Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 3110 insertions, 0 deletions

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
new file mode 100644
index 000000000..ac53ef7ee
--- /dev/null
+++ b/net/ipv4/igmp.c
@@ -0,0 +1,3110 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	Linux NET3:	Internet Group Management Protocol  [IGMP]
+ *
+ *	This code implements the IGMP protocol as defined in RFC1112. There has
+ *	been a further revision of this protocol since which is now supported.
+ *
+ *	If you have trouble with this module be careful what gcc you have used,
+ *	the older version didn't come out right using gcc 2.5.8, the newer one
+ *	seems to fall out with gcc 2.6.2.
+ *
+ *	Authors:
+ *		Alan Cox <alan@lxorguk.ukuu.org.uk>
+ *
+ *	Fixes:
+ *
+ *		Alan Cox	:	Added lots of __inline__ to optimise
+ *					the memory usage of all the tiny little
+ *					functions.
+ *		Alan Cox	:	Dumped the header building experiment.
+ *		Alan Cox	:	Minor tweaks ready for multicast routing
+ *					and extended IGMP protocol.
+ *		Alan Cox	:	Removed a load of inline directives. Gcc 2.5.8
+ *					writes utterly bogus code otherwise (sigh)
+ *					fixed IGMP loopback to behave in the manner
+ *					desired by mrouted, fixed the fact it has been
+ *					broken since 1.3.6 and cleaned up a few minor
+ *					points.
+ *
+ *		Chih-Jen Chang	:	Tried to revise IGMP to Version 2
+ *		Tsu-Sheng Tsao		E-mail: chihjenc@scf.usc.edu and tsusheng@scf.usc.edu
+ *					The enhancements are mainly based on Steve Deering's
+ * 					ipmulti-3.5 source code.
+ *		Chih-Jen Chang	:	Added the igmp_get_mrouter_info and
+ *		Tsu-Sheng Tsao		igmp_set_mrouter_info to keep track of
+ *					the mrouted version on that device.
+ *		Chih-Jen Chang	:	Added the max_resp_time parameter to
+ *		Tsu-Sheng Tsao		igmp_heard_query(). Using this parameter
+ *					to identify the multicast router version
+ *					and do what the IGMP version 2 specified.
+ *		Chih-Jen Chang	:	Added a timer to revert to IGMP V2 router
+ *		Tsu-Sheng Tsao		if the specified time expired.
+ *		Alan Cox	:	Stop IGMP from 0.0.0.0 being accepted.
+ *		Alan Cox	:	Use GFP_ATOMIC in the right places.
+ *		Christian Daudt :	igmp timer wasn't set for local group
+ *					memberships but was being deleted,
+ *					which caused a "del_timer() called
+ *					from %p with timer not initialized\n"
+ *					message (960131).
+ *		Christian Daudt :	removed del_timer from
+ *					igmp_timer_expire function (960205).
+ *             Christian Daudt :       igmp_heard_report now only calls
+ *                                     igmp_timer_expire if tm->running is
+ *                                     true (960216).
+ *		Malcolm Beattie :	ttl comparison wrong in igmp_rcv made
+ *					igmp_heard_query never trigger. Expiry
+ *					miscalculation fixed in igmp_heard_query
+ *					and random() made to return unsigned to
+ *					prevent negative expiry times.
+ *		Alexey Kuznetsov:	Wrong group leaving behaviour, backport
+ *					fix from pending 2.1.x patches.
+ *		Alan Cox:		Forget to enable FDDI support earlier.
+ *		Alexey Kuznetsov:	Fixed leaving groups on device down.
+ *		Alexey Kuznetsov:	Accordance to igmp-v2-06 draft.
+ *		David L Stevens:	IGMPv3 support, with help from
+ *					Vinay Kulkarni
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/in.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/inetdevice.h>
+#include <linux/igmp.h>
+#include <linux/if_arp.h>
+#include <linux/rtnetlink.h>
+#include <linux/times.h>
+#include <linux/pkt_sched.h>
+#include <linux/byteorder/generic.h>
+
+#include <net/net_namespace.h>
+#include <net/arp.h>
+#include <net/ip.h>
+#include <net/protocol.h>
+#include <net/route.h>
+#include <net/sock.h>
+#include <net/checksum.h>
+#include <net/inet_common.h>
+#include <linux/netfilter_ipv4.h>
+#ifdef CONFIG_IP_MROUTE
+#include <linux/mroute.h>
+#endif
+#ifdef CONFIG_PROC_FS
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#endif
+
+#ifdef CONFIG_IP_MULTICAST
+/* Parameter names and values are taken from igmp-v2-06 draft */
+
+#define IGMP_QUERY_INTERVAL			(125*HZ)
+#define IGMP_QUERY_RESPONSE_INTERVAL		(10*HZ)
+
+#define IGMP_INITIAL_REPORT_DELAY		(1)
+
+/* IGMP_INITIAL_REPORT_DELAY is not from IGMP specs!
+ * IGMP specs require to report membership immediately after
+ * joining a group, but we delay the first report by a
+ * small interval. It seems more natural and still does not
+ * contradict to specs provided this delay is small enough.
+ */
+
+#define IGMP_V1_SEEN(in_dev) \
+	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 1 || \
+	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 1 || \
+	 ((in_dev)->mr_v1_seen && \
+	  time_before(jiffies, (in_dev)->mr_v1_seen)))
+#define IGMP_V2_SEEN(in_dev) \
+	(IPV4_DEVCONF_ALL(dev_net(in_dev->dev), FORCE_IGMP_VERSION) == 2 || \
+	 IN_DEV_CONF_GET((in_dev), FORCE_IGMP_VERSION) == 2 || \
+	 ((in_dev)->mr_v2_seen && \
+	  time_before(jiffies, (in_dev)->mr_v2_seen)))
+
+static int unsolicited_report_interval(struct in_device *in_dev)
+{
+	int interval_ms, interval_jiffies;
+
+	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
+		interval_ms = IN_DEV_CONF_GET(
+			in_dev,
+			IGMPV2_UNSOLICITED_REPORT_INTERVAL);
+	else /* v3 */
+		interval_ms = IN_DEV_CONF_GET(
+			in_dev,
+			IGMPV3_UNSOLICITED_REPORT_INTERVAL);
+
+	interval_jiffies = msecs_to_jiffies(interval_ms);
+
+	/* _timer functions can't handle a delay of 0 jiffies so ensure
+	 *  we always return a positive value.
+	 */
+	if (interval_jiffies <= 0)
+		interval_jiffies = 1;
+	return interval_jiffies;
+}
+
+static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
+			      gfp_t gfp);
+static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im);
+static void igmpv3_clear_delrec(struct in_device *in_dev);
+static int sf_setstate(struct ip_mc_list *pmc);
+static void sf_markstate(struct ip_mc_list *pmc);
+#endif
+static void ip_mc_clear_src(struct ip_mc_list *pmc);
+static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
+			 int sfcount, __be32 *psfsrc, int delta);
+
+static void ip_ma_put(struct ip_mc_list *im)
+{
+	if (refcount_dec_and_test(&im->refcnt)) {
+		in_dev_put(im->interface);
+		kfree_rcu(im, rcu);
+	}
+}
+
+#define for_each_pmc_rcu(in_dev, pmc)				\
+	for (pmc = rcu_dereference(in_dev->mc_list);		\
+	     pmc != NULL;					\
+	     pmc = rcu_dereference(pmc->next_rcu))
+
+#define for_each_pmc_rtnl(in_dev, pmc)				\
+	for (pmc = rtnl_dereference(in_dev->mc_list);		\
+	     pmc != NULL;					\
+	     pmc = rtnl_dereference(pmc->next_rcu))
+
+static void ip_sf_list_clear_all(struct ip_sf_list *psf)
+{
+	struct ip_sf_list *next;
+
+	while (psf) {
+		next = psf->sf_next;
+		kfree(psf);
+		psf = next;
+	}
+}
+
+#ifdef CONFIG_IP_MULTICAST
+
+/*
+ *	Timer management
+ */
+
+static void igmp_stop_timer(struct ip_mc_list *im)
+{
+	spin_lock_bh(&im->lock);
+	if (del_timer(&im->timer))
+		refcount_dec(&im->refcnt);
+	im->tm_running = 0;
+	im->reporter = 0;
+	im->unsolicit_count = 0;
+	spin_unlock_bh(&im->lock);
+}
+
+/* It must be called with locked im->lock */
+static void igmp_start_timer(struct ip_mc_list *im, int max_delay)
+{
+	int tv = prandom_u32_max(max_delay);
+
+	im->tm_running = 1;
+	if (refcount_inc_not_zero(&im->refcnt)) {
+		if (mod_timer(&im->timer, jiffies + tv + 2))
+			ip_ma_put(im);
+	}
+}
+
+static void igmp_gq_start_timer(struct in_device *in_dev)
+{
+	int tv = prandom_u32_max(in_dev->mr_maxdelay);
+	unsigned long exp = jiffies + tv + 2;
+
+	if (in_dev->mr_gq_running &&
+	    time_after_eq(exp, (in_dev->mr_gq_timer).expires))
+		return;
+
+	in_dev->mr_gq_running = 1;
+	if (!mod_timer(&in_dev->mr_gq_timer, exp))
+		in_dev_hold(in_dev);
+}
+
+static void igmp_ifc_start_timer(struct in_device *in_dev, int delay)
+{
+	int tv = prandom_u32_max(delay);
+
+	if (!mod_timer(&in_dev->mr_ifc_timer, jiffies+tv+2))
+		in_dev_hold(in_dev);
+}
+
+static void igmp_mod_timer(struct ip_mc_list *im, int max_delay)
+{
+	spin_lock_bh(&im->lock);
+	im->unsolicit_count = 0;
+	if (del_timer(&im->timer)) {
+		if ((long)(im->timer.expires-jiffies) < max_delay) {
+			add_timer(&im->timer);
+			im->tm_running = 1;
+			spin_unlock_bh(&im->lock);
+			return;
+		}
+		refcount_dec(&im->refcnt);
+	}
+	igmp_start_timer(im, max_delay);
+	spin_unlock_bh(&im->lock);
+}
+
+
+/*
+ *	Send an IGMP report.
+ */
+
+#define IGMP_SIZE (sizeof(struct igmphdr)+sizeof(struct iphdr)+4)
+
+
+static int is_in(struct ip_mc_list *pmc, struct ip_sf_list *psf, int type,
+	int gdeleted, int sdeleted)
+{
+	switch (type) {
+	case IGMPV3_MODE_IS_INCLUDE:
+	case IGMPV3_MODE_IS_EXCLUDE:
+		if (gdeleted || sdeleted)
+			return 0;
+		if (!(pmc->gsquery && !psf->sf_gsresp)) {
+			if (pmc->sfmode == MCAST_INCLUDE)
+				return 1;
+			/* don't include if this source is excluded
+			 * in all filters
+			 */
+			if (psf->sf_count[MCAST_INCLUDE])
+				return type == IGMPV3_MODE_IS_INCLUDE;
+			return pmc->sfcount[MCAST_EXCLUDE] ==
+				psf->sf_count[MCAST_EXCLUDE];
+		}
+		return 0;
+	case IGMPV3_CHANGE_TO_INCLUDE:
+		if (gdeleted || sdeleted)
+			return 0;
+		return psf->sf_count[MCAST_INCLUDE] != 0;
+	case IGMPV3_CHANGE_TO_EXCLUDE:
+		if (gdeleted || sdeleted)
+			return 0;
+		if (pmc->sfcount[MCAST_EXCLUDE] == 0 ||
+		    psf->sf_count[MCAST_INCLUDE])
+			return 0;
+		return pmc->sfcount[MCAST_EXCLUDE] ==
+			psf->sf_count[MCAST_EXCLUDE];
+	case IGMPV3_ALLOW_NEW_SOURCES:
+		if (gdeleted || !psf->sf_crcount)
+			return 0;
+		return (pmc->sfmode == MCAST_INCLUDE) ^ sdeleted;
+	case IGMPV3_BLOCK_OLD_SOURCES:
+		if (pmc->sfmode == MCAST_INCLUDE)
+			return gdeleted || (psf->sf_crcount && sdeleted);
+		return psf->sf_crcount && !gdeleted && !sdeleted;
+	}
+	return 0;
+}
+
+static int
+igmp_scount(struct ip_mc_list *pmc, int type, int gdeleted, int sdeleted)
+{
+	struct ip_sf_list *psf;
+	int scount = 0;
+
+	for (psf = pmc->sources; psf; psf = psf->sf_next) {
+		if (!is_in(pmc, psf, type, gdeleted, sdeleted))
+			continue;
+		scount++;
+	}
+	return scount;
+}
+
+/* source address selection per RFC 3376 section 4.2.13 */
+static __be32 igmpv3_get_srcaddr(struct net_device *dev,
+				 const struct flowi4 *fl4)
+{
+	struct in_device *in_dev = __in_dev_get_rcu(dev);
+	const struct in_ifaddr *ifa;
+
+	if (!in_dev)
+		return htonl(INADDR_ANY);
+
+	in_dev_for_each_ifa_rcu(ifa, in_dev) {
+		if (fl4->saddr == ifa->ifa_local)
+			return fl4->saddr;
+	}
+
+	return htonl(INADDR_ANY);
+}
+
+static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu)
+{
+	struct sk_buff *skb;
+	struct rtable *rt;
+	struct iphdr *pip;
+	struct igmpv3_report *pig;
+	struct net *net = dev_net(dev);
+	struct flowi4 fl4;
+	int hlen = LL_RESERVED_SPACE(dev);
+	int tlen = dev->needed_tailroom;
+	unsigned int size;
+
+	size = min(mtu, IP_MAX_MTU);
+	while (1) {
+		skb = alloc_skb(size + hlen + tlen,
+				GFP_ATOMIC | __GFP_NOWARN);
+		if (skb)
+			break;
+		size >>= 1;
+		if (size < 256)
+			return NULL;
+	}
+	skb->priority = TC_PRIO_CONTROL;
+
+	rt = ip_route_output_ports(net, &fl4, NULL, IGMPV3_ALL_MCR, 0,
+				   0, 0,
+				   IPPROTO_IGMP, 0, dev->ifindex);
+	if (IS_ERR(rt)) {
+		kfree_skb(skb);
+		return NULL;
+	}
+
+	skb_dst_set(skb, &rt->dst);
+	skb->dev = dev;
+
+	skb_reserve(skb, hlen);
+	skb_tailroom_reserve(skb, mtu, tlen);
+
+	skb_reset_network_header(skb);
+	pip = ip_hdr(skb);
+	skb_put(skb, sizeof(struct iphdr) + 4);
+
+	pip->version  = 4;
+	pip->ihl      = (sizeof(struct iphdr)+4)>>2;
+	pip->tos      = 0xc0;
+	pip->frag_off = htons(IP_DF);
+	pip->ttl      = 1;
+	pip->daddr    = fl4.daddr;
+
+	rcu_read_lock();
+	pip->saddr    = igmpv3_get_srcaddr(dev, &fl4);
+	rcu_read_unlock();
+
+	pip->protocol = IPPROTO_IGMP;
+	pip->tot_len  = 0;	/* filled in later */
+	ip_select_ident(net, skb, NULL);
+	((u8 *)&pip[1])[0] = IPOPT_RA;
+	((u8 *)&pip[1])[1] = 4;
+	((u8 *)&pip[1])[2] = 0;
+	((u8 *)&pip[1])[3] = 0;
+
+	skb->transport_header = skb->network_header + sizeof(struct iphdr) + 4;
+	skb_put(skb, sizeof(*pig));
+	pig = igmpv3_report_hdr(skb);
+	pig->type = IGMPV3_HOST_MEMBERSHIP_REPORT;
+	pig->resv1 = 0;
+	pig->csum = 0;
+	pig->resv2 = 0;
+	pig->ngrec = 0;
+	return skb;
+}
+
+static int igmpv3_sendpack(struct sk_buff *skb)
+{
+	struct igmphdr *pig = igmp_hdr(skb);
+	const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
+
+	pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
+
+	return ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
+}
+
+static int grec_size(struct ip_mc_list *pmc, int type, int gdel, int sdel)
+{
+	return sizeof(struct igmpv3_grec) + 4*igmp_scount(pmc, type, gdel, sdel);
+}
+
+static struct sk_buff *add_grhead(struct sk_buff *skb, struct ip_mc_list *pmc,
+	int type, struct igmpv3_grec **ppgr, unsigned int mtu)
+{
+	struct net_device *dev = pmc->interface->dev;
+	struct igmpv3_report *pih;
+	struct igmpv3_grec *pgr;
+
+	if (!skb) {
+		skb = igmpv3_newpack(dev, mtu);
+		if (!skb)
+			return NULL;
+	}
+	pgr = skb_put(skb, sizeof(struct igmpv3_grec));
+	pgr->grec_type = type;
+	pgr->grec_auxwords = 0;
+	pgr->grec_nsrcs = 0;
+	pgr->grec_mca = pmc->multiaddr;
+	pih = igmpv3_report_hdr(skb);
+	pih->ngrec = htons(ntohs(pih->ngrec)+1);
+	*ppgr = pgr;
+	return skb;
+}
+
+#define AVAILABLE(skb)	((skb) ? skb_availroom(skb) : 0)
+
+static struct sk_buff *add_grec(struct sk_buff *skb, struct ip_mc_list *pmc,
+	int type, int gdeleted, int sdeleted)
+{
+	struct net_device *dev = pmc->interface->dev;
+	struct net *net = dev_net(dev);
+	struct igmpv3_report *pih;
+	struct igmpv3_grec *pgr = NULL;
+	struct ip_sf_list *psf, *psf_next, *psf_prev, **psf_list;
+	int scount, stotal, first, isquery, truncate;
+	unsigned int mtu;
+
+	if (pmc->multiaddr == IGMP_ALL_HOSTS)
+		return skb;
+	if (ipv4_is_local_multicast(pmc->multiaddr) &&
+	    !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
+		return skb;
+
+	mtu = READ_ONCE(dev->mtu);
+	if (mtu < IPV4_MIN_MTU)
+		return skb;
+
+	isquery = type == IGMPV3_MODE_IS_INCLUDE ||
+		  type == IGMPV3_MODE_IS_EXCLUDE;
+	truncate = type == IGMPV3_MODE_IS_EXCLUDE ||
+		    type == IGMPV3_CHANGE_TO_EXCLUDE;
+
+	stotal = scount = 0;
+
+	psf_list = sdeleted ? &pmc->tomb : &pmc->sources;
+
+	if (!*psf_list)
+		goto empty_source;
+
+	pih = skb ? igmpv3_report_hdr(skb) : NULL;
+
+	/* EX and TO_EX get a fresh packet, if needed */
+	if (truncate) {
+		if (pih && pih->ngrec &&
+		    AVAILABLE(skb) < grec_size(pmc, type, gdeleted, sdeleted)) {
+			if (skb)
+				igmpv3_sendpack(skb);
+			skb = igmpv3_newpack(dev, mtu);
+		}
+	}
+	first = 1;
+	psf_prev = NULL;
+	for (psf = *psf_list; psf; psf = psf_next) {
+		__be32 *psrc;
+
+		psf_next = psf->sf_next;
+
+		if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
+			psf_prev = psf;
+			continue;
+		}
+
+		/* Based on RFC3376 5.1. Should not send source-list change
+		 * records when there is a filter mode change.
+		 */
+		if (((gdeleted && pmc->sfmode == MCAST_EXCLUDE) ||
+		     (!gdeleted && pmc->crcount)) &&
+		    (type == IGMPV3_ALLOW_NEW_SOURCES ||
+		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount)
+			goto decrease_sf_crcount;
+
+		/* clear marks on query responses */
+		if (isquery)
+			psf->sf_gsresp = 0;
+
+		if (AVAILABLE(skb) < sizeof(__be32) +
+		    first*sizeof(struct igmpv3_grec)) {
+			if (truncate && !first)
+				break;	 /* truncate these */
+			if (pgr)
+				pgr->grec_nsrcs = htons(scount);
+			if (skb)
+				igmpv3_sendpack(skb);
+			skb = igmpv3_newpack(dev, mtu);
+			first = 1;
+			scount = 0;
+		}
+		if (first) {
+			skb = add_grhead(skb, pmc, type, &pgr, mtu);
+			first = 0;
+		}
+		if (!skb)
+			return NULL;
+		psrc = skb_put(skb, sizeof(__be32));
+		*psrc = psf->sf_inaddr;
+		scount++; stotal++;
+		if ((type == IGMPV3_ALLOW_NEW_SOURCES ||
+		     type == IGMPV3_BLOCK_OLD_SOURCES) && psf->sf_crcount) {
+decrease_sf_crcount:
+			psf->sf_crcount--;
+			if ((sdeleted || gdeleted) && psf->sf_crcount == 0) {
+				if (psf_prev)
+					psf_prev->sf_next = psf->sf_next;
+				else
+					*psf_list = psf->sf_next;
+				kfree(psf);
+				continue;
+			}
+		}
+		psf_prev = psf;
+	}
+
+empty_source:
+	if (!stotal) {
+		if (type == IGMPV3_ALLOW_NEW_SOURCES ||
+		    type == IGMPV3_BLOCK_OLD_SOURCES)
+			return skb;
+		if (pmc->crcount || isquery) {
+			/* make sure we have room for group header */
+			if (skb && AVAILABLE(skb) < sizeof(struct igmpv3_grec)) {
+				igmpv3_sendpack(skb);
+				skb = NULL; /* add_grhead will get a new one */
+			}
+			skb = add_grhead(skb, pmc, type, &pgr, mtu);
+		}
+	}
+	if (pgr)
+		pgr->grec_nsrcs = htons(scount);
+
+	if (isquery)
+		pmc->gsquery = 0;	/* clear query state on report */
+	return skb;
+}
+
+static int igmpv3_send_report(struct in_device *in_dev, struct ip_mc_list *pmc)
+{
+	struct sk_buff *skb = NULL;
+	struct net *net = dev_net(in_dev->dev);
+	int type;
+
+	if (!pmc) {
+		rcu_read_lock();
+		for_each_pmc_rcu(in_dev, pmc) {
+			if (pmc->multiaddr == IGMP_ALL_HOSTS)
+				continue;
+			if (ipv4_is_local_multicast(pmc->multiaddr) &&
+			    !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
+				continue;
+			spin_lock_bh(&pmc->lock);
+			if (pmc->sfcount[MCAST_EXCLUDE])
+				type = IGMPV3_MODE_IS_EXCLUDE;
+			else
+				type = IGMPV3_MODE_IS_INCLUDE;
+			skb = add_grec(skb, pmc, type, 0, 0);
+			spin_unlock_bh(&pmc->lock);
+		}
+		rcu_read_unlock();
+	} else {
+		spin_lock_bh(&pmc->lock);
+		if (pmc->sfcount[MCAST_EXCLUDE])
+			type = IGMPV3_MODE_IS_EXCLUDE;
+		else
+			type = IGMPV3_MODE_IS_INCLUDE;
+		skb = add_grec(skb, pmc, type, 0, 0);
+		spin_unlock_bh(&pmc->lock);
+	}
+	if (!skb)
+		return 0;
+	return igmpv3_sendpack(skb);
+}
+
+/*
+ * remove zero-count source records from a source filter list
+ */
+static void igmpv3_clear_zeros(struct ip_sf_list **ppsf)
+{
+	struct ip_sf_list *psf_prev, *psf_next, *psf;
+
+	psf_prev = NULL;
+	for (psf = *ppsf; psf; psf = psf_next) {
+		psf_next = psf->sf_next;
+		if (psf->sf_crcount == 0) {
+			if (psf_prev)
+				psf_prev->sf_next = psf->sf_next;
+			else
+				*ppsf = psf->sf_next;
+			kfree(psf);
+		} else
+			psf_prev = psf;
+	}
+}
+
+static void kfree_pmc(struct ip_mc_list *pmc)
+{
+	ip_sf_list_clear_all(pmc->sources);
+	ip_sf_list_clear_all(pmc->tomb);
+	kfree(pmc);
+}
+
+static void igmpv3_send_cr(struct in_device *in_dev)
+{
+	struct ip_mc_list *pmc, *pmc_prev, *pmc_next;
+	struct sk_buff *skb = NULL;
+	int type, dtype;
+
+	rcu_read_lock();
+	spin_lock_bh(&in_dev->mc_tomb_lock);
+
+	/* deleted MCA's */
+	pmc_prev = NULL;
