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>
46 vlib buffer access methods.
50 /** \brief Translate buffer index into buffer pointer
52 @param vm - (vlib_main_t *) vlib main data structure pointer
53 @param buffer_index - (u32) buffer index
54 @return - (vlib_buffer_t *) buffer pointer
56 always_inline vlib_buffer_t *
57 vlib_get_buffer (vlib_main_t * vm, u32 buffer_index)
59 vlib_buffer_main_t *bm = &buffer_main;
60 uword offset = ((uword) buffer_index) << CLIB_LOG2_CACHE_LINE_BYTES;
61 ASSERT (offset < bm->buffer_mem_size);
63 return uword_to_pointer (bm->buffer_mem_start + offset, void *);
66 /** \brief Translate buffer pointer into buffer index
68 @param vm - (vlib_main_t *) vlib main data structure pointer
69 @param p - (void *) buffer pointer
70 @return - (u32) buffer index
74 vlib_get_buffer_index (vlib_main_t * vm, void *p)
76 vlib_buffer_main_t *bm = &buffer_main;
77 uword offset = pointer_to_uword (p) - bm->buffer_mem_start;
78 ASSERT (pointer_to_uword (p) >= bm->buffer_mem_start);
79 ASSERT (offset < bm->buffer_mem_size);
80 ASSERT ((offset % (1 << CLIB_LOG2_CACHE_LINE_BYTES)) == 0);
81 return offset >> CLIB_LOG2_CACHE_LINE_BYTES;
84 /** \brief Get next buffer in buffer linklist, or zero for end of list.
86 @param vm - (vlib_main_t *) vlib main data structure pointer
87 @param b - (void *) buffer pointer
88 @return - (vlib_buffer_t *) next buffer, or NULL
90 always_inline vlib_buffer_t *
91 vlib_get_next_buffer (vlib_main_t * vm, vlib_buffer_t * b)
93 return (b->flags & VLIB_BUFFER_NEXT_PRESENT
94 ? vlib_get_buffer (vm, b->next_buffer) : 0);
97 uword vlib_buffer_length_in_chain_slow_path (vlib_main_t * vm,
98 vlib_buffer_t * b_first);
100 /** \brief Get length in bytes of the buffer chain
102 @param vm - (vlib_main_t *) vlib main data structure pointer
103 @param b - (void *) buffer pointer
104 @return - (uword) length of buffer chain
107 vlib_buffer_length_in_chain (vlib_main_t * vm, vlib_buffer_t * b)
109 uword len = b->current_length;
111 if (PREDICT_TRUE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0))
114 if (PREDICT_TRUE (b->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID))
115 return len + b->total_length_not_including_first_buffer;
117 return vlib_buffer_length_in_chain_slow_path (vm, b);
120 /** \brief Get length in bytes of the buffer index buffer chain
122 @param vm - (vlib_main_t *) vlib main data structure pointer
123 @param bi - (u32) buffer index
124 @return - (uword) length of buffer chain
127 vlib_buffer_index_length_in_chain (vlib_main_t * vm, u32 bi)
129 vlib_buffer_t *b = vlib_get_buffer (vm, bi);
130 return vlib_buffer_length_in_chain (vm, b);
133 /** \brief Copy buffer contents to memory
135 @param vm - (vlib_main_t *) vlib main data structure pointer
136 @param buffer_index - (u32) buffer index
137 @param contents - (u8 *) memory, <strong>must be large enough</strong>
138 @return - (uword) length of buffer chain
141 vlib_buffer_contents (vlib_main_t * vm, u32 buffer_index, u8 * contents)
143 uword content_len = 0;
149 b = vlib_get_buffer (vm, buffer_index);
150 l = b->current_length;
151 clib_memcpy (contents + content_len, b->data + b->current_data, l);
153 if (!(b->flags & VLIB_BUFFER_NEXT_PRESENT))
155 buffer_index = b->next_buffer;
161 /* Return physical address of buffer->data start. */
163 vlib_get_buffer_data_physical_address (vlib_main_t * vm, u32 buffer_index)
165 vlib_buffer_main_t *bm = &buffer_main;
