Services: Move to Userland/Services/

8 files changed, 704 insertions, 0 deletions

diff --git a/Userland/Services/LaunchServer/CMakeLists.txt b/Userland/Services/LaunchServer/CMakeLists.txt
new file mode 100644
index 0000000000..29308ce7f1
--- /dev/null
+++ b/Userland/Services/LaunchServer/CMakeLists.txt
@@ -0,0 +1,13 @@
+compile_ipc(LaunchServer.ipc LaunchServerEndpoint.h)
+compile_ipc(LaunchClient.ipc LaunchClientEndpoint.h)
+
+set(SOURCES
+    ClientConnection.cpp
+    Launcher.cpp
+    main.cpp
+    LaunchClientEndpoint.h
+    LaunchServerEndpoint.h
+)
+
+serenity_bin(LaunchServer)
+target_link_libraries(LaunchServer LibCore LibIPC LibDesktop)
diff --git a/Userland/Services/LaunchServer/ClientConnection.cpp b/Userland/Services/LaunchServer/ClientConnection.cpp
new file mode 100644
index 0000000000..7ac167c1ae
--- /dev/null
+++ b/Userland/Services/LaunchServer/ClientConnection.cpp
@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2020, Nicholas Hollett <niax@niax.co.uk>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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 HOLDER 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.
+ */
+
+#include "ClientConnection.h"
+#include "Launcher.h"
+#include <AK/HashMap.h>
+#include <AK/URL.h>
+#include <LaunchServer/LaunchClientEndpoint.h>
+
+namespace LaunchServer {
+
+static HashMap<int, RefPtr<ClientConnection>> s_connections;
+ClientConnection::ClientConnection(NonnullRefPtr<Core::LocalSocket> client_socket, int client_id)
+    : IPC::ClientConnection<LaunchClientEndpoint, LaunchServerEndpoint>(*this, move(client_socket), client_id)
+{
+    s_connections.set(client_id, *this);
+}
+
+ClientConnection::~ClientConnection()
+{
+}
+
+void ClientConnection::die()
+{
+    s_connections.remove(client_id());
+}
+
+OwnPtr<Messages::LaunchServer::GreetResponse> ClientConnection::handle(const Messages::LaunchServer::Greet&)
+{
+    return make<Messages::LaunchServer::GreetResponse>(client_id());
+}
+
+OwnPtr<Messages::LaunchServer::OpenURLResponse> ClientConnection::handle(const Messages::LaunchServer::OpenURL& request)
+{
+    if (!m_allowlist.is_empty()) {
+        bool allowed = false;
+        for (auto& allowed_handler : m_allowlist) {
+            if (allowed_handler.handler_name == request.handler_name()
+                && (allowed_handler.any_url || allowed_handler.urls.contains_slow(request.url()))) {
+                allowed = true;
+                break;
+            }
+        }
+        if (!allowed) {
+            // You are not on the list, go home!
