*prod*
On Tue, Aug 15, 2017 at 09:31:26AM +0000, Florian Obser wrote:
>
> Rename in6_get_rand_ifi() to get_last_resort_ifid() and delete the old
> get_last_resort_ifid() function because eww.
> Also if your system is so constraint that you end up in
> get_last_resort_ifid() you don't deserve a random ifid that stays
> stable over reboots.
> Simplify code a bit since get_ifid() can no longer fail.
> It couldn't fail before either because that code path was #if 0'ed.
>
> OK?
>
> diff --git netinet6/in6.h netinet6/in6.h
> index 0caae1f586a..d80bff21370 100644
> --- netinet6/in6.h
> +++ netinet6/in6.h
> @@ -418,7 +418,6 @@ void in6_proto_cksum_out(struct mbuf *, struct ifnet
> *);
> int in6_localaddr(struct in6_addr *);
> int in6_addrscope(struct in6_addr *);
> struct in6_ifaddr *in6_ifawithscope(struct ifnet *, struct in6_addr *,
> u_int);
> -void in6_get_rand_ifid(struct ifnet *, struct in6_addr *);
> int in6_mask2len(struct in6_addr *, u_char *);
> int in6_nam2sin6(const struct mbuf *, struct sockaddr_in6 **);
>
> diff --git netinet6/in6_ifattach.c netinet6/in6_ifattach.c
> index 89acde9c6a4..a8abf5fa695 100644
> --- netinet6/in6_ifattach.c
> +++ netinet6/in6_ifattach.c
> @@ -56,9 +56,9 @@
> #include <netinet6/ip6_mroute.h>
> #endif
>
> -int get_last_resort_ifid(struct ifnet *, struct in6_addr *);
> +void get_last_resort_ifid(struct ifnet *, struct in6_addr *);
> int get_hw_ifid(struct ifnet *, struct in6_addr *);
> -int get_ifid(struct ifnet *, struct in6_addr *);
> +void get_ifid(struct ifnet *, struct in6_addr *);
> int in6_ifattach_loopback(struct ifnet *);
>
> #define EUI64_GBIT 0x01
> @@ -72,52 +72,13 @@ int in6_ifattach_loopback(struct ifnet *);
> #define IFID_LOCAL(in6) (!EUI64_LOCAL(in6))
> #define IFID_UNIVERSAL(in6) (!EUI64_UNIVERSAL(in6))
>
> -/*
> - * Generate a last-resort interface identifier, when the machine has no
> - * IEEE802/EUI64 address sources.
> - * The goal here is to get an interface identifier that is
> - * (1) random enough and (2) does not change across reboot.
> - * We currently use SHA512(hostname) for it.
> - *
> - * in6 - upper 64bits are preserved
> - */
> -int
> -get_last_resort_ifid(struct ifnet *ifp, struct in6_addr *in6)
> -{
> - SHA2_CTX ctx;
> - u_int8_t digest[SHA512_DIGEST_LENGTH];
> -
> -#if 0
> - /* we need at least several letters as seed for ifid */
> - if (hostnamelen < 3)
> - return -1;
> -#endif
> -
> - /* generate 8 bytes of pseudo-random value. */
> - SHA512Init(&ctx);
> - SHA512Update(&ctx, hostname, hostnamelen);
> - SHA512Final(digest, &ctx);
> -
> - /* assumes sizeof(digest) > sizeof(ifid) */
> - bcopy(digest, &in6->s6_addr[8], 8);
> -
> - /* make sure to set "u" bit to local, and "g" bit to individual. */
> - in6->s6_addr[8] &= ~EUI64_GBIT; /* g bit to "individual" */
> - in6->s6_addr[8] |= EUI64_UBIT; /* u bit to "local" */
> -
> - /* convert EUI64 into IPv6 interface identifier */
> - EUI64_TO_IFID(in6);
> -
> - return 0;
> -}
> -
> /*
> * Generate a random interface identifier.
> *
> * in6 - upper 64bits are preserved
> */
> void
> -in6_get_rand_ifid(struct ifnet *ifp, struct in6_addr *in6)
> +get_last_resort_ifid(struct ifnet *ifp, struct in6_addr *in6)
> {
> arc4random_buf(&in6->s6_addr32[2], 8);
>
> @@ -235,7 +196,7 @@ get_hw_ifid(struct ifnet *ifp, struct in6_addr *in6)
> * available on ifp0, borrow interface identifier from other information
> * sources.
> */
> -int
> +void
> get_ifid(struct ifnet *ifp0, struct in6_addr *in6)
> {
> struct ifnet *ifp;
> @@ -267,22 +228,15 @@ get_ifid(struct ifnet *ifp0, struct in6_addr *in6)
> }
>
> /* last resort: get from random number source */
> - if (get_last_resort_ifid(ifp, in6) == 0) {
> - nd6log((LOG_DEBUG,
> - "%s: interface identifier generated by random number\n",
> - ifp0->if_xname));
> - goto success;
> - }
> -
> - printf("%s: failed to get interface identifier\n", ifp0->if_xname);
> - return -1;
> -
> + get_last_resort_ifid(ifp, in6);
> + nd6log((LOG_DEBUG,
> + "%s: interface identifier generated by random number\n",
> + ifp0->if_xname));
> success:
> nd6log((LOG_INFO, "%s: ifid: %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
> ifp0->if_xname, in6->s6_addr[8], in6->s6_addr[9], in6->s6_addr[10],
> in6->s6_addr[11], in6->s6_addr[12], in6->s6_addr[13],
> in6->s6_addr[14], in6->s6_addr[15]));
> - return 0;
> }
>
> /*
> @@ -318,13 +272,8 @@ in6_ifattach_linklocal(struct ifnet *ifp, struct
> in6_addr *ifid)
> ifra.ifra_addr.sin6_addr.s6_addr32[1] = 0;
> ifra.ifra_addr.sin6_addr.s6_addr[8] &= ~EUI64_GBIT;
> ifra.ifra_addr.sin6_addr.s6_addr[8] |= EUI64_UBIT;
> - } else {
> - if (get_ifid(ifp, &ifra.ifra_addr.sin6_addr) != 0) {
> - nd6log((LOG_ERR,
> - "%s: no ifid available\n", ifp->if_xname));
> - return (-1);
> - }
> - }
> + } else
> + get_ifid(ifp, &ifra.ifra_addr.sin6_addr);
>
> ifra.ifra_prefixmask.sin6_len = sizeof(struct sockaddr_in6);
> ifra.ifra_prefixmask.sin6_family = AF_INET6;
>
> --
> I'm not entirely sure you are real.
>
--
I'm not entirely sure you are real.
