/* 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 send some packets as VLAN-tagged * towards the CPU port (generally from VLAN-aware bridge ports) even when the * packet was not tagged on the wire. 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, proto; int err; /* software untagging for standalone ports not yet necessary */ if (!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); 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; } static inline unsigned long dsa_xmit_port_mask(const struct sk_buff *skb, const struct net_device *dev) { struct dsa_port *dp = dsa_user_to_port(dev); unsigned long mask = BIT(dp->index); if (IS_ENABLED(CONFIG_HSR) && unlikely(dev->features & NETIF_F_HW_HSR_DUP)) { struct net_device *hsr_dev = dp->hsr_dev; struct dsa_port *other_dp; dsa_hsr_foreach_port(other_dp, dp->ds, hsr_dev) mask |= BIT(other_dp->index); } return mask; } /* 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
