SMP locking for ifnet list.

21 files changed, 126 insertions, 24 deletions

diff --git a/sys/compat/linprocfs/linprocfs.c b/sys/compat/linprocfs/linprocfs.c
index aca3f06a873a..1ccd25a8ef74 100644
--- a/sys/compat/linprocfs/linprocfs.c
+++ b/sys/compat/linprocfs/linprocfs.c
@@ -725,6 +725,7 @@ linprocfs_donetdev(PFS_FILL_ARGS)
 	    "bytes    packets errs drop fifo frame compressed",
 	    "bytes    packets errs drop fifo frame compressed");
 
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		linux_ifname(ifp, ifname, sizeof ifname);
 			sbuf_printf(sb, "%6.6s:", ifname);
@@ -733,6 +734,7 @@ linprocfs_donetdev(PFS_FILL_ARGS)
 		sbuf_printf(sb, "%8lu %7lu %4lu %4lu %4lu %5lu %7lu %10lu\n",
 		    0UL, 0UL, 0UL, 0UL, 0UL, 0UL, 0UL, 0UL);
 	}
+	IFNET_RUNLOCK();
 	
 	return (0);
 }
diff --git a/sys/compat/linux/linux_ioctl.c b/sys/compat/linux/linux_ioctl.c
index 97144331d31e..186b84c8e0f0 100644
--- a/sys/compat/linux/linux_ioctl.c
+++ b/sys/compat/linux/linux_ioctl.c
@@ -1907,12 +1907,16 @@ linux_ifname(struct ifnet *ifp, char *buffer, size_t buflen)
 
 	/* Determine the (relative) unit number for ethernet interfaces */
 	ethno = 0;
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifscan, &ifnet, if_link) {
-		if (ifscan == ifp)
+		if (ifscan == ifp) {
+			IFNET_RUNLOCK();
 			return (snprintf(buffer, buflen, "eth%d", ethno));
+		}
 		if (IFP_IS_ETH(ifscan))
 			ethno++;
 	}
+	IFNET_RUNLOCK();
 
 	return (0);
 }
@@ -1942,6 +1946,7 @@ ifname_linux_to_bsd(const char *lxname, char *bsdname)
 		return (NULL);
 	index = 0;
 	is_eth = (len == 3 && !strncmp(lxname, "eth", len)) ? 1 : 0;
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		/*
 		 * Allow Linux programs to use FreeBSD names. Don't presume
@@ -1954,6 +1959,7 @@ ifname_linux_to_bsd(const char *lxname, char *bsdname)
 		if (is_eth && IFP_IS_ETH(ifp) && unit == index++)
 			break;
 	}
+	IFNET_RUNLOCK();
 	if (ifp != NULL)
 		snprintf(bsdname, IFNAMSIZ, "%s%d", ifp->if_name, ifp->if_unit);
 	return (ifp);
@@ -1993,6 +1999,7 @@ linux_ifconf(struct thread *td, struct ifconf *uifc)
 	ethno = 0;
 
 	/* Return all AF_INET addresses of all interfaces */
+	IFNET_RLOCK();		/* could sleep XXX */
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if (uio.uio_resid <= 0)
 			break;
@@ -2019,11 +2026,14 @@ linux_ifconf(struct thread *td, struct ifconf *uifc)
 
 				error = uiomove((caddr_t)&ifr, sizeof ifr,
 				    &uio);
-				if (error != 0)
+				if (error != 0) {
+					IFNET_RUNLOCK();
 					return (error);
+				}
 			}
 		}
 	}
+	IFNET_RUNLOCK();
 
