getipv4sourcefilter(3N) getipv4sourcefilter(3N)
NAME
getipv4sourcefilter() - get IPv4 multicast source filter state
SYNOPSIS
DESCRIPTION
This function retrieves the multicast source filter state for an IPv4 multicast group which the application has joined on a given socket.
Parameters
s Specifies the descriptor identifying the socket. The socket address family must be and the socket type must be
interface Holds the IPv4 address of a local interface, or If set to the system chooses a multicast group by matching the multicast address
only.
group Holds the IPv4 multicast address of the group.
fmode Points to an integer that will contain the filter mode on a successful return. The value of this field will be either or which
are defined in
numsrc On input, the numsrc argument holds the number of source addresses that will fit in the slist array. On output, the numsrc argu-
ment will hold the total number of sources in the filter.
slist Points to buffer into which an array of IPv4 addresses of included or excluded (depending on the filter mode) sources will be
written. If numsrc was 0 on input, a NULL pointer may be supplied.
If the application does not know the size of the source list beforehand, it can make a reasonable guess (for example, by setting numsrc to
0), and if upon completion, numsrc holds a larger value, the operation can be repeated with a large enough buffer.
That is, on return, numsrc is always updated to be the total number of sources in the filter, while slist will hold as many source
addresses as fit, up to the minimum of the array size passed in as the original numsrc value and the total number of sources in the filter.
RETURN VALUES
returns the following values:
Successful completion.
Failure.
is set to indicate the error.
ERRORS
If fails, is set to one of the following values:
The argument s is not a valid descriptor.
This function is not supported by the socket type.
Insufficient memory is available for internal
system data structures.
The specified IP address is not a local interface address; or
the specified multicast group has not been joined.
slist is NULL when numsrc is greater than 0; or group is not an IPv4 multicast address.
AUTHOR
was developed by HP and the IETF.
SEE ALSO
socket(2), getsourcefilter(3N), setipv4sourcefilter(3N), setsourcefilter(3N), ip(7P), ip6(7P).
STANDARDS CONFORMANCE
RFC 3678
getipv4sourcefilter(3N)
