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-rw-r--r--lib/ipv6.c349
1 files changed, 347 insertions, 2 deletions
diff --git a/lib/ipv6.c b/lib/ipv6.c
index e612af72..c1b07637 100644
--- a/lib/ipv6.c
+++ b/lib/ipv6.c
@@ -1,12 +1,357 @@
/*
* BIRD Library -- IPv6 Address Manipulation Functions
*
- * (c) 1998 Martin Mares <mj@ucw.cz>
+ * (c) 1999 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
+ *
*/
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+
#include "nest/bird.h"
#include "lib/ip.h"
+#include "lib/bitops.h"
+#include "lib/endian.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];
+
+ /* FIXME: Relax these requirements? */
+ if ((x & 0xe0000000) == 0x20000000) /* Aggregatable Global Unicast Address */
+ return IADDR_HOST | SCOPE_UNIVERSE;
+ if ((x & 0xfc000000) == 0xe8000000) /* Link-Local Address */
+ return IADDR_HOST | SCOPE_LINK;
+ if ((x & 0xfc000000) == 0xec000000) /* 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;
+ }
+ }
+ 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;
+
+ 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;
+ char *c;
+
+ /* 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 += sprintf(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 += sprintf(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 += sprintf(b, "%08x", a.addr[i]);
+ }
+ return b;
+}
+
+int
+ipv4_pton_u32(char *a, u32 *o)
+{
+ int i,j;
+ 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;
+}
+
+#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;
+}
-#error "Ought to implement these."
+#endif
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