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, TOTAL_LENGTH_VALID, 0) \
71 _( 4, EXT_HDR_VALID, "ext-hdr-valid")
73 /* NOTE: only buffer generic flags should be defined here, please consider
74 using user flags. i.e. src/vnet/buffer.h */
78 #define _(bit, name, v) VLIB_BUFFER_##name = (1 << (bit)),
79 foreach_vlib_buffer_flag
85 #define _(bit, name, v) VLIB_BUFFER_LOG2_##name = (bit),
86 foreach_vlib_buffer_flag
90 /* User defined buffer flags. */
91 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
92 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
94 /* VLIB buffer representation. */
97 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
98 STRUCT_MARK (template_start);
99 /* Offset within data[] that we are currently processing.
100 If negative current header points into predata area. */
101 i16 current_data; /**< signed offset in data[], pre_data[]
102 that we are currently processing.
103 If negative current header points into predata area.
105 u16 current_length; /**< Nbytes between current data and
106 the end of this buffer.
108 u32 flags; /**< buffer flags:
109 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
110 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
111 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
112 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
113 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
114 set to avoid adding it to a flow report
115 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
118 u32 flow_id; /**< Generic flow identifier */
121 u32 next_buffer; /**< Next buffer for this linked-list of buffers.
122 Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
125 STRUCT_MARK (template_end);
127 u32 current_config_index; /**< Used by feature subgraph arcs to
128 visit enabled feature nodes
130 vlib_error_t error; /**< Error code for buffers to be enqueued
133 u8 n_add_refs; /**< Number of additional references to this buffer. */
135 u8 buffer_pool_index; /**< index of buffer pool this buffer belongs. */
137 u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
138 See .../vnet/vnet/buffer.h
140 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
142 u32 trace_index; /**< Specifies index into trace buffer
143 if VLIB_PACKET_IS_TRACED flag is set.
145 u32 recycle_count; /**< Used by L2 path recycle code */
147 u32 total_length_not_including_first_buffer;
148 /**< Only valid for first buffer in chain. Current length plus
149 total length given here give total number of bytes in buffer chain.
151 vlib_buffer_free_list_index_t free_list_index; /** < only used if
152 VLIB_BUFFER_NON_DEFAULT_FREELIST
154 u8 align_pad[3]; /**< available */
155 u32 opaque2[12]; /**< More opaque data, see ../vnet/vnet/buffer.h */
157 /***** end of second cache line */
158 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
159 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
161 Packet rewrite string will be
162 rewritten backwards and may extend
163 back before buffer->data[0].
164 Must come directly before packet data.
167 u8 data[0]; /**< Packet data. Hardware DMA here */
168 } vlib_buffer_t; /* Must be a multiple of 64B. */
170 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
172 /** \brief Prefetch buffer metadata.
173 The first 64 bytes of buffer contains most header information
175 @param b - (vlib_buffer_t *) pointer to the buffer
176 @param type - LOAD, STORE. In most cases, STORE is the right answer
179 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
182 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
184 ASSERT (sizeof (b[0]) % 64 == 0);
186 /* Rewrite data must be before and contiguous with packet data. */
187 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
190 /** \brief Get pointer to current data to process
192 @param b - (vlib_buffer_t *) pointer to the buffer
193 @return - (void *) (b->data + b->current_data)
197 vlib_buffer_get_current (vlib_buffer_t * b)
200 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
201 return b->data + b->current_data;
204 /** \brief Advance current data pointer by the supplied (signed!) amount
206 @param b - (vlib_buffer_t *) pointer to the buffer
207 @param l - (word) signed increment
210 vlib_buffer_advance (vlib_buffer_t * b, word l)
212 ASSERT (b->current_length >= l);
213 b->current_data += l;
214 b->current_length -= l;
217 /** \brief Check if there is enough space in buffer to advance
219 @param b - (vlib_buffer_t *) pointer to the buffer
220 @param l - (word) size to check
221 @return - 0 if there is less space than 'l' in buffer
224 vlib_buffer_has_space (vlib_buffer_t * b, word l)
226 return b->current_length >= l;
229 /** \brief Reset current header & length to state they were in when
232 @param b - (vlib_buffer_t *) pointer to the buffer
236 vlib_buffer_reset (vlib_buffer_t * b)
238 b->current_length += clib_max (b->current_data, 0);
242 /** \brief Get pointer to buffer's opaque data array
