From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta1.migadu.com (out-177.mta1.migadu.com [95.215.58.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 97F3B1A4E68 for ; Mon, 2 Sep 2024 21:07:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725311275; cv=none; b=DZCqkkaNdd+GmRTmgDnxOByEwyWWjXQ/0y5jDkWEgJC6Xkpdw9rT5dByxbLCNqQg0qI3KkWJniGqUeViUVkAN8lnhCKGI+vR+8g9cglJixy5XPr8vHYhO/+BsDOTCY7WWbSgMFvWeE6xZeI4MU2AUF01KPVoDHPFpQvNhhTZtWI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725311275; c=relaxed/simple; bh=Dh5EkpXWeSXt9AFfRMaHgznJAqJzuiGoavSzLtHbr9s=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tZciHLlOjEFVMGj7ym9pbX52+pq7xSCvIOUC2XtUWrbyL6bQL5VrBF4tiRQDk71Fha0ub1zdSep9ieDIfXBImX2fAtf0pkJI0nOAEQbdYVcFjQjPo9c7gVaJX6vISiVEuh+HDnq3ZLlXwfi1o+Ma2uuDXQptQCUbiU8qi2BDhd8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=o2MoCw2c; arc=none smtp.client-ip=95.215.58.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="o2MoCw2c" Message-ID: <932f7ff3-6087-47cf-91ec-2601da38ebec@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1725311270; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BOewuayuLgmL5QXzQohaPfQDGU58cyLGAVPHaiVzZZM=; b=o2MoCw2c0S1OcS0Kj7HIAoQqZWjGfNoqKs94kZ2GGuwiYgUAmTQbFyH9H8SJkUn5wFHCgG FxoZeXhrjy9+7kcZauejB5Zz3+6eOm6TAapiR/RCdTVEH175prieT0thgTHVvyu0sS8jGb FBpvmBe1VfO9OU0OFdMOd60yWtmx97k= Date: Mon, 2 Sep 2024 22:07:44 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH net-next v2 1/2] net_tstamp: add SCM_TS_OPT_ID to provide OPT_ID in control message To: Willem de Bruijn , Willem de Bruijn Cc: netdev@vger.kernel.org, Jakub Kicinski , Jason Xing , Paolo Abeni , David Ahern References: <20240902130937.457115-1-vadfed@meta.com> <66d5cbbba9669_6138829497@willemb.c.googlers.com.notmuch> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Vadim Fedorenko In-Reply-To: <66d5cbbba9669_6138829497@willemb.c.googlers.com.notmuch> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 02/09/2024 15:29, Willem de Bruijn wrote: > Vadim Fedorenko wrote: >> SOF_TIMESTAMPING_OPT_ID socket option flag gives a way to correlate TX >> timestamps and packets sent via socket. Unfortunately, there is no way >> to reliably predict socket timestamp ID value in case of error returned >> by sendmsg. For UDP sockets it's impossible because of lockless >> nature of UDP transmit, several threads may send packets in parallel. In >> case of RAW sockets MSG_MORE option makes things complicated. More >> details are in the conversation [1]. >> This patch adds new control message type to give user-space >> software an opportunity to control the mapping between packets and >> values by providing ID with each sendmsg. This works fine for UDP >> sockets only, and explicit check is added to control message parser. >> >> [1] https://lore.kernel.org/netdev/CALCETrU0jB+kg0mhV6A8mrHfTE1D1pr1SD_B9Eaa9aDPfgHdtA@mail.gmail.com/ >> >> Signed-off-by: Vadim Fedorenko >> --- >> Documentation/networking/timestamping.rst | 14 ++++++++++++++ >> arch/alpha/include/uapi/asm/socket.h | 4 +++- >> arch/mips/include/uapi/asm/socket.h | 2 ++ >> arch/parisc/include/uapi/asm/socket.h | 2 ++ >> arch/sparc/include/uapi/asm/socket.h | 2 ++ >> include/net/inet_sock.h | 4 +++- >> include/net/sock.h | 1 + >> include/uapi/asm-generic/socket.h | 2 ++ >> include/uapi/linux/net_tstamp.h | 3 ++- >> net/core/sock.c | 12 ++++++++++++ >> net/ethtool/common.c | 1 + >> net/ipv4/ip_output.c | 16 ++++++++++++---- >> net/ipv6/ip6_output.c | 16 ++++++++++++---- >> 13 files changed, 68 insertions(+), 11 deletions(-) >> >> diff --git a/Documentation/networking/timestamping.rst b/Documentation/networking/timestamping.rst >> index 5e93cd71f99f..93b0901e4e8e 100644 >> --- a/Documentation/networking/timestamping.rst >> +++ b/Documentation/networking/timestamping.rst >> @@ -193,6 +193,20 @@ SOF_TIMESTAMPING_OPT_ID: >> among all possibly concurrently outstanding timestamp requests for >> that socket. >> >> + With this option enabled user-space application can provide custom >> + ID for each message sent via UDP socket with control message with >> + type set to SCM_TS_OPT_ID:: >> + >> + struct msghdr *msg; >> + ... >> + cmsg = CMSG_FIRSTHDR(msg); >> + cmsg->cmsg_level = SOL_SOCKET; >> + cmsg->cmsg_type = SO_TIMESTAMPING; >> + cmsg->cmsg_len = CMSG_LEN(sizeof(__u32)); >> + *((__u32 *) CMSG_DATA(cmsg)) = opt_id; >> + err = sendmsg(fd, msg, 0); >> + > > Please make it clear that this CMSG is optional. > > The process can optionally override the default generated ID, by > passing a specific ID with control message SCM_TS_OPT_ID: Ok, I'll re-phrase it this way, thanks! >> SOF_TIMESTAMPING_OPT_ID_TCP: >> Pass this modifier along with SOF_TIMESTAMPING_OPT_ID for new TCP >> timestamping applications. SOF_TIMESTAMPING_OPT_ID defines how the >> diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h >> index e94f621903fe..0698e6662cdf 100644 >> --- a/arch/alpha/include/uapi/asm/socket.h >> +++ b/arch/alpha/include/uapi/asm/socket.h >> @@ -10,7 +10,7 @@ >> * Note: we only bother about making the SOL_SOCKET options >> * same as OSF/1, as that's all that "normal" programs are >> * likely to set. We don't necessarily want to be binary >> - * compatible with _everything_. >> + * compatible with _everything_. > > Is this due to a checkpatch warning? If so, please add a brief comment > to the commit message to show that this change is intentional. If not, > please don't touch unrelated code. I'll remove it, because it looks like it was some unhappy linter... >> */ >> #define SOL_SOCKET 0xffff >> >> @@ -140,6 +140,8 @@ >> #define SO_PASSPIDFD 76 >> #define SO_PEERPIDFD 77 >> >> +#define SCM_TS_OPT_ID 78 >> + >> #if !defined(__KERNEL__) >> >> #if __BITS_PER_LONG == 64 >> diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h >> index 60ebaed28a4c..bb3dc8feb205 100644 >> --- a/arch/mips/include/uapi/asm/socket.h >> +++ b/arch/mips/include/uapi/asm/socket.h >> @@ -151,6 +151,8 @@ >> #define SO_PASSPIDFD 76 >> #define SO_PEERPIDFD 77 >> >> +#define SCM_TS_OPT_ID 78 >> + >> #if !defined(__KERNEL__) >> >> #if __BITS_PER_LONG == 64 >> diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h >> index be264c2b1a11..c3ab3b3289eb 100644 >> --- a/arch/parisc/include/uapi/asm/socket.h >> +++ b/arch/parisc/include/uapi/asm/socket.h >> @@ -132,6 +132,8 @@ >> #define SO_PASSPIDFD 0x404A >> #define SO_PEERPIDFD 0x404B >> >> +#define SCM_TS_OPT_ID 0x404C >> + >> #if !defined(__KERNEL__) >> >> #if __BITS_PER_LONG == 64 >> diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h >> index 682da3714686..9b40f0a57fbc 100644 >> --- a/arch/sparc/include/uapi/asm/socket.h >> +++ b/arch/sparc/include/uapi/asm/socket.h >> @@ -133,6 +133,8 @@ >> #define SO_PASSPIDFD 0x0055 >> #define SO_PEERPIDFD 0x0056 >> >> +#define SCM_TS_OPT_ID 0x0057 >> + >> #if !defined(__KERNEL__) >> >> >> diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h >> index 394c3b66065e..2161d50cf0fd 100644 >> --- a/include/net/inet_sock.h >> +++ b/include/net/inet_sock.h >> @@ -174,6 +174,7 @@ struct inet_cork { >> __s16 tos; >> char priority; >> __u16 gso_size; >> + u32 ts_opt_id; >> u64 transmit_time; >> u32 mark; >> }; >> @@ -241,7 +242,8 @@ struct inet_sock { >> struct inet_cork_full cork; >> }; >> >> -#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */ >> +#define IPCORK_OPT 1 /* ip-options has been held in ipcork.opt */ >> +#define IPCORK_TS_OPT_ID 2 /* timestmap opt id has been provided in cmsg */ > > typo: timestamp > > And