getipv4sourcefilter(3N)getipv4sourcefilter(3N)NAMEgetipv4sourcefilter() - get IPv4 multicast source filter state
This function retrieves the multicast source filter state for an IPv4
multicast group which the application has joined on a given socket.
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
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 argument will hold the total number of sources in the
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 before‐
hand, 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.
returns the following values:
is set to indicate the error.
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
slist is NULL when numsrc is greater than 0; or
group is not an IPv4 multicast address.
was developed by HP and the IETF.
SEE ALSOsocket(2), getsourcefilter(3N), setipv4sourcefilter(3N), setsource‐
filter(3N), ip(7P), ip6(7P).