plucky (3) lc_unshare.3.gz

NAME

       lc_share, lc_unshare - share and unshare files over multicast

LIBRARY

       Librecast library (liblibrecast, -llibrecast)

SYNOPSIS

       #include <librecast/net.h>

       lc_share_t *lc_share(lc_ctx_t *lctx, mdex_t *mdex, unsigned int ifx,
                       lc_stat_t *stats, lc_sync_options_t *opt, int flags);
       void lc_unshare(lc_share_t *share);

       Compile and link with -llibrecast.

DESCRIPTION

       The  lc_share function shares the objects indexed in mdex on the interface given by ifx.  If ifx is zero,
       the files are shared on all multicast-capable interfaces.

       lc_share starts MLD snooping (see IETF RFC 3810). When a join on a new IPv6 multicast group is  detected,
       this  is checked against the index provided by mdex.  If a matching object is found, this is added to the
       sending queue, and the data for this object continues to be sent until MLD reports that there are no more
       listeners for this group.

       The  data  sent  is  encoded  using  RaptorQ Forward Error Correction (see IETF RFC 6330), using the LCRQ
       library.

       If stats is not NULL, transfer statistics will be returned in this structure.

       opt is not used, at present, and must be NULL for compatibility with future versions.

       The flags argument is the bitwise OR of zero of more of the following flags:

       LC_SHARE_LOOPBACK
              Set the loopback option IPV6_MULTICAST_LOOP on the sending socket.

RETURN VALUE

       lc_share() returns a pointer to a lc_share_t handle, which should be freed  by  passing  to  lc_unshare()
       when done.  On error, NULL is returned, and errno is set to indicate the error.

       The lc_unshare() function returns no value, and preserves errno.

ERRORS

       ENOTSUP
              lc_share()  is not supported with your current configuration. This error occurs when the librecast
              library is built without MLD support.

       ENOMEM Not enough space/cannot allocate memory (POSIX.1-2001).

       EACCES Permission to create a socket of the specified type and/or protocol is denied.

NOTES

       lc_share uses MLD snooping from libmld to detect which multicast groups are  active,  which  uses  a  raw
       socket. On Linux, creating a raw socket requires CAP_NET_RAW.  See Capabilities(7).  On *BSD the creation
       of a raw socket is restricted to the superuser.  An application can drop these privileges  after  calling
       lc_share.

       To  restrict  syncing  to a particular network interface, call lc_ctx_ifx(3) to set the default interface
       for the Librecast context before calling the appropriate sync function.

SEE ALSO

       lc_ctx_new(3), lc_ctx_ifx(3), mdex_init(3), mdex_get(3), mdex_put(3), mdex_del(3), lcrq(7)