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         struct sock *sk = skb->sk;
  40         unsigned int type;
  41
  42         if (!sk)
  43                 return;
  44
  45         type = classify(skb);
  46
  47         switch (type) {
  48         case PTP_CLASS_V1_IPV4:
  49         case PTP_CLASS_V1_IPV6:
  50         case PTP_CLASS_V2_IPV4:
  51         case PTP_CLASS_V2_IPV6:
  52         case PTP_CLASS_V2_L2:
  53         case PTP_CLASS_V2_VLAN:
  54                 phydev = skb->dev->phydev;
  55                 if (likely(phydev->drv->txtstamp)) {
  56                         if (!atomic_inc_not_zero(&sk->sk_refcnt))
  57                                 return;
  58
  59                         clone = skb_clone(skb, GFP_ATOMIC);
  60                         if (!clone) {
  61                                 sock_put(sk);
  62                                 return;
  63                         }
  64
  65                         clone->sk = sk;
  66                         phydev->drv->txtstamp(phydev, clone, type);
  67                 }
  68                 break;
  69         default:
  70                 break;
  71         }
  72 }
  73 EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
  74
  75 void skb_complete_tx_timestamp(struct sk_buff *skb,
  76                                struct skb_shared_hwtstamps *hwtstamps)
  77 {
  78         struct sock *sk = skb->sk;
  79         struct sock_exterr_skb *serr;
  80         int err;
  81
  82         if (!hwtstamps) {
  83                 sock_put(sk);
  84                 kfree_skb(skb);
  85                 return;
  86         }
  87
  88         *skb_hwtstamps(skb) = *hwtstamps;
  89
  90         serr = SKB_EXT_ERR(skb);
  91         memset(serr, 0, sizeof(*serr));
  92         serr->ee.ee_errno = ENOMSG;
  93         serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
  94         skb->sk = NULL;
  95
  96         err = sock_queue_err_skb(sk, skb);
  97
  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);