thread_index]);
220 
221  if (PREDICT_TRUE(0 != n_clones))
222  {
223  num_cloned = vlib_buffer_clone(vm, bi0,
224  blm->blm_clones[thread_index],
225  n_clones,
226  n_bytes + 8);
227 
228  if (num_cloned != vec_len(blm->blm_fmasks[thread_index]))
229  {
231  (vm, node->node_index,
232  BIER_LOOKUP_ERROR_BUFFER_ALLOCATION_FAILURE, 1);
233  }
234 
235  for (clone = 0; clone < num_cloned; clone++)
236  {
237  vlib_buffer_t *c0;
238  u32 ci0;
239 
240  ci0 = blm->blm_clones[thread_index][clone];
241  c0 = vlib_get_buffer(vm, ci0);
242  vnet_buffer(c0)->ip.adj_index[VLIB_TX] =
243  blm->blm_fmasks[thread_index][clone];
244 
245  to_next[0] = ci0;
246  to_next += 1;
247  n_left_to_next -= 1;
248 
249  if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
250  {
252 
253  vlib_trace_buffer (vm, node, next0, c0, 0);
254  tr = vlib_add_trace (vm, node, c0, sizeof (*tr));
255  tr->bt_index = bti0;
256  tr->bfm_index = blm->blm_fmasks[thread_index][clone];
257 
258  c0->flags |= VLIB_BUFFER_IS_TRACED;
259  }
260 
261  vlib_validate_buffer_enqueue_x1(vm, node, next_index,
262  to_next, n_left_to_next,
263  ci0, next0);
264 
265  /*
266  * After the enqueue it is possible that we over-flow the
267  * frame of the to-next node. When this happens we need to
268  * 'put' that full frame to the node and get a fresh empty
269  * one. Note that these are macros with side effects that
270  * change to_next & n_left_to_next
271  */
272  if (PREDICT_FALSE(0 == n_left_to_next))
273  {
274  vlib_put_next_frame (vm, node, next_index,
275  n_left_to_next);
276  vlib_get_next_frame (vm, node, next_index,
277  to_next, n_left_to_next);
278  }
279  }
280  }
281  else
282  {
283  /*
284  * no clones/replications required. drop this packet
285  */
286  next0 = BIER_LOOKUP_NEXT_DROP;
287  to_next[0] = bi0;
288  to_next += 1;
289  n_left_to_next -= 1;
290 
291  if (PREDICT_FALSE(b0->flags & VLIB_BUFFER_IS_TRACED))
292  {
294 
295  tr = vlib_add_trace (vm, node, b0, sizeof (*tr));
296 
297  tr->bt_index = bti0;
298  tr->bfm_index = ~0;
299  }
300 
301  vlib_validate_buffer_enqueue_x1(vm, node, next_index,
302  to_next, n_left_to_next,
303  bi0, next0);
304  }
305  }
306 
307  vlib_put_next_frame(vm, node, next_index, n_left_to_next);
308  }
309 
311  BIER_LOOKUP_ERROR_NONE,
312  from_frame->n_vectors);
313  return (from_frame->n_vectors);
314 }
315 
316 static u8 *
317 format_bier_lookup_trace (u8 * s, va_list * args)
318 {
319  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
320  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
321  bier_lookup_trace_t * t = va_arg (*args, bier_lookup_trace_t *);
322 
323  s = format (s, "BIER: next [%d], tbl:%d BFM:%d",
324  t->next_index,
325  t->bt_index,
326  t->bfm_index);
327  return s;
328 }
329 
331  .function = bier_lookup,
332  .name = "bier-lookup",
333  /* Takes a vector of packets. */
334  .vector_size = sizeof (u32),
335 
336  .n_errors = BIER_LOOKUP_N_ERROR,
337  .error_strings = bier_lookup_error_strings,
338 
339  .format_trace = format_bier_lookup_trace,
340  .n_next_nodes = BIER_LOOKUP_N_NEXT,
341  .next_nodes = {
342  [BIER_LOOKUP_NEXT_DROP] = "bier-drop",
343  [BIER_LOOKUP_NEXT_OUTPUT] = "bier-output",
344  },
345 };
346 
347 clib_error_t *
349 {
351  u32 thread_index;
352 
355 
356  for (thread_index = 0;
357  thread_index <= vlib_num_workers();
358  thread_index++)
359  {
360  /*
361  * 1024 is the most we will ever need to support
362  * a Bit-Mask length of 1024
363  */
364  vec_validate(blm->blm_fmasks[thread_index], 1023);
365  vec_validate(blm->blm_clones[thread_index], 1023);
366  }
367 
368  return 0;
369 }
370 
#define vec_validate(V, I)
Make sure vector is long enough for given index (no header, unspecified alignment) ...
