Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 1 | /* |
| 2 | * net/dsa/tag_dsa.c - (Non-ethertype) DSA tagging |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 3 | * Copyright (c) 2008-2009 Marvell Semiconductor |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 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 | |
Stephen Hemminger | 6fef4c0 | 2009-08-31 19:50:41 +0000 | [diff] [blame] | 18 | netdev_tx_t dsa_xmit(struct sk_buff *skb, struct net_device *dev) |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 19 | { |
| 20 | struct dsa_slave_priv *p = netdev_priv(dev); |
| 21 | u8 *dsa_header; |
| 22 | |
| 23 | dev->stats.tx_packets++; |
| 24 | dev->stats.tx_bytes += skb->len; |
| 25 | |
| 26 | /* |
| 27 | * Convert the outermost 802.1q tag to a DSA tag for tagged |
| 28 | * packets, or insert a DSA tag between the addresses and |
| 29 | * the ethertype field for untagged packets. |
| 30 | */ |
| 31 | if (skb->protocol == htons(ETH_P_8021Q)) { |
| 32 | if (skb_cow_head(skb, 0) < 0) |
| 33 | goto out_free; |
| 34 | |
| 35 | /* |
| 36 | * Construct tagged FROM_CPU DSA tag from 802.1q tag. |
| 37 | */ |
| 38 | dsa_header = skb->data + 2 * ETH_ALEN; |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 39 | dsa_header[0] = 0x60 | p->parent->index; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 40 | dsa_header[1] = p->port << 3; |
| 41 | |
| 42 | /* |
| 43 | * Move CFI field from byte 2 to byte 1. |
| 44 | */ |
| 45 | if (dsa_header[2] & 0x10) { |
| 46 | dsa_header[1] |= 0x01; |
| 47 | dsa_header[2] &= ~0x10; |
| 48 | } |
| 49 | } else { |
| 50 | if (skb_cow_head(skb, DSA_HLEN) < 0) |
| 51 | goto out_free; |
| 52 | skb_push(skb, DSA_HLEN); |
| 53 | |
| 54 | memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN); |
| 55 | |
| 56 | /* |
| 57 | * Construct untagged FROM_CPU DSA tag. |
| 58 | */ |
| 59 | dsa_header = skb->data + 2 * ETH_ALEN; |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 60 | dsa_header[0] = 0x40 | p->parent->index; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 61 | dsa_header[1] = p->port << 3; |
| 62 | dsa_header[2] = 0x00; |
| 63 | dsa_header[3] = 0x00; |
| 64 | } |
| 65 | |
| 66 | skb->protocol = htons(ETH_P_DSA); |
| 67 | |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 68 | skb->dev = p->parent->dst->master_netdev; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 69 | dev_queue_xmit(skb); |
| 70 | |
| 71 | return NETDEV_TX_OK; |
| 72 | |
| 73 | out_free: |
| 74 | kfree_skb(skb); |
| 75 | return NETDEV_TX_OK; |
| 76 | } |
| 77 | |
| 78 | static int dsa_rcv(struct sk_buff *skb, struct net_device *dev, |
| 79 | struct packet_type *pt, struct net_device *orig_dev) |
| 80 | { |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 81 | struct dsa_switch_tree *dst = dev->dsa_ptr; |
| 82 | struct dsa_switch *ds; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 83 | u8 *dsa_header; |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 84 | int source_device; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 85 | int source_port; |
| 86 | |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 87 | if (unlikely(dst == NULL)) |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 88 | goto out_drop; |
| 89 | |
| 90 | skb = skb_unshare(skb, GFP_ATOMIC); |
| 91 | if (skb == NULL) |
| 92 | goto out; |
| 93 | |
| 94 | if (unlikely(!pskb_may_pull(skb, DSA_HLEN))) |
| 95 | goto out_drop; |
| 96 | |
| 97 | /* |
| 98 | * The ethertype field is part of the DSA header. |
| 99 | */ |
| 100 | dsa_header = skb->data - 2; |
| 101 | |
| 102 | /* |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 103 | * Check that frame type is either TO_CPU or FORWARD. |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 104 | */ |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 105 | if ((dsa_header[0] & 0xc0) != 0x00 && (dsa_header[0] & 0xc0) != 0xc0) |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 106 | goto out_drop; |
