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Date:      Wed, 29 Apr 2009 11:26:45 +0000 (UTC)
From:      Bruce M Simpson <bms@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r191665 - head/sys/netinet6
Message-ID:  <200904291126.n3TBQjVg079333@svn.freebsd.org>

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Author: bms
Date: Wed Apr 29 11:26:45 2009
New Revision: 191665
URL: http://svn.freebsd.org/changeset/base/191665

Log:
  Import IPv6 SSM module but do not connect it to the build.

Added:
  head/sys/netinet6/in6_mcast.c   (contents, props changed)

Added: head/sys/netinet6/in6_mcast.c
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/sys/netinet6/in6_mcast.c	Wed Apr 29 11:26:45 2009	(r191665)
@@ -0,0 +1,2625 @@
+/*
+ * Copyright (c) 2009 Bruce Simpson.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * IPv6 multicast socket, group, and socket option processing module.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "opt_inet6.h"
+#include "opt_route.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/malloc.h>
+#include <sys/mbuf.h>
+#include <sys/protosw.h>
+#include <sys/socket.h>
+#include <sys/socketvar.h>
+#include <sys/protosw.h>
+#include <sys/sysctl.h>
+#include <sys/priv.h>
+#include <sys/ktr.h>
+#include <sys/tree.h>
+#include <sys/vimage.h>
+
+#include <net/if.h>
+#include <net/if_dl.h>
+#include <net/route.h>
+#include <net/vnet.h>
+
+#include <netinet/in.h>
+#include <netinet/in_var.h>
+#include <netinet6/in6_var.h>
+#include <netinet/ip6.h>
+#include <netinet/icmp6.h>
+#include <netinet6/ip6_var.h>
+#include <netinet/in_pcb.h>
+#include <netinet/tcp_var.h>
+#include <netinet6/nd6.h>
+#include <netinet/vinet.h>
+#include <netinet6/vinet6.h>
+#include <netinet6/mld6_var.h>
+
+#ifndef KTR_MLD
+#define KTR_MLD KTR_INET6
+#endif
+
+#ifndef __SOCKUNION_DECLARED
+union sockunion {
+	struct sockaddr_storage	ss;
+	struct sockaddr		sa;
+	struct sockaddr_dl	sdl;
+	struct sockaddr_in6	sin6;
+};
+typedef union sockunion sockunion_t;
+#define __SOCKUNION_DECLARED
+#endif /* __SOCKUNION_DECLARED */
+
+static MALLOC_DEFINE(M_IN6MFILTER, "in6_mfilter",
+    "IPv6 multicast PCB-layer source filter");
+static MALLOC_DEFINE(M_IP6MADDR, "in6_multi", "IPv6 multicast group");
+static MALLOC_DEFINE(M_IP6MOPTS, "ip6_moptions", "IPv6 multicast options");
+static MALLOC_DEFINE(M_IP6MSOURCE, "ip6_msource",
+    "IPv6 multicast MLD-layer source filter");
+
+RB_GENERATE(ip6_msource_tree, ip6_msource, im6s_link, ip6_msource_cmp);
+
+/*
+ * Locking:
+ * - Lock order is: Giant, INP_WLOCK, IN6_MULTI_LOCK, MLD_LOCK, IF_ADDR_LOCK.
+ * - The IF_ADDR_LOCK is implicitly taken by in6m_lookup() earlier, however
+ *   it can be taken by code in net/if.c also.
+ * - ip6_moptions and in6_mfilter are covered by the INP_WLOCK.
+ *
+ * struct in6_multi is covered by IN6_MULTI_LOCK. There isn't strictly
+ * any need for in6_multi itself to be virtualized -- it is bound to an ifp
+ * anyway no matter what happens.
