ip.h

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/*
 * ip.h
 *
 * Internet Protocol (RFC 791).
 *
 * Copyright (c) 2000 Dug Song <dugsong@monkey.org>
 *
 * $Id: ip.h,v 1.25 2005/02/16 22:02:45 dugsong Exp $
 */

#ifndef DNET_IP_H
#define DNET_IP_H

#define IP_ADDR_LEN     4               /* IP address length */
#define IP_ADDR_BITS    32              /* IP address bits */

#define IP_HDR_LEN      20              /* base IP header length */
#define IP_OPT_LEN      2               /* base IP option length */
#define IP_OPT_LEN_MAX  40
#define IP_HDR_LEN_MAX  (IP_HDR_LEN + IP_OPT_LEN_MAX)

#define IP_LEN_MAX      65535
#define IP_LEN_MIN      IP_HDR_LEN

typedef uint32_t        ip_addr_t;

#ifndef __GNUC__
# define __attribute__(x)
# pragma pack(1)
#endif

/*
 * IP header, without options
 */
struct ip_hdr {
#if DNET_BYTESEX == DNET_BIG_ENDIAN
        uint8_t         ip_v:4,         /* version */
                        ip_hl:4;        /* header length (incl any options) */
#elif DNET_BYTESEX == DNET_LIL_ENDIAN
        uint8_t         ip_hl:4,
                        ip_v:4;
#else
# error "need to include <dnet.h>"      
#endif
        uint8_t         ip_tos;         /* type of service */
        uint16_t        ip_len;         /* total length (incl header) */
        uint16_t        ip_id;          /* identification */
        uint16_t        ip_off;         /* fragment offset and flags */
        uint8_t         ip_ttl;         /* time to live */
        uint8_t         ip_p;           /* protocol */
        uint16_t        ip_sum;         /* checksum */
        ip_addr_t       ip_src;         /* source address */
        ip_addr_t       ip_dst;         /* destination address */
};

/*
 * Type of service (ip_tos), RFC 1349 ("obsoleted by RFC 2474")
 */
#define IP_TOS_DEFAULT          0x00    /* default */
#define IP_TOS_LOWDELAY         0x10    /* low delay */
#define IP_TOS_THROUGHPUT       0x08    /* high throughput */
#define IP_TOS_RELIABILITY      0x04    /* high reliability */
#define IP_TOS_LOWCOST          0x02    /* low monetary cost - XXX */
#define IP_TOS_ECT              0x02    /* ECN-capable transport */
#define IP_TOS_CE               0x01    /* congestion experienced */

/*
 * IP precedence (high 3 bits of ip_tos), hopefully unused
 */
#define IP_TOS_PREC_ROUTINE             0x00
#define IP_TOS_PREC_PRIORITY            0x20
#define IP_TOS_PREC_IMMEDIATE           0x40
#define IP_TOS_PREC_FLASH               0x60
#define IP_TOS_PREC_FLASHOVERRIDE       0x80
#define IP_TOS_PREC_CRITIC_ECP          0xa0
#define IP_TOS_PREC_INTERNETCONTROL     0xc0
#define IP_TOS_PREC_NETCONTROL          0xe0

/*
 * Fragmentation flags (ip_off)
 */
#define IP_RF           0x8000          /* reserved */
#define IP_DF           0x4000          /* don't fragment */
#define IP_MF           0x2000          /* more fragments (not last frag) */
#define IP_OFFMASK      0x1fff          /* mask for fragment offset */

/*
 * Time-to-live (ip_ttl), seconds
 */
#define IP_TTL_DEFAULT  64              /* default ttl, RFC 1122, RFC 1340 */
#define IP_TTL_MAX      255             /* maximum ttl */

