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- /*
- * linklocal - print ipv6 link-local or 6to4 address of a mac address.
- * eui is ieee's extended unique identifier, per rfc2373.
- */
- #include <u.h>
- #include <libc.h>
- #include <ip.h>
- enum {
- Mac0mcast = 1<<0, /* multicast address */
- Mac0localadm = 1<<1, /* locally-administered address, */
- V60globaladm = 1<<1, /* but ipv6 reverses the meaning */
- };
- static char *v4_6to4;
- static void
- usage(void)
- {
- fprint(2, "usage: %s [-t ipv4] ether...\n", argv0);
- exits("usage");
- }
- void
- ea2eui64(uchar *lla, uchar *ea)
- {
- *lla++ = *ea++ | V60globaladm; /* oui (company id) */
- *lla++ = *ea++; /* " */
- *lla++ = *ea++; /* " */
- *lla++ = 0xFF; /* mac-48 in eui-64 (sic) */
- *lla++ = 0xFE; /* " */
- *lla++ = *ea++; /* manufacturer-assigned */
- *lla++ = *ea++; /* " */
- *lla = *ea; /* " */
- }
- void
- eaip26to4(uchar *lla, uchar *ea, uchar *ipv4)
- {
- *lla++ = 0x20; /* 6to4 address */
- *lla++ = 0x02; /* " */
- memmove(lla, ipv4, IPv4addrlen);
- lla += IPv4addrlen;
- memset(lla, 0, 2);
- ea2eui64(lla + 2, ea);
- }
- void
- ea2lla(uchar *lla, uchar *ea)
- {
- *lla++ = 0xFE; /* link-local v6 */
- *lla++ = 0x80; /* " */
- memset(lla, 0, 6);
- ea2eui64(lla + 6, ea);
- }
- static void
- process(char *ether)
- {
- uchar ethaddr[6], ipaddr[IPaddrlen], ipv4[IPv4addrlen];
- if (parseether(ethaddr, ether) < 0)
- sysfatal("%s: not an ether address", ether);
- if (v4_6to4) {
- v4parseip(ipv4, v4_6to4);
- eaip26to4(ipaddr, ethaddr, ipv4);
- } else
- ea2lla(ipaddr, ethaddr);
- print("%I\n", ipaddr);
- }
- void
- main(int argc, char *argv[])
- {
- int i;
- ARGBEGIN {
- case 't':
- v4_6to4 = EARGF(usage());
- break;
- default:
- usage();
- break;
- } ARGEND
- fmtinstall('I', eipfmt);
- if (argc <= 0)
- usage();
- for (i = 0; i < argc; i++)
- process(argv[i]);
- exits(0);
- }
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