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)

2 files changed, 8 insertions, 1 deletions

diff --git a/lib/libc/net/Makefile.inc b/lib/libc/net/Makefile.inc
index 3592f50..23c1c9d 100644
--- a/lib/libc/net/Makefile.inc
+++ b/lib/libc/net/Makefile.inc
@@ -14,7 +14,7 @@ SRCS+=	base64.c ether_addr.c eui64.c \
 	ip6opt.c linkaddr.c map_v4v6.c name6.c ntoh.c \
 	nsdispatch.c nslexer.c nsparser.c nss_compat.c \
 	rcmd.c rcmdsh.c recv.c rthdr.c sctp_sys_calls.c send.c \
-        sockatmark.c vars.c
+        sockatmark.c sourcefilter.c vars.c
 
 .if ${MK_NS_CACHING} != "no"
 SRCS+=	nscache.c nscachedcli.c
@@ -52,6 +52,7 @@ MAN+=	byteorder.3 ethers.3 eui64.3 \
 	inet6_opt_init.3 inet6_option_space.3 inet6_rth_space.3 \
 	inet6_rthdr_space.3 linkaddr.3 \
 	nsdispatch.3 rcmd.3 rcmdsh.3 resolver.3 sockatmark.3 \
+	setsourcefilter.3 \
         sctp_bindx.3 sctp_connectx.3 sctp_freepaddrs.3 \
         sctp_getaddrlen.3 sctp_getassocid.3 sctp_getpaddrs.3 \
         sctp_opt_info.3 sctp_recvmsg.3 sctp_send.3 sctp_sendmsg.3 \
@@ -121,6 +122,8 @@ MLINKS+=resolver.3 dn_comp.3 resolver.3 dn_expand.3 resolver.3 res_init.3 \
 	resolver.3 res_search.3 resolver.3 res_send.3 resolver.3 dn_skipname.3 \
 	resolver.3 ns_get16.3 resolver.3 ns_get32.3 \
 	resolver.3 ns_put16.3 resolver.3 ns_put32.3
+MLINKS+=sourcefilter.3 setipv4sourcefilter.3 getipv4sourcefilter.3 \
+	sourcefilter.3 setsourcefilter.3 getsourcefilter.3
 
 .if ${MK_HESIOD} != "no"
 SRCS+=	hesiod.c 
diff --git a/lib/libc/net/Symbol.map b/lib/libc/net/Symbol.map
index 7fb0f3b..de44cc5 100644
--- a/lib/libc/net/Symbol.map
+++ b/lib/libc/net/Symbol.map
@@ -137,6 +137,10 @@ FBSD_1.0 {
 	sctp_send;
 	sctp_sendx;
 	sctp_recvmsg;
+	setipv4sourcefilter;
+	getipv4sourcefilter;
+	getsourcefilter;
+	setsourcefilter;
 };
 
 FBSDprivate_1.0 {