Don't assume that the number of fds to select on is known quantity (in

this case 16).  Use dynamic FD_SETs and calculated high-water marks
throughout.  There are also too many versions of telnet in the tree.

Obtained from:  OpenBSD and Apple's Radar database
MFC after:      2 days

1 files changed, 56 insertions, 32 deletions

diff --git a/contrib/telnet/telnet/sys_bsd.c b/contrib/telnet/telnet/sys_bsd.c
index bcb302c..fca026d 100644
--- a/contrib/telnet/telnet/sys_bsd.c
+++ b/contrib/telnet/telnet/sys_bsd.c
@@ -32,6 +32,8 @@
  */
 
 #include <sys/cdefs.h>
+#include <stdlib.h>
+#include <err.h>
 
 __FBSDID("$FreeBSD$");
 
@@ -105,7 +107,8 @@ struct	termio old_tc = { 0, 0, 0, 0, {}, 0, 0 };
 # endif
 #endif	/* USE_TERMIO */
 
-static fd_set ibits, obits, xbits;
+static fd_set *ibitsp, *obitsp, *xbitsp;
+int fdsn;
 
 #ifdef	SIGINT
 static SIG_FUNC_RET intr(int);
@@ -125,10 +128,6 @@ init_sys(void)
 {
     tout = fileno(stdout);
     tin = fileno(stdin);
-    FD_ZERO(&ibits);
-    FD_ZERO(&obits);
-    FD_ZERO(&xbits);
-
     errno = 0;
 }
 
@@ -924,24 +923,49 @@ process_rings(int netin, int netout, int netex, int ttyin, int ttyout, int poll)
     int c;
     int returnValue = 0;
     static struct timeval TimeValue = { 0, 0 };
-
-    if (netout) {
-	FD_SET(net, &obits);
-    }
-    if (ttyout) {
-	FD_SET(tout, &obits);
-    }
-    if (ttyin) {
-	FD_SET(tin, &ibits);
-    }
-    if (netin) {
-	FD_SET(net, &ibits);
-    }
-    if (netex) {
-	FD_SET(net, &xbits);
+    int maxfd = -1;
+    int tmp;
+
+    if ((netout || netin || netex) && net > maxfd)
+	maxfd = net;
+    
+    if (ttyout && tout > maxfd)
+	maxfd = tout;
+    if (ttyin && tin > maxfd)
+	maxfd = tin;
+    tmp = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
+    if (tmp > fdsn) {
+	if (ibitsp)
+	    free(ibitsp);
+	if (obitsp)
+	    free(obitsp);
+	if (xbitsp)
+	    free(xbitsp);
+	
+	fdsn = tmp;
+	if ((ibitsp = (fd_set *)malloc(fdsn)) == NULL)
+	    err(1, "malloc");
+	if ((obitsp = (fd_set *)malloc(fdsn)) == NULL)
+	    err(1, "malloc");
+	if ((xbitsp = (fd_set *)malloc(fdsn)) == NULL)
+	    err(1, "malloc");
+	memset(ibitsp, 0, fdsn);
+	memset(obitsp, 0, fdsn);
+	memset(xbitsp, 0, fdsn);
     }
-    if ((c = select(16, &ibits, &obits, &xbits,
-			(poll == 0)? (struct timeval *)0 : &TimeValue)) < 0) {
+    
+    if (netout)
+	FD_SET(net, obitsp);
+    if (ttyout)
+	FD_SET(tout, obitsp);
+    if (ttyin)
+	FD_SET(tin, ibitsp);
+    if (netin)
+	FD_SET(net, ibitsp);
+    if (netex)
+	FD_SET(net, xbitsp);
+    if ((c = select(maxfd + 1, ibitsp, obitsp, xbitsp,
+	     (poll == 0)? (struct timeval *)0 : &TimeValue)) < 0) {
 	if (c == -1) {
 		    /*
 		     * we can get EINTR if we are in line mode,
@@ -961,8 +985,8 @@ process_rings(int netin, int netout, int netex, int ttyin, int ttyout, int poll)
     /*
      * Any urgent data?
      */
-    if (FD_ISSET(net, &xbits)) {
-	FD_CLR(net, &xbits);
+    if (FD_ISSET(net, xbitsp)) {
+	FD_CLR(net, xbitsp);
 	SYNCHing = 1;
 	(void) ttyflush(1);	/* flush already enqueued data */
     }
@@ -970,10 +994,10 @@ process_rings(int netin, int netout, int netex, int ttyin, int ttyout, int poll)
     /*
      * Something to read from the network...
      */
-    if (FD_ISSET(net, &ibits)) {
+    if (FD_ISSET(net, ibitsp)) {
 	int canread;
 
-	FD_CLR(net, &ibits);
+	FD_CLR(net, ibitsp);
 	canread = ring_empty_consecutive(&netiring);
 #if	!defined(SO_OOBINLINE)
 	    /*
@@ -1083,8 +1107,8 @@ process_rings(int netin, int netout, int netex, int ttyin, int ttyout, int poll)
     /*
      * Something to read from the tty...
      */
-    if (FD_ISSET(tin, &ibits)) {
-	FD_CLR(tin, &ibits);
+    if (FD_ISSET(tin, ibitsp)) {
+	FD_CLR(tin, ibitsp);
 	c = TerminalRead(ttyiring.supply, ring_empty_consecutive(&ttyiring));
 	if (c < 0 && errno == EIO)
 	    c = 0;
@@ -1108,12 +1132,12 @@ process_rings(int netin, int netout, int netex, int ttyin, int ttyout, int poll)
 	returnValue = 1;		/* did something useful */
     }
 
-    if (FD_ISSET(net, &obits)) {
-	FD_CLR(net, &obits);
+    if (FD_ISSET(net, obitsp)) {
+	FD_CLR(net, obitsp);
 	returnValue |= netflush();
     }
-    if (FD_ISSET(tout, &obits)) {
-	FD_CLR(tout, &obits);
+    if (FD_ISSET(tout, obitsp)) {
+	FD_CLR(tout, obitsp);
 	returnValue |= (ttyflush(SYNCHing|flushout) > 0);
     }