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
55 vlib buffer structure definition and a few select
56 access methods. This structure and the buffer allocation
57 mechanism should perhaps live in vnet, but it would take a lot
58 of typing to make it so.
61 /* VLIB buffer representation. */
64 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
65 STRUCT_MARK (template_start);
66 /* Offset within data[] that we are currently processing.
67 If negative current header points into predata area. */
68 i16 current_data; /**< signed offset in data[], pre_data[]
69 that we are currently processing.
70 If negative current header points into predata area.
72 u16 current_length; /**< Nbytes between current data and
73 the end of this buffer.
75 u32 flags; /**< buffer flags:
76 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
77 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
78 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
79 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
80 <br> VLIB_BUFFER_REPL_FAIL: packet replication failure
81 <br> VLIB_BUFFER_RECYCLE: as it says
82 <br> VLIB_BUFFER_FLOW_REPORT: buffer is a flow report,
83 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
84 set to avoid adding it to a flow report
85 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
88 /* any change to the following line requres update of
89 * vlib_buffer_get_free_list_index(...) and
90 * vlib_buffer_set_free_list_index(...) functions */
91 #define VLIB_BUFFER_FREE_LIST_INDEX_MASK ((1 << 5) - 1)
93 #define VLIB_BUFFER_IS_TRACED (1 << 5)
94 #define VLIB_BUFFER_LOG2_NEXT_PRESENT (6)
95 #define VLIB_BUFFER_NEXT_PRESENT (1 << VLIB_BUFFER_LOG2_NEXT_PRESENT)
96 #define VLIB_BUFFER_IS_RECYCLED (1 << 7)
97 #define VLIB_BUFFER_TOTAL_LENGTH_VALID (1 << 8)
98 #define VLIB_BUFFER_REPL_FAIL (1 << 9)
99 #define VLIB_BUFFER_RECYCLE (1 << 10)
100 #define VLIB_BUFFER_FLOW_REPORT (1 << 11)
101 #define VLIB_BUFFER_EXT_HDR_VALID (1 << 12)
103 /* User defined buffer flags. */
104 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
105 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
107 STRUCT_MARK (template_end);
109 u32 next_buffer; /**< Next buffer for this linked-list of buffers.
110 Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
113 vlib_error_t error; /**< Error code for buffers to be enqueued
116 u32 current_config_index; /**< Used by feature subgraph arcs to
117 visit enabled feature nodes
120 u8 feature_arc_index; /**< Used to identify feature arcs by intermediate
124 u8 n_add_refs; /**< Number of additional references to this buffer. */
126 u8 dont_waste_me[2]; /**< Available space in the (precious)
127 first 32 octets of buffer metadata
128 Before allocating any of it, discussion required!
131 u32 opaque[10]; /**< Opaque data used by sub-graphs for their own purposes.
132 See .../vnet/vnet/buffer.h
134 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
136 u32 trace_index; /**< Specifies index into trace buffer
137 if VLIB_PACKET_IS_TRACED flag is set.
139 u32 recycle_count; /**< Used by L2 path recycle code */
141 u32 total_length_not_including_first_buffer;
142 /**< Only valid for first buffer in chain. Current length plus
143 total length given here give total number of bytes in buffer chain.
145 u32 opaque2[13]; /**< More opaque data, currently unused */
147 /***** end of second cache line */
148 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
149 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
151 Packet rewrite string will be
152 rewritten backwards and may extend
153 back before buffer->data[0].
154 Must come directly before packet data.
157 u8 data[0]; /**< Packet data. Hardware DMA here */
158 } vlib_buffer_t; /* Must be a multiple of 64B. */
160 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
162 /** \brief Prefetch buffer metadata.
