pbuf API More...

Data Structures
struct	pbuf
	Main packet buffer struct. More...
struct	pbuf_rom
	Helper struct for const-correctness only. More...
struct	pbuf_custom
	A custom pbuf: like a pbuf, but following a function pointer to free it. More...
Typedefs
typedef void(*	pbuf_free_custom_fn )(struct pbuf *p)
	Prototype for a function to free a custom pbuf.
Enumerations
enum	pbuf_layer { PBUF_TRANSPORT = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN + PBUF_TRANSPORT_HLEN, PBUF_IP = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN + PBUF_IP_HLEN, PBUF_LINK = PBUF_LINK_ENCAPSULATION_HLEN + PBUF_LINK_HLEN, PBUF_RAW_TX = PBUF_LINK_ENCAPSULATION_HLEN, PBUF_RAW = 0 }
	Enumeration of pbuf layers. More...
enum	pbuf_type { PBUF_RAM = (PBUF_ALLOC_FLAG_DATA_CONTIGUOUS \| PBUF_TYPE_FLAG_STRUCT_DATA_CONTIGUOUS \| PBUF_TYPE_ALLOC_SRC_MASK_STD_HEAP), PBUF_ROM = PBUF_TYPE_ALLOC_SRC_MASK_STD_MEMP_PBUF, PBUF_REF = (PBUF_TYPE_FLAG_DATA_VOLATILE \| PBUF_TYPE_ALLOC_SRC_MASK_STD_MEMP_PBUF), PBUF_POOL = (PBUF_ALLOC_FLAG_RX \| PBUF_TYPE_FLAG_STRUCT_DATA_CONTIGUOUS \| PBUF_TYPE_ALLOC_SRC_MASK_STD_MEMP_PBUF_POOL) }
	Enumeration of pbuf types. More...
Functions
struct pbuf *	pbuf_alloc (pbuf_layer l, u16_t length, pbuf_type type)
	Allocates a pbuf of the given type (possibly a chain for PBUF_POOL type).
struct pbuf *	pbuf_alloc_reference (void *payload, u16_t length, pbuf_type type)
	Allocates a pbuf for referenced data.
struct pbuf *	pbuf_alloced_custom (pbuf_layer l, u16_t length, pbuf_type type, struct pbuf_custom p, void payload_mem, u16_t payload_mem_len)
	Initialize a custom pbuf (already allocated).
void	pbuf_realloc (struct pbuf *p, u16_t size)
	Shrink a pbuf chain to a desired length.
u8_t	pbuf_header (struct pbuf *p, s16_t header_size)
	Adjusts the payload pointer to hide or reveal headers in the payload.
u8_t	pbuf_header_force (struct pbuf *p, s16_t header_size)
	Same as pbuf_header but does not check if 'header_size > 0' is allowed.
u8_t	pbuf_add_header (struct pbuf *p, size_t header_size_increment)
	Adjusts the payload pointer to reveal headers in the payload.
u8_t	pbuf_add_header_force (struct pbuf *p, size_t header_size_increment)
	Same as pbuf_add_header but does not check if 'header_size > 0' is allowed.
u8_t	pbuf_remove_header (struct pbuf *p, size_t header_size)
	Adjusts the payload pointer to hide headers in the payload.
struct pbuf *	pbuf_free_header (struct pbuf *q, u16_t size)
	Similar to pbuf_header(-size) but de-refs header pbufs for (size >= p->len)
void	pbuf_ref (struct pbuf *p)
	Increment the reference count of the pbuf.
u8_t	pbuf_free (struct pbuf *p)
	Dereference a pbuf chain or queue and deallocate any no-longer-used pbufs at the head of this chain or queue.
u16_t	pbuf_clen (const struct pbuf *p)
	Count number of pbufs in a chain.
void	pbuf_cat (struct pbuf head, struct pbuf tail)
	Concatenate two pbufs (each may be a pbuf chain) and take over the caller's reference of the tail pbuf.
void	pbuf_chain (struct pbuf head, struct pbuf tail)
	Chain two pbufs (or pbuf chains) together.
struct pbuf *	pbuf_dechain (struct pbuf *p)
	Dechains the first pbuf from its succeeding pbufs in the chain.
err_t	pbuf_copy (struct pbuf p_to, const struct pbuf p_from)
	Create PBUF_RAM copies of pbufs.
u16_t	pbuf_copy_partial (const struct pbuf p, void dataptr, u16_t len, u16_t offset)
	Copy (part of) the contents of a packet buffer to an application supplied buffer.
void *	pbuf_get_contiguous (const struct pbuf p, void buffer, size_t bufsize, u16_t len, u16_t offset)
	Get part of a pbuf's payload as contiguous memory.
err_t	pbuf_take (struct pbuf buf, const void dataptr, u16_t len)
	Copy application supplied data into a pbuf.
err_t	pbuf_take_at (struct pbuf buf, const void dataptr, u16_t len, u16_t offset)
	Same as pbuf_take() but puts data at an offset.
struct pbuf *	pbuf_skip (struct pbuf in, u16_t in_offset, u16_t out_offset)
	Skip a number of bytes at the start of a pbuf.
struct pbuf *	pbuf_coalesce (struct pbuf *p, pbuf_layer layer)
	Creates a single pbuf out of a queue of pbufs.
struct pbuf *	pbuf_clone (pbuf_layer l, pbuf_type type, struct pbuf *p)
	Allocates a new pbuf of same length (via pbuf_alloc()) and copies the source pbuf into this new pbuf (using pbuf_copy()).
err_t	pbuf_fill_chksum (struct pbuf p, u16_t start_offset, const void dataptr, u16_t len, u16_t *chksum)
	Copies data into a single pbuf (not into a pbuf queue!) and updates the checksum while copying.
void	pbuf_split_64k (struct pbuf p, struct pbuf *rest)
	This method modifies a 'pbuf chain', so that its total length is smaller than 64K.
u8_t	pbuf_get_at (const struct pbuf *p, u16_t offset)
	Get one byte from the specified position in a pbuf WARNING: returns zero for offset >= p->tot_len.
int	pbuf_try_get_at (const struct pbuf *p, u16_t offset)
	Get one byte from the specified position in a pbuf.
void	pbuf_put_at (struct pbuf *p, u16_t offset, u8_t data)
	Put one byte to the specified position in a pbuf WARNING: silently ignores offset >= p->tot_len.
u16_t	pbuf_memcmp (const struct pbuf p, u16_t offset, const void s2, u16_t n)
	Compare pbuf contents at specified offset with memory s2, both of length n.
u16_t	pbuf_memfind (const struct pbuf p, const void mem, u16_t mem_len, u16_t start_offset)
	Find occurrence of mem (with length mem_len) in pbuf p, starting at offset start_offset.
u16_t	pbuf_strstr (const struct pbuf p, const char substr)
	Find occurrence of substr with length substr_len in pbuf p, start at offset start_offset WARNING: in contrast to strstr(), this one does not stop at the first \0 in the pbuf/source string!

