krb5 commit: Add sa_is_wildcard() helper to socket-utils.h

https://github.com/krb5/krb5/commit/715b3979525e5045fd66ffebdf98cec67fb58dfe
commit 715b3979525e5045fd66ffebdf98cec67fb58dfe
Author: Greg Hudson <[email protected]>
Date:   Mon Dec 26 18:47:00 2016 -0500

    Add sa_is_wildcard() helper to socket-utils.h

 src/include/socket-utils.h |   11 +++++++++++
 1 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/src/include/socket-utils.h b/src/include/socket-utils.h
index 1566636..e1f33aa 100644
--- a/src/include/socket-utils.h
+++ b/src/include/socket-utils.h
@@ -119,6 +119,17 @@ sa_is_inet(struct sockaddr *sa)
     return sa->sa_family == AF_INET || sa->sa_family == AF_INET6;
 }
 
+/* Return true if sa is an IPv4 or IPv6 wildcard address. */
+static inline int
+sa_is_wildcard(struct sockaddr *sa)
+{
+    if (sa->sa_family == AF_INET6)
+        return IN6_IS_ADDR_UNSPECIFIED(&sa2sin6(sa)->sin6_addr);
+    else if (sa->sa_family == AF_INET)
+        return sa2sin(sa)->sin_addr.s_addr == INADDR_ANY;
+    return 0;
+}
+
 /* Return the length of an IPv4 or IPv6 socket structure; abort if it is
  * neither. */
 static inline socklen_t