/*
 * Protocol (ip_p) - http://www.iana.org/assignments/protocol-numbers
 */
#define IP_PROTO_IP             0               /* dummy for IP */
#define IP_PROTO_HOPOPTS        IP_PROTO_IP     /* IPv6 hop-by-hop options */
#define IP_PROTO_ICMP           1               /* ICMP */
#define IP_PROTO_IGMP           2               /* IGMP */
#define IP_PROTO_GGP            3               /* gateway-gateway protocol */
#define IP_PROTO_IPIP           4               /* IP in IP */
#define IP_PROTO_ST             5               /* ST datagram mode */
#define IP_PROTO_TCP            6               /* TCP */
#define IP_PROTO_CBT            7               /* CBT */
#define IP_PROTO_EGP            8               /* exterior gateway protocol */
#define IP_PROTO_IGP            9               /* interior gateway protocol */
#define IP_PROTO_BBNRCC         10              /* BBN RCC monitoring */
#define IP_PROTO_NVP            11              /* Network Voice Protocol */
#define IP_PROTO_PUP            12              /* PARC universal packet */
#define IP_PROTO_ARGUS          13              /* ARGUS */
#define IP_PROTO_EMCON          14              /* EMCON */
#define IP_PROTO_XNET           15              /* Cross Net Debugger */
#define IP_PROTO_CHAOS          16              /* Chaos */
#define IP_PROTO_UDP            17              /* UDP */
#define IP_PROTO_MUX            18              /* multiplexing */
#define IP_PROTO_DCNMEAS        19              /* DCN measurement */
#define IP_PROTO_HMP            20              /* Host Monitoring Protocol */
#define IP_PROTO_PRM            21              /* Packet Radio Measurement */
#define IP_PROTO_IDP            22              /* Xerox NS IDP */
#define IP_PROTO_TRUNK1         23              /* Trunk-1 */
#define IP_PROTO_TRUNK2         24              /* Trunk-2 */
#define IP_PROTO_LEAF1          25              /* Leaf-1 */
#define IP_PROTO_LEAF2          26              /* Leaf-2 */
#define IP_PROTO_RDP            27              /* "Reliable Datagram" proto */
#define IP_PROTO_IRTP           28              /* Inet Reliable Transaction */
#define IP_PROTO_TP             29              /* ISO TP class 4 */
#define IP_PROTO_NETBLT         30              /* Bulk Data Transfer */
#define IP_PROTO_MFPNSP         31              /* MFE Network Services */
#define IP_PROTO_MERITINP       32              /* Merit Internodal Protocol */
#define IP_PROTO_SEP            33              /* Sequential Exchange proto */
#define IP_PROTO_3PC            34              /* Third Party Connect proto */
#define IP_PROTO_IDPR           35              /* Interdomain Policy Route */
#define IP_PROTO_XTP            36              /* Xpress Transfer Protocol */
#define IP_PROTO_DDP            37              /* Datagram Delivery Proto */
#define IP_PROTO_CMTP           38              /* IDPR Ctrl Message Trans */
#define IP_PROTO_TPPP           39              /* TP++ Transport Protocol */
#define IP_PROTO_IL             40              /* IL Transport Protocol */
#define IP_PROTO_IPV6           41              /* IPv6 */
#define IP_PROTO_SDRP           42              /* Source Demand Routing */
#define IP_PROTO_ROUTING        43              /* IPv6 routing header */
#define IP_PROTO_FRAGMENT       44              /* IPv6 fragmentation header */
#define IP_PROTO_RSVP           46              /* Reservation protocol */
#define IP_PROTO_GRE            47              /* General Routing Encap */
#define IP_PROTO_MHRP           48              /* Mobile Host Routing */
#define IP_PROTO_ENA            49              /* ENA */
#define IP_PROTO_ESP            50              /* Encap Security Payload */
#define IP_PROTO_AH             51              /* Authentication Header */
#define IP_PROTO_INLSP          52              /* Integated Net Layer Sec */
#define IP_PROTO_SWIPE          53              /* SWIPE */
#define IP_PROTO_NARP           54              /* NBMA Address Resolution */
#define IP_PROTO_MOBILE         55              /* Mobile IP, RFC 2004 */
#define IP_PROTO_TLSP           56              /* Transport Layer Security */
#define IP_PROTO_SKIP           57              /* SKIP */
#define IP_PROTO_ICMPV6         58              /* ICMP for IPv6 */
#define IP_PROTO_NONE           59              /* IPv6 no next header */
#define IP_PROTO_DSTOPTS        60              /* IPv6 destination options */
#define IP_PROTO_ANYHOST        61              /* any host internal proto */
#define IP_PROTO_CFTP           62              /* CFTP */
#define IP_PROTO_ANYNET         63              /* any local network */
#define IP_PROTO_EXPAK          64              /* SATNET and Backroom EXPAK */
#define IP_PROTO_KRYPTOLAN      65              /* Kryptolan */
#define IP_PROTO_RVD            66              /* MIT Remote Virtual Disk */
#define IP_PROTO_IPPC           67              /* Inet Pluribus Packet Core */
