1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * Licensed under GPLv2 or later, see file LICENSE in this source tree.
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4 | */
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5 | //config:config LOGIN
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6 | //config: bool "login"
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7 | //config: default y
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8 | //config: select FEATURE_SYSLOG
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9 | //config: help
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10 | //config: login is used when signing onto a system.
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11 | //config:
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12 | //config: Note that Busybox binary must be setuid root for this applet to
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13 | //config: work properly.
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14 | //config:
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15 | //config:config LOGIN_SESSION_AS_CHILD
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16 | //config: bool "Run logged in session in a child process"
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17 | //config: default y if PAM
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18 | //config: depends on LOGIN
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19 | //config: help
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20 | //config: Run the logged in session in a child process. This allows
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21 | //config: login to clean up things such as utmp entries or PAM sessions
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22 | //config: when the login session is complete. If you use PAM, you
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23 | //config: almost always would want this to be set to Y, else PAM session
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24 | //config: will not be cleaned up.
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25 | //config:
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26 | //config:config LOGIN_SCRIPTS
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27 | //config: bool "Support for login scripts"
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28 | //config: depends on LOGIN
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29 | //config: default y
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30 | //config: help
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31 | //config: Enable this if you want login to execute $LOGIN_PRE_SUID_SCRIPT
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32 | //config: just prior to switching from root to logged-in user.
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33 | //config:
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34 | //config:config FEATURE_NOLOGIN
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35 | //config: bool "Support for /etc/nologin"
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36 | //config: default y
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37 | //config: depends on LOGIN
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38 | //config: help
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39 | //config: The file /etc/nologin is used by (some versions of) login(1).
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40 | //config: If it exists, non-root logins are prohibited.
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41 | //config:
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42 | //config:config FEATURE_SECURETTY
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43 | //config: bool "Support for /etc/securetty"
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44 | //config: default y
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45 | //config: depends on LOGIN
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46 | //config: help
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47 | //config: The file /etc/securetty is used by (some versions of) login(1).
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48 | //config: The file contains the device names of tty lines (one per line,
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49 | //config: without leading /dev/) on which root is allowed to login.
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50 |
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51 | //applet:/* Needs to be run by root or be suid root - needs to change uid and gid: */
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52 | //applet:IF_LOGIN(APPLET(login, BB_DIR_BIN, BB_SUID_REQUIRE))
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53 |
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54 | //kbuild:lib-$(CONFIG_LOGIN) += login.o
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55 |
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56 | //usage:#define login_trivial_usage
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57 | //usage: "[-p] [-h HOST] [[-f] USER]"
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58 | //usage:#define login_full_usage "\n\n"
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59 | //usage: "Begin a new session on the system\n"
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60 | //usage: "\n -f Don't authenticate (user already authenticated)"
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61 | //usage: "\n -h HOST Host user came from (for network logins)"
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62 | //usage: "\n -p Preserve environment"
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63 |
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64 | #include "libbb.h"
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65 | #include "common_bufsiz.h"
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66 | #include <syslog.h>
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67 | #include <sys/resource.h>
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68 |
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69 | #if ENABLE_SELINUX
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70 | # include <selinux/selinux.h> /* for is_selinux_enabled() */
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71 | # include <selinux/get_context_list.h> /* for get_default_context() */
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72 | # include <selinux/flask.h> /* for security class definitions */
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73 | #endif
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74 |
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75 | #if ENABLE_PAM
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76 | /* PAM may include <locale.h>. We may need to undefine bbox's stub define: */
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77 | # undef setlocale
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78 | /* For some obscure reason, PAM is not in pam/xxx, but in security/xxx.
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79 | * Apparently they like to confuse people. */
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80 | # include <security/pam_appl.h>
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81 | # include <security/pam_misc.h>
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82 |
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83 | # if 0
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84 | /* This supposedly can be used to avoid double password prompt,
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85 | * if used instead of standard misc_conv():
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86 | *
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87 | * "When we want to authenticate first with local method and then with tacacs for example,
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88 | * the password is asked for local method and if not good is asked a second time for tacacs.
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89 | * So if we want to authenticate a user with tacacs, and the user exists localy, the password is
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90 | * asked two times before authentication is accepted."