 	ifc.ifc_len -= uio.uio_resid;
 	error = copyout(&ifc, uifc, sizeof ifc);
diff --git a/sys/compat/svr4/svr4_sockio.c b/sys/compat/svr4/svr4_sockio.c
index 8dc65a8112ae..8ecd1d42a5e1 100644
--- a/sys/compat/svr4/svr4_sockio.c
+++ b/sys/compat/svr4/svr4_sockio.c
@@ -100,7 +100,7 @@ svr4_sock_ioctl(fp, td, retval, fd, cmd, data)
 			 * fix is to make SVR4_SIOCGIFCONF return only one
 			 * entry per physical interface?
 			 */
-
+			IFNET_RLOCK();
 			TAILQ_FOREACH(ifp, &ifnet, if_link)
 				if (TAILQ_FIRST(&ifp->if_addrhead) == NULL)
 					ifnum++;
@@ -108,8 +108,7 @@ svr4_sock_ioctl(fp, td, retval, fd, cmd, data)
 					TAILQ_FOREACH(ifa, &ifp->if_addrhead,
 					    ifa_link)
 						ifnum++;
-
-
+			IFNET_RUNLOCK();
 			DPRINTF(("SIOCGIFNUM %d\n", ifnum));
 			return copyout(&ifnum, data, sizeof(ifnum));
 		}
diff --git a/sys/contrib/ipfilter/netinet/fil.c b/sys/contrib/ipfilter/netinet/fil.c
index 1f8f435dbb1b..434e9e63b527 100644
--- a/sys/contrib/ipfilter/netinet/fil.c
+++ b/sys/contrib/ipfilter/netinet/fil.c
@@ -1963,6 +1963,9 @@ void frsync()
      (defined(__FreeBSD_version) && (__FreeBSD_version >= 300000))
 #   if (NetBSD >= 199905) || defined(__OpenBSD__)
 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
+#   elif defined(__FreeBSD_version) && (__FreeBSD_version >= 500043)
+	IFNET_RLOCK();
+	TAILQ_FOREACH(ifp, &ifnet, if_link)
 #   else
 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_link.tqe_next)
 #   endif
@@ -1973,6 +1976,9 @@ void frsync()
 		ip_natsync(ifp);
 		ip_statesync(ifp);
 	}
+#  if defined(__FreeBSD_version) && (__FreeBSD_version >= 500043)
+	IFNET_RUNLOCK();
+#  endif
 	ip_natsync((struct ifnet *)-1);
 # endif /* !SOLARIS */
 
diff --git a/sys/kern/kern_uuid.c b/sys/kern/kern_uuid.c
index 5d0cb744e9f3..d28cb36fcd37 100644
--- a/sys/kern/kern_uuid.c
+++ b/sys/kern/kern_uuid.c
@@ -91,7 +91,7 @@ uuid_node(uint16_t *node)
 	struct sockaddr_dl *sdl;
 	int i;
 
-	/* XXX: lock ifnet. */
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		/* Walk the address list */
 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
@@ -100,12 +100,12 @@ uuid_node(uint16_t *node)
 			    sdl->sdl_type == IFT_ETHER) {
 				/* Got a MAC address. */
 				bcopy(LLADDR(sdl), node, UUID_NODE_LEN);
-				/* XXX: unlock ifnet. */
+				IFNET_RUNLOCK();
 				return;
 			}
 		}
 	}
-	/* XXX: unlock ifnet. */
+	IFNET_RUNLOCK();
 
 	for (i = 0; i < (UUID_NODE_LEN>>1); i++)
 		node[i] = (uint16_t)arc4random();
diff --git a/sys/net/bridge.c b/sys/net/bridge.c
index 295c2089e1e8..13c36cd28b2d 100644
--- a/sys/net/bridge.c
+++ b/sys/net/bridge.c
@@ -302,6 +302,7 @@ bridge_off(void)
     int i, s;
 
     DEB(printf("bridge_off: n_clusters %d\n", n_clusters);)
+    IFNET_RLOCK();
     TAILQ_FOREACH(ifp, &ifnet, if_link) {
 	struct bdg_softc *b;
 
@@ -322,6 +323,7 @@ bridge_off(void)
 	b->cluster = NULL;
 	bdg_stats.s[ifp->if_index].name[0] = '\0';
     }
+    IFNET_RUNLOCK();
     /* flush_tables */
 
     s = splimp();
@@ -345,6 +347,7 @@ bridge_on(void)
     struct ifnet *ifp ;
     int s ;
 
+    IFNET_RLOCK();
     TAILQ_FOREACH(ifp, &ifnet, if_link) {
 	struct bdg_softc *b = &ifp2sc[ifp->if_index];
 
@@ -370,6 +373,7 @@ bridge_on(void)
 	    b->flags &= ~IFF_MUTE;
 	}
     }
+    IFNET_RUNLOCK();
 }
 
 /**
@@ -435,6 +439,7 @@ parse_bdg_cfg()
 	/*
 	 * now search in interface list for a matching name
 	 */
+	IFNET_RLOCK();		/* could sleep XXX */
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 	    char buf[IFNAMSIZ];
 
@@ -460,6 +465,7 @@ parse_bdg_cfg()
 		break ;
 	    }
 	}
+	IFNET_RUNLOCK();
 	if (!found)
 	    printf("interface %s Not found in bridge\n", beg);
 	*p = c;
@@ -847,17 +853,10 @@ bdg_forward(struct mbuf *m0, struct ifnet *dst)
 	printf("xx ouch, bdg_forward for local pkt\n");
 	return m0;
     }
-    if (dst == BDG_BCAST || dst == BDG_MCAST || dst == BDG_UNKNOWN) {
-	ifp = TAILQ_FIRST(&ifnet) ; /* scan all ports */
-	once = 0 ;
-	if (dst != BDG_UNKNOWN) /* need a copy for the local stack */
-	    shared = 1 ;
-    } else {
-	ifp = dst ;
-	once = 1 ;
+    if (dst == BDG_BCAST || dst == BDG_MCAST) {
+	 /* need a copy for the local stack */
+	 shared = 1 ;
     }
-    if ((uintptr_t)(ifp) <= (u_int)BDG_FORWARD)
-	panic("bdg_forward: bad dst");
 
     /*
      * Do filtering in a very similar way to what is done in ip_output.
@@ -1023,6 +1022,17 @@ forward:
 	real_dst = src ;
 
     last = NULL;
+    IFNET_RLOCK();
+    if (dst == BDG_BCAST || dst == BDG_MCAST || dst == BDG_UNKNOWN) {
+	ifp = TAILQ_FIRST(&ifnet) ; /* scan all ports */
+	once = 0 ;
+    } else {
+	ifp = dst ;
+	once = 1 ;
+    }
+    if ((uintptr_t)(ifp) <= (u_int)BDG_FORWARD)
+	panic("bdg_forward: bad dst");
+
     for (;;) {
 	if (last) { /* need to forward packet leftover from previous loop */
 	    struct mbuf *m ;
@@ -1032,6 +1042,7 @@ forward:
 	    } else {
 		m = m_copypacket(m0, M_DONTWAIT);
 		if (m == NULL) {
+		    IFNET_RUNLOCK();
 		    printf("bdg_forward: sorry, m_copypacket failed!\n");
 		    bdg_dropped++ ;
 		    return m0 ; /* the original is still there... */
@@ -1062,6 +1073,7 @@ forward:
 	if (ifp == NULL)
 	    once = 1 ;
     }
+    IFNET_RUNLOCK();
     DEB(bdg_fw_ticks += (u_long)(rdtsc() - ticks) ; bdg_fw_count++ ;
 	if (bdg_fw_count != 0) bdg_fw_avg = bdg_fw_ticks/bdg_fw_count; )
     return m0 ;
diff --git a/sys/net/if.c b/sys/net/if.c
index 10c6c10ee413..42f2590ce4c1 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -102,6 +102,7 @@ int	if_index = 0;
 struct	ifindex_entry *ifindex_table = NULL;
 int	ifqmaxlen = IFQ_MAXLEN;
 struct	ifnethead ifnet;	/* depend on static init XXX */
+struct	mtx ifnet_lock;
 int	if_cloners_count;
 LIST_HEAD(, if_clone) if_cloners = LIST_HEAD_INITIALIZER(if_cloners);
 
@@ -263,6 +264,7 @@ if_init(dummy)
 	void *dummy;
 {
 
+	IFNET_LOCK_INIT();
 	TAILQ_INIT(&ifnet);
 	SLIST_INIT(&ifklist);
 	if_grow();				/* create initial table */
@@ -295,6 +297,7 @@ if_check(dummy)
 	int s;
 
 	s = splimp();
+	IFNET_RLOCK();	/* could sleep on rare error; mostly okay XXX */
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if (ifp->if_snd.ifq_maxlen == 0) {
 			printf("%s%d XXX: driver didn't set ifq_maxlen\n",
@@ -308,6 +311,7 @@ if_check(dummy)
 			    MTX_NETWORK_LOCK, MTX_DEF);
 		}
 	}
+	IFNET_RUNLOCK();
 	splx(s);
 	if_slowtimo(0);
 }
@@ -376,7 +380,9 @@ if_attach(ifp)
 	register struct sockaddr_dl *sdl;
 	register struct ifaddr *ifa;
 
+	IFNET_WLOCK();
 	TAILQ_INSERT_TAIL(&ifnet, ifp, if_link);
+	IFNET_WUNLOCK();
 	/*
 	 * XXX -
 	 * The old code would work if the interface passed a pre-existing
@@ -537,7 +543,9 @@ if_detach(ifp)
 	mac_destroy_ifnet(ifp);
 #endif /* MAC */
 	KNOTE(&ifp->if_klist, NOTE_EXIT);
+	IFNET_WLOCK();
 	TAILQ_REMOVE(&ifnet, ifp, if_link);
+	IFNET_WUNLOCK();
 	mtx_destroy(&ifp->if_snd.ifq_mtx);
 	splx(s);
 }
@@ -846,6 +854,7 @@ ifa_ifwithaddr(addr)
 	struct ifnet *ifp;
 	struct ifaddr *ifa;
 
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link)
 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 			if (ifa->ifa_addr->sa_family != addr->sa_family)
@@ -861,6 +870,7 @@ ifa_ifwithaddr(addr)
 		}
 	ifa = NULL;
 done:
+	IFNET_RUNLOCK();
 	return (ifa);
 }
 
@@ -875,6 +885,7 @@ ifa_ifwithdstaddr(addr)
 	struct ifnet *ifp;
 	struct ifaddr *ifa;
 
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
 			continue;
@@ -887,6 +898,7 @@ ifa_ifwithdstaddr(addr)
 	}
 	ifa = NULL;
 done:
+	IFNET_RUNLOCK();
 	return (ifa);
 }
 
@@ -918,6 +930,7 @@ ifa_ifwithnet(addr)
 	 * Scan though each interface, looking for ones that have
 	 * addresses in this address family.
 	 */
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 			register char *cp, *cp2, *cp3;
@@ -980,6 +993,7 @@ next:				continue;
 	}
 	ifa = ifa_maybe;
 done:
+	IFNET_RUNLOCK();
 	return (ifa);
 }
 
@@ -1162,12 +1176,14 @@ if_slowtimo(arg)
 	register struct ifnet *ifp;
 	int s = splimp();
 
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if (ifp->if_timer == 0 || --ifp->if_timer)
 			continue;
 		if (ifp->if_watchdog)
 			(*ifp->if_watchdog)(ifp);
 	}
+	IFNET_RUNLOCK();
 	splx(s);
 	timeout(if_slowtimo, (void *)0, hz / IFNET_SLOWHZ);
 }
@@ -1192,6 +1208,7 @@ ifunit(const char *name)
 	 * Devices should really be known as /dev/fooN, not /dev/net/fooN.
 	 */
 	snprintf(namebuf, IFNAMSIZ, "%s/%s", net_cdevsw.d_name, name);
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		dev = ifdev_byindex(ifp->if_index);
 		if (strcmp(devtoname(dev), namebuf) == 0)
@@ -1199,6 +1216,7 @@ ifunit(const char *name)
 		if (dev_named(dev, name))
 			break;
 	}
+	IFNET_RUNLOCK();
 	return (ifp);
 }
 
@@ -1625,6 +1643,7 @@ ifconf(cmd, data)
 	int space = ifc->ifc_len, error = 0;
 
 	ifrp = ifc->ifc_req;
+	IFNET_RLOCK();		/* could sleep XXX */
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		char workbuf[64];
 		int ifnlen, addrs;
@@ -1695,6 +1714,7 @@ ifconf(cmd, data)
 			ifrp++;
 		}
 	}
+	IFNET_RUNLOCK();
 	ifc->ifc_len -= space;
 	return (error);
 }
diff --git a/sys/net/if_ef.c b/sys/net/if_ef.c
index d297faff630a..b064d381045b 100644
--- a/sys/net/if_ef.c
+++ b/sys/net/if_ef.c
@@ -163,8 +163,9 @@ ef_detach(struct efnet *sc)
 		    }
 		}
 	}
-
+	IFNET_WLOCK();
 	TAILQ_REMOVE(&ifnet, ifp, if_link);
+	IFNET_WUNLOCK();
 	splx(s);
 	return 0;
 }
@@ -508,6 +509,7 @@ ef_load(void)
 	struct ef_link *efl = NULL;
 	int error = 0, d;
 
