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, 0) \
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 /** Used by feature subgraph arcs to visit enabled feature nodes */
143 u32 current_config_index;
145 /** Opaque data used by sub-graphs for their own purposes. */
148 /** part of buffer metadata which is initialized on alloc ends here. */
149 STRUCT_MARK (template_end);
151 /** start of 2nd cache line */
152 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
154 /** Specifies index into trace buffer if VLIB_PACKET_IS_TRACED flag is
158 /** Only valid for first buffer in chain. Current length plus total length
159 * given here give total number of bytes in buffer chain. */
160 u32 total_length_not_including_first_buffer;
162 /**< More opaque data, see ../vnet/vnet/buffer.h */
165 /** start of third cache line */
166 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
168 /** Space for inserting data before buffer start. Packet rewrite string
169 * will be rewritten backwards and may extend back before
170 * buffer->data[0]. Must come directly before packet data. */
171 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE];
176 #ifdef CLIB_HAVE_VEC128
179 #ifdef CLIB_HAVE_VEC256
182 #ifdef CLIB_HAVE_VEC512
187 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
189 /** \brief Prefetch buffer metadata.
190 The first 64 bytes of buffer contains most header information
192 @param b - (vlib_buffer_t *) pointer to the buffer
193 @param type - LOAD, STORE. In most cases, STORE is the right answer
196 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
197 #define vlib_prefetch_buffer_data(b,type) \
198 CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)
201 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
203 ASSERT (sizeof (b[0]) % 64 == 0);
205 /* Rewrite data must be before and contiguous with packet data. */
206 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
210 vlib_buffer_get_va (vlib_buffer_t * b)
212 return pointer_to_uword (b->data);
215 /** \brief Get pointer to current data to process
217 @param b - (vlib_buffer_t *) pointer to the buffer
218 @return - (void *) (b->data + b->current_data)
222 vlib_buffer_get_current (vlib_buffer_t * b)
225 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
226 return b->data + b->current_data;
230 vlib_buffer_get_current_va (vlib_buffer_t * b)
232 return vlib_buffer_get_va (b) + b->current_data;
235 /** \brief Advance current data pointer by the supplied (signed!) amount
237 @param b - (vlib_buffer_t *) pointer to the buffer
238 @param l - (word) signed increment
241 vlib_buffer_advance (vlib_buffer_t * b, word l)
243 ASSERT (b->current_length >= l);
244 b->current_data += l;
245 b->current_length -= l;
247 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
248 b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
251 /** \brief Check if there is enough space in buffer to advance
253 @param b - (vlib_buffer_t *) pointer to the buffer
254 @param l - (word) size to check
255 @return - 0 if there is less space than 'l' in buffer
258 vlib_buffer_has_space (vlib_buffer_t * b, word l)
260 return b->current_length >= l;
263 /** \brief Reset current header & length to state they were in when
266 @param b - (vlib_buffer_t *) pointer to the buffer
270 vlib_buffer_reset (vlib_buffer_t * b)
272 b->current_length += clib_max (b->current_data, 0);
276 /** \brief Get pointer to buffer's opaque data array
278 @param b - (vlib_buffer_t *) pointer to the buffer
279 @return - (void *) b->opaque
282 vlib_get_buffer_opaque (vlib_buffer_t * b)
284 return (void *) b->opaque;
287 /** \brief Get pointer to buffer's opaque2 data array
289 @param b - (vlib_buffer_t *) pointer to the buffer
290 @return - (void *) b->opaque2
293 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
295 return (void *) b->opaque2;
298 /** \brief Get pointer to the end of buffer's data
299 * @param b pointer to the buffer
300 * @return pointer to tail of packet's data
303 vlib_buffer_get_tail (vlib_buffer_t * b)
305 return b->data + b->current_data + b->current_length;
308 /** \brief Append uninitialized data to buffer
309 * @param b pointer to the buffer
310 * @param size number of uninitialized bytes
311 * @return pointer to beginning of uninitialized data
314 vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size)
316 void *p = vlib_buffer_get_tail (b);
317 /* XXX make sure there's enough space */
318 b->current_length += size;
322 /** \brief Prepend uninitialized data to buffer
323 * @param b pointer to the buffer
324 * @param size number of uninitialized bytes
325 * @return pointer to beginning of uninitialized data
328 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
330 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
331 b->current_data -= size;
332 b->current_length += size;
334 return vlib_buffer_get_current (b);
337 /** \brief Make head room, typically for packet headers
338 * @param b pointer to the buffer
339 * @param size number of head room bytes
340 * @return pointer to start of buffer (current data)
343 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
345 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
346 b->current_data += size;
347 return vlib_buffer_get_current (b);
350 /** \brief Retrieve bytes from buffer head
351 * @param b pointer to the buffer
352 * @param size number of bytes to pull
353 * @return pointer to start of buffer (current data)
356 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
358 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
361 void *data = vlib_buffer_get_current (b);
362 vlib_buffer_advance (b, size);
366 /* Forward declaration. */
371 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
374 } vlib_buffer_pool_thread_t;
377 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
380 uword log2_page_size;
383 u32 physmem_map_index;
388 clib_spinlock_t lock;
390 /* per-thread data */
391 vlib_buffer_pool_thread_t *threads;
393 /* buffer metadata template */
394 vlib_buffer_t buffer_template;
395 } vlib_buffer_pool_t;
397 #define VLIB_BUFFER_MAX_NUMA_NODES 32
401 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
402 /* Virtual memory address and size of buffer memory, used for calculating
404 uword buffer_mem_start;
405 uword buffer_mem_size;
406 vlib_buffer_pool_t *buffer_pools;
408 /* Hash table mapping buffer index into number
409 0 => allocated but free, 1 => allocated and not-free.
410 If buffer index is not in hash table then this buffer
411 has never been allocated. */
412 uword *buffer_known_hash;
413 clib_spinlock_t buffer_known_hash_lockp;
414 u8 default_buffer_pool_index_for_numa[VLIB_BUFFER_MAX_NUMA_NODES];
417 u32 buffers_per_numa;
419 u32 default_data_size;
422 vlib_log_class_t log_default;
423 } vlib_buffer_main_t;
425 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
430 /** \brief Compile time buffer trajectory tracing option
431 Turn this on if you run into "bad monkey" contexts,
432 and you want to know exactly which nodes they've visited...
435 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
437 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
438 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
439 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
440 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
441 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
442 vlib_buffer_trace_trajectory_init (b);
444 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
445 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
447 extern u16 __vlib_buffer_external_hdr_size;
448 #define VLIB_BUFFER_SET_EXT_HDR_SIZE(x) \
449 static void __clib_constructor \
450 vnet_buffer_set_ext_hdr_size() \
452 if (__vlib_buffer_external_hdr_size) \
453 clib_error ("buffer external header space already set"); \
454 __vlib_buffer_external_hdr_size = CLIB_CACHE_LINE_ROUND (x); \
457 #endif /* included_vlib_buffer_h */
460 * fd.io coding-style-patch-verification: ON
463 * eval: (c-set-style "gnu")