Removed bugs and memory leaks from the directory function.

lib/libc/gen/Makefile.inc

@@ -3,15 +3,15 @@
 # gen sources
 .PATH: ${.CURDIR}/${MACHINE}/gen ${.CURDIR}/gen ${.CURDIR}/gen/regexp
 
-SRCS+=	alarm.c clock.c closedir.c crypt.c ctermid.c ctime.c ctype_.c \
+SRCS+=	alarm.c clock.c crypt.c ctermid.c ctime.c ctype_.c difftime.c \
-	difftime.c disklabel.c err.c errlst.c exec.c fnmatch.c frexp.c \
+	directory.c disklabel.c err.c errlst.c exec.c fnmatch.c frexp.c \
 	fstab.c fts.c getcap.c getcwd.c getgrent.c getlogin.c getmntinfo.c \
 	getpass.c getpwent.c getsubopt.c getttyent.c getusershell.c glob.c \
 	initgroups.c isatty.c isctype.c isinf.c mktemp.c nice.c nlist.c \
-	opendir.c pause.c popen.c psignal.c raise.c readdir.c \
+	pause.c popen.c psignal.c raise.c \
-	rewinddir.c scandir.c seekdir.c setjmperr.c \
+	scandir.c setjmperr.c \
 	setmode.c setrgid.c setruid.c siginterrupt.c \
-	siglist.c signal.c sigsetops.c sleep.c syslog.c telldir.c \
+	siglist.c signal.c sigsetops.c sleep.c syslog.c \
 	termios.c time.c times.c timezone.c ttyname.c ttyslot.c \
 	ualarm.c unvis.c usleep.c utime.c valloc.c vis.c wait.c wait3.c \
 	waitpid.c

