[libvirt] [PATCHv3 2/3] v8.2 add support for DHCPv6

Laine Stump laine at laine.org
Tue Dec 4 20:03:54 UTC 2012


On 12/03/2012 11:13 AM, Gene Czarcinski wrote:
> The DHCPv6 support includes IPV6 dhcp-range and dhcp-host for one
> IPv6 subnetwork on one interface.  This support will only work
> if dnsmasq version >= 2.64; otherwise an error occurs if
> dhcp-range or dhcp-host is specified.
>
> Essentially, this change provides the same DHCP support for IPv6
> that has been available for IPv4.
>
> With dnsmasq >= 2.64, support for the RA service is now provided
> by dnsmasq (radvd is no longer used/started).
>
> Dnsmasq 2.64 does contain the bugfixes released to DHCPv6 and
> dnsmasq's handling of Router Advertisement.
>
> Documentation has been updated to reflect the new support.
>
> The network schema has been updated to reflect the new support.
> ---
>  docs/formatnetwork.html.in                         | 108 +++++-
>  docs/schemas/network.rng                           |  12 +-
>  src/conf/network_conf.c                            | 100 +++--
>  src/network/bridge_driver.c                        | 427 +++++++++++++++------
>  src/util/dnsmasq.c                                 |   9 +-
>  tests/networkxml2argvdata/dhcp6-nat-network.argv   |  15 +
>  tests/networkxml2argvdata/dhcp6-nat-network.xml    |  24 ++
>  tests/networkxml2argvdata/dhcp6-network.argv       |  15 +
>  tests/networkxml2argvdata/dhcp6-network.xml        |  14 +
>  .../dhcp6host-routed-network.argv                  |  13 +
>  .../dhcp6host-routed-network.xml                   |  19 +
>  tests/networkxml2argvdata/isolated-network.argv    |  16 +-
>  .../networkxml2argvdata/nat-network-dns-hosts.argv |  13 +-
>  .../nat-network-dns-srv-record-minimal.argv        |   9 +-
>  .../nat-network-dns-srv-record.argv                |   9 +-
>  .../nat-network-dns-txt-record.argv                |  10 +-
>  tests/networkxml2argvdata/nat-network.argv         |  17 +-
>  tests/networkxml2argvdata/netboot-network.argv     |  23 +-
>  .../networkxml2argvdata/netboot-proxy-network.argv |  19 +-
>  tests/networkxml2argvdata/routed-network.argv      |  10 +-
>  tests/networkxml2argvtest.c                        |   7 +-
>  21 files changed, 674 insertions(+), 215 deletions(-)
>  create mode 100644 tests/networkxml2argvdata/dhcp6-nat-network.argv
>  create mode 100644 tests/networkxml2argvdata/dhcp6-nat-network.xml
>  create mode 100644 tests/networkxml2argvdata/dhcp6-network.argv
>  create mode 100644 tests/networkxml2argvdata/dhcp6-network.xml
>  create mode 100644 tests/networkxml2argvdata/dhcp6host-routed-network.argv
>  create mode 100644 tests/networkxml2argvdata/dhcp6host-routed-network.xml
>
> diff --git a/docs/formatnetwork.html.in b/docs/formatnetwork.html.in
> index a3a5ced..a5f0dc7 100644
> --- a/docs/formatnetwork.html.in
> +++ b/docs/formatnetwork.html.in
> @@ -583,8 +583,10 @@
>          dotted-decimal format, or an IPv6 address in standard
>          colon-separated hexadecimal format, that will be configured on
>          the bridge
> -        device associated with the virtual network. To the guests this
> -        address will be their default route. For IPv4 addresses, the <code>netmask</code>
> +        device associated with the virtual network. To the guests this IPv4
> +        address will be their IPv4 default route.  For IPv6, the default route is
> +        established via Router Advertisement.
> +        For IPv4 addresses, the <code>netmask</code>
>          attribute defines the significant bits of the network address,
>          again specified in dotted-decimal format.  For IPv6 addresses,
>          and as an alternate method for IPv4 addresses, you can specify
> @@ -593,10 +595,13 @@
>          could also be given as <code>prefix='24'</code>. The <code>family</code>
>          attribute is used to specify the type of address - 'ipv4' or 'ipv6'; if no
>          <code>family</code> is given, 'ipv4' is assumed. A network can have more than
> -        one of each family of address defined, but only a single address can have a
> -        <code>dhcp</code> or <code>tftp</code> element. <span class="since">Since 0.3.0;
> +        one of each family of address defined, but only a single IPv4 address can have a
> +        <code>dhcp</code> or <code>tftp</code> element. <span class="since">Since 0.3.0 </span>
>          IPv6, multiple addresses on a single network, <code>family</code>, and
> -        <code>prefix</code> since 0.8.7</span>
> +        <code>prefix</code>. <span class="since">Since 0.8.7</span>  In addition
> +        to the one IPv4 address which has a <code>dhcp</code> definition, one IPv6
> +        address can have a <code>dhcp</code> definition.
> +        <span class="since"> Since 1.0.1</span>
>          <dl>
>            <dt><code>tftp</code></dt>
>            <dd>Immediately within
> @@ -617,27 +622,46 @@
>              <code>dhcp</code> element is not supported for IPv6, and
>              is only supported on a single IP address per network for IPv4.
>              <span class="since">Since 0.3.0</span>
> +            The <code>dhcp</code> element is now supported for IPv6.
> +            Again, there is a restriction that only one IPv6 address definition
> +            is able to have a <code>dhcp</code> element.
> +            <span class="since">Since 1.0.1</span>
>              <dl>
>                <dt><code>range</code></dt>
>                <dd>The <code>start</code> and <code>end</code> attributes on the
>                  <code>range</code> element specify the boundaries of a pool of
> -                IPv4 addresses to be provided to DHCP clients. These two addresses
> +                addresses to be provided to DHCP clients. These two addresses
>                  must lie within the scope of the network defined on the parent
> -                <code>ip</code> element.  <span class="since">Since 0.3.0</span>
> +                <code>ip</code> element.  There may be zero or more
> +                <code>range</code> elements specified.
> +                <span class="since">Since 0.3.0</span>
> +                <code>Range</code> can be specified for one IPv4 address,
> +                one IPv6 address, or both.   <span class="since">Since 1.0.1</span>
>                </dd>
>                <dt><code>host</code></dt>
>                <dd>Within the <code>dhcp</code> element there may be zero or more
> -                <code>host</code> elements; these specify hosts which will be given
> +                <code>host</code> elements.  These specify hosts which will be given
>                  names and predefined IP addresses by the built-in DHCP server. Any
> -                such element must specify the MAC address of the host to be assigned
> +                such IPv4 element must specify the MAC address of the host to be assigned
>                  a given name (via the <code>mac</code> attribute), the IP to be
>                  assigned to that host (via the <code>ip</code> attribute), and the
>                  name to be given that host by the DHCP server (via the
>                  <code>name</code> attribute).  <span class="since">Since 0.4.5</span>
> +                Within the IPv6 <code>dhcp</code> element zero or more
> +                <code>host</code> elements are now supported.  The definition for
> +                an IPv6 <code>host</code> element differs from that for IPv4:
> +                there is no <code>mac</code> attribute since a MAC address has no
> +                defined meaning in IPv6.  Instead, the <code>name</code> attribute is
> +                used to identify the host to be assigned the IPv6 address.  For DHCPv6,
> +                the name is the plain name of the client host sent by the
> +                client to the server.  Note that this method of assigning a
> +                specific IP address can be used instead of the <code>mac</code>
> +                attribute for IPv4.  <span class="since">Since 1.0.1</span>
>                </dd>
>                <dt><code>bootp</code></dt>
>                <dd>The optional <code>bootp</code>
> -                element specifies BOOTP options to be provided by the DHCP server.
> +                element specifies BOOTP options to be provided by the DHCP
> +                server for IPv4 only.
>                  Two attributes are supported: <code>file</code> is mandatory and
>                  gives the file to be used for the boot image; <code>server</code> is
>                  optional and gives the address of the TFTP server from which the boot
> @@ -680,6 +704,29 @@
>          <ip family="ipv6" address="2001:db8:ca2:2::1" prefix="64" />
>        </network></pre>
>  
> +
> +    <p>
> +      Below is a variation of the above example which adds an IPv6
> +      dhcp range definition.
> +    </p>
> +
> +    <pre>
> +      <network>
> +        <name>default6</name>
> +        <bridge name="virbr0" />
> +        <forward mode="nat"/>
> +        <ip address="192.168.122.1" netmask="255.255.255.0">
> +          <dhcp>
> +            <range start="192.168.122.2" end="192.168.122.254" />
> +          </dhcp>
> +        </ip>
> +        <ip family="ipv6" address="2001:db8:ca2:2::1" prefix="64" >
> +          <dhcp>
> +            <range start="2001:db8:ca2:2:1::10" end="2001:db8:ca2:2:1::ff" />
> +          </dhcp>
> +        </ip>
> +      </network></pre>
> +
>      <h3><a name="examplesRoute">Routed network config</a></h3>
>  
>      <p>
> @@ -704,6 +751,29 @@
>          <ip family="ipv6" address="2001:db8:ca2:2::1" prefix="64" />
>        </network></pre>
>  
> +    <p>
> +      Below is another IPv6 varition.  Instead of a dhcp range being
> +      specified, this example has a couple of IPv6 host definitions.
> +    </p>
> +
> +    <pre>
> +      <network>
> +        <name>local6</name>
> +        <bridge name="virbr1" />
> +        <forward mode="route" 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" />
> +          </dhcp>
> +        </ip>
> +        <ip family="ipv6" address="2001:db8:ca2:2::1" prefix="64" >
> +          <dhcp>
> +            <host name="paul"   ip="2001:db8:ca2:2:3::1" />
> +            <host name="bob"    ip="2001:db8:ca2:2:3::2" />
> +          </dhcp>
> +        </ip>
> +      </network></pre>
> +
>      <h3><a name="examplesPrivate">Isolated network config</a></h3>
>  
>      <p>
> @@ -726,6 +796,24 @@
>          <ip family="ipv6" address="2001:db8:ca2:3::1" prefix="64" />
>        </network></pre>
>  
> +    <h3><a name="examplesPrivate6">Isolated IPv6 network config</a></h3>
> +
> +    <p>
> +      This variation of an isolated network defines only IPv6.
> +    </p>
> +
> +    <pre>
> +      <network>
> +        <name>sixnet</name>
> +        <bridge name="virbr6" />
> +        <ip family="ipv6" address="2001:db8:ca2:6::1" prefix="64" >
> +          <dhcp>
> +            <host name="peter"   ip="2001:db8:ca2:6:6::1" />
> +            <host name="dariusz" ip="2001:db8:ca2:6:6::2" />
> +          </dhcp>
> +        </ip>
> +      </network></pre>
> +
>      <h3><a name="examplesBridge">Using an existing host bridge</a></h3>
>  
>      <p>
> diff --git a/docs/schemas/network.rng b/docs/schemas/network.rng
> index 0d67f7f..09d7c73 100644
> --- a/docs/schemas/network.rng
> +++ b/docs/schemas/network.rng
> @@ -218,7 +218,7 @@
>                </zeroOrMore>
>                <zeroOrMore>
>                  <element name="host">
> -                  <attribute name="ip"><ref name="ipv4Addr"/></attribute>
> +                  <attribute name="ip"><ref name="ipAddr"/></attribute>
>                    <oneOrMore>
>                      <element name="hostname"><ref name="dnsName"/></element>
>                    </oneOrMore>
> @@ -272,15 +272,17 @@
>                <element name="dhcp">
>                  <zeroOrMore>
>                    <element name="range">
> -                    <attribute name="start"><ref name="ipv4Addr"/></attribute>
> -                    <attribute name="end"><ref name="ipv4Addr"/></attribute>
> +                    <attribute name="start"><ref name="ipAddr"/></attribute>
> +                    <attribute name="end"><ref name="ipAddr"/></attribute>
>                    </element>
>                  </zeroOrMore>
>                  <zeroOrMore>
>                    <element name="host">
> -                    <attribute name="mac"><ref name="uniMacAddr"/></attribute>
> +                    <optional>
> +                      <attribute name="mac"><ref name="uniMacAddr"/></attribute>
> +                    </optional>
>                      <attribute name="name"><text/></attribute>
> -                    <attribute name="ip"><ref name="ipv4Addr"/></attribute>
> +                    <attribute name="ip"><ref name="ipAddr"/></attribute>
>                    </element>
>                  </zeroOrMore>
>                  <optional>
> diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c
> index 3f9e13c..ad6d0e1 100644
> --- a/src/conf/network_conf.c
> +++ b/src/conf/network_conf.c
> @@ -633,6 +633,7 @@ cleanup:
>  
>  static int
>  virNetworkDHCPHostDefParse(const char *networkName,
> +                           virNetworkIpDefPtr def,

