[sheepdog] [PATCH] lib: insert assert() to sd_strerror() for detecting invalid index

[Hitoshi Mitake]

Commit a4d01de did wrong treatment of request data structure. And
it caused segfault in sd_strerror() because of invalid index of the desc
array. This patch insert assert() for detecting such a bug.

Signed-off-by: Hitoshi Mitake <mitake.hitoshi at lab.ntt.co.jp>
---
 include/sheep.h |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/sheep.h b/include/sheep.h
index 1d146bd..d708122 100644
--- a/include/sheep.h
+++ b/include/sheep.h
@@ -242,6 +242,8 @@ static inline const char *sd_strerror(int err)
 		[SD_RES_CLUSTER_ERROR] = "Cluster driver error",
 	};
 
+	assert(0 <= err && err < ARRAY_SIZE(descs));
+
 	if (descs[err] == NULL) {
 		static __thread char msg[32];
 		snprintf(msg, sizeof(msg), "Invalid error code %x", err);
-- 
1.7.10.4