sys/socket.h: Fix AF_MAX

AF_MAX was always intended to be one more than the greatest allocated
value.  Jeff broke this in 2013.  Unfortunately, a bunch of people then
decided to adapt to the mistake instead of correcting it.

Fixes:          863c7e45628d (" - Reserve a special AF for SDP.  The one we were incorrectly using before    was taken by another AF.")
MFC after:	3 days
Sponsored by:	Klara, Inc.
Sponsored by:	NetApp, Inc.
Reviewed by:	kevans, glebius
Differential Revision:	https://reviews.freebsd.org/D58597

2 files changed, 3 insertions, 3 deletions

diff --git a/lib/libifconfig/libifconfig.c b/lib/libifconfig/libifconfig.c
index bc0fcb6021b2..b450c15180db 100644
--- a/lib/libifconfig/libifconfig.c
+++ b/lib/libifconfig/libifconfig.c
@@ -81,7 +81,7 @@ ifconfig_open(void)
 	if (h == NULL) {
 		return (NULL);
 	}
-	for (int i = 0; i <= AF_MAX; i++) {
+	for (int i = 0; i < AF_MAX; i++) {
 		h->sockets[i] = -1;
 	}
 
@@ -92,7 +92,7 @@ void
 ifconfig_close(ifconfig_handle_t *h)
 {
 
-	for (int i = 0; i <= AF_MAX; i++) {
+	for (int i = 0; i < AF_MAX; i++) {
 		if (h->sockets[i] != -1) {
 			(void)close(h->sockets[i]);
 		}
diff --git a/lib/libifconfig/libifconfig_internal.c b/lib/libifconfig/libifconfig_internal.c
index c6c955debb3d..91de1ece59fb 100644
--- a/lib/libifconfig/libifconfig_internal.c
+++ b/lib/libifconfig/libifconfig_internal.c
@@ -78,7 +78,7 @@ int
 ifconfig_socket(ifconfig_handle_t *h, const int addressfamily, int *s)
 {
 
-	if (addressfamily > AF_MAX) {
+	if (addressfamily >= AF_MAX) {
 		h->error.errtype = SOCKET;
 		h->error.errcode = EINVAL;
 		return (-1);