Merge branch 'dsa-sja1105-vlan-tags'

Vladimir Oltean says:

====================
Make sja1105 treat tag_8021q VLANs more like real DSA tags

This series solves a nuisance with the sja1105 driver, which is that
non-DSA tagged packets sent directly by the DSA master would still exit
the switch just fine.

We also had an issue for packets coming from the outside world with a
crafted DSA tag, the switch would not reject that tag but think it was
valid.
====================

drivers/net/dsa/sja1105/sja1105.h

@@ -115,12 +115,6 @@ struct sja1105_info {
 	const struct sja1105_dynamic_table_ops *dyn_ops;
 	const struct sja1105_table_ops *static_ops;
 	const struct sja1105_regs *regs;
-	/* Both E/T and P/Q/R/S have quirks when it comes to popping the S-Tag
-	 * from double-tagged frames. E/T will pop it only when it's equal to
-	 * TPID from the General Parameters Table, while P/Q/R/S will only
-	 * pop it when it's equal to TPID2.
-	 */
-	u16 qinq_tpid;
 	bool can_limit_mcast_flood;
 	int (*reset_cmd)(struct dsa_switch *ds);
 	int (*setup_rgmii_delay)(const void *ctx, int port);

drivers/net/dsa/sja1105/sja1105_main.c

@@ -26,7 +26,6 @@
 #include "sja1105_tas.h"
 
 #define SJA1105_UNKNOWN_MULTICAST	0x010000000000ull
-#define SJA1105_DEFAULT_VLAN		(VLAN_N_VID - 1)
 
 static void sja1105_hw_reset(struct gpio_desc *gpio, unsigned int pulse_len,
 			     unsigned int startup_delay)
@@ -120,12 +119,24 @@ static int sja1105_commit_pvid(struct dsa_switch *ds, int port)
 	if (rc)
 		return rc;
 
+	/* Only force dropping of untagged packets when the port is under a
+	 * VLAN-aware bridge. When the tag_8021q pvid is used, we are
+	 * deliberately removing the RX VLAN from the port's VMEMB_PORT list,
+	 * to prevent DSA tag spoofing from the link partner. Untagged packets
+	 * are the only ones that should be received with tag_8021q, so
+	 * definitely don't drop them.
+	 */
+	if (pvid == priv->bridge_pvid[port]) {
 		vlan = priv->static_config.tables[BLK_IDX_VLAN_LOOKUP].entries;
 
 		match = sja1105_is_vlan_configured(priv, pvid);
 
 		if (match < 0 || !(vlan[match].vmemb_port & BIT(port)))
 			drop_untagged = true;
+	}
+
+	if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
+		drop_untagged = true;
 
 	return sja1105_drop_untagged(ds, port, drop_untagged);
 }
@@ -208,6 +219,12 @@ static int sja1105_init_mac_settings(struct sja1105_private *priv)
 		 */
 		if (dsa_port_is_dsa(dp))
 			dp->learning = true;
+
+		/* Disallow untagged packets from being received on the
+		 * CPU and DSA ports.
+		 */
+		if (dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp))
+			mac[dp->index].drpuntag = true;
 	}
 
 	return 0;
@@ -2278,15 +2295,6 @@ int sja1105_vlan_filtering(struct dsa_switch *ds, int port, bool enabled,
 		tpid2 = ETH_P_SJA1105;
 	}
 
-	for (port = 0; port < ds->num_ports; port++) {
-		struct sja1105_port *sp = &priv->ports[port];
-
-		if (enabled)
-			sp->xmit_tpid = priv->info->qinq_tpid;
-		else
-			sp->xmit_tpid = ETH_P_SJA1105;
-	}
-
 	if (priv->vlan_aware == enabled)
 		return 0;
 