#define IP_PROTO_DISTFS         68              /* any distributed fs */
#define IP_PROTO_SATMON         69              /* SATNET Monitoring */
#define IP_PROTO_VISA           70              /* VISA Protocol */
#define IP_PROTO_IPCV           71              /* Inet Packet Core Utility */
#define IP_PROTO_CPNX           72              /* Comp Proto Net Executive */
#define IP_PROTO_CPHB           73              /* Comp Protocol Heart Beat */
#define IP_PROTO_WSN            74              /* Wang Span Network */
#define IP_PROTO_PVP            75              /* Packet Video Protocol */
#define IP_PROTO_BRSATMON       76              /* Backroom SATNET Monitor */
#define IP_PROTO_SUNND          77              /* SUN ND Protocol */
#define IP_PROTO_WBMON          78              /* WIDEBAND Monitoring */
#define IP_PROTO_WBEXPAK        79              /* WIDEBAND EXPAK */
#define IP_PROTO_EON            80              /* ISO CNLP */
#define IP_PROTO_VMTP           81              /* Versatile Msg Transport*/
#define IP_PROTO_SVMTP          82              /* Secure VMTP */
#define IP_PROTO_VINES          83              /* VINES */
#define IP_PROTO_TTP            84              /* TTP */
#define IP_PROTO_NSFIGP         85              /* NSFNET-IGP */
#define IP_PROTO_DGP            86              /* Dissimilar Gateway Proto */
#define IP_PROTO_TCF            87              /* TCF */
#define IP_PROTO_EIGRP          88              /* EIGRP */
#define IP_PROTO_OSPF           89              /* Open Shortest Path First */
#define IP_PROTO_SPRITERPC      90              /* Sprite RPC Protocol */
#define IP_PROTO_LARP           91              /* Locus Address Resolution */
#define IP_PROTO_MTP            92              /* Multicast Transport Proto */
#define IP_PROTO_AX25           93              /* AX.25 Frames */
#define IP_PROTO_IPIPENCAP      94              /* yet-another IP encap */
#define IP_PROTO_MICP           95              /* Mobile Internet Ctrl */
#define IP_PROTO_SCCSP          96              /* Semaphore Comm Sec Proto */
#define IP_PROTO_ETHERIP        97              /* Ethernet in IPv4 */
#define IP_PROTO_ENCAP          98              /* encapsulation header */
#define IP_PROTO_ANYENC         99              /* private encryption scheme */
#define IP_PROTO_GMTP           100             /* GMTP */
#define IP_PROTO_IFMP           101             /* Ipsilon Flow Mgmt Proto */
#define IP_PROTO_PNNI           102             /* PNNI over IP */
#define IP_PROTO_PIM            103             /* Protocol Indep Multicast */
#define IP_PROTO_ARIS           104             /* ARIS */
#define IP_PROTO_SCPS           105             /* SCPS */
#define IP_PROTO_QNX            106             /* QNX */
#define IP_PROTO_AN             107             /* Active Networks */
#define IP_PROTO_IPCOMP         108             /* IP Payload Compression */
#define IP_PROTO_SNP            109             /* Sitara Networks Protocol */
#define IP_PROTO_COMPAQPEER     110             /* Compaq Peer Protocol */
#define IP_PROTO_IPXIP          111             /* IPX in IP */
#define IP_PROTO_VRRP           112             /* Virtual Router Redundancy */
#define IP_PROTO_PGM            113             /* PGM Reliable Transport */
#define IP_PROTO_ANY0HOP        114             /* 0-hop protocol */
#define IP_PROTO_L2TP           115             /* Layer 2 Tunneling Proto */
#define IP_PROTO_DDX            116             /* D-II Data Exchange (DDX) */
#define IP_PROTO_IATP           117             /* Interactive Agent Xfer */
#define IP_PROTO_STP            118             /* Schedule Transfer Proto */
#define IP_PROTO_SRP            119             /* SpectraLink Radio Proto */
#define IP_PROTO_UTI            120             /* UTI */
#define IP_PROTO_SMP            121             /* Simple Message Protocol */
#define IP_PROTO_SM             122             /* SM */
#define IP_PROTO_PTP            123             /* Performance Transparency */
#define IP_PROTO_ISIS           124             /* ISIS over IPv4 */
#define IP_PROTO_FIRE           125             /* FIRE */
#define IP_PROTO_CRTP           126             /* Combat Radio Transport */
#define IP_PROTO_CRUDP          127             /* Combat Radio UDP */
#define IP_PROTO_SSCOPMCE       128             /* SSCOPMCE */
#define IP_PROTO_IPLT           129             /* IPLT */
#define IP_PROTO_SPS            130             /* Secure Packet Shield */
#define IP_PROTO_PIPE           131             /* Private IP Encap in IP */
#define IP_PROTO_SCTP           132             /* Stream Ctrl Transmission */
#define IP_PROTO_FC             133             /* Fibre Channel */
#define IP_PROTO_RSVPIGN        134             /* RSVP-E2E-IGNORE */
#define IP_PROTO_RAW            255             /* Raw IP packets */
#define IP_PROTO_RESERVED       IP_PROTO_RAW    /* Reserved */
#define IP_PROTO_MAX            255

