FD.io VPP  v17.01-9-ge7dcee4
Vector Packet Processing
buffer.h
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1 /*
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:
6  *
7  * http://www.apache.org/licenses/LICENSE-2.0
8  *
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.
14  */
15 /*
16  * buffer.h: VLIB buffers
17  *
18  * Copyright (c) 2008 Eliot Dresselhaus
19  *
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:
27  *
28  * The above copyright notice and this permission notice shall be
29  * included in all copies or substantial portions of the Software.
30  *
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.
38  */
39 
40 #ifndef included_vlib_buffer_h
41 #define included_vlib_buffer_h
42 
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 */
48 
49 #if DPDK > 0
50 #include <rte_config.h>
51 #define VLIB_BUFFER_DATA_SIZE (2048)
52 #define VLIB_BUFFER_PRE_DATA_SIZE RTE_PKTMBUF_HEADROOM
53 #else
54 #include <vlib/config.h> /* for __PRE_DATA_SIZE */
55 #define VLIB_BUFFER_DATA_SIZE (512)
56 #define VLIB_BUFFER_PRE_DATA_SIZE __PRE_DATA_SIZE
57 #endif
58 
59 #if defined (CLIB_HAVE_VEC128) || defined (__aarch64__)
60 typedef u8x16 vlib_copy_unit_t;
61 #else
63 #endif
64 
65 /** \file
66  vlib buffer structure definition and a few select
67  access methods. This structure and the buffer allocation
68  mechanism should perhaps live in vnet, but it would take a lot
69  of typing to make it so.
70 */
71 
72 /* VLIB buffer representation. */
73 typedef struct
74 {
75  CLIB_CACHE_LINE_ALIGN_MARK (cacheline0);
76  /* Offset within data[] that we are currently processing.
77  If negative current header points into predata area. */
78  i16 current_data; /**< signed offset in data[], pre_data[]
79  that we are currently processing.
80  If negative current header points into predata area.
81  */
82  u16 current_length; /**< Nbytes between current data and
83  the end of this buffer.
84  */
85  u32 flags; /**< buffer flags:
86  <br> VLIB_BUFFER_IS_TRACED: trace this buffer.
87  <br> VLIB_BUFFER_NEXT_PRESENT: this is a multi-chunk buffer.
88  <br> VLIB_BUFFER_TOTAL_LENGTH_VALID: as it says
89  <br> VLIB_BUFFER_REPL_FAIL: packet replication failure
90  <br> VLIB_BUFFER_RECYCLE: as it says
91  <br> VLIB_BUFFER_FLOW_REPORT: buffer is a flow report,
92  set to avoid adding it to a flow report
93  <br> VLIB_BUFFER_FLAG_USER(n): user-defined bit N
94  */
95 #define VLIB_BUFFER_IS_TRACED (1 << 0)
96 #define VLIB_BUFFER_LOG2_NEXT_PRESENT (1)
97 #define VLIB_BUFFER_NEXT_PRESENT (1 << VLIB_BUFFER_LOG2_NEXT_PRESENT)
98 #define VLIB_BUFFER_IS_RECYCLED (1 << 2)
99 #define VLIB_BUFFER_TOTAL_LENGTH_VALID (1 << 3)
100 #define VLIB_BUFFER_REPL_FAIL (1 << 4)
101 #define VLIB_BUFFER_RECYCLE (1 << 5)
102 #define VLIB_BUFFER_FLOW_REPORT (1 << 6)
103 
104  /* User defined buffer flags. */
105 #define LOG2_VLIB_BUFFER_FLAG_USER(n) (32 - (n))
106 #define VLIB_BUFFER_FLAG_USER(n) (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
107 
108  u32 free_list_index; /**< Buffer free list that this buffer was
109  allocated from and will be freed to.
110  */
111 
113  /**< Only valid for first buffer in chain. Current length plus
114  total length given here give total number of bytes in buffer chain.
115  */
116 
117  u32 next_buffer; /**< Next buffer for this linked-list of buffers.
118  Only valid if VLIB_BUFFER_NEXT_PRESENT flag is set.
119  */
120 
121  vlib_error_t error; /**< Error code for buffers to be enqueued
122  to error handler.
123  */
124  u32 current_config_index; /**< Used by feature subgraph arcs to
125  visit enabled feature nodes
126  */
127 
128  u8 feature_arc_index; /**< Used to identify feature arcs by intermediate
129  feature node
130  */
131 
132  u8 dont_waste_me[3]; /**< Available space in the (precious)
133  first 32 octets of buffer metadata
134  Before allocating any of it, discussion required!
135  */
136 
137  u32 opaque[8]; /**< Opaque data used by sub-graphs for their own purposes.
