This adds an additional directive to the dnsmasq configuration file that notifies clients via dhcp about the link's MTU. Guests can then choose adjust their link accordingly. Signed-off-by: Casey Callendrello <cdc@redhat.com> --- src/network/bridge_driver.c | 7 ++++++ .../networkxml2confdata/nat-network-mtu.conf | 19 +++++++++++++++ tests/networkxml2confdata/nat-network-mtu.xml | 22 +++++++++++++++++ tests/networkxml2conftest.c | 1 + tests/networkxml2xmlin/nat-network-mtu.xml | 22 +++++++++++++++++ tests/networkxml2xmlout/nat-network-mtu.xml | 24 +++++++++++++++++++ tests/networkxml2xmltest.c | 1 + 7 files changed, 96 insertions(+) create mode 100644 tests/networkxml2confdata/nat-network-mtu.conf create mode 100644 tests/networkxml2confdata/nat-network-mtu.xml create mode 100644 tests/networkxml2xmlin/nat-network-mtu.xml create mode 100644 tests/networkxml2xmlout/nat-network-mtu.xml diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index 4bbc4f5a6d..81edf72493 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -1506,6 +1506,13 @@ networkDnsmasqConfContents(virNetworkObjPtr obj, dctx->addnhostsfile->path); } + /* Configure DHCP to tell clients about the MTU. + */ + if (def->mtu > 0) { + virBufferAsprintf(&configbuf, "dhcp-option=option:mtu,%d\n", + def->mtu); + } + /* Are we doing RA instead of radvd? */ if (DNSMASQ_RA_SUPPORT(caps)) { if (ipv6def) { diff --git a/tests/networkxml2confdata/nat-network-mtu.conf b/tests/networkxml2confdata/nat-network-mtu.conf new file mode 100644 index 0000000000..91b574b964 --- /dev/null +++ b/tests/networkxml2confdata/nat-network-mtu.conf @@ -0,0 +1,19 @@ +##WARNING: THIS IS AN AUTO-GENERATED FILE. CHANGES TO IT ARE LIKELY TO BE +##OVERWRITTEN AND LOST. Changes to this configuration should be made using: +## virsh net-edit default +## or other application using the libvirt API. +## +## dnsmasq conf file created by libvirt +strict-order +except-interface=lo +bind-dynamic +interface=virbr0 +dhcp-range=192.168.122.2,192.168.122.254 +dhcp-no-override +dhcp-authoritative +dhcp-lease-max=253 +dhcp-hostsfile=/var/lib/libvirt/dnsmasq/default.hostsfile +addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts +dhcp-option=option:mtu,7000 +dhcp-range=2001:db8:ac10:fe01::1,ra-only +dhcp-range=2001:db8:ac10:fd01::1,ra-only diff --git a/tests/networkxml2confdata/nat-network-mtu.xml b/tests/networkxml2confdata/nat-network-mtu.xml new file mode 100644 index 0000000000..87b214e95c --- /dev/null +++ b/tests/networkxml2confdata/nat-network-mtu.xml @@ -0,0 +1,22 @@ +<network> + <name>default</name> + <uuid>81ff0d90-c91e-6742-64da-4a736edb9a9b</uuid> + <forward dev='eth1' mode='nat'/> + <bridge name='virbr0' stp='on' delay='0'/> + <mtu size='7000'/> + <ip address='192.168.122.1' netmask='255.255.255.0'> + <dhcp> + <range start='192.168.122.2' end='192.168.122.254'/> + <host mac='00:16:3e:77:e2:ed' name='a.example.com' ip='192.168.122.10'/> + <host mac='00:16:3e:3e:a9:1a' name='b.example.com' ip='192.168.122.11'/> + </dhcp> + </ip> + <ip family='ipv4' address='192.168.123.1' netmask='255.255.255.0'> + </ip> + <ip family='ipv6' address='2001:db8:ac10:fe01::1' prefix='64'> + </ip> + <ip