xref: /linux/net/core/timestamping.c (revision d524dac9279b6a41ffdf7ff7958c577f2e387db6)
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 
25 static struct sock_filter ptp_filter[] = {
26 	PTP_FILTER
27 };
28 
29 static unsigned int classify(const 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);
35 	else
36 		return PTP_CLASS_NONE;
37 }
38 
39 void 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 
72 void 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 }
92 EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
93 
94 bool 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 
125 void __init skb_timestamping_init(void)
126 {
127 	BUG_ON(sk_chk_filter(ptp_filter, ARRAY_SIZE(ptp_filter)));
128 }
129