rlogin.c

操作系统源代码

/*
 * Copyright (c) 1983, 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1983, 1990 The Regents of the University of California.\n\
 All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#ifdef ID
static char sccsid[] = "@(#)rlogin.c	5.33 (Berkeley) 3/1/91";
#endif
#endif /* not lint */

/*
 * $Source: mit/rlogin/RCS/rlogin.c,v $
 * $Header: mit/rlogin/RCS/rlogin.c,v 5.2 89/07/26 12:11:21 kfall
 *	Exp Locker: kfall $
 */

/*
 * rlogin - remote login
 */
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/wait.h>

#include <net/netlib.h>
#include <net/hton.h>
#include <net/gen/in.h>
#include <net/gen/netdb.h>
#include <net/gen/tcp.h>
#include <net/gen/tcp_io.h>

#include <termios.h>
#include <setjmp.h>
#include <errno.h>
#include <pwd.h>
#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <assert.h>
#include <ctype.h>
#include <fcntl.h>
#include <signal.h>
#include <stdlib.h>

#if __minix
typedef unsigned char u_char;
#endif

#ifdef KERBEROS
#include <kerberosIV/des.h>
#include <kerberosIV/krb.h>

CREDENTIALS cred;
Key_schedule schedule;
int use_kerberos = 1, doencrypt;
char dst_realm_buf[REALM_SZ], *dest_realm = NULL;
extern char *krb_realmofhost();
#endif

#ifndef TIOCPKT_WINDOW
#define	TIOCPKT_WINDOW	0x80
#endif

/* concession to Sun */
#ifndef SIGUSR1
#define	SIGUSR1	30
#endif

/* standard Minix doesn't really have SIGCHLD */
#if __minix && !__minix_vmd
#undef SIGCHLD
#define SIGCHLD SIGTERM
#endif

extern int errno;
int eight, litout, rem;

int noescape;
u_char escapechar = '~';

struct speed
{
	speed_t speed;
	char *name;
} speeds[] = {
	{ B0, "0" }, { B50, "50" }, { B75, "75" }, { B110, "110" }, 
	{ B134, "134" }, { B150, "150" }, { B200, "200" }, { B300, "300" }, 
	{ B600, "600" }, { B1200, "1200" }, { B1800, "1800" }, 
	{ B2400, "2400" }, { B4800, "4800" }, { B9600, "9600" }, 
	{ B19200, "19200" }, { B38400, "38400" }, { B57600, "57600" },
	{ B115200, "115200" },
	{ -1, NULL },
};

#if __minix_vmd
/* flow control variables */
int more2read_0;
int inprogress_0;
int more2write_1;
int inprogress_1;
int more2read_rem;
int inprogress_rd_rem;
int more2write_rem;
int inprogress_wr_rem;

/* write to remote */
size_t wr_rem_size;
size_t wr_rem_offset;
size_t extra_wr_rem_size;
size_t extra_wr_rem_offset;
char *extra_wr_rem;
size_t extra_wr_rem_new_size;
char *extra_wr_rem_new;

#endif /* __minix_vmd */

struct	winsize winsize;

#define	get_window_size(fd, wp)	ioctl(fd, TIOCGWINSZ, wp)

