Loading...
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 | /* * Copyright (C) 2017 Pengutronix, Juergen Borleis <jbe@pengutronix.de> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * */ #include <linux/etherdevice.h> #include <linux/list.h> #include <linux/slab.h> #include "dsa_priv.h" /* To define the outgoing port and to discover the incoming port a regular * VLAN tag is used by the LAN9303. But its VID meaning is 'special': * * Dest MAC Src MAC TAG Type * ...| 1 2 3 4 5 6 | 1 2 3 4 5 6 | 1 2 3 4 | 1 2 |... * |<------->| * TAG: * |<------------->| * | 1 2 | 3 4 | * TPID VID * 0x8100 * * VID bit 3 indicates a request for an ALR lookup. * * If VID bit 3 is zero, then bits 0 and 1 specify the destination port * (0, 1, 2) or broadcast (3) or the source port (1, 2). * * VID bit 4 is used to specify if the STP port state should be overridden. * Required when no forwarding between the external ports should happen. */ #define LAN9303_TAG_LEN 4 static struct sk_buff *lan9303_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_slave_priv *p = netdev_priv(dev); u16 *lan9303_tag; /* insert a special VLAN tag between the MAC addresses * and the current ethertype field. */ if (skb_cow_head(skb, LAN9303_TAG_LEN) < 0) { dev_dbg(&dev->dev, "Cannot make room for the special tag. Dropping packet\n"); return NULL; } /* provide 'LAN9303_TAG_LEN' bytes additional space */ skb_push(skb, LAN9303_TAG_LEN); /* make room between MACs and Ether-Type */ memmove(skb->data, skb->data + LAN9303_TAG_LEN, 2 * ETH_ALEN); lan9303_tag = (u16 *)(skb->data + 2 * ETH_ALEN); lan9303_tag[0] = htons(ETH_P_8021Q); lan9303_tag[1] = htons(p->dp->index | BIT(4)); return skb; } static struct sk_buff *lan9303_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt) { u16 *lan9303_tag; struct dsa_switch_tree *dst = dev->dsa_ptr; struct dsa_switch *ds; unsigned int source_port; ds = dst->ds[0]; if (unlikely(!ds)) { dev_warn_ratelimited(&dev->dev, "Dropping packet, due to missing DSA switch device\n"); return NULL; } if (unlikely(!pskb_may_pull(skb, LAN9303_TAG_LEN))) { dev_warn_ratelimited(&dev->dev, "Dropping packet, cannot pull\n"); return NULL; } /* '->data' points into the middle of our special VLAN tag information: * * ~ MAC src | 0x81 | 0x00 | 0xyy | 0xzz | ether type * ^ * ->data */ lan9303_tag = (u16 *)(skb->data - 2); if (lan9303_tag[0] != htons(ETH_P_8021Q)) { dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid VLAN marker\n"); return NULL; } source_port = ntohs(lan9303_tag[1]) & 0x3; if (source_port >= ds->num_ports) { dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid source port\n"); return NULL; } if (!ds->ports[source_port].netdev) { dev_warn_ratelimited(&dev->dev, "Dropping packet due to invalid netdev or device\n"); return NULL; } /* remove the special VLAN tag between the MAC addresses * and the current ethertype field. */ skb_pull_rcsum(skb, 2 + 2); memmove(skb->data - ETH_HLEN, skb->data - (ETH_HLEN + LAN9303_TAG_LEN), 2 * ETH_ALEN); /* forward the packet to the dedicated interface */ skb->dev = ds->ports[source_port].netdev; return skb; } const struct dsa_device_ops lan9303_netdev_ops = { .xmit = lan9303_xmit, .rcv = lan9303_rcv, }; |