C++ setreuid函数代码示例

void fs_private_bin_list(void) {
	char *private_list = cfg.bin_private_keep;
	assert(private_list);
	
	// create /tmp/firejail/mnt/bin directory
	fs_build_mnt_dir();
	int rv = mkdir(RUN_BIN_DIR, 0755);
	if (rv == -1)
		errExit("mkdir");
	if (chown(RUN_BIN_DIR, 0, 0) < 0)
		errExit("chown");
	if (chmod(RUN_BIN_DIR, 0755) < 0)
		errExit("chmod");
	
	
	// copy the list of files in the new etc directory
	// using a new child process without root privileges
	fs_logger_print();	// save the current log
	pid_t child = fork();
	if (child < 0)
		errExit("fork");
	if (child == 0) {
		if (arg_debug)
			printf("Copying files in the new home:\n");

		// elevate privileges - files in the new /bin directory belong to root
		if (setreuid(0, 0) < 0)
			errExit("setreuid");
		if (setregid(0, 0) < 0)
			errExit("setregid");
		
		// copy the list of files in the new home directory
		char *dlist = strdup(private_list);
		if (!dlist)
			errExit("strdup");
	
	
		char *ptr = strtok(dlist, ",");
		duplicate(ptr);
	
		while ((ptr = strtok(NULL, ",")) != NULL)
			duplicate(ptr);
		free(dlist);	
		fs_logger_print();
		exit(0);
	}
	// wait for the child to finish
	waitpid(child, NULL, 0);

	// mount-bind
	int i = 0;
	while (paths[i]) {
		struct stat s;
		if (stat(paths[i], &s) == 0) {
			if (arg_debug)
				printf("Mount-bind %s on top of %s\n", RUN_BIN_DIR, paths[i]);
			if (mount(RUN_BIN_DIR, paths[i], NULL, MS_BIND|MS_REC, NULL) < 0)
				errExit("mount bind");
			fs_logger2("tmpfs", paths[i]);
			fs_logger2("mount", paths[i]);
		}
		i++;
	}
	
	// log cloned files
	char *dlist = strdup(private_list);
	if (!dlist)
		errExit("strdup");
	
	
	char *ptr = strtok(dlist, ",");
	while (ptr) {
		i = 0;
		while (paths[i]) {
			struct stat s;
			if (stat(paths[i], &s) == 0) {
				char *fname;
				if (asprintf(&fname, "%s/%s", paths[i], ptr) == -1)
					errExit("asprintf");
				fs_logger2("clone", fname);
				free(fname);
			}
			i++;
		}
		ptr = strtok(NULL, ",");
	}
	free(dlist);
}

void call_setreuid (gid_t ruid, gid_t euid, gid_t suid) {
  setreuid(ruid, euid);
}

/* A binary wrapper is needed around python scripts if we want
 * to run them in sgid/suid mode.
 *
 * This is such a wrapper.
 */
int main(int argc, char **argv)
{
    /*
     * We disallow passing of arguments which point to writable dirs
     * and other files possibly not accessible to calling user.
     * This way, the script will always use default values for these arguments.
     */
    char **pp = argv;
    char *arg;
    while ((arg = *++pp) != NULL)
    {
        /* Allow taking ids from stdin */
        if (strcmp(arg, "--ids=-") == 0)
            continue;

        if (strncmp(arg, "--cache", 7) == 0)
            error_msg_and_die("bad option", arg);
        if (strncmp(arg, "--tmpdir", 8) == 0)
            error_msg_and_die("bad option", arg);
        if (strncmp(arg, "--ids", 5) == 0)
            error_msg_and_die("bad option", arg);
    }

    /* Switch real user/group to effective ones.
     * Otherwise yum library gets confused - gets EPERM (why??).
     */
    gid_t g = getegid();
    /* do setregid only if we have to, to not upset selinux needlessly */
    if (g != getgid())
        setregid(g, g);
    uid_t u = geteuid();
    if (u != getuid())
    {
        setreuid(u, u);
        /* We are suid'ed! */
        /* Prevent malicious user from messing up with suid'ed process: */
        /* Set safe PATH */
// TODO: honor configure --prefix here by adding it to PATH
// (otherwise abrt-action-install-debuginfo would fail to spawn abrt-action-trim-files):
        if (u == 0)
            putenv((char*) "PATH=/usr/sbin:/sbin:/usr/bin:/bin");
        else
            putenv((char*) "PATH=/usr/bin:/bin");
        /* Clear dangerous stuff from env */
        static const char forbid[] =
            "LD_LIBRARY_PATH" "\0"
            "LD_PRELOAD" "\0"
            "LD_TRACE_LOADED_OBJECTS" "\0"
            "LD_BIND_NOW" "\0"
            "LD_AOUT_LIBRARY_PATH" "\0"
            "LD_AOUT_PRELOAD" "\0"
            "LD_NOWARN" "\0"
            "LD_KEEPDIR" "\0"
        ;
        const char *p = forbid;
        do {
            unsetenv(p);
            p += strlen(p) + 1;
        } while (*p);
    }

