bit-rot xlator: strncpy()->sprintf(), reduce strlen()'s

xlators/features/bit-rot/src/bitd/bit-rot-scrub-status.c
xlators/features/bit-rot/src/stub/bit-rot-stub-helpers.c
xlators/features/bit-rot/src/stub/bit-rot-stub.c
xlators/features/bit-rot/src/stub/bit-rot-stub.h

strncpy may not be very efficient for short strings copied into
a large buffer: If the length of src is less than n,
strncpy() writes additional null bytes to dest to ensure
that a total of n bytes are written.

Instead, use snprintf(). Ensure sprintf() results do not
truncate.

Also:
- save the result of strlen() and re-use it when possible.
- move from strlen to SLEN or sizeof() for const strings.
- move ret from int32 to int.

Compile-tested only!

Change-Id: Ib9b923c45d2d59ac15a105410e8160b252061018
updates: bz#1193929
Signed-off-by: Yaniv Kaul <ykaul@redhat.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/xlators/features/bit-rot/src/bitd/bit-rot-scrub-status.c b/xlators/features/bit-rot/src/bitd/bit-rot-scrub-status.c
index 2f9aaf31a52..210beca7e2f 100644
--- a/xlators/features/bit-rot/src/bitd/bit-rot-scrub-status.c
+++ b/xlators/features/bit-rot/src/bitd/bit-rot-scrub-status.c
@@ -9,6 +9,7 @@
 */
 
 #include <string.h>
+#include <stdio.h>
 
 #include "bit-rot-scrub-status.h"
 
@@ -61,6 +62,9 @@ br_update_scrub_finish_time (br_scrub_stats_t *scrub_stat, char *timestr,
                 return;
 
         lst_size = sizeof (scrub_stat->last_scrub_time);
+        if (strlen (timestr)  >= lst_size)
+                return;
+
         pthread_mutex_lock (&scrub_stat->lock);
         {
                 scrub_stat->scrub_end_tv.tv_sec = tv->tv_sec;
@@ -69,9 +73,8 @@ br_update_scrub_finish_time (br_scrub_stats_t *scrub_stat, char *timestr,
                                  scrub_stat->scrub_end_tv.tv_sec -
                                  scrub_stat->scrub_start_tv.tv_sec;
 
-                strncpy (scrub_stat->last_scrub_time, timestr,
-                         lst_size-1);
-                scrub_stat->last_scrub_time[lst_size-1] = '\0';
+                snprintf (scrub_stat->last_scrub_time, lst_size, "%s",
+                          timestr);
         }
         pthread_mutex_unlock (&scrub_stat->lock);
 }