family='ipv6' address='2001:db8:ac10:fd01::1' prefix='64'> + </ip> + <ip family='ipv4' address='10.24.10.1'> + </ip> +</network> diff --git a/tests/networkxml2conftest.c b/tests/networkxml2conftest.c index 367e30b994..f3b4dafc1b 100644 --- a/tests/networkxml2conftest.c +++ b/tests/networkxml2conftest.c @@ -137,6 +137,7 @@ mymain(void) DO_TEST("nat-network-dns-forwarders", full); DO_TEST("nat-network-dns-forwarder-no-resolv", full); DO_TEST("nat-network-dns-local-domain", full); + DO_TEST("nat-network-mtu", dhcpv6); DO_TEST("dhcp6-network", dhcpv6); DO_TEST("dhcp6-nat-network", dhcpv6); DO_TEST("dhcp6host-routed-network", dhcpv6); diff --git a/tests/networkxml2xmlin/nat-network-mtu.xml b/tests/networkxml2xmlin/nat-network-mtu.xml new file mode 100644 index 0000000000..07d0d9f22d --- /dev/null +++ b/tests/networkxml2xmlin/nat-network-mtu.xml @@ -0,0 +1,22 @@ +<network> + <name>default</name> + <uuid>81ff0d90-c91e-6742-64da-4a736edb9a9b</uuid> + <bridge name="virbr0"/> + <mtu size='7000'/> + <forward mode="nat" dev="eth1"/> + <ip address="192.168.122.1" netmask="255.255.255.0"> + <dhcp> + <range start="192.168.122.2" end="192.168.122.254"/> + <host mac="00:16:3e:77:e2:ed" name="a.example.com" ip="192.168.122.10"/> + <host mac="00:16:3e:3e:a9:1a" name="b.example.com" ip="192.168.122.11"/> + </dhcp> + </ip> + <ip family="ipv4" address="192.168.123.1" netmask="255.255.255.0"> + </ip> + <ip family="ipv6" address="2001:db8:ac10:fe01::1" prefix="64"> + </ip> + <ip family="ipv6" address="2001:db8:ac10:fd01::1" prefix="64"> + </ip> + <ip family="ipv4" address="10.24.10.1"> + </ip> +</network> diff --git a/tests/networkxml2xmlout/nat-network-mtu.xml b/tests/networkxml2xmlout/nat-network-mtu.xml new file mode 100644 index 0000000000..715bc1b505 --- /dev/null +++ b/tests/networkxml2xmlout/nat-network-mtu.xml @@ -0,0 +1,24 @@ +<network> + <name>default</name> + <uuid>81ff0d90-c91e-6742-64da-4a736edb9a9b</uuid> + <forward dev='eth1' mode='nat'> + <interface dev='eth1'/> + </forward> + <bridge name='virbr0' stp='on' delay='0'/> + <mtu size='7000'/> + <ip address='192.168.122.1' netmask='255.255.255.0'> + <dhcp> + <range start='192.168.122.2' end='192.168.122.254'/> + <host mac='00:16:3e:77:e2:ed' name='a.example.com' ip='192.168.122.10'/> + <host mac='00:16:3e:3e:a9:1a' name='b.example.com' ip='192.168.122.11'/> + </dhcp> + </ip> + <ip family='ipv4' address='192.168.123.1' netmask='255.255.255.0'> + </ip> + <ip family='ipv6' address='2001:db8:ac10:fe01::1' prefix='64'> + </ip> + <ip family='ipv6' address='2001:db8:ac10:fd01::1' prefix='64'> + </ip> + <ip family='ipv4' address='10.24.10.1'> + </ip> +</network> diff --git a/tests/networkxml2xmltest.c b/tests/networkxml2xmltest.c index 4e4c7d20a6..b19a365ff4 100644 --- a/tests/networkxml2xmltest.c +++ b/tests/networkxml2xmltest.c @@ -141,6 +141,7 @@ mymain(void) DO_TEST("nat-network-dns-forwarder-no-resolv"); DO_TEST("nat-network-forward-nat-address"); DO_TEST("nat-network-forward-nat-no-address"); + DO_TEST("nat-network-mtu"); DO_TEST("8021Qbh-net"); DO_TEST("direct-net"); DO_TEST("host-bridge-net"); -- 2.17.2