set-verity-state: Refactor & remove even more dead code

Remove even more VB1.0 handling dead code.
Log to both logd and stderr.
Print all debug messages to LOG.
Move all non-externals to annonymous namespace.

Bug: 241688845
Test: adb shell set-verity-state [0|1]
Change-Id: Icda795f185f7bc97607b48d0b529ee02a4580b70
diff --git a/set-verity-state/set-verity-state.cpp b/set-verity-state/set-verity-state.cpp
index d8e3d31..31ceaee 100644
--- a/set-verity-state/set-verity-state.cpp
+++ b/set-verity-state/set-verity-state.cpp
@@ -14,85 +14,105 @@
  * limitations under the License.
  */
 
-#include <errno.h>
-#include <libavb_user/libavb_user.h>
 #include <stdio.h>
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <android-base/properties.h>
 #include <fs_mgr_overlayfs.h>
-#include <log/log_properties.h>
+#include <libavb_user/libavb_user.h>
 
 using namespace std::string_literals;
 
-#ifdef ALLOW_DISABLE_VERITY
-static const bool kAllowDisableVerity = true;
-#else
-static const bool kAllowDisableVerity = false;
-#endif
+namespace {
 
-static void suggest_run_adb_root() {
-  if (getuid() != 0) printf("Maybe run adb root?\n");
-}
+#ifdef ALLOW_DISABLE_VERITY
+const bool kAllowDisableVerity = true;
+#else
+const bool kAllowDisableVerity = false;
+#endif
 
 /* Helper function to get A/B suffix, if any. If the device isn't
  * using A/B the empty string is returned. Otherwise either "_a",
  * "_b", ... is returned.
  */
-static std::string get_ab_suffix() {
+std::string get_ab_suffix() {
   return android::base::GetProperty("ro.boot.slot_suffix", "");
 }
 
-static bool is_avb_device_locked() {
+bool is_avb_device_locked() {
   return android::base::GetProperty("ro.boot.vbmeta.device_state", "") == "locked";
 }
 
-static bool overlayfs_setup(bool enable) {
+bool is_debuggable() {
+  return android::base::GetBoolProperty("ro.debuggable", false);
+}
+
+bool is_using_avb() {
+  // Figure out if we're using VB1.0 or VB2.0 (aka AVB) - by
+  // contract, androidboot.vbmeta.digest is set by the bootloader
+  // when using AVB).
+  return !android::base::GetProperty("ro.boot.vbmeta.digest", "").empty();
+}
+
+bool overlayfs_setup(bool enable) {
   auto change = false;
   errno = 0;
   if (enable ? fs_mgr_overlayfs_teardown(nullptr, &change)
              : fs_mgr_overlayfs_setup(nullptr, nullptr, &change)) {
     if (change) {
-      printf("%s overlayfs\n", enable ? "disabling" : "using");
+      LOG(INFO) << (enable ? "disabling" : "using") << " overlayfs";
     }
   } else if (errno) {
-    printf("Overlayfs %s failed with error %s\n", enable ? "teardown" : "setup", strerror(errno));
-    suggest_run_adb_root();
+    PLOG(ERROR) << "Failed to " << (enable ? "teardown" : "setup") << " overlayfs";
   }
   return change;
 }
 
 /* Use AVB to turn verity on/off */
-static bool set_avb_verity_enabled_state(AvbOps* ops, bool enable_verity) {
+bool set_avb_verity_enabled_state(AvbOps* ops, bool enable_verity) {
   std::string ab_suffix = get_ab_suffix();
   bool verity_enabled;
 
   if (is_avb_device_locked()) {
-    printf("Device is locked. Please unlock the device first\n");
+    LOG(ERROR) << "Device is locked. Please unlock the device first";
     return false;
   }
 
   if (!avb_user_verity_get(ops, ab_suffix.c_str(), &verity_enabled)) {
-    printf("Error getting verity state. Try adb root first?\n");
+    LOG(ERROR) << "Error getting verity state";
     return false;
   }
 
   if ((verity_enabled && enable_verity) || (!verity_enabled && !enable_verity)) {
-    printf("verity is already %s\n", verity_enabled ? "enabled" : "disabled");
+    LOG(INFO) << "verity is already " << (verity_enabled ? "enabled" : "disabled");
     return false;
   }
 
   if (!avb_user_verity_set(ops, ab_suffix.c_str(), enable_verity)) {
-    printf("Error setting verity\n");
+    LOG(ERROR) << "Error setting verity state";
     return false;
   }
 