+	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc_next) {
+		pmc_next = pmc->next;
+		if (pmc->sfmode == MCAST_INCLUDE) {
+			type = IGMPV3_BLOCK_OLD_SOURCES;
+			dtype = IGMPV3_BLOCK_OLD_SOURCES;
+			skb = add_grec(skb, pmc, type, 1, 0);
+			skb = add_grec(skb, pmc, dtype, 1, 1);
+		}
+		if (pmc->crcount) {
+			if (pmc->sfmode == MCAST_EXCLUDE) {
+				type = IGMPV3_CHANGE_TO_INCLUDE;
+				skb = add_grec(skb, pmc, type, 1, 0);
+			}
+			pmc->crcount--;
+			if (pmc->crcount == 0) {
+				igmpv3_clear_zeros(&pmc->tomb);
+				igmpv3_clear_zeros(&pmc->sources);
+			}
+		}
+		if (pmc->crcount == 0 && !pmc->tomb && !pmc->sources) {
+			if (pmc_prev)
+				pmc_prev->next = pmc_next;
+			else
+				in_dev->mc_tomb = pmc_next;
+			in_dev_put(pmc->interface);
+			kfree_pmc(pmc);
+		} else
+			pmc_prev = pmc;
+	}
+	spin_unlock_bh(&in_dev->mc_tomb_lock);
+
+	/* change recs */
+	for_each_pmc_rcu(in_dev, pmc) {
+		spin_lock_bh(&pmc->lock);
+		if (pmc->sfcount[MCAST_EXCLUDE]) {
+			type = IGMPV3_BLOCK_OLD_SOURCES;
+			dtype = IGMPV3_ALLOW_NEW_SOURCES;
+		} else {
+			type = IGMPV3_ALLOW_NEW_SOURCES;
+			dtype = IGMPV3_BLOCK_OLD_SOURCES;
+		}
+		skb = add_grec(skb, pmc, type, 0, 0);
+		skb = add_grec(skb, pmc, dtype, 0, 1);	/* deleted sources */
+
+		/* filter mode changes */
+		if (pmc->crcount) {
+			if (pmc->sfmode == MCAST_EXCLUDE)
+				type = IGMPV3_CHANGE_TO_EXCLUDE;
+			else
+				type = IGMPV3_CHANGE_TO_INCLUDE;
+			skb = add_grec(skb, pmc, type, 0, 0);
+			pmc->crcount--;
+		}
+		spin_unlock_bh(&pmc->lock);
+	}
+	rcu_read_unlock();
+
+	if (!skb)
+		return;
+	(void) igmpv3_sendpack(skb);
+}
+
+static int igmp_send_report(struct in_device *in_dev, struct ip_mc_list *pmc,
+	int type)
+{
+	struct sk_buff *skb;
+	struct iphdr *iph;
+	struct igmphdr *ih;
+	struct rtable *rt;
+	struct net_device *dev = in_dev->dev;
+	struct net *net = dev_net(dev);
+	__be32	group = pmc ? pmc->multiaddr : 0;
+	struct flowi4 fl4;
+	__be32	dst;
+	int hlen, tlen;
+
+	if (type == IGMPV3_HOST_MEMBERSHIP_REPORT)
+		return igmpv3_send_report(in_dev, pmc);
+
+	if (ipv4_is_local_multicast(group) &&
+	    !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
+		return 0;
+
+	if (type == IGMP_HOST_LEAVE_MESSAGE)
+		dst = IGMP_ALL_ROUTER;
+	else
+		dst = group;
+
+	rt = ip_route_output_ports(net, &fl4, NULL, dst, 0,
+				   0, 0,
+				   IPPROTO_IGMP, 0, dev->ifindex);
+	if (IS_ERR(rt))
+		return -1;
+
+	hlen = LL_RESERVED_SPACE(dev);
+	tlen = dev->needed_tailroom;
+	skb = alloc_skb(IGMP_SIZE + hlen + tlen, GFP_ATOMIC);
+	if (!skb) {
+		ip_rt_put(rt);
+		return -1;
+	}
+	skb->priority = TC_PRIO_CONTROL;
+
+	skb_dst_set(skb, &rt->dst);
+
+	skb_reserve(skb, hlen);
+
+	skb_reset_network_header(skb);
+	iph = ip_hdr(skb);
+	skb_put(skb, sizeof(struct iphdr) + 4);
+
+	iph->version  = 4;
+	iph->ihl      = (sizeof(struct iphdr)+4)>>2;
+	iph->tos      = 0xc0;
+	iph->frag_off = htons(IP_DF);
+	iph->ttl      = 1;
+	iph->daddr    = dst;
+	iph->saddr    = fl4.saddr;
+	iph->protocol = IPPROTO_IGMP;
+	ip_select_ident(net, skb, NULL);
+	((u8 *)&iph[1])[0] = IPOPT_RA;
+	((u8 *)&iph[1])[1] = 4;
+	((u8 *)&iph[1])[2] = 0;
+	((u8 *)&iph[1])[3] = 0;
+
+	ih = skb_put(skb, sizeof(struct igmphdr));
+	ih->type = type;
+	ih->code = 0;
+	ih->csum = 0;
+	ih->group = group;
+	ih->csum = ip_compute_csum((void *)ih, sizeof(struct igmphdr));
+
+	return ip_local_out(net, skb->sk, skb);
+}
+
+static void igmp_gq_timer_expire(struct timer_list *t)
+{
+	struct in_device *in_dev = from_timer(in_dev, t, mr_gq_timer);
+
+	in_dev->mr_gq_running = 0;
+	igmpv3_send_report(in_dev, NULL);
+	in_dev_put(in_dev);
+}
+
+static void igmp_ifc_timer_expire(struct timer_list *t)
+{
+	struct in_device *in_dev = from_timer(in_dev, t, mr_ifc_timer);
+	u32 mr_ifc_count;
+
+	igmpv3_send_cr(in_dev);
+restart:
+	mr_ifc_count = READ_ONCE(in_dev->mr_ifc_count);
+
+	if (mr_ifc_count) {
+		if (cmpxchg(&in_dev->mr_ifc_count,
+			    mr_ifc_count,
+			    mr_ifc_count - 1) != mr_ifc_count)
+			goto restart;
+		igmp_ifc_start_timer(in_dev,
+				     unsolicited_report_interval(in_dev));
+	}
+	in_dev_put(in_dev);
+}
+
+static void igmp_ifc_event(struct in_device *in_dev)
+{
+	struct net *net = dev_net(in_dev->dev);
+	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev))
+		return;
+	WRITE_ONCE(in_dev->mr_ifc_count, in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv));
+	igmp_ifc_start_timer(in_dev, 1);
+}
+
+
+static void igmp_timer_expire(struct timer_list *t)
+{
+	struct ip_mc_list *im = from_timer(im, t, timer);
+	struct in_device *in_dev = im->interface;
+
+	spin_lock(&im->lock);
+	im->tm_running = 0;
+
+	if (im->unsolicit_count && --im->unsolicit_count)
+		igmp_start_timer(im, unsolicited_report_interval(in_dev));
+
+	im->reporter = 1;
+	spin_unlock(&im->lock);
+
+	if (IGMP_V1_SEEN(in_dev))
+		igmp_send_report(in_dev, im, IGMP_HOST_MEMBERSHIP_REPORT);
+	else if (IGMP_V2_SEEN(in_dev))
+		igmp_send_report(in_dev, im, IGMPV2_HOST_MEMBERSHIP_REPORT);
+	else
+		igmp_send_report(in_dev, im, IGMPV3_HOST_MEMBERSHIP_REPORT);
+
+	ip_ma_put(im);
+}
+
+/* mark EXCLUDE-mode sources */
+static int igmp_xmarksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
+{
+	struct ip_sf_list *psf;
+	int i, scount;
+
+	scount = 0;
+	for (psf = pmc->sources; psf; psf = psf->sf_next) {
+		if (scount == nsrcs)
+			break;
+		for (i = 0; i < nsrcs; i++) {
+			/* skip inactive filters */
+			if (psf->sf_count[MCAST_INCLUDE] ||
+			    pmc->sfcount[MCAST_EXCLUDE] !=
+			    psf->sf_count[MCAST_EXCLUDE])
+				break;
+			if (srcs[i] == psf->sf_inaddr) {
+				scount++;
+				break;
+			}
+		}
+	}
+	pmc->gsquery = 0;
+	if (scount == nsrcs)	/* all sources excluded */
+		return 0;
+	return 1;
+}
+
+static int igmp_marksources(struct ip_mc_list *pmc, int nsrcs, __be32 *srcs)
+{
+	struct ip_sf_list *psf;
+	int i, scount;
+
+	if (pmc->sfmode == MCAST_EXCLUDE)
+		return igmp_xmarksources(pmc, nsrcs, srcs);
+
+	/* mark INCLUDE-mode sources */
+	scount = 0;
+	for (psf = pmc->sources; psf; psf = psf->sf_next) {
+		if (scount == nsrcs)
+			break;
+		for (i = 0; i < nsrcs; i++)
+			if (srcs[i] == psf->sf_inaddr) {
+				psf->sf_gsresp = 1;
+				scount++;
+				break;
+			}
+	}
+	if (!scount) {
+		pmc->gsquery = 0;
+		return 0;
+	}
+	pmc->gsquery = 1;
+	return 1;
+}
+
+/* return true if packet was dropped */
+static bool igmp_heard_report(struct in_device *in_dev, __be32 group)
+{
+	struct ip_mc_list *im;
+	struct net *net = dev_net(in_dev->dev);
+
+	/* Timers are only set for non-local groups */
+
+	if (group == IGMP_ALL_HOSTS)
+		return false;
+	if (ipv4_is_local_multicast(group) &&
+	    !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
+		return false;
+
+	rcu_read_lock();
+	for_each_pmc_rcu(in_dev, im) {
+		if (im->multiaddr == group) {
+			igmp_stop_timer(im);
+			break;
+		}
+	}
+	rcu_read_unlock();
+	return false;
+}
+
+/* return true if packet was dropped */
+static bool igmp_heard_query(struct in_device *in_dev, struct sk_buff *skb,
+	int len)
+{
+	struct igmphdr 		*ih = igmp_hdr(skb);
+	struct igmpv3_query *ih3 = igmpv3_query_hdr(skb);
+	struct ip_mc_list	*im;
+	__be32			group = ih->group;
+	int			max_delay;
+	int			mark = 0;
+	struct net		*net = dev_net(in_dev->dev);
+
+
+	if (len == 8) {
+		if (ih->code == 0) {
+			/* Alas, old v1 router presents here. */
+
+			max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
+			in_dev->mr_v1_seen = jiffies +
+				(in_dev->mr_qrv * in_dev->mr_qi) +
+				in_dev->mr_qri;
+			group = 0;
+		} else {
+			/* v2 router present */
+			max_delay = ih->code*(HZ/IGMP_TIMER_SCALE);
+			in_dev->mr_v2_seen = jiffies +
+				(in_dev->mr_qrv * in_dev->mr_qi) +
+				in_dev->mr_qri;
+		}
+		/* cancel the interface change timer */
+		WRITE_ONCE(in_dev->mr_ifc_count, 0);
+		if (del_timer(&in_dev->mr_ifc_timer))
+			__in_dev_put(in_dev);
+		/* clear deleted report items */
+		igmpv3_clear_delrec(in_dev);
+	} else if (len < 12) {
+		return true;	/* ignore bogus packet; freed by caller */
+	} else if (IGMP_V1_SEEN(in_dev)) {
+		/* This is a v3 query with v1 queriers present */
+		max_delay = IGMP_QUERY_RESPONSE_INTERVAL;
+		group = 0;
+	} else if (IGMP_V2_SEEN(in_dev)) {
+		/* this is a v3 query with v2 queriers present;
+		 * Interpretation of the max_delay code is problematic here.
+		 * A real v2 host would use ih_code directly, while v3 has a
+		 * different encoding. We use the v3 encoding as more likely
+		 * to be intended in a v3 query.
+		 */
+		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
+		if (!max_delay)
+			max_delay = 1;	/* can't mod w/ 0 */
+	} else { /* v3 */
+		if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)))
+			return true;
+
+		ih3 = igmpv3_query_hdr(skb);
+		if (ih3->nsrcs) {
+			if (!pskb_may_pull(skb, sizeof(struct igmpv3_query)
+					   + ntohs(ih3->nsrcs)*sizeof(__be32)))
+				return true;
+			ih3 = igmpv3_query_hdr(skb);
+		}
+
+		max_delay = IGMPV3_MRC(ih3->code)*(HZ/IGMP_TIMER_SCALE);
+		if (!max_delay)
+			max_delay = 1;	/* can't mod w/ 0 */
+		in_dev->mr_maxdelay = max_delay;
+
+		/* RFC3376, 4.1.6. QRV and 4.1.7. QQIC, when the most recently
+		 * received value was zero, use the default or statically
+		 * configured value.
+		 */
+		in_dev->mr_qrv = ih3->qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+		in_dev->mr_qi = IGMPV3_QQIC(ih3->qqic)*HZ ?: IGMP_QUERY_INTERVAL;
+
+		/* RFC3376, 8.3. Query Response Interval:
+		 * The number of seconds represented by the [Query Response
+		 * Interval] must be less than the [Query Interval].
+		 */
+		if (in_dev->mr_qri >= in_dev->mr_qi)
+			in_dev->mr_qri = (in_dev->mr_qi/HZ - 1)*HZ;
+
+		if (!group) { /* general query */
+			if (ih3->nsrcs)
+				return true;	/* no sources allowed */
+			igmp_gq_start_timer(in_dev);
+			return false;
+		}
+		/* mark sources to include, if group & source-specific */
+		mark = ih3->nsrcs != 0;
+	}
+
+	/*
+	 * - Start the timers in all of our membership records
+	 *   that the query applies to for the interface on
+	 *   which the query arrived excl. those that belong
+	 *   to a "local" group (224.0.0.X)
+	 * - For timers already running check if they need to
+	 *   be reset.
