diff --git a/interface-definitions/system-ip.xml.in b/interface-definitions/system-ip.xml.in
index abdede979..6db4dbfc7 100644
--- a/interface-definitions/system-ip.xml.in
+++ b/interface-definitions/system-ip.xml.in
@@ -1,56 +1,114 @@
<?xml version="1.0"?>
<interfaceDefinition>
<node name="system">
<children>
<node name="ip" owner="${vyos_conf_scripts_dir}/system-ip.py">
<properties>
<help>IPv4 Settings</help>
<!-- must be before any interface, check /opt/vyatta/sbin/priority.pl -->
<priority>290</priority>
</properties>
<children>
<node name="arp">
<properties>
<help>Parameters for ARP cache</help>
</properties>
<children>
#include <include/arp-ndp-table-size.xml.i>
</children>
</node>
<leafNode name="disable-forwarding">
<properties>
<help>Disable IPv4 forwarding on all interfaces</help>
<valueless/>
</properties>
</leafNode>
<leafNode name="disable-directed-broadcast">
<properties>
<help>Disable IPv4 directed broadcast forwarding on all interfaces</help>
<valueless/>
</properties>
</leafNode>
<node name="multipath">
<properties>
<help>IPv4 multipath settings</help>
</properties>
<children>
<leafNode name="ignore-unreachable-nexthops">
<properties>
<help>Ignore next hops that are not in the ARP table</help>
<valueless/>
</properties>
</leafNode>
<leafNode name="layer4-hashing">
<properties>
<help>Use layer 4 information for ECMP hashing</help>
<valueless/>
</properties>
</leafNode>
</children>
</node>
+ <node name="tcp">
+ <properties>
+ <help>IPv4 TCP parameters</help>
+ </properties>
+ <children>
+ <node name="mss">
+ <properties>
+ <help>IPv4 TCP MSS probing options</help>
+ </properties>
+ <children>
+ <leafNode name="probing">
+ <properties>
+ <help>Attempt to lower the MSS if TCP connections fail to establish</help>
+ <completionHelp>
+ <list>on-icmp-black-hole force</list>
+ </completionHelp>
+ <valueHelp>
+ <format>on-icmp-black-hole</format>
+ <description>Attempt TCP MSS probing when an ICMP black hole is detected</description>
+ </valueHelp>
+ <valueHelp>
+ <format>force</format>
+ <description>Attempt TCP MSS probing by default</description>
+ </valueHelp>
+ <constraint>
+ <regex>(on-icmp-black-hole|force)</regex>
+ </constraint>
+ <constraintErrorMessage>Must be on-icmp-black-hole or force</constraintErrorMessage>