+ */
+struct mtx in6_multi_mtx;
+MTX_SYSINIT(in6_multi_mtx, &in6_multi_mtx, "in6_multi_mtx", MTX_DEF);
+
+static void	im6f_commit(struct in6_mfilter *);
+static int	im6f_get_source(struct in6_mfilter *imf,
+		    const struct sockaddr_in6 *psin,
+		    struct in6_msource **);
+static struct in6_msource *
+		im6f_graft(struct in6_mfilter *, const uint8_t,
+		    const struct sockaddr_in6 *);
+static void	im6f_leave(struct in6_mfilter *);
+static int	im6f_prune(struct in6_mfilter *, const struct sockaddr_in6 *);
+static void	im6f_purge(struct in6_mfilter *);
+static void	im6f_rollback(struct in6_mfilter *);
+static void	im6f_reap(struct in6_mfilter *);
+static int	im6o_grow(struct ip6_moptions *);
+static size_t	im6o_match_group(const struct ip6_moptions *,
+		    const struct ifnet *, const struct sockaddr *);
+static struct in6_msource *
+		im6o_match_source(const struct ip6_moptions *, const size_t,
+		    const struct sockaddr *);
+static void	im6s_merge(struct ip6_msource *ims,
+		    const struct in6_msource *lims, const int rollback);
+static int	in6_mc_get(struct ifnet *, const struct in6_addr *,
+		    struct in6_multi **);
+static int	in6m_get_source(struct in6_multi *inm,
+		    const struct in6_addr *addr, const int noalloc,
+		    struct ip6_msource **pims);
+static int	in6m_is_ifp_detached(const struct in6_multi *);
+static int	in6m_merge(struct in6_multi *, /*const*/ struct in6_mfilter *);
+static void	in6m_purge(struct in6_multi *);
+static void	in6m_reap(struct in6_multi *);
+static struct ip6_moptions *
+		in6p_findmoptions(struct inpcb *);
+static int	in6p_get_source_filters(struct inpcb *, struct sockopt *);
+static int	in6p_join_group(struct inpcb *, struct sockopt *);
+static int	in6p_leave_group(struct inpcb *, struct sockopt *);
+static int	in6p_block_unblock_source(struct inpcb *, struct sockopt *);
+static int	in6p_set_multicast_if(struct inpcb *, struct sockopt *);
+static int	in6p_set_source_filters(struct inpcb *, struct sockopt *);
+static int	sysctl_ip6_mcast_filters(SYSCTL_HANDLER_ARGS);
+
+SYSCTL_DECL(_net_inet6_ip6);	/* XXX Not in any common header. */
+
+SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, mcast, CTLFLAG_RW, 0, "IPv6 multicast");
+
+static u_long in6_mcast_maxgrpsrc = IPV6_MAX_GROUP_SRC_FILTER;
+SYSCTL_ULONG(_net_inet6_ip6_mcast, OID_AUTO, maxgrpsrc,
+    CTLFLAG_RW | CTLFLAG_TUN, &in6_mcast_maxgrpsrc, 0,
+    "Max source filters per group");
+TUNABLE_ULONG("net.inet6.ip6.mcast.maxgrpsrc", &in6_mcast_maxgrpsrc);
+
+static u_long in6_mcast_maxsocksrc = IPV6_MAX_SOCK_SRC_FILTER;
+SYSCTL_ULONG(_net_inet6_ip6_mcast, OID_AUTO, maxsocksrc,
+    CTLFLAG_RW | CTLFLAG_TUN, &in6_mcast_maxsocksrc, 0,
+    "Max source filters per socket");
+TUNABLE_ULONG("net.inet6.ip6.mcast.maxsocksrc", &in6_mcast_maxsocksrc);
+
+/* TODO Virtualize this switch. */
+int in6_mcast_loop = IPV6_DEFAULT_MULTICAST_LOOP;
+SYSCTL_INT(_net_inet6_ip6_mcast, OID_AUTO, loop, CTLFLAG_RW | CTLFLAG_TUN,
+    &in6_mcast_loop, 0, "Loopback multicast datagrams by default");
+TUNABLE_INT("net.inet6.ip6.mcast.loop", &in6_mcast_loop);
+
+SYSCTL_NODE(_net_inet6_ip6_mcast, OID_AUTO, filters,
+    CTLFLAG_RD | CTLFLAG_MPSAFE, sysctl_ip6_mcast_filters,
+    "Per-interface stack-wide source filters");
+
+/*
+ * Inline function which wraps assertions for a valid ifp.
+ * The ifnet layer will set the ifma's ifp pointer to NULL if the ifp
+ * is detached.
+ */
+static int __inline
+in6m_is_ifp_detached(const struct in6_multi *inm)
+{
+	struct ifnet *ifp;
+
+	KASSERT(inm->in6m_ifma != NULL, ("%s: no ifma", __func__));
+	ifp = inm->in6m_ifma->ifma_ifp;
+	if (ifp != NULL) {
+		/*
+		 * Sanity check that network-layer notion of ifp is the
+		 * same as that of link-layer.
+		 */
+		KASSERT(inm->in6m_ifp == ifp, ("%s: bad ifp", __func__));
+	}
+
+	return (ifp == NULL);
+}
+
+/*
+ * Initialize an in6_mfilter structure to a known state at t0, t1
+ * with an empty source filter list.
+ */
+static __inline void
+im6f_init(struct in6_mfilter *imf, const int st0, const int st1)
+{
+	memset(imf, 0, sizeof(struct in6_mfilter));
+	RB_INIT(&imf->im6f_sources);
+	imf->im6f_st[0] = st0;
+	imf->im6f_st[1] = st1;
+}
+
+/*
+ * Resize the ip6_moptions vector to the next power-of-two minus 1.
+ * May be called with locks held; do not sleep.
