add ELOOP support; shigio@wafu.netgate.net

src/lib/libc/stdlib/realpath.c

@@ -35,7 +35,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char *rcsid = "$OpenBSD: realpath.c,v 1.2 1996/08/19 08:33:47 tholo Exp $";
+static char *rcsid = "$OpenBSD: realpath.c,v 1.3 1997/06/20 20:37:45 deraadt Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/param.h>
@@ -62,6 +62,7 @@ realpath(path, resolved)
 	struct stat sb;
 	int fd, n, rootd, serrno;
 	char *p, *q, wbuf[MAXPATHLEN];
+	int symlinks = 0;
 
 	/* Save the starting point. */
 	if ((fd = open(".", O_RDONLY)) < 0) {
@@ -100,6 +101,10 @@ loop:
 	/* Deal with the last component. */
 	if (lstat(p, &sb) == 0) {
 		if (S_ISLNK(sb.st_mode)) {
+			if (++symlinks > MAXSYMLINKS) {
+				errno = ELOOP;
+				goto err1;
+			}
 			n = readlink(p, resolved, MAXPATHLEN);
 			if (n < 0)
 				goto err1;