1 files changed, 101 insertions, 49 deletions

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index 7ba01d8cfbae..65831b4fee1f 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -33,8 +33,10 @@
 #include <linux/in.h>
 #include <linux/in6.h>
 #include <linux/netdevice.h>
+#include <linux/if_addr.h>
 #include <linux/if_arp.h>
 #include <linux/route.h>
+#include <linux/rtnetlink.h>
 #include <linux/init.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
@@ -47,6 +49,7 @@
 #include <linux/netfilter_ipv6.h>
 
 #include <net/net_namespace.h>
+#include <net/netlink.h>
 #include <net/sock.h>
 #include <net/snmp.h>
 
@@ -586,7 +589,8 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 	const struct in6_addr *group;
 	struct ipv6_mc_socklist *pmc;
 	struct ip6_sf_socklist *psl;
-	int i, count, copycount;
+	unsigned int count;
+	int i, copycount;
 
 	group = &((struct sockaddr_in6 *)&gsf->gf_group)->sin6_addr;
 
@@ -610,7 +614,7 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 	psl = sock_dereference(pmc->sflist, sk);
 	count = psl ? psl->sl_count : 0;
 
-	copycount = count < gsf->gf_numsrc ? count : gsf->gf_numsrc;
+	copycount = min(count, gsf->gf_numsrc);
 	gsf->gf_numsrc = count;
 	for (i = 0; i < copycount; i++) {
 		struct sockaddr_in6 *psin6;
@@ -900,6 +904,41 @@ static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
 	return mc;
 }
 
+static void inet6_ifmcaddr_notify(struct net_device *dev,
+				  const struct ifmcaddr6 *ifmca, int event)
+{
+	struct inet6_fill_args fillargs = {
+		.portid = 0,
+		.seq = 0,
+		.event = event,
+		.flags = 0,
+		.netnsid = -1,
+		.force_rt_scope_universe = true,
+	};
+	struct net *net = dev_net(dev);
+	struct sk_buff *skb;
+	int err = -ENOMEM;
+
+	skb = nlmsg_new(NLMSG_ALIGN(sizeof(struct ifaddrmsg)) +
+			nla_total_size(sizeof(struct in6_addr)) +
+			nla_total_size(sizeof(struct ifa_cacheinfo)),
+			GFP_KERNEL);
+	if (!skb)
+		goto error;
+
+	err = inet6_fill_ifmcaddr(skb, ifmca, &fillargs);
+	if (err < 0) {
+		WARN_ON_ONCE(err == -EMSGSIZE);
+		nlmsg_free(skb);
+		goto error;
+	}
+
+	rtnl_notify(skb, net, 0, RTNLGRP_IPV6_MCADDR, NULL, GFP_KERNEL);
+	return;
+error:
+	rtnl_set_sk_err(net, RTNLGRP_IPV6_MCADDR, err);
+}
+
 /*
  *	device multicast group inc (add if not found)
  */
@@ -947,6 +986,7 @@ static int __ipv6_dev_mc_inc(struct net_device *dev,
 
 	mld_del_delrec(idev, mc);
 	igmp6_group_added(mc);
+	inet6_ifmcaddr_notify(dev, mc, RTM_NEWMULTICAST);
 	mutex_unlock(&idev->mc_lock);
 	ma_put(mc);
 	return 0;
@@ -976,6 +1016,8 @@ int __ipv6_dev_mc_dec(struct inet6_dev *idev, const struct in6_addr *addr)
 				*map = ma->next;
 
 				igmp6_group_dropped(ma);
+				inet6_ifmcaddr_notify(idev->dev, ma,
+						      RTM_DELMULTICAST);
 				ip6_mc_clear_src(ma);
 				mutex_unlock(&idev->mc_lock);
 
@@ -1020,29 +1062,31 @@ bool ipv6_chk_mcast_addr(struct net_device *dev, const struct in6_addr *group,
 
 	rcu_read_lock();
 	idev = __in6_dev_get(dev);
-	if (idev) {
-		for_each_mc_rcu(idev, mc) {
-			if (ipv6_addr_equal(&mc->mca_addr, group))
-				break;
-		}
-		if (mc) {
-			if (src_addr && !ipv6_addr_any(src_addr)) {
-				struct ip6_sf_list *psf;
+	if (!idev)
+		goto unlock;
+	for_each_mc_rcu(idev, mc) {
+		if (ipv6_addr_equal(&mc->mca_addr, group))
+			break;
+	}
+	if (!mc)
+		goto unlock;
+	if (src_addr && !ipv6_addr_any(src_addr)) {
+		struct ip6_sf_list *psf;
 