/*
 * Option types (opt_type) - http://www.iana.org/assignments/ip-parameters
 */
#define IP_OPT_CONTROL          0x00            /* control */
#define IP_OPT_DEBMEAS          0x40            /* debugging & measurement */
#define IP_OPT_COPY             0x80            /* copy into all fragments */
#define IP_OPT_RESERVED1        0x20
#define IP_OPT_RESERVED2        0x60

#define IP_OPT_EOL        0                     /* end of option list */
#define IP_OPT_NOP        1                     /* no operation */
#define IP_OPT_SEC       (2|IP_OPT_COPY)        /* DoD basic security */
#define IP_OPT_LSRR      (3|IP_OPT_COPY)        /* loose source route */
#define IP_OPT_TS        (4|IP_OPT_DEBMEAS)     /* timestamp */
#define IP_OPT_ESEC      (5|IP_OPT_COPY)        /* DoD extended security */
#define IP_OPT_CIPSO     (6|IP_OPT_COPY)        /* commercial security */
#define IP_OPT_RR         7                     /* record route */
#define IP_OPT_SATID     (8|IP_OPT_COPY)        /* stream ID (obsolete) */
#define IP_OPT_SSRR      (9|IP_OPT_COPY)        /* strict source route */
#define IP_OPT_ZSU       10                     /* experimental measurement */
#define IP_OPT_MTUP      11                     /* MTU probe */
#define IP_OPT_MTUR      12                     /* MTU reply */
#define IP_OPT_FINN     (13|IP_OPT_COPY|IP_OPT_DEBMEAS) /* exp flow control */
#define IP_OPT_VISA     (14|IP_OPT_COPY)        /* exp access control */
#define IP_OPT_ENCODE    15                     /* ??? */
#define IP_OPT_IMITD    (16|IP_OPT_COPY)        /* IMI traffic descriptor */
#define IP_OPT_EIP      (17|IP_OPT_COPY)        /* extended IP, RFC 1385 */
#define IP_OPT_TR       (18|IP_OPT_DEBMEAS)     /* traceroute */
#define IP_OPT_ADDEXT   (19|IP_OPT_COPY)        /* IPv7 ext addr, RFC 1475 */
#define IP_OPT_RTRALT   (20|IP_OPT_COPY)        /* router alert, RFC 2113 */
#define IP_OPT_SDB      (21|IP_OPT_COPY)        /* directed bcast, RFC 1770 */
#define IP_OPT_NSAPA    (22|IP_OPT_COPY)        /* NSAP addresses */
#define IP_OPT_DPS      (23|IP_OPT_COPY)        /* dynamic packet state */
#define IP_OPT_UMP      (24|IP_OPT_COPY)        /* upstream multicast */
#define IP_OPT_MAX       25

