LXR linux/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
  26static struct sock_filter ptp_filter[] = {
  27        PTP_FILTER
  28};
  29
  30static 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
  40void 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}
  76EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
  77
  78void 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}
 102EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
 103
 104bool 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}
 134EXPORT_SYMBOL_GPL(skb_defer_rx_timestamp);
 135
 136void __init skb_timestamping_init(void)
 137{
 138        BUG_ON(sk_chk_filter(ptp_filter, ARRAY_SIZE(ptp_filter)));
 139}
 140