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> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 13 | #include <linux/slab.h> |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 14 | #include "dsa_priv.h" |
| 15 | |
| 16 | #define DSA_HLEN 4 |
| 17 | |
Florian Fainelli | 4ed70ce | 2015-07-31 11:42:56 -0700 | [diff] [blame] | 18 | static struct sk_buff *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 | |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 23 | /* |
| 24 | * Convert the outermost 802.1q tag to a DSA tag for tagged |
| 25 | * packets, or insert a DSA tag between the addresses and |
| 26 | * the ethertype field for untagged packets. |
| 27 | */ |
| 28 | if (skb->protocol == htons(ETH_P_8021Q)) { |
| 29 | if (skb_cow_head(skb, 0) < 0) |
| 30 | goto out_free; |
| 31 | |
| 32 | /* |
| 33 | * Construct tagged FROM_CPU DSA tag from 802.1q tag. |
| 34 | */ |
| 35 | dsa_header = skb->data + 2 * ETH_ALEN; |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 36 | dsa_header[0] = 0x60 | p->parent->index; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 37 | dsa_header[1] = p->port << 3; |
| 38 | |
| 39 | /* |
| 40 | * Move CFI field from byte 2 to byte 1. |
| 41 | */ |
| 42 | if (dsa_header[2] & 0x10) { |
| 43 | dsa_header[1] |= 0x01; |
| 44 | dsa_header[2] &= ~0x10; |
| 45 | } |
| 46 | } else { |
| 47 | if (skb_cow_head(skb, DSA_HLEN) < 0) |
| 48 | goto out_free; |
| 49 | skb_push(skb, DSA_HLEN); |
| 50 | |
| 51 | memmove(skb->data, skb->data + DSA_HLEN, 2 * ETH_ALEN); |
| 52 | |
| 53 | /* |
| 54 | * Construct untagged FROM_CPU DSA tag. |
| 55 | */ |
| 56 | dsa_header = skb->data + 2 * ETH_ALEN; |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 57 | dsa_header[0] = 0x40 | p->parent->index; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 58 | dsa_header[1] = p->port << 3; |
| 59 | dsa_header[2] = 0x00; |
| 60 | dsa_header[3] = 0x00; |
| 61 | } |
| 62 | |
Florian Fainelli | 4ed70ce | 2015-07-31 11:42:56 -0700 | [diff] [blame] | 63 | return skb; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 64 | |
| 65 | out_free: |
| 66 | kfree_skb(skb); |
Florian Fainelli | 4ed70ce | 2015-07-31 11:42:56 -0700 | [diff] [blame] | 67 | return NULL; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 68 | } |
| 69 | |
| 70 | static int dsa_rcv(struct sk_buff *skb, struct net_device *dev, |
| 71 | struct packet_type *pt, struct net_device *orig_dev) |
| 72 | { |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 73 | struct dsa_switch_tree *dst = dev->dsa_ptr; |
| 74 | struct dsa_switch *ds; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 75 | u8 *dsa_header; |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 76 | int source_device; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 77 | int source_port; |
| 78 | |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 79 | if (unlikely(dst == NULL)) |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 80 | goto out_drop; |
| 81 | |
| 82 | skb = skb_unshare(skb, GFP_ATOMIC); |
| 83 | if (skb == NULL) |
| 84 | goto out; |
| 85 | |
| 86 | if (unlikely(!pskb_may_pull(skb, DSA_HLEN))) |
| 87 | goto out_drop; |
| 88 | |
| 89 | /* |
| 90 | * The ethertype field is part of the DSA header. |
| 91 | */ |
| 92 | dsa_header = skb->data - 2; |
| 93 | |
| 94 | /* |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 95 | * Check that frame type is either TO_CPU or FORWARD. |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 96 | */ |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 97 | if ((dsa_header[0] & 0xc0) != 0x00 && (dsa_header[0] & 0xc0) != 0xc0) |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 98 | goto out_drop; |
| 99 | |
