July 2018 - mptcp - Ml01.01.Org

One approach to indirect call optimization

by Mat Martineau

I noticed this patch on netdev to avoid an indirect call to md5_lookup, which was accepted. It is mitigating the cost of an existing indirect call rather than adding a new one, but shows how the maintainers are looking at the problem. -- Mat Martineau Intel OTC ---------- Forwarded message ---------- Date: Mon, 23 Apr 2018 14:46:25 From: Eric Dumazet <edumazet(a)google.com> To: David S . Miller <davem(a)davemloft.net> Cc: netdev <netdev(a)vger.kernel.org>, Eric Dumazet <edumazet(a)google.com>, Eric Dumazet <eric.dumazet(a)gmail.com> Subject: [PATCH net-next] tcp: md5: only call tp->af_specific->md5_lookup() for md5 sockets RETPOLINE made calls to tp->af_specific->md5_lookup() quite expensive, given they have no result. We can omit the calls for sockets that have no md5 keys. Signed-off-by: Eric Dumazet <edumazet(a)google.com> --- net/ipv4/tcp_output.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 383cac0ff0ec059ca7dbc1a6304cc7f8183e008d..95feffb6d53f8a9eadfb15a2fffeec498d6e993a 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -585,14 +585,15 @@ static unsigned int tcp_syn_options(struct sock *sk, struct sk_buff *skb, unsigned int remaining = MAX_TCP_OPTION_SPACE; struct tcp_fastopen_request *fastopen = tp->fastopen_req; + *md5 = NULL; #ifdef CONFIG_TCP_MD5SIG - *md5 = tp->af_specific->md5_lookup(sk, sk); - if (*md5) { - opts->options |= OPTION_MD5; - remaining -= TCPOLEN_MD5SIG_ALIGNED; + if (unlikely(rcu_access_pointer(tp->md5sig_info))) { + *md5 = tp->af_specific->md5_lookup(sk, sk); + if (*md5) { + opts->options |= OPTION_MD5; + remaining -= TCPOLEN_MD5SIG_ALIGNED; + } } -#else - *md5 = NULL; #endif /* We always get an MSS option. The option bytes which will be seen in @@ -720,14 +721,15 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb opts->options = 0; + *md5 = NULL; #ifdef CONFIG_TCP_MD5SIG - *md5 = tp->af_specific->md5_lookup(sk, sk); - if (unlikely(*md5)) { - opts->options |= OPTION_MD5; - size += TCPOLEN_MD5SIG_ALIGNED; + if (unlikely(rcu_access_pointer(tp->md5sig_info))) { + *md5 = tp->af_specific->md5_lookup(sk, sk); + if (*md5) { + opts->options |= OPTION_MD5; + size += TCPOLEN_MD5SIG_ALIGNED; + } } -#else - *md5 = NULL; #endif if (likely(tp->rx_opt.tstamp_ok)) { -- 2.17.0.484.g0c8726318c-goog

3 years, 9 months

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Weekly meeting - 1 August 2018 16:00 UTC (9am PDT, 6pm CEST)

by Matthieu Baerts

Hello, Our public MPTCP upstreaming weekly web conference is scheduled for tomorrow. The list of topics is here: https://annuel2.framapad.org/p/mptcp_upstreaming_20180801 Feel free to add/modify topics! Meeting link: https://talky.io/mptcp_upstreaming Speak to you tomorrow! Matthieu -- Matthieu Baerts | R&D Engineer matthieu.baerts(a)tessares.net Tessares SA | Hybrid Access Solutions www.tessares.net 1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium -- DISCLAIMER. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.

4 years, 1 month

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Internet Draft regarding 5G Security

by Naresh Kumar

Sir, I have submitted an Internet-Draft regarding Security issues and resolving them. You can see the draft at the following link: https://datatracker.ietf.org/submit/status/97278/c98380e8f51866cdc271f87c...

