Zephyr API Documentation 3.7.99
A Scalable Open Source RTOS
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Network buffer library . More...
Data Structures | |
struct | net_buf_simple |
Simple network buffer representation. More... | |
struct | net_buf_simple_state |
Parsing state of a buffer. More... | |
struct | net_buf |
Network buffer representation. More... | |
struct | net_buf_pool |
Network buffer pool representation. More... | |
Macros | |
#define | NET_BUF_SIMPLE_DEFINE(_name, _size) |
Define a net_buf_simple stack variable. | |
#define | NET_BUF_SIMPLE_DEFINE_STATIC(_name, _size) |
Define a static net_buf_simple variable. | |
#define | NET_BUF_SIMPLE(_size) |
Define a net_buf_simple stack variable and get a pointer to it. | |
#define | NET_BUF_EXTERNAL_DATA BIT(0) |
Flag indicating that the buffer's associated data pointer, points to externally allocated memory. | |
#define | NET_BUF_POOL_HEAP_DEFINE(_name, _count, _ud_size, _destroy) |
Define a new pool for buffers using the heap for the data. | |
#define | NET_BUF_POOL_FIXED_DEFINE(_name, _count, _data_size, _ud_size, _destroy) |
Define a new pool for buffers based on fixed-size data. | |
#define | NET_BUF_POOL_VAR_DEFINE(_name, _count, _data_size, _ud_size, _destroy) |
Define a new pool for buffers with variable size payloads. | |
#define | NET_BUF_POOL_DEFINE(_name, _count, _size, _ud_size, _destroy) |
Define a new pool for buffers. | |
Typedefs | |
typedef struct net_buf *(* | net_buf_allocator_cb) (k_timeout_t timeout, void *user_data) |
Network buffer allocator callback. | |
Functions | |
static void | net_buf_simple_init (struct net_buf_simple *buf, size_t reserve_head) |
Initialize a net_buf_simple object. | |
void | net_buf_simple_init_with_data (struct net_buf_simple *buf, void *data, size_t size) |
Initialize a net_buf_simple object with data. | |
static void | net_buf_simple_reset (struct net_buf_simple *buf) |
Reset buffer. | |
void | net_buf_simple_clone (const struct net_buf_simple *original, struct net_buf_simple *clone) |
Clone buffer state, using the same data buffer. | |
void * | net_buf_simple_add (struct net_buf_simple *buf, size_t len) |
Prepare data to be added at the end of the buffer. | |
void * | net_buf_simple_add_mem (struct net_buf_simple *buf, const void *mem, size_t len) |
Copy given number of bytes from memory to the end of the buffer. | |
uint8_t * | net_buf_simple_add_u8 (struct net_buf_simple *buf, uint8_t val) |
Add (8-bit) byte at the end of the buffer. | |
void | net_buf_simple_add_le16 (struct net_buf_simple *buf, uint16_t val) |
Add 16-bit value at the end of the buffer. | |
void | net_buf_simple_add_be16 (struct net_buf_simple *buf, uint16_t val) |
Add 16-bit value at the end of the buffer. | |
void | net_buf_simple_add_le24 (struct net_buf_simple *buf, uint32_t val) |
Add 24-bit value at the end of the buffer. | |
void | net_buf_simple_add_be24 (struct net_buf_simple *buf, uint32_t val) |
Add 24-bit value at the end of the buffer. | |
void | net_buf_simple_add_le32 (struct net_buf_simple *buf, uint32_t val) |
Add 32-bit value at the end of the buffer. | |
void | net_buf_simple_add_be32 (struct net_buf_simple *buf, uint32_t val) |
Add 32-bit value at the end of the buffer. | |
void | net_buf_simple_add_le40 (struct net_buf_simple *buf, uint64_t val) |
Add 40-bit value at the end of the buffer. | |
void | net_buf_simple_add_be40 (struct net_buf_simple *buf, uint64_t val) |
Add 40-bit value at the end of the buffer. | |
void | net_buf_simple_add_le48 (struct net_buf_simple *buf, uint64_t val) |
Add 48-bit value at the end of the buffer. | |
void | net_buf_simple_add_be48 (struct net_buf_simple *buf, uint64_t val) |
Add 48-bit value at the end of the buffer. | |
void | net_buf_simple_add_le64 (struct net_buf_simple *buf, uint64_t val) |
Add 64-bit value at the end of the buffer. | |
void | net_buf_simple_add_be64 (struct net_buf_simple *buf, uint64_t val) |
Add 64-bit value at the end of the buffer. | |
void * | net_buf_simple_remove_mem (struct net_buf_simple *buf, size_t len) |
Remove data from the end of the buffer. | |
uint8_t | net_buf_simple_remove_u8 (struct net_buf_simple *buf) |
Remove a 8-bit value from the end of the buffer. | |
uint16_t | net_buf_simple_remove_le16 (struct net_buf_simple *buf) |
Remove and convert 16 bits from the end of the buffer. | |
uint16_t | net_buf_simple_remove_be16 (struct net_buf_simple *buf) |
Remove and convert 16 bits from the end of the buffer. | |
uint32_t | net_buf_simple_remove_le24 (struct net_buf_simple *buf) |
Remove and convert 24 bits from the end of the buffer. | |
uint32_t | net_buf_simple_remove_be24 (struct net_buf_simple *buf) |
Remove and convert 24 bits from the end of the buffer. | |
uint32_t | net_buf_simple_remove_le32 (struct net_buf_simple *buf) |
Remove and convert 32 bits from the end of the buffer. | |
uint32_t | net_buf_simple_remove_be32 (struct net_buf_simple *buf) |
Remove and convert 32 bits from the end of the buffer. | |
uint64_t | net_buf_simple_remove_le40 (struct net_buf_simple *buf) |
Remove and convert 40 bits from the end of the buffer. | |
uint64_t | net_buf_simple_remove_be40 (struct net_buf_simple *buf) |
Remove and convert 40 bits from the end of the buffer. | |
uint64_t | net_buf_simple_remove_le48 (struct net_buf_simple *buf) |
Remove and convert 48 bits from the end of the buffer. | |
uint64_t | net_buf_simple_remove_be48 (struct net_buf_simple *buf) |
Remove and convert 48 bits from the end of the buffer. | |
uint64_t | net_buf_simple_remove_le64 (struct net_buf_simple *buf) |
Remove and convert 64 bits from the end of the buffer. | |
uint64_t | net_buf_simple_remove_be64 (struct net_buf_simple *buf) |
Remove and convert 64 bits from the end of the buffer. | |
void * | net_buf_simple_push (struct net_buf_simple *buf, size_t len) |
Prepare data to be added to the start of the buffer. | |
void * | net_buf_simple_push_mem (struct net_buf_simple *buf, const void *mem, size_t len) |
Copy given number of bytes from memory to the start of the buffer. | |
void | net_buf_simple_push_le16 (struct net_buf_simple *buf, uint16_t val) |
Push 16-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_be16 (struct net_buf_simple *buf, uint16_t val) |
Push 16-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_u8 (struct net_buf_simple *buf, uint8_t val) |
Push 8-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_le24 (struct net_buf_simple *buf, uint32_t val) |
Push 24-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_be24 (struct net_buf_simple *buf, uint32_t val) |
Push 24-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_le32 (struct net_buf_simple *buf, uint32_t val) |
Push 32-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_be32 (struct net_buf_simple *buf, uint32_t val) |
Push 32-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_le40 (struct net_buf_simple *buf, uint64_t val) |
Push 40-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_be40 (struct net_buf_simple *buf, uint64_t val) |
