buffer.h File Reference

vlib buffer structure definition and a few select access methods. More...

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Data Structures
union	vlib_buffer_t
	VLIB buffer representation. More...
struct	vlib_buffer_pool_thread_t
struct	vlib_buffer_pool_t
struct	vlib_buffer_main_t

Macros
#define	VLIB_BUFFER_PRE_DATA_SIZE   __PRE_DATA_SIZE
#define	VLIB_BUFFER_DEFAULT_DATA_SIZE   (2048)
#define	VLIB_BUFFER_MIN_CHAIN_SEG_SIZE   (128)
#define	VLIB_BUFFER_CLONE_HEAD_SIZE   (256)
#define	foreach_vlib_buffer_flag
	Buffer Flags. More...
#define	LOG2_VLIB_BUFFER_FLAG_USER(n)   (32 - (n))
#define	VLIB_BUFFER_FLAG_USER(n)   (1 << LOG2_VLIB_BUFFER_FLAG_USER(n))
#define	VLIB_BUFFER_FLAGS_ALL   (0x0f)
#define	VLIB_BUFFER_HDR_SIZE   (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)
#define	vlib_prefetch_buffer_header(b, type)   CLIB_PREFETCH (b, 64, type)
	Prefetch buffer metadata. More...
#define	vlib_prefetch_buffer_data(b, type)   CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)
#define	VLIB_BUFFER_POOL_PER_THREAD_CACHE_SZ   512
#define	VLIB_BUFFER_MAX_NUMA_NODES   32
#define	VLIB_BUFFER_TRACE_TRAJECTORY   0
	Compile time buffer trajectory tracing option Turn this on if you run into "bad monkey" contexts, and you want to know exactly which nodes they've visited... More...
#define	VLIB_BUFFER_TRACE_TRAJECTORY_INIT(b)
#define	VLIB_BUFFER_SET_EXT_HDR_SIZE(x)

Enumerations
enum	{ foreach_vlib_buffer_flag }
enum	{ foreach_vlib_buffer_flag }

Functions
	STATIC_ASSERT_SIZEOF (vlib_buffer_t, 128+VLIB_BUFFER_PRE_DATA_SIZE)
	STATIC_ASSERT (VLIB_BUFFER_PRE_DATA_SIZE % CLIB_CACHE_LINE_BYTES==0, "VLIB_BUFFER_PRE_DATA_SIZE must be divisible by cache line size")
static void	vlib_buffer_struct_is_sane (vlib_buffer_t *b)
static uword	vlib_buffer_get_va (vlib_buffer_t *b)
static void *	vlib_buffer_get_current (vlib_buffer_t *b)
	Get pointer to current data to process. More...
static uword	vlib_buffer_get_current_va (vlib_buffer_t *b)
static void	vlib_buffer_advance (vlib_buffer_t *b, word l)
	Advance current data pointer by the supplied (signed!) amount. More...
static u8	vlib_buffer_has_space (vlib_buffer_t *b, word l)
	Check if there is enough space in buffer to advance. More...
static void	vlib_buffer_reset (vlib_buffer_t *b)
	Reset current header & length to state they were in when packet was received. More...
static void *	vlib_get_buffer_opaque (vlib_buffer_t *b)
	Get pointer to buffer's opaque data array. More...
static void *	vlib_get_buffer_opaque2 (vlib_buffer_t *b)
	Get pointer to buffer's opaque2 data array. More...
static u8 *	vlib_buffer_get_tail (vlib_buffer_t *b)
	Get pointer to the end of buffer's data. More...
static void *	vlib_buffer_put_uninit (vlib_buffer_t *b, u16 size)
	Append uninitialized data to buffer. More...
static void *	vlib_buffer_push_uninit (vlib_buffer_t *b, u8 size)
	Prepend uninitialized data to buffer. More...
static void *	vlib_buffer_make_headroom (vlib_buffer_t *b, u8 size)
	Make head room, typically for packet headers. More...
static u32	vlib_buffer_make_trace_handle (u32 thread, u32 pool_index)
	Construct a trace handle from thread and pool index. More...
static u32	vlib_buffer_get_trace_thread (vlib_buffer_t *b)
	Extract the thread id from a trace handle. More...
static u32	vlib_buffer_get_trace_index (vlib_buffer_t *b)
	Extract the trace (pool) index from a trace handle. More...
static void *	vlib_buffer_pull (vlib_buffer_t *b, u8 size)
	Retrieve bytes from buffer head. More...
clib_error_t *	vlib_buffer_main_init (struct vlib_main_t *vm)

Detailed Description

vlib buffer structure definition and a few select access methods.

This structure and the buffer allocation mechanism should perhaps live in vnet, but it would take a lot of typing to make it so.

Definition in file buffer.h.

Macro Definition Documentation

foreach_vlib_buffer_flag

foreach_vlib_buffer_flag

Value:

_( 0, IS_TRACED, 0)                                     \
  _( 1, NEXT_PRESENT, "next-present")                   \
  _( 2, TOTAL_LENGTH_VALID, 0)                          \
  _( 3, EXT_HDR_VALID, "ext-hdr-valid")

Buffer Flags.

