Module Name: src
Committed By: riastradh
Date: Sun Jul 28 14:38:19 UTC 2024
Modified Files:
src/sys/net: if_wg.c
Log Message:
wg(4): Fix logic to ensure session initiation is underway.
Previously, wg_task_send_init_message would call
wg_send_handshake_msg_init if either:
(a) the stable session is UNKNOWN, meaning a session has not yet been
established, either by us or by the peer (but it could be in
progress); or
(b) the stable session is not UNKNOWN but the unstable session is
_not_ INIT_ACTIVE, meaning there is an established session and we
are not currently initiating a new session.
If wg_output (or wgintr) found no established session while there was
already a session being initiated, we may only enter
wg_task_send_init_message after the session is already established,
and trigger spurious reinitiation.
Instead, create a separate flag to indicate whether it is mandatory
to rekey because limits have passed. Then create a session only if:
(a) the stable session is not ESTABLISHED, or
(b) the mandatory rekey flag is not set,
and clear the mandatory rekey flag.
While here, arrange to do rekey-after-time on tx, not on callout. If
there's no data to tx, we shouldn't reinitiate a session -- we should
stay quiet on the network.
PR kern/55729: net/if_wg/t_misc:wg_rekey test case fails
PR kern/56252: wg(4) state machine has race conditions
PR kern/58463: if_wg does not work when idle.
To generate a diff of this commit:
cvs rdiff -u -r1.94 -r1.95 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:1.94 src/sys/net/if_wg.c:1.95
--- src/sys/net/if_wg.c:1.94 Sun Jul 28 14:37:59 2024
+++ src/sys/net/if_wg.c Sun Jul 28 14:38:19 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: if_wg.c,v 1.94 2024/07/28 14:37:59 riastradh Exp $ */
+/* $NetBSD: if_wg.c,v 1.95 2024/07/28 14:38:19 riastradh Exp $ */
/*
* Copyright (C) Ryota Ozaki <ozaki.ry...@gmail.com>
@@ -41,7 +41,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.94 2024/07/28 14:37:59 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.95 2024/07/28 14:38:19 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_altq_enabled.h"
@@ -612,12 +612,13 @@ struct wg_peer {
struct timespec wgp_last_handshake_time;
- callout_t wgp_rekey_timer;
callout_t wgp_handshake_timeout_timer;
callout_t wgp_session_dtor_timer;
time_t wgp_handshake_start_time;
+ volatile unsigned wgp_force_rekey;
+
int wgp_n_allowedips;
struct wg_allowedip wgp_allowedips[WG_ALLOWEDIPS];
@@ -735,7 +736,6 @@ static struct wg_session *
static void wg_update_endpoint_if_necessary(struct wg_peer *,
const struct sockaddr *);
-static void wg_schedule_rekey_timer(struct wg_peer *);
static void wg_schedule_session_dtor_timer(struct wg_peer *);
static bool wg_is_underload(struct wg_softc *, struct wg_peer *, int);
@@ -2146,8 +2146,6 @@ wg_handle_msg_resp(struct wg_softc *wg,
wgp->wgp_last_sent_mac1_valid = false;
wgp->wgp_last_sent_cookie_valid = false;
- wg_schedule_rekey_timer(wgp);
-
wg_update_endpoint_if_necessary(wgp, src);
/*
@@ -2438,14 +2436,6 @@ wg_lookup_session_by_index(struct wg_sof
}
static void
-wg_schedule_rekey_timer(struct wg_peer *wgp)
-{
- int timeout = MIN(wg_rekey_after_time, (unsigned)(INT_MAX / hz));
-
- callout_schedule(&wgp->wgp_rekey_timer, timeout * hz);
-}
-
-static void
wg_send_keepalive_msg(struct wg_peer *wgp, struct wg_session *wgs)
{
struct mbuf *m;
@@ -3146,16 +3136,22 @@ wg_task_send_init_message(struct wg_soft
return;
}
+ /*
+ * If we already have an established session, there's no need
+ * to initiate a new one -- unless the rekey-after-time or
+ * rekey-after-messages limits have passed.
