net/virtio-user: fix devargs parsing

strtoull returns 0 if it fails to parse input string. It's ignored
in get_integer_arg.

This patch handles error cases for strtoull function.

Fixes: ce2eabdd43ec ("net/virtio-user: add virtual device")
Cc: stable@dpdk.org
Signed-off-by: Ivan Dyukov <i.dyukov@samsung.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 5637001..741b3b0 100644 (file)
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -477,12 +477,17 @@ static int
 get_integer_arg(const char *key __rte_unused,
                const char *value, void *extra_args)
 {
+       uint64_t integer = 0;
        if (!value || !extra_args)
                return -EINVAL;
-
-       *(uint64_t *)extra_args = strtoull(value, NULL, 0);
-
-       return 0;
+       errno = 0;
+       integer = strtoull(value, NULL, 0);
+       /* extra_args keeps default value, it should be replaced
+        * only in case of successful parsing of the 'value' arg
+        */
+       if (errno == 0)
+               *(uint64_t *)extra_args = integer;
+       return -errno;
 }
 
 static struct rte_eth_dev *