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, 48 insertions, 0 deletions

diff --git a/sys/netinet/in_var.h b/sys/netinet/in_var.h
index 7605199..47a160a 100644
--- a/sys/netinet/in_var.h
+++ b/sys/netinet/in_var.h
@@ -147,6 +147,12 @@ struct router_info {
 	int    rti_type; /* type of router which is querier on this interface */
 	int    rti_time; /* # of slow timeouts since last old query */
 	SLIST_ENTRY(router_info) rti_list;
+#ifdef notyet
+	int	rti_timev1;	/* IGMPv1 querier present */
+	int	rti_timev2;	/* IGMPv2 querier present */
+	int	rti_timer;	/* report to general query */
+	int	rti_qrv;	/* querier robustness */
+#endif
 };
 
 /*
@@ -166,7 +172,43 @@ struct in_multi {
 	u_int	inm_state;		/*  state of the membership */
 	struct	router_info *inm_rti;	/* router info*/
 	u_int	inm_refcount;		/* reference count */
+#ifdef notyet		/* IGMPv3 source-specific multicast fields */
+	TAILQ_HEAD(, in_msfentry) inm_msf;	/* all active source filters */
+	TAILQ_HEAD(, in_msfentry) inm_msf_record;	/* recorded sources */
+	TAILQ_HEAD(, in_msfentry) inm_msf_exclude;	/* exclude sources */
+	TAILQ_HEAD(, in_msfentry) inm_msf_include;	/* include sources */
+	/* XXX: should this lot go to the router_info structure? */
+	/* XXX: can/should these be callouts? */
+	/* IGMP protocol timers */
+	int32_t		inm_ti_curstate;	/* current state timer */
+	int32_t		inm_ti_statechg;	/* state change timer */
+	/* IGMP report timers */
+	uint16_t	inm_rpt_statechg;	/* state change report timer */
+	uint16_t	inm_rpt_toxx;		/* fmode change report timer */
+	/* IGMP protocol state */
+	uint16_t	inm_fmode;		/* filter mode */
+	uint32_t	inm_recsrc_count;	/* # of recorded sources */
+	uint16_t	inm_exclude_sock_count;	/* # of exclude-mode sockets */
+	uint16_t	inm_gass_count;		/* # of g-a-s queries */
+#endif
+};
+
+#ifdef notyet
+/*
+ * Internet multicast source filter list. This list is used to store
+ * IP multicast source addresses for each membership on an interface.
+ * TODO: Allocate these structures using UMA.
+ * TODO: Find an easier way of linking the struct into two lists at once.
+ */
+struct in_msfentry {
+	TAILQ_ENTRY(in_msfentry) isf_link;	/* next filter in all-list */
+	TAILQ_ENTRY(in_msfentry) isf_next;	/* next filter in queue */
+	struct in_addr	isf_addr;	/* the address of this source */
+	uint16_t	isf_refcount;	/* reference count */
+	uint16_t	isf_reporttag;	/* what to report to the IGMP router */
+	uint16_t	isf_rexmit;	/* retransmission state/count */
 };
+#endif
 
 #ifdef _KERNEL
 
@@ -246,6 +288,12 @@ do { \
 } while(0)
 
 struct	route;
+struct	ip_moptions;
+
+size_t	imo_match_group(struct ip_moptions *, struct ifnet *,
+	    struct sockaddr *);
+struct	in_msource *imo_match_source(struct ip_moptions *, size_t,
+	    struct sockaddr *);
 struct	in_multi *in_addmulti(struct in_addr *, struct ifnet *);
 void	in_delmulti(struct in_multi *);
 void	in_delmulti_locked(struct in_multi *);