// SPDX-License-Identifier: GPL-2.0+ /* * Regular and Ethertype DSA tagging * Copyright (c) 2008-2009 Marvell Semiconductor * * Regular DSA * ----------- * For untagged (in 802.1Q terms) packets, the switch will splice in * the tag between the SA and the ethertype of the original * packet. Tagged frames will instead have their outermost .1Q tag * converted to a DSA tag. It expects the same layout when receiving * packets from the CPU. * * Example: * * .----.----.----.--------- * Pu: | DA | SA | ET | Payload ... * '----'----'----'--------- * 6 6 2 N * .----.----.--------.-----.----.--------- * Pt: | DA | SA | 0x8100 | TCI | ET | Payload ... * '----'----'--------'-----'----'--------- * 6 6 2 2 2 N * .----.----.-----.----.--------- * Pd: | DA | SA | DSA | ET | Payload ... * '----'----'-----'----'--------- * 6 6 4 2 N * * No matter if a packet is received untagged (Pu) or tagged (Pt), * they will both have the same layout (Pd) when they are sent to the * CPU. This is done by ignoring 802.3, replacing the ethertype field * with more metadata, among which is a bit to signal if the original * packet was tagged or not. * * Ethertype DSA * ------------- * Uses the exact same tag format as regular DSA, but also includes a * proper ethertype field (which the mv88e6xxx driver sets to * ETH_P_EDSA/0xdada) followed by two zero bytes: * * .----.----.--------.--------.-----.----.--------- * | DA | SA | 0xdada | 0x0000 | DSA | ET | Payload ... * '----'----'--------'--------'-----'----'--------- * 6 6 2 2 4 2 N */ #include <linux/dsa/mv88e6xxx.h> #include <linux/etherdevice.h> #include <linux/list.h> #include <linux/slab.h> #include "tag.h" #define DSA_NAME … #define EDSA_NAME … #define DSA_HLEN … /** * enum dsa_cmd - DSA Command * @DSA_CMD_TO_CPU: Set on packets that were trapped or mirrored to * the CPU port. This is needed to implement control protocols, * e.g. STP and LLDP, that must not allow those control packets to * be switched according to the normal rules. * @DSA_CMD_FROM_CPU: Used by the CPU to send a packet to a specific * port, ignoring all the barriers that the switch normally * enforces (VLANs, STP port states etc.). No source address * learning takes place. "sudo send packet" * @DSA_CMD_TO_SNIFFER: Set on the copies of packets that matched some * user configured ingress or egress monitor criteria. These are * forwarded by the switch tree to the user configured ingress or * egress monitor port, which can be set to the CPU port or a * regular port. If the destination is a regular port, the tag * will be removed before egressing the port. If the destination * is the CPU port, the tag will not be removed. * @DSA_CMD_FORWARD: This tag is used on all bulk traffic passing * through the switch tree, including the flows that are directed * towards the CPU. Its device/port tuple encodes the original * source port on which the packet ingressed. It can also be used * on transmit by the CPU to defer the forwarding decision to the * hardware, based on the current config of PVT/VTU/ATU * etc. Source address learning takes places if enabled on the * receiving DSA/CPU port. */ enum dsa_cmd { … }; /** * enum dsa_code - TO_CPU Code * * @DSA_CODE_MGMT_TRAP: DA was classified as a management * address. Typical examples include STP BPDUs and LLDP. * @DSA_CODE_FRAME2REG: Response to a "remote management" request. * @DSA_CODE_IGMP_MLD_TRAP: IGMP/MLD signaling. * @DSA_CODE_POLICY_TRAP: Frame matched some policy configuration on * the device. Typical examples are matching on DA/SA/VID and DHCP * snooping. * @DSA_CODE_ARP_MIRROR: The name says it all really. * @DSA_CODE_POLICY_MIRROR: Same as @DSA_CODE_POLICY_TRAP, but the * particular policy was set to trigger a mirror instead of a * trap. * @DSA_CODE_RESERVED_6: Unused on all devices up to at least 6393X. * @DSA_CODE_RESERVED_7: Unused on all devices up to at least 6393X. * * A 3-bit code is used to relay why a particular frame was sent to * the CPU. We only use this to determine if the packet was mirrored * or trapped, i.e. whether the packet has been forwarded by hardware * or not. * * This is the superset of all possible codes. Any particular device * may only implement a subset. */ enum dsa_code { … }; static struct sk_buff *dsa_xmit_ll(struct sk_buff *skb, struct net_device *dev, u8 extra) { … } static struct sk_buff *dsa_rcv_ll(struct sk_buff *skb, struct net_device *dev, u8 extra) { … } #if IS_ENABLED(CONFIG_NET_DSA_TAG_DSA) static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev) { … } static struct sk_buff *dsa_rcv(struct sk_buff *skb, struct net_device *dev) { … } static const struct dsa_device_ops dsa_netdev_ops = …; DSA_TAG_DRIVER(dsa_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(…); #endif /* CONFIG_NET_DSA_TAG_DSA */ #if IS_ENABLED(CONFIG_NET_DSA_TAG_EDSA) #define EDSA_HLEN … static struct sk_buff *edsa_xmit(struct sk_buff *skb, struct net_device *dev) { … } static struct sk_buff *edsa_rcv(struct sk_buff *skb, struct net_device *dev) { … } static const struct dsa_device_ops edsa_netdev_ops = …; DSA_TAG_DRIVER(edsa_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(…); #endif /* CONFIG_NET_DSA_TAG_EDSA */ static struct dsa_tag_driver *dsa_tag_drivers[] = …; module_dsa_tag_drivers(dsa_tag_drivers); MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
Codebase Browser
linux