+ </properties>
+ </leafNode>
+ <leafNode name="base">
+ <properties>
+ <help>Base MSS to start probing from (applicable to "probing force")</help>
+ <valueHelp>
+ <format>u32:48-1460</format>
+ <description>Base MSS value for probing (default: 1024)</description>
+ </valueHelp>
+ <constraint>
+ <validator name="numeric" argument="--range 48-1460"/>
+ </constraint>
+ </properties>
+ </leafNode>
+ <leafNode name="floor">
+ <properties>
+ <help>Minimum MSS to stop probing at (default: 48)</help>
+ <valueHelp>
+ <format>u32:48-1460</format>
+ <description>Minimum MSS value to probe</description>
+ </valueHelp>
+ <constraint>
+ <validator name="numeric" argument="--range 48-1460"/>
+ </constraint>
+ </properties>
+ </leafNode>
+ </children>
+ </node>
+ </children>
+ </node>
#include <include/system-ip-protocol.xml.i>
</children>
</node>
</children>
</node>
</interfaceDefinition>
diff --git a/src/conf_mode/system-ip.py b/src/conf_mode/system-ip.py
index cca996e4f..c89267afc 100755
--- a/src/conf_mode/system-ip.py
+++ b/src/conf_mode/system-ip.py
@@ -1,121 +1,142 @@
#!/usr/bin/env python3
#
# Copyright (C) 2019-2023 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/>.
from sys import exit
from vyos.config import Config
from vyos.configdict import dict_merge
from vyos.configverify import verify_route_map
from vyos.template import render_to_string
from vyos.utils.process import call
from vyos.utils.dict import dict_search
from vyos.utils.file import write_file
from vyos.utils.system import sysctl_write
from vyos.xml import defaults
from vyos import ConfigError
from vyos import frr
from vyos import airbag
airbag.enable()
def get_config(config=None):
if config:
conf = config
else:
conf = Config()
base = ['system', 'ip']
opt = conf.get_config_dict(base, key_mangling=('-', '_'), get_first_key=True)
# We have gathered the dict representation of the CLI, but there are default
# options which we need to update into the dictionary retrived.
default_values = defaults(base)
opt = dict_merge(default_values, opt)
# When working with FRR we need to know the corresponding address-family
opt['afi'] = 'ip'
# We also need the route-map information from the config
#
# XXX: one MUST always call this without the key_mangling() option! See
# vyos.configverify.verify_common_route_maps() for more information.
tmp = {'policy' : {'route-map' : conf.get_config_dict(['policy', 'route-map'],
get_first_key=True)}}
# Merge policy dict into "regular" config dict
opt = dict_merge(tmp, opt)
return opt
def verify(opt):
if 'protocol' in opt:
for protocol, protocol_options in opt['protocol'].items():
if 'route_map' in protocol_options:
verify_route_map(protocol_options['route_map'], opt)
return
def generate(opt):
if 'protocol' in opt:
opt['frr_zebra_config'] = render_to_string('frr/zebra.route-map.frr.j2', opt)
return
def apply(opt):
# Apply ARP threshold values
# table_size has a default value - thus the key always exists
size = int(dict_search('arp.table_size', opt))
# Amount upon reaching which the records begin to be cleared immediately
sysctl_write('net.ipv4.neigh.default.gc_thresh3', size)
# Amount after which the records begin to be cleaned after 5 seconds
sysctl_write('net.ipv4.neigh.default.gc_thresh2', size // 2)
# Minimum number of stored records is indicated which is not cleared
sysctl_write('net.ipv4.neigh.default.gc_thresh1', size // 8)
# enable/disable IPv4 forwarding
tmp = dict_search('disable_forwarding', opt)
value = '0' if (tmp != None) else '1'
write_file('/proc/sys/net/ipv4/conf/all/forwarding', value)
# enable/disable IPv4 directed broadcast forwarding
tmp = dict_search('disable_directed_broadcast', opt)
value = '0' if (tmp != None) else '1'
write_file('/proc/sys/net/ipv4/conf/all/bc_forwarding', value)
# configure multipath
tmp = dict_search('multipath.ignore_unreachable_nexthops', opt)
value = '1' if (tmp != None) else '0'
sysctl_write('net.ipv4.fib_multipath_use_neigh', value)
tmp = dict_search('multipath.layer4_hashing', opt)
value = '1' if (tmp != None) else '0'
sysctl_write('net.ipv4.fib_multipath_hash_policy', value)
+ # configure TCP options (defaults as of Linux 6.4)
+ tmp = dict_search('tcp.mss.probing', opt)
+ if tmp is None:
+ value = 0
+ elif tmp == 'on-icmp-black-hole':
+ value = 1
+ elif tmp == 'force':
+ value = 2
+ else:
+ # Shouldn't happen
+ raise ValueError("TCP MSS probing is neither 'on-icmp-black-hole' nor 'force'!")
+ sysctl_write('net.ipv4.tcp_mtu_probing', value)
+
+ tmp = dict_search('tcp.mss.base', opt)
+ value = '1024' if (tmp is None) else tmp
+ sysctl_write('net.ipv4.tcp_base_mss', value)
+
+ tmp = dict_search('tcp.mss.floor', opt)
+ value = '48' if (tmp is None) else tmp
+ sysctl_write('net.ipv4.tcp_mtu_probe_floor', value)
+
if 'protocol' in opt:
zebra_daemon = 'zebra'
# Save original configuration prior to starting any commit actions
frr_cfg = frr.FRRConfig()
# The route-map used for the FIB (zebra) is part of the zebra daemon
frr_cfg.load_configuration(zebra_daemon)
frr_cfg.modify_section(r'ip protocol \w+ route-map [-a-zA-Z0-9.]+', stop_pattern='(\s|!)')
if 'frr_zebra_config' in opt:
frr_cfg.add_before(frr.default_add_before, opt['frr_zebra_config'])
frr_cfg.commit_configuration(zebra_daemon)
if __name__ == '__main__':
try:
c = get_config()
verify(c)
generate(c)
apply(c)
except ConfigError as e:
print(e)
exit(1)