-  printf("Successfully %s verity\n", enable_verity ? "enabled" : "disabled");
+  LOG(INFO) << "Successfully " << (enable_verity ? "enabled" : "disabled") << " verity";
   return true;
 }
 
+void MyLogger(android::base::LogId id, android::base::LogSeverity severity, const char* tag,
+              const char* file, unsigned int line, const char* message) {
+  // Hide log starting with '[fs_mgr]' unless it's an error.
+  if (severity == android::base::ERROR || message[0] != '[') {
+    fprintf(stderr, "%s\n", message);
+  }
+  static auto logd = android::base::LogdLogger();
+  logd(id, severity, tag, file, line, message);
+}
+
+}  // namespace
+
 int main(int argc, char* argv[]) {
+  android::base::InitLogging(argv, MyLogger);
+
   if (argc == 0) {
     LOG(FATAL) << "set-verity-state called with empty argv";
   }
@@ -110,44 +130,30 @@
     return 1;
   }
 
-  // Figure out if we're using VB1.0 or VB2.0 (aka AVB) - by
-  // contract, androidboot.vbmeta.digest is set by the bootloader
-  // when using AVB).
-  bool using_avb = !android::base::GetProperty("ro.boot.vbmeta.digest", "").empty();
-
-  // If using AVB, dm-verity is used on any build so we want it to
-  // be possible to disable/enable on any build (except USER). For
-  // VB1.0 dm-verity is only enabled on certain builds.
-  if (!using_avb) {
-    if (!kAllowDisableVerity) {
-      printf("%s only works for userdebug builds\n", argv[0]);
-    }
-
-    if (!android::base::GetBoolProperty("ro.secure", false)) {
-      overlayfs_setup(enable);
-      printf("verity not enabled - ENG build\n");
-      return 0;
-    }
+  if (!kAllowDisableVerity || !is_debuggable()) {
+    errno = EPERM;
+    PLOG(ERROR) << "Cannot disable/enable verity on user build";
+    return 1;
   }
 
-  // Should never be possible to disable dm-verity on a USER build
-  // regardless of using AVB or VB1.0.
-  if (!__android_log_is_debuggable()) {
-    printf("verity cannot be disabled/enabled - USER build\n");
-    return 0;
+  if (getuid() != 0) {
+    errno = EACCES;
+    PLOG(ERROR) << "Must be running as root (adb root)";
+    return 1;
   }
 
-  bool any_changed = false;
-  if (using_avb) {
-    // Yep, the system is using AVB.
-    AvbOps* ops = avb_ops_user_new();
-    if (ops == nullptr) {
-      printf("Error getting AVB ops\n");
-      return 1;
-    }
-    any_changed |= set_avb_verity_enabled_state(ops, enable);
-    avb_ops_user_free(ops);
+  if (!is_using_avb()) {
+    LOG(ERROR) << "Expected AVB device, VB1.0 is no longer supported";
+    return 1;
   }
+
+  std::unique_ptr<AvbOps, decltype(&avb_ops_user_free)> ops(avb_ops_user_new(), &avb_ops_user_free);
+  if (!ops) {
+    LOG(ERROR) << "Error getting AVB ops";
+    return 1;
+  }
+
+  bool any_changed = set_avb_verity_enabled_state(ops.get(), enable);
   any_changed |= overlayfs_setup(enable);
 
   if (any_changed) {