mirror of
https://gitlab.nic.cz/labs/bird.git
synced 2024-11-14 07:08:42 +00:00
382 lines
6.9 KiB
C
382 lines
6.9 KiB
C
/*
|
|
* BIRD Library -- IPv6 Address Manipulation Functions
|
|
*
|
|
* (c) 1999 Martin Mares <mj@ucw.cz>
|
|
*
|
|
* Can be freely distributed and used under the terms of the GNU GPL.
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
|
|
#include "nest/bird.h"
|
|
#include "lib/ip.h"
|
|
#include "lib/bitops.h"
|
|
#include "lib/endian.h"
|
|
#include "lib/string.h"
|
|
|
|
/*
|
|
* See RFC 2373 for explanation of IPv6 addressing issues.
|
|
*/
|
|
|
|
ip_addr
|
|
ipv6_mkmask(unsigned n)
|
|
{
|
|
ip_addr a;
|
|
int i;
|
|
|
|
for(i=0; i<4; i++)
|
|
{
|
|
if (!n)
|
|
a.addr[i] = 0;
|
|
else if (n >= 32)
|
|
{
|
|
a.addr[i] = ~0;
|
|
n -= 32;
|
|
}
|
|
else
|
|
{
|
|
a.addr[i] = u32_mkmask(n);
|
|
n = 0;
|
|
}
|
|
}
|
|
return a;
|
|
}
|
|
|
|
unsigned
|
|
ipv6_mklen(ip_addr *a)
|
|
{
|
|
int i, j, n;
|
|
|
|
for(i=0, n=0; i<4; i++, n+=32)
|
|
if (a->addr[i] != ~0U)
|
|
{
|
|
j = u32_masklen(a->addr[i]);
|
|
if (j < 0)
|
|
return j;
|
|
n += j;
|
|
while (++i < 4)
|
|
if (a->addr[i])
|
|
return -1;
|
|
break;
|
|
}
|
|
return n;
|
|
}
|
|
|
|
int
|
|
ipv6_classify(ip_addr *a)
|
|
{
|
|
u32 x = a->addr[0];
|
|
|
|
if ((x & 0xe0000000) == 0x20000000) /* Aggregatable Global Unicast Address */
|
|
return IADDR_HOST | SCOPE_UNIVERSE;
|
|
if ((x & 0xffc00000) == 0xfe800000) /* Link-Local Address */
|
|
return IADDR_HOST | SCOPE_LINK;
|
|
if ((x & 0xffc00000) == 0xfec00000) /* Site-Local Address */
|
|
return IADDR_HOST | SCOPE_SITE;
|
|
if ((x & 0xff000000) == 0xff000000) /* Multicast Address */
|
|
{
|
|
unsigned int scope = (x >> 16) & 0x0f;
|
|
switch (scope)
|
|
{
|
|
case 1: return IADDR_MULTICAST | SCOPE_HOST;
|
|
case 2: return IADDR_MULTICAST | SCOPE_LINK;
|
|
case 5: return IADDR_MULTICAST | SCOPE_SITE;
|
|
case 8: return IADDR_MULTICAST | SCOPE_ORGANIZATION;
|
|
case 14: return IADDR_MULTICAST | SCOPE_UNIVERSE;
|
|
}
|
|
}
|
|
if (!x && !a->addr[1] && !a->addr[2])
|
|
{
|
|
u32 y = a->addr[3];
|
|
if (y == 1)
|
|
return IADDR_HOST | SCOPE_HOST; /* Loopback address */
|
|
/* IPv4 compatible addresses */
|
|
if (y >= 0x7f000000 && y < 0x80000000)
|
|
return IADDR_HOST | SCOPE_HOST;
|
|
if ((y & 0xff000000) == 0x0a000000 ||
|
|
(y & 0xffff0000) == 0xc0a80000 ||
|
|
(y & 0xfff00000) == 0xac100000)
|
|
return IADDR_HOST | SCOPE_SITE;
|
|
if (y >= 0x01000000 && y < 0xe0000000)
|
|
return IADDR_HOST | SCOPE_UNIVERSE;
|
|
}
|
|
return IADDR_INVALID;
|
|
}
|
|
|
|
void
|
|
ipv6_hton(ip_addr *a)
|
|
{
|
|
int i;
|
|
|
|
for(i=0; i<4; i++)
|
|
a->addr[i] = htonl(a->addr[i]);
|
|
}
|
|
|
|
void
|
|
ipv6_ntoh(ip_addr *a)
|
|
{
|
|
int i;
|
|
|
|
for(i=0; i<4; i++)
|
|
a->addr[i] = ntohl(a->addr[i]);
|
|
}
|
|
|
|
int
|
|
ipv6_compare(ip_addr X, ip_addr Y)
|
|
{
|
|
int i;
|
|
ip_addr *x = &X;
|
|
ip_addr *y = &Y;
|
|
|
|
for(i=0; i<4; i++)
|
|
if (x->addr[i] > y->addr[i])
|
|
return 1;
|
|
else if (x->addr[i] < y->addr[i])
|
|
return -1;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Conversion of IPv6 address to presentation format and vice versa.