Push 40-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_le48 (struct net_buf_simple *buf, uint64_t val) |
Push 48-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_be48 (struct net_buf_simple *buf, uint64_t val) |
Push 48-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_le64 (struct net_buf_simple *buf, uint64_t val) |
Push 64-bit value to the beginning of the buffer. | |
void | net_buf_simple_push_be64 (struct net_buf_simple *buf, uint64_t val) |
Push 64-bit value to the beginning of the buffer. | |
void * | net_buf_simple_pull (struct net_buf_simple *buf, size_t len) |
Remove data from the beginning of the buffer. | |
void * | net_buf_simple_pull_mem (struct net_buf_simple *buf, size_t len) |
Remove data from the beginning of the buffer. | |
uint8_t | net_buf_simple_pull_u8 (struct net_buf_simple *buf) |
Remove a 8-bit value from the beginning of the buffer. | |
uint16_t | net_buf_simple_pull_le16 (struct net_buf_simple *buf) |
Remove and convert 16 bits from the beginning of the buffer. | |
uint16_t | net_buf_simple_pull_be16 (struct net_buf_simple *buf) |
Remove and convert 16 bits from the beginning of the buffer. | |
uint32_t | net_buf_simple_pull_le24 (struct net_buf_simple *buf) |
Remove and convert 24 bits from the beginning of the buffer. | |
uint32_t | net_buf_simple_pull_be24 (struct net_buf_simple *buf) |
Remove and convert 24 bits from the beginning of the buffer. | |
uint32_t | net_buf_simple_pull_le32 (struct net_buf_simple *buf) |
Remove and convert 32 bits from the beginning of the buffer. | |
uint32_t | net_buf_simple_pull_be32 (struct net_buf_simple *buf) |
Remove and convert 32 bits from the beginning of the buffer. | |
uint64_t | net_buf_simple_pull_le40 (struct net_buf_simple *buf) |
Remove and convert 40 bits from the beginning of the buffer. | |
uint64_t | net_buf_simple_pull_be40 (struct net_buf_simple *buf) |
Remove and convert 40 bits from the beginning of the buffer. | |
uint64_t | net_buf_simple_pull_le48 (struct net_buf_simple *buf) |
Remove and convert 48 bits from the beginning of the buffer. | |
uint64_t | net_buf_simple_pull_be48 (struct net_buf_simple *buf) |
Remove and convert 48 bits from the beginning of the buffer. | |
uint64_t | net_buf_simple_pull_le64 (struct net_buf_simple *buf) |
Remove and convert 64 bits from the beginning of the buffer. | |
uint64_t | net_buf_simple_pull_be64 (struct net_buf_simple *buf) |
Remove and convert 64 bits from the beginning of the buffer. | |
static uint8_t * | net_buf_simple_tail (const struct net_buf_simple *buf) |
Get the tail pointer for a buffer. | |
size_t | net_buf_simple_headroom (const struct net_buf_simple *buf) |
Check buffer headroom. | |
size_t | net_buf_simple_tailroom (const struct net_buf_simple *buf) |
Check buffer tailroom. | |
uint16_t | net_buf_simple_max_len (const struct net_buf_simple *buf) |
Check maximum net_buf_simple::len value. | |
static void | net_buf_simple_save (const struct net_buf_simple *buf, struct net_buf_simple_state *state) |
Save the parsing state of a buffer. | |
static void | net_buf_simple_restore (struct net_buf_simple *buf, struct net_buf_simple_state *state) |
Restore the parsing state of a buffer. | |
struct net_buf_pool * | net_buf_pool_get (int id) |
Looks up a pool based on its ID. | |
int | net_buf_id (const struct net_buf *buf) |
Get a zero-based index for a buffer. | |
struct net_buf * | net_buf_alloc_fixed (struct net_buf_pool *pool, k_timeout_t timeout) |
Allocate a new fixed buffer from a pool. | |
static struct net_buf * | net_buf_alloc (struct net_buf_pool *pool, k_timeout_t timeout) |
struct net_buf * | net_buf_alloc_len (struct net_buf_pool *pool, size_t size, k_timeout_t timeout) |
Allocate a new variable length buffer from a pool. | |
struct net_buf * | net_buf_alloc_with_data (struct net_buf_pool *pool, void *data, size_t size, k_timeout_t timeout) |
Allocate a new buffer from a pool but with external data pointer. | |
struct net_buf * | net_buf_get (struct k_fifo *fifo, k_timeout_t timeout) |
Get a buffer from a FIFO. | |
static void | net_buf_destroy (struct net_buf *buf) |
Destroy buffer from custom destroy callback. | |
void | net_buf_reset (struct net_buf *buf) |
Reset buffer. | |
void | net_buf_simple_reserve (struct net_buf_simple *buf, size_t reserve) |
Initialize buffer with the given headroom. | |
void | net_buf_slist_put (sys_slist_t *list, struct net_buf *buf) |
Put a buffer into a list. | |
struct net_buf * | net_buf_slist_get (sys_slist_t *list) |
Get a buffer from a list. | |
void | net_buf_put (struct k_fifo *fifo, struct net_buf *buf) |
Put a buffer to the end of a FIFO. | |
void | net_buf_unref (struct net_buf *buf) |
Decrements the reference count of a buffer. | |
struct net_buf * | net_buf_ref (struct net_buf *buf) |
Increment the reference count of a buffer. | |
struct net_buf * | net_buf_clone (struct net_buf *buf, k_timeout_t timeout) |
Clone buffer. | |
static void * | net_buf_user_data (const struct net_buf *buf) |
Get a pointer to the user data of a buffer. | |
int | net_buf_user_data_copy (struct net_buf *dst, const struct net_buf *src) |
Copy user data from one to another buffer. | |
static void | net_buf_reserve (struct net_buf *buf, size_t reserve) |
Initialize buffer with the given headroom. | |
static void * | net_buf_add (struct net_buf *buf, size_t len) |
Prepare data to be added at the end of the buffer. | |
static void * | net_buf_add_mem (struct net_buf *buf, const void *mem, size_t len) |
Copies the given number of bytes to the end of the buffer. | |
static uint8_t * | net_buf_add_u8 (struct net_buf *buf, uint8_t val) |
Add (8-bit) byte at the end of the buffer. | |
static void | net_buf_add_le16 (struct net_buf *buf, uint16_t val) |
Add 16-bit value at the end of the buffer. | |
static void | net_buf_add_be16 (struct net_buf *buf, uint16_t val) |
Add 16-bit value at the end of the buffer. | |
static void | net_buf_add_le24 (struct net_buf *buf, uint32_t val) |
Add 24-bit value at the end of the buffer. | |
static void | net_buf_add_be24 (struct net_buf *buf, uint32_t val) |
Add 24-bit value at the end of the buffer. | |
static void | net_buf_add_le32 (struct net_buf *buf, uint32_t val) |
Add 32-bit value at the end of the buffer. | |
static void | net_buf_add_be32 (struct net_buf *buf, uint32_t val) |
Add 32-bit value at the end of the buffer. | |
static void | net_buf_add_le40 (struct net_buf *buf, uint64_t val) |
Add 40-bit value at the end of the buffer. | |
static void | net_buf_add_be40 (struct net_buf *buf, uint64_t val) |
Add 40-bit value at the end of the buffer. | |
static void | net_buf_add_le48 (struct net_buf *buf, uint64_t val) |
Add 48-bit value at the end of the buffer. | |
static void | net_buf_add_be48 (struct net_buf *buf, uint64_t val) |
Add 48-bit value at the end of the buffer. | |
static void | net_buf_add_le64 (struct net_buf *buf, uint64_t val) |
Add 64-bit value at the end of the buffer. | |
static void | net_buf_add_be64 (struct net_buf *buf, uint64_t val) |
Add 64-bit value at the end of the buffer. | |