maybe more relevant: /* ts_opt_id field is valid, overriding sk_tskey */ I'll change it >> enum { >> INET_FLAGS_PKTINFO = 0, >> diff --git a/include/net/sock.h b/include/net/sock.h >> index f51d61fab059..73e21dad5660 100644 >> --- a/include/net/sock.h >> +++ b/include/net/sock.h >> @@ -1794,6 +1794,7 @@ struct sockcm_cookie { >> u64 transmit_time; >> u32 mark; >> u32 tsflags; >> + u32 ts_opt_id; >> }; >> >> static inline void sockcm_init(struct sockcm_cookie *sockc, >> diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h >> index 8ce8a39a1e5f..db3df3e74b01 100644 >> --- a/include/uapi/asm-generic/socket.h >> +++ b/include/uapi/asm-generic/socket.h >> @@ -135,6 +135,8 @@ >> #define SO_PASSPIDFD 76 >> #define SO_PEERPIDFD 77 >> >> +#define SCM_TS_OPT_ID 78 > > nit: different indentation Hmm... that's interesting, it's ok in the code, there no spaces before #define. I'll re-check it in the patch in v3. >> + >> #if !defined(__KERNEL__) >> >> #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__)) >> diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h >> index a2c66b3d7f0f..e2f145e3f3a1 100644 >> --- a/include/uapi/linux/net_tstamp.h >> +++ b/include/uapi/linux/net_tstamp.h >> @@ -32,8 +32,9 @@ enum { >> SOF_TIMESTAMPING_OPT_TX_SWHW = (1<<14), >> SOF_TIMESTAMPING_BIND_PHC = (1 << 15), >> SOF_TIMESTAMPING_OPT_ID_TCP = (1 << 16), >> + SOF_TIMESTAMPING_OPT_ID_CMSG = (1 << 17), >> >> - SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_ID_TCP, >> + SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_ID_CMSG, >> SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) | >> SOF_TIMESTAMPING_LAST >> }; >> diff --git a/net/core/sock.c b/net/core/sock.c >> index 468b1239606c..560b075765fa 100644 >> --- a/net/core/sock.c >> +++ b/net/core/sock.c >> @@ -2859,6 +2859,18 @@ int __sock_cmsg_send(struct sock *sk, struct cmsghdr *cmsg, >> return -EINVAL; >> sockc->transmit_time = get_unaligned((u64 *)CMSG_DATA(cmsg)); >> break; >> + case SCM_TS_OPT_ID: >> + /* allow this option for UDP sockets only */ >> + if (!sk_is_udp(sk)) >> + return -EINVAL; > > Let's relax the restriction that this is only for UDP. > > At least to also support SOCK_RAW. I don't think that requires any > additional code at all? RAW sockets use skb_setup_tx_timestamps which does atomic operation of incrementing sk_tskey when in _sock_tx_timestamp. So I'll have to convert all spots (can, ipv4/raw, ipv6/raw, 3 x af_packet) to use the same logic as in udp path (sock_tx_timestamp) and add conditions. Or change skb_setup_tx_timestamps to do the logic and take different arguments. It may look as a big refactoring, so I would like to make it as a follow-up series. > Extending to TCP should be straightforward too, just a branch > on sockc in tcp_tx_timestamp. TCP part looks a bit easier, as you said, I have to adjust tcp_tx_timestamp and the logic is straightforward. I still have to provide a pointer to sock coockie instead of flags, but there is only one caller of this function and it's much easier than with RAW sockets. > If so, let's support all. It makes for a simpler API if it is > supported uniformly wherever OPT_ID is. If you think that the way I explained for RAW sockets is good enough, I can send all of them as a single patcheset. Otherwise I would like to add RAW sockets in follow-up series. >> + tsflags = READ_ONCE(sk->sk_tsflags); >> + if (!(tsflags & SOF_TIMESTAMPING_OPT_ID)) >> + return -EINVAL; >> + if (cmsg->cmsg_len != CMSG_LEN(sizeof(u32))) >> + return -EINVAL; >> + sockc->ts_opt_id = *(u32 *)CMSG_DATA(cmsg); >> + sockc->tsflags |= SOF_TIMESTAMPING_OPT_ID_CMSG; >> + break; >> /* SCM_RIGHTS and SCM_CREDENTIALS are semantically in SOL_UNIX. */ >> case SCM_RIGHTS: >> case SCM_CREDENTIALS: