xref: /original-bsd/sys/netinet/ip_icmp.h (revision fbed46ce)
1 /* ip_icmp.h 4.5 82/04/25 */
2 
3 /*
4  * Interface Control Message Protocol Definitions.
5  * Per RFC 792, September 1981.
6  */
7 
8 /*
9  * Structure of an icmp header.
10  */
11 struct icmp {
12 	u_char	icmp_type;		/* type of message, see below */
13 	u_char	icmp_code;		/* type sub code */
14 	u_short	icmp_cksum;		/* ones complement cksum of struct */
15 	union {
16 		u_char ih_pptr;			/* ICMP_PARAMPROB */
17 		struct in_addr ih_gwaddr;	/* ICMP_REDIRECT */
18 		struct ih_idseq {
19 			n_short	icd_id;
20 			n_short	icd_seq;
21 		} ih_idseq;
22 		int ih_void;
23 	} icmp_hun;
24 #define	icmp_pptr	icmp_hun.ih_pptr
25 #define	icmp_gwaddr	icmp_hun.ih_gwaddr
26 #define	icmp_id		icmp_hun.ih_idseq.icd_id
27 #define	icmp_seq	icmp_hun.ih_idseq.icd_seq
28 #define	icmp_void	icmp_hun.ih_void
29 	union {
30 		struct id_ts {
31 			n_time its_otime;
32 			n_time its_rtime;
33 			n_time its_ttime;
34 		} id_ts;
35 		struct id_ip  {
36 			struct ip idi_ip;
37 			/* options and then 64 bits of data */
38 		} id_ip;
39 	} icmp_dun;
40 #define	icmp_otime	icmp_dun.id_ts.its_otime
41 #define	icmp_rtime	icmp_dun.id_ts.its_rtime
42 #define	icmp_ttime	icmp_dun.id_ts.its_ttime
43 #define	icmp_ip		icmp_dun.id_ip.idi_ip
44 };
45 
46 /*
47  * Lower bounds on packet lengths for various types.
48  * For the error advice packets must first insure that the
49  * packet is large enought to contain the returned ip header.
50  * Only then can we do the check to see if 64 bits of packet
51  * data have been returned, since we need to check the returned
52  * ip header length.
53  */
54 #define	ICMP_MINLEN	8				/* abs minimum */
55 #define	ICMP_TSLEN	(8 + 3 * sizeof (n_time))	/* timestamp */
56 #define	ICMP_ADVLENMIN	(8 + sizeof (struct ip) + 8)	/* min */
57 #define	ICMP_ADVLEN(p)	(8 + ((p)->icmp_ip.ip_hl << 2) + 8)
58 	/* N.B.: must separately check that ip_hl >= 5 */
59 
60 /*
61  * Definition of type and code field values.
62  */
63 #define	ICMP_ECHOREPLY		0		/* echo reply */
64 #define	ICMP_UNREACH		3		/* dest unreachable, codes: */
65 #define		ICMP_UNREACH_NET	0		/* bad net */
66 #define		ICMP_UNREACH_HOST	1		/* bad host */
67 #define		ICMP_UNREACH_PROTOCOL	2		/* bad protocol */
68 #define		ICMP_UNREACH_PORT	3		/* bad port */
69 #define		ICMP_UNREACH_NEEDFRAG	4		/* IP_DF caused drop */
70 #define		ICMP_UNREACH_SRCFAIL	5		/* src route failed */
71 #define	ICMP_SOURCEQUENCH	4		/* packet lost, slow down */
72 #define	ICMP_REDIRECT		5		/* shorter route, codes: */
73 #define		ICMP_REDIRECT_NET	0		/* for network */
74 #define		ICMP_REDIRECT_HOST	1		/* for host */
75 #define		ICMP_REDIRECT_TOSNET	2		/* for tos and net */
76 #define		ICMP_REDIRECT_TOSHOST	3		/* for tos and host */
77 #define	ICMP_ECHO		8		/* echo service */
78 #define	ICMP_TIMXCEED		11		/* time exceeded, code: */
79 #define		ICMP_TIMXCEED_INTRANS	0		/* ttl==0 in transit */
80 #define		ICMP_TIMXCEED_REASS	1		/* ttl==0 in reass */
81 #define	ICMP_PARAMPROB		12		/* ip header bad */
82 #define	ICMP_TSTAMP		13		/* timestamp request */
83 #define	ICMP_TSTAMPREPLY	14		/* timestamp reply */
84 #define	ICMP_IREQ		15		/* information request */
85 #define	ICMP_IREQREPLY		16		/* information reply */
86