Neither sin_len nor sin6_len can be 0 so these checks are not needed.

Also reorder the RTF_HOST vs netmask check. RTF_HOST wins if both are set.
Makes the code a bit neater.
OK tb@

diff --git a/usr.sbin/bgpd/kroute.c b/usr.sbin/bgpd/kroute.c
index 69c09c6..f7b402b 100644 (file)
--- a/usr.sbin/bgpd/kroute.c
+++ b/usr.sbin/bgpd/kroute.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: kroute.c,v 1.306 2023/10/16 10:25:45 claudio Exp $ */
+/*     $OpenBSD: kroute.c,v 1.307 2023/10/17 17:59:59 claudio Exp $ */
 
 /*
  * Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
@@ -2422,8 +2422,6 @@ mask2prefixlen4(struct sockaddr_in *sa_in)
 {
        in_addr_t ina;
 
-       if (sa_in->sin_len == 0)
-               return (0);
        ina = sa_in->sin_addr.s_addr;
        if (ina == 0)
                return (0);
@@ -2437,8 +2435,6 @@ mask2prefixlen6(struct sockaddr_in6 *sa_in6)
        uint8_t *ap, *ep;
        u_int    l = 0;
 
-       if (sa_in6->sin6_len == 0)
-               return (0);
        /*
         * sin6_len is the size of the sockaddr so subtract the offset of
         * the possibly truncated sin6_addr struct.
@@ -3096,20 +3092,20 @@ dispatch_rtmsg_addr(struct rt_msghdr *rtm, struct kroute_full *kf)
        switch (sa->sa_family) {
        case AF_INET:
                sa_in = (struct sockaddr_in *)rti_info[RTAX_NETMASK];
-               if (sa_in != NULL) {
-                       kf->prefixlen = mask2prefixlen4(sa_in);
-               } else if (rtm->rtm_flags & RTF_HOST)
+               if (rtm->rtm_flags & RTF_HOST)
                        kf->prefixlen = 32;
+               else if (sa_in != NULL)
+                       kf->prefixlen = mask2prefixlen4(sa_in);
                else
                        kf->prefixlen =
                            prefixlen_classful(kf->prefix.v4.s_addr);
                break;
        case AF_INET6:
                sa_in6 = (struct sockaddr_in6 *)rti_info[RTAX_NETMASK];
-               if (sa_in6 != NULL) {
-                       kf->prefixlen = mask2prefixlen6(sa_in6);
-               } else if (rtm->rtm_flags & RTF_HOST)
+               if (rtm->rtm_flags & RTF_HOST)
                        kf->prefixlen = 128;
+               else if (sa_in6 != NULL)
+                       kf->prefixlen = mask2prefixlen6(sa_in6);
                else
                        fatalx("in6 net addr without netmask");
                break;