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
123 u32 flow_id; /**< Generic flow identifier */
126 u32 next_buffer; /**< Next buffer for this linked-list of buffers.
127 Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
130 STRUCT_MARK (template_end);
132 u32 current_config_index; /**< Used by feature subgraph arcs to
133 visit enabled feature nodes
135 vlib_error_t error; /**< Error code for buffers to be enqueued
138 u8 n_add_refs; /**< Number of additional references to this buffer. */
140 u8 buffer_pool_index; /**< index of buffer pool this buffer belongs. */
142 u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
143 See .../vnet/vnet/buffer.h
145 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
147 u32 trace_index; /**< Specifies index into trace buffer
148 if VLIB_PACKET_IS_TRACED flag is set.
150 u32 recycle_count; /**< Used by L2 path recycle code */
152 u32 total_length_not_including_first_buffer;
153 /**< Only valid for first buffer in chain. Current length plus
154 total length given here give total number of bytes in buffer chain.
156 vlib_buffer_free_list_index_t free_list_index; /** < only used if
157 VLIB_BUFFER_NON_DEFAULT_FREELIST
159 u8 align_pad[3]; /**< available */
160 u32 opaque2[12]; /**< More opaque data, see ../vnet/vnet/buffer.h */
162 /***** end of second cache line */
163 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
164 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
166 Packet rewrite string will be
167 rewritten backwards and may extend
168 back before buffer->data[0].
169 Must come directly before packet data.
172 u8 data[0]; /**< Packet data. Hardware DMA here */
173 } vlib_buffer_t; /* Must be a multiple of 64B. */
175 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
177 /** \brief Prefetch buffer metadata.
178 The first 64 bytes of buffer contains most header information
180 @param b - (vlib_buffer_t *) pointer to the buffer
181 @param type - LOAD, STORE. In most cases, STORE is the right answer
184 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
187 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
189 ASSERT (sizeof (b[0]) % 64 == 0);
191 /* Rewrite data must be before and contiguous with packet data. */
192 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
195 /** \brief Get pointer to current data to process
197 @param b - (vlib_buffer_t *) pointer to the buffer
198 @return - (void *) (b->data + b->current_data)
202 vlib_buffer_get_current (vlib_buffer_t * b)
205 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
206 return b->data + b->current_data;
209 /** \brief Advance current data pointer by the supplied (signed!) amount
211 @param b - (vlib_buffer_t *) pointer to the buffer
212 @param l - (word) signed increment
215 vlib_buffer_advance (vlib_buffer_t * b, word l)
217 ASSERT (b->current_length >= l);
218 b->current_data += l;
219 b->current_length -= l;
222 /** \brief Check if there is enough space in buffer to advance
224 @param b - (vlib_buffer_t *) pointer to the buffer
225 @param l - (word) size to check
226 @return - 0 if there is less space than 'l' in buffer
229 vlib_buffer_has_space (vlib_buffer_t * b, word l)
231 return b->current_length >= l;
234 /** \brief Reset current header & length to state they were in when
237 @param b - (vlib_buffer_t *) pointer to the buffer
241 vlib_buffer_reset (vlib_buffer_t * b)
243 b->current_length += clib_max (b->current_data, 0);
247 /** \brief Get pointer to buffer's opaque data array
249 @param b - (vlib_buffer_t *) pointer to the buffer
250 @return - (void *) b->opaque
253 vlib_get_buffer_opaque (vlib_buffer_t * b)
255 return (void *) b->opaque;
258 /** \brief Get pointer to buffer's opaque2 data array
260 @param b - (vlib_buffer_t *) pointer to the buffer
261 @return - (void *) b->opaque2
264 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
266 return (void *) b->opaque2;
269 /** \brief Get pointer to the end of buffer's data
270 * @param b pointer to the buffer
271 * @return pointer to tail of packet's data
274 vlib_buffer_get_tail (vlib_buffer_t * b)
276 return b->data + b->current_data + b->current_length;
279 /** \brief Append uninitialized data to buffer
280 * @param b pointer to the buffer
281 * @param size number of uninitialized bytes
282 * @return pointer to beginning of uninitialized data
285 vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
287 void *p = vlib_buffer_get_tail (b);
288 /* XXX make sure there's enough space */
289 b->current_length += size;
293 /** \brief Prepend uninitialized data to buffer
294 * @param b pointer to the buffer
295 * @param size number of uninitialized bytes
296 * @return pointer to beginning of uninitialized data
299 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
301 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
302 b->current_data -= size;
303 b->current_length += size;
305 return vlib_buffer_get_current (b);
308 /** \brief Make head room, typically for packet headers
309 * @param b pointer to the buffer
310 * @param size number of head room bytes
311 * @return pointer to start of buffer (current data)
314 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
316 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
317 b->current_data += size;
318 return vlib_buffer_get_current (b);
321 /** \brief Retrieve bytes from buffer head
322 * @param b pointer to the buffer
323 * @param size number of bytes to pull
324 * @return pointer to start of buffer (current data)
327 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
329 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
332 void *data = vlib_buffer_get_current (b);
333 vlib_buffer_advance (b, size);
337 /* Forward declaration. */
340 typedef struct vlib_buffer_free_list_t
342 /* Template buffer used to initialize first 16 bytes of buffers
343 allocated on this free list. */
344 vlib_buffer_t buffer_init_template;
346 /* Our index into vlib_main_t's buffer_free_list_pool. */
347 vlib_buffer_free_list_index_t index;
349 /* Number of data bytes for buffers in this free list. */
352 /* Number of buffers to allocate when we need to allocate new buffers */
353 u32 min_n_buffers_each_alloc;
355 /* Total number of buffers allocated from this free list. */
358 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
361 /* index of buffer pool used to get / put buffers */
362 u8 buffer_pool_index;
364 /* Free list name. */
367 /* Callback functions to initialize newly allocated buffers.
