initial user mode network support

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@733 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 925 insertions, 0 deletions

diff --git a/slirp/misc.c b/slirp/misc.c
new file mode 100644
index 0000000000..7f6448dffd
--- /dev/null
+++ b/slirp/misc.c
@@ -0,0 +1,925 @@
+/*
+ * Copyright (c) 1995 Danny Gasparovski.
+ * 
+ * Please read the file COPYRIGHT for the
+ * terms and conditions of the copyright.
+ */
+
+#define WANT_SYS_IOCTL_H
+#include <slirp.h>
+
+u_int curtime, time_fasttimo, last_slowtimo, detach_time;
+u_int detach_wait = 600000;	/* 10 minutes */
+
+#if 0
+int x_port = -1;
+int x_display = 0;
+int x_screen = 0;
+
+int
+show_x(buff, inso)
+	char *buff;
+	struct socket *inso;
+{
+	if (x_port < 0) {
+		lprint("X Redir: X not being redirected.\r\n");
+	} else {
+		lprint("X Redir: In sh/bash/zsh/etc. type: DISPLAY=%s:%d.%d; export DISPLAY\r\n",
+		      inet_ntoa(our_addr), x_port, x_screen);
+		lprint("X Redir: In csh/tcsh/etc. type:    setenv DISPLAY %s:%d.%d\r\n",
+		      inet_ntoa(our_addr), x_port, x_screen);
+		if (x_display)
+		   lprint("X Redir: Redirecting to display %d\r\n", x_display);
+	}
+	
+	return CFG_OK;
+}
+
+
+/*
+ * XXX Allow more than one X redirection?
+ */
+void
+redir_x(inaddr, start_port, display, screen)
+	u_int32_t inaddr;
+	int start_port;
+	int display;
+	int screen;
+{
+	int i;
+	
+	if (x_port >= 0) {
+		lprint("X Redir: X already being redirected.\r\n");
+		show_x(0, 0);
+	} else {
+		for (i = 6001 + (start_port-1); i <= 6100; i++) {
+			if (solisten(htons(i), inaddr, htons(6000 + display), 0)) {
+				/* Success */
+				x_port = i - 6000;
+				x_display = display;
+				x_screen = screen;
+				show_x(0, 0);
+				return;
+			}
+		}
+		lprint("X Redir: Error: Couldn't redirect a port for X. Weird.\r\n");
+	}
+}
+#endif
+
+#ifndef HAVE_INET_ATON
+int
+inet_aton(cp, ia)
+	const char *cp;
+	struct in_addr *ia;
+{
+	u_int32_t addr = inet_addr(cp);
+	if (addr == 0xffffffff)
+		return 0;
+	ia->s_addr = addr;
+	return 1;
+}
+#endif
+
+/*
+ * Get our IP address and put it in our_addr
+ */
+void
+getouraddr()
+{
+	char buff[256];
+	struct hostent *he;
+	
+	if (gethostname(buff,256) < 0)
+	   return;
+	
+	if ((he = gethostbyname(buff)) == NULL)
+	   return;
+	
+	our_addr = *(struct in_addr *)he->h_addr;
+}
+
+#if SIZEOF_CHAR_P == 8
+
+struct quehead_32 {
+	u_int32_t qh_link;
+	u_int32_t qh_rlink;
+};
+
+inline void
+insque_32(a, b)
+	void *a;
+	void *b;
+{
+	register struct quehead_32 *element = (struct quehead_32 *) a;
+	register struct quehead_32 *head = (struct quehead_32 *) b;
+	element->qh_link = head->qh_link;
+	head->qh_link = (u_int32_t)element;
+	element->qh_rlink = (u_int32_t)head;
+	((struct quehead_32 *)(element->qh_link))->qh_rlink
+	= (u_int32_t)element;
+}
+
+inline void
+remque_32(a)
+	void *a;
+{
+	register struct quehead_32 *element = (struct quehead_32 *) a;
+	((struct quehead_32 *)(element->qh_link))->qh_rlink = element->qh_rlink;
+	((struct quehead_32 *)(element->qh_rlink))->qh_link = element->qh_link;
+	element->qh_rlink = 0;
+}
+
+#endif /* SIZEOF_CHAR_P == 8 */
+
+struct quehead {
+	struct quehead *qh_link;
+	struct quehead *qh_rlink;
+};
+
+inline void
+insque(a, b)
+	void *a, *b;
+{