lib/libc/gen/directory.c

@@ -0,0 +1,234 @@
+/*
+ * Copyright (c) 1983 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)closedir.c	5.9 (Berkeley) 2/23/91";
+#endif /* LIBC_SCCS and not lint */
+
+/*
+ * One of these structures is malloced to describe the current directory
+ * position each time telldir is called. It records the current magic 
+ * cookie returned by getdirentries and the offset within the buffer
+ * associated with that return value.
+ */
+struct ddloc {
+	struct	ddloc *loc_next;/* next structure in list */
+	long	loc_index;	/* key associated with structure */
+	long	loc_seek;	/* magic cookie returned by getdirentries */
+	long	loc_loc;	/* offset of entry in buffer */
+};
+
+static long	dd_loccnt = 0;	/* Index of entry for sequential telldir's */
+
+#include <sys/types.h>
+#include <sys/param.h>
+#include <dirent.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+/*
+ * close a directory.
+ */
+int
+closedir(dirp)
+	register DIR *dirp;
+{
+	struct ddloc *ptr, *nextptr;
+	int fd;
+
+	fd = dirp->dd_fd;
+	dirp->dd_fd = -1;
+	dirp->dd_loc = 0;
+	for (ptr = (struct ddloc*)dirp->dd_ddloc; ptr; ptr = nextptr) {
+		nextptr = ptr->loc_next;
+		free((void *)ptr);
+	}
+	free((void *)dirp->dd_buf);
+	free((void *)dirp);
+	return(close(fd));
+}
+
+/*
+ * open a directory.
+ */
+DIR *
+opendir(name)
+	const char *name;
+{
+	register DIR *dirp;
+	register int fd;
+
+	if ((fd = open(name, 0)) == -1)
+		return NULL;
+	if (fcntl(fd, F_SETFD, 1) == -1 ||
+	    (dirp = (DIR *)malloc(sizeof(DIR))) == NULL) {
+		close (fd);
+		return NULL;
+	}
+	/*
+	 * If CLSIZE is an exact multiple of DIRBLKSIZ, use a CLSIZE
+	 * buffer that it cluster boundary aligned.
+	 * Hopefully this can be a big win someday by allowing page trades
+	 * to user space to be done by getdirentries()
+	 */
+	if ((CLSIZE % DIRBLKSIZ) == 0) {
+		dirp->dd_buf = malloc(CLSIZE);
+		dirp->dd_len = CLSIZE;
+	} else {
+		dirp->dd_buf = malloc(DIRBLKSIZ);
+		dirp->dd_len = DIRBLKSIZ;
+	}
+	if (dirp->dd_buf == NULL) {
+		close (fd);
+		free(dirp);
+		return NULL;
+	}
+	dirp->dd_fd = fd;
+	dirp->dd_loc = 0;
+	dirp->dd_seek = 0;
+	dirp->dd_ddloc = NULL;
+
+	return dirp;
+}
+
+/*
+ * get next entry in a directory.
+ */
+struct dirent *
+readdir(dirp)
+	register DIR *dirp;
+{
+	register struct dirent *dp;
+
+	for (;;) {
+		if (dirp->dd_loc == 0) {
+			dirp->dd_size = getdirentries(dirp->dd_fd,
+			    dirp->dd_buf, dirp->dd_len, &dirp->dd_seek);
+			if (dirp->dd_size <= 0)
+				return NULL;
+		}
+		if (dirp->dd_loc >= dirp->dd_size) {
+			dirp->dd_loc = 0;
+			continue;
+		}
+		dp = (struct dirent *)(dirp->dd_buf + dirp->dd_loc);
+		if ((int)dp & 03)	/* bogus pointer check */
+			return NULL;
+		if (dp->d_reclen <= 0 ||
+		    dp->d_reclen > dirp->dd_len + 1 - dirp->dd_loc)
+			return NULL;
+		dirp->dd_loc += dp->d_reclen;
+		if (dp->d_ino == 0)
+			continue;
+		return (dp);
+	}
+}
+
+void
+rewinddir(dirp)
+	DIR *dirp;
+{
+	(void)lseek(dirp->dd_fd, 0, 0);
+	dirp->dd_seek = 0;
+	dirp->dd_loc = 0;
+}
+
+/*
+ * Seek to an entry in a directory.
+ * _seekdir is in telldir.c so that it can share opaque data structures.
+ */
+void
+seekdir(dirp, loc)
+	DIR *dirp;
+	long loc;
+{
+	register struct ddloc **prevlp;
+	register struct ddloc *lp;
+	struct dirent *dp;
+	extern long lseek();
+
+	prevlp = (struct ddloc **)&(dirp->dd_ddloc);
+	lp = *prevlp;
+	while (lp != NULL) {
+		if (lp->loc_index == loc)
+			break;
+		prevlp = &lp->loc_next;
+		lp = lp->loc_next;
+	}
+	if (lp) {
+		if (lp->loc_seek != dirp->dd_seek) {
+			if (lseek(dirp->dd_fd, lp->loc_seek, 0) == -1) {
+				*prevlp = lp->loc_next;
+				free(lp);
+				return;
+			}
+			dirp->dd_seek = lp->loc_seek;
+			dirp->dd_loc = 0;
+			while (dirp->dd_loc < lp->loc_loc) {
+				if (!(dp = readdir(dirp))) {
+					*prevlp = lp->loc_next;
+					free(lp);
+					return;
+				}
+			}
+		}
+	}
+}
+
+/*
+ * return a pointer into a directory
+ */
+long
+telldir(dirp)
+	const DIR *dirp;
+{
+	register struct ddloc *lp, **fakeout;
+
+	if (lp = (struct ddloc *)malloc(sizeof(struct ddloc))) {
+		lp->loc_index = dd_loccnt++;
+		lp->loc_seek = dirp->dd_seek;
+		lp->loc_loc = dirp->dd_loc;
+		lp->loc_next = dirp->dd_ddloc;
+
+		/* Compiler won't let us change anything pointed to by db directly */
+		/* So we fake to the left and do it anyway */
+		/* Wonder if the compile optomizes it to the correct solution */
+		fakeout = (struct ddloc **)&(dirp->dd_ddloc);
+		*fakeout = lp;
+
+		return (lp->loc_index);
+	}
+	return (-1);
+}
+