inet_chksum.h File Reference

#include "lwip/opt.h"
#include "lwip/pbuf.h"
#include "lwip/ip_addr.h"

Macros
#define	FOLD_U32T(u)   (((u) >> 16) + ((u) & 0x0000ffffUL))
	Split an u32_t in two u16_ts and add them up. More...
#define	LWIP_CHKSUM_COPY_ALGORITHM   0
#define	SWAP_BYTES_IN_WORD(w)   (((w) & 0xff) << 8) | (((w) & 0xff00) >> 8)
	Swap the bytes in an u16_t: much like htons() for little-endian. More...

Functions
u16_t	inet_chksum (void *dataptr, u16_t len)
u16_t	inet_chksum_pbuf (struct pbuf *p)
	Calculate a checksum over a chain of pbufs (without pseudo-header, much like inet_chksum only pbufs are used). More...
u16_t	inet_chksum_pseudo (struct pbuf *p, ip_addr_t *src, ip_addr_t *dest, u8_t proto, u16_t proto_len)
u16_t	inet_chksum_pseudo_partial (struct pbuf *p, ip_addr_t *src, ip_addr_t *dest, u8_t proto, u16_t proto_len, u16_t chksum_len)

#define FOLD_U32T

(

u

)

(((u) >> 16) + ((u) & 0x0000ffffUL))

Split an u32_t in two u16_ts and add them up.

Referenced by inet_chksum_pbuf(), inet_chksum_pseudo(), inet_chksum_pseudo_partial(), lwip_standard_chksum(), and tcp_output_segment().

#define LWIP_CHKSUM_COPY_ALGORITHM   0

#define SWAP_BYTES_IN_WORD

(

w

)

(((w) & 0xff) << 8) | (((w) & 0xff00) >> 8)

Swap the bytes in an u16_t: much like htons() for little-endian.

Referenced by inet_chksum_pbuf(), inet_chksum_pseudo(), inet_chksum_pseudo_partial(), lwip_standard_chksum(), and tcp_output_segment().

u16_t inet_chksum	(	void *	dataptr,
		u16_t	len
	)

References LWIP_CHKSUM.

Referenced by icmp_input(), icmp_send_response(), ip_frag(), ip_input(), ip_reass(), and tcp_write().

u16_t inet_chksum_pbuf

(

struct pbuf *

p

)

Calculate a checksum over a chain of pbufs (without pseudo-header, much like inet_chksum only pbufs are used).

Parameters

p	pbuf chain over that the checksum should be calculated

Returns

checksum (as u16_t) to be saved directly in the protocol header

References FOLD_U32T, pbuf::len, LWIP_CHKSUM, pbuf::next, NULL, pbuf::payload, and SWAP_BYTES_IN_WORD.

Referenced by icmp_input().

u16_t inet_chksum_pseudo	(	struct pbuf *	p,
		ip_addr_t *	src,
		ip_addr_t *	dest,
		u8_t	proto,
		u16_t	proto_len
	)

References FOLD_U32T, htons, INET_DEBUG, ip4_addr_get_u32, pbuf::len, LWIP_CHKSUM, LWIP_DEBUGF, pbuf::next, NULL, pbuf::payload, SWAP_BYTES_IN_WORD, and X32_F.

Referenced by tcp_input(), tcp_keepalive(), tcp_output_segment(), tcp_rst(), tcp_send_empty_ack(), tcp_zero_window_probe(), and udp_input().

u16_t inet_chksum_pseudo_partial	(	struct pbuf *	p,
		ip_addr_t *	src,
		ip_addr_t *	dest,
		u8_t	proto,
		u16_t	proto_len,
		u16_t	chksum_len
	)

References FOLD_U32T, htons, INET_DEBUG, ip4_addr_get_u32, pbuf::len, LWIP_ASSERT, LWIP_CHKSUM, LWIP_DEBUGF, pbuf::next, NULL, pbuf::payload, SWAP_BYTES_IN_WORD, and X32_F.

Referenced by tcp_output_segment(), and udp_input().