Fix Huawei WebCRT hop login echo doubling and safer Change-now handling.

Co-authored-by: Cursor <cursoragent@cursor.com>

netx_api/ne_connect.py

@@ -194,6 +194,11 @@ def _classify_connect_error(creds: dict[str, Any], exc: BaseException) -> str:
             return "target_auth_failed: " + detail
         if "timed out" in raw or "timeout" in raw or "hop_connect_failed" in raw:
             return "hop_connect_failed: " + detail
+        if "no existing session" in raw:
+            return (
+                "hop_connect_failed: SSH handshake dropped (often hop VTY/session limit "
+                "or concurrent WebCRT). Close spare terminals and retry. " + detail
+            )
         if hop_v in ("linux", "bastion"):
             if "vault" in raw or "bastion" in raw:
                 return "bastion_auth_failed: " + detail
@@ -247,7 +252,15 @@ def _probe_device(creds: dict[str, Any]) -> tuple[str, str, str | None, str]:
     session_timeout = 180 if creds.get("hop_enabled") else None
     conn = None
     try:
-        conn = open_netmiko_connection(creds, session_timeout=session_timeout)
+        # CLI hop (Huawei/ZTE/Cisco): use interactive driver so Change-now / prompt
+        # waits match WebCRT (stock Netmiko ``[\]>]`` matches ``[Y/N]`` and breaks hop login).
+        hop_v = str(creds.get("hop_vendor") or "").strip().lower()
+        use_interactive = bool(creds.get("hop_enabled")) and hop_v not in ("linux", "bastion", "")
+        conn = open_netmiko_connection(
+            creds,
+            session_timeout=session_timeout,
+            interactive=use_interactive,
+        )
         prompt = str(conn.find_prompt() or "")
         command = hostname_probe_command(creds["device_type"], vendor)
         output = ""

netx_api/ne_session_connect.py

@@ -142,13 +142,18 @@ def _netmiko_driver_class(device_type: str) -> type:
 def _interactive_driver_class(base_cls: type) -> type:
     """Subclass for WebCRT: raw interactive PTY after transport auth (SecureCRT-like).
 
-    Skips Netmiko session prep (prompt discovery, terminal length/width, force RETURN)
-    and Huawei ``special_login_handler`` (read_until prompt / password-change). Those
-    waits are why WebCRT stuck on ``waiting_prompt`` while connectivity probes succeed:
-    collection still runs full Netmiko login; WebCRT must leave the PTY for live echo
-    and hop secondary auth instead.
+    Skips Netmiko session prep (prompt discovery, terminal length/width, force RETURN).
+    Huawei password-change is handled with a *safe* prompt pattern (never bare ``]``,
+    which matches ``[Y/N]`` and scrambles login).
     """
 
+    _REAL_PROMPT = r"(?:<[^>\r\n]{1,64}>|\[[^\]\r\n]{1,64}\])"
+    _mro_names = {getattr(c, "__name__", "") for c in getattr(base_cls, "__mro__", ())}
+    _is_huawei_telnet = "HuaweiTelnet" in _mro_names or getattr(base_cls, "__name__", "") == "HuaweiTelnet"
+    _is_huawei_ssh = bool(_mro_names & {"HuaweiSSH", "HuaweiVrpv8SSH"}) or getattr(
+        base_cls, "__name__", ""
+    ) in {"HuaweiSSH", "HuaweiVrpv8SSH"}
+
     class _InteractiveSession(base_cls):  # type: ignore[misc,valid-type]
         def disable_paging(self, *args: Any, **kwargs: Any) -> str:  # noqa: ANN401
             return ""
@@ -160,7 +165,35 @@ def _interactive_driver_class(base_cls: type) -> type:
             return None
 
         def special_login_handler(self, delay_factor: float = 1.0) -> None:  # noqa: ARG002
-            return None
+            # Non-Huawei: leave the PTY alone (SecureCRT-like).
+            if not (_is_huawei_ssh or hasattr(self, "password_change_prompt")):
+                return
+            if _is_huawei_telnet:
+                # Telnet answers Change-now inside telnet_login (below).
+                return
+            if not _is_huawei_ssh:
+                return
+            import re as _re
+
+            # Huawei SSH: answer Change-now, wait for real ``<sysname>`` / ``[sysname]``.
+            # Do NOT use stock ``[\]>]`` — it matches ``]`` in ``[Y/N]``.
+            wait_pat = rf"(?:Change now|Please choose|{_REAL_PROMPT})"
+            data = self.read_until_pattern(pattern=wait_pat)
+            if _re.search(r"(?:Change now|Please choose)", data):
+                self.write_channel("N" + self.RETURN)
+                self.read_until_pattern(pattern=_REAL_PROMPT)
+            # Optional "security risks in the configuration file" (stock HuaweiSSH).
+            if _re.search(
+                r"security\srisks\sin\sthe\sconfiguration\sfile.*\[y\/n\]",
+                data,
+                flags=_re.I,
+            ):
+                try:
+                    self.send_command("Y", expect_string=r"(?i)continue.*\[y\/n\]")
+                    self.send_command("Y", expect_string=r"saved\ssuccessfully", read_timeout=60)
+                    self.read_until_pattern(pattern=_REAL_PROMPT)
+                except Exception:
+                    pass
 
         def _try_session_preparation(self, force_data: bool = True) -> None:  # noqa: FBT001, FBT002
             del force_data
@@ -170,6 +203,55 @@ def _interactive_driver_class(base_cls: type) -> type:
                 self.disconnect()
                 raise
 
