diff --git a/libc/bionic/bionic_appcompat.cpp b/libc/bionic/bionic_appcompat.cpp
new file mode 100644
index 0000000..5b31c29
--- /dev/null
+++ b/libc/bionic/bionic_appcompat.cpp
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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 THE COPYRIGHT HOLDERS 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
+ * COPYRIGHT OWNER 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.
+ */
+
+// b/170214442: Intercept bind calls on NETLINK_ROUTE sockets and getifaddrs() calls.
+// This entire file will be reverted before release.
+
+#include <async_safe/log.h>
+#include <cutils/misc.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "bionic_appcompat.h"
+
+bool should_apply_soft_mac_restrictions(const char* const allowlist[]) {
+  if (getuid() < FIRST_APPLICATION_UID) {
+    // System app. No restrictions should be applied.
+    return false;
+  }
+  if (android_get_application_target_sdk_version() >= __ANDROID_API_R__) {
+    // Restrictions already applied by SELinux. Behave as normally.
+    return false;
+  }
+
+  char package_name[MAX_PACKAGE_NAME_LENGTH + 1];
+  if (get_package_name(package_name, sizeof(package_name)) < 0) {
+    // Error in getting own package name. Apply restrictions by default.
+    async_safe_format_log(ANDROID_LOG_ERROR, "mac-restrictions",
+                          "Could not determine own package name for uid %d", getuid());
+    return true;
+  }
+  for (int i = 0; allowlist[i] != nullptr; i++) {
+    if (strcmp(package_name, allowlist[i]) == 0) {
+      async_safe_format_log(ANDROID_LOG_WARN, "mac-restrictions",
+                            "Temporarily allowing %s to bypass MAC address restrictions.",
+                            package_name);
+      return false;
+    }
+  }
+  return true;
+}
+
+bool should_apply_soft_mac_bind_restrictions() {
+  return should_apply_soft_mac_restrictions(soft_mac_bind_allowlist);
+}
+
+bool should_apply_soft_mac_getlink_restrictions() {
+  return should_apply_soft_mac_restrictions(soft_mac_getlink_allowlist);
+}
+
+int get_package_name(char* buffer, const int bufferlen) {
+  int file = open("/proc/self/cmdline", O_RDONLY | O_CLOEXEC);
+  if (file < 0) {
+    return file;
+  }
+
+  ssize_t len = read(file, buffer, bufferlen - 1);
+  if (len < 0) {
+    close(file);
+    return -1;
+  }
+  buffer[len] = 0;
+
+  close(file);
+  return 0;
+}
\ No newline at end of file