pbuf.c File Reference

#include "lwip/opt.h"
#include "lwip/pbuf.h"
#include "lwip/stats.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/memp.h"
#include "lwip/sys.h"
#include "lwip/netif.h"
#include "lwip/priv/tcp_priv.h"
#include <string.h>
#include "lwip/tcpip.h"

Functions
struct pbuf *	pbuf_alloc (pbuf_layer layer, u16_t length, pbuf_type type)
struct pbuf *	pbuf_alloc_reference (void *payload, u16_t length, pbuf_type type)
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)
void	pbuf_realloc (struct pbuf *p, u16_t new_len)
u8_t	pbuf_add_header (struct pbuf *p, size_t header_size_increment)
u8_t	pbuf_add_header_force (struct pbuf *p, size_t header_size_increment)
u8_t	pbuf_remove_header (struct pbuf *p, size_t header_size_decrement)
u8_t	pbuf_header (struct pbuf *p, s16_t header_size_increment)
u8_t	pbuf_header_force (struct pbuf *p, s16_t header_size_increment)
struct pbuf *	pbuf_free_header (struct pbuf *q, u16_t size)
u8_t	pbuf_free (struct pbuf *p)
u16_t	pbuf_clen (const struct pbuf *p)
void	pbuf_ref (struct pbuf *p)
void	pbuf_cat (struct pbuf *h, struct pbuf *t)
void	pbuf_chain (struct pbuf *h, struct pbuf *t)
struct pbuf *	pbuf_dechain (struct pbuf *p)
err_t	pbuf_copy (struct pbuf *p_to, const struct pbuf *p_from)
u16_t	pbuf_copy_partial (const struct pbuf *buf, void *dataptr, u16_t len, u16_t offset)
void *	pbuf_get_contiguous (const struct pbuf *p, void *buffer, size_t bufsize, u16_t len, u16_t offset)
struct pbuf *	pbuf_skip (struct pbuf *in, u16_t in_offset, u16_t *out_offset)
err_t	pbuf_take (struct pbuf *buf, const void *dataptr, u16_t len)
err_t	pbuf_take_at (struct pbuf *buf, const void *dataptr, u16_t len, u16_t offset)
struct pbuf *	pbuf_coalesce (struct pbuf *p, pbuf_layer layer)
struct pbuf *	pbuf_clone (pbuf_layer layer, pbuf_type type, struct pbuf *p)
u8_t	pbuf_get_at (const struct pbuf *p, u16_t offset)
int	pbuf_try_get_at (const struct pbuf *p, u16_t offset)
void	pbuf_put_at (struct pbuf *p, u16_t offset, u8_t data)
u16_t	pbuf_memcmp (const struct pbuf *p, u16_t offset, const void *s2, u16_t n)
u16_t	pbuf_memfind (const struct pbuf *p, const void *mem, u16_t mem_len, u16_t start_offset)
u16_t	pbuf_strstr (const struct pbuf *p, const char *substr)

Detailed Description

Packet buffer management

Function Documentation

pbuf_add_header()

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.

pbuf_add_header_force()

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.

pbuf_clen()

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

pbuf_dechain()

struct pbuf* pbuf_dechain

(

struct pbuf *

p

)

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.

pbuf_free_header()

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)

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

pbuf_header()

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.

pbuf_header_force()

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.

pbuf_remove_header()

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.

pbuf_strstr()

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