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 \
75 _( 0, NON_DEFAULT_FREELIST, "non-default-fl") \
77 _( 2, NEXT_PRESENT, 0) \
78 _( 3, TOTAL_LENGTH_VALID, 0) \
79 _( 4, EXT_HDR_VALID, "ext-hdr-valid")
81 /* NOTE: only buffer generic flags should be defined here, please consider
82 using user flags. i.e. src/vnet/buffer.h */
86 #define _(bit, name, v) VLIB_BUFFER_##name = (1 << (bit)),
87 foreach_vlib_buffer_flag
93 #define _(bit, name, v) VLIB_BUFFER_LOG2_##name = (bit),
94 foreach_vlib_buffer_flag
98 /* User defined buffer flags. */
99 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
100 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
101 #define VLIB_BUFFER_FLAGS_ALL (0x1f)
103 /* VLIB buffer representation. */
106 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
107 /* Offset within data[] that we are currently processing.
108 If negative current header points into predata area. */
109 i16 current_data; /**< signed offset in data[], pre_data[]
110 that we are currently processing.
111 If negative current header points into predata area.
113 u16 current_length; /**< Nbytes between current data and
114 the end of this buffer.
116 u32 flags; /**< buffer flags:
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
126 u32 flow_id; /**< Generic flow identifier */
129 u32 next_buffer; /**< Next buffer for this linked-list of buffers.
130 Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
133 u32 current_config_index; /**< Used by feature subgraph arcs to
134 visit enabled feature nodes
136 vlib_error_t error; /**< Error code for buffers to be enqueued
139 u8 n_add_refs; /**< Number of additional references to this buffer. */
141 u8 buffer_pool_index; /**< index of buffer pool this buffer belongs. */
143 u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
144 See .../vnet/vnet/buffer.h
147 STRUCT_MARK (template_end); /**< part of buffer metadata which is
148 initialized on alloc ends here. It may be
149 different than cacheline on systems with
150 buffer cacheline size */
152 /***** end of first cache line */
153 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
155 u32 trace_index; /**< Specifies index into trace buffer
156 if VLIB_PACKET_IS_TRACED flag is set.
158 u32 recycle_count; /**< Used by L2 path recycle code */
160 u32 total_length_not_including_first_buffer;
161 /**< Only valid for first buffer in chain. Current length plus
162 total length given here give total number of bytes in buffer chain.
164 vlib_buffer_free_list_index_t free_list_index; /** < only used if
165 VLIB_BUFFER_NON_DEFAULT_FREELIST
167 u8 align_pad[3]; /**< available */
168 u32 opaque2[12]; /**< More opaque data, see ../vnet/vnet/buffer.h */
170 /***** end of second cache line */
171 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
172 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
174 Packet rewrite string will be
175 rewritten backwards and may extend
176 back before buffer->data[0].
177 Must come directly before packet data.
180 u8 data[0]; /**< Packet data. Hardware DMA here */
181 } vlib_buffer_t; /* Must be a multiple of 64B. */
183 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
185 /** \brief Prefetch buffer metadata.
186 The first 64 bytes of buffer contains most header information
188 @param b - (vlib_buffer_t *) pointer to the buffer
189 @param type - LOAD, STORE. In most cases, STORE is the right answer
192 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
193 #define vlib_prefetch_buffer_data(b,type) \
194 CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)
197 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
199 ASSERT (sizeof (b[0]) % 64 == 0);
201 /* Rewrite data must be before and contiguous with packet data. */
202 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
206 vlib_buffer_get_va (vlib_buffer_t * b)
208 return pointer_to_uword (b->data);
211 /** \brief Get pointer to current data to process
213 @param b - (vlib_buffer_t *) pointer to the buffer
214 @return - (void *) (b->data + b->current_data)
218 vlib_buffer_get_current (vlib_buffer_t * b)
221 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
222 return b->data + b->current_data;
226 vlib_buffer_get_current_va (vlib_buffer_t * b)
228 return vlib_buffer_get_va (b) + b->current_data;
231 /** \brief Advance current data pointer by the supplied (signed!) amount
233 @param b - (vlib_buffer_t *) pointer to the buffer
234 @param l - (word) signed increment
237 vlib_buffer_advance (vlib_buffer_t * b, word l)
239 ASSERT (b->current_length >= l);
240 b->current_data += l;
241 b->current_length -= l;
243 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
244 b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
247 /** \brief Check if there is enough space in buffer to advance
249 @param b - (vlib_buffer_t *) pointer to the buffer
250 @param l - (word) size to check
251 @return - 0 if there is less space than 'l' in buffer
254 vlib_buffer_has_space (vlib_buffer_t * b, word l)
256 return b->current_length >= l;
259 /** \brief Reset current header & length to state they were in when
262 @param b - (vlib_buffer_t *) pointer to the buffer
266 vlib_buffer_reset (vlib_buffer_t * b)
268 b->current_length += clib_max (b->current_data, 0);
272 /** \brief Get pointer to buffer's opaque data array
274 @param b - (vlib_buffer_t *) pointer to the buffer
275 @return - (void *) b->opaque
278 vlib_get_buffer_opaque (vlib_buffer_t * b)
280 return (void *) b->opaque;
283 /** \brief Get pointer to buffer's opaque2 data array
285 @param b - (vlib_buffer_t *) pointer to the buffer
286 @return - (void *) b->opaque2
289 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
291 return (void *) b->opaque2;
294 /** \brief Get pointer to the end of buffer's data
295 * @param b pointer to the buffer
296 * @return pointer to tail of packet's data
299 vlib_buffer_get_tail (vlib_buffer_t * b)
301 return b->data + b->current_data + b->current_length;
304 /** \brief Append uninitialized data to buffer
305 * @param b pointer to the buffer
306 * @param size number of uninitialized bytes
307 * @return pointer to beginning of uninitialized data
