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, 55 insertions, 1 deletions

diff --git a/sys/netinet/igmp_var.h b/sys/netinet/igmp_var.h
index aa083a8..11c3769 100644
--- a/sys/netinet/igmp_var.h
+++ b/sys/netinet/igmp_var.h
@@ -56,6 +56,7 @@ struct igmpstat {
 	u_int	igps_rcv_badreports;	/* received invalid reports */
 	u_int	igps_rcv_ourreports;	/* received reports for our groups */
 	u_int	igps_snd_reports;	/* sent membership reports */
+	u_int	igps_rcv_toolong;	/* received with too many bytes */
 };
 
 #ifdef _KERNEL
@@ -68,12 +69,20 @@ struct igmpstat {
 #define IGMP_IREPORTEDLAST			1
 
 /*
+ * State masks for IGMPv3
+ */
+#define IGMP_V3_NONEXISTENT			0x01
+#define IGMP_V3_OTHERMEMBER			0x02
+#define IGMP_V3_IREPORTEDLAST			0x04
+
+/*
  * We must remember what version the subnet's querier is.
  * We conveniently use the IGMP message type for the proper
  * membership report to keep this state.
  */
 #define IGMP_V1_ROUTER				IGMP_V1_MEMBERSHIP_REPORT
 #define IGMP_V2_ROUTER				IGMP_V2_MEMBERSHIP_REPORT
+#define IGMP_V3_ROUTER				IGMP_V3_MEMBERSHIP_REPORT
 
 /*
  * Revert to new router if we haven't heard from an old router in
@@ -81,6 +90,51 @@ struct igmpstat {
  */
 #define IGMP_AGE_THRESHOLD			540
 
+/*
+ * IGMPv3 protocol defaults
+ */
+#define IGMP_INIT_ROBVAR	2	/* Robustness */
+#define IGMP_MAX_ROBVAR		7
+#define IGMP_INIT_QRYINT	125	/* Querier's Query interval */
+#define IGMP_MAX_QRYINT		255
+#define IGMP_INIT_QRYRSP	10	/* Query Response interval */
+#define IGMP_DEF_QRYMRT		10
+#define IGMP_UNSOL_INT		1	/* Unsolicited Report interval */
+
+/*
+ * IGMPv3 report types
+ */
+#define IGMP_REPORT_MODE_IN	1	/* mode-is-include */
+#define IGMP_REPORT_MODE_EX	2	/* mode-is-exclude */
+#define IGMP_REPORT_TO_IN	3	/* change-to-include */
+#define IGMP_REPORT_TO_EX	4	/* change-to-exclude */
+#define IGMP_REPORT_ALLOW_NEW	5	/* allow-new-sources */
+#define IGMP_REPORT_BLOCK_OLD	6	/* block-old-sources */
+
+/*
+ * Report types
+ */
+#define IGMP_MASK_CUR_STATE	0x01	/* Report current-state */
+#define IGMP_MASK_ALLOW_NEW	0x02	/* Report source as allow-new */
+#define IGMP_MASK_BLOCK_OLD	0x04	/* Report source as block-old */
+#define IGMP_MASK_TO_IN		0x08	/* Report source as to_in */
+#define IGMP_MASK_TO_EX		0x10	/* Report source as to_ex */
+#define IGMP_MASK_STATE_T1	0x20	/* State at T1 */
+#define IGMP_MASK_STATE_T2	0x40	/* State at T2 */
+#define IGMP_MASK_IF_STATE	0x80	/* Report current-state per interface */
+
+#define IGMP_MASK_STATE_TX	(IGMP_MASK_STATE_T1 | IGMP_MASK_STATE_T2)
+#define IGMP_MASK_PENDING	(IGMP_MASK_CUR_STATE |			\
+				 IGMP_MASK_ALLOW_NEW |			\
+				 IGMP_MASK_BLOCK_OLD)
+
+/*
+ * List identifiers
+ */
+#define IGMP_EXCLUDE_LIST	1	/* exclude list used to tag report */
+#define IGMP_INCLUDE_LIST	2	/* include list used to tag report */
+#define IGMP_RECORDED_LIST	3	/* recorded list used to tag report */
+
 void	igmp_init(void);
 void	igmp_input(struct mbuf *, int);
 void	igmp_joingroup(struct in_multi *);
@@ -100,6 +154,6 @@ SYSCTL_DECL(_net_inet_igmp);
 
 #define IGMPCTL_NAMES { \
 	{ 0, 0 }, \
-	{ "stats", CTLTYPE_STRUCT }, \
+	{ "stats", CTLTYPE_STRUCT } \
 }
 #endif