Simplify nd6_options() initialise logic

nd_opts_{search,last,done} are exlusively used in the internal option
handling machinery;  the only two nd6_options() callers only use
nd_opts_{src,tgt}_lladdr.

nd6_options() always zeroes and initialises the caller's struct nd_opts.
If icmp6len is zero, i.e. if there are no ICMP6 header options left,
everything inside *ndopts is zero, except nd_opts_done=1 which is not
used by the callers.

Set the internal nd_opts_{search,last,done} members only when needed.

OK claudio

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 5dafa5f..f13f318 100644 (file)
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: nd6.c,v 1.260 2022/12/10 21:26:21 kn Exp $    */
+/*     $OpenBSD: nd6.c,v 1.261 2023/01/06 14:24:36 kn Exp $    */
 /*     $KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $   */
 
 /*
@@ -196,16 +196,14 @@ nd6_options(void *opt, int icmp6len, struct nd_opts *ndopts)
        int i = 0;
 
        bzero(ndopts, sizeof(*ndopts));
+
+       if (icmp6len == 0)
+               return 0;
+
        ndopts->nd_opts_search = nd_opt;
        ndopts->nd_opts_last =
            (struct nd_opt_hdr *)(((u_char *)nd_opt) + icmp6len);
 
-       if (icmp6len == 0) {
-               ndopts->nd_opts_done = 1;
-               ndopts->nd_opts_search = NULL;
-               return 0;
-       }
-
        while (1) {
                nd_opt = nd6_option(ndopts);
                if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {