[src/trunk]: src/sys/net Ensure to hold if_ioctl_lock on if_up and if_down

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/ba60e89919c1
branches:  trunk
changeset: 357964:ba60e89919c1
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Wed Dec 06 08:12:54 2017 +0000

description:
Ensure to hold if_ioctl_lock on if_up and if_down

One exception for if_down is if_detach; in the case the lock isn't needed
because it's guaranteed that no other one can access ifp at that point.

diffstat:

 sys/net/if.c      |  73 +++++++++++++++++++++++++++++++++++++++++++-----------
 sys/net/if.h      |   3 +-
 sys/net/if_vlan.c |   6 ++--
 3 files changed, 63 insertions(+), 19 deletions(-)

diffs (195 lines):

diff -r d3e9884787c1 -r ba60e89919c1 sys/net/if.c
--- a/sys/net/if.c      Wed Dec 06 07:40:16 2017 +0000
+++ b/sys/net/if.c      Wed Dec 06 08:12:54 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if.c,v 1.402 2017/12/06 05:59:59 ozaki-r Exp $ */
+/*     $NetBSD: if.c,v 1.403 2017/12/06 08:12:54 ozaki-r Exp $ */
 
 /*-
  * Copyright (c) 1999, 2000, 2001, 2008 The NetBSD Foundation, Inc.
@@ -90,7 +90,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.402 2017/12/06 05:59:59 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if.c,v 1.403 2017/12/06 08:12:54 ozaki-r Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_inet.h"
@@ -209,6 +209,9 @@
 static int if_clone_create(const char *);
 static int if_clone_destroy(const char *);
 static void if_link_state_change_si(void *);
+static void if_up_locked(struct ifnet *);
+static void _if_down(struct ifnet *);
+static void if_down_deactivated(struct ifnet *);
 
 struct if_percpuq {
        struct ifnet    *ipq_ifp;
@@ -1333,7 +1336,7 @@
        /*
         * Do an if_down() to give protocols a chance to do something.
         */
-       if_down(ifp);
+       if_down_deactivated(ifp);
 
 #ifdef ALTQ
        if (ALTQ_IS_ENABLED(&ifp->if_snd))
@@ -2400,13 +2403,8 @@
        pserialize_read_exit(s);
 }
 
-/*
- * Mark an interface down and notify protocols of
- * the transition.
- * NOTE: must be called at splsoftnet or equivalent.
- */
-void
-if_down(struct ifnet *ifp)
+static void
+_if_down(struct ifnet *ifp)
 {
        struct ifaddr *ifa;
        struct domain *dp;
@@ -2442,19 +2440,50 @@
        }
 }
 
+static void
+if_down_deactivated(struct ifnet *ifp)
+{
+
+       KASSERT(if_is_deactivated(ifp));
+       _if_down(ifp);
+}
+
+void
+if_down_locked(struct ifnet *ifp)
+{
+
+       KASSERT(mutex_owned(ifp->if_ioctl_lock));
+       _if_down(ifp);
+}
+
 /*
- * Mark an interface up and notify protocols of
+ * Mark an interface down and notify protocols of
  * the transition.
  * NOTE: must be called at splsoftnet or equivalent.
  */
 void
-if_up(struct ifnet *ifp)
+if_down(struct ifnet *ifp)
+{
+
+       mutex_enter(ifp->if_ioctl_lock);
+       if_down_locked(ifp);
+       mutex_exit(ifp->if_ioctl_lock);
+}
+
+/*
+ * Must be called with holding if_ioctl_lock.
+ */
+static void
+if_up_locked(struct ifnet *ifp)
 {
 #ifdef notyet
        struct ifaddr *ifa;
 #endif
        struct domain *dp;
 
+       KASSERT(mutex_owned(ifp->if_ioctl_lock));
+
+       KASSERT(!if_is_deactivated(ifp));
        ifp->if_flags |= IFF_UP;
        nanotime(&ifp->if_lastchange);
 #ifdef notyet
@@ -2500,6 +2529,20 @@
 }
 
 /*
+ * Mark an interface up and notify protocols of
+ * the transition.
+ * NOTE: must be called at splsoftnet or equivalent.
+ */
+void
+if_up(struct ifnet *ifp)
+{
+
+       mutex_enter(ifp->if_ioctl_lock);
+       if_up_locked(ifp);
+       mutex_exit(ifp->if_ioctl_lock);
+}
+
+/*
  * Set/clear promiscuous mode on interface ifp based on the truth value
  * of pswitch.  The calls are reference counted so that only the first
  * "on" request actually has an effect, as does the final "off" request.
@@ -2789,12 +2832,12 @@
                KERNEL_LOCK_IF_IFP_MPSAFE(ifp);
                if (ifp->if_flags & IFF_UP && (ifr->ifr_flags & IFF_UP) == 0) {
                        s = splsoftnet();
-                       if_down(ifp);
+                       if_down_locked(ifp);
                        splx(s);
                }
                if (ifr->ifr_flags & IFF_UP && (ifp->if_flags & IFF_UP) == 0) {
                        s = splsoftnet();
-                       if_up(ifp);
+                       if_up_locked(ifp);
                        splx(s);
                }
                KERNEL_UNLOCK_IF_IFP_MPSAFE(ifp);
@@ -3103,7 +3146,7 @@
        if (((oif_flags ^ ifp->if_flags) & IFF_UP) != 0) {
                if ((ifp->if_flags & IFF_UP) != 0) {
                        int s = splsoftnet();
-                       if_up(ifp);
+                       if_up_locked(ifp);
                        splx(s);
                }
        }
diff -r d3e9884787c1 -r ba60e89919c1 sys/net/if.h
--- a/sys/net/if.h      Wed Dec 06 07:40:16 2017 +0000
+++ b/sys/net/if.h      Wed Dec 06 08:12:54 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if.h,v 1.246 2017/12/06 05:59:59 ozaki-r Exp $ */
+/*     $NetBSD: if.h,v 1.247 2017/12/06 08:12:54 ozaki-r Exp $ */
 
 /*-
  * Copyright (c) 1999, 2000, 2001 The NetBSD Foundation, Inc.
@@ -1006,6 +1006,7 @@
 void   if_purgeaddrs(struct ifnet *, int, void (*)(struct ifaddr *));
 void   if_detach(struct ifnet *);
 void   if_down(struct ifnet *);
+void   if_down_locked(struct ifnet *);
 void   if_link_state_change(struct ifnet *, int);
 void   if_link_state_change_softint(struct ifnet *, int);
 void   if_up(struct ifnet *);
diff -r d3e9884787c1 -r ba60e89919c1 sys/net/if_vlan.c
--- a/sys/net/if_vlan.c Wed Dec 06 07:40:16 2017 +0000
+++ b/sys/net/if_vlan.c Wed Dec 06 08:12:54 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_vlan.c,v 1.116 2017/12/06 07:40:16 ozaki-r Exp $    */
+/*     $NetBSD: if_vlan.c,v 1.117 2017/12/06 08:12:54 ozaki-r Exp $    */
 
 /*-
  * Copyright (c) 2000, 2001 The NetBSD Foundation, Inc.
@@ -78,7 +78,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_vlan.c,v 1.116 2017/12/06 07:40:16 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_vlan.c,v 1.117 2017/12/06 08:12:54 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -653,7 +653,7 @@
 
        if ((ifp->if_flags & IFF_PROMISC) != 0)
                vlan_safe_ifpromisc_locked(ifp, 0);
-       if_down(ifp);
+       if_down_locked(ifp);
        ifp->if_capabilities = 0;
        mutex_enter(&ifv->ifv_lock);
 done: