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 align_pad; /**< available */
146 u32 opaque2[12]; /**< More opaque data, see ../vnet/vnet/buffer.h */
148 /***** end of second cache line */
149 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
150 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
152 Packet rewrite string will be
153 rewritten backwards and may extend
154 back before buffer->data[0].
155 Must come directly before packet data.
158 u8 data[0]; /**< Packet data. Hardware DMA here */
159 } vlib_buffer_t; /* Must be a multiple of 64B. */
161 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
163 /** \brief Prefetch buffer metadata.
164 The first 64 bytes of buffer contains most header information
166 @param b - (vlib_buffer_t *) pointer to the buffer
167 @param type - LOAD, STORE. In most cases, STORE is the right answer
170 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
172 always_inline vlib_buffer_t *
173 vlib_buffer_next_contiguous (vlib_buffer_t * b, u32 buffer_bytes)
175 return (void *) (b + 1) + buffer_bytes;
179 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
181 ASSERT (sizeof (b[0]) % 64 == 0);
183 /* Rewrite data must be before and contiguous with packet data. */
184 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
187 /** \brief Get pointer to current data to process
189 @param b - (vlib_buffer_t *) pointer to the buffer
190 @return - (void *) (b->data + b->current_data)
194 vlib_buffer_get_current (vlib_buffer_t * b)
197 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
198 return b->data + b->current_data;
201 /** \brief Advance current data pointer by the supplied (signed!) amount
203 @param b - (vlib_buffer_t *) pointer to the buffer
204 @param l - (word) signed increment
207 vlib_buffer_advance (vlib_buffer_t * b, word l)
209 ASSERT (b->current_length >= l);
210 b->current_data += l;
211 b->current_length -= l;
214 /** \brief Check if there is enough space in buffer to advance
216 @param b - (vlib_buffer_t *) pointer to the buffer
217 @param l - (word) size to check
218 @return - 0 if there is less space than 'l' in buffer
221 vlib_buffer_has_space (vlib_buffer_t * b, word l)
223 return b->current_length >= l;
226 /** \brief Reset current header & length to state they were in when
229 @param b - (vlib_buffer_t *) pointer to the buffer
233 vlib_buffer_reset (vlib_buffer_t * b)
235 b->current_length += clib_max (b->current_data, 0);
239 /** \brief Get pointer to buffer's opaque data array
241 @param b - (vlib_buffer_t *) pointer to the buffer
242 @return - (void *) b->opaque
245 vlib_get_buffer_opaque (vlib_buffer_t * b)
247 return (void *) b->opaque;
250 /** \brief Get pointer to buffer's opaque2 data array
252 @param b - (vlib_buffer_t *) pointer to the buffer
253 @return - (void *) b->opaque2
256 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
258 return (void *) b->opaque2;
261 /** \brief Get pointer to the end of buffer's data
262 * @param b pointer to the buffer
263 * @return pointer to tail of packet's data
266 vlib_buffer_get_tail (vlib_buffer_t * b)
268 return b->data + b->current_data + b->current_length;
271 /** \brief Append uninitialized data to buffer
272 * @param b pointer to the buffer
273 * @param size number of uninitialized bytes
274 * @return pointer to beginning of uninitialized data
277 vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
279 void *p = vlib_buffer_get_tail (b);
280 /* XXX make sure there's enough space */
281 b->current_length += size;
285 /** \brief Prepend uninitialized data to buffer
286 * @param b pointer to the buffer
287 * @param size number of uninitialized bytes
288 * @return pointer to beginning of uninitialized data
291 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
293 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
294 b->current_data -= size;
295 b->current_length += size;
297 return vlib_buffer_get_current (b);
300 /** \brief Make head room, typically for packet headers
301 * @param b pointer to the buffer
302 * @param size number of head room bytes
303 * @return pointer to start of buffer (current data)
306 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
308 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
309 b->current_data += size;
310 return vlib_buffer_get_current (b);
313 /** \brief Retrieve bytes from buffer head
314 * @param b pointer to the buffer
315 * @param size number of bytes to pull
316 * @return pointer to start of buffer (current data)
319 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
321 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
324 void *data = vlib_buffer_get_current (b);
325 vlib_buffer_advance (b, size);
329 /* Forward declaration. */
332 typedef struct vlib_buffer_free_list_t
334 /* Template buffer used to initialize first 16 bytes of buffers
335 allocated on this free list. */
336 vlib_buffer_t buffer_init_template;
338 /* Our index into vlib_main_t's buffer_free_list_pool. */
341 /* Number of data bytes for buffers in this free list. */
344 /* Number of buffers to allocate when we need to allocate new buffers
345 from physmem heap. */
346 u32 min_n_buffers_each_physmem_alloc;
348 /* Total number of buffers allocated from this free list. */
351 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
354 /* global vector of free buffers, used only on main thread.
355 Bufers are returned to global buffers only in case when number of
356 buffers on free buffers list grows about threshold */
358 clib_spinlock_t global_buffers_lock;
360 /* Memory chunks allocated for this free list
361 recorded here so they can be freed when free list
363 void **buffer_memory_allocated;
365 /* Free list name. */
368 /* Callback functions to initialize newly allocated buffers.