+    # Huawei Telnet: stock prompt_pattern ``[\]>]`` matches the ``]`` inside
+    # ``Change now? [Y/N]:``, so after sending N Netmiko can return before the
+    # Info banner / real ``<r1>`` — live echo then looks like ``<r1>N`` + late MOTD.
+    if _is_huawei_telnet:
+        def telnet_login(  # type: ignore[no-redef]
+            self,
+            pri_prompt_terminator: str = r"",
+            alt_prompt_terminator: str = r"",
+            username_pattern: str = r"(?:user:|username|login|user name)",
+            pwd_pattern: str = r"assword",
+            delay_factor: float = 1.0,
+            max_loops: int = 20,
+        ) -> str:
+            import re as _re
+
+            from netmiko.exceptions import NetmikoAuthenticationException
+
+            del pri_prompt_terminator, alt_prompt_terminator, delay_factor, max_loops
+            output = ""
+            return_msg = ""
+            try:
+                output = self.read_until_pattern(pattern=username_pattern, re_flags=_re.I)
+                return_msg += output
+                self.write_channel(self.username + self.TELNET_RETURN)
+
+                output = self.read_until_pattern(pattern=pwd_pattern, re_flags=_re.I)
+                return_msg += output
+                assert self.password is not None
+                self.write_channel(self.password + "\r")
+
+                wait_pat = rf"(?:Change now|Please choose|{_REAL_PROMPT})"
+                output = self.read_until_pattern(pattern=wait_pat)
+                return_msg += output
+
+                if _re.search(r"(?:Change now|Please choose)", output):
+                    self.write_channel("N" + self.TELNET_RETURN)
+                    output = self.read_until_pattern(pattern=_REAL_PROMPT)
+                    return_msg += output
+                    return return_msg
+                if _re.search(_REAL_PROMPT, output):
+                    return return_msg
+                raise EOFError
+            except EOFError:
+                assert self.remote_conn is not None
+                self.remote_conn.close()
+                raise NetmikoAuthenticationException(f"Login failed: {self.host}")
+
+        _InteractiveSession.telnet_login = telnet_login  # type: ignore[method-assign]
+
     _InteractiveSession.__name__ = f"Interactive{getattr(base_cls, '__name__', 'Netmiko')}"
     return _InteractiveSession
 
@@ -367,6 +449,9 @@ def _base_connect_kwargs(
     keepalive: int | None = None,
 ) -> dict[str, Any]:
     timeout = int(settings.ne_connect_timeout_sec or 30)
+    # Hop / long session_timeout paths need a roomier SSH handshake (busy VTY / MOTD).
+    if session_timeout is not None:
+        timeout = max(timeout, min(int(session_timeout), 60))
     dev: dict[str, Any] = {
         "device_type": device_type,
         "host": host,
@@ -538,14 +623,41 @@ def _looks_like_target_cli_prompt(text: str) -> bool:
     return bool(re.search(r"(?:[>#\]])\s*$", tail)) or bool(re.search(r"^<[^>\r\n]+>\s*$", tail))
 
 
+def _looks_like_password_change_prompt(text: str) -> bool:
+    """Huawei/VRP ``Change now? [Y/N]:`` after successful password (not host-key)."""
+    tail = _auth_prompt_tail(text, lines=2)
+    if not tail:
+        return False
+    return bool(
+        re.search(
+            r"(?i)(change\s*now|please\s*choose|password\s+needs\s+to\s+be\s+changed).{0,80}:\s*$",
+            tail,
+        )
+    )
+
+
+def _saw_huawei_last_login(text: str) -> bool:
+    return bool(
+        re.search(
+            r"(?is)(?:user\s+last\s+login\s+information|last\s+login\s+time|上次登录)",
+            str(text or ""),
+        )
+    )
+
+
 def _interactive_target_auth(
     conn: ConnectHandler,
     username: str,
     password: str,
     *,
     progress_cb: Any = None,
+    emit_raw: bool = True,
 ) -> None:
-    """Respond to username/password (and Huawei stelnet host-key) prompts after hop command."""
+    """Respond to username/password (and Huawei stelnet host-key) prompts after hop command.
+
+    When ``emit_raw`` is False, device bytes are assumed to already reach the UI via
+    ``session_log`` ProgressBytesIO — only emit ``[netx]`` markers (avoids doubled echo).
+    """
     from .ne_cli_errors import find_auth_failure_snippet
 
