Constify in6_addr pointer arguments in nd6_*() functions

All of them are passed to inspect/copy out fields, none of the functions
writes to the struct.

This makes it easier to argue about code (in MP context).

OK bluhm

3 files changed, 21 insertions, 19 deletions

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 35162ce597f..c06ee2924ff 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.c,v 1.244 2022/08/08 15:56:35 kn Exp $	*/
+/*	$OpenBSD: nd6.c,v 1.245 2022/08/08 17:47:59 kn Exp $	*/
 /*	$KAME: nd6.c,v 1.280 2002/06/08 19:52:07 itojun Exp $	*/
 
 /*
@@ -301,7 +301,7 @@ skip1:
  * ND6 timer routine to handle ND6 entries
  */
 void
-nd6_llinfo_settimer(struct llinfo_nd6 *ln, unsigned int secs)
+nd6_llinfo_settimer(const struct llinfo_nd6 *ln, unsigned int secs)
 {
 	time_t expire = getuptime() + secs;
 
@@ -547,7 +547,7 @@ nd6_purge(struct ifnet *ifp)
 }
 
 struct rtentry *
-nd6_lookup(struct in6_addr *addr6, int create, struct ifnet *ifp,
+nd6_lookup(const struct in6_addr *addr6, int create, struct ifnet *ifp,
     u_int rtableid)
 {
 	struct rtentry *rt;
@@ -641,7 +641,7 @@ nd6_lookup(struct in6_addr *addr6, int create, struct ifnet *ifp,
  * XXX: should take care of the destination of a p2p link?
  */
 int
-nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
+nd6_is_addr_neighbor(const struct sockaddr_in6 *addr, struct ifnet *ifp)
 {
 	struct in6_ifaddr *ia6;
 	struct ifaddr *ifa;
@@ -1079,7 +1079,7 @@ nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
  * code - type dependent information
  */
 void
-nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
+nd6_cache_lladdr(struct ifnet *ifp, const struct in6_addr *from, char *lladdr,
     int lladdrlen, int type, int code)
 {
 	struct rtentry *rt = NULL;
diff --git a/sys/netinet6/nd6.h b/sys/netinet6/nd6.h
index 8ea60eb9c5f..980524f16ea 100644
--- a/sys/netinet6/nd6.h
+++ b/sys/netinet6/nd6.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6.h,v 1.78 2022/07/28 13:11:44 kn Exp $	*/
+/*	$OpenBSD: nd6.h,v 1.79 2022/08/08 17:47:59 kn Exp $	*/
 /*	$KAME: nd6.h,v 1.95 2002/06/08 11:31:06 itojun Exp $	*/
 
 /*
@@ -157,27 +157,29 @@ union nd_opts {
 void nd6_init(void);
 struct nd_ifinfo *nd6_ifattach(struct ifnet *);
 void nd6_ifdetach(struct nd_ifinfo *);
-int nd6_is_addr_neighbor(struct sockaddr_in6 *, struct ifnet *);
+int nd6_is_addr_neighbor(const struct sockaddr_in6 *, struct ifnet *);
 void nd6_option_init(void *, int, union nd_opts *);
 struct nd_opt_hdr *nd6_option(union nd_opts *);
 int nd6_options(union nd_opts *);
-struct	rtentry *nd6_lookup(struct in6_addr *, int, struct ifnet *, u_int);
-void nd6_llinfo_settimer(struct llinfo_nd6 *, unsigned int);
+struct	rtentry *nd6_lookup(const struct in6_addr *, int, struct ifnet *,
+    u_int);
+void nd6_llinfo_settimer(const struct llinfo_nd6 *, unsigned int);
 void nd6_purge(struct ifnet *);
 void nd6_nud_hint(struct rtentry *);
 void nd6_rtrequest(struct ifnet *, int, struct rtentry *);
 int nd6_ioctl(u_long, caddr_t, struct ifnet *);
-void nd6_cache_lladdr(struct ifnet *, struct in6_addr *, char *, int, int, int);
+void nd6_cache_lladdr(struct ifnet *, const struct in6_addr *, char *,
+    int, int, int);
 int nd6_resolve(struct ifnet *, struct rtentry *, struct mbuf *,
 	 struct sockaddr *, u_char *);
 int nd6_need_cache(struct ifnet *);
 
 void nd6_na_input(struct mbuf *, int, int);
-void nd6_na_output(struct ifnet *, struct in6_addr *,
-	struct in6_addr *, u_long, int, struct sockaddr *);
+void nd6_na_output(struct ifnet *, const struct in6_addr *,
+	const struct in6_addr *, u_long, int, struct sockaddr *);
 void nd6_ns_input(struct mbuf *, int, int);
-void nd6_ns_output(struct ifnet *, struct in6_addr *,
-	struct in6_addr *, struct llinfo_nd6 *, int);
+void nd6_ns_output(struct ifnet *, const struct in6_addr *,
+	const struct in6_addr *, const struct llinfo_nd6 *, int);
 caddr_t nd6_ifptomac(struct ifnet *);
 void nd6_dad_start(struct ifaddr *);
 void nd6_dad_stop(struct ifaddr *);
diff --git a/sys/netinet6/nd6_nbr.c b/sys/netinet6/nd6_nbr.c
index 5061a325f55..57433b47d41 100644
--- a/sys/netinet6/nd6_nbr.c
+++ b/sys/netinet6/nd6_nbr.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: nd6_nbr.c,v 1.131 2022/02/07 15:23:43 bluhm Exp $	*/
+/*	$OpenBSD: nd6_nbr.c,v 1.132 2022/08/08 17:47:59 kn Exp $	*/
 /*	$KAME: nd6_nbr.c,v 1.61 2001/02/10 16:06:14 jinmei Exp $	*/
 
 /*
@@ -357,8 +357,8 @@ nd6_ns_input(struct mbuf *m, int off, int icmp6len)
  * dad - duplicated address detection
  */
 void
-nd6_ns_output(struct ifnet *ifp, struct in6_addr *daddr6, 
-    struct in6_addr *taddr6, struct llinfo_nd6 *ln, int dad)
+nd6_ns_output(struct ifnet *ifp, const struct in6_addr *daddr6,
+    const struct in6_addr *taddr6, const struct llinfo_nd6 *ln, int dad)
 {
 	struct mbuf *m;
 	struct ip6_hdr *ip6;
@@ -871,8 +871,8 @@ nd6_na_input(struct mbuf *m, int off, int icmp6len)
  * sdl0 - sockaddr_dl (= proxy NA) or NULL
  */
 void
-nd6_na_output(struct ifnet *ifp, struct in6_addr *daddr6, 
-    struct in6_addr *taddr6, u_long flags, int tlladdr, 
+nd6_na_output(struct ifnet *ifp, const struct in6_addr *daddr6,
+    const struct in6_addr *taddr6, u_long flags, int tlladdr,
     struct sockaddr *sdl0)
 {
 	struct mbuf *m;