static void * | net_buf_remove_mem (struct net_buf *buf, size_t len) |
Remove data from the end of the buffer. | |
static uint8_t | net_buf_remove_u8 (struct net_buf *buf) |
Remove a 8-bit value from the end of the buffer. | |
static uint16_t | net_buf_remove_le16 (struct net_buf *buf) |
Remove and convert 16 bits from the end of the buffer. | |
static uint16_t | net_buf_remove_be16 (struct net_buf *buf) |
Remove and convert 16 bits from the end of the buffer. | |
static uint32_t | net_buf_remove_be24 (struct net_buf *buf) |
Remove and convert 24 bits from the end of the buffer. | |
static uint32_t | net_buf_remove_le24 (struct net_buf *buf) |
Remove and convert 24 bits from the end of the buffer. | |
static uint32_t | net_buf_remove_le32 (struct net_buf *buf) |
Remove and convert 32 bits from the end of the buffer. | |
static uint32_t | net_buf_remove_be32 (struct net_buf *buf) |
Remove and convert 32 bits from the end of the buffer. | |
static uint64_t | net_buf_remove_le40 (struct net_buf *buf) |
Remove and convert 40 bits from the end of the buffer. | |
static uint64_t | net_buf_remove_be40 (struct net_buf *buf) |
Remove and convert 40 bits from the end of the buffer. | |
static uint64_t | net_buf_remove_le48 (struct net_buf *buf) |
Remove and convert 48 bits from the end of the buffer. | |
static uint64_t | net_buf_remove_be48 (struct net_buf *buf) |
Remove and convert 48 bits from the end of the buffer. | |
static uint64_t | net_buf_remove_le64 (struct net_buf *buf) |
Remove and convert 64 bits from the end of the buffer. | |
static uint64_t | net_buf_remove_be64 (struct net_buf *buf) |
Remove and convert 64 bits from the end of the buffer. | |
static void * | net_buf_push (struct net_buf *buf, size_t len) |
Prepare data to be added at the start of the buffer. | |
static void * | net_buf_push_mem (struct net_buf *buf, const void *mem, size_t len) |
Copies the given number of bytes to the start of the buffer. | |
static void | net_buf_push_u8 (struct net_buf *buf, uint8_t val) |
Push 8-bit value to the beginning of the buffer. | |
static void | net_buf_push_le16 (struct net_buf *buf, uint16_t val) |
Push 16-bit value to the beginning of the buffer. | |
static void | net_buf_push_be16 (struct net_buf *buf, uint16_t val) |
Push 16-bit value to the beginning of the buffer. | |
static void | net_buf_push_le24 (struct net_buf *buf, uint32_t val) |
Push 24-bit value to the beginning of the buffer. | |
static void | net_buf_push_be24 (struct net_buf *buf, uint32_t val) |
Push 24-bit value to the beginning of the buffer. | |
static void | net_buf_push_le32 (struct net_buf *buf, uint32_t val) |
Push 32-bit value to the beginning of the buffer. | |
static void | net_buf_push_be32 (struct net_buf *buf, uint32_t val) |
Push 32-bit value to the beginning of the buffer. | |
static void | net_buf_push_le40 (struct net_buf *buf, uint64_t val) |
Push 40-bit value to the beginning of the buffer. | |
static void | net_buf_push_be40 (struct net_buf *buf, uint64_t val) |
Push 40-bit value to the beginning of the buffer. | |
static void | net_buf_push_le48 (struct net_buf *buf, uint64_t val) |
Push 48-bit value to the beginning of the buffer. | |
static void | net_buf_push_be48 (struct net_buf *buf, uint64_t val) |
Push 48-bit value to the beginning of the buffer. | |
static void | net_buf_push_le64 (struct net_buf *buf, uint64_t val) |
Push 64-bit value to the beginning of the buffer. | |
static void | net_buf_push_be64 (struct net_buf *buf, uint64_t val) |
Push 64-bit value to the beginning of the buffer. | |
static void * | net_buf_pull (struct net_buf *buf, size_t len) |
Remove data from the beginning of the buffer. | |
static void * | net_buf_pull_mem (struct net_buf *buf, size_t len) |
Remove data from the beginning of the buffer. | |
static uint8_t | net_buf_pull_u8 (struct net_buf *buf) |
Remove a 8-bit value from the beginning of the buffer. | |
static uint16_t | net_buf_pull_le16 (struct net_buf *buf) |
Remove and convert 16 bits from the beginning of the buffer. | |
static uint16_t | net_buf_pull_be16 (struct net_buf *buf) |
Remove and convert 16 bits from the beginning of the buffer. | |
static uint32_t | net_buf_pull_le24 (struct net_buf *buf) |
Remove and convert 24 bits from the beginning of the buffer. | |
static uint32_t | net_buf_pull_be24 (struct net_buf *buf) |
Remove and convert 24 bits from the beginning of the buffer. | |
static uint32_t | net_buf_pull_le32 (struct net_buf *buf) |
Remove and convert 32 bits from the beginning of the buffer. | |
static uint32_t | net_buf_pull_be32 (struct net_buf *buf) |
Remove and convert 32 bits from the beginning of the buffer. | |
static uint64_t | net_buf_pull_le40 (struct net_buf *buf) |
Remove and convert 40 bits from the beginning of the buffer. | |
static uint64_t | net_buf_pull_be40 (struct net_buf *buf) |
Remove and convert 40 bits from the beginning of the buffer. | |
static uint64_t | net_buf_pull_le48 (struct net_buf *buf) |
Remove and convert 48 bits from the beginning of the buffer. | |
static uint64_t | net_buf_pull_be48 (struct net_buf *buf) |
Remove and convert 48 bits from the beginning of the buffer. | |
static uint64_t | net_buf_pull_le64 (struct net_buf *buf) |
Remove and convert 64 bits from the beginning of the buffer. | |
static uint64_t | net_buf_pull_be64 (struct net_buf *buf) |
Remove and convert 64 bits from the beginning of the buffer. | |
static size_t | net_buf_tailroom (const struct net_buf *buf) |
Check buffer tailroom. | |
static size_t | net_buf_headroom (const struct net_buf *buf) |
Check buffer headroom. | |
static uint16_t | net_buf_max_len (const struct net_buf *buf) |
Check maximum net_buf::len value. | |
static uint8_t * | net_buf_tail (const struct net_buf *buf) |
Get the tail pointer for a buffer. | |
struct net_buf * | net_buf_frag_last (struct net_buf *frags) |
Find the last fragment in the fragment list. | |
void | net_buf_frag_insert (struct net_buf *parent, struct net_buf *frag) |
Insert a new fragment to a chain of bufs. | |
struct net_buf * | net_buf_frag_add (struct net_buf *head, struct net_buf *frag) |
Add a new fragment to the end of a chain of bufs. | |
struct net_buf * | net_buf_frag_del (struct net_buf *parent, struct net_buf *frag) |
Delete existing fragment from a chain of bufs. | |
size_t | net_buf_linearize (void *dst, size_t dst_len, const struct net_buf *src, size_t offset, size_t len) |
Copy bytes from net_buf chain starting at offset to linear buffer. | |
size_t | net_buf_append_bytes (struct net_buf *buf, size_t len, const void *value, k_timeout_t timeout, net_buf_allocator_cb allocate_cb, void *user_data) |
Append data to a list of net_buf. | |
size_t | net_buf_data_match (const struct net_buf *buf, size_t offset, const void *data, size_t len) |
Match data with a net_buf's content. | |
static struct net_buf * | net_buf_skip (struct net_buf *buf, size_t len) |
Skip N number of bytes in a net_buf. | |
static size_t | net_buf_frags_len (const struct net_buf *buf) |
Calculate amount of bytes stored in fragments. | |
Network buffer library .