extern int main _ARGS(( int argc, char **argv ));
static void usage _ARGS(( void ));
static u_char getescape _ARGS(( char *p ));
static char *speeds2str _ARGS(( speed_t speed ));
static void lostpeer _ARGS(( int sig ));
static void doit _ARGS(( void ));
static void setsignal _ARGS(( int sig, void (*act)(int sig) ));
static void msg _ARGS(( char *str ));
static void done _ARGS(( int status ));
#if !__minix_vmd
static int reader _ARGS(( void ));
#endif
static void mode _ARGS(( int f ));
#if __minix_vmd
static void mark_async _ARGS(( int fd ));
static void init_0 _ARGS(( void ));
static void init_1 _ARGS(( void ));
static void init_rd_rem _ARGS(( void ));
static void init_wr_rem _ARGS(( void ));
static void restart_0 _ARGS(( void ));
static void restart_1 _ARGS(( void ));
static void restart_rd_rem _ARGS(( void ));
static void restart_wr_rem _ARGS(( void ));
static void completed_0 _ARGS(( int result, int error ));
static void completed_1 _ARGS(( int result, int error ));
static void completed_rd_rem _ARGS(( int result, int error ));
static void completed_wr_rem _ARGS(( int result, int error ));
static void do_urg _ARGS(( int urg_byte ));
#endif
#if !__minix_vmd
static void catch_child _ARGS(( int sig ));
static void writer _ARGS(( void ));
#endif
static void echo _ARGS(( int c ));
#if __minix_vmd
static void finish _ARGS(( void ));
static void sendwindow _ARGS(( void ));
static void sigwinch _ARGS(( int sig ));
static void subshell _ARGS(( void ));
#endif

int main(argc, argv)
	int argc;
	char **argv;
{
	extern char *optarg;
	extern int optind;
	struct passwd *pw;
	struct servent *sp;
	struct termios ttyb;
#if __minix_vmd
	nwio_tcpopt_t tcpopt;
	int error;
#endif
	int argoff, ch, dflag, one, uid;
	char *host, *p, *user, term[1024];

	argoff = dflag = 0;
	one = 1;
	host = user = NULL;

	if (p = rindex(argv[0], '/'))
		++p;
	else
		p = argv[0];

	if (strcmp(p, "rlogin"))
		host = p;

	/* handle "rlogin host flags" */
	if (!host && argc > 2 && argv[1][0] != '-') {
		host = argv[1];
		argoff = 1;
	}

#ifdef KERBEROS
#define	OPTIONS	"8EKLde:k:l:x"
#else
#define	OPTIONS	"8EKLde:l:"
#endif
	while ((ch = getopt(argc - argoff, argv + argoff, OPTIONS)) != EOF)
		switch(ch) {
		case '8':
			eight = 1;
			break;
		case 'E':
			noescape = 1;
			break;
		case 'K':
#ifdef KERBEROS
			use_kerberos = 0;
#endif
			break;
		case 'L':
			litout = 1;
			break;
		case 'd':
			dflag = 1;
			break;
		case 'e':
			escapechar = getescape(optarg);
			break;
#ifdef KERBEROS
		case 'k':
			dest_realm = dst_realm_buf;
			(void)strncpy(dest_realm, optarg, REALM_SZ);
			break;
#endif
		case 'l':
			user = optarg;
			break;
#ifdef CRYPT
#ifdef KERBEROS
		case 'x':
			doencrypt = 1;
			des_set_key(cred.session, schedule);
			break;
#endif
#endif
		case '?':
		default:
			usage();
		}
	optind += argoff;
	argc -= optind;
	argv += optind;

	/* if haven't gotten a host yet, do so */
	if (!host && !(host = *argv++))
		usage();

	if (*argv)
		usage();

	if (!(pw = getpwuid(uid = getuid()))) {
		(void)fprintf(stderr, "rlogin: unknown user id.\n");
		exit(1);
	}
	if (!user)
		user = pw->pw_name;

	sp = NULL;
#ifdef KERBEROS
	if (use_kerberos) {
		sp = getservbyname((doencrypt ? "eklogin" : "klogin"), "tcp");
		if (sp == NULL) {
			use_kerberos = 0;
			warning("can't get entry for %s/tcp service",
			    doencrypt ? "eklogin" : "klogin");
		}
	}
#endif
	if (sp == NULL)
		sp = getservbyname("login", "tcp");
	if (sp == NULL) {
		(void)fprintf(stderr, "rlogin: login/tcp: unknown service.\n");
		exit(1);
	}

