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IP
[Protocols]

RFC 791 Internet protocol version 4. More...

Data Structures
struct	_ARPENTRY
	ARP entry structure. More...
struct	_ARPENTRY
	ARP entry structure. More...
struct	_PPP_PARAMS
struct	ifnet
	Network interface structure. More...
struct	ifnet
	Network interface structure. More...
struct	ip
	Structure of an internet header. More...
struct	ip
	Structure of an internet header. More...
struct	pseudo_hdr
Defines
#define	ATF_COM
	Completed entry.
#define	ATF_PERM
	Permanent entry.
#define	IPVERSION
	IP protocol version.
#define	IP_DF
	Don't fragment flag.
#define	IP_MF
	More fragments flag.
#define	IP_OFFMASK
	Mask for fragmenting bits.
#define	IPOPT_EOL
	End of option list.
#define	IPOPT_NOP
	No operation.
#define	IPOPT_RR
	Record packet route.
#define	IPOPT_TS
	Timestamp.
#define	IPOPT_SECURITY
	Provide s,c,h,tcc.
#define	IPOPT_LSRR
	Loose source route.
#define	IPOPT_SATID
	Satnet id.
#define	IPOPT_SSRR
	Strict source route.
#define	IPOPT_OPTVAL
	Option identifier offset.
#define	IPOPT_OLEN
	Option length offset.
#define	IPOPT_OFFSET
	Offset within option.
#define	IPOPT_MINOFF
	Minimum offset within option.
#define	MAXTTL
	Maximum time to live (seconds).
#define	IPDEFTTL
	Default time to live.
#define	IPFRAGTTL
	Time to live for fragments.
#define	IPTTLDEC
	Subtracted from time to live when forwarding.
Typedefs
typedef _ARPENTRY	ARPENTRY
	ARP entry type.
typedef ifnet	IFNET
	Network interface type.
typedef ip	IPHDR
	Internet header type.
Functions
int	NutNetIfConfig (CONST char *name, void *mac_dev, u_long ip_addr, u_long ip_mask)
	Configure a network interface.
int	NutNetIfSetup (NUTDEVICE *dev, u_long ip_addr, u_long ip_mask, u_long gateway)
int	NutNetLoadConfig (CONST char *name)
	Load network configuration from EEPROM.
int	NutNetSaveConfig (void)
	Save network configuration in EEPROM.
int	NutNetAutoConfig (CONST char *name)
	Automatically configure a network interface.
int	NutIpOutput (u_char proto, u_long dest, NETBUF *nb)
	Send IP datagram.
void	NutIpInput (NUTDEVICE *dev, NETBUF *nb)
	Process incoming IP datagrams.
u_long	inet_addr (CONST u_char *str)
	Convert decimal dotted ASCII representation into numeric IP address.
u_char *	inet_ntoa (u_long addr)
	Convert numeric IP address into decimal dotted ASCII representation.
u_short	NutIpChkSumPartial (u_short partial_csum, void *buf, u_short count)
	Calculates a partial IP checksum over a block of data.
u_short	NutIpChkSum (u_short partial_csum, void *buf, u_short count)
	Calculates an the final IP checksum over a block of data.
u_long	NutIpPseudoChkSumPartial (u_long src_addr, u_long dest_addr, u_char protocol, u_short len)
	Calculates the partial IP pseudo checksum.
u_short	NutIpPseudoChkSum (u_long src_addr, u_long dest_addr, u_char protocol, u_short len)
	Calculates the IP pseudo checksum.
int	NutIpRouteAdd (u_long ip, u_long mask, u_long gate, NUTDEVICE *dev)
	Add a new entry to the IP routing table.
NUTDEVICE *	NutIpRouteQuery (u_long ip, u_long *gate)
	Find a device associated with a particular IP route.
Variables
RTENTRY *	rteList
	Linked list of routing entries.

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Detailed Description

RFC 791 Internet protocol version 4.

Todo:

Configurable checksum calculation for incoming datagrams.

Author:

Harald Kipp, egnite Software GmbH

Author:

Harald Kipp, egnite Software GmbH

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Typedef Documentation

typedef struct _ARPENTRY ARPENTRY

ARP entry type.

typedef struct ifnet IFNET

Network interface type.

typedef struct ip IPHDR

Internet header type.

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Function Documentation

u_long inet_addr (  CONST u_char *    str )

Convert decimal dotted ASCII representation into numeric IP address. Parameters: str  String containing the ASCII representation. Returns: IP address in network byte order. Examples: httpd/httpserv.c, inetq/inetq.c, portdio/portdio.c, and tcps/tcps.c.

u_char* inet_ntoa (  u_long    addr )

Convert numeric IP address into decimal dotted ASCII representation. Note: This function is not thread safe. Each subsequent call will destroy the previous result. Applications should locally store the result before calling the function again or allowing other threads to call it. Parameters: addr  IP address in network byte order. Returns: Pointer to a static buffer containing the ASCII representation. Examples: httpd/httpserv.c, inetq/inetq.c, and tcps/tcps.c.

u_short NutIpChkSum (  u_short    partial_csum, void *    buf, u_short    count )

Calculates an the final IP checksum over a block of data. Unlike the partial checksum in NutIpChkSumPartial(), this function takes the one's complement of the final result, thus making it the full checksum.

u_short NutIpChkSumPartial (  u_short    partial_csum, void *    buf, u_short    count )

