1 files changed, 18 insertions, 2 deletions

diff --git a/plugins/check_smtp.c b/plugins/check_smtp.c
index dd9f19b..7562c4c 100644
--- a/plugins/check_smtp.c
+++ b/plugins/check_smtp.c
@@ -33,11 +33,15 @@ STATE_WARNING return values.\n";
 
 const char *option_summary = "\
 -H host [-p port] [-e expect] [-C command] [-f from addr]\n\
-         [-w warn] [-c crit] [-t timeout] [-n] [-v]";
+         [-w warn] [-c crit] [-t timeout] [-n] [-v] [-4|-6]";
 
 const char *options = "\
  -H, --hostname=STRING or IPADDRESS\n\
    Check server on the indicated host\n\
+ -4, --use-ipv4\n\
+   Use IPv4 protocol\n\
+ -6, --use-ipv6\n\
+   Use IPv6 protocol\n\
  -p, --port=INTEGER\n\
    Make connection on the indicated port (default: %d)\n\
  -e, --expect=STRING\n\
@@ -233,6 +237,8 @@ process_arguments (int argc, char **argv)
                 {"nocommand", required_argument, 0, 'n'},
                 {"verbose", no_argument, 0, 'v'},
                 {"version", no_argument, 0, 'V'},
+                {"use-ipv4", no_argument, 0, '4'},
+                {"use-ipv6", no_argument, 0, '6'},
                 {"help", no_argument, 0, 'h'},
                 {0, 0, 0, 0}
         };
@@ -250,7 +256,7 @@ process_arguments (int argc, char **argv)
         }
 
         while (1) {
-                c = getopt_long (argc, argv, "+hVvt:p:f:e:c:w:H:C:",
+                c = getopt_long (argc, argv, "+hVv46t:p:f:e:c:w:H:C:",
                                  long_options, &option_index);
 
                 if (c == -1 || c == EOF)
@@ -315,6 +321,16 @@ process_arguments (int argc, char **argv)
                                 usage ("Time interval must be a nonnegative integer\n");
                         }
                         break;
+                case '4':
+                        address_family = AF_INET;
+                        break;
+                case '6':
+#ifdef USE_IPV6
+                        address_family = AF_INET6;
+#else
+                        usage ("IPv6 support not available\n");
+#endif
+                        break;
                 case 'V':                                                                       /* version */
                         print_revision (progname, revision);
                         exit (STATE_OK);