    execvp(EXECUTABLE, argv);
    error_msg_and_die("Can't execute", EXECUTABLE);
}

int main(int argc, char **argv)
{
	const char	*socket_path = UUIDD_SOCKET_PATH;
	const char	*pidfile_path = UUIDD_PIDFILE_PATH;
	const char	*err_context;
	char		buf[1024], *cp;
	char   		str[37], *tmp;
	uuid_t		uu;
	uid_t		uid;
	gid_t 		gid;
	int		i, c, ret;
	int		debug = 0, do_type = 0, do_kill = 0, num = 0;
	int		timeout = 0, quiet = 0, drop_privs = 0;

#ifdef ENABLE_NLS
	setlocale(LC_MESSAGES, "");
	setlocale(LC_CTYPE, "");
	bindtextdomain(NLS_CAT_NAME, LOCALEDIR);
	textdomain(NLS_CAT_NAME);
#endif

	while ((c = getopt (argc, argv, "dkn:qp:s:tT:r")) != EOF) {
		switch (c) {
		case 'd':
			debug++;
			drop_privs = 1;
			break;
		case 'k':
			do_kill++;
			drop_privs = 1;
			break;
		case 'n':
			num = strtol(optarg, &tmp, 0);
			if ((num < 0) || *tmp) {
				fprintf(stderr, _("Bad number: %s\n"), optarg);
				exit(1);
			}
			break;
		case 'p':
			pidfile_path = optarg;
			drop_privs = 1;
			break;
		case 'q':
			quiet++;
			break;
		case 's':
			socket_path = optarg;
			drop_privs = 1;
			break;
		case 't':
			do_type = UUIDD_OP_TIME_UUID;
			drop_privs = 1;
			break;
		case 'T':
			timeout = strtol(optarg, &tmp, 0);
			if ((timeout < 0) || *tmp) {
				fprintf(stderr, _("Bad number: %s\n"), optarg);
				exit(1);
			}
			break;
		case 'r':
			do_type = UUIDD_OP_RANDOM_UUID;
			drop_privs = 1;
			break;
		default:
			usage(argv[0]);
		}
	}
	uid = getuid();
	if (uid && drop_privs) {
		gid = getgid();
#ifdef HAVE_SETRESGID
		if (setresgid(gid, gid, gid) < 0)
			die("setresgid");
#else
		if (setregid(gid, gid) < 0)
			die("setregid");
#endif

#ifdef HAVE_SETRESUID
		if (setresuid(uid, uid, uid) < 0)
			die("setresuid");
#else
		if (setreuid(uid, uid) < 0)
			die("setreuid");
#endif
	}
	if (num && do_type) {
		ret = call_daemon(socket_path, do_type+2, buf,
				  sizeof(buf), &num, &err_context);
		if (ret < 0) {
			printf(_("Error calling uuidd daemon (%s): %s\n"),
			       err_context, strerror(errno));
			exit(1);
		}
		if (do_type == UUIDD_OP_TIME_UUID) {
			if (ret != sizeof(uu) + sizeof(num))
				goto unexpected_size;

			uuid_unparse((unsigned char *) buf, str);
//.........这里部分代码省略.........

//.........这里部分代码省略.........
	Com_Printf( "----- refresher initialization -----\n");

	/* regain root */
	seteuid( saved_euid );

	path = Cvar_Get( "basedir", ".", CVAR_NOSET )->string;

	snprintf( fn, MAX_OSPATH, "%s/%s", path, name );

	if ( stat( fn, &st ) == -1 )
	{
		Com_Printf( "LoadLibrary(\"%s\") failed: %s\n", name, strerror( errno ) );
		return ( false );
	}

	if ( ( reflib_library = dlopen( fn, RTLD_LAZY ) ) == 0 )
	{
		Com_Printf( "LoadLibrary(\"%s\") failed: %s\n", name, dlerror() );
		return ( false );
	}