#define IP_OPT_COPIED(o)        ((o) & 0x80)
#define IP_OPT_CLASS(o)         ((o) & 0x60)
#define IP_OPT_NUMBER(o)        ((o) & 0x1f)
#define IP_OPT_TYPEONLY(o)      ((o) == IP_OPT_EOL || (o) == IP_OPT_NOP)

/*
 * Security option data - RFC 791, 3.1
 */
struct ip_opt_data_sec {
        uint16_t        s;              /* security */
        uint16_t        c;              /* compartments */
        uint16_t        h;              /* handling restrictions */
        uint8_t         tcc[3];         /* transmission control code */
} __attribute__((__packed__));

#define IP_OPT_SEC_UNCLASS      0x0000  /* unclassified */
#define IP_OPT_SEC_CONFID       0xf135  /* confidential */
#define IP_OPT_SEC_EFTO         0x789a  /* EFTO */
#define IP_OPT_SEC_MMMM         0xbc4d  /* MMMM */
#define IP_OPT_SEC_PROG         0x5e26  /* PROG */
#define IP_OPT_SEC_RESTR        0xaf13  /* restricted */
#define IP_OPT_SEC_SECRET       0xd788  /* secret */
#define IP_OPT_SEC_TOPSECRET    0x6bc5  /* top secret */

/*
 * {Loose Source, Record, Strict Source} Route option data - RFC 791, 3.1
 */
struct ip_opt_data_rr {
        uint8_t         ptr;            /* from start of option, >= 4 */
        uint32_t        iplist __flexarr; /* list of IP addresses */
} __attribute__((__packed__));

/*
 * Timestamp option data - RFC 791, 3.1
 */
struct ip_opt_data_ts {
        uint8_t         ptr;            /* from start of option, >= 5 */
#if DNET_BYTESEX == DNET_BIG_ENDIAN
        uint8_t         oflw:4,         /* number of IPs skipped */
                        flg:4;          /* address[ / timestamp] flag */
#elif DNET_BYTESEX == DNET_LIL_ENDIAN
        uint8_t         flg:4,
                        oflw:4;
#endif
        uint32_t        ipts __flexarr; /* IP address [/ timestamp] pairs */
} __attribute__((__packed__));

#define IP_OPT_TS_TSONLY        0       /* timestamps only */
#define IP_OPT_TS_TSADDR        1       /* IP address / timestamp pairs */
#define IP_OPT_TS_PRESPEC       3       /* IP address / zero timestamp pairs */

/*
 * Traceroute option data - RFC 1393, 2.2
 */
struct ip_opt_data_tr {
        uint16_t        id;             /* ID number */
        uint16_t        ohc;            /* outbound hop count */
        uint16_t        rhc;            /* return hop count */
        uint32_t        origip;         /* originator IP address */
} __attribute__((__packed__));

/*
 * IP option (following IP header)
 */
struct ip_opt {
        uint8_t         opt_type;       /* option type */
        uint8_t         opt_len;        /* option length >= IP_OPT_LEN */
        union ip_opt_data {
                struct ip_opt_data_sec  sec;       /* IP_OPT_SEC */
                struct ip_opt_data_rr   rr;        /* IP_OPT_{L,S}RR */
                struct ip_opt_data_ts   ts;        /* IP_OPT_TS */
                uint16_t                satid;     /* IP_OPT_SATID */
                uint16_t                mtu;       /* IP_OPT_MTU{P,R} */
                struct ip_opt_data_tr   tr;        /* IP_OPT_TR */
                uint32_t                addext[2]; /* IP_OPT_ADDEXT */
                uint16_t                rtralt;    /* IP_OPT_RTRALT */
                uint32_t                sdb[9];    /* IP_OPT_SDB */
                uint8_t                 data8[IP_OPT_LEN_MAX - IP_OPT_LEN];
        } opt_data;
} __attribute__((__packed__));

