mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 01:10:04 +00:00
![Vladimir Oltean](/assets/img/avatar_default.png)
ocelot_xmit_get_vlan_info() calls __skb_vlan_pop() as the most
appropriate helper I could find which strips away a VLAN header.
That's all I need it to do, but __skb_vlan_pop() has more logic, which
will become incompatible with the future revert of commit 6d1ccff627
("net: reset mac header in dev_start_xmit()").
Namely, it performs a sanity check on skb_mac_header(), which will stop
being set after the above revert, so it will return an error instead of
removing the VLAN tag.
ocelot_xmit_get_vlan_info() gets called in 2 circumstances:
(1) the port is under a VLAN-aware bridge and the bridge sends
VLAN-tagged packets
(2) the port is under a VLAN-aware bridge and somebody else (an 8021q
upper) sends VLAN-tagged packets (using a VID that isn't in the
bridge vlan tables)
In case (1), there is actually no bug to defend against, because
br_dev_xmit() calls skb_reset_mac_header() and things continue to work.
However, in case (2), illustrated using the commands below, it can be
seen that our intervention is needed, since __skb_vlan_pop() complains:
$ ip link add br0 type bridge vlan_filtering 1 && ip link set br0 up
$ ip link set $eth master br0 && ip link set $eth up
$ ip link add link $eth name $eth.100 type vlan id 100 && ip link set $eth.100 up
$ ip addr add 192.168.100.1/24 dev $eth.100
I could fend off the checks in __skb_vlan_pop() with some
skb_mac_header_was_set() calls, but seeing how few callers of
__skb_vlan_pop() there are from TX paths, that seems rather
unproductive.
As an alternative solution, extract the bare minimum logic to strip a
VLAN header, and move it to a new helper named vlan_remove_tag(), close
to the definition of vlan_insert_tag(). Document it appropriately and
make ocelot_xmit_get_vlan_info() call this smaller helper instead.
Seeing that it doesn't appear illegal to test skb->protocol in the TX
path, I guess it would be a good for vlan_remove_tag() to also absorb
the vlan_set_encap_proto() function call.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
220 lines
6.5 KiB
C
220 lines
6.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/* Copyright 2019 NXP
|
|
*/
|
|
#include <linux/dsa/ocelot.h>
|
|
|
|
#include "tag.h"
|
|
|
|
#define OCELOT_NAME "ocelot"
|
|
#define SEVILLE_NAME "seville"
|
|
|
|
/* If the port is under a VLAN-aware bridge, remove the VLAN header from the
|
|
* payload and move it into the DSA tag, which will make the switch classify
|
|
* the packet to the bridge VLAN. Otherwise, leave the classified VLAN at zero,
|
|
* which is the pvid of standalone and VLAN-unaware bridge ports.
|
|
*/
|
|
static void ocelot_xmit_get_vlan_info(struct sk_buff *skb, struct dsa_port *dp,
|
|
u64 *vlan_tci, u64 *tag_type)
|
|
{
|
|
struct net_device *br = dsa_port_bridge_dev_get(dp);
|
|
struct vlan_ethhdr *hdr;
|
|
u16 proto, tci;
|
|
|
|
if (!br || !br_vlan_enabled(br)) {
|
|
*vlan_tci = 0;
|
|
*tag_type = IFH_TAG_TYPE_C;
|
|
return;
|
|
}
|
|
|
|
hdr = skb_vlan_eth_hdr(skb);
|
|
br_vlan_get_proto(br, &proto);
|
|
|
|
if (ntohs(hdr->h_vlan_proto) == proto) {
|
|
vlan_remove_tag(skb, &tci);
|
|
*vlan_tci = tci;
|
|
} else {
|
|
rcu_read_lock();
|
|
br_vlan_get_pvid_rcu(br, &tci);
|
|
rcu_read_unlock();
|
|
*vlan_tci = tci;
|
|
}
|
|
|
|
*tag_type = (proto != ETH_P_8021Q) ? IFH_TAG_TYPE_S : IFH_TAG_TYPE_C;
|
|
}
|
|
|
|
static void ocelot_xmit_common(struct sk_buff *skb, struct net_device *netdev,
|
|
__be32 ifh_prefix, void **ifh)
|
|
{
|
|
struct dsa_port *dp = dsa_slave_to_port(netdev);
|
|
struct dsa_switch *ds = dp->ds;
|
|
u64 vlan_tci, tag_type;
|
|
void *injection;
|
|
__be32 *prefix;
|
|
u32 rew_op = 0;
|
|
u64 qos_class;
|
|
|
|
ocelot_xmit_get_vlan_info(skb, dp, &vlan_tci, &tag_type);
|
|
|
|
qos_class = netdev_get_num_tc(netdev) ?
