Lennert Buytenhek | 91da11f | 2008-10-07 13:44:02 +0000 | [diff] [blame] | 1 | /* |
| 2 | * net/dsa/tag_edsa.c - Ethertype DSA tagging |
| 3 | * Copyright (c) 2008 Marvell Semiconductor |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | */ |
| 10 | |
| 11 | #include <linux/etherdevice.h> |
| 12 | #include <linux/list.h> |
| 13 | #include <linux/netdevice.h> |
| 14 | #include "dsa_priv.h" |
| 15 | |
| 16 | #define DSA_HLEN 4 |
| 17 | #define EDSA_HLEN 8 |
| 18 | |
| 19 | int edsa_xmit(struct sk_buff *skb, struct net_device *dev) |
| 20 | { |
| 21 | struct dsa_slave_priv *p = netdev_priv(dev); |
| 22 | u8 *edsa_header; |
| 23 | |
| 24 | dev->stats.tx_packets++; |
| 25 | dev->stats.tx_bytes += skb->len; |
| 26 | |
| 27 | /* |
| 28 | * Convert the outermost 802.1q tag to a DSA tag and prepend |
| 29 | * a DSA ethertype field is the packet is tagged, or insert |
| 30 | * a DSA ethertype plus DSA tag between the addresses and the |
| 31 | * current ethertype field if the packet is untagged. |
| 32 | */ |
| 33 | if (skb->protocol == htons(ETH_P_8021Q)) { |
| 34 | if (skb_cow_head(skb, DSA_HLEN) < 0) |
| 35 | goto out_free; |
| 36 | skb_push(skb, DSA_HLEN); |
| 37 | |
| 38 | memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN); |
| 39 | |
| 40 | /* |
| 41 | * Construct tagged FROM_CPU DSA tag from 802.1q tag. |
| 42 | */ |
| 43 | edsa_header = skb->data + 2 * ETH_ALEN; |
| 44 | edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff; |
| 45 | edsa_header[1] = ETH_P_EDSA & 0xff; |
| 46 | edsa_header[2] = 0x00; |
| 47 | edsa_header[3] = 0x00; |
| 48 | edsa_header[4] = 0x60; |
| 49 | edsa_header[5] = p->port << 3; |
| 50 | |
| 51 | /* |
| 52 | * Move CFI field from byte 6 to byte 5. |
| 53 | */ |
| 54 | if (edsa_header[6] & 0x10) { |
| 55 | edsa_header[5] |= 0x01; |
| 56 | edsa_header[6] &= ~0x10; |
| 57 | } |
| 58 | } else { |
| 59 | if (skb_cow_head(skb, EDSA_HLEN) < 0) |
| 60 | goto out_free; |
| 61 | skb_push(skb, EDSA_HLEN); |
| 62 | |
| 63 | memmove(skb->data, skb->data + EDSA_HLEN, 2 * ETH_ALEN); |
| 64 | |
| 65 | /* |
| 66 | * Construct untagged FROM_CPU DSA tag. |
| 67 | */ |
| 68 | edsa_header = skb->data + 2 * ETH_ALEN; |
| 69 | edsa_header[0] = (ETH_P_EDSA >> 8) & 0xff; |
| 70 | edsa_header[1] = ETH_P_EDSA & 0xff; |
| 71 | edsa_header[2] = 0x00; |
| 72 | edsa_header[3] = 0x00; |
| 73 | edsa_header[4] = 0x40; |
| 74 | edsa_header[5] = p->port << 3; |
| 75 | edsa_header[6] = 0x00; |
| 76 | edsa_header[7] = 0x00; |
| 77 | } |
| 78 | |
| 79 | skb->protocol = htons(ETH_P_EDSA); |
| 80 | |
| 81 | skb->dev = p->parent->master_netdev; |
| 82 | dev_queue_xmit(skb); |
| 83 | |
| 84 | return NETDEV_TX_OK; |
| 85 | |
| 86 | out_free: |
| 87 | kfree_skb(skb); |
| 88 | return NETDEV_TX_OK; |
| 89 | } |
| 90 | |
| 91 | static int edsa_rcv(struct sk_buff *skb, struct net_device *dev, |
| 92 | struct packet_type *pt, struct net_device *orig_dev) |
| 93 | { |
| 94 | struct dsa_switch *ds = dev->dsa_ptr; |
| 95 | u8 *edsa_header; |
| 96 | int source_port; |
| 97 | |
| 98 | if (unlikely(ds == NULL)) |
| 99 | goto out_drop; |
| 100 | |
| 101 | skb = skb_unshare(skb, GFP_ATOMIC); |
| 102 | if (skb == NULL) |
| 103 | goto out; |
| 104 | |
| 105 | if (unlikely(!pskb_may_pull(skb, EDSA_HLEN))) |
| 106 | goto out_drop; |
| 107 | |
| 108 | /* |
| 109 | * Skip the two null bytes after the ethertype. |
| 110 | */ |
| 111 | edsa_header = skb->data + 2; |
| 112 | |
| 113 | /* |
