summaryrefslogtreecommitdiffstats
path: root/src/vlib/buffer.h
blob: 56d855101d55b97c1b410541e0d885eb38776159 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
/*
 * Copyright (c) 2015 Cisco and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at:
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * buffer.h: VLIB buffers
 *
 * Copyright (c) 2008 Eliot Dresselhaus
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 *  EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 *  MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 *  NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 *  LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 *  OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 *  WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef included_vlib_buffer_h
#define included_vlib_buffer_h

#include <vppinfra/types.h>
#include <vppinfra/cache.h>
#include <vppinfra/serialize.h>
#include <vppinfra/vector.h>
#include <vppinfra/lock.h>
#include <vlib/error.h>		/* for vlib_error_t */

#include <vlib/config.h>	/* for __PRE_DATA_SIZE */
#define VLIB_BUFFER_DATA_SIZE		(2048)
#define VLIB_BUFFER_PRE_DATA_SIZE	__PRE_DATA_SIZE

/* Minimum buffer chain segment size. Does not apply to last buffer in chain.
   Dataplane code can safely asume that specified amount of data is not split
   into 2 chained buffers */
#define VLIB_BUFFER_MIN_CHAIN_SEG_SIZE	(128)

/* Amount of head buffer data copied to each replica head buffer */
#define VLIB_BUFFER_CLONE_HEAD_SIZE (256)

typedef u8 vlib_buffer_free_list_index_t;

/** \file
    vlib buffer structure definition and a few select
    access methods. This structure and the buffer allocation
    mechanism should perhaps live in vnet, but it would take a lot
    of typing to make it so.
*/

/**
 * Buffer Flags
 */
#define foreach_vlib_buffer_flag \
  _( 0, IS_TRACED, 0)					\
  _( 1, NEXT_PRESENT, 0)				\
  _( 2, TOTAL_LENGTH_VALID, 0)				\
  _( 3, EXT_HDR_VALID, "ext-hdr-valid")

/* NOTE: only buffer generic flags should be defined here, please consider
   using user flags. i.e. src/vnet/buffer.h */

enum
{
#define _(bit, name, v) VLIB_BUFFER_##name  = (1 << (bit)),
  foreach_vlib_buffer_flag
#undef _
};

enum
{
#define _(bit, name, v) VLIB_BUFFER_LOG2_##name  = (bit),
  foreach_vlib_buffer_flag
#undef _
};

  /* User defined buffer flags. */
#define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
#define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
#define VLIB_BUFFER_FLAGS_ALL (0x0f)

/* VLIB buffer representation. */
typedef struct
{
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  /* Offset within data[] that we are currently processing.
     If negative current header points into predata area. */
  i16 current_data;  /**< signed offset in data[], pre_data[]
                        that we are currently processing.
                        If negative current header points into predata area.
                     */
  u16 current_length;  /**< Nbytes between current data and
                          the end of this buffer.
                       */
  u32 flags; /**< buffer flags:
                <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
                <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
                <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
                <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
                <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
                set to avoid adding it to a flow report
                <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
             */

  u32 flow_id;	/**< Generic flow identifier */


  u32 next_buffer;   /**< Next buffer for this linked-list of buffers.
                        Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
                     */

  u32 current_config_index; /**< Used by feature subgraph arcs to
                               visit enabled feature nodes
                            */
  vlib_error_t error;	/**< Error code for buffers to be enqueued
                           to error handler.
                        */
  u8 n_add_refs; /**< Number of additional references to this buffer. */

  u8 buffer_pool_index;	/**< index of buffer pool this buffer belongs. */

  u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
                    See .../vnet/vnet/buffer.h
                 */

    STRUCT_MARK (template_end);	/**< part of buffer metadata which is
				   initialized on alloc ends here. It may be
				   different than cacheline on systems with
				   buffer cacheline size */

  /***** end of first cache line */
    CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);

  u32 trace_index; /**< Specifies index into trace buffer
                      if VLIB_PACKET_IS_TRACED flag is set.
                   */
  u32 recycle_count; /**< Used by L2 path recycle code */

  u32 total_length_not_including_first_buffer;
  /**< Only valid for first buffer in chain. Current length plus
     total length given here give total number of bytes in buffer chain.
  */
  u8 align_pad[4]; /**< available */
  u32 opaque2[12];  /**< More opaque data, see ../vnet/vnet/buffer.h */

  /***** end of second cache line */
    CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
  u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE];  /**< Space for inserting data
                                               before buffer start.
                                               Packet rewrite string will be
                                               rewritten backwards and may extend
                                               back before buffer->data[0].
                                               Must come directly before packet data.
                                            */

  u8 data[0]; /**< Packet data. Hardware DMA here */
} vlib_buffer_t;		/* Must be a multiple of 64B. */

