John Crispin | cafdc45 | 2016-09-15 16:26:40 +0200 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2015, The Linux Foundation. All rights reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 and |
| 6 | * only version 2 as published by the Free Software Foundation. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, |
| 9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | * GNU General Public License for more details. |
| 12 | */ |
| 13 | |
| 14 | #include <linux/etherdevice.h> |
| 15 | #include "dsa_priv.h" |
| 16 | |
| 17 | #define QCA_HDR_LEN 2 |
| 18 | #define QCA_HDR_VERSION 0x2 |
| 19 | |
| 20 | #define QCA_HDR_RECV_VERSION_MASK GENMASK(15, 14) |
| 21 | #define QCA_HDR_RECV_VERSION_S 14 |
| 22 | #define QCA_HDR_RECV_PRIORITY_MASK GENMASK(13, 11) |
| 23 | #define QCA_HDR_RECV_PRIORITY_S 11 |
| 24 | #define QCA_HDR_RECV_TYPE_MASK GENMASK(10, 6) |
| 25 | #define QCA_HDR_RECV_TYPE_S 6 |
| 26 | #define QCA_HDR_RECV_FRAME_IS_TAGGED BIT(3) |
| 27 | #define QCA_HDR_RECV_SOURCE_PORT_MASK GENMASK(2, 0) |
| 28 | |
| 29 | #define QCA_HDR_XMIT_VERSION_MASK GENMASK(15, 14) |
| 30 | #define QCA_HDR_XMIT_VERSION_S 14 |
| 31 | #define QCA_HDR_XMIT_PRIORITY_MASK GENMASK(13, 11) |
| 32 | #define QCA_HDR_XMIT_PRIORITY_S 11 |
| 33 | #define QCA_HDR_XMIT_CONTROL_MASK GENMASK(10, 8) |
| 34 | #define QCA_HDR_XMIT_CONTROL_S 8 |
| 35 | #define QCA_HDR_XMIT_FROM_CPU BIT(7) |
| 36 | #define QCA_HDR_XMIT_DP_BIT_MASK GENMASK(6, 0) |
| 37 | |
| 38 | static struct sk_buff *qca_tag_xmit(struct sk_buff *skb, struct net_device *dev) |
| 39 | { |
| 40 | struct dsa_slave_priv *p = netdev_priv(dev); |
| 41 | u16 *phdr, hdr; |
| 42 | |
| 43 | dev->stats.tx_packets++; |
| 44 | dev->stats.tx_bytes += skb->len; |
| 45 | |
| 46 | if (skb_cow_head(skb, 0) < 0) |
| 47 | goto out_free; |
| 48 | |
| 49 | skb_push(skb, QCA_HDR_LEN); |
| 50 | |
| 51 | memmove(skb->data, skb->data + QCA_HDR_LEN, 2 * ETH_ALEN); |
| 52 | phdr = (u16 *)(skb->data + 2 * ETH_ALEN); |
| 53 | |
| 54 | /* Set the version field, and set destination port information */ |
| 55 | hdr = QCA_HDR_VERSION << QCA_HDR_XMIT_VERSION_S | |
| 56 | QCA_HDR_XMIT_FROM_CPU | |
| 57 | BIT(p->port); |
| 58 | |
| 59 | *phdr = htons(hdr); |
| 60 | |
| 61 | return skb; |
| 62 | |
| 63 | out_free: |
| 64 | kfree_skb(skb); |
| 65 | return NULL; |
| 66 | } |
| 67 | |
| 68 | static int qca_tag_rcv(struct sk_buff *skb, struct net_device *dev, |
| 69 | struct packet_type *pt, struct net_device *orig_dev) |
| 70 | { |
| 71 | struct dsa_switch_tree *dst = dev->dsa_ptr; |
| 72 | struct dsa_switch *ds; |
| 73 | u8 ver; |
| 74 | int port; |
| 75 | __be16 *phdr, hdr; |
| 76 | |
| 77 | if (unlikely(!dst)) |
| 78 | goto out_drop; |
| 79 | |
| 80 | skb = skb_unshare(skb, GFP_ATOMIC); |
| 81 | if (!skb) |
| 82 | goto out; |
| 83 | |
| 84 | if (unlikely(!pskb_may_pull(skb, QCA_HDR_LEN))) |
| 85 | goto out_drop; |
| 86 | |
| 87 | /* The QCA header is added by the switch between src addr and Ethertype |
| 88 | * At this point, skb->data points to ethertype so header should be |
| 89 | * right before |
| 90 | */ |
| 91 | phdr = (__be16 *)(skb->data - 2); |
| 92 | hdr = ntohs(*phdr); |
| 93 | |
| 94 | /* Make sure the version is correct */ |
| 95 | ver = (hdr & QCA_HDR_RECV_VERSION_MASK) >> QCA_HDR_RECV_VERSION_S; |
| 96 | if (unlikely(ver != QCA_HDR_VERSION)) |
| 97 | goto out_drop; |
| 98 | |
| 99 | /* Remove QCA tag and recalculate checksum */ |
| 100 | skb_pull_rcsum(skb, QCA_HDR_LEN); |
| 101 | memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - QCA_HDR_LEN, |
| 102 | ETH_HLEN - QCA_HDR_LEN); |
| 103 | |
| 104 | /* This protocol doesn't support cascading multiple switches so it's |
| 105 | * safe to assume the switch is first in the tree |
| 106 | */ |
| 107 | ds = dst->ds[0]; |
| 108 | if (!ds) |
| 109 | goto out_drop; |
| 110 | |
| 111 | /* Get source port information */ |
| 112 | port = (hdr & QCA_HDR_RECV_SOURCE_PORT_MASK); |
| 113 | if (!ds->ports[port].netdev) |
| 114 | goto out_drop; |
| 115 | |
| 116 | /* Update skb & forward the frame accordingly */ |
| 117 | skb_push(skb, ETH_HLEN); |
| 118 | skb->pkt_type = PACKET_HOST; |
| 119 | skb->dev = ds->ports[port].netdev; |
| 120 | skb->protocol = eth_type_trans(skb, skb->dev); |
| 121 | |
| 122 | skb->dev->stats.rx_packets++; |
| 123 | skb->dev->stats.rx_bytes += skb->len; |
| 124 | |
| 125 | netif_receive_skb(skb); |
| 126 | |
| 127 | return 0; |
| 128 | |
| 129 | out_drop: |
| 130 | kfree_skb(skb); |
| 131 | out: |
| 132 | return 0; |
| 133 | } |
| 134 | |
| 135 | const struct dsa_device_ops qca_netdev_ops = { |
| 136 | .xmit = qca_tag_xmit, |
| 137 | .rcv = qca_tag_rcv, |
| 138 | }; |