Mfp4 CH=177274,177280,177284-177285,177297,177324-177325

  VNET socket push back:
  try to minimize the number of places where we have to switch vnets
  and narrow down the time we stay switched.  Add assertions to the
  socket code to catch possibly unset vnets as seen in r204147.

  While this reduces the number of vnet recursion in some places like
  NFS, POSIX local sockets and some netgraph, .. recursions are
  impossible to fix.

  The current expectations are documented at the beginning of
  uipc_socket.c along with the other information there.

  Sponsored by: The FreeBSD Foundation
  Sponsored by: CK Software GmbH
  Reviewed by:  jhb
  Tested by:    zec

Tested by:	Mikolaj Golub (to.my.trociny gmail.com)
MFC after:	2 weeks

1 files changed, 34 insertions, 15 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index ccd4689..2e21ae9 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -2440,10 +2440,13 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct thread *td)
 	int error;
 	int oif_flags;
 
+	CURVNET_SET(so->so_vnet);
 	switch (cmd) {
 	case SIOCGIFCONF:
 	case OSIOCGIFCONF:
-		return (ifconf(cmd, data));
+		error = ifconf(cmd, data);
+		CURVNET_RESTORE();
+		return (error);
 
 #ifdef COMPAT_FREEBSD32
 	case SIOCGIFCONF32:
@@ -2455,7 +2458,9 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct thread *td)
 			ifc.ifc_len = ifc32->ifc_len;
 			ifc.ifc_buf = PTRIN(ifc32->ifc_buf);
 
-			return (ifconf(SIOCGIFCONF, (void *)&ifc));
+			error = ifconf(SIOCGIFCONF, (void *)&ifc);
+			CURVNET_RESTORE();
+			return (error);
 		}
 #endif
 	}
@@ -2465,42 +2470,55 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct thread *td)
 #ifdef VIMAGE
 	case SIOCSIFRVNET:
 		error = priv_check(td, PRIV_NET_SETIFVNET);
-		if (error)
-			return (error);
-		return (if_vmove_reclaim(td, ifr->ifr_name, ifr->ifr_jid));
+		if (error == 0)
+			error = if_vmove_reclaim(td, ifr->ifr_name,
+			    ifr->ifr_jid);
+		CURVNET_RESTORE();
+		return (error);
 #endif
 	case SIOCIFCREATE:
 	case SIOCIFCREATE2:
 		error = priv_check(td, PRIV_NET_IFCREATE);
-		if (error)
-			return (error);
-		return (if_clone_create(ifr->ifr_name, sizeof(ifr->ifr_name),
-			cmd == SIOCIFCREATE2 ? ifr->ifr_data : NULL));
+		if (error == 0)
+			error = if_clone_create(ifr->ifr_name,
+			    sizeof(ifr->ifr_name),
+			    cmd == SIOCIFCREATE2 ? ifr->ifr_data : NULL);
+		CURVNET_RESTORE();
+		return (error);
 	case SIOCIFDESTROY:
 		error = priv_check(td, PRIV_NET_IFDESTROY);
-		if (error)
-			return (error);
-		return if_clone_destroy(ifr->ifr_name);
+		if (error == 0)
+			error = if_clone_destroy(ifr->ifr_name);
+		CURVNET_RESTORE();
+		return (error);
 
 	case SIOCIFGCLONERS:
-		return (if_clone_list((struct if_clonereq *)data));
+		error = if_clone_list((struct if_clonereq *)data);
+		CURVNET_RESTORE();
+		return (error);
 	case SIOCGIFGMEMB:
-		return (if_getgroupmembers((struct ifgroupreq *)data));
+		error = if_getgroupmembers((struct ifgroupreq *)data);
+		CURVNET_RESTORE();
+		return (error);
 	}
 
 	ifp = ifunit_ref(ifr->ifr_name);
-	if (ifp == NULL)
+	if (ifp == NULL) {
+		CURVNET_RESTORE();
 		return (ENXIO);
+	}
 
 	error = ifhwioctl(cmd, ifp, data, td);
 	if (error != ENOIOCTL) {
 		if_rele(ifp);
+		CURVNET_RESTORE();
 		return (error);
 	}
 
 	oif_flags = ifp->if_flags;
 	if (so->so_proto == NULL) {
 		if_rele(ifp);
+		CURVNET_RESTORE();
 		return (EOPNOTSUPP);
 	}
 #ifndef COMPAT_43
@@ -2575,6 +2593,7 @@ ifioctl(struct socket *so, u_long cmd, caddr_t data, struct thread *td)
 #endif
 	}
 	if_rele(ifp);
+	CURVNET_RESTORE();
 	return (error);
 }