From 7bcf4273696aa5b941add7669c7bc9ef82937fa4 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Mon, 2 Nov 2020 15:31:56 -0800
Subject: [PATCH] Utils: add IsDotOrDotDot() and use it in the appropriate
 places

Change-Id: I704522b26acfb3e7c423d9a14d69ede513b50482
---
 MoveStorage.cpp |  4 +---
 Utils.cpp       | 14 ++++++--------
 Utils.h         |  2 ++
 3 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/MoveStorage.cpp b/MoveStorage.cpp
index 2447cce..3f636a2 100644
--- a/MoveStorage.cpp
+++ b/MoveStorage.cpp
@@ -70,9 +70,7 @@ static bool pushBackContents(const std::string& path, std::vector<std::string>&
     bool found = false;
     struct dirent* ent;
     while ((ent = readdir(dirp.get())) != NULL) {
-        if ((!strcmp(ent->d_name, ".")) || (!strcmp(ent->d_name, ".."))) {
-            continue;
-        }
+        if (IsDotOrDotDot(*ent)) continue;
         auto subdir = path + "/" + ent->d_name;
         found |= pushBackContents(subdir, cmd, searchLevels - 1);
     }
diff --git a/Utils.cpp b/Utils.cpp
index 2e28246..7f53a92 100644
--- a/Utils.cpp
+++ b/Utils.cpp
@@ -956,10 +956,7 @@ int64_t calculate_dir_size(int dfd) {
             int subfd;
 
             /* always skip "." and ".." */
-            if (name[0] == '.') {
-                if (name[1] == 0) continue;
-                if ((name[1] == '.') && (name[2] == 0)) continue;
-            }
+            if (IsDotOrDotDot(*de)) continue;
 
             subfd = openat(dfd, name, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
             if (subfd >= 0) {
@@ -1256,6 +1253,10 @@ status_t UnmountTree(const std::string& mountPoint) {
     return OK;
 }
 
+bool IsDotOrDotDot(const struct dirent& ent) {
+    return strcmp(ent.d_name, ".") == 0 || strcmp(ent.d_name, "..") == 0;
+}
+
 static status_t delete_dir_contents(DIR* dir) {
     // Shamelessly borrowed from android::installd
     int dfd = dirfd(dir);
@@ -1269,10 +1270,7 @@ static status_t delete_dir_contents(DIR* dir) {
         const char* name = de->d_name;
         if (de->d_type == DT_DIR) {
             /* always skip "." and ".." */
-            if (name[0] == '.') {
-                if (name[1] == 0) continue;
-                if ((name[1] == '.') && (name[2] == 0)) continue;
-            }
+            if (IsDotOrDotDot(*de)) continue;
 
             android::base::unique_fd subfd(
                 openat(dfd, name, O_RDONLY | O_DIRECTORY | O_NOFOLLOW | O_CLOEXEC));
diff --git a/Utils.h b/Utils.h
index 5351450..27889c6 100644
--- a/Utils.h
+++ b/Utils.h
@@ -168,6 +168,8 @@ bool IsVirtioBlkDevice(unsigned int major);
 status_t UnmountTreeWithPrefix(const std::string& prefix);
 status_t UnmountTree(const std::string& mountPoint);
 
+bool IsDotOrDotDot(const struct dirent& ent);
+
 status_t DeleteDirContentsAndDir(const std::string& pathname);
 status_t DeleteDirContents(const std::string& pathname);