+	 * - Use the igmp->igmp_code field as the maximum
+	 *   delay possible
+	 */
+	rcu_read_lock();
+	for_each_pmc_rcu(in_dev, im) {
+		int changed;
+
+		if (group && group != im->multiaddr)
+			continue;
+		if (im->multiaddr == IGMP_ALL_HOSTS)
+			continue;
+		if (ipv4_is_local_multicast(im->multiaddr) &&
+		    !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
+			continue;
+		spin_lock_bh(&im->lock);
+		if (im->tm_running)
+			im->gsquery = im->gsquery && mark;
+		else
+			im->gsquery = mark;
+		changed = !im->gsquery ||
+			igmp_marksources(im, ntohs(ih3->nsrcs), ih3->srcs);
+		spin_unlock_bh(&im->lock);
+		if (changed)
+			igmp_mod_timer(im, max_delay);
+	}
+	rcu_read_unlock();
+	return false;
+}
+
+/* called in rcu_read_lock() section */
+int igmp_rcv(struct sk_buff *skb)
+{
+	/* This basically follows the spec line by line -- see RFC1112 */
+	struct igmphdr *ih;
+	struct net_device *dev = skb->dev;
+	struct in_device *in_dev;
+	int len = skb->len;
+	bool dropped = true;
+
+	if (netif_is_l3_master(dev)) {
+		dev = dev_get_by_index_rcu(dev_net(dev), IPCB(skb)->iif);
+		if (!dev)
+			goto drop;
+	}
+
+	in_dev = __in_dev_get_rcu(dev);
+	if (!in_dev)
+		goto drop;
+
+	if (!pskb_may_pull(skb, sizeof(struct igmphdr)))
+		goto drop;
+
+	if (skb_checksum_simple_validate(skb))
+		goto drop;
+
+	ih = igmp_hdr(skb);
+	switch (ih->type) {
+	case IGMP_HOST_MEMBERSHIP_QUERY:
+		dropped = igmp_heard_query(in_dev, skb, len);
+		break;
+	case IGMP_HOST_MEMBERSHIP_REPORT:
+	case IGMPV2_HOST_MEMBERSHIP_REPORT:
+		/* Is it our report looped back? */
+		if (rt_is_output_route(skb_rtable(skb)))
+			break;
+		/* don't rely on MC router hearing unicast reports */
+		if (skb->pkt_type == PACKET_MULTICAST ||
+		    skb->pkt_type == PACKET_BROADCAST)
+			dropped = igmp_heard_report(in_dev, ih->group);
+		break;
+	case IGMP_PIM:
+#ifdef CONFIG_IP_PIMSM_V1
+		return pim_rcv_v1(skb);
+#endif
+	case IGMPV3_HOST_MEMBERSHIP_REPORT:
+	case IGMP_DVMRP:
+	case IGMP_TRACE:
+	case IGMP_HOST_LEAVE_MESSAGE:
+	case IGMP_MTRACE:
+	case IGMP_MTRACE_RESP:
+		break;
+	default:
+		break;
+	}
+
+drop:
+	if (dropped)
+		kfree_skb(skb);
+	else
+		consume_skb(skb);
+	return 0;
+}
+
+#endif
+
+
+/*
+ *	Add a filter to a device
+ */
+
+static void ip_mc_filter_add(struct in_device *in_dev, __be32 addr)
+{
+	char buf[MAX_ADDR_LEN];
+	struct net_device *dev = in_dev->dev;
+
+	/* Checking for IFF_MULTICAST here is WRONG-WRONG-WRONG.
+	   We will get multicast token leakage, when IFF_MULTICAST
+	   is changed. This check should be done in ndo_set_rx_mode
+	   routine. Something sort of:
+	   if (dev->mc_list && dev->flags&IFF_MULTICAST) { do it; }
+	   --ANK
+	   */
+	if (arp_mc_map(addr, buf, dev, 0) == 0)
+		dev_mc_add(dev, buf);
+}
+
+/*
+ *	Remove a filter from a device
+ */
+
+static void ip_mc_filter_del(struct in_device *in_dev, __be32 addr)
+{
+	char buf[MAX_ADDR_LEN];
+	struct net_device *dev = in_dev->dev;
+
+	if (arp_mc_map(addr, buf, dev, 0) == 0)
+		dev_mc_del(dev, buf);
+}
+
+#ifdef CONFIG_IP_MULTICAST
+/*
+ * deleted ip_mc_list manipulation
+ */
+static void igmpv3_add_delrec(struct in_device *in_dev, struct ip_mc_list *im,
+			      gfp_t gfp)
+{
+	struct ip_mc_list *pmc;
+	struct net *net = dev_net(in_dev->dev);
+
+	/* this is an "ip_mc_list" for convenience; only the fields below
+	 * are actually used. In particular, the refcnt and users are not
+	 * used for management of the delete list. Using the same structure
+	 * for deleted items allows change reports to use common code with
+	 * non-deleted or query-response MCA's.
+	 */
+	pmc = kzalloc(sizeof(*pmc), gfp);
+	if (!pmc)
+		return;
+	spin_lock_init(&pmc->lock);
+	spin_lock_bh(&im->lock);
+	pmc->interface = im->interface;
+	in_dev_hold(in_dev);
+	pmc->multiaddr = im->multiaddr;
+	pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+	pmc->sfmode = im->sfmode;
+	if (pmc->sfmode == MCAST_INCLUDE) {
+		struct ip_sf_list *psf;
+
+		pmc->tomb = im->tomb;
+		pmc->sources = im->sources;
+		im->tomb = im->sources = NULL;
+		for (psf = pmc->sources; psf; psf = psf->sf_next)
+			psf->sf_crcount = pmc->crcount;
+	}
+	spin_unlock_bh(&im->lock);
+
+	spin_lock_bh(&in_dev->mc_tomb_lock);
+	pmc->next = in_dev->mc_tomb;
+	in_dev->mc_tomb = pmc;
+	spin_unlock_bh(&in_dev->mc_tomb_lock);
+}
+
+/*
+ * restore ip_mc_list deleted records
+ */
+static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
+{
+	struct ip_mc_list *pmc, *pmc_prev;
+	struct ip_sf_list *psf;
+	struct net *net = dev_net(in_dev->dev);
+	__be32 multiaddr = im->multiaddr;
+
+	spin_lock_bh(&in_dev->mc_tomb_lock);
+	pmc_prev = NULL;
+	for (pmc = in_dev->mc_tomb; pmc; pmc = pmc->next) {
+		if (pmc->multiaddr == multiaddr)
+			break;
+		pmc_prev = pmc;
+	}
+	if (pmc) {
+		if (pmc_prev)
+			pmc_prev->next = pmc->next;
+		else
+			in_dev->mc_tomb = pmc->next;
+	}
+	spin_unlock_bh(&in_dev->mc_tomb_lock);
+
+	spin_lock_bh(&im->lock);
+	if (pmc) {
+		im->interface = pmc->interface;
+		if (im->sfmode == MCAST_INCLUDE) {
+			swap(im->tomb, pmc->tomb);
+			swap(im->sources, pmc->sources);
+			for (psf = im->sources; psf; psf = psf->sf_next)
+				psf->sf_crcount = in_dev->mr_qrv ?:
+					READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+		} else {
+			im->crcount = in_dev->mr_qrv ?:
+				READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+		}
+		in_dev_put(pmc->interface);
+		kfree_pmc(pmc);
+	}
+	spin_unlock_bh(&im->lock);
+}
+
+/*
+ * flush ip_mc_list deleted records
+ */
+static void igmpv3_clear_delrec(struct in_device *in_dev)
+{
+	struct ip_mc_list *pmc, *nextpmc;
+
+	spin_lock_bh(&in_dev->mc_tomb_lock);
+	pmc = in_dev->mc_tomb;
+	in_dev->mc_tomb = NULL;
+	spin_unlock_bh(&in_dev->mc_tomb_lock);
+
+	for (; pmc; pmc = nextpmc) {
+		nextpmc = pmc->next;
+		ip_mc_clear_src(pmc);
+		in_dev_put(pmc->interface);
+		kfree_pmc(pmc);
+	}
+	/* clear dead sources, too */
+	rcu_read_lock();
+	for_each_pmc_rcu(in_dev, pmc) {
+		struct ip_sf_list *psf;
+
+		spin_lock_bh(&pmc->lock);
+		psf = pmc->tomb;
+		pmc->tomb = NULL;
+		spin_unlock_bh(&pmc->lock);
+		ip_sf_list_clear_all(psf);
+	}
+	rcu_read_unlock();
+}
+#endif
+
+static void __igmp_group_dropped(struct ip_mc_list *im, gfp_t gfp)
+{
+	struct in_device *in_dev = im->interface;
+#ifdef CONFIG_IP_MULTICAST
+	struct net *net = dev_net(in_dev->dev);
+	int reporter;
+#endif
+
+	if (im->loaded) {
+		im->loaded = 0;
+		ip_mc_filter_del(in_dev, im->multiaddr);
+	}
+
+#ifdef CONFIG_IP_MULTICAST
+	if (im->multiaddr == IGMP_ALL_HOSTS)
+		return;
+	if (ipv4_is_local_multicast(im->multiaddr) &&
+	    !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
+		return;
+
+	reporter = im->reporter;
+	igmp_stop_timer(im);
+
+	if (!in_dev->dead) {
+		if (IGMP_V1_SEEN(in_dev))
+			return;
+		if (IGMP_V2_SEEN(in_dev)) {
+			if (reporter)
+				igmp_send_report(in_dev, im, IGMP_HOST_LEAVE_MESSAGE);
+			return;
+		}
+		/* IGMPv3 */
+		igmpv3_add_delrec(in_dev, im, gfp);
+
+		igmp_ifc_event(in_dev);
+	}
+#endif
+}
+
+static void igmp_group_dropped(struct ip_mc_list *im)
+{
+	__igmp_group_dropped(im, GFP_KERNEL);
+}
+
+static void igmp_group_added(struct ip_mc_list *im)
+{
+	struct in_device *in_dev = im->interface;
+#ifdef CONFIG_IP_MULTICAST
+	struct net *net = dev_net(in_dev->dev);
+#endif
+
+	if (im->loaded == 0) {
+		im->loaded = 1;
+		ip_mc_filter_add(in_dev, im->multiaddr);
+	}
+
+#ifdef CONFIG_IP_MULTICAST
+	if (im->multiaddr == IGMP_ALL_HOSTS)
+		return;
+	if (ipv4_is_local_multicast(im->multiaddr) &&
+	    !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
+		return;
+
+	if (in_dev->dead)
+		return;
+
+	im->unsolicit_count = READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+	if (IGMP_V1_SEEN(in_dev) || IGMP_V2_SEEN(in_dev)) {
+		spin_lock_bh(&im->lock);
+		igmp_start_timer(im, IGMP_INITIAL_REPORT_DELAY);
+		spin_unlock_bh(&im->lock);
+		return;
+	}
+	/* else, v3 */
+
+	/* Based on RFC3376 5.1, for newly added INCLUDE SSM, we should
+	 * not send filter-mode change record as the mode should be from
+	 * IN() to IN(A).
+	 */
+	if (im->sfmode == MCAST_EXCLUDE)
+		im->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+
+	igmp_ifc_event(in_dev);
+#endif
+}
+
+
+/*
+ *	Multicast list managers
+ */
+
+static u32 ip_mc_hash(const struct ip_mc_list *im)
+{
+	return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
+}
+
+static void ip_mc_hash_add(struct in_device *in_dev,
+			   struct ip_mc_list *im)
+{
+	struct ip_mc_list __rcu **mc_hash;
+	u32 hash;
+
+	mc_hash = rtnl_dereference(in_dev->mc_hash);
+	if (mc_hash) {
+		hash = ip_mc_hash(im);
+		im->next_hash = mc_hash[hash];
+		rcu_assign_pointer(mc_hash[hash], im);
+		return;
+	}
+
+	/* do not use a hash table for small number of items */
+	if (in_dev->mc_count < 4)
+		return;
+
+	mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
+			  GFP_KERNEL);
+	if (!mc_hash)
+		return;
+
+	for_each_pmc_rtnl(in_dev, im) {
+		hash = ip_mc_hash(im);
+		im->next_hash = mc_hash[hash];
+		RCU_INIT_POINTER(mc_hash[hash], im);
+	}
+
+	rcu_assign_pointer(in_dev->mc_hash, mc_hash);
+}
+
+static void ip_mc_hash_remove(struct in_device *in_dev,
+			      struct ip_mc_list *im)
+{
+	struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
+	struct ip_mc_list *aux;
+
+	if (!mc_hash)
+		return;
+	mc_hash += ip_mc_hash(im);
+	while ((aux = rtnl_dereference(*mc_hash)) != im)
+		mc_hash = &aux->next_hash;
+	*mc_hash = im->next_hash;
+}
+
+
+/*
+ *	A socket has joined a multicast group on device dev.
