linux/net/dsa/tag.h
Florian Fainelli 6ca80638b9 net: dsa: Use conduit and user terms
Use more inclusive terms throughout the DSA subsystem by moving away
from "master" which is replaced by "conduit" and "slave" which is
replaced by "user". No functional changes.

Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20231023181729.1191071-2-florian.fainelli@broadcom.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-24 13:08:14 -07:00

311 lines
10 KiB
C

/* 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;
}
/* If under a bridge with vlan_filtering=0, make sure to send pvid-tagged
* frames as untagged, since the bridge will not untag them.
*/
static inline struct sk_buff *dsa_untag_bridge_pvid(struct sk_buff *skb)
{
struct dsa_port *dp = dsa_user_to_port(skb->dev);
struct net_device *br = dsa_port_bridge_dev_get(dp);
struct net_device *dev = skb->dev;
struct net_device *upper_dev;
u16 vid, pvid, proto;
int err;
if (!br || br_vlan_enabled(br))
return skb;
err = br_vlan_get_proto(br, &proto);
if (err)
return skb;
/* Move VLAN tag from data to hwaccel */
if (!skb_vlan_tag_present(skb) && skb->protocol == htons(proto)) {
skb = skb_vlan_untag(skb);
if (!skb)
return NULL;
}
if (!skb_vlan_tag_present(skb))
return skb;
vid = skb_vlan_tag_get_id(skb);
/* We already run under an RCU read-side critical section since
* we are called from netif_receive_skb_list_internal().
*/
err = br_vlan_get_pvid_rcu(dev, &pvid);
if (err)
return skb;
if (vid != pvid)
return skb;
/* 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)
return skb;
__vlan_hwaccel_clear_tag(skb);
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