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 along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <zebra.h>
  22 #include <lib/version.h>
  23
  24 #include <pwd.h>
  25
  26 #ifdef USE_PAM
  27 #include <security/pam_appl.h>
  28 #ifdef HAVE_PAM_MISC_H
  29 #include <security/pam_misc.h>
  30 #endif
  31 #ifdef HAVE_OPENPAM_H
  32 #include <security/openpam.h>
  33 #endif
  34 #endif /* USE_PAM */
  35
  36 #include "memory.h"
  37 #include "linklist.h"
  38 #include "command.h"
  39 #include "vtysh/vtysh_user.h"
  40
  41 /*
  42  * Compiler is warning about prototypes not being declared.
  43  * The DEFUNSH and DEFUN macro's are messing with the
  44  * compiler I believe.  This is just to make it happy.
  45  */
  46 #ifdef USE_PAM
  47 static int vtysh_pam(const char *);
  48 #endif
  49 int vtysh_auth(void);
  50 void vtysh_user_init(void);
  51
  52 extern struct list *config_top;
  53 extern void config_add_line(struct list *config, const char *line);
  54
  55 #ifdef USE_PAM
  56 static struct pam_conv conv =
  57 {
  58   PAM_CONV_FUNC,
  59   NULL
  60 };
  61
  62 static int
  63 vtysh_pam (const char *user)
  64 {
  65   int ret;
  66   pam_handle_t *pamh = NULL;
  67
  68   /* Start PAM. */
  69   ret = pam_start(FRR_PAM_NAME, user, &conv, &pamh);
  70   /* printf ("ret %d\n", ret); */
  71
  72   /* Is user really user? */
  73   if (ret == PAM_SUCCESS)
  74     ret = pam_authenticate (pamh, 0);
  75   /* printf ("ret %d\n", ret); */
  76
  77 #if 0
  78   /* Permitted access? */
  79   if (ret == PAM_SUCCESS)
  80     ret = pam_acct_mgmt (pamh, 0);
  81   printf ("ret %d\n", ret);
  82
  83   if (ret == PAM_AUTHINFO_UNAVAIL)
  84     ret = PAM_SUCCESS;
  85 #endif /* 0 */
  86
  87   /* This is where we have been authorized or not. */
  88 #ifdef DEBUG
  89   if (ret == PAM_SUCCESS)
  90     printf("Authenticated\n");
  91   else
  92     printf("Not Authenticated\n");
  93 #endif /* DEBUG */
  94
  95   /* close Linux-PAM */
  96   if (pam_end (pamh, ret) != PAM_SUCCESS)
  97     {
  98       pamh = NULL;
  99       fprintf(stderr, "vtysh_pam: failed to release authenticator\n");
 100       exit(1);
 101     }
 102
 103   return ret == PAM_SUCCESS ? 0 : 1;
 104 }
 105 #endif /* USE_PAM */
 106
 107 struct vtysh_user
 108 {
 109   char *name;
 110   u_char nopassword;
 111 };
 112
 113 struct list *userlist;
 114
 115 static struct vtysh_user *
 116 user_new (void)
 117 {
 118   return XCALLOC (MTYPE_TMP, sizeof (struct vtysh_user));
 119 }
 120
 121 static struct vtysh_user *
 122 user_lookup (const char *name)
 123 {
 124   struct listnode *node, *nnode;
 125   struct vtysh_user *user;
 126
 127   for (ALL_LIST_ELEMENTS (userlist, node, nnode, user))
 128     {
 129       if (strcmp (user->name, name) == 0)
 130         return user;
 131     }
 132   return NULL;
 133 }
 134
 135 void
 136 user_config_write ()
 137 {
 138   struct listnode *node, *nnode;
 139   struct vtysh_user *user;
 140   char line[128];
 141
 142   for (ALL_LIST_ELEMENTS (userlist, node, nnode, user))
 143     {
 144       if (user->nopassword)
 145         {
 146           sprintf(line, "username %s nopassword", user->name);
 147           config_add_line (config_top, line);
 148         }
 149     }
 150 }
 151
 152 static struct vtysh_user *
 153 user_get (const char *name)
 154 {
 155   struct vtysh_user *user;
 156   user = user_lookup (name);
 157   if (user)
 158     return user;
 159
 160   user = user_new ();
 161   user->name = strdup (name);
 162   listnode_add (userlist, user);
 163
 164   return user;
 165 }
 166
 167 DEFUN (vtysh_banner_motd_file,
 168        vtysh_banner_motd_file_cmd,
 169        "banner motd file FILE",
 170        "Set banner\n"
 171        "Banner for motd\n"
 172        "Banner from a file\n"
 173        "Filename\n")
 174 {
 175   int idx_file = 3;
 176   return cmd_banner_motd_file (argv[idx_file]->arg);
 177 }
 178
 179 DEFUN (username_nopassword,
 180        username_nopassword_cmd,
 181        "username WORD nopassword",
 182        "\n"
 183        "\n"
 184        "\n")
 185 {
 186   int idx_word = 1;
 187   struct vtysh_user *user;
 188   user = user_get (argv[idx_word]->arg);
 189   user->nopassword = 1;
 190   return CMD_SUCCESS;
 191 }
 192
 193 int
 194 vtysh_auth (void)
 195 {
 196   struct vtysh_user *user;
 197   struct passwd *passwd;
 198
 199   if ((passwd = getpwuid (geteuid ())) == NULL)
 200   {
 201     fprintf (stderr, "could not lookup user ID %d\n", (int) geteuid());
 202     exit (1);
 203   }
 204
 205   user = user_lookup (passwd->pw_name);
 206   if (user && user->nopassword)
 207     /* Pass through */;
 208   else
 209     {
 210 #ifdef USE_PAM
 211       if (vtysh_pam (passwd->pw_name))
 212         exit (0);
 213 #endif /* USE_PAM */
 214     }
 215   return 0;
 216 }
 217
 218 char *
 219 vtysh_get_home (void)
 220 {
 221   struct passwd *passwd;
 222   char * homedir;
 223
 224   if ((homedir = getenv("HOME")) != 0)
 225     return homedir;
 226
 227   /* Fallback if HOME is undefined */
 228   passwd = getpwuid (getuid ());
 229
 230   return passwd ? passwd->pw_dir : NULL;
 231 }
 232
 233 void
 234 vtysh_user_init (void)
 235 {
 236   userlist = list_new ();
 237   install_element (CONFIG_NODE, &username_nopassword_cmd);
 238   install_element (CONFIG_NODE, &vtysh_banner_motd_file_cmd);
 239 }