l2tp: Fix error creating L2TP tunnels

[ Upstream commit 853effc55b0f975abd6d318cca486a9c1b67e10f ]

A previous commit (33f72e6) added notification via netlink for tunnels
when created/modified/deleted. If the notification returned an error,
this error was returned from the tunnel function. If there were no
listeners, the error code ESRCH was returned, even though having no
listeners is not an error. Other calls to this and other similar
notification functions either ignore the error code, or filter ESRCH.
This patch checks for ESRCH and does not flag this as an error.

Reviewed-by: Hamish Martin <hamish.martin@alliedtelesis.co.nz>
Signed-off-by: Mark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index f93c5be612a7cb43611708ebb66c25b4db0d27cf..2caaa84ce92dac811c7813ebbb233c9596d03ca0 100644 (file)
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -124,8 +124,13 @@ static int l2tp_tunnel_notify(struct genl_family *family,
        ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq,
                                  NLM_F_ACK, tunnel, cmd);
 
-       if (ret >= 0)
-               return genlmsg_multicast_allns(family, msg, 0,  0, GFP_ATOMIC);
+       if (ret >= 0) {
+               ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
+               /* We don't care if no one is listening */
+               if (ret == -ESRCH)
+                       ret = 0;
+               return ret;
+       }
 
        nlmsg_free(msg);
 
@@ -147,8 +152,13 @@ static int l2tp_session_notify(struct genl_family *family,
        ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq,
                                   NLM_F_ACK, session, cmd);
 
-       if (ret >= 0)
-               return genlmsg_multicast_allns(family, msg, 0,  0, GFP_ATOMIC);
+       if (ret >= 0) {
+               ret = genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC);
+               /* We don't care if no one is listening */
+               if (ret == -ESRCH)
+                       ret = 0;
+               return ret;
+       }
 
        nlmsg_free(msg);