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111 lines
1.8 KiB
C
111 lines
1.8 KiB
C
/*
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* BIRD Library -- IPv4 Address Manipulation Functions
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*
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* (c) 1998 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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#include <stdlib.h>
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#include "nest/bird.h"
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#include "lib/ip.h"
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#include "lib/string.h"
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int
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ipv4_classify(u32 a)
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{
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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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char *
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ip_ntop(ip_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",
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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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}
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char *
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ip_ntox(ip_addr a, char *b)
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{
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return b + bsprintf(b, "%08x", _I(a));
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}
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u32
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ipv4_class_mask(u32 a)
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{
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u32 m;
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if (a < 0x80000000)
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m = 0xff000000;
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if (a < 0xc0000000)
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m = 0xffff0000;
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else
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m = 0xffffff00;
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while (a & ~m)
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m |= m >> 1;
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return m;
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}
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int
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ip_pton(char *a, ip_addr *o)
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{
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int i,j;
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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 = ipa_from_u32(ia);
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return 1;
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}
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byte *
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ipv4_skip_header(byte *pkt, int *len)
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{
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int l = *len;
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int q;
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if (l < 20 || (*pkt & 0xf0) != 0x40)
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return NULL;
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q = (*pkt & 0x0f) * 4;
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if (q > l)
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return NULL;
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*len -= q;
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return pkt + q;
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}
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