linsysfs(4): Reimplement listnics() using ifAPI

Handle if arrival/departure events.

Reviewed by:		melifaro (early version)
Differential Revision:	https://reviews.freebsd.org/D38901
MFC after:		1 month
XMFC with:		ifAPI

4 files changed, 373 insertions, 179 deletions

diff --git a/sys/compat/linsysfs/linsysfs.c b/sys/compat/linsysfs/linsysfs.c
index 3b1bdfc280fc..298ce4508b4d 100644
--- a/sys/compat/linsysfs/linsysfs.c
+++ b/sys/compat/linsysfs/linsysfs.c
@@ -37,22 +37,19 @@ __FBSDID("$FreeBSD$");
 #include <sys/mount.h>
 #include <sys/sbuf.h>
 #include <sys/smp.h>
-#include <sys/socket.h>
 #include <sys/bus.h>
 #include <sys/pciio.h>
 
 #include <dev/pci/pcivar.h>
 #include <dev/pci/pcireg.h>
 
-#include <net/if.h>
-#include <net/if_var.h>
-#include <net/if_dl.h>
-
-#include <compat/linux/linux.h>
-#include <compat/linux/linux_common.h>
 #include <compat/linux/linux_util.h>
 #include <fs/pseudofs/pseudofs.h>
 
+#include <compat/linsysfs/linsysfs.h>
+
+MALLOC_DEFINE(M_LINSYSFS, "linsysfs", "Linsysfs structures");
+
 struct scsi_host_queue {
 	TAILQ_ENTRY(scsi_host_queue) scsi_host_next;
 	char *path;
@@ -69,175 +66,6 @@ atoi(const char *str)
 	return (int)strtol(str, (char **)NULL, 10);
 }
 
-static int
-linsysfs_ifnet_addr(PFS_FILL_ARGS)
-{
-	struct epoch_tracker et;
-	struct l_sockaddr lsa;
-	struct ifnet *ifp;
-	int error;
-
-	CURVNET_SET(TD_TO_VNET(td));
-	NET_EPOCH_ENTER(et);
-	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
-	if (ifp != NULL && (error = linux_ifhwaddr(ifp, &lsa)) == 0)
-		error = sbuf_printf(sb, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx\n",
-		    lsa.sa_data[0], lsa.sa_data[1], lsa.sa_data[2],
-		    lsa.sa_data[3], lsa.sa_data[4], lsa.sa_data[5]);
-	else
-		error = ENOENT;
-	NET_EPOCH_EXIT(et);
-	CURVNET_RESTORE();
-	return (error == -1 ? ERANGE : error);
-}
-
-static int
-linsysfs_ifnet_addrlen(PFS_FILL_ARGS)
-{
-
-	sbuf_printf(sb, "%d\n", LINUX_IFHWADDRLEN);
-	return (0);
-}
-
-static int
-linsysfs_ifnet_flags(PFS_FILL_ARGS)
-{
-	struct epoch_tracker et;
-	struct ifnet *ifp;
-	int error;
-
-	CURVNET_SET(TD_TO_VNET(td));
-	NET_EPOCH_ENTER(et);
-	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
-	if (ifp != NULL)
-		error = sbuf_printf(sb, "0x%x\n", linux_ifflags(ifp));
-	else
-		error = ENOENT;
-	NET_EPOCH_EXIT(et);
-	CURVNET_RESTORE();
-	return (error == -1 ? ERANGE : error);
-}
-
-static int
-linsysfs_ifnet_ifindex(PFS_FILL_ARGS)
-{
-	struct epoch_tracker et;
-	struct ifnet *ifp;
-	int error;
-
-	CURVNET_SET(TD_TO_VNET(td));
-	NET_EPOCH_ENTER(et);
-	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
-	if (ifp != NULL)
-		error = sbuf_printf(sb, "%u\n", if_getindex(ifp));
-	else
-		error = ENOENT;
-	NET_EPOCH_EXIT(et);
-	CURVNET_RESTORE();
-	return (error == -1 ? ERANGE : error);
-}
-
-static int
-linsysfs_ifnet_mtu(PFS_FILL_ARGS)
-{
-	struct epoch_tracker et;
-	struct ifnet *ifp;
-	int error;
-
-	CURVNET_SET(TD_TO_VNET(td));
-	NET_EPOCH_ENTER(et);
-	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
-	if (ifp != NULL)
-		error = sbuf_printf(sb, "%u\n", if_getmtu(ifp));
-	else
-		error = ENOENT;
-	NET_EPOCH_EXIT(et);
-	CURVNET_RESTORE();
-	return (error == -1 ? ERANGE : error);
-}
-
-static int
-linsysfs_ifnet_tx_queue_len(PFS_FILL_ARGS)
-{
-
-	/* XXX */
-	sbuf_printf(sb, "1000\n");
-	return (0);
-}
-
-static int
-linsysfs_ifnet_type(PFS_FILL_ARGS)
-{
-	struct epoch_tracker et;
-	struct l_sockaddr lsa;
-	struct ifnet *ifp;
-	int error;
-
-	CURVNET_SET(TD_TO_VNET(td));
-	NET_EPOCH_ENTER(et);
-	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
-	if (ifp != NULL && (error = linux_ifhwaddr(ifp, &lsa)) == 0)
-		error = sbuf_printf(sb, "%d\n", lsa.sa_family);
-	else
-		error = ENOENT;
-	NET_EPOCH_EXIT(et);
-	CURVNET_RESTORE();
-	return (error == -1 ? ERANGE : error);
-}
-
-static void
-linsysfs_listnics(struct pfs_node *dir)
-{
-	struct pfs_node *nic;
-	struct pfs_node *lo;
-
-	nic = pfs_create_dir(dir, "eth0", NULL, NULL, NULL, 0);
-
-	pfs_create_file(nic, "address", &linsysfs_ifnet_addr,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(nic, "addr_len", &linsysfs_ifnet_addrlen,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(nic, "flags", &linsysfs_ifnet_flags,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(nic, "ifindex", &linsysfs_ifnet_ifindex,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(nic, "mtu", &linsysfs_ifnet_mtu,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(nic, "tx_queue_len", &linsysfs_ifnet_tx_queue_len,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(nic, "type", &linsysfs_ifnet_type,
-	    NULL, NULL, NULL, PFS_RD);
-
-	lo = pfs_create_dir(dir, "lo", NULL, NULL, NULL, 0);
-
-	pfs_create_file(lo, "address", &linsysfs_ifnet_addr,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(lo, "addr_len", &linsysfs_ifnet_addrlen,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(lo, "flags", &linsysfs_ifnet_flags,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(lo, "ifindex", &linsysfs_ifnet_ifindex,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(lo, "mtu", &linsysfs_ifnet_mtu,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(lo, "tx_queue_len", &linsysfs_ifnet_tx_queue_len,
-	    NULL, NULL, NULL, PFS_RD);
-
-	pfs_create_file(lo, "type", &linsysfs_ifnet_type,
-	    NULL, NULL, NULL, PFS_RD);
-}
-
 /*
  * Filler function for proc_name
  */
@@ -650,7 +478,6 @@ linsysfs_init(PFS_INIT_ARGS)
 	struct pfs_node *drm;
 	struct pfs_node *pci;
 	struct pfs_node *scsi;
-	struct pfs_node *net;
 	struct pfs_node *devdir, *chardev;
 	struct pfs_node *kernel;
 	devclass_t devclass;
@@ -702,7 +529,6 @@ linsysfs_init(PFS_INIT_ARGS)
 	    NULL, NULL, NULL, PFS_RD);
 
 	linsysfs_listcpus(cpu);
-	linsysfs_listnics(net);
 
 	/* /sys/kernel */
 	kernel = pfs_create_dir(root, "kernel", NULL, NULL, NULL, 0);
@@ -712,6 +538,8 @@ linsysfs_init(PFS_INIT_ARGS)
 	/* /sys/subsystem/... */
 	dir = pfs_create_dir(root, "subsystem", NULL, NULL, NULL, 0);
 
+	linsysfs_net_init();
+
 	return (0);
 }
 
@@ -730,6 +558,8 @@ linsysfs_uninit(PFS_INIT_ARGS)
 		free(scsi_host, M_TEMP);
 	}
 
