• Enrico Mioso's avatar
    cdc_ncm: Add support for moving NDP to end of NCM frame · 4a0e3e98
    Enrico Mioso authored
    NCM specs are not actually mandating a specific position in the frame for
    the NDP (Network Datagram Pointer). However, some Huawei devices will
    ignore our aggregates if it is not placed after the datagrams it points
    to. Add support for doing just this, in a per-device configurable way.
    While at it, update NCM subdrivers, disabling this functionality in all of
    them, except in huawei_cdc_ncm where it is enabled instead.
    We aren't making any distinction between different Huawei NCM devices,
    based on what the vendor driver does. Standard NCM devices are left
    unaffected: if they are compliant, they should be always usable, still
    stay on the safe side.
    
    This change has been tested and working with a Huawei E3131 device (which
    works regardless of NDP position), a Huawei E3531 (also working both
    ways) and an E3372 (which mandates NDP to be after indexed datagrams).
    
    V1->V2:
    - corrected wrong NDP acronym definition
    - fixed possible NULL pointer dereference
    - patch cleanup
    V2->V3:
    - Properly account for the NDP size when writing new packets to SKB
    Signed-off-by: default avatarEnrico Mioso <mrkiko.rs@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    4a0e3e98
cdc_ncm.c 49.3 KB