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_PRE_DATA_SIZE __PRE_DATA_SIZE
53 #define VLIB_BUFFER_DEFAULT_DATA_SIZE (2048)
55 /* Minimum buffer chain segment size. Does not apply to last buffer in chain.
56 Dataplane code can safely asume that specified amount of data is not split
57 into 2 chained buffers */
58 #define VLIB_BUFFER_MIN_CHAIN_SEG_SIZE (128)
60 /* Amount of head buffer data copied to each replica head buffer */
61 #define VLIB_BUFFER_CLONE_HEAD_SIZE (256)
64 vlib buffer structure definition and a few select
65 access methods. This structure and the buffer allocation
66 mechanism should perhaps live in vnet, but it would take a lot
67 of typing to make it so.
73 #define foreach_vlib_buffer_flag \
75 _( 1, NEXT_PRESENT, "next-present") \
76 _( 2, TOTAL_LENGTH_VALID, 0) \
77 _( 3, EXT_HDR_VALID, "ext-hdr-valid")
79 /* NOTE: only buffer generic flags should be defined here, please consider
80 using user flags. i.e. src/vnet/buffer.h */
84 #define _(bit, name, v) VLIB_BUFFER_##name = (1 << (bit)),
85 foreach_vlib_buffer_flag
91 #define _(bit, name, v) VLIB_BUFFER_LOG2_##name = (bit),
92 foreach_vlib_buffer_flag
96 /* User defined buffer flags. */
97 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
98 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
99 #define VLIB_BUFFER_FLAGS_ALL (0x0f)
101 /** VLIB buffer representation. */
106 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
108 /** signed offset in data[], pre_data[] that we are currently
109 * processing. If negative current header points into predata area. */
112 /** Nbytes between current data and the end of this buffer. */
116 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
117 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
118 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
119 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
120 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
121 set to avoid adding it to a flow report
122 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
126 /** Generic flow identifier */
129 /** Reference count for this buffer. */
130 volatile u8 ref_count;
132 /** index of buffer pool this buffer belongs. */
133 u8 buffer_pool_index;
135 /** Error code for buffers to be enqueued to error handler. */
138 /** Next buffer for this linked-list of buffers. Only valid if
139 * VLIB_BUFFER_NEXT_PRESENT flag is set. */
142 /** The following fields can be in a union because once a packet enters
143 * the punt path, it is no longer on a feature arc */
146 /** Used by feature subgraph arcs to visit enabled feature nodes */
147 u32 current_config_index;
148 /* the reason the packet once punted */
152 /** Opaque data used by sub-graphs for their own purposes. */
155 /** part of buffer metadata which is initialized on alloc ends here. */
156 STRUCT_MARK (template_end);
158 /** start of 2nd half (2nd cacheline on systems where cacheline size is 64) */
159 CLIB_ALIGN_MARK (second_half, 64);
161 /** Specifies trace buffer handle if VLIB_PACKET_IS_TRACED flag is
165 /** Only valid for first buffer in chain. Current length plus total length
166 * given here give total number of bytes in buffer chain. */
167 u32 total_length_not_including_first_buffer;
169 /**< More opaque data, see ../vnet/vnet/buffer.h */
172 /** start of buffer headroom */
173 CLIB_ALIGN_MARK (headroom, 64);
175 /** Space for inserting data before buffer start. Packet rewrite string
176 * will be rewritten backwards and may extend back before
177 * buffer->data[0]. Must come directly before packet data. */
178 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE];
183 #ifdef CLIB_HAVE_VEC128
186 #ifdef CLIB_HAVE_VEC256
189 #ifdef CLIB_HAVE_VEC512
194 STATIC_ASSERT_SIZEOF (vlib_buffer_t, 128 + VLIB_BUFFER_PRE_DATA_SIZE);
195 STATIC_ASSERT (VLIB_BUFFER_PRE_DATA_SIZE % CLIB_CACHE_LINE_BYTES == 0,
196 "VLIB_BUFFER_PRE_DATA_SIZE must be divisible by cache line size");
198 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
200 /** \brief Prefetch buffer metadata.
