Packet buffer management. More...

Functions
static void	pbuf_free_ooseq (void)
	Attempt to reclaim some memory from queued out-of-sequence TCP segments if we run out of pool pbufs.
static void	pbuf_free_ooseq_callback (void *arg)
	Just a callback function for tcpip_callback() that calls pbuf_free_ooseq().
static void	pbuf_pool_is_empty (void)
	Queue a call to pbuf_free_ooseq if not already queued.
struct pbuf *	pbuf_alloc (pbuf_layer layer, u16_t length, pbuf_type type)
	Allocates a pbuf of the given type (possibly a chain for PBUF_POOL 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)
	Initialize a custom pbuf (already allocated).
void	pbuf_realloc (struct pbuf *p, u16_t new_len)
	Shrink a pbuf chain to a desired length.
static u8_t	pbuf_header_impl (struct pbuf *p, s16_t header_size_increment, u8_t force)
	Adjusts the payload pointer to hide or reveal headers in the payload.
u8_t	pbuf_header (struct pbuf *p, s16_t header_size_increment)
	Adjusts the payload pointer to hide or reveal headers in the payload.
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.
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_ref (struct pbuf *p)
	Increment the reference count of the pbuf.
void	pbuf_cat (struct pbuf h, struct pbuf t)
	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 h, struct pbuf t)
	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 buf, void dataptr, u16_t len, u16_t offset)
	Copy (part of) the contents of a packet buffer to an application supplied buffer.
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.
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.
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_coalesce (struct pbuf *p, pbuf_layer layer)
	Creates a single pbuf out of a queue of pbufs.
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.
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

Packet buffer management.

Definition in file lwip_pbuf.c.

Function Documentation

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 800 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 899 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 1262 of file lwip_pbuf.c.

static void pbuf_free_ooseq ( void ) [static]

Attempt to reclaim some memory from queued out-of-sequence TCP segments if we run out of pool pbufs.

It's better to give priority to new packets if we're running out.

This must be done in the correct thread context therefore this function can only be used with NO_SYS=0 and through tcpip_callback.

Free the ooseq pbufs of one PCB only

Definition at line 165 of file lwip_pbuf.c.

static void pbuf_free_ooseq_callback ( void * arg ) [static]

Just a callback function for tcpip_callback() that calls pbuf_free_ooseq().

Definition at line 186 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 hdr_size_inc 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 665 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 675 of file lwip_pbuf.c.

static u8_t pbuf_header_impl	(	struct pbuf *	p,
		s16_t	header_size_increment,
		u8_t	force
	)		`[static]`

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

See also:: pbuf_header.

Parameters:

p	pbuf to change the header size.
header_size_increment	Number of bytes to increment header size.
force	Allow 'header_size_increment > 0' for PBUF_REF/PBUF_ROM types

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

Definition at line 569 of file lwip_pbuf.c.

static void pbuf_pool_is_empty ( void ) [static]

Queue a call to pbuf_free_ooseq if not already queued.

Definition at line 195 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 1066 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 1431 of file lwip_pbuf.c.

Type:	Program
Mbed OS support:	Mbed OS
Created:	23 Feb 2019
Imports:	43
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	1

lwip_pbuf.c File Reference

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lwip_pbuf.c File Reference

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