+ */
+static int
+im6o_grow(struct ip6_moptions *imo)
+{
+	struct in6_multi	**nmships;
+	struct in6_multi	**omships;
+	struct in6_mfilter	 *nmfilters;
+	struct in6_mfilter	 *omfilters;
+	size_t			  idx;
+	size_t			  newmax;
+	size_t			  oldmax;
+
+	nmships = NULL;
+	nmfilters = NULL;
+	omships = imo->im6o_membership;
+	omfilters = imo->im6o_mfilters;
+	oldmax = imo->im6o_max_memberships;
+	newmax = ((oldmax + 1) * 2) - 1;
+
+	if (newmax <= IPV6_MAX_MEMBERSHIPS) {
+		nmships = (struct in6_multi **)realloc(omships,
+		    sizeof(struct in6_multi *) * newmax, M_IP6MOPTS, M_NOWAIT);
+		nmfilters = (struct in6_mfilter *)realloc(omfilters,
+		    sizeof(struct in6_mfilter) * newmax, M_IN6MFILTER,
+		    M_NOWAIT);
+		if (nmships != NULL && nmfilters != NULL) {
+			/* Initialize newly allocated source filter heads. */
+			for (idx = oldmax; idx < newmax; idx++) {
+				im6f_init(&nmfilters[idx], MCAST_UNDEFINED,
+				    MCAST_EXCLUDE);
+			}
+			imo->im6o_max_memberships = newmax;
+			imo->im6o_membership = nmships;
+			imo->im6o_mfilters = nmfilters;
+		}
+	}
+
+	if (nmships == NULL || nmfilters == NULL) {
+		if (nmships != NULL)
+			free(nmships, M_IP6MOPTS);
+		if (nmfilters != NULL)
+			free(nmfilters, M_IN6MFILTER);
+		return (ETOOMANYREFS);
+	}
+
+	return (0);
+}
+
+/*
+ * Find an IPv6 multicast group entry for this ip6_moptions instance
+ * which matches the specified group, and optionally an interface.
+ * Return its index into the array, or -1 if not found.
+ */
+static size_t
+im6o_match_group(const struct ip6_moptions *imo, const struct ifnet *ifp,
+    const struct sockaddr *group)
+{
+	const struct sockaddr_in6 *gsin6;
+	struct in6_multi	**pinm;
+	int		  idx;
+	int		  nmships;
+
+	gsin6 = (const struct sockaddr_in6 *)group;
+
+	/* The im6o_membership array may be lazy allocated. */
+	if (imo->im6o_membership == NULL || imo->im6o_num_memberships == 0)
+		return (-1);
+
+	nmships = imo->im6o_num_memberships;
+	pinm = &imo->im6o_membership[0];
+	for (idx = 0; idx < nmships; idx++, pinm++) {
+		if (*pinm == NULL)
+			continue;
+		if ((ifp == NULL || ((*pinm)->in6m_ifp == ifp)) &&
+		    IN6_ARE_ADDR_EQUAL(&(*pinm)->in6m_addr,
+		    &gsin6->sin6_addr)) {
+			break;
+		}
+	}
+	if (idx >= nmships)
+		idx = -1;
+
+	return (idx);
+}
+
+/*
+ * Find an IPv6 multicast source entry for this imo which matches
+ * the given group index for this socket, and source address.
+ *
+ * NOTE: This does not check if the entry is in-mode, merely if
+ * it exists, which may not be the desired behaviour.
+ */
+static struct in6_msource *
+im6o_match_source(const struct ip6_moptions *imo, const size_t gidx,
+    const struct sockaddr *src)
+{
+	struct ip6_msource	 find;
+	struct in6_mfilter	*imf;
+	struct ip6_msource	*ims;
+	const sockunion_t	*psa;
+
+	KASSERT(src->sa_family == AF_INET6, ("%s: !AF_INET6", __func__));
+	KASSERT(gidx != -1 && gidx < imo->im6o_num_memberships,
+	    ("%s: invalid index %d\n", __func__, (int)gidx));
+
+	/* The im6o_mfilters array may be lazy allocated. */
+	if (imo->im6o_mfilters == NULL)
+		return (NULL);
+	imf = &imo->im6o_mfilters[gidx];
+
+	psa = (const sockunion_t *)src;
+	find.im6s_addr = psa->sin6.sin6_addr;
+	ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
+
+	return ((struct in6_msource *)ims);
+}
+
+/*
+ * Perform filtering for multicast datagrams on a socket by group and source.
+ *
+ * Returns 0 if a datagram should be allowed through, or various error codes
+ * if the socket was not a member of the group, or the source was muted, etc.
+ */
+int
+im6o_mc_filter(const struct ip6_moptions *imo, const struct ifnet *ifp,
+    const struct sockaddr *group, const struct sockaddr *src)
+{
+	size_t gidx;
+	struct in6_msource *ims;
+	int mode;
+
+	KASSERT(ifp != NULL, ("%s: null ifp", __func__));
+
+	gidx = im6o_match_group(imo, ifp, group);
+	if (gidx == -1)
+		return (MCAST_NOTGMEMBER);
+
+	/*
+	 * Check if the source was included in an (S,G) join.
+	 * Allow reception on exclusive memberships by default,
+	 * reject reception on inclusive memberships by default.
+	 * Exclude source only if an in-mode exclude filter exists.
+	 * Include source only if an in-mode include filter exists.
+	 * NOTE: We are comparing group state here at MLD t1 (now)
+	 * with socket-layer t0 (since last downcall).
