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:          863c7e4562 (" - 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

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]);
 		}

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);

sys/kern/vfs_export.c

@@ -146,7 +146,7 @@ vfs_hang_addrlist(struct mount *mp, struct netexport *nep,
 	saddr = (struct sockaddr *) (np + 1);
 	if ((error = copyin(argp->ex_addr, saddr, argp->ex_addrlen)))
 		goto out;
-	if (saddr->sa_family == AF_UNSPEC || saddr->sa_family > AF_MAX) {
+	if (saddr->sa_family == AF_UNSPEC || saddr->sa_family >= AF_MAX) {
 		error = EINVAL;
 		vfs_mount_error(mp, "Invalid saddr->sa_family: %d");
 		goto out;

sys/net/route/nhop_ctl.c

@@ -1339,7 +1339,7 @@ nhops_ifnet_state_changed(struct ifnet *ifp, bool status)
 	struct nhop_iter iter = { .fibnum = ifp->if_fib, .wlock = true };
 	bool nhops_changed;
 
-	for (iter.family = 1; iter.family <= AF_MAX; iter.family++) {
+	for (iter.family = 1; iter.family < AF_MAX; iter.family++) {
 		/*
 		 * By tracking nhop changes, we avoid redundant nhgrp
 		 * recompilation triggered by multiple events.

sys/net/route/route_ddb.c

@@ -174,7 +174,7 @@ DB_SHOW_COMMAND(routetable, db_show_routetable)
 		i = lim = addr;
 	else {
 		i = 1;
-		lim = AF_MAX;
+		lim = AF_MAX - 1;
 	}
 
 	for (; i <= lim; i++) {

sys/net/route/route_helpers.c

@@ -183,7 +183,7 @@ rib_foreach_table_walk(int family, bool wlock, rib_walktree_f_t *wa_f,
 			continue;
 		}
 
-		for (int i = 1; i <= AF_MAX; i++)
+		for (int i = 1; i < AF_MAX; i++)
 			rib_walk_ext(fibnum, i, wlock, wa_f, hook_f, arg);
 	}
 }
@@ -205,7 +205,7 @@ rib_foreach_table_walk_del(int family, rib_filter_f_t *filter_f, void *arg)
 			continue;
 		}
 
-		for (int i = 1; i <= AF_MAX; i++)
+		for (int i = 1; i < AF_MAX; i++)
 			rib_walk_del(fibnum, i, filter_f, arg, 0);
 	}
 }

sys/net/rtsock.c

@@ -2623,7 +2623,7 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS)
 	} else if (namelen != 3)
 		return ((namelen < 3) ? EISDIR : ENOTDIR);
 	af = name[0];
-	if (af > AF_MAX)
+	if (af >= AF_MAX)
 		return (EINVAL);
 	bzero(&w, sizeof(w));
 	w.w_op = name[1];
@@ -2647,7 +2647,7 @@ sysctl_rtsock(SYSCTL_HANDLER_ARGS)
 	case NET_RT_FLAGS:
 		if (af == 0) {			/* dump all tables */
 			i = 1;
-			lim = AF_MAX;
+			lim = AF_MAX - 1;
 		} else				/* dump only one table */
 			i = lim = af;
 

sys/netlink/route/rt.c

@@ -1053,7 +1053,7 @@ rtnl_handle_newroute(struct nlmsghdr *hdr, struct nlpcb *nlp,
 	}
 
 	old_linux_compat(&attrs);
-	if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family > AF_MAX) {
+	if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family >= AF_MAX) {
 		NLMSG_REPORT_ERR_MSG(npt, "invalid fib");
 		return (EINVAL);
 	}
@@ -1120,7 +1120,7 @@ rtnl_handle_delroute(struct nlmsghdr *hdr, struct nlpcb *nlp,
 	}
 
 	old_linux_compat(&attrs);
-	if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family > AF_MAX) {
+	if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family >= AF_MAX) {
 		NLMSG_REPORT_ERR_MSG(npt, "invalid fib");
 		return (EINVAL);
 	}
@@ -1144,7 +1144,7 @@ rtnl_handle_getroute(struct nlmsghdr *hdr, struct nlpcb *nlp, struct nl_pstate *
 		return (error);
 
 	old_linux_compat(&attrs);
-	if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family > AF_MAX) {
+	if (attrs.rta_table >= V_rt_numfibs || attrs.rtm_family >= AF_MAX) {
 		NLMSG_REPORT_ERR_MSG(npt, "invalid fib");
 		return (EINVAL);
 	}

sys/sys/socket.h

@@ -272,7 +272,9 @@ struct accept_filter_arg {
 #define	AF_HYPERV	43		/* HyperV sockets */
 #define	AF_DIVERT	44		/* divert(4) */
 #define	AF_IPFWLOG	46
-#define	AF_MAX		46
+
+#define	AF_MAX		47
+
 /*
  * When allocating a new AF_ constant, please only allocate
  * even numbered constants for FreeBSD until 134 as odd numbered AF_