166 vlib_buffer_t *b = vlib_get_buffer (vm, buffer_index);
167 vlib_buffer_pool_t *pool = vec_elt_at_index (bm->buffer_pools,
168 b->buffer_pool_index);
170 return vlib_physmem_virtual_to_physical (vm, pool->physmem_region, b->data);
173 /** \brief Prefetch buffer metadata by buffer index
174 The first 64 bytes of buffer contains most header information
176 @param vm - (vlib_main_t *) vlib main data structure pointer
177 @param bi - (u32) buffer index
178 @param type - LOAD, STORE. In most cases, STORE is the right answer
180 /* Prefetch buffer header given index. */
181 #define vlib_prefetch_buffer_with_index(vm,bi,type) \
183 vlib_buffer_t * _b = vlib_get_buffer (vm, bi); \
184 vlib_prefetch_buffer_header (_b, type); \
188 /* Iterate over known allocated vlib bufs. You probably do not want
190 @param vm the vlib_main_t
191 @param bi found allocated buffer index
192 @param body operation to perform on buffer index
193 function executes body for each allocated buffer index
195 #define vlib_buffer_foreach_allocated(vm,bi,body) \
197 vlib_main_t * _vmain = (vm); \
198 vlib_buffer_main_t * _bmain = &_vmain->buffer_main; \
199 hash_pair_t * _vbpair; \
200 hash_foreach_pair(_vbpair, _bmain->buffer_known_hash, ({ \
201 if (VLIB_BUFFER_KNOWN_ALLOCATED == _vbpair->value[0]) { \
202 (bi) = _vbpair->key; \
211 /* Index is unknown. */
214 /* Index is known and free/allocated. */
215 VLIB_BUFFER_KNOWN_FREE,
216 VLIB_BUFFER_KNOWN_ALLOCATED,
217 } vlib_buffer_known_state_t;
219 void vlib_buffer_validate_alloc_free (vlib_main_t * vm, u32 * buffers,
221 vlib_buffer_known_state_t
224 always_inline vlib_buffer_known_state_t
225 vlib_buffer_is_known (u32 buffer_index)
227 vlib_buffer_main_t *bm = &buffer_main;
229 clib_spinlock_lock (&bm->buffer_known_hash_lockp);
230 uword *p = hash_get (bm->buffer_known_hash, buffer_index);
231 clib_spinlock_unlock (&bm->buffer_known_hash_lockp);
232 return p ? p[0] : VLIB_BUFFER_UNKNOWN;
236 vlib_buffer_set_known_state (u32 buffer_index,
237 vlib_buffer_known_state_t state)
239 vlib_buffer_main_t *bm = &buffer_main;
241 clib_spinlock_lock (&bm->buffer_known_hash_lockp);
242 hash_set (bm->buffer_known_hash, buffer_index, state);
243 clib_spinlock_unlock (&bm->buffer_known_hash_lockp);
246 /* Validates sanity of a single buffer.
247 Returns format'ed vector with error message if any. */
248 u8 *vlib_validate_buffer (vlib_main_t * vm, u32 buffer_index,
252 vlib_buffer_round_size (u32 size)
254 return round_pow2 (size, sizeof (vlib_buffer_t));
257 always_inline vlib_buffer_free_list_index_t
258 vlib_buffer_get_free_list_index (vlib_buffer_t * b)
260 if (PREDICT_FALSE (b->flags & VLIB_BUFFER_NON_DEFAULT_FREELIST))
261 return b->free_list_index;
267 vlib_buffer_set_free_list_index (vlib_buffer_t * b,
268 vlib_buffer_free_list_index_t index)
270 if (PREDICT_FALSE (index))
272 b->flags |= VLIB_BUFFER_NON_DEFAULT_FREELIST;
273 b->free_list_index = index;
276 b->flags &= ~VLIB_BUFFER_NON_DEFAULT_FREELIST;
279 /** \brief Allocate buffers from specific freelist into supplied array
281 @param vm - (vlib_main_t *) vlib main data structure pointer
282 @param buffers - (u32 * ) buffer index array
283 @param n_buffers - (u32) number of buffers requested
284 @return - (u32) number of buffers actually allocated, may be
285 less than the number requested or zero
288 vlib_buffer_alloc_from_free_list (vlib_main_t * vm,
291 vlib_buffer_free_list_index_t index)
293 vlib_buffer_main_t *bm = &buffer_main;
294 vlib_buffer_free_list_t *fl;
