Merge pull request #5092 from c-po/kernel-serial-activation

serial: T8375: use boot activation script to define a serial console on the CLI

6 files changed, 150 insertions, 21 deletions

diff --git a/python/vyos/flavor.py b/python/vyos/flavor.py
new file mode 100644
index 000000000..a9dccf448
--- /dev/null
+++ b/python/vyos/flavor.py
@@ -0,0 +1,69 @@
+# Copyright (C) VyOS Inc.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+VyOS flavor data access library.
+
+VyOS stores its flavor specific data in a JSON file. This module provides a
+convenient interface to reading it.
+
+Example of the version data dict::
+  {
+   'console_type': 'ttyS',
+   'console_num': '0',
+   'console_speed': '115200'
+  }
+"""
+
+import os
+import vyos.defaults
+
+from vyos.utils.file import read_json
+
+flavor_file = os.path.join(vyos.defaults.directories['data'], 'flavor.json')
+
+def get_flavor_data(fname=flavor_file):
+    """
+    Get complete flavor data
+
+    Args:
+        file (str): path to the flavor file
+
+    Returns:
+        dict: flavor data, if it can not be found and empty dict
+
+    The optional ``file`` argument comes in handy in upgrade scripts
+    that need to retrieve information from images other than the running image.
+    It should not be used on a running system since the location of that file
+    is an implementation detail and may change in the future, while the interface
+    of this module will stay the same.
+    """
+    return read_json(flavor_file, {})
+
+def get_image_serial_console(fname=flavor_file):
+    """
+    Get serial console parameters baked into the image flavor.
+
+    Args:
+        file (str): path to the flavor file
+
+    Returns:
+        dict: serial interface data baked into the image flavor. Example:
+          {"console_type": "ttyS", "console_speed": "115200", "console_num":"0"}
+    """
+    console_type = get_flavor_data(fname=fname).get('console_type', '')
+    console_num = get_flavor_data(fname=fname).get('console_num', '')
+    console_speed = get_flavor_data(fname=fname).get('console_speed', '')
+    return (console_type, console_num, console_speed)
diff --git a/python/vyos/system/compat.py b/python/vyos/system/compat.py
index f4a50b237..40b38b366 100644
--- a/python/vyos/system/compat.py
+++ b/python/vyos/system/compat.py
@@ -14,12 +14,18 @@
 # along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 from pathlib import Path
-from re import compile, MULTILINE, DOTALL
+from re import compile
+from re import MULTILINE
+from re import DOTALL
 from functools import wraps
 from copy import deepcopy
 from typing import Union
 
-from vyos.system import disk, grub, image, SYSTEM_CFG_VER
+from vyos.flavor import get_image_serial_console
+from vyos.system import disk
+from vyos.system import grub
+from vyos.system import image
+from vyos.system import SYSTEM_CFG_VER
 from vyos.template import render
 
 TMPL_GRUB_COMPAT: str = 'grub/grub_compat.j2'
@@ -128,11 +134,15 @@ def parse_entry(entry: tuple) -> dict:
         entry_dict['bootmode'] = 'pw_reset'
     else:
         entry_dict['bootmode'] = 'normal'
+    (_, _, default_speed) = get_image_serial_console()
     # find console type and number
     regex_filter = compile(REGEX_CONSOLE)
     entry_dict.update(regex_filter.match(entry[1]).groupdict())
+    # Set new or default console speed - this line must always be present to
+    # keep backward compatibility. It is needed to boot into old images and
+    # use the serial console speed
     speed = entry_dict.get('console_speed', None)
-    entry_dict['console_speed'] = speed if speed is not None else '115200'
+    entry_dict['console_speed'] = speed if speed is not None else default_speed
     entry_dict['boot_opts'] = sanitize_boot_opts(entry[1])
 
     return entry_dict
diff --git a/python/vyos/system/grub.py b/python/vyos/system/grub.py
index 0f04fa5e9..9435d18d2 100644
--- a/python/vyos/system/grub.py
+++ b/python/vyos/system/grub.py
@@ -16,13 +16,18 @@
 import platform
 
 from pathlib import Path
-from re import MULTILINE, compile as re_compile
+from re import MULTILINE
+from re import compile as re_compile
 from shutil import copy2
-from uuid import uuid5, NAMESPACE_URL, UUID
+from uuid import uuid5
+from uuid import NAMESPACE_URL
+from uuid import UUID
 