	Com_Printf( "LoadLibrary(\"%s\")\n", fn );

	ri.Cmd_AddCommand = Cmd_AddCommand;
	ri.Cmd_RemoveCommand = Cmd_RemoveCommand;
	ri.Cmd_Argc = Cmd_Argc;
	ri.Cmd_Argv = Cmd_Argv;
	ri.Cmd_ExecuteText = Cbuf_ExecuteText;
	ri.Con_Printf = VID_Printf;
	ri.Sys_Error = VID_Error;
	ri.Sys_Mkdir = Sys_Mkdir;
	ri.FS_LoadFile = FS_LoadFile;
	ri.FS_FreeFile = FS_FreeFile;
	ri.FS_Gamedir = FS_Gamedir;
	ri.Cvar_Get = Cvar_Get;
	ri.Cvar_Set = Cvar_Set;
	ri.Cvar_SetValue = Cvar_SetValue;
	ri.Vid_GetModeInfo = VID_GetModeInfo;
	ri.Vid_MenuInit = VID_MenuInit;
	ri.Vid_NewWindow = VID_NewWindow;

	if ( ( R_GetRefAPI = (void *) dlsym( reflib_library, "R_GetRefAPI" ) ) == 0 )
	{
		Com_Error( ERR_FATAL, "dlsym failed on %s", name );
	}

	re = R_GetRefAPI( ri );

	if ( re.api_version != API_VERSION )
	{
		VID_FreeReflib();
		Com_Error( ERR_FATAL, "%s has incompatible api_version", name );
	}

	/* Init IN (Mouse) */
	in_state.IN_CenterView_fp = IN_CenterView;
	in_state.Key_Event_fp = Do_Key_Event;
	in_state.viewangles = cl.viewangles;
	in_state.in_strafe_state = &in_strafe.state;
	in_state.in_speed_state = &in_speed.state;

	if ( ( ( IN_BackendInit_fp = dlsym( reflib_library, "IN_BackendInit" ) ) == NULL ) ||
		 ( ( IN_BackendShutdown_fp = dlsym( reflib_library, "IN_BackendShutdown" ) ) == NULL ) ||
		 ( ( IN_BackendMouseButtons_fp = dlsym( reflib_library, "IN_BackendMouseButtons" ) ) == NULL ) ||
		 ( ( IN_BackendMove_fp = dlsym( reflib_library, "IN_BackendMove" ) ) == NULL ) )
	{
		Sys_Error( "No input backend init functions in REF.\n" );
	}

	if ( IN_BackendInit_fp )
	{
		IN_BackendInit_fp( &in_state );
	}

	if ( re.Init( 0, 0 ) == -1 )
	{
		re.Shutdown();
		VID_FreeReflib();
		return ( false );
	}

	/* Init IN */
	if ( ( ( IN_KeyboardInit_fp = dlsym( reflib_library, "IN_KeyboardInit" ) ) == NULL ) ||
		 ( ( IN_Update_fp = dlsym( reflib_library, "IN_Update" ) ) == NULL ) ||
		 ( ( IN_Close_fp = dlsym( reflib_library, "IN_Close" ) ) == NULL ) )
	{
		Sys_Error( "No keyboard input functions in REF.\n" );
	}

	IN_KeyboardInit_fp( Do_Key_Event );
	Key_ClearStates();

	/* give up root now */
	setreuid( getuid(), getuid() );
	setegid( getgid() );

	Com_Printf( "------------------------------------\n\n" );
	reflib_active = true;
	return ( true );
}

int main(int ac, char **av)
{
	int lc;			/* loop counter */
	char *msg;		/* message returned from parse_opts */

	pid_t pid, pid1;
	int status;

	/* parse standard options */
	if ((msg = parse_opts(ac, av, (option_t *) NULL, NULL)) != (char *)NULL) {
		tst_brkm(TBROK, cleanup, "OPTION PARSING ERROR - %s", msg);
	}

	setup();

	/* set up the expected errnos */
	TEST_EXP_ENOS(exp_enos);

	/* check for looping state if -i option is given */
	for (lc = 0; TEST_LOOPING(lc); lc++) {
		/* reset Tst_count in case we are looping */
		Tst_count = 0;

		if ((pid = FORK_OR_VFORK()) < 0) {
			tst_brkm(TBROK, cleanup, "first fork failed");
		}

		if (pid == 0) {	/* first child */
			/* set the child's ID to ltpuser1 */
			if (setreuid(ltpuser1->pw_uid, ltpuser1->pw_uid) != 0) {
				tst_resm(TINFO, "setreuid failed in child #1");
				exit(1);
			}
			if (mkdir(good_dir, 00700) != 0) {
				tst_resm(TINFO, "mkdir failed in child #1");
				exit(1);
			}
			exit(0);
		}
		wait(&status);

		if ((pid1 = FORK_OR_VFORK()) < 0) {
			tst_brkm(TBROK, cleanup, "second fork failed");
		}

		if (pid1 == 0) {	/* second child */
			/*
			 * set the child's ID to ltpuser2 using seteuid()
			 * so that the ID can be changed back after the
			 * TEST call is made.
			 */
			if (seteuid(ltpuser2->pw_uid) != 0) {
				tst_resm(TINFO, "setreuid failed in child #2");
				exit(1);
			}

			TEST(chdir(good_dir));

			if (TEST_RETURN != -1) {
				tst_resm(TFAIL, "call succeeded unexpectedly");
			} else if (TEST_ERRNO != EACCES) {
				tst_resm(TFAIL|TTERRNO, "expected EACCES");
			} else {
				TEST_ERROR_LOG(TEST_ERRNO);
				tst_resm(TPASS|TTERRNO, "expected failure");
			}

			/* reset the process ID to the saved ID (root) */
			if (setuid(0) == -1) {
				tst_resm(TINFO|TERRNO, "setuid(0) failed");
			}

		} else {	/* parent */
			wait(&status);

			/* let the child carry on */
			exit(0);
		}

		/* clean up things in case we are looping */
		if (rmdir(good_dir) == -1) {
			tst_brkm(TBROK|TERRNO, cleanup, "rmdir(%s) failed", good_dir);
		}
	}
	cleanup();

	return 0;
 /*NOTREACHED*/}

//.........这里部分代码省略.........
    switch(fork()) {
    case -1:
      msg_out(crit, "fork: %m");
      exit(1);
    case 0:
      /* child */
      pid = setsid();
      if (pid == -1) {
	msg_out(crit, "setsid: %m");
	exit(1);
      }
      break;
    default:
      /* parent */
      exit(0);
    }
  }

  master_pid = getpid();
  umask(S_IWGRP|S_IWOTH);
  if ((fp = fopen(pidfile, "w")) != NULL) {
    fprintf(fp, "%u\n", (unsigned)master_pid);
    fchown(fileno(fp), PROCUID, PROCGID);
    fclose(fp);
  } else {
    msg_out(warn, "cannot open pidfile %s", pidfile);
  }

  setsignal(SIGHUP, reload);
  setsignal(SIGINT, SIG_IGN);
  setsignal(SIGQUIT, SIG_IGN);
  setsignal(SIGILL, SIG_IGN);
  setsignal(SIGTRAP, SIG_IGN);
  setsignal(SIGABRT, SIG_IGN);
#ifdef SIGEMT
  setsignal(SIGEMT, SIG_IGN);
#endif
  setsignal(SIGFPE, SIG_IGN);
  setsignal(SIGBUS, SIG_IGN);
  setsignal(SIGSEGV, SIG_IGN);
  setsignal(SIGSYS, SIG_IGN);
  setsignal(SIGPIPE, SIG_IGN);
  setsignal(SIGALRM, SIG_IGN);
  setsignal(SIGTERM, cleanup);
  setsignal(SIGUSR1, SIG_IGN);
  setsignal(SIGUSR2, SIG_IGN);
#ifdef SIGPOLL
  setsignal(SIGPOLL, SIG_IGN);
#endif
  setsignal(SIGVTALRM, SIG_IGN);
  setsignal(SIGPROF, SIG_IGN);
  setsignal(SIGXCPU, SIG_IGN);
  setsignal(SIGXFSZ, SIG_IGN);

#ifdef USE_THREAD
  if ( threading ) {
    if (max_thread <= 0 || max_thread > THREAD_LIMIT) {
      max_thread = THREAD_LIMIT;
    }
    /* resource limit is problem in threadig (e.g. Solaris:=64)*/
    memset((caddr_t)&rl, 0, sizeof rl);
    if (getrlimit(RLIMIT_NOFILE, &rl) != 0)
      msg_out(warn, "getrlimit: %m");
    else
      save_fd = rl.rlim_cur;
    if (rl.rlim_cur < (rlim_t)max_fd)
      rl.rlim_cur = max_fd;        /* willing to fix to max_fd */
    if ( rl.rlim_cur != save_fd )  /* if rlim_cur is changed   */
      if (setrlimit(RLIMIT_NOFILE, &rl) != 0)
        msg_out(warn, "cannot set rlimit(max_fd)");

    setregid(0, PROCGID);
    setreuid(0, PROCUID);

    pthread_mutex_init(&mutex_select, NULL);
    pthread_attr_init(&attr);
    pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);

