stop assuming prefix lengths, remove inet6_makenetandmask()

This removes any logic that implies IPv6 destination host addresses to be
/64 subnets so they are taken as is.
RFC 3587 deprecated this in 2003 and our manual page actually states:

  The route is assumed to be to a network if any of the following apply to
  destination:

  *   [...]
  *   it is an IPv6 address with a “/XX” suffix (where XX is the number of
      bits in the network portion of the address and is less than 128)
  *   [...]

  If destination is a valid IP address or host name, it is presumed to be a
  route to a host.

Stripping relevant code from `inet6_makenetandmask()' left the function as
dummy wrapper around `prefixlen()', so zap it completely.

Discussed with and positive feedback from many, OK benno henning

diff --git a/sbin/route/route.c b/sbin/route/route.c
index 115eae2..7bf2662 100644 (file)
--- a/sbin/route/route.c
+++ b/sbin/route/route.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: route.c,v 1.222 2018/07/14 13:37:44 benno Exp $       */
+/*     $OpenBSD: route.c,v 1.223 2018/07/17 20:57:27 kn Exp $  */
 /*     $NetBSD: route.c,v 1.16 1996/04/15 18:27:05 cgd Exp $   */
 
 /*
@@ -108,7 +108,6 @@ void         pmsg_common(struct rt_msghdr *);
 void    pmsg_addrs(char *, int);
 void    bprintf(FILE *, int, char *);
 void    mask_addr(union sockunion *, union sockunion *, int);
-int     inet6_makenetandmask(struct sockaddr_in6 *, char *);
 int     getaddr(int, int, char *, struct hostent **);
 void    getmplslabel(char *, int);
 int     rtmsg(int, int, int, uint8_t);
@@ -792,52 +791,6 @@ inet_makenetandmask(u_int32_t net, struct sockaddr_in *sin, int bits)
        sin->sin_len = 1 + cp - (char *)sin;
 }
 
-/*
- * XXX the function may need more improvement...
- */
-int
-inet6_makenetandmask(struct sockaddr_in6 *sin6, char *plen)
-{
-       struct in6_addr in6;
-       const char *errstr;
-       int i, len, q, r;
-
-       if (NULL==plen) {
-               if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) &&
-                   sin6->sin6_scope_id == 0) {
-                       plen = "0";
-               } else if ((sin6->sin6_addr.s6_addr[0] & 0xe0) == 0x20) {
-                       /* aggregatable global unicast - RFC2374 */
-                       memset(&in6, 0, sizeof(in6));
-                       if (!memcmp(&sin6->sin6_addr.s6_addr[8],
-                           &in6.s6_addr[8], 8))
-                               plen = "64";
-               }
-       }
-
-       if (!plen || strcmp(plen, "128") == 0)
-               return (1);
-       else {
-               rtm_addrs |= RTA_NETMASK;
-               prefixlen(AF_INET6, plen);
-
-               len = strtonum(plen, 0, 128, &errstr);
-               if (errstr)
-                       errx(1, "prefixlen %s is %s", plen, errstr);
-
-               q = (128-len) >> 3;
-               r = (128-len) & 7;
-               i = 15;
-
-               while (q-- > 0)
-                       sin6->sin6_addr.s6_addr[i--] = 0;
-               if (r > 0)
-                       sin6->sin6_addr.s6_addr[i] &= 0xff << r;
-
-               return (0);
-       }
-}
-
 /*
  * Interpret an argument as a network address of some kind,
  * returning 1 if a host address, 0 if a network address.
@@ -938,8 +891,13 @@ getaddr(int which, int af, char *s, struct hostent **hpp)
                        su->sin6.sin6_scope_id = 0;
                }
                if (hints.ai_flags == AI_NUMERICHOST) {
-                       if (which == RTA_DST)
-                               return (inet6_makenetandmask(&su->sin6, sep));
+                       if (which == RTA_DST) {
+                               if (sep == NULL && su->sin6.sin6_scope_id == 0 &&
+                                   IN6_IS_ADDR_UNSPECIFIED(&su->sin6.sin6_addr))
+                                       sep = "0";
+                               if (sep == NULL || prefixlen(AF_INET6, sep))
+                                       return (1);
+                       }
                        return (0);
                } else
                        return (1);