1 /* ip_icmp.h 4.1 81/11/08 */ 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 ip_addr ih_gwaddr; /* ICMP_REDIRECT */ 18 struct ih_idseq { 19 n_short icd_id; 20 n_short icd_seq; 21 } ih_idseq; 22 } icmp_hun; 23 #define icmp_pptr icmp_hun.ih_pptr 24 #define icmp_gwaddr icmp_hun.ih_gwaddr 25 #define icmp_id icmp_hun.ih_idseq.icd_id 26 #define icmp_seq icmp_hun.ih_idseq.icd_seq 27 union { 28 struct id_ts { 29 n_time its_otime; 30 n_time its_rtime; 31 n_time its_ttime; 32 } id_ts; 33 struct id_ip { 34 struct ip idi_ip; 35 /* options and then 64 bits of data */ 36 } id_ip; 37 } icmp_dun; 38 #define icmp_otime icmp_dun.id_ts.its_otime 39 #define icmp_rtime icmp_dun.id_ts.its_rtime 40 #define icmp_ttime icmp_dun.id_ts.its_ttime 41 #define icmp_ip icmp_dun.id_ip.idi_ip 42 }; 43 44 /* 45 * Lower bounds on packet lengths for various types. 46 * For the error advice packets must first insure that the 47 * packet is large enought to contain the returned ip header. 48 * Only then can we do the check to see if 64 bits of packet 49 * data have been returned, since we need to check the returned 50 * ip header length. 51 */ 52 #define ICMP_MINLEN 8 /* abs minimum */ 53 #define ICMP_TSLEN (8 + 3 * sizeof (n_time)) /* timestamp */ 54 #define ICMP_ADVLENMIN (8 + sizeof (struct ip) + 8) /* min */ 55 #define ICMP_ADVLEN(p) (8 + ((p)->icmp_ip.ip_len << 2) + 8) 56 /* N.B.: must separately check that ip_hl >= 5 */ 57 58 /* 59 * Definition of type and code field values. 60 */ 61 #define ICMP_ECHOREPLY 0 /* echo reply */ 62 #define ICMP_UNREACH 3 /* dest unreachable, codes: */ 63 #define ICMP_UNREACH_NET 0 /* bad net */ 64 #define ICMP_UNREACH_HOST 1 /* bad host */ 65 #define ICMP_UNREACH_PROTOCOL 2 /* bad protocol */ 66 #define ICMP_UNREACH_PORT 3 /* bad port */ 67 #define ICMP_UNREACH_NEEDFRAG 4 /* IP_DF caused drop */ 68 #define ICMP_UNREACH_SRCFAIL 5 /* src route failed */ 69 #define ICMP_SOURCEQUENCH 4 /* packet lost, slow down */ 70 #define ICMP_REDIRECT 5 /* shorter route, codes: */ 71 #define ICMP_REDIRECT_NET 0 /* for network */ 72 #define ICMP_REDIRECT_HOST 1 /* for host */ 73 #define ICMP_REDIRECT_TOSNET 2 /* for tos and net */ 74 #define ICMP_REDIRECT_TOSHOST 3 /* for tos and host */ 75 #define ICMP_ECHO 8 /* echo service */ 76 #define ICMP_TIMXCEED 11 /* time exceeded, code: */ 77 #define ICMP_TIMXCEED_INTRANS 0 /* ttl==0 in transit */ 78 #define ICMP_TIMXCEED_REASS 1 /* ttl==0 in reass */ 79 #define ICMP_TSTAMP 13 /* timestamp request */ 80 #define ICMP_TSTAMPREPLY 14 /* timestamp reply */ 81 #define ICMP_IREQ 15 /* information request */ 82 #define ICMP_IREQREPLY 16 /* information reply */ 83 #define ICMP_PARAMPROB 12 /* ip header bad */ 84