	(void)strcpy(term, (p = getenv("TERM")) ? p : "network");

	if (tcgetattr(0, &ttyb) == 0) {
		(void)strcat(term, "/");
		(void)strcat(term, speeds2str(cfgetospeed(&ttyb)));
	}

	(void)get_window_size(0, &winsize);

	(void)signal(SIGPIPE, lostpeer);

#ifdef KERBEROS
try_connect:
	if (use_kerberos) {
		rem = KSUCCESS;
		errno = 0;
		if (dest_realm == NULL)
			dest_realm = krb_realmofhost(host);

#ifdef CRYPT
		if (doencrypt)
			rem = krcmd_mutual(&host, sp->s_port, user, term, 0,
			    dest_realm, &cred, schedule);
		else
#endif /* CRYPT */
			rem = krcmd(&host, sp->s_port, user, term, 0,
			    dest_realm);
		if (rem < 0) {
			use_kerberos = 0;
			sp = getservbyname("login", "tcp");
			if (sp == NULL) {
				(void)fprintf(stderr,
				    "rlogin: unknown service login/tcp.\n");
				exit(1);
			}
			if (errno == ECONNREFUSED)
				warning("remote host doesn't support Kerberos");
			if (errno == ENOENT)
				warning("can't provide Kerberos auth data");
			goto try_connect;
		}
	} else {
#ifdef CRYPT
		if (doencrypt) {
			(void)fprintf(stderr,
			    "rlogin: the -x flag requires Kerberos authentication.\n");
			exit(1);
		}
#endif /* CRYPT */
		rem = rcmd(&host, sp->s_port, pw->pw_name, user, term, 0);
	}
#else
	rem = rcmd(&host, sp->s_port, pw->pw_name, user, term, 0);
#endif /* KERBEROS */

	if (rem < 0)
		exit(1);

#if __minix_vmd
	/* Enable BSD compatibility for urgent data. */
	tcpopt.nwto_flags= NWTO_BSD_URG;
	error= ioctl(rem, NWIOSTCPOPT, &tcpopt);
	if (error == -1)
	{
		fprintf(stderr, "rlogin: NWIOSTCPOPT failed: %s\n",
			strerror(errno));
	}
#endif

	(void)setuid(uid);
	doit();
	/*NOTREACHED*/
}

struct termios defattr, rawattr;
#if __minix_vmd
int mustsendwindow;
#else
int child;
#endif

static void
doit()
{
	struct termios sb;
#if !__minix_vmd
	int r;
#else
	asio_fd_set_t fd_set;
	struct fwait fw;
	int result;
#endif

	(void)tcgetattr(0, &sb);
	defattr = sb;
	rawattr = sb;

	rawattr.c_iflag &= ~(ICRNL | IGNCR | INLCR | ISTRIP | IXOFF | IXON | 
							PARMRK | IXANY);
	rawattr.c_oflag &= ~(OPOST);
	rawattr.c_lflag &= ~(ECHONL | ECHO | ICANON | IEXTEN | ISIG);

	(void)signal(SIGINT, SIG_IGN);
	setsignal(SIGHUP, exit);
	setsignal(SIGQUIT, exit);

#if !__minix_vmd
	child = fork();
	if (child == -1) {
		(void)fprintf(stderr, "rlogin: fork: %s.\n", strerror(errno));
		done(1);
	}
	if (child == 0) {
		mode(1);
		r = reader();
		if (r == 0) {
			msg("connection closed.");
#if __minix && !__minix_vmd
			kill(getppid(), SIGCHLD);
#endif
			exit(0);
		}
		sleep(1);
		msg("\007connection closed.");
#if __minix && !__minix_vmd
		kill(getppid(), SIGCHLD);
#endif
		exit(1);
	}

	(void)signal(SIGCHLD, catch_child);
	writer();