+	linsysfs_net_uninit();
+
 	return (0);
 }
 
diff --git a/sys/compat/linsysfs/linsysfs.h b/sys/compat/linsysfs/linsysfs.h
new file mode 100644
index 000000000000..005c0e090a6b
--- /dev/null
+++ b/sys/compat/linsysfs/linsysfs.h
@@ -0,0 +1,38 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef _COMPAT_LINSYSFS_LINSYSFS_H_
+#define _COMPAT_LINSYSFS_LINSYSFS_H_
+
+MALLOC_DECLARE(M_LINSYSFS);
+
+extern struct pfs_node *net;
+
+void	linsysfs_net_init(void);
+void	linsysfs_net_uninit(void);
+
+#endif /* _COMPAT_LINSYSFS_LINSYSFS_H_ */
diff --git a/sys/compat/linsysfs/linsysfs_net.c b/sys/compat/linsysfs/linsysfs_net.c
new file mode 100644
index 000000000000..00eb642f1db2
--- /dev/null
+++ b/sys/compat/linsysfs/linsysfs_net.c
@@ -0,0 +1,326 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2023 Dmitry Chagin <dchagin@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/eventhandler.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/sbuf.h>
+#include <sys/socket.h>
+
+#include <net/if.h>
+#include <net/if_var.h>
+#include <net/if_dl.h>
+
+#include <compat/linux/linux.h>
+#include <compat/linux/linux_common.h>
+#include <fs/pseudofs/pseudofs.h>
+
+#include <compat/linsysfs/linsysfs.h>
+
+struct pfs_node *net;
+static eventhandler_tag if_arrival_tag, if_departure_tag;
+
+static uint32_t net_latch_count = 0;
+static struct mtx net_latch_mtx;
+MTX_SYSINIT(net_latch_mtx, &net_latch_mtx, "lsfnet", MTX_DEF);
+
+struct ifp_nodes_queue {
+	TAILQ_ENTRY(ifp_nodes_queue) ifp_nodes_next;
+	if_t ifp;
+	struct pfs_node *pn;
+};
+TAILQ_HEAD(,ifp_nodes_queue) ifp_nodes_q;
+
+static void
+linsysfs_net_latch_hold(void)
+{
+
+	mtx_lock(&net_latch_mtx);
+	if (net_latch_count++ > 0)
+		mtx_sleep(&net_latch_count, &net_latch_mtx, PDROP, "lsfnet", 0);
+	else
+		mtx_unlock(&net_latch_mtx);
+}
+
+static void
+linsysfs_net_latch_rele(void)
+{
+
+	mtx_lock(&net_latch_mtx);
+	if (--net_latch_count > 0)
+		wakeup_one(&net_latch_count);
+	mtx_unlock(&net_latch_mtx);
+}
+
+static int
+linsysfs_ifnet_addr(PFS_FILL_ARGS)
+{
+	struct epoch_tracker et;
+	struct l_sockaddr lsa;
+	struct ifnet *ifp;
+	int error;
+
+	CURVNET_SET(TD_TO_VNET(td));
+	NET_EPOCH_ENTER(et);
+	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
+	if (ifp != NULL && (error = linux_ifhwaddr(ifp, &lsa)) == 0)
+		error = sbuf_printf(sb, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx\n",
+		    lsa.sa_data[0], lsa.sa_data[1], lsa.sa_data[2],
+		    lsa.sa_data[3], lsa.sa_data[4], lsa.sa_data[5]);
+	else
+		error = ENOENT;
+	NET_EPOCH_EXIT(et);
+	CURVNET_RESTORE();
+	return (error == -1 ? ERANGE : error);
+}
+
+static int
+linsysfs_ifnet_addrlen(PFS_FILL_ARGS)
+{
+
+	sbuf_printf(sb, "%d\n", LINUX_IFHWADDRLEN);
+	return (0);
+}
+
+static int
+linsysfs_ifnet_flags(PFS_FILL_ARGS)
