ICMP

RFC 792 Internet Control Message Protocol. More...

Collaboration diagram for ICMP:

Functions
void	NutIcmpInput (NUTDEVICE *dev, NETBUF *nb)
	Handle incoming ICMP packets.
int	NutIcmpOutput (uint8_t type, uint32_t dest, NETBUF *nb)
	Send an ICMP datagram.
int	NutIcmpReply (uint8_t type, uint8_t code, uint32_t spec, uint32_t dest, NETBUF *nb)
	Send an ICMP message to a given destination.
int	NutIcmpResponse (uint8_t type, uint8_t code, uint32_t spec, NETBUF *nb)
	Send an ICMP message as a response to a given destination.

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Detailed Description

RFC 792 Internet Control Message Protocol.

Provides routing, diagnostic and error functionality for IP. Although ICMP messages are encapsulated within IP datagrams, ICMP processing is considered to be part of the IP layer.

There is currently no API support for this layer.

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Function Documentation

void NutIcmpInput	(	NUTDEVICE *	dev,
		NETBUF *	nb
	)

Handle incoming ICMP packets.

Incoming ICMP packets are processed in the background. NutNet currently handles echo request and destination unreachable packets. Any other packet type is silently discarded.

Note:

This routine is called by the IP layer on incoming ICMP datagrams. Applications typically do not call this function.

Parameters:

dev	Identifies the device that received the packet.
nb	Pointer to a network buffer structure containing the ICMP datagram.

Definition at line 261 of file icmpin.c.

References icmp::icmp_code, ICMP_ECHO, ICMP_ECHOREPLY, icmp::icmp_type, ICMP_UNREACH, _NETBUF::nb_ap, _NETBUF::nb_tp, NutNetBufFree(), _NBDATA::sz, and _NBDATA::vp.

Referenced by NutIpInput().

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int NutIcmpOutput	(	uint8_t	type,
		uint32_t	dest,
		NETBUF *	nb
	)

Send an ICMP datagram.

Known ICMP types are:

• ICMP_ECHOREPLY Echo reply
• ICMP_UNREACH Destination unreachable
• ICMP_SOURCEQUENCH Packet lost
• ICMP_REDIRECT Shorter route
• ICMP_ECHO Echo reply
• ICMP_ROUTERADVERT Router advertisement
• ICMP_ROUTERSOLICIT Router solicitation
• ICMP_TIMXCEED Time exceeded
• ICMP_PARAMPROB Bad IP header
• ICMP_TSTAMP Timestamp request
• ICMP_TSTAMPREPLY Timestamp reply
• ICMP_IREQ Information request
• ICMP_IREQREPLY Information reply
• ICMP_MASKREQ Address mask request
• ICMP_MASKREPLY Address mask reply

Parameters:

type	Type of the ICMP message.
dest	Destination IP address.
nb	Network buffer structure containing the datagram.

Returns:

0 on success, -1 otherwise.

Definition at line 159 of file icmpout.c.

References icmp::icmp_cksum, icmp::icmp_type, IPPROTO_ICMP, _NETBUF::nb_ap, _NETBUF::nb_tp, NutIpChkSum(), NutIpChkSumPartial(), NutIpOutput(), _NBDATA::sz, and _NBDATA::vp.

Referenced by NutIcmpReply().

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int NutIcmpReply	(	uint8_t	type,
		uint8_t	code,
		uint32_t	spec,
		uint32_t	dest,
		NETBUF *	nb
	)

Send an ICMP message to a given destination.

Parameters:

type	Type of the ICMP message. See NutIcmpOutput() for a list of valid types.
code	Type subcode.
spec	Type specific data item.
dest	IP address of the target.
nb	Network buffer structure containing the message to be sent. The structure must have been allocated by a previous call NutNetBufAlloc() and will be freed if this function returns with an error.

Returns:

0 on success, -1 otherwise.

Definition at line 189 of file icmpout.c.

References icmp::icmp_code, icmp::icmp_spec, _NETBUF::nb_tp, NBAF_TRANSPORT, NutIcmpOutput(), NutNetBufAlloc(), and _NBDATA::vp.

Referenced by NutIcmpResponse().

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int NutIcmpResponse	(	uint8_t	type,
		uint8_t	code,
		uint32_t	spec,
		NETBUF *	nb
	)

Send an ICMP message as a response to a given destination.

Parameters:

type	Type of the ICMP message. See NutIcmpOutput() for a list of valid types.
code	Type subcode.
spec	Type specific data item.
nb	Network buffer structure containing the previously recevied network packet. According to RFC792 the complete ip header and the first 8 bytes of the transport netbuf is used as the application data for the response. If this function returns with an error, the buffer is freed. The destination addess is taken from the ip header.

Returns:

0 on success, -1 otherwise.

Definition at line 219 of file icmpout.c.

References ip::ip_src, memcpy(), _NETBUF::nb_ap, _NETBUF::nb_nw, _NETBUF::nb_tp, NBAF_APPLICATION, NutIcmpReply(), NutNetBufAlloc(), and _NBDATA::vp.

Referenced by NutIpInput(), and NutUdpInput().

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