Switch nd_opts from a union to just a struct.

The ND6 option handling in the kernel got a lot simpler since only
the tgt and src lladdr option are inspected by the kernel. The magic
of assigning options via one side of the union and accessing them
via the other is total overkill and actually quite error prone.
OK florian@

1 files changed, 24 insertions, 26 deletions

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 0647837b2ef..37c2f320af1 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.c,v 1.258 2022/12/07 17:34:20 kn Exp $	*/
+/*	$OpenBSD: nd6.c,v 1.259 2022/12/09 17:32:53 claudio Exp $	*/
 /*	$KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $	*/
 
 /*
@@ -101,6 +101,8 @@ 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)
 {
@@ -138,7 +140,7 @@ nd6_ifdetach(struct ifnet *ifp)
 }
 
 void
-nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
+nd6_option_init(void *opt, int icmp6len, struct nd_opts *ndopts)
 {
 	bzero(ndopts, sizeof(*ndopts));
 	ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
@@ -155,15 +157,11 @@ nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
  * Take one ND option.
  */
 struct nd_opt_hdr *
-nd6_option(union nd_opts *ndopts)
+nd6_option(struct nd_opts *ndopts)
 {
 	struct nd_opt_hdr *nd_opt;
 	int olen;
 
-	if (!ndopts)
-		panic("%s: ndopts == NULL", __func__);
-	if (!ndopts->nd_opts_last)
-		panic("%s: uninitialized ndopts", __func__);
 	if (!ndopts->nd_opts_search)
 		return NULL;
 	if (ndopts->nd_opts_done)
@@ -206,21 +204,18 @@ nd6_option(union nd_opts *ndopts)
  * multiple options of the same type.
  */
 int
-nd6_options(union nd_opts *ndopts)
+nd6_options(struct nd_opts *ndopts)
 {
 	struct nd_opt_hdr *nd_opt;
 	int i = 0;
 
-	if (!ndopts)
-		panic("%s: ndopts == NULL", __func__);
-	if (!ndopts->nd_opts_last)
-		panic("%s: uninitialized ndopts", __func__);
-	if (!ndopts->nd_opts_search)
+	KASSERT(ndopts->nd_opts_last != NULL);
+	if (ndopts->nd_opts_search == NULL)
 		return 0;
 
 	while (1) {
 		nd_opt = nd6_option(ndopts);
-		if (!nd_opt && !ndopts->nd_opts_last) {
+		if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
 			/*
 			 * Message validation requires that all included
 			 * options have a length that is greater than zero.
@@ -230,28 +225,30 @@ nd6_options(union nd_opts *ndopts)
 			return -1;
 		}
 
-		if (!nd_opt)
+		if (nd_opt == NULL)
 			goto skip1;
 
 		switch (nd_opt->nd_opt_type) {
 		case ND_OPT_SOURCE_LINKADDR:
+			if (ndopts->nd_opts_src_lladdr != NULL)
+				nd6log((LOG_INFO, "duplicated ND6 option found "
+				    "(type=%d)\n", nd_opt->nd_opt_type));
+			else
+				ndopts->nd_opts_src_lladdr = nd_opt;
+			break;
 		case ND_OPT_TARGET_LINKADDR:
+			if (ndopts->nd_opts_tgt_lladdr != NULL)
+				nd6log((LOG_INFO, "duplicated ND6 option found "
+				    "(type=%d)\n", nd_opt->nd_opt_type));
+			else
+				ndopts->nd_opts_tgt_lladdr = nd_opt;
+			break;
 		case ND_OPT_MTU:
 		case ND_OPT_REDIRECTED_HEADER:
-			if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
-				nd6log((LOG_INFO,
-				    "duplicated ND6 option found (type=%d)\n",
-				    nd_opt->nd_opt_type));
-				/* XXX bark? */
-			} else {
-				ndopts->nd_opt_array[nd_opt->nd_opt_type]
-					= nd_opt;
-			}
-			break;
 		case ND_OPT_PREFIX_INFORMATION:
 		case ND_OPT_DNSSL:
 		case ND_OPT_RDNSS:
-			/* Don't warn */
+			/* Don't warn, not used by kernel */
 			break;
 		default:
 			/*
@@ -261,6 +258,7 @@ nd6_options(union nd_opts *ndopts)
 			nd6log((LOG_DEBUG,
 			    "nd6_options: unsupported option %d - "
 			    "option ignored\n", nd_opt->nd_opt_type));
+			break;
 		}
 
 skip1: