4 files changed, 39 insertions, 9 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 6bea048a3..7fbeb4fb7 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -490,9 +490,9 @@ void xprint_and_close_file(FILE *file);
 
 #define FAIL_DELAY    3
 extern void bb_do_delay(int seconds);
-extern void change_identity ( const struct passwd *pw );
-extern const char *change_identity_e2str ( const struct passwd *pw );
-extern void run_shell ( const char *shell, int loginshell, const char *command, const char **additional_args);
+extern void change_identity(const struct passwd *pw);
+extern const char *change_identity_e2str(const struct passwd *pw);
+extern void run_shell(const char *shell, int loginshell, const char *command, const char **additional_args);
 #ifdef CONFIG_SELINUX
 extern void renew_current_security_context(void);
 extern void set_current_security_context(security_context_t sid);
diff --git a/libbb/change_identity.c b/libbb/change_identity.c
index 74ffccbd3..63c5ae1c8 100644
--- a/libbb/change_identity.c
+++ b/libbb/change_identity.c
@@ -40,21 +40,21 @@
 
 
 /* Become the user and group(s) specified by PW.  */
-const char *change_identity_e2str ( const struct passwd *pw )
+const char *change_identity_e2str(const struct passwd *pw)
 {
-        if ( initgroups ( pw-> pw_name, pw-> pw_gid ) == -1 )
+        if (initgroups(pw->pw_name, pw->pw_gid) == -1)
                 return "cannot set groups";
-        endgrent ( );
+        endgrent();
 
-        xsetgid(pw-> pw_gid);
+        xsetgid(pw->pw_gid);
         xsetuid(pw->pw_uid);
         return NULL;
 }
 
-void change_identity ( const struct passwd *pw )
+void change_identity(const struct passwd *pw)
 {
         const char *err_msg = change_identity_e2str(pw);
 
         if(err_msg)
-                bb_perror_msg_and_die ( "%s", err_msg );
+                bb_perror_msg_and_die("%s", err_msg);
 }
diff --git a/loginutils/Config.in b/loginutils/Config.in
index 71e0a3ae1..6e45b706a 100644
--- a/loginutils/Config.in
+++ b/loginutils/Config.in
@@ -111,6 +111,14 @@ config CONFIG_LOGIN
           Note that Busybox binary must be setuid root for this applet to
           work properly.
 
+config CONFIG_LOGIN_SCRIPTS
+        bool "Support for login scripts"
+        depends on CONFIG_LOGIN
+        default n
+        help
+          Enable this if you want login to execute $LOGIN_PRE_SUID_SCRIPT
+          just prior to swithching from root to logged-in user.
+
 config CONFIG_FEATURE_SECURETTY
         bool "Support for /etc/securetty"
         default y
diff --git a/loginutils/login.c b/loginutils/login.c
index 5b4edd8de..39d980fa8 100644
--- a/loginutils/login.c
+++ b/loginutils/login.c
@@ -15,6 +15,7 @@
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <sys/wait.h>
 #include <ctype.h>
 #include <time.h>
 
@@ -258,6 +259,27 @@ auth_ok:
         chown ( full_tty, pw-> pw_uid, pw-> pw_gid );
         chmod ( full_tty, 0600 );
 
+        if (ENABLE_LOGIN_SCRIPTS) {
+                char *script = getenv("LOGIN_PRE_SUID_SCRIPT");
+                if (script) {
+                        char *t_argv[2] = { script, NULL };
+                        switch(fork()) {
+                        case -1: break;
+                        case 0: /* child */
+                                xchdir("/");
+                                setenv("LOGIN_TTY", full_tty, 1);
+                                setenv("LOGIN_USER", pw->pw_name, 1);
+                                setenv("LOGIN_UID", utoa(pw->pw_uid), 1);
+                                setenv("LOGIN_GID", utoa(pw->pw_gid), 1);
+                                setenv("LOGIN_SHELL", pw->pw_shell, 1);
+                                execvp(script, t_argv);
+                                exit(1);
+                        default: /* parent */
+                                wait(NULL);
+                        }
+                }
+        }
+
         change_identity ( pw );
         tmp = pw-> pw_shell;
         if(!tmp || !*tmp)