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 STRUCT_MARK (template_start);
108 /* Offset within data[] that we are currently processing.
109 If negative current header points into predata area. */
110 i16 current_data; /**< signed offset in data[], pre_data[]
111 that we are currently processing.
112 If negative current header points into predata area.
114 u16 current_length; /**< Nbytes between current data and
115 the end of this buffer.
117 u32 flags; /**< buffer flags:
118 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
119 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
120 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
121 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
122 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
123 set to avoid adding it to a flow report
124 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
127 u32 flow_id; /**< Generic flow identifier */
130 u32 next_buffer; /**< Next buffer for this linked-list of buffers.
131 Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
134 STRUCT_MARK (template_end);
136 u32 current_config_index; /**< Used by feature subgraph arcs to
137 visit enabled feature nodes
139 vlib_error_t error; /**< Error code for buffers to be enqueued
142 u8 n_add_refs; /**< Number of additional references to this buffer. */
144 u8 buffer_pool_index; /**< index of buffer pool this buffer belongs. */
146 u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
147 See .../vnet/vnet/buffer.h
149 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
151 u32 trace_index; /**< Specifies index into trace buffer
152 if VLIB_PACKET_IS_TRACED flag is set.
154 u32 recycle_count; /**< Used by L2 path recycle code */
156 u32 total_length_not_including_first_buffer;
157 /**< Only valid for first buffer in chain. Current length plus
158 total length given here give total number of bytes in buffer chain.
160 vlib_buffer_free_list_index_t free_list_index; /** < only used if
161 VLIB_BUFFER_NON_DEFAULT_FREELIST
163 u8 align_pad[3]; /**< available */
164 u32 opaque2[12]; /**< More opaque data, see ../vnet/vnet/buffer.h */
166 /***** end of second cache line */
167 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
168 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
170 Packet rewrite string will be
171 rewritten backwards and may extend
172 back before buffer->data[0].
173 Must come directly before packet data.
176 u8 data[0]; /**< Packet data. Hardware DMA here */
177 } vlib_buffer_t; /* Must be a multiple of 64B. */
179 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
181 /** \brief Prefetch buffer metadata.
182 The first 64 bytes of buffer contains most header information
184 @param b - (vlib_buffer_t *) pointer to the buffer
185 @param type - LOAD, STORE. In most cases, STORE is the right answer
188 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
189 #define vlib_prefetch_buffer_data(b,type) \
190 CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)
193 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
195 ASSERT (sizeof (b[0]) % 64 == 0);
197 /* Rewrite data must be before and contiguous with packet data. */
198 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
202 vlib_buffer_get_va (vlib_buffer_t * b)
204 return pointer_to_uword (b->data);
207 /** \brief Get pointer to current data to process
209 @param b - (vlib_buffer_t *) pointer to the buffer
210 @return - (void *) (b->data + b->current_data)
214 vlib_buffer_get_current (vlib_buffer_t * b)
217 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
218 return b->data + b->current_data;
222 vlib_buffer_get_current_va (vlib_buffer_t * b)
224 return vlib_buffer_get_va (b) + b->current_data;
227 /** \brief Advance current data pointer by the supplied (signed!) amount
229 @param b - (vlib_buffer_t *) pointer to the buffer
230 @param l - (word) signed increment
233 vlib_buffer_advance (vlib_buffer_t * b, word l)
235 ASSERT (b->current_length >= l);
236 b->current_data += l;
237 b->current_length -= l;
239 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
240 b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
243 /** \brief Check if there is enough space in buffer to advance
245 @param b - (vlib_buffer_t *) pointer to the buffer
246 @param l - (word) size to check
247 @return - 0 if there is less space than 'l' in buffer
250 vlib_buffer_has_space (vlib_buffer_t * b, word l)
252 return b->current_length >= l;
255 /** \brief Reset current header & length to state they were in when
258 @param b - (vlib_buffer_t *) pointer to the buffer
262 vlib_buffer_reset (vlib_buffer_t * b)
264 b->current_length += clib_max (b->current_data, 0);
268 /** \brief Get pointer to buffer's opaque data array
270 @param b - (vlib_buffer_t *) pointer to the buffer
271 @return - (void *) b->opaque
