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 <vlib/error.h> /* for vlib_error_t */
49 #include <vlib/config.h> /* for __PRE_DATA_SIZE */
50 #define VLIB_BUFFER_DATA_SIZE (2048)
51 #define VLIB_BUFFER_PRE_DATA_SIZE __PRE_DATA_SIZE
54 vlib buffer structure definition and a few select
55 access methods. This structure and the buffer allocation
56 mechanism should perhaps live in vnet, but it would take a lot
57 of typing to make it so.
60 /* VLIB buffer representation. */
63 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
64 STRUCT_MARK (template_start);
65 /* Offset within data[] that we are currently processing.
66 If negative current header points into predata area. */
67 i16 current_data; /**< signed offset in data[], pre_data[]
68 that we are currently processing.
69 If negative current header points into predata area.
71 u16 current_length; /**< Nbytes between current data and
72 the end of this buffer.
74 u32 flags; /**< buffer flags:
75 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
76 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
77 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
78 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
79 <br> VLIB_BUFFER_REPL_FAIL: packet replication failure
80 <br> VLIB_BUFFER_RECYCLE: as it says
81 <br> VLIB_BUFFER_FLOW_REPORT: buffer is a flow report,
82 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
83 set to avoid adding it to a flow report
84 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
87 /* any change to the following line requres update of
88 * vlib_buffer_get_free_list_index(...) and
89 * vlib_buffer_set_free_list_index(...) functions */
90 #define VLIB_BUFFER_FREE_LIST_INDEX_MASK ((1 << 4) - 1)
92 #define VLIB_BUFFER_IS_TRACED (1 << 4)
93 #define VLIB_BUFFER_LOG2_NEXT_PRESENT (5)
94 #define VLIB_BUFFER_NEXT_PRESENT (1 << VLIB_BUFFER_LOG2_NEXT_PRESENT)
95 #define VLIB_BUFFER_IS_RECYCLED (1 << 6)
96 #define VLIB_BUFFER_TOTAL_LENGTH_VALID (1 << 7)
97 #define VLIB_BUFFER_REPL_FAIL (1 << 8)
98 #define VLIB_BUFFER_RECYCLE (1 << 9)
99 #define VLIB_BUFFER_FLOW_REPORT (1 << 10)
100 #define VLIB_BUFFER_EXT_HDR_VALID (1 << 11)
102 /* User defined buffer flags. */
103 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
104 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
106 STRUCT_MARK (template_end);
108 u32 next_buffer; /**< Next buffer for this linked-list of buffers.
109 Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
112 vlib_error_t error; /**< Error code for buffers to be enqueued
115 u32 current_config_index; /**< Used by feature subgraph arcs to
116 visit enabled feature nodes
119 u8 feature_arc_index; /**< Used to identify feature arcs by intermediate
123 u8 n_add_refs; /**< Number of additional references to this buffer. */
125 u8 dont_waste_me[2]; /**< Available space in the (precious)
126 first 32 octets of buffer metadata
127 Before allocating any of it, discussion required!
130 u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
131 See .../vnet/vnet/buffer.h
133 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
135 u32 trace_index; /**< Specifies index into trace buffer
136 if VLIB_PACKET_IS_TRACED flag is set.
138 u32 recycle_count; /**< Used by L2 path recycle code */
140 u32 total_length_not_including_first_buffer;
141 /**< Only valid for first buffer in chain. Current length plus
142 total length given here give total number of bytes in buffer chain.
144 u32 opaque2[13]; /**< More opaque data, currently unused */
146 /***** end of second cache line */
147 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
148 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
150 Packet rewrite string will be
151 rewritten backwards and may extend
152 back before buffer->data[0].
153 Must come directly before packet data.
156 u8 data[0]; /**< Packet data. Hardware DMA here */
157 } vlib_buffer_t; /* Must be a multiple of 64B. */
159 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
161 /** \brief Prefetch buffer metadata.
