Merge pull request #3683 from dmbaturin/T6501-lsmod-on-steroids

op mode: T6501: add "run show kernel modules"

3 files changed, 178 insertions, 1 deletions

diff --git a/op-mode-definitions/show-kernel-modules.xml.in b/op-mode-definitions/show-kernel-modules.xml.in
new file mode 100644
index 000000000..28eb28212
--- /dev/null
+++ b/op-mode-definitions/show-kernel-modules.xml.in
@@ -0,0 +1,20 @@
+<?xml version="1.0"?>
+<interfaceDefinition>
+  <node name="show">
+    <children>
+      <node name="kernel">
+        <properties>
+          <help>Show kernel information</help>
+        </properties>
+        <children>
+          <node name="modules">
+            <properties>
+              <help>Show kernel modules</help>
+            </properties>
+            <command>sudo ${vyos_op_scripts_dir}/kernel_modules.py show</command>
+          </node>
+        </children>
+      </node>
+    </children>
+  </node>
+</interfaceDefinition>
diff --git a/python/vyos/utils/kernel.py b/python/vyos/utils/kernel.py
index 1f3bbdffe..847f80108 100644
--- a/python/vyos/utils/kernel.py
+++ b/python/vyos/utils/kernel.py
@@ -1,4 +1,4 @@
-# Copyright 2023 VyOS maintainers and contributors <maintainers@vyos.io>
+# Copyright 2023-2024 VyOS maintainers and contributors <maintainers@vyos.io>
 #
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
@@ -36,3 +36,78 @@ def unload_kmod(k_mod):
         if os.path.exists(f'/sys/module/{module}'):
             if call(f'rmmod {module}') != 0:
                 raise ConfigError(f'Unloading Kernel module {module} failed')
+
+def list_loaded_modules():
+    """ Returns the list of currently loaded kernel modules """
+    from os import listdir
+    return listdir('/sys/module/')
+
+def get_module_data(module: str):
+    """ Retrieves information about a module """
+    from os import listdir
+    from os.path import isfile, dirname, basename, join
+    from vyos.utils.file import read_file
+
+    def _get_file(path):
+        # Some files inside some modules are not readable at all,
+        # we just skip them.
+        try:
+            return read_file(path)
+        except PermissionError:
+            return None
+
+    mod_path = join('/sys/module', module)
+    mod_data = {"name": module, "fields": {}, "parameters": {}}
+
+    for f in listdir(mod_path):
+        if f in ["sections", "notes", "uevent"]:
+            # The uevent file is not readable
+            # and module build info and memory layout
+            # in notes and sections generally aren't useful
+            # for anything but kernel debugging.
+            pass
+        elif f == "drivers":
+            # Drivers are dir symlinks,
+            # we just list them
+            drivers = listdir(join(mod_path, f))
+            if drivers:
+                mod_data["drivers"] = drivers
+        elif f == "holders":
+            # Holders (module that use this one)
+            # are always symlink to other modules.
+            # We only need the list.
+            holders = listdir(join(mod_path, f))
+            if holders:
+                mod_data["holders"] = holders
+        elif f == "parameters":
+            # Many modules keep their configuration
+            # in the "parameters" subdir.
+            ppath = join(mod_path, "parameters")
+            ps = listdir(ppath)
+            for p in ps:
+                data = _get_file(join(ppath, p))
+                if data:
+                    mod_data["parameters"][p] = data
+        else:
+            # Everything else...
+            # There are standard fields like refcount and initstate,
+            # but many modules also keep custom information or settings
+            # in top-level fields.
+            # For now we don't separate well-known and custom fields.
+            if isfile(join(mod_path, f)):
+                data = _get_file(join(mod_path, f))
+                if data:
+                    mod_data["fields"][f] = data
+            else:
+                raise RuntimeError(f"Unexpected directory inside module {module}: {f}")
+
+    return mod_data
+
+def lsmod():
+    """ Returns information about all loaded modules.
+        Like lsmod(8), but more detailed.
+    """
+    mods_data = []
+    for m in list_loaded_modules():
+        mods_data.append(get_module_data(m))
+    return mods_data
diff --git a/src/op_mode/kernel_modules.py b/src/op_mode/kernel_modules.py
new file mode 100755
index 000000000..e381a1df7
--- /dev/null
+++ b/src/op_mode/kernel_modules.py
@@ -0,0 +1,82 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2024 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# Purpose:
+#     Provides commands for retrieving information about kernel modules.
+
+import sys
+import typing
+
+import vyos.opmode
+
+
+lsmod_tmpl = """
+{% for m in modules -%}
+Module: {{m.name}}
+
+{% if m.holders -%}
+Holders: {{m.holders | join(", ")}}
+{%- endif %}
+
+{% if m.drivers -%}
+Drivers: {{m.drivers | join(", ")}}
+{%- endif %}
+
+{% for k in m.fields -%}
+{{k}}: {{m["fields"][k]}}
+{% endfor %}
+{% if m.parameters %}
+
+Parameters:
+
+{% for p in m.parameters -%}
+{{p}}: {{m["parameters"][p]}}
+{% endfor -%}
+{% endif -%}
+
+-------------
+
+{% endfor %}
+"""
+
+def _get_raw_data(module=None):
+    from vyos.utils.kernel import get_module_data, lsmod
+
+    if module:
+        return [get_module_data(module)]
+    else:
+        return lsmod()
+
+def show(raw: bool, module: typing.Optional[str]):
+    from jinja2 import Template
+
+    data = _get_raw_data(module=module)
+
+    if raw:
+        return data
+    else:
+        t = Template(lsmod_tmpl)
+        output = t.render({"modules": data})
+        return output
+
+if __name__ == '__main__':
+    try:
+        res = vyos.opmode.run(sys.modules[__name__])
+        if res:
+            print(res)
+    except (ValueError, vyos.opmode.Error) as e:
+        print(e)
+        sys.exit(1)