+{
+	struct epoch_tracker et;
+	struct ifnet *ifp;
+	int error;
+
+	CURVNET_SET(TD_TO_VNET(td));
+	NET_EPOCH_ENTER(et);
+	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
+	if (ifp != NULL)
+		error = sbuf_printf(sb, "0x%x\n", linux_ifflags(ifp));
+	else
+		error = ENOENT;
+	NET_EPOCH_EXIT(et);
+	CURVNET_RESTORE();
+	return (error == -1 ? ERANGE : error);
+}
+
+static int
+linsysfs_ifnet_ifindex(PFS_FILL_ARGS)
+{
+	struct epoch_tracker et;
+	struct ifnet *ifp;
+	int error;
+
+	CURVNET_SET(TD_TO_VNET(td));
+	NET_EPOCH_ENTER(et);
+	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
+	if (ifp != NULL)
+		error = sbuf_printf(sb, "%u\n", if_getindex(ifp));
+	else
+		error = ENOENT;
+	NET_EPOCH_EXIT(et);
+	CURVNET_RESTORE();
+	return (error == -1 ? ERANGE : error);
+}
+
+static int
+linsysfs_ifnet_mtu(PFS_FILL_ARGS)
+{
+	struct epoch_tracker et;
+	struct ifnet *ifp;
+	int error;
+
+	CURVNET_SET(TD_TO_VNET(td));
+	NET_EPOCH_ENTER(et);
+	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
+	if (ifp != NULL)
+		error = sbuf_printf(sb, "%u\n", if_getmtu(ifp));
+	else
+		error = ENOENT;
+	NET_EPOCH_EXIT(et);
+	CURVNET_RESTORE();
+	return (error == -1 ? ERANGE : error);
+}
+
+static int
+linsysfs_ifnet_tx_queue_len(PFS_FILL_ARGS)
+{
+
+	/* XXX */
+	sbuf_printf(sb, "1000\n");
+	return (0);
+}
+
+static int
+linsysfs_ifnet_type(PFS_FILL_ARGS)
+{
+	struct epoch_tracker et;
+	struct l_sockaddr lsa;
+	struct ifnet *ifp;
+	int error;
+
+	CURVNET_SET(TD_TO_VNET(td));
+	NET_EPOCH_ENTER(et);
+	ifp = ifname_linux_to_ifp(td, pn->pn_parent->pn_name);
+	if (ifp != NULL && (error = linux_ifhwaddr(ifp, &lsa)) == 0)
+		error = sbuf_printf(sb, "%d\n", lsa.sa_family);
+	else
+		error = ENOENT;
+	NET_EPOCH_EXIT(et);
+	CURVNET_RESTORE();
+	return (error == -1 ? ERANGE : error);
+}
+
+static struct pfs_node *
+linsysfs_net_find_node(if_t ifp)
+{
+	struct ifp_nodes_queue *nq, *nq_tmp;
+
+	TAILQ_FOREACH_SAFE(nq, &ifp_nodes_q, ifp_nodes_next, nq_tmp) {
+		if (nq->ifp == ifp)
+			return (nq->pn);
+	}
+	return (NULL);
+}
+
+static int
+linsysfs_net_addnic(if_t ifp, void *arg)
+{
+	char ifname[LINUX_IFNAMSIZ];
+	struct ifp_nodes_queue *nq;
+	struct epoch_tracker et;
+	struct pfs_node *dir = arg;
+	struct pfs_node *nic = NULL;
+	int ret __diagused;
+
+	NET_EPOCH_ENTER(et);
+	ret = ifname_bsd_to_linux_ifp(ifp, ifname, sizeof(ifname));
+	NET_EPOCH_EXIT(et);
+	KASSERT(ret > 0, ("Interface (%s) is not converted", if_name(ifp)));
+
+	nic = linsysfs_net_find_node(ifp);
+	MPASS(nic == NULL);
+
+	nic = pfs_create_dir(dir, ifname, NULL, NULL, NULL, 0);
+	pfs_create_file(nic, "address", &linsysfs_ifnet_addr,
+	    NULL, NULL, NULL, PFS_RD);
+	pfs_create_file(nic, "addr_len", &linsysfs_ifnet_addrlen,
+	    NULL, NULL, NULL, PFS_RD);
