Bigger patch for (partial) tinylogin integration

- Made a new dir loginutils
- Moved all applets from pwd_grp to loginutils
- Added new applets su.c login.c to loginutils
- Made a new dir libpwdgrp
- Moved everything from pwd_grp/libpwd_grp there
- Added shadow.c to libpwdgrp
- Removed dir pwd_grp
- Added usage strings for login and su to usage.h
- Changed main Makefile to reflect the dir rearrangements
[Parts of this patch may overlap with my other two patches]

1 files changed, 167 insertions, 0 deletions

diff --git a/loginutils/su.c b/loginutils/su.c
new file mode 100644
index 000000000..33e62e837
--- /dev/null
+++ b/loginutils/su.c
@@ -0,0 +1,167 @@
+/* vi: set sw=4 ts=4: */
+
+#include "busybox.h"
+
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <termios.h>
+#include <unistd.h>
+#include <utmp.h>
+#include <sys/resource.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <ctype.h>
+#include <time.h>
+
+#include "pwd.h"
+#include "grp.h"
+
+#include "tinylogin.h"
+
+
+
+/* The shell to run if none is given in the user's passwd entry.  */
+#define DEFAULT_SHELL "/bin/sh"
+#define DEFAULT_USER  "root"
+
+//#define SYSLOG_SUCCESS
+#define SYSLOG_FAILURE
+
+
+#if defined( SYSLOG_SUCCESS ) || defined( SYSLOG_FAILURE )
+/* Log the fact that someone has run su to the user given by PW;
+   if SUCCESSFUL is nonzero, they gave the correct password, etc.  */
+
+static void log_su ( const struct passwd *pw, int successful )
+{
+	const char *old_user, *tty;
+
+#if !defined( SYSLOG_SUCESS )
+	if ( successful )
+		return;
+#endif
+#if !defined( SYSLOG_FAILURE )
+	if ( !successful )
+		return;
+#endif
+
+	if ( pw-> pw_uid ) // not to root -> ignored
+		return;
+
+	/* The utmp entry (via getlogin) is probably the best way to identify
+	   the user, especially if someone su's from a su-shell.  */
+	old_user = getlogin ( );
+	if ( !old_user ) {
+		/* getlogin can fail -- usually due to lack of utmp entry. Resort to getpwuid.  */
+		struct passwd *pwd = getpwuid ( getuid ( ));
+		old_user = ( pwd ? pwd-> pw_name : "" );
+	}
+	
+	tty = ttyname ( 2 );
+
+	openlog ( "su", 0, LOG_AUTH );
+	syslog ( LOG_NOTICE, "%s%s on %s", successful ? "" : "FAILED SU ", old_user, tty ? tty : "none" );
+}
+#endif
+
+
+
+int su_main ( int argc, char **argv )
+{
+	int flag;
+	int opt_preserve = 0;
+	int opt_loginshell = 0;
+	char *opt_shell = 0;
+	char *opt_command = 0;
+	char *opt_username = DEFAULT_USER;
+	char **opt_args = 0;
+	struct passwd *pw, pw_copy;
+
+
+	while (( flag = getopt ( argc, argv, "c:lmps:" )) != -1 ) {
+		switch ( flag ) {
+		case 'c':
+			opt_command = optarg;
+			break;
+		case 'm':
+		case 'p':
+			opt_preserve = 1;
+			break;
+		case 's':
+			opt_shell = optarg;
+			break;
+		case 'l':
+			opt_loginshell = 1;
+			break;
+		default:
+			show_usage ( );
+			break;
+		}
+	}
+
+	if (( optind < argc ) && ( argv [optind][0] == '-' ) && ( argv [optind][1] == 0 )) {
+		opt_loginshell = 1;
+		++optind;
+    }
+
+	/* get user if specified */
+	if ( optind < argc ) 
+		opt_username = argv [optind++];
+
+	if ( optind < argc )
+		opt_args = argv + optind;
+		
+		
+	pw = getpwnam ( opt_username );
+	if ( !pw )
+		error_msg_and_die ( "user %s does not exist", opt_username );
+		
+	/* Make sure pw->pw_shell is non-NULL.  It may be NULL when NEW_USER
+	   is a username that is retrieved via NIS (YP), but that doesn't have
+	   a default shell listed.  */
+	if ( !pw-> pw_shell || !pw->pw_shell [0] )
+		pw-> pw_shell = (char *) DEFAULT_SHELL;
+
+	/* Make a copy of the password information and point pw at the local
+	   copy instead.  Otherwise, some systems (e.g. Linux) would clobber
+	   the static data through the getlogin call from log_su.  */
+	pw_copy = *pw;
+	pw = &pw_copy;
+	pw-> pw_name  = xstrdup ( pw-> pw_name );
+	pw-> pw_dir   = xstrdup ( pw-> pw_dir );
+	pw-> pw_shell = xstrdup ( pw-> pw_shell );
+
+	if (( getuid ( ) == 0 ) || correct_password ( pw )) 
+		log_su ( pw, 1 );
+	else {
+		log_su ( pw, 0 );
+		error_msg_and_die ( "incorrect password" );
+	}
+
+	if ( !opt_shell && opt_preserve )
+		opt_shell = getenv ( "SHELL" );
+
+	if ( opt_shell && getuid ( ) && restricted_shell ( pw-> pw_shell ))
+	{
+		/* The user being su'd to has a nonstandard shell, and so is
+		   probably a uucp account or has restricted access.  Don't
+		   compromise the account by allowing access with a standard
+		   shell.  */
+		fputs ( "using restricted shell\n", stderr );
+		opt_shell = 0;
+	}
+
+	if ( !opt_shell )
+		opt_shell = xstrdup ( pw-> pw_shell );
+
+	change_identity ( pw );	
+	setup_environment ( opt_shell, opt_loginshell, !opt_preserve, pw );
+	run_shell ( opt_shell, opt_loginshell, opt_command, opt_args );
+	
+	return EXIT_FAILURE;
+}