[IPSEC]: Make xfrm_user key manager return proper errors.

include/linux/netlink.h

@@ -110,8 +110,8 @@ extern int init_netlink(void);
 extern struct sock *netlink_kernel_create(int unit, void (*input)(struct sock *sk, int len));
 extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);
 extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
-extern void netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
-			      __u32 group, int allocation);
+extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,
+			     __u32 group, int allocation);
 extern void netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);
 extern int netlink_register_notifier(struct notifier_block *nb);
 extern int netlink_unregister_notifier(struct notifier_block *nb);

net/ipv4/xfrm_user.c

@@ -910,9 +910,8 @@ static int xfrm_send_notify(struct xfrm_state *x, int hard)
 		BUG();
 
 	NETLINK_CB(skb).dst_groups = XFRMGRP_EXPIRE;
-	netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_EXPIRE, GFP_ATOMIC);
 
-	return 0;
+	return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_EXPIRE, GFP_ATOMIC);
 }
 
 /* XXX Make this xfrm_state.c:xfrm_get_acqseq() */
@@ -971,9 +970,8 @@ static int xfrm_send_acquire(struct xfrm_state *x, struct xfrm_tmpl *xt,
 		BUG();
 
 	NETLINK_CB(skb).dst_groups = XFRMGRP_ACQUIRE;
-	netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_ACQUIRE, GFP_ATOMIC);
 
-	return 0;
+	return netlink_broadcast(xfrm_nl, skb, 0, XFRMGRP_ACQUIRE, GFP_ATOMIC);
 }
 
 /* User gives us xfrm_user_policy_info followed by an array of 0

net/netlink/af_netlink.c

@@ -503,13 +503,13 @@ static __inline__ int netlink_broadcast_deliver(struct sock *sk, struct sk_buff
 	return -1;
 }
 
-void netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
-		       u32 group, int allocation)
+int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
+		      u32 group, int allocation)
 {
 	struct sock *sk;
 	struct sk_buff *skb2 = NULL;
 	int protocol = ssk->protocol;
-	int failure = 0;
+	int failure = 0, delivered = 0;
 
 	/* While we sleep in clone, do not allow to change socket list */
 
@@ -544,8 +544,10 @@ void netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
 			failure = 1;
 		} else if (netlink_broadcast_deliver(sk, skb2)) {
 			netlink_overrun(sk);
-		} else
+		} else {
+			delivered = 1;
 			skb2 = NULL;
+		}
 		sock_put(sk);
 	}
 
@@ -554,6 +556,12 @@ void netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid,
 	if (skb2)
 		kfree_skb(skb2);
 	kfree_skb(skb);
+
+	if (delivered)
+		return 0;
+	if (failure)
+		return -ENOBUFS;
+	return -ESRCH;
 }
 
 void netlink_set_err(struct sock *ssk, u32 pid, u32 group, int code)