Support mountable-content DLC (addcont with real content) (#1581)

Support mountable-content DLC (addcont) and fix PlayGo chunk count query

src/kernel/fileSystem.cpp

@@ -338,14 +338,20 @@ static bool HasWindowsForbiddenFilenameCharacter(const std::string& relative_pat
 std::filesystem::path MountPoints::ResolvePath(const std::string& mounted_name) {
 	Common::LockGuard lock(m_mutex);
 
+	// Guests join mount points and names with extra slashes (e.g. "/addcont0//file").
+	std::string normalized = Common::FixFilenameSlash(mounted_name);
+	normalized.erase(std::unique(normalized.begin(), normalized.end(),
+	                             [](char a, char b) { return a == '/' && b == '/'; }),
+	                 normalized.end());
+
 	// Match the entire guest path so a mount root works with or without a trailing slash.
-	const auto mounted_path = Common::FixDirectorySlash(mounted_name);
+	const auto mounted_path = Common::FixDirectorySlash(normalized);
 	const auto it           = std::find_if(
 	    m_mount_pairs.begin(), m_mount_pairs.end(),
 	    [&mounted_path](const MountPair& p) { return mounted_path.starts_with(p.point); });
 	if (it != m_mount_pairs.end()) {
 		const auto& p = *it;
-		auto rel_path = Common::RemoveFirst(Common::FixFilenameSlash(mounted_name), p.point.size());
+		auto rel_path = Common::RemoveFirst(normalized, p.point.size());
 		while (rel_path.starts_with('/')) {
 			rel_path = Common::RemoveFirst(rel_path, 1);
 		}

src/libs/libAmpr.cpp

@@ -25,6 +25,9 @@
 #include <string>
 #include <thread>
 #include <unordered_map>
+#include <atomic>
+#include <cinttypes>
+#include <iterator>
 #include <variant>
 #include <vector>
 
@@ -176,6 +179,14 @@ static int GetHostPathStat(const std::filesystem::path& host_path, LibKernel::Fi
 	return OK;
 }
 
+// Mounts can appear after a failed lookup (e.g. additional content), so forget negative results.
+void InvalidateFailedResolves() {
+	std::scoped_lock lock(g_mutex);
+	for (auto it = g_resolved_paths.begin(); it != g_resolved_paths.end();) {
+		it = it->second.result != OK ? g_resolved_paths.erase(it) : std::next(it);
+	}
+}
+
 static int ResolveOnePath(const char* guest_path, uint32_t* id, uint64_t* size) {
 	if (guest_path == nullptr || guest_path[0] == '\0') {
 		return LibKernel::KERNEL_ERROR_EINVAL;
@@ -225,6 +236,10 @@ static int ResolveOnePath(const char* guest_path, uint32_t* id, uint64_t* size)
 				log_missing = true;
 			}
 		}
+		if (!log_missing && info.result == OK && path.starts_with("/addcont")) {
+			LOGF("\tAPR resolve: %s -> %s (%" PRIu64 " bytes)\n", guest_path,
+			     Common::PathToString(info.host_path).c_str(), info.file_size);
+		}
 		if (log_missing) {
 			LOGF("\tAPR resolve missing path: %s -> %s\n", guest_path, Common::PathToString(info.host_path).c_str());
 		}
@@ -1181,6 +1196,13 @@ static int ExecuteCommand(const CommandBufferState::Command& entry) {
 		uint64_t bytes_read = 0;
 		auto     result = ReadHostFileToGuest(host_path, command.file_offset, command.destination,
 		                                      command.size, &bytes_read);
+		static std::atomic<uint32_t> s_logged_dlc_reads {0};
+		if (host_path.filename() == "re_dlc_000.pak" && s_logged_dlc_reads.fetch_add(1) < 32) {
+			LOGF("\tAPR read dlc: id=0x%08" PRIx32 ", offset=0x%016" PRIx64 ", size=0x%016" PRIx64
+			     ", read=0x%016" PRIx64 ", result=0x%08" PRIx32 "\n",
+			     command.file_id, command.file_offset, command.size, bytes_read,
+			     static_cast<uint32_t>(result));
+		}
 		if (result != OK) {
 			LOGF("\tAPR submit read failed: id=0x%08" PRIx32 ", result=0x%08" PRIx32 ", path=%s\n",
 			     command.file_id, static_cast<uint32_t>(result), Common::PathToString(host_path).c_str());

src/libs/libAppContent.cpp

@@ -22,13 +22,16 @@
 
 namespace Libs {
 
+namespace AprShared {
+void InvalidateFailedResolves();
+}
+
 LIB_VERSION("AppContent", 1, "AppContentUtil", 1, 1);
 
 namespace AppContent {
 
 constexpr uint32_t APP_CONTENT_APPPARAM_SKU_FLAG_FULL = 3;
 constexpr int      APP_CONTENT_ERROR_PARAMETER        = -2133262334; /* 0x80D90002 */
-constexpr int      APP_CONTENT_ERROR_BUSY             = -2133262333; /* 0x80D90003 */
 constexpr int      APP_CONTENT_ERROR_NOT_MOUNTED      = -2133262332; /* 0x80D90004 */
 constexpr int      APP_CONTENT_ERROR_NOT_FOUND        = -2133262331; /* 0x80D90005 */
 constexpr int      APP_CONTENT_ERROR_MOUNT_FULL       = -2133262330; /* 0x80D90006 */
@@ -207,7 +210,10 @@ int KYTY_SYSV_ABI AppContentAddcontMount(uint32_t                         servic
 
 	for (const auto& m: g_addcont_mounts) {
 		if (m.label == entry->entitlement_label) {
-			return APP_CONTENT_ERROR_BUSY;
+			const auto guest_point = m.point.substr(0, m.point.size() - 1);
+			std::strncpy(mount_point->data, guest_point.c_str(), sizeof(mount_point->data) - 1);
+			LOGF("\t already mounted %s\n", guest_point.c_str());
+			return OK;
 		}
 	}
 
@@ -232,7 +238,15 @@ int KYTY_SYSV_ABI AppContentAddcontMount(uint32_t                         servic
 	LOGF("\t mounted %s -> %s\n", mount.point.c_str(),
 	     Common::PathToString(entry->mount_dir).c_str());
 
-	std::strncpy(mount_point->data, mount.point.c_str(), sizeof(mount_point->data) - 1);
+	AprShared::InvalidateFailedResolves();
+
+	// Titles scan /download0/pdlc for downloaded content; it must exist even when empty.
+	if (const auto pdlc = LibKernel::FileSystem::GetRealFilename("/download0/pdlc"); !pdlc.empty()) {
+		std::filesystem::create_directories(pdlc, ec);
+	}
+
+	const auto guest_point = mount.point.substr(0, mount.point.size() - 1);
+	std::strncpy(mount_point->data, guest_point.c_str(), sizeof(mount_point->data) - 1);
 	g_addcont_mounts.push_back(std::move(mount));
 
 	return OK;
@@ -251,8 +265,8 @@ int KYTY_SYSV_ABI AppContentAddcontUnmount(const AppContentMountPoint* mount_poi
 		return APP_CONTENT_ERROR_NOT_MOUNTED;
 	}
 
-	const std::string point(mount_point->data,
+	const std::string point = Common::FixDirectorySlash(
-	                        strnlen(mount_point->data, sizeof(mount_point->data)));
+	    std::string_view(mount_point->data, strnlen(mount_point->data, sizeof(mount_point->data))));
 
 	std::lock_guard lock(g_addcont_mutex);
 
@@ -263,6 +277,7 @@ int KYTY_SYSV_ABI AppContentAddcontUnmount(const AppContentMountPoint* mount_poi
 	}
 	LibKernel::FileSystem::Umount(point);
 	g_addcont_mounts.erase(it);
+	AprShared::InvalidateFailedResolves();
 
 	return OK;
 }

src/libs/libPlayGo.cpp

@@ -221,11 +221,17 @@ int KYTY_SYSV_ABI PlayGoGetChunkId(int handle, uint16_t* out_chunk_id_list,
 	if (out_entries == nullptr) {
 		return PLAYGO_ERROR_BAD_POINTER;
 	}
-	if (number_of_entries != 0 && out_chunk_id_list == nullptr) {
+	if (out_chunk_id_list != nullptr && number_of_entries == 0) {
-		return PLAYGO_ERROR_BAD_POINTER;
+		return PLAYGO_ERROR_BAD_SIZE;
 	}
 	ensure_chunks_loaded();
 
+	// A null output buffer asks for the total chunk count.
+	if (out_chunk_id_list == nullptr) {
+		*out_entries = g_chunks_num;
+		return OK;
+	}
+
 	const uint32_t entries = std::min(number_of_entries, g_chunks_num);
 	for (uint32_t i = 0; i < entries; i++) {
 		out_chunk_id_list[i] = static_cast<uint16_t>(i);

tests/KernelFileSystemTests.cpp

@@ -413,7 +413,9 @@ void TestAddContent(const std::filesystem::path& root) {
   Check(mount(0, nullptr, &point) == static_cast<int>(0x80d90002u) &&
             list(0, nullptr, 0, nullptr) == static_cast<int>(0x817d0002u),
         "null add-on parameters return parameter errors");
-  Check(mount(0, &info[3].label, &point) == OK, "mount owned add-on");
+  Check(mount(0, &info[3].label, &point) == OK &&
+            !std::string_view(point.data).ends_with('/'),
+        "mount owned add-on without trailing slash");
   const std::string mounted_file = std::string(point.data) + "/payload.txt";
   const int fd = FileSystem::KernelOpen(mounted_file.c_str(), 0, 0);
   std::array<char, 11> payload {};
@@ -422,8 +424,9 @@ void TestAddContent(const std::filesystem::path& root) {
             FileSystem::KernelClose(fd) == OK,
         "guest reads files from the selected title's add-on");
   MountPoint repeated {};
-  Check(mount(0, &info[3].label, &repeated) == static_cast<int>(0x80d90003u),
+  Check(mount(0, &info[3].label, &repeated) == OK &&
-        "duplicate mount returns BUSY");
+            std::strcmp(repeated.data, point.data) == 0,
+        "duplicate mount returns the same mount point");
   Check(unmount(&point) == OK && FileSystem::GetRealFilename(mounted_file).empty() &&
             unmount(&point) == static_cast<int>(0x80d90004u),
         "unmount removes mapping and repeated unmount reports NOT_MOUNTED");