1. 16 Mar, 2009 10 commits
  2. 14 Mar, 2009 25 commits
  3. 13 Mar, 2009 5 commits
    • Gabriele Paoloni's avatar
      ppp: ppp_mp_explode() redesign · 9c705260
      Gabriele Paoloni authored
      I found the PPP subsystem to not work properly when connecting channels
      with different speeds to the same bundle.
      
      Problem Description:
      
      As the "ppp_mp_explode" function fragments the sk_buff buffer evenly
      among the PPP channels that are connected to a certain PPP unit to
      make up a bundle, if we are transmitting using an upper layer protocol
      that requires an Ack before sending the next packet (like TCP/IP for
      example), we will have a bandwidth bottleneck on the slowest channel
      of the bundle.
      
      Let's clarify by an example. Let's consider a scenario where we have
      two PPP links making up a bundle: a slow link (10KB/sec) and a fast
      link (1000KB/sec) working at the best (full bandwidth). On the top we
      have a TCP/IP stack sending a 1000 Bytes sk_buff buffer down to the
      PPP subsystem. The "ppp_mp_explode" function will divide the buffer in
      two fragments of 500B each (we are neglecting all the headers, crc,
      flags etc?.). Before the TCP/IP stack sends out the next buffer, it
      will have to wait for the ACK response from the remote peer, so it
      will have to wait for both fragments to have been sent over the two
      PPP links, received by the remote peer and reconstructed. The
      resulting behaviour is that, rather than having a bundle working
      @1010KB/sec (the sum of the channels bandwidths), we'll have a bundle
      working @20KB/sec (the double of the slowest channels bandwidth).
      
      
      Problem Solution:
      
      The problem has been solved by redesigning the "ppp_mp_explode"
      function in such a way to make it split the sk_buff buffer according
      to the speeds of the underlying PPP channels (the speeds of the serial
      interfaces respectively attached to the PPP channels). Referring to
      the above example, the redesigned "ppp_mp_explode" function will now
      divide the 1000 Bytes buffer into two fragments whose sizes are set
      according to the speeds of the channels where they are going to be
      sent on (e.g .  10 Byets on 10KB/sec channel and 990 Bytes on
      1000KB/sec channel).  The reworked function grants the same
      performances of the original one in optimal working conditions (i.e. a
      bundle made up of PPP links all working at the same speed), while
      greatly improving performances on the bundles made up of channels
      working at different speeds.
      Signed-off-by: default avatarGabriele Paoloni <gabriele.paoloni@intel.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9c705260
    • Roel Kluin's avatar
      tcp: '< 0' test on unsigned · a2025b8b
      Roel Kluin authored
      promote 'cnt' to size_t, to match 'len'.
      Signed-off-by: default avatarRoel Kluin <roel.kluin@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a2025b8b
    • Roel Kluin's avatar
      x25: '< 0' and '>= 0' test on unsigned · 8db09f26
      Roel Kluin authored
      skb->len is an unsigned int, so the test in x25_rx_call_request() always
      evaluates to true.
      
      len in x25_sendmsg() is unsigned as well. so -ERRORS returned by x25_output()
      are not noticed.
      Signed-off-by: default avatarRoel Kluin <roel.kluin@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8db09f26
    • Denys Fedoryshchenko's avatar
      ipv4: arp announce, arp_proxy and windows ip conflict verification · 73ce7b01
      Denys Fedoryshchenko authored
      Windows (XP at least) hosts on boot, with configured static ip, performing 
      address conflict detection, which is defined in RFC3927.
      Here is quote of important information:
      
      "
      An ARP announcement is identical to the ARP Probe described above, 
      except    that now the sender and target IP addresses are both set 
      to the host's newly selected IPv4 address. 
      "
      
      But it same time this goes wrong with RFC5227.
      "
      The 'sender IP address' field MUST be set to all zeroes; this is to avoid
      polluting ARP caches in other hosts on the same link in the case
      where the address turns out to be already in use by another host.
      "
      
      When ARP proxy configured, it must not answer to both cases, because 
      it is address conflict verification in any case. For Windows it is just 
      causing to detect false "ip conflict". Already there is code for RFC5227, so 
      just trivially we just check also if source ip == target ip.
      Signed-off-by: default avatarDenys Fedoryshchenko <denys@visp.net.lb>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      73ce7b01
    • Tomasz Lemiech's avatar
      tulip: Fix for MTU problems with 802.1q tagged frames · 1f8ae0a2
      Tomasz Lemiech authored
      The original patch was submitted last year but wasn't discussed or applied
      because of missing maintainer's CCs. I only fixed some formatting errors,
      but as I saw tulip is very badly formatted and needs further work.
      
      Original description:
      This patch fixes MTU problem, which occurs when using 802.1q VLANs. We
      should allow receiving frames of up to 1518 bytes in length, instead of
      1514.
      
      Based on patch written by Ben McKeegan for 2.4.x kernels. It is archived
      at http://www.candelatech.com/~greear/vlan/howto.html#tulip
      I've adjusted a few things to make it apply on 2.6.x kernels.
      
      Tested on D-Link DFE-570TX quad-fastethernet card.
      Signed-off-by: default avatarTomasz Lemiech <szpajder@staszic.waw.pl>
      Signed-off-by: default avatarIvan Vecera <ivecera@redhat.com>
      Signed-off-by: default avatarBen McKeegan <ben@netservers.co.uk>
      Acked-by: default avatarGrant Grundler <grundler@parisc-linux.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1f8ae0a2