malloc fd_set dynamically, for very large fd uses

2 files changed, 27 insertions, 13 deletions

diff --git a/lib/libc/net/rcmd.c b/lib/libc/net/rcmd.c
index a0adaf8ed0d..3c483a809bf 100644
--- a/lib/libc/net/rcmd.c
+++ b/lib/libc/net/rcmd.c
@@ -34,7 +34,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char *rcsid = "$OpenBSD: rcmd.c,v 1.20 1997/04/05 21:13:15 millert Exp $";
+static char *rcsid = "$OpenBSD: rcmd.c,v 1.21 1997/05/28 21:40:11 deraadt Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/param.h>
@@ -69,7 +69,7 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
 {
 	struct hostent *hp;
 	struct sockaddr_in sin, from;
-	fd_set reads;
+	fd_set *readsp = NULL;
 	int oldmask;
 	pid_t pid;
 	int s, lport, timo;
@@ -166,6 +166,10 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
 
 		if (s2 < 0)
 			goto bad;
+		readsp = (fd_set *)malloc(howmany(MAX(s, s2), NFDBITS) *
+		    sizeof(fd_mask));
+		if (readsp == NULL)
+			goto bad;
 		listen(s2, 1);
 		(void)snprintf(num, sizeof(num), "%d", lport);
 		if (write(s, num, strlen(num)+1) != strlen(num)+1) {
@@ -176,12 +180,12 @@ rcmd(ahost, rport, locuser, remuser, cmd, fd2p)
 			goto bad;
 		}
 again:
-		FD_ZERO(&reads);
-		FD_SET(s, &reads);
-		FD_SET(s2, &reads);
+		FD_ZERO(readsp);
+		FD_SET(s, readsp);
+		FD_SET(s2, readsp);
 		errno = 0;
-		if (select(MAX(s, s2) + 1, &reads, 0, 0, 0) < 1 ||
-		    !FD_ISSET(s2, &reads)) {
+		if (select(MAX(s, s2) + 1, readsp, 0, 0, 0) < 1 ||
+		    !FD_ISSET(s2, readsp)) {
 			if (errno != 0)
 				(void)fprintf(stderr,
 				    "rcmd: select (setting up stderr): %s\n",
@@ -235,11 +239,14 @@ again:
 		goto bad2;
 	}
 	sigsetmask(oldmask);
+	free(readsp);
 	return (s);
 bad2:
 	if (lport)
 		(void)close(*fd2p);
 bad:
+	if (readsp)
+		free(readsp);
 	(void)close(s);
 	sigsetmask(oldmask);
 	return (-1);
diff --git a/lib/libc/net/res_send.c b/lib/libc/net/res_send.c
index bfc01f9b6af..284f85d7fe9 100644
--- a/lib/libc/net/res_send.c
+++ b/lib/libc/net/res_send.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: res_send.c,v 1.4 1997/03/13 19:07:41 downsj Exp $	*/
+/*	$OpenBSD: res_send.c,v 1.5 1997/05/28 21:38:57 deraadt Exp $	*/
 
 /*
  * ++Copyright++ 1985, 1989, 1993
@@ -60,7 +60,7 @@
 static char sccsid[] = "@(#)res_send.c	8.1 (Berkeley) 6/4/93";
 static char rcsid[] = "$From: res_send.c,v 8.12 1996/10/08 04:51:06 vixie Exp $";
 #else
-static char rcsid[] = "$OpenBSD: res_send.c,v 1.4 1997/03/13 19:07:41 downsj Exp $";
+static char rcsid[] = "$OpenBSD: res_send.c,v 1.5 1997/05/28 21:38:57 deraadt Exp $";
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -489,7 +489,7 @@ read_len:
 			 * Use datagrams.
 			 */
 			struct timeval timeout;
-			fd_set dsmask;
+			fd_set *dsmaskp;
 			struct sockaddr_in from;
 			int fromlen;
 
@@ -595,10 +595,17 @@ read_len:
 				timeout.tv_sec = 1;
 			timeout.tv_usec = 0;
     wait:
-			FD_ZERO(&dsmask);
-			FD_SET(s, &dsmask);
-			n = select(s+1, &dsmask, (fd_set *)NULL,
+			dsmaskp = (fd_set *)malloc(howmany(s, NFDBITS) *
+				sizeof(fd_mask));
+			if (dsmaskp == NULL) {
+				res_close();
+				goto next_ns;
+			}
+			FD_ZERO(dsmaskp);
+			FD_SET(s, dsmaskp);
+			n = select(s+1, dsmaskp, (fd_set *)NULL,
 				   (fd_set *)NULL, &timeout);
+			free(dsmaskp);
 			if (n < 0) {
 				if (errno == EINTR)
 					goto wait;