+ */
+static void ____ip_mc_inc_group(struct in_device *in_dev, __be32 addr,
+				unsigned int mode, gfp_t gfp)
+{
+	struct ip_mc_list *im;
+
+	ASSERT_RTNL();
+
+	for_each_pmc_rtnl(in_dev, im) {
+		if (im->multiaddr == addr) {
+			im->users++;
+			ip_mc_add_src(in_dev, &addr, mode, 0, NULL, 0);
+			goto out;
+		}
+	}
+
+	im = kzalloc(sizeof(*im), gfp);
+	if (!im)
+		goto out;
+
+	im->users = 1;
+	im->interface = in_dev;
+	in_dev_hold(in_dev);
+	im->multiaddr = addr;
+	/* initial mode is (EX, empty) */
+	im->sfmode = mode;
+	im->sfcount[mode] = 1;
+	refcount_set(&im->refcnt, 1);
+	spin_lock_init(&im->lock);
+#ifdef CONFIG_IP_MULTICAST
+	timer_setup(&im->timer, igmp_timer_expire, 0);
+#endif
+
+	im->next_rcu = in_dev->mc_list;
+	in_dev->mc_count++;
+	rcu_assign_pointer(in_dev->mc_list, im);
+
+	ip_mc_hash_add(in_dev, im);
+
+#ifdef CONFIG_IP_MULTICAST
+	igmpv3_del_delrec(in_dev, im);
+#endif
+	igmp_group_added(im);
+	if (!in_dev->dead)
+		ip_rt_multicast_event(in_dev);
+out:
+	return;
+}
+
+void __ip_mc_inc_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
+{
+	____ip_mc_inc_group(in_dev, addr, MCAST_EXCLUDE, gfp);
+}
+EXPORT_SYMBOL(__ip_mc_inc_group);
+
+void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
+{
+	__ip_mc_inc_group(in_dev, addr, GFP_KERNEL);
+}
+EXPORT_SYMBOL(ip_mc_inc_group);
+
+static int ip_mc_check_iphdr(struct sk_buff *skb)
+{
+	const struct iphdr *iph;
+	unsigned int len;
+	unsigned int offset = skb_network_offset(skb) + sizeof(*iph);
+
+	if (!pskb_may_pull(skb, offset))
+		return -EINVAL;
+
+	iph = ip_hdr(skb);
+
+	if (iph->version != 4 || ip_hdrlen(skb) < sizeof(*iph))
+		return -EINVAL;
+
+	offset += ip_hdrlen(skb) - sizeof(*iph);
+
+	if (!pskb_may_pull(skb, offset))
+		return -EINVAL;
+
+	iph = ip_hdr(skb);
+
+	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
+		return -EINVAL;
+
+	len = skb_network_offset(skb) + ntohs(iph->tot_len);
+	if (skb->len < len || len < offset)
+		return -EINVAL;
+
+	skb_set_transport_header(skb, offset);
+
+	return 0;
+}
+
+static int ip_mc_check_igmp_reportv3(struct sk_buff *skb)
+{
+	unsigned int len = skb_transport_offset(skb);
+
+	len += sizeof(struct igmpv3_report);
+
+	return ip_mc_may_pull(skb, len) ? 0 : -EINVAL;
+}
+
+static int ip_mc_check_igmp_query(struct sk_buff *skb)
+{
+	unsigned int transport_len = ip_transport_len(skb);
+	unsigned int len;
+
+	/* IGMPv{1,2}? */
+	if (transport_len != sizeof(struct igmphdr)) {
+		/* or IGMPv3? */
+		if (transport_len < sizeof(struct igmpv3_query))
+			return -EINVAL;
+
+		len = skb_transport_offset(skb) + sizeof(struct igmpv3_query);
+		if (!ip_mc_may_pull(skb, len))
+			return -EINVAL;
+	}
+
+	/* RFC2236+RFC3376 (IGMPv2+IGMPv3) require the multicast link layer
+	 * all-systems destination addresses (224.0.0.1) for general queries
+	 */
+	if (!igmp_hdr(skb)->group &&
+	    ip_hdr(skb)->daddr != htonl(INADDR_ALLHOSTS_GROUP))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int ip_mc_check_igmp_msg(struct sk_buff *skb)
+{
+	switch (igmp_hdr(skb)->type) {
+	case IGMP_HOST_LEAVE_MESSAGE:
+	case IGMP_HOST_MEMBERSHIP_REPORT:
+	case IGMPV2_HOST_MEMBERSHIP_REPORT:
+		return 0;
+	case IGMPV3_HOST_MEMBERSHIP_REPORT:
+		return ip_mc_check_igmp_reportv3(skb);
+	case IGMP_HOST_MEMBERSHIP_QUERY:
+		return ip_mc_check_igmp_query(skb);
+	default:
+		return -ENOMSG;
+	}
+}
+
+static __sum16 ip_mc_validate_checksum(struct sk_buff *skb)
+{
+	return skb_checksum_simple_validate(skb);
+}
+
+static int ip_mc_check_igmp_csum(struct sk_buff *skb)
+{
+	unsigned int len = skb_transport_offset(skb) + sizeof(struct igmphdr);
+	unsigned int transport_len = ip_transport_len(skb);
+	struct sk_buff *skb_chk;
+
+	if (!ip_mc_may_pull(skb, len))
+		return -EINVAL;
+
+	skb_chk = skb_checksum_trimmed(skb, transport_len,
+				       ip_mc_validate_checksum);
+	if (!skb_chk)
+		return -EINVAL;
+
+	if (skb_chk != skb)
+		kfree_skb(skb_chk);
+
+	return 0;
+}
+
+/**
+ * ip_mc_check_igmp - checks whether this is a sane IGMP packet
+ * @skb: the skb to validate
+ *
+ * Checks whether an IPv4 packet is a valid IGMP packet. If so sets
+ * skb transport header accordingly and returns zero.
+ *
+ * -EINVAL: A broken packet was detected, i.e. it violates some internet
+ *  standard
+ * -ENOMSG: IP header validation succeeded but it is not an IGMP packet.
+ * -ENOMEM: A memory allocation failure happened.
+ *
+ * Caller needs to set the skb network header and free any returned skb if it
+ * differs from the provided skb.
+ */
+int ip_mc_check_igmp(struct sk_buff *skb)
+{
+	int ret = ip_mc_check_iphdr(skb);
+
+	if (ret < 0)
+		return ret;
+
+	if (ip_hdr(skb)->protocol != IPPROTO_IGMP)
+		return -ENOMSG;
+
+	ret = ip_mc_check_igmp_csum(skb);
+	if (ret < 0)
+		return ret;
+
+	return ip_mc_check_igmp_msg(skb);
+}
+EXPORT_SYMBOL(ip_mc_check_igmp);
+
+/*
+ *	Resend IGMP JOIN report; used by netdev notifier.
+ */
+static void ip_mc_rejoin_groups(struct in_device *in_dev)
+{
+#ifdef CONFIG_IP_MULTICAST
+	struct ip_mc_list *im;
+	int type;
+	struct net *net = dev_net(in_dev->dev);
+
+	ASSERT_RTNL();
+
+	for_each_pmc_rtnl(in_dev, im) {
+		if (im->multiaddr == IGMP_ALL_HOSTS)
+			continue;
+		if (ipv4_is_local_multicast(im->multiaddr) &&
+		    !READ_ONCE(net->ipv4.sysctl_igmp_llm_reports))
+			continue;
+
+		/* a failover is happening and switches
+		 * must be notified immediately
+		 */
+		if (IGMP_V1_SEEN(in_dev))
+			type = IGMP_HOST_MEMBERSHIP_REPORT;
+		else if (IGMP_V2_SEEN(in_dev))
+			type = IGMPV2_HOST_MEMBERSHIP_REPORT;
+		else
+			type = IGMPV3_HOST_MEMBERSHIP_REPORT;
+		igmp_send_report(in_dev, im, type);
+	}
+#endif
+}
+
+/*
+ *	A socket has left a multicast group on device dev
+ */
+
+void __ip_mc_dec_group(struct in_device *in_dev, __be32 addr, gfp_t gfp)
+{
+	struct ip_mc_list *i;
+	struct ip_mc_list __rcu **ip;
+
+	ASSERT_RTNL();
+
+	for (ip = &in_dev->mc_list;
+	     (i = rtnl_dereference(*ip)) != NULL;
+	     ip = &i->next_rcu) {
+		if (i->multiaddr == addr) {
+			if (--i->users == 0) {
+				ip_mc_hash_remove(in_dev, i);
+				*ip = i->next_rcu;
+				in_dev->mc_count--;
+				__igmp_group_dropped(i, gfp);
+				ip_mc_clear_src(i);
+
+				if (!in_dev->dead)
+					ip_rt_multicast_event(in_dev);
+
+				ip_ma_put(i);
+				return;
+			}
+			break;
+		}
+	}
+}
+EXPORT_SYMBOL(__ip_mc_dec_group);
+
+/* Device changing type */
+
+void ip_mc_unmap(struct in_device *in_dev)
+{
+	struct ip_mc_list *pmc;
+
+	ASSERT_RTNL();
+
+	for_each_pmc_rtnl(in_dev, pmc)
+		igmp_group_dropped(pmc);
+}
+
+void ip_mc_remap(struct in_device *in_dev)
+{
+	struct ip_mc_list *pmc;
+
+	ASSERT_RTNL();
+
+	for_each_pmc_rtnl(in_dev, pmc) {
+#ifdef CONFIG_IP_MULTICAST
+		igmpv3_del_delrec(in_dev, pmc);
+#endif
+		igmp_group_added(pmc);
+	}
+}
+
+/* Device going down */
+
+void ip_mc_down(struct in_device *in_dev)
+{
+	struct ip_mc_list *pmc;
+
+	ASSERT_RTNL();
+
+	for_each_pmc_rtnl(in_dev, pmc)
+		igmp_group_dropped(pmc);
+
+#ifdef CONFIG_IP_MULTICAST
+	WRITE_ONCE(in_dev->mr_ifc_count, 0);
+	if (del_timer(&in_dev->mr_ifc_timer))
+		__in_dev_put(in_dev);
+	in_dev->mr_gq_running = 0;
+	if (del_timer(&in_dev->mr_gq_timer))
+		__in_dev_put(in_dev);
+#endif
+
+	ip_mc_dec_group(in_dev, IGMP_ALL_HOSTS);
+}
+
+#ifdef CONFIG_IP_MULTICAST
+static void ip_mc_reset(struct in_device *in_dev)
+{
+	struct net *net = dev_net(in_dev->dev);
+
+	in_dev->mr_qi = IGMP_QUERY_INTERVAL;
+	in_dev->mr_qri = IGMP_QUERY_RESPONSE_INTERVAL;
+	in_dev->mr_qrv = READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+}
+#else
+static void ip_mc_reset(struct in_device *in_dev)
+{
+}
+#endif
+
+void ip_mc_init_dev(struct in_device *in_dev)
+{
+	ASSERT_RTNL();
+
+#ifdef CONFIG_IP_MULTICAST
+	timer_setup(&in_dev->mr_gq_timer, igmp_gq_timer_expire, 0);
+	timer_setup(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire, 0);
+#endif
+	ip_mc_reset(in_dev);
+
+	spin_lock_init(&in_dev->mc_tomb_lock);
+}
+
+/* Device going up */
+
+void ip_mc_up(struct in_device *in_dev)
+{
+	struct ip_mc_list *pmc;
+
+	ASSERT_RTNL();
+
+	ip_mc_reset(in_dev);
+	ip_mc_inc_group(in_dev, IGMP_ALL_HOSTS);
+
+	for_each_pmc_rtnl(in_dev, pmc) {
+#ifdef CONFIG_IP_MULTICAST
+		igmpv3_del_delrec(in_dev, pmc);
+#endif
+		igmp_group_added(pmc);
+	}
+}
+
+/*
+ *	Device is about to be destroyed: clean up.