298 ASSERT (bm->cb.vlib_buffer_fill_free_list_cb);
300 fl = pool_elt_at_index (vm->buffer_free_list_pool, index);
302 len = vec_len (fl->buffers);
304 if (PREDICT_FALSE (len < n_buffers))
306 bm->cb.vlib_buffer_fill_free_list_cb (vm, fl, n_buffers);
307 if (PREDICT_FALSE ((len = vec_len (fl->buffers)) == 0))
310 /* even if fill free list didn't manage to refill free list
311 we should give what we have */
312 n_buffers = clib_min (len, n_buffers);
314 /* following code is intentionaly duplicated to allow compiler
315 to optimize fast path when n_buffers is constant value */
316 src = fl->buffers + len - n_buffers;
317 clib_memcpy (buffers, src, n_buffers * sizeof (u32));
318 _vec_len (fl->buffers) -= n_buffers;
320 /* Verify that buffers are known free. */
321 vlib_buffer_validate_alloc_free (vm, buffers, n_buffers,
322 VLIB_BUFFER_KNOWN_FREE);
327 src = fl->buffers + len - n_buffers;
328 clib_memcpy (buffers, src, n_buffers * sizeof (u32));
329 _vec_len (fl->buffers) -= n_buffers;
331 /* Verify that buffers are known free. */
332 vlib_buffer_validate_alloc_free (vm, buffers, n_buffers,
333 VLIB_BUFFER_KNOWN_FREE);
338 /** \brief Allocate buffers into supplied array
340 @param vm - (vlib_main_t *) vlib main data structure pointer
341 @param buffers - (u32 * ) buffer index array
342 @param n_buffers - (u32) number of buffers requested
343 @return - (u32) number of buffers actually allocated, may be
344 less than the number requested or zero
347 vlib_buffer_alloc (vlib_main_t * vm, u32 * buffers, u32 n_buffers)
349 return vlib_buffer_alloc_from_free_list (vm, buffers, n_buffers,
350 VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
353 /** \brief Allocate buffers into ring
355 @param vm - (vlib_main_t *) vlib main data structure pointer
356 @param buffers - (u32 * ) buffer index ring
357 @param start - (u32) first slot in the ring
358 @param ring_size - (u32) ring size
359 @param n_buffers - (u32) number of buffers requested
360 @return - (u32) number of buffers actually allocated, may be
361 less than the number requested or zero
364 vlib_buffer_alloc_to_ring (vlib_main_t * vm, u32 * ring, u32 start,
365 u32 ring_size, u32 n_buffers)
369 ASSERT (n_buffers <= ring_size);
371 if (PREDICT_TRUE (start + n_buffers <= ring_size))
372 return vlib_buffer_alloc (vm, ring + start, n_buffers);
374 n_alloc = vlib_buffer_alloc (vm, ring + start, ring_size - start);
376 if (PREDICT_TRUE (n_alloc == ring_size - start))
377 n_alloc += vlib_buffer_alloc (vm, ring, n_buffers - n_alloc);
382 /** \brief Free buffers
383 Frees the entire buffer chain for each buffer
385 @param vm - (vlib_main_t *) vlib main data structure pointer
386 @param buffers - (u32 * ) buffer index array
387 @param n_buffers - (u32) number of buffers to free
391 vlib_buffer_free (vlib_main_t * vm,
392 /* pointer to first buffer */
394 /* number of buffers to free */
397 vlib_buffer_main_t *bm = &buffer_main;
399 ASSERT (bm->cb.vlib_buffer_free_cb);
401 return bm->cb.vlib_buffer_free_cb (vm, buffers, n_buffers);
404 /** \brief Free buffers, does not free the buffer chain for each buffer
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 to free
412 vlib_buffer_free_no_next (vlib_main_t * vm,
413 /* pointer to first buffer */
415 /* number of buffers to free */
418 vlib_buffer_main_t *bm = &buffer_main;
420 ASSERT (bm->cb.vlib_buffer_free_no_next_cb);
422 return bm->cb.vlib_buffer_free_no_next_cb (vm, buffers, n_buffers);
