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.h: VLIB buffers
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_h
41 #define included_vlib_buffer_h
43 #include <vppinfra/types.h>
44 #include <vppinfra/cache.h>
45 #include <vppinfra/serialize.h>
46 #include <vppinfra/vector.h>
47 #include <vppinfra/lock.h>
48 #include <vlib/error.h> /* for vlib_error_t */
50 #include <vlib/config.h> /* for __PRE_DATA_SIZE */
51 #define VLIB_BUFFER_DATA_SIZE (2048)
52 #define VLIB_BUFFER_PRE_DATA_SIZE __PRE_DATA_SIZE
54 /* Minimum buffer chain segment size. Does not apply to last buffer in chain.
55 Dataplane code can safely asume that specified amount of data is not split
56 into 2 chained buffers */
57 #define VLIB_BUFFER_MIN_CHAIN_SEG_SIZE (128)
59 /* Amount of head buffer data copied to each replica head buffer */
60 #define VLIB_BUFFER_CLONE_HEAD_SIZE (256)
62 typedef u8 vlib_buffer_free_list_index_t;
65 vlib buffer structure definition and a few select
66 access methods. This structure and the buffer allocation
67 mechanism should perhaps live in vnet, but it would take a lot
68 of typing to make it so.
74 #define foreach_vlib_buffer_flag \
76 _( 1, NEXT_PRESENT, 0) \
77 _( 2, TOTAL_LENGTH_VALID, 0) \
78 _( 3, EXT_HDR_VALID, "ext-hdr-valid")
80 /* NOTE: only buffer generic flags should be defined here, please consider
81 using user flags. i.e. src/vnet/buffer.h */
85 #define _(bit, name, v) VLIB_BUFFER_##name = (1 << (bit)),
86 foreach_vlib_buffer_flag
92 #define _(bit, name, v) VLIB_BUFFER_LOG2_##name = (bit),
93 foreach_vlib_buffer_flag
97 /* User defined buffer flags. */
98 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
99 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
100 #define VLIB_BUFFER_FLAGS_ALL (0x0f)
102 /** VLIB buffer representation. */
107 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
109 /** signed offset in data[], pre_data[] that we are currently
110 * processing. If negative current header points into predata area. */
113 /** Nbytes between current data and the end of this buffer. */
117 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
118 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
119 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
120 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
121 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
122 set to avoid adding it to a flow report
123 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
127 /** Generic flow identifier */
130 /** Number of additional references to this buffer. */
133 /** index of buffer pool this buffer belongs. */
134 u8 buffer_pool_index;
136 /** Error code for buffers to be enqueued to error handler. */
139 /** Next buffer for this linked-list of buffers. Only valid if
140 * VLIB_BUFFER_NEXT_PRESENT flag is set. */
143 /** Used by feature subgraph arcs to visit enabled feature nodes */
144 u32 current_config_index;
146 /** Opaque data used by sub-graphs for their own purposes. */
149 /** part of buffer metadata which is initialized on alloc ends here. */
150 STRUCT_MARK (template_end);
152 /** start of 2nd cache line */
153 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
155 /** Specifies index into trace buffer if VLIB_PACKET_IS_TRACED flag is
159 /** Only valid for first buffer in chain. Current length plus total length
160 * given here give total number of bytes in buffer chain. */
161 u32 total_length_not_including_first_buffer;
163 /**< More opaque data, see ../vnet/vnet/buffer.h */
166 /** start of third cache line */
167 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
169 /** Space for inserting data before buffer start. Packet rewrite string
170 * will be rewritten backwards and may extend back before
171 * buffer->data[0]. Must come directly before packet data. */
172 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE];
177 #ifdef CLIB_HAVE_VEC128
180 #ifdef CLIB_HAVE_VEC256
183 #ifdef CLIB_HAVE_VEC512
188 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
190 /** \brief Prefetch buffer metadata.
191 The first 64 bytes of buffer contains most header information
193 @param b - (vlib_buffer_t *) pointer to the buffer
194 @param type - LOAD, STORE. In most cases, STORE is the right answer
197 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
198 #define vlib_prefetch_buffer_data(b,type) \
199 CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)
202 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
204 ASSERT (sizeof (b[0]) % 64 == 0);
206 /* Rewrite data must be before and contiguous with packet data. */
207 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
211 vlib_buffer_get_va (vlib_buffer_t * b)
213 return pointer_to_uword (b->data);
216 /** \brief Get pointer to current data to process
218 @param b - (vlib_buffer_t *) pointer to the buffer
219 @return - (void *) (b->data + b->current_data)
223 vlib_buffer_get_current (vlib_buffer_t * b)
226 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
227 return b->data + b->current_data;
231 vlib_buffer_get_current_va (vlib_buffer_t * b)
233 return vlib_buffer_get_va (b) + b->current_data;
236 /** \brief Advance current data pointer by the supplied (signed!) amount
238 @param b - (vlib_buffer_t *) pointer to the buffer
239 @param l - (word) signed increment
242 vlib_buffer_advance (vlib_buffer_t * b, word l)
244 ASSERT (b->current_length >= l);
245 b->current_data += l;
246 b->current_length -= l;
248 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
249 b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
252 /** \brief Check if there is enough space in buffer to advance
254 @param b - (vlib_buffer_t *) pointer to the buffer
255 @param l - (word) size to check
256 @return - 0 if there is less space than 'l' in buffer
259 vlib_buffer_has_space (vlib_buffer_t * b, word l)
261 return b->current_length >= l;
264 /** \brief Reset current header & length to state they were in when
267 @param b - (vlib_buffer_t *) pointer to the buffer
271 vlib_buffer_reset (vlib_buffer_t * b)
273 b->current_length += clib_max (b->current_data, 0);
277 /** \brief Get pointer to buffer's opaque data array
279 @param b - (vlib_buffer_t *) pointer to the buffer
280 @return - (void *) b->opaque
283 vlib_get_buffer_opaque (vlib_buffer_t * b)
285 return (void *) b->opaque;
288 /** \brief Get pointer to buffer's opaque2 data array