4 years, 2 months

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[Weekly meetings] MoM - 26th of July 2018

by Matthieu Baerts

Hello, We just had our 15th meeting with Mat, Ossama, Peter (Intel OTC), Christoph (Apple) and myself (Tessares). Thanks again for this new good meeting! Here are the minutes of the meeting: Linux Plumber: - we sent a proposition of talk but no news - now a 2-days track - there are new announcements on the list (new talks accepted) mptcp_net-next: - new patches (3) are coming from mptcp_trunk (and applied) - sync with net-next done by Mat - Christoph will look at upstreaming MPTCPv1 (first on mptcp_trunk) Netdev's debriefing: - we got good feedbacks: - people want to have MPTCP upstream and are supportive (Tom Herbert and Eric Dumazet) - some concerns about not modifying binaries and still use MPTCP (without LD_PRELOAD), something possible with mptcp_trunk. - there were some discussions/reminders about using per cgroups ebpf hooks (e.g. for API extension): - BPF/netdev background: http://vger.kernel.org/netconf2018_files/AlexeiStarovoitov_netconf2018.pdf - skb buff: we got advises from Eric Dumazet: add a pointer at the end is no longer costly (see the next topic) - changes in TCP stack: we didn't got propositions/discussions about that, what we could do then: - either propose code change (RFC) - having other possibilities to talk about architecture - RFC about a design/API (internal API first before exposing that to userspace) - for the userspace API, it could be nice to expose subflows or only a part of them (err queue, send queue info) Mat and Peter's patches: - can be updated after Eric Dumazet comments: - it is fine to add a few bytes *as long as we don't touch them* (not to affect cache misses) - "size doesn't matter"... he said (somehow) - Mat: could still be good to check if we need a separated queue - Christoph: callback + memory generator: - could be good in case of splitting (tcp_fragment: to point to the same memory if it is linked to the same DSS) - should be ok for the incoming and outgoing path - TODO: write in the wiki a design based on Eric's idea (adding a few bytes at the end of the SKB is OK) - Mat will start that and share the wiki page. Next steps: - Peter: working on MP_JOIN stuff - Christoph: MPTCPv1 + bug fixes + test mptcp_net-next - Mat: new design + new test setup between two VMs but difficult to track regression (for mptcp_net-next) - Matth: use recent kernel and try to test mptcp_net-next with our test-suite. + update netlink code after that. - Ossama: more debugging on userspace code Next meeting: - We propose to have it next Wednesday this time to have more people available, the 1st of August then. Usual time 9am PDT - 16:00 UTC (9am PDT, 6pm CEST) - Still open to everyone! - https://annuel2.framapad.org/p/mptcp_upstreaming_20180801 Feel free to comment on these points and propose new ones for the next meeting! Talk to you next week, Matthieu -- Matthieu Baerts | R&D Engineer matthieu.baerts(a)tessares.net Tessares SA | Hybrid Access Solutions www.tessares.net 1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium -- DISCLAIMER. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.

4 years, 2 months

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[PATCH 0/2] Forward-ports from mptcp_trunk

by Christoph Paasch

Two of the recent additions to mptcp_trunk. Christoph Paasch (2): mptcp: Fix: Correct version-negotiation when SYN-cookies are set mptcp: Disable MPTCP when interface is non-MPTCP include/net/mptcp.h | 6 +++--- net/mptcp/mptcp_ctrl.c | 29 +++++++++++++++++++++-------- 2 files changed, 24 insertions(+), 11 deletions(-) -- 2.16.2

4 years, 2 months

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Weekly meeting - 26 July 2018 16:00 UTC (9am PDT, 6pm CEST)

by Matthieu Baerts

Hello, Our public MPTCP upstreaming weekly web conference is scheduled for tomorrow. The list of topics is here: https://annuel2.framapad.org/p/mptcp_upstreaming_20180726 Feel free to add/modify topics! Meeting link: https://talky.io/mptcp_upstreaming Speak to you tomorrow! Matthieu -- Matthieu Baerts | R&D Engineer matthieu.baerts(a)tessares.net Tessares SA | Hybrid Access Solutions www.tessares.net 1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium -- DISCLAIMER. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.

4 years, 2 months

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[PATCH] mptcp:fullmesh: fix compilation warning if no IPv6

by Christoph Paasch

From: Matthieu Baerts <matthieu.baerts(a)tessares.net> if_idx would be seen as an unitialized variable even if it should never happen in case of !CONFIG_IPV6. But let makes the compiler happy! Fixes: 9e763119cccc6 (mptcp: Check interface index in fullmesh pm) Signed-off-by: Matthieu Baerts <matthieu.baerts(a)tessares.net> Signed-off-by: Christoph Paasch <cpaasch(a)apple.com> (cherry picked from commit e2b2f250f15fe9c4442483c1263af83cf8d8a0d5) Signed-off-by: Christoph Paasch <cpaasch(a)apple.com> --- net/mptcp/mptcp_fullmesh.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/mptcp/mptcp_fullmesh.c b/net/mptcp/mptcp_fullmesh.c index cbeea9b83910..1e12af79a1b8 100644 --- a/net/mptcp/mptcp_fullmesh.c +++ b/net/mptcp/mptcp_fullmesh.c @@ -1301,9 +1301,9 @@ static void full_mesh_new_session(const struct sock *meta_sk) struct fullmesh_priv *fmp = fullmesh_get_priv(mpcb); const struct mptcp_fm_ns *fm_ns = fm_get_ns(sock_net(meta_sk)); struct tcp_sock *master_tp = tcp_sk(mpcb->master_sk); - int i, index, if_idx; + int i, index, if_idx = 0; union inet_addr saddr, daddr; - sa_family_t family; + sa_family_t family = AF_INET; bool meta_v4 = meta_sk->sk_family == AF_INET; /* Init local variables necessary for the rest */ -- 2.16.2