#define NET_BUF_EXTERNAL_DATA BIT(0) |
#include <zephyr/net_buf.h>
Flag indicating that the buffer's associated data pointer, points to externally allocated memory.
Therefore once ref goes down to zero, the pointed data will not need to be deallocated. This never needs to be explicitly set or unset by the net_buf API user. Such net_buf is exclusively instantiated via net_buf_alloc_with_data() function. Reference count mechanism however will behave the same way, and ref count going to 0 will free the net_buf but no the data pointer in it.
#define NET_BUF_POOL_DEFINE | ( | _name, | |
_count, | |||
_size, | |||
_ud_size, | |||
_destroy ) |
#include <zephyr/net_buf.h>
Define a new pool for buffers.
Defines a net_buf_pool struct and the necessary memory storage (array of structs) for the needed amount of buffers. After this,the buffers can be accessed from the pool through net_buf_alloc. The pool is defined as a static variable, so if it needs to be exported outside the current module this needs to happen with the help of a separate pointer rather than an extern declaration.
If provided with a custom destroy callback this callback is responsible for eventually calling net_buf_destroy() to complete the process of returning the buffer to the pool.
_name | Name of the pool variable. |
_count | Number of buffers in the pool. |
_size | Maximum data size for each buffer. |
_ud_size | Amount of user data space to reserve. |
_destroy | Optional destroy callback when buffer is freed. |
#define NET_BUF_POOL_FIXED_DEFINE | ( | _name, | |
_count, | |||
_data_size, | |||
_ud_size, | |||
_destroy ) |
#include <zephyr/net_buf.h>
Define a new pool for buffers based on fixed-size data.
Defines a net_buf_pool struct and the necessary memory storage (array of structs) for the needed amount of buffers. After this, the buffers can be accessed from the pool through net_buf_alloc. The pool is defined as a static variable, so if it needs to be exported outside the current module this needs to happen with the help of a separate pointer rather than an extern declaration.
The data payload of the buffers will be allocated from a byte array of fixed sized chunks. This kind of pool does not support blocking on the data allocation, so the timeout passed to net_buf_alloc will be always treated as K_NO_WAIT when trying to allocate the data. This means that allocation failures, i.e. NULL returns, must always be handled cleanly.
If provided with a custom destroy callback, this callback is responsible for eventually calling net_buf_destroy() to complete the process of returning the buffer to the pool.
_name | Name of the pool variable. |
_count | Number of buffers in the pool. |
_data_size | Maximum data payload per buffer. |
_ud_size | User data space to reserve per buffer. |
_destroy | Optional destroy callback when buffer is freed. |
#define NET_BUF_POOL_HEAP_DEFINE | ( | _name, | |
_count, | |||
_ud_size, | |||
_destroy ) |
#include <zephyr/net_buf.h>
Define a new pool for buffers using the heap for the data.
Defines a net_buf_pool struct and the necessary memory storage (array of structs) for the needed amount of buffers. After this, the buffers can be accessed from the pool through net_buf_alloc. The pool is defined as a static variable, so if it needs to be exported outside the current module this needs to happen with the help of a separate pointer rather than an extern declaration.
The data payload of the buffers will be allocated from the heap using k_malloc, so CONFIG_HEAP_MEM_POOL_SIZE must be set to a positive value. This kind of pool does not support blocking on the data allocation, so the timeout passed to net_buf_alloc will be always treated as K_NO_WAIT when trying to allocate the data. This means that allocation failures, i.e. NULL returns, must always be handled cleanly.
If provided with a custom destroy callback, this callback is responsible for eventually calling net_buf_destroy() to complete the process of returning the buffer to the pool.
_name | Name of the pool variable. |
_count | Number of buffers in the pool. |
_ud_size | User data space to reserve per buffer. |
_destroy | Optional destroy callback when buffer is freed. |
#define NET_BUF_POOL_VAR_DEFINE | ( | _name, | |
_count, | |||
_data_size, | |||
_ud_size, | |||
_destroy ) |
#include <zephyr/net_buf.h>
Define a new pool for buffers with variable size payloads.
Defines a net_buf_pool struct and the necessary memory storage (array of structs) for the needed amount of buffers. After this, the buffers can be accessed from the pool through net_buf_alloc. The pool is defined as a static variable, so if it needs to be exported outside the current module this needs to happen with the help of a separate pointer rather than an extern declaration.
The data payload of the buffers will be based on a memory pool from which variable size payloads may be allocated.
If provided with a custom destroy callback, this callback is responsible for eventually calling net_buf_destroy() to complete the process of returning the buffer to the pool.
_name | Name of the pool variable. |
_count | Number of buffers in the pool. |
_data_size | Total amount of memory available for data payloads. |
_ud_size | User data space to reserve per buffer. |
_destroy | Optional destroy callback when buffer is freed. |
#define NET_BUF_SIMPLE | ( | _size | ) |
#include <zephyr/net_buf.h>
Define a net_buf_simple stack variable and get a pointer to it.
This is a helper macro which is used to define a net_buf_simple object on the stack and the get a pointer to it as follows:
struct net_buf_simple *my_buf = NET_BUF_SIMPLE(10);
After creating the object it needs to be initialized by calling net_buf_simple_init().
_size | Maximum data storage for the buffer. |
#define NET_BUF_SIMPLE_DEFINE | ( | _name, | |
_size ) |
#include <zephyr/net_buf.h>
Define a net_buf_simple stack variable.
This is a helper macro which is used to define a net_buf_simple object on the stack.
_name | Name of the net_buf_simple object. |
_size | Maximum data storage for the buffer. |
#define NET_BUF_SIMPLE_DEFINE_STATIC | ( | _name, | |
_size ) |
#include <zephyr/net_buf.h>
Define a static net_buf_simple variable.
