1. 08 6月, 2015 1 次提交
  2. 25 3月, 2015 1 次提交
    • E
      tcp: fix ipv4 mapped request socks · 0144a81c
      Eric Dumazet 提交于
      ss should display ipv4 mapped request sockets like this :
      
      tcp    SYN-RECV   0      0  ::ffff:192.168.0.1:8080   ::ffff:192.0.2.1:35261
      
      and not like this :
      
      tcp    SYN-RECV   0      0  192.168.0.1:8080   192.0.2.1:35261
      
      We should init ireq->ireq_family based on listener sk_family,
      not the actual protocol carried by SYN packet.
      
      This means we can set ireq_family in inet_reqsk_alloc()
      
      Fixes: 3f66b083 ("inet: introduce ireq_family")
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0144a81c
  3. 21 3月, 2015 1 次提交
    • E
      inet: get rid of central tcp/dccp listener timer · fa76ce73
      Eric Dumazet 提交于
      One of the major issue for TCP is the SYNACK rtx handling,
      done by inet_csk_reqsk_queue_prune(), fired by the keepalive
      timer of a TCP_LISTEN socket.
      
      This function runs for awful long times, with socket lock held,
      meaning that other cpus needing this lock have to spin for hundred of ms.
      
      SYNACK are sent in huge bursts, likely to cause severe drops anyway.
      
      This model was OK 15 years ago when memory was very tight.
      
      We now can afford to have a timer per request sock.
      
      Timer invocations no longer need to lock the listener,
      and can be run from all cpus in parallel.
      
      With following patch increasing somaxconn width to 32 bits,
      I tested a listener with more than 4 million active request sockets,
      and a steady SYNFLOOD of ~200,000 SYN per second.
      Host was sending ~830,000 SYNACK per second.
      
      This is ~100 times more what we could achieve before this patch.
      
      Later, we will get rid of the listener hash and use ehash instead.
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      fa76ce73
  4. 19 3月, 2015 1 次提交
  5. 18 3月, 2015 3 次提交
  6. 17 3月, 2015 1 次提交
  7. 15 3月, 2015 1 次提交
  8. 13 3月, 2015 1 次提交
  9. 12 3月, 2015 2 次提交
  10. 05 11月, 2014 3 次提交
    • F
      net: allow setting ecn via routing table · f7b3bec6
      Florian Westphal 提交于
      This patch allows to set ECN on a per-route basis in case the sysctl
      tcp_ecn is not set to 1. In other words, when ECN is set for specific
      routes, it provides a tcp_ecn=1 behaviour for that route while the rest
      of the stack acts according to the global settings.
      
      One can use 'ip route change dev $dev $net features ecn' to toggle this.
      
      Having a more fine-grained per-route setting can be beneficial for various
      reasons, for example, 1) within data centers, or 2) local ISPs may deploy
      ECN support for their own video/streaming services [1], etc.
      
      There was a recent measurement study/paper [2] which scanned the Alexa's
      publicly available top million websites list from a vantage point in US,
      Europe and Asia:
      
      Half of the Alexa list will now happily use ECN (tcp_ecn=2, most likely
      blamed to commit 255cac91 ("tcp: extend ECN sysctl to allow server-side
      only ECN") ;)); the break in connectivity on-path was found is about
      1 in 10,000 cases. Timeouts rather than receiving back RSTs were much
      more common in the negotiation phase (and mostly seen in the Alexa
      middle band, ranks around 50k-150k): from 12-thousand hosts on which
      there _may_ be ECN-linked connection failures, only 79 failed with RST
      when _not_ failing with RST when ECN is not requested.
      
      It's unclear though, how much equipment in the wild actually marks CE
      when buffers start to fill up.
      
      We thought about a fallback to non-ECN for retransmitted SYNs as another
      global option (which could perhaps one day be made default), but as Eric
      points out, there's much more work needed to detect broken middleboxes.
      
      Two examples Eric mentioned are buggy firewalls that accept only a single
      SYN per flow, and middleboxes that successfully let an ECN flow establish,
      but later mark CE for all packets (so cwnd converges to 1).
      
       [1] http://www.ietf.org/proceedings/89/slides/slides-89-tsvarea-1.pdf, p.15
       [2] http://ecn.ethz.ch/
      
      Joint work with Daniel Borkmann.
      
      Reference: http://thread.gmane.org/gmane.linux.network/335797Suggested-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
      Signed-off-by: NFlorian Westphal <fw@strlen.de>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f7b3bec6
    • F
      syncookies: split cookie_check_timestamp() into two functions · f1673381
      Florian Westphal 提交于
      The function cookie_check_timestamp(), both called from IPv4/6 context,
      is being used to decode the echoed timestamp from the SYN/ACK into TCP
      options used for follow-up communication with the peer.
      
      We can remove ECN handling from that function, split it into a separate
      one, and simply rename the original function into cookie_decode_options().
      cookie_decode_options() just fills in tcp_option struct based on the
      echoed timestamp received from the peer. Anything that fails in this
      function will actually discard the request socket.
      
      While this is the natural place for decoding options such as ECN which
      commit 172d69e6 ("syncookies: add support for ECN") added, we argue
      that in particular for ECN handling, it can be checked at a later point
      in time as the request sock would actually not need to be dropped from
      this, but just ECN support turned off.
      
      Therefore, we split this functionality into cookie_ecn_ok(), which tells
      us if the timestamp indicates ECN support AND the tcp_ecn sysctl is enabled.
      
      This prepares for per-route ECN support: just looking at the tcp_ecn sysctl
      won't be enough anymore at that point; if the timestamp indicates ECN
      and sysctl tcp_ecn == 0, we will also need to check the ECN dst metric.
      
      This would mean adding a route lookup to cookie_check_timestamp(), which
      we definitely want to avoid. As we already do a route lookup at a later
      point in cookie_{v4,v6}_check(), we can simply make use of that as well
      for the new cookie_ecn_ok() function w/o any additional cost.
      
      Joint work with Daniel Borkmann.
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
      Signed-off-by: NFlorian Westphal <fw@strlen.de>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f1673381
    • F
      syncookies: avoid magic values and document which-bit-is-what-option · 274e2da0
      Florian Westphal 提交于
      Was a bit more difficult to read than needed due to magic shifts;
      add defines and document the used encoding scheme.
      
      Joint work with Daniel Borkmann.
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDaniel Borkmann <dborkman@redhat.com>
      Signed-off-by: NFlorian Westphal <fw@strlen.de>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      274e2da0
  11. 31 10月, 2014 1 次提交
  12. 18 10月, 2014 3 次提交
  13. 28 8月, 2014 1 次提交
  14. 27 8月, 2014 1 次提交
  15. 28 6月, 2014 1 次提交
  16. 14 5月, 2014 1 次提交
    • L
      net: support marking accepting TCP sockets · 84f39b08
      Lorenzo Colitti 提交于
      When using mark-based routing, sockets returned from accept()
      may need to be marked differently depending on the incoming
      connection request.
      
      This is the case, for example, if different socket marks identify
      different networks: a listening socket may want to accept
      connections from all networks, but each connection should be
      marked with the network that the request came in on, so that
      subsequent packets are sent on the correct network.
      
      This patch adds a sysctl to mark TCP sockets based on the fwmark
      of the incoming SYN packet. If enabled, and an unmarked socket
      receives a SYN, then the SYN packet's fwmark is written to the
      connection's inet_request_sock, and later written back to the
      accepted socket when the connection is established.  If the
      socket already has a nonzero mark, then the behaviour is the same
      as it is today, i.e., the listening socket's fwmark is used.
      
      Black-box tested using user-mode linux:
      
      - IPv4/IPv6 SYN+ACK, FIN, etc. packets are routed based on the
        mark of the incoming SYN packet.
      - The socket returned by accept() is marked with the mark of the
        incoming SYN packet.
      - Tested with syncookies=1 and syncookies=2.
      Signed-off-by: NLorenzo Colitti <lorenzo@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      84f39b08
  17. 27 12月, 2013 1 次提交
  18. 20 10月, 2013 1 次提交
  19. 11 10月, 2013 1 次提交
  20. 10 10月, 2013 1 次提交
    • E
      inet: includes a sock_common in request_sock · 634fb979
      Eric Dumazet 提交于
      TCP listener refactoring, part 5 :
      
      We want to be able to insert request sockets (SYN_RECV) into main
      ehash table instead of the per listener hash table to allow RCU
      lookups and remove listener lock contention.
      
      This patch includes the needed struct sock_common in front
      of struct request_sock
      
      This means there is no more inet6_request_sock IPv6 specific
      structure.
      
      Following inet_request_sock fields were renamed as they became
      macros to reference fields from struct sock_common.
      Prefix ir_ was chosen to avoid name collisions.
      
      loc_port   -> ir_loc_port
      loc_addr   -> ir_loc_addr
      rmt_addr   -> ir_rmt_addr
      rmt_port   -> ir_rmt_port
      iif        -> ir_iif
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      634fb979
  21. 24 9月, 2013 2 次提交
  22. 28 8月, 2013 1 次提交
  23. 12 4月, 2013 1 次提交
  24. 18 3月, 2013 1 次提交
    • C
      tcp: Remove TCPCT · 1a2c6181
      Christoph Paasch 提交于
      TCPCT uses option-number 253, reserved for experimental use and should
      not be used in production environments.
      Further, TCPCT does not fully implement RFC 6013.
      
