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net: dsa: tag_ocelot: use VLAN information from tagging header when available

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When the Extraction Frame Header contains a valid classified VLAN, use
that instead of the VLAN header present in the packet.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Vladimir Oltean 2020-10-08 14:56:59 +03:00 committed by Jakub Kicinski
parent 70edfae15a
commit ea440cd2d9
1 changed files with 34 additions and 0 deletions
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34
net/dsa/tag_ocelot.c
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@ -184,9 +184,14 @@ static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
struct net_device *netdev,
struct packet_type *pt)
{
struct dsa_port *cpu_dp = netdev->dsa_ptr;
struct dsa_switch *ds = cpu_dp->ds;
struct ocelot *ocelot = ds->priv;
u64 src_port, qos_class;
u64 vlan_tci, tag_type;
u8 *start = skb->data;
u8 *extraction;
u16 vlan_tpid;
/* Revert skb->data by the amount consumed by the DSA master,
* so it points to the beginning of the frame.
@ -214,6 +219,8 @@ static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
packing(extraction, &src_port, 46, 43, OCELOT_TAG_LEN, UNPACK, 0);
packing(extraction, &qos_class, 19, 17, OCELOT_TAG_LEN, UNPACK, 0);
packing(extraction, &tag_type, 16, 16, OCELOT_TAG_LEN, UNPACK, 0);
packing(extraction, &vlan_tci, 15, 0, OCELOT_TAG_LEN, UNPACK, 0);
skb->dev = dsa_master_find_slave(netdev, 0, src_port);
if (!skb->dev)
@ -228,6 +235,33 @@ static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
skb->offload_fwd_mark = 1;
skb->priority = qos_class;
/* Ocelot switches copy frames unmodified to the CPU. However, it is
* possible for the user to request a VLAN modification through
* VCAP_IS1_ACT_VID_REPLACE_ENA. In this case, what will happen is that
* the VLAN ID field from the Extraction Header gets updated, but the
* 802.1Q header does not (the classified VLAN only becomes visible on
* egress through the "port tag" of front-panel ports).
* So, for traffic extracted by the CPU, we want to pick up the
* classified VLAN and manually replace the existing 802.1Q header from
* the packet with it, so that the operating system is always up to
* date with the result of tc-vlan actions.
* NOTE: In VLAN-unaware mode, we don't want to do that, we want the
* frame to remain unmodified, because the classified VLAN is always
* equal to the pvid of the ingress port and should not be used for
* processing.
*/
vlan_tpid = tag_type ? ETH_P_8021AD : ETH_P_8021Q;
if (ocelot->ports[src_port]->vlan_aware &&
eth_hdr(skb)->h_proto == htons(vlan_tpid)) {
u16 dummy_vlan_tci;
skb_push_rcsum(skb, ETH_HLEN);
__skb_vlan_pop(skb, &dummy_vlan_tci);
skb_pull_rcsum(skb, ETH_HLEN);
__vlan_hwaccel_put_tag(skb, htons(vlan_tpid), vlan_tci);
}
return skb;
}