+ */
wgs = wgp->wgp_session_stable;
- if (wgs->wgs_state == WGS_STATE_UNKNOWN) {
- /* XXX What if the unstable session is already INIT_ACTIVE? */
- wg_send_handshake_msg_init(wg, wgp);
- } else {
- /* rekey */
- wgs = wgp->wgp_session_unstable;
- if (wgs->wgs_state != WGS_STATE_INIT_ACTIVE)
- wg_send_handshake_msg_init(wg, wgp);
- }
+ if (wgs->wgs_state == WGS_STATE_ESTABLISHED &&
+ !atomic_swap_uint(&wgp->wgp_force_rekey, 0))
+ return;
+
+ /*
+ * Ensure we're initiating a new session. If the unstable
+ * session is already INIT_ACTIVE or INIT_PASSIVE, this does
+ * nothing.
+ */
+ wg_send_handshake_msg_init(wg, wgp);
}
static void
@@ -3576,14 +3572,6 @@ next0: m_freem(m);
}
static void
-wg_rekey_timer(void *arg)
-{
- struct wg_peer *wgp = arg;
-
- wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
-}
-
-static void
wg_purge_pending_packets(struct wg_peer *wgp)
{
struct mbuf *m;
@@ -3611,8 +3599,6 @@ wg_alloc_peer(struct wg_softc *wg)
wgp = kmem_zalloc(sizeof(*wgp), KM_SLEEP);
wgp->wgp_sc = wg;
- callout_init(&wgp->wgp_rekey_timer, CALLOUT_MPSAFE);
- callout_setfunc(&wgp->wgp_rekey_timer, wg_rekey_timer, wgp);
callout_init(&wgp->wgp_handshake_timeout_timer, CALLOUT_MPSAFE);
callout_setfunc(&wgp->wgp_handshake_timeout_timer,
wg_handshake_timeout_timer, wgp);
@@ -3690,7 +3676,6 @@ wg_destroy_peer(struct wg_peer *wgp)
wg_purge_pending_packets(wgp);
/* Halt all packet processing and timeouts. */
- callout_halt(&wgp->wgp_rekey_timer, NULL);
callout_halt(&wgp->wgp_handshake_timeout_timer, NULL);
callout_halt(&wgp->wgp_session_dtor_timer, NULL);
@@ -4302,7 +4287,8 @@ wg_send_data_msg(struct wg_peer *wgp, st
if_statadd(ifp, if_obytes, mlen);
if_statinc(ifp, if_opackets);
if (wgs->wgs_is_initiator &&
- wgs->wgs_time_last_data_sent == 0) {
+ ((time_uptime - wgs->wgs_time_established) >=
+ wg_rekey_after_time)) {
/*
* [W] 6.2 Transport Message Limits
* "if a peer is the initiator of a current secure
@@ -4311,7 +4297,9 @@ wg_send_data_msg(struct wg_peer *wgp, st
* transmitting a transport data message, the current
* secure session is REKEY-AFTER-TIME seconds old,"
*/
- wg_schedule_rekey_timer(wgp);
+ WG_TRACE("rekey after time");
+ atomic_store_relaxed(&wgp->wgp_force_rekey, 1);
+ wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
}
wgs->wgs_time_last_data_sent = time_uptime;
if (wg_session_get_send_counter(wgs) >=
@@ -4323,6 +4311,8 @@ wg_send_data_msg(struct wg_peer *wgp, st
* 5.4.2), after it has sent REKEY-AFTER-MESSAGES
* transport data messages..."
*/
+ WG_TRACE("rekey after messages");
+ atomic_store_relaxed(&wgp->wgp_force_rekey, 1);
wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
}
}
