// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019, Vladimir Oltean <[email protected]>
*
* This module is not a complete tagger implementation. It only provides
* primitives for taggers that rely on 802.1Q VLAN tags to use.
*/
#include <linux/if_vlan.h>
#include <linux/dsa/8021q.h>
#include "port.h"
#include "switch.h"
#include "tag.h"
#include "tag_8021q.h"
/* Binary structure of the fake 12-bit VID field (when the TPID is
* ETH_P_DSA_8021Q):
*
* | 11 | 10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
* +-----------+-----+-----------------+-----------+-----------------------+
* | RSV | VBID| SWITCH_ID | VBID | PORT |
* +-----------+-----+-----------------+-----------+-----------------------+
*
* RSV - VID[11:10]:
* Reserved. Must be set to 3 (0b11).
*
* SWITCH_ID - VID[8:6]:
* Index of switch within DSA tree. Must be between 0 and 7.
*
* VBID - { VID[9], VID[5:4] }:
* Virtual bridge ID. If between 1 and 7, packet targets the broadcast
* domain of a bridge. If transmitted as zero, packet targets a single
* port.
*
* PORT - VID[3:0]:
* Index of switch port. Must be between 0 and 15.
*/
#define DSA_8021Q_RSV_VAL 3
#define DSA_8021Q_RSV_SHIFT 10
#define DSA_8021Q_RSV_MASK GENMASK(11, 10)
#define DSA_8021Q_RSV ((DSA_8021Q_RSV_VAL << DSA_8021Q_RSV_SHIFT) & \
DSA_8021Q_RSV_MASK)
#define DSA_8021Q_SWITCH_ID_SHIFT 6
#define DSA_8021Q_SWITCH_ID_MASK GENMASK(8, 6)
#define DSA_8021Q_SWITCH_ID(x) (((x) << DSA_8021Q_SWITCH_ID_SHIFT) & \
DSA_8021Q_SWITCH_ID_MASK)
#define DSA_8021Q_VBID_HI_SHIFT 9
#define DSA_8021Q_VBID_HI_MASK GENMASK(9, 9)
#define DSA_8021Q_VBID_LO_SHIFT 4
#define DSA_8021Q_VBID_LO_MASK GENMASK(5, 4)
#define DSA_8021Q_VBID_HI(x) (((x) & GENMASK(2, 2)) >> 2)
#define DSA_8021Q_VBID_LO(x) ((x) & GENMASK(1, 0))
#define DSA_8021Q_VBID(x) \
(((DSA_8021Q_VBID_LO(x) << DSA_8021Q_VBID_LO_SHIFT) & \
DSA_8021Q_VBID_LO_MASK) | \
((DSA_8021Q_VBID_HI(x) << DSA_8021Q_VBID_HI_SHIFT) & \
DSA_8021Q_VBID_HI_MASK))
#define DSA_8021Q_PORT_SHIFT 0
#define DSA_8021Q_PORT_MASK GENMASK(3, 0)
#define DSA_8021Q_PORT(x) (((x) << DSA_8021Q_PORT_SHIFT) & \
DSA_8021Q_PORT_MASK)
struct dsa_tag_8021q_vlan {
struct list_head list;
int port;
u16 vid;
refcount_t refcount;
};
struct dsa_8021q_context {
struct dsa_switch *ds;
struct list_head vlans;
/* EtherType of RX VID, used for filtering on conduit interface */
__be16 proto;
};
u16 dsa_tag_8021q_bridge_vid(unsigned int bridge_num)
{
/* The VBID value of 0 is reserved for precise TX, but it is also
* reserved/invalid for the bridge_num, so all is well.
*/
return DSA_8021Q_RSV | DSA_8021Q_VBID(bridge_num);
}
EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_vid);
/* Returns the VID that will be installed as pvid for this switch port, sent as
* tagged egress towards the CPU port and decoded by the rcv function.
