xref: /openbmc/linux/net/core/timestamping.c (revision 12eb4683)
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 #include <linux/export.h>
25 
26 static struct sock_filter ptp_filter[] = {
27 	PTP_FILTER
28 };
29 
30 static unsigned int classify(const struct sk_buff *skb)
31 {
32 	if (likely(skb->dev &&
33 		   skb->dev->phydev &&
34 		   skb->dev->phydev->drv))
35 		return sk_run_filter(skb, ptp_filter);
36 	else
37 		return PTP_CLASS_NONE;
38 }
39 
40 void skb_clone_tx_timestamp(struct sk_buff *skb)
41 {
42 	struct phy_device *phydev;
43 	struct sk_buff *clone;
44 	struct sock *sk = skb->sk;
45 	unsigned int type;
46 
47 	if (!sk)
48 		return;
49 
50 	type = classify(skb);
51 
52 	switch (type) {
53 	case PTP_CLASS_V1_IPV4:
54 	case PTP_CLASS_V1_IPV6:
55 	case PTP_CLASS_V2_IPV4:
56 	case PTP_CLASS_V2_IPV6:
57 	case PTP_CLASS_V2_L2:
58 	case PTP_CLASS_V2_VLAN:
59 		phydev = skb->dev->phydev;
60 		if (likely(phydev->drv->txtstamp)) {
61 			if (!atomic_inc_not_zero(&sk->sk_refcnt))
62 				return;
63 			clone = skb_clone(skb, GFP_ATOMIC);
64 			if (!clone) {
65 				sock_put(sk);
66 				return;
67 			}
68 			clone->sk = sk;
69 			phydev->drv->txtstamp(phydev, clone, type);
70 		}
71 		break;
72 	default:
73 		break;
74 	}
75 }
76 EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
77 
78 void skb_complete_tx_timestamp(struct sk_buff *skb,
79 			       struct skb_shared_hwtstamps *hwtstamps)
80 {
81 	struct sock *sk = skb->sk;
82 	struct sock_exterr_skb *serr;
83 	int err;
84 
85 	if (!hwtstamps) {
86 		sock_put(sk);
87 		kfree_skb(skb);
88 		return;
89 	}
90 
91 	*skb_hwtstamps(skb) = *hwtstamps;
92 	serr = SKB_EXT_ERR(skb);
93 	memset(serr, 0, sizeof(*serr));
94 	serr->ee.ee_errno = ENOMSG;
95 	serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
96 	skb->sk = NULL;
97 	err = sock_queue_err_skb(sk, skb);
98 	sock_put(sk);
99 	if (err)
100 		kfree_skb(skb);
101 }
102 EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
103 
104 bool skb_defer_rx_timestamp(struct sk_buff *skb)
105 {
106 	struct phy_device *phydev;
107 	unsigned int type;
108 
109 	if (skb_headroom(skb) < ETH_HLEN)
110 		return false;
111 	__skb_push(skb, ETH_HLEN);
112 
113 	type = classify(skb);
114 
115 	__skb_pull(skb, ETH_HLEN);
116 
117 	switch (type) {
118 	case PTP_CLASS_V1_IPV4:
119 	case PTP_CLASS_V1_IPV6:
120 	case PTP_CLASS_V2_IPV4:
121 	case PTP_CLASS_V2_IPV6:
122 	case PTP_CLASS_V2_L2:
123 	case PTP_CLASS_V2_VLAN:
124 		phydev = skb->dev->phydev;
125 		if (likely(phydev->drv->rxtstamp))
126 			return phydev->drv->rxtstamp(phydev, skb, type);
127 		break;
128 	default:
129 		break;
130 	}
131 
132 	return false;
133 }
134 EXPORT_SYMBOL_GPL(skb_defer_rx_timestamp);
135 
136 void __init skb_timestamping_init(void)
137 {
138 	BUG_ON(sk_chk_filter(ptp_filter, ARRAY_SIZE(ptp_filter)));
139 }
140