ipv6/mcast: init as INCLUDE when join SSM INCLUDE group
This an IPv6 version patch of "ipv4/igmp: init group mode as INCLUDE when
join source group". From RFC3810, part 6.1:
If no per-interface state existed for that
multicast address before the change (i.e., the change consisted of
creating a new per-interface record), or if no state exists after the
change (i.e., the change consisted of deleting a per-interface
record), then the "non-existent" state is considered to have an
INCLUDE filter mode and an empty source list.
Which means a new multicast group should start with state IN(). Currently,
for MLDv2 SSM JOIN_SOURCE_GROUP mode, we first call ipv6_sock_mc_join(),
then ip6_mc_source(), which will trigger a TO_IN() message instead of
ALLOW().
The issue was exposed by commit a052517a8ff65 ("net/multicast: should not
send source list records when have filter mode change"). Before this change,
we sent both ALLOW(A) and TO_IN(A). Now, we only send TO_IN(A).
Fix it by adding a new parameter to init group mode. Also add some wrapper
functions to avoid changing too much code.
v1 -> v2:
In the first version I only cleared the group change record. But this is not
enough. Because when a new group join, it will init as EXCLUDE and trigger
a filter mode change in ip/ip6_mc_add_src(), which will clear all source
addresses sf_crcount. This will prevent early joined address sending state
change records if multi source addressed joined at the same time.
In v2 patch, I fixed it by directly initializing the mode to INCLUDE for SSM
JOIN_SOURCE_GROUP. I also split the original patch into two separated patches
for IPv4 and IPv6.
There is also a difference between v4 and v6 version. For IPv6, when the
interface goes down and up, we will send correct state change record with
unspecified IPv6 address (::) with function ipv6_mc_up(). But after DAD is
completed, we resend the change record TO_IN() in mld_send_initial_cr().
Fix it by sending ALLOW() for INCLUDE mode in mld_send_initial_cr().
Fixes: a052517a8ff65 ("net/multicast: should not send source list records when have filter mode change")
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index c0c7408..2699be7 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -95,6 +95,8 @@ static int ip6_mc_add_src(struct inet6_dev *idev, const struct in6_addr *pmca,
int delta);
static int ip6_mc_leave_src(struct sock *sk, struct ipv6_mc_socklist *iml,
struct inet6_dev *idev);
+static int __ipv6_dev_mc_inc(struct net_device *dev,
+ const struct in6_addr *addr, unsigned int mode);
#define MLD_QRV_DEFAULT 2
/* RFC3810, 9.2. Query Interval */
@@ -132,7 +134,8 @@ static int unsolicited_report_interval(struct inet6_dev *idev)
return iv > 0 ? iv : 1;
}
-int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
+static int __ipv6_sock_mc_join(struct sock *sk, int ifindex,
+ const struct in6_addr *addr, unsigned int mode)
{
struct net_device *dev = NULL;
struct ipv6_mc_socklist *mc_lst;
@@ -179,7 +182,7 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
}
mc_lst->ifindex = dev->ifindex;
- mc_lst->sfmode = MCAST_EXCLUDE;
+ mc_lst->sfmode = mode;
rwlock_init(&mc_lst->sflock);
mc_lst->sflist = NULL;
@@ -187,7 +190,7 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
* now add/increase the group membership on the device
*/
- err = ipv6_dev_mc_inc(dev, addr);
+ err = __ipv6_dev_mc_inc(dev, addr, mode);
if (err) {
sock_kfree_s(sk, mc_lst, sizeof(*mc_lst));
@@ -199,8 +202,19 @@ int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
return 0;
}
+
+int ipv6_sock_mc_join(struct sock *sk, int ifindex, const struct in6_addr *addr)
+{
+ return __ipv6_sock_mc_join(sk, ifindex, addr, MCAST_EXCLUDE);
+}
EXPORT_SYMBOL(ipv6_sock_mc_join);
+int ipv6_sock_mc_join_ssm(struct sock *sk, int ifindex,
+ const struct in6_addr *addr, unsigned int mode)
+{
+ return __ipv6_sock_mc_join(sk, ifindex, addr, mode);
+}
+
/*
* socket leave on multicast group
*/
@@ -646,7 +660,7 @@ bool inet6_mc_check(struct sock *sk, const struct in6_addr *mc_addr,
return rv;
}
-static void igmp6_group_added(struct ifmcaddr6 *mc)
+static void igmp6_group_added(struct ifmcaddr6 *mc, unsigned int mode)
{
struct net_device *dev = mc->idev->dev;
char buf[MAX_ADDR_LEN];
@@ -672,7 +686,13 @@ static void igmp6_group_added(struct ifmcaddr6 *mc)
}
/* else v2 */
- mc->mca_crcount = mc->idev->mc_qrv;
+ /* Based on RFC3810 6.1, for newly added INCLUDE SSM, we
+ * should not send filter-mode change record as the mode
+ * should be from IN() to IN(A).
