IP(3)                      Library Functions Manual                      IP(3)

       eipfmt, parseip, parseipmask, v4parseip, v4parsecidr, parseether,
       myipaddr, myetheraddr, maskip, equivip, defmask, isv4, v4tov6, v6tov4,
       nhgetl, nhgets, nhgetv, hnputl, hnputs, hnputv, ptclbsum, readipifc -
       Internet protocol

       #include <u.h>
       #include <libc.h>
       #include <ip.h>

       int  eipfmt(Fmt*)

       ulong     parseip(uchar *ipaddr, char *str)

       ulong     parseipmask(uchar *ipaddr, char *str)

       char*     v4parseip(uchar *ipaddr, char *str)

       ulong     v4parsecidr(uchar *addr, uchar *mask, char *str)

       int  parseether(uchar *eaddr, char *str)

       int  myetheraddr(uchar *eaddr, char *dev)

       int  myipaddr(uchar *ipaddr, char *net)

       void maskip(uchar *from, uchar *mask, uchar *to)

       int  equivip(uchar *ipaddr1, uchar *ipaddr2)

       uchar*    defmask(uchar *ipaddr)

       int  isv4(uchar *ipaddr)

       void v4tov6(uchar *ipv6, uchar *ipv4)

       void v6tov4(uchar *ipv4, uchar *ipv6)

       ushort    nhgets(void *p)

       uint nhgetl(void *p)

       uvlong    nhgetv(void *p)

       void hnputs(void *p, ushort v)

       void hnputl(void *p, uint v)

       void hnputv(void *p, uvlong v)

       ushort    ptclbsum(uchar *a, int n)

       Ipifc*    readipifc(char *net, Ipifc *ifc, int index)

       uchar     IPv4bcast[IPaddrlen];

       uchar     IPv4allsys[IPaddrlen];

       uchar     IPv4allrouter[IPaddrlen];

       uchar     IPallbits[IPaddrlen];

       uchar     IPnoaddr[IPaddrlen];

       uchar     v4prefix[IPaddrlen];

       These routines are used by Internet Protocol (IP) programs to
       manipulate IP and Ethernet addresses.  Plan 9, by default, uses V6
       format IP addresses.  Since V4 addresses fit into the V6 space, all IP
       addresses can be represented.  IP addresses are stored as a string of
       16 unsigned chars, Ethernet addresses as 6 unsigned chars.  Either V4
       or V6 string representation can be used for IP addresses.  For V4
       addresses, the representation can be (up to) 4 decimal integers from 0
       to 255 separated by periods.  For V6 addresses, the representation is
       (up to) 8 hex integers from 0x0 to 0xFFFF separated by colons.  Strings
       of 0 integers can be elided using two colons.  For example, FFFF::1111
       is equivalent to FFFF:0:0:0:0:0:0:1111.  The string representation for
       IP masks is a superset of the address representation.  It includes
       slash notation that indicates the number of leading 1 bits in the mask.
       Thus, a V4 class C mask can be represented as
       FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FF00,, or /120.  The
       string representation of Ethernet addresses is exactly 12 hexadecimal

       Eipfmt is a print(3) formatter for Ethernet (verb E) addresses, IP V6
       (verb I) addresses, IP V4 (verb V) addresses, and IP V6 (verb M) masks.

       Parseip converts a string pointed to by str to a 16-byte IP address
       starting at ipaddr.  As a concession to backwards compatibility, if the
       string is a V4 address, the return value is an unsigned long integer
       containing the big-endian V4 address.  If not, the return value is 6.
       Parseipmask converts a string pointed to by str to a 6-byte IP mask
       starting at ipaddr.  It too returns an unsigned long big-endian V4
       address or 6.  Both routines return -1 on errors.

       V4parseip converts a string pointed to by str to a 4-byte V4 IP address
       starting at ipaddr.

       V4parsecidr converts a string of the form addr/mask, pointed to by str,
       to a 4-byte V4 IP address starting at ipaddr and a 4-byte V4 IP mask
       starting at mask.

       Myipaddr returns the first valid IP address in the IP stack rooted at

       Parseether converts a string pointed to by str to a 6-byte Ethernet
       address starting at eaddr.  Myetheraddr reads the Ethernet address
       string from file dev/1/stats and parses it into eaddr.  Both routines
       return a negative number on errors.

       Maskip places the bit-wise AND of the IP addresses pointed to by its
       first two arguments into the buffer pointed to by the third.

       Equivip returns non-zero if the IP addresses pointed to by its two
       arguments are equal.

       Defmask returns the standard class A, B, or C mask for ipaddr.

       Isv4 returns non-zero if the V6 address is in the V4 space, that is, if
       it starts with 0:0:0:0:0:0:FFFF.  V4tov6 converts the V4 address, v4ip,
       to a V6 address and puts the result in v6ip.  V6tov4 converts the V6
       address, v6ip, to a V4 address and puts the result in v4ip.

       Hnputs, hnputl, and hnputv are used to store 16-, 32-, and 64-bit
       integers into IP big-endian form.  Nhgets, nhgetl, and nhgetv convert
       big-endian 2-, 4-, and 8-byte quantities into integers.

       Pctlbsum returns the one's complement checksum used in IP protocols,
       typically invoked as
       hnputs(hdr->cksum, ~ptclbsum(data, len) & 0xffff);

       A number of standard IP addresses in V6 format are also defined.  They

              the V4 broadcast address

              the V4 all systems multicast address

              the V4 all routers multicast address

              the V6 all bits on address

              the V6 null address, all zeros

              the IP V6 prefix to all embedded V4 addresses

       Readipifc returns information about a particular interface  (index >=
       0) or all IP interfaces (index < 0) configured under a mount point net,
       default /net.  Each interface is described by one Ipifc structure which
       in turn points to a linked list of Iplifc structures describing the
       addresses assigned to this interface.  If the list ifc is supplied,
       that list is freed.  Thus, subsequent calls can be used to free the
       list returned by the previous call.  Ipifc is:

       typedef struct Ipifc
            Ipifc     *next;
            Iplifc    *lifc;         /* local addressses */

            /* per ip interface */
            int  index;         /* number of interface in ipifc dir */
            char dev[64];  /* associated physical device */
            int  mtu;      /* max transfer unit */

            long validlt;  /* valid life time */
            long preflt;        /* preferred life time */
            uchar     sendra6;  /* on == send router adv */
            uchar     recvra6;  /* on == rcv router adv */

            ulong     pktin;         /* packets read */
            ulong     pktout;        /* packets written */
            ulong     errin;         /* read errors */
            ulong     errout;        /* write errors */
            Ipv6rp    rp;       /* route advertisement params */
       } Ipifc;

       Iplifc is:

       struct Iplifc
            Iplifc    *next;

            uchar     ip[IPaddrlen];
            uchar     mask[IPaddrlen];
            uchar     net[IPaddrlen];          /* ip & mask */
            ulong     preflt;             /* preferred lifetime */
            ulong     validlt;       /* valid lifetime */

       Ipv6rp is: struct Ipv6rp {      int  mflag;      int  oflag;      int
        maxraint; /* max route adv interval */      int  minraint; /* min
       route adv interval */      int  linkmtu;      int  reachtime;
            int  rxmitra;      int  ttl;      int  routerlt;  };

       Dev contains the first 64 bytes of the device configured with this
       interface.  Net is ip&mask if the network is multipoint or the remote
       address if the network is point to point.