Kernel Functions for Drivers                         mac_lso_get(9F)

NAME

     mac_lso_get -- LSO routine

     #include <sys/mac_provider.h>

     void mac_lso_get(mblk_t *mp, uint32_t *mss, uint32_t *flags)

DESCRIPTION

     LSO (Large Segment Offload, or Large Send Offload) allows the
     network stack to send larger buffers to a device driver. These
     large buffers can then segmented in hardware, allowing for
     reduced CPU utilization, PCI overhead, and reduced buffer
     management costs.

     LSO is enabled only for device driver instances that advertise
     support for the MAC_CAPAB_LSO capability through the
     mc_getcapab(9E) entry point.

     Once a device driver advertises the LSO capability, it must use
     the mac_lso_get() entry point to query whether LSO must be
     performed on the packet. The following flags are currently
     supported:

     HW_LSO			When set, this flag indicates that
				LSO is enabled for that packet. 
				The maximum segment size (MSS) to be
				used during segmentation of the large
				segment is returned through the
				location pointed to by mss.

ATTRIBUTES

     See attributes(5) for descriptions of the  following  attri-
     butes:

     ____________________________________________________________
    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    |_____________________________|_____________________________|
    | Availability                | SUNWhea                     |
    |_____________________________|_____________________________|
    | Interface Stability         | Committed                   |
    |_____________________________|_____________________________|


SEE ALSO

     mac(9E), attributes(5)