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 VLIB_BUFFER_PRE_DATA_SIZE */
52 #define VLIB_BUFFER_DEFAULT_DATA_SIZE (2048)
54 /* Minimum buffer chain segment size. Does not apply to last buffer in chain.
55 Dataplane code can safely asume that specified amount of data is not split
56 into 2 chained buffers */
57 #define VLIB_BUFFER_MIN_CHAIN_SEG_SIZE (128)
59 /* Amount of head buffer data copied to each replica head buffer */
60 #define VLIB_BUFFER_CLONE_HEAD_SIZE (256)
63 vlib buffer structure definition and a few select
64 access methods. This structure and the buffer allocation
65 mechanism should perhaps live in vnet, but it would take a lot
66 of typing to make it so.
72 #define foreach_vlib_buffer_flag \
74 _( 1, NEXT_PRESENT, "next-present") \
75 _( 2, TOTAL_LENGTH_VALID, 0) \
76 _( 3, EXT_HDR_VALID, "ext-hdr-valid")
78 /* NOTE: only buffer generic flags should be defined here, please consider
79 using user flags. i.e. src/vnet/buffer.h */
83 #define _(bit, name, v) VLIB_BUFFER_##name = (1 << (bit)),
84 foreach_vlib_buffer_flag
90 #define _(bit, name, v) VLIB_BUFFER_LOG2_##name = (bit),
91 foreach_vlib_buffer_flag
95 /* User defined buffer flags. */
96 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
97 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
98 #define VLIB_BUFFER_FLAGS_ALL (0x0f)
100 /** \brief Compile time buffer trajectory tracing option
101 Turn this on if you run into "bad monkey" contexts,
102 and you want to know exactly which nodes they've visited...
105 #ifndef VLIB_BUFFER_TRACE_TRAJECTORY
106 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
107 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
109 #define vlib_buffer_template_fields \
110 /** signed offset in data[], pre_data[] that we are currently \
111 * processing. If negative current header points into predata area. */ \
114 /** Nbytes between current data and the end of this buffer. */ \
115 u16 current_length; \
117 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list \
118 index, <br> VLIB_BUFFER_IS_TRACED: trace this buffer. <br> \
119 VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer. <br> \
120 VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says <br> \
121 VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager \
122 header, set to avoid adding it to a flow report <br> \
123 VLIB_BUFFER_FLAG_USER(n): user-defined bit N \
127 /** Generic flow identifier */ \
130 /** Reference count for this buffer. */ \
131 volatile u8 ref_count; \
133 /** index of buffer pool this buffer belongs. */ \
134 u8 buffer_pool_index; \
136 /** Error code for buffers to be enqueued to error handler. */ \
137 vlib_error_t error; \
139 /** Next buffer for this linked-list of buffers. Only valid if \
140 * VLIB_BUFFER_NEXT_PRESENT flag is set. */ \
143 /** The following fields can be in a union because once a packet enters \
144 * the punt path, it is no longer on a feature arc */ \
147 /** Used by feature subgraph arcs to visit enabled feature nodes */ \
148 u32 current_config_index; \
149 /* the reason the packet once punted */ \
153 /** Opaque data used by sub-graphs for their own purposes. */ \
158 CLIB_ALIGN_MARK (align_mark, 64);
159 vlib_buffer_template_fields
160 } vlib_buffer_template_t;
162 STATIC_ASSERT_SIZEOF (vlib_buffer_template_t, 64);
164 /** VLIB buffer representation. */
167 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
174 vlib_buffer_template_fields
176 vlib_buffer_template_t template;
179 /* Data above is initialized or zeroed on alloc, data bellow is not
180 * and it is app responsibility to ensure data is valid */
182 /** start of 2nd half (2nd cacheline on systems where cacheline size is 64) */
183 CLIB_ALIGN_MARK (second_half, 64);
185 /** Specifies trace buffer handle if VLIB_PACKET_IS_TRACED flag is
189 /** Only valid for first buffer in chain. Current length plus total length
190 * given here give total number of bytes in buffer chain. */
191 u32 total_length_not_including_first_buffer;
193 /**< More opaque data, see ../vnet/vnet/buffer.h */
196 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
197 /** trace trajectory data - we use a specific cacheline for that in the
198 * buffer when it is compiled-in */
199 #define VLIB_BUFFER_TRACE_TRAJECTORY_MAX 31
200 #define VLIB_BUFFER_TRACE_TRAJECTORY_SZ 64