     # Hop stelnet can show Trying/Connected + two [Y/N] before password; keep budget generous.
@@ -554,13 +666,15 @@ def _interactive_target_auth(
     sent_pass = False
     answered_continue = False
     answered_save_key = False
+    answered_pw_change = False
     empty_after_pass = 0
     acc = ""
     while time.time() < deadline:
         buf = _read_channel(conn, wait=0.12, max_loops=12)
         if buf:
             acc += buf
-            _emit_progress(progress_cb, buf)
+            if emit_raw:
+                _emit_progress(progress_cb, buf)
             denied = find_auth_failure_snippet(acc)
             if denied:
                 raise paramiko.AuthenticationException(f"target_auth_rejected: {denied}")
@@ -578,6 +692,15 @@ def _interactive_target_auth(
             answered_save_key = True
             continue
 
+        # Post-auth password-change must be answered or auth loops until timeout while
+        # the terminal already shows a near-login state (live echo) and stdin is blocked.
+        if sent_pass and not answered_pw_change and _looks_like_password_change_prompt(acc):
+            _emit_progress(progress_cb, "\r\n[netx] password-change → N\r\n")
+            _send_line(conn, "N")
+            answered_pw_change = True
+            empty_after_pass = 0
+            continue
+
         need_user, need_pass = _prompt_needs_auth(acc)
         if need_pass and not sent_pass:
             _emit_progress(progress_cb, "\r\n[netx] sending password\r\n")
@@ -597,15 +720,20 @@ def _interactive_target_auth(
                 raise paramiko.AuthenticationException(f"target_auth_rejected: {denied}")
             if _looks_like_target_cli_prompt(acc):
                 return
+            # Last-login banner already printed — hand off quickly even if prompt parse lags.
+            if _saw_huawei_last_login(acc) and empty_after_pass >= 1:
+                return
             # Do not treat a single empty read right after password as success —
             # Huawei still prints last-login banner / prompt.
             if not buf.strip():
                 empty_after_pass += 1
-                if empty_after_pass >= 4:
+                # Faster handoff: live echo already shows login; WS cannot accept stdin
+                # until open_netmiko_connection returns.
+                if empty_after_pass >= (2 if _saw_huawei_last_login(acc) else 3):
                     return
             else:
                 empty_after_pass = 0
-            time.sleep(0.15)
+            time.sleep(0.12)
             continue
 
         if not buf.strip():
@@ -702,13 +830,16 @@ def _connect_via_cli_hop(
         keepalive=keepalive,
     )
     _emit_progress(progress_cb, f"\r\n[netx] connecting hop {_hop_vendor(creds)} {hop_host}…\r\n")
+    # WebCRT passes ProgressBytesIO(session_log) that already tees device bytes to progress_cb.
+    # Re-emitting the same reads doubles every line (stelnet, Y/N, MOTD, prompts).
+    teed = isinstance(session_log, _ProgressBytesIO)
     conn = _build_netmiko_connection(hop_dev, interactive=interactive)
     try:
         # MUST resize before stelnet/telnet — nested session captures hop TTY size at start
         # and often ignores later WINCH. Wrong width → mid-line edit redraw wraps in WebCRT.
         _resize_pty(conn, cols, rows)
         pre = _read_channel(conn, wait=0.35)
-        if pre:
+        if pre and not teed:
             _emit_progress(progress_cb, pre)
         hop_prompt = extract_cli_prompt_marker(pre)
         if not hop_prompt:
@@ -718,7 +849,7 @@ def _connect_via_cli_hop(
             except Exception:
                 _send_line(conn, "")
             more = _read_channel(conn, wait=0.25, max_loops=12)
-            if more:
+            if more and not teed:
                 _emit_progress(progress_cb, more)
             pre = pre + more
             hop_prompt = extract_cli_prompt_marker(pre)
@@ -728,7 +859,8 @@ def _connect_via_cli_hop(
             for _ in range(6):
                 more = _read_channel(conn, wait=0.3, max_loops=10)
                 if more:
-                    _emit_progress(progress_cb, more)
+                    if not teed:
+                        _emit_progress(progress_cb, more)
                     pre += more
                     hop_prompt = extract_cli_prompt_marker(pre)
                     if hop_prompt:
@@ -741,6 +873,7 @@ def _connect_via_cli_hop(
             str(creds["username"]),
             str(creds["password"]),
             progress_cb=progress_cb,
+            emit_raw=not teed,
         )
         _attach_cli_hop_guard(
             conn,
@@ -776,10 +909,11 @@ def _maybe_secondary_target_auth(
     *,
     progress_cb: Any = None,
     force: bool = False,
+    emit_raw: bool = True,
 ) -> None:
     """Run interactive target auth when the PTY still shows login / host-key prompts."""
     peek = _read_channel(conn, wait=0.45, max_loops=14)
-    if peek:
+    if peek and emit_raw:
         _emit_progress(progress_cb, peek)
     need_user, need_pass = _prompt_needs_auth(peek)
     cont, save = _prompt_needs_host_key_confirm(peek)
@@ -796,7 +930,13 @@ def _maybe_secondary_target_auth(
     if not target_user and need_user:
         _emit_progress(progress_cb, "\r\n[netx] username prompt but target username empty\r\n")
         return
-    _interactive_target_auth(conn, target_user, target_pass, progress_cb=progress_cb)
+    _interactive_target_auth(
+        conn,
+        target_user,
+        target_pass,
+        progress_cb=progress_cb,
+        emit_raw=emit_raw,
+    )
 
