3091 add -n to zlogin so its more compatible with rsh command line

*** 19,28 ****
--- 19,29 ----
   * CDDL HEADER END
   */
  /*
   * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
   * Copyright 2013 DEY Storage Systems, Inc.
+  * Copyright (c) 2014 Gary Mills
   */
  
  /*
   * zlogin provides three types of login which allow users in the global
   * zone to access non-global zones.
*** 58,67 ****
--- 59,69 ----
  #include <sys/brand.h>
  #include <sys/wait.h>
  #include <alloca.h>
  #include <assert.h>
  #include <ctype.h>
+ #include <paths.h>
  #include <door.h>
  #include <errno.h>
  #include <nss_dbdefs.h>
  #include <poll.h>
  #include <priv.h>
*** 147,157 ****
  #define CANONIFY_LEN 5
  
  static void
  usage(void)
  {
!         (void) fprintf(stderr, gettext("usage: %s [ -QCES ] [ -e cmdchar ] "
              "[-l user] zonename [command [args ...] ]\n"), pname);
          exit(2);
  }
  
  static const char *
--- 149,159 ----
  #define CANONIFY_LEN 5
  
  static void
  usage(void)
  {
!         (void) fprintf(stderr, gettext("usage: %s [ -nQCES ] [ -e cmdchar ] "
              "[-l user] zonename [command [args ...] ]\n"), pname);
          exit(2);
  }
  
  static const char *
*** 1727,1736 ****
--- 1729,1739 ----
          int arg, console = 0;
          zoneid_t zoneid;
          zone_state_t st;
          char *login = "root";
          int lflag = 0;
+         int nflag = 0;
          char *zonename = NULL;
          char **proc_args = NULL;
          char **new_args, **new_env;
          sigset_t block_cld;
          char devroot[MAXPATHLEN];
*** 1749,1759 ****
          (void) textdomain(TEXT_DOMAIN);
  
          (void) getpname(argv[0]);
          username = get_username();
  
!         while ((arg = getopt(argc, argv, "ECR:Se:l:Q")) != EOF) {
                  switch (arg) {
                  case 'C':
                          console = 1;
                          break;
                  case 'E':
--- 1752,1762 ----
          (void) textdomain(TEXT_DOMAIN);
  
          (void) getpname(argv[0]);
          username = get_username();
  
!         while ((arg = getopt(argc, argv, "nECR:Se:l:Q")) != EOF) {
                  switch (arg) {
                  case 'C':
                          console = 1;
                          break;
                  case 'E':
*** 1782,1811 ****
                          break;
                  case 'l':
                          login = optarg;
                          lflag = 1;
                          break;
                  default:
                          usage();
                  }
          }
  
!         if (console != 0 && lflag != 0) {
!                 zerror(gettext("-l may not be specified for console login"));
                  usage();
          }
  
!         if (console != 0 && failsafe != 0) {
!                 zerror(gettext("-S may not be specified for console login"));
                  usage();
          }
  
!         if (console != 0 && zonecfg_in_alt_root()) {
!                 zerror(gettext("-R may not be specified for console login"));
                  exit(2);
          }
  
          if (failsafe != 0 && lflag != 0) {
                  zerror(gettext("-l may not be specified for failsafe login"));
                  usage();
          }
  
--- 1785,1830 ----
                          break;
                  case 'l':
                          login = optarg;
                          lflag = 1;
                          break;
+                 case 'n':
+                         nflag = 1;
+                         break;
                  default:
                          usage();
                  }
          }
  
!         if (console != 0) {
! 
!                 if (lflag != 0) {
!                         zerror(gettext(
!                             "-l may not be specified for console login"));
                          usage();
                  }
  
!                 if (nflag != 0) {
!                         zerror(gettext(
!                             "-n may not be specified for console login"));
                          usage();
                  }
  
!                 if (failsafe != 0) {
!                         zerror(gettext(
!                             "-S may not be specified for console login"));
!                         usage();
!                 }
! 
!                 if (zonecfg_in_alt_root()) {
!                         zerror(gettext(
!                             "-R may not be specified for console login"));
                          exit(2);
                  }
  
+         }
+ 
          if (failsafe != 0 && lflag != 0) {
                  zerror(gettext("-l may not be specified for failsafe login"));
                  usage();
          }
  
*** 1812,1821 ****
--- 1831,1845 ----
          if (optind == (argc - 1)) {
                  /*
                   * zone name, no process name; this should be an interactive
                   * as long as STDIN is really a tty.
                   */
+                 if (nflag != 0) {
+                         zerror(gettext(
+                             "-n may not be specified for interactive login"));
+                         usage();
+                 }
                  if (isatty(STDIN_FILENO))
                          interactive = 1;
                  zonename = argv[optind];
          } else if (optind < (argc - 1)) {
                  if (console) {
*** 2041,2053 ****
          if ((new_env = prep_env()) == NULL) {
                  zperror(gettext("could not assemble new environment"));
                  return (1);
          }
  
!         if (!interactive)
                  return (noninteractive_login(zonename, user_cmd, zoneid,
                      new_args, new_env));
  
          if (zonecfg_in_alt_root()) {
                  zerror(gettext("cannot use interactive login with scratch "
                      "zone"));
                  return (1);
--- 2065,2095 ----
          if ((new_env = prep_env()) == NULL) {
                  zperror(gettext("could not assemble new environment"));
                  return (1);
          }
  
!         if (!interactive) {
!                 if (nflag) {
!                         int nfd;
! 
!                         if ((nfd = open(_PATH_DEVNULL, O_RDONLY)) < 0) {
!                                 zperror(gettext("failed to open null device"));
!                                 return (1);
!                         }
!                         if (nfd != STDIN_FILENO) {
!                                 if (dup2(nfd, STDIN_FILENO) < 0) {
!                                         zperror(gettext(
!                                             "failed to dup2 null device"));
!                                         return (1);
!                                 }
!                                 (void) close(nfd);
!                         }
!                         /* /dev/null is now standard input */
!                 }
                  return (noninteractive_login(zonename, user_cmd, zoneid,
                      new_args, new_env));
+         }
  
          if (zonecfg_in_alt_root()) {
                  zerror(gettext("cannot use interactive login with scratch "
                      "zone"));
                  return (1);