[dpdk-dev] [PATCH] app/testpmd: add sanity checks when retrieving xstats

[David Marchand <david.marchand@6wind.com>]

Testpmd should not expect the xstats names and values arrays to be
aligned: neither the arrays sizes, nor the order in which the values are.

This hid some bugs where pmds would either return wrong values count or
invalid statistics indexes.

Link: http://dpdk.org/browse/dpdk/commit/?id=5fd4d049692b2fde8bf49c7461b18180a8fd2545
Link: http://dpdk.org/dev/patchwork/patch/40705/

Signed-off-by: David Marchand <david.marchand@6wind.com>
---

@stable: when this goes in, I recommend backporting this to all existing
branches, as it makes it easier to show this kind of pmds bugs.

---
 app/test-pmd/config.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 97020fb..8edb80c 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -210,9 +210,11 @@ nic_stats_clear(portid_t port_id)
 void
 nic_xstats_display(portid_t port_id)
 {
-	struct rte_eth_xstat *xstats;
-	int cnt_xstats, idx_xstat;
 	struct rte_eth_xstat_name *xstats_names;
+	struct rte_eth_xstat *xstats;
+	int cnt_xnames;
+	int cnt_xstats;
+	int idx_xstat;
 
 	printf("###### NIC extended statistics for port %-2d\n", port_id);
 	if (!rte_eth_dev_is_valid_port(port_id)) {
@@ -221,33 +223,34 @@ nic_xstats_display(portid_t port_id)
 	}
 
 	/* Get count */
-	cnt_xstats = rte_eth_xstats_get_names(port_id, NULL, 0);
-	if (cnt_xstats  < 0) {
+	cnt_xnames = rte_eth_xstats_get_names(port_id, NULL, 0);
+	if (cnt_xnames  < 0) {
 		printf("Error: Cannot get count of xstats\n");
 		return;
 	}
 
 	/* Get id-name lookup table */
-	xstats_names = malloc(sizeof(struct rte_eth_xstat_name) * cnt_xstats);
+	xstats_names = malloc(sizeof(struct rte_eth_xstat_name) * cnt_xnames);
 	if (xstats_names == NULL) {
 		printf("Cannot allocate memory for xstats lookup\n");
 		return;
 	}
-	if (cnt_xstats != rte_eth_xstats_get_names(
-			port_id, xstats_names, cnt_xstats)) {
+	if (cnt_xnames != rte_eth_xstats_get_names(
+			port_id, xstats_names, cnt_xnames)) {
 		printf("Error: Cannot get xstats lookup\n");
 		free(xstats_names);
 		return;
 	}
 
 	/* Get stats themselves */
-	xstats = malloc(sizeof(struct rte_eth_xstat) * cnt_xstats);
+	xstats = malloc(sizeof(struct rte_eth_xstat) * cnt_xnames);
 	if (xstats == NULL) {
 		printf("Cannot allocate memory for xstats\n");
 		free(xstats_names);
 		return;
 	}
-	if (cnt_xstats != rte_eth_xstats_get(port_id, xstats, cnt_xstats)) {
+	cnt_xstats = rte_eth_xstats_get(port_id, xstats, cnt_xnames);
+	if (cnt_xstats > cnt_xnames) {
 		printf("Error: Unable to get xstats\n");
 		free(xstats_names);
 		free(xstats);
@@ -256,10 +259,15 @@ nic_xstats_display(portid_t port_id)
 
 	/* Display xstats */
 	for (idx_xstat = 0; idx_xstat < cnt_xstats; idx_xstat++) {
+		if (xstats[idx_xstat].id > (uint64_t)cnt_xnames) {
+			printf("Error: Invalid statistic index: %"PRId64
+			       ", max %d\n", xstats[idx_xstat].id, cnt_xnames);
+			continue;
+		}
 		if (xstats_hide_zero && !xstats[idx_xstat].value)
 			continue;
 		printf("%s: %"PRIu64"\n",
-			xstats_names[idx_xstat].name,
+			xstats_names[xstats[idx_xstat].id].name,
 			xstats[idx_xstat].value);
 	}
 	free(xstats_names);
-- 
2.7.4