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583 lines
12 KiB
C
583 lines
12 KiB
C
/*
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* BIRD Library -- IP address functions
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*
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* (c) 1998--2000 Martin Mares <mj@ucw.cz>
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*
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* Can be freely distributed and used under the terms of the GNU GPL.
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*/
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/**
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* DOC: IP addresses
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*
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* BIRD uses its own abstraction of IP address in order to share the same
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* code for both IPv4 and IPv6. IP addresses are represented as entities
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* of type &ip_addr which are never to be treated as numbers and instead
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* they must be manipulated using the following functions and macros.
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*/
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#include <stdlib.h>
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#include "nest/bird.h"
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#include "lib/ip.h"
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int
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ip6_compare(ip6_addr a, ip6_addr b)
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{
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int i;
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for (i=0; i<4; i++)
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if (a.addr[i] > b.addr[i])
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return 1;
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else if (a.addr[i] < b.addr[i])
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return -1;
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return 0;
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}
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ip6_addr
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ip6_mkmask(uint n)
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{
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ip6_addr a;
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int i;
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for (i=0; i<4; i++)
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{
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if (!n)
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a.addr[i] = 0;
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else if (n >= 32)
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{
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a.addr[i] = ~0;
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n -= 32;
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}
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else
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{
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a.addr[i] = u32_mkmask(n);
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n = 0;
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}
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}
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return a;
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}
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uint
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ip6_masklen(ip6_addr *a)
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{
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int i, j, n;
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for (i=0, n=0; i<4; i++, n+=32)
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if (a->addr[i] != ~0U)
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{
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j = u32_masklen(a->addr[i]);
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if (j < 0)
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return j;
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n += j;
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while (++i < 4)
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if (a->addr[i])
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return 255;
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break;
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}
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return n;
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}
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int
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ip4_classify(ip4_addr ad)
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{
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u32 a = _I(ad);
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u32 b = a >> 24U;
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if (b && b <= 0xdf)
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{
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if (b == 0x7f)
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return IADDR_HOST | SCOPE_HOST;
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else if ((b == 0x0a) ||
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((a & 0xffff0000) == 0xc0a80000) ||
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((a & 0xfff00000) == 0xac100000))
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return IADDR_HOST | SCOPE_SITE;
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else
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return IADDR_HOST | SCOPE_UNIVERSE;
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}
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if (b >= 0xe0 && b <= 0xef)
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return IADDR_MULTICAST | SCOPE_UNIVERSE;
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if (a == 0xffffffff)
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return IADDR_BROADCAST | SCOPE_LINK;
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return IADDR_INVALID;
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}
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int
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ip6_classify(ip6_addr *a)
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{
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u32 x = a->addr[0];
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if ((x & 0xe0000000) == 0x20000000) /* 2000::/3 Aggregatable Global Unicast Address */
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return IADDR_HOST | SCOPE_UNIVERSE;
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if ((x & 0xffc00000) == 0xfe800000) /* fe80::/10 Link-Local Address */
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return IADDR_HOST | SCOPE_LINK;
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if ((x & 0xffc00000) == 0xfec00000) /* fec0::/10 Site-Local Address */
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return IADDR_HOST | SCOPE_SITE;
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if ((x & 0xfe000000) == 0xfc000000) /* fc00::/7 Unique Local Unicast Address (RFC 4193) */
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return IADDR_HOST | SCOPE_SITE;
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if ((x & 0xff000000) == 0xff000000) /* ff00::/8 Multicast Address */
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{
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uint scope = (x >> 16) & 0x0f;
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switch (scope)
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{
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case 1: return IADDR_MULTICAST | SCOPE_HOST;
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case 2: return IADDR_MULTICAST | SCOPE_LINK;
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case 5: return IADDR_MULTICAST | SCOPE_SITE;
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case 8: return IADDR_MULTICAST | SCOPE_ORGANIZATION;
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case 14: return IADDR_MULTICAST | SCOPE_UNIVERSE;
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default: return IADDR_MULTICAST | SCOPE_UNDEFINED;
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}
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}
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if (!x && !a->addr[1])
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{
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u32 a2 = a->addr[2];
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u32 a3 = a->addr[3];
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if (a2 == 0 && a3 == 1)
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return IADDR_HOST | SCOPE_HOST; /* Loopback address */
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if (a2 == 0)
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return ip4_classify(_MI4(a3)); /* IPv4 compatible addresses */
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if (a2 == 0xffff)
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return ip4_classify(_MI4(a3)); /* IPv4 mapped addresses */
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return IADDR_INVALID;
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}
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return IADDR_HOST | SCOPE_UNDEFINED;
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}
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/*
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* Conversion of IPv6 address to presentation format and vice versa.