+	register struct quehead *element = (struct quehead *) a;
+	register struct quehead *head = (struct quehead *) b;
+	element->qh_link = head->qh_link;
+	head->qh_link = (struct quehead *)element;
+	element->qh_rlink = (struct quehead *)head;
+	((struct quehead *)(element->qh_link))->qh_rlink
+	= (struct quehead *)element;
+}
+
+inline void
+remque(a)
+     void *a;
+{
+  register struct quehead *element = (struct quehead *) a;
+  ((struct quehead *)(element->qh_link))->qh_rlink = element->qh_rlink;
+  ((struct quehead *)(element->qh_rlink))->qh_link = element->qh_link;
+  element->qh_rlink = NULL;
+  /*  element->qh_link = NULL;  TCP FIN1 crashes if you do this.  Why ? */
+}
+
+/* #endif */
+
+
+int
+add_exec(ex_ptr, do_pty, exec, addr, port)
+	struct ex_list **ex_ptr;
+	int do_pty;
+	char *exec;
+	int addr;
+	int port;
+{
+	struct ex_list *tmp_ptr;
+	
+	/* First, check if the port is "bound" */
+	for (tmp_ptr = *ex_ptr; tmp_ptr; tmp_ptr = tmp_ptr->ex_next) {
+		if (port == tmp_ptr->ex_fport && addr == tmp_ptr->ex_addr)
+		   return -1;
+	}
+	
+	tmp_ptr = *ex_ptr;
+	*ex_ptr = (struct ex_list *)malloc(sizeof(struct ex_list));
+	(*ex_ptr)->ex_fport = port;
+	(*ex_ptr)->ex_addr = addr;
+	(*ex_ptr)->ex_pty = do_pty;
+	(*ex_ptr)->ex_exec = strdup(exec);
+	(*ex_ptr)->ex_next = tmp_ptr;
+	return 0;
+}
+
+#ifndef HAVE_STRERROR
+
+/*
+ * For systems with no strerror
+ */
+
+extern int sys_nerr;
+extern char *sys_errlist[];
+
+char *
+strerror(error)
+	int error;
+{
+	if (error < sys_nerr)
+	   return sys_errlist[error];
+	else
+	   return "Unknown error.";
+}
+
+#endif
+
+
+#if 0
+int
+openpty(amaster, aslave)
+	int *amaster, *aslave;
+{
+	register int master, slave;
+
+#ifdef HAVE_GRANTPT
+	char *ptr;
+	
+	if ((master = open("/dev/ptmx", O_RDWR)) < 0 ||
+	    grantpt(master) < 0 ||
+	    unlockpt(master) < 0 ||
+	    (ptr = ptsname(master)) == NULL)  {
+		close(master);
+		return -1;
+	}
+	
+	if ((slave = open(ptr, O_RDWR)) < 0 ||
+	    ioctl(slave, I_PUSH, "ptem") < 0 ||
+	    ioctl(slave, I_PUSH, "ldterm") < 0 ||
+	    ioctl(slave, I_PUSH, "ttcompat") < 0) {
+		close(master);
+		close(slave);
+		return -1;
+	}
+	
+	*amaster = master;
+	*aslave = slave;
+	return 0;
+	
+#else
+	
+	static char line[] = "/dev/ptyXX";
+	register const char *cp1, *cp2;
+	
+	for (cp1 = "pqrsPQRS"; *cp1; cp1++) {
+		line[8] = *cp1;
+		for (cp2 = "0123456789abcdefghijklmnopqrstuv"; *cp2; cp2++) {
+			line[9] = *cp2;
+			if ((master = open(line, O_RDWR, 0)) == -1) {
+				if (errno == ENOENT)
+				   return (-1);    /* out of ptys */
+			} else {
+				line[5] = 't';
+				/* These will fail */
+				(void) chown(line, getuid(), 0);
+				(void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP);
+#ifdef HAVE_REVOKE
+				(void) revoke(line);
+#endif
+				if ((slave = open(line, O_RDWR, 0)) != -1) {
+					*amaster = master;
+					*aslave = slave;
+					return 0;
+				}
+				(void) close(master);
+				line[5] = 'p';
+			}
+		}
+	}
+	errno = ENOENT; /* out of ptys */
+	return (-1);
+#endif
+}
+
+/*
+ * XXX This is ugly
+ * We create and bind a socket, then fork off to another
+ * process, which connects to this socket, after which we
+ * exec the wanted program.  If something (strange) happens,
+ * the accept() call could block us forever.
