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
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, 0) \
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 /** VLIB buffer representation. */
105 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
107 /** signed offset in data[], pre_data[] that we are currently
108 * processing. If negative current header points into predata area. */
111 /** Nbytes between current data and the end of this buffer. */
115 <br> VLIB_BUFFER_FREE_LIST_INDEX_MASK: bits used to store free list index,
116 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
117 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
118 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
119 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
120 set to avoid adding it to a flow report
121 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
125 /** Generic flow identifier */
128 /** Reference count for this buffer. */
129 volatile u8 ref_count;
131 /** index of buffer pool this buffer belongs. */
132 u8 buffer_pool_index;
134 /** Error code for buffers to be enqueued to error handler. */
137 /** Next buffer for this linked-list of buffers. Only valid if
138 * VLIB_BUFFER_NEXT_PRESENT flag is set. */
141 /** Used by feature subgraph arcs to visit enabled feature nodes */
142 u32 current_config_index;
144 /** Opaque data used by sub-graphs for their own purposes. */
147 /** part of buffer metadata which is initialized on alloc ends here. */
148 STRUCT_MARK (template_end);
150 /** start of 2nd cache line */
151 CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
153 /** Specifies index into trace buffer if VLIB_PACKET_IS_TRACED flag is
157 /** Only valid for first buffer in chain. Current length plus total length
158 * given here give total number of bytes in buffer chain. */
159 u32 total_length_not_including_first_buffer;
161 /**< More opaque data, see ../vnet/vnet/buffer.h */
164 /** start of third cache line */
165 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
167 /** Space for inserting data before buffer start. Packet rewrite string
168 * will be rewritten backwards and may extend back before
169 * buffer->data[0]. Must come directly before packet data. */
170 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE];
175 #ifdef CLIB_HAVE_VEC128
178 #ifdef CLIB_HAVE_VEC256
181 #ifdef CLIB_HAVE_VEC512
186 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
188 /** \brief Prefetch buffer metadata.
189 The first 64 bytes of buffer contains most header information
191 @param b - (vlib_buffer_t *) pointer to the buffer
192 @param type - LOAD, STORE. In most cases, STORE is the right answer
195 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
196 #define vlib_prefetch_buffer_data(b,type) \
197 CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)
200 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
202 ASSERT (sizeof (b[0]) % 64 == 0);
204 /* Rewrite data must be before and contiguous with packet data. */
205 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
209 vlib_buffer_get_va (vlib_buffer_t * b)
211 return pointer_to_uword (b->data);
214 /** \brief Get pointer to current data to process
216 @param b - (vlib_buffer_t *) pointer to the buffer
217 @return - (void *) (b->data + b->current_data)
221 vlib_buffer_get_current (vlib_buffer_t * b)
224 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
225 return b->data + b->current_data;
229 vlib_buffer_get_current_va (vlib_buffer_t * b)
231 return vlib_buffer_get_va (b) + b->current_data;
234 /** \brief Advance current data pointer by the supplied (signed!) amount
236 @param b - (vlib_buffer_t *) pointer to the buffer
237 @param l - (word) signed increment
240 vlib_buffer_advance (vlib_buffer_t * b, word l)
242 ASSERT (b->current_length >= l);
243 b->current_data += l;
244 b->current_length -= l;
246 ASSERT ((b->flags & VLIB_BUFFER_NEXT_PRESENT) == 0 ||
247 b->current_length >= VLIB_BUFFER_MIN_CHAIN_SEG_SIZE);
250 /** \brief Check if there is enough space in buffer to advance
252 @param b - (vlib_buffer_t *) pointer to the buffer
253 @param l - (word) size to check
254 @return - 0 if there is less space than 'l' in buffer
257 vlib_buffer_has_space (vlib_buffer_t * b, word l)
259 return b->current_length >= l;
262 /** \brief Reset current header & length to state they were in when
265 @param b - (vlib_buffer_t *) pointer to the buffer
269 vlib_buffer_reset (vlib_buffer_t * b)
271 b->current_length += clib_max (b->current_data, 0);
275 /** \brief Get pointer to buffer's opaque data array
277 @param b - (vlib_buffer_t *) pointer to the buffer
278 @return - (void *) b->opaque
281 vlib_get_buffer_opaque (vlib_buffer_t * b)
283 return (void *) b->opaque;
286 /** \brief Get pointer to buffer's opaque2 data array
288 @param b - (vlib_buffer_t *) pointer to the buffer
289 @return - (void *) b->opaque2
292 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
294 return (void *) b->opaque2;
297 /** \brief Get pointer to the end of buffer's data
298 * @param b pointer to the buffer
299 * @return pointer to tail of packet's data
302 vlib_buffer_get_tail (vlib_buffer_t * b)
304 return b->data + b->current_data + b->current_length;
307 /** \brief Append uninitialized data to buffer
308 * @param b pointer to the buffer
309 * @param size number of uninitialized bytes
310 * @return pointer to beginning of uninitialized data
313 vlib_buffer_put_uninit (vlib_buffer_t * b, u16 size)
315 void *p = vlib_buffer_get_tail (b);
316 /* XXX make sure there's enough space */
317 b->current_length += size;
321 /** \brief Prepend uninitialized data to buffer
322 * @param b pointer to the buffer
323 * @param size number of uninitialized bytes
324 * @return pointer to beginning of uninitialized data
327 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
329 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
330 b->current_data -= size;
331 b->current_length += size;
333 return vlib_buffer_get_current (b);
336 /** \brief Make head room, typically for packet headers
337 * @param b pointer to the buffer
338 * @param size number of head room bytes
339 * @return pointer to start of buffer (current data)
342 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
344 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
345 b->current_data += size;
346 return vlib_buffer_get_current (b);
349 /** \brief Retrieve bytes from buffer head
350 * @param b pointer to the buffer
351 * @param size number of bytes to pull
352 * @return pointer to start of buffer (current data)
355 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
357 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
360 void *data = vlib_buffer_get_current (b);
361 vlib_buffer_advance (b, size);
365 /* Forward declaration. */
370 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
373 } vlib_buffer_pool_thread_t;
376 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
379 uword log2_page_size;
382 u32 physmem_map_index;
387 clib_spinlock_t lock;
389 /* per-thread data */
390 vlib_buffer_pool_thread_t *threads;
392 /* buffer metadata template */
393 vlib_buffer_t buffer_template;
394 } vlib_buffer_pool_t;
398 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
399 /* Virtual memory address and size of buffer memory, used for calculating
401 uword buffer_mem_start;
402 uword buffer_mem_size;
403 vlib_buffer_pool_t *buffer_pools;
405 /* Hash table mapping buffer index into number
406 0 => allocated but free, 1 => allocated and not-free.
407 If buffer index is not in hash table then this buffer
408 has never been allocated. */
409 uword *buffer_known_hash;
410 clib_spinlock_t buffer_known_hash_lockp;
414 u32 buffers_per_numa;
418 vlib_log_class_t log_default;
419 } vlib_buffer_main_t;
421 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
426 /** \brief Compile time buffer trajectory tracing option
427 Turn this on if you run into "bad monkey" contexts,
428 and you want to know exactly which nodes they've visited...
431 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
433 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
434 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
435 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
436 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
437 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
438 vlib_buffer_trace_trajectory_init (b);
440 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
441 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
443 extern u16 __vlib_buffer_external_hdr_size;
444 #define VLIB_BUFFER_SET_EXT_HDR_SIZE(x) \
445 static void __clib_constructor \
446 vnet_buffer_set_ext_hdr_size() \
448 if (__vlib_buffer_external_hdr_size) \
449 clib_error ("buffer external header space already set"); \
450 __vlib_buffer_external_hdr_size = CLIB_CACHE_LINE_ROUND (x); \
453 #endif /* included_vlib_buffer_h */
456 * fd.io coding-style-patch-verification: ON
459 * eval: (c-set-style "gnu")