#define VLIB_BUFFER_HDR_SIZE  (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)

/** \brief Prefetch buffer metadata.
    The first 64 bytes of buffer contains most header information

    @param b - (vlib_buffer_t *) pointer to the buffer
    @param type - LOAD, STORE. In most cases, STORE is the right answer
*/

#define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
#define vlib_prefetch_buffer_data(b,type) \
  CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)

always_inline void
vlib_buffer_struct_is_sane (vlib_buffer_t * b)
{
  ASSERT (sizeof (b[0]) % 64 == 0);

  /* Rewrite data must be before and contiguous with packet data. */
  ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
}

always_inline uword
vlib_buffer_get_va (vlib_buffer_t * b)
{
  return pointer_to_uword (b->data);
}

/** \brief Get pointer to current data to process

    @param b - (vlib_buffer_t *) pointer to the buffer
    @return - (void *) (b->data + b->current_data)
*/

always_inline void *
vlib_buffer_get_current (vlib_buffer_t * b)
{
  /* Check bounds. */
  ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
  return b->data + b->current_data;
}

always_inline uword
vlib_buffer_get_current_va (vlib_buffer_t * b)
{
  return vlib_buffer_get_va (b) + b->current_data;
}

/** \brief Advance current data pointer by the supplied (signed!) amount

    @param b - (vlib_buffer_t *) pointer to the buffer
    @param l - (word) signed increment
*/
always_inline void
vlib_buffer_advance (vlib_buffer_t * b, word l)
{
  ASSERT (b->current_length >= l);
  b->current_data += l;
  b->current_length -= l;

  ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
	  b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
}

/** \brief Check if there is enough space in buffer to advance

    @param b - (vlib_buffer_t *) pointer to the buffer
    @param l - (word) size to check
    @return - 0 if there is less space than 'l' in buffer
*/
always_inline u8
vlib_buffer_has_space (vlib_buffer_t * b, word l)
{
  return b->current_length >= l;
}

/** \brief Reset current header & length to state they were in when
    packet was received.

    @param b - (vlib_buffer_t *) pointer to the buffer
*/

always_inline void
vlib_buffer_reset (vlib_buffer_t * b)
{
  b->current_length += clib_max (b->current_data, 0);
  b->current_data = 0;
}

/** \brief Get pointer to buffer's opaque data array

    @param b - (vlib_buffer_t *) pointer to the buffer
    @return - (void *) b->opaque
*/
always_inline void *
vlib_get_buffer_opaque (vlib_buffer_t * b)
{
  return (void *) b->opaque;
}

/** \brief Get pointer to buffer's opaque2 data array

    @param b - (vlib_buffer_t *) pointer to the buffer
    @return - (void *) b->opaque2
*/
always_inline void *
vlib_get_buffer_opaque2 (vlib_buffer_t * b)
{
  return (void *) b->opaque2;
}

/** \brief Get pointer to the end of buffer's data
 * @param b     pointer to the buffer
 * @return      pointer to tail of packet's data
 */
always_inline u8 *
vlib_buffer_get_tail (vlib_buffer_t * b)
{
  return b->data + b->current_data + b->current_length;
}

/** \brief Append uninitialized data to buffer
 * @param b     pointer to the buffer
 * @param size  number of uninitialized bytes
 * @return      pointer to beginning of uninitialized data
 */
always_inline void *
vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size)
{
  void *p = vlib_buffer_get_tail (b);
  /* XXX make sure there's enough space */
  b->current_length += size;
  return p;
}

/** \brief Prepend uninitialized data to buffer
 * @param b     pointer to the buffer
 * @param size  number of uninitialized bytes
 * @return      pointer to beginning of uninitialized data
 */
always_inline void *
vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
{
  ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
  b->current_data -= size;
  b->current_length += size;

  return vlib_buffer_get_current (b);
}

/** \brief Make head room, typically for packet headers
 * @param b     pointer to the buffer
 * @param size  number of head room bytes
 * @return      pointer to start of buffer (current data)
 */
always_inline void *
vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
{
  ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
  b->current_data += size;
  return vlib_buffer_get_current (b);
}

/** \brief Retrieve bytes from buffer head
 * @param b     pointer to the buffer
 * @param size  number of bytes to pull
 * @return      pointer to start of buffer (current data)
 */
always_inline void *
vlib_buffer_pull (vlib_buffer_t * b, u8 size)
{
  if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
    return 0;

  void *data = vlib_buffer_get_current (b);
  vlib_buffer_advance (b, size);
  return data;
}

/* Forward declaration. */
struct vlib_main_t;

typedef struct vlib_buffer_free_list_t
{
  /* Template buffer used to initialize first 16 bytes of buffers
     allocated on this free list. */
  vlib_buffer_t buffer_init_template;