+            did_misbehave(String::formatted("Client requested a combination of handler/URL that was not on the list: '{}' with '{}'", request.handler_name(), request.url()).characters());
+            return {};
+        }
+    }
+
+    URL url(request.url());
+    auto result = Launcher::the().open_url(url, request.handler_name());
+    return make<Messages::LaunchServer::OpenURLResponse>(result);
+}
+
+OwnPtr<Messages::LaunchServer::GetHandlersForURLResponse> ClientConnection::handle(const Messages::LaunchServer::GetHandlersForURL& request)
+{
+    URL url(request.url());
+    auto result = Launcher::the().handlers_for_url(url);
+    return make<Messages::LaunchServer::GetHandlersForURLResponse>(result);
+}
+
+OwnPtr<Messages::LaunchServer::GetHandlersWithDetailsForURLResponse> ClientConnection::handle(const Messages::LaunchServer::GetHandlersWithDetailsForURL& request)
+{
+    URL url(request.url());
+    auto result = Launcher::the().handlers_with_details_for_url(url);
+    return make<Messages::LaunchServer::GetHandlersWithDetailsForURLResponse>(result);
+}
+
+OwnPtr<Messages::LaunchServer::AddAllowedURLResponse> ClientConnection::handle(const Messages::LaunchServer::AddAllowedURL& request)
+{
+    if (m_allowlist_is_sealed) {
+        did_misbehave("Got request to add more allowed handlers after list was sealed");
+        return {};
+    }
+
+    if (!request.url().is_valid()) {
+        did_misbehave("Got request to allow invalid URL");
+        return {};
+    }
+
+    m_allowlist.empend(String(), false, Vector<URL> { request.url() });
+
+    return make<Messages::LaunchServer::AddAllowedURLResponse>();
+}
+
+OwnPtr<Messages::LaunchServer::AddAllowedHandlerWithAnyURLResponse> ClientConnection::handle(const Messages::LaunchServer::AddAllowedHandlerWithAnyURL& request)
+{
+    if (m_allowlist_is_sealed) {
+        did_misbehave("Got request to add more allowed handlers after list was sealed");
+        return {};
+    }
+
+    if (request.handler_name().is_empty()) {
+        did_misbehave("Got request to allow empty handler name");
+        return {};
+    }
+
+    m_allowlist.empend(request.handler_name(), true, Vector<URL>());
+
+    return make<Messages::LaunchServer::AddAllowedHandlerWithAnyURLResponse>();
+}
+
+OwnPtr<Messages::LaunchServer::AddAllowedHandlerWithOnlySpecificURLsResponse> ClientConnection::handle(const Messages::LaunchServer::AddAllowedHandlerWithOnlySpecificURLs& request)
+{
+    if (m_allowlist_is_sealed) {
+        did_misbehave("Got request to add more allowed handlers after list was sealed");
+        return {};
+    }
+
+    if (request.handler_name().is_empty()) {
+        did_misbehave("Got request to allow empty handler name");
+        return {};
+    }
+
+    if (request.urls().is_empty()) {
+        did_misbehave("Got request to allow empty URL list");
+        return {};
+    }
+
+    m_allowlist.empend(request.handler_name(), false, request.urls());
+
+    return make<Messages::LaunchServer::AddAllowedHandlerWithOnlySpecificURLsResponse>();
+}
+
+OwnPtr<Messages::LaunchServer::SealAllowlistResponse> ClientConnection::handle(const Messages::LaunchServer::SealAllowlist&)
+{
+    if (m_allowlist_is_sealed) {
+        did_misbehave("Got more than one request to seal the allowed handlers list");
+        return {};
+    }
+
+    return make<Messages::LaunchServer::SealAllowlistResponse>();
+}
+
+}
diff --git a/Userland/Services/LaunchServer/ClientConnection.h b/Userland/Services/LaunchServer/ClientConnection.h
new file mode 100644
index 0000000000..77eef53374
--- /dev/null
+++ b/Userland/Services/LaunchServer/ClientConnection.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2020, Nicholas Hollett <niax@niax.co.uk>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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 HOLDER 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.