369 If null buffers are zeroed. */
370 void (*buffer_init_function) (struct vlib_main_t * vm,
371 struct vlib_buffer_free_list_t * fl,
372 u32 * buffers, u32 n_buffers);
374 /* Callback function to announce that buffers have been
375 added to the freelist */
376 void (*buffers_added_to_freelist_function)
377 (struct vlib_main_t * vm, struct vlib_buffer_free_list_t * fl);
379 uword buffer_init_function_opaque;
380 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
384 u32 (*vlib_buffer_alloc_cb) (struct vlib_main_t * vm, u32 * buffers,
386 u32 (*vlib_buffer_alloc_from_free_list_cb) (struct vlib_main_t * vm,
387 u32 * buffers, u32 n_buffers,
388 u32 free_list_index);
389 void (*vlib_buffer_free_cb) (struct vlib_main_t * vm, u32 * buffers,
391 void (*vlib_buffer_free_no_next_cb) (struct vlib_main_t * vm, u32 * buffers,
393 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
395 uword n_packet_data_bytes,
397 min_n_buffers_each_physmem_alloc,
399 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
400 u32 free_list_index);
401 } vlib_buffer_callbacks_t;
403 extern vlib_buffer_callbacks_t *vlib_buffer_callbacks;
407 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
408 /* Virtual memory address and size of buffer memory, used for calculating
410 uword buffer_mem_start;
411 uword buffer_mem_size;
412 vlib_physmem_region_index_t physmem_region;
414 /* Buffer free callback, for subversive activities */
415 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
417 u32 n_buffers, u32 follow_buffer_next);
418 /* Pool of buffer free lists.
419 Multiple free lists exist for packet generator which uses
420 separate free lists for each packet stream --- so as to avoid
421 initializing static data for each packet generated. */
422 vlib_buffer_free_list_t *buffer_free_list_pool;
423 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
424 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
426 /* Hash table mapping buffer size (rounded to next unit of
427 sizeof (vlib_buffer_t)) to free list index. */
428 uword *free_list_by_size;
430 /* Hash table mapping buffer index into number
431 0 => allocated but free, 1 => allocated and not-free.
432 If buffer index is not in hash table then this buffer
433 has never been allocated. */
434 uword *buffer_known_hash;
435 clib_spinlock_t buffer_known_hash_lockp;
437 /* List of free-lists needing Blue Light Special announcements */
438 vlib_buffer_free_list_t **announce_list;
441 vlib_buffer_callbacks_t cb;
442 int callbacks_registered;
443 } vlib_buffer_main_t;
445 void vlib_buffer_add_mem_range (struct vlib_main_t *vm, uword start,
447 clib_error_t *vlib_buffer_main_init (struct vlib_main_t *vm);
451 struct vlib_main_t *vlib_main;
453 u32 first_buffer, last_buffer;
459 /* Total accumulated bytes in chain starting with first_buffer. */
460 u32 n_total_data_bytes;
462 /* Max number of bytes to accumulate in chain starting with first_buffer.
463 As this limit is reached buffers are enqueued to next node. */
464 u32 max_n_data_bytes_per_chain;
466 /* Next node to enqueue buffers to relative to current process node. */
469 /* Free list to use to allocate new buffers. */
475 /* CLIB fifo of buffer indices waiting to be unserialized. */
478 /* Event type used to signal that RX buffers have been added to fifo. */
479 uword ready_one_time_event;
482 } vlib_serialize_buffer_main_t;
484 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
485 vlib_serialize_buffer_main_t * sm);
486 void unserialize_open_vlib_buffer (serialize_main_t * m,
487 struct vlib_main_t *vm,
488 vlib_serialize_buffer_main_t * sm);
490 u32 serialize_close_vlib_buffer (serialize_main_t * m);
491 void unserialize_close_vlib_buffer (serialize_main_t * m);
492 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
495 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
497 serialize_stream_t *s = &m->stream;
498 vlib_serialize_buffer_main_t *sm
499 = uword_to_pointer (m->stream.data_function_opaque,
500 vlib_serialize_buffer_main_t *);
501 return sm->tx.n_total_data_bytes + s->current_buffer_index +
502 vec_len (s->overflow_buffer);
508 /** \brief Compile time buffer trajectory tracing option
509 Turn this on if you run into "bad monkey" contexts,
510 and you want to know exactly which nodes they've visited...
513 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
515 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
516 extern void (*vlib_buffer_trace_trajectory_cb) (vlib_buffer_t * b, u32 index);
517 extern void (*vlib_buffer_trace_trajectory_init_cb) (vlib_buffer_t * b);
518 extern void vlib_buffer_trace_trajectory_init (vlib_buffer_t * b);
519 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) \
520 vlib_buffer_trace_trajectory_init (b);
522 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
523 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
525 #endif /* included_vlib_buffer_h */
527 #define VLIB_BUFFER_REGISTER_CALLBACKS(x,...) \
528 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks; \
529 static void __vlib_add_buffer_callbacks_t_##x (void) \
530 __attribute__((__constructor__)) ; \
531 static void __vlib_add_buffer_callbacks_t_##x (void) \
533 if (vlib_buffer_callbacks) \
534 clib_panic ("vlib buffer callbacks already registered"); \
535 vlib_buffer_callbacks = &__##x##_buffer_callbacks; \
537 __VA_ARGS__ vlib_buffer_callbacks_t __##x##_buffer_callbacks
540 * fd.io coding-style-patch-verification: ON
543 * eval: (c-set-style "gnu")