138  See .../vnet/vnet/buffer.h
139  */
140  CLIB_CACHE_LINE_ALIGN_MARK (cacheline1);
141 
142  u32 trace_index; /**< Specifies index into trace buffer
143  if VLIB_PACKET_IS_TRACED flag is set.
144  */
145  u32 recycle_count; /**< Used by L2 path recycle code */
146  u32 opaque2[14]; /**< More opaque data, currently unused */
147 
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
151  before buffer start.
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.
156  */
157 
158  u8 data[0]; /**< Packet data. Hardware DMA here */
159 } vlib_buffer_t; /* Must be a multiple of 64B. */
160 
161 #define VLIB_BUFFER_HDR_SIZE (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
162 
163 /** \brief Prefetch buffer metadata.
164  The first 64 bytes of buffer contains most header information
165 
166  @param b - (vlib_buffer_t *) pointer to the buffer
167  @param type - LOAD, STORE. In most cases, STORE is the right answer
168 */
169 
170 #define vlib_prefetch_buffer_header(b,type) CLIB_PREFETCH (b, 64, type)
171 
174 {
175  return (void *) (b + 1) + buffer_bytes;
176 }
177 
178 always_inline void
180 {
181  ASSERT (sizeof (b[0]) % 64 == 0);
182 
183  /* Rewrite data must be before and contiguous with packet data. */
185 }
186 
187 /** \brief Get pointer to current data to process
188 
189  @param b - (vlib_buffer_t *) pointer to the buffer
190  @return - (void *) (b->data + b->current_data)
191 */
192 
193 always_inline void *
195 {
196  /* Check bounds. */
197  ASSERT ((signed) b->current_data >= (signed) -VLIB_BUFFER_PRE_DATA_SIZE);
198  return b->data + b->current_data;
199 }
200 
201 /** \brief Advance current data pointer by the supplied (signed!) amount
202 
203  @param b - (vlib_buffer_t *) pointer to the buffer
204  @param l - (word) signed increment
205 */
206 always_inline void
208 {
209  ASSERT (b->current_length >= l);
210  b->current_data += l;
211  b->current_length -= l;
212 }
213 
214 /** \brief Reset current header & length to state they were in when
215  packet was received.
216 
217  @param b - (vlib_buffer_t *) pointer to the buffer
218 */
219 
220 always_inline void
222 {
223  b->current_length += clib_max (b->current_data, 0);
224  b->current_data = 0;
225 }
226 
227 /** \brief Get pointer to buffer's opaque data array
228 
229  @param b - (vlib_buffer_t *) pointer to the buffer
230  @return - (void *) b->opaque
231 */
232 always_inline void *
234 {
235  return (void *) b->opaque;
236 }
237 
238 /** \brief Get pointer to buffer's opaque2 data array
239 
240  @param b - (vlib_buffer_t *) pointer to the buffer
241  @return - (void *) b->opaque2
242 */
243 always_inline void *
245 {
246  return (void *) b->opaque2;
247 }
248 
249 /* Forward declaration. */
250 struct vlib_main_t;
251 
253 {
254  /* Template buffer used to initialize first 16 bytes of buffers
255  allocated on this free list. */
257 
258  /* Our index into vlib_main_t's buffer_free_list_pool. */
260 
261  /* Number of data bytes for buffers in this free list. */
263 
264  /* Number of buffers to allocate when we need to allocate new buffers
265  from physmem heap. */
267 
268  /* Total number of buffers allocated from this free list. */
270 
271  /* Vector of free buffers. Each element is a byte offset into I/O heap.
272  Aligned vectors always has naturally aligned vlib_copy_unit_t sized chunks
273  of buffer indices. Unaligned vector has any left over. This is meant to
274  speed up copy routines. */
276 
277  /* Memory chunks allocated for this free list
278  recorded here so they can be freed when free list
279  is deleted. */
281 
282  /* Free list name. */
284 
285  /* Callback functions to initialize newly allocated buffers.
286  If null buffers are zeroed. */
287  void (*buffer_init_function) (struct vlib_main_t * vm,
288  struct vlib_buffer_free_list_t * fl,
289  u32 * buffers, u32 n_buffers);
290 
291  /* Callback function to announce that buffers have been
292  added to the freelist */
294  (struct vlib_main_t * vm, struct vlib_buffer_free_list_t * fl);
295 
297 } __attribute__ ((aligned (16))) vlib_buffer_free_list_t;
298 
299 typedef struct
300 {
301  /* Buffer free callback, for subversive activities */
302  u32 (*buffer_free_callback) (struct vlib_main_t * vm,
303  u32 * buffers,
304  u32 n_buffers, u32 follow_buffer_next);
305  /* Pool of buffer free lists.
306  Multiple free lists exist for packet generator which uses
307  separate free lists for each packet stream --- so as to avoid
308  initializing static data for each packet generated. */
310 #define VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX (0)
311 #define VLIB_BUFFER_DEFAULT_FREE_LIST_BYTES VLIB_BUFFER_DATA_SIZE
312 
313  /* Hash table mapping buffer size (rounded to next unit of
314  sizeof (vlib_buffer_t)) to free list index. */
316 
317  /* Hash table mapping buffer index into number
318  0 => allocated but free, 1 => allocated and not-free.
319  If buffer index is not in hash table then this buffer
320  has never been allocated. */
322 
323  /* List of free-lists needing Blue Light Special announcements */
325 
326  /* Vector of rte_mempools per socket */
327 #if DPDK == 1
328  struct rte_mempool **pktmbuf_pools;
329 #endif
331 
332 typedef struct
333 {
335 
336  u32 first_buffer, last_buffer;
337 
338  union
339  {
340  struct
341  {
342  /* Total accumulated bytes in chain starting with first_buffer. */
344 
345  /* Max number of bytes to accumulate in chain starting with first_buffer.
346  As this limit is reached buffers are enqueued to next node. */
348 
349  /* Next node to enqueue buffers to relative to current process node. */
351 
352  /* Free list to use to allocate new buffers. */
354  } tx;
355 
356  struct
357  {
358  /* CLIB fifo of buffer indices waiting to be unserialized. */
360 
361  /* Event type used to signal that RX buffers have been added to fifo. */
363  } rx;
364  };
366 
370  struct vlib_main_t *vm,
372 
375 void *vlib_set_buffer_free_callback (struct vlib_main_t *vm, void *fp);
376 
379 {
380  serialize_stream_t *s = &m->stream;
384  return sm->tx.n_total_data_bytes + s->current_buffer_index +
386 }
387 
388 #if DPDK > 0
389 #define rte_mbuf_from_vlib_buffer(x) (((struct rte_mbuf *)x) - 1)
390 #define vlib_buffer_from_rte_mbuf(x) ((vlib_buffer_t *)(x+1))
391 #endif
392 
393 /*
394  */
395 
396 /** \brief Compile time buffer trajectory tracing option
397  Turn this on if you run into "bad monkey" contexts,
398  and you want to know exactly which nodes they've visited...
399  See vlib/main.c...
400 */
401 #define VLIB_BUFFER_TRACE_TRAJECTORY 0
402 
403 #if VLIB_BUFFER_TRACE_TRAJECTORY > 0
404 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b) (b)->pre_data[0]=0
405 #else
406 #define VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
407 #endif /* VLIB_BUFFER_TRACE_TRAJECTORY */
408 
409 #endif /* included_vlib_buffer_h */
410 
411 /*
412  * fd.io coding-style-patch-verification: ON
413  *
414  * Local Variables:
415  * eval: (c-set-style "gnu")
416  * End:
417  */
#define CLIB_CACHE_LINE_ALIGN_MARK(mark)
Definition: cache.h:68
u32 current_config_index
Used by feature subgraph arcs to visit enabled feature nodes.
Definition: buffer.h:124
u32 free_list_index
Buffer free list that this buffer was allocated from and will be freed to.
Definition: buffer.h:108
static void vlib_buffer_struct_is_sane(vlib_buffer_t *b)
Definition: buffer.h:179
vlib_buffer_t buffer_init_template
Definition: buffer.h:256
struct vlib_serialize_buffer_main_t::@22::@24 tx
struct vlib_main_t * vlib_main
Definition: buffer.h:334
u32 serialize_close_vlib_buffer(serialize_main_t *m)
void ** buffer_memory_allocated
Definition: buffer.h:280
u32 recycle_count
Used by L2 path recycle code.
