1cf85d08fSLennert Buytenhek /* 2cf85d08fSLennert Buytenhek * net/dsa/tag_dsa.c - (Non-ethertype) DSA tagging 3e84665c9SLennert Buytenhek * Copyright (c) 2008-2009 Marvell Semiconductor 4cf85d08fSLennert Buytenhek * 5cf85d08fSLennert Buytenhek * This program is free software; you can redistribute it and/or modify 6cf85d08fSLennert Buytenhek * it under the terms of the GNU General Public License as published by 7cf85d08fSLennert Buytenhek * the Free Software Foundation; either version 2 of the License, or 8cf85d08fSLennert Buytenhek * (at your option) any later version. 9cf85d08fSLennert Buytenhek */ 10cf85d08fSLennert Buytenhek 11cf85d08fSLennert Buytenhek #include <linux/etherdevice.h> 12cf85d08fSLennert Buytenhek #include <linux/list.h> 135a0e3ad6STejun Heo #include <linux/slab.h> 14cf85d08fSLennert Buytenhek #include "dsa_priv.h" 15cf85d08fSLennert Buytenhek 16cf85d08fSLennert Buytenhek #define DSA_HLEN 4 17cf85d08fSLennert Buytenhek 184ed70ce9SFlorian Fainelli static struct sk_buff *dsa_xmit(struct sk_buff *skb, struct net_device *dev) 19cf85d08fSLennert Buytenhek { 20cf85d08fSLennert Buytenhek struct dsa_slave_priv *p = netdev_priv(dev); 21cf85d08fSLennert Buytenhek u8 *dsa_header; 22cf85d08fSLennert Buytenhek 23cf85d08fSLennert Buytenhek /* 24cf85d08fSLennert Buytenhek * Convert the outermost 802.1q tag to a DSA tag for tagged 25cf85d08fSLennert Buytenhek * packets, or insert a DSA tag between the addresses and 26cf85d08fSLennert Buytenhek * the ethertype field for untagged packets. 27cf85d08fSLennert Buytenhek */ 28cf85d08fSLennert Buytenhek if (skb->protocol == htons(ETH_P_8021Q)) { 29cf85d08fSLennert Buytenhek if (skb_cow_head(skb, 0) < 0) 30cf85d08fSLennert Buytenhek goto out_free; 31cf85d08fSLennert Buytenhek 32cf85d08fSLennert Buytenhek /* 33cf85d08fSLennert Buytenhek * Construct tagged FROM_CPU DSA tag from 802.1q tag. 34cf85d08fSLennert Buytenhek */ 35cf85d08fSLennert Buytenhek dsa_header = skb->data + 2 * ETH_ALEN; 36e84665c9SLennert Buytenhek dsa_header[0] = 0x60 | p->parent->index; 37cf85d08fSLennert Buytenhek dsa_header[1] = p->port << 3; 38cf85d08fSLennert Buytenhek 39cf85d08fSLennert Buytenhek /* 40cf85d08fSLennert Buytenhek * Move CFI field from byte 2 to byte 1. 41cf85d08fSLennert Buytenhek */ 42cf85d08fSLennert Buytenhek if (dsa_header[2] & 0x10) { 43cf85d08fSLennert Buytenhek dsa_header[1] |= 0x01; 44cf85d08fSLennert Buytenhek dsa_header[2] &= ~0x10; 45cf85d08fSLennert Buytenhek } 46cf85d08fSLennert Buytenhek } else { 47cf85d08fSLennert Buytenhek if (skb_cow_head(skb, DSA_HLEN) < 0) 48cf85d08fSLennert Buytenhek goto out_free; 49cf85d08fSLennert Buytenhek skb_push(skb, DSA_HLEN); 50cf85d08fSLennert Buytenhek 51cf85d08fSLennert Buytenhek memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN); 52cf85d08fSLennert Buytenhek 53cf85d08fSLennert Buytenhek /* 54cf85d08fSLennert Buytenhek * Construct untagged FROM_CPU DSA tag. 55cf85d08fSLennert Buytenhek */ 56cf85d08fSLennert Buytenhek dsa_header = skb->data + 2 * ETH_ALEN; 57e84665c9SLennert Buytenhek dsa_header[0] = 0x40 | p->parent->index; 58cf85d08fSLennert Buytenhek dsa_header[1] = p->port << 3; 59cf85d08fSLennert Buytenhek dsa_header[2] = 0x00; 