 
 def _connect_via_bastion(
@@ -860,20 +1000,25 @@ def _connect_via_bastion(
         raise
 
     auth_mode = str(creds.get("hop_target_auth_mode") or "bastion_managed").strip().lower()
+    teed = isinstance(session_log, _ProgressBytesIO)
     try:
         if auth_mode == "manual":
             target_pass = str(creds.get("password") or "")
             if target_pass:
-                _maybe_secondary_target_auth(conn, creds, progress_cb=progress_cb, force=True)
+                _maybe_secondary_target_auth(
+                    conn, creds, progress_cb=progress_cb, force=True, emit_raw=not teed
+                )
             else:
                 # Still drain banner so WebCRT live echo shows what the proxy printed.
                 peek = _read_channel(conn, wait=0.4, max_loops=12)
-                if peek:
+                if peek and not teed:
                     _emit_progress(progress_cb, peek)
         else:
             # bastion_managed: normally no secondary auth, but if the proxy still presents
             # Username/Password or Huawei host-key prompts, answer them when creds exist.
-            _maybe_secondary_target_auth(conn, creds, progress_cb=progress_cb, force=False)
+            _maybe_secondary_target_auth(
+                conn, creds, progress_cb=progress_cb, force=False, emit_raw=not teed
+            )
     except Exception:
         try:
             conn.disconnect()

netx_api/webcrt_channel.py

@@ -128,44 +128,90 @@ def _session_log_text(buf: io.BytesIO | None) -> str:
     return str(raw or "")
 
 
-def _looks_like_cli_prompt(text: str) -> bool:
-    s = str(text or "").rstrip()
-    if not s:
+def _cli_prompt_candidate_lines(text: str) -> list[str]:
+    """Non-empty transcript lines, stripping ANSI and ignoring trailing ``[netx]`` markers."""
+    s = str(text or "").replace("\r\n", "\n").replace("\r", "\n")
+    s = re.sub(r"\x1b\[[0-9;?]*[A-Za-z]", "", s)
+    lines = [ln.strip() for ln in s.split("\n") if ln.strip()]
+    while lines and lines[-1].startswith("[netx]"):
+        lines.pop()
+    return lines
+
+
+def _line_looks_like_cli_prompt(line: str) -> bool:
+    last = str(line or "").strip()
+    if not last:
         return False
-    # Buffer races can leave a stray ':' after Huawei ``<r1>`` (from prior ``[Y/N]:``).
-    if s.endswith(":") and ">" in s:
-        s = s[:-1].rstrip()
-    # Common network CLI prompts: <r1>  [HUAWEI]  Router#  Router>
-    return bool(re.search(r"(?:[>\]]|#)\s*$", s)) or bool(re.search(r"<[^>\r\n]+>\s*$", s))
+    # Buffer races: ``<r1>:`` (stray from [Y/N]:) or ``<r1>N`` (password-change answer glued).
+    if last.endswith(":") and (">" in last or "]" in last):
+        last = last[:-1].rstrip()
+    if len(last) >= 2 and last[-1] in "NYny" and (last[-2] in ">]" or last.endswith(">")):
+        # ``<r1>N`` / ``[HW]Y`` after Change-now answer — treat as prompted.
+        last = last[:-1].rstrip()
+    return bool(re.search(r"(?:[>\]]|#)\s*$", last)) or bool(re.search(r"<[^>\r\n]+>\s*$", last))
+
+
+def _looks_like_cli_prompt(text: str) -> bool:
+    lines = _cli_prompt_candidate_lines(text)
+    if not lines:
+        return False
+    return _line_looks_like_cli_prompt(lines[-1])
 
 
 def _looks_like_login_prompt(text: str) -> bool:
     """True when the transcript ends at Username:/Login:/Password: (interactive auth)."""
-    s = str(text or "").replace("\r\n", "\n").replace("\r", "\n")
-    lines = [ln.strip() for ln in s.split("\n") if ln.strip()]
+    lines = _cli_prompt_candidate_lines(text)
     if not lines:
         return False
     last = lines[-1]
     return bool(re.search(r"(?i)(user\s*name|login|password)\s*:\s*$", last))
 
 
+_PASSWORD_CHANGE_LINE_RE = re.compile(
+    r"(?i)(change\s*now|please\s*choose|password\s+needs\s+to\s+be\s+changed).{0,80}:\s*$"
+)
+
+
 def _looks_like_password_change_prompt(text: str) -> bool:
     """Huawei/VRP post-auth ``Change now? [Y/N]:`` (Netmiko already answers N).
 
