uIP packet forwarding
[The uIP TCP/IP stack]

Collaboration diagram for uIP packet forwarding:

Data Structures
struct	tcpip_hdr
struct	icmpip_hdr
struct	fwcache_entry
struct	uip_fw_netif
Files
file	uip-fw.c
file	uip-fw.h
Defines
#define	ICMP_ECHO 8
#define	ICMP_TE 11
#define	BUF ((struct tcpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define	ICMPBUF ((struct icmpip_hdr *)&uip_buf[UIP_LLH_LEN])
#define	FWCACHE_SIZE 2
#define	FW_TIME 20
#define	UIP_FW_NETIF(ip1, ip2, ip3, ip4, nm1, nm2, nm3, nm4, outputfunc)
#define	uip_fw_setipaddr(netif, addr)
#define	uip_fw_setnetmask(netif, addr)
#define	UIP_FW_LOCAL
#define	UIP_FW_OK
#define	UIP_FW_FORWARDED
#define	UIP_FW_ZEROLEN
#define	UIP_FW_TOOLARGE
#define	UIP_FW_NOROUTE
#define	UIP_FW_DROPPED
Functions
void	uip_fw_init (void)
u8_t	uip_fw_output (void)
u8_t	uip_fw_forward (void)
void	uip_fw_register (struct uip_fw_netif *netif)
void	uip_fw_default (struct uip_fw_netif *netif)
void	uip_fw_periodic (void)
Variables
u16_t	tcpip_hdr::len
u16_t	tcpip_hdr::ipid
u16_t	tcpip_hdr::ipoffset
u8_t	tcpip_hdr::ttl
u8_t	tcpip_hdr::proto
u16_t	tcpip_hdr::ipchksum
u16_t	tcpip_hdr::srcipaddr [2]
u16_t	tcpip_hdr::destipaddr [2]
u16_t	tcpip_hdr::srcport
u16_t	tcpip_hdr::destport
u8_t	tcpip_hdr::seqno [4]
u8_t	tcpip_hdr::ackno [4]
u8_t	tcpip_hdr::tcpoffset
u8_t	tcpip_hdr::flags
u8_t	tcpip_hdr::wnd [2]
u16_t	tcpip_hdr::tcpchksum
u8_t	tcpip_hdr::urgp [2]
u8_t	tcpip_hdr::optdata [4]
u16_t	icmpip_hdr::ipchksum
u16_t	icmpip_hdr::srcipaddr [2]
u16_t	icmpip_hdr::destipaddr [2]
u8_t	icmpip_hdr::type
u8_t	icmpip_hdr::icode
u16_t	icmpip_hdr::icmpchksum
u16_t	icmpip_hdr::id
u16_t	icmpip_hdr::seqno
u8_t	icmpip_hdr::payload [1]
u16_t	fwcache_entry::srcipaddr [2]
u16_t	fwcache_entry::destipaddr [2]
u16_t	fwcache_entry::ipid
u8_t	fwcache_entry::proto
u8_t	fwcache_entry::unused

Define Documentation

#define BUF ((struct tcpip_hdr *)&uip_buf[UIP_LLH_LEN])

#define FW_TIME 20

#define FWCACHE_SIZE 2

#define ICMP_ECHO 8

#define ICMP_TE 11

#define ICMPBUF ((struct icmpip_hdr *)&uip_buf[UIP_LLH_LEN])

#define UIP_FW_DROPPED

An error message that indicates that a packet that should be forwarded or output was dropped.

#define UIP_FW_FORWARDED

A non-error message that indicates that a packet was forwarded.

#define UIP_FW_LOCAL

A non-error message that indicates that a packet should be processed locally.

#define UIP_FW_NETIF	(	ip1,
		ip2,
		ip3,
		ip4,
		nm1,
		nm2,
		nm3,
		nm4,
		outputfunc	)

Intantiating macro for a uIP network interface.

Example:

 struct uip_fw_netif slipnetif =
   {UIP_FW_NETIF(192,168,76,1, 255,255,255,0, slip_output)};

Parameters:

	ip1,ip2,ip3,ip4	The IP address of the network interface.
	nm1,nm2,nm3,nm4	The netmask of the network interface.
	outputfunc	A pointer to the output function of the network interface.

#define UIP_FW_NOROUTE

An error message that indicates that no suitable interface could be found for an outbound packet.

#define UIP_FW_OK

A non-error message that indicates that something went OK.

#define uip_fw_setipaddr	(	netif,
		addr		)

Set the IP address of a network interface.

Parameters:

	netif	A pointer to the uip_fw_netif structure for the network interface.
	addr	A pointer to an IP address.

#define uip_fw_setnetmask	(	netif,
		addr		)

Set the netmask of a network interface.

Parameters:

	netif	A pointer to the uip_fw_netif structure for the network interface.
	addr	A pointer to an IP address representing the netmask.

#define UIP_FW_TOOLARGE

An error message that indicates that a packet that was too large for the outbound network interface was detected.

#define UIP_FW_ZEROLEN

A non-error message that indicates that a zero-length packet transmission was attempted, and that no packet was sent.

Function Documentation

void uip_fw_default ( struct uip_fw_netif * netif )

Register a default network interface.

All packets that don't go out on any of the other interfaces will be routed to the default interface.

Parameters:

netif

A pointer to the network interface that is to be registered.

u8_t uip_fw_forward ( void )

Forward an IP packet in the uip_buf buffer.

Returns:: UIP_FW_FORWARDED if the packet was forwarded, UIP_FW_LOCAL if the packet should be processed locally.

void uip_fw_init ( void )

Initialize the uIP packet forwarding module.

u8_t uip_fw_output ( void )

Output an IP packet on the correct network interface.

The IP packet should be present in the uip_buf buffer and its length in the global uip_len variable.

Return values:

	UIP_FW_ZEROLEN	Indicates that a zero-length packet transmission was attempted and that no packet was sent.
	UIP_FW_NOROUTE	No suitable network interface could be found for the outbound packet, and the packet was not sent.