I might have just passed in the family rather than the entire ipdef,
just to make sure that nobody accidentally modified def instead of
host->ip. Going that far isn't necessary, but we at least need to make
it "const virNetworkIpDefPtr def".

>                             xmlNodePtr node,
>                             virNetworkDHCPHostDefPtr host,
>                             bool partialOkay)
> @@ -644,6 +645,13 @@ virNetworkDHCPHostDefParse(const char *networkName,
>  
>      mac = virXMLPropString(node, "mac");
>      if (mac != NULL) {
> +        if (VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET6)) {
> +            virReportError(VIR_ERR_XML_ERROR,
> +                           _("Invalid to specify MAC address '%s' "
> +                             "in IPv6 network '%s'"),

"in network '%s' IPv6 static host definition."

> +                           mac, networkName);
> +            goto cleanup;
> +        }
>          if (virMacAddrParse(mac, &addr) < 0) {
>              virReportError(VIR_ERR_XML_ERROR,
>                             _("Cannot parse MAC address '%s' in network '%s'"),
> @@ -686,10 +694,19 @@ virNetworkDHCPHostDefParse(const char *networkName,
>                             networkName);
>          }
>      } else {

Out of curiousity: have you tried doing virsh net-update ip-dhcp-host
... for an IPv6 dhcp entry? (that's one of the callers of this function)


> +        if (VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET6)) {
> +            if (!name) {
> +                virReportError(VIR_ERR_XML_ERROR,
> +                           _("Static host definition in IPv6 network '%s' "
> +                             "must have name attribute"),
> +                           networkName);
> +                goto cleanup;
> +            }
> +        }
>          /* normal usage - you need at least one MAC address or one host name */
> -        if (!(mac || name)) {
> +        else if (!(mac || name)) {

The else must be on the same line as the closing brace of the preceding
if clause (put the comment up above if "if (VIR_SOCKET_ADDR...)" and
expend it to describe what's needed for IPv6 as well).