60cf85d08fSLennert Buytenhek dsa_header[3] = 0x00; 61cf85d08fSLennert Buytenhek } 62cf85d08fSLennert Buytenhek 634ed70ce9SFlorian Fainelli return skb; 64cf85d08fSLennert Buytenhek 65cf85d08fSLennert Buytenhek out_free: 66cf85d08fSLennert Buytenhek kfree_skb(skb); 674ed70ce9SFlorian Fainelli return NULL; 68cf85d08fSLennert Buytenhek } 69cf85d08fSLennert Buytenhek 70cf85d08fSLennert Buytenhek static int dsa_rcv(struct sk_buff *skb, struct net_device *dev, 71cf85d08fSLennert Buytenhek struct packet_type *pt, struct net_device *orig_dev) 72cf85d08fSLennert Buytenhek { 73e84665c9SLennert Buytenhek struct dsa_switch_tree *dst = dev->dsa_ptr; 74e84665c9SLennert Buytenhek struct dsa_switch *ds; 75cf85d08fSLennert Buytenhek u8 *dsa_header; 76e84665c9SLennert Buytenhek int source_device; 77cf85d08fSLennert Buytenhek int source_port; 78cf85d08fSLennert Buytenhek 79e84665c9SLennert Buytenhek if (unlikely(dst == NULL)) 80cf85d08fSLennert Buytenhek goto out_drop; 81cf85d08fSLennert Buytenhek 82cf85d08fSLennert Buytenhek skb = skb_unshare(skb, GFP_ATOMIC); 83cf85d08fSLennert Buytenhek if (skb == NULL) 84cf85d08fSLennert Buytenhek goto out; 85cf85d08fSLennert Buytenhek 86cf85d08fSLennert Buytenhek if (unlikely(!pskb_may_pull(skb, DSA_HLEN))) 87cf85d08fSLennert Buytenhek goto out_drop; 88cf85d08fSLennert Buytenhek 89cf85d08fSLennert Buytenhek /* 90cf85d08fSLennert Buytenhek * The ethertype field is part of the DSA header. 91cf85d08fSLennert Buytenhek */ 92cf85d08fSLennert Buytenhek dsa_header = skb->data - 2; 93cf85d08fSLennert Buytenhek 94cf85d08fSLennert Buytenhek /* 95e84665c9SLennert Buytenhek * Check that frame type is either TO_CPU or FORWARD. 96cf85d08fSLennert Buytenhek */ 97e84665c9SLennert Buytenhek if ((dsa_header[0] & 0xc0) != 0x00 && (dsa_header[0] & 0xc0) != 0xc0) 98cf85d08fSLennert Buytenhek goto out_drop; 99cf85d08fSLennert Buytenhek 100cf85d08fSLennert Buytenhek /* 101e84665c9SLennert Buytenhek * Determine source device and port. 102cf85d08fSLennert Buytenhek */ 103e84665c9SLennert Buytenhek source_device = dsa_header[0] & 0x1f; 104cf85d08fSLennert Buytenhek source_port = (dsa_header[1] >> 3) & 0x1f; 105e84665c9SLennert Buytenhek 106e84665c9SLennert Buytenhek /* 107e84665c9SLennert Buytenhek * Check that the source device exists and that the source 108e84665c9SLennert Buytenhek * port is a registered DSA port. 109e84665c9SLennert Buytenhek */ 110149cafd7SAndrew Lunn if (source_device >= DSA_MAX_SWITCHES) 111e84665c9SLennert Buytenhek goto out_drop; 112149cafd7SAndrew Lunn 113e84665c9SLennert Buytenhek ds = dst->ds[source_device]; 114149cafd7SAndrew Lunn if (!ds) 115149cafd7SAndrew Lunn goto out_drop; 116149cafd7SAndrew Lunn 11726895e29SVivien Didelot if (source_port >= ds->num_ports || !ds->ports[source_port].netdev) 118cf85d08fSLennert Buytenhek goto out_drop; 119cf85d08fSLennert Buytenhek 120cf85d08fSLennert Buytenhek /* 121cf85d08fSLennert Buytenhek * Convert the DSA header to an 802.1q header if the 'tagged' 122cf85d08fSLennert Buytenhek * bit in the DSA header is set. If the 'tagged' bit is clear, 123cf85d08fSLennert Buytenhek * delete the DSA header entirely. 