@@ -2343,7 +2351,7 @@ int sja1105_vlan_filtering(struct dsa_switch *ds, int port, bool enabled,
 }
 
 static int sja1105_vlan_add(struct sja1105_private *priv, int port, u16 vid,
-			    u16 flags)
+			    u16 flags, bool allowed_ingress)
 {
 	struct sja1105_vlan_lookup_entry *vlan;
 	struct sja1105_table *table;
@@ -2365,7 +2373,12 @@ static int sja1105_vlan_add(struct sja1105_private *priv, int port, u16 vid,
 	vlan[match].type_entry = SJA1110_VLAN_D_TAG;
 	vlan[match].vlanid = vid;
 	vlan[match].vlan_bc |= BIT(port);
+
+	if (allowed_ingress)
 		vlan[match].vmemb_port |= BIT(port);
+	else
+		vlan[match].vmemb_port &= ~BIT(port);
+
 	if (flags & BRIDGE_VLAN_INFO_UNTAGGED)
 		vlan[match].tag_port &= ~BIT(port);
 	else
@@ -2437,7 +2450,7 @@ static int sja1105_bridge_vlan_add(struct dsa_switch *ds, int port,
 	if (dsa_is_cpu_port(ds, port) || dsa_is_dsa_port(ds, port))
 		flags = 0;
 
-	rc = sja1105_vlan_add(priv, port, vlan->vid, flags);
+	rc = sja1105_vlan_add(priv, port, vlan->vid, flags, true);
 	if (rc)
 		return rc;
 
@@ -2467,9 +2480,16 @@ static int sja1105_dsa_8021q_vlan_add(struct dsa_switch *ds, int port, u16 vid,
 				      u16 flags)
 {
 	struct sja1105_private *priv = ds->priv;
+	bool allowed_ingress = true;
 	int rc;
 
-	rc = sja1105_vlan_add(priv, port, vid, flags);
+	/* Prevent attackers from trying to inject a DSA tag from
+	 * the outside world.
+	 */
+	if (dsa_is_user_port(ds, port))
+		allowed_ingress = false;
+
+	rc = sja1105_vlan_add(priv, port, vid, flags, allowed_ingress);
 	if (rc)
 		return rc;
 
@@ -2959,7 +2979,6 @@ static int sja1105_setup_ports(struct sja1105_private *priv)
 		}
 		sp->xmit_worker = worker;
 		skb_queue_head_init(&sp->xmit_queue);
-		sp->xmit_tpid = ETH_P_SJA1105;
 	}
 
 	return 0;

