login: make /etc/nologin support configurable. -240 bytes if not selected.

diff --git a/include/libbb.h b/include/libbb.h
index c4743cf..4f418e7 100644 (file)
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -943,12 +943,10 @@ extern const char bb_str_default[];
 extern const char bb_hexdigits_upcase[];
 
 extern const char bb_path_mtab_file[];
-extern const char bb_path_nologin_file[];
 extern const char bb_path_passwd_file[];
 extern const char bb_path_shadow_file[];
 extern const char bb_path_gshadow_file[];
 extern const char bb_path_group_file[];
-extern const char bb_path_securetty_file[];
 extern const char bb_path_motd_file[];
 extern const char bb_path_wtmp_file[];
 extern const char bb_dev_null[];

diff --git a/libbb/messages.c b/libbb/messages.c
index 9f62b9b..27d2cc1 100644 (file)
--- a/libbb/messages.c
+++ b/libbb/messages.c
@@ -34,8 +34,6 @@ const char bb_path_passwd_file[] = "/etc/passwd";
 const char bb_path_shadow_file[] = "/etc/shadow";
 const char bb_path_group_file[] = "/etc/group";
 const char bb_path_gshadow_file[] = "/etc/gshadow";
-const char bb_path_nologin_file[] = "/etc/nologin";
-const char bb_path_securetty_file[] = "/etc/securetty";
 const char bb_path_motd_file[] = "/etc/motd";
 const char bb_dev_null[] = "/dev/null";
 const char bb_busybox_exec_path[] = CONFIG_BUSYBOX_EXEC_PATH;

diff --git a/loginutils/Config.in b/loginutils/Config.in
index cab7a11..f9ae122 100644 (file)
--- a/loginutils/Config.in
+++ b/loginutils/Config.in
@@ -136,12 +136,20 @@ config LOGIN_SCRIPTS
          Enable this if you want login to execute $LOGIN_PRE_SUID_SCRIPT
          just prior to switching from root to logged-in user.
 
+config FEATURE_NOLOGIN
+       bool "Support for /etc/nologin"
+       default y
+       depends on LOGIN
+       help
+         The file /etc/nologin is used by (some versions of) login(1).
+         If it exists, non-root logins are prohibited.
+
 config FEATURE_SECURETTY
        bool "Support for /etc/securetty"
        default y
        depends on LOGIN
        help
-         The file  /etc/securetty  is used by (some versions of) login(1).
+         The file /etc/securetty is used by (some versions of) login(1).
          The file contains the device names of tty lines (one per line,
          without leading /dev/) on which root is allowed to login.
 

diff --git a/loginutils/login.c b/loginutils/login.c
index b6924b6..0f71a2a 100644 (file)
--- a/loginutils/login.c
+++ b/loginutils/login.c
@@ -100,15 +100,16 @@ static void write_utent(struct utmp *utptr, const char *username)
 #define write_utent(utptr, username) ((void)0)
 #endif /* !ENABLE_FEATURE_UTMP */
 
+#if ENABLE_FEATURE_NOLOGIN
 static void die_if_nologin_and_non_root(int amroot)
 {
        FILE *fp;
        int c;
 
-       if (access(bb_path_nologin_file, F_OK))
+       if (access("/etc/nologin", F_OK))
                return;
 
-       fp = fopen(bb_path_nologin_file, "r");
+       fp = fopen("/etc/nologin", "r");
        if (fp) {
                while ((c = getc(fp)) != EOF)
                        putchar((c=='\n') ? '\r' : c);
@@ -118,28 +119,31 @@ static void die_if_nologin_and_non_root(int amroot)
                puts("\r\nSystem closed for routine maintenance\r");
        if (!amroot)
                exit(1);
-       puts("\r\n[Disconnect bypassed -- root login allowed.]\r");
+       puts("\r\n[Disconnect bypassed -- root login allowed]\r");
 }
+#else
+static ALWAYS_INLINE void die_if_nologin_and_non_root(int amroot) {}
+#endif
 
 #if ENABLE_FEATURE_SECURETTY
 static int check_securetty(void)
 {
        FILE *fp;
        int i;
-       char buf[BUFSIZ];
+       char buf[256];
 
-       fp = fopen(bb_path_securetty_file, "r");
+       fp = fopen("/etc/securetty", "r");
        if (!fp) {
                /* A missing securetty file is not an error. */
                return 1;
        }
        while (fgets(buf, sizeof(buf)-1, fp)) {
-               for (i = strlen(buf)-1; i>=0; --i) {
+               for (i = strlen(buf)-1; i >= 0; --i) {
                        if (!isspace(buf[i]))
                                break;
                }
                buf[++i] = '\0';
-               if ((buf[0]=='\0') || (buf[0]=='#'))
+               if (!buf[0] || (buf[0] == '#'))
                        continue;
                if (strcmp(buf, short_tty) == 0) {
                        fclose(fp);
@@ -150,7 +154,7 @@ static int check_securetty(void)
        return 0;
 }
 #else
-static inline int check_securetty(void) { return 1; }
+static ALWAYS_INLINE int check_securetty(void) { return 1; }
 #endif
 
 static void get_username_or_die(char *buf, int size_buf)
@@ -313,7 +317,7 @@ int login_main(int argc, char **argv)
 
        write_utent(&utent, username);
 
-#ifdef CONFIG_SELINUX
+#if ENABLE_SELINUX
        if (is_selinux_enabled()) {
                security_context_t old_tty_sid, new_tty_sid;
 
@@ -368,7 +372,7 @@ int login_main(int argc, char **argv)
 
        if (pw->pw_uid == 0)
                syslog(LOG_INFO, "root login%s", fromhost);
-#ifdef CONFIG_SELINUX
+#if ENABLE_SELINUX
        /* well, a simple setexeccon() here would do the job as well,
         * but let's play the game for now */
        set_current_security_context(user_sid);