ethernet: T2241: check if interface supports changing speed/duplex settings

Not all interface drivers have the ability to change the speed and duplex
settings. Known drivers with this limitation are vmxnet3, virtio_net and
xen_netfront. If this driver is detected, an error will be presented to the
user.

(cherry picked from commit cc742d48579e4f76e5d3230d87e22f71f76f9301)

3 files changed, 32 insertions, 1 deletions

diff --git a/python/vyos/ethtool.py b/python/vyos/ethtool.py
index 55b7b776f..fb2e49c1d 100644
--- a/python/vyos/ethtool.py
+++ b/python/vyos/ethtool.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
 import re
+
 from vyos.util import popen
 
 class Ethtool:
@@ -41,8 +43,18 @@ class Ethtool:
     #  }
     _speed_duplex = { }
     _ring_buffers = { }
+    _driver_name = None
 
     def __init__(self, ifname):
+        # Get driver used for interface
+        sysfs_file = f'/sys/class/net/{ifname}/device/driver/module'
+        if os.path.exists(sysfs_file):
+            link = os.readlink(sysfs_file)
+            self._driver_name = os.path.basename(link)
+
+        if not self._driver_name:
+            raise ValueError(f'Could not determine driver for interface {ifname}!')
+
         # Build a dictinary of supported link-speed and dupley settings.
         out, err = popen(f'ethtool {ifname}')
         reading = False
@@ -142,6 +154,9 @@ class Ethtool:
         if duplex not in ['full', 'half']:
             raise ValueError(f'Value "{duplex}" for duplex is invalid!')
 
+        if self._driver_name in ['vmxnet3', 'virtio_net', 'xen_netfront']:
+            return False
+
         if speed in self._speed_duplex:
             if duplex in self._speed_duplex[speed]:
                 return True
diff --git a/src/conf_mode/interfaces-ethernet.py b/src/conf_mode/interfaces-ethernet.py
index a7e01e279..57e05d4ea 100755
--- a/src/conf_mode/interfaces-ethernet.py
+++ b/src/conf_mode/interfaces-ethernet.py
@@ -75,7 +75,8 @@ def verify(ethernet):
         speed = ethernet['speed']
         duplex = ethernet['duplex']
         if not ethtool.check_speed_duplex(speed, duplex):
-            raise ConfigError(f'Adapter does not support speed "{speed}" and duplex "{duplex}"!')
+            raise ConfigError(f'Adapter does not support changing speed and duplex '\
+                              f'settings to: {speed}/{duplex}!')
 
     if 'ring_buffer' in ethernet:
         max_rx = ethtool.get_rx_buffer()
diff --git a/src/migration-scripts/interfaces/20-to-21 b/src/migration-scripts/interfaces/20-to-21
index 4b0e70d35..bd89dcdb4 100755
--- a/src/migration-scripts/interfaces/20-to-21
+++ b/src/migration-scripts/interfaces/20-to-21
@@ -89,6 +89,21 @@ for ifname in config.list_nodes(base):
     if config.exists(base + [ifname, 'offload', 'ufo']):
         config.delete(base + [ifname, 'offload', 'ufo'])
 
+    # Also while processing the interface configuration, not all adapters support
+    # changing the speed and duplex settings. If the desired speed and duplex
+    # values do not work for the NIC driver, we change them back to the default
+    # value of "auto" - which will be applied if the CLI node is deleted.
+    speed_path = base + [ifname, 'speed']
+    duplex_path = base + [ifname, 'duplex']
+    # speed and duplex must always be set at the same time if not set to "auto"
+    if config.exists(speed_path) and config.exists(duplex_path):
+        speed = config.return_value(speed_path)
+        duplex = config.return_value(duplex_path)
+        if speed != 'auto' and duplex != 'auto':
+            if not eth.check_speed_duplex(speed, duplex):
+                config.delete(speed_path)
+                config.delete(duplex_path)
+
 try:
     with open(file_name, 'w') as f:
         f.write(config.to_string())