-				for_each_psf_rcu(mc, psf) {
-					if (ipv6_addr_equal(&psf->sf_addr, src_addr))
-						break;
-				}
-				if (psf)
-					rv = psf->sf_count[MCAST_INCLUDE] ||
-						psf->sf_count[MCAST_EXCLUDE] !=
-						mc->mca_sfcount[MCAST_EXCLUDE];
-				else
-					rv = mc->mca_sfcount[MCAST_EXCLUDE] != 0;
-			} else
-				rv = true; /* don't filter unspecified source */
+		for_each_psf_rcu(mc, psf) {
+			if (ipv6_addr_equal(&psf->sf_addr, src_addr))
+				break;
 		}
+		if (psf)
+			rv = READ_ONCE(psf->sf_count[MCAST_INCLUDE]) ||
+				READ_ONCE(psf->sf_count[MCAST_EXCLUDE]) !=
+				READ_ONCE(mc->mca_sfcount[MCAST_EXCLUDE]);
+		else
+			rv = READ_ONCE(mc->mca_sfcount[MCAST_EXCLUDE]) != 0;
+	} else {
+		rv = true; /* don't filter unspecified source */
 	}
+unlock:
 	rcu_read_unlock();
 	return rv;
 }
@@ -1729,21 +1773,19 @@ static struct sk_buff *mld_newpack(struct inet6_dev *idev, unsigned int mtu)
 	struct net_device *dev = idev->dev;
 	int hlen = LL_RESERVED_SPACE(dev);
 	int tlen = dev->needed_tailroom;
-	struct net *net = dev_net(dev);
 	const struct in6_addr *saddr;
 	struct in6_addr addr_buf;
 	struct mld2_report *pmr;
 	struct sk_buff *skb;
 	unsigned int size;
 	struct sock *sk;
-	int err;
+	struct net *net;
 
-	sk = net->ipv6.igmp_sk;
 	/* we assume size > sizeof(ra) here
 	 * Also try to not allocate high-order pages for big MTU
 	 */
 	size = min_t(int, mtu, PAGE_SIZE / 2) + hlen + tlen;
-	skb = sock_alloc_send_skb(sk, size, 1, &err);
+	skb = alloc_skb(size, GFP_KERNEL);
 	if (!skb)
 		return NULL;
 
@@ -1751,6 +1793,12 @@ static struct sk_buff *mld_newpack(struct inet6_dev *idev, unsigned int mtu)
 	skb_reserve(skb, hlen);
 	skb_tailroom_reserve(skb, mtu, tlen);
 
+	rcu_read_lock();
+
+	net = dev_net_rcu(dev);
+	sk = net->ipv6.igmp_sk;
+	skb_set_owner_w(skb, sk);
+
 	if (ipv6_get_lladdr(dev, &addr_buf, IFA_F_TENTATIVE)) {
 		/* <draft-ietf-magma-mld-source-05.txt>:
 		 * use unspecified address as the source address
@@ -1762,6 +1810,8 @@ static struct sk_buff *mld_newpack(struct inet6_dev *idev, unsigned int mtu)
 
 	ip6_mc_hdr(sk, skb, dev, saddr, &mld2_all_mcr, NEXTHDR_HOP, 0);
 
+	rcu_read_unlock();
+
 	skb_put_data(skb, ra, sizeof(ra));
 
 	skb_set_transport_header(skb, skb_tail_pointer(skb) - skb->data);
@@ -2121,21 +2171,21 @@ static void mld_send_cr(struct inet6_dev *idev)
 
 static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
 {
-	struct net *net = dev_net(dev);
-	struct sock *sk = net->ipv6.igmp_sk;
+	const struct in6_addr *snd_addr, *saddr;
+	int err, len, payload_len, full_len;
+	struct in6_addr addr_buf;
 	struct inet6_dev *idev;
 	struct sk_buff *skb;
 	struct mld_msg *hdr;
-	const struct in6_addr *snd_addr, *saddr;
-	struct in6_addr addr_buf;
 	int hlen = LL_RESERVED_SPACE(dev);
 	int tlen = dev->needed_tailroom;
-	int err, len, payload_len, full_len;
 	u8 ra[8] = { IPPROTO_ICMPV6, 0,
 		     IPV6_TLV_ROUTERALERT, 2, 0, 0,
 		     IPV6_TLV_PADN, 0 };
-	struct flowi6 fl6;
 	struct dst_entry *dst;
+	struct flowi6 fl6;
+	struct net *net;
+	struct sock *sk;
 
 	if (type == ICMPV6_MGM_REDUCTION)
 		snd_addr = &in6addr_linklocal_allrouters;
@@ -2146,19 +2196,21 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
 	payload_len = len + sizeof(ra);
 	full_len = sizeof(struct ipv6hdr) + payload_len;
 