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* Heavily inspired by routines written by Paul Vixie for the BIND project
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* and of course by RFC 2373.
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*/
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char *
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ip4_ntop(ip4_addr a, char *b)
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{
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u32 x = _I(a);
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return b + bsprintf(b, "%d.%d.%d.%d", (x >> 24) & 0xff, (x >> 16) & 0xff, (x >> 8) & 0xff, x & 0xff);
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}
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char *
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ip6_ntop(ip6_addr a, char *b)
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{
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u16 words[8];
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int bestpos, bestlen, curpos, curlen, i;
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/* First of all, preprocess the address and find the longest run of zeros */
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bestlen = bestpos = curpos = curlen = 0;
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for (i=0; i<8; i++)
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{
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u32 x = a.addr[i/2];
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words[i] = ((i%2) ? x : (x >> 16)) & 0xffff;
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if (words[i])
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curlen = 0;
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else
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{
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if (!curlen)
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curpos = i;
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curlen++;
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if (curlen > bestlen)
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{
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bestpos = curpos;
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bestlen = curlen;
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}
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}
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}
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if (bestlen < 2)
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bestpos = -1;
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/* Is it an encapsulated IPv4 address? */
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if (!bestpos && ((bestlen == 5 && a.addr[2] == 0xffff) || (bestlen == 6)))
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{
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u32 x = a.addr[3];
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b += bsprintf(b, "::%s%d.%d.%d.%d",
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a.addr[2] ? "ffff:" : "",
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(x >> 24) & 0xff,
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(x >> 16) & 0xff,
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(x >> 8) & 0xff,
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x & 0xff);
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return b;
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}
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/* Normal IPv6 formatting, compress the largest sequence of zeros */
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for (i=0; i<8; i++)
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{
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if (i == bestpos)
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{
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i += bestlen - 1;
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*b++ = ':';
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if (i == 7)
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*b++ = ':';
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}
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else
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{
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if (i)
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*b++ = ':';
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b += bsprintf(b, "%x", words[i]);
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}
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}
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*b = 0;
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return b;
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}
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int
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ip4_pton(const char *a, ip4_addr *o)
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{
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int i;
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unsigned long int l;
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u32 ia = 0;
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i=4;
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while (i--)
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{
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char *d, *c = strchr(a, '.');
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if (!c != !i)
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return 0;
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l = strtoul(a, &d, 10);
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if (((d != c) && *d) || (l > 255))
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return 0;
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ia = (ia << 8) | l;
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if (c)
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c++;
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a = c;
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}
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*o = ip4_from_u32(ia);
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return 1;
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}
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int
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ip6_pton(const char *a, ip6_addr *o)
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{
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u16 words[8];
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int i, j, k, l, hfil;
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const char *start;
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if (a[0] == ':') /* Leading :: */
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{
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if (a[1] != ':')
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return 0;
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a++;
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}
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hfil = -1;
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i = 0;
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while (*a)
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{
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if (*a == ':') /* :: */
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{
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if (hfil >= 0)
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return 0;
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hfil = i;
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a++;
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continue;
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}
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j = 0;
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l = 0;
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start = a;
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for (;;)
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{
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if (*a >= '0' && *a <= '9')
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k = *a++ - '0';
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else if (*a >= 'A' && *a <= 'F')
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k = *a++ - 'A' + 10;
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else if (*a >= 'a' && *a <= 'f')
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k = *a++ - 'a' + 10;
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else
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break;
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j = (j << 4) + k;
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if (j >= 0x10000 || ++l > 4)
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return 0;
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}
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if (*a == ':' && a[1])
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a++;
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else if (*a == '.' && (i == 6 || i < 6 && hfil >= 0))
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{ /* Embedded IPv4 address */
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ip4_addr x;
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if (!ip4_pton(start, &x))
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return 0;
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words[i++] = _I(x) >> 16;
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words[i++] = _I(x);
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break;
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}
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else if (*a)
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return 0;
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if (i >= 8)
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return 0;
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words[i++] = j;
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}
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/* Replace :: with an appropriate number of zeros */
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if (hfil >= 0)
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{
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j = 8 - i;
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for (i=7; i-j >= hfil; i--)
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words[i] = words[i-j];
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for (; i>=hfil; i--)
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words[i] = 0;
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}
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/* Convert the address to ip6_addr format */
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for (i=0; i<4; i++)
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o->addr[i] = (words[2*i] << 16) | words[2*i+1];
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return 1;
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}
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/**
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* ip_scope_text - get textual representation of address scope
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* @scope: scope (%SCOPE_xxx)
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*
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* Returns a pointer to a textual name of the scope given.