|
|
* Heavily inspired by routines written by Paul Vixie for the BIND project
|
|
* and of course by RFC 2373.
|
|
*/
|
|
|
|
char *
|
|
ip_ntop(ip_addr a, char *b)
|
|
{
|
|
u16 words[8];
|
|
int bestpos, bestlen, curpos, curlen, i;
|
|
|
|
/* First of all, preprocess the address and find the longest run of zeros */
|
|
bestlen = bestpos = curpos = curlen = 0;
|
|
for(i=0; i<8; i++)
|
|
{
|
|
u32 x = a.addr[i/2];
|
|
words[i] = ((i%2) ? x : (x >> 16)) & 0xffff;
|
|
if (words[i])
|
|
curlen = 0;
|
|
else
|
|
{
|
|
if (!curlen)
|
|
curpos = i;
|
|
curlen++;
|
|
if (curlen > bestlen)
|
|
{
|
|
bestpos = curpos;
|
|
bestlen = curlen;
|
|
}
|
|
}
|
|
}
|
|
if (bestlen < 2)
|
|
bestpos = -1;
|
|
|
|
/* Is it an encapsulated IPv4 address? */
|
|
if (!bestpos &&
|
|
(bestlen == 5 && a.addr[2] == 0xffff ||
|
|
bestlen == 6))
|
|
{
|
|
u32 x = a.addr[3];
|
|
b += bsprintf(b, "::%s%d.%d.%d.%d",
|
|
a.addr[2] ? "ffff:" : "",
|
|
((x >> 24) & 0xff),
|
|
((x >> 16) & 0xff),
|
|
((x >> 8) & 0xff),
|
|
(x & 0xff));
|
|
return b;
|
|
}
|
|
|
|
/* Normal IPv6 formatting, compress the largest sequence of zeros */
|
|
for(i=0; i<8; i++)
|
|
{
|
|
if (i == bestpos)
|
|
{
|
|
i += bestlen - 1;
|
|
*b++ = ':';
|
|
if (i == 7)
|
|
*b++ = ':';
|
|
}
|
|
else
|
|
{
|
|
if (i)
|
|
*b++ = ':';
|
|
b += bsprintf(b, "%x", words[i]);
|
|
}
|
|
}
|
|
*b = 0;
|
|
return b;
|
|
}
|
|
|
|
char *
|
|
ip_ntox(ip_addr a, char *b)
|
|
{
|
|
int i;
|
|
|
|
for(i=0; i<4; i++)
|
|
{
|
|
if (i)
|
|
*b++ = '.';
|
|
b += bsprintf(b, "%08x", a.addr[i]);
|
|
}
|
|
return b;
|
|
}
|
|
|
|
int
|
|
ipv4_pton_u32(char *a, u32 *o)
|
|
{
|
|
int i;
|
|
unsigned long int l;
|
|
u32 ia = 0;
|
|
|
|
i=4;
|
|
while (i--)
|
|
{
|
|
char *d, *c = strchr(a, '.');
|
|
if (!c != !i)
|
|
return 0;
|
|
l = strtoul(a, &d, 10);
|
|
if (d != c && *d || l > 255)
|
|
return 0;
|
|
ia = (ia << 8) | l;
|
|
if (c)
|
|
c++;
|
|
a = c;
|
|
}
|
|
*o = ia;
|
|
return 1;
|
|
}
|
|
|
|
int
|
|
ip_pton(char *a, ip_addr *o)
|
|
{
|
|
u16 words[8];
|
|
int i, j, k, l, hfil;
|
|
char *start;
|
|
|
|
if (a[0] == ':') /* Leading :: */
|
|
{
|
|
if (a[1] != ':')
|
|
return 0;
|
|
a++;
|
|
}
|
|
hfil = -1;
|
|
i = 0;
|
|
while (*a)
|
|
{
|
|
if (*a == ':') /* :: */
|
|
{
|
|
if (hfil >= 0)
|
|
return 0;
|
|
hfil = i;
|
|
a++;
|
|
continue;
|
|
}
|
|