    msg_out(norm, "Starting: MAX_TH(%d)", max_thread);
    for (i=0; i<max_thread; i++) {
      if (pthread_create(&tid, &attr,
			 (void *)&serv_loop, (void *)NULL) != 0)
        exit(1);
    }
    main_thread = pthread_self();   /* store main thread ID */
    for (;;) {
      pause();
    }
  } else {
#endif
    setsignal(SIGCHLD, reapchild);
    setregid(0, PROCGID);
    setreuid(0, PROCUID);
    msg_out(norm, "Starting: MAX_CH(%d)", max_child);
    serv_loop();
#ifdef USE_THREAD
  }
#endif
  return(0);
}

int sh_access(register const char *name, register int mode)
{
	Shell_t	*shp = sh_getinterp();
	struct stat statb;
	if(*name==0)
		return(-1);
	if(sh_isdevfd(name))
		return(sh_ioaccess((int)strtol(name+8, (char**)0, 10),mode));
	/* can't use access function for execute permission with root */
	if(mode==X_OK && shp->gd->euserid==0)
		goto skip;
	if(shp->gd->userid==shp->gd->euserid && shp->gd->groupid==shp->gd->egroupid)
		return(access(name,mode));
#ifdef _lib_setreuid
	/* swap the real uid to effective, check access then restore */
	/* first swap real and effective gid, if different */
	if(shp->gd->groupid==shp->gd->euserid || setregid(shp->gd->egroupid,shp->gd->groupid)==0) 
	{
		/* next swap real and effective uid, if needed */
		if(shp->gd->userid==shp->gd->euserid || setreuid(shp->gd->euserid,shp->gd->userid)==0)
		{
			mode = access(name,mode);
			/* restore ids */
			if(shp->gd->userid!=shp->gd->euserid)
				setreuid(shp->gd->userid,shp->gd->euserid);
			if(shp->gd->groupid!=shp->gd->egroupid)
				setregid(shp->gd->groupid,shp->gd->egroupid);
			return(mode);
		}
		else if(shp->gd->groupid!=shp->gd->egroupid)
			setregid(shp->gd->groupid,shp->gd->egroupid);
	}
#endif /* _lib_setreuid */
skip:
	if(test_stat(name, &statb) == 0)
	{
		if(mode == F_OK)
			return(mode);
		else if(shp->gd->euserid == 0)
		{
			if(!S_ISREG(statb.st_mode) || mode!=X_OK)
				return(0);
		    	/* root needs execute permission for someone */
			mode = (S_IXUSR|S_IXGRP|S_IXOTH);
		}
		else if(shp->gd->euserid == statb.st_uid)
			mode <<= 6;
		else if(shp->gd->egroupid == statb.st_gid)
			mode <<= 3;
#ifdef _lib_getgroups
		/* on some systems you can be in several groups */
		else
		{
			static int maxgroups;
			gid_t *groups; 
			register int n;
			if(maxgroups==0)
			{
				/* first time */
				if((maxgroups=getgroups(0,(gid_t*)0)) <= 0)
				{
					/* pre-POSIX system */
					maxgroups=NGROUPS_MAX;
				}
			}
			groups = (gid_t*)stakalloc((maxgroups+1)*sizeof(gid_t));
			n = getgroups(maxgroups,groups);
			while(--n >= 0)
			{
				if(groups[n] == statb.st_gid)
				{
					mode <<= 3;
					break;
				}
			}
		}
#   endif /* _lib_getgroups */
		if(statb.st_mode & mode)
			return(0);
	}
	return(-1);
}

/*@-bounds -boundswrite @*/
static int execCommand(poptContext con)
	/*@globals internalState @*/
	/*@modifies internalState @*/
{
    poptItem item = con->doExec;
    const char ** argv;
    int argc = 0;
    int rc;

    if (item == NULL) /*XXX can't happen*/
	return POPT_ERROR_NOARG;

    if (item->argv == NULL || item->argc < 1 ||
	(!con->execAbsolute && strchr(item->argv[0], '/')))
	    return POPT_ERROR_NOARG;

    argv = malloc(sizeof(*argv) *
			(6 + item->argc + con->numLeftovers + con->finalArgvCount));
    if (argv == NULL) return POPT_ERROR_MALLOC;

    if (!strchr(item->argv[0], '/') && con->execPath != NULL) {
	char *s = alloca(strlen(con->execPath) + strlen(item->argv[0]) + sizeof("/"));
	sprintf(s, "%s/%s", con->execPath, item->argv[0]);
	argv[argc] = s;
    } else
	argv[argc] = findProgramPath(item->argv[0]);
    if (argv[argc++] == NULL) return POPT_ERROR_NOARG;

