Import rewrite of IPv4 socket multicast layer to support source-specific

and protocol-independent host mode multicast. The code is written to
accomodate IPv6, IGMPv3 and MLDv2 with only a little additional work.

This change only pertains to FreeBSD's use as a multicast end-station and
does not concern multicast routing; for an IGMPv3/MLDv2 router
implementation, consider the XORP project.

The work is based on Wilbert de Graaf's IGMPv3 code drop for FreeBSD 4.6,
which is available at: http://www.kloosterhof.com/wilbert/igmpv3.html

Summary
 * IPv4 multicast socket processing is now moved out of ip_output.c
   into a new module, in_mcast.c.
 * The in_mcast.c module implements the IPv4 legacy any-source API in
   terms of the protocol-independent source-specific API.
 * Source filters are lazy allocated as the common case does not use them.
   They are part of per inpcb state and are covered by the inpcb lock.
 * struct ip_mreqn is now supported to allow applications to specify
   multicast joins by interface index in the legacy IPv4 any-source API.
 * In UDP, an incoming multicast datagram only requires that the source
   port matches the 4-tuple if the socket was already bound by source port.
   An unbound socket SHOULD be able to receive multicasts sent from an
   ephemeral source port.
 * The UDP socket multicast filter mode defaults to exclusive, that is,
   sources present in the per-socket list will be blocked from delivery.
 * The RFC 3678 userland functions have been added to libc: setsourcefilter,
   getsourcefilter, setipv4sourcefilter, getipv4sourcefilter.
 * Definitions for IGMPv3 are merged but not yet used.
 * struct sockaddr_storage is now referenced from <netinet/in.h>. It
   is therefore defined there if not already declared in the same way
   as for the C99 types.
 * The RFC 1724 hack (specify 0.0.0.0/8 addresses to IP_MULTICAST_IF
   which are then interpreted as interface indexes) is now deprecated.
 * A patch for the Rhyolite.com routed in the FreeBSD base system
   is available in the -net archives. This only affects individuals
   running RIPv1 or RIPv2 via point-to-point and/or unnumbered interfaces.
 * Make IPv6 detach path similar to IPv4's in code flow; functionally same.
 * Bump __FreeBSD_version to 700048; see UPDATING.

This work was financially supported by another FreeBSD committer.

Obtained from:  p4://bms_netdev
Submitted by:   Wilbert de Graaf (original work)
Reviewed by:    rwatson (locking), silence from fenner,
		net@ (but with encouragement)

1 files changed, 20 insertions, 0 deletions

diff --git a/sys/netinet6/in6.h b/sys/netinet6/in6.h
index 4df2b87..380b8c3 100644
--- a/sys/netinet6/in6.h
+++ b/sys/netinet6/in6.h
@@ -467,6 +467,14 @@ struct route_in6 {
 				    * the source address.
 				    */
 
+/*
+ * The following option is private; do not use it from user applications.
+ * It is deliberately defined to the same value as IP_MSFILTER.
+ */
+#define	IPV6_MSFILTER		74 /* struct __msfilterreq;
+				    * set/get multicast source filter list.
+				    */
+
 /* to define items, should talk with KAME guys first, for *BSD compatibility */
 
 #define IPV6_RTHDR_LOOSE     0 /* this hop need not be a neighbor. XXX old spec */
@@ -487,6 +495,18 @@ struct ipv6_mreq {
 	unsigned int	ipv6mr_interface;
 };
 
+#ifdef notyet
+/*
+ * Argument structure for IPV6_ADD_SOURCE_MEMBERSHIP,
+ * IPV6_DROP_SOURCE_MEMBERSHIP, IPV6_BLOCK_SOURCE, and IPV6_UNBLOCK_SOURCE.
+ */
+struct ipv6_mreq_source {
+	struct in6_addr	ipv6mr_multiaddr;
+	struct in6_addr	ipv6mr_sourceaddr;
+	uint32_t	ipv6mr_interface;
+};
+#endif
+
 /*
  * IPV6_PKTINFO: Packet information(RFC2292 sec 5)
  */