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

7 files changed, 13 insertions, 11 deletions

diff --git a/sys/kern/vfs_export.c b/sys/kern/vfs_export.c
index 6dc4eafc4c60..ca5b66426c5c 100644
--- a/sys/kern/vfs_export.c
+++ b/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;
diff --git a/sys/net/route/nhop_ctl.c b/sys/net/route/nhop_ctl.c
index f34721c888b4..59a81ecde4df 100644
--- a/sys/net/route/nhop_ctl.c
+++ b/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.
diff --git a/sys/net/route/route_ddb.c b/sys/net/route/route_ddb.c
index 71bffd98663b..c93370d0a570 100644
--- a/sys/net/route/route_ddb.c
+++ b/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++) {
diff --git a/sys/net/route/route_helpers.c b/sys/net/route/route_helpers.c
index f09a8bbbd3e5..9160a5872534 100644
--- a/sys/net/route/route_helpers.c
+++ b/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);
 	}
 }
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index 47da83b5561b..fcccbc98470c 100644
--- a/sys/net/rtsock.c
+++ b/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;
 
diff --git a/sys/netlink/route/rt.c b/sys/netlink/route/rt.c
index fbd96bb9fdc6..bf6ef035eb1d 100644
--- a/sys/netlink/route/rt.c
+++ b/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);
 	}
diff --git a/sys/sys/socket.h b/sys/sys/socket.h
index d9c31d572b4f..cc910a2a8efa 100644
--- a/sys/sys/socket.h
+++ b/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_