201 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) (b)->trajectory_nb = 0
202 CLIB_ALIGN_MARK (trajectory, 64);
204 u16 trajectory_trace[VLIB_BUFFER_TRACE_TRAJECTORY_MAX];
205 #else /* VLIB_BUFFER_TRACE_TRAJECTORY */
206 #define VLIB_BUFFER_TRACE_TRAJECTORY_SZ 0
207 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
208 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
210 /** start of buffer headroom */
211 CLIB_ALIGN_MARK (headroom, 64);
213 /** Space for inserting data before buffer start. Packet rewrite string
214 * will be rewritten backwards and may extend back before
215 * buffer->data[0]. Must come directly before packet data. */
216 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE];
221 #ifdef CLIB_HAVE_VEC128
224 #ifdef CLIB_HAVE_VEC256
227 #ifdef CLIB_HAVE_VEC512
232 STATIC_ASSERT_SIZEOF (vlib_buffer_t, 128 + VLIB_BUFFER_TRACE_TRAJECTORY_SZ +
233 VLIB_BUFFER_PRE_DATA_SIZE);
234 STATIC_ASSERT (VLIB_BUFFER_PRE_DATA_SIZE % CLIB_CACHE_LINE_BYTES == 0,
235 "VLIB_BUFFER_PRE_DATA_SIZE must be divisible by cache line size");
237 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
238 #define VLIB_BUFFER_INVALID_INDEX 0xffffffff
240 /** \brief Prefetch buffer metadata.
241 The first 64 bytes of buffer contains most header information
243 @param b - (vlib_buffer_t *) pointer to the buffer
244 @param type - LOAD, STORE. In most cases, STORE is the right answer
247 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
248 #define vlib_prefetch_buffer_data(b,type) \
249 CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)
252 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
254 ASSERT (sizeof (b[0]) % 64 == 0);
256 /* Rewrite data must be before and contiguous with packet data. */
257 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
261 vlib_buffer_get_va (vlib_buffer_t * b)
263 return pointer_to_uword (b->data);
266 /** \brief Get pointer to current data to process
268 @param b - (vlib_buffer_t *) pointer to the buffer
269 @return - (void *) (b->data + b->current_data)
273 vlib_buffer_get_current (vlib_buffer_t * b)
276 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
277 return b->data + b->current_data;
281 vlib_buffer_get_current_va (vlib_buffer_t * b)
283 return vlib_buffer_get_va (b) + b->current_data;
286 /** \brief Advance current data pointer by the supplied (signed!) amount
288 @param b - (vlib_buffer_t *) pointer to the buffer
289 @param l - (word) signed increment
292 vlib_buffer_advance (vlib_buffer_t * b, word l)
294 ASSERT (b->current_length >= l);
295 b->current_data += l;
296 b->current_length -= l;
298 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
299 b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
302 /** \brief Check if there is enough space in buffer to advance
304 @param b - (vlib_buffer_t *) pointer to the buffer
305 @param l - (word) size to check
306 @return - 0 if there is less space than 'l' in buffer
309 vlib_buffer_has_space (vlib_buffer_t * b, word l)
311 return b->current_length >= l;
314 /** \brief Reset current header & length to state they were in when
317 @param b - (vlib_buffer_t *) pointer to the buffer
321 vlib_buffer_reset (vlib_buffer_t * b)
323 b->current_length += clib_max (b->current_data, 0);
327 /** \brief Get pointer to buffer's opaque data array
329 @param b - (vlib_buffer_t *) pointer to the buffer
330 @return - (void *) b->opaque
333 vlib_get_buffer_opaque (vlib_buffer_t * b)
335 return (void *) b->opaque;
338 /** \brief Get pointer to buffer's opaque2 data array
340 @param b - (vlib_buffer_t *) pointer to the buffer
341 @return - (void *) b->opaque2
344 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
346 return (void *) b->opaque2;
349 /** \brief Get pointer to the end of buffer's data
350 * @param b pointer to the buffer
351 * @return pointer to tail of packet's data
354 vlib_buffer_get_tail (vlib_buffer_t * b)
356 return b->data + b->current_data + b->current_length;
359 /** \brief Append uninitialized data to buffer
360 * @param b pointer to the buffer
361 * @param size number of uninitialized bytes
362 * @return pointer to beginning of uninitialized data
365 vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size)
367 void *p = vlib_buffer_get_tail (b);
368 /* XXX make sure there's enough space */
