Recursively list directories that break encryption

If we're unable to set or change encryption policy because the
directory is not empty, log the contents that cause the problem

Bug: 78592001
Test: adb shell mkdir -p /data/media/10/foo, then create second user
Change-Id: I87cc46f09551728a7949659b21ae0401ae253e5e

2 files changed, 26 insertions, 0 deletions

diff --git a/ext4_utils/Android.bp b/ext4_utils/Android.bp
index 817cdff5..8530c91a 100644
--- a/ext4_utils/Android.bp
+++ b/ext4_utils/Android.bp
@@ -36,6 +36,7 @@ cc_library {
             shared_libs: [
                 "libbase",
                 "libkeyutils",
+                "liblogwrap",
                 "libselinux",
             ],
 
diff --git a/ext4_utils/ext4_crypt.cpp b/ext4_utils/ext4_crypt.cpp
index f392046a..bdf80b09 100644
--- a/ext4_utils/ext4_crypt.cpp
+++ b/ext4_utils/ext4_crypt.cpp
@@ -16,6 +16,8 @@
 
 #include "ext4_utils/ext4_crypt.h"
 
+#include <array>
+
 #include <asm/ioctl.h>
 #include <dirent.h>
 #include <errno.h>
@@ -29,6 +31,8 @@
 #include <android-base/file.h>
 #include <android-base/logging.h>
 #include <cutils/properties.h>
+#include <logwrap/logwrap.h>
+#include <utils/misc.h>
 
 #define XATTR_NAME_ENCRYPTION_POLICY "encryption.policy"
 #define EXT4_KEYREF_DELIMITER ((char)'.')
@@ -72,6 +76,25 @@ bool e4crypt_is_native() {
     return !strcmp(value, "file");
 }
 
+static void log_lslr(const char* dirname) {
+    std::array<const char*, 3> argv = {"ls", "-lR", dirname};
+    int status = 0;
+    auto res =
+        android_fork_execvp(argv.size(), const_cast<char**>(argv.data()), &status, false, true);
+    if (res != 0) {
+        PLOG(ERROR) << "ls -lR " << dirname << "failed";
+        return;
+    }
+    if (!WIFEXITED(status)) {
+        LOG(ERROR) << "ls -lR " << dirname << " did not exit normally, status: " << status;
+        return;
+    }
+    if (WEXITSTATUS(status) != 0) {
+        LOG(ERROR) << "ls -lR " << dirname << " returned failure: " << WEXITSTATUS(status);
+        return;
+    }
+}
+
 static void policy_to_hex(const char* policy, char* hex) {
     for (size_t i = 0, j = 0; i < EXT4_KEY_DESCRIPTOR_SIZE; i++) {
         hex[j++] = HEX_LOOKUP[(policy[i] & 0xF0) >> 4];
@@ -178,6 +201,7 @@ static bool e4crypt_policy_get(const char *directory, char *policy,
     if (ioctl(fd, EXT4_IOC_GET_ENCRYPTION_POLICY, &eep) != 0) {
         PLOG(ERROR) << "Failed to get encryption policy for " << directory;
         close(fd);
+        log_lslr(directory);
         return false;
     }
     close(fd);
@@ -216,6 +240,7 @@ static bool e4crypt_policy_check(const char *directory, const char *policy,
         policy_to_hex(policy, policy_hex);
         LOG(ERROR) << "Found policy " << existing_policy_hex << " at " << directory
                    << " which doesn't match expected value " << policy_hex;
+        log_lslr(directory);
         return false;
     }
     LOG(INFO) << "Found policy " << existing_policy_hex << " at " << directory