Module Name: src
Committed By: riastradh
Date: Sun Sep 13 17:18:54 UTC 2020
Modified Files:
src/sys/net: if_wg.c
Log Message:
wg: Fix detach logic.
Not tested but this should be less of a rake to step on if anyone
made an unloadable wg module.
To generate a diff of this commit:
cvs rdiff -u -r1.58 -r1.59 src/sys/net/if_wg.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/net/if_wg.c
diff -u src/sys/net/if_wg.c:1.58 src/sys/net/if_wg.c:1.59
--- src/sys/net/if_wg.c:1.58 Sun Sep 13 17:18:13 2020
+++ src/sys/net/if_wg.c Sun Sep 13 17:18:54 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: if_wg.c,v 1.58 2020/09/13 17:18:13 riastradh Exp $ */
+/* $NetBSD: if_wg.c,v 1.59 2020/09/13 17:18:54 riastradh Exp $ */
/*
* Copyright (C) Ryota Ozaki <[email protected]>
@@ -41,7 +41,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.58 2020/09/13 17:18:13 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.59 2020/09/13 17:18:54 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_inet.h"
@@ -144,8 +144,6 @@ __KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.
* - Data messages are always sent via a stable session
*
* Locking notes:
- * - wg interfaces (struct wg_softc, wg) is listed in wg_softcs.list and
- * protected by wg_softcs.lock
* - Each wg has a mutex(9) wg_lock, and a rwlock(9) wg_rwlock
* - Changes to the peer list are serialized by wg_lock
* - The peer list may be read with pserialize(9) and psref(9)
@@ -780,11 +778,7 @@ wg_rnh(struct wg_softc *wg, const int fa
/*
* Global variables
*/
-LIST_HEAD(wg_sclist, wg_softc);
-static struct {
- struct wg_sclist list;
- kmutex_t lock;
-} wg_softcs __cacheline_aligned;
+static volatile unsigned wg_count __cacheline_aligned;
struct psref_class *wg_psref_class __read_mostly;
@@ -811,9 +805,6 @@ wginit(void)
wg_psref_class = psref_class_create("wg", IPL_SOFTNET);
- mutex_init(&wg_softcs.lock, MUTEX_DEFAULT, IPL_NONE);
- LIST_INIT(&wg_softcs.list);
-
if_clone_attach(&wg_cloner);
}
@@ -848,23 +839,49 @@ wg_guarantee_initialized(void)
}
static int
-wgdetach(void)
+wg_count_inc(void)
{
- int error = 0;
+ unsigned o, n;
- mutex_enter(&wg_softcs.lock);
- if (!LIST_EMPTY(&wg_softcs.list)) {
- mutex_exit(&wg_softcs.lock);
- error = EBUSY;
- }
+ do {
+ o = atomic_load_relaxed(&wg_count);
+ if (o == UINT_MAX)
+ return ENFILE;
+ n = o + 1;
+ } while (atomic_cas_uint(&wg_count, o, n) != o);
- if (error == 0) {
- psref_class_destroy(wg_psref_class);
+ return 0;
+}
+
+static void
+wg_count_dec(void)
+{
+ unsigned c __diagused;
+
+ c = atomic_dec_uint_nv(&wg_count);
+ KASSERT(c != UINT_MAX);
+}
- if_clone_detach(&wg_cloner);
+static int
+wgdetach(void)
+{
+
+ /* Prevent new interface creation. */
+ if_clone_detach(&wg_cloner);
+
+ /* Check whether there are any existing interfaces. */
+ if (atomic_load_relaxed(&wg_count)) {
+ /* Back out -- reattach the cloner. */
+ if_clone_attach(&wg_cloner);
+ return EBUSY;
}
- return error;
+ /* No interfaces left. Nuke it. */
+ workqueue_destroy(wg_wq);
+ pktq_destroy(wg_pktq);
+ psref_class_destroy(wg_psref_class);
+
+ return 0;
}
static void
@@ -3555,6 +3572,10 @@ wg_clone_create(struct if_clone *ifc, in
wg_guarantee_initialized();
+ error = wg_count_inc();
+ if (error)
+ return error;
+
wg = kmem_zalloc(sizeof(*wg), KM_SLEEP);
if_initname(&wg->wg_if, ifc->ifc_name, unit);
@@ -3593,16 +3614,9 @@ wg_clone_create(struct if_clone *ifc, in
if (error)
goto fail3;
- mutex_enter(&wg_softcs.lock);
- LIST_INSERT_HEAD(&wg_softcs.list, wg, wg_list);
- mutex_exit(&wg_softcs.lock);
-
return 0;
fail4: __unused
- mutex_enter(&wg_softcs.lock);
- LIST_REMOVE(wg, wg_list);
- mutex_exit(&wg_softcs.lock);
wg_if_detach(wg);
fail3: wg_destroy_all_peers(wg);
#ifdef INET6
@@ -3640,6 +3654,7 @@ fail0: threadpool_job_destroy(&wg->wg_jo
thmap_destroy(wg->wg_peers_bypubkey);
PSLIST_DESTROY(&wg->wg_peers);
kmem_free(wg, sizeof(*wg));
+ wg_count_dec();
return error;
}
@@ -3655,9 +3670,6 @@ wg_clone_destroy(struct ifnet *ifp)
}
#endif
- mutex_enter(&wg_softcs.lock);
- LIST_REMOVE(wg, wg_list);
- mutex_exit(&wg_softcs.lock);
wg_if_detach(wg);
wg_destroy_all_peers(wg);
#ifdef INET6
@@ -3693,6 +3705,7 @@ wg_clone_destroy(struct ifnet *ifp)
thmap_destroy(wg->wg_peers_bypubkey);
PSLIST_DESTROY(&wg->wg_peers);
kmem_free(wg, sizeof(*wg));
+ wg_count_dec();
return 0;
}