-from vyos.template import render
-from vyos.utils.process import cmd, rc_cmd
+from vyos.flavor import get_image_serial_console
 from vyos.system import disk
+from vyos.template import render
+from vyos.utils.process import cmd
+from vyos.utils.process import rc_cmd
 
 # Define variables
 GRUB_DIR_MAIN: str = '/boot/grub'
@@ -385,7 +390,7 @@ def set_console_type(console_type: str, root_dir: str = '') -> None:
     """Write default console type to GRUB configuration
 
     Args:
-        console_type (str): a default console type
+        console_type (str): GRUB default console type, e.g. tty, ttyS or ttyAMA
         root_dir (str, optional): an optional path to the root directory.
         Defaults to empty.
     """
@@ -397,10 +402,13 @@ def set_console_type(console_type: str, root_dir: str = '') -> None:
     vars_current['console_type'] = str(console_type)
     vars_write(vars_file, vars_current)
 
-def set_console_speed(console_speed: str, root_dir: str = '') -> None:
+def set_serial_console(console_type: str, console_num: str,
+                       console_speed: str, root_dir: str = '') -> None:
     """Write default console speed to GRUB configuration
 
     Args:
+        console_type (str): console device, e.g. 'ttyS' or 'ttyAMA'
+        console_num (str): console instance, e.g. '0'
         console_speed (str): default console speed
         root_dir (str, optional): an optional path to the root directory.
         Defaults to empty.
@@ -408,9 +416,13 @@ def set_console_speed(console_speed: str, root_dir: str = '') -> None:
     if not root_dir:
         root_dir = disk.find_persistence()
 
+    (default_type, default_num, default_speed) = get_image_serial_console()
+
     vars_file: str = f'{root_dir}/{CFG_VYOS_VARS}'
     vars_current: dict[str, str] = vars_read(vars_file)
-    vars_current['console_speed'] = str(console_speed)
+    vars_current['console_type'] = console_type if console_type else default_type
+    vars_current['console_num'] = console_num if console_num else default_num
+    vars_current['console_speed'] = console_speed if console_speed else default_speed
     vars_write(vars_file, vars_current)
 
 def set_kernel_cmdline_options(cmdline_options: str, version_name: str,
diff --git a/python/vyos/system/grub_util.py b/python/vyos/system/grub_util.py
index e534334e6..edaea8ad3 100644
--- a/python/vyos/system/grub_util.py
+++ b/python/vyos/system/grub_util.py
@@ -13,10 +13,14 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
-from vyos.system import disk, grub, image, compat
+from vyos.system import disk
+from vyos.system import grub
+from vyos.system import image
+from vyos.system import compat
 
 @compat.grub_cfg_update
-def set_console_speed(console_speed: str, root_dir: str = '') -> None:
+def set_serial_console(console_type: str, console_num: str,
+                       console_speed: str, root_dir: str = '') -> None:
     """Write default console speed to GRUB configuration
 
     Args:
@@ -27,10 +31,11 @@ def set_console_speed(console_speed: str, root_dir: str = '') -> None:
     if not root_dir:
         root_dir = disk.find_persistence()
 
-    grub.set_console_speed(console_speed, root_dir)
+    grub.set_serial_console(console_type, console_num, console_speed, root_dir)
 