+ */
+
+#pragma once
+
+#include <LaunchServer/LaunchClientEndpoint.h>
+#include <LaunchServer/LaunchServerEndpoint.h>
+#include <LibIPC/ClientConnection.h>
+
+namespace LaunchServer {
+
+class ClientConnection final : public IPC::ClientConnection<LaunchClientEndpoint, LaunchServerEndpoint>
+    , public LaunchServerEndpoint {
+    C_OBJECT(ClientConnection)
+public:
+    ~ClientConnection() override;
+
+    virtual void die() override;
+
+private:
+    explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>, int client_id);
+
+    virtual OwnPtr<Messages::LaunchServer::GreetResponse> handle(const Messages::LaunchServer::Greet&) override;
+    virtual OwnPtr<Messages::LaunchServer::OpenURLResponse> handle(const Messages::LaunchServer::OpenURL&) override;
+    virtual OwnPtr<Messages::LaunchServer::GetHandlersForURLResponse> handle(const Messages::LaunchServer::GetHandlersForURL&) override;
+    virtual OwnPtr<Messages::LaunchServer::GetHandlersWithDetailsForURLResponse> handle(const Messages::LaunchServer::GetHandlersWithDetailsForURL&) override;
+    virtual OwnPtr<Messages::LaunchServer::AddAllowedURLResponse> handle(const Messages::LaunchServer::AddAllowedURL&) override;
+    virtual OwnPtr<Messages::LaunchServer::AddAllowedHandlerWithAnyURLResponse> handle(const Messages::LaunchServer::AddAllowedHandlerWithAnyURL&) override;
+    virtual OwnPtr<Messages::LaunchServer::AddAllowedHandlerWithOnlySpecificURLsResponse> handle(const Messages::LaunchServer::AddAllowedHandlerWithOnlySpecificURLs&) override;
+    virtual OwnPtr<Messages::LaunchServer::SealAllowlistResponse> handle(const Messages::LaunchServer::SealAllowlist&) override;
+
+    struct AllowlistEntry {
+        String handler_name;
+        bool any_url { false };
+        Vector<URL> urls;
+    };
+
+    Vector<AllowlistEntry> m_allowlist;
+    bool m_allowlist_is_sealed { false };
+};
+}
diff --git a/Userland/Services/LaunchServer/LaunchClient.ipc b/Userland/Services/LaunchServer/LaunchClient.ipc
new file mode 100644
index 0000000000..abd4e9ba3d
--- /dev/null
+++ b/Userland/Services/LaunchServer/LaunchClient.ipc
@@ -0,0 +1,4 @@
+endpoint LaunchClient = 102
+{
+    Dummy() =|
+}
diff --git a/Userland/Services/LaunchServer/LaunchServer.ipc b/Userland/Services/LaunchServer/LaunchServer.ipc
new file mode 100644
index 0000000000..4f50221f4b
--- /dev/null
+++ b/Userland/Services/LaunchServer/LaunchServer.ipc
@@ -0,0 +1,12 @@
+endpoint LaunchServer = 101
+{
+    Greet() => (i32 client_id)
+    OpenURL(URL url, String handler_name) => (bool response)
+    GetHandlersForURL(URL url) => (Vector<String> handlers)
+    GetHandlersWithDetailsForURL(URL url) => (Vector<String> handlers_details)
+
+    AddAllowedURL(URL url) => ()
+    AddAllowedHandlerWithAnyURL(String handler_name) => ()
+    AddAllowedHandlerWithOnlySpecificURLs(String handler_name, Vector<URL> urls) => ()
+    SealAllowlist() => ()
+}
diff --git a/Userland/Services/LaunchServer/Launcher.cpp b/Userland/Services/LaunchServer/Launcher.cpp
new file mode 100644
index 0000000000..ad6d025035
--- /dev/null
+++ b/Userland/Services/LaunchServer/Launcher.cpp
@@ -0,0 +1,309 @@
+/*
+ * Copyright (c) 2020, Nicholas Hollett <niax@niax.co.uk>, Andreas Kling <kling@serenityos.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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 HOLDER 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.