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if (ifp->if_type != IFT_ETHER) continue;
 		EFDEBUG("Found interface %s%d\n", ifp->if_name, ifp->if_unit);
@@ -538,6 +540,7 @@ ef_load(void)
 		efcount++;
 		SLIST_INSERT_HEAD(&efdev, efl, el_next);
 	}
+	IFNET_RUNLOCK();
 	if (error) {
 		if (efl)
 			SLIST_INSERT_HEAD(&efdev, efl, el_next);
diff --git a/sys/net/if_var.h b/sys/net/if_var.h
index 3e3300ee7454..fa4082baaece 100644
--- a/sys/net/if_var.h
+++ b/sys/net/if_var.h
@@ -410,6 +410,13 @@ struct ifmultiaddr {
 		IFA_UNLOCK(ifa);			\
 	} while (0)
 
+extern	struct mtx ifnet_lock;
+#define	IFNET_LOCK_INIT()	mtx_init(&ifnet_lock, "ifnet", NULL, MTX_DEF)
+#define	IFNET_WLOCK()		mtx_lock(&ifnet_lock)
+#define	IFNET_WUNLOCK()		mtx_unlock(&ifnet_lock)
+#define	IFNET_RLOCK()		IFNET_WLOCK()
+#define	IFNET_RUNLOCK()		IFNET_WUNLOCK()
+
 struct ifindex_entry {
 	struct	ifnet *ife_ifnet;
 	struct	ifaddr *ife_ifnet_addr;
diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c
index d8ec4895156f..40f2ee130da1 100644
--- a/sys/net/rtsock.c
+++ b/sys/net/rtsock.c
@@ -414,11 +414,12 @@ route_output(m, so)
 			/* new gateway could require new ifaddr, ifp;
 			   flags may also be different; ifp may be specified
 			   by ll sockaddr when protocol address is ambiguous */
-#define	equal(a1, a2) (bcmp((caddr_t)(a1), (caddr_t)(a2), (a1)->sa_len) == 0)
+/* compare two sockaddr structures */
+#define	sa_equal(a1, a2) (bcmp((a1), (a2), (a1)->sa_len) == 0)
 			if ((rt->rt_flags & RTF_GATEWAY && gate != NULL) ||
 			    ifpaddr != NULL ||
 			    (ifaaddr != NULL &&
-			    !equal(ifaaddr, rt->rt_ifa->ifa_addr))) {
+			    !sa_equal(ifaaddr, rt->rt_ifa->ifa_addr))) {
 				if ((error = rt_getifa(&info)) != 0)
 					senderr(error);
 			}
@@ -946,6 +947,7 @@ sysctl_iflist(af, w)
 	int	len, error = 0;
 
 	bzero((caddr_t)&info, sizeof(info));
+	/* IFNET_RLOCK(); */		/* could sleep XXX */
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if (w->w_arg && w->w_arg != ifp->if_index)
 			continue;
@@ -991,6 +993,7 @@ sysctl_iflist(af, w)
 		ifaaddr = netmask = brdaddr = 0;
 	}
 done:
+	/* IFNET_RUNLOCK(); */ /* XXX */
 	return (error);
 }
 
diff --git a/sys/netatm/atm_if.c b/sys/netatm/atm_if.c
index 206531242f77..e5fdb6bd5427 100644
--- a/sys/netatm/atm_if.c
+++ b/sys/netatm/atm_if.c
@@ -875,7 +875,9 @@ atm_nif_detach(nip)
 	/*
 	 * Remove from system interface list (ie. if_detach())
 	 */
+	IFNET_WLOCK();
 	TAILQ_REMOVE(&ifnet, ifp, if_link);
+	IFNET_WUNLOCK();
 