*/
u16 dsa_tag_8021q_standalone_vid(const struct dsa_port *dp)
{
return DSA_8021Q_RSV | DSA_8021Q_SWITCH_ID(dp->ds->index) |
DSA_8021Q_PORT(dp->index);
}
EXPORT_SYMBOL_GPL(dsa_tag_8021q_standalone_vid);
/* Returns the decoded switch ID from the RX VID. */
int dsa_8021q_rx_switch_id(u16 vid)
{
return (vid & DSA_8021Q_SWITCH_ID_MASK) >> DSA_8021Q_SWITCH_ID_SHIFT;
}
EXPORT_SYMBOL_GPL(dsa_8021q_rx_switch_id);
/* Returns the decoded port ID from the RX VID. */
int dsa_8021q_rx_source_port(u16 vid)
{
return (vid & DSA_8021Q_PORT_MASK) >> DSA_8021Q_PORT_SHIFT;
}
EXPORT_SYMBOL_GPL(dsa_8021q_rx_source_port);
/* Returns the decoded VBID from the RX VID. */
static int dsa_tag_8021q_rx_vbid(u16 vid)
{
u16 vbid_hi = (vid & DSA_8021Q_VBID_HI_MASK) >> DSA_8021Q_VBID_HI_SHIFT;
u16 vbid_lo = (vid & DSA_8021Q_VBID_LO_MASK) >> DSA_8021Q_VBID_LO_SHIFT;
return (vbid_hi << 2) | vbid_lo;
}
bool vid_is_dsa_8021q(u16 vid)
{
u16 rsv = (vid & DSA_8021Q_RSV_MASK) >> DSA_8021Q_RSV_SHIFT;
return rsv == DSA_8021Q_RSV_VAL;
}
EXPORT_SYMBOL_GPL(vid_is_dsa_8021q);
static struct dsa_tag_8021q_vlan *
dsa_tag_8021q_vlan_find(struct dsa_8021q_context *ctx, int port, u16 vid)
{
struct dsa_tag_8021q_vlan *v;
list_for_each_entry(v, &ctx->vlans, list)
if (v->vid == vid && v->port == port)
return v;
return NULL;
}
static int dsa_port_do_tag_8021q_vlan_add(struct dsa_port *dp, u16 vid,
u16 flags)
{
struct dsa_8021q_context *ctx = dp->ds->tag_8021q_ctx;
struct dsa_switch *ds = dp->ds;
struct dsa_tag_8021q_vlan *v;
int port = dp->index;
int err;
/* No need to bother with refcounting for user ports */
if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp)))
return ds->ops->tag_8021q_vlan_add(ds, port, vid, flags);
v = dsa_tag_8021q_vlan_find(ctx, port, vid);
if (v) {
refcount_inc(&v->refcount);
return 0;
}
v = kzalloc(sizeof(*v), GFP_KERNEL);
if (!v)
return -ENOMEM;
err = ds->ops->tag_8021q_vlan_add(ds, port, vid, flags);
if (err) {
kfree(v);
return err;
}
v->vid = vid;
v->port = port;
refcount_set(&v->refcount, 1);
list_add_tail(&v->list, &ctx->vlans);
return 0;
}
static int dsa_port_do_tag_8021q_vlan_del(struct dsa_port *dp, u16 vid)
{
struct dsa_8021q_context *ctx = dp->ds->tag_8021q_ctx;
struct dsa_switch *ds = dp->ds;
struct dsa_tag_8021q_vlan *v;
int port = dp->index;
int err;
/* No need to bother with refcounting for user ports */
if (!(dsa_port_is_cpu(dp) || dsa_port_is_dsa(dp)))
return ds->ops->tag_8021q_vlan_del(ds, port, vid);
v = dsa_tag_8021q_vlan_find(ctx, port, vid);
if (!v)
return -ENOENT;
if (!refcount_dec_and_test(&v->refcount))
return 0;
err = ds->ops->tag_8021q_vlan_del(ds, port, vid);
if (err) {
refcount_inc(&v->refcount);
return err;
}
list_del(&v->list);
kfree(v);
return 0;
}
static bool
dsa_port_tag_8021q_vlan_match(struct dsa_port *dp,
struct dsa_notifier_tag_8021q_vlan_info *info)
{
return dsa_port_is_dsa(dp) || dsa_port_is_cpu(dp) || dp == info->dp;
}
int dsa_switch_tag_8021q_vlan_add(struct dsa_switch *ds,
struct dsa_notifier_tag_8021q_vlan_info *info)
{
struct dsa_port *dp;
int err;
/* Since we use dsa_broadcast(), there might be other switches in other
* trees which don't support tag_8021q, so don't return an error.