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*/
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char *
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ip_scope_text(uint scope)
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{
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static char *scope_table[] = { "host", "link", "site", "org", "univ", "undef" };
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if (scope > SCOPE_UNDEFINED)
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return "?";
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else
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return scope_table[scope];
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}
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ip4_addr
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ip4_class_mask(ip4_addr ad)
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{
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u32 m, a = _I(ad);
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if (a == 0x00000000)
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m = 0x00000000;
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else if (a < 0x80000000)
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m = 0xff000000;
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else if (a < 0xc0000000)
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m = 0xffff0000;
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else
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m = 0xffffff00;
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if (a & ~m)
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m = 0xffffffff;
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return _MI4(m);
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}
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#if 0
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/**
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* ipa_equal - compare two IP addresses for equality
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* @x: IP address
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* @y: IP address
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*
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* ipa_equal() returns 1 if @x and @y represent the same IP address, else 0.
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*/
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int ipa_equal(ip_addr x, ip_addr y) { DUMMY }
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/**
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* ipa_nonzero - test if an IP address is defined
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* @x: IP address
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*
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* ipa_nonzero returns 1 if @x is a defined IP address (not all bits are zero),
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* else 0.
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*
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* The undefined all-zero address is reachable as a |IPA_NONE| macro.
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*/
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int ipa_nonzero(ip_addr x) { DUMMY }
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/**
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* ipa_and - compute bitwise and of two IP addresses
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* @x: IP address
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* @y: IP address
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*
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* This function returns a bitwise and of @x and @y. It's primarily
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* used for network masking.
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*/
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ip_addr ipa_and(ip_addr x, ip_addr y) { DUMMY }
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/**
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* ipa_or - compute bitwise or of two IP addresses
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* @x: IP address
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* @y: IP address
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*
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* This function returns a bitwise or of @x and @y.
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*/
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ip_addr ipa_or(ip_addr x, ip_addr y) { DUMMY }
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/**
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* ipa_xor - compute bitwise xor of two IP addresses
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* @x: IP address
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* @y: IP address
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*
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* This function returns a bitwise xor of @x and @y.
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*/
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ip_addr ipa_xor(ip_addr x, ip_addr y) { DUMMY }
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/**
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* ipa_not - compute bitwise negation of two IP addresses
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* @x: IP address
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*
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* This function returns a bitwise negation of @x.
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*/
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ip_addr ipa_not(ip_addr x) { DUMMY }
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/**
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* ipa_mkmask - create a netmask
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* @x: prefix length
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*
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* This function returns an &ip_addr corresponding of a netmask
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* of an address prefix of size @x.
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*/
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ip_addr ipa_mkmask(int x) { DUMMY }
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/**
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* ipa_masklen - calculate netmask length
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* @x: IP address
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*
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* This function checks whether @x represents a valid netmask and
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* returns the size of the associate network prefix or -1 for invalid
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* mask.
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*/
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int ipa_masklen(ip_addr x) { DUMMY }
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/**
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* ipa_hash - hash IP addresses
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* @x: IP address
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*
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* ipa_hash() returns a 16-bit hash value of the IP address @x.
