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-rw-r--r--net/dsa/tag.h310
1 files changed, 310 insertions, 0 deletions
diff --git a/net/dsa/tag.h b/net/dsa/tag.h
new file mode 100644
index 000000000000..7cfbca824f1c
--- /dev/null
+++ b/net/dsa/tag.h
@@ -0,0 +1,310 @@
+/* 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 "slave.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_master_find_slave(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->slave;
+
+ 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_slave_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 *master, u16 vid)
+{
+ struct dsa_port *cpu_dp = master->dsa_ptr;
+ struct dsa_switch_tree *dst = cpu_dp->dst;
+ struct bridge_vlan_info vinfo;
+ struct net_device *slave;
+ 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;
+
+ slave = dp->slave;
+
+ err = br_vlan_get_info_rcu(slave, vid, &vinfo);
+ if (err)
+ continue;
+
+ return slave;
+ }
+
+ 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_slave_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 master pulls ETH_HLEN bytes starting from
+ * skb_mac_header(skb), which leaves skb->data pointing at the first byte after
+ * what the DSA master 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 skb_mac_header(skb), 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
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