+ */
+
+void ip_mc_destroy_dev(struct in_device *in_dev)
+{
+	struct ip_mc_list *i;
+
+	ASSERT_RTNL();
+
+	/* Deactivate timers */
+	ip_mc_down(in_dev);
+#ifdef CONFIG_IP_MULTICAST
+	igmpv3_clear_delrec(in_dev);
+#endif
+
+	while ((i = rtnl_dereference(in_dev->mc_list)) != NULL) {
+		in_dev->mc_list = i->next_rcu;
+		in_dev->mc_count--;
+		ip_mc_clear_src(i);
+		ip_ma_put(i);
+	}
+}
+
+/* RTNL is locked */
+static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr)
+{
+	struct net_device *dev = NULL;
+	struct in_device *idev = NULL;
+
+	if (imr->imr_ifindex) {
+		idev = inetdev_by_index(net, imr->imr_ifindex);
+		return idev;
+	}
+	if (imr->imr_address.s_addr) {
+		dev = __ip_dev_find(net, imr->imr_address.s_addr, false);
+		if (!dev)
+			return NULL;
+	}
+
+	if (!dev) {
+		struct rtable *rt = ip_route_output(net,
+						    imr->imr_multiaddr.s_addr,
+						    0, 0, 0);
+		if (!IS_ERR(rt)) {
+			dev = rt->dst.dev;
+			ip_rt_put(rt);
+		}
+	}
+	if (dev) {
+		imr->imr_ifindex = dev->ifindex;
+		idev = __in_dev_get_rtnl(dev);
+	}
+	return idev;
+}
+
+/*
+ *	Join a socket to a group
+ */
+
+static int ip_mc_del1_src(struct ip_mc_list *pmc, int sfmode,
+	__be32 *psfsrc)
+{
+	struct ip_sf_list *psf, *psf_prev;
+	int rv = 0;
+
+	psf_prev = NULL;
+	for (psf = pmc->sources; psf; psf = psf->sf_next) {
+		if (psf->sf_inaddr == *psfsrc)
+			break;
+		psf_prev = psf;
+	}
+	if (!psf || psf->sf_count[sfmode] == 0) {
+		/* source filter not found, or count wrong =>  bug */
+		return -ESRCH;
+	}
+	psf->sf_count[sfmode]--;
+	if (psf->sf_count[sfmode] == 0) {
+		ip_rt_multicast_event(pmc->interface);
+	}
+	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
+#ifdef CONFIG_IP_MULTICAST
+		struct in_device *in_dev = pmc->interface;
+		struct net *net = dev_net(in_dev->dev);
+#endif
+
+		/* no more filters for this source */
+		if (psf_prev)
+			psf_prev->sf_next = psf->sf_next;
+		else
+			pmc->sources = psf->sf_next;
+#ifdef CONFIG_IP_MULTICAST
+		if (psf->sf_oldin &&
+		    !IGMP_V1_SEEN(in_dev) && !IGMP_V2_SEEN(in_dev)) {
+			psf->sf_crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+			psf->sf_next = pmc->tomb;
+			pmc->tomb = psf;
+			rv = 1;
+		} else
+#endif
+			kfree(psf);
+	}
+	return rv;
+}
+
+#ifndef CONFIG_IP_MULTICAST
+#define igmp_ifc_event(x)	do { } while (0)
+#endif
+
+static int ip_mc_del_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
+			 int sfcount, __be32 *psfsrc, int delta)
+{
+	struct ip_mc_list *pmc;
+	int	changerec = 0;
+	int	i, err;
+
+	if (!in_dev)
+		return -ENODEV;
+	rcu_read_lock();
+	for_each_pmc_rcu(in_dev, pmc) {
+		if (*pmca == pmc->multiaddr)
+			break;
+	}
+	if (!pmc) {
+		/* MCA not found?? bug */
+		rcu_read_unlock();
+		return -ESRCH;
+	}
+	spin_lock_bh(&pmc->lock);
+	rcu_read_unlock();
+#ifdef CONFIG_IP_MULTICAST
+	sf_markstate(pmc);
+#endif
+	if (!delta) {
+		err = -EINVAL;
+		if (!pmc->sfcount[sfmode])
+			goto out_unlock;
+		pmc->sfcount[sfmode]--;
+	}
+	err = 0;
+	for (i = 0; i < sfcount; i++) {
+		int rv = ip_mc_del1_src(pmc, sfmode, &psfsrc[i]);
+
+		changerec |= rv > 0;
+		if (!err && rv < 0)
+			err = rv;
+	}
+	if (pmc->sfmode == MCAST_EXCLUDE &&
+	    pmc->sfcount[MCAST_EXCLUDE] == 0 &&
+	    pmc->sfcount[MCAST_INCLUDE]) {
+#ifdef CONFIG_IP_MULTICAST
+		struct ip_sf_list *psf;
+		struct net *net = dev_net(in_dev->dev);
+#endif
+
+		/* filter mode change */
+		pmc->sfmode = MCAST_INCLUDE;
+#ifdef CONFIG_IP_MULTICAST
+		pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+		WRITE_ONCE(in_dev->mr_ifc_count, pmc->crcount);
+		for (psf = pmc->sources; psf; psf = psf->sf_next)
+			psf->sf_crcount = 0;
+		igmp_ifc_event(pmc->interface);
+	} else if (sf_setstate(pmc) || changerec) {
+		igmp_ifc_event(pmc->interface);
+#endif
+	}
+out_unlock:
+	spin_unlock_bh(&pmc->lock);
+	return err;
+}
+
+/*
+ * Add multicast single-source filter to the interface list
+ */
+static int ip_mc_add1_src(struct ip_mc_list *pmc, int sfmode,
+	__be32 *psfsrc)
+{
+	struct ip_sf_list *psf, *psf_prev;
+
+	psf_prev = NULL;
+	for (psf = pmc->sources; psf; psf = psf->sf_next) {
+		if (psf->sf_inaddr == *psfsrc)
+			break;
+		psf_prev = psf;
+	}
+	if (!psf) {
+		psf = kzalloc(sizeof(*psf), GFP_ATOMIC);
+		if (!psf)
+			return -ENOBUFS;
+		psf->sf_inaddr = *psfsrc;
+		if (psf_prev) {
+			psf_prev->sf_next = psf;
+		} else
+			pmc->sources = psf;
+	}
+	psf->sf_count[sfmode]++;
+	if (psf->sf_count[sfmode] == 1) {
+		ip_rt_multicast_event(pmc->interface);
+	}
+	return 0;
+}
+
+#ifdef CONFIG_IP_MULTICAST
+static void sf_markstate(struct ip_mc_list *pmc)
+{
+	struct ip_sf_list *psf;
+	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
+
+	for (psf = pmc->sources; psf; psf = psf->sf_next)
+		if (pmc->sfcount[MCAST_EXCLUDE]) {
+			psf->sf_oldin = mca_xcount ==
+				psf->sf_count[MCAST_EXCLUDE] &&
+				!psf->sf_count[MCAST_INCLUDE];
+		} else
+			psf->sf_oldin = psf->sf_count[MCAST_INCLUDE] != 0;
+}
+
+static int sf_setstate(struct ip_mc_list *pmc)
+{
+	struct ip_sf_list *psf, *dpsf;
+	int mca_xcount = pmc->sfcount[MCAST_EXCLUDE];
+	int qrv = pmc->interface->mr_qrv;
+	int new_in, rv;
+
+	rv = 0;
+	for (psf = pmc->sources; psf; psf = psf->sf_next) {
+		if (pmc->sfcount[MCAST_EXCLUDE]) {
+			new_in = mca_xcount == psf->sf_count[MCAST_EXCLUDE] &&
+				!psf->sf_count[MCAST_INCLUDE];
+		} else
+			new_in = psf->sf_count[MCAST_INCLUDE] != 0;
+		if (new_in) {
+			if (!psf->sf_oldin) {
+				struct ip_sf_list *prev = NULL;
+
+				for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next) {
+					if (dpsf->sf_inaddr == psf->sf_inaddr)
+						break;
+					prev = dpsf;
+				}
+				if (dpsf) {
+					if (prev)
+						prev->sf_next = dpsf->sf_next;
+					else
+						pmc->tomb = dpsf->sf_next;
+					kfree(dpsf);
+				}
+				psf->sf_crcount = qrv;
+				rv++;
+			}
+		} else if (psf->sf_oldin) {
+
+			psf->sf_crcount = 0;
+			/*
+			 * add or update "delete" records if an active filter
+			 * is now inactive
+			 */
+			for (dpsf = pmc->tomb; dpsf; dpsf = dpsf->sf_next)
+				if (dpsf->sf_inaddr == psf->sf_inaddr)
+					break;
+			if (!dpsf) {
+				dpsf = kmalloc(sizeof(*dpsf), GFP_ATOMIC);
+				if (!dpsf)
+					continue;
+				*dpsf = *psf;
+				/* pmc->lock held by callers */
+				dpsf->sf_next = pmc->tomb;
+				pmc->tomb = dpsf;
+			}
+			dpsf->sf_crcount = qrv;
+			rv++;
+		}
+	}
+	return rv;
+}
+#endif
+
+/*
+ * Add multicast source filter list to the interface list
+ */
+static int ip_mc_add_src(struct in_device *in_dev, __be32 *pmca, int sfmode,
+			 int sfcount, __be32 *psfsrc, int delta)
+{
+	struct ip_mc_list *pmc;
+	int	isexclude;
+	int	i, err;
+
+	if (!in_dev)
+		return -ENODEV;
+	rcu_read_lock();
+	for_each_pmc_rcu(in_dev, pmc) {
+		if (*pmca == pmc->multiaddr)
+			break;
+	}
+	if (!pmc) {
+		/* MCA not found?? bug */
+		rcu_read_unlock();
+		return -ESRCH;
+	}
+	spin_lock_bh(&pmc->lock);
+	rcu_read_unlock();
+
+#ifdef CONFIG_IP_MULTICAST
+	sf_markstate(pmc);
+#endif
+	isexclude = pmc->sfmode == MCAST_EXCLUDE;
+	if (!delta)
+		pmc->sfcount[sfmode]++;
+	err = 0;
+	for (i = 0; i < sfcount; i++) {
+		err = ip_mc_add1_src(pmc, sfmode, &psfsrc[i]);
+		if (err)
+			break;
+	}
+	if (err) {
+		int j;
+
+		if (!delta)
+			pmc->sfcount[sfmode]--;
+		for (j = 0; j < i; j++)
+			(void) ip_mc_del1_src(pmc, sfmode, &psfsrc[j]);
+	} else if (isexclude != (pmc->sfcount[MCAST_EXCLUDE] != 0)) {
+#ifdef CONFIG_IP_MULTICAST
+		struct ip_sf_list *psf;
+		struct net *net = dev_net(pmc->interface->dev);
+		in_dev = pmc->interface;
+#endif
+
+		/* filter mode change */
+		if (pmc->sfcount[MCAST_EXCLUDE])
+			pmc->sfmode = MCAST_EXCLUDE;
+		else if (pmc->sfcount[MCAST_INCLUDE])
+			pmc->sfmode = MCAST_INCLUDE;
+#ifdef CONFIG_IP_MULTICAST
+		/* else no filters; keep old mode for reports */
+
+		pmc->crcount = in_dev->mr_qrv ?: READ_ONCE(net->ipv4.sysctl_igmp_qrv);
+		WRITE_ONCE(in_dev->mr_ifc_count, pmc->crcount);
+		for (psf = pmc->sources; psf; psf = psf->sf_next)
+			psf->sf_crcount = 0;
+		igmp_ifc_event(in_dev);
+	} else if (sf_setstate(pmc)) {
+		igmp_ifc_event(in_dev);
+#endif
+	}
+	spin_unlock_bh(&pmc->lock);
+	return err;
+}
+
+static void ip_mc_clear_src(struct ip_mc_list *pmc)
+{
+	struct ip_sf_list *tomb, *sources;
+
+	spin_lock_bh(&pmc->lock);
+	tomb = pmc->tomb;
+	pmc->tomb = NULL;
+	sources = pmc->sources;
+	pmc->sources = NULL;
+	pmc->sfmode = MCAST_EXCLUDE;
+	pmc->sfcount[MCAST_INCLUDE] = 0;
+	pmc->sfcount[MCAST_EXCLUDE] = 1;
+	spin_unlock_bh(&pmc->lock);
+
+	ip_sf_list_clear_all(tomb);
+	ip_sf_list_clear_all(sources);
+}
+
+/* Join a multicast group
+ */
+static int __ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr,
+			      unsigned int mode)
+{
+	__be32 addr = imr->imr_multiaddr.s_addr;
+	struct ip_mc_socklist *iml, *i;
+	struct in_device *in_dev;
+	struct inet_sock *inet = inet_sk(sk);
+	struct net *net = sock_net(sk);
+	int ifindex;
+	int count = 0;
+	int err;
+
+	ASSERT_RTNL();
+
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+
+	in_dev = ip_mc_find_dev(net, imr);
+
+	if (!in_dev) {
+		err = -ENODEV;
+		goto done;
+	}
+
+	err = -EADDRINUSE;
+	ifindex = imr->imr_ifindex;
+	for_each_pmc_rtnl(inet, i) {
+		if (i->multi.imr_multiaddr.s_addr == addr &&
+		    i->multi.imr_ifindex == ifindex)
+			goto done;
+		count++;
+	}
+	err = -ENOBUFS;
+	if (count >= READ_ONCE(net->ipv4.sysctl_igmp_max_memberships))
+		goto done;
+	iml = sock_kmalloc(sk, sizeof(*iml), GFP_KERNEL);
+	if (!iml)
+		goto done;
+
+	memcpy(&iml->multi, imr, sizeof(*imr));
+	iml->next_rcu = inet->mc_list;
+	iml->sflist = NULL;
+	iml->sfmode = mode;
+	rcu_assign_pointer(inet->mc_list, iml);
+	____ip_mc_inc_group(in_dev, addr, mode, GFP_KERNEL);
+	err = 0;
+done:
+	return err;
+}
+
+/* Join ASM (Any-Source Multicast) group
+ */
+int ip_mc_join_group(struct sock *sk, struct ip_mreqn *imr)
+{
+	return __ip_mc_join_group(sk, imr, MCAST_EXCLUDE);
+}
+EXPORT_SYMBOL(ip_mc_join_group);
+
+/* Join SSM (Source-Specific Multicast) group
+ */
+int ip_mc_join_group_ssm(struct sock *sk, struct ip_mreqn *imr,
+			 unsigned int mode)
+{
+	return __ip_mc_join_group(sk, imr, mode);
+}
+
+static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
+			   struct in_device *in_dev)
+{
+	struct ip_sf_socklist *psf = rtnl_dereference(iml->sflist);
+	int err;
+
+	if (!psf) {
+		/* any-source empty exclude case */
+		return ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
+			iml->sfmode, 0, NULL, 0);
+	}
+	err = ip_mc_del_src(in_dev, &iml->multi.imr_multiaddr.s_addr,
+			iml->sfmode, psf->sl_count, psf->sl_addr, 0);
+	RCU_INIT_POINTER(iml->sflist, NULL);
+	/* decrease mem now to avoid the memleak warning */
+	atomic_sub(struct_size(psf, sl_addr, psf->sl_max), &sk->sk_omem_alloc);
+	kfree_rcu(psf, rcu);
+	return err;
+}
+
+int ip_mc_leave_group(struct sock *sk, struct ip_mreqn *imr)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_mc_socklist *iml;
+	struct ip_mc_socklist __rcu **imlp;
+	struct in_device *in_dev;
+	struct net *net = sock_net(sk);
+	__be32 group = imr->imr_multiaddr.s_addr;