Definition: vec.h:437
vlib_node_registration_t bier_lookup_node
(constructor) VLIB_REGISTER_NODE (bier_lookup_node)
Definition: bier_lookup.c:67
#define CLIB_UNUSED(x)
Definition: clib.h:79
struct bier_lookup_trace_t_ bier_lookup_trace_t
Packet trace recoed for a BIER lookup.
#define PREDICT_TRUE(x)
Definition: clib.h:106
bier_lookup_error_t
Definition: bier_lookup.c:60
static bier_fmask_t * bier_fmask_get(u32 index)
Definition: bier_fmask.h:177
u32 index_t
A Data-Path Object is an object that represents actions that are applied to packets are they are swit...
Definition: dpo.h:41
#define vec_add1(V, E)
Add 1 element to end of vector (unspecified alignment).
Definition: vec.h:523
static void bier_bit_string_clear_string(const bier_bit_string_t *src, bier_bit_string_t *dest)
static bier_lookup_main_t bier_lookup_main
Single instance of the lookup main.
Definition: bier_lookup.c:38
u8 * format(u8 *s, const char *fmt,...)
Definition: format.c:419
static bier_table_t * bier_table_get(index_t bti)
Definition: bier_table.h:154
bier_fmask_bits_t bfm_bits
The bits, and their ref counts, that are set on this mask This mask changes as BIER entries link to a...
Definition: bier_fmask.h:119
unsigned char u8
Definition: types.h:56
#define vec_reset_length(v)
Reset vector length to zero NULL-pointer tolerant.
u16 bbs_len
The length of the string in BYTES.
Definition: bier_types.h:282
static void vlib_trace_buffer(vlib_main_t *vm, vlib_node_runtime_t *r, u32 next_index, vlib_buffer_t *b, int follow_chain)
Definition: trace_funcs.h:104
static int bier_find_first_bit_string_set(int mask)
A Variable length BitString.
Definition: bier_types.h:278
#define VLIB_INIT_FUNCTION(x)
Definition: init.h:156
int bier_table_is_main(const bier_table_t *bt)
Definition: bier_table.c:53
unsigned int u32
Definition: types.h:88
u32 bier_bp_t
A bit positon as assigned to egress PEs.
Definition: bier_types.h:294
bier_hdr_len_id_t bti_hdr_len
The size of the bit string processed by this table.
Definition: bier_types.h:419
unsigned short u16
Definition: types.h:57
static void * vlib_buffer_get_current(vlib_buffer_t *b)
Get pointer to current data to process.
Definition: buffer.h:202
static const index_t bier_table_fwd_lookup(const bier_table_t *bt, bier_bp_t bp)
Definition: bier_table.h:167
void bier_bit_string_clear_bit(bier_bit_string_t *bit_string, bier_bp_t bp)
#define PREDICT_FALSE(x)
Definition: clib.h:105
u32 node_index
Node index.
Definition: node.h:473
#define vlib_validate_buffer_enqueue_x1(vm, node, next_index, to_next, n_left_to_next, bi0, next0)
Finish enqueueing one buffer forward in the graph.
Definition: buffer_node.h:218
#define vlib_get_next_frame(vm, node, next_index, vectors, n_vectors_left)
Get pointer to next frame vector data by (vlib_node_runtime_t, next_index).
Definition: node_funcs.h:364
An outgoing BIER mask.
Definition: bier_fmask.h:99
Struct maintining the per-worker thread data for BIER lookups.