+ * 
+ * do_pty = 0   Fork/exec inetd style
+ * do_pty = 1   Fork/exec using slirp.telnetd
+ * do_ptr = 2   Fork/exec using pty
+ */
+int
+fork_exec(so, ex, do_pty)
+	struct socket *so;
+	char *ex;
+	int do_pty;
+{
+	int s;
+	struct sockaddr_in addr;
+	int addrlen = sizeof(addr);
+	int opt;
+        int master;
+	char *argv[256];
+	char buff[256];
+	/* don't want to clobber the original */
+	char *bptr;
+	char *curarg;
+	int c, i;
+	
+	DEBUG_CALL("fork_exec");
+	DEBUG_ARG("so = %lx", (long)so);
+	DEBUG_ARG("ex = %lx", (long)ex);
+	DEBUG_ARG("do_pty = %lx", (long)do_pty);
+	
+	if (do_pty == 2) {
+		if (openpty(&master, &s) == -1) {
+			lprint("Error: openpty failed: %s\n", strerror(errno));
+			return 0;
+		}
+	} else {
+		addr.sin_family = AF_INET;
+		addr.sin_port = 0;
+		addr.sin_addr.s_addr = INADDR_ANY;
+		
+		if ((s = socket(AF_INET, SOCK_STREAM, 0)) < 0 ||
+		    bind(s, (struct sockaddr *)&addr, addrlen) < 0 ||
+		    listen(s, 1) < 0) {
+			lprint("Error: inet socket: %s\n", strerror(errno));
+			close(s);
+			
+			return 0;
+		}
+	}
+	
+	switch(fork()) {
+	 case -1:
+		lprint("Error: fork failed: %s\n", strerror(errno));
+		close(s);
+		if (do_pty == 2)
+		   close(master);
+		return 0;
+		
+	 case 0:
+		/* Set the DISPLAY */
+		if (do_pty == 2) {
+			(void) close(master);
+#ifdef TIOCSCTTY /* XXXXX */
+			(void) setsid();
+			ioctl(s, TIOCSCTTY, (char *)NULL);
+#endif
+		} else {
+			getsockname(s, (struct sockaddr *)&addr, &addrlen);
+			close(s);
+			/*
+			 * Connect to the socket
+			 * XXX If any of these fail, we're in trouble!