425 /** \brief Free one buffer
426 Shorthand to free a single buffer chain.
428 @param vm - (vlib_main_t *) vlib main data structure pointer
429 @param buffer_index - (u32) buffer index to free
432 vlib_buffer_free_one (vlib_main_t * vm, u32 buffer_index)
434 vlib_buffer_free (vm, &buffer_index, /* n_buffers */ 1);
437 /** \brief Free buffers from ring
439 @param vm - (vlib_main_t *) vlib main data structure pointer
440 @param buffers - (u32 * ) buffer index ring
441 @param start - (u32) first slot in the ring
442 @param ring_size - (u32) ring size
443 @param n_buffers - (u32) number of buffers
446 vlib_buffer_free_from_ring (vlib_main_t * vm, u32 * ring, u32 start,
447 u32 ring_size, u32 n_buffers)
449 ASSERT (n_buffers <= ring_size);
451 if (PREDICT_TRUE (start + n_buffers <= ring_size))
453 vlib_buffer_free (vm, ring + start, n_buffers);
457 vlib_buffer_free (vm, ring + start, ring_size - start);
458 vlib_buffer_free (vm, ring, n_buffers - (ring_size - start));
463 /* Add/delete buffer free lists. */
464 vlib_buffer_free_list_index_t vlib_buffer_create_free_list (vlib_main_t * vm,
468 vlib_buffer_delete_free_list (vlib_main_t * vm,
469 vlib_buffer_free_list_index_t free_list_index)
471 vlib_buffer_main_t *bm = &buffer_main;
473 ASSERT (bm->cb.vlib_buffer_delete_free_list_cb);
475 bm->cb.vlib_buffer_delete_free_list_cb (vm, free_list_index);
478 /* Make sure we have at least given number of unaligned buffers. */
479 void vlib_buffer_free_list_fill_unaligned (vlib_main_t * vm,
480 vlib_buffer_free_list_t *
482 uword n_unaligned_buffers);
484 always_inline vlib_buffer_free_list_t *
485 vlib_buffer_get_buffer_free_list (vlib_main_t * vm, vlib_buffer_t * b,
486 vlib_buffer_free_list_index_t * index)
488 vlib_buffer_free_list_index_t i;
490 *index = i = vlib_buffer_get_free_list_index (b);
491 return pool_elt_at_index (vm->buffer_free_list_pool, i);
494 always_inline vlib_buffer_free_list_t *
495 vlib_buffer_get_free_list (vlib_main_t * vm,
496 vlib_buffer_free_list_index_t free_list_index)
498 vlib_buffer_free_list_t *f;
500 f = pool_elt_at_index (vm->buffer_free_list_pool, free_list_index);
502 /* Sanity: indices must match. */
503 ASSERT (f->index == free_list_index);
509 vlib_buffer_free_list_buffer_size (vlib_main_t * vm,
510 vlib_buffer_free_list_index_t index)
512 vlib_buffer_free_list_t *f = vlib_buffer_get_free_list (vm, index);
513 return f->n_data_bytes;
516 void vlib_aligned_memcpy (void *_dst, void *_src, int n_bytes);
518 /* Reasonably fast buffer copy routine. */
520 vlib_copy_buffers (u32 * dst, u32 * src, u32 n)
541 /* Append given data to end of buffer, possibly allocating new buffers. */
542 u32 vlib_buffer_add_data (vlib_main_t * vm,
543 vlib_buffer_free_list_index_t free_list_index,
544 u32 buffer_index, void *data, u32 n_data_bytes);
546 /* duplicate all buffers in chain */
547 always_inline vlib_buffer_t *
548 vlib_buffer_copy (vlib_main_t * vm, vlib_buffer_t * b)
550 vlib_buffer_t *s, *d, *fd;
551 uword n_alloc, n_buffers = 1;
552 u32 flag_mask = VLIB_BUFFER_NEXT_PRESENT | VLIB_BUFFER_TOTAL_LENGTH_VALID;
556 while (s->flags & VLIB_BUFFER_NEXT_PRESENT)
559 s = vlib_get_buffer (vm, s->next_buffer);
561 u32 new_buffers[n_buffers];
563 n_alloc = vlib_buffer_alloc (vm, new_buffers, n_buffers);
565 /* No guarantee that we'll get all the buffers we asked for */
566 if (PREDICT_FALSE (n_alloc < n_buffers))
569 vlib_buffer_free (vm, new_buffers, n_alloc);
575 fd = d = vlib_get_buffer (vm, new_buffers[0]);