| 114 | * Check that frame type is either TO_CPU or FORWARD, and |
| 115 | * that the source device is zero. |
| 116 | */ |
| 117 | if ((edsa_header[0] & 0xdf) != 0x00 && (edsa_header[0] & 0xdf) != 0xc0) |
| 118 | goto out_drop; |
| 119 | |
| 120 | /* |
| 121 | * Check that the source port is a registered DSA port. |
| 122 | */ |
| 123 | source_port = (edsa_header[1] >> 3) & 0x1f; |
| 124 | if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL) |
| 125 | goto out_drop; |
| 126 | |
| 127 | /* |
| 128 | * If the 'tagged' bit is set, convert the DSA tag to a 802.1q |
| 129 | * tag and delete the ethertype part. If the 'tagged' bit is |
| 130 | * clear, delete the ethertype and the DSA tag parts. |
| 131 | */ |
| 132 | if (edsa_header[0] & 0x20) { |
| 133 | u8 new_header[4]; |
| 134 | |
| 135 | /* |
| 136 | * Insert 802.1q ethertype and copy the VLAN-related |
| 137 | * fields, but clear the bit that will hold CFI (since |
| 138 | * DSA uses that bit location for another purpose). |
| 139 | */ |
| 140 | new_header[0] = (ETH_P_8021Q >> 8) & 0xff; |
| 141 | new_header[1] = ETH_P_8021Q & 0xff; |
| 142 | new_header[2] = edsa_header[2] & ~0x10; |
| 143 | new_header[3] = edsa_header[3]; |
| 144 | |
| 145 | /* |
| 146 | * Move CFI bit from its place in the DSA header to |
| 147 | * its 802.1q-designated place. |
| 148 | */ |
| 149 | if (edsa_header[1] & 0x01) |
| 150 | new_header[2] |= 0x10; |
| 151 | |
| 152 | skb_pull_rcsum(skb, DSA_HLEN); |
| 153 | |
| 154 | /* |
| 155 | * Update packet checksum if skb is CHECKSUM_COMPLETE. |
| 156 | */ |
| 157 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
| 158 | __wsum c = skb->csum; |
| 159 | c = csum_add(c, csum_partial(new_header + 2, 2, 0)); |
| 160 | c = csum_sub(c, csum_partial(edsa_header + 2, 2, 0)); |
| 161 | skb->csum = c; |
| 162 | } |
| 163 | |
| 164 | memcpy(edsa_header, new_header, DSA_HLEN); |
| 165 | |
| 166 | memmove(skb->data - ETH_HLEN, |
| 167 | skb->data - ETH_HLEN - DSA_HLEN, |
| 168 | 2 * ETH_ALEN); |
| 169 | } else { |
| 170 | /* |
| 171 | * Remove DSA tag and update checksum. |
| 172 | */ |
| 173 | skb_pull_rcsum(skb, EDSA_HLEN); |
| 174 | memmove(skb->data - ETH_HLEN, |
| 175 | skb->data - ETH_HLEN - EDSA_HLEN, |
| 176 | 2 * ETH_ALEN); |
| 177 | } |
| 178 | |
| 179 | skb->dev = ds->ports[source_port]; |
| 180 | skb_push(skb, ETH_HLEN); |
Lennert Buytenhek | 14ee674 | 2008-11-10 21:52:42 -0800 | [diff] [blame] | 181 | skb->pkt_type = PACKET_HOST; |
Lennert Buytenhek | 91da11f | 2008-10-07 13:44:02 +0000 | [diff] [blame] | 182 | skb->protocol = eth_type_trans(skb, skb->dev); |
| 183 | |
Lennert Buytenhek | 91da11f | 2008-10-07 13:44:02 +0000 | [diff] [blame] | 184 | skb->dev->stats.rx_packets++; |
| 185 | skb->dev->stats.rx_bytes += skb->len; |
| 186 | |
| 187 | netif_receive_skb(skb); |
| 188 | |
| 189 | return 0; |
| 190 | |
| 191 | out_drop: |
| 192 | kfree_skb(skb); |
| 193 | out: |
| 194 | return 0; |
| 195 | } |
| 196 | |
| 197 | static struct packet_type edsa_packet_type = { |
| 198 | .type = __constant_htons(ETH_P_EDSA), |
| 199 | .func = edsa_rcv, |
| 200 | }; |
| 201 | |
| 202 | static int __init edsa_init_module(void) |
| 203 | { |
| 204 | dev_add_pack(&edsa_packet_type); |
| 205 | return 0; |
| 206 | } |
| 207 | module_init(edsa_init_module); |
| 208 | |
| 209 | static void __exit edsa_cleanup_module(void) |
| 210 | { |
| 211 | dev_remove_pack(&edsa_packet_type); |
| 212 | } |
| 213 | module_exit(edsa_cleanup_module); |