projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 396138f0 LB |
1 | /* |
| 2 | * net/dsa/tag_trailer.c - Trailer tag format handling | |
| e84665c9 | 3 | * Copyright (c) 2008-2009 Marvell Semiconductor |
| 396138f0 LB |
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> | |
| 5a0e3ad6 | 13 | #include <linux/slab.h> |
| ea5dd34b | 14 | |
| 396138f0 LB |
15 | #include "dsa_priv.h" |
| 16 | ||
| 4ed70ce9 | 17 | static struct sk_buff *trailer_xmit(struct sk_buff *skb, struct net_device *dev) |
| 396138f0 | 18 | { |
| d945097b | 19 | struct dsa_port *dp = dsa_slave_to_port(dev); |
| 396138f0 LB |
20 | struct sk_buff *nskb; |
| 21 | int padlen; | |
| 22 | u8 *trailer; | |
| 23 | ||
| 396138f0 LB |
24 | /* |
| 25 | * We have to make sure that the trailer ends up as the very | |
| 26 | * last 4 bytes of the packet. This means that we have to pad | |
| 27 | * the packet to the minimum ethernet frame size, if necessary, | |
| 28 | * before adding the trailer. | |
| 29 | */ | |
| 30 | padlen = 0; | |
| 31 | if (skb->len < 60) | |
| 32 | padlen = 60 - skb->len; | |
| 33 | ||
| 34 | nskb = alloc_skb(NET_IP_ALIGN + skb->len + padlen + 4, GFP_ATOMIC); | |
| fe47d563 | 35 | if (!nskb) |
| 4ed70ce9 | 36 | return NULL; |
| 396138f0 LB |
37 | skb_reserve(nskb, NET_IP_ALIGN); |
| 38 | ||
| 39 | skb_reset_mac_header(nskb); | |
| 40 | skb_set_network_header(nskb, skb_network_header(skb) - skb->head); | |
| 41 | skb_set_transport_header(nskb, skb_transport_header(skb) - skb->head); | |
| 42 | skb_copy_and_csum_dev(skb, skb_put(nskb, skb->len)); | |
| 2b33bc8a | 43 | consume_skb(skb); |
| 396138f0 LB |
44 | |
| 45 | if (padlen) { | |
| b952f4df | 46 | skb_put_zero(nskb, padlen); |
| 396138f0 LB |
47 | } |
| 48 | ||
| 49 | trailer = skb_put(nskb, 4); | |
| 50 | trailer[0] = 0x80; | |
| d945097b | 51 | trailer[1] = 1 << dp->index; |
| 396138f0 LB |
52 | trailer[2] = 0x10; |
| 53 | trailer[3] = 0x00; | |
| 54 | ||
| 4ed70ce9 | 55 | return nskb; |
| 396138f0 LB |
56 | } |
| 57 | ||
| a86d8bec | 58 | static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev, |
| 89e49506 | 59 | struct packet_type *pt) |
| 396138f0 | 60 | { |
| 396138f0 LB |
61 | u8 *trailer; |
| 62 | int source_port; | |
| 63 | ||
| 396138f0 | 64 | if (skb_linearize(skb)) |
| 54709795 | 65 | return NULL; |
| 396138f0 LB |
66 | |
| 67 | trailer = skb_tail_pointer(skb) - 4; | |
| 68 | if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 || | |
| fbd03513 | 69 | (trailer[2] & 0xef) != 0x00 || trailer[3] != 0x00) |
| 54709795 | 70 | return NULL; |
| 396138f0 LB |
71 | |
| 72 | source_port = trailer[1] & 7; | |
| 3775b1b7 | 73 | |
| 2231c43b | 74 | skb->dev = dsa_master_find_slave(dev, 0, source_port); |
| 3775b1b7 | 75 | if (!skb->dev) |
| 54709795 | 76 | return NULL; |
| 396138f0 | 77 | |
| 349b71d6 ZJ |
78 | if (pskb_trim_rcsum(skb, skb->len - 4)) |
| 79 | return NULL; | |
| 396138f0 | 80 | |
| a86d8bec | 81 | return skb; |
| 396138f0 LB |
82 | } |
| 83 | ||
| 3e8a72d1 FF |
84 | const struct dsa_device_ops trailer_netdev_ops = { |
| 85 | .xmit = trailer_xmit, | |
| 86 | .rcv = trailer_rcv, | |
| 396138f0 | 87 | }; |