+	 		 */
+			s = socket(AF_INET, SOCK_STREAM, 0);
+			addr.sin_addr = loopback_addr;
+			connect(s, (struct sockaddr *)&addr, addrlen);
+		}
+		
+		if (x_port >= 0) {
+#ifdef HAVE_SETENV
+			sprintf(buff, "%s:%d.%d", inet_ntoa(our_addr), x_port, x_screen);
+			setenv("DISPLAY", buff, 1);
+#else
+			sprintf(buff, "DISPLAY=%s:%d.%d", inet_ntoa(our_addr), x_port, x_screen);
+			putenv(buff);
+#endif
+		}
+	
+		dup2(s, 0);
+		dup2(s, 1);
+		dup2(s, 2);
+		for (s = 3; s <= 255; s++)
+		   close(s);
+		
+		i = 0;
+		bptr = strdup(ex); /* No need to free() this */
+		if (do_pty == 1) {
+			/* Setup "slirp.telnetd -x" */
+			argv[i++] = "slirp.telnetd";
+			argv[i++] = "-x";
+			argv[i++] = bptr;
+		} else
+		   do {
+			/* Change the string into argv[] */
+			curarg = bptr;
+			while (*bptr != ' ' && *bptr != (char)0)
+			   bptr++;
+			c = *bptr;
+			*bptr++ = (char)0;
+			argv[i++] = strdup(curarg);
+		   } while (c);
+		
+		argv[i] = 0;
+		execvp(argv[0], argv);
+		
+		/* Ooops, failed, let's tell the user why */
+		  {
+			  char buff[256];
+			  
+			  sprintf(buff, "Error: execvp of %s failed: %s\n", 
+				  argv[0], strerror(errno));
+			  write(2, buff, strlen(buff)+1);
+		  }
+		close(0); close(1); close(2); /* XXX */
+		exit(1);
+		
+	 default:
+		if (do_pty == 2) {
+			close(s);
+			so->s = master;
+		} else {
+			/*
+			 * XXX this could block us...
+			 * XXX Should set a timer here, and if accept() doesn't
+		 	 * return after X seconds, declare it a failure
+		 	 * The only reason this will block forever is if socket()
+		 	 * of connect() fail in the child process
+		 	 */
+			so->s = accept(s, (struct sockaddr *)&addr, &addrlen);
+			close(s);
+			opt = 1;
+			setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
+			opt = 1;
+			setsockopt(so->s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
+		}
+		fd_nonblock(so->s);
+		
+		/* Append the telnet options now */
+		if (so->so_m != 0 && do_pty == 1)  {
+			sbappend(so, so->so_m);
+			so->so_m = 0;
+		}
+		
+		return 1;
+	}
+}
+#endif
+
+#ifndef HAVE_STRDUP
+char *
+strdup(str)
+	const char *str;
+{
+	char *bptr;
+	
+	bptr = (char *)malloc(strlen(str)+1);
+	strcpy(bptr, str);
+	
+	return bptr;
+}
+#endif
+
+#if 0
+void
+snooze_hup(num)
+	int num;
+{
+	int s, ret;
+#ifndef NO_UNIX_SOCKETS
+	struct sockaddr_un sock_un;
+#endif
+	struct sockaddr_in sock_in;
+	char buff[256];
+	
+	ret = -1;
+	if (slirp_socket_passwd) {
+		s = socket(AF_INET, SOCK_STREAM, 0);
+		if (s < 0)
+		   slirp_exit(1);
+		sock_in.sin_family = AF_INET;
+		sock_in.sin_addr.s_addr = slirp_socket_addr;
+		sock_in.sin_port = htons(slirp_socket_port);
+		if (connect(s, (struct sockaddr *)&sock_in, sizeof(sock_in)) != 0)
+		   slirp_exit(1); /* just exit...*/
+		sprintf(buff, "kill %s:%d", slirp_socket_passwd, slirp_socket_unit);
+		write(s, buff, strlen(buff)+1);
+	}
+#ifndef NO_UNIX_SOCKETS
+	  else {
+		s = socket(AF_UNIX, SOCK_STREAM, 0);
+		if (s < 0)
+		   slirp_exit(1);
+		sock_un.sun_family = AF_UNIX;