>              virReportError(VIR_ERR_XML_ERROR,
> -                           _("Static host definition in network '%s' "
> +                           _("Static host definition in IPv4 network '%s' "
>                               "must have mac or name attribute"),
>                             networkName);
>              goto cleanup;
> @@ -748,36 +765,39 @@ virNetworkDHCPDefParse(const char *networkName,
>                  virReportOOMError();
>                  return -1;
>              }
> -            if (virNetworkDHCPHostDefParse(networkName, cur,
> +            if (virNetworkDHCPHostDefParse(networkName, def, cur,
>                                             &def->hosts[def->nhosts],
>                                             false) < 0) {
>                  return -1;
>              }
>              def->nhosts++;
>  
> -        } else if (cur->type == XML_ELEMENT_NODE &&
> -            xmlStrEqual(cur->name, BAD_CAST "bootp")) {
> -            char *file;
> -            char *server;
> -            virSocketAddr inaddr;
> -            memset(&inaddr, 0, sizeof(inaddr));
> -
> -            if (!(file = virXMLPropString(cur, "file"))) {
> -                cur = cur->next;
> -                continue;
> -            }
> -            server = virXMLPropString(cur, "server");
> +        } else if (VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET)) {
> +            /* the following only applies to IPv4 */
> +            if (cur->type == XML_ELEMENT_NODE &&
> +                xmlStrEqual(cur->name, BAD_CAST "bootp")) {

You don't need to add the extra nesting - just add the
VIR_SOCKET_ADDR... as another term of the else if expression (i.e.
combine the two):

           } else if (VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET) &&
                      cur->type == XML_ELEMENT_NODE &&
                      xmlStrEqual(cur->name, BAD_CAST "bootp")) {


Not only is the code simpler, but then the body of the else isn't
re-indented, so it doesn't create a strange diff that needs to be
hand-examined :-)

> +                char *file;
> +                char *server;
> +                virSocketAddr inaddr;
> +                memset(&inaddr, 0, sizeof(inaddr));
> +
> +                if (!(file = virXMLPropString(cur, "file"))) {
> +                    cur = cur->next;
> +                    continue;
> +                }
> +                server = virXMLPropString(cur, "server");
> +
> +                if (server &&
> +                    virSocketAddrParse(&inaddr, server, AF_UNSPEC) < 0) {
> +                    VIR_FREE(file);
> +                    VIR_FREE(server);
> +                    return -1;
> +                }
>  
> -            if (server &&
> -                virSocketAddrParse(&inaddr, server, AF_UNSPEC) < 0) {
> -                VIR_FREE(file);
> +                def->bootfile = file;
> +                def->bootserver = inaddr;
>                  VIR_FREE(server);
> -                return -1;
>              }
> -
> -            def->bootfile = file;
> -            def->bootserver = inaddr;
> -            VIR_FREE(server);
>          }
>  
>          cur = cur->next;
> @@ -1139,6 +1159,20 @@ virNetworkIPParseXML(const char *networkName,
>          }
>      }
>  
> +    if (VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET6)) {
> +        /* parse IPv6-related info */
> +        cur = node->children;
> +        while (cur != NULL) {
> +            if (cur->type == XML_ELEMENT_NODE &&
> +                xmlStrEqual(cur->name, BAD_CAST "dhcp")) {
> +                result = virNetworkDHCPDefParse(networkName, def, cur);
> +                if (result)
> +                    goto error;
> +            }
> +            cur = cur->next;
> +        }
> +    }
> +

Rather than adding an entirely new loop for IPv6 (which is doing a
perfect subset of what's done for IPv4), just move the "if IPv4"
qualifier into the bit of the existing loop that is no IPv4-only. For
that matter, it's probably worth checking that somebody doesn't try to
specify a <tftp> node for an IPv6 network (hmm, I assume PXE boot can be
done with dhcp6 and IPv6. What would it take to make that work too?)

>      result = 0;
>  
>  error:
> @@ -2361,11 +2395,9 @@ virNetworkIpDefByIndex(virNetworkDefPtr def, int parentIndex)
>      /* first find which ip element's dhcp host list to work on */
>      if (parentIndex >= 0) {
>          ipdef = virNetworkDefGetIpByIndex(def, AF_UNSPEC, parentIndex);
> -        if (!(ipdef &&
> -              VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET))) {
> +        if (!(ipdef)) {
>              virReportError(VIR_ERR_OPERATION_INVALID,
>                             _("couldn't update dhcp host entry - "
> -                             "no <ip family='ipv4'> "
>                               "element found at index %d in network '%s'"),
>                             parentIndex, def->name);

You accidentally took out the "no <ip>".


>          }
> @@ -2378,17 +2410,17 @@ virNetworkIpDefByIndex(virNetworkDefPtr def, int parentIndex)
>      for (ii = 0;
>           (ipdef = virNetworkDefGetIpByIndex(def, AF_UNSPEC, ii));
>           ii++) {
> -        if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET) &&
> -            (ipdef->nranges || ipdef->nhosts)) {
> +        if (ipdef->nranges || ipdef->nhosts)
>              break;
> -        }
>      }
> -    if (!ipdef)
> +    if (!ipdef) {
>          ipdef = virNetworkDefGetIpByIndex(def, AF_INET, 0);
> +        if (!ipdef)
> +            ipdef = virNetworkDefGetIpByIndex(def, AF_INET6, 0);
> +    }
>      if (!ipdef) {
>          virReportError(VIR_ERR_OPERATION_INVALID,
>                         _("couldn't update dhcp host entry - "
> -                         "no <ip family='ipv4'> "
>                           "element found in network '%s'"), def->name);

And again.

>      }
>      return ipdef;
> @@ -2418,7 +2450,7 @@ virNetworkDefUpdateIPDHCPHost(virNetworkDefPtr def,
>      /* parse the xml into a virNetworkDHCPHostDef */
>      if (command == VIR_NETWORK_UPDATE_COMMAND_MODIFY) {
>  
> -        if (virNetworkDHCPHostDefParse(def->name, ctxt->node, &host, false) < 0)
> +        if (virNetworkDHCPHostDefParse(def->name, ipdef, ctxt->node, &host, false) < 0)
>              goto cleanup;
>  
>          /* search for the entry with this (mac|name),
> @@ -2451,7 +2483,7 @@ virNetworkDefUpdateIPDHCPHost(virNetworkDefPtr def,
>      } else if ((command == VIR_NETWORK_UPDATE_COMMAND_ADD_FIRST) ||
>                 (command == VIR_NETWORK_UPDATE_COMMAND_ADD_LAST)) {
>  
> -        if (virNetworkDHCPHostDefParse(def->name, ctxt->node, &host, true) < 0)
> +        if (virNetworkDHCPHostDefParse(def->name, ipdef, ctxt->node, &host, true) < 0)
>              goto cleanup;
>  
>          /* log error if an entry with same name/address/ip already exists */
> @@ -2497,7 +2529,7 @@ virNetworkDefUpdateIPDHCPHost(virNetworkDefPtr def,
>  
>      } else if (command == VIR_NETWORK_UPDATE_COMMAND_DELETE) {
>  
> -        if (virNetworkDHCPHostDefParse(def->name, ctxt->node, &host, false) < 0)
> +        if (virNetworkDHCPHostDefParse(def->name, ipdef, ctxt->node, &host, false) < 0)
>              goto cleanup;
>  
>          /* find matching entry - all specified attributes must match */
> diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
> index cb2997d..c07d61a 100644
> --- a/src/network/bridge_driver.c
> +++ b/src/network/bridge_driver.c
> @@ -75,6 +75,11 @@
>  
>  #define VIR_FROM_THIS VIR_FROM_NETWORK
>  
> +#define CHECK_VERSION_DHCP(CAPS)                 \
> +                (dnsmasqCapsGetVersion(CAPS) >= 2064000)
> +#define CHECK_VERSION_RA(CAPS)                   \
> +                (dnsmasqCapsGetVersion(CAPS) >= 2064000)

(I originally thought both of these version numbers should be
encapsulated as flags in dnsmasqCaps, rather than exposing the version
number here (there are, several examples of this in
qemu_capabilities.c), but fully removing mention of the version number
from bridge_driver.c would also require getting the version number for
the error log messages from somewhere too, so I decided against that.
However, these macros *do* need to get their version info from the same
source as the log messsages. So I suggest something like this:

#define DNSMASQ_DHCPv6_MAJOR_REQD 2
#define DNSMASQ_DHCPv6_MINOR_REQD 64
#define DNSMQASQ_RA_MAJOR_REQD 2
#define DNSMSAQ_RA_MINOR_REQD 64

#define DNSMASQ_DHCPv6_SUPPORT(CAPS) \
                (dnsmasqCapsGetVersion(CAPS) >= (DNSMASQ_DHCPv6_MAJOR_REQD * 1000000) + \
                                                (DNSMASQ_DHCPv6_MINOR_REQD * 1000))
#define DNSMASQ_RA_SUPPORT(CAPS) \
                (dnsmasqCapsGetVersion(CAPS) >= (DNSMASQ_RA_MAJOR_REQD * 1000000) + \
				                (DNSMASQ_RA_MINOR_REQD * 1000))

Then use the XXX_REQD in the error logs. That way if we ever needed to change it for some reason, it would just need changing in a single place.

(actually, now that I think about it, the above #defines should be moved into dnsmasq.h)
 

> +
>  /* Main driver state */
>  struct network_driver {
>      virMutex lock;
> @@ -588,20 +593,32 @@ cleanup:
>      return ret;
>  }
>  
> +    /* the following does not build a file, it builds a list
> +     * which is later saved into a file
> +     */
> +
>  static int
> -networkBuildDnsmasqHostsfile(dnsmasqContext *dctx,
> -                             virNetworkIpDefPtr ipdef,
> -                             virNetworkDNSDefPtr dnsdef)
> +networkBuildDnsmasqDhcpHostsList(dnsmasqContext *dctx,
> +                                 virNetworkIpDefPtr ipdef)
>  {
> -    unsigned int i, j;
> +    unsigned int i;
>  
>      for (i = 0; i < ipdef->nhosts; i++) {
>          virNetworkDHCPHostDefPtr host = &(ipdef->hosts[i]);
> -        if ((host->mac) && VIR_SOCKET_ADDR_VALID(&host->ip))
> +        if (VIR_SOCKET_ADDR_VALID(&host->ip))
>              if (dnsmasqAddDhcpHost(dctx, host->mac, &host->ip, host->name) < 0)
>                  return -1;
>      }
>  
> +    return 0;
> +}
> +
> +static int
> +networkBuildDnsmasqHostsList(dnsmasqContext *dctx,
> +                             virNetworkDNSDefPtr dnsdef)
> +{
> +    unsigned int i, j;
> +
>      if (dnsdef) {
>          for (i = 0; i < dnsdef->nhosts; i++) {
>              virNetworkDNSHostsDefPtr host = &(dnsdef->hosts[i]);
> @@ -619,7 +636,6 @@ networkBuildDnsmasqHostsfile(dnsmasqContext *dctx,
>  
>  static int
>  networkBuildDnsmasqArgv(virNetworkObjPtr network,
> -                        virNetworkIpDefPtr ipdef,
>                          const char *pidfile,
>                          virCommandPtr cmd,
>                          dnsmasqContext *dctx,
> @@ -632,7 +648,8 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
>      char *recordPort = NULL;
>      char *recordWeight = NULL;
>      char *recordPriority = NULL;
> -    virNetworkIpDefPtr tmpipdef;
> +    virNetworkIpDefPtr tmpipdef, ipdef, ipv4def, ipv6def;
> +    bool dhcp4flag, dhcp6flag, ipv6SLAAC;

It looks to me like dhcp4flag and dhcp6flag are exactly equivalent to
"ipvXdef != NULL", so they are redundant. They should be removed.

>  
>      /*
>       * NB, be careful about syntax for dnsmasq options in long format.
> @@ -657,14 +674,17 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
>       * Needed to ensure dnsmasq uses same algorithm for processing
>       * multiple namedriver entries in /etc/resolv.conf as GLibC.
>       */
> -    virCommandAddArg(cmd, "--strict-order");
> +    virCommandAddArgList(cmd, "--strict-order",
> +                              "--domain-needed",
> +                              NULL);
>  
> -    if (network->def->domain)
> +    if (network->def->domain) {
>          virCommandAddArgPair(cmd, "--domain", network->def->domain);
> +        virCommandAddArg(cmd, "--expand-hosts");
> +    }
>      /* need to specify local even if no domain specified */
>      virCommandAddArgFormat(cmd, "--local=/%s/",
>                             network->def->domain ? network->def->domain : "");
> -    virCommandAddArg(cmd, "--domain-needed");
>  
>      if (pidfile)
>          virCommandAddArgPair(cmd, "--pid-file", pidfile);
> @@ -687,7 +707,7 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
>      } else {
>          virCommandAddArgList(cmd,
>                               "--bind-interfaces",
> -                             "--except-interface", "lo",
> +                             "--except-interface=lo",
>                               NULL);

All of the above movement of options seems to be unrelated to adding
support for DHCPv6; as a matter of fact, it all adds up to a NOP (when
combined with the removal of --expand-hosts further down in the file).
Since the next patch is about to replace all of this code anyway, and it
isn't necessary for DHCPv6 support, it should be eliminated from this
diff. Try to keep this patch to only the changes needed for supporting
DHCPv6.

>          /*
>           * --interface does not actually work with dnsmasq < 2.47,
> @@ -791,14 +811,75 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
>          }
>      }
>  
> -    if (ipdef) {
> +    /* Find the first dhcp for both IPv4 and IPv6 */
> +    for (ii = 0, ipv4def = NULL, ipv6def = NULL,
> +                 dhcp4flag = false, dhcp6flag = false, ipv6SLAAC = false;
> +         (ipdef = virNetworkDefGetIpByIndex(network->def, AF_UNSPEC, ii));
> +         ii++) {
> +        if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET)) {
> +            if (ipdef->nranges || ipdef->nhosts) {
> +                if (ipv4def) {
> +                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                        _("For IPv4, multiple DHCP definitions cannot "
> +                          "be specified."));
> +                    goto cleanup;
> +                } else {
> +                    ipv4def = ipdef;
> +                    dhcp4flag = true;
> +                }
> +            }
> +        }
> +        if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET6)) {
> +            if (ipdef->nranges || ipdef->nhosts) {
> +                if (!CHECK_VERSION_DHCP(caps)) {
> +                    unsigned long version = dnsmasqCapsGetVersion(caps);
> +                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
> +                            _("The version of dnsmasq on this host (%d.%d) doesn't "
> +                              "adequately support dhcp range or dhcp host "
> +                              "specification.  Version 2.64 or later is required."),

"2.64" should be replaced with %d.%d, and the constants I suggested
above should be added to the args.

> +                            (int)version / 1000000, (int)(version % 1000000) / 1000);
> +                    goto cleanup;
> +                }
> +                if (ipv6def) {
> +                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                        _("For IPv6, multiple DHCP definitions cannot "
> +                          "be specified."));
> +                    goto cleanup;
> +                } else {
> +                    ipv6def = ipdef;
> +                    dhcp6flag = true;
> +                }
> +            } else {
> +                ipv6SLAAC = true;
> +            }
> +        }
> +    }
> +
> +    if (dhcp6flag && ipv6SLAAC) {
> +        VIR_WARN("For IPv6, when DHCP is specified for one address, then "
> +                 "state-full Router Advertising will occur.  The additional "
> +                  "IPv6 addresses specified require manually configured guest "
> +                  "network to work properly since both state-full (DHCP) "
> +                  "and state-less (SLAAC) addressing are not supported "
> +                  "on the same network interface.");
> +    }
> +
> +    if (ipv4def)
> +        ipdef = ipv4def;
> +    else
> +        ipdef = ipv6def;

You could shorten this:

      ipdef = ipv4def ? ipv4def : ipv6def;

> +
> +    while (ipdef) {
>          for (r = 0 ; r < ipdef->nranges ; r++) {
>              char *saddr = virSocketAddrFormat(&ipdef->ranges[r].start);
> -            if (!saddr)
> +            if (!saddr) {
> +                virReportOOMError();

This error log should be removed - it's already done in
virSocketAddrFormat(). And remove the {} that you added while you're at it.

>                  goto cleanup;
> +            }
>              char *eaddr = virSocketAddrFormat(&ipdef->ranges[r].end);
>              if (!eaddr) {
>                  VIR_FREE(saddr);
> +                virReportOOMError();

This one too.

>                  goto cleanup;
>              }
>              virCommandAddArg(cmd, "--dhcp-range");
> @@ -812,72 +893,110 @@ networkBuildDnsmasqArgv(virNetworkObjPtr network,
>          /*
>           * For static-only DHCP, i.e. with no range but at least one host element,
>           * we have to add a special --dhcp-range option to enable the service in
> -         * dnsmasq.
> +         * dnsmasq. [this is for dhcp-hosts= support]

Really trivial, but () is more common around parenthetical comments than
[] :-)

>           */
>          if (!ipdef->nranges && ipdef->nhosts) {
>              char *bridgeaddr = virSocketAddrFormat(&ipdef->address);
> -            if (!bridgeaddr)
> +            if (!bridgeaddr) {
> +                virReportOOMError();

Again - remove the virReportOOMError() and surrounding {} that you've added.

>                  goto cleanup;
> +            }
>              virCommandAddArg(cmd, "--dhcp-range");
>              virCommandAddArgFormat(cmd, "%s,static", bridgeaddr);
>              VIR_FREE(bridgeaddr);
>          }
>  
> -        if (ipdef->nranges > 0) {
> -            char *leasefile = networkDnsmasqLeaseFileName(network->def->name);
> -            if (!leasefile)
> -                goto cleanup;
> -            virCommandAddArgFormat(cmd, "--dhcp-leasefile=%s", leasefile);
> -            VIR_FREE(leasefile);
> -            virCommandAddArgFormat(cmd, "--dhcp-lease-max=%d", nbleases);
> -        }
> -
> -        if (ipdef->nranges || ipdef->nhosts)
> -            virCommandAddArg(cmd, "--dhcp-no-override");
> +        if (networkBuildDnsmasqDhcpHostsList(dctx, ipdef) < 0)
> +            goto cleanup;
>  
> -        /* add domain to any non-qualified hostnames in /etc/hosts or addn-hosts */
> -        if (network->def->domain)
> -           virCommandAddArg(cmd, "--expand-hosts");

Here's ^^^ another piece that's part of the NOP I mentioned above.

> +        /* Note: the following is IPv4 only */
> +        if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET)) {
> +            if (ipdef->nranges || ipdef->nhosts)
> +                virCommandAddArg(cmd, "--dhcp-no-override");
>  
> -        if (networkBuildDnsmasqHostsfile(dctx, ipdef, network->def->dns) < 0)
> -            goto cleanup;
> +            if (ipdef->tftproot) {
> +                virCommandAddArgList(cmd, "--enable-tftp",
> +                                     "--tftp-root", ipdef->tftproot,
> +                                     NULL);
> +            }
>  
> -        /* Even if there are currently no static hosts, if we're
> -         * listening for DHCP, we should write a 0-length hosts
> -         * file to allow for runtime additions.
> -         */
> -        if (ipdef->nranges || ipdef->nhosts)
> -            virCommandAddArgPair(cmd, "--dhcp-hostsfile",
> -                                 dctx->hostsfile->path);
> +            if (ipdef->bootfile) {
> +                virCommandAddArg(cmd, "--dhcp-boot");
> +                if (VIR_SOCKET_ADDR_VALID(&ipdef->bootserver)) {
> +                    char *bootserver = virSocketAddrFormat(&ipdef->bootserver);
>  
> -        /* Likewise, always create this file and put it on the commandline, to allow for
> -         * for runtime additions.
> -         */
> -        virCommandAddArgPair(cmd, "--addn-hosts",
> -                             dctx->addnhostsfile->path);
> +                    if (!bootserver) {
> +                        virReportOOMError();
> +                        goto cleanup;
> +                    }
> +                    virCommandAddArgFormat(cmd, "%s%s%s",
> +                                       ipdef->bootfile, ",,", bootserver);
> +                    VIR_FREE(bootserver);
> +                } else {
> +                    virCommandAddArg(cmd, ipdef->bootfile);
> +                }
> +            }
> +        }
> +        if (ipdef == ipv6def)
> +            ipdef = NULL;
> +        else
> +            ipdef = ipv6def;

    ipdef = (ipdef == ipv6def) ? NULL : ipv6def;

> +    }
>  
> -        if (ipdef->tftproot) {
> -            virCommandAddArgList(cmd, "--enable-tftp",
> -                                 "--tftp-root", ipdef->tftproot,
> -                                 NULL);
> +    if (nbleases > 0) {

Hmm. This reminded me that dnsmasq puts static hosts in the leases file
as well, so we need to also account for that in nbleases. But that's a
separate bug that should have a separate patch.

> +        char *leasefile = networkDnsmasqLeaseFileName(network->def->name);
> +        if (!leasefile) {
> +            virReportOOMError();
> +            goto cleanup;
>          }

Here's a case where you added in an OOM log that really *was* missing :-)

> -        if (ipdef->bootfile) {
> -            virCommandAddArg(cmd, "--dhcp-boot");
> -            if (VIR_SOCKET_ADDR_VALID(&ipdef->bootserver)) {
> -                char *bootserver = virSocketAddrFormat(&ipdef->bootserver);
> +        virCommandAddArgFormat(cmd, "--dhcp-leasefile=%s", leasefile);
> +        VIR_FREE(leasefile);
> +        virCommandAddArgFormat(cmd, "--dhcp-lease-max=%d", nbleases);
> +    }
>  
> -                if (!bootserver)
> -                    goto cleanup;
> -                virCommandAddArgFormat(cmd, "%s%s%s",
> -                                       ipdef->bootfile, ",,", bootserver);
> -                VIR_FREE(bootserver);
> -            } else {
> -                virCommandAddArg(cmd, ipdef->bootfile);
> +    /* this is done once per interface */
> +    if (networkBuildDnsmasqHostsList(dctx, network->def->dns) < 0)
> +       goto cleanup;
> +
> +    /* Even if there are currently no static hosts, if we're
> +     * listening for DHCP, we should write a 0-length hosts
> +     * file to allow for runtime additions.
> +     */
> +    if (dhcp4flag || dhcp6flag)

replace this with (iopv4def || ipv6def) as discussed above.

> +        virCommandAddArgPair(cmd, "--dhcp-hostsfile",
> +                             dctx->hostsfile->path);
> +
> +    /* Likewise, always create this file and put it on the commandline, to allow for
> +     * for runtime additions.

You repeated the word "for"

> +     */
> +    virCommandAddArgPair(cmd, "--addn-hosts",
> +                         dctx->addnhostsfile->path);
> +
> +    /* Are we doing RA instead of radvd? */
> +    if (CHECK_VERSION_RA(caps)) {
> +        if (dhcp6flag)

          if (ipv6def)

> +            virCommandAddArg(cmd, "--enable-ra");
> +        else {
> +            for (ii = 0;
> +                (ipdef = virNetworkDefGetIpByIndex(network->def, AF_INET6, ii));
> +                ii++) {
> +                if (!(ipdef->nranges || ipdef->nhosts)) {
> +                    char *bridgeaddr = virSocketAddrFormat(&ipdef->address);
> +                    if (bridgeaddr) {
> +                        virCommandAddArgFormat(cmd,
> +                            "--dhcp-range=%s,ra-only", bridgeaddr);
> +                    } else {
> +                        virReportOOMError();

This error log is unnecessary - virSocketAddrFormat() already logs the
error.

> +                        goto cleanup;
> +                    }
> +                    VIR_FREE(bridgeaddr);
> +                }
>              }
>          }
>      }
>  
>      ret = 0;
> +

spurious extra whitespace added.

>  cleanup:
>      VIR_FREE(record);
>      VIR_FREE(recordPort);
> @@ -893,32 +1012,20 @@ networkBuildDhcpDaemonCommandLine(virNetworkObjPtr network, virCommandPtr *cmdou
>  {
>      virCommandPtr cmd = NULL;
>      int ret = -1, ii;

You've removed the loop that used ii, so it is now unused, and since I
have -Werror, it fails to build. Remove ii.


> -    virNetworkIpDefPtr ipdef;
>  
>      network->dnsmasqPid = -1;
>  
> -    /* Look for first IPv4 address that has dhcp defined. */
> -    /* We support dhcp config on 1 IPv4 interface only. */
> -    for (ii = 0;
> -         (ipdef = virNetworkDefGetIpByIndex(network->def, AF_INET, ii));
> -         ii++) {
> -        if (ipdef->nranges || ipdef->nhosts)
> -            break;
> -    }
> -    /* If no IPv4 addresses had dhcp info, pick the first (if there were any). */
> -    if (!ipdef)
> -        ipdef = virNetworkDefGetIpByIndex(network->def, AF_INET, 0);
> -
>      /* If there are no IP addresses at all (v4 or v6), return now, since
>       * there won't be any address for dnsmasq to listen on anyway.
>       * If there are any addresses, even if no dhcp ranges or static entries,
>       * we should continue and run dnsmasq, just for the DNS capabilities.
> +     * This should not happen.  This code may not be needed.

What do you mean by this?


>       */
>      if (!virNetworkDefGetIpByIndex(network->def, AF_UNSPEC, 0))
>          return 0;
>  
>      cmd = virCommandNew(dnsmasqCapsGetBinaryPath(caps));
> -    if (networkBuildDnsmasqArgv(network, ipdef, pidfile, cmd, dctx, caps) < 0) {
> +    if (networkBuildDnsmasqArgv(network, pidfile, cmd, dctx, caps) < 0) {
>          goto cleanup;
>      }
>  
> @@ -939,11 +1046,9 @@ networkStartDhcpDaemon(struct network_driver *driver,
>      char *pidfile = NULL;
>      int ret = -1;
>      dnsmasqContext *dctx = NULL;
> -    virNetworkIpDefPtr ipdef;
> -    int i;
>  
>      if (!virNetworkDefGetIpByIndex(network->def, AF_UNSPEC, 0)) {
> -        /* no IPv6 addresses, so we don't need to run radvd */
> +        /* no IP addresses, so we don't need to run */
>          ret = 0;
>          goto cleanup;
>      }
> @@ -984,18 +1089,6 @@ networkStartDhcpDaemon(struct network_driver *driver,
>      if (ret < 0)
>          goto cleanup;
>  
> -    /* populate dnsmasq hosts file */
> -    for (i = 0; (ipdef = virNetworkDefGetIpByIndex(network->def, AF_UNSPEC, i)); i++) {
> -        if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET) &&
> -            (ipdef->nranges || ipdef->nhosts)) {
> -            if (networkBuildDnsmasqHostsfile(dctx, ipdef,
> -                                             network->def->dns) < 0)
> -                goto cleanup;
> -
> -            break;
> -        }
> -    }
> -

Hmm. Yeah, this was just added recently (and even ACKed by me) in commit
23ae3f, but I now see it was wrong to put it here, because the same
thing is already being done in a subordinate function.

>      ret = dnsmasqSave(dctx);
>      if (ret < 0)
>          goto cleanup;
> @@ -1028,7 +1121,8 @@ cleanup:
>  
>  /* networkRefreshDhcpDaemon:
>   *  Update dnsmasq config files, then send a SIGHUP so that it rereads
> - *  them.
> + *  them.   This only works for the dhcp-hostsfile and the
> + *  addn-hosts file.
>   *
>   *  Returns 0 on success, -1 on failure.
>   */
> @@ -1037,34 +1131,57 @@ networkRefreshDhcpDaemon(struct network_driver *driver,
>                           virNetworkObjPtr network)
>  {
>      int ret = -1, ii;
> -    virNetworkIpDefPtr ipdef;
> +    virNetworkIpDefPtr ipdef, ipv4def, ipv6def;
>      dnsmasqContext *dctx = NULL;
>  
> +    /* if no IP addresses specified, nothing to do */
> +    if (virNetworkDefGetIpByIndex(network->def, AF_UNSPEC, 0))
> +        return 0;
> +
>      /* if there's no running dnsmasq, just start it */
>      if (network->dnsmasqPid <= 0 || (kill(network->dnsmasqPid, 0) < 0))
>          return networkStartDhcpDaemon(driver, network);
>  
> -    /* Look for first IPv4 address that has dhcp defined. */
> -    /* We support dhcp config on 1 IPv4 interface only. */
> +    VIR_INFO("REFRESH: DhcpDaemon: for %s", network->def->bridge);
I don't like the all CAPS or the use of "DhcpDaemon". Instead, you can say

    "Refreshing dnsmasq for network '%s'"

> +    if (!(dctx = dnsmasqContextNew(network->def->name, DNSMASQ_STATE_DIR)))
> +        goto cleanup;
> +
> +    /* Look for first IPv4 address that has dhcp defined.
> +     * We only support dhcp-host config on one IPv4 subnetwork
> +     * and on one IPv6 subnetwork.
> +     */
> +    ipv4def = NULL;
>      for (ii = 0;
>           (ipdef = virNetworkDefGetIpByIndex(network->def, AF_INET, ii));
>           ii++) {
> -        if (ipdef->nranges || ipdef->nhosts)
> -            break;
> +        if (ipdef->nranges || ipdef->nhosts) {
> +            if (!ipv4def)
> +                ipv4def = ipdef;
> +        }

           if (!ipv4def && (ipdef->nranges || ipdef->nhosts))
               ipv4def = ipdef;

>      }
>      /* If no IPv4 addresses had dhcp info, pick the first (if there were any). */
>      if (!ipdef)
>          ipdef = virNetworkDefGetIpByIndex(network->def, AF_INET, 0);
>  
> -    if (!ipdef) {
> -        /* no <ip> elements, so nothing to do */
> -        return 0;
> +    ipv6def = NULL;
> +    for (ii = 0;
> +         (ipdef = virNetworkDefGetIpByIndex(network->def, AF_INET6, ii));
> +         ii++) {
> +        if (ipdef->nranges || ipdef->nhosts) {
> +            if (!ipv6def)
> +                ipv6def = ipdef;
> +        }

           if (!ipv6def && (ipdef->nranges || ipdef->nhosts))
               ipv6def = ipdef;

>      }
>  
> -    if (!(dctx = dnsmasqContextNew(network->def->name, DNSMASQ_STATE_DIR)))
> -        goto cleanup;
> +    if (ipv4def)
> +        if (networkBuildDnsmasqDhcpHostsList(dctx, ipv4def) < 0)
> +           goto cleanup;
       if (ipv4def && (networkBuildDnsmasqDhcpHostsList(dctx, ipv4def) < 0)
           goto cleanup;

>  
> -    if (networkBuildDnsmasqHostsfile(dctx, ipdef, network->def->dns) < 0)
> +    if (ipv6def)
> +        if (networkBuildDnsmasqDhcpHostsList(dctx, ipv6def) < 0)
> +           goto cleanup;

Same as above - combine the nested ifs.

> +
> +    if (networkBuildDnsmasqHostsList(dctx, network->def->dns) < 0)
>         goto cleanup;
>  
>      if ((ret = dnsmasqSave(dctx)) < 0)
> @@ -1097,27 +1214,51 @@ networkRestartDhcpDaemon(struct network_driver *driver,
>      return networkStartDhcpDaemon(driver, network);
>  }
>  
> +static char radvd1[] = "  AdvOtherConfigFlag off;\n\n";
> +static char radvd2[] = "    AdvAutonomous off;\n";
> +static char radvd3[] = "    AdvOnLink on;\n"
> +                       "    AdvAutonomous on;\n"
> +                       "    AdvRouterAddr off;\n";
> +
>  static int
>  networkRadvdConfContents(virNetworkObjPtr network, char **configstr)
>  {
>      virBuffer configbuf = VIR_BUFFER_INITIALIZER;
>      int ret = -1, ii;
>      virNetworkIpDefPtr ipdef;
> -    bool v6present = false;
> +    bool v6present = false, dhcp6 = false;
>  
>      *configstr = NULL;
>  
> +    /* Check if DHCPv6 is needed */
> +    for (ii = 0;
> +         (ipdef = virNetworkDefGetIpByIndex(network->def, AF_INET6, ii));
> +         ii++) {
> +        v6present = true;
> +        if (ipdef->nranges || ipdef->nhosts) {
> +            dhcp6 = true;
> +            break;
> +        }
> +    }
> +
> +    /* If there are no IPv6 addresses, then we are done */
> +    if (!v6present) {
> +        ret = 0;
> +        goto cleanup;
> +    }
> +
>      /* create radvd config file appropriate for this network;
>       * IgnoreIfMissing allows radvd to start even when the bridge is down
>       */
>      virBufferAsprintf(&configbuf, "interface %s\n"
>                        "{\n"
>                        "  AdvSendAdvert on;\n"
> -                      "  AdvManagedFlag off;\n"
> -                      "  AdvOtherConfigFlag off;\n"
>                        "  IgnoreIfMissing on;\n"
> -                      "\n",
> -                      network->def->bridge);
> +                      "  AdvManagedFlag %s;\n"
> +                      "%s",
> +                      network->def->bridge,
> +                      dhcp6 ? "on" : "off",
> +                      dhcp6 ? "\n" : radvd1);
>  
>      /* add a section for each IPv6 address in the config */
>      for (ii = 0;
> @@ -1126,7 +1267,6 @@ networkRadvdConfContents(virNetworkObjPtr network, char **configstr)
>          int prefix;
>          char *netaddr;
>  
> -        v6present = true;
>          prefix = virNetworkIpDefPrefix(ipdef);
>          if (prefix < 0) {
>              virReportError(VIR_ERR_INTERNAL_ERROR,
> @@ -1138,12 +1278,9 @@ networkRadvdConfContents(virNetworkObjPtr network, char **configstr)
>              goto cleanup;
>          virBufferAsprintf(&configbuf,
>                            "  prefix %s/%d\n"
> -                          "  {\n"
> -                          "    AdvOnLink on;\n"
> -                          "    AdvAutonomous on;\n"
> -                          "    AdvRouterAddr off;\n"
> -                          "  };\n",
> -                          netaddr, prefix);
> +                          "  {\n%s  };\n",
> +                          netaddr, prefix,
> +                          dhcp6 ? radvd2 : radvd3);
>          VIR_FREE(netaddr);
>      }
>  
> @@ -1209,7 +1346,8 @@ cleanup:
>  }
>  
>  static int
> -networkStartRadvd(virNetworkObjPtr network)
> +networkStartRadvd(struct network_driver *driver ATTRIBUTE_UNUSED,
> +                        virNetworkObjPtr network)
>  {
>      char *pidfile = NULL;
>      char *radvdpidbase = NULL;
> @@ -1217,6 +1355,12 @@ networkStartRadvd(virNetworkObjPtr network)
>      virCommandPtr cmd = NULL;
>      int ret = -1;
>  
> +    /* Is dnsmasq handling RA? */
> +    if (CHECK_VERSION_RA(driver->dnsmasqCaps)) {
> +        ret = 0;
> +        goto cleanup;
> +    }
> +
>      network->radvdPid = -1;

I think you want to set radvdPid = -1 *before* checking if dnsmasq
supports RA, otherwise you could later end up trying to kill a bogus pid.


>  
>      if (!virNetworkDefGetIpByIndex(network->def, AF_INET6, 0)) {
> @@ -1295,9 +1439,13 @@ static int
>  networkRefreshRadvd(struct network_driver *driver ATTRIBUTE_UNUSED,
>                      virNetworkObjPtr network)
>  {
> +    /* Is dnsmasq handling RA? */
> +    if (CHECK_VERSION_RA(driver->dnsmasqCaps))
> +        return 0;
> +

I don't think this is what you want here. Instead, you should check if
radvd is running and, if so, kill it so that dnsmasq can take over - you
need to think about the case where you're upgrading from an older
libvirt that didn't support using dnsmasq for RA (and also for the case
where you upgrade dnsmasq from pre-2.64 to post-2.64, then restart
libvirtd).


>      /* if there's no running radvd, just start it */
>      if (network->radvdPid <= 0 || (kill(network->radvdPid, 0) < 0))
> -        return networkStartRadvd(network);
> +        return networkStartRadvd(driver, network);
>  
>      if (!virNetworkDefGetIpByIndex(network->def, AF_INET6, 0)) {
>          /* no IPv6 addresses, so we don't need to run radvd */
> @@ -1679,9 +1827,19 @@ networkAddGeneralIp6tablesRules(struct network_driver *driver,
>          goto err5;
>      }
>  
> +    if (iptablesAddUdpInput(driver->iptables, AF_INET6,
> +                            network->def->bridge, 547) < 0) {
> +        virReportError(VIR_ERR_SYSTEM_ERROR,
> +                       _("failed to add ip6tables rule to allow DHCP6 requests from '%s'"),
> +                       network->def->bridge);
> +        goto err6;
> +    }
> +
>      return 0;
>  
>      /* unwind in reverse order from the point of failure */
> +err6:
> +    iptablesRemoveUdpInput(driver->iptables, AF_INET6, network->def->bridge, 53);
>  err5:
>      iptablesRemoveTcpInput(driver->iptables, AF_INET6, network->def->bridge, 53);
>  err4:
> @@ -1702,6 +1860,7 @@ networkRemoveGeneralIp6tablesRules(struct network_driver *driver,
>                  !network->def->ipv6nogw)
>          return;
>      if (virNetworkDefGetIpByIndex(network->def, AF_INET6, 0)) {
> +        iptablesRemoveUdpInput(driver->iptables, AF_INET6, network->def->bridge, 547);
>          iptablesRemoveUdpInput(driver->iptables, AF_INET6, network->def->bridge, 53);
>          iptablesRemoveTcpInput(driver->iptables, AF_INET6, network->def->bridge, 53);
>      }
> @@ -2293,7 +2452,7 @@ networkStartNetworkVirtual(struct network_driver *driver,
>          goto err3;
>  
>      /* start radvd if there are any ipv6 addresses */
> -    if (v6present && networkStartRadvd(network) < 0)
> +    if (v6present && networkStartRadvd(driver, network) < 0)
>          goto err4;
>  
>      /* DAD has happened (dnsmasq waits for it), dnsmasq is now bound to the
> @@ -2754,8 +2913,7 @@ networkValidate(struct network_driver *driver,
>      bool vlanUsed, vlanAllowed, badVlanUse = false;
>      virPortGroupDefPtr defaultPortGroup = NULL;
>      virNetworkIpDefPtr ipdef;
> -    bool ipv4def = false;
> -    int i;
> +    bool ipv4def = false, ipv6def = false;
>  
>      /* check for duplicate networks */
>      if (virNetworkObjIsDuplicate(&driver->networks, def, check_active) < 0)
> @@ -2774,17 +2932,36 @@ networkValidate(struct network_driver *driver,
>          virNetworkSetBridgeMacAddr(def);
>      }
>  
> -    /* We only support dhcp on one IPv4 address per defined network */
> -    for (i = 0; (ipdef = virNetworkDefGetIpByIndex(def, AF_INET, i)); i++) {
> -        if (ipdef->nranges || ipdef->nhosts) {
> -            if (ipv4def) {
> -                virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> -                               _("Multiple dhcp sections found. "
> +    /* We only support dhcp on one IPv4 address and
> +     * on one IPv6 address per defined network
> +     */
> +    for (ii = 0;
> +         (ipdef = virNetworkDefGetIpByIndex(def, AF_UNSPEC, ii));
> +         ii++) {
> +        if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET)) {
> +            if (ipdef->nranges || ipdef->nhosts) {
> +                if (ipv4def) {
> +                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                               _("Multiple IPv4 dhcp sections found -- "
>                                   "dhcp is supported only for a "
>                                   "single IPv4 address on each network"));
> -                return -1;
> -            } else {
> -                ipv4def = true;
> +                    return -1;
> +                } else {
> +                    ipv4def = true;
> +                }
> +            }
> +        }
> +        if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET6)) {
> +            if (ipdef->nranges || ipdef->nhosts) {
> +                if (ipv6def) {
> +                    virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> +                               _("Multiple IPv6 dhcp sections found -- "
> +                                 "dhcp is supported only for a "
> +                                 "single IPv6 address on each network"));
> +                    return -1;
> +                } else {
> +                    ipv6def = true;
> +                }
>              }
>          }
>      }
> diff --git a/src/util/dnsmasq.c b/src/util/dnsmasq.c
> index 4f210d2..8f26d42 100644
> --- a/src/util/dnsmasq.c
> +++ b/src/util/dnsmasq.c
> @@ -306,7 +306,14 @@ hostsfileAdd(dnsmasqHostsfile *hostsfile,
>      if (!(ipstr = virSocketAddrFormat(ip)))
>          return -1;
>  
> -    if (name) {
> +    /* the first test determins if it is a dhcpv6 host */

s/determins/determines/


And is that actually true? I thought you could have ipv4 static hosts
based on name as well.
You should instead check the FAMILY of the address that is passed in.


> +    if (mac==NULL) {
> +        if (virAsprintf(&hostsfile->hosts[hostsfile->nhosts].host, "%s,[%s]",
> +                        name, ipstr) < 0) {
> +            goto alloc_error;
> +        }
> +    }
> +    else if (name) {
>          if (virAsprintf(&hostsfile->hosts[hostsfile->nhosts].host, "%s,%s,%s",

Hmm, but according to this just giving name and IP for IPv4 would blow
up in your face...

Can you ask about this on dnsmasq list (or verify in the code)? If
name+ip-only is allowed for IPv4, we need to change the hostsfileAdd
function, and if not, we need to change the parse to always require a
mac address for ipv4 (currently it requires either name or ip but not both).


>                          mac, ipstr, name) < 0) {
>              goto alloc_error;

I'll trust that the changes to the tests are correct, since they all
still pass :-)


It's taking me *forever to get through this, so I'm splitting the review
here and sending what I've written so far.

I've attached a diff that includes all the changes I requested for
network_conf.c and formatnetwork.html.in. Once I got into
bridge_driver.c, it got too complicated and too likely to break the next
patch, so I stopped. If you can squash the included patch into your
current patch, then take up making the changes with bridge_driver.c,
then everything should be good.

(BTW, I'm including diffs because that's often easier to do than try and
explain exactly what I want, and also because we'll be freezing for
release later this week, and I want to get these all in if at all possible.)

Oh, and also - a bit later today I'll squash my changes into your 1/3
and push, so you'll probably want to make a new branch off master and
cherry-pick your 2/3 and 3/3 over into that to continue. (unfortunately
I first have to make a trip to the doctor for a daughter with a fever,
so it may be awhile :-()

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