sys_term.c

早期freebsd实现

	request.signal = SIGCLD;
	request.pid = getpid();
#endif
#ifdef BFTPDAEMON
	/*
	 * Are we working as the bftp daemon?
	 */
	if (bftpd) {
		SCPYN(request.exec_name, BFTPPATH);
	}
#endif /* BFTPDAEMON */
	if (write(i, (char *)&request, sizeof(request)) < 0) {
		char tbuf[128];
		(void) sprintf(tbuf, "Can't write to %s\n", INIT_FIFO);
		fatalperror(net, tbuf);
	}
	(void) close(i);
	(void) signal(SIGALRM, nologinproc);
	for (i = 0; ; i++) {
		char tbuf[128];
		alarm(15);
		n = read(pty, ptyip, BUFSIZ);
		if (i == 3 || n >= 0 || !gotalarm)
			break;
		gotalarm = 0;
		sprintf(tbuf, "telnetd: waiting for /etc/init to start login process on %s\r\n", line);
		(void) write(net, tbuf, strlen(tbuf));
	}
	if (n < 0 && gotalarm)
		fatal(net, "/etc/init didn't start login process");
	pcc += n;
	alarm(0);
	(void) signal(SIGALRM, SIG_DFL);

	return;
#endif	/* NEWINIT */
}

char	*envinit[3];
extern char **environ;

	void
init_env()
{
	extern char *getenv();
	char **envp;

	envp = envinit;
	if (*envp = getenv("TZ"))
		*envp++ -= 3;
#if	defined(CRAY) || defined(__hpux)
	else
		*envp++ = "TZ=GMT0";
#endif
	*envp = 0;
	environ = envinit;
}

#ifndef	NEWINIT

/*
 * start_login(host)
 *
 * Assuming that we are now running as a child processes, this
 * function will turn us into the login process.
 */

	void
start_login(host, autologin, name)
	char *host;
	int autologin;
	char *name;
{
	register char *cp;
	register char **argv;
	char **addarg();
	extern char *getenv();
#ifdef	UTMPX
	register int pid = getpid();
	struct utmpx utmpx;
#endif
#ifdef SOLARIS
	char *term;
	char termbuf[64];
#endif

#ifdef	UTMPX
	/*
	 * Create utmp entry for child
	 */

	bzero(&utmpx, sizeof(utmpx));
	SCPYN(utmpx.ut_user, ".telnet");
	SCPYN(utmpx.ut_line, line + sizeof("/dev/") - 1);
	utmpx.ut_pid = pid;
	utmpx.ut_id[0] = 't';
	utmpx.ut_id[1] = 'n';
	utmpx.ut_id[2] = SC_WILDC;
	utmpx.ut_id[3] = SC_WILDC;
	utmpx.ut_type = LOGIN_PROCESS;
	(void) time(&utmpx.ut_tv.tv_sec);
	if (makeutx(&utmpx) == NULL)
		fatal(net, "makeutx failed");
#endif

	/*
	 * -h : pass on name of host.
	 *		WARNING:  -h is accepted by login if and only if
	 *			getuid() == 0.
	 * -p : don't clobber the environment (so terminal type stays set).
	 *
	 * -f : force this login, he has already been authenticated
	 */
	argv = addarg(0, "login");

#if	!defined(NO_LOGIN_H)

