2 * Copyright (c) 2015 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:
7 * http://www.apache.org/licenses/LICENSE-2.0
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.
16 * buffer_funcs.h: VLIB buffer related functions/inlines
18 * Copyright (c) 2008 Eliot Dresselhaus
20 * Permission is hereby granted, free of charge, to any person obtaining
21 * a copy of this software and associated documentation files (the
22 * "Software"), to deal in the Software without restriction, including
23 * without limitation the rights to use, copy, modify, merge, publish,
24 * distribute, sublicense, and/or sell copies of the Software, and to
25 * permit persons to whom the Software is furnished to do so, subject to
26 * the following conditions:
28 * The above copyright notice and this permission notice shall be
29 * included in all copies or substantial portions of the Software.
31 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
32 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
33 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
34 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
35 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
36 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
37 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
40 #ifndef included_vlib_buffer_funcs_h
41 #define included_vlib_buffer_funcs_h
43 #include <vppinfra/hash.h>
44 #include <vppinfra/fifo.h>
47 vlib buffer access methods.
51 /** \brief Translate buffer index into buffer pointer
53 @param vm - (vlib_main_t *) vlib main data structure pointer
54 @param buffer_index - (u32) buffer index
55 @return - (vlib_buffer_t *) buffer pointer
57 always_inline vlib_buffer_t *
58 vlib_get_buffer (vlib_main_t * vm, u32 buffer_index)
60 vlib_buffer_main_t *bm = vm->buffer_main;
61 uword offset = ((uword) buffer_index) << CLIB_LOG2_CACHE_LINE_BYTES;
62 ASSERT (offset < bm->buffer_mem_size);
64 return uword_to_pointer (bm->buffer_mem_start + offset, void *);
67 static_always_inline void
68 vlib_buffer_copy_indices (u32 * dst, u32 * src, u32 n_indices)
70 clib_memcpy_fast (dst, src, n_indices * sizeof (u32));
73 static_always_inline void
74 vlib_buffer_copy_template (vlib_buffer_t * b, vlib_buffer_t * bt)
76 clib_memcpy_fast (b, bt, STRUCT_OFFSET_OF (vlib_buffer_t, template_end));
79 /** \brief Translate array of buffer indices into buffer pointers with offset
81 @param vm - (vlib_main_t *) vlib main data structure pointer
82 @param bi - (u32 *) array of buffer indices
83 @param b - (void **) array to store buffer pointers
84 @param count - (uword) number of elements
85 @param offset - (i32) offset applied to each pointer
87 static_always_inline void
88 vlib_get_buffers_with_offset (vlib_main_t * vm, u32 * bi, void **b, int count,
91 uword buffer_mem_start = vm->buffer_main->buffer_mem_start;
92 #ifdef CLIB_HAVE_VEC256
93 u64x4 off = u64x4_splat (buffer_mem_start + offset);
94 /* if count is not const, compiler will not unroll while loop
95 se we maintain two-in-parallel variant */
98 u64x4 b0 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi));
99 u64x4 b1 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi + 4));
100 /* shift and add to get vlib_buffer_t pointer */
101 u64x4_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b);
102 u64x4_store_unaligned ((b1 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 4);
110 #ifdef CLIB_HAVE_VEC256
111 u64x4 b0 = u32x4_extend_to_u64x4 (u32x4_load_unaligned (bi));
112 /* shift and add to get vlib_buffer_t pointer */
113 u64x4_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b);
114 #elif defined (CLIB_HAVE_VEC128)
115 u64x2 off = u64x2_splat (buffer_mem_start + offset);
116 u32x4 bi4 = u32x4_load_unaligned (bi);
117 u64x2 b0 = u32x4_extend_to_u64x2 ((u32x4) bi4);
118 #if defined (__aarch64__)
