udplite (4)

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Copyright (c) 2014, Kevin Lo.
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(The comments found at the beginning of the groff file "man4/udplite.4freebsd".)

NAME

udplite - Lightweight User Datagram Protocol

SYNOPSIS

In sys/types.h In sys/socket.h In netinet/udplite.h Ft int Fn socket AF_INET SOCK_DGRAM IPPROTO_UDPLITE

DESCRIPTION

The UDP-Lite protocol provides a partial checksum which allows corrupted packets to be transmitted to the receiving application. This has advantages for some types of multimedia transport that may be able to make use of slightly damaged datagrams, rather than having them discarded by lower-layer protocols.

UDP-Lite supports a number of socket options which can be set with setsockopt(2) and tested with getsockopt(2):

UDPLITE_SEND_CSCOV

This option sets the sender checksum coverage. A value of zero indicates that the entire packet is covered by the checksum. A value of 1 to 7 must be discarded by the receiver.

UDPLITE_RECV_CSCOV

This option is the receiver-side analogue. It is truly optional, i.e. not required to enable traffic with partial checksum coverage. Its function is that of a traffic filter: when enabled, it instructs the kernel to drop all packets which have a coverage less than this value.

ERRORS

A socket operation may fail with one of the following errors returned:

Bq Er EISCONN

when trying to establish a connection on a socket which already has one, or when trying to send a datagram with the destination address specified and the socket is already connected;

Bq Er ENOTCONN

when trying to send a datagram, but no destination address is specified, and the socket has not been connected;

Bq Er ENOBUFS

when the system runs out of memory for an internal data structure;

Bq Er EADDRINUSE

when an attempt is made to create a socket with a port which has already been allocated;

Bq Er EADDRNOTAVAIL

when an attempt is made to create a socket with a network address for which no network interface exists.

SEE ALSO

getsockopt(2), recv(2), send(2), socket(2)