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 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 }