119 u64x2 b1 = u32x4_extend_to_u64x2_high ((u32x4) bi4);
121 bi4 = u32x4_shuffle (bi4, 2, 3, 0, 1);
122 u64x2 b1 = u32x4_extend_to_u64x2 ((u32x4) bi4);
124 u64x2_store_unaligned ((b0 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b);
125 u64x2_store_unaligned ((b1 << CLIB_LOG2_CACHE_LINE_BYTES) + off, b + 2);
127 b[0] = ((u8 *) vlib_get_buffer (vm, bi[0])) + offset;
128 b[1] = ((u8 *) vlib_get_buffer (vm, bi[1])) + offset;
129 b[2] = ((u8 *) vlib_get_buffer (vm, bi[2])) + offset;
130 b[3] = ((u8 *) vlib_get_buffer (vm, bi[3])) + offset;
138 b[0] = ((u8 *) vlib_get_buffer (vm, bi[0])) + offset;
145 /** \brief Translate array of buffer indices into buffer pointers
147 @param vm - (vlib_main_t *) vlib main data structure pointer
148 @param bi - (u32 *) array of buffer indices
149 @param b - (vlib_buffer_t **) array to store buffer pointers
150 @param count - (uword) number of elements
153 static_always_inline void
154 vlib_get_buffers (vlib_main_t * vm, u32 * bi, vlib_buffer_t ** b, int count)
156 vlib_get_buffers_with_offset (vm, bi, (void **) b, count, 0);
159 /** \brief Translate buffer pointer into buffer index
161 @param vm - (vlib_main_t *) vlib main data structure pointer
162 @param p - (void *) buffer pointer
163 @return - (u32) buffer index
167 vlib_get_buffer_index (vlib_main_t * vm, void *p)
169 vlib_buffer_main_t *bm = vm->buffer_main;
170 uword offset = pointer_to_uword (p) - bm->buffer_mem_start;
171 ASSERT (pointer_to_uword (p) >= bm->buffer_mem_start);
172 ASSERT (offset < bm->buffer_mem_size);
173 ASSERT ((offset % (1 << CLIB_LOG2_CACHE_LINE_BYTES)) == 0);
174 return offset >> CLIB_LOG2_CACHE_LINE_BYTES;
177 /** \brief Translate array of buffer pointers into buffer indices with offset
179 @param vm - (vlib_main_t *) vlib main data structure pointer
180 @param b - (void **) array of buffer pointers
181 @param bi - (u32 *) array to store buffer indices
182 @param count - (uword) number of elements
183 @param offset - (i32) offset applied to each pointer
185 static_always_inline void
186 vlib_get_buffer_indices_with_offset (vlib_main_t * vm, void **b, u32 * bi,
187 uword count, i32 offset)
189 #ifdef CLIB_HAVE_VEC256
190 u32x8 mask = { 0, 2, 4, 6, 1, 3, 5, 7 };
191 u64x4 off4 = u64x4_splat (vm->buffer_main->buffer_mem_start - offset);
195 /* load 4 pointers into 256-bit register */
196 u64x4 v0 = u64x4_load_unaligned (b);
197 u64x4 v1 = u64x4_load_unaligned (b + 4);
203 v0 >>= CLIB_LOG2_CACHE_LINE_BYTES;
204 v1 >>= CLIB_LOG2_CACHE_LINE_BYTES;
206 /* permute 256-bit register so lower u32s of each buffer index are
207 * placed into lower 128-bits */
208 v2 = u32x8_permute ((u32x8) v0, mask);
209 v3 = u32x8_permute ((u32x8) v1, mask);
211 /* extract lower 128-bits and save them to the array of buffer indices */
212 u32x4_store_unaligned (u32x8_extract_lo (v2), bi);
213 u32x4_store_unaligned (u32x8_extract_lo (v3), bi + 4);
221 /* equivalent non-nector implementation */
222 bi[0] = vlib_get_buffer_index (vm, ((u8 *) b[0]) + offset);
223 bi[1] = vlib_get_buffer_index (vm, ((u8 *) b[1]) + offset);
224 bi[2] = vlib_get_buffer_index (vm, ((u8 *) b[2]) + offset);
225 bi[3] = vlib_get_buffer_index (vm, ((u8 *) b[3]) + offset);
232 bi[0] = vlib_get_buffer_index (vm, ((u8 *) b[0]) + offset);
239 /** \brief Translate array of buffer pointers into buffer indices
241 @param vm - (vlib_main_t *) vlib main data structure pointer
242 @param b - (vlib_buffer_t **) array of buffer pointers
243 @param bi - (u32 *) array to store buffer indices
244 @param count - (uword) number of elements
246 static_always_inline void
247 vlib_get_buffer_indices (vlib_main_t * vm, vlib_buffer_t ** b, u32 * bi,
250 vlib_get_buffer_indices_with_offset (vm, (void **) b, bi, count, 0);
253 /** \brief Get next buffer in buffer linklist, or zero for end of list.