Detailed Description

pbuf API

Definition in file pbuf.h.

Typedef Documentation

typedef void(* pbuf_free_custom_fn)(struct pbuf *p)

Prototype for a function to free a custom pbuf.

Definition at line 239 of file pbuf.h.

Function Documentation

u8_t pbuf_add_header	(	struct pbuf *	p,
		size_t	header_size_increment
	)

Adjusts the payload pointer to reveal headers in the payload.

Adjusts the ->payload pointer so that space for a header appears in the pbuf payload.

The ->payload, ->tot_len and ->len fields are adjusted.

Parameters:

p	pbuf to change the header size.
header_size_increment	Number of bytes to increment header size which increases the size of the pbuf. New space is on the front. If header_size_increment is 0, this function does nothing and returns successful.

PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so the call will fail. A check is made that the increase in header size does not move the payload pointer in front of the start of the buffer.

Returns:: non-zero on failure, zero on success.

Definition at line 550 of file lwip_pbuf.c.

u8_t pbuf_add_header_force	(	struct pbuf *	p,
		size_t	header_size_increment
	)

Same as pbuf_add_header but does not check if 'header_size > 0' is allowed.

This is used internally only, to allow PBUF_REF for RX.

Definition at line 560 of file lwip_pbuf.c.

u16_t pbuf_clen ( const struct pbuf * p )

Count number of pbufs in a chain.

Parameters:

p	first pbuf of chain

Returns:: the number of pbufs in a chain

Definition at line 808 of file lwip_pbuf.c.

struct pbuf* pbuf_dechain ( struct pbuf * p ) [read]

Dechains the first pbuf from its succeeding pbufs in the chain.

Makes p->tot_len field equal to p->len.