+	 */
+	mode = imo->im6o_mfilters[gidx].im6f_st[1];
+	ims = im6o_match_source(imo, gidx, src);
+
+	if ((ims == NULL && mode == MCAST_INCLUDE) ||
+	    (ims != NULL && ims->im6sl_st[0] != mode))
+		return (MCAST_NOTSMEMBER);
+
+	return (MCAST_PASS);
+}
+
+/*
+ * Find and return a reference to an in6_multi record for (ifp, group),
+ * and bump its reference count.
+ * If one does not exist, try to allocate it, and update link-layer multicast
+ * filters on ifp to listen for group.
+ * Assumes the IN6_MULTI lock is held across the call.
+ * Return 0 if successful, otherwise return an appropriate error code.
+ */
+static int
+in6_mc_get(struct ifnet *ifp, const struct in6_addr *group,
+    struct in6_multi **pinm)
+{
+	struct sockaddr_in6	 gsin6;
+	struct ifmultiaddr	*ifma;
+	struct in6_multi	*inm;
+	int			 error;
+
+	error = 0;
+
+	/*
+	 * XXX: Accesses to ifma_protospec must be covered by IF_ADDR_LOCK;
+	 * if_addmulti() takes this mutex itself, so we must drop and
+	 * re-acquire around the call.
+	 */
+	IN6_MULTI_LOCK_ASSERT();
+	IF_ADDR_LOCK(ifp);
+
+	inm = in6m_lookup_locked(ifp, group);
+	if (inm != NULL) {
+		/*
+		 * If we already joined this group, just bump the
+		 * refcount and return it.
+		 */
+		KASSERT(inm->in6m_refcount >= 1,
+		    ("%s: bad refcount %d", __func__, inm->in6m_refcount));
+		++inm->in6m_refcount;
+		*pinm = inm;
+		goto out_locked;
+	}
+
+	memset(&gsin6, 0, sizeof(gsin6));
+	gsin6.sin6_family = AF_INET6;
+	gsin6.sin6_len = sizeof(struct sockaddr_in6);
+	gsin6.sin6_addr = *group;
+
+	/*
+	 * Check if a link-layer group is already associated
+	 * with this network-layer group on the given ifnet.
+	 */
+	IF_ADDR_UNLOCK(ifp);
+	error = if_addmulti(ifp, (struct sockaddr *)&gsin6, &ifma);
+	if (error != 0)
+		return (error);
+	IF_ADDR_LOCK(ifp);
+
+	/*
+	 * If something other than netinet6 is occupying the link-layer
+	 * group, print a meaningful error message and back out of
+	 * the allocation.
+	 * Otherwise, bump the refcount on the existing network-layer
+	 * group association and return it.
+	 */
+	if (ifma->ifma_protospec != NULL) {
+		inm = (struct in6_multi *)ifma->ifma_protospec;
+#ifdef INVARIANTS
+		KASSERT(ifma->ifma_addr != NULL, ("%s: no ifma_addr",
+		    __func__));
+		KASSERT(ifma->ifma_addr->sa_family == AF_INET6,
+		    ("%s: ifma not AF_INET6", __func__));
+		KASSERT(inm != NULL, ("%s: no ifma_protospec", __func__));
+		if (inm->in6m_ifma != ifma || inm->in6m_ifp != ifp ||
+		    !IN6_ARE_ADDR_EQUAL(&inm->in6m_addr, group))
+			panic("%s: ifma %p is inconsistent with %p (%p)",
+			    __func__, ifma, inm, group);
+#endif
+		++inm->in6m_refcount;
+		*pinm = inm;
+		goto out_locked;
+	}
+
+	IF_ADDR_LOCK_ASSERT(ifp);
+
+	/*
+	 * A new in6_multi record is needed; allocate and initialize it.
+	 * We DO NOT perform an MLD join as the in6_ layer may need to
+	 * push an initial source list down to MLD to support SSM.
+	 *
+	 * The initial source filter state is INCLUDE, {} as per the RFC.
+	 * Pending state-changes per group are subject to a bounds check.
+	 */
+	inm = malloc(sizeof(*inm), M_IP6MADDR, M_NOWAIT | M_ZERO);
+	if (inm == NULL) {
+		if_delmulti_ifma(ifma);
+		error = ENOMEM;
+		goto out_locked;
+	}
+	inm->in6m_addr = *group;
+	inm->in6m_ifp = ifp;
+	inm->in6m_mli = MLD_IFINFO(ifp);
+	inm->in6m_ifma = ifma;
+	inm->in6m_refcount = 1;
+	inm->in6m_state = MLD_NOT_MEMBER;
+	IFQ_SET_MAXLEN(&inm->in6m_scq, MLD_MAX_STATE_CHANGES);
+
+	inm->in6m_st[0].iss_fmode = MCAST_UNDEFINED;
+	inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
+	RB_INIT(&inm->in6m_srcs);
+
+	ifma->ifma_protospec = inm;
+	*pinm = inm;
+
+out_locked:
+	IF_ADDR_UNLOCK(ifp);
+	return (error);
+}
+
+/*
+ * Drop a reference to an in6_multi record.
+ *
+ * If the refcount drops to 0, free the in6_multi record and
+ * delete the underlying link-layer membership.
+ */
+void
+in6m_release_locked(struct in6_multi *inm)
+{
+	struct ifmultiaddr *ifma;
+
+	IN6_MULTI_LOCK_ASSERT();
+
+	CTR2(KTR_MLD, "%s: refcount is %d", __func__, inm->in6m_refcount);
+
+	if (--inm->in6m_refcount > 0) {
+		CTR2(KTR_MLD, "%s: refcount is now %d", __func__,
+		    inm->in6m_refcount);
+		return;
+	}
+
+	CTR2(KTR_MLD, "%s: freeing inm %p", __func__, inm);
+
+	ifma = inm->in6m_ifma;
+
+	/* XXX this access is not covered by IF_ADDR_LOCK */
+	CTR2(KTR_MLD, "%s: purging ifma %p", __func__, ifma);
+	KASSERT(ifma->ifma_protospec == inm,
+	    ("%s: ifma_protospec != inm", __func__));
+	ifma->ifma_protospec = NULL;
+
+	in6m_purge(inm);
+
+	free(inm, M_IP6MADDR);
+
+	if_delmulti_ifma(ifma);
+}
+
+/*
+ * Clear recorded source entries for a group.
+ * Used by the MLD code. Caller must hold the IN6_MULTI lock.
+ * FIXME: Should reap.
+ */
+void
+in6m_clear_recorded(struct in6_multi *inm)
+{
+	struct ip6_msource	*ims;
+
+	IN6_MULTI_LOCK_ASSERT();
+
+	RB_FOREACH(ims, ip6_msource_tree, &inm->in6m_srcs) {
+		if (ims->im6s_stp) {
+			ims->im6s_stp = 0;
+			--inm->in6m_st[1].iss_rec;
+		}
+	}
+	KASSERT(inm->in6m_st[1].iss_rec == 0,
+	    ("%s: iss_rec %d not 0", __func__, inm->in6m_st[1].iss_rec));
+}
+
+/*
+ * Record a source as pending for a Source-Group MLDv2 query.
+ * This lives here as it modifies the shared tree.
+ *
+ * inm is the group descriptor.
+ * naddr is the address of the source to record in network-byte order.
+ *
+ * If the net.inet6.mld.sgalloc sysctl is non-zero, we will
+ * lazy-allocate a source node in response to an SG query.
+ * Otherwise, no allocation is performed. This saves some memory
+ * with the trade-off that the source will not be reported to the
+ * router if joined in the window between the query response and
+ * the group actually being joined on the local host.
+ *
+ * VIMAGE: XXX: Currently the mld_sgalloc feature has been removed.
+ * This turns off the allocation of a recorded source entry if
+ * the group has not been joined.
+ *
+ * Return 0 if the source didn't exist or was already marked as recorded.
+ * Return 1 if the source was marked as recorded by this function.
+ * Return <0 if any error occured (negated errno code).
+ */
+int
+in6m_record_source(struct in6_multi *inm, const struct in6_addr *addr)
+{
+	struct ip6_msource	 find;
+	struct ip6_msource	*ims, *nims;
+
+	IN6_MULTI_LOCK_ASSERT();
+
+	find.im6s_addr = *addr;
+	ims = RB_FIND(ip6_msource_tree, &inm->in6m_srcs, &find);
+	if (ims && ims->im6s_stp)
+		return (0);
+	if (ims == NULL) {
+		if (inm->in6m_nsrc == in6_mcast_maxgrpsrc)
+			return (-ENOSPC);
+		nims = malloc(sizeof(struct ip6_msource), M_IP6MSOURCE,
+		    M_NOWAIT | M_ZERO);
+		if (nims == NULL)
+			return (-ENOMEM);
+		nims->im6s_addr = find.im6s_addr;
+		RB_INSERT(ip6_msource_tree, &inm->in6m_srcs, nims);
+		++inm->in6m_nsrc;
+		ims = nims;
+	}
+
+	/*
+	 * Mark the source as recorded and update the recorded
+	 * source count.
+	 */
+	++ims->im6s_stp;
+	++inm->in6m_st[1].iss_rec;
+
+	return (1);
+}
+
+/*
+ * Return a pointer to an in6_msource owned by an in6_mfilter,
+ * given its source address.
+ * Lazy-allocate if needed. If this is a new entry its filter state is
+ * undefined at t0.
+ *
+ * imf is the filter set being modified.
+ * addr is the source address.
+ *
+ * SMPng: May be called with locks held; malloc must not block.
+ */
+static int
+im6f_get_source(struct in6_mfilter *imf, const struct sockaddr_in6 *psin,
+    struct in6_msource **plims)
+{
+	struct ip6_msource	 find;
+	struct ip6_msource	*ims, *nims;
+	struct in6_msource	*lims;
+	int			 error;
+
+	error = 0;
+	ims = NULL;
+	lims = NULL;
+
+	find.im6s_addr = psin->sin6_addr;
+	ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
+	lims = (struct in6_msource *)ims;
+	if (lims == NULL) {
+		if (imf->im6f_nsrc == in6_mcast_maxsocksrc)
+			return (ENOSPC);
+		nims = malloc(sizeof(struct in6_msource), M_IN6MFILTER,
+		    M_NOWAIT | M_ZERO);
+		if (nims == NULL)
+			return (ENOMEM);
+		lims = (struct in6_msource *)nims;
+		lims->im6s_addr = find.im6s_addr;
+		lims->im6sl_st[0] = MCAST_UNDEFINED;
+		RB_INSERT(ip6_msource_tree, &imf->im6f_sources, nims);
+		++imf->im6f_nsrc;
+	}
+
+	*plims = lims;
+
+	return (error);
+}
+
+/*
+ * Graft a source entry into an existing socket-layer filter set,
+ * maintaining any required invariants and checking allocations.
+ *
+ * The source is marked as being in the new filter mode at t1.
+ *
+ * Return the pointer to the new node, otherwise return NULL.
+ */
+static struct in6_msource *
+im6f_graft(struct in6_mfilter *imf, const uint8_t st1,
+    const struct sockaddr_in6 *psin)
+{
+	struct ip6_msource	*nims;
+	struct in6_msource	*lims;
+
+	nims = malloc(sizeof(struct in6_msource), M_IN6MFILTER,
+	    M_NOWAIT | M_ZERO);
+	if (nims == NULL)
+		return (NULL);
+	lims = (struct in6_msource *)nims;
+	lims->im6s_addr = psin->sin6_addr;
+	lims->im6sl_st[0] = MCAST_UNDEFINED;
+	lims->im6sl_st[1] = st1;
+	RB_INSERT(ip6_msource_tree, &imf->im6f_sources, nims);
+	++imf->im6f_nsrc;
+
+	return (lims);
+}
+
+/*
+ * Prune a source entry from an existing socket-layer filter set,
+ * maintaining any required invariants and checking allocations.
+ *
+ * The source is marked as being left at t1, it is not freed.
+ *
+ * Return 0 if no error occurred, otherwise return an errno value.
+ */
+static int
+im6f_prune(struct in6_mfilter *imf, const struct sockaddr_in6 *psin)
+{
+	struct ip6_msource	 find;
+	struct ip6_msource	*ims;
+	struct in6_msource	*lims;
+
+	find.im6s_addr = psin->sin6_addr;
+	ims = RB_FIND(ip6_msource_tree, &imf->im6f_sources, &find);
+	if (ims == NULL)
+		return (ENOENT);
+	lims = (struct in6_msource *)ims;
+	lims->im6sl_st[1] = MCAST_UNDEFINED;
+	return (0);
+}
+
+/*
+ * Revert socket-layer filter set deltas at t1 to t0 state.
+ */
+static void
+im6f_rollback(struct in6_mfilter *imf)
+{
+	struct ip6_msource	*ims, *tims;
+	struct in6_msource	*lims;
+
+	RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
+		lims = (struct in6_msource *)ims;
+		if (lims->im6sl_st[0] == lims->im6sl_st[1]) {
+			/* no change at t1 */
+			continue;
+		} else if (lims->im6sl_st[0] != MCAST_UNDEFINED) {
+			/* revert change to existing source at t1 */
+			lims->im6sl_st[1] = lims->im6sl_st[0];
+		} else {
+			/* revert source added t1 */
+			CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
+			RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
+			free(ims, M_IN6MFILTER);
+			imf->im6f_nsrc--;
+		}
+	}
+	imf->im6f_st[1] = imf->im6f_st[0];
+}
+
+/*
+ * Mark socket-layer filter set as INCLUDE {} at t1.
+ */
+static void
+im6f_leave(struct in6_mfilter *imf)
+{
+	struct ip6_msource	*ims;
+	struct in6_msource	*lims;
+
+	RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
+		lims = (struct in6_msource *)ims;
+		lims->im6sl_st[1] = MCAST_UNDEFINED;
+	}
+	imf->im6f_st[1] = MCAST_INCLUDE;
+}
+
+/*
+ * Mark socket-layer filter set deltas as committed.
+ */
+static void
+im6f_commit(struct in6_mfilter *imf)
+{
+	struct ip6_msource	*ims;
+	struct in6_msource	*lims;
+
+	RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
+		lims = (struct in6_msource *)ims;
+		lims->im6sl_st[0] = lims->im6sl_st[1];
+	}
+	imf->im6f_st[0] = imf->im6f_st[1];
+}
+
+/*
+ * Reap unreferenced sources from socket-layer filter set.
+ */
+static void
+im6f_reap(struct in6_mfilter *imf)
+{
+	struct ip6_msource	*ims, *tims;
+	struct in6_msource	*lims;
+
+	RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
+		lims = (struct in6_msource *)ims;
+		if ((lims->im6sl_st[0] == MCAST_UNDEFINED) &&
+		    (lims->im6sl_st[1] == MCAST_UNDEFINED)) {
+			CTR2(KTR_MLD, "%s: free lims %p", __func__, ims);
+			RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
+			free(ims, M_IN6MFILTER);
+			imf->im6f_nsrc--;
+		}
+	}
+}
+
+/*
+ * Purge socket-layer filter set.