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91 | *
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92 | * However, code looks shaky. For example, why misc_conv() return value is ignored?
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93 | * Are msg[i] and resp[i] indexes handled correctly?
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94 | */
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95 | static char *passwd = NULL;
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96 | static int my_conv(int num_msg, const struct pam_message **msg,
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97 | struct pam_response **resp, void *data)
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98 | {
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99 | int i;
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100 | for (i = 0; i < num_msg; i++) {
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101 | switch (msg[i]->msg_style) {
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102 | case PAM_PROMPT_ECHO_OFF:
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103 | if (passwd == NULL) {
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104 | misc_conv(num_msg, msg, resp, data);
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105 | passwd = xstrdup(resp[i]->resp);
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106 | return PAM_SUCCESS;
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107 | }
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108 |
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109 | resp[0] = xzalloc(sizeof(struct pam_response));
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110 | resp[0]->resp = passwd;
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111 | passwd = NULL;
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112 | resp[0]->resp_retcode = PAM_SUCCESS;
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113 | resp[1] = NULL;
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114 | return PAM_SUCCESS;
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115 |
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116 | default:
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117 | break;
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118 | }
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119 | }
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120 |
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121 | return PAM_SUCCESS;
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122 | }
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123 | # endif
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124 |
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125 | static const struct pam_conv conv = {
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126 | misc_conv,
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127 | NULL
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128 | };
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129 | #endif
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130 |
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131 | enum {
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132 | TIMEOUT = 60,
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133 | EMPTY_USERNAME_COUNT = 10,
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134 | /* Some users found 32 chars limit to be too low: */
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135 | USERNAME_SIZE = 64,
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136 | TTYNAME_SIZE = 32,
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137 | };
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138 |
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139 | struct globals {
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140 | struct termios tty_attrs;
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141 | } FIX_ALIASING;
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142 | #define G (*(struct globals*)bb_common_bufsiz1)
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143 | #define INIT_G() do { setup_common_bufsiz(); } while (0)
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144 |
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145 |
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146 | #if ENABLE_FEATURE_NOLOGIN
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147 | static void die_if_nologin(void)
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148 | {
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149 | FILE *fp;
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150 | int c;
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151 | int empty = 1;
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152 |
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153 | fp = fopen_for_read("/etc/nologin");
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154 | if (!fp) /* assuming it does not exist */
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155 | return;
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156 |
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157 | while ((c = getc(fp)) != EOF) {
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158 | if (c == '\n')
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159 | bb_putchar('\r');
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160 | bb_putchar(c);
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161 | empty = 0;
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162 | }
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163 | if (empty)
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164 | puts("\r\nSystem closed for routine maintenance\r");
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165 |
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166 | fclose(fp);
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167 | fflush_all();
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168 | /* Users say that they do need this prior to exit: */
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169 | tcdrain(STDOUT_FILENO);
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170 | exit(EXIT_FAILURE);
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171 | }
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172 | #else
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173 | # define die_if_nologin() ((void)0)
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174 | #endif
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175 |
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176 | #if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM
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177 | static int check_securetty(const char *short_tty)
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178 | {
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179 | char *buf = (char*)"/etc/securetty"; /* any non-NULL is ok */
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180 | parser_t *parser = config_open2("/etc/securetty", fopen_for_read);
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181 | while (config_read(parser, &buf, 1, 1, "# \t", PARSE_NORMAL)) {
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182 | if (strcmp(buf, short_tty) == 0)
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183 | break;
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184 | buf = NULL;
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185 | }
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186 | config_close(parser);
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187 | /* buf != NULL here if config file was not found, empty
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188 | * or line was found which equals short_tty */
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189 | return buf != NULL;
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190 | }
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191 | #else
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192 | static ALWAYS_INLINE int check_securetty(const char *short_tty UNUSED_PARAM) { return 1; }
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193 | #endif
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194 |
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195 | #if ENABLE_SELINUX
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196 | static void initselinux(char *username, char *full_tty,
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197 | security_context_t *user_sid)
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198 | {
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199 | security_context_t old_tty_sid, new_tty_sid;
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200 |
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201 | if (!is_selinux_enabled())
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202 | return;