 	/*
 	 * Remove from physical interface list
diff --git a/sys/netatm/atm_usrreq.c b/sys/netatm/atm_usrreq.c
index 4abc66b6dced..e050b6c8c8da 100644
--- a/sys/netatm/atm_usrreq.c
+++ b/sys/netatm/atm_usrreq.c
@@ -394,6 +394,7 @@ atm_dgram_control(so, cmd, data, ifp, td)
 			/*
 			 * Make sure prefix name is unique
 			 */
+			IFNET_RLOCK();
 			TAILQ_FOREACH(ifp2, &ifnet, if_link) {
 				if (!strcmp(ifp2->if_name, asp->asr_nif_pref)) {
 					/*
@@ -407,9 +408,11 @@ atm_dgram_control(so, cmd, data, ifp, td)
 					}
 					if (nip)
 						continue;
+					IFNET_RUNLOCK();
 					ATM_RETERR(EEXIST);
 				}
 			}
+			IFNET_RUNLOCK();
 
 			/*
 			 * Let interface handle it from here
diff --git a/sys/netgraph/ng_ether.c b/sys/netgraph/ng_ether.c
index da2012f08439..041999c6092a 100644
--- a/sys/netgraph/ng_ether.c
+++ b/sys/netgraph/ng_ether.c
@@ -728,11 +728,13 @@ ng_ether_mod_event(module_t mod, int event, void *data)
 		ng_ether_input_orphan_p = ng_ether_input_orphan;
 
 		/* Create nodes for any already-existing Ethernet interfaces */
+		IFNET_RLOCK();
 		TAILQ_FOREACH(ifp, &ifnet, if_link) {
 			if (ifp->if_type == IFT_ETHER
 			    || ifp->if_type == IFT_L2VLAN)
 				ng_ether_attach(ifp);
 		}
+		IFNET_RUNLOCK();
 		break;
 
 	case MOD_UNLOAD:
diff --git a/sys/netgraph/ng_gif.c b/sys/netgraph/ng_gif.c
index c2c87eb75dd6..2d999590f412 100644
--- a/sys/netgraph/ng_gif.c
+++ b/sys/netgraph/ng_gif.c
@@ -564,10 +564,12 @@ ng_gif_mod_event(module_t mod, int event, void *data)
 		ng_gif_input_orphan_p = ng_gif_input_orphan;
 
 		/* Create nodes for any already-existing gif interfaces */
+		IFNET_RLOCK();
 		TAILQ_FOREACH(ifp, &ifnet, if_link) {
 			if (ifp->if_type == IFT_GIF)
 				ng_gif_attach(ifp);
 		}
+		IFNET_RUNLOCK();
 		break;
 
 	case MOD_UNLOAD:
diff --git a/sys/netgraph/ng_source.c b/sys/netgraph/ng_source.c
index b2e976c10f6f..78525e89672d 100644
--- a/sys/netgraph/ng_source.c
+++ b/sys/netgraph/ng_source.c
@@ -481,10 +481,12 @@ ng_source_store_output_ifp(sc_p sc, struct ng_mesg *msg)
 	 * way of verifying if_index is valid since if_indexlim is
 	 * local to if_attach()
 	 */
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if (ifp->if_index == if_index)
 			break;
 	}
+	IFNET_RUNLOCK();
 
 	if (ifp == NULL) {
 		printf("%s: can't find interface %d\n", __FUNCTION__, if_index);
diff --git a/sys/netinet6/icmp6.c b/sys/netinet6/icmp6.c
index edb41f755dc8..9e3015dc5503 100644
--- a/sys/netinet6/icmp6.c
+++ b/sys/netinet6/icmp6.c
@@ -1672,6 +1672,7 @@ ni6_addrs(ni6, m, ifpp, subj)
 		}
 	}
 
+	IFNET_RLOCK();
 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
 	{
 		addrsofif = 0;
@@ -1729,11 +1730,13 @@ ni6_addrs(ni6, m, ifpp, subj)
 		}
 		if (iffound) {
 			*ifpp = ifp;
+			IFNET_RUNLOCK();
 			return(addrsofif);
 		}
 
 		addrs += addrsofif;
 	}
+	IFNET_RUNLOCK();
 
 	return(addrs);
 }
@@ -1755,9 +1758,9 @@ ni6_store_addrs(ni6, nni6, ifp0, resid)
 
 	if (ifp0 == NULL && !(niflags & NI_NODEADDR_FLAG_ALL))
 		return(0);	/* needless to copy */
-
+		
+	IFNET_RLOCK();
   again:
-
 	for (; ifp; ifp = TAILQ_NEXT(ifp, if_list))
 	{
 		for (ifa = ifp->if_addrlist.tqh_first; ifa;
@@ -1823,6 +1826,7 @@ ni6_store_addrs(ni6, nni6, ifp0, resid)
 				 */
 				nni6->ni_flags |=
 					NI_NODEADDR_FLAG_TRUNCATE;
+				IFNET_RUNLOCK();
 				return(copied);
 			}
 
