/* * net/dsa/tag_edsa.c - Ethertype DSA tagging * Copyright (c) 2008 Marvell Semiconductor * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. */ #include <linux/etherdevice.h> #include <linux/list.h> #include <linux/netdevice.h> #include "dsa_priv.h" #define DSA_HLEN 4 #define EDSA_HLEN 8 int edsa_xmit(struct sk_buff *skb, struct net_device *dev) { struct dsa_slave_priv *p = netdev_priv(dev); u8 *edsa_header; dev->stats.tx_packets++; dev->stats.tx_bytes += skb->len; /* * Convert the outermost 802.1q tag to a DSA tag and prepend * a DSA ethertype field is the packet is tagged, or insert * a DSA ethertype plus DSA tag between the addresses and the * current ethertype field if the packet is untagged. */ if (skb->protocol == htons(ETH_P_8021Q)) { if (skb_cow_head(skb, DSA_HLEN) < 0) goto out_free; skb_push(skb, DSA_HLEN); memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN); /* * Construct tagged FROM_CPU DSA tag from 802.1q tag. */ edsa_header = skb->data + 2 * ETH_ALEN; edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff; edsa_header[1] = ETH_P_EDSA & 0xff; edsa_header[2] = 0x00; edsa_header[3] = 0x00; edsa_header[4] = 0x60; edsa_header[5] = p->port << 3; /* * Move CFI field from byte 6 to byte 5. */ if (edsa_header[6] & 0x10) { edsa_header[5] |= 0x01; edsa_header[6] &= ~0x10; } } else { if (skb_cow_head(skb, EDSA_HLEN) < 0) goto out_free; skb_push(skb, EDSA_HLEN); memmove(skb->data, skb->data + EDSA_HLEN, 2 * ETH_ALEN); /* * Construct untagged FROM_CPU DSA tag. */ edsa_header = skb->data + 2 * ETH_ALEN; edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff; edsa_header[1] = ETH_P_EDSA & 0xff; edsa_header[2] = 0x00; edsa_header[3] = 0x00; edsa_header[4] = 0x40; edsa_header[5] = p->port << 3; edsa_header[6] = 0x00; edsa_header[7] = 0x00; } skb->protocol = htons(ETH_P_EDSA); skb->dev = p->parent->master_netdev; dev_queue_xmit(skb); return NETDEV_TX_OK; out_free: kfree_skb(skb); return NETDEV_TX_OK; } static int edsa_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt, struct net_device *orig_dev) { struct dsa_switch *ds = dev->dsa_ptr; u8 *edsa_header; int source_port; if (unlikely(ds == NULL)) goto out_drop; skb = skb_unshare(skb, GFP_ATOMIC); if (skb == NULL) goto out; if (unlikely(!pskb_may_pull(skb, EDSA_HLEN))) goto out_drop; /* * Skip the two null bytes after the ethertype. */ edsa_header = skb->data + 2; /* * Check that frame type is either TO_CPU or FORWARD, and * that the source device is zero. */ if ((edsa_header[0] & 0xdf) != 0x00 && (edsa_header[0] & 0xdf) != 0xc0) goto out_drop; /* * Check that the source port is a registered DSA port. */ source_port = (edsa_header[1] >> 3) & 0x1f; if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL) goto out_drop; /* * If the 'tagged' bit is set, convert the DSA tag to a 802.1q * tag and delete the ethertype part. If the 'tagged' bit is * clear, delete the ethertype and the DSA tag parts. */ if (edsa_header[0] & 0x20) { u8 new_header[4]; /* * Insert 802.1q ethertype and copy the VLAN-related * fields, but clear the bit that will hold CFI (since * DSA uses that bit location for another purpose). */ new_header[0] = (ETH_P_8021Q >> 8) & 0xff; new_header[1] = ETH_P_8021Q & 0xff; new_header[2] = edsa_header[2] & ~0x10; new_header[3] = edsa_header[3]; /* * Move CFI bit from its place in the DSA header to * its 802.1q-designated place. */ if (edsa_header[1] & 0x01) new_header[2] |= 0x10; skb_pull_rcsum(skb, DSA_HLEN); /* * Update packet checksum if skb is CHECKSUM_COMPLETE. */ if (skb->ip_summed == CHECKSUM_COMPLETE) { __wsum c = skb->csum; c = csum_add(c, csum_partial(new_header + 2, 2, 0)); c = csum_sub(c, csum_partial(edsa_header + 2, 2, 0)); skb->csum = c; } memcpy(edsa_header, new_header, DSA_HLEN); memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - DSA_HLEN, 2 * ETH_ALEN); } else { /* * Remove DSA tag and update checksum. */ skb_pull_rcsum(skb, EDSA_HLEN); memmove(skb->data - ETH_HLEN, skb->data - ETH_HLEN - EDSA_HLEN, 2 * ETH_ALEN); } skb->dev = ds->ports[source_port]; skb_push(skb, ETH_HLEN); skb->pkt_type = PACKET_HOST; skb->protocol = eth_type_trans(skb, skb->dev); skb->dev->last_rx = jiffies; skb->dev->stats.rx_packets++; skb->dev->stats.rx_bytes += skb->len; netif_receive_skb(skb); return 0; out_drop: kfree_skb(skb); out: return 0; } static struct packet_type edsa_packet_type = { .type = __constant_htons(ETH_P_EDSA), .func = edsa_rcv, }; static int __init edsa_init_module(void) { dev_add_pack(&edsa_packet_type); return 0; } module_init(edsa_init_module); static void __exit edsa_cleanup_module(void) { dev_remove_pack(&edsa_packet_type); } module_exit(edsa_cleanup_module);