j = 0;
|
|
l = 0;
|
|
start = a;
|
|
for(;;)
|
|
{
|
|
if (*a >= '0' && *a <= '9')
|
|
k = *a++ - '0';
|
|
else if (*a >= 'A' && *a <= 'F')
|
|
k = *a++ - 'A' + 10;
|
|
else if (*a >= 'a' && *a <= 'f')
|
|
k = *a++ - 'a' + 10;
|
|
else
|
|
break;
|
|
j = (j << 4) + k;
|
|
if (j >= 0x10000 || ++l > 4)
|
|
return 0;
|
|
}
|
|
if (*a == ':' && a[1])
|
|
a++;
|
|
else if (*a == '.' && (i == 6 || i < 6 && hfil >= 0))
|
|
{ /* Embedded IPv4 address */
|
|
u32 x;
|
|
if (!ipv4_pton_u32(start, &x))
|
|
return 0;
|
|
words[i++] = x >> 16;
|
|
words[i++] = x;
|
|
break;
|
|
}
|
|
else if (*a)
|
|
return 0;
|
|
if (i >= 8)
|
|
return 0;
|
|
words[i++] = j;
|
|
}
|
|
|
|
/* Replace :: with an appropriate number of zeros */
|
|
if (hfil >= 0)
|
|
{
|
|
j = 8 - i;
|
|
for(i=7; i-j >= hfil; i--)
|
|
words[i] = words[i-j];
|
|
for(; i>=hfil; i--)
|
|
words[i] = 0;
|
|
}
|
|
|
|
/* Convert the address to ip_addr format */
|
|
for(i=0; i<4; i++)
|
|
o->addr[i] = (words[2*i] << 16) | words[2*i+1];
|
|
return 1;
|
|
}
|
|
|
|
void ipv6_absolutize(ip_addr *a, ip_addr *ifa)
|
|
{
|
|
if ((a->addr[0] & 0xffc00000) == 0xfe800000 && /* a is link-scope */
|
|
((ifa->addr[0] & 0xe0000000) == 0x20000000 | /* ifa is AGU ... */
|
|
(ifa->addr[0] & 0xffc00000) == 0xfec00000)) /* ... or site-scope */
|
|
{
|
|
a->addr[0] = ifa->addr[0]; /* Copy the prefix, leave interface ID */
|
|
a->addr[1] = ifa->addr[1];
|
|
}
|
|
}
|
|
|
|
#ifdef TEST
|
|
|
|
#include "bitops.c"
|
|
|
|
static void test(char *x)
|
|
{
|
|
ip_addr a;
|
|
char c[STD_ADDRESS_P_LENGTH+1];
|
|
|
|
printf("%-40s ", x);
|
|
if (!ip_pton(x, &a))
|
|
{
|
|
puts("BAD");
|
|
return;
|
|
}
|
|
ip_ntop(a, c);
|
|
printf("%-40s %04x\n", c, ipv6_classify(&a));
|
|
}
|
|
|
|
int main(void)
|
|
{
|
|
puts("Positive tests:");
|
|
test("1:2:3:4:5:6:7:8");
|
|
test("dead:beef:DEAD:BEEF::f00d");
|
|
test("::");
|
|
test("::1");
|
|
test("1::");
|
|
test("::1.234.5.6");
|
|
test("::ffff:1.234.5.6");
|
|
test("::fffe:1.234.5.6");
|
|
test("1:2:3:4:5:6:7::8");
|
|
test("2080::8:800:200c:417a");
|
|
test("ff01::101");
|
|
|
|
puts("Negative tests:");
|
|
test(":::");
|
|
test("1:2:3:4:5:6:7:8:");
|
|
test("1::2::3");
|
|
test("::12345");
|
|
test("::1.2.3.4:5");
|
|
test(":1:2:3:4:5:6:7:8");
|
|
test("g:1:2:3:4:5:6:7");
|
|
return 0;
|
|
}
|
|
|
|
#endif
|