+ */
+static void
+im6f_purge(struct in6_mfilter *imf)
+{
+	struct ip6_msource	*ims, *tims;
+
+	RB_FOREACH_SAFE(ims, ip6_msource_tree, &imf->im6f_sources, tims) {
+		CTR2(KTR_MLD, "%s: free ims %p", __func__, ims);
+		RB_REMOVE(ip6_msource_tree, &imf->im6f_sources, ims);
+		free(ims, M_IN6MFILTER);
+		imf->im6f_nsrc--;
+	}
+	imf->im6f_st[0] = imf->im6f_st[1] = MCAST_UNDEFINED;
+	KASSERT(RB_EMPTY(&imf->im6f_sources),
+	    ("%s: im6f_sources not empty", __func__));
+}
+
+/*
+ * Look up a source filter entry for a multicast group.
+ *
+ * inm is the group descriptor to work with.
+ * addr is the IPv6 address to look up.
+ * noalloc may be non-zero to suppress allocation of sources.
+ * *pims will be set to the address of the retrieved or allocated source.
+ *
+ * SMPng: NOTE: may be called with locks held.
+ * Return 0 if successful, otherwise return a non-zero error code.
+ */
+static int
+in6m_get_source(struct in6_multi *inm, const struct in6_addr *addr,
+    const int noalloc, struct ip6_msource **pims)
+{
+	struct ip6_msource	 find;
+	struct ip6_msource	*ims, *nims;
+#ifdef KTR
+	char			 ip6tbuf[INET6_ADDRSTRLEN];
+#endif
+
+	find.im6s_addr = *addr;
+	ims = RB_FIND(ip6_msource_tree, &inm->in6m_srcs, &find);
+	if (ims == NULL && !noalloc) {
+		if (inm->in6m_nsrc == in6_mcast_maxgrpsrc)
+			return (ENOSPC);
+		nims = malloc(sizeof(struct ip6_msource), M_IP6MSOURCE,
+		    M_NOWAIT | M_ZERO);
+		if (nims == NULL)
+			return (ENOMEM);
+		nims->im6s_addr = *addr;
+		RB_INSERT(ip6_msource_tree, &inm->in6m_srcs, nims);
+		++inm->in6m_nsrc;
+		ims = nims;
+		CTR3(KTR_MLD, "%s: allocated %s as %p", __func__,
+		    ip6_sprintf(ip6tbuf, addr), ims);
+	}
+
+	*pims = ims;
+	return (0);
+}
+
+/*
+ * Merge socket-layer source into MLD-layer source.
+ * If rollback is non-zero, perform the inverse of the merge.
+ */
+static void
+im6s_merge(struct ip6_msource *ims, const struct in6_msource *lims,
+    const int rollback)
+{
+	int n = rollback ? -1 : 1;
+#ifdef KTR
+	char ip6tbuf[INET6_ADDRSTRLEN];
+
+	ip6_sprintf(ip6tbuf, &lims->im6s_addr);
+#endif
+
+	if (lims->im6sl_st[0] == MCAST_EXCLUDE) {
+		CTR3(KTR_MLD, "%s: t1 ex -= %d on %s", __func__, n, ip6tbuf);
+		ims->im6s_st[1].ex -= n;
+	} else if (lims->im6sl_st[0] == MCAST_INCLUDE) {
+		CTR3(KTR_MLD, "%s: t1 in -= %d on %s", __func__, n, ip6tbuf);
+		ims->im6s_st[1].in -= n;
+	}
+
+	if (lims->im6sl_st[1] == MCAST_EXCLUDE) {
+		CTR3(KTR_MLD, "%s: t1 ex += %d on %s", __func__, n, ip6tbuf);
+		ims->im6s_st[1].ex += n;
+	} else if (lims->im6sl_st[1] == MCAST_INCLUDE) {
+		CTR3(KTR_MLD, "%s: t1 in += %d on %s", __func__, n, ip6tbuf);
+		ims->im6s_st[1].in += n;
+	}
+}
+
+/*
+ * Atomically update the global in6_multi state, when a membership's
+ * filter list is being updated in any way.
+ *
+ * imf is the per-inpcb-membership group filter pointer.
+ * A fake imf may be passed for in-kernel consumers.
+ *
+ * XXX This is a candidate for a set-symmetric-difference style loop
+ * which would eliminate the repeated lookup from root of ims nodes,
+ * as they share the same key space.
+ *
+ * If any error occurred this function will back out of refcounts
+ * and return a non-zero value.
+ */
+static int
+in6m_merge(struct in6_multi *inm, /*const*/ struct in6_mfilter *imf)
+{
+	struct ip6_msource	*ims, *nims;
+	struct in6_msource	*lims;
+	int			 schanged, error;
+	int			 nsrc0, nsrc1;
+
+	schanged = 0;
+	error = 0;
+	nsrc1 = nsrc0 = 0;
+
+	/*
+	 * Update the source filters first, as this may fail.