+ */
+
+#include "Launcher.h"
+#include <AK/Function.h>
+#include <AK/JsonObject.h>
+#include <AK/JsonObjectSerializer.h>
+#include <AK/JsonValue.h>
+#include <AK/LexicalPath.h>
+#include <AK/StringBuilder.h>
+#include <LibCore/ConfigFile.h>
+#include <LibDesktop/AppFile.h>
+#include <serenity.h>
+#include <spawn.h>
+#include <stdio.h>
+#include <sys/stat.h>
+
+namespace LaunchServer {
+
+static Launcher* s_the;
+static bool spawn(String executable, String argument);
+
+String Handler::name_from_executable(const StringView& executable)
+{
+    auto separator = executable.find_last_of('/');
+    if (separator.has_value()) {
+        auto start = separator.value() + 1;
+        return executable.substring_view(start, executable.length() - start);
+    }
+    return executable;
+}
+
+void Handler::from_executable(Type handler_type, const String& executable)
+{
+    this->handler_type = handler_type;
+    this->name = name_from_executable(executable);
+    this->executable = executable;
+}
+
+String Handler::to_details_str() const
+{
+    StringBuilder builder;
+    JsonObjectSerializer obj { builder };
+    obj.add("executable", executable);
+    obj.add("name", name);
+    switch (handler_type) {
+    case Type::Application:
+        obj.add("type", "app");
+        break;
+    case Type::UserDefault:
+        obj.add("type", "userdefault");
+        break;
+    case Type::UserPreferred:
+        obj.add("type", "userpreferred");
+        break;
+    default:
+        break;
+    }
+    obj.finish();
+    return builder.build();
+}
+
+Launcher::Launcher()
+{
+    ASSERT(s_the == nullptr);
+    s_the = this;
+}
+
+Launcher& Launcher::the()
+{
+    ASSERT(s_the);
+    return *s_the;
+}
+
+void Launcher::load_handlers(const String& af_dir)
+{
+    Desktop::AppFile::for_each([&](auto af) {
+        auto app_name = af->name();
+        auto app_executable = af->executable();
+        HashTable<String> file_types;
+        for (auto& file_type : af->launcher_file_types())
+            file_types.set(file_type);
+        HashTable<String> protocols;
+        for (auto& protocol : af->launcher_protocols())
+            protocols.set(protocol);
+        m_handlers.set(app_executable, { Handler::Type::Default, app_name, app_executable, file_types, protocols });
+    },
+        af_dir);
+}
+
+void Launcher::load_config(const Core::ConfigFile& cfg)
+{
+    for (auto key : cfg.keys("FileType")) {
+        auto handler = cfg.read_entry("FileType", key).trim_whitespace();
+        if (handler.is_empty())
+            continue;
+        m_file_handlers.set(key.to_lowercase(), handler);
+    }
+
+    for (auto key : cfg.keys("Protocol")) {
+        auto handler = cfg.read_entry("Protocol", key).trim_whitespace();
+        if (handler.is_empty())
+            continue;
+        m_protocol_handlers.set(key.to_lowercase(), handler);
+    }
+}
+
+Vector<String> Launcher::handlers_for_url(const URL& url)
+{
+    Vector<String> handlers;
+    if (url.protocol() == "file") {
+        for_each_handler_for_path(url.path(), [&](auto& handler) -> bool {
+            handlers.append(handler.executable);
+            return true;
+        });
+    } else {
+        for_each_handler(url.protocol(), m_protocol_handlers, [&](const auto& handler) -> bool {
+            if (handler.handler_type != Handler::Type::Default || handler.protocols.contains(url.protocol())) {
+                handlers.append(handler.executable);
+                return true;
+            }
+            return false;
+        });
+    }
+    return handlers;
+}
+
+Vector<String> Launcher::handlers_with_details_for_url(const URL& url)
+{
+    Vector<String> handlers;
+    if (url.protocol() == "file") {
+        for_each_handler_for_path(url.path(), [&](auto& handler) -> bool {
+            handlers.append(handler.to_details_str());
+            return true;
+        });
+    } else {
+        for_each_handler(url.protocol(), m_protocol_handlers, [&](const auto& handler) -> bool {
+            if (handler.handler_type != Handler::Type::Default || handler.protocols.contains(url.protocol())) {
+                handlers.append(handler.to_details_str());
+                return true;
+            }
+            return false;
+        });
+    }
+    return handlers;
+}
+
+bool Launcher::open_url(const URL& url, const String& handler_name)
+{
+    if (!handler_name.is_null())
+        return open_with_handler_name(url, handler_name);
+
+    if (url.protocol() == "file")
+        return open_file_url(url);
+
+    return open_with_user_preferences(m_protocol_handlers, url.protocol(), url.to_string());
+}
+
+bool Launcher::open_with_handler_name(const URL& url, const String& handler_name)
+{
+    auto handler_optional = m_handlers.get(handler_name);
+    if (!handler_optional.has_value())