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203 |
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204 | if (get_default_context(username, NULL, user_sid)) {
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205 | bb_error_msg_and_die("can't get SID for %s", username);
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206 | }
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207 | if (getfilecon(full_tty, &old_tty_sid) < 0) {
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208 | bb_perror_msg_and_die("getfilecon(%s) failed", full_tty);
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209 | }
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210 | if (security_compute_relabel(*user_sid, old_tty_sid,
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211 | SECCLASS_CHR_FILE, &new_tty_sid) != 0) {
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212 | bb_perror_msg_and_die("security_change_sid(%s) failed", full_tty);
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213 | }
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214 | if (setfilecon(full_tty, new_tty_sid) != 0) {
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215 | bb_perror_msg_and_die("chsid(%s, %s) failed", full_tty, new_tty_sid);
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216 | }
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217 | }
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218 | #endif
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219 |
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220 | #if ENABLE_LOGIN_SCRIPTS
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221 | static void run_login_script(struct passwd *pw, char *full_tty)
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222 | {
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223 | char *t_argv[2];
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224 |
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225 | t_argv[0] = getenv("LOGIN_PRE_SUID_SCRIPT");
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226 | if (t_argv[0]) {
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227 | t_argv[1] = NULL;
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228 | xsetenv("LOGIN_TTY", full_tty);
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229 | xsetenv("LOGIN_USER", pw->pw_name);
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230 | xsetenv("LOGIN_UID", utoa(pw->pw_uid));
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231 | xsetenv("LOGIN_GID", utoa(pw->pw_gid));
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232 | xsetenv("LOGIN_SHELL", pw->pw_shell);
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233 | spawn_and_wait(t_argv); /* NOMMU-friendly */
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234 | unsetenv("LOGIN_TTY");
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235 | unsetenv("LOGIN_USER");
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236 | unsetenv("LOGIN_UID");
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237 | unsetenv("LOGIN_GID");
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238 | unsetenv("LOGIN_SHELL");
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239 | }
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240 | }
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241 | #else
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242 | void run_login_script(struct passwd *pw, char *full_tty);
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243 | #endif
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244 |
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245 | #if ENABLE_LOGIN_SESSION_AS_CHILD && ENABLE_PAM
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246 | static void login_pam_end(pam_handle_t *pamh)
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247 | {
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248 | int pamret;
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249 |
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250 | pamret = pam_setcred(pamh, PAM_DELETE_CRED);
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251 | if (pamret != PAM_SUCCESS) {
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252 | bb_error_msg("pam_%s failed: %s (%d)", "setcred",
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253 | pam_strerror(pamh, pamret), pamret);
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254 | }
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255 | pamret = pam_close_session(pamh, 0);
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256 | if (pamret != PAM_SUCCESS) {
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257 | bb_error_msg("pam_%s failed: %s (%d)", "close_session",
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258 | pam_strerror(pamh, pamret), pamret);
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259 | }
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260 | pamret = pam_end(pamh, pamret);
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261 | if (pamret != PAM_SUCCESS) {
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262 | bb_error_msg("pam_%s failed: %s (%d)", "end",
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263 | pam_strerror(pamh, pamret), pamret);
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264 | }
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265 | }
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266 | #endif /* ENABLE_PAM */
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267 |
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268 | static void get_username_or_die(char *buf, int size_buf)
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269 | {
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270 | int c, cntdown;
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271 |
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272 | cntdown = EMPTY_USERNAME_COUNT;
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273 | prompt:
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274 | print_login_prompt();
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275 | /* skip whitespace */
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276 | do {
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277 | c = getchar();
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278 | if (c == EOF)
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279 | exit(EXIT_FAILURE);
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280 | if (c == '\n') {
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281 | if (!--cntdown)
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282 | exit(EXIT_FAILURE);
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283 | goto prompt;
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284 | }
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285 | } while (isspace(c)); /* maybe isblank? */
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286 |
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287 | *buf++ = c;
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288 | if (!fgets(buf, size_buf-2, stdin))
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289 | exit(EXIT_FAILURE);
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290 | if (!strchr(buf, '\n'))
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291 | exit(EXIT_FAILURE);
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292 | while ((unsigned char)*buf > ' ')
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293 | buf++;
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294 | *buf = '\0';
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295 | }
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296 |
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297 | static void motd(void)
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298 | {
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299 | int fd;
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300 |
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301 | fd = open(bb_path_motd_file, O_RDONLY);
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302 | if (fd >= 0) {
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303 | fflush_all();
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304 | bb_copyfd_eof(fd, STDOUT_FILENO);
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305 | close(fd);
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306 | }
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307 | }
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308 |
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309 | static void alarm_handler(int sig UNUSED_PARAM)
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310 | {
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311 | /* This is the escape hatch! Poor serial line users and the like
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312 | * arrive here when their connection is broken.