244 @param b - (vlib_buffer_t *) pointer to the buffer
245 @return - (void *) b->opaque
248 vlib_get_buffer_opaque (vlib_buffer_t * b)
250 return (void *) b->opaque;
253 /** \brief Get pointer to buffer's opaque2 data array
255 @param b - (vlib_buffer_t *) pointer to the buffer
256 @return - (void *) b->opaque2
259 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
261 return (void *) b->opaque2;
264 /** \brief Get pointer to the end of buffer's data
265 * @param b pointer to the buffer
266 * @return pointer to tail of packet's data
269 vlib_buffer_get_tail (vlib_buffer_t * b)
271 return b->data + b->current_data + b->current_length;
274 /** \brief Append uninitialized data to buffer
275 * @param b pointer to the buffer
276 * @param size number of uninitialized bytes
277 * @return pointer to beginning of uninitialized data
280 vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
282 void *p = vlib_buffer_get_tail (b);
283 /* XXX make sure there's enough space */
284 b->current_length += size;
288 /** \brief Prepend uninitialized data to buffer
289 * @param b pointer to the buffer
290 * @param size number of uninitialized bytes
291 * @return pointer to beginning of uninitialized data
294 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
296 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
297 b->current_data -= size;
298 b->current_length += size;
300 return vlib_buffer_get_current (b);
303 /** \brief Make head room, typically for packet headers
304 * @param b pointer to the buffer
305 * @param size number of head room bytes
306 * @return pointer to start of buffer (current data)
309 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
311 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
312 b->current_data += size;
313 return vlib_buffer_get_current (b);
316 /** \brief Retrieve bytes from buffer head
317 * @param b pointer to the buffer
318 * @param size number of bytes to pull
319 * @return pointer to start of buffer (current data)
322 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
324 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
327 void *data = vlib_buffer_get_current (b);
328 vlib_buffer_advance (b, size);
332 /* Forward declaration. */
335 typedef struct vlib_buffer_free_list_t
337 /* Template buffer used to initialize first 16 bytes of buffers
338 allocated on this free list. */
339 vlib_buffer_t buffer_init_template;
341 /* Our index into vlib_main_t's buffer_free_list_pool. */
342 vlib_buffer_free_list_index_t index;
344 /* Number of data bytes for buffers in this free list. */
347 /* Number of buffers to allocate when we need to allocate new buffers */
348 u32 min_n_buffers_each_alloc;
350 /* Total number of buffers allocated from this free list. */
353 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
356 /* index of buffer pool used to get / put buffers */
357 u8 buffer_pool_index;
359 /* Free list name. */
362 /* Callback functions to initialize newly allocated buffers.
363 If null buffers are zeroed. */
364 void (*buffer_init_function) (struct vlib_main_t * vm,
365 struct vlib_buffer_free_list_t * fl,
366 u32 * buffers, u32 n_buffers);
368 uword buffer_init_function_opaque;
369 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
371 typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm,
372 vlib_buffer_free_list_t * fl,
373 uword min_free_buffers);
374 typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers,
376 typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm,
377 u32 * buffers, u32 n_buffers);
381 vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb;
382 vlib_buffer_free_cb_t *vlib_buffer_free_cb;
383 vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb;
384 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
386 uword n_packet_data_bytes,
388 min_n_buffers_each_physmem_alloc,
390 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
391 vlib_buffer_free_list_index_t
393 } vlib_buffer_callbacks_t;
395 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
399 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
402 uword log2_page_size;
403 vlib_physmem_region_index_t physmem_region;
408 uword buffers_per_page;
413 clib_spinlock_t lock;
414 } vlib_buffer_pool_t;
418 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
419 /* Virtual memory address and size of buffer memory, used for calculating
421 uword buffer_mem_start;
422 uword buffer_mem_size;
423 vlib_buffer_pool_t *buffer_pools;
425 /* Buffer free callback, for subversive activities */
426 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
428 u32 n_buffers, u32 follow_buffer_next);
429 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
430 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
432 /* Hash table mapping buffer size (rounded to next unit of
433 sizeof (vlib_buffer_t)) to free list index. */
434 uword *free_list_by_size;
436 /* Hash table mapping buffer index into number
437 0 => allocated but free, 1 => allocated and not-free.