This is a helper macro which is used to define a static net_buf_simple object.
_name | Name of the net_buf_simple object. |
_size | Maximum data storage for the buffer. |
typedef struct net_buf *(* net_buf_allocator_cb) (k_timeout_t timeout, void *user_data) |
#include <zephyr/net_buf.h>
Network buffer allocator callback.
The allocator callback is called when net_buf_append_bytes needs to allocate a new net_buf.
timeout | Affects the action taken should the net buf pool be empty. If K_NO_WAIT, then return immediately. If K_FOREVER, then wait as long as necessary. Otherwise, wait until the specified timeout. |
user_data | The user data given in net_buf_append_bytes call. |
#include <zephyr/net_buf.h>
Prepare data to be added at the end of the buffer.
Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
len | Number of bytes to increment the length with. |
#include <zephyr/net_buf.h>
Add 16-bit value at the end of the buffer.
Adds 16-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 16-bit value to be added. |
#include <zephyr/net_buf.h>
Add 24-bit value at the end of the buffer.
Adds 24-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 24-bit value to be added. |
#include <zephyr/net_buf.h>
Add 32-bit value at the end of the buffer.
Adds 32-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 32-bit value to be added. |
#include <zephyr/net_buf.h>
Add 40-bit value at the end of the buffer.
Adds 40-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 40-bit value to be added. |
#include <zephyr/net_buf.h>
Add 48-bit value at the end of the buffer.
Adds 48-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 48-bit value to be added. |
#include <zephyr/net_buf.h>
Add 64-bit value at the end of the buffer.
Adds 64-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 64-bit value to be added. |
#include <zephyr/net_buf.h>
Add 16-bit value at the end of the buffer.
Adds 16-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 16-bit value to be added. |
#include <zephyr/net_buf.h>
Add 24-bit value at the end of the buffer.
Adds 24-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 24-bit value to be added. |
#include <zephyr/net_buf.h>
Add 32-bit value at the end of the buffer.
Adds 32-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 32-bit value to be added. |
#include <zephyr/net_buf.h>
Add 40-bit value at the end of the buffer.
Adds 40-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 40-bit value to be added. |
#include <zephyr/net_buf.h>
Add 48-bit value at the end of the buffer.
Adds 48-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 48-bit value to be added. |
#include <zephyr/net_buf.h>
Add 64-bit value at the end of the buffer.
Adds 64-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 64-bit value to be added. |
#include <zephyr/net_buf.h>
Copies the given number of bytes to the end of the buffer.
Increments the data length of the buffer to account for more data at the end.
buf | Buffer to update. |
mem | Location of data to be added. |
len | Length of data to be added |
#include <zephyr/net_buf.h>
Add (8-bit) byte at the end of the buffer.
Increments the data length of the buffer to account for more data at the end.
buf | Buffer to update. |
val | byte value to be added. |
|
inlinestatic |
#include <zephyr/net_buf.h>
pool | Which pool to allocate the buffer from. |
timeout | Affects the action taken should the pool be empty. If K_NO_WAIT, then return immediately. If K_FOREVER, then wait as long as necessary. Otherwise, wait until the specified timeout. |
struct net_buf * net_buf_alloc_fixed | ( | struct net_buf_pool * | pool, |
k_timeout_t | timeout ) |
#include <zephyr/net_buf.h>
Allocate a new fixed buffer from a pool.
pool | Which pool to allocate the buffer from. |
timeout | Affects the action taken should the pool be empty. If K_NO_WAIT, then return immediately. If K_FOREVER, then wait as long as necessary. Otherwise, wait until the specified timeout. |
struct net_buf * net_buf_alloc_len | ( | struct net_buf_pool * | pool, |
size_t | size, | ||
k_timeout_t | timeout ) |
#include <zephyr/net_buf.h>
Allocate a new variable length buffer from a pool.
pool | Which pool to allocate the buffer from. |
size | Amount of data the buffer must be able to fit. |
timeout | Affects the action taken should the pool be empty. If K_NO_WAIT, then return immediately. If K_FOREVER, then wait as long as necessary. Otherwise, wait until the specified timeout. |
struct net_buf * net_buf_alloc_with_data | ( | struct net_buf_pool * | pool, |
void * | data, | ||
size_t | size, | ||
k_timeout_t | timeout ) |
#include <zephyr/net_buf.h>
Allocate a new buffer from a pool but with external data pointer.
Allocate a new buffer from a pool, where the data pointer comes from the user and not from the pool.
pool | Which pool to allocate the buffer from. |
data | External data pointer |
size | Amount of data the pointed data buffer if able to fit. |
timeout | Affects the action taken should the pool be empty. If K_NO_WAIT, then return immediately. If K_FOREVER, then wait as long as necessary. Otherwise, wait until the specified timeout. |
size_t net_buf_append_bytes | ( | struct net_buf * | buf, |
size_t | len, | ||
const void * | value, | ||
k_timeout_t | timeout, | ||
net_buf_allocator_cb | allocate_cb, | ||
void * | user_data ) |
#include <zephyr/net_buf.h>
Append data to a list of net_buf.
Append data to a net_buf. If there is not enough space in the net_buf then more net_buf will be added, unless there are no free net_buf and timeout occurs. If not allocator is provided it attempts to allocate from the same pool as the original buffer.
buf | Network buffer. |
len | Total length of input data |
value | Data to be added |
timeout | Timeout is passed to the net_buf allocator callback. |
allocate_cb | When a new net_buf is required, use this callback. |
user_data | A user data pointer to be supplied to the allocate_cb. This pointer is can be anything from a mem_pool or a net_pkt, the logic is left up to the allocate_cb function. |
struct net_buf * net_buf_clone | ( | struct net_buf * | buf, |
k_timeout_t | timeout ) |
#include <zephyr/net_buf.h>
Clone buffer.
Duplicate given buffer including any (user) data and headers currently stored.
buf | A valid pointer on a buffer |
timeout | Affects the action taken should the pool be empty. If K_NO_WAIT, then return immediately. If K_FOREVER, then wait as long as necessary. Otherwise, wait until the specified timeout. |
size_t net_buf_data_match | ( | const struct net_buf * | buf, |
size_t | offset, | ||
const void * | data, | ||
size_t | len ) |
#include <zephyr/net_buf.h>
Match data with a net_buf's content.
Compare data with a content of a net_buf. Provide information about the number of bytes matching between both. If needed, traverse through multiple buffer fragments.
buf | Network buffer |
offset | Starting offset to compare from |
data | Data buffer for comparison |
len | Number of bytes to compare |
|
inlinestatic |
#include <zephyr/net_buf.h>
Destroy buffer from custom destroy callback.
This helper is only intended to be used from custom destroy callbacks. If no custom destroy callback is given to NET_BUF_POOL_*_DEFINE() then there is no need to use this API.
buf | Buffer to destroy. |
#include <zephyr/net_buf.h>
Add a new fragment to the end of a chain of bufs.
Append a new fragment into the buffer fragments list.
Note: This function takes ownership of the fragment reference so the caller is not required to unref.
head | Head of the fragment chain. |
frag | Fragment to add. |
#include <zephyr/net_buf.h>
Delete existing fragment from a chain of bufs.
parent | Parent buffer/fragment, or NULL if there is no parent. |
frag | Fragment to delete. |
#include <zephyr/net_buf.h>
Insert a new fragment to a chain of bufs.
