support exporting UAB in "onlyApp" mode

.reuse/dep5

@@ -146,3 +146,8 @@ Copyright: UnionTech Software Technology Co., Ltd.
 Files: misc/image/*.jpeg misc/image/*.svg
 License: LGPL-3.0-or-later
 Copyright: UnionTech Software Technology Co., Ltd.
+
+# uab black list
+Files: misc/share/linglong/builder/uab/blacklist
+License: MIT
+Copyright: AppImageCommunity

api/schema/v1.json

@@ -216,6 +216,10 @@
           "type": "string",
           "const": "1"
         },
+        "onlyApp": {
+          "description": "whether this UAB file has been exported in only-App mode.",
+          "type": "boolean"
+        },
         "sections": {
           "type": "object",
           "required": [

api/schema/v1.yaml

@@ -181,6 +181,9 @@ $defs:
         description: The format version of linglong.meta data.
         type: string
         const: '1'
+      onlyApp:
+        description: whether this UAB file has been exported in only-App mode.
+        type: boolean
       sections:
         type: object
         required:

apps/ll-box/src/container/container.cpp

@@ -362,8 +362,11 @@ struct ContainerPrivate
         // default link
         for (const auto &[from, to] : linkMap) {
             if (auto ret = symlink(from.data(), to.data()); ret == -1) {
-                logErr() << "symlink" << from << "to" << to << "failed:" << util::RetErrString(ret);
-                return -1;
+                if (errno != EEXIST) {
+                    logErr() << "symlink" << from << "to" << to
+                             << "failed:" << util::RetErrString(ret);
+                    return -1;
+                }
             }
         }
 
@@ -545,49 +548,44 @@ struct ContainerPrivate
             return -1;
         }
 
-        int flag = MS_BIND | MS_REC;
-        ret = mount(".", ".", "bind", flag, nullptr);
-        if (0 != ret) {
+        int flag = MS_SILENT | MS_BIND | MS_REC;
+        ret = mount(".", ".", nullptr, flag, nullptr);
+        if (ret < 0) {
             logErr() << "mount / failed" << util::RetErrString(ret);
             return -1;
         }
 
-        const auto *llHostFilename = "ll-host";
-        auto llHostInPath = std::string{ "/run/" } + llHostFilename;
-        auto llHostOutPath = hostRoot + llHostInPath;
-        ret = mkdir(llHostOutPath.c_str(), 0755);
-        if (ret != 0) {
-            logErr() << "mkdir" << llHostOutPath << "err:" << util::RetErrString(ret);
-            return -1;
-        }
-
-        ret = syscall(SYS_pivot_root, hostRoot.c_str(), llHostOutPath.c_str());
-        if (0 != ret) {
-            logErr() << "SYS_pivot_root failed" << hostRoot << util::errnoString() << errno << ret;
+        // pivot with fd
+        int oldRootFd = open("/", O_DIRECTORY | O_PATH | O_CLOEXEC);
+        int newRootFd = open(hostRoot.c_str(), O_DIRECTORY | O_RDONLY | O_CLOEXEC);
+        ret = fchdir(newRootFd);
+        if (ret < 0) {
+            logErr() << "fchdir new root" << newRootFd << "failed:" << util::RetErrString(ret);
             return -1;
         }
 
-        ret = chdir("/");
-        if (ret != 0) {
-            logErr() << "chdir to root [before chroot]:" << util::RetErrString(ret);
+        ret = syscall(SYS_pivot_root, ".", ".");
+        if (ret < 0) {
+            logErr() << "SYS_pivot_root" << hostRoot << "failed:" << util::errnoString() << errno
+                     << ret;
             return -1;
         }
 
-        ret = chroot(".");
-        if (0 != ret) {
-            logErr() << "chroot failed" << hostRoot << util::errnoString() << errno;
+        ret = fchdir(oldRootFd);
+        if (ret < 0) {
+            logErr() << "fchdir old root" << oldRootFd << "failed:" << util::RetErrString(ret);
             return -1;
         }
 
-        ret = chdir("/");
-        if (ret != 0) {
-            logErr() << "chdir to root [after chroot]:" << util::RetErrString(ret);
+        ret = mount(".", ".", NULL, MS_SILENT | MS_REC | MS_PRIVATE, NULL);
+        if (ret < 0) {
+            logErr() << "mount old root" << oldRootFd << "failed:" << util::RetErrString(ret);
             return -1;
         }
 
-        ret = umount2(llHostInPath.c_str(), MNT_DETACH);
-        if (ret != 0) {
-            logErr() << "umount2" << llHostInPath << "err:" << util::RetErrString(ret);
+        ret = umount2(".", MNT_DETACH);
+        if (ret < 0) {
+            logErr() << "umount old root" << oldRootFd << "failed:" << util::RetErrString(ret);
             return -1;
         }
 

apps/ll-box/src/container/mount/filesystem_driver.cpp

@@ -6,12 +6,13 @@
 
 #include "filesystem_driver.h"
 