     Do not match bare ``[Y/N]:`` — stelnet host-key trust prompts share that suffix
     and are answered in ``_interactive_target_auth``, not by skipping Enter here.
     """
-    s = str(text or "").replace("\r\n", "\n").replace("\r", "\n")
-    lines = [ln.strip() for ln in s.split("\n") if ln.strip()]
+    lines = _cli_prompt_candidate_lines(text)
     if not lines:
         return False
-    last = lines[-1]
-    return bool(
-        re.search(
-            r"(?i)(change\s*now|please\s*choose|password\s+needs\s+to\s+be\s+changed).{0,80}:\s*$",
-            last,
-        )
-    )
+    return bool(_PASSWORD_CHANGE_LINE_RE.search(lines[-1]))
+
+
+def _password_change_still_pending(text: str) -> bool:
+    """True only when Change-now is still awaiting an answer.
+
+    Netmiko ``HuaweiTelnet.telnet_login`` often already sent ``N`` before WebCRT
+    ``_finish_connect`` runs. Re-sending ``N`` lands as a command on ``<r1>``.
+    Treat a lone ``N``/``Y`` echo (or a later CLI prompt) as already answered.
+    """
+    lines = _cli_prompt_candidate_lines(text)
+    if not lines:
+        return False
+    last_change = -1
+    for i, ln in enumerate(lines):
+        if _PASSWORD_CHANGE_LINE_RE.search(ln):
+            last_change = i
+    if last_change < 0:
+        return False
+    after = lines[last_change + 1 :]
+    if not after:
+        # Still sitting on Change now? [Y/N]:
+        return True
+    if any(_line_looks_like_cli_prompt(ln) for ln in after):
+        return False
+    # Device already echoed N/Y from Netmiko (or a prior answer) — do not send again.
+    if any(ln.strip().upper() in {"N", "Y"} for ln in after):
+        return False
+    # Banner / last-login text after Change-now without a prompt yet: Netmiko may still
+    # be draining; do not inject a second N (would race onto the prompt).
+    return False
 
 
 # Cisco/Netmiko often yields "R2#R2#" when a sync Enter is appended without a newline.

netx_api/webcrt_router.py

@@ -464,6 +464,7 @@ async def websocket_session(websocket: WebSocket, session_id: str) -> None:
         loop = asyncio.get_running_loop()
         budget = max(30, int(settings.webcrt_connect_timeout_sec or 90)) + 15
         deadline = time.time() + budget
+        early_stdin: list[str] = []
 
         async def _flush_connect_echo(cur_sess: Any) -> None:
             try:
@@ -481,6 +482,50 @@ async def websocket_session(websocket: WebSocket, session_id: str) -> None:
                 except Exception:
                     return
 
+        async def _drain_client_during_connect() -> bool:
+            """Handle ping/stdin/resize while connect runs. False = client gone."""
+            nonlocal early_stdin
+            while True:
+                try:
+                    msg_raw = await asyncio.wait_for(websocket.receive(), timeout=0.01)
+                except asyncio.TimeoutError:
+                    return True
+                except Exception:
+                    return False
+                if msg_raw.get("type") == "websocket.disconnect":
+                    return False
+                raw = msg_raw.get("text")
+                if raw is None:
+                    # Binary frames during connect: treat as stdin if decodeable.
+                    if "bytes" in msg_raw and msg_raw["bytes"] is not None:
+                        try:
+                            early_stdin.append(
+                                _decode_bytes(bytes(msg_raw["bytes"]), sess.encoding)
+                            )
+                        except Exception:
+                            pass
+                    continue
+                try:
+                    msg = json.loads(raw)
+                except json.JSONDecodeError:
+                    early_stdin.append(str(raw))
+                    continue
+                mtype = str(msg.get("type") or "").strip().lower()
+                if mtype == "ping":
+                    try:
+                        await websocket.send_json({"type": "pong"})
+                    except Exception:
+                        return False
+                elif mtype == "stdin":
+                    data = msg.get("data")
+                    if data is not None:
+                        early_stdin.append(str(data))
+                elif mtype == "resize":
+                    # Ignore until ready (PTY size already set from create).
+                    pass
+                elif mtype == "close":
+                    return False
+
         while True:
             cur = get_session(session_id) or sess
             if cur.state != "connecting":
@@ -505,6 +550,14 @@ async def websocket_session(websocket: WebSocket, session_id: str) -> None:
                 # Client dropped during connect wait (StrictMode remount etc.) — keep PTY.
                 return
             await _flush_connect_echo(cur)
+            if not await _drain_client_during_connect():
+                return
+            # If connect finished while we drained client frames, exit promptly.
+            cur = get_session(session_id) or sess
+            if cur.state != "connecting":
+                await _flush_connect_echo(cur)
+                sess = cur
+                break
             remaining = deadline - time.time()
             if remaining <= 0:
                 await websocket.send_json(
@@ -512,7 +565,7 @@ async def websocket_session(websocket: WebSocket, session_id: str) -> None:
                 )
                 await websocket.close(code=4502)
                 return
-            slice_timeout = min(0.35, max(0.15, remaining))
+            slice_timeout = min(0.25, max(0.12, remaining))
             try:
                 await loop.run_in_executor(
                     webcrt_io_executor(),
@@ -545,6 +598,18 @@ async def websocket_session(websocket: WebSocket, session_id: str) -> None:
                 await websocket.close(code=4502)
                 return
 