Insert a new fragment into the buffer fragments list after the parent.
Note: This function takes ownership of the fragment reference so the caller is not required to unref.
parent | Parent buffer/fragment. |
frag | Fragment to insert. |
#include <zephyr/net_buf.h>
Find the last fragment in the fragment list.
#include <zephyr/net_buf.h>
Calculate amount of bytes stored in fragments.
Calculates the total amount of data stored in the given buffer and the fragments linked to it.
buf | Buffer to start off with. |
struct net_buf * net_buf_get | ( | struct k_fifo * | fifo, |
k_timeout_t | timeout ) |
#include <zephyr/net_buf.h>
Get a buffer from a FIFO.
fifo | Which FIFO to take the buffer from. |
timeout | Affects the action taken should the FIFO be empty. If K_NO_WAIT, then return immediately. If K_FOREVER, then wait as long as necessary. Otherwise, wait until the specified timeout. |
#include <zephyr/net_buf.h>
Check buffer headroom.
Check how much free space there is in the beginning of the buffer.
buf A valid pointer on a buffer
int net_buf_id | ( | const struct net_buf * | buf | ) |
#include <zephyr/net_buf.h>
Get a zero-based index for a buffer.
This function will translate a buffer into a zero-based index, based on its placement in its buffer pool. This can be useful if you want to associate an external array of meta-data contexts with the buffers of a pool.
buf | Network buffer. |
size_t net_buf_linearize | ( | void * | dst, |
size_t | dst_len, | ||
const struct net_buf * | src, | ||
size_t | offset, | ||
size_t | len ) |
#include <zephyr/net_buf.h>
Copy bytes from net_buf chain starting at offset to linear buffer.
Copy (extract) len bytes from src net_buf chain, starting from offset in it, to a linear buffer dst. Return number of bytes actually copied, which may be less than requested, if net_buf chain doesn't have enough data, or destination buffer is too small.
dst | Destination buffer |
dst_len | Destination buffer length |
src | Source net_buf chain |
offset | Starting offset to copy from |
len | Number of bytes to copy |
#include <zephyr/net_buf.h>
Check maximum net_buf::len value.
This value is depending on the number of bytes being reserved as headroom.
buf | A valid pointer on a buffer |
struct net_buf_pool * net_buf_pool_get | ( | int | id | ) |
#include <zephyr/net_buf.h>
Looks up a pool based on its ID.
id | Pool ID (e.g. from buf->pool_id). |
#include <zephyr/net_buf.h>
Remove data from the beginning of the buffer.
Removes data from the beginning of the buffer by modifying the data pointer and buffer length.
buf | Buffer to update. |
len | Number of bytes to remove. |
#include <zephyr/net_buf.h>
Remove and convert 16 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 16-bit big endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 24 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 24-bit big endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 32 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 32-bit big endian data.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 40 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 40-bit big endian data.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 48 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 48-bit big endian data.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 64 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 64-bit big endian data.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 16 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 16-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 24 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 24-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 32 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 32-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 40 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 40-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 48 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 48-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 64 bits from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 64-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove data from the beginning of the buffer.
Removes data from the beginning of the buffer by modifying the data pointer and buffer length.
buf | Buffer to update. |
len | Number of bytes to remove. |
#include <zephyr/net_buf.h>
Remove a 8-bit value from the beginning of the buffer.
Same idea as with net_buf_pull(), but a helper for operating on 8-bit values.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Prepare data to be added at the start of the buffer.
Modifies the data pointer and buffer length to account for more data in the beginning of the buffer.
buf | Buffer to update. |
len | Number of bytes to add to the beginning. |
#include <zephyr/net_buf.h>
Push 16-bit value to the beginning of the buffer.
Adds 16-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 16-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 24-bit value to the beginning of the buffer.
Adds 24-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 24-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 32-bit value to the beginning of the buffer.
Adds 32-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 32-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 40-bit value to the beginning of the buffer.
Adds 40-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 40-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 48-bit value to the beginning of the buffer.
Adds 48-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 48-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 64-bit value to the beginning of the buffer.
Adds 64-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 64-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 16-bit value to the beginning of the buffer.
Adds 16-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 16-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 24-bit value to the beginning of the buffer.
Adds 24-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 24-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 32-bit value to the beginning of the buffer.
Adds 32-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 32-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 40-bit value to the beginning of the buffer.
Adds 40-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 40-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 48-bit value to the beginning of the buffer.
Adds 48-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 48-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Push 64-bit value to the beginning of the buffer.
Adds 64-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 64-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Copies the given number of bytes to the start of the buffer.
Modifies the data pointer and buffer length to account for more data in the beginning of the buffer.
buf | Buffer to update. |
mem | Location of data to be added. |
len | Length of data to be added. |
#include <zephyr/net_buf.h>
Push 8-bit value to the beginning of the buffer.
Adds 8-bit value the beginning of the buffer.
buf | Buffer to update. |
val | 8-bit value to be pushed to the buffer. |
#include <zephyr/net_buf.h>
Put a buffer to the end of a FIFO.
fifo | Which FIFO to put the buffer to. |
buf | Buffer. |
#include <zephyr/net_buf.h>
Increment the reference count of a buffer.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 16 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 16-bit big endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 24 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 24-bit big endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 32 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 32-bit big endian data.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 40 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 40-bit big endian data.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 48 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 48-bit big endian data.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 64 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 64-bit big endian data.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Remove and convert 16 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 16-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 24 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 24-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 32 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 32-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 40 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 40-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 48 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 48-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove and convert 64 bits from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 64-bit little endian data.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Remove data from the end of the buffer.
Removes data from the end of the buffer by modifying the buffer length.
buf | Buffer to update. |
len | Number of bytes to remove. |
#include <zephyr/net_buf.h>
Remove a 8-bit value from the end of the buffer.
Same idea as with net_buf_remove_mem(), but a helper for operating on 8-bit values.
buf | A valid pointer on a buffer. |
#include <zephyr/net_buf.h>
Initialize buffer with the given headroom.
The buffer is not expected to contain any data when this API is called.
buf | Buffer to initialize. |
reserve | How much headroom to reserve. |
void net_buf_reset | ( | struct net_buf * | buf | ) |
#include <zephyr/net_buf.h>
Reset buffer.
Reset buffer data and flags so it can be reused for other purposes.
buf | Buffer to reset. |
void * net_buf_simple_add | ( | struct net_buf_simple * | buf, |
size_t | len ) |
#include <zephyr/net_buf.h>
Prepare data to be added at the end of the buffer.
Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
len | Number of bytes to increment the length with. |
void net_buf_simple_add_be16 | ( | struct net_buf_simple * | buf, |
uint16_t | val ) |
#include <zephyr/net_buf.h>
Add 16-bit value at the end of the buffer.
Adds 16-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 16-bit value to be added. |
void net_buf_simple_add_be24 | ( | struct net_buf_simple * | buf, |
uint32_t | val ) |
#include <zephyr/net_buf.h>
Add 24-bit value at the end of the buffer.
