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))
102 /* VLIB buffer representation. */
105 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
106 STRUCT_MARK (template_start);
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 STRUCT_MARK (template_end);
135 u32 current_config_index; /**< Used by feature subgraph arcs to
136 visit enabled feature nodes
138 vlib_error_t error; /**< Error code for buffers to be enqueued
141 u8 n_add_refs; /**< Number of additional references to this buffer. */
143 u8 buffer_pool_index; /**< index of buffer pool this buffer belongs. */
145 u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
146 See .../vnet/vnet/buffer.h
148 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
150 u32 trace_index; /**< Specifies index into trace buffer
151 if VLIB_PACKET_IS_TRACED flag is set.
153 u32 recycle_count; /**< Used by L2 path recycle code */
155 u32 total_length_not_including_first_buffer;
156 /**< Only valid for first buffer in chain. Current length plus
157 total length given here give total number of bytes in buffer chain.
159 vlib_buffer_free_list_index_t free_list_index; /** < only used if
160 VLIB_BUFFER_NON_DEFAULT_FREELIST
162 u8 align_pad[3]; /**< available */
163 u32 opaque2[12]; /**< More opaque data, see ../vnet/vnet/buffer.h */
165 /***** end of second cache line */
166 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
167 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
169 Packet rewrite string will be
170 rewritten backwards and may extend
171 back before buffer->data[0].
172 Must come directly before packet data.
175 u8 data[0]; /**< Packet data. Hardware DMA here */
176 } vlib_buffer_t; /* Must be a multiple of 64B. */
178 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
180 /** \brief Prefetch buffer metadata.
181 The first 64 bytes of buffer contains most header information
183 @param b - (vlib_buffer_t *) pointer to the buffer
184 @param type - LOAD, STORE. In most cases, STORE is the right answer
187 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
190 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
192 ASSERT (sizeof (b[0]) % 64 == 0);
194 /* Rewrite data must be before and contiguous with packet data. */
195 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
199 vlib_buffer_get_va (vlib_buffer_t * b)
201 return pointer_to_uword (b->data);
204 /** \brief Get pointer to current data to process
206 @param b - (vlib_buffer_t *) pointer to the buffer
207 @return - (void *) (b->data + b->current_data)
211 vlib_buffer_get_current (vlib_buffer_t * b)
214 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
215 return b->data + b->current_data;
219 vlib_buffer_get_current_va (vlib_buffer_t * b)
221 return vlib_buffer_get_va (b) + b->current_data;
224 /** \brief Advance current data pointer by the supplied (signed!) amount
226 @param b - (vlib_buffer_t *) pointer to the buffer
227 @param l - (word) signed increment
230 vlib_buffer_advance (vlib_buffer_t * b, word l)
232 ASSERT (b->current_length >= l);
233 b->current_data += l;
234 b->current_length -= l;
236 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
237 b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
240 /** \brief Check if there is enough space in buffer to advance
242 @param b - (vlib_buffer_t *) pointer to the buffer
243 @param l - (word) size to check
244 @return - 0 if there is less space than 'l' in buffer
247 vlib_buffer_has_space (vlib_buffer_t * b, word l)
249 return b->current_length >= l;
252 /** \brief Reset current header & length to state they were in when
255 @param b - (vlib_buffer_t *) pointer to the buffer
259 vlib_buffer_reset (vlib_buffer_t * b)
261 b->current_length += clib_max (b->current_data, 0);
265 /** \brief Get pointer to buffer's opaque data array
267 @param b - (vlib_buffer_t *) pointer to the buffer
268 @return - (void *) b->opaque
271 vlib_get_buffer_opaque (vlib_buffer_t * b)
273 return (void *) b->opaque;
276 /** \brief Get pointer to buffer's opaque2 data array
278 @param b - (vlib_buffer_t *) pointer to the buffer
279 @return - (void *) b->opaque2
282 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
284 return (void *) b->opaque2;
287 /** \brief Get pointer to the end of buffer's data
288 * @param b pointer to the buffer
289 * @return pointer to tail of packet's data
292 vlib_buffer_get_tail (vlib_buffer_t * b)
294 return b->data + b->current_data + b->current_length;
297 /** \brief Append uninitialized data to buffer
298 * @param b pointer to the buffer
299 * @param size number of uninitialized bytes
300 * @return pointer to beginning of uninitialized data
303 vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
305 void *p = vlib_buffer_get_tail (b);
306 /* XXX make sure there's enough space */
307 b->current_length += size;
311 /** \brief Prepend uninitialized data to buffer
312 * @param b pointer to the buffer
313 * @param size number of uninitialized bytes
314 * @return pointer to beginning of uninitialized data
317 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
319 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
320 b->current_data -= size;
321 b->current_length += size;
323 return vlib_buffer_get_current (b);
326 /** \brief Make head room, typically for packet headers
327 * @param b pointer to the buffer
328 * @param size number of head room bytes
329 * @return pointer to start of buffer (current data)
332 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
334 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
335 b->current_data += size;
336 return vlib_buffer_get_current (b);
339 /** \brief Retrieve bytes from buffer head
340 * @param b pointer to the buffer
341 * @param size number of bytes to pull
342 * @return pointer to start of buffer (current data)
345 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
347 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
350 void *data = vlib_buffer_get_current (b);
351 vlib_buffer_advance (b, size);
355 /* Forward declaration. */
358 typedef struct vlib_buffer_free_list_t
360 /* Template buffer used to initialize first 16 bytes of buffers
361 allocated on this free list. */
362 vlib_buffer_t buffer_init_template;
364 /* Our index into vlib_main_t's buffer_free_list_pool. */
365 vlib_buffer_free_list_index_t index;
367 /* Number of data bytes for buffers in this free list. */
370 /* Number of buffers to allocate when we need to allocate new buffers */
371 u32 min_n_buffers_each_alloc;
373 /* Total number of buffers allocated from this free list. */
376 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
379 /* index of buffer pool used to get / put buffers */
380 u8 buffer_pool_index;
382 /* Free list name. */
385 /* Callback functions to initialize newly allocated buffers.