576 d->current_data = s->current_data;
577 d->current_length = s->current_length;
578 d->flags = s->flags & flag_mask;
579 d->total_length_not_including_first_buffer =
580 s->total_length_not_including_first_buffer;
581 clib_memcpy (d->opaque, s->opaque, sizeof (s->opaque));
582 clib_memcpy (vlib_buffer_get_current (d),
583 vlib_buffer_get_current (s), s->current_length);
586 for (i = 1; i < n_buffers; i++)
589 d->next_buffer = new_buffers[i];
591 s = vlib_get_buffer (vm, s->next_buffer);
592 d = vlib_get_buffer (vm, new_buffers[i]);
593 d->current_data = s->current_data;
594 d->current_length = s->current_length;
595 clib_memcpy (vlib_buffer_get_current (d),
596 vlib_buffer_get_current (s), s->current_length);
597 d->flags = s->flags & flag_mask;
603 /** \brief Create a maximum of 256 clones of buffer and store them
604 in the supplied array
606 @param vm - (vlib_main_t *) vlib main data structure pointer
607 @param src_buffer - (u32) source buffer index
608 @param buffers - (u32 * ) buffer index array
609 @param n_buffers - (u16) number of buffer clones requested (<=256)
610 @param head_end_offset - (u16) offset relative to current position
611 where packet head ends
612 @return - (u16) number of buffers actually cloned, may be
613 less than the number requested or zero
616 vlib_buffer_clone_256 (vlib_main_t * vm, u32 src_buffer, u32 * buffers,
617 u16 n_buffers, u16 head_end_offset)
620 vlib_buffer_t *s = vlib_get_buffer (vm, src_buffer);
622 ASSERT (s->n_add_refs == 0);
624 ASSERT (n_buffers <= 256);
626 if (s->current_length <= head_end_offset + CLIB_CACHE_LINE_BYTES * 2)
628 buffers[0] = src_buffer;
629 for (i = 1; i < n_buffers; i++)
632 d = vlib_buffer_copy (vm, s);
635 buffers[i] = vlib_get_buffer_index (vm, d);
641 if (PREDICT_FALSE (n_buffers == 1))
643 buffers[0] = src_buffer;
647 n_buffers = vlib_buffer_alloc_from_free_list (vm, buffers, n_buffers,
648 vlib_buffer_get_free_list_index
651 for (i = 0; i < n_buffers; i++)
653 vlib_buffer_t *d = vlib_get_buffer (vm, buffers[i]);
654 d->current_data = s->current_data;
655 d->current_length = head_end_offset;
656 vlib_buffer_set_free_list_index (d,
657 vlib_buffer_get_free_list_index (s));
658 d->total_length_not_including_first_buffer =
659 s->total_length_not_including_first_buffer + s->current_length -
661 d->flags = s->flags | VLIB_BUFFER_NEXT_PRESENT;
662 d->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
663 clib_memcpy (d->opaque, s->opaque, sizeof (s->opaque));
664 clib_memcpy (vlib_buffer_get_current (d), vlib_buffer_get_current (s),
666 d->next_buffer = src_buffer;
668 vlib_buffer_advance (s, head_end_offset);
669 s->n_add_refs = n_buffers - 1;
670 while (s->flags & VLIB_BUFFER_NEXT_PRESENT)
672 s = vlib_get_buffer (vm, s->next_buffer);
673 s->n_add_refs = n_buffers - 1;
679 /** \brief Create multiple clones of buffer and store them
680 in the supplied array
682 @param vm - (vlib_main_t *) vlib main data structure pointer
683 @param src_buffer - (u32) source buffer index
684 @param buffers - (u32 * ) buffer index array
685 @param n_buffers - (u16) number of buffer clones requested (<=256)
686 @param head_end_offset - (u16) offset relative to current position
687 where packet head ends
688 @return - (u16) number of buffers actually cloned, may be
689 less than the number requested or zero
692 vlib_buffer_clone (vlib_main_t * vm, u32 src_buffer, u32 * buffers,
693 u16 n_buffers, u16 head_end_offset)
