xfrm: Flushing empty SPD generates false events

To see the effect make sure you have an empty SPD.
On window1 "ip xfrm mon" and on window2 issue "ip xfrm policy flush"
You get prompt back in window2 and you see the flush event on window1.
With this fix, you still get prompt on window1 but no event on window2.

Thanks to Alexey Dobriyan for finding a bug in earlier version
when using pfkey to do the flushing.

Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/key/af_key.c b/net/key/af_key.c
index c269ce6094d6462be54f656c7bb76d90f8be3f2e..a20d2fa88db96875bbe5c2cc937085d13395c8d4 100644 (file)
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -2735,8 +2735,11 @@ static int pfkey_spdflush(struct sock *sk, struct sk_buff *skb, struct sadb_msg
        audit_info.secid = 0;
        err = xfrm_policy_flush(net, XFRM_POLICY_TYPE_MAIN, &audit_info);
        err2 = unicast_flush_resp(sk, hdr);
-       if (err || err2)
-               return err ? err : err2;
+       if (err || err2) {
+               if (err == -ESRCH) /* empty table - old silent behavior */
+                       return 0;
+               return err;
+       }
 
        c.data.type = XFRM_POLICY_TYPE_MAIN;
        c.event = XFRM_MSG_FLUSHPOLICY;

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 4368e7b88469ee35b2cd2adeeb0d155e8c1548da..d6eb16d75243717736fb94110d96dfdce7b3c014 100644 (file)
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -771,7 +771,8 @@ xfrm_policy_flush_secctx_check(struct net *net, u8 type, struct xfrm_audit *audi
 
 int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 {
-       int dir, err = 0;
+       int dir, err = 0, cnt = 0;
+       struct xfrm_policy *dp;
 
        write_lock_bh(&xfrm_policy_lock);
 
@@ -789,8 +790,10 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
                                     &net->xfrm.policy_inexact[dir], bydst) {
                        if (pol->type != type)
                                continue;
-                       __xfrm_policy_unlink(pol, dir);
+                       dp = __xfrm_policy_unlink(pol, dir);
                        write_unlock_bh(&xfrm_policy_lock);
+                       if (dp)
+                               cnt++;
 
                        xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
                                                 audit_info->sessionid,
@@ -809,8 +812,10 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
                                             bydst) {
                                if (pol->type != type)
                                        continue;
-                               __xfrm_policy_unlink(pol, dir);
+                               dp = __xfrm_policy_unlink(pol, dir);
                                write_unlock_bh(&xfrm_policy_lock);
+                               if (dp)
+                                       cnt++;
 
                                xfrm_audit_policy_delete(pol, 1,
                                                         audit_info->loginuid,
@@ -824,6 +829,8 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
                }
 
        }
+       if (!cnt)
+               err = -ESRCH;
        atomic_inc(&flow_cache_genid);
 out:
        write_unlock_bh(&xfrm_policy_lock);

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index cd94a9dd1badd29398fc1e06f283a665262ba447..ee04e6bf0e54d55636534866ddfbc0e1bdb52e2f 100644 (file)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1679,8 +1679,12 @@ static int xfrm_flush_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
        audit_info.sessionid = NETLINK_CB(skb).sessionid;
        audit_info.secid = NETLINK_CB(skb).sid;
        err = xfrm_policy_flush(net, type, &audit_info);
-       if (err)
+       if (err) {
+               if (err == -ESRCH) /* empty table */
+                       return 0;
                return err;
+       }
+
        c.data.type = type;
        c.event = nlh->nlmsg_type;
        c.seq = nlh->nlmsg_seq;