diff options
Diffstat (limited to 'release/src/router/busybox/loginutils/su.c')
| -rw-r--r-- | release/src/router/busybox/loginutils/su.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/release/src/router/busybox/loginutils/su.c b/release/src/router/busybox/loginutils/su.c new file mode 100644 index 00000000..85f5cbe7 --- /dev/null +++ b/release/src/router/busybox/loginutils/su.c @@ -0,0 +1,166 @@ +/* vi: set sw=4 ts=4: */ + +#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 "busybox.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: + bb_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 ) + bb_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 = bb_xstrdup ( pw-> pw_name ); + pw-> pw_dir = bb_xstrdup ( pw-> pw_dir ); + pw-> pw_shell = bb_xstrdup ( pw-> pw_shell ); + + if (( getuid ( ) == 0 ) || correct_password ( pw )) + log_su ( pw, 1 ); + else { + log_su ( pw, 0 ); + bb_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 = bb_xstrdup ( pw-> pw_shell ); + + change_identity ( pw ); + setup_environment ( opt_shell, opt_loginshell, !opt_preserve, pw ); + run_shell ( opt_shell, opt_loginshell, opt_command, (const char**)opt_args +#ifdef CONFIG_SELINUX + , 0 +#endif + ); + + return EXIT_FAILURE; +} |