1. 06 1月, 2006 1 次提交
  2. 06 12月, 2005 1 次提交
  3. 10 11月, 2005 1 次提交
    • Y
      [NETFILTER]: Add nf_conntrack subsystem. · 9fb9cbb1
      Yasuyuki Kozakai 提交于
      The existing connection tracking subsystem in netfilter can only
      handle ipv4.  There were basically two choices present to add
      connection tracking support for ipv6.  We could either duplicate all
      of the ipv4 connection tracking code into an ipv6 counterpart, or (the
      choice taken by these patches) we could design a generic layer that
      could handle both ipv4 and ipv6 and thus requiring only one sub-protocol
      (TCP, UDP, etc.) connection tracking helper module to be written.
      
      In fact nf_conntrack is capable of working with any layer 3
      protocol.
      
      The existing ipv4 specific conntrack code could also not deal
      with the pecularities of doing connection tracking on ipv6,
      which is also cured here.  For example, these issues include:
      
      1) ICMPv6 handling, which is used for neighbour discovery in
         ipv6 thus some messages such as these should not participate
         in connection tracking since effectively they are like ARP
         messages
      
      2) fragmentation must be handled differently in ipv6, because
         the simplistic "defrag, connection track and NAT, refrag"
         (which the existing ipv4 connection tracking does) approach simply
         isn't feasible in ipv6
      
      3) ipv6 extension header parsing must occur at the correct spots
         before and after connection tracking decisions, and there were
         no provisions for this in the existing connection tracking
         design
      
      4) ipv6 has no need for stateful NAT
      
      The ipv4 specific conntrack layer is kept around, until all of
      the ipv4 specific conntrack helpers are ported over to nf_conntrack
      and it is feature complete.  Once that occurs, the old conntrack
      stuff will get placed into the feature-removal-schedule and we will
      fully kill it off 6 months later.
      Signed-off-by: NYasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
      Signed-off-by: NHarald Welte <laforge@netfilter.org>
      Signed-off-by: NArnaldo Carvalho de Melo <acme@mandriva.com>
      9fb9cbb1
  4. 30 8月, 2005 3 次提交