290 @param b - (vlib_buffer_t *) pointer to the buffer
291 @return - (void *) b->opaque2
294 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
296 return (void *) b->opaque2;
299 /** \brief Get pointer to the end of buffer's data
300 * @param b pointer to the buffer
301 * @return pointer to tail of packet's data
304 vlib_buffer_get_tail (vlib_buffer_t * b)
306 return b->data + b->current_data + b->current_length;
309 /** \brief Append uninitialized data to buffer
310 * @param b pointer to the buffer
311 * @param size number of uninitialized bytes
312 * @return pointer to beginning of uninitialized data
315 vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size)
317 void *p = vlib_buffer_get_tail (b);
318 /* XXX make sure there's enough space */
319 b->current_length += size;
323 /** \brief Prepend uninitialized data to buffer
324 * @param b pointer to the buffer
325 * @param size number of uninitialized bytes
326 * @return pointer to beginning of uninitialized data
329 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
331 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
332 b->current_data -= size;
333 b->current_length += size;
335 return vlib_buffer_get_current (b);
338 /** \brief Make head room, typically for packet headers
339 * @param b pointer to the buffer
340 * @param size number of head room bytes
341 * @return pointer to start of buffer (current data)
344 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
346 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
347 b->current_data += size;
348 return vlib_buffer_get_current (b);
351 /** \brief Retrieve bytes from buffer head
352 * @param b pointer to the buffer
353 * @param size number of bytes to pull
354 * @return pointer to start of buffer (current data)
357 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
359 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
362 void *data = vlib_buffer_get_current (b);
363 vlib_buffer_advance (b, size);
367 /* Forward declaration. */
370 typedef struct vlib_buffer_free_list_t
372 /* Template buffer used to initialize first 16 bytes of buffers
373 allocated on this free list. */
374 vlib_buffer_t buffer_init_template;
376 /* Our index into vlib_main_t's buffer_free_list_pool. */
377 vlib_buffer_free_list_index_t index;
379 /* Number of buffers to allocate when we need to allocate new buffers */
380 u32 min_n_buffers_each_alloc;
382 /* Total number of buffers allocated from this free list. */
385 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
388 /* index of buffer pool used to get / put buffers */
389 u8 buffer_pool_index;
391 /* Free list name. */
394 /* Callback functions to initialize newly allocated buffers.
395 If null buffers are zeroed. */
396 void (*buffer_init_function) (struct vlib_main_t * vm,
397 struct vlib_buffer_free_list_t * fl,
398 u32 * buffers, u32 n_buffers);
400 uword buffer_init_function_opaque;
401 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
403 typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm,
404 vlib_buffer_free_list_t * fl,
405 uword min_free_buffers);
406 typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers,
408 typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm,
409 u32 * buffers, u32 n_buffers);
413 vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb;
414 vlib_buffer_free_cb_t *vlib_buffer_free_cb;
415 vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb;
416 } vlib_buffer_callbacks_t;
418 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
422 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
425 uword log2_page_size;
426 u32 physmem_map_index;
429 clib_spinlock_t lock;
430 } vlib_buffer_pool_t;
434 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
435 /* Virtual memory address and size of buffer memory, used for calculating
437 uword buffer_mem_start;
438 uword buffer_mem_size;
439 vlib_buffer_pool_t *buffer_pools;
441 /* Buffer free callback, for subversive activities */
442 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
444 u32 n_buffers, u32 follow_buffer_next);
445 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
447 /* Hash table mapping buffer size (rounded to next unit of
448 sizeof (vlib_buffer_t)) to free list index. */
449 uword *free_list_by_size;
451 /* Hash table mapping buffer index into number
452 0 => allocated but free, 1 => allocated and not-free.
453 If buffer index is not in hash table then this buffer
454 has never been allocated. */
455 uword *buffer_known_hash;
456 clib_spinlock_t buffer_known_hash_lockp;
459 vlib_buffer_callbacks_t cb;
460 int callbacks_registered;
461 } vlib_buffer_main_t;
463 u8 vlib_buffer_register_physmem_map (struct vlib_main_t *vm,
464 u32 physmem_map_index);
466 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
469 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
474 /** \brief Compile time buffer trajectory tracing option
475 Turn this on if you run into "bad monkey" contexts,
476 and you want to know exactly which nodes they've visited...
479 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
481 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
482 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
483 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
484 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
485 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
486 vlib_buffer_trace_trajectory_init (b);
488 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
489 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
491 #endif /* included_vlib_buffer_h */
493 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
494 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
495 static void __vlib_add_buffer_callbacks_t_##x (void) \
496 __attribute__((__constructor__)) ; \
497 static void __vlib_add_buffer_callbacks_t_##x (void) \
499 if (vlib_buffer_callbacks) \
500 clib_panic ("vlib buffer callbacks already registered"); \
501 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
503 static void __vlib_rm_buffer_callbacks_t_##x (void) \
504 __attribute__((__destructor__)) ; \
505 static void __vlib_rm_buffer_callbacks_t_##x (void) \
506 { vlib_buffer_callbacks = 0; } \
507 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
510 * fd.io coding-style-patch-verification: ON
513 * eval: (c-set-style "gnu")