SVR5 and SCO OpenServer

mdi_do_loopback(D3mdi)

mdi_do_loopback -- loopback convenience routine

Syntax

   #include <sys/types.h>
   #include <sys/stream.h>
   #include <sys/types.h>
   #include <sys/stream.h>
   #include <sys/mdi.h>
   #include <sys/ddi.h>
   
   void mdi_do_loopback(queue_t * q, mblk_t * mp, int minsize);

Description

mdi_do_loopback( ) is a loopback convenience routine. It loops the message back to the next module's read queue, if it is not blocked by flow control.

Arguments

q: Read queue call.
mp: Pointer to message to be duplicated
minsize: Minimum size of the message. If necessary, the message will be padded to reach this size.

Return values

None

Usage

The mdi_do_loopback( ) function is used to loop the frame back to the MDI user when the network adapter hardware does not loop back messages that are bound for the following addresses:

the broadcast MAC address
a multicast address in the multicast table, or any multicast address if all MCAs are set.
the device's MAC address
all messages being transmitted if the adapter is in promiscuous mode; see MACIOC_PROMISC

The msgpullup(D3str) function is then called to collate the data into a single message before placing it on the next module's read queue.

Context and synchronization

All contexts

Hardware applicability

All

Version applicability

mdi: 1, 2, 2.1

References

mdi_addrs_equal(D3mdi), mdi_valid_mca(D3mdi), uwput(D2mdi)