|
|
netdev_get_prio_tc_map(netdev, skb->priority) : skb->priority;
|
|
|
|
injection = skb_push(skb, OCELOT_TAG_LEN);
|
|
prefix = skb_push(skb, OCELOT_SHORT_PREFIX_LEN);
|
|
|
|
*prefix = ifh_prefix;
|
|
memset(injection, 0, OCELOT_TAG_LEN);
|
|
ocelot_ifh_set_bypass(injection, 1);
|
|
ocelot_ifh_set_src(injection, ds->num_ports);
|
|
ocelot_ifh_set_qos_class(injection, qos_class);
|
|
ocelot_ifh_set_vlan_tci(injection, vlan_tci);
|
|
ocelot_ifh_set_tag_type(injection, tag_type);
|
|
|
|
rew_op = ocelot_ptp_rew_op(skb);
|
|
if (rew_op)
|
|
ocelot_ifh_set_rew_op(injection, rew_op);
|
|
|
|
*ifh = injection;
|
|
}
|
|
|
|
static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
|
|
struct net_device *netdev)
|
|
{
|
|
struct dsa_port *dp = dsa_slave_to_port(netdev);
|
|
void *injection;
|
|
|
|
ocelot_xmit_common(skb, netdev, cpu_to_be32(0x8880000a), &injection);
|
|
ocelot_ifh_set_dest(injection, BIT_ULL(dp->index));
|
|
|
|
return skb;
|
|
}
|
|
|
|
static struct sk_buff *seville_xmit(struct sk_buff *skb,
|
|
struct net_device *netdev)
|
|
{
|
|
struct dsa_port *dp = dsa_slave_to_port(netdev);
|
|
void *injection;
|
|
|
|
ocelot_xmit_common(skb, netdev, cpu_to_be32(0x88800005), &injection);
|
|
seville_ifh_set_dest(injection, BIT_ULL(dp->index));
|
|
|
|
return skb;
|
|
}
|
|
|
|
static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
|
|
struct net_device *netdev)
|
|
{
|
|
u64 src_port, qos_class;
|
|
u64 vlan_tci, tag_type;
|
|
u8 *start = skb->data;
|
|
struct dsa_port *dp;
|
|
u8 *extraction;
|
|
u16 vlan_tpid;
|
|
u64 rew_val;
|
|
|
|
/* Revert skb->data by the amount consumed by the DSA master,
|
|
* so it points to the beginning of the frame.
|
|
*/
|
|
skb_push(skb, ETH_HLEN);
|
|
/* We don't care about the short prefix, it is just for easy entrance
|
|
* into the DSA master's RX filter. Discard it now by moving it into
|
|
* the headroom.
|
|
*/
|
|
skb_pull(skb, OCELOT_SHORT_PREFIX_LEN);
|
|
/* And skb->data now points to the extraction frame header.
|
|
* Keep a pointer to it.
|
|
*/
|
|
extraction = skb->data;
|
|
/* Now the EFH is part of the headroom as well */
|
|
skb_pull(skb, OCELOT_TAG_LEN);
|
|
/* Reset the pointer to the real MAC header */
|
|
skb_reset_mac_header(skb);
|
|
skb_reset_mac_len(skb);
|
|
/* And move skb->data to the correct location again */
|
|
skb_pull(skb, ETH_HLEN);
|
|
|
|
/* Remove from inet csum the extraction header */
|
|
skb_postpull_rcsum(skb, start, OCELOT_TOTAL_TAG_LEN);
|
|
|
|
ocelot_xfh_get_src_port(extraction, &src_port);
|
|
ocelot_xfh_get_qos_class(extraction, &qos_class);
|
|
ocelot_xfh_get_tag_type(extraction, &tag_type);
|
|
ocelot_xfh_get_vlan_tci(extraction, &vlan_tci);
|
|
ocelot_xfh_get_rew_val(extraction, &rew_val);
|
|
|
|
skb->dev = dsa_master_find_slave(netdev, 0, src_port);
|
|
if (!skb->dev)
|
|
/* The switch will reflect back some frames sent through
|
|
* sockets opened on the bare DSA master. These will come back
|
|
* with src_port equal to the index of the CPU port, for which
|
|
* there is no slave registered. So don't print any error
|
|
* message here (ignore and drop those frames).
|
|
*/
|
|
return NULL;
|
|
|
|
dsa_default_offload_fwd_mark(skb);
|
|
skb->priority = qos_class;
|
|
OCELOT_SKB_CB(skb)->tstamp_lo = rew_val;
|
|
|
|
/* 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.
|
|
*/
|
|
dp = dsa_slave_to_port(skb->dev);
|
|
vlan_tpid = tag_type ? ETH_P_8021AD : ETH_P_8021Q;
|
|
|
|
if (dsa_port_is_vlan_filtering(dp) &&
|
|
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;
|
|
}
|
|
|
|
static const struct dsa_device_ops ocelot_netdev_ops = {
|
|
.name = OCELOT_NAME,
|
|
.proto = DSA_TAG_PROTO_OCELOT,
|
|
.xmit = ocelot_xmit,
|
|
.rcv = ocelot_rcv,
|
|
.needed_headroom = OCELOT_TOTAL_TAG_LEN,
|
|
.promisc_on_master = true,
|
|
};
|
|
|
|
DSA_TAG_DRIVER(ocelot_netdev_ops);
|
|
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT, OCELOT_NAME);
|
|
|
|
static const struct dsa_device_ops seville_netdev_ops = {
|
|
.name = SEVILLE_NAME,
|
|
.proto = DSA_TAG_PROTO_SEVILLE,
|
|
.xmit = seville_xmit,
|
|
.rcv = ocelot_rcv,
|
|
.needed_headroom = OCELOT_TOTAL_TAG_LEN,
|
|
.promisc_on_master = true,
|
|
};
|
|
|
|
DSA_TAG_DRIVER(seville_netdev_ops);
|
|
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_SEVILLE, SEVILLE_NAME);
|
|
|
|
static struct dsa_tag_driver *ocelot_tag_driver_array[] = {
|
|
&DSA_TAG_DRIVER_NAME(ocelot_netdev_ops),
|
|
&DSA_TAG_DRIVER_NAME(seville_netdev_ops),
|
|
};
|
|
|
|
module_dsa_tag_drivers(ocelot_tag_driver_array);
|
|
|
|
MODULE_LICENSE("GPL v2");
|