# if	defined (AUTHENTICATION) && defined(NO_LOGIN_F) && defined(LOGIN_R)
	/*
	 * Don't add the "-h host" option if we are going
	 * to be adding the "-r host" option down below...
	 */
	if ((auth_level < 0) || (autologin != AUTH_VALID))
# endif
	{
		argv = addarg(argv, "-h");
		argv = addarg(argv, host);
#ifdef	SOLARIS
		/*
		 * SVR4 version of -h takes TERM= as second arg, or -
		 */
		term = getenv("TERM");
		if (term == NULL || term[0] == 0) {
			term = "-";
		} else {
			strcpy(termbuf, "TERM=");
			strncat(termbuf, term, sizeof(termbuf) - 6);
			term = termbuf;
		}
		argv = addarg(argv, term);
#endif
	}
#endif
#if	!defined(NO_LOGIN_P)
	argv = addarg(argv, "-p");
#endif
#ifdef	BFTPDAEMON
	/*
	 * Are we working as the bftp daemon?  If so, then ask login
	 * to start bftp instead of shell.
	 */
	if (bftpd) {
		argv = addarg(argv, "-e");
		argv = addarg(argv, BFTPPATH);
	} else 
#endif
#if	defined (SecurID)
	/*
	 * don't worry about the -f that might get sent.
	 * A -s is supposed to override it anyhow.
	 */
	if (require_SecurID)
		argv = addarg(argv, "-s");
#endif
#if	defined (AUTHENTICATION)
	if (auth_level >= 0 && autologin == AUTH_VALID) {
# if	!defined(NO_LOGIN_F)
		argv = addarg(argv, "-f");
		argv = addarg(argv, name);
# else
#  if defined(LOGIN_R)
		/*
		 * We don't have support for "login -f", but we
		 * can fool /bin/login into thinking that we are
		 * rlogind, and allow us to log in without a
		 * password.  The rlogin protocol expects
		 *	local-user\0remote-user\0term/speed\0
		 */

		if (pty > 2) {
			register char *cp;
			char speed[128];
			int isecho, israw, xpty, len;
			extern int def_rspeed;
#  ifndef LOGIN_HOST
			/*
			 * Tell login that we are coming from "localhost".
			 * If we passed in the real host name, then the
			 * user would have to allow .rhost access from
			 * every machine that they want authenticated
			 * access to work from, which sort of defeats
			 * the purpose of an authenticated login...
			 * So, we tell login that the session is coming
			 * from "localhost", and the user will only have
			 * to have "localhost" in their .rhost file.
			 */
#			define LOGIN_HOST "localhost"
#  endif
			argv = addarg(argv, "-r");
			argv = addarg(argv, LOGIN_HOST);

			xpty = pty;
# ifndef  STREAMSPTY
			pty = 0;
# else
			ttyfd = 0;
# endif
			init_termbuf();
			isecho = tty_isecho();
			israw = tty_israw();
			if (isecho || !israw) {
				tty_setecho(0);		/* Turn off echo */
				tty_setraw(1);		/* Turn on raw */
				set_termbuf();
			}
			len = strlen(name)+1;
			write(xpty, name, len);
			write(xpty, name, len);
			sprintf(speed, "%s/%d", (cp = getenv("TERM")) ? cp : "",
				(def_rspeed > 0) ? def_rspeed : 9600);
			len = strlen(speed)+1;
			write(xpty, speed, len);

			if (isecho || !israw) {
				init_termbuf();
				tty_setecho(isecho);
				tty_setraw(israw);
				set_termbuf();
				if (!israw) {
					/*
					 * Write a newline to ensure
					 * that login will be able to
					 * read the line...
					 */
					write(xpty, "\n", 1);
				}
			}
			pty = xpty;
		}
#  else
		argv = addarg(argv, name);
#  endif
# endif
	} else
#endif
	if (getenv("USER")) {
		argv = addarg(argv, getenv("USER"));
#if	defined(LOGIN_ARGS) && defined(NO_LOGIN_P)
		{
			register char **cpp;
			for (cpp = environ; *cpp; cpp++)
				argv = addarg(argv, *cpp);
		}
#endif
		/*
		 * Assume that login will set the USER variable
		 * correctly.  For SysV systems, this means that
		 * USER will no longer be set, just LOGNAME by
		 * login.  (The problem is that if the auto-login
		 * fails, and the user then specifies a different
		 * account name, he can get logged in with both
		 * LOGNAME and USER in his environment, but the
		 * USER value will be wrong.
		 */
		unsetenv("USER");
	}
#if	defined(AUTHENTICATION) && defined(NO_LOGIN_F) && defined(LOGIN_R)
	if (pty > 2)
		close(pty);
#endif
	closelog();
	execv(_PATH_LOGIN, argv);

