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 = {PAM_CONV_FUNC, NULL};
  57
  58 static int vtysh_pam(const char *user)
  59 {
  60         int ret;
  61         pam_handle_t *pamh = NULL;
  62
  63         /* Start PAM. */
  64         ret = pam_start(FRR_PAM_NAME, user, &conv, &pamh);
  65
  66         /* Is user really user? */
  67         if (ret == PAM_SUCCESS)
  68                 ret = pam_authenticate(pamh, 0);
  69
  70         if (ret != PAM_SUCCESS)
  71                 fprintf(stderr, "vtysh_pam: Failure to initialize pam: %s(%d)",
  72                         pam_strerror(pamh, ret), ret);
  73
  74         /* close Linux-PAM */
  75         if (pam_end(pamh, ret) != PAM_SUCCESS) {
  76                 pamh = NULL;
  77                 fprintf(stderr, "vtysh_pam: failed to release authenticator: %s(%d)\n",
  78                         pam_strerror(pamh, ret), ret);
  79                 exit(1);
  80         }
  81
  82         return ret == PAM_SUCCESS ? 0 : 1;
  83 }
  84 #endif /* USE_PAM */
  85
  86 struct vtysh_user {
  87         char *name;
  88         uint8_t nopassword;
  89 };
  90
  91 struct list *userlist;
  92
  93 static struct vtysh_user *user_new(void)
  94 {
  95         return XCALLOC(MTYPE_TMP, sizeof(struct vtysh_user));
  96 }
  97
  98 static struct vtysh_user *user_lookup(const char *name)
  99 {
 100         struct listnode *node, *nnode;
 101         struct vtysh_user *user;
 102
 103         for (ALL_LIST_ELEMENTS(userlist, node, nnode, user)) {
 104                 if (strcmp(user->name, name) == 0)
 105                         return user;
 106         }
 107         return NULL;
 108 }
 109
 110 void user_config_write(void)
 111 {
 112         struct listnode *node, *nnode;
 113         struct vtysh_user *user;
 114         char line[128];
 115
 116         for (ALL_LIST_ELEMENTS(userlist, node, nnode, user)) {
 117                 if (user->nopassword) {
 118                         sprintf(line, "username %s nopassword", user->name);
 119                         config_add_line(config_top, line);
 120                 }
 121         }
 122 }
 123
 124 static struct vtysh_user *user_get(const char *name)
 125 {
 126         struct vtysh_user *user;
 127         user = user_lookup(name);
 128         if (user)
 129                 return user;
 130
 131         user = user_new();
 132         user->name = strdup(name);
 133         listnode_add(userlist, user);
 134
 135         return user;
 136 }
 137
 138 DEFUN (vtysh_banner_motd_file,
 139        vtysh_banner_motd_file_cmd,
 140        "banner motd file FILE",
 141        "Set banner\n"
 142        "Banner for motd\n"
 143        "Banner from a file\n"
 144        "Filename\n")
 145 {
 146         int idx_file = 3;
 147         return cmd_banner_motd_file(argv[idx_file]->arg);
 148 }
 149
 150 DEFUN (username_nopassword,
 151        username_nopassword_cmd,
 152        "username WORD nopassword",
 153        "\n"
 154        "\n"
 155        "\n")
 156 {
 157         int idx_word = 1;
 158         struct vtysh_user *user;
 159         user = user_get(argv[idx_word]->arg);
 160         user->nopassword = 1;
 161         return CMD_SUCCESS;
 162 }
 163
 164 int vtysh_auth(void)
 165 {
 166         struct vtysh_user *user;
 167         struct passwd *passwd;
 168
 169         if ((passwd = getpwuid(geteuid())) == NULL) {
 170                 fprintf(stderr, "could not lookup user ID %d\n",
 171                         (int)geteuid());
 172                 exit(1);
 173         }
 174
 175         user = user_lookup(passwd->pw_name);
 176         if (user && user->nopassword)
 177                 /* Pass through */;
 178         else {
 179 #ifdef USE_PAM
 180                 if (vtysh_pam(passwd->pw_name))
 181                         exit(0);
 182 #endif /* USE_PAM */
 183         }
 184         return 0;
 185 }
 186
 187 char *vtysh_get_home(void)
 188 {
 189         struct passwd *passwd;
 190         char *homedir;
 191
 192         if ((homedir = getenv("HOME")) != NULL)
 193                 return homedir;
 194
 195         /* Fallback if HOME is undefined */
 196         passwd = getpwuid(getuid());
 197
 198         return passwd ? passwd->pw_dir : NULL;
 199 }
 200
 201 void vtysh_user_init(void)
 202 {
 203         userlist = list_new();
 204         install_element(CONFIG_NODE, &username_nopassword_cmd);
 205         install_element(CONFIG_NODE, &vtysh_banner_motd_file_cmd);
 206 }