/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef __DSA_TAG_H
#define __DSA_TAG_H
#include <linux/if_vlan.h>
#include <linux/list.h>
#include <linux/types.h>
#include <net/dsa.h>
#include "port.h"
#include "user.h"
struct dsa_tag_driver {
const struct dsa_device_ops *ops;
struct list_head list;
struct module *owner;
};
extern struct packet_type dsa_pack_type;
const struct dsa_device_ops *dsa_tag_driver_get_by_id(int tag_protocol);
const struct dsa_device_ops *dsa_tag_driver_get_by_name(const char *name);
void dsa_tag_driver_put(const struct dsa_device_ops *ops);
const char *dsa_tag_protocol_to_str(const struct dsa_device_ops *ops);
static inline int dsa_tag_protocol_overhead(const struct dsa_device_ops *ops)
{
return ops->needed_headroom + ops->needed_tailroom;
}
static inline struct net_device *dsa_conduit_find_user(struct net_device *dev,
int device, int port)
{
struct dsa_port *cpu_dp = dev->dsa_ptr;
struct dsa_switch_tree *dst = cpu_dp->dst;
struct dsa_port *dp;
list_for_each_entry(dp, &dst->ports, list)
if (dp->ds->index == device && dp->index == port &&
dp->type == DSA_PORT_TYPE_USER)
return dp->user;
return NULL;
}
/**
* dsa_software_untag_vlan_aware_bridge: Software untagging for VLAN-aware bridge
* @skb: Pointer to received socket buffer (packet)
* @br: Pointer to bridge upper interface of ingress port
* @vid: Parsed VID from packet
*
* The bridge can process tagged packets. Software like STP/PTP may not. The
* bridge can also process untagged packets, to the same effect as if they were
* tagged with the PVID of the ingress port. So packets tagged with the PVID of
* the bridge port must be software-untagged, to support both use cases.
*/
static inline void dsa_software_untag_vlan_aware_bridge(struct sk_buff *skb,
struct net_device *br,
u16 vid)
{
u16 pvid, proto;
int err;
err = br_vlan_get_proto(br, &proto);
if (err)
return;
err = br_vlan_get_pvid_rcu(skb->dev, &pvid);
if (err)
return;
if (vid == pvid && skb->vlan_proto == htons(proto))
__vlan_hwaccel_clear_tag(skb);
}
/**
* dsa_software_untag_vlan_unaware_bridge: Software untagging for VLAN-unaware bridge
* @skb: Pointer to received socket buffer (packet)
* @br: Pointer to bridge upper interface of ingress port
* @vid: Parsed VID from packet
*
* The bridge ignores all VLAN tags. Software like STP/PTP may not (it may run
* on the plain port, or on a VLAN upper interface). Maybe packets are coming
* to software as tagged with a driver-defined VID which is NOT equal to the
* PVID of the bridge port (since the bridge is VLAN-unaware, its configuration
* should NOT be committed to hardware). DSA needs a method for this private
* VID to be communicated by software to it, and if packets are tagged with it,
* software-untag them. Note: the private VID may be different per bridge, to
* support the FDB isolation use case.
*
* FIXME: this is currently implemented based on the broken assumption that
* the "private VID" used by the driver in VLAN-unaware mode is equal to the
* bridge PVID. It should not be, except for a coincidence; the bridge PVID is
* irrelevant to the data path in the VLAN-unaware mode. Thus, the VID that
* this function removes is wrong.
*
* All users of ds->untag_bridge_pvid should fix their drivers, if necessary,
* to make the two independent. Only then, if there still remains a need to
* strip the private VID from packets, then a new ds->ops->get_private_vid()
* API shall be introduced to communicate to DSA what this VID is, which needs
* to be stripped here.
*/
static inline void dsa_software_untag_vlan_unaware_bridge(struct sk_buff *skb,
struct net_device *br,
u16 vid)
{
struct net_device *upper_dev;
u16 pvid, proto;
int err;
err = br_vlan_get_proto(br, &proto);
if (err)
return;
err = br_vlan_get_pvid_rcu(skb->dev, &pvid);
if (err)
return;
if (vid != pvid || skb->vlan_proto != htons(proto))
return;
/* The sad part about attempting to untag from DSA is that we
* don't know, unless we check, if the skb will end up in
* the bridge's data path - br_allowed_ingress() - or not.
* For example, there might be an 8021q upper for the
* default_pvid of the bridge, which will steal VLAN-tagged traffic
* from the bridge's data path. This is a configuration that DSA
* supports because vlan_filtering is 0. In that case, we should
* definitely keep the tag, to make sure it keeps working.