695 vlib_buffer_t *s = vlib_get_buffer (vm, src_buffer);
698 while (n_buffers > 256)
701 copy = vlib_buffer_copy (vm, s);
702 n_cloned += vlib_buffer_clone_256 (vm,
703 vlib_get_buffer_index (vm, copy),
704 (buffers + n_cloned),
705 256, head_end_offset);
708 n_cloned += vlib_buffer_clone_256 (vm, src_buffer,
710 n_buffers, head_end_offset);
715 /** \brief Attach cloned tail to the buffer
717 @param vm - (vlib_main_t *) vlib main data structure pointer
718 @param head - (vlib_buffer_t *) head buffer
719 @param tail - (Vlib buffer_t *) tail buffer to clone and attach to head
723 vlib_buffer_attach_clone (vlib_main_t * vm, vlib_buffer_t * head,
724 vlib_buffer_t * tail)
726 ASSERT ((head->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
727 ASSERT (vlib_buffer_get_free_list_index (head) ==
728 vlib_buffer_get_free_list_index (tail));
730 head->flags |= VLIB_BUFFER_NEXT_PRESENT;
731 head->flags &= ~VLIB_BUFFER_TOTAL_LENGTH_VALID;
732 head->flags &= ~VLIB_BUFFER_EXT_HDR_VALID;
733 head->flags |= (tail->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID);
734 head->next_buffer = vlib_get_buffer_index (vm, tail);
735 head->total_length_not_including_first_buffer = tail->current_length +
736 tail->total_length_not_including_first_buffer;
739 __sync_add_and_fetch (&tail->n_add_refs, 1);
741 if (tail->flags & VLIB_BUFFER_NEXT_PRESENT)
743 tail = vlib_get_buffer (vm, tail->next_buffer);
748 /* Initializes the buffer as an empty packet with no chained buffers. */
750 vlib_buffer_chain_init (vlib_buffer_t * first)
752 first->total_length_not_including_first_buffer = 0;
753 first->current_length = 0;
754 first->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
755 first->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
758 /* The provided next_bi buffer index is appended to the end of the packet. */
759 always_inline vlib_buffer_t *
760 vlib_buffer_chain_buffer (vlib_main_t * vm,
761 vlib_buffer_t * first,
762 vlib_buffer_t * last, u32 next_bi)
764 vlib_buffer_t *next_buffer = vlib_get_buffer (vm, next_bi);
765 last->next_buffer = next_bi;
766 last->flags |= VLIB_BUFFER_NEXT_PRESENT;
767 next_buffer->current_length = 0;
768 next_buffer->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
772 /* Increases or decreases the packet length.
773 * It does not allocate or deallocate new buffers.
774 * Therefore, the added length must be compatible
775 * with the last buffer. */
777 vlib_buffer_chain_increase_length (vlib_buffer_t * first,
778 vlib_buffer_t * last, i32 len)
780 last->current_length += len;
782 first->total_length_not_including_first_buffer += len;
785 /* Copy data to the end of the packet and increases its length.
786 * It does not allocate new buffers.
787 * Returns the number of copied bytes. */
789 vlib_buffer_chain_append_data (vlib_main_t * vm,
790 vlib_buffer_free_list_index_t free_list_index,
791 vlib_buffer_t * first,
792 vlib_buffer_t * last, void *data, u16 data_len)
795 vlib_buffer_free_list_buffer_size (vm, free_list_index);
796 ASSERT (n_buffer_bytes >= last->current_length + last->current_data);
797 u16 len = clib_min (data_len,
798 n_buffer_bytes - last->current_length -
800 clib_memcpy (vlib_buffer_get_current (last) + last->current_length, data,
802 vlib_buffer_chain_increase_length (first, last, len);
806 /* Copy data to the end of the packet and increases its length.
807 * Allocates additional buffers from the free list if necessary.
808 * Returns the number of copied bytes.