Definition at line 73 of file buffer.h.

LOG2_VLIB_BUFFER_FLAG_USER

#define LOG2_VLIB_BUFFER_FLAG_USER

(

n

)

(32 - (n))

Definition at line 97 of file buffer.h.

VLIB_BUFFER_CLONE_HEAD_SIZE

#define VLIB_BUFFER_CLONE_HEAD_SIZE   (256)

Definition at line 61 of file buffer.h.

VLIB_BUFFER_DEFAULT_DATA_SIZE

#define VLIB_BUFFER_DEFAULT_DATA_SIZE   (2048)

Definition at line 53 of file buffer.h.

VLIB_BUFFER_FLAG_USER

#define VLIB_BUFFER_FLAG_USER

(

n

)

(1 << LOG2_VLIB_BUFFER_FLAG_USER(n))

Definition at line 98 of file buffer.h.

VLIB_BUFFER_FLAGS_ALL

#define VLIB_BUFFER_FLAGS_ALL   (0x0f)

Definition at line 99 of file buffer.h.

VLIB_BUFFER_HDR_SIZE

#define VLIB_BUFFER_HDR_SIZE   (sizeof(vlib_buffer_t) - VLIB_BUFFER_PRE_DATA_SIZE)

Definition at line 198 of file buffer.h.

VLIB_BUFFER_MAX_NUMA_NODES

#define VLIB_BUFFER_MAX_NUMA_NODES   32

Definition at line 449 of file buffer.h.

VLIB_BUFFER_MIN_CHAIN_SEG_SIZE

#define VLIB_BUFFER_MIN_CHAIN_SEG_SIZE   (128)

Definition at line 58 of file buffer.h.

VLIB_BUFFER_POOL_PER_THREAD_CACHE_SZ

#define VLIB_BUFFER_POOL_PER_THREAD_CACHE_SZ   512

Definition at line 417 of file buffer.h.

VLIB_BUFFER_PRE_DATA_SIZE

#define VLIB_BUFFER_PRE_DATA_SIZE   __PRE_DATA_SIZE

Definition at line 51 of file buffer.h.

VLIB_BUFFER_SET_EXT_HDR_SIZE

#define VLIB_BUFFER_SET_EXT_HDR_SIZE

(

x

)

Value:

static void __clib_constructor \
vnet_buffer_set_ext_hdr_size() \
{ \
  if (__vlib_buffer_external_hdr_size) \
    clib_error ("buffer external header space already set"); \
  __vlib_buffer_external_hdr_size = CLIB_CACHE_LINE_ROUND (x); \
}

Definition at line 501 of file buffer.h.

VLIB_BUFFER_TRACE_TRAJECTORY

#define VLIB_BUFFER_TRACE_TRAJECTORY   0

Compile time buffer trajectory tracing option Turn this on if you run into "bad monkey" contexts, and you want to know exactly which nodes they've visited...

See vlib/main.c...

Definition at line 488 of file buffer.h.

VLIB_BUFFER_TRACE_TRAJECTORY_INIT

#define VLIB_BUFFER_TRACE_TRAJECTORY_INIT

(

b

)

Definition at line 497 of file buffer.h.

vlib_prefetch_buffer_data

#define vlib_prefetch_buffer_data	(		b,
			type
	)		CLIB_PREFETCH (vlib_buffer_get_current(b), CLIB_CACHE_LINE_BYTES, type)

Definition at line 208 of file buffer.h.

vlib_prefetch_buffer_header

#define vlib_prefetch_buffer_header	(		b,
			type
	)		CLIB_PREFETCH (b, 64, type)

Prefetch buffer metadata.

The first 64 bytes of buffer contains most header information

Parameters

b	- (vlib_buffer_t *) pointer to the buffer
type	- LOAD, STORE. In most cases, STORE is the right answer

Definition at line 207 of file buffer.h.

Enumeration Type Documentation

anonymous enum

anonymous enum

Enumerator
foreach_vlib_buffer_flag

Definition at line 82 of file buffer.h.

anonymous enum

anonymous enum

Enumerator
foreach_vlib_buffer_flag

Definition at line 89 of file buffer.h.

Function Documentation

STATIC_ASSERT()

STATIC_ASSERT	(	VLIB_BUFFER_PRE_DATA_SIZE %	CLIB_CACHE_LINE_BYTES = =0,
		"VLIB_BUFFER_PRE_DATA_SIZE must be divisible by cache line size"
	)

STATIC_ASSERT_SIZEOF()

STATIC_ASSERT_SIZEOF	(	vlib_buffer_t	,
		128+	VLIB_BUFFER_PRE_DATA_SIZE
	)

vlib_buffer_advance()

static void vlib_buffer_advance ( vlib_buffer_t *  b, word  l  )

inlinestatic

Advance current data pointer by the supplied (signed!) amount.