201 The first 64 bytes of buffer contains most header information
203 @param b - (vlib_buffer_t *) pointer to the buffer
204 @param type - LOAD, STORE. In most cases, STORE is the right answer
207 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
208 #define vlib_prefetch_buffer_data(b,type) \
209 CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)
212 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
214 ASSERT (sizeof (b[0]) % 64 == 0);
216 /* Rewrite data must be before and contiguous with packet data. */
217 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
221 vlib_buffer_get_va (vlib_buffer_t * b)
223 return pointer_to_uword (b->data);
226 /** \brief Get pointer to current data to process
228 @param b - (vlib_buffer_t *) pointer to the buffer
229 @return - (void *) (b->data + b->current_data)
233 vlib_buffer_get_current (vlib_buffer_t * b)
236 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
237 return b->data + b->current_data;
241 vlib_buffer_get_current_va (vlib_buffer_t * b)
243 return vlib_buffer_get_va (b) + b->current_data;
246 /** \brief Advance current data pointer by the supplied (signed!) amount
248 @param b - (vlib_buffer_t *) pointer to the buffer
249 @param l - (word) signed increment
252 vlib_buffer_advance (vlib_buffer_t * b, word l)
254 ASSERT (b->current_length >= l);
255 b->current_data += l;
256 b->current_length -= l;
258 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
259 b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
262 /** \brief Check if there is enough space in buffer to advance
264 @param b - (vlib_buffer_t *) pointer to the buffer
265 @param l - (word) size to check
266 @return - 0 if there is less space than 'l' in buffer
269 vlib_buffer_has_space (vlib_buffer_t * b, word l)
271 return b->current_length >= l;
274 /** \brief Reset current header & length to state they were in when
277 @param b - (vlib_buffer_t *) pointer to the buffer
281 vlib_buffer_reset (vlib_buffer_t * b)
283 b->current_length += clib_max (b->current_data, 0);
287 /** \brief Get pointer to buffer's opaque data array
289 @param b - (vlib_buffer_t *) pointer to the buffer
290 @return - (void *) b->opaque
293 vlib_get_buffer_opaque (vlib_buffer_t * b)
295 return (void *) b->opaque;
298 /** \brief Get pointer to buffer's opaque2 data array
300 @param b - (vlib_buffer_t *) pointer to the buffer
301 @return - (void *) b->opaque2
304 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
306 return (void *) b->opaque2;
309 /** \brief Get pointer to the end of buffer's data
310 * @param b pointer to the buffer
311 * @return pointer to tail of packet's data
314 vlib_buffer_get_tail (vlib_buffer_t * b)
316 return b->data + b->current_data + b->current_length;
319 /** \brief Append uninitialized data to buffer
320 * @param b pointer to the buffer
321 * @param size number of uninitialized bytes
322 * @return pointer to beginning of uninitialized data
325 vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size)
327 void *p = vlib_buffer_get_tail (b);
328 /* XXX make sure there's enough space */
329 b->current_length += size;
333 /** \brief Prepend uninitialized data to buffer
334 * @param b pointer to the buffer
335 * @param size number of uninitialized bytes
336 * @return pointer to beginning of uninitialized data
339 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
341 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
342 b->current_data -= size;
343 b->current_length += size;
345 return vlib_buffer_get_current (b);
348 /** \brief Make head room, typically for packet headers
349 * @param b pointer to the buffer
350 * @param size number of head room bytes
351 * @return pointer to start of buffer (current data)
354 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
356 b->current_data += size;
357 return vlib_buffer_get_current (b);
360 /** \brief Construct a trace handle from thread and pool index
361 * @param thread Thread id
362 * @param pool_index Pool index
363 * @return trace handle
366 vlib_buffer_make_trace_handle (u32 thread, u32 pool_index)
369 ASSERT (thread < 0xff);
370 ASSERT (pool_index < 0x00FFFFFF);
371 rv = (thread << 24) | (pool_index & 0x00FFFFFF);
375 /** \brief Extract the thread id from a trace handle
376 * @param trace_handle the trace handle
377 * @return the thread id
380 vlib_buffer_get_trace_thread (vlib_buffer_t * b)
382 u32 trace_handle = b->trace_handle;
384 return trace_handle >> 24;
387 /** \brief Extract the trace (pool) index from a trace handle
388 * @param trace_handle the trace handle
389 * @return the trace index
392 vlib_buffer_get_trace_index (vlib_buffer_t * b)
394 u32 trace_handle = b->trace_handle;
395 return trace_handle & 0x00FFFFFF;
398 /** \brief Retrieve bytes from buffer head
399 * @param b pointer to the buffer
400 * @param size number of bytes to pull
401 * @return pointer to start of buffer (current data)
404 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
406 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
409 void *data = vlib_buffer_get_current (b);
410 vlib_buffer_advance (b, size);
414 /* Forward declaration. */
417 #define VLIB_BUFFER_POOL_PER_THREAD_CACHE_SZ 512
421 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
422 u32 cached_buffers[VLIB_BUFFER_POOL_PER_THREAD_CACHE_SZ];
424 } vlib_buffer_pool_thread_t;
428 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
431 uword log2_page_size;
434 u32 physmem_map_index;
440 clib_spinlock_t lock;
442 /* per-thread data */
443 vlib_buffer_pool_thread_t *threads;
445 /* buffer metadata template */
446 vlib_buffer_t buffer_template;
447 } vlib_buffer_pool_t;
449 #define VLIB_BUFFER_MAX_NUMA_NODES 32
453 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
454 /* Virtual memory address and size of buffer memory, used for calculating
456 uword buffer_mem_start;
457 uword buffer_mem_size;
458 vlib_buffer_pool_t *buffer_pools;
460 /* Hash table mapping buffer index into number
461 0 => allocated but free, 1 => allocated and not-free.
462 If buffer index is not in hash table then this buffer
463 has never been allocated. */
464 uword *buffer_known_hash;
465 clib_spinlock_t buffer_known_hash_lockp;
466 u8 default_buffer_pool_index_for_numa[VLIB_BUFFER_MAX_NUMA_NODES];
469 u32 buffers_per_numa;
471 u32 default_data_size;
472 clib_mem_page_sz_t log2_page_size;
475 vlib_log_class_t log_default;
476 } vlib_buffer_main_t;
478 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
483 /** \brief Compile time buffer trajectory tracing option
484 Turn this on if you run into "bad monkey" contexts,
485 and you want to know exactly which nodes they've visited...
488 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
490 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
491 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
492 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
493 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
494 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
495 vlib_buffer_trace_trajectory_init (b);
497 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
498 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
500 extern u16 __vlib_buffer_external_hdr_size;
501 #define VLIB_BUFFER_SET_EXT_HDR_SIZE(x) \
502 static void __clib_constructor \
503 vnet_buffer_set_ext_hdr_size() \
505 if (__vlib_buffer_external_hdr_size) \
506 clib_error ("buffer external header space already set"); \
507 __vlib_buffer_external_hdr_size = CLIB_CACHE_LINE_ROUND (x); \
510 #endif /* included_vlib_buffer_h */
513 * fd.io coding-style-patch-verification: ON
516 * eval: (c-set-style "gnu")