255 @param vm - (vlib_main_t *) vlib main data structure pointer
256 @param b - (void *) buffer pointer
257 @return - (vlib_buffer_t *) next buffer, or NULL
259 always_inline vlib_buffer_t *
260 vlib_get_next_buffer (vlib_main_t * vm, vlib_buffer_t * b)
262 return (b->flags & VLIB_BUFFER_NEXT_PRESENT
263 ? vlib_get_buffer (vm, b->next_buffer) : 0);
266 uword vlib_buffer_length_in_chain_slow_path (vlib_main_t * vm,
267 vlib_buffer_t * b_first);
269 /** \brief Get length in bytes of the buffer chain
271 @param vm - (vlib_main_t *) vlib main data structure pointer
272 @param b - (void *) buffer pointer
273 @return - (uword) length of buffer chain
276 vlib_buffer_length_in_chain (vlib_main_t * vm, vlib_buffer_t * b)
278 uword len = b->current_length;
280 if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
283 if (PREDICT_TRUE (b->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID))
284 return len + b->total_length_not_including_first_buffer;
286 return vlib_buffer_length_in_chain_slow_path (vm, b);
289 /** \brief Get length in bytes of the buffer index buffer chain
291 @param vm - (vlib_main_t *) vlib main data structure pointer
292 @param bi - (u32) buffer index
293 @return - (uword) length of buffer chain
296 vlib_buffer_index_length_in_chain (vlib_main_t * vm, u32 bi)
298 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
299 return vlib_buffer_length_in_chain (vm, b);
302 /** \brief Copy buffer contents to memory
304 @param vm - (vlib_main_t *) vlib main data structure pointer
305 @param buffer_index - (u32) buffer index
306 @param contents - (u8 *) memory, <strong>must be large enough</strong>
307 @return - (uword) length of buffer chain
310 vlib_buffer_contents (vlib_main_t * vm, u32 buffer_index, u8 * contents)
312 uword content_len = 0;
318 b = vlib_get_buffer (vm, buffer_index);
319 l = b->current_length;
320 clib_memcpy_fast (contents + content_len, b->data + b->current_data, l);
322 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
324 buffer_index = b->next_buffer;
331 vlib_buffer_get_pa (vlib_main_t * vm, vlib_buffer_t * b)
333 return vlib_physmem_get_pa (vm, b->data);
337 vlib_buffer_get_current_pa (vlib_main_t * vm, vlib_buffer_t * b)
339 return vlib_buffer_get_pa (vm, b) + b->current_data;
342 /** \brief Prefetch buffer metadata by buffer index
343 The first 64 bytes of buffer contains most header information
345 @param vm - (vlib_main_t *) vlib main data structure pointer
346 @param bi - (u32) buffer index
347 @param type - LOAD, STORE. In most cases, STORE is the right answer
349 /* Prefetch buffer header given index. */
350 #define vlib_prefetch_buffer_with_index(vm,bi,type) \
352 vlib_buffer_t * _b = vlib_get_buffer (vm, bi); \
353 vlib_prefetch_buffer_header (_b, type); \
358 /* Index is unknown. */
361 /* Index is known and free/allocated. */
362 VLIB_BUFFER_KNOWN_FREE,
363 VLIB_BUFFER_KNOWN_ALLOCATED,
364 } vlib_buffer_known_state_t;
366 void vlib_buffer_validate_alloc_free (vlib_main_t * vm, u32 * buffers,
368 vlib_buffer_known_state_t
371 always_inline vlib_buffer_known_state_t
372 vlib_buffer_is_known (vlib_main_t * vm, u32 buffer_index)
374 vlib_buffer_main_t *bm = vm->buffer_main;
376 clib_spinlock_lock (&bm->buffer_known_hash_lockp);
377 uword *p = hash_get (bm->buffer_known_hash, buffer_index);
378 clib_spinlock_unlock (&bm->buffer_known_hash_lockp);
379 return p ? p[0] : VLIB_BUFFER_UNKNOWN;
383 vlib_buffer_set_known_state (vlib_main_t * vm, u32 buffer_index,
384 vlib_buffer_known_state_t state)
386 vlib_buffer_main_t *bm = vm->buffer_main;
388 clib_spinlock_lock (&bm->buffer_known_hash_lockp);
389 hash_set (bm->buffer_known_hash, buffer_index, state);
390 clib_spinlock_unlock (&bm->buffer_known_hash_lockp);
393 /* Validates sanity of a single buffer.
394 Returns format'ed vector with error message if any. */
395 u8 *vlib_validate_buffer (vlib_main_t * vm, u32 buffer_index,
399 vlib_buffer_round_size (u32 size)
401 return round_pow2 (size, sizeof (vlib_buffer_t));
404 /** \brief Allocate buffers from specific freelist into supplied array
406 @param vm - (vlib_main_t *) vlib main data structure pointer
407 @param buffers - (u32 * ) buffer index array
408 @param n_buffers - (u32) number of buffers requested
409 @return - (u32) number of buffers actually allocated, may be
410 less than the number requested or zero
413 vlib_buffer_alloc_from_free_list (vlib_main_t * vm,
416 vlib_buffer_free_list_index_t index)
418 vlib_buffer_free_list_t *fl;
419 vlib_buffer_main_t *bm = vm->buffer_main;