drivers/net/dsa/sja1105/sja1105_spi.c

@@ -575,7 +575,6 @@ const struct sja1105_info sja1105e_info = {
 	.part_no		= SJA1105ET_PART_NO,
 	.static_ops		= sja1105e_table_ops,
 	.dyn_ops		= sja1105et_dyn_ops,
-	.qinq_tpid		= ETH_P_8021Q,
 	.tag_proto		= DSA_TAG_PROTO_SJA1105,
 	.can_limit_mcast_flood	= false,
 	.ptp_ts_bits		= 24,
@@ -608,7 +607,6 @@ const struct sja1105_info sja1105t_info = {
 	.part_no		= SJA1105ET_PART_NO,
 	.static_ops		= sja1105t_table_ops,
 	.dyn_ops		= sja1105et_dyn_ops,
-	.qinq_tpid		= ETH_P_8021Q,
 	.tag_proto		= DSA_TAG_PROTO_SJA1105,
 	.can_limit_mcast_flood	= false,
 	.ptp_ts_bits		= 24,
@@ -641,7 +639,6 @@ const struct sja1105_info sja1105p_info = {
 	.part_no		= SJA1105P_PART_NO,
 	.static_ops		= sja1105p_table_ops,
 	.dyn_ops		= sja1105pqrs_dyn_ops,
-	.qinq_tpid		= ETH_P_8021AD,
 	.tag_proto		= DSA_TAG_PROTO_SJA1105,
 	.can_limit_mcast_flood	= true,
 	.ptp_ts_bits		= 32,
@@ -675,7 +672,6 @@ const struct sja1105_info sja1105q_info = {
 	.part_no		= SJA1105Q_PART_NO,
 	.static_ops		= sja1105q_table_ops,
 	.dyn_ops		= sja1105pqrs_dyn_ops,
-	.qinq_tpid		= ETH_P_8021AD,
 	.tag_proto		= DSA_TAG_PROTO_SJA1105,
 	.can_limit_mcast_flood	= true,
 	.ptp_ts_bits		= 32,
@@ -709,7 +705,6 @@ const struct sja1105_info sja1105r_info = {
 	.part_no		= SJA1105R_PART_NO,
 	.static_ops		= sja1105r_table_ops,
 	.dyn_ops		= sja1105pqrs_dyn_ops,
-	.qinq_tpid		= ETH_P_8021AD,
 	.tag_proto		= DSA_TAG_PROTO_SJA1105,
 	.can_limit_mcast_flood	= true,
 	.ptp_ts_bits		= 32,
@@ -747,7 +742,6 @@ const struct sja1105_info sja1105s_info = {
 	.static_ops		= sja1105s_table_ops,
 	.dyn_ops		= sja1105pqrs_dyn_ops,
 	.regs			= &sja1105pqrs_regs,
-	.qinq_tpid		= ETH_P_8021AD,
 	.tag_proto		= DSA_TAG_PROTO_SJA1105,
 	.can_limit_mcast_flood	= true,
 	.ptp_ts_bits		= 32,
@@ -784,7 +778,6 @@ const struct sja1105_info sja1110a_info = {
 	.static_ops		= sja1110_table_ops,
 	.dyn_ops		= sja1110_dyn_ops,
 	.regs			= &sja1110_regs,
-	.qinq_tpid		= ETH_P_8021AD,
 	.tag_proto		= DSA_TAG_PROTO_SJA1110,
 	.can_limit_mcast_flood	= true,
 	.multiple_cascade_ports	= true,
@@ -835,7 +828,6 @@ const struct sja1105_info sja1110b_info = {
 	.static_ops		= sja1110_table_ops,
 	.dyn_ops		= sja1110_dyn_ops,
 	.regs			= &sja1110_regs,
-	.qinq_tpid		= ETH_P_8021AD,
 	.tag_proto		= DSA_TAG_PROTO_SJA1110,
 	.can_limit_mcast_flood	= true,
 	.multiple_cascade_ports	= true,
@@ -886,7 +878,6 @@ const struct sja1105_info sja1110c_info = {
 	.static_ops		= sja1110_table_ops,
 	.dyn_ops		= sja1110_dyn_ops,
 	.regs			= &sja1110_regs,
-	.qinq_tpid		= ETH_P_8021AD,
 	.tag_proto		= DSA_TAG_PROTO_SJA1110,
 	.can_limit_mcast_flood	= true,
 	.multiple_cascade_ports	= true,
@@ -937,7 +928,6 @@ const struct sja1105_info sja1110d_info = {
 	.static_ops		= sja1110_table_ops,
 	.dyn_ops		= sja1110_dyn_ops,
 	.regs			= &sja1110_regs,
-	.qinq_tpid		= ETH_P_8021AD,
 	.tag_proto		= DSA_TAG_PROTO_SJA1110,
 	.can_limit_mcast_flood	= true,
 	.multiple_cascade_ports	= true,

include/linux/dsa/sja1105.h

@@ -16,6 +16,8 @@
 #define ETH_P_SJA1105_META			0x0008
 #define ETH_P_SJA1110				0xdadc
 
+#define SJA1105_DEFAULT_VLAN			(VLAN_N_VID - 1)
+
 /* IEEE 802.3 Annex 57A: Slow Protocols PDUs (01:80:C2:xx:xx:xx) */
 #define SJA1105_LINKLOCAL_FILTER_A		0x0180C2000000ull
 #define SJA1105_LINKLOCAL_FILTER_A_MASK		0xFFFFFF000000ull
@@ -65,7 +67,6 @@ struct sja1105_port {
 	struct sja1105_tagger_data *data;
 	struct dsa_port *dp;
 	bool hwts_tx_en;
-	u16 xmit_tpid;
 };
 
 enum sja1110_meta_tstamp {

net/dsa/tag_sja1105.c

@@ -133,14 +133,44 @@ static struct sk_buff *sja1105_defer_xmit(struct dsa_port *dp,
 	return NULL;
 }
 
+/* Send VLAN tags with a TPID that blends in with whatever VLAN protocol a
+ * bridge spanning ports of this switch might have.
+ */
 static u16 sja1105_xmit_tpid(struct dsa_port *dp)
 {
-	struct sja1105_port *sp = dp->priv;
+	struct dsa_switch *ds = dp->ds;
+	struct dsa_port *other_dp;
+	u16 proto;
 
