[IPV4]: (INCLUDE,empty)/leave-group equivalence for full-state MSF APIs & errno fix

1) Adds (INCLUDE, empty)/leave-group equivalence to the full-state 
   multicast source filter APIs (IPv4 and IPv6)

2) Fixes an incorrect errno in the IPv6 leave-group (ENOENT should be
   EADDRNOTAVAIL)

Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 1 deletions

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index dbbfa09de4e8..7af3146939dc 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1849,13 +1849,14 @@ done:
 
 int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
 {
-        int err;
+        int err = 0;
         struct ip_mreqn imr;
         u32 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;
+        int leavegroup = 0;
 
         if (!MULTICAST(addr))
                 return -EINVAL;
@@ -1875,6 +1876,12 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
                 goto done;
         }
 
+        /* special case - (INCLUDE, empty) == LEAVE_GROUP */
+        if (msf->imsf_fmode == MCAST_INCLUDE && msf->imsf_numsrc == 0) {
+                leavegroup = 1;
+                goto done;
+        }
+
         for (pmc=inet->mc_list; pmc; pmc=pmc->next) {
                 if (pmc->multi.imr_multiaddr.s_addr == msf->imsf_multiaddr &&
                     pmc->multi.imr_ifindex == imr.imr_ifindex)
@@ -1915,6 +1922,8 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
         err = 0;
 done:
         rtnl_shunlock();
+        if (leavegroup)
+                err = ip_mc_leave_group(sk, &imr);
         return err;
 }