X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/8f2758db19869ab441ebc2c1cd59037f1189e865..fe5c5547066496480f77152fbcfbd68c56e9cf6f:/usr/src/libexec/telnetd/telnetd.c

diff --git a/usr/src/libexec/telnetd/telnetd.c b/usr/src/libexec/telnetd/telnetd.c
index a86f912194..1698d4ccf8 100644
--- a/usr/src/libexec/telnetd/telnetd.c
+++ b/usr/src/libexec/telnetd/telnetd.c
@@ -1,5 +1,5 @@
 #ifndef lint
-static char sccsid[] = "@(#)telnetd.c	4.11 82/11/15";
+static char sccsid[] = "@(#)telnetd.c	4.25 (Berkeley) 83/07/06";
 #endif
 
 /*
@@ -7,19 +7,20 @@ static char sccsid[] = "@(#)telnetd.c	4.11 82/11/15";
  */
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/wait.h>
 
 #include <netinet/in.h>
 
+#include <arpa/telnet.h>
+
 #include <stdio.h>
 #include <signal.h>
 #include <errno.h>
 #include <sgtty.h>
-#include <wait.h>
 #include <netdb.h>
 
-#include "telnet.h"
-
-#define	BELL		'\07'
+#define	BELL	'\07'
+#define BANNER	"\r\n\r\n4.2 BSD UNIX (%s)\r\n\r\r\n\r%s"
 
 char	hisopts[256];
 char	myopts[256];
@@ -40,6 +41,8 @@ int	pcc, ncc;
 
 int	pty, net;
 int	inter;
+int	reapchild();
+extern	char **environ;
 extern	int errno;
 char	line[] = "/dev/ptyp0";
 
@@ -48,8 +51,7 @@ struct	sockaddr_in sin = { AF_INET };
 main(argc, argv)
 	char *argv[];
 {
-	int s, pid;
-	union wait status;
+	int s, pid, options;
 	struct servent *sp;
 
 	sp = getservbyname("telnet", "tcp");
@@ -59,14 +61,18 @@ main(argc, argv)
 	}
 	sin.sin_port = sp->s_port;
 	argc--, argv++;
+	if (argc > 0 && !strcmp(*argv, "-d")) {
+		options |= SO_DEBUG;
+		argc--, argv++;
+	}
 	if (argc > 0) {
 		sin.sin_port = atoi(*argv);
 		if (sin.sin_port <= 0) {
 			fprintf(stderr, "telnetd: %s: bad port #\n", *argv);
 			exit(1);
 		}
+		sin.sin_port = htons((u_short)sin.sin_port);
 	}
-	sin.sin_port = htons((u_short)sin.sin_port);
 #ifndef DEBUG
 	if (fork())
 		exit(0);
@@ -83,47 +89,68 @@ main(argc, argv)
 	}
 #endif
 again:
-	s = socket(0, SOCK_STREAM, 0, 0);
+	s = socket(AF_INET, SOCK_STREAM, 0, 0);
 	if (s < 0) {
 		perror("telnetd: socket");;
 		sleep(5);
 		goto again;
 	}
+	if (options & SO_DEBUG)
+		if (setsockopt(s, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
+			perror("telnetd: setsockopt (SO_DEBUG)");
+	if (setsockopt(s, SOL_SOCKET, SO_KEEPALIVE, 0, 0) < 0)
+		perror("telnetd: setsockopt (SO_KEEPALIVE)");
 	while (bind(s, (caddr_t)&sin, sizeof (sin), 0) < 0) {
 		perror("telnetd: bind");
 		sleep(5);
 	}
+	signal(SIGCHLD, reapchild);
 	listen(s, 10);
 	for (;;) {
-		int s2;
+		struct sockaddr_in from;
+		int s2, fromlen = sizeof (from);
 
-		s2 = accept(s, (caddr_t)0, 0, 0);
+		s2 = accept(s, (caddr_t)&from, &fromlen);
 		if (s2 < 0) {
+			if (errno == EINTR)
+				continue;
 			perror("telnetd: accept");
 			sleep(1);
 			continue;
 		}
 		if ((pid = fork()) < 0)
 			printf("Out of processes\n");
-		else if (pid == 0)
-			doit(s2);
+		else if (pid == 0) {
+			signal(SIGCHLD, SIG_IGN);
+			doit(s2, &from);
+		}
 		close(s2);
-		while (wait3(status, WNOHANG, 0) > 0)
-			continue;
 	}
 	/*NOTREACHED*/
 }
 
