Change atoi to the safter strtol and display warning for unexpected -…

…-loc values
certego · Jul 31, 2018 · 06344a6 · 06344a6
1 parent b2525fe
commit 06344a6
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Showing 2 changed files with 18 additions and 9 deletions.
diff --git a/fw1-loggrabber.c b/fw1-loggrabber.c
@@ -132,21 +132,28 @@ main (int argc, char *argv[])
       else if (strcmp (argv[i], "--loc") == 0)
         {
           i++;
-          if ( argv[i] == NULL )
+          if ( argv[i] == NULL || argv[i][0] == '-')
             {
-              fprintf (stderr, "ERROR: Value expected for argument: %s\n", argv[i - 1]);
-              usage (argv[0]);
-              exit_loggrabber (1);
-            }
-          if (argv[i][0] == '-')
-            {
-              fprintf (stderr, "ERROR: Value expected for argument %s\n",
+              fprintf (stderr, "ERROR: 0 or positive value expected for argument %s\n",
                        argv[i - 1]);
               usage (argv[0]);
               exit_loggrabber (1);
             }
 
-          record_num = atoi ( argv[i] );
+          errno = 0;
+          long raw_record_num = strtol ( argv[i], NULL, 10 );
+          if ( errno == ERANGE || raw_record_num < 0 || raw_record_num > INT_MAX)
+            {
+              fprintf (stderr,
+                       "WARNING: %s expects an integer range value greater than or equal to 0\n"
+                       "         The provided value will be treated as if it were 0\n",
+                       argv[i-1] );
+              record_num = 0;
+            }
+          else
+            {
+              record_num = (int) raw_record_num;
+            }
         }
       else if ((strcmp (argv[i], "-f") == 0)
                || (strcmp (argv[i], "--logfile") == 0))

diff --git a/fw1-loggrabber.h b/fw1-loggrabber.h
@@ -36,6 +36,8 @@
 #include <ctype.h>
 #include <time.h>
 #include <signal.h>
+#include <errno.h>
+#include <limits.h>
 
 #define  SLEEP(sec) sleep(sec)
 #include <netinet/in.h>