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313 | * We don't want to block here */
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314 | ndelay_on(STDOUT_FILENO);
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315 | /* Test for correct attr restoring:
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316 | * run "getty 0 -" from a shell, enter bogus username, stop at
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317 | * password prompt, let it time out. Without the tcsetattr below,
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318 | * when you are back at shell prompt, echo will be still off.
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319 | */
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320 | tcsetattr_stdin_TCSANOW(&G.tty_attrs);
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321 | printf("\r\nLogin timed out after %u seconds\r\n", TIMEOUT);
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322 | fflush_all();
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323 | /* unix API is brain damaged regarding O_NONBLOCK,
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324 | * we should undo it, or else we can affect other processes */
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325 | ndelay_off(STDOUT_FILENO);
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326 | _exit(EXIT_SUCCESS);
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327 | }
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328 |
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329 | int login_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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330 | int login_main(int argc UNUSED_PARAM, char **argv)
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331 | {
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332 | enum {
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333 | LOGIN_OPT_f = (1<<0),
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334 | LOGIN_OPT_h = (1<<1),
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335 | LOGIN_OPT_p = (1<<2),
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336 | };
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337 | char *fromhost;
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338 | char username[USERNAME_SIZE];
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339 | int run_by_root;
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340 | unsigned opt;
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341 | int count = 0;
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342 | struct passwd *pw;
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343 | char *opt_host = NULL;
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344 | char *opt_user = opt_user; /* for compiler */
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345 | char *full_tty;
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346 | char *short_tty;
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347 | IF_SELINUX(security_context_t user_sid = NULL;)
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348 | #if ENABLE_PAM
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349 | int pamret;
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350 | pam_handle_t *pamh;
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351 | const char *pamuser;
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352 | const char *failed_msg;
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353 | struct passwd pwdstruct;
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354 | char pwdbuf[256];
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355 | char **pamenv;
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356 | #endif
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357 | #if ENABLE_LOGIN_SESSION_AS_CHILD
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358 | pid_t child_pid;
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359 | #endif
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360 |
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361 | INIT_G();
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362 |
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363 | /* More of suid paranoia if called by non-root: */
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364 | /* Clear dangerous stuff, set PATH */
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365 | run_by_root = !sanitize_env_if_suid();
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366 |
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367 | /* Mandatory paranoia for suid applet:
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368 | * ensure that fd# 0,1,2 are opened (at least to /dev/null)
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369 | * and any extra open fd's are closed.