	syslog(LOG_ERR, "%s: %m\n", _PATH_LOGIN);
	fatalperror(net, _PATH_LOGIN);
	/*NOTREACHED*/
}

	char **
addarg(argv, val)
	register char **argv;
	register char *val;
{
	register char **cpp;

	if (argv == NULL) {
		/*
		 * 10 entries, a leading length, and a null
		 */
		argv = (char **)malloc(sizeof(*argv) * 12);
		if (argv == NULL)
			return(NULL);
		*argv++ = (char *)10;
		*argv = (char *)0;
	}
	for (cpp = argv; *cpp; cpp++)
		;
	if (cpp == &argv[(int)argv[-1]]) {
		--argv;
		*argv = (char *)((int)(*argv) + 10);
		argv = (char **)realloc(argv, (int)(*argv) + 2);
		if (argv == NULL)
			return(NULL);
		argv++;
		cpp = &argv[(int)argv[-1] - 10];
	}
	*cpp++ = val;
	*cpp = 0;
	return(argv);
}
#endif	/* NEWINIT */

/*
 * cleanup()
 *
 * This is the routine to call when we are all through, to
 * clean up anything that needs to be cleaned up.
 */
	/* ARGSUSED */
	void
cleanup(sig)
	int sig;
{
#ifndef	PARENT_DOES_UTMP
# if (BSD > 43) || defined(convex)
	char *p;

	p = line + sizeof("/dev/") - 1;
	if (logout(p))
		logwtmp(p, "", "");
	(void)chmod(line, 0666);
	(void)chown(line, 0, 0);
	*p = 'p';
	(void)chmod(line, 0666);
	(void)chown(line, 0, 0);
	(void) shutdown(net, 2);
	exit(1);
# else
	void rmut();

	rmut();
	vhangup();	/* XXX */
	(void) shutdown(net, 2);
	exit(1);
# endif
#else	/* PARENT_DOES_UTMP */
# ifdef	NEWINIT
	(void) shutdown(net, 2);
	exit(1);
# else	/* NEWINIT */
#  ifdef CRAY
	static int incleanup = 0;
	register int t;

	/*
	 * 1: Pick up the zombie, if we are being called
	 *    as the signal handler.
	 * 2: If we are a nested cleanup(), return.
	 * 3: Try to clean up TMPDIR.
	 * 4: Fill in utmp with shutdown of process.
	 * 5: Close down the network and pty connections.
	 * 6: Finish up the TMPDIR cleanup, if needed.
	 */
	if (sig == SIGCHLD)
		while (waitpid(-1, 0, WNOHANG) > 0)
			;	/* VOID */
	t = sigblock(sigmask(SIGCHLD));
	if (incleanup) {
		sigsetmask(t);
		return;
	}
	incleanup = 1;
	sigsetmask(t);
	if (secflag) {
		/*
		 *	We need to set ourselves back to a null
		 *	label to clean up.
		 */

		setulvl(sysv.sy_minlvl);
		setucmp((long)0);
	}

	t = cleantmp(&wtmp);
	setutent();	/* just to make sure */
#  endif /* CRAY */
	rmut(line);
	close(pty);
	(void) shutdown(net, 2);
#  ifdef CRAY
	if (t == 0)
		cleantmp(&wtmp);
#  endif /* CRAY */
	exit(1);
# endif	/* NEWINT */
#endif	/* PARENT_DOES_UTMP */
}

#if defined(PARENT_DOES_UTMP) && !defined(NEWINIT)
/*
 * _utmp_sig_rcv
 * utmp_sig_init
 * utmp_sig_wait
 *	These three functions are used to coordinate the handling of
 *	the utmp file between the server and the soon-to-be-login shell.
 *	The server actually creates the utmp structure, the child calls
 *	utmp_sig_wait(), until the server calls utmp_sig_notify() and
 *	signals the future-login shell to proceed.
 */
static int caught=0;		/* NZ when signal intercepted */
static void (*func)();		/* address of previous handler */

	void
_utmp_sig_rcv(sig)
	int sig;
{
	caught = 1;
	(void) signal(SIGUSR1, func);
}

	void
utmp_sig_init()
{
	/*
	 * register signal handler for UTMP creation
	 */
	if ((int)(func = signal(SIGUSR1, _utmp_sig_rcv)) == -1)
		fatalperror(net, "telnetd/signal");
}

	void
utmp_sig_reset()
{
	(void) signal(SIGUSR1, func);	/* reset handler to default */
}

