.\" $OpenBSD: getifaddrs.3,v 1.7 2001/10/01 21:58:53 millert Exp $
|
.\" $OpenBSD: getifaddrs.3,v 1.7 2001/10/01 21:58:53 millert Exp $
|
.\" BSDI getifaddrs.3,v 2.5 2000/02/23 14:51:59 dab Exp
|
.\" BSDI getifaddrs.3,v 2.5 2000/02/23 14:51:59 dab Exp
|
.\"
|
.\"
|
.\" Copyright (c) 1995, 1999
|
.\" Copyright (c) 1995, 1999
|
.\" Berkeley Software Design, Inc. All rights reserved.
|
.\" Berkeley Software Design, Inc. All rights reserved.
|
.\"
|
.\"
|
.\" Redistribution and use in source and binary forms, with or without
|
.\" Redistribution and use in source and binary forms, with or without
|
.\" modification, are permitted provided that the following conditions
|
.\" modification, are permitted provided that the following conditions
|
.\" are met:
|
.\" are met:
|
.\" 1. Redistributions of source code must retain the above copyright
|
.\" 1. Redistributions of source code must retain the above copyright
|
.\" notice, this list of conditions and the following disclaimer.
|
.\" notice, this list of conditions and the following disclaimer.
|
.\"
|
.\"
|
.\" THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
|
.\" THIS SOFTWARE IS PROVIDED BY Berkeley Software Design, Inc. ``AS IS'' AND
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL Berkeley Software Design, Inc. BE LIABLE
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
.\" 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
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
.\" SUCH DAMAGE.
|
.\" SUCH DAMAGE.
|
.Dd "October 12, 1995"
|
.Dd "October 12, 1995"
|
.Dt GETIFADDRS 3
|
.Dt GETIFADDRS 3
|
.Sh NAME
|
.Sh NAME
|
.Nm getifaddrs
|
.Nm getifaddrs
|
.Nd get interface addresses
|
.Nd get interface addresses
|
.Sh SYNOPSIS
|
.Sh SYNOPSIS
|
.Fd #include
|
.Fd #include
|
.Fd #include
|
.Fd #include
|
.Fd #include
|
.Fd #include
|
.Ft int
|
.Ft int
|
.Fn getifaddrs "struct ifaddrs **ifap"
|
.Fn getifaddrs "struct ifaddrs **ifap"
|
.Ft void
|
.Ft void
|
.Fn freeifaddrs "struct ifaddrs *ifap"
|
.Fn freeifaddrs "struct ifaddrs *ifap"
|
.Sh DESCRIPTION
|
.Sh DESCRIPTION
|
The
|
The
|
.Fn getifaddrs
|
.Fn getifaddrs
|
function stores a reference to a linked list of the network interfaces
|
function stores a reference to a linked list of the network interfaces
|
on the local machine in the memory referenced by
|
on the local machine in the memory referenced by
|
.Fa ifap .
|
.Fa ifap .
|
The list consists of
|
The list consists of
|
.Nm ifaddrs
|
.Nm ifaddrs
|
structures, as defined in the include file
|
structures, as defined in the include file
|
.Aq Pa ifaddrs.h .
|
.Aq Pa ifaddrs.h .
|
The
|
The
|
.Nm ifaddrs
|
.Nm ifaddrs
|
structure contains at least the following entries:
|
structure contains at least the following entries:
|
.Bd -literal
|
.Bd -literal
|
struct ifaddrs *ifa_next; /* Pointer to next struct */
|
struct ifaddrs *ifa_next; /* Pointer to next struct */
|
char *ifa_name; /* Interface name */
|
char *ifa_name; /* Interface name */
|
u_int ifa_flags; /* Interface flags */
|
u_int ifa_flags; /* Interface flags */
|
struct sockaddr *ifa_addr; /* Interface address */
|
struct sockaddr *ifa_addr; /* Interface address */
|
struct sockaddr *ifa_netmask; /* Interface netmask */
|
struct sockaddr *ifa_netmask; /* Interface netmask */
|
struct sockaddr *ifa_broadaddr; /* Interface broadcast address */
|
struct sockaddr *ifa_broadaddr; /* Interface broadcast address */
|
struct sockaddr *ifa_dstaddr; /* P2P interface destination */
|
struct sockaddr *ifa_dstaddr; /* P2P interface destination */
|
void *ifa_data; /* Address specific data */
|
void *ifa_data; /* Address specific data */
|
.Ed
|
.Ed
|
.Pp
|
.Pp
|
.Bl -tag -width Ds
|
.Bl -tag -width Ds
|
.It Fa ifa_next
|
.It Fa ifa_next
|
Contains a pointer to the next structure on the list.
|
Contains a pointer to the next structure on the list.
|
This field is set to
|
This field is set to
|
.Dv NULL
|
.Dv NULL
|
in last structure on the list.
|
in last structure on the list.
|
.It Fa ifa_name
|
.It Fa ifa_name
|
Contains the interface name.
|
Contains the interface name.
|
.It Fa ifa_flags
|
.It Fa ifa_flags
|
Contains the interface flags, as set by
|
Contains the interface flags, as set by
|
.Xr ifconfig 8 .
|
.Xr ifconfig 8 .
|
.It Fa ifa_addr
|
.It Fa ifa_addr
|
References either the address of the interface or the link level
|
References either the address of the interface or the link level
|
address of the interface, if one exists, otherwise it is
|
address of the interface, if one exists, otherwise it is
|
.Dv NULL .
|
.Dv NULL .
|
(The
|
(The
|
.Fa sa_family
|
.Fa sa_family
|
field of the
|
field of the
|
.Fa ifa_addr
|
.Fa ifa_addr
|
field should be consulted to determine the format of the
|
field should be consulted to determine the format of the
|
.Fa ifa_addr
|
.Fa ifa_addr
|
address.)
|
address.)
|
.It Fa ifa_netmask
|
.It Fa ifa_netmask
|
References the netmask associated with
|
References the netmask associated with
|
.Fa ifa_addr ,
|
.Fa ifa_addr ,
|
if one is set, otherwise it is
|
if one is set, otherwise it is
|
.Dv NULL .
|
.Dv NULL .
|
.It Fa ifa_broadaddr
|
.It Fa ifa_broadaddr
|
This field, which should only be referenced for non-P2P interfaces,
|
This field, which should only be referenced for non-P2P interfaces,
|
references the broadcast address associated with
|
references the broadcast address associated with
|
.Fa ifa_addr ,
|
.Fa ifa_addr ,
|
if one exists, otherwise it is
|
if one exists, otherwise it is
|
.Dv NULL .
|
.Dv NULL .
|
.It Fa ifa_dstaddr
|
.It Fa ifa_dstaddr
|
References the destination address on a P2P interface,
|
References the destination address on a P2P interface,
|
if one exists, otherwise it is
|
if one exists, otherwise it is
|
.Dv NULL .
|
.Dv NULL .
|
.It Fa ifa_data
|
.It Fa ifa_data
|
References address family specific data.
|
References address family specific data.
|
For
|
For
|
.Dv AF_LINK
|
.Dv AF_LINK
|
addresses it contains a pointer to the
|
addresses it contains a pointer to the
|
.Li struct if_data
|
.Li struct if_data
|
(as defined in include file
|
(as defined in include file
|
.Aq Pa net/if.h )
|
.Aq Pa net/if.h )
|
which contains various interface attributes and statistics.
|
which contains various interface attributes and statistics.
|
For all other address families, it contains a pointer to the
|
For all other address families, it contains a pointer to the
|
.Li struct ifa_data
|
.Li struct ifa_data
|
(as defined in include file
|
(as defined in include file
|
.Aq Pa net/if.h )
|
.Aq Pa net/if.h )
|
which contains per-address interface statistics.
|
which contains per-address interface statistics.
|
.El
|
.El
|
.Pp
|
.Pp
|
The data returned by
|
The data returned by
|
.Fn getifaddrs
|
.Fn getifaddrs
|
is dynamically allocated and should be freed using
|
is dynamically allocated and should be freed using
|
.Fn freeifaddrs
|
.Fn freeifaddrs
|
when no longer needed.
|
when no longer needed.
|
.Sh RETURN VALUES
|
.Sh RETURN VALUES
|
Upon successful completion, a value of 0 is returned.
|
Upon successful completion, a value of 0 is returned.
|
Otherwise, a value of \-1 is returned and
|
Otherwise, a value of \-1 is returned and
|
.Va errno
|
.Va errno
|
is set to indicate the error.
|
is set to indicate the error.
|
.Sh ERRORS
|
.Sh ERRORS
|
The
|
The
|
.Fn getifaddrs
|
.Fn getifaddrs
|
may fail and set
|
may fail and set
|
.Va errno
|
.Va errno
|
for any of the errors specified for the library routines
|
for any of the errors specified for the library routines
|
.Xr ioctl 2 ,
|
.Xr ioctl 2 ,
|
.Xr socket 2 ,
|
.Xr socket 2 ,
|
.Xr malloc 3 ,
|
.Xr malloc 3 ,
|
or
|
or
|
.Xr sysctl 3 .
|
.Xr sysctl 3 .
|
.Sh BUGS
|
.Sh BUGS
|
If both
|
If both
|
.Aq Pa net/if.h
|
.Aq Pa net/if.h
|
and
|
and
|
.Aq Pa ifaddrs.h
|
.Aq Pa ifaddrs.h
|
are being included,
|
are being included,
|
.Aq Pa net/if.h
|
.Aq Pa net/if.h
|
.Em must
|
.Em must
|
be included before
|
be included before
|
.Aq Pa ifaddrs.h .
|
.Aq Pa ifaddrs.h .
|
.Sh SEE ALSO
|
.Sh SEE ALSO
|
.Xr ioctl 2 ,
|
.Xr ioctl 2 ,
|
.Xr socket 2 ,
|
.Xr socket 2 ,
|
.Xr sysctl 3 ,
|
.Xr sysctl 3 ,
|
.Xr networking 4 ,
|
.Xr networking 4 ,
|
.Xr ifconfig 8
|
.Xr ifconfig 8
|
.Sh HISTORY
|
.Sh HISTORY
|
The
|
The
|
.Fn getifaddrs
|
.Fn getifaddrs
|
function first appeared in BSDI BSD/OS.
|
function first appeared in BSDI BSD/OS.
|
The function is supplied on
|
The function is supplied on
|
.Ox
|
.Ox
|
since
|
since
|
.Ox 2.7 .
|
.Ox 2.7 .
|
|
|
