[PATCH 3/8] dmadev: validate telemetry parameters

[Stephen Hemminger <stephen@networkplumber.org>]

Tighten parsing of the dmadev telemetry device and vchan parameters:
reject non-numeric and out-of-range ids through a bounded helper rather
than narrowing strtoul()'s result to int and leaning on the downstream
int16_t/uint16_t API to revalidate. This also drops the thread-unsafe
strtok() in the stats handler.

Fixes: 39b5ab60df30 ("dmadev: add telemetry")
Cc: stable@dpdk.org

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 lib/dmadev/rte_dmadev.c | 44 ++++++++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 14 deletions(-)

diff --git a/lib/dmadev/rte_dmadev.c b/lib/dmadev/rte_dmadev.c
index b75b4f9bd1..822bb7c89f 100644
--- a/lib/dmadev/rte_dmadev.c
+++ b/lib/dmadev/rte_dmadev.c
@@ -4,6 +4,7 @@
  */
 
 #include <ctype.h>
+#include <errno.h>
 #include <inttypes.h>
 #include <stdlib.h>
 
@@ -1157,6 +1158,25 @@ dmadev_handle_dev_list(const char *cmd __rte_unused,
 	return 0;
 }
 
+/* Parse an unsigned integer telemetry parameter, returning the value or
+ * -EINVAL.  'max' must be <= INT_MAX.
+ */
+static int
+dmadev_parse_uint(const char *str, char **end, unsigned long max)
+{
+	unsigned long val;
+
+	if (str == NULL || !isdigit((unsigned char)*str))
+		return -EINVAL;
+
+	errno = 0;
+	val = strtoul(str, end, 0);
+	if (errno != 0 || val > max)
+		return -EINVAL;
+
+	return (int)val;
+}
+
 #define ADD_CAPA(td, dc, c) rte_tel_data_add_dict_int(td, dma_capability_name(c), !!(dc & c))
 
 static int
@@ -1169,10 +1189,9 @@ dmadev_handle_dev_info(const char *cmd __rte_unused,
 	uint64_t dev_capa;
 	char *end_param;
 
-	if (params == NULL || strlen(params) == 0 || !isdigit(*params))
+	dev_id = dmadev_parse_uint(params, &end_param, INT16_MAX);
+	if (dev_id < 0)
 		return -EINVAL;
-
-	dev_id = strtoul(params, &end_param, 0);
 	if (*end_param != '\0')
 		RTE_DMA_LOG(WARNING, "Extra parameters passed to dmadev telemetry command, ignoring");
 
@@ -1227,13 +1246,11 @@ dmadev_handle_dev_stats(const char *cmd __rte_unused,
 	struct rte_dma_stats dma_stats;
 	int dev_id, ret, vchan_id;
 	char *end_param;
-	const char *vchan_param;
 
-	if (params == NULL || strlen(params) == 0 || !isdigit(*params))
+	dev_id = dmadev_parse_uint(params, &end_param, INT16_MAX);
+	if (dev_id < 0)
 		return -EINVAL;
 
-	dev_id = strtoul(params, &end_param, 0);
-
 	/* Function info_get validates dev_id so we don't need to. */
 	ret = rte_dma_info_get(dev_id, &dma_info);
 	if (ret < 0)
@@ -1245,11 +1262,11 @@ dmadev_handle_dev_stats(const char *cmd __rte_unused,
 	if (dma_info.nb_vchans == 1 && *end_param == '\0')
 		vchan_id = 0;
 	else {
-		vchan_param = strtok(end_param, ",");
-		if (!vchan_param || strlen(vchan_param) == 0 || !isdigit(*vchan_param))
+		if (*end_param != ',')
+			return -EINVAL;
+		vchan_id = dmadev_parse_uint(end_param + 1, &end_param, UINT16_MAX);
+		if (vchan_id < 0)
 			return -EINVAL;
-
-		vchan_id = strtoul(vchan_param, &end_param, 0);
 	}
 	if (*end_param != '\0')
 		RTE_DMA_LOG(WARNING, "Extra parameters passed to dmadev telemetry command, ignoring");
@@ -1276,10 +1293,9 @@ dmadev_handle_dev_dump(const char *cmd __rte_unused,
 	int dev_id, ret;
 	FILE *f;
 
-	if (params == NULL || strlen(params) == 0 || !isdigit(*params))
+	dev_id = dmadev_parse_uint(params, &end_param, INT16_MAX);
+	if (dev_id < 0)
 		return -EINVAL;
-
-	dev_id = strtoul(params, &end_param, 0);
 	if (*end_param != '\0')
 		RTE_DMA_LOG(WARNING, "Extra parameters passed to dmadev telemetry command, ignoring");
 
-- 
2.53.0