From a2064e51c1ebc79ead33885c3474aa7b674a4723 Mon Sep 17 00:00:00 2001
From: matt335672 <30179339+matt335672@users.noreply.github.com>
Date: Fri, 26 Apr 2024 11:43:18 +0100
Subject: [PATCH] Some changes to Unicode input processing

- xrdp is not now built with XRDP_IBUS to allow other input
  methods to be more easily supported.
- chansrv is only aked to start an input method if the client
  supports it.
- chansrv sends a status report back to xrdp when asked to start
  and input method.
- ./configure without --enable-ibus now works.
---
 common/xrdp_client_info.h  | 11 +++++
 libxrdp/xrdp_caps.c        | 14 ++++++
 sesman/chansrv/Makefile.am | 14 +++---
 sesman/chansrv/chansrv.c   | 45 ++++++++++++++++--
 xrdp/Makefile.am           |  7 +--
 xrdp/xrdp_mm.c             | 96 ++++++++++++++++++++++++--------------
 xrdp/xrdp_wm.c             | 24 +++++-----
 7 files changed, 151 insertions(+), 60 deletions(-)

diff --git a/common/xrdp_client_info.h b/common/xrdp_client_info.h
index 0516f63c..aa76f098 100644
--- a/common/xrdp_client_info.h
+++ b/common/xrdp_client_info.h
@@ -74,6 +74,15 @@ enum client_resize_mode
     CRMODE_MULTI_SCREEN
 };
 
+/**
+ * Type describing Unicode input state
+ */
+enum unicode_input_state
+{
+    UIS_UNSUPPORTED = 0, ///< Client does not support Unicode
+    UIS_SUPPORTED,       ///< Client supports Unicode, but it's not active
+    UIS_ACTIVE           ///< Unicode input is active
+};
 /**
  * Information about the xrdp client
  *
@@ -228,6 +237,8 @@ struct xrdp_client_info
 
     // Can we resize the desktop by using a Deactivation-Reactivation Sequence?
     enum client_resize_mode client_resize_mode;
+
+    enum unicode_input_state unicode_input_support;
 };
 
 enum xrdp_encoder_flags
diff --git a/libxrdp/xrdp_caps.c b/libxrdp/xrdp_caps.c
index 7570968a..9ecf2486 100644
--- a/libxrdp/xrdp_caps.c
+++ b/libxrdp/xrdp_caps.c
@@ -422,6 +422,20 @@ xrdp_caps_process_input(struct xrdp_rdp *self, struct stream *s,
     {
         self->client_info.use_fast_path &= ~2;
     }
+
+    // We always advertise Unicode support, so if the client supports it too,
+    // we can use it
+    if ((inputFlags & INPUT_FLAG_UNICODE) != 0)
+    {
+        self->client_info.unicode_input_support = UIS_SUPPORTED;
+        LOG(LOG_LEVEL_INFO, "Client supports Unicode input");
+    }
+    else
+    {
+        self->client_info.unicode_input_support = UIS_UNSUPPORTED;
+        LOG(LOG_LEVEL_INFO, "Client does not support Unicode input");
+    }
+
     return 0;
 }
 
diff --git a/sesman/chansrv/Makefile.am b/sesman/chansrv/Makefile.am
index 7afc98c8..4b0154fa 100644
--- a/sesman/chansrv/Makefile.am
+++ b/sesman/chansrv/Makefile.am
@@ -38,11 +38,6 @@ if XRDP_RDPSNDAUDIN
 AM_CPPFLAGS += -DXRDP_RDPSNDAUDIN
 endif
 
-if XRDP_IBUS
-AM_CPPFLAGS += -DXRDP_IBUS $(IBUS_CFLAGS) $(GLIB2_CFLAGS)
-CHANSRV_EXTRA_LIBS += $(IBUS_LIBS) $(GLIB2_LIBS)
-endif
-
 AM_CFLAGS = $(X_CFLAGS)
 
 sbin_PROGRAMS = \
@@ -78,11 +73,18 @@ xrdp_chansrv_SOURCES = \
   sound.h \
   xcommon.c \
   xcommon.h \
-  input_ibus.c \
   input.h \
   audin.c \
   audin.h
 
