[libvirt] [PATCH] add --interface to dnsmasq command line so bind-interfaces works
Gene Czarcinski
gene at czarc.net
Fri Oct 19 05:04:20 UTC 2012
The problem is that, without SO_BINDTODEVICE, there is no guarantee
that the kernel will route DHCP (v4 or v6) packets to the correct
instance of dnsmasq, when there is more than one.
---
src/network/bridge_driver.c | 20 ++++++++++++++------
tests/networkxml2argvdata/isolated-network.argv | 1 +
tests/networkxml2argvdata/nat-network-dns-hosts.argv | 3 ++-
.../nat-network-dns-srv-record-minimal.argv | 1 +
.../nat-network-dns-srv-record.argv | 1 +
.../nat-network-dns-txt-record.argv | 1 +
tests/networkxml2argvdata/nat-network.argv | 3 ++-
tests/networkxml2argvdata/netboot-network.argv | 3 ++-
tests/networkxml2argvdata/netboot-proxy-network.argv | 3 ++-
tests/networkxml2argvdata/routed-network.argv | 3 ++-
10 files changed, 28 insertions(+), 11 deletions(-)
diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 5578373..821b955 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -682,14 +682,22 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
}
}
- /*
- * --interface does not actually work with dnsmasq < 2.47,
- * due to DAD for ipv6 addresses on the interface.
- *
- * virCommandAddArgList(cmd, "--interface", ipdef->bridge, NULL);
+ /* It may have been important not to use --interface at one time,
+ * but with with dnsmasq => 2.61 there is a problem if
+ * --interface is not specified because --bind-interfaces
+ * will have no effect. Here is what Simon Kelly (dnsmasq
+ * developer) has to say on the subject:
+ * "The problem is that, without SO_BINDTODEVICE, there is
+ * no guarantee that the kernel will route DHCP (v4 or v6)
+ * packets to the correct instance of dnsmasq,
+ * when there is more than one."
*
- * So listen on all defined IPv[46] addresses
+ * --interface is added but the --listen-address parameters
+ * are left in.
*/
+
+ virCommandAddArgList(cmd, "--interface", network->def->bridge, NULL);
+
for (ii = 0;
(tmpipdef = virNetworkDefGetIpByIndex(network->def, AF_UNSPEC, ii));
ii++) {
diff --git a/tests/networkxml2argvdata/isolated-network.argv b/tests/networkxml2argvdata/isolated-network.argv
index 048c72b..c27f793 100644
--- a/tests/networkxml2argvdata/isolated-network.argv
+++ b/tests/networkxml2argvdata/isolated-network.argv
@@ -1,6 +1,7 @@
@DNSMASQ@ --strict-order --bind-interfaces \
--local=// --domain-needed --conf-file= \
--except-interface lo --dhcp-option=3 --no-resolv \
+--interface virbr2 \
--listen-address 192.168.152.1 \
--dhcp-range 192.168.152.2,192.168.152.254 \
--dhcp-leasefile=/var/lib/libvirt/dnsmasq/private.leases --dhcp-lease-max=253 \
diff --git a/tests/networkxml2argvdata/nat-network-dns-hosts.argv b/tests/networkxml2argvdata/nat-network-dns-hosts.argv
index 03a0676..0b72bcd 100644
--- a/tests/networkxml2argvdata/nat-network-dns-hosts.argv
+++ b/tests/networkxml2argvdata/nat-network-dns-hosts.argv
@@ -1,4 +1,5 @@
@DNSMASQ@ --strict-order --bind-interfaces --domain=example.com \
--local=/example.com/ --domain-needed \
---conf-file= --except-interface lo --listen-address 192.168.122.1 \
+--conf-file= --except-interface lo \
+--interface virbr0 --listen-address 192.168.122.1 \
--expand-hosts --addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts\
diff --git a/tests/networkxml2argvdata/nat-network-dns-srv-record-minimal.argv b/tests/networkxml2argvdata/nat-network-dns-srv-record-minimal.argv
index a1e4200..f1273de 100644
--- a/tests/networkxml2argvdata/nat-network-dns-srv-record-minimal.argv
+++ b/tests/networkxml2argvdata/nat-network-dns-srv-record-minimal.argv
@@ -4,6 +4,7 @@
--local=// --domain-needed --conf-file= \
--except-interface lo \
--srv-host=name.tcp.,,,, \
+--interface virbr0 \
--listen-address 192.168.122.1 \
--listen-address 192.168.123.1 \
