Add a new function, ifa_ifwithaddr_check(), which rather than returning

a pointer to an ifaddr matching the passed socket address, returns a
boolean indicating whether one was present.  In the (near) future,
ifa_ifwithaddr() will return a referenced ifaddr rather than a raw
ifaddr pointer, and the new wrapper will allow callers that care only
about the boolean condition to avoid having to free that reference.

MFC after:	3 weeks

1 files changed, 16 insertions, 2 deletions

diff --git a/sys/net/if.c b/sys/net/if.c
index bc13501..eb5e519 100644
--- a/sys/net/if.c
+++ b/sys/net/if.c
@@ -1466,8 +1466,8 @@ ifa_free(struct ifaddr *ifa)
  * Locate an interface based on a complete address.
  */
 /*ARGSUSED*/
-struct ifaddr *
-ifa_ifwithaddr(struct sockaddr *addr)
+static struct ifaddr *
+ifa_ifwithaddr_internal(struct sockaddr *addr)
 {
 	INIT_VNET_NET(curvnet);
 	struct ifnet *ifp;
@@ -1500,6 +1500,20 @@ done:
 	return (ifa);
 }
 
+struct ifaddr *
+ifa_ifwithaddr(struct sockaddr *addr)
+{
+
+	return (ifa_ifwithaddr_internal(addr));
+}
+
+int
+ifa_ifwithaddr_check(struct sockaddr *addr)
+{
+
+	return (ifa_ifwithaddr_internal(addr) != NULL);
+}
+
 /*
  * Locate an interface based on the broadcast address.
  */