| 100 | /* |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 101 | * Determine source device and port. |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 102 | */ |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 103 | source_device = dsa_header[0] & 0x1f; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 104 | source_port = (dsa_header[1] >> 3) & 0x1f; |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 105 | |
| 106 | /* |
| 107 | * Check that the source device exists and that the source |
| 108 | * port is a registered DSA port. |
| 109 | */ |
Andrew Lunn | 149cafd | 2016-06-04 21:16:56 +0200 | [diff] [blame] | 110 | if (source_device >= DSA_MAX_SWITCHES) |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 111 | goto out_drop; |
Andrew Lunn | 149cafd | 2016-06-04 21:16:56 +0200 | [diff] [blame] | 112 | |
Lennert Buytenhek | e84665c | 2009-03-20 09:52:09 +0000 | [diff] [blame] | 113 | ds = dst->ds[source_device]; |
Andrew Lunn | 149cafd | 2016-06-04 21:16:56 +0200 | [diff] [blame] | 114 | if (!ds) |
| 115 | goto out_drop; |
| 116 | |
Andrew Lunn | c8b0980 | 2016-06-04 21:16:57 +0200 | [diff] [blame] | 117 | if (source_port >= DSA_MAX_PORTS || !ds->ports[source_port].netdev) |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 118 | goto out_drop; |
| 119 | |
| 120 | /* |
| 121 | * Convert the DSA header to an 802.1q header if the 'tagged' |
| 122 | * bit in the DSA header is set. If the 'tagged' bit is clear, |
| 123 | * delete the DSA header entirely. |
| 124 | */ |
| 125 | if (dsa_header[0] & 0x20) { |
| 126 | u8 new_header[4]; |
| 127 | |
| 128 | /* |
| 129 | * Insert 802.1q ethertype and copy the VLAN-related |
| 130 | * fields, but clear the bit that will hold CFI (since |
| 131 | * DSA uses that bit location for another purpose). |
| 132 | */ |
| 133 | new_header[0] = (ETH_P_8021Q >> 8) & 0xff; |
| 134 | new_header[1] = ETH_P_8021Q & 0xff; |
| 135 | new_header[2] = dsa_header[2] & ~0x10; |
| 136 | new_header[3] = dsa_header[3]; |
| 137 | |
| 138 | /* |
| 139 | * Move CFI bit from its place in the DSA header to |
| 140 | * its 802.1q-designated place. |
| 141 | */ |
| 142 | if (dsa_header[1] & 0x01) |
| 143 | new_header[2] |= 0x10; |
| 144 | |
| 145 | /* |
| 146 | * Update packet checksum if skb is CHECKSUM_COMPLETE. |
| 147 | */ |
| 148 | if (skb->ip_summed == CHECKSUM_COMPLETE) { |
| 149 | __wsum c = skb->csum; |
| 150 | c = csum_add(c, csum_partial(new_header + 2, 2, 0)); |
| 151 | c = csum_sub(c, csum_partial(dsa_header + 2, 2, 0)); |
| 152 | skb->csum = c; |
| 153 | } |
| 154 | |
| 155 | memcpy(dsa_header, new_header, DSA_HLEN); |
| 156 | } else { |
| 157 | /* |
| 158 | * Remove DSA tag and update checksum. |
| 159 | */ |
| 160 | skb_pull_rcsum(skb, DSA_HLEN); |
| 161 | memmove(skb->data - ETH_HLEN, |
| 162 | skb->data - ETH_HLEN - DSA_HLEN, |
| 163 | 2 * ETH_ALEN); |
| 164 | } |
| 165 | |
Andrew Lunn | c8b0980 | 2016-06-04 21:16:57 +0200 | [diff] [blame] | 166 | skb->dev = ds->ports[source_port].netdev; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 167 | skb_push(skb, ETH_HLEN); |
Lennert Buytenhek | 14ee674 | 2008-11-10 21:52:42 -0800 | [diff] [blame] | 168 | skb->pkt_type = PACKET_HOST; |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 169 | skb->protocol = eth_type_trans(skb, skb->dev); |
| 170 | |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 171 | skb->dev->stats.rx_packets++; |
| 172 | skb->dev->stats.rx_bytes += skb->len; |
| 173 | |
| 174 | netif_receive_skb(skb); |
| 175 | |
| 176 | return 0; |
| 177 | |
| 178 | out_drop: |
| 179 | kfree_skb(skb); |
| 180 | out: |
| 181 | return 0; |
| 182 | } |
| 183 | |
Florian Fainelli | 3e8a72d | 2014-08-27 17:04:46 -0700 | [diff] [blame] | 184 | const struct dsa_device_ops dsa_netdev_ops = { |
| 185 | .xmit = dsa_xmit, |
| 186 | .rcv = dsa_rcv, |
Lennert Buytenhek | cf85d08 | 2008-10-07 13:45:02 +0000 | [diff] [blame] | 187 | }; |