+		strcpy(sock_un.sun_path, socket_path);
+		if (connect(s, (struct sockaddr *)&sock_un,
+			      sizeof(sock_un.sun_family) + sizeof(sock_un.sun_path)) != 0)
+		   slirp_exit(1);
+		sprintf(buff, "kill none:%d", slirp_socket_unit);
+		write(s, buff, strlen(buff)+1);
+	}
+#endif
+	slirp_exit(0);
+}
+	
+	
+void
+snooze()
+{
+	sigset_t s;
+	int i;
+	
+	/* Don't need our data anymore */
+	/* XXX This makes SunOS barf */
+/*	brk(0); */
+	
+	/* Close all fd's */
+	for (i = 255; i >= 0; i--)
+	   close(i);
+	
+	signal(SIGQUIT, slirp_exit);
+	signal(SIGHUP, snooze_hup);
+	sigemptyset(&s);
+	
+	/* Wait for any signal */
+	sigsuspend(&s);
+	
+	/* Just in case ... */
+	exit(255);
+}
+
+void
+relay(s)
+	int s;
+{
+	char buf[8192];
+	int n;
+	fd_set readfds;
+	struct ttys *ttyp;
+	
+	/* Don't need our data anymore */
+	/* XXX This makes SunOS barf */
+/*	brk(0); */
+	
+	signal(SIGQUIT, slirp_exit);
+	signal(SIGHUP, slirp_exit);
+        signal(SIGINT, slirp_exit);
+	signal(SIGTERM, slirp_exit);
+	
+	/* Fudge to get term_raw and term_restore to work */
+	if (NULL == (ttyp = tty_attach (0, slirp_tty))) {
+         lprint ("Error: tty_attach failed in misc.c:relay()\r\n");
+         slirp_exit (1);
+    }
+	ttyp->fd = 0;
+	ttyp->flags |= TTY_CTTY;
+	term_raw(ttyp);
+	
+	while (1) {
+		FD_ZERO(&readfds);
+		
+		FD_SET(0, &readfds);
+		FD_SET(s, &readfds);
+		
+		n = select(s+1, &readfds, (fd_set *)0, (fd_set *)0, (struct timeval *)0);
+		
+		if (n <= 0)
+		   slirp_exit(0);
+		
+		if (FD_ISSET(0, &readfds)) {
+			n = read(0, buf, 8192);
+			if (n <= 0)
+			   slirp_exit(0);
+			n = writen(s, buf, n);
+			if (n <= 0)
+			   slirp_exit(0);
+		}
+		
+		if (FD_ISSET(s, &readfds)) {
+			n = read(s, buf, 8192);
+			if (n <= 0)
+			   slirp_exit(0);
+			n = writen(0, buf, n);
+			if (n <= 0)
+			   slirp_exit(0);
+		}
+	}
+	
+	/* Just in case.... */
+	exit(1);
+}
+#endif
+
+int (*lprint_print) _P((void *, const char *, va_list));
+char *lprint_ptr, *lprint_ptr2, **lprint_arg;
+
+void
+#ifdef __STDC__
+lprint(const char *format, ...)
+#else
+lprint(va_alist) va_dcl
+#endif
+{
+	va_list args;
+        
+#ifdef __STDC__
+        va_start(args, format);
+#else
+        char *format;
+        va_start(args);
+        format = va_arg(args, char *);
+#endif
+#if 0
+	/* If we're printing to an sbuf, make sure there's enough room */
+	/* XXX +100? */
+	if (lprint_sb) {
+		if ((lprint_ptr - lprint_sb->sb_wptr) >=
+		    (lprint_sb->sb_datalen - (strlen(format) + 100))) {
+			int deltaw = lprint_sb->sb_wptr - lprint_sb->sb_data;
+			int deltar = lprint_sb->sb_rptr - lprint_sb->sb_data;
+			int deltap = lprint_ptr -         lprint_sb->sb_data;
+			                        
+			lprint_sb->sb_data = (char *)realloc(lprint_sb->sb_data,
+							     lprint_sb->sb_datalen + TCP_SNDSPACE);
+			
+			/* Adjust all values */
+			lprint_sb->sb_wptr = lprint_sb->sb_data + deltaw;
+			lprint_sb->sb_rptr = lprint_sb->sb_data + deltar;
+			lprint_ptr =         lprint_sb->sb_data + deltap;
+			
