malloc fd_set dynamically, for very large fd uses

2 files changed, 27 insertions, 13 deletions

diff --git a/src/lib/libc/net/rcmd.c b/src/lib/libc/net/rcmd.c
index a0adaf8ed0..3c483a809b 100644
--- a/src/lib/libc/net/rcmd.c
+++ b/src/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/src/lib/libc/net/res_send.c b/src/lib/libc/net/res_send.c
index bfc01f9b6a..284f85d7fe 100644
--- a/src/lib/libc/net/res_send.c
+++ b/src/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;