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Diffstat (limited to 'lib/libc/net/getifmaddrs.3')
-rw-r--r-- | lib/libc/net/getifmaddrs.3 | 116 |
1 files changed, 116 insertions, 0 deletions
diff --git a/lib/libc/net/getifmaddrs.3 b/lib/libc/net/getifmaddrs.3 new file mode 100644 index 0000000..2d2a936 --- /dev/null +++ b/lib/libc/net/getifmaddrs.3 @@ -0,0 +1,116 @@ +.\" 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. +.\" +.\" $FreeBSD$ +.\" +.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 . |