Kernel+LibKeyboard: Enable querying the current keymap

Kernel/API/Syscall.h

@@ -156,6 +156,7 @@ namespace Kernel {
     S(get_process_name)       \
     S(fchdir)                 \
     S(getrandom)              \
+    S(getkeymap)              \
     S(setkeymap)              \
     S(clock_gettime)          \
     S(clock_settime)          \
@@ -330,6 +331,15 @@ struct SC_setkeymap_params {
     StringArgument map_name;
 };
 
+struct SC_getkeymap_params {
+    u32* map;
+    u32* shift_map;
+    u32* alt_map;
+    u32* altgr_map;
+    u32* shift_altgr_map;
+    MutableBufferArgument<char, size_t> map_name;
+};
+
 struct SC_create_thread_params {
     unsigned int m_detach_state = 0; // JOINABLE or DETACHED
     int m_schedule_priority = 30;    // THREAD_PRIORITY_NORMAL

Kernel/CMakeLists.txt

@@ -132,6 +132,7 @@ set(KERNEL_SOURCES
     Syscalls/getuid.cpp
     Syscalls/hostname.cpp
     Syscalls/ioctl.cpp
+    Syscalls/keymap.cpp
     Syscalls/kill.cpp
     Syscalls/link.cpp
     Syscalls/lseek.cpp
@@ -157,7 +158,6 @@ set(KERNEL_SOURCES
     Syscalls/sched.cpp
     Syscalls/select.cpp
     Syscalls/sendfd.cpp
-    Syscalls/setkeymap.cpp
     Syscalls/setpgid.cpp
     Syscalls/setuid.cpp
     Syscalls/shutdown.cpp

Kernel/Devices/KeyboardDevice.h

@@ -56,6 +56,7 @@ public:
 
     void set_client(KeyboardClient* client) { m_client = client; }
     void set_maps(const Keyboard::CharacterMapData& character_map, const String& character_map_name);
+    const Keyboard::CharacterMapData& character_maps() const { return m_character_map.character_map_data(); }
 
     const String keymap_name() { return m_character_map.character_map_name(); }
 

Kernel/Process.h

@@ -344,6 +344,7 @@ public:
     int sys$reboot();
     int sys$realpath(Userspace<const Syscall::SC_realpath_params*>);
     ssize_t sys$getrandom(Userspace<void*>, size_t, unsigned int);
+    int sys$getkeymap(Userspace<const Syscall::SC_getkeymap_params*>);
     int sys$setkeymap(Userspace<const Syscall::SC_setkeymap_params*>);
     int sys$module_load(Userspace<const char*> path, size_t path_length);
     int sys$module_unload(Userspace<const char*> name, size_t name_length);

Kernel/Syscalls/keymap.cpp

@@ -29,6 +29,8 @@
 
 namespace Kernel {
 
+constexpr size_t map_name_max_size = 50;
+
 int Process::sys$setkeymap(Userspace<const Syscall::SC_setkeymap_params*> user_params)
 {
     REQUIRE_PROMISE(setkeymap);
@@ -57,7 +59,6 @@ int Process::sys$setkeymap(Userspace<const Syscall::SC_setkeymap_params*> user_p
     if (map_name.is_error()) {
         return map_name.error();
     }
-    constexpr size_t map_name_max_size = 50;
     if (map_name.value().length() > map_name_max_size) {
         return -ENAMETOOLONG;
     }
@@ -66,4 +67,34 @@ int Process::sys$setkeymap(Userspace<const Syscall::SC_setkeymap_params*> user_p
     return 0;
 }
 
+int Process::sys$getkeymap(Userspace<const Syscall::SC_getkeymap_params*> user_params)
+{
+    REQUIRE_PROMISE(stdio);
+
+    Syscall::SC_getkeymap_params params;
+    if (!copy_from_user(&params, user_params))
+        return -EFAULT;
+
+    String keymap_name = KeyboardDevice::the().keymap_name();
+    const Keyboard::CharacterMapData& character_maps = KeyboardDevice::the().character_maps();
+
+    if (!copy_to_user(params.map, character_maps.map, CHAR_MAP_SIZE * sizeof(u32)))
+        return -EFAULT;
+    if (!copy_to_user(params.shift_map, character_maps.shift_map, CHAR_MAP_SIZE * sizeof(u32)))
+        return -EFAULT;
+    if (!copy_to_user(params.alt_map, character_maps.alt_map, CHAR_MAP_SIZE * sizeof(u32)))
+        return -EFAULT;
+    if (!copy_to_user(params.altgr_map, character_maps.altgr_map, CHAR_MAP_SIZE * sizeof(u32)))
+        return -EFAULT;
+    if (!copy_to_user(params.shift_altgr_map, character_maps.shift_altgr_map, CHAR_MAP_SIZE * sizeof(u32)))
+        return -EFAULT;
+
+    if (params.map_name.size < keymap_name.length())
+        return -ENAMETOOLONG;
+    if (!copy_to_user(params.map_name.data, keymap_name.characters(), keymap_name.length()))
+        return -EFAULT;
+
+    return 0;
+}
+
 }

Userland/Libraries/LibKeyboard/CharacterMap.h

@@ -45,6 +45,7 @@ public:
     void set_character_map_data(CharacterMapData character_map_data);
     void set_character_map_name(const String& character_map_name);
 
+    const CharacterMapData& character_map_data() const { return m_character_map_data; };
     const String character_map_name();
 
 private: