| Message ID | 20170502101103.30444-5-mlichvar@redhat.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
On Tue, May 2, 2017 at 6:11 AM, Miroslav Lichvar <mlichvar@redhat.com> wrote: > Add SOF_TIMESTAMPING_OPT_PKTINFO option to request a new control message > for incoming packets with hardware timestamps. It contains the index of > the real interface which received the packet and the length of the > packet at layer 2. > > The index is useful with bonding, bridges and other interfaces, where > IP_PKTINFO doesn't allow applications to determine which PHC made the > timestamp. With the L2 length (and link speed) it is possible to > transpose preamble timestamps to trailer timestamps, which are used in > the NTP protocol. > > While this information could be provided by two new socket options > independently from timestamping, it doesn't look like it would be very > useful. With this option any performance impact is limited to hardware > timestamping. > > Use dev_get_by_napi_id() to look up the device and its index. This > limits the option to kernels with enabled CONFIG_NET_RX_BUSY_POLL and > drivers using napi, but it should cover all current MAC drivers that > support hardware timestamping. > > CC: Richard Cochran <richardcochran@gmail.com> > CC: Willem de Bruijn <willemb@google.com> > Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com> > --- > Documentation/networking/timestamping.txt | 8 ++++++++ > include/uapi/asm-generic/socket.h | 2 ++ > include/uapi/linux/net_tstamp.h | 9 ++++++++- > net/socket.c | 30 +++++++++++++++++++++++++++++- > 4 files changed, 47 insertions(+), 2 deletions(-) > > diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt > index 96f5069..6c07e7c 100644 > --- a/Documentation/networking/timestamping.txt > +++ b/Documentation/networking/timestamping.txt > @@ -193,6 +193,14 @@ SOF_TIMESTAMPING_OPT_STATS: > the transmit timestamps, such as how long a certain block of > data was limited by peer's receiver window. > > +SOF_TIMESTAMPING_OPT_PKTINFO: > + > + Enable the SCM_TIMESTAMPING_PKTINFO control message for incoming > + packets with hardware timestamps. The message contains struct > + scm_ts_pktinfo, which supplies the index of the real interface > + which received the packet and its length at layer 2. This option > + works only if CONFIG_NET_RX_BUSY_POLL is enabled. > + > New applications are encouraged to pass SOF_TIMESTAMPING_OPT_ID to > disambiguate timestamps and SOF_TIMESTAMPING_OPT_TSONLY to operate > regardless of the setting of sysctl net.core.tstamp_allow_data. > diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h > index 2b48856..a5f6e81 100644 > --- a/include/uapi/asm-generic/socket.h > +++ b/include/uapi/asm-generic/socket.h > @@ -100,4 +100,6 @@ > > #define SO_COOKIE 57 > > +#define SCM_TIMESTAMPING_PKTINFO 58 > + > #endif /* __ASM_GENERIC_SOCKET_H */ > diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h > index 0749fb1..8fcae35 100644 > --- a/include/uapi/linux/net_tstamp.h > +++ b/include/uapi/linux/net_tstamp.h > @@ -26,8 +26,9 @@ enum { > SOF_TIMESTAMPING_OPT_CMSG = (1<<10), > SOF_TIMESTAMPING_OPT_TSONLY = (1<<11), > SOF_TIMESTAMPING_OPT_STATS = (1<<12), > + SOF_TIMESTAMPING_OPT_PKTINFO = (1<<13), > > - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_STATS, > + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_PKTINFO, > SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | > SOF_TIMESTAMPING_LAST > }; > @@ -130,4 +131,10 @@ enum hwtstamp_rx_filters { > HWTSTAMP_FILTER_NTP_ALL, > }; > > +/* SCM_TIMESTAMPING_PKTINFO control message */ > +struct scm_ts_pktinfo { > + int if_index; > + int pkt_length; > +}; Use fixed width integer types across the ABI. > +static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) > +{ > + struct scm_ts_pktinfo ts_pktinfo; > + struct net_device *orig_dev; > + int ifindex = 0; > + > + if (!skb_mac_header_was_set(skb)) > + return; > + > + rcu_read_lock(); > + orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); > + if (orig_dev) > + ifindex = orig_dev->ifindex; > + rcu_read_unlock(); > + > + if (ifindex == 0) > + return; If the caller requests PKTINFO, it might be better to explicitly return a structure with illegal value 0, than to silently skip the message if no device can be found.