+        return false;
+
+    auto& handler = handler_optional.value();
+    String argument;
+    if (url.protocol() == "file")
+        argument = url.path();
+    else
+        argument = url.to_string();
+    return spawn(handler.executable, argument);
+}
+
+bool spawn(String executable, String argument)
+{
+    pid_t child_pid;
+    const char* argv[] = { executable.characters(), argument.characters(), nullptr };
+    if ((errno = posix_spawn(&child_pid, executable.characters(), nullptr, nullptr, const_cast<char**>(argv), environ))) {
+        perror("posix_spawn");
+        return false;
+    } else {
+        if (disown(child_pid) < 0)
+            perror("disown");
+    }
+    return true;
+}
+
+Handler Launcher::get_handler_for_executable(Handler::Type handler_type, const String& executable) const
+{
+    Handler handler;
+    auto existing_handler = m_handlers.get(executable);
+    if (existing_handler.has_value()) {
+        handler = existing_handler.value();
+        handler.handler_type = handler_type;
+    } else {
+        handler.from_executable(handler_type, executable);
+    }
+    return handler;
+}
+
+bool Launcher::open_with_user_preferences(const HashMap<String, String>& user_preferences, const String key, const String argument, const String default_program)
+{
+    auto program_path = user_preferences.get(key);
+    if (program_path.has_value())
+        return spawn(program_path.value(), argument);
+
+    // There wasn't a handler for this, so try the fallback instead
+    program_path = user_preferences.get("*");
+    if (program_path.has_value())
+        return spawn(program_path.value(), argument);
+
+    // Absolute worst case, try the provided default program, if any
+    if (!default_program.is_empty())
+        return spawn(default_program, argument);
+
+    return false;
+}
+
+void Launcher::for_each_handler(const String& key, HashMap<String, String>& user_preference, Function<bool(const Handler&)> f)
+{
+    auto user_preferred = user_preference.get(key);
+    if (user_preferred.has_value())
+        f(get_handler_for_executable(Handler::Type::UserPreferred, user_preferred.value()));
+
+    size_t counted = 0;
+    for (auto& handler : m_handlers) {
+        // Skip over the existing item in the list
+        if (user_preferred.has_value() && user_preferred.value() == handler.value.executable)
+            continue;
+        if (f(handler.value))
+            counted++;
+    }
+
+    auto user_default = user_preference.get("*");
+    if (counted == 0 && user_default.has_value())
+        f(get_handler_for_executable(Handler::Type::UserDefault, user_default.value()));
+}
+
+void Launcher::for_each_handler_for_path(const String& path, Function<bool(const Handler&)> f)
+{
+    struct stat st;
+    if (stat(path.characters(), &st) < 0) {
+        perror("stat");
+        return;
+    }
+
+    // TODO: Make directory opening configurable
+    if (S_ISDIR(st.st_mode)) {
+        f(get_handler_for_executable(Handler::Type::Default, "/bin/FileManager"));
+        return;
+    }
+
+    if ((st.st_mode & S_IFMT) == S_IFREG && (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)))
+        f(get_handler_for_executable(Handler::Type::Application, path));
+
+    auto extension = LexicalPath(path).extension().to_lowercase();
+
+    for_each_handler(extension, m_file_handlers, [&](const auto& handler) -> bool {
+        if (handler.handler_type != Handler::Type::Default || handler.file_types.contains(extension))
+            return f(handler);
+        return false;
+    });
+}
+
+bool Launcher::open_file_url(const URL& url)
+{
+    struct stat st;
+    if (stat(url.path().characters(), &st) < 0) {
+        perror("stat");
+        return false;
+    }
+
+    // TODO: Make directory opening configurable
+    if (S_ISDIR(st.st_mode))
+        return spawn("/bin/FileManager", url.path());
+
+    if ((st.st_mode & S_IFMT) == S_IFREG && st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
+        return spawn(url.path(), {});
+
+    auto extension_parts = url.path().to_lowercase().split('.');
+    String extension = {};
+    if (extension_parts.size() > 1)
+        extension = extension_parts.last();
+    return open_with_user_preferences(m_file_handlers, extension, url.path(), "/bin/TextEditor");
+}
+}
diff --git a/Userland/Services/LaunchServer/Launcher.h b/Userland/Services/LaunchServer/Launcher.h
new file mode 100644
index 0000000000..8708cdc258
--- /dev/null
+++ b/Userland/Services/LaunchServer/Launcher.h
@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2020, Nicholas Hollett <niax@niax.co.uk>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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 HOLDER 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.