+if XRDP_IBUS
+AM_CPPFLAGS += -DXRDP_IBUS $(IBUS_CFLAGS) $(GLIB2_CFLAGS)
+CHANSRV_EXTRA_LIBS += $(IBUS_LIBS) $(GLIB2_LIBS)
+xrdp_chansrv_SOURCES += \
+  input_ibus.c
+endif
+
+
 xrdp_chansrv_LDFLAGS = \
   $(X_LIBS)
 
diff --git a/sesman/chansrv/chansrv.c b/sesman/chansrv/chansrv.c
index a99e18f8..8f0a2c15 100644
--- a/sesman/chansrv/chansrv.c
+++ b/sesman/chansrv/chansrv.c
@@ -721,6 +721,26 @@ chansrv_drdynvc_open(const char *name, int flags,
     return error;
 }
 
+
+/*****************************************************************************/
+/* tell xrdp we can do Unicode input */
+static int
+chansrv_advertise_unicode_input(int status)
+{
+    struct stream *s = trans_get_out_s(g_con_trans, 8192);
+    if (s == NULL)
+    {
+        return 1;
+    }
+    out_uint32_le(s, 0); /* version */
+    out_uint32_le(s, 8 + 8 + 4);
+    out_uint32_le(s, 20); /* msg id */
+    out_uint32_le(s, 8 + 4);
+    out_uint32_le(s, status);
+    s_mark_end(s);
+    return trans_write_copy(g_con_trans);
+}
+
 /*****************************************************************************/
 /* close call from chansrv */
 int
@@ -861,7 +881,18 @@ process_message_unicode_data(struct stream *s)
 static int
 process_message_unicode_setup(struct stream *s)
 {
-    return xrdp_input_unicode_init();
+    int rv = xrdp_input_unicode_init();
+    if (rv == 0)
+    {
+        // Tell xrdp we can support Unicode input
+        rv = chansrv_advertise_unicode_input(0);
+    }
+    else
+    {
+        // Tell xrdp there's a problem starting the framework
+        chansrv_advertise_unicode_input(2);
+    }
+    return rv;
 }
 
 /*****************************************************************************/
@@ -924,17 +955,25 @@ process_message(void)
             case 19: /* drdynvc data */
                 rv = process_message_drdynvc_data(s);
                 break;
-#ifdef XRDP_IBUS
             case 21: /* unicode setup */
+#ifdef XRDP_IBUS
                 rv = process_message_unicode_setup(s);
+#else
+                // We don't support this.
+                rv = chansrv_advertise_unicode_input(1);
+#endif
                 break;
             case 23: /* unicode key event */
+#ifdef XRDP_IBUS
                 rv = process_message_unicode_data(s);
+#endif
                 break;
             case 25: /* unicode shut down */
+#ifdef XRDP_IBUS
                 rv = process_message_unicode_shutdown(s);
-                break;
 #endif
+                break;
+
             default:
                 LOG_DEVEL(LOG_LEVEL_ERROR, "process_message: unknown msg %d", id);
                 break;
diff --git a/xrdp/Makefile.am b/xrdp/Makefile.am
index cf38cece..b771ff8c 100644
--- a/xrdp/Makefile.am
+++ b/xrdp/Makefile.am
@@ -15,8 +15,7 @@ AM_CPPFLAGS = \
   -I$(top_srcdir)/libipm \
   -I$(top_srcdir)/libxrdp \
   -I$(top_srcdir)/third_party \
-  -I$(top_srcdir)/third_party/tomlc99 \
-  $(IBUS_CFLAGS)
+  -I$(top_srcdir)/third_party/tomlc99
 
 XRDP_EXTRA_LIBS =
 
@@ -38,10 +37,6 @@ AM_CPPFLAGS += -I$(top_srcdir)/libpainter/include
 XRDP_EXTRA_LIBS += $(top_builddir)/libpainter/src/.libs/libpainter.a
 endif
 