 @image.if_not_live_boot
-def update_console_speed(console_speed: str, root_dir: str = '') -> None:
+def update_serial_console(console_type: str, console_num: str,
+                          console_speed: str, root_dir: str = '') -> None:
     """Update console_speed if different from current value"""
 
     if not root_dir:
@@ -38,9 +43,15 @@ def update_console_speed(console_speed: str, root_dir: str = '') -> None:
 
     vars_file: str = f'{root_dir}/{grub.CFG_VYOS_VARS}'
     vars_current: dict[str, str] = grub.vars_read(vars_file)
-    console_speed_current = vars_current.get('console_speed', None)
-    if console_speed != console_speed_current:
-        set_console_speed(console_speed, root_dir)
+
+    console_type_current = vars_current.get('console_type')
+    console_num_current = vars_current.get('console_num')
+    console_speed_current = vars_current.get('console_speed')
+
+    if console_type != console_type_current or \
+       console_num != console_num_current or \
+       console_speed != console_speed_current:
+        set_serial_console(console_type, console_num, console_speed, root_dir)
 
 @compat.grub_cfg_update
 def set_kernel_cmdline_options(cmdline_options: str, version: str = '',
diff --git a/python/vyos/utils/kernel.py b/python/vyos/utils/kernel.py
index 48a7e88ea..726025605 100644
--- a/python/vyos/utils/kernel.py
+++ b/python/vyos/utils/kernel.py
@@ -14,12 +14,13 @@
 # License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
 import os
+from typing import Tuple
+from typing import Optional
 
 # A list of used Kernel constants
 # https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/net/wireguard/messages.h?h=linux-6.6.y#n45
 WIREGUARD_REKEY_AFTER_TIME = 120
 
-
 def load_module(name: str, quiet: bool = True, dry_run: bool = False) -> int:
     """Load a kernel module via modprobe.
 
@@ -39,7 +40,6 @@ def load_module(name: str, quiet: bool = True, dry_run: bool = False) -> int:
     cmd.append(name)
     return run(cmd)
 
-
 def unload_module(name: str) -> int:
     """Unload a kernel module via rmmod.
 
@@ -150,3 +150,25 @@ def lsmod():
     for m in list_loaded_modules():
         mods_data.append(get_module_data(m))
     return mods_data
+
+def get_kernel_serial_console() -> Tuple[Optional[str], Optional[str], Optional[str]]:
+    """
+    Extract the serial console type, number, and speed setting from the kernel
+    command line which was used during system boot.
+    """
+    import re
+    from vyos.utils.file import read_file
+
+    cmdline_console_re = re.compile(
+        r'(?:^|\s)console=(?P<console_type>tty(?:S|AMA))(?P<console_num>\d+),(?P<console_speed>\d+)(?=\s|$)'
+    )
+
+    kernel_cmdline = read_file('/proc/cmdline')
+    if m := cmdline_console_re.search(kernel_cmdline):
+        return (
+            m.group('console_type'),
+            m.group('console_num'),
+            m.group('console_speed'),
+        )
+
+    return (None, None, None)
diff --git a/python/vyos/utils/serial.py b/python/vyos/utils/serial.py
index 36b483e91..fcb7a21c9 100644
--- a/python/vyos/utils/serial.py
+++ b/python/vyos/utils/serial.py
@@ -13,7 +13,9 @@
 # You should have received a copy of the GNU Lesser General Public
 # License along with this library.  If not, see <http://www.gnu.org/licenses/>.
 
-import os, re, json
+import os
+import re
+import json
 from typing import List
 
 from vyos.base import Warning
@@ -117,7 +119,7 @@ def restart_login_consoles(prompt_user=False, quiet=True, devices: List[str]=[])
 
     return True
 
-def is_tty(name: str) -> bool:
+def is_tty(name: str, warning=False) -> bool:
     """ Check if a given device file (e.g. /dev/ttyS0) is a TTY (teletypewriter)
     device in Linux
     """
@@ -128,4 +130,7 @@ def is_tty(name: str) -> bool:
             fd = f.fileno()
             # True if filename is a TTY
             return os.isatty(fd)
+    elif warning:
+        from vyos.base import Warning
+        Warning(f'Device "{name}" does not exist!')
     return False