+ */
+ if (mode == MCAST_EXCLUDE)
+ mc->mca_crcount = mc->idev->mc_qrv;
+
mld_ifc_event(mc->idev);
}
@@ -770,13 +790,14 @@ static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
spin_lock_bh(&im->mca_lock);
if (pmc) {
im->idev = pmc->idev;
- im->mca_crcount = idev->mc_qrv;
im->mca_sfmode = pmc->mca_sfmode;
if (pmc->mca_sfmode == MCAST_INCLUDE) {
im->mca_tomb = pmc->mca_tomb;
im->mca_sources = pmc->mca_sources;
for (psf = im->mca_sources; psf; psf = psf->sf_next)
- psf->sf_crcount = im->mca_crcount;
+ psf->sf_crcount = idev->mc_qrv;
+ } else {
+ im->mca_crcount = idev->mc_qrv;
}
in6_dev_put(pmc->idev);
kfree(pmc);
@@ -831,7 +852,8 @@ static void ma_put(struct ifmcaddr6 *mc)
}
static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
- const struct in6_addr *addr)
+ const struct in6_addr *addr,
+ unsigned int mode)
{
struct ifmcaddr6 *mc;
@@ -849,9 +871,8 @@ static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
refcount_set(&mc->mca_refcnt, 1);
spin_lock_init(&mc->mca_lock);
- /* initial mode is (EX, empty) */
- mc->mca_sfmode = MCAST_EXCLUDE;
- mc->mca_sfcount[MCAST_EXCLUDE] = 1;
+ mc->mca_sfmode = mode;
+ mc->mca_sfcount[mode] = 1;
if (ipv6_addr_is_ll_all_nodes(&mc->mca_addr) ||
IPV6_ADDR_MC_SCOPE(&mc->mca_addr) < IPV6_ADDR_SCOPE_LINKLOCAL)
@@ -863,7 +884,8 @@ static struct ifmcaddr6 *mca_alloc(struct inet6_dev *idev,
/*
* device multicast group inc (add if not found)
*/
-int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
+static int __ipv6_dev_mc_inc(struct net_device *dev,
+ const struct in6_addr *addr, unsigned int mode)
{
struct ifmcaddr6 *mc;
struct inet6_dev *idev;
@@ -887,14 +909,13 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
if (ipv6_addr_equal(&mc->mca_addr, addr)) {
mc->mca_users++;
write_unlock_bh(&idev->lock);
- ip6_mc_add_src(idev, &mc->mca_addr, MCAST_EXCLUDE, 0,
- NULL, 0);
+ ip6_mc_add_src(idev, &mc->mca_addr, mode, 0, NULL, 0);
in6_dev_put(idev);
return 0;
}
}
- mc = mca_alloc(idev, addr);
+ mc = mca_alloc(idev, addr, mode);
if (!mc) {
write_unlock_bh(&idev->lock);
in6_dev_put(idev);
@@ -911,11 +932,16 @@ int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
write_unlock_bh(&idev->lock);
mld_del_delrec(idev, mc);
- igmp6_group_added(mc);
+ igmp6_group_added(mc, mode);
ma_put(mc);
return 0;
}
+int ipv6_dev_mc_inc(struct net_device *dev, const struct in6_addr *addr)
+{
+ return __ipv6_dev_mc_inc(dev, addr, MCAST_EXCLUDE);
+}
+
/*
* device multicast group del
*/
@@ -1751,7 +1777,7 @@ static struct sk_buff *add_grec(struct sk_buff *skb, struct ifmcaddr6 *pmc,
psf_next = psf->sf_next;
- if (!is_in(pmc, psf, type, gdeleted, sdeleted)) {
+ if (!is_in(pmc, psf, type, gdeleted, sdeleted) && !crsend) {
psf_prev = psf;
continue;
}
@@ -2066,7 +2092,7 @@ static void mld_send_initial_cr(struct inet6_dev *idev)
if (pmc->mca_sfcount[MCAST_EXCLUDE])
type = MLD2_CHANGE_TO_EXCLUDE;
else
- type = MLD2_CHANGE_TO_INCLUDE;
+ type = MLD2_ALLOW_NEW_SOURCES;
skb = add_grec(skb, pmc, type, 0, 0, 1);
spin_unlock_bh(&pmc->mca_lock);
}
@@ -2546,7 +2572,7 @@ void ipv6_mc_up(struct inet6_dev *idev)
ipv6_mc_reset(idev);
for (i = idev->mc_list; i; i = i->next) {
mld_del_delrec(idev, i);
- igmp6_group_added(i);
+ igmp6_group_added(i, i->mca_sfmode);
}
read_unlock_bh(&idev->lock);
}