net/core/timestamping.c

   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 unsigned int classify(const struct sk_buff *skb)
  27 {
  28         if (likely(skb->dev && skb->dev->phydev &&
  29                    skb->dev->phydev->drv))
  30                 return ptp_classify_raw(skb);
  31         else
  32                 return PTP_CLASS_NONE;
  33 }
  34
  35 void skb_clone_tx_timestamp(struct sk_buff *skb)
  36 {
  37         struct phy_device *phydev;
  38         struct sk_buff *clone;
  39         unsigned int type;
  40
  41         if (!skb->sk)
  42                 return;
  43
  44         type = classify(skb);
  45         if (type == PTP_CLASS_NONE)
  46                 return;
  47
  48         phydev = skb->dev->phydev;
  49         if (likely(phydev->drv->txtstamp)) {
  50                 clone = skb_clone_sk(skb);
  51                 if (!clone)
  52                         return;
  53                 phydev->drv->txtstamp(phydev, clone, type);
  54         }
  55 }
  56 EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
  57
  58 bool skb_defer_rx_timestamp(struct sk_buff *skb)
  59 {
  60         struct phy_device *phydev;
  61         unsigned int type;
  62
  63         if (skb_headroom(skb) < ETH_HLEN)
  64                 return false;
  65         __skb_push(skb, ETH_HLEN);
  66
  67         type = classify(skb);
  68
  69         __skb_pull(skb, ETH_HLEN);
  70
  71         if (type == PTP_CLASS_NONE)
  72                 return false;
  73
  74         phydev = skb->dev->phydev;
  75         if (likely(phydev->drv->rxtstamp))
  76                 return phydev->drv->rxtstamp(phydev, skb, type);
  77
  78         return false;
  79 }
  80 EXPORT_SYMBOL_GPL(skb_defer_rx_timestamp);