+reapchild()
+{
+	union wait status;
+
+	while (wait3(&status, WNOHANG, 0) > 0)
+		;
+}
+
+char	*envinit[] = { "TERM=network", 0 };
 int	cleanup();
 
 /*
  * Get a pty, scan input lines.
  */
-doit(f)
+doit(f, who)
+	int f;
+	struct sockaddr_in *who;
 {
-	char *cp = line;
+	char *cp = line, *host, *ntoa();
 	int i, p, cc, t;
 	struct sgttyb b;
+	struct hostent *hp;
 
 	for (i = 0; i < 16; i++) {
 		cp[strlen("/dev/ptyp")] = "0123456789abcdef"[i];
@@ -150,6 +177,12 @@ gotpty:
 	ioctl(p, TIOCGETP, &b);
 	b.sg_flags &= ~ECHO;
 	ioctl(p, TIOCSETP, &b);
+	hp = gethostbyaddr(&who->sin_addr, sizeof (struct in_addr),
+		who->sin_family);
+	if (hp)
+		host = hp->h_name;
+	else
+		host = ntoa(who->sin_addr);
 	if ((i = fork()) < 0)
 		fatalperror(f, "fork", errno);
 	if (i)
@@ -160,7 +193,8 @@ gotpty:
 	dup2(t, 1);
 	dup2(t, 2);
 	close(t);
-	execl("/bin/login", "telnet-login", 0);
+	environ = envinit;
+	execl("/bin/login", "login", "-h", host, 0);
 	fatalperror(f, "/bin/login", errno);
 	/*NOTREACHED*/
 }
@@ -195,18 +229,25 @@ fatalperror(f, msg, errno)
 telnet(f, p)
 {
 	int on = 1;
+	char hostname[32];
 
 	net = f, pty = p;
 	ioctl(f, FIONBIO, &on);
 	ioctl(p, FIONBIO, &on);
 	signal(SIGTSTP, SIG_IGN);
-	sigset(SIGCHLD, cleanup);
+	signal(SIGCHLD, cleanup);
 
 	/*
 	 * Request to do remote echo.
 	 */
 	dooption(TELOPT_ECHO);
 	myopts[TELOPT_ECHO] = 1;
+	/*
+	 * Show banner that getty never gave.
+	 */
+	gethostname(hostname, sizeof (hostname));
+	sprintf(nfrontp, BANNER, hostname, "");
+	nfrontp += strlen(nfrontp);
 	for (;;) {
 		int ibits = 0, obits = 0;
 		register int c;
@@ -579,13 +620,10 @@ netflush()
 
 cleanup()
 {
-	int how = 2;
 
 	rmut();
-#ifdef notdef
-	vhangup();
-#endif
-	ioctl(net, SIOCDONE, &how);
+	vhangup();	/* XXX */
+	shutdown(net, 2);
 	kill(0, SIGKILL);
 	exit(1);
 }
@@ -610,6 +648,7 @@ rmut()
 				continue;
 			lseek(f, -(long)sizeof (wtmp), 1);
 			SCPYN(wtmp.ut_name, "");
+			SCPYN(wtmp.ut_host, "");
 			time(&wtmp.ut_time);
 			write(f, (char *)&wtmp, sizeof (wtmp));
 			found++;
@@ -621,6 +660,7 @@ rmut()
 		if (f >= 0) {
 			SCPYN(wtmp.ut_line, line+5);
 			SCPYN(wtmp.ut_name, "");
+			SCPYN(wtmp.ut_host, "");
 			time(&wtmp.ut_time);
 			lseek(f, (long)0, 2);
 			write(f, (char *)&wtmp, sizeof (wtmp));
@@ -633,3 +673,20 @@ rmut()
 	chmod(line, 0666);
 	chown(line, 0, 0);
 }
+
+/*
+ * Convert network-format internet address
+ * to base 256 d.d.d.d representation.
+ */
+char *
+ntoa(in)
+	struct in_addr in;
+{
+	static char b[18];
+	register char *p;
+
+	p = (char *)&in;
+#define	UC(b)	(((int)b)&0xff)
+	sprintf(b, "%d.%d.%d.%d", UC(p[0]), UC(p[1]), UC(p[2]), UC(p[3]));
+	return (b);
+}