[dm-devel] [PATCH v3 07/18] libmultipath: fix sgio_get_vpd looping

[Benjamin Marzinski]

If do_inq returns a page with a length that is less than maxlen, but
larger than DEFAULT_SGIO_LEN, this function will loop forever. Also
if do_inq returns with a length equal to or greater than maxlen,
sgio_get_vpd will exit immediately, even if it hasn't read the entire
page.  Fix these issues, modify the tests to verify the new behavior.

Signed-off-by: Benjamin Marzinski <bmarzins at redhat.com>
---
 libmultipath/discovery.c | 12 +++----
 tests/vpd.c              | 77 ++++++++++++++++++++++++----------------
 2 files changed, 52 insertions(+), 37 deletions(-)

diff --git a/libmultipath/discovery.c b/libmultipath/discovery.c
index 5f41dcb7..19a8d2af 100644
--- a/libmultipath/discovery.c
+++ b/libmultipath/discovery.c
@@ -928,6 +928,7 @@ static int
 sgio_get_vpd (unsigned char * buff, int maxlen, int fd, int pg)
 {
 	int len = DEFAULT_SGIO_LEN;
+	int rlen;
 
 	if (fd < 0) {
 		errno = EBADF;
@@ -935,12 +936,11 @@ sgio_get_vpd (unsigned char * buff, int maxlen, int fd, int pg)
 	}
 retry:
 	if (0 == do_inq(fd, 0, 1, pg, buff, len)) {
-		len = get_unaligned_be16(&buff[2]) + 4;
-		if (len >= maxlen)
-			return len;
-		if (len > DEFAULT_SGIO_LEN)
-			goto retry;
-		return len;
+		rlen = get_unaligned_be16(&buff[2]) + 4;
+		if (rlen <= len || len >= maxlen)
+			return rlen;
+		len = (rlen < maxlen)? rlen : maxlen;
+		goto retry;
 	}
 	return -1;
 }
diff --git a/tests/vpd.c b/tests/vpd.c
index d9f80eaa..1e653ed4 100644
--- a/tests/vpd.c
+++ b/tests/vpd.c
@@ -506,9 +506,10 @@ static void test_vpd_naa_ ## naa ## _ ## wlen(void **state)             \
  * test_vpd_eui_LEN_WLEN() - test code for VPD 83, EUI64
  * @LEN:	EUI64 length (8, 12, or 16)
  * @WLEN:	WWID buffer size
+ * @SML:	Use small VPD page size
  */
-#define make_test_vpd_eui(len, wlen)					\
-static void test_vpd_eui_ ## len ## _ ## wlen(void **state)             \
+#define make_test_vpd_eui(len, wlen, sml)				\
+static void test_vpd_eui_ ## len ## _ ## wlen ## _ ## sml(void **state)	\
 {									\
 	struct vpdtest *vt = *state;                                    \
 	int n, ret;							\
@@ -518,10 +519,16 @@ static void test_vpd_eui_ ## len ## _ ## wlen(void **state)             \
 									\
 	n = create_vpd83(vt->vpdbuf, sizeof(vt->vpdbuf), test_id,	\
 			 2, 0, len);					\
+	if (sml) {							\
+		/* overwrite the page side to DEFAULT_SGIO_LEN + 1 */	\
+		put_unaligned_be16(255, vt->vpdbuf + 2);		\
+		will_return(__wrap_ioctl, n);				\
+		will_return(__wrap_ioctl, vt->vpdbuf);			\
+	}								\
 	will_return(__wrap_ioctl, n);					\
 	will_return(__wrap_ioctl, vt->vpdbuf);				\
 	ret = get_vpd_sgio(10, 0x83, vt->wwid, wlen);			\
-	assert_correct_wwid("test_vpd_eui_" #len "_" #wlen,		\
+	assert_correct_wwid("test_vpd_eui_" #len "_" #wlen "_" #sml,	\
 			    exp_len, ret, '2', 0, true,			\
 			    test_id, vt->wwid);				\
 }
@@ -603,25 +610,30 @@ make_test_vpd_vnd(20, 10);
 make_test_vpd_vnd(10, 10);
 