369 b->current_length += size;
373 /** \brief Prepend uninitialized data to buffer
374 * @param b pointer to the buffer
375 * @param size number of uninitialized bytes
376 * @return pointer to beginning of uninitialized data
379 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
381 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
382 b->current_data -= size;
383 b->current_length += size;
385 return vlib_buffer_get_current (b);
388 /** \brief Make head room, typically for packet headers
389 * @param b pointer to the buffer
390 * @param size number of head room bytes
391 * @return pointer to start of buffer (current data)
394 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
396 b->current_data += size;
397 return vlib_buffer_get_current (b);
400 /** \brief Construct a trace handle from thread and pool index
401 * @param thread Thread id
402 * @param pool_index Pool index
403 * @return trace handle
406 vlib_buffer_make_trace_handle (u32 thread, u32 pool_index)
409 ASSERT (thread < 0xff);
410 ASSERT (pool_index < 0x00FFFFFF);
411 rv = (thread << 24) | (pool_index & 0x00FFFFFF);
415 /** \brief Extract the thread id from a trace handle
416 * @param trace_handle the trace handle
417 * @return the thread id
420 vlib_buffer_get_trace_thread (vlib_buffer_t * b)
422 u32 trace_handle = b->trace_handle;
424 return trace_handle >> 24;
427 /** \brief Extract the trace (pool) index from a trace handle
428 * @param trace_handle the trace handle
429 * @return the trace index
432 vlib_buffer_get_trace_index (vlib_buffer_t * b)
434 u32 trace_handle = b->trace_handle;
435 return trace_handle & 0x00FFFFFF;
438 /** \brief Retrieve bytes from buffer head
439 * @param b pointer to the buffer
440 * @param size number of bytes to pull
441 * @return pointer to start of buffer (current data)
444 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
446 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
449 void *data = vlib_buffer_get_current (b);
450 vlib_buffer_advance (b, size);
454 /* Forward declaration. */
457 #define VLIB_BUFFER_POOL_PER_THREAD_CACHE_SZ 512
461 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
462 u32 cached_buffers[VLIB_BUFFER_POOL_PER_THREAD_CACHE_SZ];
464 } vlib_buffer_pool_thread_t;
468 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
474 u32 physmem_map_index;
481 clib_spinlock_t lock;
483 /* per-thread data */
484 vlib_buffer_pool_thread_t *threads;
486 /* buffer metadata template */
487 vlib_buffer_template_t buffer_template;
488 } vlib_buffer_pool_t;
490 #define VLIB_BUFFER_MAX_NUMA_NODES 32
492 typedef u32 (vlib_buffer_alloc_free_callback_t) (struct vlib_main_t *vm,
493 u8 buffer_pool_index,
494 u32 *buffers, u32 n_buffers);
498 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
499 /* Virtual memory address and size of buffer memory, used for calculating
501 uword buffer_mem_start;
502 uword buffer_mem_size;
503 vlib_buffer_pool_t *buffer_pools;
505 vlib_buffer_alloc_free_callback_t *alloc_callback_fn;
506 vlib_buffer_alloc_free_callback_t *free_callback_fn;
508 u8 default_buffer_pool_index_for_numa[VLIB_BUFFER_MAX_NUMA_NODES];
511 u32 buffers_per_numa;
513 u32 default_data_size;
514 clib_mem_page_sz_t log2_page_size;
516 /* Hash table mapping buffer index into number
517 0 => allocated but free, 1 => allocated and not-free.
518 If buffer index is not in hash table then this buffer
519 has never been allocated. */
520 uword *buffer_known_hash;
521 clib_spinlock_t buffer_known_hash_lockp;
524 vlib_log_class_t log_default;
525 } vlib_buffer_main_t;
527 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
529 format_function_t format_vlib_buffer_pool_all;
531 int vlib_buffer_set_alloc_free_callback (
532 struct vlib_main_t *vm, vlib_buffer_alloc_free_callback_t *alloc_callback_fn,
533 vlib_buffer_alloc_free_callback_t *free_callback_fn);
535 extern u16 __vlib_buffer_external_hdr_size;
536 #define VLIB_BUFFER_SET_EXT_HDR_SIZE(x) \
537 static void __clib_constructor \
538 vnet_buffer_set_ext_hdr_size() \
540 if (__vlib_buffer_external_hdr_size) \
541 clib_error ("buffer external header space already set"); \
542 __vlib_buffer_external_hdr_size = CLIB_CACHE_LINE_ROUND (x); \
545 #endif /* included_vlib_buffer_h */
548 * fd.io coding-style-patch-verification: ON
551 * eval: (c-set-style "gnu")