Adds 24-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 24-bit value to be added. |
void net_buf_simple_add_be32 | ( | struct net_buf_simple * | buf, |
uint32_t | val ) |
#include <zephyr/net_buf.h>
Add 32-bit value at the end of the buffer.
Adds 32-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 32-bit value to be added. |
void net_buf_simple_add_be40 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Add 40-bit value at the end of the buffer.
Adds 40-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 40-bit value to be added. |
void net_buf_simple_add_be48 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Add 48-bit value at the end of the buffer.
Adds 48-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 48-bit value to be added. |
void net_buf_simple_add_be64 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Add 64-bit value at the end of the buffer.
Adds 64-bit value in big endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 64-bit value to be added. |
void net_buf_simple_add_le16 | ( | struct net_buf_simple * | buf, |
uint16_t | val ) |
#include <zephyr/net_buf.h>
Add 16-bit value at the end of the buffer.
Adds 16-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 16-bit value to be added. |
void net_buf_simple_add_le24 | ( | struct net_buf_simple * | buf, |
uint32_t | val ) |
#include <zephyr/net_buf.h>
Add 24-bit value at the end of the buffer.
Adds 24-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 24-bit value to be added. |
void net_buf_simple_add_le32 | ( | struct net_buf_simple * | buf, |
uint32_t | val ) |
#include <zephyr/net_buf.h>
Add 32-bit value at the end of the buffer.
Adds 32-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 32-bit value to be added. |
void net_buf_simple_add_le40 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Add 40-bit value at the end of the buffer.
Adds 40-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 40-bit value to be added. |
void net_buf_simple_add_le48 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Add 48-bit value at the end of the buffer.
Adds 48-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 48-bit value to be added. |
void net_buf_simple_add_le64 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Add 64-bit value at the end of the buffer.
Adds 64-bit value in little endian format at the end of buffer. Increments the data length of a buffer to account for more data at the end.
buf | Buffer to update. |
val | 64-bit value to be added. |
void * net_buf_simple_add_mem | ( | struct net_buf_simple * | buf, |
const void * | mem, | ||
size_t | len ) |
#include <zephyr/net_buf.h>
Copy given number of bytes from memory to the end of the buffer.
Increments the data length of the buffer to account for more data at the end.
buf | Buffer to update. |
mem | Location of data to be added. |
len | Length of data to be added |
uint8_t * net_buf_simple_add_u8 | ( | struct net_buf_simple * | buf, |
uint8_t | val ) |
#include <zephyr/net_buf.h>
Add (8-bit) byte at the end of the buffer.
Increments the data length of the buffer to account for more data at the end.
buf | Buffer to update. |
val | byte value to be added. |
void net_buf_simple_clone | ( | const struct net_buf_simple * | original, |
struct net_buf_simple * | clone ) |
#include <zephyr/net_buf.h>
Clone buffer state, using the same data buffer.
Initializes a buffer to point to the same data as an existing buffer. Allows operations on the same data without altering the length and offset of the original.
original | Buffer to clone. |
clone | The new clone. |
size_t net_buf_simple_headroom | ( | const struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Check buffer headroom.
Check how much free space there is in the beginning of the buffer.
buf A valid pointer on a buffer
|
inlinestatic |
#include <zephyr/net_buf.h>
Initialize a net_buf_simple object.
This needs to be called after creating a net_buf_simple object using the NET_BUF_SIMPLE macro.
buf | Buffer to initialize. |
reserve_head | Headroom to reserve. |
void net_buf_simple_init_with_data | ( | struct net_buf_simple * | buf, |
void * | data, | ||
size_t | size ) |
#include <zephyr/net_buf.h>
Initialize a net_buf_simple object with data.
Initialized buffer object with external data.
buf | Buffer to initialize. |
data | External data pointer |
size | Amount of data the pointed data buffer if able to fit. |
uint16_t net_buf_simple_max_len | ( | const struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Check maximum net_buf_simple::len value.
This value is depending on the number of bytes being reserved as headroom.
buf | A valid pointer on a buffer |
void * net_buf_simple_pull | ( | struct net_buf_simple * | buf, |
size_t | len ) |
#include <zephyr/net_buf.h>
Remove data from the beginning of the buffer.
Removes data from the beginning of the buffer by modifying the data pointer and buffer length.
buf | Buffer to update. |
len | Number of bytes to remove. |
uint16_t net_buf_simple_pull_be16 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 16 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 16-bit big endian data.
buf | A valid pointer on a buffer. |
uint32_t net_buf_simple_pull_be24 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 24 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 24-bit big endian data.
buf | A valid pointer on a buffer. |
uint32_t net_buf_simple_pull_be32 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 32 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 32-bit big endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_pull_be40 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 40 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 40-bit big endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_pull_be48 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 48 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 48-bit big endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_pull_be64 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 64 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 64-bit big endian data.
buf | A valid pointer on a buffer. |
uint16_t net_buf_simple_pull_le16 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 16 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 16-bit little endian data.
buf | A valid pointer on a buffer. |
uint32_t net_buf_simple_pull_le24 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 24 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 24-bit little endian data.
buf | A valid pointer on a buffer. |
uint32_t net_buf_simple_pull_le32 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 32 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 32-bit little endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_pull_le40 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 40 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 40-bit little endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_pull_le48 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 48 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 48-bit little endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_pull_le64 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 64 bits from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 64-bit little endian data.
buf | A valid pointer on a buffer. |
void * net_buf_simple_pull_mem | ( | struct net_buf_simple * | buf, |
size_t | len ) |
#include <zephyr/net_buf.h>
Remove data from the beginning of the buffer.
Removes data from the beginning of the buffer by modifying the data pointer and buffer length.
buf | Buffer to update. |
len | Number of bytes to remove. |
uint8_t net_buf_simple_pull_u8 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove a 8-bit value from the beginning of the buffer.
Same idea as with net_buf_simple_pull(), but a helper for operating on 8-bit values.
buf | A valid pointer on a buffer. |
void * net_buf_simple_push | ( | struct net_buf_simple * | buf, |
size_t | len ) |
#include <zephyr/net_buf.h>
Prepare data to be added to the start of the buffer.
Modifies the data pointer and buffer length to account for more data in the beginning of the buffer.
buf | Buffer to update. |
len | Number of bytes to add to the beginning. |
void net_buf_simple_push_be16 | ( | struct net_buf_simple * | buf, |
uint16_t | val ) |
#include <zephyr/net_buf.h>
Push 16-bit value to the beginning of the buffer.
Adds 16-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 16-bit value to be pushed to the buffer. |
void net_buf_simple_push_be24 | ( | struct net_buf_simple * | buf, |
uint32_t | val ) |
#include <zephyr/net_buf.h>
Push 24-bit value to the beginning of the buffer.
Adds 24-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 24-bit value to be pushed to the buffer. |
void net_buf_simple_push_be32 | ( | struct net_buf_simple * | buf, |
uint32_t | val ) |
#include <zephyr/net_buf.h>
Push 32-bit value to the beginning of the buffer.
Adds 32-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 32-bit value to be pushed to the buffer. |
void net_buf_simple_push_be40 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Push 40-bit value to the beginning of the buffer.