+        # Keystrokes typed while login was already on screen (before ready).
+        if early_stdin and sess is not None and not sess.closed and sess.conn is not None:
+            try:
+                await loop.run_in_executor(
+                    webcrt_io_executor(),
+                    sess.write_stdin,
+                    "".join(early_stdin),
+                )
+            except Exception:
+                _log.debug(
+                    "webcrt early stdin flush failed session=%s", session_id, exc_info=True
+                )
     # Session may have been deleted while the previous wait loop was exiting.
     if get_session(session_id) is None or sess.closed or sess.state in {"closed", "error"}:
         if sess.state == "error":
@@ -560,6 +625,21 @@ async def websocket_session(websocket: WebSocket, session_id: str) -> None:
                 pass
         return
 
+    # Drain any leftover connect-echo (e.g. WS attached after connect already ready).
+    try:
+        leftover_echo = sess.drain_connect_echo()
+    except Exception:
+        leftover_echo = ""
+    if leftover_echo:
+        raw = _encode_text(leftover_echo, getattr(sess, "encoding", None) or "utf-8")
+        try:
+            await websocket.send_bytes(raw)
+        except Exception:
+            try:
+                await websocket.send_json({"type": "stdout", "data": leftover_echo})
+            except Exception:
+                pass
+
     await websocket.send_json(
         {
             "type": "status",

netx_api/webcrt_service.py

@@ -13,6 +13,7 @@ from .webcrt_channel import (
     _looks_like_cli_prompt,
     _looks_like_login_prompt,
     _looks_like_password_change_prompt,
+    _password_change_still_pending,
     _normalize_encoding,
     _session_log_path,
     channel_return,
@@ -56,6 +57,7 @@ __all__ = [
     "_looks_like_cli_prompt",
     "_looks_like_login_prompt",
     "_looks_like_password_change_prompt",
+    "_password_change_still_pending",
     "_normalize_encoding",
     "_reap_sessions",
     "_session_log_path",

