remarkable-linux/net/core/timestamping.c
Daniel Borkmann 408eccce32 net: ptp: move PTP classifier in its own file
This commit fixes a build error reported by Fengguang, that is
triggered when CONFIG_NETWORK_PHY_TIMESTAMPING is not set:

  ERROR: "ptp_classify_raw" [drivers/net/ethernet/oki-semi/pch_gbe/pch_gbe.ko] undefined!

The fix is to introduce its own file for the PTP BPF classifier,
so that PTP_1588_CLOCK and/or NETWORK_PHY_TIMESTAMPING can select
it independently from each other. IXP4xx driver on ARM needs to
select it as well since it does not seem to select PTP_1588_CLOCK
or similar that would pull it in automatically.

This also allows for hiding all of the internals of the BPF PTP
program inside that file, and only exporting relevant API bits
to drivers.

This patch also adds a kdoc documentation of ptp_classify_raw()
API to make it clear that it can return PTP_CLASS_* defines. Also,
the BPF program has been translated into bpf_asm code, so that it
can be more easily read and altered (extensively documented in [1]).

In the kernel tree under tools/net/ we have bpf_asm and bpf_dbg
tools, so the commented program can simply be translated via
`./bpf_asm -c prog` where prog is a file that contains the
commented code. This makes it easily readable/verifiable and when
there's a need to change something, jump offsets etc do not need
to be replaced manually which can be very error prone. Instead,
a newly translated version via bpf_asm can simply replace the old
code. I have checked opcode diffs before/after and it's the very
same filter.

  [1] Documentation/networking/filter.txt

Fixes: 164d8c6665 ("net: ptp: do not reimplement PTP/BPF classifier")
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jiri Benc <jbenc@redhat.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-04-01 16:43:18 -04:00

135 lines
3 KiB
C

/*
* PTP 1588 clock support - support for timestamping in PHY devices
*
* Copyright (C) 2010 OMICRON electronics GmbH
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/errqueue.h>
#include <linux/phy.h>
#include <linux/ptp_classify.h>
#include <linux/skbuff.h>
#include <linux/export.h>
static unsigned int classify(const struct sk_buff *skb)
{
if (likely(skb->dev && skb->dev->phydev &&
skb->dev->phydev->drv))
return ptp_classify_raw(skb);
else
return PTP_CLASS_NONE;
}
void skb_clone_tx_timestamp(struct sk_buff *skb)
{
struct phy_device *phydev;
struct sk_buff *clone;
struct sock *sk = skb->sk;
unsigned int type;
if (!sk)
return;
type = classify(skb);
switch (type) {
case PTP_CLASS_V1_IPV4:
case PTP_CLASS_V1_IPV6:
case PTP_CLASS_V2_IPV4:
case PTP_CLASS_V2_IPV6:
case PTP_CLASS_V2_L2:
case PTP_CLASS_V2_VLAN:
phydev = skb->dev->phydev;
if (likely(phydev->drv->txtstamp)) {
if (!atomic_inc_not_zero(&sk->sk_refcnt))
return;
clone = skb_clone(skb, GFP_ATOMIC);
if (!clone) {
sock_put(sk);
return;
}
clone->sk = sk;
phydev->drv->txtstamp(phydev, clone, type);
}
break;
default:
break;
}
}
EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
void skb_complete_tx_timestamp(struct sk_buff *skb,
struct skb_shared_hwtstamps *hwtstamps)
{
struct sock *sk = skb->sk;
struct sock_exterr_skb *serr;
int err;
if (!hwtstamps) {
sock_put(sk);
kfree_skb(skb);
return;
}
*skb_hwtstamps(skb) = *hwtstamps;
serr = SKB_EXT_ERR(skb);
memset(serr, 0, sizeof(*serr));
serr->ee.ee_errno = ENOMSG;
serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
skb->sk = NULL;
err = sock_queue_err_skb(sk, skb);
sock_put(sk);
if (err)
kfree_skb(skb);
}
EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
bool skb_defer_rx_timestamp(struct sk_buff *skb)
{
struct phy_device *phydev;
unsigned int type;
if (skb_headroom(skb) < ETH_HLEN)
return false;
__skb_push(skb, ETH_HLEN);
type = classify(skb);
__skb_pull(skb, ETH_HLEN);
switch (type) {
case PTP_CLASS_V1_IPV4:
case PTP_CLASS_V1_IPV6:
case PTP_CLASS_V2_IPV4:
case PTP_CLASS_V2_IPV6:
case PTP_CLASS_V2_L2:
case PTP_CLASS_V2_VLAN:
phydev = skb->dev->phydev;
if (likely(phydev->drv->rxtstamp))
return phydev->drv->rxtstamp(phydev, skb, type);
break;
default:
break;
}
return false;
}
EXPORT_SYMBOL_GPL(skb_defer_rx_timestamp);