809 * 'last' value is modified whenever new buffers are allocated and
810 * chained and points to the last buffer in the chain. */
812 vlib_buffer_chain_append_data_with_alloc (vlib_main_t * vm,
813 vlib_buffer_free_list_index_t
815 vlib_buffer_t * first,
816 vlib_buffer_t ** last, void *data,
818 void vlib_buffer_chain_validate (vlib_main_t * vm, vlib_buffer_t * first);
820 format_function_t format_vlib_buffer, format_vlib_buffer_and_data,
821 format_vlib_buffer_contents;
825 /* Vector of packet data. */
828 /* Number of buffers to allocate in each call to allocator. */
829 u32 min_n_buffers_each_alloc;
831 /* Buffer free list for this template. */
832 vlib_buffer_free_list_index_t free_list_index;
835 } vlib_packet_template_t;
837 void vlib_packet_template_get_packet_helper (vlib_main_t * vm,
838 vlib_packet_template_t * t);
840 void vlib_packet_template_init (vlib_main_t * vm,
841 vlib_packet_template_t * t,
843 uword n_packet_data_bytes,
844 uword min_n_buffers_each_alloc,
847 void *vlib_packet_template_get_packet (vlib_main_t * vm,
848 vlib_packet_template_t * t,
852 vlib_packet_template_free (vlib_main_t * vm, vlib_packet_template_t * t)
854 vec_free (t->packet_data);
858 unserialize_vlib_buffer_n_bytes (serialize_main_t * m)
860 serialize_stream_t *s = &m->stream;
861 vlib_serialize_buffer_main_t *sm
862 = uword_to_pointer (m->stream.data_function_opaque,
863 vlib_serialize_buffer_main_t *);
864 vlib_main_t *vm = sm->vlib_main;
867 n = s->n_buffer_bytes - s->current_buffer_index;
868 if (sm->last_buffer != ~0)
870 vlib_buffer_t *b = vlib_get_buffer (vm, sm->last_buffer);
871 while (b->flags & VLIB_BUFFER_NEXT_PRESENT)
873 b = vlib_get_buffer (vm, b->next_buffer);
874 n += b->current_length;
879 clib_fifo_foreach (f, sm->rx.buffer_fifo, ({
880 n += vlib_buffer_index_length_in_chain (vm, f[0]);
887 /* Set a buffer quickly into "uninitialized" state. We want this to
888 be extremely cheap and arrange for all fields that need to be
889 initialized to be in the first 128 bits of the buffer. */
891 vlib_buffer_init_for_free_list (vlib_buffer_t * dst,
892 vlib_buffer_free_list_t * fl)
894 vlib_buffer_t *src = &fl->buffer_init_template;
896 /* Make sure vlib_buffer_t is cacheline aligned and sized */
897 ASSERT (STRUCT_OFFSET_OF (vlib_buffer_t, cacheline0) == 0);
898 ASSERT (STRUCT_OFFSET_OF (vlib_buffer_t, cacheline1) ==
899 CLIB_CACHE_LINE_BYTES);
900 ASSERT (STRUCT_OFFSET_OF (vlib_buffer_t, cacheline2) ==
901 CLIB_CACHE_LINE_BYTES * 2);
903 /* Make sure buffer template is sane. */
904 ASSERT (fl->index == vlib_buffer_get_free_list_index (src));
906 clib_memcpy (STRUCT_MARK_PTR (dst, template_start),
907 STRUCT_MARK_PTR (src, template_start),
908 STRUCT_OFFSET_OF (vlib_buffer_t, template_end) -
909 STRUCT_OFFSET_OF (vlib_buffer_t, template_start));
911 /* Not in the first 16 octets. */
912 dst->n_add_refs = src->n_add_refs;
913 vlib_buffer_set_free_list_index (dst, fl->index);
915 /* Make sure it really worked. */
916 #define _(f) ASSERT (dst->f == src->f);
921 /* ASSERT (dst->total_length_not_including_first_buffer == 0); */
922 /* total_length_not_including_first_buffer is not in the template anymore
923 * so it may actually not zeroed for some buffers. One option is to
924 * uncomment the line lower (comes at a cost), the other, is to just not
926 /* dst->total_length_not_including_first_buffer = 0; */
927 ASSERT (dst->n_add_refs == 0);
931 vlib_buffer_add_to_free_list (vlib_main_t * vm,
932 vlib_buffer_free_list_t * f,
933 u32 buffer_index, u8 do_init)
935 vlib_buffer_pool_t *bp = vlib_buffer_pool_get (f->buffer_pool_index);
937 b = vlib_get_buffer (vm, buffer_index);
938 if (PREDICT_TRUE (do_init))
939 vlib_buffer_init_for_free_list (b, f);
940 vec_add1_aligned (f->buffers, buffer_index, CLIB_CACHE_LINE_BYTES);
942 if (vec_len (f->buffers) > 4 * VLIB_FRAME_SIZE)
