Import a few relatively minor fixes from current Borman telnet.

Add some buffer overrun fixes from OpenBSD and myself.
Add skey calculator kludge from OpenBSD.

TODO: do a real merge of dab's sources... probably just make telnet and
	telnetd contrib software.

Obtained from: OpenBSD, dab@bsdi.com

usr.bin/telnet/Makefile

@@ -37,6 +37,7 @@ PROG=	telnet
 
 CFLAGS+=-DTERMCAP -DKLUDGELINEMODE -DUSE_TERMIO #-DAUTHENTICATION -DENCRYPTION
 CFLAGS+=-DENV_HACK
+CFLAGS+=-DPATH_SKEY
 CFLAGS+=-I${.CURDIR}/../../lib
 
 #CFLAGS+= -DKRB4

usr.bin/telnet/commands.c

@@ -107,6 +107,37 @@ static char saveline[256];
 static int margc;
 static char *margv[20];
 
+#if	defined(SKEY)
+#include <sys/wait.h>
+#define PATH_SKEY	"/usr/bin/key"
+    int
+skey_calc(argc, argv)
+	int argc;
+	char **argv;
+{
+	int status;
+
+	if(argc != 3) {
+		printf("%s sequence challenge\n", argv[0]);
+		return;
+	}
+
+	switch(fork()) {
+	case 0:
+		execv(PATH_SKEY, argv);
+		exit (1);
+	case -1:
+		perror("fork");
+		break;
+	default:
+		(void) wait(&status);
+		if (WIFEXITED(status))
+			return (WEXITSTATUS(status));
+		return (0);
+	}
+}
+#endif
+
     static void
 makeargv()
 {
@@ -499,7 +530,7 @@ togdebug()
     }
 #else	/* NOT43 */
     if (debug) {
-	if (net > 0 && SetSockOpt(net, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
+	if (net > 0 && SetSockOpt(net, SOL_SOCKET, SO_DEBUG, 1) < 0)
 	    perror("setsockopt (SO_DEBUG)");
     } else
 	printf("Cannot turn off socket debugging\n");
@@ -2153,20 +2184,25 @@ tn(argc, argv)
     } else {
 #endif
 	temp = inet_addr(hostp);
-	if (temp != (unsigned long) -1) {
+	if (temp != INADDR_NONE) {
 	    sin.sin_addr.s_addr = temp;
 	    sin.sin_family = AF_INET;
-	    (void) strcpy(_hostname, hostp);
+	    host = gethostbyaddr((char *)&temp, sizeof(temp), AF_INET);
+	    if (host)
+	        (void) strncpy(_hostname, host->h_name, sizeof(_hostname));
+	    else
+		(void) strncpy(_hostname, hostp, sizeof(_hostname));
+	    _hostname[sizeof(_hostname)-1] = '\0';
 	    hostname = _hostname;
 	} else {
 	    host = gethostbyname(hostp);
 	    if (host) {
 		sin.sin_family = host->h_addrtype;
 #if	defined(h_addr)		/* In 4.3, this is a #define */
-		memcpy((caddr_t)&sin.sin_addr,
+		memmove((caddr_t)&sin.sin_addr,
 				host->h_addr_list[0], host->h_length);
 #else	/* defined(h_addr) */
-		memcpy((caddr_t)&sin.sin_addr, host->h_addr, host->h_length);
+		memmove((caddr_t)&sin.sin_addr, host->h_addr, host->h_length);
 #endif	/* defined(h_addr) */
 		strncpy(_hostname, host->h_name, sizeof(_hostname));
 		_hostname[sizeof(_hostname)-1] = '\0';
@@ -2356,6 +2392,9 @@ static Command cmdtab[] = {
 #endif
 	{ "environ",	envhelp,	env_cmd,	0 },
 	{ "?",		helphelp,	help,		0 },
+#if	defined(SKEY)
+	{ "skey",	NULL,		skey_calc,	0 },
+#endif		
 	0
 };
 