162 The first 64 bytes of buffer contains most header information
164 @param b - (vlib_buffer_t *) pointer to the buffer
165 @param type - LOAD, STORE. In most cases, STORE is the right answer
168 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
170 always_inline vlib_buffer_t *
171 vlib_buffer_next_contiguous (vlib_buffer_t * b, u32 buffer_bytes)
173 return (void *) (b + 1) + buffer_bytes;
177 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
179 ASSERT (sizeof (b[0]) % 64 == 0);
181 /* Rewrite data must be before and contiguous with packet data. */
182 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
185 /** \brief Get pointer to current data to process
187 @param b - (vlib_buffer_t *) pointer to the buffer
188 @return - (void *) (b->data + b->current_data)
192 vlib_buffer_get_current (vlib_buffer_t * b)
195 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
196 return b->data + b->current_data;
199 /** \brief Advance current data pointer by the supplied (signed!) amount
201 @param b - (vlib_buffer_t *) pointer to the buffer
202 @param l - (word) signed increment
205 vlib_buffer_advance (vlib_buffer_t * b, word l)
207 ASSERT (b->current_length >= l);
208 b->current_data += l;
209 b->current_length -= l;
212 /** \brief Check if there is enough space in buffer to advance
214 @param b - (vlib_buffer_t *) pointer to the buffer
215 @param l - (word) size to check
216 @return - 0 if there is less space than 'l' in buffer
219 vlib_buffer_has_space (vlib_buffer_t * b, word l)
221 return b->current_length >= l;
224 /** \brief Reset current header & length to state they were in when
227 @param b - (vlib_buffer_t *) pointer to the buffer
231 vlib_buffer_reset (vlib_buffer_t * b)
233 b->current_length += clib_max (b->current_data, 0);
237 /** \brief Get pointer to buffer's opaque data array
239 @param b - (vlib_buffer_t *) pointer to the buffer
240 @return - (void *) b->opaque
243 vlib_get_buffer_opaque (vlib_buffer_t * b)
245 return (void *) b->opaque;
248 /** \brief Get pointer to buffer's opaque2 data array
250 @param b - (vlib_buffer_t *) pointer to the buffer
251 @return - (void *) b->opaque2
254 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
256 return (void *) b->opaque2;
259 /** \brief Get pointer to the end of buffer's data
260 * @param b pointer to the buffer
261 * @return pointer to tail of packet's data
264 vlib_buffer_get_tail (vlib_buffer_t * b)
266 return b->data + b->current_data + b->current_length;
269 /** \brief Append uninitialized data to buffer
270 * @param b pointer to the buffer
271 * @param size number of uninitialized bytes
272 * @return pointer to beginning of uninitialized data
275 vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
277 void *p = vlib_buffer_get_tail (b);
278 /* XXX make sure there's enough space */
279 b->current_length += size;
283 /** \brief Prepend uninitialized data to buffer
284 * @param b pointer to the buffer
285 * @param size number of uninitialized bytes
286 * @return pointer to beginning of uninitialized data
289 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
291 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
292 b->current_data -= size;
293 b->current_length += size;
295 return vlib_buffer_get_current (b);
298 /** \brief Make head room, typically for packet headers
299 * @param b pointer to the buffer
300 * @param size number of head room bytes
301 * @return pointer to start of buffer (current data)
304 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
306 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
307 b->current_data += size;
308 return vlib_buffer_get_current (b);
311 /** \brief Retrieve bytes from buffer head
312 * @param b pointer to the buffer
313 * @param size number of bytes to pull
314 * @return pointer to start of buffer (current data)
317 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
319 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
322 void *data = vlib_buffer_get_current (b);
323 vlib_buffer_advance (b, size);
327 /* Forward declaration. */
330 typedef struct vlib_buffer_free_list_t
332 /* Template buffer used to initialize first 16 bytes of buffers
333 allocated on this free list. */
334 vlib_buffer_t buffer_init_template;
336 /* Our index into vlib_main_t's buffer_free_list_pool. */
339 /* Number of data bytes for buffers in this free list. */
342 /* Number of buffers to allocate when we need to allocate new buffers
343 from physmem heap. */
344 u32 min_n_buffers_each_physmem_alloc;
346 /* Total number of buffers allocated from this free list. */
349 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
352 /* Memory chunks allocated for this free list
353 recorded here so they can be freed when free list
355 void **buffer_memory_allocated;
357 /* Free list name. */
360 /* Callback functions to initialize newly allocated buffers.
