[networking] collect commands only when required kernel modules are loaded

- "ip -s macsec show" requires "macsec" kmod loaded
- "ss -peaonmi" requires 6 *_diag kernel modules

Execute the commands only when the modules are loaded, or when explicitly
requested via --allow-system-changes option.

Resolves: #1435

Signed-off-by: Pavel Moravec <pmoravec@redhat.com>

1 files changed, 42 insertions, 4 deletions

diff --git a/sos/plugins/networking.py b/sos/plugins/networking.py
index 015fb19e..b698816a 100644
--- a/sos/plugins/networking.py
+++ b/sos/plugins/networking.py
@@ -6,7 +6,8 @@
 #
 # See the LICENSE file in the source distribution for further information.
 
-from sos.plugins import Plugin, RedHatPlugin, UbuntuPlugin, DebianPlugin
+from sos.plugins import (Plugin, RedHatPlugin, UbuntuPlugin, DebianPlugin,
+                         SoSPredicate)
 from os import listdir
 import re
 
@@ -130,7 +131,6 @@ class Networking(Plugin):
         self.add_cmd_output([
             "netstat -s",
             "netstat %s -agn" % self.ns_wide,
-            "ss -peaonmi",
             "ip route show table all",
             "ip -6 route show table all",
             "ip -4 rule",
@@ -144,9 +144,34 @@ class Networking(Plugin):
             "ip neigh show nud noarp",
             "biosdevname -d",
             "tc -s qdisc show",
-            "ip -s macsec show",
         ])
 
+        # below commands require some kernel module(s) to be loaded
+        # run them only if the modules are loaded, or if explicitly requested
+        # via --allow-system-changes option
+        ip_macsec_show_cmd = "ip -s macsec show"
+        macsec_pred = SoSPredicate(self, kmods=['macsec'])
+        if self.test_predicate(self, pred=macsec_pred) or \
+                self.get_option("allow_system_changes"):
+            self.add_cmd_output(ip_macsec_show_cmd)
+        else:
+            self._log_warn("skipped command '%s' as it requires kernel module "
+                           "'macsecs' that is unloaded; use "
+                           "--allow-system-changes to collect it"
+                           % ip_macsec_show_cmd)
+
+        ss_cmd = "ss -peaonmi"
+        ss_pred = SoSPredicate(self, kmods=['tcp_diag', 'udp_diag',
+                                            'inet_diag', 'unix_diag',
+                                            'netlink_diag', 'af_packet_diag'])
+        if self.test_predicate(self, pred=ss_pred) or \
+                self.get_option("allow_system_changes"):
+            self.add_cmd_output(ss_cmd)
+        else:
+            self._log_warn("skipped command '%s' as it requires some *_diag "
+                           "kernel module that is unloaded; use "
+                           "--allow-system-changes to collect it" % ss_cmd)
+
         # When iptables is called it will load the modules
         # iptables and iptables_filter if they are not loaded.
         # The same goes for ipv6.
@@ -203,12 +228,25 @@ class Networking(Plugin):
                     ns_cmd_prefix + "ip address show",
                     ns_cmd_prefix + "ip route show table all",
                     ns_cmd_prefix + "iptables-save",
-                    ns_cmd_prefix + "ss -peaonmi",
                     ns_cmd_prefix + "netstat %s -neopa" % self.ns_wide,
                     ns_cmd_prefix + "netstat -s",
                     ns_cmd_prefix + "netstat %s -agn" % self.ns_wide
                 ])
 
+                ss_cmd = ns_cmd_prefix + "ss -peaonmi"
+                ss_pred = SoSPredicate(self, kmods=['tcp_diag', 'udp_diag',
+                                                    'inet_diag', 'unix_diag',
+                                                    'netlink_diag',
+                                                    'af_packet_diag'])
+                if self.test_predicate(self, pred=ss_pred) or \
+                        self.get_option("allow_system_changes"):
+                    self.add_cmd_output(ss_cmd)
+                else:
+                    self._log_warn("skipped command '%s' as it requires some "
+                                   "*_diag kernel module that is unloaded; "
+                                   "use --allow-system-changes to collect it"
+                                   % ss_cmd)
+
             # Devices that exist in a namespace use less ethtool
             # parameters. Run this per namespace.
             for namespace in self.get_ip_netns(ip_netns_file):