1/*
2 * PTP 1588 clock support - support for timestamping in PHY devices
3 *
4 * Copyright (C) 2010 OMICRON electronics GmbH
5 *
6 *  This program is free software; you can redistribute it and/or modify
7 *  it under the terms of the GNU General Public License as published by
8 *  the Free Software Foundation; either version 2 of the License, or
9 *  (at your option) any later version.
10 *
11 *  This program is distributed in the hope that it will be useful,
12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14 *  GNU General Public License for more details.
15 *
16 *  You should have received a copy of the GNU General Public License
17 *  along with this program; if not, write to the Free Software
18 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20#include <linux/errqueue.h>
21#include <linux/phy.h>
22#include <linux/ptp_classify.h>
23#include <linux/skbuff.h>
24
25static struct sock_filter ptp_filter[] = {
26	PTP_FILTER
27};
28
29static unsigned int classify(struct sk_buff *skb)
30{
31	if (likely(skb->dev &&
32		   skb->dev->phydev &&
33		   skb->dev->phydev->drv))
34		return sk_run_filter(skb, ptp_filter, ARRAY_SIZE(ptp_filter));
35	else
36		return PTP_CLASS_NONE;
37}
38
39void skb_clone_tx_timestamp(struct sk_buff *skb)
40{
41	struct phy_device *phydev;
42	struct sk_buff *clone;
43	struct sock *sk = skb->sk;
44	unsigned int type;
45
46	if (!sk)
47		return;
48
49	type = classify(skb);
50
51	switch (type) {
52	case PTP_CLASS_V1_IPV4:
53	case PTP_CLASS_V1_IPV6:
54	case PTP_CLASS_V2_IPV4:
55	case PTP_CLASS_V2_IPV6:
56	case PTP_CLASS_V2_L2:
57	case PTP_CLASS_V2_VLAN:
58		phydev = skb->dev->phydev;
59		if (likely(phydev->drv->txtstamp)) {
60			clone = skb_clone(skb, GFP_ATOMIC);
61			if (!clone)
62				return;
63			clone->sk = sk;
64			phydev->drv->txtstamp(phydev, clone, type);
65		}
66		break;
67	default:
68		break;
69	}
70}
71
72void skb_complete_tx_timestamp(struct sk_buff *skb,
73			       struct skb_shared_hwtstamps *hwtstamps)
74{
75	struct sock *sk = skb->sk;
76	struct sock_exterr_skb *serr;
77	int err;
78
79	if (!hwtstamps)
80		return;
81
82	*skb_hwtstamps(skb) = *hwtstamps;
83	serr = SKB_EXT_ERR(skb);
84	memset(serr, 0, sizeof(*serr));
85	serr->ee.ee_errno = ENOMSG;
86	serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
87	skb->sk = NULL;
88	err = sock_queue_err_skb(sk, skb);
89	if (err)
90		kfree_skb(skb);
91}
92EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
93
94bool skb_defer_rx_timestamp(struct sk_buff *skb)
95{
96	struct phy_device *phydev;
97	unsigned int type;
98
99	if (skb_headroom(skb) < ETH_HLEN)
100		return false;
101	__skb_push(skb, ETH_HLEN);
102
103	type = classify(skb);
104
105	__skb_pull(skb, ETH_HLEN);
106
107	switch (type) {
108	case PTP_CLASS_V1_IPV4:
109	case PTP_CLASS_V1_IPV6:
110	case PTP_CLASS_V2_IPV4:
111	case PTP_CLASS_V2_IPV6:
112	case PTP_CLASS_V2_L2:
113	case PTP_CLASS_V2_VLAN:
114		phydev = skb->dev->phydev;
115		if (likely(phydev->drv->rxtstamp))
116			return phydev->drv->rxtstamp(phydev, skb, type);
117		break;
118	default:
119		break;
120	}
121
122	return false;
123}
124
125void __init skb_timestamping_init(void)
126{
127	BUG_ON(sk_chk_filter(ptp_filter, ARRAY_SIZE(ptp_filter)));
128}
129