* Or they might even support tag_8021q but have not registered yet to
* use it (maybe they use another tagger currently).
*/
if (!ds->ops->tag_8021q_vlan_add || !ds->tag_8021q_ctx)
return 0;
dsa_switch_for_each_port(dp, ds) {
if (dsa_port_tag_8021q_vlan_match(dp, info)) {
u16 flags = 0;
if (dsa_port_is_user(dp))
flags |= BRIDGE_VLAN_INFO_UNTAGGED |
BRIDGE_VLAN_INFO_PVID;
err = dsa_port_do_tag_8021q_vlan_add(dp, info->vid,
flags);
if (err)
return err;
}
}
return 0;
}
int dsa_switch_tag_8021q_vlan_del(struct dsa_switch *ds,
struct dsa_notifier_tag_8021q_vlan_info *info)
{
struct dsa_port *dp;
int err;
if (!ds->ops->tag_8021q_vlan_del || !ds->tag_8021q_ctx)
return 0;
dsa_switch_for_each_port(dp, ds) {
if (dsa_port_tag_8021q_vlan_match(dp, info)) {
err = dsa_port_do_tag_8021q_vlan_del(dp, info->vid);
if (err)
return err;
}
}
return 0;
}
/* There are 2 ways of offloading tag_8021q VLANs.
*
* One is to use a hardware TCAM to push the port's standalone VLAN into the
* frame when forwarding it to the CPU, as an egress modification rule on the
* CPU port. This is preferable because it has no side effects for the
* autonomous forwarding path, and accomplishes tag_8021q's primary goal of
* identifying the source port of each packet based on VLAN ID.
*
* The other is to commit the tag_8021q VLAN as a PVID to the VLAN table, and
* to configure the port as VLAN-unaware. This is less preferable because
* unique source port identification can only be done for standalone ports;
* under a VLAN-unaware bridge, all ports share the same tag_8021q VLAN as
* PVID, and under a VLAN-aware bridge, packets received by software will not
* have tag_8021q VLANs appended, just bridge VLANs.
*
* For tag_8021q implementations of the second type, this method is used to
* replace the standalone tag_8021q VLAN of a port with the tag_8021q VLAN to
* be used for VLAN-unaware bridging.
*/
int dsa_tag_8021q_bridge_join(struct dsa_switch *ds, int port,
struct dsa_bridge bridge, bool *tx_fwd_offload,
struct netlink_ext_ack *extack)
{
struct dsa_port *dp = dsa_to_port(ds, port);
u16 standalone_vid, bridge_vid;
int err;
/* Delete the standalone VLAN of the port and replace it with a
* bridging VLAN
*/
standalone_vid = dsa_tag_8021q_standalone_vid(dp);
bridge_vid = dsa_tag_8021q_bridge_vid(bridge.num);
err = dsa_port_tag_8021q_vlan_add(dp, bridge_vid, true);
if (err)
return err;
dsa_port_tag_8021q_vlan_del(dp, standalone_vid, false);
*tx_fwd_offload = true;
return 0;
}
EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_join);
void dsa_tag_8021q_bridge_leave(struct dsa_switch *ds, int port,
struct dsa_bridge bridge)
{
struct dsa_port *dp = dsa_to_port(ds, port);
u16 standalone_vid, bridge_vid;
int err;
/* Delete the bridging VLAN of the port and replace it with a
* standalone VLAN
*/
standalone_vid = dsa_tag_8021q_standalone_vid(dp);
bridge_vid = dsa_tag_8021q_bridge_vid(bridge.num);