--listen-address 2001:db8:ac10:fe01::1 \
diff --git a/tests/networkxml2argvdata/nat-network-dns-srv-record.argv b/tests/networkxml2argvdata/nat-network-dns-srv-record.argv
index 8af38c4..6aac056 100644
--- a/tests/networkxml2argvdata/nat-network-dns-srv-record.argv
+++ b/tests/networkxml2argvdata/nat-network-dns-srv-record.argv
@@ -4,6 +4,7 @@
--local=// --domain-needed --conf-file= \
--except-interface lo \
--srv-host=name.tcp.test-domain-name,.,1024,10,10 \
+--interface virbr0 \
--listen-address 192.168.122.1 \
--listen-address 192.168.123.1 \
--listen-address 2001:db8:ac10:fe01::1 \
diff --git a/tests/networkxml2argvdata/nat-network-dns-txt-record.argv b/tests/networkxml2argvdata/nat-network-dns-txt-record.argv
index 404b56a..a65e9a8 100644
--- a/tests/networkxml2argvdata/nat-network-dns-txt-record.argv
+++ b/tests/networkxml2argvdata/nat-network-dns-txt-record.argv
@@ -1,6 +1,7 @@
@DNSMASQ@ --strict-order --bind-interfaces \
--local=// --domain-needed --conf-file= \
--except-interface lo '--txt-record=example,example value' \
+--interface virbr0 \
--listen-address 192.168.122.1 --listen-address 192.168.123.1 \
--listen-address 2001:db8:ac10:fe01::1 \
--listen-address 2001:db8:ac10:fd01::1 --listen-address 10.24.10.1 \
diff --git a/tests/networkxml2argvdata/nat-network.argv b/tests/networkxml2argvdata/nat-network.argv
index 1dc8f73..f25979d 100644
--- a/tests/networkxml2argvdata/nat-network.argv
+++ b/tests/networkxml2argvdata/nat-network.argv
@@ -1,6 +1,7 @@
@DNSMASQ@ --strict-order --bind-interfaces \
--local=// --domain-needed --conf-file= \
---except-interface lo --listen-address 192.168.122.1 \
+--except-interface lo --interface virbr0 \
+--listen-address 192.168.122.1 \
--listen-address 192.168.123.1 --listen-address 2001:db8:ac10:fe01::1 \
--listen-address 2001:db8:ac10:fd01::1 --listen-address 10.24.10.1 \
--dhcp-range 192.168.122.2,192.168.122.254 \
diff --git a/tests/networkxml2argvdata/netboot-network.argv b/tests/networkxml2argvdata/netboot-network.argv
index 5a85ec2..59a0266 100644
--- a/tests/networkxml2argvdata/netboot-network.argv
+++ b/tests/networkxml2argvdata/netboot-network.argv
@@ -1,6 +1,7 @@
@DNSMASQ@ --strict-order --bind-interfaces --domain=example.com \
--local=/example.com/ --domain-needed --conf-file= \
---except-interface lo --listen-address 192.168.122.1 \
+--except-interface lo --interface virbr1 \
+--listen-address 192.168.122.1 \
--dhcp-range 192.168.122.2,192.168.122.254 \
--dhcp-leasefile=/var/lib/libvirt/dnsmasq/netboot.leases \
--dhcp-lease-max=253 --dhcp-no-override --expand-hosts --enable-tftp \
diff --git a/tests/networkxml2argvdata/netboot-proxy-network.argv b/tests/networkxml2argvdata/netboot-proxy-network.argv
index 36836b0..e3fe668 100644
--- a/tests/networkxml2argvdata/netboot-proxy-network.argv
+++ b/tests/networkxml2argvdata/netboot-proxy-network.argv
@@ -1,6 +1,7 @@
@DNSMASQ@ --strict-order --bind-interfaces --domain=example.com \
--local=/example.com/ --domain-needed --conf-file= \
---except-interface lo --listen-address 192.168.122.1 \
+--except-interface lo --interface virbr1 \
+--listen-address 192.168.122.1 \
--dhcp-range 192.168.122.2,192.168.122.254 \
--dhcp-leasefile=/var/lib/libvirt/dnsmasq/netboot.leases \
--dhcp-lease-max=253 --dhcp-no-override --expand-hosts \
diff --git a/tests/networkxml2argvdata/routed-network.argv b/tests/networkxml2argvdata/routed-network.argv
index 77e802f..093c0ee 100644
--- a/tests/networkxml2argvdata/routed-network.argv
+++ b/tests/networkxml2argvdata/routed-network.argv
@@ -1,3 +1,4 @@
@DNSMASQ@ --strict-order --bind-interfaces \
--local=// --domain-needed --conf-file= \
---except-interface lo --listen-address 192.168.122.1\
+--except-interface lo --interface virbr1 \
+--listen-address 192.168.122.1\
--
1.7.11.7
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