icmp.h

#ifndef __ICMP_H
#define __ICMP_H

struct icmp {
	unsigned char icmp_type;
	unsigned char icmp_code;
	unsigned short icmp_cksum;
	union {
		struct {
			unsigned short id;	/* identifier */
			unsigned short seq;	/* sequence number */
		} echo;
		unsigned int gw;		/* icmp redirect gateway */
		unsigned int pad;
	} icmp_un;
	unsigned char icmp_data[0];
} __attribute__((packed));

#define icmp_id icmp_un.echo.id
#define icmp_seq icmp_un.echo.seq
#define icmp_undata icmp_un.pad
#define icmp_gw icmp_un.gw

#define ICMP_HRD_SZ sizeof(struct icmp)
#define ip2icmp(ip) ((struct icmp *)ipdata(ip))

/* icmp type */
#define ICMP_T_ECHORLY		0
#define ICMP_T_DUMMY_1		1
#define ICMP_T_DUMMY_2		2
#define ICMP_T_DESTUNREACH	3
#define ICMP_T_SOURCEQUENCH	4
#define ICMP_T_REDIRECT		5
#define ICMP_T_DUMMY_6		6
#define ICMP_T_DUMMY_7		7
#define ICMP_T_ECHOREQ		8
#define ICMP_T_DUMMY_9		9
#define ICMP_T_DUMMY_10		10
#define ICMP_T_TIMEEXCEED	11
#define ICMP_T_PARAMPROBLEM	12	/* parameter problem */
#define ICMP_T_TIMESTAMPREQ	13
#define ICMP_T_TIMESTAMPRLY	14
#define ICMP_T_INFOREQ		15
#define ICMP_T_INFORLY		16
#define ICMP_T_ADDRMASKREQ	17
#define ICMP_T_ADDRMASKRLY	18
#define ICMP_T_MAXNUM		18

/* icmp code of ICMP_T_DESTUNREACH type */
#define ICMP_NET_UNREACH	0
#define ICMP_HOST_UNREACH	1
#define ICMP_PROTO_UNREACH	2
#define ICMP_PORT_UNREACH	3
#define ICMP_FRAG_NEEDED	4
#define ICMP_SROUTE_FAILED	5	/* source route: according to ip option */
#define ICMP_NET_UNKNOWN	6	/* RFC 1812: should use code 0 */
#define ICMP_HOST_UNKNOWN	7
#define ICMP_SHOST_ISOLATED	8
#define ICMP_NET_ADMINPRO	9
#define ICMP_HOST_ADMINPRO	10
#define ICMP_NET_UNREACHTOS	11
#define ICMP_HOST_UNREACHTOS	12
#define ICMP_ADMINPRO		13	/* administratively prohibited */
#define ICMP_PREC_VIOLATION	14	/* host precedence violation */
#define ICMP_PREC_CUTOFF	15	/* precedence cutoff in effect */

/* icmp code of ICMP_T_REDIRECT type */
#define ICMP_REDIRECT_NET	0	/* net, obsolete(RFC 1812-5.2.7.2) */
#define ICMP_REDIRECT_HOST	1	/* host */
#define ICMP_REDIRECT_TOSNET	2	/* type of service and net ,obsolete */
#define ICMP_REDIRECT_TOSHOST	3	/* type of service and host */

/* icmp code of ICMP_T_TIMEEXCEED type */
#define ICMP_EXC_TTL		0
#define ICMP_EXC_FRAGTIME	1

/* icmp handler descriptor */
struct icmp_desc {
	int error;
	char *info;
	void (*handler)(struct icmp_desc *, struct pkbuf *);
};

#define ICMP_DESC_DUMMY_ENTRY \
{\
	.error = 1,\
	.info = NULL,\
	.handler = icmp_drop_reply,\
}

#define icmp_type_error(type) icmp_table[type].error
#define icmp_error(icmphdr) icmp_type_error((icmphdr)->icmp_type)
extern void icmp_send(unsigned char type, unsigned char code,
		unsigned int data, struct pkbuf *pkb_in);
extern void icmp_in(struct pkbuf *pkb);
#endif	/* icmp.h */