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370 | * (The name of the function is misleading. Not daemonizing here.) */
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371 | bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE | DAEMON_CLOSE_EXTRA_FDS, NULL);
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372 |
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373 | username[0] = '\0';
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374 | opt = getopt32(argv, "f:h:p", &opt_user, &opt_host);
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375 | if (opt & LOGIN_OPT_f) {
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376 | if (!run_by_root)
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377 | bb_error_msg_and_die("-f is for root only");
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378 | safe_strncpy(username, opt_user, sizeof(username));
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379 | }
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380 | argv += optind;
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381 | if (argv[0]) /* user from command line (getty) */
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382 | safe_strncpy(username, argv[0], sizeof(username));
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383 |
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384 | /* Save tty attributes - and by doing it, check that it's indeed a tty */
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385 | if (tcgetattr(STDIN_FILENO, &G.tty_attrs) < 0
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386 | || !isatty(STDOUT_FILENO)
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387 | /*|| !isatty(STDERR_FILENO) - no, guess some people might want to redirect this */
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388 | ) {
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389 | return EXIT_FAILURE; /* Must be a terminal */
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390 | }
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391 |
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392 | /* We install timeout handler only _after_ we saved G.tty_attrs */
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393 | signal(SIGALRM, alarm_handler);
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394 | alarm(TIMEOUT);
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395 |
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396 | /* Find out and memorize our tty name */
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397 | full_tty = xmalloc_ttyname(STDIN_FILENO);
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398 | if (!full_tty)
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399 | full_tty = xstrdup("UNKNOWN");
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400 | short_tty = skip_dev_pfx(full_tty);
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401 |
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402 | if (opt_host) {
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403 | fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host);
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404 | } else {
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405 | fromhost = xasprintf(" on '%s'", short_tty);
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406 | }
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407 |
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408 | /* Was breaking "login <username>" from shell command line: */
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409 | /*bb_setpgrp();*/
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410 |
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411 | openlog(applet_name, LOG_PID | LOG_CONS, LOG_AUTH);
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412 |
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413 | while (1) {
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414 | /* flush away any type-ahead (as getty does) */
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415 | tcflush(0, TCIFLUSH);
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416 |
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417 | if (!username[0])
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418 | get_username_or_die(username, sizeof(username));
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419 |
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420 | #if ENABLE_PAM
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421 | pamret = pam_start("login", username, &conv, &pamh);
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422 | if (pamret != PAM_SUCCESS) {
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423 | failed_msg = "start";
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424 | goto pam_auth_failed;
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425 | }
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426 | /* set TTY (so things like securetty work) */
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427 | pamret = pam_set_item(pamh, PAM_TTY, short_tty);
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428 | if (pamret != PAM_SUCCESS) {
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429 | failed_msg = "set_item(TTY)";
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430 | goto pam_auth_failed;
|
---|
431 | }
|
---|
432 | /* set RHOST */
|
---|
433 | if (opt_host) {
|
---|
434 | pamret = pam_set_item(pamh, PAM_RHOST, opt_host);
|
---|
435 | if (pamret != PAM_SUCCESS) {
|
---|
436 | failed_msg = "set_item(RHOST)";
|
---|
437 | goto pam_auth_failed;
|
---|
438 | }
|
---|
439 | }
|
---|
440 | if (!(opt & LOGIN_OPT_f)) {
|
---|
441 | pamret = pam_authenticate(pamh, 0);
|
---|
442 | if (pamret != PAM_SUCCESS) {
|
---|
443 | failed_msg = "authenticate";
|
---|
444 | goto pam_auth_failed;
|
---|
445 | /* TODO: or just "goto auth_failed"
|
---|
446 | * since user seems to enter wrong password
|
---|
447 | * (in this case pamret == 7)
|
---|
448 | */
|
---|
449 | }
|
---|
450 | }
|
---|
451 | /* check that the account is healthy */
|
---|
452 | pamret = pam_acct_mgmt(pamh, 0);
|
---|
453 | if (pamret != PAM_SUCCESS) {
|
---|
454 | failed_msg = "acct_mgmt";
|
---|
455 | goto pam_auth_failed;
|
---|
456 | }
|
---|
457 | /* read user back */
|
---|
458 | pamuser = NULL;
|
---|
459 | /* gcc: "dereferencing type-punned pointer breaks aliasing rules..."