+	u32 ifindex;
+	int ret = -EADDRNOTAVAIL;
+
+	ASSERT_RTNL();
+
+	in_dev = ip_mc_find_dev(net, imr);
+	if (!imr->imr_ifindex && !imr->imr_address.s_addr && !in_dev) {
+		ret = -ENODEV;
+		goto out;
+	}
+	ifindex = imr->imr_ifindex;
+	for (imlp = &inet->mc_list;
+	     (iml = rtnl_dereference(*imlp)) != NULL;
+	     imlp = &iml->next_rcu) {
+		if (iml->multi.imr_multiaddr.s_addr != group)
+			continue;
+		if (ifindex) {
+			if (iml->multi.imr_ifindex != ifindex)
+				continue;
+		} else if (imr->imr_address.s_addr && imr->imr_address.s_addr !=
+				iml->multi.imr_address.s_addr)
+			continue;
+
+		(void) ip_mc_leave_src(sk, iml, in_dev);
+
+		*imlp = iml->next_rcu;
+
+		if (in_dev)
+			ip_mc_dec_group(in_dev, group);
+
+		/* decrease mem now to avoid the memleak warning */
+		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
+		kfree_rcu(iml, rcu);
+		return 0;
+	}
+out:
+	return ret;
+}
+EXPORT_SYMBOL(ip_mc_leave_group);
+
+int ip_mc_source(int add, int omode, struct sock *sk, struct
+	ip_mreq_source *mreqs, int ifindex)
+{
+	int err;
+	struct ip_mreqn imr;
+	__be32 addr = mreqs->imr_multiaddr;
+	struct ip_mc_socklist *pmc;
+	struct in_device *in_dev = NULL;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_sf_socklist *psl;
+	struct net *net = sock_net(sk);
+	int leavegroup = 0;
+	int i, j, rv;
+
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+
+	ASSERT_RTNL();
+
+	imr.imr_multiaddr.s_addr = mreqs->imr_multiaddr;
+	imr.imr_address.s_addr = mreqs->imr_interface;
+	imr.imr_ifindex = ifindex;
+	in_dev = ip_mc_find_dev(net, &imr);
+
+	if (!in_dev) {
+		err = -ENODEV;
+		goto done;
+	}
+	err = -EADDRNOTAVAIL;
+
+	for_each_pmc_rtnl(inet, pmc) {
+		if ((pmc->multi.imr_multiaddr.s_addr ==
+		     imr.imr_multiaddr.s_addr) &&
+		    (pmc->multi.imr_ifindex == imr.imr_ifindex))
+			break;
+	}
+	if (!pmc) {		/* must have a prior join */
+		err = -EINVAL;
+		goto done;
+	}
+	/* if a source filter was set, must be the same mode as before */
+	if (pmc->sflist) {
+		if (pmc->sfmode != omode) {
+			err = -EINVAL;
+			goto done;
+		}
+	} else if (pmc->sfmode != omode) {
+		/* allow mode switches for empty-set filters */
+		ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 0, NULL, 0);
+		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, pmc->sfmode, 0,
+			NULL, 0);
+		pmc->sfmode = omode;
+	}
+
+	psl = rtnl_dereference(pmc->sflist);
+	if (!add) {
+		if (!psl)
+			goto done;	/* err = -EADDRNOTAVAIL */
+		rv = !0;
+		for (i = 0; i < psl->sl_count; i++) {
+			rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
+				sizeof(__be32));
+			if (rv == 0)
+				break;
+		}
+		if (rv)		/* source not found */
+			goto done;	/* err = -EADDRNOTAVAIL */
+
+		/* special case - (INCLUDE, empty) == LEAVE_GROUP */
+		if (psl->sl_count == 1 && omode == MCAST_INCLUDE) {
+			leavegroup = 1;
+			goto done;
+		}
+
+		/* update the interface filter */
+		ip_mc_del_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
+			&mreqs->imr_sourceaddr, 1);
+
+		for (j = i+1; j < psl->sl_count; j++)
+			psl->sl_addr[j-1] = psl->sl_addr[j];
+		psl->sl_count--;
+		err = 0;
+		goto done;
+	}
+	/* else, add a new source to the filter */
+
+	if (psl && psl->sl_count >= READ_ONCE(net->ipv4.sysctl_igmp_max_msf)) {
+		err = -ENOBUFS;
+		goto done;
+	}
+	if (!psl || psl->sl_count == psl->sl_max) {
+		struct ip_sf_socklist *newpsl;
+		int count = IP_SFBLOCK;
+
+		if (psl)
+			count += psl->sl_max;
+		newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr, count),
+				      GFP_KERNEL);
+		if (!newpsl) {
+			err = -ENOBUFS;
+			goto done;
+		}
+		newpsl->sl_max = count;
+		newpsl->sl_count = count - IP_SFBLOCK;
+		if (psl) {
+			for (i = 0; i < psl->sl_count; i++)
+				newpsl->sl_addr[i] = psl->sl_addr[i];
+			/* decrease mem now to avoid the memleak warning */
+			atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
+				   &sk->sk_omem_alloc);
+		}
+		rcu_assign_pointer(pmc->sflist, newpsl);
+		if (psl)
+			kfree_rcu(psl, rcu);
+		psl = newpsl;
+	}
+	rv = 1;	/* > 0 for insert logic below if sl_count is 0 */
+	for (i = 0; i < psl->sl_count; i++) {
+		rv = memcmp(&psl->sl_addr[i], &mreqs->imr_sourceaddr,
+			sizeof(__be32));
+		if (rv == 0)
+			break;
+	}
+	if (rv == 0)		/* address already there is an error */
+		goto done;
+	for (j = psl->sl_count-1; j >= i; j--)
+		psl->sl_addr[j+1] = psl->sl_addr[j];
+	psl->sl_addr[i] = mreqs->imr_sourceaddr;
+	psl->sl_count++;
+	err = 0;
+	/* update the interface list */
+	ip_mc_add_src(in_dev, &mreqs->imr_multiaddr, omode, 1,
+		&mreqs->imr_sourceaddr, 1);
+done:
+	if (leavegroup)
+		err = ip_mc_leave_group(sk, &imr);
+	return err;
+}
+
+int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
+{
+	int err = 0;
+	struct ip_mreqn	imr;
+	__be32 addr = msf->imsf_multiaddr;
+	struct ip_mc_socklist *pmc;
+	struct in_device *in_dev;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_sf_socklist *newpsl, *psl;
+	struct net *net = sock_net(sk);
+	int leavegroup = 0;
+
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+	if (msf->imsf_fmode != MCAST_INCLUDE &&
+	    msf->imsf_fmode != MCAST_EXCLUDE)
+		return -EINVAL;
+
+	ASSERT_RTNL();
+
+	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
+	imr.imr_address.s_addr = msf->imsf_interface;
+	imr.imr_ifindex = ifindex;
+	in_dev = ip_mc_find_dev(net, &imr);
+
+	if (!in_dev) {
+		err = -ENODEV;
+		goto done;
+	}
+
+	/* special case - (INCLUDE, empty) == LEAVE_GROUP */
+	if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
+		leavegroup = 1;
+		goto done;
+	}
+
+	for_each_pmc_rtnl(inet, pmc) {
+		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
+		    pmc->multi.imr_ifindex == imr.imr_ifindex)
+			break;
+	}
+	if (!pmc) {		/* must have a prior join */
+		err = -EINVAL;
+		goto done;
+	}
+	if (msf->imsf_numsrc) {
+		newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr,
+						      msf->imsf_numsrc),
+				      GFP_KERNEL);
+		if (!newpsl) {
+			err = -ENOBUFS;
+			goto done;
+		}
+		newpsl->sl_max = newpsl->sl_count = msf->imsf_numsrc;
+		memcpy(newpsl->sl_addr, msf->imsf_slist_flex,
+		       flex_array_size(msf, imsf_slist_flex, msf->imsf_numsrc));
+		err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
+			msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
+		if (err) {
+			sock_kfree_s(sk, newpsl,
+				     struct_size(newpsl, sl_addr,
+						 newpsl->sl_max));
+			goto done;
+		}
+	} else {
+		newpsl = NULL;
+		(void) ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
+				     msf->imsf_fmode, 0, NULL, 0);
+	}
+	psl = rtnl_dereference(pmc->sflist);
+	if (psl) {
+		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
+			psl->sl_count, psl->sl_addr, 0);
+		/* decrease mem now to avoid the memleak warning */
+		atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
+			   &sk->sk_omem_alloc);
+	} else {
+		(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
+			0, NULL, 0);
+	}
+	rcu_assign_pointer(pmc->sflist, newpsl);
+	if (psl)
+		kfree_rcu(psl, rcu);
+	pmc->sfmode = msf->imsf_fmode;
+	err = 0;
+done:
+	if (leavegroup)
+		err = ip_mc_leave_group(sk, &imr);
+	return err;
+}
+int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
+		 sockptr_t optval, sockptr_t optlen)
+{
+	int err, len, count, copycount, msf_size;
+	struct ip_mreqn	imr;
+	__be32 addr = msf->imsf_multiaddr;
+	struct ip_mc_socklist *pmc;
+	struct in_device *in_dev;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_sf_socklist *psl;
+	struct net *net = sock_net(sk);
+
+	ASSERT_RTNL();
+
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+
+	imr.imr_multiaddr.s_addr = msf->imsf_multiaddr;
+	imr.imr_address.s_addr = msf->imsf_interface;
+	imr.imr_ifindex = 0;
+	in_dev = ip_mc_find_dev(net, &imr);
+
+	if (!in_dev) {
+		err = -ENODEV;
+		goto done;
+	}
+	err = -EADDRNOTAVAIL;
+
+	for_each_pmc_rtnl(inet, pmc) {
+		if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
+		    pmc->multi.imr_ifindex == imr.imr_ifindex)
+			break;
+	}
+	if (!pmc)		/* must have a prior join */
+		goto done;
+	msf->imsf_fmode = pmc->sfmode;
+	psl = rtnl_dereference(pmc->sflist);
+	if (!psl) {
+		count = 0;
+	} else {
+		count = psl->sl_count;
+	}
+	copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc;
+	len = flex_array_size(psl, sl_addr, copycount);
+	msf->imsf_numsrc = count;
+	msf_size = IP_MSFILTER_SIZE(copycount);
+	if (copy_to_sockptr(optlen, &msf_size, sizeof(int)) ||
+	    copy_to_sockptr(optval, msf, IP_MSFILTER_SIZE(0))) {
+		return -EFAULT;
+	}
+	if (len &&
+	    copy_to_sockptr_offset(optval,
+				   offsetof(struct ip_msfilter, imsf_slist_flex),
+				   psl->sl_addr, len))
+		return -EFAULT;
+	return 0;
+done:
+	return err;
+}
+
+int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
+		 sockptr_t optval, size_t ss_offset)
+{
+	int i, count, copycount;
+	struct sockaddr_in *psin;
+	__be32 addr;
+	struct ip_mc_socklist *pmc;
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_sf_socklist *psl;
+
+	ASSERT_RTNL();
+
+	psin = (struct sockaddr_in *)&gsf->gf_group;
+	if (psin->sin_family != AF_INET)
+		return -EINVAL;
+	addr = psin->sin_addr.s_addr;
+	if (!ipv4_is_multicast(addr))
+		return -EINVAL;
+
+	for_each_pmc_rtnl(inet, pmc) {
+		if (pmc->multi.imr_multiaddr.s_addr == addr &&
+		    pmc->multi.imr_ifindex == gsf->gf_interface)
+			break;
+	}
+	if (!pmc)		/* must have a prior join */
+		return -EADDRNOTAVAIL;
+	gsf->gf_fmode = pmc->sfmode;
+	psl = rtnl_dereference(pmc->sflist);
+	count = psl ? psl->sl_count : 0;
+	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
+	gsf->gf_numsrc = count;
+	for (i = 0; i < copycount; i++) {
+		struct sockaddr_storage ss;
+
+		psin = (struct sockaddr_in *)&ss;
+		memset(&ss, 0, sizeof(ss));
+		psin->sin_family = AF_INET;
+		psin->sin_addr.s_addr = psl->sl_addr[i];
+		if (copy_to_sockptr_offset(optval, ss_offset,
+					   &ss, sizeof(ss)))
+			return -EFAULT;
+		ss_offset += sizeof(ss);
+	}
+	return 0;
+}
+
+/*
+ * check if a multicast source filter allows delivery for a given <src,dst,intf>
+ */
+int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr,
+		   int dif, int sdif)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_mc_socklist *pmc;
+	struct ip_sf_socklist *psl;
+	int i;
+	int ret;
+
+	ret = 1;
+	if (!ipv4_is_multicast(loc_addr))
+		goto out;
+
+	rcu_read_lock();
+	for_each_pmc_rcu(inet, pmc) {
+		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
+		    (pmc->multi.imr_ifindex == dif ||
+		     (sdif && pmc->multi.imr_ifindex == sdif)))
+			break;
+	}
+	ret = inet->mc_all;
+	if (!pmc)
+		goto unlock;
+	psl = rcu_dereference(pmc->sflist);
+	ret = (pmc->sfmode == MCAST_EXCLUDE);
+	if (!psl)
+		goto unlock;
+
+	for (i = 0; i < psl->sl_count; i++) {
+		if (psl->sl_addr[i] == rmt_addr)
+			break;
+	}
+	ret = 0;
+	if (pmc->sfmode == MCAST_INCLUDE && i >= psl->sl_count)
+		goto unlock;
+	if (pmc->sfmode == MCAST_EXCLUDE && i < psl->sl_count)
+		goto unlock;
+	ret = 1;
+unlock:
+	rcu_read_unlock();
+out:
+	return ret;
+}
+
+/*
+ *	A socket is closing.
