[apple/libinfo.git] / gen.subproj / getifmaddrs.3

.\" Copyright (c) 2003 Bruce M. Simpson. All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\"
.\" THIS SOFTWARE IS PROVIDED BY Bruce M. Simpson ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL Bruce M. Simpson BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD: src/lib/libc/net/getifmaddrs.3,v 1.3.22.1.4.1 2010/06/14 02:09:06 kensmith Exp $
.\"
.Dd November 14, 2003
.Dt GETIFMADDRS 3
.Os
.Sh NAME
.Nm getifmaddrs
.Nd get multicast group memberships
.Sh SYNOPSIS
.In sys/types.h
.In sys/socket.h
.In ifaddrs.h
.Ft int
.Fn getifmaddrs "struct ifmaddrs **ifmap"
.Ft void
.Fn freeifmaddrs "struct ifmaddrs *ifmp"
.Sh DESCRIPTION
The
.Fn getifmaddrs
function stores a reference to a linked list of the multicast memberships
on the local machine in the memory referenced by
.Fa ifmap .
The list consists of
.Vt ifmaddrs
structures, as defined in the include file
.In ifaddrs.h .
The
.Vt ifmaddrs
structure contains at least the following entries:
.Bd -literal
    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 */
.Ed
.Pp
The
.Va ifma_next
field contains a pointer to the next structure on the list.
This field is
.Dv NULL
in last structure on the list.
.Pp
The
.Va ifma_name
field references an
.Dv AF_LINK
address structure, containing the name of the
interface where the membership exists.
.Pp
The
.Va ifma_addr
references the address that this membership is for.
.Pp
The
.Va ifma_lladdr
field references a link-layer translation for the protocol-level address in
.Va ifma_addr ,
if one is set, otherwise it is
.Dv NULL .
.Pp
The data returned by
.Fn getifmaddrs
is dynamically allocated and should be freed using
.Fn freeifmaddrs
when no longer needed.
.Sh RETURN VALUES
.Rv -std getifmaddrs
.Sh ERRORS
The
.Fn getifmaddrs
may fail and set
.Va errno
for any of the errors specified for the library routines
.Xr malloc 3
or
.Xr sysctl 3 .
.Sh SEE ALSO
.Xr sysctl 3 ,
.Xr networking 4 ,
.Xr ifconfig 8
.Sh HISTORY
The
.Fn getifmaddrs
function first appeared in
.Fx 5.2 .
.Sh BUGS
If both
.In net/if.h
and
.In ifaddrs.h
are being included,
.In net/if.h
.Em must
be included before
.In ifaddrs.h .
Commit	Line	Data
e44d8d47 A	1	.\" Copyright (c) 2003 Bruce M. Simpson. All rights reserved.
	2	.\"
	3	.\" Redistribution and use in source and binary forms, with or without
	4	.\" modification, are permitted provided that the following conditions
	5	.\" are met:
	6	.\" 1. Redistributions of source code must retain the above copyright
	7	.\" notice, this list of conditions and the following disclaimer.
	8	.\"
	9	.\" THIS SOFTWARE IS PROVIDED BY Bruce M. Simpson ``AS IS'' AND
	10	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	11	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	12	.\" ARE DISCLAIMED. IN NO EVENT SHALL Bruce M. Simpson BE LIABLE
	13	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	14	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	15	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	16	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	17	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	18	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	19	.\" SUCH DAMAGE.
	20	.\"
	21	.\" $FreeBSD: src/lib/libc/net/getifmaddrs.3,v 1.3.22.1.4.1 2010/06/14 02:09:06 kensmith Exp $
	22	.\"
	23	.Dd November 14, 2003
	24	.Dt GETIFMADDRS 3
	25	.Os
	26	.Sh NAME
	27	.Nm getifmaddrs
	28	.Nd get multicast group memberships
	29	.Sh SYNOPSIS
	30	.In sys/types.h
	31	.In sys/socket.h
	32	.In ifaddrs.h
	33	.Ft int
	34	.Fn getifmaddrs "struct ifmaddrs **ifmap"
	35	.Ft void
	36	.Fn freeifmaddrs "struct ifmaddrs *ifmp"
	37	.Sh DESCRIPTION
	38	The
	39	.Fn getifmaddrs
	40	function stores a reference to a linked list of the multicast memberships
	41	on the local machine in the memory referenced by
	42	.Fa ifmap .
	43	The list consists of
	44	.Vt ifmaddrs
	45	structures, as defined in the include file
	46	.In ifaddrs.h .
	47	The
	48	.Vt ifmaddrs
	49	structure contains at least the following entries:
	50	.Bd -literal
	51	struct ifmaddrs ifma_next; / Pointer to next struct */
	52	struct sockaddr ifma_name; / Interface name (AF_LINK) */
	53	struct sockaddr ifma_addr; / Multicast address */
	54	struct sockaddr ifma_lladdr; / Link-layer translation, if any */
	55	.Ed
	56	.Pp
	57	The
	58	.Va ifma_next
	59	field contains a pointer to the next structure on the list.
	60	This field is
	61	.Dv NULL
	62	in last structure on the list.
	63	.Pp
	64	The
65	.Va ifma_name
66	field references an
67	.Dv AF_LINK
68	address structure, containing the name of the
69	interface where the membership exists.
70	.Pp
71	The
72	.Va ifma_addr
73	references the address that this membership is for.
74	.Pp
75	The
76	.Va ifma_lladdr
77	field references a link-layer translation for the protocol-level address in
78	.Va ifma_addr ,
79	if one is set, otherwise it is
80	.Dv NULL .
81	.Pp
82	The data returned by
83	.Fn getifmaddrs
84	is dynamically allocated and should be freed using
85	.Fn freeifmaddrs
86	when no longer needed.
87	.Sh RETURN VALUES
88	.Rv -std getifmaddrs
89	.Sh ERRORS
90	The
91	.Fn getifmaddrs
92	may fail and set
93	.Va errno
94	for any of the errors specified for the library routines
95	.Xr malloc 3
96	or
97	.Xr sysctl 3 .
98	.Sh SEE ALSO
99	.Xr sysctl 3 ,
100	.Xr networking 4 ,
101	.Xr ifconfig 8
102	.Sh HISTORY
103	The
104	.Fn getifmaddrs
105	function first appeared in
106	.Fx 5.2 .
107	.Sh BUGS
108	If both
109	.In net/if.h
110	and
111	.In ifaddrs.h
112	are being included,
113	.In net/if.h
114	.Em must
115	be included before
116	.In ifaddrs.h .