Parameters:

p	pbuf to dechain

Returns:: remainder of the pbuf chain, or NULL if it was de-allocated.

Note:: May not be called on a packet queue.

Definition at line 911 of file lwip_pbuf.c.

err_t pbuf_fill_chksum	(	struct pbuf *	p,
		u16_t	start_offset,
		const void *	dataptr,
		u16_t	len,
		u16_t *	chksum
	)

Copies data into a single pbuf (*not* into a pbuf queue!) and updates the checksum while copying.

Parameters:

p	the pbuf to copy data into
start_offset	offset of p->payload where to copy the data to
dataptr	data to copy into the pbuf
len	length of data to copy into the pbuf
chksum	pointer to the checksum which is updated

Returns:: ERR_OK if successful, another error if the data does not fit within the (first) pbuf (no pbuf queues!)

Definition at line 1333 of file lwip_pbuf.c.

struct pbuf* pbuf_free_header	(	struct pbuf *	q,
		u16_t	size
	)		`[read]`

Similar to pbuf_header(-size) but de-refs header pbufs for (size >= p->len)

Parameters:

q	pbufs to operate on
size	The number of bytes to remove from the beginning of the pbuf list. While size >= p->len, pbufs are freed. ATTENTION: this is the opposite direction as pbuf_header, but takes an u16_t not s16_t!

Returns:: the new head pbuf

Definition at line 670 of file lwip_pbuf.c.

u8_t pbuf_header	(	struct pbuf *	p,
		s16_t	header_size_increment
	)

Adjusts the payload pointer to hide or reveal headers in the payload.

Adjusts the ->payload pointer so that space for a header (dis)appears in the pbuf payload.

The ->payload, ->tot_len and ->len fields are adjusted.

Parameters:

p	pbuf to change the header size.
header_size_increment	Number of bytes to increment header size which increases the size of the pbuf. New space is on the front. (Using a negative value decreases the header size.) If header_size_increment is 0, this function does nothing and returns successful.

PBUF_ROM and PBUF_REF type buffers cannot have their sizes increased, so the call will fail. A check is made that the increase in header size does not move the payload pointer in front of the start of the buffer.

Returns:: non-zero on failure, zero on success.

Definition at line 645 of file lwip_pbuf.c.

u8_t pbuf_header_force	(	struct pbuf *	p,
		s16_t	header_size_increment
	)

Same as pbuf_header but does not check if 'header_size > 0' is allowed.

This is used internally only, to allow PBUF_REF for RX.

Definition at line 655 of file lwip_pbuf.c.

u8_t pbuf_remove_header	(	struct pbuf *	p,
		size_t	header_size_decrement
	)

Adjusts the payload pointer to hide headers in the payload.

Adjusts the ->payload pointer so that space for a header disappears in the pbuf payload.

The ->payload, ->tot_len and ->len fields are adjusted.

Parameters:

p	pbuf to change the header size.
header_size_decrement	Number of bytes to decrement header size which decreases the size of the pbuf. If header_size_decrement is 0, this function does nothing and returns successful.

Returns:: non-zero on failure, zero on success.

Definition at line 581 of file lwip_pbuf.c.

void pbuf_split_64k	(	struct pbuf *	p,
		struct pbuf **	rest
	)

This method modifies a 'pbuf chain', so that its total length is smaller than 64K.

The remainder of the original pbuf chain is stored in *rest. This function never creates new pbufs, but splits an existing chain in two parts. The tot_len of the modified packet queue will likely be smaller than 64K. 'packet queues' are not supported by this function.

Parameters:

p	the pbuf queue to be split
rest	pointer to store the remainder (after the first 64K)

Definition at line 1112 of file lwip_pbuf.c.

u16_t pbuf_strstr	(	const struct pbuf *	p,
		const char *	substr
	)

Find occurrence of substr with length substr_len in pbuf p, start at offset start_offset WARNING: in contrast to strstr(), this one does not stop at the first \0 in the pbuf/source string!

Parameters:

p	pbuf to search, maximum length is 0xFFFE since 0xFFFF is used as return value 'not found'
substr	string to search for in p, maximum length is 0xFFFE

Returns:: 0xFFFF if substr was not found in p or the index where it was found

Definition at line 1502 of file lwip_pbuf.c.

Type:	Library
Created:	17 Dec 2019
Imports:	79
Forks:	0
Commits:	2
Dependents:	2
Dependencies:	0
Followers:	1

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