daemon.c: avoid accessing ss_family member of struct sockaddr_storage

When NO_SOCKADDR_STORAGE is set for a platform, either sockaddr_in or
sockaddr_in6 is used intead.  Neither of which has an ss_family member.
They have an sin_family and sin6_family member respectively.  Since the
addrcmp() function accesses the ss_family member of a sockaddr_storage
struct, compilation fails on platforms which define NO_SOCKADDR_STORAGE.

Since any sockaddr_* structure can be cast to a struct sockaddr and
have its sa_family member read, do so here to workaround this issue.

Thanks to Martin Storsjö for pointing out the fix, and Gary Vaughan
for drawing attention to the issue.

Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/daemon.c b/daemon.c
index 3769b6f570..2e6766fd0e 100644
--- a/daemon.c
+++ b/daemon.c
@@ -590,14 +590,17 @@ static int execute(struct sockaddr *addr)
 static int addrcmp(const struct sockaddr_storage *s1,
     const struct sockaddr_storage *s2)
 {
-	if (s1->ss_family != s2->ss_family)
-		return s1->ss_family - s2->ss_family;
-	if (s1->ss_family == AF_INET)
+	const struct sockaddr *sa1 = (const struct sockaddr*) s1;
+	const struct sockaddr *sa2 = (const struct sockaddr*) s2;
+
+	if (sa1->sa_family != sa2->sa_family)
+		return sa1->sa_family - sa2->sa_family;
+	if (sa1->sa_family == AF_INET)
 		return memcmp(&((struct sockaddr_in *)s1)->sin_addr,
 		    &((struct sockaddr_in *)s2)->sin_addr,
 		    sizeof(struct in_addr));
 #ifndef NO_IPV6
-	if (s1->ss_family == AF_INET6)
+	if (sa1->sa_family == AF_INET6)
 		return memcmp(&((struct sockaddr_in6 *)s1)->sin6_addr,
 		    &((struct sockaddr_in6 *)s2)->sin6_addr,
 		    sizeof(struct in6_addr));