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 }; 139