Definition: buffer.h:145
u32 min_n_buffers_each_physmem_alloc
Definition: buffer.h:266
void * vlib_set_buffer_free_callback(struct vlib_main_t *vm, void *fp)
static u32 serialize_vlib_buffer_n_bytes(serialize_main_t *m)
Definition: buffer.h:378
i16 current_data
signed offset in data[], pre_data[] that we are currently processing.
Definition: buffer.h:78
void(* buffer_init_function)(struct vlib_main_t *vm, struct vlib_buffer_free_list_t *fl, u32 *buffers, u32 n_buffers)
Definition: buffer.h:287
void unserialize_close_vlib_buffer(serialize_main_t *m)
#define always_inline
Definition: clib.h:84
static void * vlib_buffer_get_current(vlib_buffer_t *b)
Get pointer to current data to process.
Definition: buffer.h:194
u8 feature_arc_index
Used to identify feature arcs by intermediate feature node.
Definition: buffer.h:128
u8 pre_data[VLIB_BUFFER_PRE_DATA_SIZE]
Space for inserting data before buffer start.
Definition: buffer.h:150
unsigned long u64
Definition: types.h:89
vlib_buffer_free_list_t ** announce_list
Definition: buffer.h:324
#define VLIB_BUFFER_PRE_DATA_SIZE
Definition: buffer.h:52
u32 vlib_error_t
Definition: error.h:44
u16 current_length
Nbytes between current data and the end of this buffer.
Definition: buffer.h:82
static void * vlib_get_buffer_opaque(vlib_buffer_t *b)
Get pointer to buffer&#39;s opaque data array.
Definition: buffer.h:233
void serialize_open_vlib_buffer(serialize_main_t *m, struct vlib_main_t *vm, vlib_serialize_buffer_main_t *sm)
static void * vlib_get_buffer_opaque2(vlib_buffer_t *b)
Get pointer to buffer&#39;s opaque2 data array.
Definition: buffer.h:244
static void vlib_buffer_reset(vlib_buffer_t *b)
Reset current header & length to state they were in when packet was received.
Definition: buffer.h:221
vlib_error_t error
Error code for buffers to be enqueued to error handler.
Definition: buffer.h:121
#define uword_to_pointer(u, type)
Definition: types.h:136
struct rte_mempool ** pktmbuf_pools
Definition: buffer.h:328
serialize_stream_t stream
Definition: serialize.h:147
u32 current_buffer_index
Definition: serialize.h:62
static void vlib_buffer_advance(vlib_buffer_t *b, word l)
Advance current data pointer by the supplied (signed!) amount.
Definition: buffer.h:207
void(* buffers_added_to_freelist_function)(struct vlib_main_t *vm, struct vlib_buffer_free_list_t *fl)
Definition: buffer.h:294
uword data_function_opaque
Definition: serialize.h:74
#define ASSERT(truth)
unsigned int u32
Definition: types.h:88
u32 next_buffer
Next buffer for this linked-list of buffers.
Definition: buffer.h:117
u64 vlib_copy_unit_t
Definition: buffer.h:62
void unserialize_open_vlib_buffer(serialize_main_t *m, struct vlib_main_t *vm, vlib_serialize_buffer_main_t *sm)
#define clib_max(x, y)
Definition: clib.h:319
u64 uword
Definition: types.h:112
u32 total_length_not_including_first_buffer
Only valid for first buffer in chain.
Definition: buffer.h:112
unsigned short u16
Definition: types.h:57
i64 word
Definition: types.h:111
static vlib_buffer_t * vlib_buffer_next_contiguous(vlib_buffer_t *b, u32 buffer_bytes)
Definition: buffer.h:173
#define vec_len(v)
Number of elements in vector (rvalue-only, NULL tolerant)
unsigned char u8
Definition: types.h:56
vlib_buffer_free_list_t * buffer_free_list_pool
Definition: buffer.h:309
uword * buffer_known_hash
Definition: buffer.h:321
u32 opaque[8]
Opaque data used by sub-graphs for their own purposes.
Definition: buffer.h:137
short i16
Definition: types.h:46
u8 data[0]
Packet data.
Definition: buffer.h:158
uword buffer_init_function_opaque
Definition: buffer.h:296
u32 flags
buffer flags: VLIB_BUFFER_IS_TRACED: trace this buffer.
Definition: buffer.h:85
u32 trace_index
Specifies index into trace buffer if VLIB_PACKET_IS_TRACED flag is set.
Definition: buffer.h:142
uword * free_list_by_size
Definition: buffer.h:315
u32 opaque2[14]
More opaque data, currently unused.
Definition: buffer.h:146