// SPDX-License-Identifier: GPL-2.0 /* * Handler for Realtek 8 byte switch tags * * Copyright (C) 2021 Alvin Šipraga <[email protected]> * * NOTE: Currently only supports protocol "4" found in the RTL8365MB, hence * named tag_rtl8_4. * * This tag has the following format: * * 0 7|8 15 * |-----------------------------------+-----------------------------------|--- * | (16-bit) | ^ * | Realtek EtherType [0x8899] | | * |-----------------------------------+-----------------------------------| 8 * | (8-bit) | (8-bit) | * | Protocol [0x04] | REASON | b * |-----------------------------------+-----------------------------------| y * | (1) | (1) | (2) | (1) | (3) | (1) | (1) | (1) | (5) | t * | FID_EN | X | FID | PRI_EN | PRI | KEEP | X | LEARN_DIS | X | e * |-----------------------------------+-----------------------------------| s * | (1) | (15-bit) | | * | ALLOW | TX/RX | v * |-----------------------------------+-----------------------------------|--- * * With the following field descriptions: * * field | description * ------------+------------- * Realtek | 0x8899: indicates that this is a proprietary Realtek tag; * EtherType | note that Realtek uses the same EtherType for * | other incompatible tag formats (e.g. tag_rtl4_a.c) * Protocol | 0x04: indicates that this tag conforms to this format * X | reserved * ------------+------------- * REASON | reason for forwarding packet to CPU * | 0: packet was forwarded or flooded to CPU * | 80: packet was trapped to CPU * FID_EN | 1: packet has an FID * | 0: no FID * FID | FID of packet (if FID_EN=1) * PRI_EN | 1: force priority of packet * | 0: don't force priority * PRI | priority of packet (if PRI_EN=1) * KEEP | preserve packet VLAN tag format * LEARN_DIS | don't learn the source MAC address of the packet * ALLOW | 1: treat TX/RX field as an allowance port mask, meaning the * | packet may only be forwarded to ports specified in the * | mask * | 0: no allowance port mask, TX/RX field is the forwarding * | port mask * TX/RX | TX (switch->CPU): port number the packet was received on * | RX (CPU->switch): forwarding port mask (if ALLOW=0) * | allowance port mask (if ALLOW=1) * * The tag can be positioned before Ethertype, using tag "rtl8_4": * * +--------+--------+------------+------+----- * | MAC DA | MAC SA | 8 byte tag | Type | ... * +--------+--------+------------+------+----- * * The tag can also appear between the end of the payload and before the CRC, * using tag "rtl8_4t": * * +--------+--------+------+-----+---------+------------+-----+ * | MAC DA | MAC SA | TYPE | ... | payload | 8-byte tag | CRC | * +--------+--------+------+-----+---------+------------+-----+ * * The added bytes after the payload will break most checksums, either in * software or hardware. To avoid this issue, if the checksum is still pending, * this tagger checksums the packet in software before adding the tag. * */ #include <linux/bitfield.h> #include <linux/bits.h> #include <linux/etherdevice.h> #include "tag.h" /* Protocols supported: * * 0x04 = RTL8365MB DSA protocol */ #define RTL8_4_NAME … #define RTL8_4T_NAME … #define RTL8_4_TAG_LEN … #define RTL8_4_PROTOCOL … #define RTL8_4_PROTOCOL_RTL8365MB … #define RTL8_4_REASON … #define RTL8_4_REASON_FORWARD … #define RTL8_4_REASON_TRAP … #define RTL8_4_LEARN_DIS … #define RTL8_4_TX … #define RTL8_4_RX … static void rtl8_4_write_tag(struct sk_buff *skb, struct net_device *dev, void *tag) { … } static struct sk_buff *rtl8_4_tag_xmit(struct sk_buff *skb, struct net_device *dev) { … } static struct sk_buff *rtl8_4t_tag_xmit(struct sk_buff *skb, struct net_device *dev) { … } static int rtl8_4_read_tag(struct sk_buff *skb, struct net_device *dev, void *tag) { … } static struct sk_buff *rtl8_4_tag_rcv(struct sk_buff *skb, struct net_device *dev) { … } static struct sk_buff *rtl8_4t_tag_rcv(struct sk_buff *skb, struct net_device *dev) { … } /* Ethertype version */ static const struct dsa_device_ops rtl8_4_netdev_ops = …; DSA_TAG_DRIVER(rtl8_4_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(…); /* Tail version */ static const struct dsa_device_ops rtl8_4t_netdev_ops = …; DSA_TAG_DRIVER(rtl8_4t_netdev_ops); MODULE_ALIAS_DSA_TAG_DRIVER(…); static struct dsa_tag_driver *dsa_tag_drivers[] = …; module_dsa_tag_drivers(dsa_tag_drivers); MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …;
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