386 If null buffers are zeroed. */
387 void (*buffer_init_function) (struct vlib_main_t * vm,
388 struct vlib_buffer_free_list_t * fl,
389 u32 * buffers, u32 n_buffers);
391 uword buffer_init_function_opaque;
392 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
394 typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm,
395 vlib_buffer_free_list_t * fl,
396 uword min_free_buffers);
397 typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers,
399 typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm,
400 u32 * buffers, u32 n_buffers);
404 vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb;
405 vlib_buffer_free_cb_t *vlib_buffer_free_cb;
406 vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb;
407 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
409 uword n_packet_data_bytes,
411 min_n_buffers_each_physmem_alloc,
413 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
414 vlib_buffer_free_list_index_t
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)
446 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
448 /* Hash table mapping buffer size (rounded to next unit of
449 sizeof (vlib_buffer_t)) to free list index. */
450 uword *free_list_by_size;
452 /* Hash table mapping buffer index into number
453 0 => allocated but free, 1 => allocated and not-free.
454 If buffer index is not in hash table then this buffer
455 has never been allocated. */
456 uword *buffer_known_hash;
457 clib_spinlock_t buffer_known_hash_lockp;
460 vlib_buffer_callbacks_t cb;
461 int callbacks_registered;
462 } vlib_buffer_main_t;
464 extern vlib_buffer_main_t buffer_main;
466 static_always_inline vlib_buffer_pool_t *
467 vlib_buffer_pool_get (u8 buffer_pool_index)
469 vlib_buffer_main_t *bm = &buffer_main;
470 return vec_elt_at_index (bm->buffer_pools, buffer_pool_index);
473 u8 vlib_buffer_register_physmem_map (struct vlib_main_t * vm,
474 u32 physmem_map_index);
476 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
480 struct vlib_main_t *vlib_main;
482 u32 first_buffer, last_buffer;
488 /* Total accumulated bytes in chain starting with first_buffer. */
489 u32 n_total_data_bytes;
491 /* Max number of bytes to accumulate in chain starting with first_buffer.
492 As this limit is reached buffers are enqueued to next node. */
493 u32 max_n_data_bytes_per_chain;
495 /* Next node to enqueue buffers to relative to current process node. */
498 /* Free list to use to allocate new buffers. */
499 vlib_buffer_free_list_index_t free_list_index;
504 /* CLIB fifo of buffer indices waiting to be unserialized. */
507 /* Event type used to signal that RX buffers have been added to fifo. */
508 uword ready_one_time_event;
511 } vlib_serialize_buffer_main_t;
513 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
514 vlib_serialize_buffer_main_t * sm);
515 void unserialize_open_vlib_buffer (serialize_main_t * m,
516 struct vlib_main_t *vm,
517 vlib_serialize_buffer_main_t * sm);
519 u32 serialize_close_vlib_buffer (serialize_main_t * m);
520 void unserialize_close_vlib_buffer (serialize_main_t * m);
521 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
524 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
526 serialize_stream_t *s = &m->stream;
527 vlib_serialize_buffer_main_t *sm
528 = uword_to_pointer (m->stream.data_function_opaque,
529 vlib_serialize_buffer_main_t *);
530 return sm->tx.n_total_data_bytes + s->current_buffer_index +
531 vec_len (s->overflow_buffer);
537 /** \brief Compile time buffer trajectory tracing option
538 Turn this on if you run into "bad monkey" contexts,
539 and you want to know exactly which nodes they've visited...
542 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
544 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
545 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
546 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
547 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
548 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
549 vlib_buffer_trace_trajectory_init (b);
551 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
552 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
554 #endif /* included_vlib_buffer_h */
556 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
557 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
558 static void __vlib_add_buffer_callbacks_t_##x (void) \
559 __attribute__((__constructor__)) ; \
560 static void __vlib_add_buffer_callbacks_t_##x (void) \
562 if (vlib_buffer_callbacks) \
563 clib_panic ("vlib buffer callbacks already registered"); \
564 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
566 static void __vlib_rm_buffer_callbacks_t_##x (void) \
567 __attribute__((__destructor__)) ; \
568 static void __vlib_rm_buffer_callbacks_t_##x (void) \
569 { vlib_buffer_callbacks = 0; } \
570 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
573 * fd.io coding-style-patch-verification: ON
576 * eval: (c-set-style "gnu")