163 The first 64 bytes of buffer contains most header information
165 @param b - (vlib_buffer_t *) pointer to the buffer
166 @param type - LOAD, STORE. In most cases, STORE is the right answer
169 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
171 always_inline vlib_buffer_t *
172 vlib_buffer_next_contiguous (vlib_buffer_t * b, u32 buffer_bytes)
174 return (void *) (b + 1) + buffer_bytes;
178 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
180 ASSERT (sizeof (b[0]) % 64 == 0);
182 /* Rewrite data must be before and contiguous with packet data. */
183 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
186 /** \brief Get pointer to current data to process
188 @param b - (vlib_buffer_t *) pointer to the buffer
189 @return - (void *) (b->data + b->current_data)
193 vlib_buffer_get_current (vlib_buffer_t * b)
196 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
197 return b->data + b->current_data;
200 /** \brief Advance current data pointer by the supplied (signed!) amount
202 @param b - (vlib_buffer_t *) pointer to the buffer
203 @param l - (word) signed increment
206 vlib_buffer_advance (vlib_buffer_t * b, word l)
208 ASSERT (b->current_length >= l);
209 b->current_data += l;
210 b->current_length -= l;
213 /** \brief Check if there is enough space in buffer to advance
215 @param b - (vlib_buffer_t *) pointer to the buffer
216 @param l - (word) size to check
217 @return - 0 if there is less space than 'l' in buffer
220 vlib_buffer_has_space (vlib_buffer_t * b, word l)
222 return b->current_length >= l;
225 /** \brief Reset current header & length to state they were in when
228 @param b - (vlib_buffer_t *) pointer to the buffer
232 vlib_buffer_reset (vlib_buffer_t * b)
234 b->current_length += clib_max (b->current_data, 0);
238 /** \brief Get pointer to buffer's opaque data array
240 @param b - (vlib_buffer_t *) pointer to the buffer
241 @return - (void *) b->opaque
244 vlib_get_buffer_opaque (vlib_buffer_t * b)
246 return (void *) b->opaque;
249 /** \brief Get pointer to buffer's opaque2 data array
251 @param b - (vlib_buffer_t *) pointer to the buffer
252 @return - (void *) b->opaque2
255 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
257 return (void *) b->opaque2;
260 /** \brief Get pointer to the end of buffer's data
261 * @param b pointer to the buffer
262 * @return pointer to tail of packet's data
265 vlib_buffer_get_tail (vlib_buffer_t * b)
267 return b->data + b->current_data + b->current_length;
270 /** \brief Append uninitialized data to buffer
271 * @param b pointer to the buffer
272 * @param size number of uninitialized bytes
273 * @return pointer to beginning of uninitialized data
276 vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
278 void *p = vlib_buffer_get_tail (b);
279 /* XXX make sure there's enough space */
280 b->current_length += size;
284 /** \brief Prepend uninitialized data to buffer
285 * @param b pointer to the buffer
286 * @param size number of uninitialized bytes
287 * @return pointer to beginning of uninitialized data
290 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
292 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
293 b->current_data -= size;
294 b->current_length += size;
296 return vlib_buffer_get_current (b);
299 /** \brief Make head room, typically for packet headers
300 * @param b pointer to the buffer
301 * @param size number of head room bytes
302 * @return pointer to start of buffer (current data)
305 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
307 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
308 b->current_data += size;
309 return vlib_buffer_get_current (b);
312 /** \brief Retrieve bytes from buffer head
313 * @param b pointer to the buffer
314 * @param size number of bytes to pull
315 * @return pointer to start of buffer (current data)
318 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
320 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
323 void *data = vlib_buffer_get_current (b);
324 vlib_buffer_advance (b, size);
328 /* Forward declaration. */
331 typedef struct vlib_buffer_free_list_t
333 /* Template buffer used to initialize first 16 bytes of buffers
334 allocated on this free list. */
335 vlib_buffer_t buffer_init_template;
337 /* Our index into vlib_main_t's buffer_free_list_pool. */
340 /* Number of data bytes for buffers in this free list. */
343 /* Number of buffers to allocate when we need to allocate new buffers
344 from physmem heap. */
345 u32 min_n_buffers_each_physmem_alloc;
347 /* Total number of buffers allocated from this free list. */
350 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
353 /* global vector of free buffers, used only on main thread.