@@ -2541,7 +2580,7 @@ cmdrc(m1, m2)
 
     if (rcname == 0) {
 	rcname = getenv("HOME");
-	if (rcname)
+	if (rcname && (strlen(rcname) + 10) < sizeof(rcbuf))
 	    strcpy(rcbuf, rcname);
 	else
 	    rcbuf[0] = '\0';

usr.bin/telnet/externs.h

@@ -144,7 +144,8 @@ extern int
 #endif	/* defined(TN3270) */
     termdata,		/* Print out terminal data flow */
 #endif	/* defined(unix) */
-    debug;			/* Debug level */
+    debug,		/* Debug level */
+    clienteof;		/* Client received EOF */
 
 extern cc_t escape;	/* Escape to command mode */
 extern cc_t rlogin;	/* Rlogin mode escape character */

usr.bin/telnet/sys_bsd.c

@@ -48,6 +48,7 @@ static char sccsid[] = "@(#)sys_bsd.c	8.2 (Berkeley) 12/15/93";
 #include <signal.h>
 #include <errno.h>
 #include <arpa/telnet.h>
+#include <unistd.h>
 
 #include "ring.h"
 
@@ -1150,17 +1151,24 @@ process_rings(netin, netout, netex, ttyin, ttyout, poll)
     if (FD_ISSET(tin, &ibits)) {
 	FD_CLR(tin, &ibits);
 	c = TerminalRead(ttyiring.supply, ring_empty_consecutive(&ttyiring));
+	if (c < 0 && errno == EIO)
+	    c = 0;
 	if (c < 0 && errno == EWOULDBLOCK) {
 	    c = 0;
 	} else {
-	    /* EOF detection for line mode!!!! */
-	    if ((c == 0) && MODE_LOCAL_CHARS(globalmode) && isatty(tin)) {
+	    if (c < 0) {
+		return -1;
+	    }
+	    if (c == 0) {
 			/* must be an EOF... */
+		if (MODE_LOCAL_CHARS(globalmode) && isatty(tin)) {
 		*ttyiring.supply = termEofChar;
 		c = 1;
+		} else {
+		    clienteof = 1;
+		    shutdown(net, 1);
+		    return 0;
 	    }
-	    if (c <= 0) {
-		return -1;
 	    }
 	    if (termdata) {
 		Dump('<', ttyiring.supply, c);

usr.bin/telnet/telnet.c

@@ -57,7 +57,7 @@ static char sccsid[] = "@(#)telnet.c	8.2 (Berkeley) 12/15/93";
 #include "general.h"
 
 
-#define	strip(x)	((x)&0x7f)
+#define	strip(x)	((my_want_state_is_wont(TELOPT_BINARY)) ? ((x)&0x7f) : (x))
 
 static unsigned char	subbuffer[SUBBUFSIZE],
 			*subpointer, *subend;	 /* buffer for sub-options */
@@ -104,7 +104,8 @@ int
 	donelclchars,	/* the user has set "localchars" */
 	donebinarytoggle,	/* the user has put us in binary */
 	dontlecho,	/* do we suppress local echoing right now? */
-	globalmode;
+	globalmode,
+	clienteof = 0;
 
 char *prompt = 0;
 
@@ -2097,9 +2098,9 @@ Scheduler(block)
     ttyout = ring_full_count(&ttyoring);
 
 #if	defined(TN3270)
-    ttyin = ring_empty_count(&ttyiring) && (shell_active == 0);
+    ttyin = ring_empty_count(&ttyiring) && (clienteof == 0) && (shell_active == 0);
 #else	/* defined(TN3270) */
-    ttyin = ring_empty_count(&ttyiring);
+    ttyin = ring_empty_count(&ttyiring) && (clienteof == 0);
 #endif	/* defined(TN3270) */
 
 #if	defined(TN3270)

usr.bin/telnet/terminal.c

@@ -140,7 +140,8 @@ ttyflush(drop)
 		n1 = n0 - n;
 		if (!drop)
 			n1 = TerminalWrite(ttyoring.bottom, n1);
-		n += n1;
+		if (n1 > 0)
+			n += n1;
 	}
 	ring_consumed(&ttyoring, n);
     }