Avoid huge sockaddr_storage

sockaddr_{in,in6} are enough and a simple sockaddr pointer is enough to
abstract them  (sockaddr_storage is what worked for me, there is no other
reason to use it).

While here, be portable and pass a non-zero length to getnameinfo(3);
while OpenBSD's implementation ignores it in the NI_NUMERICHOST case,
at least the old KAME stack didn't.

No functional change.

Prodded by florian
OK florian

diff --git a/sbin/resolvd/resolvd.c b/sbin/resolvd/resolvd.c
index bce56ba..e51e7d5 100644 (file)
--- a/sbin/resolvd/resolvd.c
+++ b/sbin/resolvd/resolvd.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: resolvd.c,v 1.21 2021/11/13 17:49:40 kn Exp $ */
+/*     $OpenBSD: resolvd.c,v 1.22 2021/11/15 17:33:51 kn Exp $ */
 /*
  * Copyright (c) 2021 Florian Obser <florian@openbsd.org>
  * Copyright (c) 2021 Theo de Raadt <deraadt@openbsd.org>
@@ -467,27 +467,32 @@ handle_route_message(struct rt_msghdr *rtm, struct sockaddr **rti_info)
 
                /* Add the new proposals */
                for (i = 0; i < rdns_count; i++) {
-                       struct sockaddr_storage ss;
-                       struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
-                       struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
-                       int new, err;
+                       struct sockaddr_in       sin;
+                       struct sockaddr_in6      sin6;
+                       struct sockaddr         *sa;
+                       int                      new, err;
 
-                       memset(&ss, 0, sizeof(ss));
-                       ss.ss_family = af;
                        new = findslot(learning);
                        switch (af) {
                        case AF_INET:
-                               memcpy(&sin->sin_addr, src, addrsz);
+                               memset(&sin, 0, sizeof(sin));
+                               memcpy(&sin.sin_addr, src, addrsz);
+                               sa = (struct sockaddr *) &sin;
+                               sa->sa_len = sizeof(sin);
                                break;
                        case AF_INET6:
-                               memcpy(&sin6->sin6_addr, src, addrsz);
-                               if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
-                                       sin6->sin6_scope_id = rtm->rtm_index;
+                               memset(&sin6, 0, sizeof(sin6));
+                               memcpy(&sin6.sin6_addr, src, addrsz);
+                               if (IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr))
+                                       sin6.sin6_scope_id = rtm->rtm_index;
+                               sa = (struct sockaddr *) &sin6;
+                               sa->sa_len = sizeof(sin6);
                                break;
                        }
+                       sa->sa_family = af;
                        src += addrsz;
 
-                       if ((err = getnameinfo((struct sockaddr *)&ss, ss.ss_len,
+                       if ((err = getnameinfo(sa, sa->sa_len,
                            learning[new].ip, sizeof(learning[new].ip),
                            NULL, 0, NI_NUMERICHOST)) == 0) {
                                learning[new].prio = rtm->rtm_priority;