core: use channels to give feedback over debuglink

all debug input signals are now channels, and DebugLinkDecision handler
waits until the input was consumed. This means that the input events are
queued; originally, if an input event arrived before the previous was
consumed, the previous input would be lost.

reset words and their positions are now also channels, and
DebugLinkGetState can wait for their updates, if required

common/protob/messages-debug.proto

@@ -24,6 +24,8 @@ message DebugLinkDecision {
  * @next DebugLinkState
  */
 message DebugLinkGetState {
+    optional bool wait_word_list = 1;  // Trezor T only - wait until mnemonic words are shown
+    optional bool wait_word_pos = 2;   // Trezor T only - wait until reset word position is requested
 }
 
 /**

core/src/apps/debug/__init__.py

@@ -4,36 +4,60 @@ if not __debug__:
     halt("debug mode inactive")
 
 if __debug__:
-    from trezor import config, loop, utils
+    from trezor import config, log, loop, utils
     from trezor.messages import MessageType
     from trezor.wire import register, protobuf_workflow
 
     if False:
-        from typing import List, Optional
+        from typing import Optional
         from trezor import wire
         from trezor.messages.DebugLinkDecision import DebugLinkDecision
         from trezor.messages.DebugLinkGetState import DebugLinkGetState
         from trezor.messages.DebugLinkState import DebugLinkState
 
     reset_internal_entropy = None  # type: Optional[bytes]
-    reset_current_words = None  # type: Optional[List[str]]
-    reset_word_index = None  # type: Optional[int]
+    reset_current_words = loop.chan()
+    reset_word_index = loop.chan()
 
-    confirm_signal = loop.signal()
-    swipe_signal = loop.signal()
-    input_signal = loop.signal()
+    confirm_chan = loop.chan()
+    swipe_chan = loop.chan()
+    input_chan = loop.chan()
+    confirm_signal = confirm_chan.take
+    swipe_signal = swipe_chan.take
+    input_signal = input_chan.take
 
     async def dispatch_DebugLinkDecision(
         ctx: wire.Context, msg: DebugLinkDecision
     ) -> None:
         from trezor.ui import confirm, swipe
 
+        waiting_signals = [
+            bool(s.putters) for s in (confirm_chan, swipe_chan, input_chan)
+        ]
+        if sum(waiting_signals) > 0:
+            log.warning(
+                __name__,
+                "Received new DebugLinkDecision before the previous one was handled.",
+            )
+            log.warning(
+                __name__,
+                "received: button {}, swipe {}, input {}".format(
+                    msg.yes_no, msg.up_down, msg.input
+                ),
+            )
+            log.warning(
+                __name__,
+                "waiting: button {}, swipe {}, input {}".format(*waiting_signals),
+            )
+
         if msg.yes_no is not None:
-            confirm_signal.send(confirm.CONFIRMED if msg.yes_no else confirm.CANCELLED)
+            await confirm_chan.put(
+                confirm.CONFIRMED if msg.yes_no else confirm.CANCELLED
+            )
         if msg.up_down is not None:
-            swipe_signal.send(swipe.SWIPE_DOWN if msg.up_down else swipe.SWIPE_UP)
+            await swipe_chan.put(swipe.SWIPE_DOWN if msg.up_down else swipe.SWIPE_UP)
         if msg.input is not None:
-            input_signal.send(msg.input)
+            await input_chan.put(msg.input)
 
     async def dispatch_DebugLinkGetState(
         ctx: wire.Context, msg: DebugLinkGetState
@@ -45,10 +69,12 @@ if __debug__:
         m.mnemonic_secret = mnemonic.get_secret()
         m.mnemonic_type = mnemonic.get_type()
         m.passphrase_protection = storage.device.has_passphrase()
-        m.reset_word_pos = reset_word_index
         m.reset_entropy = reset_internal_entropy
-        if reset_current_words:
-            m.reset_word = " ".join(reset_current_words)
+
+        if msg.wait_word_pos:
+            m.reset_word_pos = await reset_word_index.take()
+        if msg.wait_word_list:
+            m.reset_word = " ".join(await reset_current_words.take())
         return m
 
     def boot() -> None:

core/src/apps/management/common/layout.py

@@ -93,7 +93,7 @@ async def _confirm_word(ctx, share_index, numbered_share_words, count):
     # we always confirm the first (random) word index
     checked_index, checked_word = numbered_choices[0]
     if __debug__:
-        debug.reset_word_index = checked_index
+        debug.reset_word_index.publish(checked_index)
 
     # shuffle again so the confirmed word is not always the first choice
     random.shuffle(numbered_choices)
@@ -200,7 +200,7 @@ async def _bip39_show_mnemonic(ctx, words: list):
 
         def export_displayed_words():
             # export currently displayed mnemonic words into debuglink
-            debug.reset_current_words = [w for _, w in words[paginated.page]]
+            debug.reset_current_words.publish([w for _, w in words[paginated.page]])
 
         paginated.on_change = export_displayed_words
         export_displayed_words()
@@ -393,7 +393,8 @@ async def _slip39_show_share_words(ctx, share_index, share_words):
 
         def export_displayed_words():
             # export currently displayed mnemonic words into debuglink
-            debug.reset_current_words = [w for _, w in word_pages[paginated.page]]
+            words = [w for _, w in word_pages[paginated.page]]
+            debug.reset_current_words.publish(words)
 
         paginated.on_change = export_displayed_words
         export_displayed_words()

core/src/trezor/messages/DebugLinkGetState.py

@@ -12,3 +12,18 @@ if __debug__:
 
 class DebugLinkGetState(p.MessageType):
     MESSAGE_WIRE_TYPE = 101
+
+    def __init__(
+        self,
+        wait_word_list: bool = None,
+        wait_word_pos: bool = None,
+    ) -> None:
+        self.wait_word_list = wait_word_list
+        self.wait_word_pos = wait_word_pos
+
+    @classmethod
+    def get_fields(cls) -> Dict:
+        return {
+            1: ('wait_word_list', p.BoolType, 0),
+            2: ('wait_word_pos', p.BoolType, 0),
+        }

python/trezorlib/messages/DebugLinkGetState.py

@@ -12,3 +12,18 @@ if __debug__:
 
 class DebugLinkGetState(p.MessageType):
     MESSAGE_WIRE_TYPE = 101
+
+    def __init__(
+        self,
+        wait_word_list: bool = None,
+        wait_word_pos: bool = None,
+    ) -> None:
+        self.wait_word_list = wait_word_list
+        self.wait_word_pos = wait_word_pos
+
+    @classmethod
+    def get_fields(cls) -> Dict:
+        return {
+            1: ('wait_word_list', p.BoolType, 0),
+            2: ('wait_word_pos', p.BoolType, 0),
+        }