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*/
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int ipa_hash(ip_addr x) { DUMMY }
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/**
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* ipa_hton - convert IP address to network order
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* @x: IP address
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*
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* Converts the IP address @x to the network byte order.
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*
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* Beware, this is a macro and it alters the argument!
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*/
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void ipa_hton(ip_addr x) { DUMMY }
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/**
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* ipa_ntoh - convert IP address to host order
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* @x: IP address
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*
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* Converts the IP address @x from the network byte order.
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*
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* Beware, this is a macro and it alters the argument!
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*/
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void ipa_ntoh(ip_addr x) { DUMMY }
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/**
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* ipa_classify - classify an IP address
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* @x: IP address
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*
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* ipa_classify() returns an address class of @x, that is a bitwise or
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* of address type (%IADDR_INVALID, %IADDR_HOST, %IADDR_BROADCAST, %IADDR_MULTICAST)
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* with address scope (%SCOPE_HOST to %SCOPE_UNIVERSE) or -1 (%IADDR_INVALID)
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* for an invalid address.
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*/
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int ipa_classify(ip_addr x) { DUMMY }
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/**
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* ip4_class_mask - guess netmask according to address class
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* @x: IPv4 address
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*
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* This function (available in IPv4 version only) returns a
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* network mask according to the address class of @x. Although
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* classful addressing is nowadays obsolete, there still live
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* routing protocols transferring no prefix lengths nor netmasks
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* and this function could be useful to them.
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*/
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ip4_addr ip4_class_mask(ip4_addr x) { DUMMY }
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/**
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* ipa_from_u32 - convert IPv4 address to an integer
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* @x: IP address
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*
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* This function takes an IPv4 address and returns its numeric
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* representation.
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*/
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u32 ipa_from_u32(ip_addr x) { DUMMY }
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/**
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* ipa_to_u32 - convert integer to IPv4 address
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* @x: a 32-bit integer
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*
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* ipa_to_u32() takes a numeric representation of an IPv4 address
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* and converts it to the corresponding &ip_addr.
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*/
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ip_addr ipa_to_u32(u32 x) { DUMMY }
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/**
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* ipa_compare - compare two IP addresses for order
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* @x: IP address
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* @y: IP address
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*
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* The ipa_compare() function takes two IP addresses and returns
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* -1 if @x is less than @y in canonical ordering (lexicographical
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* order of the bit strings), 1 if @x is greater than @y and 0
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* if they are the same.
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*/
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int ipa_compare(ip_addr x, ip_addr y) { DUMMY }
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|
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/**
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* ipa_build6 - build an IPv6 address from parts
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* @a1: part #1
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* @a2: part #2
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* @a3: part #3
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* @a4: part #4
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*
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* ipa_build() takes @a1 to @a4 and assembles them to a single IPv6
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* address. It's used for example when a protocol wants to bind its
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* socket to a hard-wired multicast address.
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*/
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ip_addr ipa_build6(u32 a1, u32 a2, u32 a3, u32 a4) { DUMMY }
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|
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/**
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* ip_ntop - convert IP address to textual representation
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* @a: IP address
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* @buf: buffer of size at least %STD_ADDRESS_P_LENGTH
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*
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* This function takes an IP address and creates its textual
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|
* representation for presenting to the user.
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*/
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char *ip_ntop(ip_addr a, char *buf) { DUMMY }
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|
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/**
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* ip_ntox - convert IP address to hexadecimal representation
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|
* @a: IP address
|
|
* @buf: buffer of size at least %STD_ADDRESS_P_LENGTH
|
|
*
|
|
* This function takes an IP address and creates its hexadecimal
|
|
* textual representation. Primary use: debugging dumps.
|
|
*/
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|
char *ip_ntox(ip_addr a, char *buf) { DUMMY }
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|
|
|
/**
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|
* ip_pton - parse textual representation of IP address
|
|
* @a: textual representation
|
|
* @o: where to put the resulting address
|
|
*
|
|
* This function parses a textual IP address representation and
|
|
* stores the decoded address to a variable pointed to by @o.
|
|
* Returns 0 if a parse error has occurred, else 0.
|
|
*/
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|
int ip_pton(char *a, ip_addr *o) { DUMMY }
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|
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#endif
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