368 If null buffers are zeroed. */
369 void (*buffer_init_function) (struct vlib_main_t * vm,
370 struct vlib_buffer_free_list_t * fl,
371 u32 * buffers, u32 n_buffers);
373 /* Callback function to announce that buffers have been
374 added to the freelist */
375 void (*buffers_added_to_freelist_function)
376 (struct vlib_main_t * vm, struct vlib_buffer_free_list_t * fl);
378 uword buffer_init_function_opaque;
379 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
381 typedef uword (vlib_buffer_fill_free_list_cb_t) (struct vlib_main_t * vm,
382 vlib_buffer_free_list_t * fl,
383 uword min_free_buffers);
384 typedef void (vlib_buffer_free_cb_t) (struct vlib_main_t * vm, u32 * buffers,
386 typedef void (vlib_buffer_free_no_next_cb_t) (struct vlib_main_t * vm,
387 u32 * buffers, u32 n_buffers);
391 vlib_buffer_fill_free_list_cb_t *vlib_buffer_fill_free_list_cb;
392 vlib_buffer_free_cb_t *vlib_buffer_free_cb;
393 vlib_buffer_free_no_next_cb_t *vlib_buffer_free_no_next_cb;
394 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
396 uword n_packet_data_bytes,
398 min_n_buffers_each_physmem_alloc,
400 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
401 vlib_buffer_free_list_index_t
403 } vlib_buffer_callbacks_t;
405 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
409 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
412 uword log2_page_size;
413 vlib_physmem_region_index_t physmem_region;
418 uword buffers_per_page;
423 clib_spinlock_t lock;
424 } vlib_buffer_pool_t;
428 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
429 /* Virtual memory address and size of buffer memory, used for calculating
431 uword buffer_mem_start;
432 uword buffer_mem_size;
433 vlib_buffer_pool_t *buffer_pools;
435 /* Buffer free callback, for subversive activities */
436 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
438 u32 n_buffers, u32 follow_buffer_next);
439 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
440 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
442 /* Hash table mapping buffer size (rounded to next unit of
443 sizeof (vlib_buffer_t)) to free list index. */
444 uword *free_list_by_size;
446 /* Hash table mapping buffer index into number
447 0 => allocated but free, 1 => allocated and not-free.
448 If buffer index is not in hash table then this buffer
449 has never been allocated. */
450 uword *buffer_known_hash;
451 clib_spinlock_t buffer_known_hash_lockp;
454 vlib_buffer_callbacks_t cb;
455 int callbacks_registered;
456 } vlib_buffer_main_t;
458 extern vlib_buffer_main_t buffer_main;
460 static_always_inline vlib_buffer_pool_t *
461 vlib_buffer_pool_get (u8 buffer_pool_index)
463 vlib_buffer_main_t *bm = &buffer_main;
464 return vec_elt_at_index (bm->buffer_pools, buffer_pool_index);
467 u8 vlib_buffer_pool_create (struct vlib_main_t * vm,
468 vlib_physmem_region_index_t region,
471 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
475 struct vlib_main_t *vlib_main;
477 u32 first_buffer, last_buffer;
483 /* Total accumulated bytes in chain starting with first_buffer. */
484 u32 n_total_data_bytes;
486 /* Max number of bytes to accumulate in chain starting with first_buffer.
487 As this limit is reached buffers are enqueued to next node. */
488 u32 max_n_data_bytes_per_chain;
490 /* Next node to enqueue buffers to relative to current process node. */
493 /* Free list to use to allocate new buffers. */
494 vlib_buffer_free_list_index_t free_list_index;
499 /* CLIB fifo of buffer indices waiting to be unserialized. */
502 /* Event type used to signal that RX buffers have been added to fifo. */
503 uword ready_one_time_event;
506 } vlib_serialize_buffer_main_t;
508 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
509 vlib_serialize_buffer_main_t * sm);
510 void unserialize_open_vlib_buffer (serialize_main_t * m,
511 struct vlib_main_t *vm,
512 vlib_serialize_buffer_main_t * sm);
514 u32 serialize_close_vlib_buffer (serialize_main_t * m);
515 void unserialize_close_vlib_buffer (serialize_main_t * m);
516 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
519 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
521 serialize_stream_t *s = &m->stream;
522 vlib_serialize_buffer_main_t *sm
523 = uword_to_pointer (m->stream.data_function_opaque,
524 vlib_serialize_buffer_main_t *);
525 return sm->tx.n_total_data_bytes + s->current_buffer_index +
526 vec_len (s->overflow_buffer);
532 /** \brief Compile time buffer trajectory tracing option
533 Turn this on if you run into "bad monkey" contexts,
534 and you want to know exactly which nodes they've visited...
537 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
539 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
540 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
541 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
542 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
543 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
544 vlib_buffer_trace_trajectory_init (b);
546 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
547 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
549 #endif /* included_vlib_buffer_h */
551 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
552 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
553 static void __vlib_add_buffer_callbacks_t_##x (void) \
554 __attribute__((__constructor__)) ; \
555 static void __vlib_add_buffer_callbacks_t_##x (void) \
557 if (vlib_buffer_callbacks) \
558 clib_panic ("vlib buffer callbacks already registered"); \
559 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
561 static void __vlib_rm_buffer_callbacks_t_##x (void) \
562 __attribute__((__destructor__)) ; \
563 static void __vlib_rm_buffer_callbacks_t_##x (void) \
564 { vlib_buffer_callbacks = 0; } \
565 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
568 * fd.io coding-style-patch-verification: ON
571 * eval: (c-set-style "gnu")