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 <vlib/error.h> /* for vlib_error_t */
49 #include <vlib/config.h> /* for __PRE_DATA_SIZE */
50 #define VLIB_BUFFER_DATA_SIZE (2048)
51 #define VLIB_BUFFER_PRE_DATA_SIZE __PRE_DATA_SIZE
54 vlib buffer structure definition and a few select
55 access methods. This structure and the buffer allocation
56 mechanism should perhaps live in vnet, but it would take a lot
57 of typing to make it so.
60 /* VLIB buffer representation. */
63 CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
64 STRUCT_MARK (template_start);
65 /* Offset within data[] that we are currently processing.
66 If negative current header points into predata area. */
67 i16 current_data; /**< signed offset in data[], pre_data[]
68 that we are currently processing.
69 If negative current header points into predata area.
71 u16 current_length; /**< Nbytes between current data and
72 the end of this buffer.
74 u32 flags; /**< buffer flags:
75 <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
76 <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
77 <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
78 <br> VLIB_BUFFER_REPL_FAIL: packet replication failure
79 <br> VLIB_BUFFER_RECYCLE: as it says
80 <br> VLIB_BUFFER_FLOW_REPORT: buffer is a flow report,
81 <br> VLIB_BUFFER_EXT_HDR_VALID: buffer contains valid external buffer manager header,
82 set to avoid adding it to a flow report
83 <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
85 #define VLIB_BUFFER_IS_TRACED (1 << 0)
86 #define VLIB_BUFFER_LOG2_NEXT_PRESENT (1)
87 #define VLIB_BUFFER_NEXT_PRESENT (1 << VLIB_BUFFER_LOG2_NEXT_PRESENT)
88 #define VLIB_BUFFER_IS_RECYCLED (1 << 2)
89 #define VLIB_BUFFER_TOTAL_LENGTH_VALID (1 << 3)
90 #define VLIB_BUFFER_REPL_FAIL (1 << 4)
91 #define VLIB_BUFFER_RECYCLE (1 << 5)
92 #define VLIB_BUFFER_FLOW_REPORT (1 << 6)
93 #define VLIB_BUFFER_EXT_HDR_VALID (1 << 7)
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))
99 u32 free_list_index; /**< Buffer free list that this buffer was
100 allocated from and will be freed to.
103 u32 total_length_not_including_first_buffer;
104 /**< Only valid for first buffer in chain. Current length plus
105 total length given here give total number of bytes in buffer chain.
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[8]; /**< 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 */
140 u32 opaque2[14]; /**< More opaque data, currently unused */
142 /***** end of second cache line */
143 CLIB_CACHE_LINE_ALIGN_MARK (cacheline2);
144 u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]; /**< Space for inserting data
146 Packet rewrite string will be
147 rewritten backwards and may extend
148 back before buffer->data[0].
149 Must come directly before packet data.
152 u8 data[0]; /**< Packet data. Hardware DMA here */
153 } vlib_buffer_t; /* Must be a multiple of 64B. */
155 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
157 /** \brief Prefetch buffer metadata.