  /* Our index into vlib_main_t's buffer_free_list_pool. */
  vlib_buffer_free_list_index_t index;

  /* Number of data bytes for buffers in this free list. */
  u32 n_data_bytes;

  /* Number of buffers to allocate when we need to allocate new buffers */
  u32 min_n_buffers_each_alloc;

  /* Total number of buffers allocated from this free list. */
  u32 n_alloc;

  /* Vector of free buffers.  Each element is a byte offset into I/O heap. */
  u32 *buffers;

  /* index of buffer pool used to get / put buffers */
  u8 buffer_pool_index;

  /* Free list name. */
  u8 *name;

  /* Callback functions to initialize newly allocated buffers.
     If null buffers are zeroed. */
  void (*buffer_init_function) (struct vlib_main_t * vm,
				struct vlib_buffer_free_list_t * fl,
				u32 * buffers, u32 n_buffers);

  uword buffer_init_function_opaque;
} __attribute__ ((aligned (16))) vlib_buffer_free_list_t;

typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm,
						 vlib_buffer_free_list_t * fl,
						 uword min_free_buffers);
typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers,
				      u32 n_buffers);
typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm,
					      u32 * buffers, u32 n_buffers);

typedef struct
{
  vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb;
  vlib_buffer_free_cb_t *vlib_buffer_free_cb;
  vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb;
  void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
					   vlib_buffer_free_list_index_t
					   free_list_index);
} vlib_buffer_callbacks_t;

extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;

typedef struct
{
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  uword start;
  uword size;
  uword log2_page_size;
  u32 physmem_map_index;
  u32 buffer_size;
  u32 *buffers;
  clib_spinlock_t lock;
} vlib_buffer_pool_t;

typedef struct
{
  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
  /* Virtual memory address and size of buffer memory, used for calculating
     buffer index */
  uword buffer_mem_start;
  uword buffer_mem_size;
  vlib_buffer_pool_t *buffer_pools;

  /* Buffer free callback, for subversive activities */
    u32 (*buffer_free_callback) (struct vlib_main_t * vm,
				 u32 * buffers,
				 u32 n_buffers, u32 follow_buffer_next);
#define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
#define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE

  /* Hash table mapping buffer size (rounded to next unit of
     sizeof (vlib_buffer_t)) to free list index. */
  uword *free_list_by_size;

  /* Hash table mapping buffer index into number
     0 => allocated but free, 1 => allocated and not-free.
     If buffer index is not in hash table then this buffer
     has never been allocated. */
  uword *buffer_known_hash;
  clib_spinlock_t buffer_known_hash_lockp;

  /* Callbacks */
  vlib_buffer_callbacks_t cb;
  int callbacks_registered;
} vlib_buffer_main_t;

extern vlib_buffer_main_t buffer_main;

static_always_inline vlib_buffer_pool_t *
vlib_buffer_pool_get (u8 buffer_pool_index)
{
  vlib_buffer_main_t *bm = &buffer_main;
  return vec_elt_at_index (bm->buffer_pools, buffer_pool_index);
}

u8 vlib_buffer_register_physmem_map (struct vlib_main_t * vm,
				     u32 physmem_map_index);

clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);


void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);

/*
 */

/** \brief Compile time buffer trajectory tracing option
    Turn this on if you run into "bad monkey" contexts,
    and you want to know exactly which nodes they've visited...
    See vlib/main.c...
*/
#define VLIB_BUFFER_TRACE_TRAJECTORY 0

#if VLIB_BUFFER_TRACE_TRAJECTORY > 0
extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
#define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
  vlib_buffer_trace_trajectory_init (b);
#else
#define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
#endif /* VLIB_BUFFER_TRACE_TRAJECTORY */

#endif /* included_vlib_buffer_h */

#define VLIB_BUFFER_REGISTER_CALLBACKS(x,...)                           \
    __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks;       \
static void __vlib_add_buffer_callbacks_t_##x (void)                    \
    __attribute__((__constructor__)) ;                                  \
static void __vlib_add_buffer_callbacks_t_##x (void)                    \
{                                                                       \
    if (vlib_buffer_callbacks)                                          \
      clib_panic ("vlib buffer callbacks already registered");          \
    vlib_buffer_callbacks = &__##x##_buffer_callbacks;                  \
}                                                                       \
static void __vlib_rm_buffer_callbacks_t_##x (void)                     \
    __attribute__((__destructor__)) ;                                   \
static void __vlib_rm_buffer_callbacks_t_##x (void)                     \
{ vlib_buffer_callbacks = 0; }                                          \
__VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */