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 typedef u8 vlib_buffer_free_list_index_t;
57 vlib buffer structure definition and a few select
58 access methods. This structure and the buffer allocation
59 mechanism should perhaps live in vnet, but it would take a lot
60 of typing to make it so.
66 #define foreach_vlib_buffer_flag \
67 _( 0, NON_DEFAULT_FREELIST, "non-default-fl") \
69 _( 2, NEXT_PRESENT, 0) \
70 _( 3, IS_RECYCLED, "is-recycled") \
71 _( 4, TOTAL_LENGTH_VALID, 0) \
72 _( 5, REPL_FAIL, "repl-fail") \
73 _( 6, RECYCLE, "recycle") \
74 _( 7, EXT_HDR_VALID, "ext-hdr-valid")
76 /* NOTE: only buffer generic flags should be defined here, please consider
77 using user flags. i.e. src/vnet/buffer.h */
81 #define _(bit, name, v) VLIB_BUFFER_##name = (1 << (bit)),
82 foreach_vlib_buffer_flag
88 #define _(bit, name, v) VLIB_BUFFER_LOG2_##name = (bit),
89 foreach_vlib_buffer_flag
93 /* User defined buffer flags. */
94 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
95 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
97 /* VLIB buffer representation. */
100 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
101 STRUCT_MARK (template_start);
102 /* Offset within data[] that we are currently processing.
103 If negative current header points into predata area. */
104 i16 current_data; /**< signed offset in data[], pre_data[]
105 that we are currently processing.
106 If negative current header points into predata area.
108 u16 current_length; /**< Nbytes between current data and
109 the end of this buffer.
111 u32 flags; /**< buffer flags:
112 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
113 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
114 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
115 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
116 <br> VLIB_BUFFER_REPL_FAIL: packet replication failure
117 <br> VLIB_BUFFER_RECYCLE: as it says
118 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
119 set to avoid adding it to a flow report
120 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
124 STRUCT_MARK (template_end);
126 u32 next_buffer; /**< Next buffer for this linked-list of buffers.
127 Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
130 vlib_error_t error; /**< Error code for buffers to be enqueued
133 u32 current_config_index; /**< Used by feature subgraph arcs to
134 visit enabled feature nodes
137 u8 feature_arc_index; /**< Used to identify feature arcs by intermediate
141 u8 n_add_refs; /**< Number of additional references to this buffer. */
143 u8 buffer_pool_index; /**< index of buffer pool this buffer belongs. */
144 u8 dont_waste_me[1]; /**< Available space in the (precious)
145 first 32 octets of buffer metadata
146 Before allocating any of it, discussion required!
149 u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
150 See .../vnet/vnet/buffer.h
152 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
154 u32 trace_index; /**< Specifies index into trace buffer
155 if VLIB_PACKET_IS_TRACED flag is set.
157 u32 recycle_count; /**< Used by L2 path recycle code */
159 u32 total_length_not_including_first_buffer;
160 /**< Only valid for first buffer in chain. Current length plus
161 total length given here give total number of bytes in buffer chain.
163 vlib_buffer_free_list_index_t free_list_index; /** < only used if
164 VLIB_BUFFER_NON_DEFAULT_FREELIST
166 u8 align_pad[3]; /**< available */
167 u32 opaque2[12]; /**< More opaque data, see ../vnet/vnet/buffer.h */
169 /***** end of second cache line */
170 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
171 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
173 Packet rewrite string will be
174 rewritten backwards and may extend
175 back before buffer->data[0].
176 Must come directly before packet data.
179 u8 data[0]; /**< Packet data. Hardware DMA here */
180 } vlib_buffer_t; /* Must be a multiple of 64B. */
182 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
184 /** \brief Prefetch buffer metadata.
185 The first 64 bytes of buffer contains most header information
187 @param b - (vlib_buffer_t *) pointer to the buffer
188 @param type - LOAD, STORE. In most cases, STORE is the right answer
191 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
194 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
196 ASSERT (sizeof (b[0]) % 64 == 0);
198 /* Rewrite data must be before and contiguous with packet data. */
199 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
202 /** \brief Get pointer to current data to process
204 @param b - (vlib_buffer_t *) pointer to the buffer
205 @return - (void *) (b->data + b->current_data)
209 vlib_buffer_get_current (vlib_buffer_t * b)
212 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
213 return b->data + b->current_data;
216 /** \brief Advance current data pointer by the supplied (signed!) amount
218 @param b - (vlib_buffer_t *) pointer to the buffer
219 @param l - (word) signed increment
222 vlib_buffer_advance (vlib_buffer_t * b, word l)
224 ASSERT (b->current_length >= l);
225 b->current_data += l;
226 b->current_length -= l;
229 /** \brief Check if there is enough space in buffer to advance
231 @param b - (vlib_buffer_t *) pointer to the buffer
232 @param l - (word) size to check
233 @return - 0 if there is less space than 'l' in buffer
236 vlib_buffer_has_space (vlib_buffer_t * b, word l)
238 return b->current_length >= l;
241 /** \brief Reset current header & length to state they were in when
244 @param b - (vlib_buffer_t *) pointer to the buffer
248 vlib_buffer_reset (vlib_buffer_t * b)
250 b->current_length += clib_max (b->current_data, 0);
254 /** \brief Get pointer to buffer's opaque data array
256 @param b - (vlib_buffer_t *) pointer to the buffer
257 @return - (void *) b->opaque
260 vlib_get_buffer_opaque (vlib_buffer_t * b)
262 return (void *) b->opaque;
265 /** \brief Get pointer to buffer's opaque2 data array
267 @param b - (vlib_buffer_t *) pointer to the buffer
268 @return - (void *) b->opaque2
271 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
273 return (void *) b->opaque2;
276 /** \brief Get pointer to the end of buffer's data
277 * @param b pointer to the buffer
278 * @return pointer to tail of packet's data
281 vlib_buffer_get_tail (vlib_buffer_t * b)
283 return b->data + b->current_data + b->current_length;
286 /** \brief Append uninitialized data to buffer
287 * @param b pointer to the buffer
288 * @param size number of uninitialized bytes
289 * @return pointer to beginning of uninitialized data
292 vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
294 void *p = vlib_buffer_get_tail (b);
295 /* XXX make sure there's enough space */
296 b->current_length += size;
300 /** \brief Prepend 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_push_uninit (vlib_buffer_t * b, u8 size)
308 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
309 b->current_data -= size;
310 b->current_length += size;
312 return vlib_buffer_get_current (b);
315 /** \brief Make head room, typically for packet headers
316 * @param b pointer to the buffer
317 * @param size number of head room bytes
318 * @return pointer to start of buffer (current data)
321 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
323 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
324 b->current_data += size;
325 return vlib_buffer_get_current (b);
328 /** \brief Retrieve bytes from buffer head
329 * @param b pointer to the buffer
330 * @param size number of bytes to pull
331 * @return pointer to start of buffer (current data)
334 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
336 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
339 void *data = vlib_buffer_get_current (b);
340 vlib_buffer_advance (b, size);
344 /* Forward declaration. */
347 typedef struct vlib_buffer_free_list_t
349 /* Template buffer used to initialize first 16 bytes of buffers
350 allocated on this free list. */
351 vlib_buffer_t buffer_init_template;
353 /* Our index into vlib_main_t's buffer_free_list_pool. */
354 vlib_buffer_free_list_index_t index;
356 /* Number of data bytes for buffers in this free list. */
359 /* Number of buffers to allocate when we need to allocate new buffers */
360 u32 min_n_buffers_each_alloc;
362 /* Total number of buffers allocated from this free list. */
365 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
368 /* index of buffer pool used to get / put buffers */
369 u8 buffer_pool_index;
371 /* Free list name. */
374 /* Callback functions to initialize newly allocated buffers.
375 If null buffers are zeroed. */
376 void (*buffer_init_function) (struct vlib_main_t * vm,
377 struct vlib_buffer_free_list_t * fl,
378 u32 * buffers, u32 n_buffers);
380 /* Callback function to announce that buffers have been
381 added to the freelist */
382 void (*buffers_added_to_freelist_function)
383 (struct vlib_main_t * vm, struct vlib_buffer_free_list_t * fl);
385 uword buffer_init_function_opaque;
386 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
388 typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm,
389 vlib_buffer_free_list_t * fl,
390 uword min_free_buffers);
391 typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers,
393 typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm,
394 u32 * buffers, u32 n_buffers);
398 vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb;
399 vlib_buffer_free_cb_t *vlib_buffer_free_cb;
400 vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb;
401 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
403 uword n_packet_data_bytes,
405 min_n_buffers_each_physmem_alloc,
407 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
408 vlib_buffer_free_list_index_t
410 } vlib_buffer_callbacks_t;
412 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
416 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
419 uword log2_page_size;
420 vlib_physmem_region_index_t physmem_region;
425 uword buffers_per_page;
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_pool_create (struct vlib_main_t * vm,
475 vlib_physmem_region_index_t region,
478 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
482 struct vlib_main_t *vlib_main;
484 u32 first_buffer, last_buffer;
490 /* Total accumulated bytes in chain starting with first_buffer. */
491 u32 n_total_data_bytes;
493 /* Max number of bytes to accumulate in chain starting with first_buffer.
494 As this limit is reached buffers are enqueued to next node. */
495 u32 max_n_data_bytes_per_chain;
497 /* Next node to enqueue buffers to relative to current process node. */
500 /* Free list to use to allocate new buffers. */
501 vlib_buffer_free_list_index_t free_list_index;
506 /* CLIB fifo of buffer indices waiting to be unserialized. */
509 /* Event type used to signal that RX buffers have been added to fifo. */
510 uword ready_one_time_event;
513 } vlib_serialize_buffer_main_t;
515 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
516 vlib_serialize_buffer_main_t * sm);
517 void unserialize_open_vlib_buffer (serialize_main_t * m,
518 struct vlib_main_t *vm,
519 vlib_serialize_buffer_main_t * sm);
521 u32 serialize_close_vlib_buffer (serialize_main_t * m);
522 void unserialize_close_vlib_buffer (serialize_main_t * m);
523 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
526 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
528 serialize_stream_t *s = &m->stream;
529 vlib_serialize_buffer_main_t *sm
530 = uword_to_pointer (m->stream.data_function_opaque,
531 vlib_serialize_buffer_main_t *);
532 return sm->tx.n_total_data_bytes + s->current_buffer_index +
533 vec_len (s->overflow_buffer);
539 /** \brief Compile time buffer trajectory tracing option
540 Turn this on if you run into "bad monkey" contexts,
541 and you want to know exactly which nodes they've visited...
544 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
546 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
547 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
548 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
549 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
550 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
551 vlib_buffer_trace_trajectory_init (b);
553 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
554 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
556 #endif /* included_vlib_buffer_h */
558 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
559 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
560 static void __vlib_add_buffer_callbacks_t_##x (void) \
561 __attribute__((__constructor__)) ; \
562 static void __vlib_add_buffer_callbacks_t_##x (void) \
564 if (vlib_buffer_callbacks) \
565 clib_panic ("vlib buffer callbacks already registered"); \
566 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
568 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
571 * fd.io coding-style-patch-verification: ON
574 * eval: (c-set-style "gnu")