# ifdef __hpux
# define sigoff() /* do nothing */
# define sigon() /* do nothing */
# endif

	void
utmp_sig_wait()
{
	/*
	 * Wait for parent to write our utmp entry.
	 */
	sigoff();
	while (caught == 0) {
		pause();	/* wait until we get a signal (sigon) */
		sigoff();	/* turn off signals while we check caught */
	}
	sigon();		/* turn on signals again */
}

	void
utmp_sig_notify(pid)
{
	kill(pid, SIGUSR1);
}

# ifdef CRAY
static int gotsigjob = 0;

	/*ARGSUSED*/
	void
sigjob(sig)
	int sig;
{
	register int jid;
	register struct jobtemp *jp;

	while ((jid = waitjob(NULL)) != -1) {
		if (jid == 0) {
			return;
		}
		gotsigjob++;
		jobend(jid, NULL, NULL);
	}
}

/*
 * Clean up the TMPDIR that login created.
 * The first time this is called we pick up the info
 * from the utmp.  If the job has already gone away,
 * then we'll clean up and be done.  If not, then
 * when this is called the second time it will wait
 * for the signal that the job is done.
 */
	int
cleantmp(wtp)
	register struct utmp *wtp;
{
	struct utmp *utp;
	static int first = 1;
	register int mask, omask, ret;
	extern struct utmp *getutid P((const struct utmp *_Id));


	mask = sigmask(WJSIGNAL);

	if (first == 0) {
		omask = sigblock(mask);
		while (gotsigjob == 0)
			sigpause(omask);
		return(1);
	}
	first = 0;
	setutent();	/* just to make sure */

	utp = getutid(wtp);
	if (utp == 0) {
		syslog(LOG_ERR, "Can't get /etc/utmp entry to clean TMPDIR");
		return(-1);
	}
	/*
	 * Nothing to clean up if the user shell was never started.
	 */
	if (utp->ut_type != USER_PROCESS || utp->ut_jid == 0)
		return(1);

	/*
	 * Block the WJSIGNAL while we are in jobend().
	 */
	omask = sigblock(mask);
	ret = jobend(utp->ut_jid, utp->ut_tpath, utp->ut_user);
	sigsetmask(omask);
	return(ret);
}

	int
jobend(jid, path, user)
	register int jid;
	register char *path;
	register char *user;
{
	static int saved_jid = 0;
	static char saved_path[sizeof(wtmp.ut_tpath)+1];
	static char saved_user[sizeof(wtmp.ut_user)+1];

	if (path) {
		strncpy(saved_path, path, sizeof(wtmp.ut_tpath));
		strncpy(saved_user, user, sizeof(wtmp.ut_user));
		saved_path[sizeof(saved_path)] = '\0';
		saved_user[sizeof(saved_user)] = '\0';
	}
	if (saved_jid == 0) {
		saved_jid = jid;
		return(0);
	}
	cleantmpdir(jid, saved_path, saved_user);
	return(1);
}

/*
 * Fork a child process to clean up the TMPDIR
 */
cleantmpdir(jid, tpath, user)
	register int jid;
	register char *tpath;
	register char *user;
{
	switch(fork()) {
	case -1:
		syslog(LOG_ERR, "TMPDIR cleanup(%s): fork() failed: %m\n",
							tpath);
		break;
	case 0:
		execl(CLEANTMPCMD, CLEANTMPCMD, user, tpath, 0);
		syslog(LOG_ERR, "TMPDIR cleanup(%s): execl(%s) failed: %m\n",
							tpath, CLEANTMPCMD);
		exit(1);
	default:
		/*
		 * Forget about child.  We will exit, and
		 * /etc/init will pick it up.
		 */
		break;
	}
}
# endif /* CRAY */
#endif	/* defined(PARENT_DOES_UTMP) && !defined(NEWINIT) */