err = dsa_port_tag_8021q_vlan_add(dp, standalone_vid, false);
if (err) {
dev_err(ds->dev,
"Failed to delete tag_8021q standalone VLAN %d from port %d: %pe\n",
standalone_vid, port, ERR_PTR(err));
}
dsa_port_tag_8021q_vlan_del(dp, bridge_vid, true);
}
EXPORT_SYMBOL_GPL(dsa_tag_8021q_bridge_leave);
/* Set up a port's standalone tag_8021q VLAN */
static int dsa_tag_8021q_port_setup(struct dsa_switch *ds, int port)
{
struct dsa_8021q_context *ctx = ds->tag_8021q_ctx;
struct dsa_port *dp = dsa_to_port(ds, port);
u16 vid = dsa_tag_8021q_standalone_vid(dp);
struct net_device *conduit;
int err;
/* The CPU port is implicitly configured by
* configuring the front-panel ports
*/
if (!dsa_port_is_user(dp))
return 0;
conduit = dsa_port_to_conduit(dp);
err = dsa_port_tag_8021q_vlan_add(dp, vid, false);
if (err) {
dev_err(ds->dev,
"Failed to apply standalone VID %d to port %d: %pe\n",
vid, port, ERR_PTR(err));
return err;
}
/* Add the VLAN to the conduit's RX filter. */
vlan_vid_add(conduit, ctx->proto, vid);
return err;
}
static void dsa_tag_8021q_port_teardown(struct dsa_switch *ds, int port)
{
struct dsa_8021q_context *ctx = ds->tag_8021q_ctx;
struct dsa_port *dp = dsa_to_port(ds, port);
u16 vid = dsa_tag_8021q_standalone_vid(dp);
struct net_device *conduit;
/* The CPU port is implicitly configured by
* configuring the front-panel ports
*/
if (!dsa_port_is_user(dp))
return;
conduit = dsa_port_to_conduit(dp);
dsa_port_tag_8021q_vlan_del(dp, vid, false);
vlan_vid_del(conduit, ctx->proto, vid);
}
static int dsa_tag_8021q_setup(struct dsa_switch *ds)
{
int err, port;
ASSERT_RTNL();
for (port = 0; port < ds->num_ports; port++) {
err = dsa_tag_8021q_port_setup(ds, port);
if (err < 0) {
dev_err(ds->dev,
"Failed to setup VLAN tagging for port %d: %pe\n",
port, ERR_PTR(err));
return err;
}
}
return 0;
}
static void dsa_tag_8021q_teardown(struct dsa_switch *ds)
{
int port;
ASSERT_RTNL();
for (port = 0; port < ds->num_ports; port++)
dsa_tag_8021q_port_teardown(ds, port);
}
int dsa_tag_8021q_register(struct dsa_switch *ds, __be16 proto)
{
struct dsa_8021q_context *ctx;
int err;
ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
if (!ctx)
return -ENOMEM;
ctx->proto = proto;
ctx->ds = ds;
INIT_LIST_HEAD(&ctx->vlans);
ds->tag_8021q_ctx = ctx;
err = dsa_tag_8021q_setup(ds);
if (err)
goto err_free;
return 0;
err_free:
kfree(ctx);
return err;
}
EXPORT_SYMBOL_GPL(dsa_tag_8021q_register);
void dsa_tag_8021q_unregister(struct dsa_switch *ds)
{
struct dsa_8021q_context *ctx = ds->tag_8021q_ctx;
struct dsa_tag_8021q_vlan *v, *n;
dsa_tag_8021q_teardown(ds);
list_for_each_entry_safe(v, n, &ctx->vlans, list) {
list_del(&v->list);
kfree(v);
}
ds->tag_8021q_ctx = NULL;
kfree(ctx);
}
EXPORT_SYMBOL_GPL(dsa_tag_8021q_unregister);
struct sk_buff *dsa_8021q_xmit(struct sk_buff *skb, struct net_device *netdev,
u16 tpid, u16 tci)
{
/* skb->data points at the MAC header, which is fine
* for vlan_insert_tag().
