vtysh/vtysh_user.c

   1 /* User authentication for vtysh.
   2  * Copyright (C) 2000 Kunihiro Ishiguro
   3  *
   4  * This file is part of GNU Zebra.
   5  *
   6  * GNU Zebra is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * GNU Zebra is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  18  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  19  * 02111-1307, USA.
  20  */
  21
  22 #include <zebra.h>
  23 #include <lib/version.h>
  24
  25 #include <pwd.h>
  26
  27 #ifdef USE_PAM
  28 #include <security/pam_appl.h>
  29 #ifdef HAVE_PAM_MISC_H
  30 #include <security/pam_misc.h>
  31 #endif
  32 #ifdef HAVE_OPENPAM_H
  33 #include <security/openpam.h>
  34 #endif
  35 #endif /* USE_PAM */
  36
  37 #include "memory.h"
  38 #include "linklist.h"
  39 #include "command.h"
  40 #include "vtysh/vtysh_user.h"
  41
  42 /*
  43  * Compiler is warning about prototypes not being declared.
  44  * The DEFUNSH and DEFUN macro's are messing with the
  45  * compiler I believe.  This is just to make it happy.
  46  */
  47 #ifdef USE_PAM
  48 static int vtysh_pam(const char *);
  49 #endif
  50 int vtysh_auth(void);
  51 void vtysh_user_init(void);
  52
  53 extern struct list *config_top;
  54 extern void config_add_line(struct list *config, const char *line);
  55
  56 #ifdef USE_PAM
  57 static struct pam_conv conv =
  58 {
  59   PAM_CONV_FUNC,
  60   NULL
  61 };
  62
  63 static int
  64 vtysh_pam (const char *user)
  65 {
  66   int ret;
  67   pam_handle_t *pamh = NULL;
  68
  69   /* Start PAM. */
  70   ret = pam_start(FRR_PAM_NAME, user, &conv, &pamh);
  71   /* printf ("ret %d\n", ret); */
  72
  73   /* Is user really user? */
  74   if (ret == PAM_SUCCESS)
  75     ret = pam_authenticate (pamh, 0);
  76   /* printf ("ret %d\n", ret); */
  77
  78 #if 0
  79   /* Permitted access? */
  80   if (ret == PAM_SUCCESS)
  81     ret = pam_acct_mgmt (pamh, 0);
  82   printf ("ret %d\n", ret);
  83
  84   if (ret == PAM_AUTHINFO_UNAVAIL)
  85     ret = PAM_SUCCESS;
  86 #endif /* 0 */
  87
  88   /* This is where we have been authorized or not. */
  89 #ifdef DEBUG
  90   if (ret == PAM_SUCCESS)
  91     printf("Authenticated\n");
  92   else
  93     printf("Not Authenticated\n");
  94 #endif /* DEBUG */
  95
  96   /* close Linux-PAM */
  97   if (pam_end (pamh, ret) != PAM_SUCCESS)
  98     {
  99       pamh = NULL;
 100       fprintf(stderr, "vtysh_pam: failed to release authenticator\n");
 101       exit(1);
 102     }
 103
 104   return ret == PAM_SUCCESS ? 0 : 1;
 105 }
 106 #endif /* USE_PAM */
 107
 108 struct vtysh_user
 109 {
 110   char *name;
 111   u_char nopassword;
 112 };
 113
 114 struct list *userlist;
 115
 116 static struct vtysh_user *
 117 user_new (void)
 118 {
 119   return XCALLOC (MTYPE_TMP, sizeof (struct vtysh_user));
 120 }
 121
 122 static struct vtysh_user *
 123 user_lookup (const char *name)
 124 {
 125   struct listnode *node, *nnode;
 126   struct vtysh_user *user;
 127
 128   for (ALL_LIST_ELEMENTS (userlist, node, nnode, user))
 129     {
 130       if (strcmp (user->name, name) == 0)
 131         return user;
 132     }
 133   return NULL;
 134 }
 135
 136 void
 137 user_config_write ()
 138 {
 139   struct listnode *node, *nnode;
 140   struct vtysh_user *user;
 141   char line[128];
 142
 143   for (ALL_LIST_ELEMENTS (userlist, node, nnode, user))
 144     {
 145       if (user->nopassword)
 146         {
 147           sprintf(line, "username %s nopassword", user->name);
 148           config_add_line (config_top, line);
 149         }
 150     }
 151 }
 152
 153 static struct vtysh_user *
 154 user_get (const char *name)
 155 {
 156   struct vtysh_user *user;
 157   user = user_lookup (name);
 158   if (user)
 159     return user;
 160
 161   user = user_new ();
 162   user->name = strdup (name);
 163   listnode_add (userlist, user);
 164
 165   return user;
 166 }
 167
 168 DEFUN (vtysh_banner_motd_file,
 169        vtysh_banner_motd_file_cmd,
 170        "banner motd file FILE",
 171        "Set banner\n"
 172        "Banner for motd\n"
 173        "Banner from a file\n"
 174        "Filename\n")
 175 {
 176   int idx_file = 3;
 177   return cmd_banner_motd_file (argv[idx_file]->arg);
 178 }
 179
 180 DEFUN (username_nopassword,
 181        username_nopassword_cmd,
 182        "username WORD nopassword",
 183        "\n"
 184        "\n"
 185        "\n")
 186 {
 187   int idx_word = 1;
 188   struct vtysh_user *user;
 189   user = user_get (argv[idx_word]->arg);
 190   user->nopassword = 1;
 191   return CMD_SUCCESS;
 192 }
 193
 194 int
 195 vtysh_auth (void)
 196 {
 197   struct vtysh_user *user;
 198   struct passwd *passwd;
 199
 200   if ((passwd = getpwuid (geteuid ())) == NULL)
 201   {
 202     fprintf (stderr, "could not lookup user ID %d\n", (int) geteuid());
 203     exit (1);
 204   }
 205
 206   user = user_lookup (passwd->pw_name);
 207   if (user && user->nopassword)
 208     /* Pass through */;
 209   else
 210     {
 211 #ifdef USE_PAM
 212       if (vtysh_pam (passwd->pw_name))
 213         exit (0);
 214 #endif /* USE_PAM */
 215     }
 216   return 0;
 217 }
 218
 219 char *
 220 vtysh_get_home (void)
 221 {
 222   struct passwd *passwd;
 223   char * homedir;
 224
 225   if ((homedir = getenv("HOME")) != 0)
 226     return homedir;
 227
 228   /* Fallback if HOME is undefined */
 229   passwd = getpwuid (getuid ());
 230
 231   return passwd ? passwd->pw_dir : NULL;
 232 }
 233
 234 void
 235 vtysh_user_init (void)
 236 {
 237   userlist = list_new ();
 238   install_element (CONFIG_NODE, &username_nopassword_cmd);
 239   install_element (CONFIG_NODE, &vtysh_banner_motd_file_cmd);
 240 }