1. 06 Apr, 2019 11 commits
    • Tinderbox User's avatar
    • Tinderbox User's avatar
      doc rebuild · 40b034f5
      Tinderbox User authored
    • Tinderbox User's avatar
      prep 9.11.6-P1 · 6195f229
      Tinderbox User authored
    • Evan Hunt's avatar
    • Evan Hunt's avatar
      CHANGES, release note · 5e18ad05
      Evan Hunt authored
    • Evan Hunt's avatar
      restore allowance for tcp-clients < interfaces · d01023aa
      Evan Hunt authored
      in the "refactor tcpquota and pipeline refs" commit, the counting
      of active interfaces was tightened in such a way that named could
      fail to listen on an interface if there were more interfaces than
      tcp-clients. when checking the quota to start accepting on an
      interface, if the number of active clients was above zero, then
      it was presumed that some other client was able to handle accepting
      new connections. this, however, ignored the fact that the current client
      could be included in that count, so if the quota was already exceeded
      before all the interfaces were listening, some interfaces would never
      we now check whether the current client has been marked active; if so,
      then the number of active clients on the interface must be greater
      than 1, not 0.
      (cherry picked from commit 0b4e2cd4c3192ba88569dd344f542a8cc43742b5)
    • Evan Hunt's avatar
      refactor tcpquota and pipeline refs; allow special-case overrun in isc_quota · 13f7c918
      Evan Hunt authored
      - if the TCP quota has been exceeded but there are no clients listening
        for new connections on the interface, we can now force attachment to the
        quota using isc_quota_force(), instead of carrying on with the quota not
      - the TCP client quota is now referenced via a reference-counted
        'ns_tcpconn' object, one of which is created whenever a client begins
        listening for new connections, and attached to by members of that
        client's pipeline group. when the last reference to the tcpconn
        object is detached, it is freed and the TCP quota slot is released.
      - reduce code duplication by adding mark_tcp_active() function.
      - convert counters to atomic.
      (cherry picked from commit 7e8222378ca24f1302a0c1c638565050ab04681b)
      (cherry picked from commit 4939451275722bfda490ea86ca13e84f6bc71e46)
    • Evan Hunt's avatar
      better tcpquota accounting and client mortality checks · 87d43116
      Evan Hunt authored
      - ensure that tcpactive is cleaned up correctly when accept() fails.
      - set 'client->tcpattached' when the client is attached to the tcpquota.
        carry this value on to new clients sharing the same pipeline group.
        don't call isc_quota_detach() on the tcpquota unless tcpattached is
        set.  this way clients that were allowed to accept TCP connections
        despite being over quota (and therefore, were never attached to the
        quota) will not inadvertently detach from it and mess up the
      - simplify the code for tcpquota disconnection by using a new function
      - before deciding whether to reject a new connection due to quota
        exhaustion, check to see whether there are at least two active
        clients. previously, this was "at least one", but that could be
        insufficient if there was one other client in READING state (waiting
        for messages on an open connection) but none in READY (listening
        for new connections).
      - before deciding whether a TCP client object can to go inactive, we
        must ensure there are enough other clients to maintain service
        afterward -- both accepting new connections and reading/processing new
        queries.  A TCP client can't shut down unless at least one
        client is accepting new connections and (in the case of pipelined
        clients) at least one additional client is waiting to read.
      (cherry picked from commit c7394738b2445c16f728a88394864dd61baad900)
      (cherry picked from commit e965d5f11d3d0f6d59704e614fceca2093cb1856)
    • Michał Kępień's avatar
      use reference counter for pipeline groups (v3) · 9446629b
      Michał Kępień authored
      Track pipeline groups using a shared reference counter
      instead of a linked list.
      (cherry picked from commit 513afd33eb17d5dc41a3f0d2d38204ef8c5f6f91)
    • Witold Krecicki's avatar
      tcp-clients could still be exceeded (v2) · 55a7a458
      Witold Krecicki authored
      the TCP client quota could still be ineffective under some
      circumstances.  this change:
      - improves quota accounting to ensure that TCP clients are
        properly limited, while still guaranteeing that at least one client
        is always available to serve TCP connections on each interface.
      - uses more descriptive names and removes one (ntcptarget) that
        was no longer needed
      - adds comments
      (cherry picked from commit 924651f1d5e605cd186d03f4f7340bcc54d77cc2)
    • Witold Krecicki's avatar
      fix enforcement of tcp-clients (v1) · 9689ffc4
      Witold Krecicki authored
      tcp-clients settings could be exceeded in some cases by
      creating more and more active TCP clients that are over
      the set quota limit, which in the end could lead to a
      DoS attack by e.g. exhaustion of file descriptors.
      If TCP client we're closing went over the quota (so it's
      not attached to a quota) mark it as mortal - so that it
      will be destroyed and not set up to listen for new
      connections - unless it's the last client for a specific
      (cherry picked from commit f97131d21b97381cef72b971b157345c1f9b4115)
  2. 27 Feb, 2019 2 commits
  3. 21 Feb, 2019 27 commits