Adds 40-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 40-bit value to be pushed to the buffer. |
void net_buf_simple_push_be48 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Push 48-bit value to the beginning of the buffer.
Adds 48-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 48-bit value to be pushed to the buffer. |
void net_buf_simple_push_be64 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Push 64-bit value to the beginning of the buffer.
Adds 64-bit value in big endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 64-bit value to be pushed to the buffer. |
void net_buf_simple_push_le16 | ( | struct net_buf_simple * | buf, |
uint16_t | val ) |
#include <zephyr/net_buf.h>
Push 16-bit value to the beginning of the buffer.
Adds 16-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 16-bit value to be pushed to the buffer. |
void net_buf_simple_push_le24 | ( | struct net_buf_simple * | buf, |
uint32_t | val ) |
#include <zephyr/net_buf.h>
Push 24-bit value to the beginning of the buffer.
Adds 24-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 24-bit value to be pushed to the buffer. |
void net_buf_simple_push_le32 | ( | struct net_buf_simple * | buf, |
uint32_t | val ) |
#include <zephyr/net_buf.h>
Push 32-bit value to the beginning of the buffer.
Adds 32-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 32-bit value to be pushed to the buffer. |
void net_buf_simple_push_le40 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Push 40-bit value to the beginning of the buffer.
Adds 40-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 40-bit value to be pushed to the buffer. |
void net_buf_simple_push_le48 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Push 48-bit value to the beginning of the buffer.
Adds 48-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 48-bit value to be pushed to the buffer. |
void net_buf_simple_push_le64 | ( | struct net_buf_simple * | buf, |
uint64_t | val ) |
#include <zephyr/net_buf.h>
Push 64-bit value to the beginning of the buffer.
Adds 64-bit value in little endian format to the beginning of the buffer.
buf | Buffer to update. |
val | 64-bit value to be pushed to the buffer. |
void * net_buf_simple_push_mem | ( | struct net_buf_simple * | buf, |
const void * | mem, | ||
size_t | len ) |
#include <zephyr/net_buf.h>
Copy given number of bytes from memory to the start of the buffer.
Modifies the data pointer and buffer length to account for more data in the beginning of the buffer.
buf | Buffer to update. |
mem | Location of data to be added. |
len | Length of data to be added. |
void net_buf_simple_push_u8 | ( | struct net_buf_simple * | buf, |
uint8_t | val ) |
#include <zephyr/net_buf.h>
Push 8-bit value to the beginning of the buffer.
Adds 8-bit value the beginning of the buffer.
buf | Buffer to update. |
val | 8-bit value to be pushed to the buffer. |
uint16_t net_buf_simple_remove_be16 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 16 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 16-bit big endian data.
buf | A valid pointer on a buffer. |
uint32_t net_buf_simple_remove_be24 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 24 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 24-bit big endian data.
buf | A valid pointer on a buffer. |
uint32_t net_buf_simple_remove_be32 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 32 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 32-bit big endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_remove_be40 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 40 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 40-bit big endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_remove_be48 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 48 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 48-bit big endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_remove_be64 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 64 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 64-bit big endian data.
buf | A valid pointer on a buffer. |
uint16_t net_buf_simple_remove_le16 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 16 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 16-bit little endian data.
buf | A valid pointer on a buffer. |
uint32_t net_buf_simple_remove_le24 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 24 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 24-bit little endian data.
buf | A valid pointer on a buffer. |
uint32_t net_buf_simple_remove_le32 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 32 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 32-bit little endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_remove_le40 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 40 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 40-bit little endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_remove_le48 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 48 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 48-bit little endian data.
buf | A valid pointer on a buffer. |
uint64_t net_buf_simple_remove_le64 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove and convert 64 bits from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 64-bit little endian data.
buf | A valid pointer on a buffer. |
void * net_buf_simple_remove_mem | ( | struct net_buf_simple * | buf, |
size_t | len ) |
#include <zephyr/net_buf.h>
Remove data from the end of the buffer.
Removes data from the end of the buffer by modifying the buffer length.
buf | Buffer to update. |
len | Number of bytes to remove. |
uint8_t net_buf_simple_remove_u8 | ( | struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Remove a 8-bit value from the end of the buffer.
Same idea as with net_buf_simple_remove_mem(), but a helper for operating on 8-bit values.
buf | A valid pointer on a buffer. |
void net_buf_simple_reserve | ( | struct net_buf_simple * | buf, |
size_t | reserve ) |
#include <zephyr/net_buf.h>
Initialize buffer with the given headroom.
The buffer is not expected to contain any data when this API is called.
buf | Buffer to initialize. |
reserve | How much headroom to reserve. |
|
inlinestatic |
#include <zephyr/net_buf.h>
Reset buffer.
Reset buffer data so it can be reused for other purposes.
buf | Buffer to reset. |
|
inlinestatic |
#include <zephyr/net_buf.h>
Restore the parsing state of a buffer.
Restores the parsing state of a buffer from a state previously stored by net_buf_simple_save().
buf | Buffer to which the state should be restored. |
state | Stored state. |
|
inlinestatic |
#include <zephyr/net_buf.h>
Save the parsing state of a buffer.
Saves the parsing state of a buffer so it can be restored later.
buf | Buffer from which the state should be saved. |
state | Storage for the state. |
|
inlinestatic |
#include <zephyr/net_buf.h>
Get the tail pointer for a buffer.
Get a pointer to the end of the data in a buffer.
buf | Buffer. |
size_t net_buf_simple_tailroom | ( | const struct net_buf_simple * | buf | ) |
#include <zephyr/net_buf.h>
Check buffer tailroom.
Check how much free space there is at the end of the buffer.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Skip N number of bytes in a net_buf.
Skip N number of bytes starting from fragment's offset. If the total length of data is placed in multiple fragments, this function will skip from all fragments until it reaches N number of bytes. Any fully skipped buffers are removed from the net_buf list.
buf | Network buffer. |
len | Total length of data to be skipped. |
struct net_buf * net_buf_slist_get | ( | sys_slist_t * | list | ) |
#include <zephyr/net_buf.h>
Get a buffer from a list.
list | Which list to take the buffer from. |
void net_buf_slist_put | ( | sys_slist_t * | list, |
struct net_buf * | buf ) |
#include <zephyr/net_buf.h>
Put a buffer into a list.
list | Which list to append the buffer to. |
buf | Buffer. |
#include <zephyr/net_buf.h>
Get the tail pointer for a buffer.
Get a pointer to the end of the data in a buffer.
buf | Buffer. |
#include <zephyr/net_buf.h>
Check buffer tailroom.
Check how much free space there is at the end of the buffer.
buf | A valid pointer on a buffer |
void net_buf_unref | ( | struct net_buf * | buf | ) |
#include <zephyr/net_buf.h>
Decrements the reference count of a buffer.
The buffer is put back into the pool if the reference count reaches zero.
buf | A valid pointer on a buffer |
|
inlinestatic |
#include <zephyr/net_buf.h>
Get a pointer to the user data of a buffer.
buf | A valid pointer on a buffer |
#include <zephyr/net_buf.h>
Copy user data from one to another buffer.
dst | A valid pointer to a buffer gettings its user data overwritten. |
src | A valid pointer to a buffer gettings its user data copied. User data size must be equal to or exceed dst. |