423 ASSERT (bm->cb.vlib_buffer_fill_free_list_cb);
425 fl = pool_elt_at_index (vm->buffer_free_list_pool, index);
427 len = vec_len (fl->buffers);
429 if (PREDICT_FALSE (len < n_buffers))
431 bm->cb.vlib_buffer_fill_free_list_cb (vm, fl, n_buffers);
432 if (PREDICT_FALSE ((len = vec_len (fl->buffers)) == 0))
435 /* even if fill free list didn't manage to refill free list
436 we should give what we have */
437 n_buffers = clib_min (len, n_buffers);
439 /* following code is intentionaly duplicated to allow compiler
440 to optimize fast path when n_buffers is constant value */
441 src = fl->buffers + len - n_buffers;
442 vlib_buffer_copy_indices (buffers, src, n_buffers);
443 _vec_len (fl->buffers) -= n_buffers;
445 /* Verify that buffers are known free. */
446 vlib_buffer_validate_alloc_free (vm, buffers, n_buffers,
447 VLIB_BUFFER_KNOWN_FREE);
452 src = fl->buffers + len - n_buffers;
453 vlib_buffer_copy_indices (buffers, src, n_buffers);
454 _vec_len (fl->buffers) -= n_buffers;
456 /* Verify that buffers are known free. */
457 vlib_buffer_validate_alloc_free (vm, buffers, n_buffers,
458 VLIB_BUFFER_KNOWN_FREE);
463 /** \brief Allocate buffers into supplied array
465 @param vm - (vlib_main_t *) vlib main data structure pointer
466 @param buffers - (u32 * ) buffer index array
467 @param n_buffers - (u32) number of buffers requested
468 @return - (u32) number of buffers actually allocated, may be
469 less than the number requested or zero
472 vlib_buffer_alloc (vlib_main_t * vm, u32 * buffers, u32 n_buffers)
474 return vlib_buffer_alloc_from_free_list (vm, buffers, n_buffers,
475 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
478 /** \brief Allocate buffers into ring
480 @param vm - (vlib_main_t *) vlib main data structure pointer
481 @param buffers - (u32 * ) buffer index ring
482 @param start - (u32) first slot in the ring
483 @param ring_size - (u32) ring size
484 @param n_buffers - (u32) number of buffers requested
485 @return - (u32) number of buffers actually allocated, may be
486 less than the number requested or zero
489 vlib_buffer_alloc_to_ring (vlib_main_t * vm, u32 * ring, u32 start,
490 u32 ring_size, u32 n_buffers)
494 ASSERT (n_buffers <= ring_size);
496 if (PREDICT_TRUE (start + n_buffers <= ring_size))
497 return vlib_buffer_alloc (vm, ring + start, n_buffers);
499 n_alloc = vlib_buffer_alloc (vm, ring + start, ring_size - start);
501 if (PREDICT_TRUE (n_alloc == ring_size - start))
502 n_alloc += vlib_buffer_alloc (vm, ring, n_buffers - n_alloc);
507 /** \brief Free buffers
508 Frees the entire buffer chain for each buffer
510 @param vm - (vlib_main_t *) vlib main data structure pointer
511 @param buffers - (u32 * ) buffer index array
512 @param n_buffers - (u32) number of buffers to free
516 vlib_buffer_free (vlib_main_t * vm,
517 /* pointer to first buffer */
519 /* number of buffers to free */
522 vlib_buffer_main_t *bm = vm->buffer_main;
524 ASSERT (bm->cb.vlib_buffer_free_cb);
526 return bm->cb.vlib_buffer_free_cb (vm, buffers, n_buffers);
529 /** \brief Free buffers, does not free the buffer chain for each buffer
531 @param vm - (vlib_main_t *) vlib main data structure pointer
532 @param buffers - (u32 * ) buffer index array
533 @param n_buffers - (u32) number of buffers to free
537 vlib_buffer_free_no_next (vlib_main_t * vm,
538 /* pointer to first buffer */
540 /* number of buffers to free */
543 vlib_buffer_main_t *bm = vm->buffer_main;
545 ASSERT (bm->cb.vlib_buffer_free_no_next_cb);
547 return bm->cb.vlib_buffer_free_no_next_cb (vm, buffers, n_buffers);
550 /** \brief Free one buffer
551 Shorthand to free a single buffer chain.
553 @param vm - (vlib_main_t *) vlib main data structure pointer
554 @param buffer_index - (u32) buffer index to free
557 vlib_buffer_free_one (vlib_main_t * vm, u32 buffer_index)
559 vlib_buffer_free (vm, &buffer_index, /* n_buffers */ 1);
562 /** \brief Free buffers from ring
564 @param vm - (vlib_main_t *) vlib main data structure pointer
565 @param buffers - (u32 * ) buffer index ring
566 @param start - (u32) first slot in the ring
567 @param ring_size - (u32) ring size
568 @param n_buffers - (u32) number of buffers
571 vlib_buffer_free_from_ring (vlib_main_t * vm, u32 * ring, u32 start,
572 u32 ring_size, u32 n_buffers)
574 ASSERT (n_buffers <= ring_size);
576 if (PREDICT_TRUE (start + n_buffers <= ring_size))
578 vlib_buffer_free (vm, ring + start, n_buffers);
582 vlib_buffer_free (vm, ring + start, ring_size - start);
583 vlib_buffer_free (vm, ring, n_buffers - (ring_size - start));