+	pfs_create_file(nic, "flags", &linsysfs_ifnet_flags,
+	    NULL, NULL, NULL, PFS_RD);
+	pfs_create_file(nic, "ifindex", &linsysfs_ifnet_ifindex,
+	    NULL, NULL, NULL, PFS_RD);
+	pfs_create_file(nic, "mtu", &linsysfs_ifnet_mtu,
+	    NULL, NULL, NULL, PFS_RD);
+	pfs_create_file(nic, "tx_queue_len", &linsysfs_ifnet_tx_queue_len,
+	    NULL, NULL, NULL, PFS_RD);
+	pfs_create_file(nic, "type", &linsysfs_ifnet_type,
+	    NULL, NULL, NULL, PFS_RD);
+
+	nq = malloc(sizeof(*nq), M_LINSYSFS, M_WAITOK);
+	nq->pn = nic;
+	nq->ifp = ifp;
+	TAILQ_INSERT_TAIL(&ifp_nodes_q, nq, ifp_nodes_next);
+	return (0);
+}
+
+static int
+linsysfs_net_delnic(if_t ifp, void *arg)
+{
+	struct ifp_nodes_queue *nq, *nq_tmp;
+
+	TAILQ_FOREACH_SAFE(nq, &ifp_nodes_q, ifp_nodes_next, nq_tmp) {
+		if (nq->ifp == ifp) {
+			TAILQ_REMOVE(&ifp_nodes_q, nq, ifp_nodes_next);
+			pfs_destroy(nq->pn);
+			free(nq, M_LINSYSFS);
+			return (0);
+		}
+	}
+	return (1);
+}
+
+static void
+linsysfs_net_listnics(struct pfs_node *dir)
+{
+
+	CURVNET_SET(TD_TO_VNET(curthread));
+	if_foreach_sleep(NULL, NULL, linsysfs_net_addnic, dir);
+	CURVNET_RESTORE();
+}
+
+static void
+linsysfs_ifnet_arrival(void *arg __unused, struct ifnet *ifp)
+{
+
+	linsysfs_net_latch_hold();
+	linsysfs_net_addnic(ifp, net);
+	linsysfs_net_latch_rele();
+}
+
+static void
+linsysfs_ifnet_departure(void *arg __unused, struct ifnet *ifp)
+{
+
+	linsysfs_net_latch_hold();
+	linsysfs_net_delnic(ifp, net);
+	linsysfs_net_latch_rele();
+}
+
+void
+linsysfs_net_init(void)
+{
+
+	MPASS(net != NULL);
+	TAILQ_INIT(&ifp_nodes_q);
+	if_arrival_tag = EVENTHANDLER_REGISTER(ifnet_arrival_event,
+	    linsysfs_ifnet_arrival, NULL, EVENTHANDLER_PRI_ANY);
+	if_departure_tag = EVENTHANDLER_REGISTER(ifnet_departure_event,
+	    linsysfs_ifnet_departure, NULL, EVENTHANDLER_PRI_ANY);
+
+	linsysfs_net_latch_hold();
+	linsysfs_net_listnics(net);
+	linsysfs_net_latch_rele();
+}
+
+void
+linsysfs_net_uninit(void)
+{
+	struct ifp_nodes_queue *nq, *nq_tmp;
+
+	EVENTHANDLER_DEREGISTER(ifnet_arrival_event, if_arrival_tag);
+	EVENTHANDLER_DEREGISTER(ifnet_departure_event, if_departure_tag);
+
+	linsysfs_net_latch_hold();
+	TAILQ_FOREACH_SAFE(nq, &ifp_nodes_q, ifp_nodes_next, nq_tmp) {
+		TAILQ_REMOVE(&ifp_nodes_q, nq, ifp_nodes_next);
+		free(nq, M_LINSYSFS);
+	}
+	linsysfs_net_latch_rele();
+}
diff --git a/sys/modules/linsysfs/Makefile b/sys/modules/linsysfs/Makefile
index 058fbbc521b1..8ec02da435e4 100644
--- a/sys/modules/linsysfs/Makefile
+++ b/sys/modules/linsysfs/Makefile
@@ -5,7 +5,7 @@
 KMOD=	linsysfs
 SRCS=	vnode_if.h \
 	device_if.h bus_if.h  pci_if.h \
-	linsysfs.c
+	linsysfs.c linsysfs_net.c
 
 .if !defined(KERNBUILDDIR)
 .warning Building Linuxulator outside of a kernel does not make sense