Definition: bier_lookup.c:27
#define foreach_bier_lookup_next
Definition: bier_lookup.c:49
static uword bier_lookup(vlib_main_t *vm, vlib_node_runtime_t *node, vlib_frame_t *from_frame)
Definition: bier_lookup.c:80
static void vlib_node_increment_counter(vlib_main_t *vm, u32 node_index, u32 counter_index, u64 increment)
Definition: node_funcs.h:1168
#define VLIB_REGISTER_NODE(x,...)
Definition: node.h:153
static u16 vlib_buffer_clone(vlib_main_t *vm, u32 src_buffer, u32 *buffers, u16 n_buffers, u16 head_end_offset)
Create multiple clones of buffer and store them in the supplied array.
Definition: buffer_funcs.h:864
u16 n_vectors
Definition: node.h:380
static_always_inline uword vlib_get_thread_index(void)
Definition: threads.h:221
vlib_main_t * vm
Definition: buffer.c:294
#define BIER_BIT_MASK_BITS_PER_INT
u32 bier_hdr_len_id_to_num_buckets(bier_hdr_len_id_t id)
Conversion functions for the enumerated bit-string length values, to bit and bytes.
Definition: bier_types.c:60
void vlib_put_next_frame(vlib_main_t *vm, vlib_node_runtime_t *r, u32 next_index, u32 n_vectors_left)
Release pointer to next frame vector data.
Definition: main.c:454
static void bier_bit_string_init(bier_bit_string_t *bbs, bier_hdr_len_id_t len, bier_bit_mask_bucket_t *buckets)
Packet trace recoed for a BIER lookup.
Definition: bier_lookup.c:72
static u8 * format_bier_lookup_trace(u8 *s, va_list *args)
Definition: bier_lookup.c:317
#define ASSERT(truth)
bier_bit_mask_bucket_t * bbs_buckets
The buckets in the string.
Definition: bier_types.h:287
struct bier_lookup_main_t_ bier_lookup_main_t
Struct maintining the per-worker thread data for BIER lookups.
bier_bit_mask_bucket_t bh_bit_string[0]
The variable length bit-string.
Definition: bier_types.h:359
static void * vlib_add_trace(vlib_main_t *vm, vlib_node_runtime_t *r, vlib_buffer_t *b, u32 n_data_bytes)
Definition: trace_funcs.h:55
struct _vlib_node_registration vlib_node_registration_t
bier_table_id_t bt_id
The identity/key or the table.
Definition: bier_table.h:76
Definition: defs.h:47
A BIER header of variable length The encoding follows: https://tools.ietf.org/html/draft-ietf-bier-mp...
Definition: bier_types.h:321
#define vec_len(v)
Number of elements in vector (rvalue-only, NULL tolerant)
#define INDEX_INVALID
Invalid index - used when no index is known blazoned capitals INVALID speak volumes where ~0 does not...
Definition: dpo.h:47
A BIER Table is the bit-indexed forwarding table.
Definition: bier_table.h:38
u64 uword
Definition: types.h:112
static void * vlib_frame_vector_args(vlib_frame_t *f)
Get pointer to frame vector data.
Definition: node_funcs.h:267
bier_bit_string_t bfmb_input_reset_string
each bit in the mask needs to be reference counted and set/cleared on the 0->1 and 1->0 transitions...
Definition: bier_fmask.h:50
#define vnet_buffer(b)
Definition: buffer.h:360
static u32 vlib_num_workers()
Definition: threads.h:375
clib_error_t * bier_lookup_module_init(vlib_main_t *vm)
Definition: bier_lookup.c:348
u32 flags
buffer flags: VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index, VLIB_BUFFER_IS_TRACED: trace this buffer.
Definition: buffer.h:111
u8 bier_bit_mask_bucket_t
A bucket is a byte.
Definition: bier_types.h:257
static char * bier_lookup_error_strings[]
Definition: bier_lookup.c:40
static vlib_buffer_t * vlib_get_buffer(vlib_main_t *vm, u32 buffer_index)
Translate buffer index into buffer pointer.
Definition: buffer_funcs.h:57
bier_lookup_next_t
Definition: bier_lookup.c:53