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GETIFMADDRS(3)		    Library Functions Manual		GETIFMADDRS(3)

NAME
       getifmaddrs -- get multicast group memberships

SYNOPSIS
       #include	<ifaddrs.h>

       int
       getifmaddrs(struct ifmaddrs **ifmap);

       void
       freeifmaddrs(struct ifmaddrs *ifmp);

DESCRIPTION
       The  getifmaddrs()  function stores a reference to a linked list	of the
       multicast memberships on	the local machine in the memory	referenced  by
       ifmap.  The list	consists of ifmaddrs structures, as defined in the in-
       clude  file  <ifaddrs.h>.  The ifmaddrs structure contains at least the
       following entries:

	   struct ifmaddrs   *ifma_next;     /*	Pointer	to next	struct */
	   struct sockaddr   *ifma_name;     /*	Interface name (AF_LINK) */
	   struct sockaddr   *ifma_addr;     /*	Multicast address */
	   struct sockaddr   *ifma_lladdr;   /*	Link-layer translation,	if any */

       The ifma_next field contains a pointer to the  next  structure  on  the
       list.  This field is NULL in last structure on the list.

       The ifma_name field references an AF_LINK address structure, containing
       the name	of the interface where the membership exists.

       The ifma_addr references	the address that this membership is for.

       The  ifma_lladdr	field references a link-layer translation for the pro-
       tocol-level address in ifma_addr, if one	is set,	otherwise it is	NULL.

       The data	returned by getifmaddrs() is dynamically allocated and	should
       be freed	using freeifmaddrs() when no longer needed.

RETURN VALUES
       The getifmaddrs() function returns the value 0 if successful; otherwise
       the  value -1 is	returned and the global	variable errno is set to indi-
       cate the	error.

ERRORS
       The getifmaddrs() may fail and set errno	for any	of the	errors	speci-
       fied for	the library routines malloc(3) or sysctl(3).

SEE ALSO
       sysctl(3), networking(4), ifconfig(8)

HISTORY
       The getifmaddrs() function first	appeared in FreeBSD 5.2.

BUGS
       If  both	<net/if.h> and <ifaddrs.h> are being included, <net/if.h> must
       be included before <ifaddrs.h>.

FreeBSD	13.4			 May 21, 2013			GETIFMADDRS(3)

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