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-rw-r--r--ext/dnet/ip.h487
1 files changed, 487 insertions, 0 deletions
diff --git a/ext/dnet/ip.h b/ext/dnet/ip.h
new file mode 100644
index 000000000..95b7718fb
--- /dev/null
+++ b/ext/dnet/ip.h
@@ -0,0 +1,487 @@
+/*
+ * ip.h
+ *
+ * Internet Protocol (RFC 791).
+ *
+ * Copyright (c) 2000 Dug Song <dugsong@monkey.org>
+ *
+ * $Id: ip.h,v 1.23 2003/03/16 17:39:17 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)) /* 224.0.0.225 */
+
+#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);
+size_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
+
+size_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);
+
+inline int
+ip_cksum_add(const void *buf, size_t len, int cksum)
+{
+ uint16_t *sp = (uint16_t *)buf;
+ int n, sn;
+
+ sn = len / 2;
+ n = (sn + 15) / 16;
+
+ /* XXX - unroll loop using Duff's device. */
+ switch (sn % 16) {
+ case 0: do {
+ cksum += *sp++;
+ case 15:
+ cksum += *sp++;
+ case 14:
+ cksum += *sp++;
+ case 13:
+ cksum += *sp++;
+ case 12:
+ cksum += *sp++;
+ case 11:
+ cksum += *sp++;
+ case 10:
+ cksum += *sp++;
+ case 9:
+ cksum += *sp++;
+ case 8:
+ cksum += *sp++;
+ case 7:
+ cksum += *sp++;
+ case 6:
+ cksum += *sp++;
+ case 5:
+ cksum += *sp++;
+ case 4:
+ cksum += *sp++;
+ case 3:
+ cksum += *sp++;
+ case 2:
+ cksum += *sp++;
+ case 1:
+ cksum += *sp++;
+ } while (--n > 0);
+ }
+ if (len & 1)
+ cksum += htons(*(u_char *)sp << 8);
+
+ return (cksum);
+}
+
+inline uint16_t
+ip_cksum_carry(int x)
+{
+ x = (x >> 16) + (x & 0xffff);
+ return ~(x + (x >> 16)) & 0xffff;
+}
+
+__END_DECLS
+
+#endif /* DNET_IP_H */