netx_api/webcrt_session_registry.py

@@ -4,6 +4,7 @@ from __future__ import annotations
 import io
 import logging
 import queue
+import re
 import threading
 import time
 import uuid
@@ -29,7 +30,7 @@ from .webcrt_channel import (
     _is_prompt_only_echo,
     _looks_like_cli_prompt,
     _looks_like_login_prompt,
-    _looks_like_password_change_prompt,
+    _password_change_still_pending,
     _normalize_encoding,
     _prime_interactive_channel,
     _session_log_text,
@@ -278,53 +279,97 @@ def _finish_connect(
     pre_log = _session_log_text(log_buf)
     # Pull post-auth banner/MOTD from the PTY. With interactive no-op session_preparation
     # (generic_termserver), Netmiko session_log is often empty — do not discard these bytes.
+    # Keep this short: live echo already streamed login; long settle blocks WS stdin.
     try:
-        early = _capture_raw_channel(conn, duration=0.35)
+        early = _capture_raw_channel(conn, duration=0.2)
     except Exception:
         early = ""
     if early:
         sess.push_connect_echo(early)
     seed = f"{pre_log}{early}"
     already_prompted = _looks_like_cli_prompt(seed) or _looks_like_cli_prompt(pre_log)
+    saw_password_change = bool(
+        re.search(
+            r"(?i)(change\s*now|please\s*choose|password\s+needs\s+to\s+be\s+changed).{0,80}:",
+            seed,
+        )
+    )
     primed = ""
-    # Auto-answer Huawei post-login password-change only if still sitting on the prompt
-    # (Netmiko telnet_login usually already answered N — do not send a second N/Enter).
-    if _looks_like_password_change_prompt(seed) and not already_prompted:
+    # Huawei Telnet/SSH interactive drivers already answer Change-now during login.
+    # Never send a second N here — it lands as ``<r1>N`` / Unrecognized command.
+    netmiko_handles_pw_change = any(
+        getattr(c, "__name__", "") in {"HuaweiTelnet", "HuaweiSSH", "HuaweiVrpv8SSH"}
+        for c in type(conn).__mro__
+    )
+    if (
+        (not netmiko_handles_pw_change)
+        and _password_change_still_pending(seed)
+        and not already_prompted
+    ):
+        # Brief peek — another path may have answered while session_log still ends on Change-now.
         try:
-            conn.write_channel("N" + (getattr(conn, "RETURN", None) or "\n"))
-            sess.push_connect_echo("\r\n[netx] password-change → N\r\n")
-            primed = _capture_raw_channel(conn, duration=0.9)
-            if primed:
-                sess.push_connect_echo(primed)
+            peek = _capture_raw_channel(conn, duration=0.35)
         except Exception:
-            primed = ""
+            peek = ""
+        if peek:
+            sess.push_connect_echo(peek)
+            seed = f"{seed}{peek}"
+            already_prompted = _looks_like_cli_prompt(seed)
+        if _password_change_still_pending(seed) and not already_prompted:
+            try:
+                conn.write_channel("N" + (getattr(conn, "RETURN", None) or "\n"))
+                sess.push_connect_echo("\r\n[netx] password-change → N\r\n")
+                primed = _capture_raw_channel(conn, duration=0.6)
+                if primed:
+                    sess.push_connect_echo(primed)
+            except Exception:
+                primed = ""
     elif _looks_like_login_prompt(seed):
         # Do not send Enter at Username:/Password: (would empty-submit login).
         try:
-            primed = _capture_raw_channel(conn, duration=0.9)
+            primed = _capture_raw_channel(conn, duration=0.45)
             if primed:
                 sess.push_connect_echo(primed)
         except Exception:
             primed = ""
-    else:
+    elif not already_prompted and not saw_password_change:
+        # Only nudge Enter when we do not already have a CLI prompt (avoids duplicate
+        # prompts and delays ready while the user can already see login via live echo).
+        # After Huawei Change-now, Netmiko already drove login — Enter here reorders MOTD.
         try:
-            primed = _prime_interactive_channel(conn, already_prompted=already_prompted)
+            primed = _prime_interactive_channel(conn, already_prompted=False)
+            if primed:
+                sess.push_connect_echo(primed)
+        except Exception:
+            primed = ""
+    elif not already_prompted and saw_password_change:
+        # Drain MOTD/prompt only — never Enter (would glue onto <r1> or reprint prompt).
+        try:
+            primed = _capture_raw_channel(conn, duration=0.45)
             if primed:
                 sess.push_connect_echo(primed)
         except Exception:
             primed = ""
     combined = f"{seed}{primed}"
-    # Final settle: keep stragglers (normalize collapses duplicate prompts when bootstrapping).
+    # Brief settle only — do not burn seconds here while the terminal shows a prompt.
+    settle_sec = 0.12 if already_prompted or _looks_like_cli_prompt(combined) else 0.3
     try:
-        more = _capture_raw_channel(conn, duration=0.35)
+        more = _capture_raw_channel(conn, duration=settle_sec)
         if more:
-            sess.push_connect_echo(more)
-            combined += more
+            # Drop a second ``<r1>`` that often races in after password-change login.
+            hint = ""
+            for ln in reversed(str(combined).replace("\r\n", "\n").split("\n")):
+                if _looks_like_cli_prompt(ln):
+                    hint = ln.strip()
+                    break
+            if not (hint and _is_prompt_only_echo(more, hint)):
+                sess.push_connect_echo(more)
+                combined += more
     except Exception:
         pass
     if not str(combined).strip():
         try:
-            combined = _drain_channel(conn, rounds=6, wait=0.08)
+            combined = _drain_channel(conn, rounds=4, wait=0.06)
             if combined:
                 sess.push_connect_echo(combined)
         except Exception:
@@ -334,22 +379,38 @@ def _finish_connect(
     # Replaying prepare_bootstrap_output(combined) caused a full duplicate login.
     echoed = sess.connect_echo_text()
     bootstrap = ""
+    # Prefer last real prompt line as hint so we can drop duplicate prompt leftovers.
+    prompt_hint = ""
+    if echoed or combined:
+        for ln in reversed(
+            str(echoed or combined).replace("\r\n", "\n").replace("\r", "\n").split("\n")
+        ):
+            if _looks_like_cli_prompt(ln):
+                prompt_hint = ln.strip()
+                break
     if not echoed.strip():
         bootstrap = prepare_bootstrap_output(combined)
         try:
-            leftover = _capture_raw_channel(conn, duration=0.12)
+            leftover = _capture_raw_channel(conn, duration=0.1)
         except Exception:
             leftover = ""
-        if leftover and leftover.strip() not in {":", ">", "#", "]", "$"}:
+        if (
+            leftover
+            and leftover.strip() not in {":", ">", "#", "]", "$"}
+            and not _is_prompt_only_echo(leftover, prompt_hint)
+        ):
             sess.push_connect_echo(leftover)
             bootstrap = prepare_bootstrap_output(f"{bootstrap}{leftover}")
     else:
-        # Optional unseen tail only (already pushed to connect-echo above when present).
         try:
-            leftover = _capture_raw_channel(conn, duration=0.12)
+            leftover = _capture_raw_channel(conn, duration=0.08)
         except Exception:
             leftover = ""
-        if leftover and leftover.strip() not in {":", ">", "#", "]", "$"}:
+        if (
+            leftover
+            and leftover.strip() not in {":", ">", "#", "]", "$"}
+            and not _is_prompt_only_echo(leftover, prompt_hint)
+        ):
             sess.push_connect_echo(leftover)
 