      As a nice side-effect, removing TCPCT increases TCP's performance for
      very short flows:
      
      Doing an apache-benchmark with -c 100 -n 100000, sending HTTP-requests
      for files of 1KB size.
      
      before this patch:
      	average (among 7 runs) of 20845.5 Requests/Second
      after:
      	average (among 7 runs) of 21403.6 Requests/Second
      Signed-off-by: NChristoph Paasch <christoph.paasch@uclouvain.be>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1a2c6181
  25. 07 1月, 2013 1 次提交
  26. 04 11月, 2012 1 次提交
    • E
      tcp: better retrans tracking for defer-accept · e6c022a4
      Eric Dumazet 提交于
      For passive TCP connections using TCP_DEFER_ACCEPT facility,
      we incorrectly increment req->retrans each time timeout triggers
      while no SYNACK is sent.
      
      SYNACK are not sent for TCP_DEFER_ACCEPT that were established (for
      which we received the ACK from client). Only the last SYNACK is sent
      so that we can receive again an ACK from client, to move the req into
      accept queue. We plan to change this later to avoid the useless
      retransmit (and potential problem as this SYNACK could be lost)
      
      TCP_INFO later gives wrong information to user, claiming imaginary
      retransmits.
      
      Decouple req->retrans field into two independent fields :
      
      num_retrans : number of retransmit
      num_timeout : number of timeouts
      
      num_timeout is the counter that is incremented at each timeout,
      regardless of actual SYNACK being sent or not, and used to
      compute the exponential timeout.
      
      Introduce inet_rtx_syn_ack() helper to increment num_retrans
      only if ->rtx_syn_ack() succeeded.
      
      Use inet_rtx_syn_ack() from tcp_check_req() to increment num_retrans
      when we re-send a SYNACK in answer to a (retransmitted) SYN.
      Prior to this patch, we were not counting these retransmits.
      
      Change tcp_v[46]_rtx_synack() to increment TCP_MIB_RETRANSSEGS
      only if a synack packet was successfully queued.
      Reported-by: NYuchung Cheng <ycheng@google.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Cc: Julian Anastasov <ja@ssi.bg>
      Cc: Vijay Subramanian <subramanian.vijay@gmail.com>
      Cc: Elliott Hughes <enh@google.com>
      Cc: Neal Cardwell <ncardwell@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      e6c022a4
  27. 01 9月, 2012 1 次提交
    • J
      tcp: TCP Fast Open Server - support TFO listeners · 8336886f
      Jerry Chu 提交于
      This patch builds on top of the previous patch to add the support
      for TFO listeners. This includes -
      
      1. allocating, properly initializing, and managing the per listener
      fastopen_queue structure when TFO is enabled
      
      2. changes to the inet_csk_accept code to support TFO. E.g., the
      request_sock can no longer be freed upon accept(), not until 3WHS
      finishes
      
      3. allowing a TCP_SYN_RECV socket to properly poll() and sendmsg()
      if it's a TFO socket
      
      4. properly closing a TFO listener, and a TFO socket before 3WHS
      finishes
      
      5. supporting TCP_FASTOPEN socket option
      
      6. modifying tcp_check_req() to use to check a TFO socket as well
      as request_sock
      
      7. supporting TCP's TFO cookie option
      
      8. adding a new SYN-ACK retransmit handler to use the timer directly
      off the TFO socket rather than the listener socket. Note that TFO
      server side will not retransmit anything other than SYN-ACK until
      the 3WHS is completed.
      
      The patch also contains an important function
      "reqsk_fastopen_remove()" to manage the somewhat complex relation
      between a listener, its request_sock, and the corresponding child
      socket. See the comment above the function for the detail.
      Signed-off-by: NH.K. Jerry Chu <hkchu@google.com>
      Cc: Yuchung Cheng <ycheng@google.com>
      Cc: Neal Cardwell <ncardwell@google.com>
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Tom Herbert <therbert@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      8336886f
  28. 20 7月, 2012 1 次提交
    • Y
      net-tcp: Fast Open base · 2100c8d2
      Yuchung Cheng 提交于
      This patch impelements the common code for both the client and server.
      
      1. TCP Fast Open option processing. Since Fast Open does not have an
         option number assigned by IANA yet, it shares the experiment option
         code 254 by implementing draft-ietf-tcpm-experimental-options
         with a 16 bits magic number 0xF989. This enables global experiments
         without clashing the scarce(2) experimental options available for TCP.
      
         When the draft status becomes standard (maybe), the client should
         switch to the new option number assigned while the server supports
         both numbers for transistion.
      
      2. The new sysctl tcp_fastopen
      
      3. A place holder init function
      Signed-off-by: NYuchung Cheng <ycheng@google.com>
      Acked-by: NEric Dumazet <edumazet@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      2100c8d2
  29. 12 3月, 2012 1 次提交
  30. 21 12月, 2011 1 次提交
  31. 01 11月, 2011 1 次提交
  32. 21 10月, 2011 1 次提交