@@ -1877,6 +1881,8 @@ ni6_store_addrs(ni6, nni6, ifp0, resid)
 		goto again;
 	}
 
+	IFNET_RUNLOCK();
+
 	return(copied);
 }
 
diff --git a/sys/netinet6/in6.c b/sys/netinet6/in6.c
index bb38bde9976c..c450dea64907 100644
--- a/sys/netinet6/in6.c
+++ b/sys/netinet6/in6.c
@@ -1973,6 +1973,7 @@ in6_ifawithscope(oifp, dst)
 	 * Comparing an interface with the outgoing interface will be done
 	 * only at the final stage of tiebreaking.
 	 */
+	IFNET_RLOCK();
 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
 	{
 		/*
@@ -2204,6 +2205,7 @@ in6_ifawithscope(oifp, dst)
 			best_scope = in6_addrscope(&ifa_best->ia_addr.sin6_addr);
 		}
 	}
+	IFNET_RUNLOCK();
 
 	/* count statistics for future improvements */
 	if (ifa_best == NULL)
@@ -2385,12 +2387,14 @@ in6_setmaxmtu()
 	unsigned long maxmtu = 0;
 	struct ifnet *ifp;
 
+	IFNET_RLOCK();
 	for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
 	{
 		if ((ifp->if_flags & IFF_LOOPBACK) == 0 &&
 		    nd_ifinfo[ifp->if_index].linkmtu > maxmtu)
 			maxmtu =  nd_ifinfo[ifp->if_index].linkmtu;
 	}
+	IFNET_RUNLOCK();
 	if (maxmtu)	/* update only when maxmtu is positive */
 		in6_maxmtu = maxmtu;
 }
diff --git a/sys/netinet6/in6_ifattach.c b/sys/netinet6/in6_ifattach.c
index 9150a3660d41..5abcca1b12aa 100644
--- a/sys/netinet6/in6_ifattach.c
+++ b/sys/netinet6/in6_ifattach.c
@@ -381,6 +381,7 @@ get_ifid(ifp0, altifp, in6)
 	}
 
 	/* next, try to get it from some other hardware interface */
+	IFNET_RLOCK();
 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
 	{
 		if (ifp == ifp0)
@@ -396,9 +397,11 @@ get_ifid(ifp0, altifp, in6)
 			nd6log((LOG_DEBUG,
 			    "%s: borrow interface identifier from %s\n",
 			    if_name(ifp0), if_name(ifp)));
+			IFNET_RUNLOCK();
 			goto success;
 		}
 	}
+	IFNET_RUNLOCK();
 
 	/* last resort: get from random number source */
 	if (get_rand_ifid(ifp, in6) == 0) {
@@ -688,6 +691,7 @@ in6_nigroup_attach(name, namelen)
 	if (in6_nigroup(NULL, name, namelen, &mltaddr.sin6_addr) != 0)
 		return;
 
+	IFNET_RLOCK();
 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
 	{
 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
@@ -701,6 +705,7 @@ in6_nigroup_attach(name, namelen)
 			}
 		}
 	}
+	IFNET_RUNLOCK();
 }
 
 void
@@ -718,6 +723,7 @@ in6_nigroup_detach(name, namelen)
 	if (in6_nigroup(NULL, name, namelen, &mltaddr.sin6_addr) != 0)
 		return;
 
+	IFNET_RLOCK();
 	for (ifp = ifnet.tqh_first; ifp; ifp = ifp->if_list.tqe_next)
 	{
 		mltaddr.sin6_addr.s6_addr16[1] = htons(ifp->if_index);
@@ -725,6 +731,7 @@ in6_nigroup_detach(name, namelen)
 		if (in6m)
 			in6_delmulti(in6m);
 	}
+	IFNET_RUNLOCK();	
 }
 
