Intel Extensible Firmware Interface, Specification

Page: 282 / 494

Extensible Firmware Interface Specification
264 12/12/00 Version 1.02
Description
This function reads a UDP packet from a network interface. The data contents are returned in (the
optional
HeaderPtr
and)
BufferPtr
, and the size of the buffer received is returned in
BufferSize
. If the input
BufferSize
is smaller than the UDP packet received (less optional
HeaderSize
), it will be set to the required size, and
EFI_BUFFER_TOO_SMALL
will be
returned. In this case, the contents of
BufferPtr
are undefined, and the packet is lost. If a UDP
packet is successfully received, then
EFI_SUCCESS
will be returned, and the information from the
UDP header will be returned in
DestIp
,
DestPort
,
SrcIp
, and
SrcPort
if they are not
NULL
. Depending on the values of
OpFlags
and the
DestIp
,
DestPort
,
SrcIp
, and
SrcPort
input values, different types of UDP packet receive filtering will be performed. The
following tables summarize these receive filter operations.
Table 14-2. Destination IP Filter Operation
OpFlags
USE_FILTER OpFlags
ANY_DEST_IP
DestIp Action
0 0 NULL Receive a packet sent to
StationIp
.
0 1 NULL Receive a packet sent to any IP address.
1 x NULL Receive a packet whose destination IP address passes
the IP filter.
0 0 not NULL Receive a packet whose destination IP address matches
DestIp
.
0 1 not NULL Receive a packet sent to any IP address and, return the
destination IP address in
DestIp .
1 x not NULL Receive a packet whose destination IP address passes the
IP filter, and return the destination IP address in
DestIp
.
Table 14-3. Destination UDP Port Filter Operation
OpFlags
ANY_DEST_PORT
DestPort Action
0 NULL
Return EFI_INVALID_PARAMETER .
1 NULL Receive a packet sent to any UDP port.
0 not NULL
Receive a packet whose destination Port matches
DestPort
.
1 not NULL Receive a packet sent to any UDP port, and return the destination port in
DestPort
.