1 files changed, 168 insertions, 0 deletions
diff --git a/contrib/ntp/tests/sandbox/smeartest.c b/contrib/ntp/tests/sandbox/smeartest.c
new file mode 100644
index 0000000..e1b04e5
--- /dev/null
+++ b/contrib/ntp/tests/sandbox/smeartest.c
@@ -0,0 +1,168 @@
+#include <config.h>
+
+#include <ntp.h>
+#include <ntp_fp.h>
+
+/*
+ * we want to test a refid format of:
+ * 254.x.y.x
+ *
+ * where x.y.z are 24 bits containing 2 (signed) integer bits
+ * and 22 fractional bits.
+ *
+ * we want functions to convert to/from this format, with unit tests.
+ *
+ * Interesting test cases include:
+ * 254.0.0.0
+ * 254.0.0.1
+ * 254.127.255.255
+ * 254.128.0.0
+ * 254.255.255.255
+ */
+
+char *progname = "";
+
+l_fp convertRefIDToLFP(uint32_t r);
+uint32_t convertLFPToRefID(l_fp num);
+
+
+/*
+ * The smear data in the refid is the bottom 3 bytes of the refid,
+ * 2 bits of integer
+ * 22 bits of fraction
+ */
+l_fp
+convertRefIDToLFP(uint32_t r)
+{
+	l_fp temp;
+
+	r = ntohl(r);
+
+	printf("%03d %08x: ", (r >> 24) & 0xFF, (r & 0x00FFFFFF) );
+
+	temp.l_uf = (r << 10);	/* 22 fractional bits */
+
+	temp.l_ui = (r >> 22) & 0x3;
+	temp.l_ui |= ~(temp.l_ui & 2) + 1;
+
+	return temp;
+}
+
+
+uint32_t
+convertLFPToRefID(l_fp num)
+{
+	uint32_t temp;
+
+	/* round the input with the highest bit to shift out from the
+	 * fraction, then keep just two bits from the integral part.
+	 *
+	 * TODO: check for overflows; should we clamp/saturate or just
+	 * complain?
+	 */
+	L_ADDUF(&num, 0x200);
+	num.l_ui &= 3;
+
+	/* combine integral and fractional part to 24 bits */
+	temp  = (num.l_ui << 22) | (num.l_uf >> 10);
+
+	/* put in the leading 254.0.0.0 */
+	temp |= UINT32_C(0xFE000000);
+
+	printf("%03d %08x: ", (temp >> 24) & 0xFF, (temp & 0x00FFFFFF) );
+
+	return htonl(temp);
+}
+
+/* Tests start here */
+
+void rtol(uint32_t r);
+
+void
+rtol(uint32_t r)
+{
+	l_fp l;
+
+	printf("rtol: ");
+
+	l = convertRefIDToLFP(htonl(r));
+	printf("refid %#x, smear %s\n", r, lfptoa(&l, 8));
+
+	return;
+}
+
+
+void rtoltor(uint32_t r);
+
+void
+rtoltor(uint32_t r)
+{
+	l_fp l;
+
+	printf("rtoltor: ");
+	l = convertRefIDToLFP(htonl(r));
+
+	r = convertLFPToRefID(l);
+	printf("smear %s, refid %#.8x\n", lfptoa(&l, 8), ntohl(r));
+
+	return;
+}
+
+
+void ltor(l_fp l);
+
+void
+ltor(l_fp l)
+{
+	uint32_t r;
+
+	printf("ltor: ");
+
+	r = convertLFPToRefID(l);
+	printf("smear %s, refid %#.8x\n", lfptoa(&l, 8), ntohl(r));
+
+	return;
+}
+
+
+main()
+{
+
+	rtol(0xfe800000);
+	rtol(0xfe800001);
+	rtol(0xfe8ffffe);
+	rtol(0xfe8fffff);
+	rtol(0xfef00000);
+	rtol(0xfef00001);
+	rtol(0xfefffffe);
+	rtol(0xfeffffff);
+
+	rtol(0xfe000000);
+	rtol(0xfe000001);
+	rtol(0xfe6ffffe);
+	rtol(0xfe6fffff);
+	rtol(0xfe700000);
+	rtol(0xfe700001);
+	rtol(0xfe7ffffe);
+	rtol(0xfe7fffff);
+
+	rtoltor(0xfe800000);
+	rtoltor(0xfe800001);
+	rtoltor(0xfe8ffffe);
+	rtoltor(0xfe8fffff);
+	rtoltor(0xfef00000);
+	rtoltor(0xfef00001);
+	rtoltor(0xfefffffe);
+	rtoltor(0xfeffffff);
+
+	rtoltor(0xfe000000);
+	rtoltor(0xfe000001);
+	rtoltor(0xfe6ffffe);
+	rtoltor(0xfe6fffff);
+	rtoltor(0xfe700000);
+	rtoltor(0xfe700001);
+	rtoltor(0xfe7ffffe);
+	rtoltor(0xfe7fffff);
+
+	return 0;
+}