-if XRDP_IBUS
-AM_CPPFLAGS += -DXRDP_IBUS
-endif
-
 sbin_PROGRAMS = \
   xrdp
 
diff --git a/xrdp/xrdp_mm.c b/xrdp/xrdp_mm.c
index cd0e8eab..6910efbd 100644
--- a/xrdp/xrdp_mm.c
+++ b/xrdp/xrdp_mm.c
@@ -43,10 +43,8 @@ xrdp_mm_chansrv_connect(struct xrdp_mm *self, const char *port);
 static void
 xrdp_mm_connect_sm(struct xrdp_mm *self);
 
-#ifdef XRDP_IBUS
 static int
 xrdp_mm_send_unicode_shutdown(struct xrdp_mm *self, struct trans *trans);
-#endif
 
 /*****************************************************************************/
 struct xrdp_mm *
@@ -151,10 +149,8 @@ xrdp_mm_delete(struct xrdp_mm *self)
         return;
     }
 
-#ifdef XRDP_IBUS
     /* shutdown input method */
     xrdp_mm_send_unicode_shutdown(self, self->chan_trans);
-#endif
 
     /* free any module stuff */
     xrdp_mm_module_cleanup(self);
@@ -667,7 +663,6 @@ xrdp_mm_trans_process_channel_data(struct xrdp_mm *self, struct stream *s)
     return rv;
 }
 
-#ifdef XRDP_IBUS
 /*****************************************************************************/
 static int
 xrdp_mm_send_unicode_shutdown(struct xrdp_mm *self, struct trans *trans)
@@ -691,19 +686,28 @@ xrdp_mm_send_unicode_shutdown(struct xrdp_mm *self, struct trans *trans)
 static int
 xrdp_mm_send_unicode_setup(struct xrdp_mm *self, struct trans *trans)
 {
-    struct stream *s = trans_get_out_s(self->chan_trans, 8192);
-    if (s == NULL)
+    int rv = 0;
+
+    if (self->wm->client_info->unicode_input_support == UIS_SUPPORTED)
     {
-        return 1;
+        struct stream *s = trans_get_out_s(self->chan_trans, 8192);
+        if (s == NULL)
+        {
+            rv = 1;
+        }
+        else
+        {
+            out_uint32_le(s, 0); /* version */
+            out_uint32_le(s, 8 + 8); /* size */
+            out_uint32_le(s, 21); /* msg id */
+            out_uint32_le(s, 8); /* size */
+            s_mark_end(s);
+
+            rv = trans_write_copy(self->chan_trans);
+        }
     }
 
-    out_uint32_le(s, 0); /* version */
-    out_uint32_le(s, 8 + 8); /* size */
-    out_uint32_le(s, 21); /* msg id */
-    out_uint32_le(s, 8); /* size */
-    s_mark_end(s);
-
-    return trans_write_copy(self->chan_trans);
+    return rv;
 }
 
 /******************************************************************************/
@@ -725,7 +729,6 @@ int xrdp_mm_send_unicode_to_chansrv(struct xrdp_mm *self,
     s_mark_end(s);
     return trans_write_copy(self->chan_trans);
 }
-#endif
 
 /*****************************************************************************/
 /* returns error
@@ -2465,6 +2468,39 @@ xrdp_mm_trans_process_drdynvc_data(struct xrdp_mm *self,
     return 0;
 }
 