587 /** \brief Free buffers from ring without freeing tail buffers
589 @param vm - (vlib_main_t *) vlib main data structure pointer
590 @param buffers - (u32 * ) buffer index ring
591 @param start - (u32) first slot in the ring
592 @param ring_size - (u32) ring size
593 @param n_buffers - (u32) number of buffers
596 vlib_buffer_free_from_ring_no_next (vlib_main_t * vm, u32 * ring, u32 start,
597 u32 ring_size, u32 n_buffers)
599 ASSERT (n_buffers <= ring_size);
601 if (PREDICT_TRUE (start + n_buffers <= ring_size))
603 vlib_buffer_free_no_next (vm, ring + start, n_buffers);
607 vlib_buffer_free_no_next (vm, ring + start, ring_size - start);
608 vlib_buffer_free_no_next (vm, ring, n_buffers - (ring_size - start));
612 /* Add/delete buffer free lists. */
613 vlib_buffer_free_list_index_t vlib_buffer_create_free_list (vlib_main_t * vm,
617 always_inline vlib_buffer_free_list_t *
618 vlib_buffer_get_free_list (vlib_main_t * vm,
619 vlib_buffer_free_list_index_t free_list_index)
621 vlib_buffer_free_list_t *f;
623 f = pool_elt_at_index (vm->buffer_free_list_pool, free_list_index);
625 /* Sanity: indices must match. */
626 ASSERT (f->index == free_list_index);
632 vlib_buffer_free_list_buffer_size (vlib_main_t * vm,
633 vlib_buffer_free_list_index_t index)
635 vlib_buffer_free_list_t *f = vlib_buffer_get_free_list (vm, index);
636 return f->n_data_bytes;
639 /* Append given data to end of buffer, possibly allocating new buffers. */
640 int vlib_buffer_add_data (vlib_main_t * vm, u32 * buffer_index, void *data,
643 /* duplicate all buffers in chain */
644 always_inline vlib_buffer_t *
645 vlib_buffer_copy (vlib_main_t * vm, vlib_buffer_t * b)
647 vlib_buffer_t *s, *d, *fd;
648 uword n_alloc, n_buffers = 1;
649 u32 flag_mask = VLIB_BUFFER_NEXT_PRESENT | VLIB_BUFFER_TOTAL_LENGTH_VALID;
653 while (s->flags & VLIB_BUFFER_NEXT_PRESENT)
656 s = vlib_get_buffer (vm, s->next_buffer);
658 u32 new_buffers[n_buffers];
660 n_alloc = vlib_buffer_alloc (vm, new_buffers, n_buffers);
662 /* No guarantee that we'll get all the buffers we asked for */
663 if (PREDICT_FALSE (n_alloc < n_buffers))
666 vlib_buffer_free (vm, new_buffers, n_alloc);
672 fd = d = vlib_get_buffer (vm, new_buffers[0]);
673 d->current_data = s->current_data;
674 d->current_length = s->current_length;
675 d->flags = s->flags & flag_mask;
676 d->total_length_not_including_first_buffer =
677 s->total_length_not_including_first_buffer;
678 clib_memcpy_fast (d->opaque, s->opaque, sizeof (s->opaque));
679 clib_memcpy_fast (d->opaque2, s->opaque2, sizeof (s->opaque2));
680 clib_memcpy_fast (vlib_buffer_get_current (d),
681 vlib_buffer_get_current (s), s->current_length);
684 for (i = 1; i < n_buffers; i++)
687 d->next_buffer = new_buffers[i];
689 s = vlib_get_buffer (vm, s->next_buffer);
690 d = vlib_get_buffer (vm, new_buffers[i]);
691 d->current_data = s->current_data;
692 d->current_length = s->current_length;
693 clib_memcpy_fast (vlib_buffer_get_current (d),
694 vlib_buffer_get_current (s), s->current_length);
695 d->flags = s->flags & flag_mask;
701 /** \brief Create a maximum of 256 clones of buffer and store them
702 in the supplied array
704 @param vm - (vlib_main_t *) vlib main data structure pointer
705 @param src_buffer - (u32) source buffer index
706 @param buffers - (u32 * ) buffer index array
707 @param n_buffers - (u16) number of buffer clones requested (<=256)
708 @param head_end_offset - (u16) offset relative to current position
709 where packet head ends
710 @return - (u16) number of buffers actually cloned, may be
711 less than the number requested or zero
714 vlib_buffer_clone_256 (vlib_main_t * vm, u32 src_buffer, u32 * buffers,
715 u16 n_buffers, u16 head_end_offset)
718 vlib_buffer_t *s = vlib_get_buffer (vm, src_buffer);
720 ASSERT (s->n_add_refs == 0);
722 ASSERT (n_buffers <= 256);
724 if (s->current_length <= head_end_offset + CLIB_CACHE_LINE_BYTES * 2)
726 buffers[0] = src_buffer;
727 for (i = 1; i < n_buffers; i++)
730 d = vlib_buffer_copy (vm, s);
733 buffers[i] = vlib_get_buffer_index (vm, d);
739 if (PREDICT_FALSE (n_buffers == 1))
741 buffers[0] = src_buffer;
745 n_buffers = vlib_buffer_alloc (vm, buffers, n_buffers);
747 for (i = 0; i < n_buffers; i++)
749 vlib_buffer_t *d = vlib_get_buffer (vm, buffers[i]);
750 d->current_data = s->current_data;
751 d->current_length = head_end_offset;
752 d->total_length_not_including_first_buffer = s->current_length -
754 if (PREDICT_FALSE (s->flags & VLIB_BUFFER_NEXT_PRESENT))
756 d->total_length_not_including_first_buffer +=