274 vlib_get_buffer_opaque (vlib_buffer_t * b)
276 return (void *) b->opaque;
279 /** \brief Get pointer to buffer's opaque2 data array
281 @param b - (vlib_buffer_t *) pointer to the buffer
282 @return - (void *) b->opaque2
285 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
287 return (void *) b->opaque2;
290 /** \brief Get pointer to the end of buffer's data
291 * @param b pointer to the buffer
292 * @return pointer to tail of packet's data
295 vlib_buffer_get_tail (vlib_buffer_t * b)
297 return b->data + b->current_data + b->current_length;
300 /** \brief Append uninitialized data to buffer
301 * @param b pointer to the buffer
302 * @param size number of uninitialized bytes
303 * @return pointer to beginning of uninitialized data
306 vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size)
308 void *p = vlib_buffer_get_tail (b);
309 /* XXX make sure there's enough space */
310 b->current_length += size;
314 /** \brief Prepend uninitialized data to buffer
315 * @param b pointer to the buffer
316 * @param size number of uninitialized bytes
317 * @return pointer to beginning of uninitialized data
320 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
322 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
323 b->current_data -= size;
324 b->current_length += size;
326 return vlib_buffer_get_current (b);
329 /** \brief Make head room, typically for packet headers
330 * @param b pointer to the buffer
331 * @param size number of head room bytes
332 * @return pointer to start of buffer (current data)
335 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
337 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
338 b->current_data += size;
339 return vlib_buffer_get_current (b);
342 /** \brief Retrieve bytes from buffer head
343 * @param b pointer to the buffer
344 * @param size number of bytes to pull
345 * @return pointer to start of buffer (current data)
348 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
350 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
353 void *data = vlib_buffer_get_current (b);
354 vlib_buffer_advance (b, size);
358 /* Forward declaration. */
361 typedef struct vlib_buffer_free_list_t
363 /* Template buffer used to initialize first 16 bytes of buffers
364 allocated on this free list. */
365 vlib_buffer_t buffer_init_template;
367 /* Our index into vlib_main_t's buffer_free_list_pool. */
368 vlib_buffer_free_list_index_t index;
370 /* Number of data bytes for buffers in this free list. */
373 /* Number of buffers to allocate when we need to allocate new buffers */
374 u32 min_n_buffers_each_alloc;
376 /* Total number of buffers allocated from this free list. */
379 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
382 /* index of buffer pool used to get / put buffers */
383 u8 buffer_pool_index;
385 /* Free list name. */
388 /* Callback functions to initialize newly allocated buffers.
389 If null buffers are zeroed. */
390 void (*buffer_init_function) (struct vlib_main_t * vm,
391 struct vlib_buffer_free_list_t * fl,
392 u32 * buffers, u32 n_buffers);
394 uword buffer_init_function_opaque;
395 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
397 typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm,
398 vlib_buffer_free_list_t * fl,
399 uword min_free_buffers);
400 typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers,
402 typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm,
403 u32 * buffers, u32 n_buffers);
407 vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb;
408 vlib_buffer_free_cb_t *vlib_buffer_free_cb;
409 vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb;
410 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
412 uword n_packet_data_bytes,
414 min_n_buffers_each_physmem_alloc,
416 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
417 vlib_buffer_free_list_index_t
419 } vlib_buffer_callbacks_t;
421 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
425 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
428 uword log2_page_size;
429 u32 physmem_map_index;
432 clib_spinlock_t lock;
433 } vlib_buffer_pool_t;
437 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
438 /* Virtual memory address and size of buffer memory, used for calculating
440 uword buffer_mem_start;
441 uword buffer_mem_size;
442 vlib_buffer_pool_t *buffer_pools;
444 /* Buffer free callback, for subversive activities */
445 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
447 u32 n_buffers, u32 follow_buffer_next);
448 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
449 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
451 /* Hash table mapping buffer size (rounded to next unit of
452 sizeof (vlib_buffer_t)) to free list index. */
453 uword *free_list_by_size;
455 /* Hash table mapping buffer index into number
456 0 => allocated but free, 1 => allocated and not-free.