354 Bufers are returned to global buffers only in case when number of
355 buffers on free buffers list grows about threshold */
357 clib_spinlock_t global_buffers_lock;
359 /* Memory chunks allocated for this free list
360 recorded here so they can be freed when free list
362 void **buffer_memory_allocated;
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;
383 u32 (*vlib_buffer_alloc_cb) (struct vlib_main_t * vm, u32 * buffers,
385 u32 (*vlib_buffer_alloc_from_free_list_cb) (struct vlib_main_t * vm,
386 u32 * buffers, u32 n_buffers,
387 u32 free_list_index);
388 void (*vlib_buffer_free_cb) (struct vlib_main_t * vm, u32 * buffers,
390 void (*vlib_buffer_free_no_next_cb) (struct vlib_main_t * vm, u32 * buffers,
392 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
394 uword n_packet_data_bytes,
396 min_n_buffers_each_physmem_alloc,
398 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
399 u32 free_list_index);
400 } vlib_buffer_callbacks_t;
402 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
406 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
407 /* Virtual memory address and size of buffer memory, used for calculating
409 uword buffer_mem_start;
410 uword buffer_mem_size;
411 vlib_physmem_region_index_t physmem_region;
413 /* Buffer free callback, for subversive activities */
414 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
416 u32 n_buffers, u32 follow_buffer_next);
417 /* Pool of buffer free lists.
418 Multiple free lists exist for packet generator which uses
419 separate free lists for each packet stream --- so as to avoid
420 initializing static data for each packet generated. */
421 vlib_buffer_free_list_t *buffer_free_list_pool;
422 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
423 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
425 /* Hash table mapping buffer size (rounded to next unit of
426 sizeof (vlib_buffer_t)) to free list index. */
427 uword *free_list_by_size;
429 /* Hash table mapping buffer index into number
430 0 => allocated but free, 1 => allocated and not-free.
431 If buffer index is not in hash table then this buffer
432 has never been allocated. */
433 uword *buffer_known_hash;
434 clib_spinlock_t buffer_known_hash_lockp;
436 /* List of free-lists needing Blue Light Special announcements */
437 vlib_buffer_free_list_t **announce_list;
440 vlib_buffer_callbacks_t cb;
441 int callbacks_registered;
442 } vlib_buffer_main_t;
444 void vlib_buffer_add_mem_range (struct vlib_main_t *vm, uword start,
446 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
450 struct vlib_main_t *vlib_main;
452 u32 first_buffer, last_buffer;
458 /* Total accumulated bytes in chain starting with first_buffer. */
459 u32 n_total_data_bytes;
461 /* Max number of bytes to accumulate in chain starting with first_buffer.
462 As this limit is reached buffers are enqueued to next node. */
463 u32 max_n_data_bytes_per_chain;
465 /* Next node to enqueue buffers to relative to current process node. */
468 /* Free list to use to allocate new buffers. */
474 /* CLIB fifo of buffer indices waiting to be unserialized. */
477 /* Event type used to signal that RX buffers have been added to fifo. */
478 uword ready_one_time_event;
481 } vlib_serialize_buffer_main_t;
483 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
484 vlib_serialize_buffer_main_t * sm);
485 void unserialize_open_vlib_buffer (serialize_main_t * m,
486 struct vlib_main_t *vm,
487 vlib_serialize_buffer_main_t * sm);
489 u32 serialize_close_vlib_buffer (serialize_main_t * m);
490 void unserialize_close_vlib_buffer (serialize_main_t * m);
491 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
494 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
496 serialize_stream_t *s = &m->stream;
497 vlib_serialize_buffer_main_t *sm
498 = uword_to_pointer (m->stream.data_function_opaque,
499 vlib_serialize_buffer_main_t *);
500 return sm->tx.n_total_data_bytes + s->current_buffer_index +
501 vec_len (s->overflow_buffer);
507 /** \brief Compile time buffer trajectory tracing option
508 Turn this on if you run into "bad monkey" contexts,
509 and you want to know exactly which nodes they've visited...
512 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
514 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
515 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) (b)->pre_data[0]=0
517 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
518 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
520 #endif /* included_vlib_buffer_h */
522 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
523 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
524 static void __vlib_add_buffer_callbacks_t_##x (void) \
525 __attribute__((__constructor__)) ; \
526 static void __vlib_add_buffer_callbacks_t_##x (void) \
528 if (vlib_buffer_callbacks) \
529 clib_panic ("vlib buffer callbacks already registered"); \
530 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
532 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
535 * fd.io coding-style-patch-verification: ON
538 * eval: (c-set-style "gnu")