757 s->total_length_not_including_first_buffer;
759 d->flags = s->flags | VLIB_BUFFER_NEXT_PRESENT;
760 d->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
761 clib_memcpy_fast (d->opaque, s->opaque, sizeof (s->opaque));
762 clib_memcpy_fast (d->opaque2, s->opaque2, sizeof (s->opaque2));
763 clib_memcpy_fast (vlib_buffer_get_current (d),
764 vlib_buffer_get_current (s), head_end_offset);
765 d->next_buffer = src_buffer;
767 vlib_buffer_advance (s, head_end_offset);
768 s->n_add_refs = n_buffers - 1;
769 while (s->flags & VLIB_BUFFER_NEXT_PRESENT)
771 s = vlib_get_buffer (vm, s->next_buffer);
772 s->n_add_refs = n_buffers - 1;
778 /** \brief Create multiple clones of buffer and store them
779 in the supplied array
781 @param vm - (vlib_main_t *) vlib main data structure pointer
782 @param src_buffer - (u32) source buffer index
783 @param buffers - (u32 * ) buffer index array
784 @param n_buffers - (u16) number of buffer clones requested (<=256)
785 @param head_end_offset - (u16) offset relative to current position
786 where packet head ends
787 @return - (u16) number of buffers actually cloned, may be
788 less than the number requested or zero
791 vlib_buffer_clone (vlib_main_t * vm, u32 src_buffer, u32 * buffers,
792 u16 n_buffers, u16 head_end_offset)
794 vlib_buffer_t *s = vlib_get_buffer (vm, src_buffer);
797 while (n_buffers > 256)
800 copy = vlib_buffer_copy (vm, s);
801 n_cloned += vlib_buffer_clone_256 (vm,
802 vlib_get_buffer_index (vm, copy),
803 (buffers + n_cloned),
804 256, head_end_offset);
807 n_cloned += vlib_buffer_clone_256 (vm, src_buffer,
809 n_buffers, head_end_offset);
814 /** \brief Attach cloned tail to the buffer
816 @param vm - (vlib_main_t *) vlib main data structure pointer
817 @param head - (vlib_buffer_t *) head buffer
818 @param tail - (Vlib buffer_t *) tail buffer to clone and attach to head
822 vlib_buffer_attach_clone (vlib_main_t * vm, vlib_buffer_t * head,
823 vlib_buffer_t * tail)
825 ASSERT ((head->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
827 head->flags |= VLIB_BUFFER_NEXT_PRESENT;
828 head->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID;
829 head->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
830 head->flags |= (tail->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID);
831 head->next_buffer = vlib_get_buffer_index (vm, tail);
832 head->total_length_not_including_first_buffer = tail->current_length +
833 tail->total_length_not_including_first_buffer;
836 clib_atomic_add_fetch (&tail->n_add_refs, 1);
838 if (tail->flags & VLIB_BUFFER_NEXT_PRESENT)
840 tail = vlib_get_buffer (vm, tail->next_buffer);
845 /* Initializes the buffer as an empty packet with no chained buffers. */
847 vlib_buffer_chain_init (vlib_buffer_t * first)
849 first->total_length_not_including_first_buffer = 0;
850 first->current_length = 0;
851 first->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
852 first->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
855 /* The provided next_bi buffer index is appended to the end of the packet. */
856 always_inline vlib_buffer_t *
857 vlib_buffer_chain_buffer (vlib_main_t * vm, vlib_buffer_t * last, u32 next_bi)
859 vlib_buffer_t *next_buffer = vlib_get_buffer (vm, next_bi);
860 last->next_buffer = next_bi;
861 last->flags |= VLIB_BUFFER_NEXT_PRESENT;
862 next_buffer->current_length = 0;
863 next_buffer->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
867 /* Increases or decreases the packet length.
868 * It does not allocate or deallocate new buffers.
869 * Therefore, the added length must be compatible
870 * with the last buffer. */
872 vlib_buffer_chain_increase_length (vlib_buffer_t * first,
873 vlib_buffer_t * last, i32 len)
875 last->current_length += len;
877 first->total_length_not_including_first_buffer += len;
880 /* Copy data to the end of the packet and increases its length.
881 * It does not allocate new buffers.
882 * Returns the number of copied bytes. */
884 vlib_buffer_chain_append_data (vlib_main_t * vm,
885 vlib_buffer_free_list_index_t free_list_index,
886 vlib_buffer_t * first,
887 vlib_buffer_t * last, void *data, u16 data_len)
890 vlib_buffer_free_list_buffer_size (vm, free_list_index);
891 ASSERT (n_buffer_bytes >= last->current_length + last->current_data);
892 u16 len = clib_min (data_len,
893 n_buffer_bytes - last->current_length -
895 clib_memcpy_fast (vlib_buffer_get_current (last) + last->current_length,
897 vlib_buffer_chain_increase_length (first, last, len);
901 /* Copy data to the end of the packet and increases its length.