+	 * Maintain count of in-mode filters at t0, t1. These are
+	 * used to work out if we transition into ASM mode or not.
+	 * Maintain a count of source filters whose state was
+	 * actually modified by this operation.
+	 */
+	RB_FOREACH(ims, ip6_msource_tree, &imf->im6f_sources) {
+		lims = (struct in6_msource *)ims;
+		if (lims->im6sl_st[0] == imf->im6f_st[0]) nsrc0++;
+		if (lims->im6sl_st[1] == imf->im6f_st[1]) nsrc1++;
+		if (lims->im6sl_st[0] == lims->im6sl_st[1]) continue;
+		error = in6m_get_source(inm, &lims->im6s_addr, 0, &nims);
+		++schanged;
+		if (error)
+			break;
+		im6s_merge(nims, lims, 0);
+	}
+	if (error) {
+		struct ip6_msource *bims;
+
+		RB_FOREACH_REVERSE_FROM(ims, ip6_msource_tree, nims) {
+			lims = (struct in6_msource *)ims;
+			if (lims->im6sl_st[0] == lims->im6sl_st[1])
+				continue;
+			(void)in6m_get_source(inm, &lims->im6s_addr, 1, &bims);
+			if (bims == NULL)
+				continue;
+			im6s_merge(bims, lims, 1);
+		}
+		goto out_reap;
+	}
+
+	CTR3(KTR_MLD, "%s: imf filters in-mode: %d at t0, %d at t1",
+	    __func__, nsrc0, nsrc1);
+
+	/* Handle transition between INCLUDE {n} and INCLUDE {} on socket. */
+	if (imf->im6f_st[0] == imf->im6f_st[1] &&
+	    imf->im6f_st[1] == MCAST_INCLUDE) {
+		if (nsrc1 == 0) {
+			CTR1(KTR_MLD, "%s: --in on inm at t1", __func__);
+			--inm->in6m_st[1].iss_in;
+		}
+	}
+
+	/* Handle filter mode transition on socket. */
+	if (imf->im6f_st[0] != imf->im6f_st[1]) {
+		CTR3(KTR_MLD, "%s: imf transition %d to %d",
+		    __func__, imf->im6f_st[0], imf->im6f_st[1]);
+
+		if (imf->im6f_st[0] == MCAST_EXCLUDE) {
+			CTR1(KTR_MLD, "%s: --ex on inm at t1", __func__);
+			--inm->in6m_st[1].iss_ex;
+		} else if (imf->im6f_st[0] == MCAST_INCLUDE) {
+			CTR1(KTR_MLD, "%s: --in on inm at t1", __func__);
+			--inm->in6m_st[1].iss_in;
+		}
+
+		if (imf->im6f_st[1] == MCAST_EXCLUDE) {
+			CTR1(KTR_MLD, "%s: ex++ on inm at t1", __func__);
+			inm->in6m_st[1].iss_ex++;
+		} else if (imf->im6f_st[1] == MCAST_INCLUDE && nsrc1 > 0) {
+			CTR1(KTR_MLD, "%s: in++ on inm at t1", __func__);
+			inm->in6m_st[1].iss_in++;
+		}
+	}
+
+	/*
+	 * Track inm filter state in terms of listener counts.
+	 * If there are any exclusive listeners, stack-wide
+	 * membership is exclusive.
+	 * Otherwise, if only inclusive listeners, stack-wide is inclusive.
+	 * If no listeners remain, state is undefined at t1,
+	 * and the MLD lifecycle for this group should finish.
+	 */
+	if (inm->in6m_st[1].iss_ex > 0) {
+		CTR1(KTR_MLD, "%s: transition to EX", __func__);
+		inm->in6m_st[1].iss_fmode = MCAST_EXCLUDE;
+	} else if (inm->in6m_st[1].iss_in > 0) {
+		CTR1(KTR_MLD, "%s: transition to IN", __func__);
+		inm->in6m_st[1].iss_fmode = MCAST_INCLUDE;
+	} else {
+		CTR1(KTR_MLD, "%s: transition to UNDEF", __func__);
+		inm->in6m_st[1].iss_fmode = MCAST_UNDEFINED;
+	}
+
+	/* Decrement ASM listener count on transition out of ASM mode. */
+	if (imf->im6f_st[0] == MCAST_EXCLUDE && nsrc0 == 0) {
+		if ((imf->im6f_st[1] != MCAST_EXCLUDE) ||
+		    (imf->im6f_st[1] == MCAST_EXCLUDE && nsrc1 > 0))
+			CTR1(KTR_MLD, "%s: --asm on inm at t1", __func__);
+			--inm->in6m_st[1].iss_asm;
+	}
+
+	/* Increment ASM listener count on transition to ASM mode. */

*** DIFF OUTPUT TRUNCATED AT 1000 LINES ***



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