*/
upper_dev = __vlan_find_dev_deep_rcu(br, htons(proto), vid);
if (!upper_dev)
__vlan_hwaccel_clear_tag(skb);
}
/**
* dsa_software_vlan_untag: Software VLAN untagging in DSA receive path
* @skb: Pointer to socket buffer (packet)
*
* Receive path method for switches which cannot avoid tagging all packets
* towards the CPU port. Called when ds->untag_bridge_pvid (legacy) or
* ds->untag_vlan_aware_bridge_pvid is set to true.
*
* As a side effect of this method, any VLAN tag from the skb head is moved
* to hwaccel.
*/
static inline struct sk_buff *dsa_software_vlan_untag(struct sk_buff *skb)
{
struct dsa_port *dp = dsa_user_to_port(skb->dev);
struct net_device *br = dsa_port_bridge_dev_get(dp);
u16 vid;
/* software untagging for standalone ports not yet necessary */
if (!br)
return skb;
/* Move VLAN tag from data to hwaccel */
if (!skb_vlan_tag_present(skb)) {
skb = skb_vlan_untag(skb);
if (!skb)
return NULL;
}
if (!skb_vlan_tag_present(skb))
return skb;
vid = skb_vlan_tag_get_id(skb);
if (br_vlan_enabled(br)) {
if (dp->ds->untag_vlan_aware_bridge_pvid)
dsa_software_untag_vlan_aware_bridge(skb, br, vid);
} else {
if (dp->ds->untag_bridge_pvid)
dsa_software_untag_vlan_unaware_bridge(skb, br, vid);
}
return skb;
}
/* For switches without hardware support for DSA tagging to be able
* to support termination through the bridge.
*/
static inline struct net_device *
dsa_find_designated_bridge_port_by_vid(struct net_device *conduit, u16 vid)
{
struct dsa_port *cpu_dp = conduit->dsa_ptr;
struct dsa_switch_tree *dst = cpu_dp->dst;
struct bridge_vlan_info vinfo;
struct net_device *user;
struct dsa_port *dp;
int err;
list_for_each_entry(dp, &dst->ports, list) {
if (dp->type != DSA_PORT_TYPE_USER)
continue;
if (!dp->bridge)
continue;
if (dp->stp_state != BR_STATE_LEARNING &&
dp->stp_state != BR_STATE_FORWARDING)
continue;
/* Since the bridge might learn this packet, keep the CPU port
* affinity with the port that will be used for the reply on
* xmit.
*/
if (dp->cpu_dp != cpu_dp)
continue;
user = dp->user;
err = br_vlan_get_info_rcu(user, vid, &vinfo);
if (err)
continue;
return user;
}
return NULL;
}
/* If the ingress port offloads the bridge, we mark the frame as autonomously
* forwarded by hardware, so the software bridge doesn't forward in twice, back
* to us, because we already did. However, if we're in fallback mode and we do
* software bridging, we are not offloading it, therefore the dp->bridge
* pointer is not populated, and flooding needs to be done by software (we are
* effectively operating in standalone ports mode).
*/
static inline void dsa_default_offload_fwd_mark(struct sk_buff *skb)
{
struct dsa_port *dp = dsa_user_to_port(skb->dev);
skb->offload_fwd_mark = !!(dp->bridge);
}
/* Helper for removing DSA header tags from packets in the RX path.
* Must not be called before skb_pull(len).
* skb->data
* |
* v
* | | | | | | | | | | | | | | | | | | |
* +-----------------------+-----------------------+---------------+-------+
* | Destination MAC | Source MAC | DSA header | EType |
* +-----------------------+-----------------------+---------------+-------+
* | |
* <----- len -----> <----- len ----->
* |
* >>>>>>> v
* >>>>>>> | | | | | | | | | | | | | | |
* >>>>>>> +-----------------------+-----------------------+-------+
* >>>>>>> | Destination MAC | Source MAC | EType |
* +-----------------------+-----------------------+-------+
* ^
* |
* skb->data
*/
static inline void dsa_strip_etype_header(struct sk_buff *skb, int len)
{
memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - len, 2 * ETH_ALEN);
}
/* Helper for creating space for DSA header tags in TX path packets.
* Must not be called before skb_push(len).