457 If buffer index is not in hash table then this buffer
458 has never been allocated. */
459 uword *buffer_known_hash;
460 clib_spinlock_t buffer_known_hash_lockp;
463 vlib_buffer_callbacks_t cb;
464 int callbacks_registered;
465 } vlib_buffer_main_t;
467 extern vlib_buffer_main_t buffer_main;
469 static_always_inline vlib_buffer_pool_t *
470 vlib_buffer_pool_get (u8 buffer_pool_index)
472 vlib_buffer_main_t *bm = &buffer_main;
473 return vec_elt_at_index (bm->buffer_pools, buffer_pool_index);
476 u8 vlib_buffer_register_physmem_map (struct vlib_main_t * vm,
477 u32 physmem_map_index);
479 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
483 struct vlib_main_t *vlib_main;
485 u32 first_buffer, last_buffer;
491 /* Total accumulated bytes in chain starting with first_buffer. */
492 u32 n_total_data_bytes;
494 /* Max number of bytes to accumulate in chain starting with first_buffer.
495 As this limit is reached buffers are enqueued to next node. */
496 u32 max_n_data_bytes_per_chain;
498 /* Next node to enqueue buffers to relative to current process node. */
501 /* Free list to use to allocate new buffers. */
502 vlib_buffer_free_list_index_t free_list_index;
507 /* CLIB fifo of buffer indices waiting to be unserialized. */
510 /* Event type used to signal that RX buffers have been added to fifo. */
511 uword ready_one_time_event;
514 } vlib_serialize_buffer_main_t;
516 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
517 vlib_serialize_buffer_main_t * sm);
518 void unserialize_open_vlib_buffer (serialize_main_t * m,
519 struct vlib_main_t *vm,
520 vlib_serialize_buffer_main_t * sm);
522 u32 serialize_close_vlib_buffer (serialize_main_t * m);
523 void unserialize_close_vlib_buffer (serialize_main_t * m);
524 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
527 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
529 serialize_stream_t *s = &m->stream;
530 vlib_serialize_buffer_main_t *sm
531 = uword_to_pointer (m->stream.data_function_opaque,
532 vlib_serialize_buffer_main_t *);
533 return sm->tx.n_total_data_bytes + s->current_buffer_index +
534 vec_len (s->overflow_buffer);
540 /** \brief Compile time buffer trajectory tracing option
541 Turn this on if you run into "bad monkey" contexts,
542 and you want to know exactly which nodes they've visited...
545 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
547 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
548 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
549 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
550 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
551 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
552 vlib_buffer_trace_trajectory_init (b);
554 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
555 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
557 #endif /* included_vlib_buffer_h */
559 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
560 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
561 static void __vlib_add_buffer_callbacks_t_##x (void) \
562 __attribute__((__constructor__)) ; \
563 static void __vlib_add_buffer_callbacks_t_##x (void) \
565 if (vlib_buffer_callbacks) \
566 clib_panic ("vlib buffer callbacks already registered"); \
567 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
569 static void __vlib_rm_buffer_callbacks_t_##x (void) \
570 __attribute__((__destructor__)) ; \
571 static void __vlib_rm_buffer_callbacks_t_##x (void) \
572 { vlib_buffer_callbacks = 0; } \
573 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
576 * fd.io coding-style-patch-verification: ON
579 * eval: (c-set-style "gnu")