-	if (unlikely(!dsa_port_is_sja1105(dp)))
-		return ETH_P_8021Q;
+	/* Since VLAN awareness is global, then if this port is VLAN-unaware,
+	 * all ports are. Use the VLAN-unaware TPID used for tag_8021q.
+	 */
+	if (!dsa_port_is_vlan_filtering(dp))
+		return ETH_P_SJA1105;
+
+	/* Port is VLAN-aware, so there is a bridge somewhere (a single one,
+	 * we're sure about that). It may not be on this port though, so we
+	 * need to find it.
+	 */
+	list_for_each_entry(other_dp, &ds->dst->ports, list) {
+		if (other_dp->ds != ds)
+			continue;
+
+		if (!other_dp->bridge_dev)
+			continue;
+
+		/* Error is returned only if CONFIG_BRIDGE_VLAN_FILTERING,
+		 * which seems pointless to handle, as our port cannot become
+		 * VLAN-aware in that case.
+		 */
+		br_vlan_get_proto(other_dp->bridge_dev, &proto);
 
-	return sp->xmit_tpid;
+		return proto;
+	}
+
+	WARN_ONCE(1, "Port is VLAN-aware but cannot find associated bridge!\n");
+
+	return ETH_P_SJA1105;
 }
 
 static struct sk_buff *sja1105_imprecise_xmit(struct sk_buff *skb,
@@ -168,6 +198,36 @@ static struct sk_buff *sja1105_imprecise_xmit(struct sk_buff *skb,
 	return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp), tx_vid);
 }
 
+/* Transform untagged control packets into pvid-tagged control packets so that
+ * all packets sent by this tagger are VLAN-tagged and we can configure the
+ * switch to drop untagged packets coming from the DSA master.
+ */
+static struct sk_buff *sja1105_pvid_tag_control_pkt(struct dsa_port *dp,
+						    struct sk_buff *skb, u8 pcp)
+{
+	__be16 xmit_tpid = htons(sja1105_xmit_tpid(dp));
+	struct vlan_ethhdr *hdr;
+
+	/* If VLAN tag is in hwaccel area, move it to the payload
+	 * to deal with both cases uniformly and to ensure that
+	 * the VLANs are added in the right order.
+	 */
+	if (unlikely(skb_vlan_tag_present(skb))) {
+		skb = __vlan_hwaccel_push_inside(skb);
+		if (!skb)
+			return NULL;
+	}
+
+	hdr = (struct vlan_ethhdr *)skb_mac_header(skb);
+
+	/* If skb is already VLAN-tagged, leave that VLAN ID in place */
+	if (hdr->h_vlan_proto == xmit_tpid)
+		return skb;
+
+	return vlan_insert_tag(skb, xmit_tpid, (pcp << VLAN_PRIO_SHIFT) |
+			       SJA1105_DEFAULT_VLAN);
+}
+
 static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
 				    struct net_device *netdev)
 {
@@ -183,8 +243,13 @@ static struct sk_buff *sja1105_xmit(struct sk_buff *skb,
 	 * but instead SPI-installed management routes. Part 2 of this
 	 * is the .port_deferred_xmit driver callback.
 	 */
-	if (unlikely(sja1105_is_link_local(skb)))
+	if (unlikely(sja1105_is_link_local(skb))) {
+		skb = sja1105_pvid_tag_control_pkt(dp, skb, pcp);
+		if (!skb)
+			return NULL;
+
 		return sja1105_defer_xmit(dp, skb);
+	}
 
 	return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
 			     ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
@@ -213,6 +278,10 @@ static struct sk_buff *sja1110_xmit(struct sk_buff *skb,
 		return dsa_8021q_xmit(skb, netdev, sja1105_xmit_tpid(dp),
 				     ((pcp << VLAN_PRIO_SHIFT) | tx_vid));
 
+	skb = sja1105_pvid_tag_control_pkt(dp, skb, pcp);
+	if (!skb)
+		return NULL;
+
 	skb_push(skb, SJA1110_HEADER_LEN);
 
 	dsa_alloc_etype_header(skb, SJA1110_HEADER_LEN);