*
* Before:
*
* <<<<<<< | | | | | | | | | | | | | | |
* ^ <<<<<<< +-----------------------+-----------------------+-------+
* | <<<<<<< | Destination MAC | Source MAC | EType |
* | +-----------------------+-----------------------+-------+
* <----- len ----->
* |
* |
* skb->data
*
* After:
*
* | | | | | | | | | | | | | | | | | | |
* +-----------------------+-----------------------+---------------+-------+
* | Destination MAC | Source MAC | DSA header | EType |
* +-----------------------+-----------------------+---------------+-------+
* ^ | |
* | <----- len ----->
* skb->data
*/
static inline void dsa_alloc_etype_header(struct sk_buff *skb, int len)
{
memmove(skb->data, skb->data + len, 2 * ETH_ALEN);
}
/* On RX, eth_type_trans() on the DSA conduit pulls ETH_HLEN bytes starting from
* skb_mac_header(skb), which leaves skb->data pointing at the first byte after
* what the DSA conduit perceives as the EtherType (the beginning of the L3
* protocol). Since DSA EtherType header taggers treat the EtherType as part of
* the DSA tag itself, and the EtherType is 2 bytes in length, the DSA header
* is located 2 bytes behind skb->data. Note that EtherType in this context
* means the first 2 bytes of the DSA header, not the encapsulated EtherType
* that will become visible after the DSA header is stripped.
*/
static inline void *dsa_etype_header_pos_rx(struct sk_buff *skb)
{
return skb->data - 2;
}
/* On TX, skb->data points to the MAC header, which means that EtherType
* header taggers start exactly where the EtherType is (the EtherType is
* treated as part of the DSA header).
*/
static inline void *dsa_etype_header_pos_tx(struct sk_buff *skb)
{
return skb->data + 2 * ETH_ALEN;
}
/* Create 2 modaliases per tagging protocol, one to auto-load the module
* given the ID reported by get_tag_protocol(), and the other by name.
*/
#define DSA_TAG_DRIVER_ALIAS "dsa_tag:"
#define MODULE_ALIAS_DSA_TAG_DRIVER(__proto, __name) \
MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS __name); \
MODULE_ALIAS(DSA_TAG_DRIVER_ALIAS "id-" \
__stringify(__proto##_VALUE))
void dsa_tag_drivers_register(struct dsa_tag_driver *dsa_tag_driver_array[],
unsigned int count,
struct module *owner);
void dsa_tag_drivers_unregister(struct dsa_tag_driver *dsa_tag_driver_array[],
unsigned int count);
#define dsa_tag_driver_module_drivers(__dsa_tag_drivers_array, __count) \
static int __init dsa_tag_driver_module_init(void) \
{ \
dsa_tag_drivers_register(__dsa_tag_drivers_array, __count, \
THIS_MODULE); \
return 0; \
} \
module_init(dsa_tag_driver_module_init); \
\
static void __exit dsa_tag_driver_module_exit(void) \
{ \
dsa_tag_drivers_unregister(__dsa_tag_drivers_array, __count); \
} \
module_exit(dsa_tag_driver_module_exit)
/**
* module_dsa_tag_drivers() - Helper macro for registering DSA tag
* drivers
* @__ops_array: Array of tag driver structures
*
* Helper macro for DSA tag drivers which do not do anything special
* in module init/exit. Each module may only use this macro once, and
* calling it replaces module_init() and module_exit().
*/
#define module_dsa_tag_drivers(__ops_array) \
dsa_tag_driver_module_drivers(__ops_array, ARRAY_SIZE(__ops_array))
#define DSA_TAG_DRIVER_NAME(__ops) dsa_tag_driver ## _ ## __ops
/* Create a static structure we can build a linked list of dsa_tag
* drivers
*/
#define DSA_TAG_DRIVER(__ops) \
static struct dsa_tag_driver DSA_TAG_DRIVER_NAME(__ops) = { \
.ops = &__ops, \
}
/**
* module_dsa_tag_driver() - Helper macro for registering a single DSA tag
* driver
* @__ops: Single tag driver structures
*
* Helper macro for DSA tag drivers which do not do anything special
* in module init/exit. Each module may only use this macro once, and
* calling it replaces module_init() and module_exit().
*/
#define module_dsa_tag_driver(__ops) \
DSA_TAG_DRIVER(__ops); \
\
static struct dsa_tag_driver *dsa_tag_driver_array[] = { \
&DSA_TAG_DRIVER_NAME(__ops) \
}; \
module_dsa_tag_drivers(dsa_tag_driver_array)
#endif
Codebase Browser
linux