    if (item->argc > 1) {
	memcpy(argv + argc, item->argv + 1, sizeof(*argv) * (item->argc - 1));
	argc += (item->argc - 1);
    }

    if (con->finalArgv != NULL && con->finalArgvCount > 0) {
	memcpy(argv + argc, con->finalArgv,
		sizeof(*argv) * con->finalArgvCount);
	argc += con->finalArgvCount;
    }

    if (con->leftovers != NULL && con->numLeftovers > 0) {
	memcpy(argv + argc, con->leftovers, sizeof(*argv) * con->numLeftovers);
	argc += con->numLeftovers;
    }

    argv[argc] = NULL;

#if defined(hpux) || defined(__hpux)
    rc = setresgid(getgid(), getgid(),-1);
    if (rc) return POPT_ERROR_ERRNO;
    rc = setresuid(getuid(), getuid(),-1);
    if (rc) return POPT_ERROR_ERRNO;
#else
/*
 * XXX " ... on BSD systems setuid() should be preferred over setreuid()"
 * XXX 	sez' Timur Bakeyev <[email protected]>
 * XXX	from Norbert Warmuth <[email protected]>
 */
#if defined(HAVE_SETUID)
    rc = setgid(getgid());
    if (rc) return POPT_ERROR_ERRNO;
    rc = setuid(getuid());
    if (rc) return POPT_ERROR_ERRNO;
#elif defined (HAVE_SETREUID)
    rc = setregid(getgid(), getgid());
    if (rc) return POPT_ERROR_ERRNO;
    rc = setreuid(getuid(), getuid());
    if (rc) return POPT_ERROR_ERRNO;
#else
    ; /* Can't drop privileges */
#endif
#endif

    if (argv[0] == NULL)
	return POPT_ERROR_NOARG;

#ifdef	MYDEBUG
if (_popt_debug)
    {	const char ** avp;
	fprintf(stderr, "==> execvp(%s) argv[%d]:", argv[0], argc);
	for (avp = argv; *avp; avp++)
	    fprintf(stderr, " '%s'", *avp);
	fprintf(stderr, "\n");
    }
#endif

    rc = execvp(argv[0], (char *const *)argv);

    return POPT_ERROR_ERRNO;
}

//.........这里部分代码省略.........
        if (sleepmode) {
            DPMSEnable(dpy);
            DPMSForceLevel(dpy, DPMSModeOff);
            XFlush(dpy);
        }

        if (update) {
            int x, y, dir, ascent, descent;
            XCharStruct overall;

            XClearWindow(dpy, w);
            XTextExtents (font, passdisp, len, &dir, &ascent, &descent, &overall);
            x = (width - overall.width) / 2;
            y = (height + ascent - descent) / 2;

            XDrawString(dpy,w,gc, (width - XTextWidth(font, username, strlen(username))) / 2 + xshift, y - ascent - 20, username, strlen(username));

            if (showline)
                XDrawLine(dpy, w, gc, width * 3 / 8 + xshift, y - ascent - 10, width * 5 / 8 + xshift, y - ascent - 10);

            XDrawString(dpy,w,gc, x + xshift, y, passdisp, len);
            update = False;
        }

        if (ev.type == MotionNotify) {
            sleepmode = False;
        }

        if(ev.type == KeyPress) {
            sleepmode = False;

            buf[0] = 0;
            num = XLookupString(&ev.xkey, buf, sizeof buf, &ksym, 0);
            if(IsKeypadKey(ksym)) {
                if(ksym == XK_KP_Enter)
                    ksym = XK_Return;
                else if(ksym >= XK_KP_0 && ksym <= XK_KP_9)
                    ksym = (ksym - XK_KP_0) + XK_0;
            }
            if(IsFunctionKey(ksym) || IsKeypadKey(ksym)
                    || IsMiscFunctionKey(ksym) || IsPFKey(ksym)
                    || IsPrivateKeypadKey(ksym))
                continue;

            switch(ksym) {
            case XK_Return:
                passwd[len] = 0;
#ifdef HAVE_BSD_AUTH
                running = !auth_userokay(getlogin(), NULL, "auth-xlock", passwd);
#else
                running = strcmp(crypt(passwd, pws), pws);
#endif
                if (running != 0)
                    // change background on wrong password
                    XSetWindowBackground(dpy, w, red.pixel);
                len = 0;
                break;
            case XK_Escape:
                len = 0;