*/
return vlan_insert_tag(skb, htons(tpid), tci);
}
EXPORT_SYMBOL_GPL(dsa_8021q_xmit);
static struct net_device *
dsa_tag_8021q_find_port_by_vbid(struct net_device *conduit, int vbid)
{
struct dsa_port *cpu_dp = conduit->dsa_ptr;
struct dsa_switch_tree *dst = cpu_dp->dst;
struct dsa_port *dp;
if (WARN_ON(!vbid))
return NULL;
dsa_tree_for_each_user_port(dp, dst) {
if (!dp->bridge)
continue;
if (dp->stp_state != BR_STATE_LEARNING &&
dp->stp_state != BR_STATE_FORWARDING)
continue;
if (dp->cpu_dp != cpu_dp)
continue;
if (dsa_port_bridge_num_get(dp) == vbid)
return dp->user;
}
return NULL;
}
struct net_device *dsa_tag_8021q_find_user(struct net_device *conduit,
int source_port, int switch_id,
int vid, int vbid)
{
/* Always prefer precise source port information, if available */
if (source_port != -1 && switch_id != -1)
return dsa_conduit_find_user(conduit, switch_id, source_port);
else if (vbid >= 1)
return dsa_tag_8021q_find_port_by_vbid(conduit, vbid);
return dsa_find_designated_bridge_port_by_vid(conduit, vid);
}
EXPORT_SYMBOL_GPL(dsa_tag_8021q_find_user);
/**
* dsa_8021q_rcv - Decode source information from tag_8021q header
* @skb: RX socket buffer
* @source_port: pointer to storage for precise source port information.
* If this is known already from outside tag_8021q, the pre-initialized
* value is preserved. If not known, pass -1.
* @switch_id: similar to source_port.
* @vbid: pointer to storage for imprecise bridge ID. Must be pre-initialized
* with -1. If a positive value is returned, the source_port and switch_id
* are invalid.
* @vid: pointer to storage for original VID, in case tag_8021q decoding failed.
*
* If the packet has a tag_8021q header, decode it and set @source_port,
* @switch_id and @vbid, and strip the header. Otherwise set @vid and keep the
* header in the hwaccel area of the packet.
*/
void dsa_8021q_rcv(struct sk_buff *skb, int *source_port, int *switch_id,
int *vbid, int *vid)
{
int tmp_source_port, tmp_switch_id, tmp_vbid;
__be16 vlan_proto;
u16 tmp_vid, tci;
if (skb_vlan_tag_present(skb)) {
vlan_proto = skb->vlan_proto;
tci = skb_vlan_tag_get(skb);
__vlan_hwaccel_clear_tag(skb);
} else {
struct vlan_ethhdr *hdr = vlan_eth_hdr(skb);
vlan_proto = hdr->h_vlan_proto;
skb_push_rcsum(skb, ETH_HLEN);
__skb_vlan_pop(skb, &tci);
skb_pull_rcsum(skb, ETH_HLEN);
}
tmp_vid = tci & VLAN_VID_MASK;
if (!vid_is_dsa_8021q(tmp_vid)) {
/* Not a tag_8021q frame, so return the VID to the
* caller for further processing, and put the tag back
*/
if (vid)
*vid = tmp_vid;
__vlan_hwaccel_put_tag(skb, vlan_proto, tci);
return;
}
tmp_source_port = dsa_8021q_rx_source_port(tmp_vid);
tmp_switch_id = dsa_8021q_rx_switch_id(tmp_vid);
tmp_vbid = dsa_tag_8021q_rx_vbid(tmp_vid);
/* Precise source port information is unknown when receiving from a
* VLAN-unaware bridging domain, and tmp_source_port and tmp_switch_id
* are zeroes in this case.
*
* Preserve the source information from hardware-specific mechanisms,
* if available. This allows us to not overwrite a valid source port
* and switch ID with less precise values.
*/
if (tmp_vbid == 0 && *source_port == -1)
*source_port = tmp_source_port;
if (tmp_vbid == 0 && *switch_id == -1)
*switch_id = tmp_switch_id;
if (vbid)
*vbid = tmp_vbid;
skb->priority = (tci & VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
return;
}
EXPORT_SYMBOL_GPL(dsa_8021q_rcv);
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