+ */
+
+#pragma once
+
+#include <AK/HashMap.h>
+#include <AK/HashTable.h>
+#include <AK/URL.h>
+#include <LibCore/ConfigFile.h>
+#include <LibDesktop/AppFile.h>
+
+namespace LaunchServer {
+
+struct Handler {
+    enum class Type {
+        Default = 0,
+        Application,
+        UserPreferred,
+        UserDefault
+    };
+    Type handler_type;
+    String name;
+    String executable;
+    HashTable<String> file_types {};
+    HashTable<String> protocols {};
+
+    static String name_from_executable(const StringView&);
+    void from_executable(Type, const String&);
+    String to_details_str() const;
+};
+
+class Launcher {
+public:
+    Launcher();
+    static Launcher& the();
+
+    void load_handlers(const String& af_dir = Desktop::AppFile::APP_FILES_DIRECTORY);
+    void load_config(const Core::ConfigFile&);
+    bool open_url(const URL&, const String& handler_name);
+    Vector<String> handlers_for_url(const URL&);
+    Vector<String> handlers_with_details_for_url(const URL&);
+
+private:
+    HashMap<String, Handler> m_handlers;
+    HashMap<String, String> m_protocol_handlers;
+    HashMap<String, String> m_file_handlers;
+
+    Handler get_handler_for_executable(Handler::Type, const String&) const;
+    void for_each_handler(const String& key, HashMap<String, String>& user_preferences, Function<bool(const Handler&)> f);
+    void for_each_handler_for_path(const String&, Function<bool(const Handler&)> f);
+    bool open_file_url(const URL&);
+    bool open_with_user_preferences(const HashMap<String, String>& user_preferences, const String key, const String argument, const String default_program = {});
+    bool open_with_handler_name(const URL&, const String& handler_name);
+};
+}
diff --git a/Userland/Services/LaunchServer/main.cpp b/Userland/Services/LaunchServer/main.cpp
new file mode 100644
index 0000000000..2535d1e8bb
--- /dev/null
+++ b/Userland/Services/LaunchServer/main.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2020, Nicholas Hollett <niax@niax.co.uk>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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 HOLDER 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.
+ */
+
+#include "ClientConnection.h"
+#include "Launcher.h"
+#include <LibCore/ConfigFile.h>
+#include <LibCore/EventLoop.h>
+#include <LibCore/LocalServer.h>
+#include <stdio.h>
+#include <unistd.h>
+
+int main([[maybe_unused]] int argc, [[maybe_unused]] char** argv)
+{
+    Core::EventLoop event_loop;
+    auto server = Core::LocalServer::construct();
+
+    auto launcher = LaunchServer::Launcher();
+
+    launcher.load_handlers();
+    launcher.load_config(Core::ConfigFile::get_for_app("LaunchServer"));
+
+    if (pledge("stdio accept rpath proc exec", nullptr) < 0) {
+        perror("pledge");
+        return 1;
+    }
+
+    bool ok = server->take_over_from_system_server();
+    ASSERT(ok);
+    server->on_ready_to_accept = [&] {
+        auto client_socket = server->accept();
+        if (!client_socket) {
+            dbgln("LaunchServer: accept failed.");
+            return;
+        }
+        static int s_next_client_id = 0;
+        int client_id = ++s_next_client_id;
+        dbgln("Received connection");
+        IPC::new_client_connection<LaunchServer::ClientConnection>(client_socket.release_nonnull(), client_id);
+    };
+
+    return event_loop.exec();
+}