                if (DPMSCapable(dpy)) {
                    sleepmode = True;
                }

                break;
            case XK_BackSpace:
                if(len)
                    --len;
                break;
            default:
                if(num && !iscntrl((int) buf[0]) && (len + num < sizeof passwd)) {
                    memcpy(passwd + len, buf, num);
                    len += num;
                }

                break;
            }

            update = True; // show changes
        }
    }

    /* free and unlock */
    setreuid(geteuid(), 0);
    if ((ioctl(term, VT_UNLOCKSWITCH)) == -1) {
        perror("error unlocking console");
    }

    close(term);
    setuid(getuid()); // drop rights permanently


    XUngrabPointer(dpy, CurrentTime);
    XFreePixmap(dpy, pmap);
    XFreeFont(dpy, font);
    XFreeGC(dpy, gc);
    XDestroyWindow(dpy, w);
    XCloseDisplay(dpy);
    return 0;
}

int main(int argc, char * argv[])
{
	server_configuration config;
	bzero(&config, sizeof(config));

	if(!network_subsystem_init())
	{
		fprintf(stderr, "Network subsystem init failed.\n");
		return error_network_subsystem;
	}

	if(!read_configuration(argc, argv, &config))
	{
		fprintf(stderr, PROG_NAME ": configuration error! Exit.\n");
		return error_config;
	}

	if(config.discover)
		interfaces_discover(0);

	if(config.print_header_offsets)
	{
		print_dhcp_header_offsets();
		return 0;
	}

	if(!log_init(config.log_file_name,
			(config.debug_mode ? LOG_DEBUG_FLAG : 0) |
			(config.log_stdout ? LOG_STDOUT_FLAG : 0),
			config.uid)
		)
	{
		fprintf(stderr, "Can't open log file.\n");
		return error_log;
	}

	log_wr(ILOG, "Program " PROG_NAME " " PROG_VERS " " PROG_DESC " started.");

	struct sigaction sig_handler_s;
	sig_handler_s.sa_handler = sig_handler;
	sigemptyset(&sig_handler_s.sa_mask);
	sig_handler_s.sa_flags = 0;

	if(config.daemon)
		daemonize();

	/* Init DHCP cache */
	if(config.cache_ttl && !dhcp_cache_init(config.cache_ttl))
	{
		log_wr(CLOG, "Can't init DHCP cache. Exit.");
		return error_abnormal;
	}

	/* STARTING DATABASE CLIENTS */

	/* Create array of childen threads */
	request_handler_thread_t **handler_threads =
		(request_handler_thread_t **) malloc(sizeof(request_handler_thread_t *) * config.db_clients_count);

	CHECK_VALUE(handler_threads, "Can't allocate memory for array of children threads for connecting to DB.",
		error_memory);

	/* Create DHCP messages queue */
	config.dhcp_queue = dhcp_queue_create("DHCP requests", YES, DEFAULT_QUEUE_MAX_SIZE);
	CHECK_VALUE(config.dhcp_queue, "Can't create DHCP queue.", error_queue_init);

	/* Running DB clients */
	CHECK_VALUE(run_requests_handlers(handler_threads, &config), "", error_run_db_clients);

	/* STARTING DHCP PROCESSES  */
	dhcp_proc_thread_t **dhcp_threads =
		(dhcp_proc_thread_t**) malloc(sizeof(dhcp_proc_thread_t *) * config.if_count);

	CHECK_VALUE(dhcp_threads, "Can't allocate memory for array of children threads for "
			"processing DHCP clients.", error_run_dhcp_procs);

	CHECK_VALUE(run_dhcp_threads(dhcp_threads, &config, handler_threads), "", error_run_dhcp_procs);

	/* Set signal handlers */
    if( sigaction(SIGINT, &sig_handler_s, NULL) ||
        sigaction(SIGTERM, &sig_handler_s, NULL) ||
        sigaction(SIGUSR1, &sig_handler_s, NULL))
    {
		log_wr(CLOG, "Can't set signal handlers: '%s'", strerror(errno));
        return error_abnormal;
    }

#ifndef _WIN32
	if(config.uid)
	{
		log_wr(DLOG, "Set effective and real user ID to %u.", config.uid);
		if(setreuid(config.uid, config.uid))
		{
			log_wr(CLOG, "Can't execute setreuid(%u): '%s'", config.uid, strerror(errno));
			return 0;
		}
	}
	else
		log_wr(WLOG, "Running with uid 0 - it is not safe!!! Use configuration directive 'User' for set uid.");
#endif
//.........这里部分代码省略.........

//.........这里部分代码省略.........

