Re: Get multicast addresses from interface
On Thu, Oct 14, 2004 at 08:01:49AM -0700, Brooks Davis wrote: > On Thu, Oct 14, 2004 at 05:44:57PM +0400, Grigory Klyuchnikov wrote: > > How can a user process get IPv6 multicast addresses of ethernet > > interfaces? I have FreeBSD 5.2.1 and get interface addresses > > via ioctl(SIOCGIFCONF) or sysctl(witch NET_RT_IFLIST), > > but all returned addresses are unicast. > > getifaddrs(3) and getifmaddrs(3) may do what you want. See http://people.freebsd.org/~bms/dump/mcastlist/ for the original code (harti@ submitted most of the kernel bits). I didn't specifically set out to test getifmaddrs(3) with AF_INET6 addresses when I wrote it, but I seem to recall that it should work with them, from testing. If not, please feel free to submit a PR with a patch. Thanks, BMS pgpfeYl0of2Ky.pgp Description: PGP signature
Re: Get multicast addresses from interface
On Thu, Oct 14, 2004 at 05:44:57PM +0400, Grigory Klyuchnikov wrote:
> Hello,
>
> How can a user process get IPv6 multicast addresses of ethernet
> interfaces? I have FreeBSD 5.2.1 and get interface addresses
> via ioctl(SIOCGIFCONF) or sysctl(witch NET_RT_IFLIST),
> but all returned addresses are unicast.
getifaddrs(3) and getifmaddrs(3) may do what you want.
> In net/if.h there is a struct ifma_msghdr:
>
> /*
> * Message format for use in obtaining information about multicast addresses
> * from the routing socket
> */
> struct ifma_msghdr {
> u_short ifmam_msglen; /* to skip over non-understood messages */
> u_char ifmam_version; /* future binary compatibility */
> u_char ifmam_type; /* message type */
> int ifmam_addrs;/* like rtm_addrs */
> int ifmam_flags;/* value of ifa_flags */
> u_short ifmam_index;/* index for associated ifp */
> };
>
>
> How it may be used?
In addition to the functions above, you can directly access these
structures via sysctl (see src/lib/libc/net/getifmaddrs.c for an
example).
-- Brooks
--
Any statement of the form "X is the one, true Y" is FALSE.
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