| 107 | |
| 108 | /* |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 109 | * Determine source device and port. |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 110 | */ |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 111 | source_device = dsa_header[0] & 0x1f; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 112 | source_port = (dsa_header[1] >> 3) & 0x1f; |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 113 | |
| 114 | /* |
| 115 | * Check that the source device exists and that the source |
| 116 | * port is a registered DSA port. |
| 117 | */ |
| 118 | if (source_device >= dst->pd->nr_chips) |
| 119 | goto out_drop; |
| 120 | ds = dst->ds[source_device]; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 121 | if (source_port >= DSA_MAX_PORTS || ds->ports[source_port] == NULL) |
| 122 | goto out_drop; |
| 123 | |
| 124 | /* |
| 125 | * Convert the DSA header to an 802.1q header if the 'tagged' |
| 126 | * bit in the DSA header is set. If the 'tagged' bit is clear, |
| 127 | * delete the DSA header entirely. |
| 128 | */ |
| 129 | if (dsa_header[0] & 0x20) { |
| 130 | u8 new_header[4]; |
| 131 | |
| 132 | /* |
| 133 | * Insert 802.1q ethertype and copy the VLAN-related |
| 134 | * fields, but clear the bit that will hold CFI (since |
| 135 | * DSA uses that bit location for another purpose). |
| 136 | */ |
| 137 | new_header[0] = (ETH_P_8021Q >> 8) & 0xff; |
| 138 | new_header[1] = ETH_P_8021Q & 0xff; |
| 139 | new_header[2] = dsa_header[2] & ~0x10; |
| 140 | new_header[3] = dsa_header[3]; |
| 141 | |
| 142 | /* |
| 143 | * Move CFI bit from its place in the DSA header to |
| 144 | * its 802.1q-designated place. |
| 145 | */ |
| 146 | if (dsa_header[1] & 0x01) |
| 147 | new_header[2] |= 0x10; |
| 148 | |
| 149 | /* |
| 150 | * Update packet checksum if skb is CHECKSUM_COMPLETE. |
| 151 | */ |
| 152 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
| 153 | __wsum c = skb->csum; |
| 154 | c = csum_add(c, csum_partial(new_header + 2, 2, 0)); |
| 155 | c = csum_sub(c, csum_partial(dsa_header + 2, 2, 0)); |
| 156 | skb->csum = c; |
| 157 | } |
| 158 | |
| 159 | memcpy(dsa_header, new_header, DSA_HLEN); |
| 160 | } else { |
| 161 | /* |
| 162 | * Remove DSA tag and update checksum. |
| 163 | */ |
| 164 | skb_pull_rcsum(skb, DSA_HLEN); |
| 165 | memmove(skb->data - ETH_HLEN, |
| 166 | skb->data - ETH_HLEN - DSA_HLEN, |
| 167 | 2 * ETH_ALEN); |
| 168 | } |
| 169 | |
| 170 | skb->dev = ds->ports[source_port]; |
| 171 | skb_push(skb, ETH_HLEN); |
Lennert Buytenhek | 14ee674 | 2008-11-10 21:52:42 -0800 | [diff] [blame] | 172 | skb->pkt_type = PACKET_HOST; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 173 | skb->protocol = eth_type_trans(skb, skb->dev); |
| 174 | |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 175 | skb->dev->stats.rx_packets++; |
| 176 | skb->dev->stats.rx_bytes += skb->len; |
| 177 | |
| 178 | netif_receive_skb(skb); |
| 179 | |
| 180 | return 0; |
| 181 | |
| 182 | out_drop: |
| 183 | kfree_skb(skb); |
| 184 | out: |
| 185 | return 0; |
| 186 | } |
| 187 | |
Stephen Hemminger | 7546dd9 | 2009-03-09 08:18:29 +0000 | [diff] [blame] | 188 | static struct packet_type dsa_packet_type __read_mostly = { |
Harvey Harrison | 09640e63 | 2009-02-01 00:45:17 -0800 | [diff] [blame] | 189 | .type = cpu_to_be16(ETH_P_DSA), |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 190 | .func = dsa_rcv, |
| 191 | }; |
| 192 | |
| 193 | static int __init dsa_init_module(void) |
| 194 | { |
| 195 | dev_add_pack(&dsa_packet_type); |
| 196 | return 0; |
| 197 | } |
| 198 | module_init(dsa_init_module); |
| 199 | |
| 200 | static void __exit dsa_cleanup_module(void) |
| 201 | { |
| 202 | dev_remove_pack(&dsa_packet_type); |
| 203 | } |
| 204 | module_exit(dsa_cleanup_module); |