361 If null buffers are zeroed. */
362 void (*buffer_init_function) (struct vlib_main_t * vm,
363 struct vlib_buffer_free_list_t * fl,
364 u32 * buffers, u32 n_buffers);
366 /* Callback function to announce that buffers have been
367 added to the freelist */
368 void (*buffers_added_to_freelist_function)
369 (struct vlib_main_t * vm, struct vlib_buffer_free_list_t * fl);
371 uword buffer_init_function_opaque;
372 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
376 u32 (*vlib_buffer_alloc_cb) (struct vlib_main_t * vm, u32 * buffers,
378 u32 (*vlib_buffer_alloc_from_free_list_cb) (struct vlib_main_t * vm,
379 u32 * buffers, u32 n_buffers,
380 u32 free_list_index);
381 void (*vlib_buffer_free_cb) (struct vlib_main_t * vm, u32 * buffers,
383 void (*vlib_buffer_free_no_next_cb) (struct vlib_main_t * vm, u32 * buffers,
385 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
387 uword n_packet_data_bytes,
389 min_n_buffers_each_physmem_alloc,
391 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
392 u32 free_list_index);
393 } vlib_buffer_callbacks_t;
395 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
399 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
400 /* Virtual memory address and size of buffer memory, used for calculating
402 uword buffer_mem_start;
403 uword buffer_mem_size;
405 /* Buffer free callback, for subversive activities */
406 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
408 u32 n_buffers, u32 follow_buffer_next);
409 /* Pool of buffer free lists.
410 Multiple free lists exist for packet generator which uses
411 separate free lists for each packet stream --- so as to avoid
412 initializing static data for each packet generated. */
413 vlib_buffer_free_list_t *buffer_free_list_pool;
414 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
415 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
417 /* Hash table mapping buffer size (rounded to next unit of
418 sizeof (vlib_buffer_t)) to free list index. */
419 uword *free_list_by_size;
421 /* Hash table mapping buffer index into number
422 0 => allocated but free, 1 => allocated and not-free.
423 If buffer index is not in hash table then this buffer
424 has never been allocated. */
425 uword *buffer_known_hash;
427 /* List of free-lists needing Blue Light Special announcements */
428 vlib_buffer_free_list_t **announce_list;
431 vlib_buffer_callbacks_t cb;
432 int callbacks_registered;
433 } vlib_buffer_main_t;
435 void vlib_buffer_add_mem_range (struct vlib_main_t *vm, uword start,
437 void vlib_buffer_cb_init (struct vlib_main_t *vm);
441 struct vlib_main_t *vlib_main;
443 u32 first_buffer, last_buffer;
449 /* Total accumulated bytes in chain starting with first_buffer. */
450 u32 n_total_data_bytes;
452 /* Max number of bytes to accumulate in chain starting with first_buffer.
453 As this limit is reached buffers are enqueued to next node. */
454 u32 max_n_data_bytes_per_chain;
456 /* Next node to enqueue buffers to relative to current process node. */
459 /* Free list to use to allocate new buffers. */
465 /* CLIB fifo of buffer indices waiting to be unserialized. */
468 /* Event type used to signal that RX buffers have been added to fifo. */
469 uword ready_one_time_event;
472 } vlib_serialize_buffer_main_t;
474 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
475 vlib_serialize_buffer_main_t * sm);
476 void unserialize_open_vlib_buffer (serialize_main_t * m,
477 struct vlib_main_t *vm,
478 vlib_serialize_buffer_main_t * sm);
480 u32 serialize_close_vlib_buffer (serialize_main_t * m);
481 void unserialize_close_vlib_buffer (serialize_main_t * m);
482 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
485 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
487 serialize_stream_t *s = &m->stream;
488 vlib_serialize_buffer_main_t *sm
489 = uword_to_pointer (m->stream.data_function_opaque,
490 vlib_serialize_buffer_main_t *);
491 return sm->tx.n_total_data_bytes + s->current_buffer_index +
492 vec_len (s->overflow_buffer);
498 /** \brief Compile time buffer trajectory tracing option
499 Turn this on if you run into "bad monkey" contexts,
500 and you want to know exactly which nodes they've visited...
503 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
505 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
506 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) (b)->pre_data[0]=0
508 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
509 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
511 #endif /* included_vlib_buffer_h */
513 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
514 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
515 static void __vlib_add_buffer_callbacks_t_##x (void) \
516 __attribute__((__constructor__)) ; \
517 static void __vlib_add_buffer_callbacks_t_##x (void) \
519 if (vlib_buffer_callbacks) \
520 clib_panic ("vlib buffer callbacks already registered"); \
521 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
523 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
526 * fd.io coding-style-patch-verification: ON
529 * eval: (c-set-style "gnu")