 #include "util/logger.h"
 #include "util/platform.h"
 
+#include <cerrno>
 #include <utility>
 
 #include <sys/wait.h>
 
 namespace linglong {
 
@@ -97,7 +98,10 @@
 
     auto host_destination_path = util::fs::path(root_path_) / container_destination_path;
 
-    util::fs::create_directories(host_destination_path, dest_mode);
+    if (!util::fs::create_directories(host_destination_path, dest_mode)) {
+        logErr() << "failed to create" << host_destination_path;
+        return -1;
+    }
 
     return 0;
 }

apps/ll-box/src/util/filesystem.cpp

@@ -40,10 +40,11 @@ bool create_directories(const path &p, __mode_t mode)
 
         auto ret = mkdir(fullPath.c_str(), mode);
         if (0 != ret) {
-            logErr() << util::RetErrString(errno) << fullPath << mode;
+            logErr() << util::RetErrString(ret) << fullPath << mode;
             return false;
         }
     }
+
     return true;
 }
 

apps/ll-builder/src/main.cpp

@@ -285,16 +285,17 @@ You can report bugs to the linyaps team under this project: https://github.com/O
 
     // build export
     bool layerMode = false;
-    std::string iconFile;
-    auto buildExport = commandParser.add_subcommand("export", _("Export to linyaps layer or uab"));
+    linglong::builder::UABOption UABOption{ .exportDevelop = false, .exportI18n = true };
+    auto *buildExport = commandParser.add_subcommand("export", _("Export to linyaps layer or uab"));
     buildExport->usage(_("Usage: ll-builder export [OPTIONS]"));
     buildExport->add_option("-f, --file", filePath, _("File path of the linglong.yaml"))
       ->type_name("FILE")
       ->capture_default_str()
       ->check(CLI::ExistingFile);
-    buildExport->add_option("--icon", iconFile, _("Uab icon (optional)"))
+    buildExport->add_option("--icon", UABOption.iconPath, _("Uab icon (optional)"))
       ->type_name("FILE")
       ->check(CLI::ExistingFile);
+    buildExport->add_flag("--only-app", UABOption.onlyApp, _("Export uab in only-app mode"));
     buildExport->add_flag("--layer", layerMode, _("Export to linyaps layer file"));
 
     // build push
@@ -759,10 +760,7 @@ You can report bugs to the linyaps team under this project: https://github.com/O
             return 0;
         }
 
-        auto result = builder.exportUAB(QDir::currentPath(),
-                                        { .iconPath = QString::fromStdString(iconFile),
-                                          .exportDevelop = true,
-                                          .exportI18n = true });
+        auto result = builder.exportUAB(QDir::currentPath(), UABOption);
         if (!result) {
             qCritical() << result.error();
             return -1;

apps/uab/header/src/main.cpp

@@ -64,6 +64,10 @@ std::string resolveRealPath(std::string_view source) noexcept
 
 std::string detectLinglong() noexcept
 {
+    if (::getenv("LINGLONG_UAB_DIRECT_EXEC") != nullptr) {
+        return {};
+    }
+
     auto *pathPtr = ::getenv("PATH");
     if (pathPtr == nullptr) {
         std::cerr << "failed to get PATH" << std::endl;
@@ -464,7 +468,8 @@ int extractBundle(std::string_view destination) noexcept
     return 0;
 }
 
-[[noreturn]] void runAppLoader(const std::vector<std::string_view> &loaderArgs) noexcept
+[[noreturn]] void runAppLoader(bool onlyApp,
+                               const std::vector<std::string_view> &loaderArgs) noexcept
 {
     auto loader = mountPoint / "loader";
     auto loaderStr = loader.string();
@@ -492,6 +497,12 @@ int extractBundle(std::string_view destination) noexcept
     }
 
     if (loaderPid == 0) {
+        std::string_view newEnv{ "LINGLONG_UAB_LOADER_ONLY_APP=true" };
+        if (onlyApp && ::putenv(const_cast<char *>(newEnv.data())) < 0) {
+            std::cerr << "putenv error: " << ::strerror(errno) << std::endl;
+            cleanAndExit(errno);
+        }
+
         if (::execv(loaderStr.c_str(), reinterpret_cast<char *const *>(const_cast<char **>(argv)))
             == -1) {
             std::cerr << "execv(" << loaderStr << ") error: " << ::strerror(errno) << std::endl;
@@ -693,5 +704,5 @@ int main(int argc, char **argv)
         cleanAndExit(-1);
     }
 
-    runAppLoader(opts.loaderArgs);
+    runAppLoader(metaInfo.onlyApp.value_or(false), opts.loaderArgs);
 }