#ifndef __GNUC__
# pragma pack()
#endif

/*
 * Classful addressing
 */
#define IP_CLASSA(i)            (((uint32_t)(i) & htonl(0x80000000)) == \
                                 htonl(0x00000000))
#define IP_CLASSA_NET           (htonl(0xff000000))
#define IP_CLASSA_NSHIFT        24
#define IP_CLASSA_HOST          (htonl(0x00ffffff))
#define IP_CLASSA_MAX           128

#define IP_CLASSB(i)            (((uint32_t)(i) & htonl(0xc0000000)) == \
                                 htonl(0x80000000))
#define IP_CLASSB_NET           (htonl(0xffff0000))
#define IP_CLASSB_NSHIFT        16
#define IP_CLASSB_HOST          (htonl(0x0000ffff))
#define IP_CLASSB_MAX           65536

#define IP_CLASSC(i)            (((uint32_t)(i) & htonl(0xe0000000)) == \
                                 htonl(0xc0000000))
#define IP_CLASSC_NET           (htonl(0xffffff00))
#define IP_CLASSC_NSHIFT        8
#define IP_CLASSC_HOST          (htonl(0x000000ff))

#define IP_CLASSD(i)            (((uint32_t)(i) & htonl(0xf0000000)) == \
                                 htonl(0xe0000000))
/* These ones aren't really net and host fields, but routing needn't know. */
#define IP_CLASSD_NET           (htonl(0xf0000000))
#define IP_CLASSD_NSHIFT        28
#define IP_CLASSD_HOST          (htonl(0x0fffffff))
#define IP_MULTICAST(i)         IP_CLASSD(i)

#define IP_EXPERIMENTAL(i)      (((uint32_t)(i) & htonl(0xf0000000)) == \
                                 htonl(0xf0000000))
#define IP_BADCLASS(i)          (((uint32_t)(i) & htonl(0xf0000000)) == \
                                 htonl(0xf0000000))
#define IP_LOCAL_GROUP(i)       (((uint32_t)(i) & htonl(0xffffff00)) == \
                                 htonl(0xe0000000))
/*
 * Reserved addresses
 */
#define IP_ADDR_ANY             (htonl(0x00000000))     /* 0.0.0.0 */
#define IP_ADDR_BROADCAST       (htonl(0xffffffff))     /* 255.255.255.255 */
#define IP_ADDR_LOOPBACK        (htonl(0x7f000001))     /* 127.0.0.1 */
#define IP_ADDR_MCAST_ALL       (htonl(0xe0000001))     /* 224.0.0.1 */
#define IP_ADDR_MCAST_LOCAL     (htonl(0xe00000ff))     /* 224.0.0.255 */

#define ip_pack_hdr(hdr, tos, len, id, off, ttl, p, src, dst) do {      \
        struct ip_hdr *ip_pack_p = (struct ip_hdr *)(hdr);              \
        ip_pack_p->ip_v = 4; ip_pack_p->ip_hl = 5;                      \
        ip_pack_p->ip_tos = tos; ip_pack_p->ip_len = htons(len);        \
        ip_pack_p->ip_id = htons(id); ip_pack_p->ip_off = htons(off);   \
        ip_pack_p->ip_ttl = ttl; ip_pack_p->ip_p = p;                   \
        ip_pack_p->ip_src = src; ip_pack_p->ip_dst = dst;               \
} while (0)

typedef struct ip_handle ip_t;

__BEGIN_DECLS
ip_t    *ip_open(void);
ssize_t  ip_send(ip_t *i, const void *buf, size_t len);
ip_t    *ip_close(ip_t *i);

char    *ip_ntop(const ip_addr_t *ip, char *dst, size_t len);
int      ip_pton(const char *src, ip_addr_t *dst);
char    *ip_ntoa(const ip_addr_t *ip);
#define  ip_aton ip_pton

ssize_t  ip_add_option(void *buf, size_t len,
            int proto, const void *optbuf, size_t optlen);
void     ip_checksum(void *buf, size_t len);

int      ip_cksum_add(const void *buf, size_t len, int cksum);
#define  ip_cksum_carry(x) \
            (x = (x >> 16) + (x & 0xffff), (~(x + (x >> 16)) & 0xffff))
__END_DECLS

#endif /* DNET_IP_H */

---