-	rcu_read_lock();
-	IP6_INC_STATS(net, __in6_dev_get(dev), IPSTATS_MIB_OUTREQUESTS);
-	rcu_read_unlock();
+	skb = alloc_skb(hlen + tlen + full_len, GFP_KERNEL);
 
-	skb = sock_alloc_send_skb(sk, hlen + tlen + full_len, 1, &err);
+	rcu_read_lock();
 
+	net = dev_net_rcu(dev);
+	idev = __in6_dev_get(dev);
+	IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTREQUESTS);
 	if (!skb) {
-		rcu_read_lock();
-		IP6_INC_STATS(net, __in6_dev_get(dev),
-			      IPSTATS_MIB_OUTDISCARDS);
+		IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
 		rcu_read_unlock();
 		return;
 	}
+	sk = net->ipv6.igmp_sk;
+	skb_set_owner_w(skb, sk);
+
 	skb->priority = TC_PRIO_CONTROL;
 	skb_reserve(skb, hlen);
 
@@ -2183,9 +2235,6 @@ static void igmp6_send(struct in6_addr *addr, struct net_device *dev, int type)
 					 IPPROTO_ICMPV6,
 					 csum_partial(hdr, len, 0));
 
-	rcu_read_lock();
-	idev = __in6_dev_get(skb->dev);
-
 	icmpv6_flow_init(sk, &fl6, type,
 			 &ipv6_hdr(skb)->saddr, &ipv6_hdr(skb)->daddr,
 			 skb->dev->ifindex);
@@ -2284,7 +2333,7 @@ static int ip6_mc_del1_src(struct ifmcaddr6 *pmc, int sfmode,
 		/* source filter not found, or count wrong =>  bug */
 		return -ESRCH;
 	}
-	psf->sf_count[sfmode]--;
+	WRITE_ONCE(psf->sf_count[sfmode], psf->sf_count[sfmode] - 1);
 	if (!psf->sf_count[MCAST_INCLUDE] && !psf->sf_count[MCAST_EXCLUDE]) {
 		struct inet6_dev *idev = pmc->idev;
 
@@ -2390,7 +2439,7 @@ static int ip6_mc_add1_src(struct ifmcaddr6 *pmc, int sfmode,
 			rcu_assign_pointer(pmc->mca_sources, psf);
 		}
 	}
-	psf->sf_count[sfmode]++;
+	WRITE_ONCE(psf->sf_count[sfmode], psf->sf_count[sfmode] + 1);
 	return 0;
 }
 
@@ -2502,7 +2551,8 @@ static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
 	sf_markstate(pmc);
 	isexclude = pmc->mca_sfmode == MCAST_EXCLUDE;
 	if (!delta)
-		pmc->mca_sfcount[sfmode]++;
+		WRITE_ONCE(pmc->mca_sfcount[sfmode],
+			   pmc->mca_sfcount[sfmode] + 1);
 	err = 0;
 	for (i = 0; i < sfcount; i++) {
 		err = ip6_mc_add1_src(pmc, sfmode, &psfsrc[i]);
@@ -2513,7 +2563,8 @@ static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
 		int j;
 
 		if (!delta)
-			pmc->mca_sfcount[sfmode]--;
+			WRITE_ONCE(pmc->mca_sfcount[sfmode],
+				   pmc->mca_sfcount[sfmode] - 1);
 		for (j = 0; j < i; j++)
 			ip6_mc_del1_src(pmc, sfmode, &psfsrc[j]);
 	} else if (isexclude != (pmc->mca_sfcount[MCAST_EXCLUDE] != 0)) {
@@ -2558,7 +2609,8 @@ static void ip6_mc_clear_src(struct ifmcaddr6 *pmc)
 	RCU_INIT_POINTER(pmc->mca_sources, NULL);
 	pmc->mca_sfmode = MCAST_EXCLUDE;
 	pmc->mca_sfcount[MCAST_INCLUDE] = 0;
-	pmc->mca_sfcount[MCAST_EXCLUDE] = 1;
+	/* Paired with the READ_ONCE() from ipv6_chk_mcast_addr() */
+	WRITE_ONCE(pmc->mca_sfcount[MCAST_EXCLUDE], 1);
 }
 
 /* called with mc_lock */
@@ -3073,8 +3125,8 @@ static int igmp6_mcf_seq_show(struct seq_file *seq, void *v)
 			   state->dev->ifindex, state->dev->name,
 			   &state->im->mca_addr,
 			   &psf->sf_addr,
-			   psf->sf_count[MCAST_INCLUDE],
-			   psf->sf_count[MCAST_EXCLUDE]);
+			   READ_ONCE(psf->sf_count[MCAST_INCLUDE]),
+			   READ_ONCE(psf->sf_count[MCAST_EXCLUDE]));
 	}
 	return 0;
 }