git: eaba3fe1483f - stable/13 - bridge/stp: Ensure we enter NET_EPOCH whenever we can send traffic

[Kristof Provost]

The branch stable/13 has been updated by kp:

URL: https://cgit.FreeBSD.org/src/commit/?id=eaba3fe1483fe82baccb6d3930347bbd548c6fcd

commit eaba3fe1483fe82baccb6d3930347bbd548c6fcd
Author:     Kristof Provost <kp at FreeBSD.org>
AuthorDate: 2021-02-21 20:18:46 +0000
Commit:     Kristof Provost <kp at FreeBSD.org>
CommitDate: 2021-03-02 14:50:21 +0000

    bridge/stp: Ensure we enter NET_EPOCH whenever we can send traffic
    
    Reviewed by:    donner@
    MFC after:      1 week
    Sponsored by:   Orange Business Services
    Differential Revision:  https://reviews.freebsd.org/D28858
    
    (cherry picked from commit 89fa9c34d76bbf85cd7cda60c1868f5e3dba4ec7)
---
 sys/net/bridgestp.c | 9 +++++++++
 sys/net/if_bridge.c | 9 ++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/sys/net/bridgestp.c b/sys/net/bridgestp.c
index c36dc61d1397..82524440c241 100644
--- a/sys/net/bridgestp.c
+++ b/sys/net/bridgestp.c
@@ -154,6 +154,8 @@ static void	bstp_reinit(struct bstp_state *);
 static void
 bstp_transmit(struct bstp_state *bs, struct bstp_port *bp)
 {
+	NET_EPOCH_ASSERT();
+
 	if (bs->bs_running == 0)
 		return;
 
@@ -346,6 +348,7 @@ bstp_send_bpdu(struct bstp_state *bs, struct bstp_port *bp,
 	struct ether_header *eh;
 
 	BSTP_LOCK_ASSERT(bs);
+	NET_EPOCH_ASSERT();
 
 	ifp = bp->bp_ifp;
 
@@ -923,6 +926,8 @@ bstp_update_state(struct bstp_state *bs, struct bstp_port *bp)
 static void
 bstp_update_roles(struct bstp_state *bs, struct bstp_port *bp)
 {
+	NET_EPOCH_ASSERT();
+
 	switch (bp->bp_role) {
 	case BSTP_ROLE_DISABLED:
 		/* Clear any flags if set */
@@ -1862,6 +1867,7 @@ bstp_disable_port(struct bstp_state *bs, struct bstp_port *bp)
 static void
 bstp_tick(void *arg)
 {
+	struct epoch_tracker et;
 	struct bstp_state *bs = arg;
 	struct bstp_port *bp;
 
@@ -1870,6 +1876,7 @@ bstp_tick(void *arg)
 	if (bs->bs_running == 0)
 		return;
 
+	NET_EPOCH_ENTER(et);
 	CURVNET_SET(bs->bs_vnet);
 
 	/* poll link events on interfaces that do not support linkstate */
@@ -1908,6 +1915,7 @@ bstp_tick(void *arg)
 	}
 
 	CURVNET_RESTORE();
+	NET_EPOCH_EXIT(et);
 
 	callout_reset(&bs->bs_bstpcallout, hz, bstp_tick, bs);
 }
@@ -2229,6 +2237,7 @@ bstp_enable(struct bstp_port *bp)
 	struct ifnet *ifp = bp->bp_ifp;
 
 	KASSERT(bp->bp_active == 0, ("already a bstp member"));
+	NET_EPOCH_ASSERT(); /* Because bstp_update_roles() causes traffic. */
 
 	switch (ifp->if_type) {
 		case IFT_ETHER:	/* These can do spanning tree. */
diff --git a/sys/net/if_bridge.c b/sys/net/if_bridge.c
index 24338267229b..3e6b5ba8e0c2 100644
--- a/sys/net/if_bridge.c
+++ b/sys/net/if_bridge.c
@@ -1351,6 +1351,7 @@ bridge_ioctl_gifflags(struct bridge_softc *sc, void *arg)
 static int
 bridge_ioctl_sifflags(struct bridge_softc *sc, void *arg)
 {
+	struct epoch_tracker et;
 	struct ifbreq *req = arg;
 	struct bridge_iflist *bif;
 	struct bstp_port *bp;
@@ -1365,11 +1366,15 @@ bridge_ioctl_sifflags(struct bridge_softc *sc, void *arg)
 		/* SPAN is readonly */
 		return (EINVAL);
 
+	NET_EPOCH_ENTER(et);
+
 	if (req->ifbr_ifsflags & IFBIF_STP) {
 		if ((bif->bif_flags & IFBIF_STP) == 0) {
 			error = bstp_enable(&bif->bif_stp);
-			if (error)
+			if (error) {
+				NET_EPOCH_EXIT(et);
 				return (error);
+			}
 		}
 	} else {
 		if ((bif->bif_flags & IFBIF_STP) != 0)
@@ -1385,6 +1390,8 @@ bridge_ioctl_sifflags(struct bridge_softc *sc, void *arg)
 	/* Save the bits relating to the bridge */
 	bif->bif_flags = req->ifbr_ifsflags & IFBIFMASK;
 
+	NET_EPOCH_EXIT(et);
+
 	return (0);
 }