+ */
+
+void ip_mc_drop_socket(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct ip_mc_socklist *iml;
+	struct net *net = sock_net(sk);
+
+	if (!inet->mc_list)
+		return;
+
+	rtnl_lock();
+	while ((iml = rtnl_dereference(inet->mc_list)) != NULL) {
+		struct in_device *in_dev;
+
+		inet->mc_list = iml->next_rcu;
+		in_dev = inetdev_by_index(net, iml->multi.imr_ifindex);
+		(void) ip_mc_leave_src(sk, iml, in_dev);
+		if (in_dev)
+			ip_mc_dec_group(in_dev, iml->multi.imr_multiaddr.s_addr);
+		/* decrease mem now to avoid the memleak warning */
+		atomic_sub(sizeof(*iml), &sk->sk_omem_alloc);
+		kfree_rcu(iml, rcu);
+	}
+	rtnl_unlock();
+}
+
+/* called with rcu_read_lock() */
+int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u8 proto)
+{
+	struct ip_mc_list *im;
+	struct ip_mc_list __rcu **mc_hash;
+	struct ip_sf_list *psf;
+	int rv = 0;
+
+	mc_hash = rcu_dereference(in_dev->mc_hash);
+	if (mc_hash) {
+		u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
+
+		for (im = rcu_dereference(mc_hash[hash]);
+		     im != NULL;
+		     im = rcu_dereference(im->next_hash)) {
+			if (im->multiaddr == mc_addr)
+				break;
+		}
+	} else {
+		for_each_pmc_rcu(in_dev, im) {
+			if (im->multiaddr == mc_addr)
+				break;
+		}
+	}
+	if (im && proto == IPPROTO_IGMP) {
+		rv = 1;
+	} else if (im) {
+		if (src_addr) {
+			spin_lock_bh(&im->lock);
+			for (psf = im->sources; psf; psf = psf->sf_next) {
+				if (psf->sf_inaddr == src_addr)
+					break;
+			}
+			if (psf)
+				rv = psf->sf_count[MCAST_INCLUDE] ||
+					psf->sf_count[MCAST_EXCLUDE] !=
+					im->sfcount[MCAST_EXCLUDE];
+			else
+				rv = im->sfcount[MCAST_EXCLUDE] != 0;
+			spin_unlock_bh(&im->lock);
+		} else
+			rv = 1; /* unspecified source; tentatively allow */
+	}
+	return rv;
+}
+
+#if defined(CONFIG_PROC_FS)
+struct igmp_mc_iter_state {
+	struct seq_net_private p;
+	struct net_device *dev;
+	struct in_device *in_dev;
+};
+
+#define	igmp_mc_seq_private(seq)	((struct igmp_mc_iter_state *)(seq)->private)
+
+static inline struct ip_mc_list *igmp_mc_get_first(struct seq_file *seq)
+{
+	struct net *net = seq_file_net(seq);
+	struct ip_mc_list *im = NULL;
+	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
+
+	state->in_dev = NULL;
+	for_each_netdev_rcu(net, state->dev) {
+		struct in_device *in_dev;
+
+		in_dev = __in_dev_get_rcu(state->dev);
+		if (!in_dev)
+			continue;
+		im = rcu_dereference(in_dev->mc_list);
+		if (im) {
+			state->in_dev = in_dev;
+			break;
+		}
+	}
+	return im;
+}
+
+static struct ip_mc_list *igmp_mc_get_next(struct seq_file *seq, struct ip_mc_list *im)
+{
+	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
+
+	im = rcu_dereference(im->next_rcu);
+	while (!im) {
+		state->dev = next_net_device_rcu(state->dev);
+		if (!state->dev) {
+			state->in_dev = NULL;
+			break;
+		}
+		state->in_dev = __in_dev_get_rcu(state->dev);
+		if (!state->in_dev)
+			continue;
+		im = rcu_dereference(state->in_dev->mc_list);
+	}
+	return im;
+}
+
+static struct ip_mc_list *igmp_mc_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct ip_mc_list *im = igmp_mc_get_first(seq);
+	if (im)
+		while (pos && (im = igmp_mc_get_next(seq, im)) != NULL)
+			--pos;
+	return pos ? NULL : im;
+}
+
+static void *igmp_mc_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(rcu)
+{
+	rcu_read_lock();
+	return *pos ? igmp_mc_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *igmp_mc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct ip_mc_list *im;
+	if (v == SEQ_START_TOKEN)
+		im = igmp_mc_get_first(seq);
+	else
+		im = igmp_mc_get_next(seq, v);
+	++*pos;
+	return im;
+}
+
+static void igmp_mc_seq_stop(struct seq_file *seq, void *v)
+	__releases(rcu)
+{
+	struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
+
+	state->in_dev = NULL;
+	state->dev = NULL;
+	rcu_read_unlock();
+}
+
+static int igmp_mc_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN)
+		seq_puts(seq,
+			 "Idx\tDevice    : Count Querier\tGroup    Users Timer\tReporter\n");
+	else {
+		struct ip_mc_list *im = v;
+		struct igmp_mc_iter_state *state = igmp_mc_seq_private(seq);
+		char   *querier;
+		long delta;
+
+#ifdef CONFIG_IP_MULTICAST
+		querier = IGMP_V1_SEEN(state->in_dev) ? "V1" :
+			  IGMP_V2_SEEN(state->in_dev) ? "V2" :
+			  "V3";
+#else
+		querier = "NONE";
+#endif
+
+		if (rcu_access_pointer(state->in_dev->mc_list) == im) {
+			seq_printf(seq, "%d\t%-10s: %5d %7s\n",
+				   state->dev->ifindex, state->dev->name, state->in_dev->mc_count, querier);
+		}
+
+		delta = im->timer.expires - jiffies;
+		seq_printf(seq,
+			   "\t\t\t\t%08X %5d %d:%08lX\t\t%d\n",
+			   im->multiaddr, im->users,
+			   im->tm_running,
+			   im->tm_running ? jiffies_delta_to_clock_t(delta) : 0,
+			   im->reporter);
+	}
+	return 0;
+}
+
+static const struct seq_operations igmp_mc_seq_ops = {
+	.start	=	igmp_mc_seq_start,
+	.next	=	igmp_mc_seq_next,
+	.stop	=	igmp_mc_seq_stop,
+	.show	=	igmp_mc_seq_show,
+};
+
+struct igmp_mcf_iter_state {
+	struct seq_net_private p;
+	struct net_device *dev;
+	struct in_device *idev;
+	struct ip_mc_list *im;
+};
+
+#define igmp_mcf_seq_private(seq)	((struct igmp_mcf_iter_state *)(seq)->private)
+
+static inline struct ip_sf_list *igmp_mcf_get_first(struct seq_file *seq)
+{
+	struct net *net = seq_file_net(seq);
+	struct ip_sf_list *psf = NULL;
+	struct ip_mc_list *im = NULL;
+	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
+
+	state->idev = NULL;
+	state->im = NULL;
+	for_each_netdev_rcu(net, state->dev) {
+		struct in_device *idev;
+		idev = __in_dev_get_rcu(state->dev);
+		if (unlikely(!idev))
+			continue;
+		im = rcu_dereference(idev->mc_list);
+		if (likely(im)) {
+			spin_lock_bh(&im->lock);
+			psf = im->sources;
+			if (likely(psf)) {
+				state->im = im;
+				state->idev = idev;
+				break;
+			}
+			spin_unlock_bh(&im->lock);
+		}
+	}
+	return psf;
+}
+
+static struct ip_sf_list *igmp_mcf_get_next(struct seq_file *seq, struct ip_sf_list *psf)
+{
+	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
+
+	psf = psf->sf_next;
+	while (!psf) {
+		spin_unlock_bh(&state->im->lock);
+		state->im = state->im->next;
+		while (!state->im) {
+			state->dev = next_net_device_rcu(state->dev);
+			if (!state->dev) {
+				state->idev = NULL;
+				goto out;
+			}
+			state->idev = __in_dev_get_rcu(state->dev);
+			if (!state->idev)
+				continue;
+			state->im = rcu_dereference(state->idev->mc_list);
+		}
+		if (!state->im)
+			break;
+		spin_lock_bh(&state->im->lock);
+		psf = state->im->sources;
+	}
+out:
+	return psf;
+}
+
+static struct ip_sf_list *igmp_mcf_get_idx(struct seq_file *seq, loff_t pos)
+{
+	struct ip_sf_list *psf = igmp_mcf_get_first(seq);
+	if (psf)
+		while (pos && (psf = igmp_mcf_get_next(seq, psf)) != NULL)
+			--pos;
+	return pos ? NULL : psf;
+}
+
+static void *igmp_mcf_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(rcu)
+{
+	rcu_read_lock();
+	return *pos ? igmp_mcf_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+}
+
+static void *igmp_mcf_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	struct ip_sf_list *psf;
+	if (v == SEQ_START_TOKEN)
+		psf = igmp_mcf_get_first(seq);
+	else
+		psf = igmp_mcf_get_next(seq, v);
+	++*pos;
+	return psf;
+}
+
+static void igmp_mcf_seq_stop(struct seq_file *seq, void *v)
+	__releases(rcu)
+{
+	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
+	if (likely(state->im)) {
+		spin_unlock_bh(&state->im->lock);
+		state->im = NULL;
+	}
+	state->idev = NULL;
+	state->dev = NULL;
+	rcu_read_unlock();
+}
+
+static int igmp_mcf_seq_show(struct seq_file *seq, void *v)
+{
+	struct ip_sf_list *psf = v;
+	struct igmp_mcf_iter_state *state = igmp_mcf_seq_private(seq);
+
+	if (v == SEQ_START_TOKEN) {
+		seq_puts(seq, "Idx Device        MCA        SRC    INC    EXC\n");
+	} else {
+		seq_printf(seq,
+			   "%3d %6.6s 0x%08x "
+			   "0x%08x %6lu %6lu\n",
+			   state->dev->ifindex, state->dev->name,
+			   ntohl(state->im->multiaddr),
+			   ntohl(psf->sf_inaddr),
+			   psf->sf_count[MCAST_INCLUDE],
+			   psf->sf_count[MCAST_EXCLUDE]);
+	}
+	return 0;
+}
+
+static const struct seq_operations igmp_mcf_seq_ops = {
+	.start	=	igmp_mcf_seq_start,
+	.next	=	igmp_mcf_seq_next,
+	.stop	=	igmp_mcf_seq_stop,
+	.show	=	igmp_mcf_seq_show,
+};
+
+static int __net_init igmp_net_init(struct net *net)
+{
+	struct proc_dir_entry *pde;
+	int err;
+
+	pde = proc_create_net("igmp", 0444, net->proc_net, &igmp_mc_seq_ops,
+			sizeof(struct igmp_mc_iter_state));
+	if (!pde)
+		goto out_igmp;
+	pde = proc_create_net("mcfilter", 0444, net->proc_net,
+			&igmp_mcf_seq_ops, sizeof(struct igmp_mcf_iter_state));
+	if (!pde)
+		goto out_mcfilter;
+	err = inet_ctl_sock_create(&net->ipv4.mc_autojoin_sk, AF_INET,
+				   SOCK_DGRAM, 0, net);
+	if (err < 0) {
+		pr_err("Failed to initialize the IGMP autojoin socket (err %d)\n",
+		       err);
+		goto out_sock;
+	}
+
+	return 0;
+
+out_sock:
+	remove_proc_entry("mcfilter", net->proc_net);
+out_mcfilter:
+	remove_proc_entry("igmp", net->proc_net);
+out_igmp:
+	return -ENOMEM;
+}
+
+static void __net_exit igmp_net_exit(struct net *net)
+{
+	remove_proc_entry("mcfilter", net->proc_net);
+	remove_proc_entry("igmp", net->proc_net);
+	inet_ctl_sock_destroy(net->ipv4.mc_autojoin_sk);
+}
+
+static struct pernet_operations igmp_net_ops = {
+	.init = igmp_net_init,
+	.exit = igmp_net_exit,
+};
+#endif
+
+static int igmp_netdev_event(struct notifier_block *this,
+			     unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct in_device *in_dev;
+
+	switch (event) {
+	case NETDEV_RESEND_IGMP:
+		in_dev = __in_dev_get_rtnl(dev);
+		if (in_dev)
+			ip_mc_rejoin_groups(in_dev);
+		break;
+	default:
+		break;
+	}
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block igmp_notifier = {
+	.notifier_call = igmp_netdev_event,
+};
+
+int __init igmp_mc_init(void)
+{
+#if defined(CONFIG_PROC_FS)
+	int err;
+
+	err = register_pernet_subsys(&igmp_net_ops);
+	if (err)
+		return err;
+	err = register_netdevice_notifier(&igmp_notifier);
+	if (err)
+		goto reg_notif_fail;
+	return 0;
+
+reg_notif_fail:
+	unregister_pernet_subsys(&igmp_net_ops);
+	return err;
+#else
+	return register_netdevice_notifier(&igmp_notifier);
+#endif
+}