MFC 311475

    if: Defer the if_up until the ifnet.if_ioctl is called.

    This ensures the interface is initialized by the interface driver
    before it can be used by the rest of the system.

    Reviewed by:    jhb, karels, gnn
    Sponsored by:   Microsoft
    Differential Revision:  https://reviews.freebsd.org/D8905

1 files changed, 4 insertions, 2 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index 881cd60..67f086b 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -2266,7 +2266,7 @@ ifhwioctl(u_long cmd, struct ifnet *ifp, caddr_t data, struct thread *td)
 {
 	struct ifreq *ifr;
 	struct ifstat *ifs;
-	int error = 0;
+	int error = 0, do_ifup = 0;
 	int new_flags, temp_flags;
 	size_t namelen, onamelen;
 	size_t descrlen;
@@ -2394,7 +2394,7 @@ ifhwioctl(u_long cmd, struct ifnet *ifp, caddr_t data, struct thread *td)
 			if_down(ifp);
 		} else if (new_flags & IFF_UP &&
 		    (ifp->if_flags & IFF_UP) == 0) {
-			if_up(ifp);
+			do_ifup = 1;
 		}
 		/* See if permanently promiscuous mode bit is about to flip */
 		if ((ifp->if_flags ^ new_flags) & IFF_PPROMISC) {
@@ -2413,6 +2413,8 @@ ifhwioctl(u_long cmd, struct ifnet *ifp, caddr_t data, struct thread *td)
 		if (ifp->if_ioctl) {
 			(void) (*ifp->if_ioctl)(ifp, cmd, data);
 		}
+		if (do_ifup)
+			if_up(ifp);
 		getmicrotime(&ifp->if_lastchange);
 		break;