Avoid overflowing the file buffer

Submitted by:	db
Approved by:	cperciva
MFC after:	2 weeks

1 files changed, 75 insertions, 0 deletions

diff --git a/pw/rm_r.c b/pw/rm_r.c
new file mode 100644
index 0000000..797ca9d
--- /dev/null
+++ b/pw/rm_r.c
@@ -0,0 +1,75 @@
+/*-
+ * Copyright (C) 1996
+ *	David L. Nugent.  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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY DAVID L. NUGENT 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 DAVID L. NUGENT 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.
+ */
+
+#ifndef lint
+static const char rcsid[] =
+  "$FreeBSD$";
+#endif /* not lint */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/param.h>
+#include <unistd.h>
+#include <dirent.h>
+
+#include "pwupd.h"
+
+void
+rm_r(char const * dir, uid_t uid)
+{
+	DIR            *d = opendir(dir);
+
+	if (d != NULL) {
+		struct dirent  *e;
+		struct stat     st;
+		char            file[MAXPATHLEN];
+
+		while ((e = readdir(d)) != NULL) {
+			if (strcmp(e->d_name, ".") != 0 && strcmp(e->d_name, "..") != 0) {
+				snprintf(file, sizeof(file), "%s/%s", dir, e->d_name);
+				if (lstat(file, &st) == 0) {	/* Need symlinks, not
+								 * linked file */
+					if (S_ISDIR(st.st_mode))	/* Directory - recurse */
+						rm_r(file, uid);
+					else {
+						if (S_ISLNK(st.st_mode) || st.st_uid == uid)
+							remove(file);
+					}
+				}
+			}
+		}
+		closedir(d);
+		if (lstat(dir, &st) == 0) {
+			if (S_ISLNK(st.st_mode))
+				remove(dir);
+			else if (st.st_uid == uid)
+				rmdir(dir);
+		}
+	}
+}