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
  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                         if (!atomic_inc_not_zero(&sk->sk_refcnt))
  61                                 return;
  62                         clone = skb_clone(skb, GFP_ATOMIC);
  63                         if (!clone) {
  64                                 sock_put(sk);
  65                                 return;
  66                         }
  67                         clone->sk = sk;
  68                         phydev->drv->txtstamp(phydev, clone, type);
  69                 }
  70                 break;
  71         default:
  72                 break;
  73         }
  74 }
  75 EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
  76
  77 void skb_complete_tx_timestamp(struct sk_buff *skb,
  78                                struct skb_shared_hwtstamps *hwtstamps)
  79 {
  80         struct sock *sk = skb->sk;
  81         struct sock_exterr_skb *serr;
  82         int err;
  83
  84         if (!hwtstamps) {
  85                 sock_put(sk);
  86                 kfree_skb(skb);
  87                 return;
  88         }
  89
  90         *skb_hwtstamps(skb) = *hwtstamps;
  91         serr = SKB_EXT_ERR(skb);
  92         memset(serr, 0, sizeof(*serr));
  93         serr->ee.ee_errno = ENOMSG;
  94         serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
  95         skb->sk = NULL;
  96         err = sock_queue_err_skb(sk, skb);
  97         sock_put(sk);
  98         if (err)
  99                 kfree_skb(skb);
 100 }
 101 EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
 102
 103 bool skb_defer_rx_timestamp(struct sk_buff *skb)
 104 {
 105         struct phy_device *phydev;
 106         unsigned int type;
 107
 108         if (skb_headroom(skb) < ETH_HLEN)
 109                 return false;
 110         __skb_push(skb, ETH_HLEN);
 111
 112         type = classify(skb);
 113
 114         __skb_pull(skb, ETH_HLEN);
 115
 116         switch (type) {
 117         case PTP_CLASS_V1_IPV4:
 118         case PTP_CLASS_V1_IPV6:
 119         case PTP_CLASS_V2_IPV4:
 120         case PTP_CLASS_V2_IPV6:
 121         case PTP_CLASS_V2_L2:
 122         case PTP_CLASS_V2_VLAN:
 123                 phydev = skb->dev->phydev;
 124                 if (likely(phydev->drv->rxtstamp))
 125                         return phydev->drv->rxtstamp(phydev, skb, type);
 126                 break;
 127         default:
 128                 break;
 129         }
 130
 131         return false;
 132 }
 133 EXPORT_SYMBOL_GPL(skb_defer_rx_timestamp);
 134
 135 void __init skb_timestamping_init(void)
 136 {
 137         BUG_ON(sk_chk_filter(ptp_filter, ARRAY_SIZE(ptp_filter)));
 138 }