Commit | Line | Data |
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dfedd3b6 | 1 | // SPDX-License-Identifier: GPL-2.0+ |
396138f0 LB |
2 | /* |
3 | * net/dsa/tag_trailer.c - Trailer tag format handling | |
e84665c9 | 4 | * Copyright (c) 2008-2009 Marvell Semiconductor |
396138f0 LB |
5 | */ |
6 | ||
7 | #include <linux/etherdevice.h> | |
8 | #include <linux/list.h> | |
5a0e3ad6 | 9 | #include <linux/slab.h> |
ea5dd34b | 10 | |
bd954b82 | 11 | #include "tag.h" |
396138f0 | 12 | |
94793a56 VO |
13 | #define TRAILER_NAME "trailer" |
14 | ||
4ed70ce9 | 15 | static struct sk_buff *trailer_xmit(struct sk_buff *skb, struct net_device *dev) |
396138f0 | 16 | { |
6ca80638 | 17 | struct dsa_port *dp = dsa_user_to_port(dev); |
396138f0 LB |
18 | u8 *trailer; |
19 | ||
ef3f72fe | 20 | trailer = skb_put(skb, 4); |
396138f0 | 21 | trailer[0] = 0x80; |
d945097b | 22 | trailer[1] = 1 << dp->index; |
396138f0 LB |
23 | trailer[2] = 0x10; |
24 | trailer[3] = 0x00; | |
25 | ||
ef3f72fe | 26 | return skb; |
396138f0 LB |
27 | } |
28 | ||
29a097b7 | 29 | static struct sk_buff *trailer_rcv(struct sk_buff *skb, struct net_device *dev) |
396138f0 | 30 | { |
396138f0 LB |
31 | u8 *trailer; |
32 | int source_port; | |
33 | ||
396138f0 | 34 | if (skb_linearize(skb)) |
54709795 | 35 | return NULL; |
396138f0 LB |
36 | |
37 | trailer = skb_tail_pointer(skb) - 4; | |
38 | if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 || | |
fbd03513 | 39 | (trailer[2] & 0xef) != 0x00 || trailer[3] != 0x00) |
54709795 | 40 | return NULL; |
396138f0 LB |
41 | |
42 | source_port = trailer[1] & 7; | |
3775b1b7 | 43 | |
6ca80638 | 44 | skb->dev = dsa_conduit_find_user(dev, 0, source_port); |
3775b1b7 | 45 | if (!skb->dev) |
54709795 | 46 | return NULL; |
396138f0 | 47 | |
349b71d6 ZJ |
48 | if (pskb_trim_rcsum(skb, skb->len - 4)) |
49 | return NULL; | |
396138f0 | 50 | |
a86d8bec | 51 | return skb; |
396138f0 LB |
52 | } |
53 | ||
f81a43e8 | 54 | static const struct dsa_device_ops trailer_netdev_ops = { |
94793a56 | 55 | .name = TRAILER_NAME, |
056eed2f | 56 | .proto = DSA_TAG_PROTO_TRAILER, |
3e8a72d1 FF |
57 | .xmit = trailer_xmit, |
58 | .rcv = trailer_rcv, | |
4e500251 | 59 | .needed_tailroom = 4, |
396138f0 | 60 | }; |
0b42f033 | 61 | |
0ed6e952 | 62 | MODULE_DESCRIPTION("DSA tag driver for switches using a trailer tag"); |
f18bba50 | 63 | MODULE_LICENSE("GPL"); |
94793a56 | 64 | MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_TRAILER, TRAILER_NAME); |
d3b8c049 AL |
65 | |
66 | module_dsa_tag_driver(trailer_netdev_ops); |