902 * Allocates additional buffers from the free list if necessary.
903 * Returns the number of copied bytes.
904 * 'last' value is modified whenever new buffers are allocated and
905 * chained and points to the last buffer in the chain. */
907 vlib_buffer_chain_append_data_with_alloc (vlib_main_t * vm,
908 vlib_buffer_free_list_index_t
910 vlib_buffer_t * first,
911 vlib_buffer_t ** last, void *data,
913 void vlib_buffer_chain_validate (vlib_main_t * vm, vlib_buffer_t * first);
915 format_function_t format_vlib_buffer, format_vlib_buffer_and_data,
916 format_vlib_buffer_contents;
920 /* Vector of packet data. */
923 /* Number of buffers to allocate in each call to allocator. */
924 u32 min_n_buffers_each_alloc;
926 /* Buffer free list for this template. */
927 vlib_buffer_free_list_index_t free_list_index;
932 } vlib_packet_template_t;
934 void vlib_packet_template_get_packet_helper (vlib_main_t * vm,
935 vlib_packet_template_t * t);
937 void vlib_packet_template_init (vlib_main_t * vm,
938 vlib_packet_template_t * t,
940 uword n_packet_data_bytes,
941 uword min_n_buffers_each_alloc,
944 void *vlib_packet_template_get_packet (vlib_main_t * vm,
945 vlib_packet_template_t * t,
949 vlib_packet_template_free (vlib_main_t * vm, vlib_packet_template_t * t)
951 vec_free (t->packet_data);
954 static_always_inline vlib_buffer_pool_t *
955 vlib_buffer_pool_get (vlib_main_t * vm, u8 buffer_pool_index)
957 vlib_buffer_main_t *bm = vm->buffer_main;
958 return vec_elt_at_index (bm->buffer_pools, buffer_pool_index);
962 vlib_buffer_add_to_free_list (vlib_main_t * vm,
963 vlib_buffer_free_list_t * f,
964 u32 buffer_index, u8 do_init)
966 vlib_buffer_pool_t *bp = vlib_buffer_pool_get (vm, f->buffer_pool_index);
968 b = vlib_get_buffer (vm, buffer_index);
969 if (PREDICT_TRUE (do_init))
970 clib_memset (b, 0, STRUCT_OFFSET_OF (vlib_buffer_t, template_end));
971 vec_add1_aligned (f->buffers, buffer_index, CLIB_CACHE_LINE_BYTES);
973 if (vec_len (f->buffers) > 4 * VLIB_FRAME_SIZE)
975 clib_spinlock_lock (&bp->lock);
976 /* keep last stored buffers, as they are more likely hot in the cache */
977 vec_add_aligned (bp->buffers, f->buffers, VLIB_FRAME_SIZE,
978 CLIB_CACHE_LINE_BYTES);
979 vec_delete (f->buffers, VLIB_FRAME_SIZE, 0);
980 f->n_alloc -= VLIB_FRAME_SIZE;
981 clib_spinlock_unlock (&bp->lock);
986 extern u32 *vlib_buffer_state_validation_lock;
987 extern uword *vlib_buffer_state_validation_hash;
988 extern void *vlib_buffer_state_heap;
992 vlib_validate_buffer_in_use (vlib_buffer_t * b, u32 expected)
998 oldheap = clib_mem_set_heap (vlib_buffer_state_heap);
1000 while (clib_atomic_test_and_set (vlib_buffer_state_validation_lock))
1003 p = hash_get (vlib_buffer_state_validation_hash, b);
1005 /* If we don't know about b, declare it to be in the expected state */
1008 hash_set (vlib_buffer_state_validation_hash, b, expected);
1012 if (p[0] != expected)
1014 void cj_stop (void);
1016 vlib_main_t *vm = &vlib_global_main;
1020 bi = vlib_get_buffer_index (vm, b);
1022 clib_mem_set_heap (oldheap);
1023 clib_warning ("%.6f buffer %llx (%d): %s, not %s",
1024 vlib_time_now (vm), bi,
1025 p[0] ? "busy" : "free", expected ? "busy" : "free");
1029 CLIB_MEMORY_BARRIER ();
1030 *vlib_buffer_state_validation_lock = 0;
1031 clib_mem_set_heap (oldheap);
1036 vlib_validate_buffer_set_in_use (vlib_buffer_t * b, u32 expected)
1041 oldheap = clib_mem_set_heap (vlib_buffer_state_heap);
1043 while (clib_atomic_test_and_set (vlib_buffer_state_validation_lock))
1046 hash_set (vlib_buffer_state_validation_hash, b, expected);
1048 CLIB_MEMORY_BARRIER ();
1049 *vlib_buffer_state_validation_lock = 0;
1050 clib_mem_set_heap (oldheap);
1054 /** minimum data size of first buffer in a buffer chain */
1055 #define VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE (256)
1058 * @brief compress buffer chain in a way where the first buffer is at least
1059 * VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE long
1061 * @param[in] vm - vlib_main
1062 * @param[in,out] first - first buffer in chain
1063 * @param[in,out] discard_vector - vector of buffer indexes which were removed
1067 vlib_buffer_chain_compress (vlib_main_t * vm,