4 years, 2 months

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Weekly meeting - canceled this week

by Matthieu Baerts

Hello, With Mat, Peter and Christoph, we are proposing to cancel our meeting this week. Not all of us are available this week and we would prefer to be all present to debrief what we did last week. Feel free to say something if you have (urgent) topic(s) you which to discuss. If you have other topics that you would like to discuss next week, as always, feel free to add them in the list ;-) https://annuel2.framapad.org/p/mptcp_upstreaming_20180726 Speak to you next week! Matthieu -- Matthieu Baerts | R&D Engineer matthieu.baerts(a)tessares.net Tessares SA | Hybrid Access Solutions www.tessares.net 1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium -- DISCLAIMER. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.

4 years, 2 months

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LPC proposal draft

by Mat Martineau

Hello - Those of us in the weekly web conference yesterday discussed options for a Linux Plumber's Conference networking track talk (http://vger.kernel.org/lpc-networking.html). The deadline is coming up very soon, on Wednesday, 11 July. Here's a draft proposal, please comment! """ Implementing Multipath TCP requires both adding a layer above TCP and modifying the core in a number of places. The layer additions are relatively straightforward: adding a new IPPROTO_MPTCP protocol type, overriding existing callbacks from the IP layer, and adding to TCP option handling. But even after extensive efforts to minimize changes to the TCP core there are a handful of modifications required in order to support MPTCP. Unlike protocols that layer cleanly entirely above TCP, MPTCP must integrate with low-level TCP operations involving receive windows, sending and receiving ACKs, and the RST and FIN signals. We will show where the TCP core will be affected, why the changes cannot be avoided, and what we have done to avoid impacting TCP performance. """ -- Mat Martineau Intel OTC

4 years, 2 months

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[Weekly meetings] MoM - 5th of July 2018

by Matthieu Baerts

Hello, We just had our 14th meeting with Mat, Ossama, Peter (Intel OTC), Christoph (Apple) and myself (Tessares). Thanks again for this new good meeting! Here are the minutes of the meeting: Netdev paper: - We just fixed a few details about the phrasing - Remaining topic: the introduction that Olivier would like to improve. - Matthieu: will send a new version tomorrow (still possible to do some corrections, even next week, but just in case we forget!) Netdev Slides: - We did some comments directly on the slides - Matthieu: will send a new version on Monday, just in case we forget Netdev in Montreal: - if you want to discuss about MPTCP, feel free to contact one of us going there or on the ML! Linux Plumber conf: - we will focus on technical aspects, maybe focus in changes in TCP core (and struct skbuff?) - Mat and Peter will look at producing a description this end of the week. Next steps: - Matthieu: - paper: improve the introduction with Olivier - slides: removed last TODO in the slides - re-check the timing with a dry-run - Christoph & Matthieu: support Belgium soccer team tomorrow! - Mat: - slides: improve his part, maybe add some parts in the backup slides desk - slides: dry-run and check the timing - Linux Plumber Conf: prepare a description with Peter. - Mat and Peter's patches: review and discussion should continue on the ML. - As usual, update the wiki if there are new stuffs to put in! Next meeting: - There will no be any meeting next week online but many on site - It can change but next one should be the 19th of July. Usual time 9am PDT - 16:00 UTC (9am PDT, 6pm CEST) - Still open to everyone! - https://annuel2.framapad.org/p/mptcp_upstreaming_20180719 Feel free to comment on these points and propose new ones for the next meeting! Talk to you next week, Matthieu -- Matthieu Baerts | R&D Engineer matthieu.baerts(a)tessares.net Tessares SA | Hybrid Access Solutions www.tessares.net 1 Avenue Jean Monnet, 1348 Louvain-la-Neuve, Belgium -- DISCLAIMER. This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.

4 years, 2 months

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mptcp July 2018