lkml.org 
[lkml]   [1999]   [Oct]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: 2.2.13 ISDN funnies
    >>>>> "Alan" == Alan Cox <alan@lxorguk.ukuu.org.uk> writes:

    >> I heared similar problems with ppp over ethernet and normal
    >> ppp.

    Alan> There was a sign bug months ago with this that bit Alpha
    Alan> users for one. That was fixed. Other than that we haven't
    Alan> seen anything. So right now I believe the bug is in the isdn

    Maybe there is still another bug in ip_output.c::ip_queue_xmit():
    There, the re-allocation of header space is only done if the
    device has a dev->hard_header() method:

    if (skb_headroom(skb) < dev->hard_header_len && dev->hard_header) {
    struct sk_buff *skb2;

    skb2 = skb_realloc_headroom(skb, (dev->hard_header_len + 15) & ~

    Async ppp in 2.2.x as well as the generic ppp in 2.3.x have no
    dev->hard_header() method. Karsten's routing scenario
    (e.g. from slip or raw hdlc device to ppp-over-ethernet) will result in
    header space growing larger then the implict space of 16 byte
    as provided by dev_alloc_skb(). Now, if ip_output does not reallocate
    headroom because ppp has no dev->hard_header() method, problems might
    occur.

    Henner



    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.rutgers.edu
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:54    [W:0.020 / U:29.396 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site