- Ensure the path cost does not exceed 65535 in legacy STP mode.

- If the path cost is calculated when the link is down, set a pending flag so
  it is calculated again when it comes back up.
- To not use 00:00:00:00:00:00 as the bridge id, all interfaces are scanned and
  the lowest number wins. All zeros is too low.

Approved by:	re (rwatson)

1 files changed, 30 insertions, 2 deletions

diff --git a/sys/net/bridgestp.c b/sys/net/bridgestp.c
index 7d3d3c737e7e..dcb258f0d37b 100644
--- a/sys/net/bridgestp.c
+++ b/sys/net/bridgestp.c
@@ -1331,6 +1331,9 @@ bstp_set_port_proto(struct bstp_port *bp, int proto)
 			bstp_timer_stop(&bp->bp_migrate_delay_timer);
 			/* clear unsupported features */
 			bp->bp_operedge = 0;
+			/* STP compat mode only uses 16 bits of the 32 */
+			if (bp->bp_path_cost > 65535)
+				bp->bp_path_cost = 65535;
 			break;
 
 		case BSTP_PROTO_RSTP:
@@ -1617,6 +1620,10 @@ bstp_set_path_cost(struct bstp_port *bp, uint32_t path_cost)
 	if (path_cost > BSTP_MAX_PATH_COST)
 		return (EINVAL);
 
+	/* STP compat mode only uses 16 bits of the 32 */
+	if (bp->bp_protover == BSTP_PROTO_STP && path_cost > 65535)
+		path_cost = 65535;
+
 	BSTP_LOCK(bs);
 
 	if (path_cost == 0) {	/* use auto */
@@ -1701,6 +1708,12 @@ bstp_calc_path_cost(struct bstp_port *bp)
 	if (bp->bp_flags & BSTP_PORT_ADMCOST)
 		return bp->bp_path_cost;
 
+	if (ifp->if_link_state == LINK_STATE_DOWN) {
+		/* Recalc when the link comes up again */
+		bp->bp_flags |= BSTP_PORT_PNDCOST;
+		return (BSTP_DEFAULT_PATH_COST);
+	}
+
 	if (ifp->if_baudrate < 1000)
 		return (BSTP_DEFAULT_PATH_COST);
 
@@ -1809,6 +1822,12 @@ bstp_ifupdstatus(struct bstp_state *bs, struct bstp_port *bp)
 				    ifmr.ifm_active & IFM_FDX ? 1 : 0;
 			}
 
+			/* Calc the cost if the link was down previously */
+			if (bp->bp_flags & BSTP_PORT_PNDCOST) {
+				bp->bp_path_cost = bstp_calc_path_cost(bp);
+				bp->bp_flags &= ~BSTP_PORT_PNDCOST;
+			}
+
 			if (bp->bp_role == BSTP_ROLE_DISABLED)
 				bstp_enable_port(bs, bp);
 		} else {
@@ -1999,6 +2018,7 @@ bstp_reinit(struct bstp_state *bs)
 	struct bstp_port *bp;
 	struct ifnet *ifp, *mif;
 	u_char *e_addr;
+	static const u_char llzero[ETHER_ADDR_LEN];	/* 00:00:00:00:00:00 */
 
 	BSTP_LOCK_ASSERT(bs);
 
@@ -2012,14 +2032,16 @@ bstp_reinit(struct bstp_state *bs)
 	 * Search through the Ethernet adapters and find the one with the
 	 * lowest value. The adapter which we take the MAC address from does
 	 * not need to be part of the bridge, it just needs to be a unique
-	 * value. It is not possible for mif to be null, at this point we have
-	 * at least one stp port and hence at least one NIC.
+	 * value.
 	 */
 	IFNET_RLOCK();
 	TAILQ_FOREACH(ifp, &ifnet, if_link) {
 		if (ifp->if_type != IFT_ETHER)
 			continue;
 
+		if (bstp_addr_cmp(IF_LLADDR(ifp), llzero) == 0)
+			continue;
+
 		if (mif == NULL) {
 			mif = ifp;
 			continue;
@@ -2031,6 +2053,12 @@ bstp_reinit(struct bstp_state *bs)
 	}
 	IFNET_RUNLOCK();
 
+	/* Can only happen if all interfaces have a zero MAC address */
+	if (mif == NULL) {
+		callout_stop(&bs->bs_bstpcallout);
+		return;
+	}
+
 	e_addr = IF_LLADDR(mif);
 	bs->bs_bridge_pv.pv_dbridge_id =
 	    (((uint64_t)bs->bs_bridge_priority) << 48) |