158 The first 64 bytes of buffer contains most header information
160 @param b - (vlib_buffer_t *) pointer to the buffer
161 @param type - LOAD, STORE. In most cases, STORE is the right answer
164 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
166 always_inline vlib_buffer_t *
167 vlib_buffer_next_contiguous (vlib_buffer_t * b, u32 buffer_bytes)
169 return (void *) (b + 1) + buffer_bytes;
173 vlib_buffer_struct_is_sane (vlib_buffer_t * b)
175 ASSERT (sizeof (b[0]) % 64 == 0);
177 /* Rewrite data must be before and contiguous with packet data. */
178 ASSERT (b->pre_data + VLIB_BUFFER_PRE_DATA_SIZE == b->data);
181 /** \brief Get pointer to current data to process
183 @param b - (vlib_buffer_t *) pointer to the buffer
184 @return - (void *) (b->data + b->current_data)
188 vlib_buffer_get_current (vlib_buffer_t * b)
191 ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
192 return b->data + b->current_data;
195 /** \brief Advance current data pointer by the supplied (signed!) amount
197 @param b - (vlib_buffer_t *) pointer to the buffer
198 @param l - (word) signed increment
201 vlib_buffer_advance (vlib_buffer_t * b, word l)
203 ASSERT (b->current_length >= l);
204 b->current_data += l;
205 b->current_length -= l;
208 /** \brief Check if there is enough space in buffer to advance
210 @param b - (vlib_buffer_t *) pointer to the buffer
211 @param l - (word) size to check
212 @return - 0 if there is less space than 'l' in buffer
215 vlib_buffer_has_space (vlib_buffer_t * b, word l)
217 return b->current_length >= l;
220 /** \brief Reset current header & length to state they were in when
223 @param b - (vlib_buffer_t *) pointer to the buffer
227 vlib_buffer_reset (vlib_buffer_t * b)
229 b->current_length += clib_max (b->current_data, 0);
233 /** \brief Get pointer to buffer's opaque data array
235 @param b - (vlib_buffer_t *) pointer to the buffer
236 @return - (void *) b->opaque
239 vlib_get_buffer_opaque (vlib_buffer_t * b)
241 return (void *) b->opaque;
244 /** \brief Get pointer to buffer's opaque2 data array
246 @param b - (vlib_buffer_t *) pointer to the buffer
247 @return - (void *) b->opaque2
250 vlib_get_buffer_opaque2 (vlib_buffer_t * b)
252 return (void *) b->opaque2;
255 /** \brief Get pointer to the end of buffer's data
256 * @param b pointer to the buffer
257 * @return pointer to tail of packet's data
260 vlib_buffer_get_tail (vlib_buffer_t * b)
262 return b->data + b->current_data + b->current_length;
265 /** \brief Append uninitialized data to buffer
266 * @param b pointer to the buffer
267 * @param size number of uninitialized bytes
268 * @return pointer to beginning of uninitialized data
271 vlib_buffer_put_uninit (vlib_buffer_t * b, u8 size)
273 void *p = vlib_buffer_get_tail (b);
274 /* XXX make sure there's enough space */
275 b->current_length += size;
279 /** \brief Prepend uninitialized data to buffer
280 * @param b pointer to the buffer
281 * @param size number of uninitialized bytes
282 * @return pointer to beginning of uninitialized data
285 vlib_buffer_push_uninit (vlib_buffer_t * b, u8 size)
287 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
288 b->current_data -= size;
289 b->current_length += size;
291 return vlib_buffer_get_current (b);
294 /** \brief Make head room, typically for packet headers
295 * @param b pointer to the buffer
296 * @param size number of head room bytes
297 * @return pointer to start of buffer (current data)
300 vlib_buffer_make_headroom (vlib_buffer_t * b, u8 size)
302 ASSERT (b->current_data + VLIB_BUFFER_PRE_DATA_SIZE >= size);
303 b->current_data += size;
304 return vlib_buffer_get_current (b);
307 /** \brief Retrieve bytes from buffer head
308 * @param b pointer to the buffer
309 * @param size number of bytes to pull
310 * @return pointer to start of buffer (current data)
313 vlib_buffer_pull (vlib_buffer_t * b, u8 size)
315 if (b->current_length + VLIB_BUFFER_PRE_DATA_SIZE < size)
318 void *data = vlib_buffer_get_current (b);
319 vlib_buffer_advance (b, size);
323 /* Forward declaration. */
326 typedef struct vlib_buffer_free_list_t
328 /* Template buffer used to initialize first 16 bytes of buffers
329 allocated on this free list. */
330 vlib_buffer_t buffer_init_template;
332 /* Our index into vlib_main_t's buffer_free_list_pool. */
335 /* Number of data bytes for buffers in this free list. */
338 /* Number of buffers to allocate when we need to allocate new buffers
339 from physmem heap. */
340 u32 min_n_buffers_each_physmem_alloc;
342 /* Total number of buffers allocated from this free list. */
345 /* Vector of free buffers. Each element is a byte offset into I/O heap. */
348 /* Memory chunks allocated for this free list
349 recorded here so they can be freed when free list
351 void **buffer_memory_allocated;
353 /* Free list name. */
356 /* Callback functions to initialize newly allocated buffers.
357 If null buffers are zeroed. */
358 void (*buffer_init_function) (struct vlib_main_t * vm,
359 struct vlib_buffer_free_list_t * fl,
360 u32 * buffers, u32 n_buffers);
362 /* Callback function to announce that buffers have been
363 added to the freelist */
364 void (*buffers_added_to_freelist_function)
365 (struct vlib_main_t * vm, struct vlib_buffer_free_list_t * fl);
367 uword buffer_init_function_opaque;
368 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
372 u32 (*vlib_buffer_alloc_cb) (struct vlib_main_t * vm, u32 * buffers,
374 u32 (*vlib_buffer_alloc_from_free_list_cb) (struct vlib_main_t * vm,
375 u32 * buffers, u32 n_buffers,
376 u32 free_list_index);
377 void (*vlib_buffer_free_cb) (struct vlib_main_t * vm, u32 * buffers,
379 void (*vlib_buffer_free_no_next_cb) (struct vlib_main_t * vm, u32 * buffers,
381 void (*vlib_packet_template_init_cb) (struct vlib_main_t * vm, void *t,
383 uword n_packet_data_bytes,
385 min_n_buffers_each_physmem_alloc,
387 void (*vlib_buffer_delete_free_list_cb) (struct vlib_main_t * vm,
388 u32 free_list_index);
389 } vlib_buffer_callbacks_t;
393 /* Buffer free callback, for subversive activities */
394 u32 (*buffer_free_callback) (struct vlib_main_t * vm,
396 u32 n_buffers, u32 follow_buffer_next);
397 /* Pool of buffer free lists.
398 Multiple free lists exist for packet generator which uses
399 separate free lists for each packet stream --- so as to avoid
400 initializing static data for each packet generated. */
401 vlib_buffer_free_list_t *buffer_free_list_pool;
402 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
403 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
405 /* Hash table mapping buffer size (rounded to next unit of
406 sizeof (vlib_buffer_t)) to free list index. */
407 uword *free_list_by_size;
409 /* Hash table mapping buffer index into number
410 0 => allocated but free, 1 => allocated and not-free.
411 If buffer index is not in hash table then this buffer
412 has never been allocated. */
413 uword *buffer_known_hash;
415 /* List of free-lists needing Blue Light Special announcements */
416 vlib_buffer_free_list_t **announce_list;
419 vlib_buffer_callbacks_t cb;
420 int extern_buffer_mgmt;
421 } vlib_buffer_main_t;
423 void vlib_buffer_cb_init (struct vlib_main_t *vm);
424 int vlib_buffer_cb_register (struct vlib_main_t *vm,
425 vlib_buffer_callbacks_t * cb);
429 struct vlib_main_t *vlib_main;
431 u32 first_buffer, last_buffer;
437 /* Total accumulated bytes in chain starting with first_buffer. */
438 u32 n_total_data_bytes;
440 /* Max number of bytes to accumulate in chain starting with first_buffer.
441 As this limit is reached buffers are enqueued to next node. */
442 u32 max_n_data_bytes_per_chain;
444 /* Next node to enqueue buffers to relative to current process node. */
447 /* Free list to use to allocate new buffers. */
453 /* CLIB fifo of buffer indices waiting to be unserialized. */
456 /* Event type used to signal that RX buffers have been added to fifo. */
457 uword ready_one_time_event;
460 } vlib_serialize_buffer_main_t;
462 void serialize_open_vlib_buffer (serialize_main_t * m, struct vlib_main_t *vm,
463 vlib_serialize_buffer_main_t * sm);
464 void unserialize_open_vlib_buffer (serialize_main_t * m,
465 struct vlib_main_t *vm,
466 vlib_serialize_buffer_main_t * sm);
468 u32 serialize_close_vlib_buffer (serialize_main_t * m);
469 void unserialize_close_vlib_buffer (serialize_main_t * m);
470 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
473 serialize_vlib_buffer_n_bytes (serialize_main_t * m)
475 serialize_stream_t *s = &m->stream;
476 vlib_serialize_buffer_main_t *sm
477 = uword_to_pointer (m->stream.data_function_opaque,
478 vlib_serialize_buffer_main_t *);
479 return sm->tx.n_total_data_bytes + s->current_buffer_index +
480 vec_len (s->overflow_buffer);
486 /** \brief Compile time buffer trajectory tracing option
487 Turn this on if you run into "bad monkey" contexts,
488 and you want to know exactly which nodes they've visited...
491 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
493 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
494 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) (b)->pre_data[0]=0
496 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
497 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
499 #endif /* included_vlib_buffer_h */
502 * fd.io coding-style-patch-verification: ON
505 * eval: (c-set-style "gnu")