Intel Extensible Firmware Interface - Manual (Page 663)

Protocols — Network Support
Version 1.10 12/01/02 15-57
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 15-2. 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 15-3. 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 .