Calculates a partial IP checksum over a block of data. Note that this returns the checksum in network byte order, and thus does not need to be converted via hton16(), etc. Of course this means that we mustn't use this value for normal arithmetic! This is a partial checksum because it doesn't take the 1's complement of the overall sum. Note: by Dave Hudson: This doesn't look particularly intuitive at first sight - in fact it probably looks plain wrong. It does work however (take my word for it), but for some explanation the reader is referred to RFC1071 where the maths is explained in detail. by Harald Kipp: Yes, the GCC version looks wrong. I assume that this will not work for all packet sizes. Not yet confirmed.

void NutIpInput (  NUTDEVICE *    dev, NETBUF *    nb )

Process incoming IP datagrams. Datagrams addressed to other destinations and datagrams whose version number is not 4 are silently discarded. Note: This routine is called by the Ethernet layer on incoming IP datagrams. Applications typically do not call this function. Parameters: dev  Identifies the device that received this datagram. nb  The network buffer received.

int NutIpOutput (  u_char    proto, u_long    dest, NETBUF *    nb )

Send IP datagram. Route an IP datagram to the proper interface. The function will not return until the data has been stored in the network device hardware for transmission. If the device is not ready for transmitting a new packet, the calling thread will be suspended until the device becomes ready again. If the hardware address of the target host needs to be resolved the function will be suspended too. Parameters: proto  Protocol type. dest  Destination IP address. The function will determine the proper network interface by checking the routing table. It will also perform any neccessary hardware address resolution. nb  Network buffer structure containing the datagram. This buffer will be released if the function returns an error. Returns: 0 on success, -1 otherwise. Bug: Broadcasts to multiple network devices will fail after the first device returns an error.

u_short NutIpPseudoChkSum (  u_long    src_addr, u_long    dest_addr, u_char    protocol, u_short    len )

Calculates the IP pseudo checksum.

u_long NutIpPseudoChkSumPartial (  u_long    src_addr, u_long    dest_addr, u_char    protocol, u_short    len )

Calculates the partial IP pseudo checksum.

int NutIpRouteAdd (  u_long    ip, u_long    mask, u_long    gate, NUTDEVICE *    dev )

Add a new entry to the IP routing table. Note, that there is currently no support for removing entries or detecting duplicates. Anyway, newer entries will be found first, because they are inserted in front of older entries. However, this works only for equal masks, i.e. new network routes will never overwrite old host routes. Parameters: ip  Network or host IP address to be route. Set 0 for default route. mask  Mask for this entry. -1 for host routes, 0 for default or net mask for net routes. gate  Route through this gateway, otherwise 0. dev  Network interface to use. Returns: 0 on success, -1 otherwise. Examples: inetq/inetq.c.

NUTDEVICE* NutIpRouteQuery (  u_long    ip, u_long *    gate )

Find a device associated with a particular IP route. Gateway routes will be automatically resolved up to four levels of redirection. Parameters: ip  IP address to find a route for, given in network byte order. gate  Points to a buffer which optionally receives the IP address of a gateway. The pointer may be NULL, if the caller is not interested in this information. Returns: Pointer to the interface structure or NULL if no route was found.

int NutNetAutoConfig (  CONST char *    name )

Automatically configure a network interface. This function is deprecated. New applications should call NutDhcpIfConfig(). Parameters: name  Name of the device. Returns: 0 on success, -1 otherwise. Examples: rs232d/rs232d.c.

int NutNetIfConfig (  CONST char *    name, void *    params, u_long    ip_addr, u_long    ip_mask )

Configure a network interface. Devices must have been registered by NutRegisterDevice() before calling this function. For Ethernet devices applications may alternatively call NutNetAutoConfig(), which allows automatic configuration by DHCP or the so called ARP method. Parameters: name  Name of the device to configure. params  Pointer to interface specific parameters. For PPP interfaces this is a pointer to the PPP_PARAMS structure. For Ethernet interfaces this parameter is ignored. ip_addr  Specified IP address in network byte order. This must be a unique address within the Internet. If you do not directly communicate with other Internet hosts, you can use a locally assigned address. With PPP interfaces this may be set to 0.0.0.0, in which case the remote peer will be queried for an IP address. ip_mask  Specified IP network mask in network byte order. Typical Ethernet networks use 255.255.255.0, which allows upto 254 hosts. For PPP interfaces 255.255.255.255 is the default. Returns: 0 on success, -1 otherwise. Examples: httpd/httpserv.c, inetq/inetq.c, portdio/portdio.c, and tcps/tcps.c.

int NutNetIfSetup (  NUTDEVICE *    dev, u_long    ip_addr, u_long    ip_mask, u_long    gateway )

Network interface setup. Parameters: dev  Identifies the network device to setup. This pointer must have been retrieved previously by calling NutDeviceOpen(). ip_addr  Specified IP address in network byte order. ip_mask  Specified IP network mask in network byte order. gateway  Optional default gateway. Returns: 0 on success, -1 otherwise. Note: Typical applications do not use this function, but call NutNetIfConfig() or NutNetAutoConfig().

int NutNetLoadConfig (  CONST char *    name )

Load network configuration from EEPROM. If no configuration is available in EEPROM, all configuration parameters are cleared to zero. Except the MAC address, which is set to the Ethernet broadcast address. Parameters: name  Name of the device. Returns: 0 if configuration has been read. Otherwise the return value is -1. Examples: tcps/tcps.c.

int NutNetSaveConfig (  void    )

Save network configuration in EEPROM. Returns: Allways 0. Examples: tcps/tcps.c.

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