944 clib_spinlock_lock (&bp->lock);
945 /* keep last stored buffers, as they are more likely hot in the cache */
946 vec_add_aligned (bp->buffers, f->buffers, VLIB_FRAME_SIZE,
947 CLIB_CACHE_LINE_BYTES);
948 vec_delete (f->buffers, VLIB_FRAME_SIZE, 0);
949 f->n_alloc -= VLIB_FRAME_SIZE;
950 clib_spinlock_unlock (&bp->lock);
955 extern u32 *vlib_buffer_state_validation_lock;
956 extern uword *vlib_buffer_state_validation_hash;
957 extern void *vlib_buffer_state_heap;
961 vlib_validate_buffer_in_use (vlib_buffer_t * b, u32 expected)
967 oldheap = clib_mem_set_heap (vlib_buffer_state_heap);
969 while (__sync_lock_test_and_set (vlib_buffer_state_validation_lock, 1))
972 p = hash_get (vlib_buffer_state_validation_hash, b);
974 /* If we don't know about b, declare it to be in the expected state */
977 hash_set (vlib_buffer_state_validation_hash, b, expected);
981 if (p[0] != expected)
985 vlib_main_t *vm = &vlib_global_main;
989 bi = vlib_get_buffer_index (vm, b);
991 clib_mem_set_heap (oldheap);
992 clib_warning ("%.6f buffer %llx (%d): %s, not %s",
993 vlib_time_now (vm), bi,
994 p[0] ? "busy" : "free", expected ? "busy" : "free");
998 CLIB_MEMORY_BARRIER ();
999 *vlib_buffer_state_validation_lock = 0;
1000 clib_mem_set_heap (oldheap);
1005 vlib_validate_buffer_set_in_use (vlib_buffer_t * b, u32 expected)
1010 oldheap = clib_mem_set_heap (vlib_buffer_state_heap);
1012 while (__sync_lock_test_and_set (vlib_buffer_state_validation_lock, 1))
1015 hash_set (vlib_buffer_state_validation_hash, b, expected);
1017 CLIB_MEMORY_BARRIER ();
1018 *vlib_buffer_state_validation_lock = 0;
1019 clib_mem_set_heap (oldheap);
1023 /** minimum data size of first buffer in a buffer chain */
1024 #define VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE (256)
1027 * @brief compress buffer chain in a way where the first buffer is at least
1028 * VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE long
1030 * @param[in] vm - vlib_main
1031 * @param[in,out] first - first buffer in chain
1032 * @param[in,out] discard_vector - vector of buffer indexes which were removed
1036 vlib_buffer_chain_compress (vlib_main_t * vm,
1037 vlib_buffer_t * first, u32 ** discard_vector)
1039 if (first->current_length >= VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE ||
1040 !(first->flags & VLIB_BUFFER_NEXT_PRESENT))
1042 /* this is already big enough or not a chain */
1045 /* probe free list to find allocated buffer size to avoid overfill */
1046 vlib_buffer_free_list_index_t index;
1047 vlib_buffer_free_list_t *free_list =
1048 vlib_buffer_get_buffer_free_list (vm, first, &index);
1050 u32 want_first_size = clib_min (VLIB_BUFFER_CHAIN_MIN_FIRST_DATA_SIZE,
1051 free_list->n_data_bytes -
1052 first->current_data);
1055 vlib_buffer_t *second = vlib_get_buffer (vm, first->next_buffer);
1056 u32 need = want_first_size - first->current_length;
1057 u32 amount_to_copy = clib_min (need, second->current_length);
1058 clib_memcpy (((u8 *) vlib_buffer_get_current (first)) +
1059 first->current_length,
1060 vlib_buffer_get_current (second), amount_to_copy);
1061 first->current_length += amount_to_copy;
1062 vlib_buffer_advance (second, amount_to_copy);
1063 if (first->flags & VLIB_BUFFER_TOTAL_LENGTH_VALID)
1065 first->total_length_not_including_first_buffer -= amount_to_copy;
1067 if (!second->current_length)
1069 vec_add1 (*discard_vector, first->next_buffer);
1070 if (second->flags & VLIB_BUFFER_NEXT_PRESENT)
1072 first->next_buffer = second->next_buffer;
1076 first->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
1078 second->flags &= ~VLIB_BUFFER_NEXT_PRESENT;
1081 while ((first->current_length < want_first_size) &&
1082 (first->flags & VLIB_BUFFER_NEXT_PRESENT));
1085 #endif /* included_vlib_buffer_funcs_h */
1088 * fd.io coding-style-patch-verification: ON
1091 * eval: (c-set-style "gnu")