310 vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size)
312 void *p = vlib_buffer_get_tail (b);
313 /* XXX make sure there's enough space */
314 b->current_length += size;
318 /** \brief Prepend uninitialized data to buffer
319 * @param b pointer to the buffer
320 * @param size number of uninitialized bytes
321 * @return pointer to beginning of uninitialized data
324 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
326 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
327 b->current_data -= size;
328 b->current_length += size;
330 return vlib_buffer_get_current (b);
333 /** \brief Make head room, typically for packet headers
334 * @param b pointer to the buffer
335 * @param size number of head room bytes
336 * @return pointer to start of buffer (current data)
339 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
341 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
342 b->current_data += size;
343 return vlib_buffer_get_current (b);
346 /** \brief Retrieve bytes from buffer head
347 * @param b pointer to the buffer
348 * @param size number of bytes to pull
349 * @return pointer to start of buffer (current data)
352 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
354 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
357 void *data = vlib_buffer_get_current (b);
358 vlib_buffer_advance (b, size);
362 /* Forward declaration. */
365 typedef struct vlib_buffer_free_list_t
367 /* Template buffer used to initialize first 16 bytes of buffers
368 allocated on this free list. */
369 vlib_buffer_t buffer_init_template;
371 /* Our index into vlib_main_t's buffer_free_list_pool. */
372 vlib_buffer_free_list_index_t index;
374 /* Number of data bytes for buffers in this free list. */
377 /* Number of buffers to allocate when we need to allocate new buffers */
378 u32 min_n_buffers_each_alloc;
380 /* Total number of buffers allocated from this free list. */
383 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
386 /* index of buffer pool used to get / put buffers */
387 u8 buffer_pool_index;
389 /* Free list name. */
392 /* Callback functions to initialize newly allocated buffers.
393 If null buffers are zeroed. */
394 void (*buffer_init_function) (struct vlib_main_t * vm,
395 struct vlib_buffer_free_list_t * fl,
396 u32 * buffers, u32 n_buffers);
398 uword buffer_init_function_opaque;
399 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
401 typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm,
402 vlib_buffer_free_list_t * fl,
403 uword min_free_buffers);
404 typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers,
406 typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm,
407 u32 * buffers, u32 n_buffers);
411 vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb;
412 vlib_buffer_free_cb_t *vlib_buffer_free_cb;
413 vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb;
414 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
415 vlib_buffer_free_list_index_t
417 } vlib_buffer_callbacks_t;
419 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
423 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
426 uword log2_page_size;
427 u32 physmem_map_index;
430 clib_spinlock_t lock;
431 } vlib_buffer_pool_t;
435 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
436 /* Virtual memory address and size of buffer memory, used for calculating
438 uword buffer_mem_start;
439 uword buffer_mem_size;
440 vlib_buffer_pool_t *buffer_pools;
442 /* Buffer free callback, for subversive activities */
443 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
445 u32 n_buffers, u32 follow_buffer_next);
446 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
447 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
449 /* Hash table mapping buffer size (rounded to next unit of
450 sizeof (vlib_buffer_t)) to free list index. */
451 uword *free_list_by_size;
453 /* Hash table mapping buffer index into number
454 0 => allocated but free, 1 => allocated and not-free.
455 If buffer index is not in hash table then this buffer
456 has never been allocated. */
457 uword *buffer_known_hash;
458 clib_spinlock_t buffer_known_hash_lockp;
461 vlib_buffer_callbacks_t cb;
462 int callbacks_registered;
463 } vlib_buffer_main_t;
465 extern vlib_buffer_main_t buffer_main;
467 static_always_inline vlib_buffer_pool_t *
468 vlib_buffer_pool_get (u8 buffer_pool_index)
470 vlib_buffer_main_t *bm = &buffer_main;
471 return vec_elt_at_index (bm->buffer_pools, buffer_pool_index);
474 u8 vlib_buffer_register_physmem_map (struct vlib_main_t * vm,
475 u32 physmem_map_index);
477 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
480 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
485 /** \brief Compile time buffer trajectory tracing option
486 Turn this on if you run into "bad monkey" contexts,
487 and you want to know exactly which nodes they've visited...
490 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
492 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
493 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
494 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
495 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
496 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
497 vlib_buffer_trace_trajectory_init (b);
499 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
500 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
502 #endif /* included_vlib_buffer_h */
504 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
505 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
506 static void __vlib_add_buffer_callbacks_t_##x (void) \
507 __attribute__((__constructor__)) ; \
508 static void __vlib_add_buffer_callbacks_t_##x (void) \
510 if (vlib_buffer_callbacks) \
511 clib_panic ("vlib buffer callbacks already registered"); \
512 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
514 static void __vlib_rm_buffer_callbacks_t_##x (void) \
515 __attribute__((__destructor__)) ; \
516 static void __vlib_rm_buffer_callbacks_t_##x (void) \
517 { vlib_buffer_callbacks = 0; } \
518 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
521 * fd.io coding-style-patch-verification: ON
524 * eval: (c-set-style "gnu")