Parameters

b	- (vlib_buffer_t *) pointer to the buffer
l	- (word) signed increment

Definition at line 252 of file buffer.h.

vlib_buffer_get_current()

static void* vlib_buffer_get_current ( vlib_buffer_t *  b )

inlinestatic

Get pointer to current data to process.

Parameters

b	- (vlib_buffer_t *) pointer to the buffer

Returns

- (void *) (b->data + b->current_data)

Definition at line 233 of file buffer.h.

vlib_buffer_get_current_va()

static uword vlib_buffer_get_current_va ( vlib_buffer_t *  b )

inlinestatic

Definition at line 241 of file buffer.h.

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vlib_buffer_get_tail()

static u8* vlib_buffer_get_tail ( vlib_buffer_t *  b )

inlinestatic

Get pointer to the end of buffer's data.

Parameters

b	pointer to the buffer

Returns

pointer to tail of packet's data

Definition at line 314 of file buffer.h.

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vlib_buffer_get_trace_index()

static u32 vlib_buffer_get_trace_index ( vlib_buffer_t *  b )

inlinestatic

Extract the trace (pool) index from a trace handle.

Parameters

trace_handle

the trace handle

Returns

the trace index

Definition at line 392 of file buffer.h.

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vlib_buffer_get_trace_thread()

static u32 vlib_buffer_get_trace_thread ( vlib_buffer_t *  b )

inlinestatic

Extract the thread id from a trace handle.

Parameters

trace_handle

the trace handle

Returns

the thread id

Definition at line 380 of file buffer.h.

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vlib_buffer_get_va()

static uword vlib_buffer_get_va ( vlib_buffer_t *  b )

inlinestatic

Definition at line 221 of file buffer.h.

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vlib_buffer_has_space()

static u8 vlib_buffer_has_space ( vlib_buffer_t *  b, word  l  )

inlinestatic

Check if there is enough space in buffer to advance.

Parameters

b	- (vlib_buffer_t *) pointer to the buffer
l	- (word) size to check

Returns

- 0 if there is less space than 'l' in buffer

Definition at line 269 of file buffer.h.

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vlib_buffer_main_init()

clib_error_t* vlib_buffer_main_init

(

struct vlib_main_t *

vm

)

Definition at line 852 of file buffer.c.

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vlib_buffer_make_headroom()

static void* vlib_buffer_make_headroom ( vlib_buffer_t *  b, u8  size  )

inlinestatic

Make head room, typically for packet headers.

Parameters

b	pointer to the buffer
size	number of head room bytes

Returns

pointer to start of buffer (current data)

Definition at line 354 of file buffer.h.

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vlib_buffer_make_trace_handle()

static u32 vlib_buffer_make_trace_handle ( u32  thread, u32  pool_index  )

inlinestatic

Construct a trace handle from thread and pool index.

Parameters

thread	Thread id
pool_index	Pool index

Returns

trace handle

Definition at line 366 of file buffer.h.

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vlib_buffer_pull()

static void* vlib_buffer_pull ( vlib_buffer_t *  b, u8  size  )

inlinestatic

Retrieve bytes from buffer head.

Parameters

b	pointer to the buffer
size	number of bytes to pull

Returns

pointer to start of buffer (current data)

Definition at line 404 of file buffer.h.

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vlib_buffer_push_uninit()

static void* vlib_buffer_push_uninit ( vlib_buffer_t *  b, u8  size  )

inlinestatic

Prepend uninitialized data to buffer.

Parameters

b	pointer to the buffer
size	number of uninitialized bytes

Returns

pointer to beginning of uninitialized data

Definition at line 339 of file buffer.h.

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vlib_buffer_put_uninit()

static void* vlib_buffer_put_uninit ( vlib_buffer_t *  b, u16  size  )

inlinestatic

Append uninitialized data to buffer.

Parameters

b	pointer to the buffer
size	number of uninitialized bytes

Returns

pointer to beginning of uninitialized data

Definition at line 325 of file buffer.h.

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vlib_buffer_reset()

static void vlib_buffer_reset ( vlib_buffer_t *  b )

inlinestatic

Reset current header & length to state they were in when packet was received.

Parameters

b	- (vlib_buffer_t *) pointer to the buffer

Definition at line 281 of file buffer.h.

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vlib_buffer_struct_is_sane()

static void vlib_buffer_struct_is_sane ( vlib_buffer_t *  b )

inlinestatic

Definition at line 212 of file buffer.h.

vlib_get_buffer_opaque()

static void* vlib_get_buffer_opaque ( vlib_buffer_t *  b )

inlinestatic

Get pointer to buffer's opaque data array.

Parameters

b	- (vlib_buffer_t *) pointer to the buffer

Returns

- (void *) b->opaque

Definition at line 293 of file buffer.h.

vlib_get_buffer_opaque2()

static void* vlib_get_buffer_opaque2 ( vlib_buffer_t *  b )

inlinestatic

Get pointer to buffer's opaque2 data array.

Parameters

b	- (vlib_buffer_t *) pointer to the buffer

Returns

- (void *) b->opaque2

Definition at line 304 of file buffer.h.