Inline nd6_option() helper, remove indirections

Move the function body into the while loop, merge identical variables,
pull the `invalid' label out of the loop and straighten `skip' into the
`skip1' label.

Merging nd6_option() into nd6_options() is now much clearer after the
previous clean up.

nd_opts_{search,last,done} are now clearly "private" to n6_options() and
can be cleaned up from struct nd_opts next.

OK claudio

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 9d430d3..b0339a0 100644 (file)
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: nd6.c,v 1.262 2023/01/06 14:29:47 kn Exp $    */
+/*     $OpenBSD: nd6.c,v 1.263 2023/01/06 14:32:55 kn Exp $    */
 /*     $KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $   */
 
 /*
@@ -101,8 +101,6 @@ struct timeout nd6_slowtimo_ch;
 struct timeout nd6_expire_timeout;
 struct task nd6_expire_task;
 
-struct nd_opt_hdr *nd6_option(struct nd_opts *);
-
 void
 nd6_init(void)
 {
@@ -139,50 +137,6 @@ nd6_ifdetach(struct ifnet *ifp)
        free(nd, M_IP6NDP, sizeof(*nd));
 }
 
-/*
- * Take one ND option.
- */
-struct nd_opt_hdr *
-nd6_option(struct nd_opts *ndopts)
-{
-       struct nd_opt_hdr *nd_opt;
-       int olen;
-
-       if (ndopts->nd_opts_search == NULL || ndopts->nd_opts_done)
-               goto skip;
-
-       nd_opt = ndopts->nd_opts_search;
-
-       /* make sure nd_opt_len is inside the buffer */
-       if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
-               goto invalid;
-       }
-
-       olen = nd_opt->nd_opt_len << 3;
-       if (olen == 0) {
-               /*
-                * Message validation requires that all included
-                * options have a length that is greater than zero.
-                */
-               goto invalid;
-       }
-
-       ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
-       if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
-               /* option overruns the end of buffer, invalid */
-               goto invalid;
-       } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
-               /* reached the end of options chain */
-               ndopts->nd_opts_done = 1;
-               ndopts->nd_opts_search = NULL;
-       }
-       return nd_opt;
-invalid:
-       bzero(ndopts, sizeof(*ndopts));
-skip:
-       return NULL;
-}
-
 /*
  * Parse multiple ND options.
  * This function is much easier to use, for ND routines that do not need
@@ -204,19 +158,32 @@ nd6_options(void *opt, int icmp6len, struct nd_opts *ndopts)
            (struct nd_opt_hdr *)(((u_char *)nd_opt) + icmp6len);
 
        while (1) {
-               nd_opt = nd6_option(ndopts);
-               if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
-                       /*
-                        * Message validation requires that all included
-                        * options have a length that is greater than zero.
-                        */
-                       icmp6stat_inc(icp6s_nd_badopt);
-                       return -1;
-               }
+               int olen;
 
-               if (nd_opt == NULL)
+               if (ndopts->nd_opts_search == NULL || ndopts->nd_opts_done)
                        goto skip1;
 
+               nd_opt = ndopts->nd_opts_search;
+
+               /* make sure nd_opt_len is inside the buffer */
+               if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last)
+                       goto invalid;
+
+               /* every option must have a length greater than zero */
+               olen = nd_opt->nd_opt_len << 3;
+               if (olen == 0)
+                       goto invalid;
+
+               ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
+               if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
+                       /* option overruns the end of buffer */
+                       goto invalid;
+               } else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
+                       /* reached the end of options chain */
+                       ndopts->nd_opts_done = 1;
+                       ndopts->nd_opts_search = NULL;
+               }
+
                switch (nd_opt->nd_opt_type) {
                case ND_OPT_SOURCE_LINKADDR:
                        if (ndopts->nd_opts_src_lladdr != NULL)
@@ -263,6 +230,11 @@ skip1:
        }
 
        return 0;
+
+invalid:
+       bzero(ndopts, sizeof(*ndopts));
+       icmp6stat_inc(icp6s_nd_badopt);
+       return -1;
 }
 
 /*