|
---|
460 | * thus we cast to (void*) */
|
---|
461 | if (pam_get_item(pamh, PAM_USER, (void*)&pamuser) != PAM_SUCCESS) {
|
---|
462 | failed_msg = "get_item(USER)";
|
---|
463 | goto pam_auth_failed;
|
---|
464 | }
|
---|
465 | if (!pamuser || !pamuser[0])
|
---|
466 | goto auth_failed;
|
---|
467 | safe_strncpy(username, pamuser, sizeof(username));
|
---|
468 | /* Don't use "pw = getpwnam(username);",
|
---|
469 | * PAM is said to be capable of destroying static storage
|
---|
470 | * used by getpwnam(). We are using safe(r) function */
|
---|
471 | pw = NULL;
|
---|
472 | getpwnam_r(username, &pwdstruct, pwdbuf, sizeof(pwdbuf), &pw);
|
---|
473 | if (!pw)
|
---|
474 | goto auth_failed;
|
---|
475 | pamret = pam_open_session(pamh, 0);
|
---|
476 | if (pamret != PAM_SUCCESS) {
|
---|
477 | failed_msg = "open_session";
|
---|
478 | goto pam_auth_failed;
|
---|
479 | }
|
---|
480 | pamret = pam_setcred(pamh, PAM_ESTABLISH_CRED);
|
---|
481 | if (pamret != PAM_SUCCESS) {
|
---|
482 | failed_msg = "setcred";
|
---|
483 | goto pam_auth_failed;
|
---|
484 | }
|
---|
485 | break; /* success, continue login process */
|
---|
486 |
|
---|
487 | pam_auth_failed:
|
---|
488 | /* syslog, because we don't want potential attacker
|
---|
489 | * to know _why_ login failed */
|
---|
490 | syslog(LOG_WARNING, "pam_%s call failed: %s (%d)", failed_msg,
|
---|
491 | pam_strerror(pamh, pamret), pamret);
|
---|
492 | safe_strncpy(username, "UNKNOWN", sizeof(username));
|
---|
493 | #else /* not PAM */
|
---|
494 | pw = getpwnam(username);
|
---|
495 | if (!pw) {
|
---|
496 | strcpy(username, "UNKNOWN");
|
---|
497 | goto fake_it;
|
---|
498 | }
|
---|
499 |
|
---|
500 | if (pw->pw_passwd[0] == '!' || pw->pw_passwd[0] == '*')
|
---|
501 | goto auth_failed;
|
---|
502 |
|
---|
503 | if (opt & LOGIN_OPT_f)
|
---|
504 | break; /* -f USER: success without asking passwd */
|
---|
505 |
|
---|
506 | if (pw->pw_uid == 0 && !check_securetty(short_tty))
|
---|
507 | goto auth_failed;
|
---|
508 |
|
---|
509 | /* Don't check the password if password entry is empty (!) */
|
---|
510 | if (!pw->pw_passwd[0])
|
---|
511 | break;
|
---|
512 | fake_it:
|
---|
513 | /* Password reading and authorization takes place here.
|
---|
514 | * Note that reads (in no-echo mode) trash tty attributes.
|
---|
515 | * If we get interrupted by SIGALRM, we need to restore attrs.
|
---|
516 | */
|
---|
517 | if (ask_and_check_password(pw) > 0)
|
---|
518 | break;
|
---|
519 | #endif /* ENABLE_PAM */
|
---|
520 | auth_failed:
|
---|
521 | opt &= ~LOGIN_OPT_f;
|
---|
522 | bb_do_delay(LOGIN_FAIL_DELAY);
|
---|
523 | /* TODO: doesn't sound like correct English phrase to me */
|
---|
524 | puts("Login incorrect");
|
---|
525 | if (++count == 3) {
|
---|
526 | syslog(LOG_WARNING, "invalid password for '%s'%s",
|
---|
527 | username, fromhost);
|
---|
528 |
|
---|
529 | if (ENABLE_FEATURE_CLEAN_UP)
|
---|
530 | free(fromhost);
|
---|
531 |
|
---|
532 | return EXIT_FAILURE;
|
---|
533 | }
|
---|
534 | username[0] = '\0';
|
---|
535 | } /* while (1) */
|
---|
536 |
|
---|
537 | alarm(0);
|
---|
538 | /* We can ignore /etc/nologin if we are logging in as root,
|
---|
539 | * it doesn't matter whether we are run by root or not */
|
---|
540 | if (pw->pw_uid != 0)
|
---|
541 | die_if_nologin();
|
---|
542 |
|
---|
543 | #if ENABLE_LOGIN_SESSION_AS_CHILD
|
---|
544 | child_pid = vfork();
|
---|
545 | if (child_pid != 0) {
|
---|
546 | if (child_pid < 0)
|
---|
547 | bb_perror_msg("vfork");
|
---|
548 | else {
|
---|
549 | if (safe_waitpid(child_pid, NULL, 0) == -1)
|
---|
550 | bb_perror_msg("waitpid");
|
---|
551 | update_utmp_DEAD_PROCESS(child_pid);
|
---|
552 | }
|
---|
553 | IF_PAM(login_pam_end(pamh);)
|
---|
554 | return 0;
|
---|
555 | }
|
---|
556 | #endif
|
---|
557 |
|
---|
558 | IF_SELINUX(initselinux(username, full_tty, &user_sid);)
|
---|
559 |
|
---|
560 | /* Try these, but don't complain if they fail.
|
---|
561 | * _f_chown is safe wrt race t=ttyname(0);...;chown(t); */
|
---|
562 | fchown(0, pw->pw_uid, pw->pw_gid);
|
---|
563 | fchmod(0, 0600);
|
---|
564 |
|
---|
565 | update_utmp(getpid(), USER_PROCESS, short_tty, username, run_by_root ? opt_host : NULL);
|
---|
566 |
|
---|
567 | /* We trust environment only if we run by root */
|
---|
568 | if (ENABLE_LOGIN_SCRIPTS && run_by_root)
|
---|
569 | run_login_script(pw, full_tty);
|
---|
570 |
|
---|
571 | change_identity(pw);
|
---|
572 | setup_environment(pw->pw_shell,
|
---|
573 | (!(opt & LOGIN_OPT_p) * SETUP_ENV_CLEARENV) + SETUP_ENV_CHANGEENV,
|
---|
574 | pw);
|
---|
575 |
|
---|
576 | #if ENABLE_PAM
|
---|
577 | /* Modules such as pam_env will setup the PAM environment,
|
---|
578 | * which should be copied into the new environment. */
|
---|
579 | pamenv = pam_getenvlist(pamh);
|
---|
580 | if (pamenv) while (*pamenv) {
|
---|
581 | putenv(*pamenv);
|
---|
582 | pamenv++;
|
---|
583 | }
|
---|
584 | #endif
|
---|
585 |
|
---|
586 | if (access(".hushlogin", F_OK) != 0)
|
---|
587 | motd();
|
---|
588 |
|
---|
589 | if (pw->pw_uid == 0)
|
---|
590 | syslog(LOG_INFO, "root login%s", fromhost);
|
---|
591 |
|
---|
592 | if (ENABLE_FEATURE_CLEAN_UP)
|
---|
593 | free(fromhost);
|
---|
594 |
|
---|
595 | /* well, a simple setexeccon() here would do the job as well,
|
---|
596 | * but let's play the game for now */
|
---|
597 | IF_SELINUX(set_current_security_context(user_sid);)
|
---|
598 |
|
---|
599 | // util-linux login also does:
|
---|
600 | // /* start new session */
|
---|
601 | // setsid();
|
---|
602 | // /* TIOCSCTTY: steal tty from other process group */
|
---|
603 | // if (ioctl(0, TIOCSCTTY, 1)) error_msg...
|
---|
604 | // BBox login used to do this (see above):
|
---|
605 | // bb_setpgrp();
|
---|
606 | // If this stuff is really needed, add it and explain why!
|
---|
607 |
|
---|
608 | /* Set signals to defaults */
|
---|
609 | /* Non-ignored signals revert to SIG_DFL on exec anyway */
|
---|
610 | /*signal(SIGALRM, SIG_DFL);*/
|
---|
611 |
|
---|
612 | /* Is this correct? This way user can ctrl-c out of /etc/profile,
|
---|
613 | * potentially creating security breach (tested with bash 3.0).
|
---|
614 | * But without this, bash 3.0 will not enable ctrl-c either.
|
---|
615 | * Maybe bash is buggy?
|
---|
616 | * Need to find out what standards say about /bin/login -
|
---|
617 | * should we leave SIGINT etc enabled or disabled? */
|
---|
618 | signal(SIGINT, SIG_DFL);
|
---|
619 |
|
---|
620 | /* Exec login shell with no additional parameters */
|
---|
621 | run_shell(pw->pw_shell, 1, NULL, NULL);
|
---|
622 |
|
---|
623 | /* return EXIT_FAILURE; - not reached */
|
---|
624 | }
|
---|