1 files changed, 116 insertions, 0 deletions

diff --git a/otautil/dirutil.cpp b/otautil/dirutil.cpp
new file mode 100644
index 000000000..ae1cd5c28
--- /dev/null
+++ b/otautil/dirutil.cpp
@@ -0,0 +1,116 @@
+/*
+ * Copyright (C) 2007 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "otautil/dirutil.h"
+
+#include <dirent.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <string>
+
+#include <selinux/label.h>
+#include <selinux/selinux.h>
+
+enum class DirStatus { DMISSING, DDIR, DILLEGAL };
+
+static DirStatus dir_status(const std::string& path) {
+  struct stat sb;
+  if (stat(path.c_str(), &sb) == 0) {
+    // Something's there; make sure it's a directory.
+    if (S_ISDIR(sb.st_mode)) {
+      return DirStatus::DDIR;
+    }
+    errno = ENOTDIR;
+    return DirStatus::DILLEGAL;
+  } else if (errno != ENOENT) {
+    // Something went wrong, or something in the path is bad. Can't do anything in this situation.
+    return DirStatus::DILLEGAL;
+  }
+  return DirStatus::DMISSING;
+}
+
+int mkdir_recursively(const std::string& input_path, mode_t mode, bool strip_filename,
+                      const selabel_handle* sehnd) {
+  // Check for an empty string before we bother making any syscalls.
+  if (input_path.empty()) {
+    errno = ENOENT;
+    return -1;
+  }
+
+  // Allocate a path that we can modify; stick a slash on the end to make things easier.
+  std::string path = input_path;
+  if (strip_filename) {
+    // Strip everything after the last slash.
+    size_t pos = path.rfind('/');
+    if (pos == std::string::npos) {
+      errno = ENOENT;
+      return -1;
+    }
+    path.resize(pos + 1);
+  } else {
+    // Make sure that the path ends in a slash.
+    path.push_back('/');
+  }
+
+  // See if it already exists.
+  DirStatus ds = dir_status(path);
+  if (ds == DirStatus::DDIR) {
+    return 0;
+  } else if (ds == DirStatus::DILLEGAL) {
+    return -1;
+  }
+
+  // Walk up the path from the root and make each level.
+  size_t prev_end = 0;
+  while (prev_end < path.size()) {
+    size_t next_end = path.find('/', prev_end + 1);
+    if (next_end == std::string::npos) {
+      break;
+    }
+    std::string dir_path = path.substr(0, next_end);
+    // Check this part of the path and make a new directory if necessary.
+    switch (dir_status(dir_path)) {
+      case DirStatus::DILLEGAL:
+        // Could happen if some other process/thread is messing with the filesystem.
+        return -1;
+      case DirStatus::DMISSING: {
+        char* secontext = nullptr;
+        if (sehnd) {
+          selabel_lookup(const_cast<selabel_handle*>(sehnd), &secontext, dir_path.c_str(), mode);
+          setfscreatecon(secontext);
+        }
+        int err = mkdir(dir_path.c_str(), mode);
+        if (secontext) {
+          freecon(secontext);
+          setfscreatecon(nullptr);
+        }
+        if (err != 0) {
+          return -1;
+        }
+        break;
+      }
+      default:
+        // Already exists.
+        break;
+    }
+    prev_end = next_end;
+  }
+  return 0;
+}