 /* EUI64 tests */
+/* small vpd page test */
+make_test_vpd_eui(8, 32, 1);
+make_test_vpd_eui(12, 32, 1);
+make_test_vpd_eui(16, 40, 1);
+
 /* 64bit, WWID size: 18 */
-make_test_vpd_eui(8, 32);
-make_test_vpd_eui(8, 18);
-make_test_vpd_eui(8, 17);
-make_test_vpd_eui(8, 16);
-make_test_vpd_eui(8, 10);
+make_test_vpd_eui(8, 32, 0);
+make_test_vpd_eui(8, 18, 0);
+make_test_vpd_eui(8, 17, 0);
+make_test_vpd_eui(8, 16, 0);
+make_test_vpd_eui(8, 10, 0);
 
 /* 96 bit, WWID size: 26 */
-make_test_vpd_eui(12, 32);
-make_test_vpd_eui(12, 26);
-make_test_vpd_eui(12, 25);
-make_test_vpd_eui(12, 20);
-make_test_vpd_eui(12, 10);
+make_test_vpd_eui(12, 32, 0);
+make_test_vpd_eui(12, 26, 0);
+make_test_vpd_eui(12, 25, 0);
+make_test_vpd_eui(12, 20, 0);
+make_test_vpd_eui(12, 10, 0);
 
 /* 128 bit, WWID size: 34 */
-make_test_vpd_eui(16, 40);
-make_test_vpd_eui(16, 34);
-make_test_vpd_eui(16, 33);
-make_test_vpd_eui(16, 20);
+make_test_vpd_eui(16, 40, 0);
+make_test_vpd_eui(16, 34, 0);
+make_test_vpd_eui(16, 33, 0);
+make_test_vpd_eui(16, 20, 0);
 
 /* NAA IEEE registered extended (36), WWID size: 34 */
 make_test_vpd_naa(6, 40);
@@ -722,20 +734,23 @@ static int test_vpd(void)
 		cmocka_unit_test(test_vpd_vnd_19_20),
 		cmocka_unit_test(test_vpd_vnd_20_10),
 		cmocka_unit_test(test_vpd_vnd_10_10),
-		cmocka_unit_test(test_vpd_eui_8_32),
-		cmocka_unit_test(test_vpd_eui_8_18),
-		cmocka_unit_test(test_vpd_eui_8_17),
-		cmocka_unit_test(test_vpd_eui_8_16),
-		cmocka_unit_test(test_vpd_eui_8_10),
-		cmocka_unit_test(test_vpd_eui_12_32),
-		cmocka_unit_test(test_vpd_eui_12_26),
-		cmocka_unit_test(test_vpd_eui_12_25),
-		cmocka_unit_test(test_vpd_eui_12_20),
-		cmocka_unit_test(test_vpd_eui_12_10),
-		cmocka_unit_test(test_vpd_eui_16_40),
-		cmocka_unit_test(test_vpd_eui_16_34),
-		cmocka_unit_test(test_vpd_eui_16_33),
-		cmocka_unit_test(test_vpd_eui_16_20),
+		cmocka_unit_test(test_vpd_eui_8_32_1),
+		cmocka_unit_test(test_vpd_eui_12_32_1),
+		cmocka_unit_test(test_vpd_eui_16_40_1),
+		cmocka_unit_test(test_vpd_eui_8_32_0),
+		cmocka_unit_test(test_vpd_eui_8_18_0),
+		cmocka_unit_test(test_vpd_eui_8_17_0),
+		cmocka_unit_test(test_vpd_eui_8_16_0),
+		cmocka_unit_test(test_vpd_eui_8_10_0),
+		cmocka_unit_test(test_vpd_eui_12_32_0),
+		cmocka_unit_test(test_vpd_eui_12_26_0),
+		cmocka_unit_test(test_vpd_eui_12_25_0),
+		cmocka_unit_test(test_vpd_eui_12_20_0),
+		cmocka_unit_test(test_vpd_eui_12_10_0),
+		cmocka_unit_test(test_vpd_eui_16_40_0),
+		cmocka_unit_test(test_vpd_eui_16_34_0),
+		cmocka_unit_test(test_vpd_eui_16_33_0),
+		cmocka_unit_test(test_vpd_eui_16_20_0),
 		cmocka_unit_test(test_vpd_naa_6_40),
 		cmocka_unit_test(test_vpd_naa_6_34),
 		cmocka_unit_test(test_vpd_naa_6_33),
-- 
2.17.2