124cf85d08fSLennert Buytenhek */ 125cf85d08fSLennert Buytenhek if (dsa_header[0] & 0x20) { 126cf85d08fSLennert Buytenhek u8 new_header[4]; 127cf85d08fSLennert Buytenhek 128cf85d08fSLennert Buytenhek /* 129cf85d08fSLennert Buytenhek * Insert 802.1q ethertype and copy the VLAN-related 130cf85d08fSLennert Buytenhek * fields, but clear the bit that will hold CFI (since 131cf85d08fSLennert Buytenhek * DSA uses that bit location for another purpose). 132cf85d08fSLennert Buytenhek */ 133cf85d08fSLennert Buytenhek new_header[0] = (ETH_P_8021Q >> 8) & 0xff; 134cf85d08fSLennert Buytenhek new_header[1] = ETH_P_8021Q & 0xff; 135cf85d08fSLennert Buytenhek new_header[2] = dsa_header[2] & ~0x10; 136cf85d08fSLennert Buytenhek new_header[3] = dsa_header[3]; 137cf85d08fSLennert Buytenhek 138cf85d08fSLennert Buytenhek /* 139cf85d08fSLennert Buytenhek * Move CFI bit from its place in the DSA header to 140cf85d08fSLennert Buytenhek * its 802.1q-designated place. 141cf85d08fSLennert Buytenhek */ 142cf85d08fSLennert Buytenhek if (dsa_header[1] & 0x01) 143cf85d08fSLennert Buytenhek new_header[2] |= 0x10; 144cf85d08fSLennert Buytenhek 145cf85d08fSLennert Buytenhek /* 146cf85d08fSLennert Buytenhek * Update packet checksum if skb is CHECKSUM_COMPLETE. 147cf85d08fSLennert Buytenhek */ 148cf85d08fSLennert Buytenhek if (skb->ip_summed == CHECKSUM_COMPLETE) { 149cf85d08fSLennert Buytenhek __wsum c = skb->csum; 150cf85d08fSLennert Buytenhek c = csum_add(c, csum_partial(new_header + 2, 2, 0)); 151cf85d08fSLennert Buytenhek c = csum_sub(c, csum_partial(dsa_header + 2, 2, 0)); 152cf85d08fSLennert Buytenhek skb->csum = c; 153cf85d08fSLennert Buytenhek } 154cf85d08fSLennert Buytenhek 155cf85d08fSLennert Buytenhek memcpy(dsa_header, new_header, DSA_HLEN); 156cf85d08fSLennert Buytenhek } else { 157cf85d08fSLennert Buytenhek /* 158cf85d08fSLennert Buytenhek * Remove DSA tag and update checksum. 159cf85d08fSLennert Buytenhek */ 160cf85d08fSLennert Buytenhek skb_pull_rcsum(skb, DSA_HLEN); 161cf85d08fSLennert Buytenhek memmove(skb->data - ETH_HLEN, 162cf85d08fSLennert Buytenhek skb->data - ETH_HLEN - DSA_HLEN, 163cf85d08fSLennert Buytenhek 2 * ETH_ALEN); 164cf85d08fSLennert Buytenhek } 165cf85d08fSLennert Buytenhek 166c8b09808SAndrew Lunn skb->dev = ds->ports[source_port].netdev; 167cf85d08fSLennert Buytenhek skb_push(skb, ETH_HLEN); 16814ee6742SLennert Buytenhek skb->pkt_type = PACKET_HOST; 169cf85d08fSLennert Buytenhek skb->protocol = eth_type_trans(skb, skb->dev); 170cf85d08fSLennert Buytenhek 171cf85d08fSLennert Buytenhek skb->dev->stats.rx_packets++; 172cf85d08fSLennert Buytenhek skb->dev->stats.rx_bytes += skb->len; 173cf85d08fSLennert Buytenhek 174cf85d08fSLennert Buytenhek netif_receive_skb(skb); 175cf85d08fSLennert Buytenhek 176cf85d08fSLennert Buytenhek return 0; 177cf85d08fSLennert Buytenhek 178cf85d08fSLennert Buytenhek out_drop: 179cf85d08fSLennert Buytenhek kfree_skb(skb); 180cf85d08fSLennert Buytenhek out: 181cf85d08fSLennert Buytenhek return 0; 182cf85d08fSLennert Buytenhek } 183cf85d08fSLennert Buytenhek 1843e8a72d1SFlorian Fainelli const struct dsa_device_ops dsa_netdev_ops = { 1853e8a72d1SFlorian Fainelli .xmit = dsa_xmit, 1863e8a72d1SFlorian Fainelli .rcv = dsa_rcv, 187cf85d08fSLennert Buytenhek }; 188