 /*
diff --git a/sys/netipsec/xform_ipip.c b/sys/netipsec/xform_ipip.c
index a9c0edb41206..9d49a3e55948 100644
--- a/sys/netipsec/xform_ipip.c
+++ b/sys/netipsec/xform_ipip.c
@@ -309,6 +309,7 @@ _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
 	if ((m->m_pkthdr.rcvif == NULL ||
 	    !(m->m_pkthdr.rcvif->if_flags & IFF_LOOPBACK)) &&
 	    ipip_allow != 2) {
+	    	IFNET_RLOCK();
 		for (ifp = ifnet.tqh_first; ifp != 0;
 		     ifp = ifp->if_list.tqe_next) {
 			for (ifa = ifp->if_addrlist.tqh_first; ifa != 0;
@@ -325,6 +326,7 @@ _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
 					    ipo->ip_src.s_addr)	{
 						ipipstat.ipips_spoof++;
 						m_freem(m);
+						IFNET_RUNLOCK();
 						return;
 					}
 				}
@@ -341,6 +343,7 @@ _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
 					if (IN6_ARE_ADDR_EQUAL(&sin6->sin6_addr, &ip6->ip6_src)) {
 						ipipstat.ipips_spoof++;
 						m_freem(m);
+						IFNET_RUNLOCK();
 						return;
 					}
 
@@ -348,6 +351,7 @@ _ipip_input(struct mbuf *m, int iphlen, struct ifnet *gifp)
 #endif /* INET6 */
 			}
 		}
+		IFNET_RUNLOCK();
 	}
 
 	/* Statistics */
diff --git a/sys/nfsclient/bootp_subr.c b/sys/nfsclient/bootp_subr.c
index a9c504f6bdcb..50f3b1f4dddc 100644
--- a/sys/nfsclient/bootp_subr.c
+++ b/sys/nfsclient/bootp_subr.c
@@ -401,6 +401,7 @@ bootpboot_p_iflist(void)
 	struct ifaddr *ifa;
 
 	printf("Interface list:\n");
+	IFNET_RLOCK(); /* could sleep, but okay for debugging XXX */
 	for (ifp = TAILQ_FIRST(&ifnet);
 	     ifp != NULL;
 	     ifp = TAILQ_NEXT(ifp, if_link)) {
@@ -410,6 +411,7 @@ bootpboot_p_iflist(void)
 			if (ifa->ifa_addr->sa_family == AF_INET)
 				bootpboot_p_if(ifp, ifa);
 	}
+	IFNET_RUNLOCK();
 }
 #endif /* defined(BOOTP_DEBUG) */
 
@@ -1689,6 +1691,7 @@ bootpc_init(void)
 	       __XSTRING(BOOTP_WIRED_TO));
 #endif
 	bzero(&ifctx->ireq, sizeof(ifctx->ireq));
+	IFNET_RLOCK();
 	for (ifp = TAILQ_FIRST(&ifnet);
 	     ifp != NULL;
 	     ifp = TAILQ_NEXT(ifp, if_link)) {
@@ -1712,6 +1715,7 @@ bootpc_init(void)
 		gctx->lastinterface = ifctx;
 		ifctx = allocifctx(gctx);
 	}
+	IFNET_RUNLOCK();
 	free(ifctx, M_TEMP);
 
 	if (gctx->interfaces == NULL) {
diff --git a/sys/nfsclient/nfs_diskless.c b/sys/nfsclient/nfs_diskless.c
index 791c61e1ee59..c5f167ef52ce 100644
--- a/sys/nfsclient/nfs_diskless.c
+++ b/sys/nfsclient/nfs_diskless.c
@@ -102,6 +102,7 @@ nfs_setup_diskless(void)
 		return;
 	}
 	ifa = NULL;
+	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
 			if ((ifa->ifa_addr->sa_family == AF_LINK) &&
@@ -110,11 +111,14 @@ nfs_setup_diskless(void)
 				    (sdl->sdl_alen == ourdl.sdl_alen) &&
 				    !bcmp(sdl->sdl_data + sdl->sdl_nlen,
 					  ourdl.sdl_data + ourdl.sdl_nlen, 
-					  sdl->sdl_alen))
+					  sdl->sdl_alen)) {
+				    IFNET_RUNLOCK();
 				    goto match_done;
+				}
 			}
 		}
 	}
+	IFNET_RUNLOCK();
 	printf("nfs_diskless: no interface\n");
 	return;	/* no matching interface */
 match_done: