In some use cases we don't want the virtual network's DNS to only listen to the vnet interface. Adding a publiclyAccessible attribute to the dns element in the configuration allows the DNS to listen to all interfaces. It simply disables the bind-dynamic option of dnsmasq for the network. --- This patch is v2 for this one: https://www.redhat.com/archives/libvir-list/2015-June/msg00018.html Diff to v1: * Use bind-interface if public DNS is requested * Add more tests * Write out the public value in the format function * Fixed the rng * Renamed the attribute to public: shouldn't mislead users I tested this patch with several configurations of running networks. The only thing I noted though is that the user may need to adapt the system dnsmasq to avoid address:port conflicts... but hey, when one uses such a hacky feature of the libvirt network, he needs to take care of the rest ;) docs/formatnetwork.html.in | 9 +++++++ docs/schemas/network.rng | 5 ++++ src/conf/network_conf.c | 28 ++++++++++++++++++++-- src/conf/network_conf.h | 1 + src/network/bridge_driver.c | 3 ++- .../nat-network-dns-not-public.conf | 15 ++++++++++++ .../nat-network-dns-not-public.xml | 15 ++++++++++++ .../nat-network-dns-public.conf | 15 ++++++++++++ .../networkxml2confdata/nat-network-dns-public.xml | 15 ++++++++++++ tests/networkxml2xmlin/nat-network-dns-public.xml | 9 +++++++ tests/networkxml2xmlout/nat-network-dns-public.xml | 11 +++++++++ tests/networkxml2xmltest.c | 1 + 12 files changed, 124 insertions(+), 3 deletions(-) create mode 100644 tests/networkxml2confdata/nat-network-dns-not-public.conf create mode 100644 tests/networkxml2confdata/nat-network-dns-not-public.xml create mode 100644 tests/networkxml2confdata/nat-network-dns-public.conf create mode 100644 tests/networkxml2confdata/nat-network-dns-public.xml create mode 100644 tests/networkxml2xmlin/nat-network-dns-public.xml create mode 100644 tests/networkxml2xmlout/nat-network-dns-public.xml diff --git a/docs/formatnetwork.html.in b/docs/formatnetwork.html.in index 6abed8f..0141d93 100644 --- a/docs/formatnetwork.html.in +++ b/docs/formatnetwork.html.in @@ -851,6 +851,15 @@ DNS server. </p> + <p> + The dns element + can have an optional <code>public</code> attribute + <span class="since">Since 1.2.17</span>. If <code>public</code> + is "yes", then the DNS server will handle requests for all interfaces. + If <code>public</code> is not set or "no", the DNS server will + only handle requests for the interface of the virtual network. + </p> + Currently supported sub-elements of <code>&lt;dns&gt;</code> are: <dl> <dt><code>forwarder</code></dt> diff --git a/docs/schemas/network.rng b/docs/schemas/network.rng index 4edb6eb..f70e3dc 100644 --- a/docs/schemas/network.rng +++ b/docs/schemas/network.rng @@ -249,6 +249,11 @@ <ref name="virYesNo"/> </attribute> </optional> + <optional> + <attribute name="public"> + <ref name="virYesNo"/> + </attribute> + </optional> <interleave> <zeroOrMore> <element name="forwarder"> diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c index 72006e9..e90c004 100644 --- a/src/conf/network_conf.c +++ b/src/conf/network_conf.c @@ -1332,9 +1332,14 @@ virNetworkDNSDefParseXML(const char *networkName, size_t i; int ret = -1; xmlNodePtr save = ctxt->node; + char *public = NULL; ctxt->node = node; + public = virXPathString("string(./@public)", ctxt); + if (public) + def->public = virTristateBoolTypeFromString(public); + forwardPlainNames = virXPathString("string(./@forwardPlainNames)", ctxt); if (forwardPlainNames) { def->forwardPlainNames = virTristateBoolTypeFromString(forwardPlainNames); @@ -1433,6 +1438,7 @@ virNetworkDNSDefParseXML(const char *networkName, ret = 0; cleanup: + VIR_FREE(public); VIR_FREE(forwardPlainNames); VIR_FREE(fwdNodes); VIR_FREE(hostNodes); @@ -2416,7 +2422,7 @@ virNetworkDNSDefFormat(virBufferPtr buf, size_t i, j; if (!(def->forwardPlainNames || def->nfwds || def->nhosts || - def->nsrvs || def->ntxts)) + def->nsrvs || def->ntxts || def->public)) return 0; virBufferAddLit(buf, "<dns"); @@ -2431,7 +2437,25 @@ virNetworkDNSDefFormat(virBufferPtr buf, return -1; } virBufferAsprintf(buf, " forwardPlainNames='%s'", fwd); - if (!(def->nfwds || def->nhosts || def->nsrvs || def->ntxts)) { + if (!(def->nfwds || def->nhosts || def->nsrvs || def->ntxts || + def->public)) { + virBufferAddLit(buf, "/>\n"); + return 0; + } + } + + if (def->public) { + const char *public = virTristateBoolTypeToString(def->public); + + if (!public) { + virReportError(VIR_ERR_INTERNAL_ERROR, + _("Unknown public type %d in network"), + def->public); + return -1; + } + virBufferAsprintf(buf, " public='%s'", public); + if (!