ip6mr: fix mfc notification flags

[ Upstream commit f518338b16038beeb73e155e60d0f70beb9379f4 ]

Commit 812e44dd1829 ("ip6mr: advertise new mfc entries via rtnl") reuses the
function ip6mr_fill_mroute() to notify mfc events.
But this function was used only for dump and thus was always setting the
flag NLM_F_MULTI, which is wrong in case of a single notification.

Libraries like libnl will wait forever for NLMSG_DONE.

CC: Thomas Graf <tgraf@suug.ch>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/net/ipv6/ip6mr.c b/net/ipv6/ip6mr.c
index 9f44ebc17759..2c84072b1da7 100644
--- a/net/ipv6/ip6mr.c
+++ b/net/ipv6/ip6mr.c
@@ -2351,13 +2351,14 @@ int ip6mr_get_route(struct net *net,
 }
 
 static int ip6mr_fill_mroute(struct mr6_table *mrt, struct sk_buff *skb,
-                             u32 portid, u32 seq, struct mfc6_cache *c, int cmd)
+                             u32 portid, u32 seq, struct mfc6_cache *c, int cmd,
+                             int flags)
 {
         struct nlmsghdr *nlh;
         struct rtmsg *rtm;
         int err;
 
-        nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), NLM_F_MULTI);
+        nlh = nlmsg_put(skb, portid, seq, cmd, sizeof(*rtm), flags);
         if (nlh == NULL)
                 return -EMSGSIZE;
 
@@ -2425,7 +2426,7 @@ static void mr6_netlink_event(struct mr6_table *mrt, struct mfc6_cache *mfc,
         if (skb == NULL)
                 goto errout;
 
-        err = ip6mr_fill_mroute(mrt, skb, 0, 0, mfc, cmd);
+        err = ip6mr_fill_mroute(mrt, skb, 0, 0, mfc, cmd, 0);
         if (err < 0)
                 goto errout;
 
@@ -2464,7 +2465,8 @@ static int ip6mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb)
                                 if (ip6mr_fill_mroute(mrt, skb,
                                                       NETLINK_CB(cb->skb).portid,
                                                       cb->nlh->nlmsg_seq,
-                                                      mfc, RTM_NEWROUTE) < 0)
+                                                      mfc, RTM_NEWROUTE,
+                                                      NLM_F_MULTI) < 0)
                                         goto done;
 next_entry:
                                 e++;
@@ -2478,7 +2480,8 @@ next_entry:
                         if (ip6mr_fill_mroute(mrt, skb,
                                               NETLINK_CB(cb->skb).portid,
                                               cb->nlh->nlmsg_seq,
-                                              mfc, RTM_NEWROUTE) < 0) {
+                                              mfc, RTM_NEWROUTE,
+                                              NLM_F_MULTI) < 0) {
                                 spin_unlock_bh(&mfc_unres_lock);
                                 goto done;
                         }