	/*
	 * If no pre-authentication and a password exists
	 * for this user, prompt for one and verify it.
	 */
	if (!passwd_req || (pwd && !*pwd->pw_passwd))
	  break;
	
	setpriority(PRIO_PROCESS, 0, -4);
	pp = getpass(_("Password: "));
	
#  ifdef CRYPTOCARD
	if (strncmp(pp, "CRYPTO", 6) == 0) {
	    if (pwd && cryptocard()) break;
	}
#  endif /* CRYPTOCARD */
	
	p = crypt(pp, salt);
	setpriority(PRIO_PROCESS, 0, 0);

#  ifdef KERBEROS
	/*
	 * If not present in pw file, act as we normally would.
	 * If we aren't Kerberos-authenticated, try the normal
	 * pw file for a password.  If that's ok, log the user
	 * in without issueing any tickets.
	 */
	
	if (pwd && !krb_get_lrealm(realm,1)) {
	    /*
	     * get TGT for local realm; be careful about uid's
	     * here for ticket file ownership
	     */
	    setreuid(geteuid(),pwd->pw_uid);
	    kerror = krb_get_pw_in_tkt(pwd->pw_name, "", realm,
				       "krbtgt", realm, DEFAULT_TKT_LIFE, pp);
	    setuid(0);
	    if (kerror == INTK_OK) {
		memset(pp, 0, strlen(pp));
		notickets = 0;	/* user got ticket */
		break;
	    }
	}
#  endif /* KERBEROS */
	memset(pp, 0, strlen(pp));

	if (pwd && !strcmp(p, pwd->pw_passwd))
	  break;
	
	printf(_("Login incorrect\n"));
	badlogin(username); /* log ALL bad logins */
	failures++;
	
	/* we allow 10 tries, but after 3 we start backing off */
	if (++cnt > 3) {
	    if (cnt >= 10) {
		sleepexit(1);
	    }
	    sleep((unsigned int)((cnt - 3) * 5));
	}
    }
#endif /* !HAVE_SECURITY_PAM_MISC_H */
    
    /* committed to login -- turn off timeout */
    alarm((unsigned int)0);
    

int seteuid(uid_t euid)
{
	return (setreuid(-1, euid));
}

int main(int argc, char *argv[])
{
	int tdcount, tlimit, mlimit;
	char exename[1024], inputfile[1024];
	struct rlimit r;

	if (argc < 6)
	{
		printf("Usage: [id] [probid] [input] [time limit] [memory limit]\n");
		exit(RET_SE);
	}

	tlimit = atoi(argv[4]);
	mlimit = atoi(argv[5]);

	sprintf(exename, "./%s", argv[1]);
	strcpy(inputfile, argv[3]);


	if ((pid = fork()) == 0)
	{
		freopen("input.txt", "r", stdin);
		chdir("sandbox");
		chroot(".");
		freopen("output.txt", "w", stdout);
		setregid(99, 99);
		setreuid(99, 99);
		ptrace(PTRACE_TRACEME, 0, NULL, NULL);
		execl(exename, exename, NULL);
		exit(0);
	}
	
	signal(SIGALRM, timer);
	alarm(1);

	int stat, tmpmem, sig;
	for (;;)
	{
		wait4(pid, &stat, 0, &rinfo);
		if (WIFEXITED(stat))
		{
			puts("exited!\n");
			break;
		}
		else if (WIFSTOPPED(stat))
		{
			sig = WSTOPSIG(stat);
			if (sig == SIGTRAP)
			{
					if (checkSyscall() == RET_RF)
					{
						ptrace(PTRACE_KILL, pid, NULL, NULL);
						final_result(RET_RF);
					}
			}
			else if (sig == SIGUSR1)
			{
			}
			else
				printf("Stopped due to signal: %d\n", sig);
		}
		else if (WIFSIGNALED(stat))
		{
			//Runtime Error
			printf("Runtime Error. Received signal: %d\n", WTERMSIG(stat));
			final_result(RET_RE);
			break;
		}
		tmpmem = getMemory();
		if (tmpmem > maxmem) maxmem = tmpmem;

		if (maxmem > mlimit)
			final_result(RET_MLE);
		if (getRuntime() > tlimit)
		{
			ptrace(PTRACE_KILL, pid, NULL, NULL);
			final_result(RET_TLE);
		}
		ptrace(PTRACE_SYSCALL, pid, NULL, NULL);
	}
	final_result(RET_AC);
	
	return 0;
}

void xsetreuid(uid_t ruid, uid_t euid)
{
    if (setreuid(ruid, euid) != 0)
        perror_msg_and_die("Can't set %cid %lu", 'u', (long)ruid);
}