icmp.h

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/* -*- c-basic-offset: 4 -*- */
#ifndef CLICKNET_ICMP_H
#define CLICKNET_ICMP_H
#include <clicknet/ip.h>

/*
 * <clicknet/icmp.h> -- ICMP packet definitions, based on FreeBSD.
 *
 * Relevant RFCs include:
 *   RFC792	Internet Control Message Protocol
 *   RFC1122	Requirements for Internet Hosts - Communication Layers
 *   RFC1123	Requirements for Internet Hosts - Application and Support
 *   RFC1812	Requirements for IP Version 4 Routers
 */

/* most icmp request types: ICMP_UNREACH, ICMP_SOURCEQUENCH, ICMP_TIMXCEED */
struct click_icmp {
    uint8_t	icmp_type;		/* 0     ICMP type (see below)	     */
    uint8_t	icmp_code;		/* 1     ICMP code (see below)	     */
    uint16_t	icmp_cksum;		/* 2-3   checksum		     */
    uint32_t	padding;		/* 4-7   should be zero		     */
    /* followed by original IP header and initial portion of data */
};

/* header for types with sequence numbers: ICMP_ECHO, ICMP_ECHOREPLY,
   ICMP_IREQ, ICMP_IREQREPLY */
struct click_icmp_sequenced {
    uint8_t	icmp_type;		/* 0     ICMP type (see below)	     */
    uint8_t	icmp_code;		/* 1     ICMP code (see below)	     */
    uint16_t	icmp_cksum;		/* 2-3   checksum		     */
    uint16_t	icmp_identifier;	/* 4-5   flow identifier	     */
    uint16_t	icmp_sequence;		/* 6-7   sequence number in flow     */
};

/* ICMP_PARAMPROB header */
struct click_icmp_paramprob {
    uint8_t	icmp_type;		/* 0     ICMP type (see below)	     */
    uint8_t	icmp_code;		/* 1     ICMP code (see below)	     */
    uint16_t	icmp_cksum;		/* 2-3   checksum		     */
    uint8_t	icmp_pointer;		/* 4     parameter pointer	     */
    uint8_t	padding[3];		/* 5-7   should be zero		     */
    /* followed by original IP header and initial portion of data */
};

/* Redirect header: ICMP_REDIRECT */
struct click_icmp_redirect {
    uint8_t	icmp_type;		/* 0     ICMP_REDIRECT (see below)   */
    uint8_t	icmp_code;		/* 1     ICMP code (see below)	     */
    uint16_t	icmp_cksum;		/* 2-3   checksum		     */
    struct in_addr icmp_gateway;	/* 4-7   address of gateway	     */
    /* followed by original IP header and initial portion of data */
};

/* Timestamp and TimestampReply header: ICMP_TSTAMP and ICMP_TSTAMPREPLY */
struct click_icmp_tstamp { 
    uint8_t	icmp_type;		/* 0     ICMP type (see below)	     */
    uint8_t	icmp_code;		/* 1     ICMP code (see below)	     */
    uint16_t	icmp_cksum;		/* 2-3   checksum		     */
    uint16_t	icmp_identifier;	/* 4-5   flow identifier	     */
    uint16_t	icmp_sequence;		/* 6-7   sequence number in flow     */
    uint32_t	icmp_originate;		/* 8-11  originate timestamp	     */
    uint32_t	icmp_receive;		/* 12-15 receive timestamp	     */
    uint32_t	icmp_transmit;		/* 16-19 transmit timestamp	     */
};

/* Path MTU Discovery header: ICMP_UNREACH_NEEDFRAG */
struct click_icmp_needfrag { 
    uint8_t	icmp_type;		/* 0     ICMP_UNREACH (see below)    */
    uint8_t	icmp_code;		/* 1     ICMP_UNREACH_NEEDFRAG	     */
    uint16_t	icmp_cksum;		/* 2-3   checksum		     */
    uint16_t	padding;		/* 4-5   should be zero		     */
    uint16_t	icmp_nextmtu;		/* 6-7   Next-Hop MTU		     */
    /* followed by original IP header and initial portion of data */
};

