1 files changed, 48 insertions, 0 deletions

diff --git a/libntp/netof.c b/libntp/netof.c
new file mode 100644
index 000000000000..fd57568d3130
--- /dev/null
+++ b/libntp/netof.c
@@ -0,0 +1,48 @@
+/* 
+ * netof - return the net address part of an ip address in a sockaddr_storage structure
+ *         (zero out host part)
+ */
+#include <stdio.h>
+
+#include "ntp_fp.h"
+#include "ntp_stdlib.h"
+#include "ntp.h"
+
+#define NUM_NETOF_BUFS	10
+static struct sockaddr_storage ssbuf[NUM_NETOF_BUFS];
+static int next_ssbuf = 0;
+
+struct sockaddr_storage*
+netof(
+        struct sockaddr_storage* hostaddr
+	)
+{
+	register u_int32 netnum;
+        struct sockaddr_storage *netaddr;
+
+	netaddr = &ssbuf[next_ssbuf++];
+	if (next_ssbuf == NUM_NETOF_BUFS)
+		next_ssbuf = 0;
+        memcpy(netaddr, hostaddr, sizeof(struct sockaddr_storage));
+
+        if(netaddr->ss_family == AF_INET) {
+                netnum = ((struct sockaddr_in*)netaddr)->sin_addr.s_addr;
+
+		/*
+		 * We live in a modern CIDR world where the basement nets, which
+		 * used to be class A, are now probably associated with each
+		 * host address. So, for class-A nets, all bits are significant.
+		 */
+		if(IN_CLASSC(netnum))
+		    netnum &= IN_CLASSC_NET;
+		else if (IN_CLASSB(netnum))
+		    netnum &= IN_CLASSB_NET;
+			((struct sockaddr_in*)netaddr)->sin_addr.s_addr = netnum;
+		 }
+         else if(netaddr->ss_family == AF_INET6) {
+		/* Here we put 0 at the local link address so we get net address */
+		  memset(&((struct sockaddr_in6*)netaddr)->sin6_addr.s6_addr[8], 0, 8*sizeof(u_char));
+         }
+
+         return netaddr;
+}