(def->nfwds || def->nhosts || def->nsrvs || def->ntxts || + def->forwardPlainNames)) { virBufferAddLit(buf, "/>\n"); return 0; } diff --git a/src/conf/network_conf.h b/src/conf/network_conf.h index 1cd5100..ae239b8 100644 --- a/src/conf/network_conf.h +++ b/src/conf/network_conf.h @@ -136,6 +136,7 @@ struct _virNetworkDNSDef { virNetworkDNSSrvDefPtr srvs; size_t nfwds; char **forwarders; + int public; /* enum virTristateBool */ }; typedef struct _virNetworkIpDef virNetworkIpDef; diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index 3d6721b..8b11b51 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -991,7 +991,8 @@ networkDnsmasqConfContents(virNetworkObjPtr network, /* dnsmasq will *always* listen on localhost unless told otherwise */ virBufferAddLit(&configbuf, "except-interface=lo\n"); - if (dnsmasqCapsGet(caps, DNSMASQ_CAPS_BIND_DYNAMIC)) { + if (dnsmasqCapsGet(caps, DNSMASQ_CAPS_BIND_DYNAMIC) && + network->def->dns.public != VIR_TRISTATE_BOOL_YES) { /* using --bind-dynamic with only --interface (no * --listen-address) prevents dnsmasq from responding to dns * queries that arrive on some interface other than our bridge diff --git a/tests/networkxml2confdata/nat-network-dns-not-public.conf b/tests/networkxml2confdata/nat-network-dns-not-public.conf new file mode 100644 index 0000000..021316f --- /dev/null +++ b/tests/networkxml2confdata/nat-network-dns-not-public.conf @@ -0,0 +1,15 @@ +##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 +domain=example.com +expand-hosts +domain-needed +local=// +except-interface=lo +bind-dynamic +interface=virbr0 +addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts diff --git a/tests/networkxml2confdata/nat-network-dns-not-public.xml b/tests/networkxml2confdata/nat-network-dns-not-public.xml new file mode 100644 index 0000000..cc78f34 --- /dev/null +++ b/tests/networkxml2confdata/nat-network-dns-not-public.xml @@ -0,0 +1,15 @@ +<network> + <name>default</name> + <uuid>81ff0d90-c91e-6742-64da-4a736edb9a9c</uuid> + <forward dev='eth0' mode='nat'/> + <bridge name='virbr0' stp='on' delay='0'/> + <domain name="example.com"/> + <dns forwardPlainNames='no' public='no'> + <host ip='192.168.122.1'> + <hostname>host</hostname> + <hostname>gateway</hostname> + </host> + </dns> + <ip address='192.168.122.1' netmask='255.255.255.0'> + </ip> +</network> diff --git a/tests/networkxml2confdata/nat-network-dns-public.conf b/tests/networkxml2confdata/nat-network-dns-public.conf new file mode 100644 index 0000000..05cbf43 --- /dev/null +++ b/tests/networkxml2confdata/nat-network-dns-public.conf @@ -0,0 +1,15 @@ +##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 +domain=example.com +expand-hosts +domain-needed +local=// +except-interface=lo +bind-interfaces +interface=virbr0 +addn-hosts=/var/lib/libvirt/dnsmasq/default.addnhosts diff --git a/tests/networkxml2confdata/nat-network-dns-public.xml b/tests/networkxml2confdata/nat-network-dns-public.xml new file mode 100644 index 0000000..9c59c7b --- /dev/null +++ b/tests/networkxml2confdata/nat-network-dns-public.xml @@ -0,0 +1,15 @@ +<network> + <name>default</name> + <uuid>81ff0d90-c91e-6742-64da-4a736edb9a9c</uuid> + <forward dev='eth0' mode='nat'/> + <bridge name='virbr0' stp='on' delay='0'/> + <domain name="example.com"/> + <dns forwardPlainNames='no' public='yes'> + <host ip='192.168.122.1'> + <hostname>host</hostname> + <hostname>gateway</hostname> + </host> + </dns> + <ip address='192.168.122.1' netmask='255.255.255.0'> + </ip> +</network> diff --git a/tests/networkxml2xmlin/nat-network-dns-public.xml b/tests/networkxml2xmlin/nat-network-dns-public.xml new file mode 100644 index 0000000..0765a83 --- /dev/null +++ b/tests/networkxml2xmlin/nat-network-dns-public.xml @@ -0,0 +1,9 @@ +<network> + <name>default</name> + <uuid>81ff0d90-c91e-6742-64da-4a736edb9a9c</uuid> + <forward dev='eth0' mode='nat'/> + <bridge name='virbr0' stp='on' delay='0' /> + <dns public='yes'/> + <ip address='192.168.122.1' netmask='255.255.255.0'> + </ip> +</network> diff --git a/tests/networkxml2xmlout/nat-network-dns-public.xml b/tests/networkxml2xmlout/nat-network-dns-public.xml new file mode 100644 index 0000000..66caacd --- /dev/null +++ b/tests/networkxml2xmlout/nat-network-dns-public.xml @@ -0,0 +1,11 @@ +<network> + <name>default</name> + <uuid>81ff0d90-c91e-6742-64da-4a736edb9a9c</uuid> + <forward dev='eth0' mode='nat'> + <interface dev='eth0'/> + </forward> + <bridge name='virbr0' stp='on' delay='0'/> + <dns public='yes'/> + <ip address='192.168.122.1' netmask='255.255.255.0'> + </ip> +</network> diff --git a/tests/networkxml2xmltest.c b/tests/networkxml2xmltest.c index 290336e..ba565bc 100644 --- a/tests/networkxml2xmltest.c +++ b/tests/networkxml2xmltest.c @@ -97,6 +97,7 @@ mymain(void) DO_TEST("nat-network-dns-srv-record-minimal"); DO_TEST("nat-network-dns-hosts"); DO_TEST("nat-network-dns-forward-plain"); + DO_TEST("nat-network-dns-public"); DO_TEST("nat-network-dns-forwarders"); DO_TEST("nat-network-forward-nat-address"); DO_TEST("8021Qbh-net"); -- 2.1.4