+			lprint_sb->sb_datalen += TCP_SNDSPACE;
+		}
+	}
+#endif	
+	if (lprint_print)
+	   lprint_ptr += (*lprint_print)(*lprint_arg, format, args);
+	
+	/* Check if they want output to be logged to file as well */
+	if (lfd) {
+		/* 
+		 * Remove \r's
+		 * otherwise you'll get ^M all over the file
+		 */
+		int len = strlen(format);
+		char *bptr1, *bptr2;
+		
+		bptr1 = bptr2 = strdup(format);
+		
+		while (len--) {
+			if (*bptr1 == '\r')
+			   memcpy(bptr1, bptr1+1, len+1);
+			else
+			   bptr1++;
+		}
+		vfprintf(lfd, bptr2, args);
+		free(bptr2);
+	}
+	va_end(args);
+}
+
+void
+add_emu(buff)
+	char *buff;
+{
+	u_int lport, fport;
+	u_int8_t tos = 0, emu = 0;
+	char buff1[256], buff2[256], buff4[128];
+	char *buff3 = buff4;
+	struct emu_t *emup;
+	struct socket *so;
+	
+	if (sscanf(buff, "%256s %256s", buff2, buff1) != 2) {
+		lprint("Error: Bad arguments\r\n");
+		return;
+	}
+	
+	if (sscanf(buff1, "%d:%d", &lport, &fport) != 2) {
+		lport = 0;
+		if (sscanf(buff1, "%d", &fport) != 1) {
+			lprint("Error: Bad first argument\r\n");
+			return;
+		}
+	}
+	
+	if (sscanf(buff2, "%128[^:]:%128s", buff1, buff3) != 2) {
+		buff3 = 0;
+		if (sscanf(buff2, "%256s", buff1) != 1) {
+			lprint("Error: Bad second argument\r\n");
+			return;
+		}
+	}
+	
+	if (buff3) {
+		if (strcmp(buff3, "lowdelay") == 0)
+		   tos = IPTOS_LOWDELAY;
+		else if (strcmp(buff3, "throughput") == 0)
+		   tos = IPTOS_THROUGHPUT;
+		else {
+			lprint("Error: Expecting \"lowdelay\"/\"throughput\"\r\n");
+			return;
+		}
+	}
+	
+	if (strcmp(buff1, "ftp") == 0)
+	   emu = EMU_FTP;
+	else if (strcmp(buff1, "irc") == 0)
+	   emu = EMU_IRC;
+	else if (strcmp(buff1, "none") == 0)
+	   emu = EMU_NONE; /* ie: no emulation */
+	else {
+		lprint("Error: Unknown service\r\n");
+		return;
+	}
+	
+	/* First, check that it isn't already emulated */
+	for (emup = tcpemu; emup; emup = emup->next) {
+		if (emup->lport == lport && emup->fport == fport) {
+			lprint("Error: port already emulated\r\n");
+			return;
+		}
+	}
+	
+	/* link it */
+	emup = (struct emu_t *)malloc(sizeof (struct emu_t));
+	emup->lport = (u_int16_t)lport;
+	emup->fport = (u_int16_t)fport;
+	emup->tos = tos;
+	emup->emu = emu;
+	emup->next = tcpemu;
+	tcpemu = emup;
+	
+	/* And finally, mark all current sessions, if any, as being emulated */
+	for (so = tcb.so_next; so != &tcb; so = so->so_next) {
+		if ((lport && lport == ntohs(so->so_lport)) ||
+		    (fport && fport == ntohs(so->so_fport))) {
+			if (emu)
+			   so->so_emu = emu;
+			if (tos)
+			   so->so_iptos = tos;
+		}
+	}
+	
+	lprint("Adding emulation for %s to port %d/%d\r\n", buff1, emup->lport, emup->fport);
+}
+
+#ifdef BAD_SPRINTF
+
+#undef vsprintf
+#undef sprintf
+
+/*
+ * Some BSD-derived systems have a sprintf which returns char *
+ */
+
+int
+vsprintf_len(string, format, args)
+	char *string;
+	const char *format;
+	va_list args;
+{
+	vsprintf(string, format, args);
+	return strlen(string);
+}
+
+int
+#ifdef __STDC__
+sprintf_len(char *string, const char *format, ...)
