random: Check fwrite return value to avoid warnings

Some compilers complain about fwrite calls if the return value is
not checked, so check the value even if it does not really make
much of a difference in this particular case.

diff --git a/src/crypto/random.c b/src/crypto/random.c
index 7f5c08a6dc94d4a635536132dd96ea180f6e4923..5b15354b7ec13e2ce60365ef4539373048a36277 100644 (file)
--- a/src/crypto/random.c
+++ b/src/crypto/random.c
@@ -354,6 +354,7 @@ static void random_write_entropy(void)
        char buf[RANDOM_ENTROPY_SIZE];
        FILE *f;
        u8 opr;
+       int fail = 0;
 
        if (!random_entropy_file)
                return;
@@ -369,9 +370,15 @@ static void random_write_entropy(void)
        }
 
        opr = own_pool_ready > 0xff ? 0xff : own_pool_ready;
-       fwrite(&opr, 1, 1, f);
-       fwrite(buf, RANDOM_ENTROPY_SIZE, 1, f);
+       if (fwrite(&opr, 1, 1, f) != 1 ||
+           fwrite(buf, RANDOM_ENTROPY_SIZE, 1, f) != 1)
+               fail = 1;
        fclose(f);
+       if (fail) {
+               wpa_printf(MSG_ERROR, "random: Could not entropy data to %s",
+                          random_entropy_file);
+               return;
+       }
 
        wpa_printf(MSG_DEBUG, "random: Updated entropy file %s "
                   "(own_pool_ready=%u)",