#define click_icmp_unreach	click_icmp
#define click_icmp_sourcequench	click_icmp
#define click_icmp_timxceed	click_icmp
#define click_icmp_echo		click_icmp_sequenced


/* ICMP type definitions and (indented) code definitions */
#define	ICMP_ECHOREPLY		0		/* echo reply		     */
#define	ICMP_UNREACH		3		/* dest unreachable, codes:  */
#define	  ICMP_UNREACH_NET		0	/*   bad net		     */
#define	  ICMP_UNREACH_HOST		1	/*   bad host		     */
#define	  ICMP_UNREACH_PROTOCOL		2	/*   bad protocol	     */
#define	  ICMP_UNREACH_PORT		3	/*   bad port		     */
#define	  ICMP_UNREACH_NEEDFRAG		4	/*   IP_DF caused drop	     */
#define	  ICMP_UNREACH_SRCFAIL		5	/*   src route failed	     */
#define	  ICMP_UNREACH_NET_UNKNOWN	6	/*   unknown net	     */
#define	  ICMP_UNREACH_HOST_UNKNOWN	7	/*   unknown host	     */
#define	  ICMP_UNREACH_ISOLATED		8	/*   src host isolated	     */
#define	  ICMP_UNREACH_NET_PROHIB	9	/*   net prohibited access   */
#define	  ICMP_UNREACH_HOST_PROHIB	10	/*   host prohibited access  */
#define	  ICMP_UNREACH_TOSNET		11	/*   bad tos for net	     */
#define	  ICMP_UNREACH_TOSHOST		12	/*   bad tos for host	     */
#define	  ICMP_UNREACH_FILTER_PROHIB	13	/*   admin prohib	     */
#define	  ICMP_UNREACH_HOST_PRECEDENCE	14	/*   host prec violation     */
#define	  ICMP_UNREACH_PRECEDENCE_CUTOFF 15	/*   prec cutoff	     */
#define	ICMP_SOURCEQUENCH	4		/* packet lost, slow down    */
#define	ICMP_REDIRECT		5		/* shorter route, codes:     */
#define	  ICMP_REDIRECT_NET		0	/*   for network	     */
#define	  ICMP_REDIRECT_HOST		1	/*   for host		     */
#define	  ICMP_REDIRECT_TOSNET		2	/*   for tos and net	     */
#define	  ICMP_REDIRECT_TOSHOST		3	/*   for tos and host	     */
#define	ICMP_ECHO		8		/* echo service		     */
#define	ICMP_ROUTERADVERT	9		/* router advertisement	     */
#define	ICMP_ROUTERSOLICIT	10		/* router solicitation	     */
#define	ICMP_TIMXCEED		11		/* time exceeded, code:	     */
#define	  ICMP_TIMXCEED_TRANSIT		0	/*   ttl==0 in transit	     */
#define	  ICMP_TIMXCEED_REASSEMBLY	1	/*   ttl==0 in reassembly    */
#define	ICMP_PARAMPROB		12		/* ip header bad	     */
#define	  ICMP_PARAMPROB_ERRATPTR	0	/*   error at param ptr	     */
#define	  ICMP_PARAMPROB_OPTABSENT	1	/*   req. opt. absent	     */
#define	  ICMP_PARAMPROB_LENGTH 	2	/*   bad length		     */
#define	ICMP_TSTAMP		13		/* timestamp request	     */
#define	ICMP_TSTAMPREPLY	14		/* timestamp reply	     */
#define	ICMP_IREQ		15		/* information request	     */
#define	ICMP_IREQREPLY		16		/* information reply	     */
#define	ICMP_MASKREQ		17		/* address mask request	     */
#define	ICMP_MASKREQREPLY	18		/* address mask reply	     */

static inline size_t
click_icmp_hl(uint8_t icmp_type)
{
    if (icmp_type == ICMP_TSTAMP || icmp_type == ICMP_TSTAMPREPLY)
	return sizeof(click_icmp_tstamp);
    else
	return sizeof(click_icmp);
}

#endif