+#else
+sprintf_len(va_alist) va_dcl
+#endif
+{
+	va_list args;
+#ifdef __STDC__
+	va_start(args, format);
+#else
+	char *string;
+	char *format;
+	va_start(args);
+	string = va_arg(args, char *);
+	format = va_arg(args, char *);
+#endif
+	vsprintf(string, format, args);
+	return strlen(string);
+}
+
+#endif
+
+void
+u_sleep(usec)
+	int usec;
+{
+	struct timeval t;
+	fd_set fdset;
+	
+	FD_ZERO(&fdset);
+	
+	t.tv_sec = 0;
+	t.tv_usec = usec * 1000;
+	
+	select(0, &fdset, &fdset, &fdset, &t);
+}
+
+/*
+ * Set fd blocking and non-blocking
+ */
+
+void
+fd_nonblock(fd)
+	int fd;
+{
+#ifdef FIONBIO
+	int opt = 1;
+	
+	ioctl(fd, FIONBIO, &opt);
+#else
+	int opt;
+	
+	opt = fcntl(fd, F_GETFL, 0);
+	opt |= O_NONBLOCK;
+	fcntl(fd, F_SETFL, opt);
+#endif
+}
+
+void
+fd_block(fd)
+	int fd;
+{
+#ifdef FIONBIO
+	int opt = 0;
+	
+	ioctl(fd, FIONBIO, &opt);
+#else
+	int opt;
+	
+	opt = fcntl(fd, F_GETFL, 0);
+	opt &= ~O_NONBLOCK;
+	fcntl(fd, F_SETFL, opt);
+#endif
+}
+
+
+#if 0
+/*
+ * invoke RSH
+ */
+int
+rsh_exec(so,ns, user, host, args)
+	struct socket *so;
+	struct socket *ns;
+	char *user;
+	char *host;
+	char *args;
+{
+	int fd[2];
+	int fd0[2];
+	int s;
+	char buff[256];
+	
+	DEBUG_CALL("rsh_exec");
+	DEBUG_ARG("so = %lx", (long)so);
+	
+	if (pipe(fd)<0) {
+          lprint("Error: pipe failed: %s\n", strerror(errno));
+          return 0;
+	}
+/* #ifdef HAVE_SOCKETPAIR */
+#if 1
+        if (socketpair(PF_UNIX,SOCK_STREAM,0, fd0) == -1) {
+          close(fd[0]);
+          close(fd[1]);
+          lprint("Error: openpty failed: %s\n", strerror(errno));
+          return 0;
+        }
+#else
+        if (openpty(&fd0[0], &fd0[1]) == -1) {
+          close(fd[0]);
+          close(fd[1]);
+          lprint("Error: openpty failed: %s\n", strerror(errno));
+          return 0;
+        }
+#endif
+	
+	switch(fork()) {
+	 case -1:
+           lprint("Error: fork failed: %s\n", strerror(errno));
+           close(fd[0]);
+           close(fd[1]);
+           close(fd0[0]);
+           close(fd0[1]);
+           return 0;
+           
+	 case 0:
+           close(fd[0]);
+           close(fd0[0]);
+           
+		/* Set the DISPLAY */
+           if (x_port >= 0) {
+#ifdef HAVE_SETENV
+             sprintf(buff, "%s:%d.%d", inet_ntoa(our_addr), x_port, x_screen);
+             setenv("DISPLAY", buff, 1);
+#else
+             sprintf(buff, "DISPLAY=%s:%d.%d", inet_ntoa(our_addr), x_port, x_screen);
+             putenv(buff);
+#endif
+           }
+           
+           dup2(fd0[1], 0);
+           dup2(fd0[1], 1);
+           dup2(fd[1], 2);
+           for (s = 3; s <= 255; s++)
+             close(s);
+           
+           execlp("rsh","rsh","-l", user, host, args, NULL);
+           
+           /* Ooops, failed, let's tell the user why */
+           
+           sprintf(buff, "Error: execlp of %s failed: %s\n", 
+                   "rsh", strerror(errno));
+           write(2, buff, strlen(buff)+1);
+           close(0); close(1); close(2); /* XXX */
+           exit(1);
+           
+        default:
+          close(fd[1]);
+          close(fd0[1]);
+          ns->s=fd[0];
+          so->s=fd0[0];
+          
+          return 1;
+	}
+}
+#endif