/*
 * rmut()
 *
 * This is the function called by cleanup() to
 * remove the utmp entry for this person.
 */

#ifdef	UTMPX
	void
rmut()
{
	register f;
	int found = 0;
	struct utmp *u, *utmp;
	int nutmp;
	struct stat statbf;

	struct utmpx *utxp, utmpx;

	/*
	 * This updates the utmpx and utmp entries and make a wtmp/x entry
	 */

	SCPYN(utmpx.ut_line, line + sizeof("/dev/") - 1);
	utxp = getutxline(&utmpx);
	if (utxp) {
		utxp->ut_type = DEAD_PROCESS;
		utxp->ut_exit.e_termination = 0;
		utxp->ut_exit.e_exit = 0;
		(void) time(&utmpx.ut_tv.tv_sec);
		utmpx.ut_tv.tv_usec = 0;
		modutx(utxp);
	}
	endutxent();
}  /* end of rmut */
#endif

#if	!defined(UTMPX) && !(defined(CRAY) || defined(__hpux)) && BSD <= 43
	void
rmut()
{
	register f;
	int found = 0;
	struct utmp *u, *utmp;
	int nutmp;
	struct stat statbf;

	f = open(utmpf, O_RDWR);
	if (f >= 0) {
		(void) fstat(f, &statbf);
		utmp = (struct utmp *)malloc((unsigned)statbf.st_size);
		if (!utmp)
			syslog(LOG_ERR, "utmp malloc failed");
		if (statbf.st_size && utmp) {
			nutmp = read(f, (char *)utmp, (int)statbf.st_size);
			nutmp /= sizeof(struct utmp);
		
			for (u = utmp ; u < &utmp[nutmp] ; u++) {
				if (SCMPN(u->ut_line, line+5) ||
				    u->ut_name[0]==0)
					continue;
				(void) lseek(f, ((long)u)-((long)utmp), L_SET);
				SCPYN(u->ut_name, "");
				SCPYN(u->ut_host, "");
				(void) time(&u->ut_time);
				(void) write(f, (char *)u, sizeof(wtmp));
				found++;
			}
		}
		(void) close(f);
	}
	if (found) {
		f = open(wtmpf, O_WRONLY|O_APPEND);
		if (f >= 0) {
			SCPYN(wtmp.ut_line, line+5);
			SCPYN(wtmp.ut_name, "");
			SCPYN(wtmp.ut_host, "");
			(void) time(&wtmp.ut_time);
			(void) write(f, (char *)&wtmp, sizeof(wtmp));
			(void) close(f);
		}
	}
	(void) chmod(line, 0666);
	(void) chown(line, 0, 0);
	line[strlen("/dev/")] = 'p';
	(void) chmod(line, 0666);
	(void) chown(line, 0, 0);
}  /* end of rmut */
#endif	/* CRAY */

#ifdef __hpux
rmut (line)
char *line;
{
	struct utmp utmp;
	struct utmp *utptr;
	int fd;			/* for /etc/wtmp */

	utmp.ut_type = USER_PROCESS;
	(void) strncpy(utmp.ut_id, line+12, sizeof(utmp.ut_id));
	(void) setutent();
	utptr = getutid(&utmp);
	/* write it out only if it exists */
	if (utptr) {
		utptr->ut_type = DEAD_PROCESS;
		utptr->ut_time = time((long *) 0);
		(void) pututline(utptr);
		/* set wtmp entry if wtmp file exists */
		if ((fd = open(wtmpf, O_WRONLY | O_APPEND)) >= 0) {
			(void) write(fd, utptr, sizeof(utmp));
			(void) close(fd);
		}
	}
	(void) endutent();

	(void) chmod(line, 0666);
	(void) chown(line, 0, 0);
	line[14] = line[13];
	line[13] = line[12];
	line[8] = 'm';
	line[9] = '/';
	line[10] = 'p';
	line[11] = 't';
	line[12] = 'y';
	(void) chmod(line, 0666);
	(void) chown(line, 0, 0);
}
#endif