438 If buffer index is not in hash table then this buffer
439 has never been allocated. */
440 uword *buffer_known_hash;
441 clib_spinlock_t buffer_known_hash_lockp;
444 vlib_buffer_callbacks_t cb;
445 int callbacks_registered;
446 } vlib_buffer_main_t;
448 extern vlib_buffer_main_t buffer_main;
450 static_always_inline vlib_buffer_pool_t *
451 vlib_buffer_pool_get (u8 buffer_pool_index)
453 vlib_buffer_main_t *bm = &buffer_main;
454 return vec_elt_at_index (bm->buffer_pools, buffer_pool_index);
457 u8 vlib_buffer_pool_create (struct vlib_main_t * vm,
458 vlib_physmem_region_index_t region,
461 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
465 struct vlib_main_t *vlib_main;
467 u32 first_buffer, last_buffer;
473 /* Total accumulated bytes in chain starting with first_buffer. */
474 u32 n_total_data_bytes;
476 /* Max number of bytes to accumulate in chain starting with first_buffer.
477 As this limit is reached buffers are enqueued to next node. */
478 u32 max_n_data_bytes_per_chain;
480 /* Next node to enqueue buffers to relative to current process node. */
483 /* Free list to use to allocate new buffers. */
484 vlib_buffer_free_list_index_t free_list_index;
489 /* CLIB fifo of buffer indices waiting to be unserialized. */
492 /* Event type used to signal that RX buffers have been added to fifo. */
493 uword ready_one_time_event;
496 } vlib_serialize_buffer_main_t;
498 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
499 vlib_serialize_buffer_main_t * sm);
500 void unserialize_open_vlib_buffer (serialize_main_t * m,
501 struct vlib_main_t *vm,
502 vlib_serialize_buffer_main_t * sm);
504 u32 serialize_close_vlib_buffer (serialize_main_t * m);
505 void unserialize_close_vlib_buffer (serialize_main_t * m);
506 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
509 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
511 serialize_stream_t *s = &m->stream;
512 vlib_serialize_buffer_main_t *sm
513 = uword_to_pointer (m->stream.data_function_opaque,
514 vlib_serialize_buffer_main_t *);
515 return sm->tx.n_total_data_bytes + s->current_buffer_index +
516 vec_len (s->overflow_buffer);
522 /** \brief Compile time buffer trajectory tracing option
523 Turn this on if you run into "bad monkey" contexts,
524 and you want to know exactly which nodes they've visited...
527 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
529 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
530 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
531 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
532 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
533 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
534 vlib_buffer_trace_trajectory_init (b);
536 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
537 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
539 #endif /* included_vlib_buffer_h */
541 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
542 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
543 static void __vlib_add_buffer_callbacks_t_##x (void) \
544 __attribute__((__constructor__)) ; \
545 static void __vlib_add_buffer_callbacks_t_##x (void) \
547 if (vlib_buffer_callbacks) \
548 clib_panic ("vlib buffer callbacks already registered"); \
549 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
551 static void __vlib_rm_buffer_callbacks_t_##x (void) \
552 __attribute__((__destructor__)) ; \
553 static void __vlib_rm_buffer_callbacks_t_##x (void) \
554 { vlib_buffer_callbacks = 0; } \
555 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
558 * fd.io coding-style-patch-verification: ON
561 * eval: (c-set-style "gnu")