pam_tally2 --reset: avoid creating a missing tallylog file

There is no need for pam_tally2 in --reset=0 mode to create a missing
tallylog file because its absence has the same meaning as its existence
with the appropriate entry reset.

This was not a big deal until useradd(8) from shadow suite release 4.5
started to invoke /sbin/pam_tally2 --reset routinely regardless of PAM
configuration.

The positive effect of this change is noticeable when using tools like
cpio(1) that cannot archive huge sparse files efficiently.

* modules/pam_tally2/pam_tally2.c [MAIN] (main) <cline_user>: Stat
cline_filename when cline_reset == 0, exit early if the file is missing.

diff --git a/modules/pam_tally2/pam_tally2.c b/modules/pam_tally2/pam_tally2.c
index 9f3bebeb742b5804b6330a5896e967a686b7767c..da1c0481fbd4423d5605fdde3d1e2a4752dd13a2 100644 (file)
--- a/modules/pam_tally2/pam_tally2.c
+++ b/modules/pam_tally2/pam_tally2.c
@@ -959,6 +959,18 @@ main( int argc UNUSED, char **argv )
       exit(1);
     }
 
+    if (cline_reset == 0) {
+      struct stat st;
+
+      if (stat(cline_filename, &st) && errno == ENOENT) {
+       if (!cline_quiet) {
+         memset(&tally, 0, sizeof(tally));
+         print_one(&tally, uid);
+       }
+       return 0;       /* no file => nothing to reset */
+      }
+    }
+
     i=get_tally(NULL, uid, cline_filename, &tfile, &tally, 0);
     if ( i != PAM_SUCCESS ) {
       if (tfile != -1)