     hop_guard = get_cli_hop_guard(conn)
@@ -360,8 +421,11 @@ def _finish_connect(
     # Nudge Enter on WS attach only when we still need a shell prompt.
     # Never when already at CLI prompt or Username:/Password: (would empty-submit login).
     final_view = echoed or bootstrap
+    # After Huawei Change-now, never send a sync Enter on WS attach (reorders MOTD / glues N).
     sess.needs_live_prompt = (
-        not _looks_like_cli_prompt(final_view) and not _looks_like_login_prompt(final_view)
+        not saw_password_change
+        and not _looks_like_cli_prompt(final_view)
+        and not _looks_like_login_prompt(final_view)
     )
     sess.open_session_log()
     log_seed = echoed or bootstrap
@@ -369,10 +433,9 @@ def _finish_connect(
         sess.append_session_log(log_seed if str(log_seed).endswith("\n") else str(log_seed) + "\n")
     sess.start_reader()
     # Drop late prompt echoes that race into the queue right after reader start.
-    prompt_hint = ""
-    if final_view:
+    if not prompt_hint and final_view:
         prompt_hint = str(final_view).replace("\r\n", "\n").replace("\r", "\n").strip().split("\n")[-1].strip()
-    settle_deadline = time.time() + 0.45
+    settle_deadline = time.time() + (0.2 if already_prompted or saw_password_change else 0.35)
     while time.time() < settle_deadline:
         try:
             chunk = sess.out_queue.get_nowait()
@@ -395,12 +458,39 @@ def _finish_connect(
         sess.run_post_login_commands()
     except Exception:
         _log.debug("post_login failed session=%s", sess.session_id, exc_info=True)
-    # Same SSH transport: open SFTP channel when the device supports it.
-    sftp_ok = sess.try_attach_sftp()
+
+    # Mark ready BEFORE SFTP. Opening an SFTP channel on some Huawei SSH boxes can
+    # block for a long time; meanwhile live echo already showed login and the WS
+    # wait loop still rejects stdin — looks like "logged in but cannot type", then
+    # connect_timeout / proxy 1011.
     sess.state = "ready"
     sess.connect_finished_at = time.time()
     sess._ready_event.set()
     elapsed_ms = int((sess.connect_finished_at - sess.connect_started_at) * 1000)
+
+    def _probe_sftp() -> None:
+        try:
+            ok = bool(sess.try_attach_sftp())
+            if ok:
+                _audit(
+                    "session_sftp_ready",
+                    session_id=sess.session_id,
+                    ne_id=sess.ne_id,
+                    ne_ip=sess.ne_ip,
+                    client=client or "",
+                )
+        except Exception:
+            _log.debug("deferred sftp probe failed session=%s", sess.session_id, exc_info=True)
+
+    if str(sess.protocol or "ssh").lower() == "ssh" and not hop_guard:
+        threading.Thread(
+            target=_probe_sftp,
+            name=f"webcrt-sftp-{sess.session_id[:8]}",
+            daemon=True,
+        ).start()
+    else:
+        sess.sftp_ready = False
+
     _audit(
         "session_created",
         session_id=sess.session_id,
@@ -414,7 +504,7 @@ def _finish_connect(
         hop_vendor=str(creds.get("hop_vendor") or "") if creds.get("hop_enabled") else "",
         cli_hop_guard=bool(hop_guard),
         cli_hop_prompt=str((hop_guard or {}).get("hop_prompt") or ""),
-        sftp_ready=bool(sftp_ok),
+        sftp_ready=bool(sess.sftp_ready),
         client=client or "",
         connect_ms=elapsed_ms,
         active=active_session_count(),