Hi Miroslav,
[auto build test ERROR on net-next/master]
url: https://github.com/0day-ci/linux/commits/Miroslav-Lichvar/Extend-socket-timestamping-API/20170502-212515
config: xtensa-allmodconfig (attached as .config)
compiler: xtensa-linux-gcc (GCC) 4.9.0
reproduce:
wget https://raw.githubusercontent.com/01org/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=xtensa
All errors (new ones prefixed by >>):
net/socket.c: In function 'put_ts_pktinfo':
>> net/socket.c:685:28: error: 'SCM_TIMESTAMPING_PKTINFO' undeclared (first use in this function)
put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO,
^
net/socket.c:685:28: note: each undeclared identifier is reported only once for each function it appears in
vim +/SCM_TIMESTAMPING_PKTINFO +685 net/socket.c
679
680 if (ifindex == 0)
681 return;
682
683 ts_pktinfo.if_index = ifindex;
684 ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb);
> 685 put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO,
686 sizeof(ts_pktinfo), &ts_pktinfo);
687 }
688
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt index 96f5069..6c07e7c 100644 --- a/Documentation/networking/timestamping.txt +++ b/Documentation/networking/timestamping.txt @@ -193,6 +193,14 @@ SOF_TIMESTAMPING_OPT_STATS: the transmit timestamps, such as how long a certain block of data was limited by peer's receiver window. +SOF_TIMESTAMPING_OPT_PKTINFO: + + Enable the SCM_TIMESTAMPING_PKTINFO control message for incoming + packets with hardware timestamps. The message contains struct + scm_ts_pktinfo, which supplies the index of the real interface + which received the packet and its length at layer 2. This option + works only if CONFIG_NET_RX_BUSY_POLL is enabled. + New applications are encouraged to pass SOF_TIMESTAMPING_OPT_ID to disambiguate timestamps and SOF_TIMESTAMPING_OPT_TSONLY to operate regardless of the setting of sysctl net.core.tstamp_allow_data. diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 2b48856..a5f6e81 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -100,4 +100,6 @@ #define SO_COOKIE 57 +#define SCM_TIMESTAMPING_PKTINFO 58 + #endif /* __ASM_GENERIC_SOCKET_H */ diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h index 0749fb1..8fcae35 100644 --- a/include/uapi/linux/net_tstamp.h +++ b/include/uapi/linux/net_tstamp.h @@ -26,8 +26,9 @@ enum { SOF_TIMESTAMPING_OPT_CMSG = (1<<10), SOF_TIMESTAMPING_OPT_TSONLY = (1<<11), SOF_TIMESTAMPING_OPT_STATS = (1<<12), + SOF_TIMESTAMPING_OPT_PKTINFO = (1<<13), - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_STATS, + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_PKTINFO, SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | SOF_TIMESTAMPING_LAST }; @@ -130,4 +131,10 @@ enum hwtstamp_rx_filters { HWTSTAMP_FILTER_NTP_ALL, }; +/* SCM_TIMESTAMPING_PKTINFO control message */ +struct scm_ts_pktinfo { + int if_index; + int pkt_length; +}; + #endif /* _NET_TIMESTAMPING_H */ diff --git a/net/socket.c b/net/socket.c index c2564eb..da4d4ab 100644 --- a/net/socket.c +++ b/net/socket.c @@ -662,6 +662,30 @@ static bool skb_is_err_queue(const struct sk_buff *skb) return skb->pkt_type == PACKET_OUTGOING; } +static void put_ts_pktinfo(struct msghdr *msg, struct sk_buff *skb) +{ + struct scm_ts_pktinfo ts_pktinfo; + struct net_device *orig_dev; + int ifindex = 0; + + if (!skb_mac_header_was_set(skb)) + return; + + rcu_read_lock(); + orig_dev = dev_get_by_napi_id(skb_napi_id(skb)); + if (orig_dev) + ifindex = orig_dev->ifindex; + rcu_read_unlock(); + + if (ifindex == 0) + return; + + ts_pktinfo.if_index = ifindex; + ts_pktinfo.pkt_length = skb->len - skb_mac_offset(skb); + put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING_PKTINFO, + sizeof(ts_pktinfo), &ts_pktinfo); +} + /* * called from sock_recv_timestamp() if sock_flag(sk, SOCK_RCVTSTAMP) */ @@ -699,8 +723,12 @@ void __sock_recv_timestamp(struct msghdr *msg, struct sock *sk, empty = 0; if (shhwtstamps && (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE) && - ktime_to_timespec_cond(shhwtstamps->hwtstamp, tss.ts + 2)) + ktime_to_timespec_cond(shhwtstamps->hwtstamp, tss.ts + 2)) { empty = 0; + if ((sk->sk_tsflags & SOF_TIMESTAMPING_OPT_PKTINFO) && + !skb_is_err_queue(skb)) + put_ts_pktinfo(msg, skb); + } if (!empty) { put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING, sizeof(tss), &tss);
Add SOF_TIMESTAMPING_OPT_PKTINFO option to request a new control message for incoming packets with hardware timestamps. It contains the index of the real interface which received the packet and the length of the packet at layer 2. The index is useful with bonding, bridges and other interfaces, where IP_PKTINFO doesn't allow applications to determine which PHC made the timestamp. With the L2 length (and link speed) it is possible to transpose preamble timestamps to trailer timestamps, which are used in the NTP protocol. While this information could be provided by two new socket options independently from timestamping, it doesn't look like it would be very useful. With this option any performance impact is limited to hardware timestamping. Use dev_get_by_napi_id() to look up the device and its index. This limits the option to kernels with enabled CONFIG_NET_RX_BUSY_POLL and drivers using napi, but it should cover all current MAC drivers that support hardware timestamping. CC: Richard Cochran <richardcochran@gmail.com> CC: Willem de Bruijn <willemb@google.com> Signed-off-by: Miroslav Lichvar <mlichvar@redhat.com> --- Documentation/networking/timestamping.txt | 8 ++++++++ include/uapi/asm-generic/socket.h | 2 ++ include/uapi/linux/net_tstamp.h | 9 ++++++++- net/socket.c | 30 +++++++++++++++++++++++++++++- 4 files changed, 47 insertions(+), 2 deletions(-)