+/*****************************************************************************/
+/* Acknowledgement from chansrv that Unicode input is supported
+ */
+static int
+xrdp_mm_trans_process_unicode_ack(struct xrdp_mm *self,
+                                  struct stream *s)
+{
+    int status;
+    if (!s_check_rem(s, 4))
+    {
+        return 1;
+    }
+    in_uint32_le(s, status);
+    switch (status)
+    {
+        case 0:
+            LOG(LOG_LEVEL_INFO, "Chansrv is handling Unicode input");
+            self->wm->client_info->unicode_input_support = UIS_ACTIVE;
+            break;
+
+        case 1:
+            LOG(LOG_LEVEL_INFO, "Chansrv does not support Unicode input");
+            break;
+
+        default:
+            LOG(LOG_LEVEL_INFO,
+                "Chansrv reported an error starting the Unicode input method");
+            break;
+    }
+
+    return 0;
+}
+
 /*****************************************************************************/
 /* returns error
    process a message for the channel handler */
@@ -2517,6 +2553,9 @@ xrdp_mm_chan_process_msg(struct xrdp_mm *self, struct trans *trans,
             case 18:
                 rv = xrdp_mm_trans_process_drdynvc_data(self, s);
                 break;
+            case 20:
+                rv = xrdp_mm_trans_process_unicode_ack(self, s);
+
             default:
                 LOG(LOG_LEVEL_ERROR, "xrdp_mm_chan_process_msg: unknown id %d", id);
                 break;
@@ -3034,30 +3073,19 @@ xrdp_mm_chansrv_connect(struct xrdp_mm *self, const char *port)
         trans_delete(self->chan_trans);
         self->chan_trans = NULL;
     }
+    else if (xrdp_mm_send_unicode_setup(self, self->chan_trans) != 0)
+    {
+        LOG(LOG_LEVEL_ERROR, "xrdp_mm_chansrv_connect: error in "
+            "xrdp_mm_send_unicode_setup");
+        trans_delete(self->chan_trans);
+        self->chan_trans = NULL;
+    }
     else
     {
         LOG(LOG_LEVEL_DEBUG, "xrdp_mm_chansrv_connect: chansrv "
             "connect successful");
     }
 
-#ifdef XRDP_IBUS
-    /* if client supports unicode input, initialize the input method */
-    if (1)
-    {
-        LOG(LOG_LEVEL_INFO, "xrdp_mm_chansrv_connect: chansrv "
-            "client support unicode input, init the input method");
-
-        if (xrdp_mm_send_unicode_setup(self, self->chan_trans) != 0)
-        {
-            LOG(LOG_LEVEL_ERROR, "xrdp_mm_chansrv_connect: error in "
-                "xrdp_mm_send_unicode_setup");
-
-            /* disable unicode input */
-            // self->wm->client_info->unicode_input = 0;
-        }
-    }
-#endif
-
     return 0;
 }
 
diff --git a/xrdp/xrdp_wm.c b/xrdp/xrdp_wm.c
index eebe0da4..9f6e7d18 100644
--- a/xrdp/xrdp_wm.c
+++ b/xrdp/xrdp_wm.c
@@ -1722,6 +1722,7 @@ get_unicode_character(struct xrdp_wm *self, int device_flags, char16_t c16)
 static int
 xrdp_wm_key_unicode(struct xrdp_wm *self, int device_flags, char32_t c16)
 {
+    int index;
     char32_t c32 = get_unicode_character(self, device_flags, c16);
 
     if (c32 == 0)
@@ -1729,8 +1730,19 @@ xrdp_wm_key_unicode(struct xrdp_wm *self, int device_flags, char32_t c16)
         return 0;
     }
 
-    int index;
+    // Send the character to chansrv if it's capable of doing something
+    // with it
+    if (self->mm->chan_trans != NULL &&
+            self->client_info->unicode_input_support == UIS_ACTIVE &&
+            self->mm->chan_trans->status == TRANS_STATUS_UP)
+    {
+        xrdp_mm_send_unicode_to_chansrv(self->mm,
+                                        !(device_flags & KBD_FLAG_UP), c32);
+        return 0;
+    }
 
+    // Fallback - see if we can find the character in the existing keymap,
+    // and if so, generate a normal key event.
     for (index = XR_MIN_KEY_CODE; index < XR_MAX_KEY_CODE; index++)
     {
         if (c32 == self->keymap.keys_noshift[index].chr)
@@ -1799,16 +1811,6 @@ xrdp_wm_key_unicode(struct xrdp_wm *self, int device_flags, char32_t c16)
         }
     }
 
-#ifdef XRDP_IBUS
-    if (self->mm->chan_trans != NULL &&
-            self->mm->chan_trans->status == TRANS_STATUS_UP)
-    {
-        xrdp_mm_send_unicode_to_chansrv(self->mm,
-                                        !(device_flags & KBD_FLAG_UP), c32);
-        return 0;
-    }
-#endif
-
     return 0;
 }