net: dsa: tag_{e}dsa.c: Remove dependency on platform data

The platform data nr_chips is used when validating a received packet,
to ensure it comes from a know switch chip. The number of possible
switches is limited to DSA_MAX_SWITCHES, so use this as the first
validation step. The new binding allows holes in the dst->ds[] array,
so also ensure ensure there is a valid dsa_switch for this packet.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 10 insertions, 2 deletions

diff --git a/net/dsa/tag_dsa.c b/net/dsa/tag_dsa.c
index aa780e4ac0bd..f9832f097681 100644
--- a/net/dsa/tag_dsa.c
+++ b/net/dsa/tag_dsa.c
@@ -107,9 +107,13 @@ static int dsa_rcv(struct sk_buff *skb, struct net_device *dev,
          * Check that the source device exists and that the source
          * port is a registered DSA port.
          */
-        if (source_device >= dst->pd->nr_chips)
+        if (source_device >= DSA_MAX_SWITCHES)
                 goto out_drop;
+
         ds = dst->ds[source_device];
+        if (!ds)
+                goto out_drop;
+
         if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
                 goto out_drop;
 
diff --git a/net/dsa/tag_edsa.c b/net/dsa/tag_edsa.c
index 2288c8098c42..3890aac8190f 100644
--- a/net/dsa/tag_edsa.c
+++ b/net/dsa/tag_edsa.c
@@ -120,9 +120,13 @@ static int edsa_rcv(struct sk_buff *skb, struct net_device *dev,
          * Check that the source device exists and that the source
          * port is a registered DSA port.
          */
-        if (source_device >= dst->pd->nr_chips)
+        if (source_device >= DSA_MAX_SWITCHES)
                 goto out_drop;
+
         ds = dst->ds[source_device];
+        if (!ds)
+                goto out_drop;
+
         if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL)
                 goto out_drop;