From 03e02f71013eb957f0c6c09db5982106558fdeb2 Mon Sep 17 00:00:00 2001
From: huangyuchen <huangyuchen3@huawei.com>
Date: Sun, 25 Jun 2023 16:49:20 +0800
Subject: [PATCH] Fix failing to remove a dangling symlink file in
 `ForceRemoveDirectory`.

1. Replace `access` to `faccessat`
2. Add related test cases.

Issue:I7FUB2
Test:UT

Signed-off-by: huangyuchen <huangyuchen3@huawei.com>
Change-Id: I8409f783ed9eb88a06517c26f7120989278c70b3
---
 base/src/directory_ex.cpp                     |  9 +--
 .../unittest/common/utils_directory_test.cpp  | 72 ++++++++++++++++++-
 2 files changed, 76 insertions(+), 5 deletions(-)

diff --git a/base/src/directory_ex.cpp b/base/src/directory_ex.cpp
index dd8e6f7..9e79b9b 100644
--- a/base/src/directory_ex.cpp
+++ b/base/src/directory_ex.cpp
@@ -15,7 +15,8 @@
 
 #include "directory_ex.h"
 #include <dirent.h>
-#include <errno.h>
+#include <cerrno>
+#include <fcntl.h>
 #include "securec.h"
 #include "unistd.h"
 #include "utils_log.h"
@@ -217,7 +218,7 @@ bool ForceRemoveDirectory(const string& path)
         if (ptr->d_type == DT_DIR) {
             ret = ForceRemoveDirectory(subPath);
         } else {
-            if (access(subPath.c_str(), F_OK) == 0) {
+            if (faccessat(AT_FDCWD, subPath.c_str(), F_OK, AT_SYMLINK_NOFOLLOW) == 0) {
                 if (remove(subPath.c_str()) != 0) {
                     closedir(dir);
                     return false;
@@ -228,13 +229,13 @@ bool ForceRemoveDirectory(const string& path)
     closedir(dir);
 
     string currentPath = ExcludeTrailingPathDelimiter(path);
-    if (access(currentPath.c_str(), F_OK) == 0) {
+    if (faccessat(AT_FDCWD, currentPath.c_str(), F_OK, AT_SYMLINK_NOFOLLOW) == 0) {
         if (remove(currentPath.c_str()) != 0) {
             return false;
         }
     }
 
-    return ret && (access(path.c_str(), F_OK) != 0);
+    return ret && (faccessat(AT_FDCWD, path.c_str(), F_OK, AT_SYMLINK_NOFOLLOW) != 0);
 }
 
 bool RemoveFile(const string& fileName)
diff --git a/base/test/unittest/common/utils_directory_test.cpp b/base/test/unittest/common/utils_directory_test.cpp
index d8d0f95..3ac7148 100644
--- a/base/test/unittest/common/utils_directory_test.cpp
+++ b/base/test/unittest/common/utils_directory_test.cpp
@@ -12,11 +12,14 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-#include <gtest/gtest.h>
+
 #include "directory_ex.h"
+#include <gtest/gtest.h>
+#include <fcntl.h>
 #include <algorithm>
 #include <iostream>
 #include <fstream>
+
 using namespace testing::ext;
 using namespace std;
 
@@ -212,6 +215,73 @@ HWTEST_F(UtilsDirectoryTest, testRemoveFile001, TestSize.Level0)
     EXPECT_EQ(ret, true);
 }
 
+/*
+ * @tc.name: testRemoveFile002
+ * @tc.desc: Remove soft link file.
+ */
+HWTEST_F(UtilsDirectoryTest, testRemoveFile002, TestSize.Level0)
+{
+    string dirpath = "/data/test_dir";
+    bool ret = ForceCreateDirectory(dirpath);
+    EXPECT_EQ(ret, true);
+
+    string targetname = "/data/test_target.txt";
+    FILE *fp = fopen(targetname.c_str(), "w");
+    if (NULL != fp) {
+        fclose(fp);
+    }
+
+    // symlink to a directory
+    string linkpath = "/data/test_symlink_dir";
+    int res = symlink(dirpath.c_str(), linkpath.c_str());
+    EXPECT_EQ(res, 0);
+
+    ret = ForceRemoveDirectory(linkpath);
+    EXPECT_EQ(ret, true);
+
+    // Target dir is not removed.
+    ret = faccessat(AT_FDCWD, dirpath.c_str(), F_OK, AT_SYMLINK_NOFOLLOW);
+    EXPECT_EQ(ret, 0);
+
+    // symlink to a file
+    string filename = dirpath + "/test.txt";
+    res = symlink(targetname.c_str(), filename.c_str());
+    EXPECT_EQ(res, 0);
+
+    ret = ForceRemoveDirectory(dirpath);
+    EXPECT_EQ(ret, true);
+
+    // Target file is not removed.
+    ret = faccessat(AT_FDCWD, targetname.c_str(), F_OK, AT_SYMLINK_NOFOLLOW);
+    EXPECT_EQ(ret, 0);
+
+    ret = RemoveFile(targetname);
+    EXPECT_EQ(ret, true);
+}
+
+/*
+ * @tc.name: testRemoveFile003
+ * @tc.desc: Remove dangling soft link file.
+ */
+HWTEST_F(UtilsDirectoryTest, testRemoveFile003, TestSize.Level0)
+{
+    string dirpath = "/data/test_dir";
+    bool ret = ForceCreateDirectory(dirpath);
+    EXPECT_EQ(ret, true);
+
+    // symlink to a file
+    string targetname = "/data/nonexisted.txt";
+    string filename = dirpath + "/test.txt";
+    int res = symlink(targetname.c_str(), filename.c_str());
+    EXPECT_EQ(res, 0);
+
+    ret = ForceRemoveDirectory(dirpath);
+    EXPECT_EQ(ret, true);
+
+    ret = RemoveFile(targetname);
+    EXPECT_EQ(ret, true);
+}
+
 /*
  * @tc.name: testGetFolderSize001
  * @tc.desc: directory unit test
-- 
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