#else /* __minix_vmd */

	mode(1);
	/* mark the file descriptors 0, 1, and rem as asynchronous. */
	mark_async(0);
	mark_async(1);
	mark_async(rem);
	init_0();
	init_1();
	init_rd_rem();
	init_wr_rem();

	for (;;)
	{
		ASIO_FD_ZERO(&fd_set);
		fw.fw_flags= 0;
		fw.fw_bits= fd_set.afds_bits;
		fw.fw_maxfd= ASIO_FD_SETSIZE;

		if (more2read_0 && !inprogress_0)
		{
			restart_0();
			fw.fw_flags |= FWF_NONBLOCK;
		}

		if (more2write_1 && !inprogress_1)
		{
			restart_1();
			fw.fw_flags |= FWF_NONBLOCK;
		}

		if (more2read_rem && !inprogress_rd_rem)
		{
			restart_rd_rem();
			fw.fw_flags |= FWF_NONBLOCK;
		}

		if (more2write_rem && !inprogress_wr_rem)
		{
			restart_wr_rem();
			fw.fw_flags |= FWF_NONBLOCK;
		}

		if (more2read_0 && inprogress_0)
			ASIO_FD_SET(0, ASIO_READ, &fd_set);
		if (more2write_1 && inprogress_1)
			ASIO_FD_SET(1, ASIO_WRITE, &fd_set);
		if (more2read_rem && inprogress_rd_rem)
			ASIO_FD_SET(rem, ASIO_READ, &fd_set);
		if (more2write_rem && inprogress_wr_rem)
			ASIO_FD_SET(rem, ASIO_WRITE, &fd_set);

		for (;;)
		{
			result= fwait(&fw);
			if (result == -1 && (errno == EAGAIN || 
							errno == EINTR))
			{
				break;
			}
			if (result == -1)
			{
				fprintf(stderr, "fwait failed (%s)\n", 
							strerror(errno));
				exit(1);
			}
			assert(result == 0);
#if 0
printf("fwait: fw_fw= %d, fw_operation= %d, fw_result= %d, fw.fw_errno= %d\n",
	fw.fw_fd, fw.fw_operation, fw.fw_result, fw.fw_errno);
#endif
			if (fw.fw_fd == 0 && fw.fw_operation == ASIO_READ)
			{
				completed_0(fw.fw_result, fw.fw_errno);
			}
			else if (fw.fw_fd == 1 && 
					fw.fw_operation == ASIO_WRITE)
			{
				completed_1(fw.fw_result, fw.fw_errno);
			}
			else if (fw.fw_fd == rem && 
					fw.fw_operation == ASIO_READ)
			{
				completed_rd_rem(fw.fw_result, fw.fw_errno);
			}
			else if (fw.fw_fd == rem && 
					fw.fw_operation == ASIO_WRITE)
			{
				completed_wr_rem(fw.fw_result, fw.fw_errno);
			}
			else
			{
				fprintf(stderr,
			"strange result from fwait: fd= %d, operation= %d\n",
					fw.fw_fd, fw.fw_operation);
				exit(1);
			}
			if (!(fw.fw_flags & FWF_MORE))
				break;
		}
		if (mustsendwindow)
		{
			mustsendwindow= 0;
			sendwindow();
		}
	}
#endif /* __minix_vmd */
	msg("connection closed.");
	done(0);
}

/* trap a signal, unless it is being ignored. */
static void
setsignal(sig, act)
	int sig;
	void (*act) _ARGS(( int sig ));
{
	if (signal(sig, act) == SIG_IGN)
		(void)signal(sig, SIG_IGN);
}

static void
done(status)
	int status;
{
	int w, wstatus;

	mode(0);
#if !__minix_vmd
	if (child > 0) {
		/* make sure catch_child does not snap it up */
		(void)signal(SIGCHLD, SIG_DFL);
		if (kill(child, SIGKILL) >= 0)
			while ((w = wait(&wstatus)) > 0 && w != child);
	}
#endif
	exit(status);
}

int dosigwinch;
#if !__minix
void sigwinch();
#endif