1068 vlib_buffer_t * first, u32 ** discard_vector)
1070 if (first->current_length >= VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE ||
1071 !(first->flags & VLIB_BUFFER_NEXT_PRESENT))
1073 /* this is already big enough or not a chain */
1076 /* probe free list to find allocated buffer size to avoid overfill */
1077 vlib_buffer_free_list_t *free_list;
1079 free_list = pool_elt_at_index (vm->buffer_free_list_pool,
1080 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
1082 u32 want_first_size = clib_min (VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE,
1083 free_list->n_data_bytes -
1084 first->current_data);
1087 vlib_buffer_t *second = vlib_get_buffer (vm, first->next_buffer);
1088 u32 need = want_first_size - first->current_length;
1089 u32 amount_to_copy = clib_min (need, second->current_length);
1090 clib_memcpy_fast (((u8 *) vlib_buffer_get_current (first)) +
1091 first->current_length,
1092 vlib_buffer_get_current (second), amount_to_copy);
1093 first->current_length += amount_to_copy;
1094 second->current_data += amount_to_copy;
1095 second->current_length -= amount_to_copy;
1096 if (first->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID)
1098 first->total_length_not_including_first_buffer -= amount_to_copy;
1100 if (!second->current_length)
1102 vec_add1 (*discard_vector, first->next_buffer);
1103 if (second->flags & VLIB_BUFFER_NEXT_PRESENT)
1105 first->next_buffer = second->next_buffer;
1109 first->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
1111 second->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
1114 while ((first->current_length < want_first_size) &&
1115 (first->flags & VLIB_BUFFER_NEXT_PRESENT));
1119 * @brief linearize buffer chain - the first buffer is filled, if needed,
1120 * buffers are allocated and filled, returns free space in last buffer or
1121 * negative on failure
1123 * @param[in] vm - vlib_main
1124 * @param[in,out] first - first buffer in chain
1127 vlib_buffer_chain_linearize (vlib_main_t * vm, vlib_buffer_t * first)
1129 vlib_buffer_t *b = first;
1130 vlib_buffer_free_list_t *fl =
1131 vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
1132 u32 buf_len = fl->n_data_bytes;
1133 // free buffer chain starting from the second buffer
1134 int free_count = (b->flags & VLIB_BUFFER_NEXT_PRESENT) != 0;
1135 u32 chain_to_free = b->next_buffer;
1137 u32 len = vlib_buffer_length_in_chain (vm, b);
1138 u32 free_len = buf_len - b->current_data - b->current_length;
1139 int alloc_len = clib_max (len - free_len, 0); //use the free len in the first buffer
1140 int n_buffers = (alloc_len + buf_len - 1) / buf_len;
1141 u32 new_buffers[n_buffers];
1143 u32 n_alloc = vlib_buffer_alloc (vm, new_buffers, n_buffers);
1144 if (n_alloc != n_buffers)
1146 vlib_buffer_free_no_next (vm, new_buffers, n_alloc);
1150 vlib_buffer_t *s = b;
1151 while (s->flags & VLIB_BUFFER_NEXT_PRESENT)
1153 s = vlib_get_buffer (vm, s->next_buffer);
1154 int d_free_len = buf_len - b->current_data - b->current_length;
1155 ASSERT (d_free_len >= 0);
1156 // chain buf and split write
1157 u32 copy_len = clib_min (d_free_len, s->current_length);
1158 u8 *d = vlib_buffer_put_uninit (b, copy_len);
1159 clib_memcpy (d, vlib_buffer_get_current (s), copy_len);
1160 int rest = s->current_length - copy_len;
1164 ASSERT (vlib_buffer_get_tail (b) == b->data + buf_len);
1165 ASSERT (n_buffers > 0);
1166 b = vlib_buffer_chain_buffer (vm, b, new_buffers[--n_buffers]);
1167 //make full use of the new buffers
1168 b->current_data = 0;
1169 d = vlib_buffer_put_uninit (b, rest);
1170 clib_memcpy (d, vlib_buffer_get_current (s) + copy_len, rest);
1173 vlib_buffer_free (vm, &chain_to_free, free_count);
1174 b->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID;
1175 if (b == first) /* no buffers addeed */
1176 b->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
1177 ASSERT (len == vlib_buffer_length_in_chain (vm, first));
1178 ASSERT (n_buffers == 0);
1179 return buf_len - b->current_data - b->current_length;
1182 #endif /* included_vlib_buffer_funcs_h */
1185 * fd.io coding-style-patch-verification: ON
1188 * eval: (c-set-style "gnu")