[libvirt] [PATCH 0/3] network: Add support for local PTR domains
I run a system dnsmasq to be able to forward specific DNS requests to specific servers. And I have it configured for both forward and reverse lookups. Another dnsmasq is started for a virtual network with domain "virt". The system dnsmasq knows it needs to forward any requests for the "virt" domain and corresponding PTR domain to the dnsmasq started by libvirt. The problem is dnsmasq forwards queries for unknown names to the upstream name server (which is the system instance in my case). One can get nice endless loops of DNS requests pretty easily. Forward loops can be avoided by specifying localOnly='yes', but there was no way to avoid reverse lookup loops. And this is what I'm trying to address in the following patches. Jiri Denemark (3): conf: Make virNetworkIPDefParseXML a little bit saner util: Introduce virSocketAddrPTRDomain network: Add support for local PTR domains docs/formatnetwork.html.in | 37 ++++++-- src/conf/network_conf.c | 108 +++++++++++++++++++----- src/conf/network_conf.h | 4 + src/libvirt_private.syms | 1 + src/network/bridge_driver.c | 47 +++++++++++ src/util/virsocketaddr.c | 85 +++++++++++++++++++ src/util/virsocketaddr.h | 9 ++ tests/networkxml2confdata/ptr-domains-auto.conf | 20 +++++ tests/networkxml2confdata/ptr-domains-auto.xml | 21 +++++ tests/networkxml2confdata/ptr-domains.conf | 24 ++++++ tests/networkxml2confdata/ptr-domains.xml | 24 ++++++ tests/networkxml2conftest.c | 2 + 12 files changed, 353 insertions(+), 29 deletions(-) create mode 100644 tests/networkxml2confdata/ptr-domains-auto.conf create mode 100644 tests/networkxml2confdata/ptr-domains-auto.xml create mode 100644 tests/networkxml2confdata/ptr-domains.conf create mode 100644 tests/networkxml2confdata/ptr-domains.xml -- 2.11.0
Iterating over all child nodes when we only support one instance of each child is pretty weired. And it would even cause memory leaks if more than one <tftp> element was specified. Signed-off-by: Jiri Denemark <jdenemar@redhat.com> --- src/conf/network_conf.c | 36 ++++++++++++++---------------------- 1 file changed, 14 insertions(+), 22 deletions(-) diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c index aabf315c9..b6849ceab 100644 --- a/src/conf/network_conf.c +++ b/src/conf/network_conf.c @@ -1501,7 +1501,8 @@ virNetworkIPDefParseXML(const char *networkName, * On failure clear it out, but don't free it. */ - xmlNodePtr cur, save; + xmlNodePtr save; + xmlNodePtr dhcp; char *address = NULL, *netmask = NULL; unsigned long prefix = 0; int prefixRc; @@ -1603,29 +1604,20 @@ virNetworkIPDefParseXML(const char *networkName, goto cleanup; } - cur = node->children; - while (cur != NULL) { - if (cur->type == XML_ELEMENT_NODE && - xmlStrEqual(cur->name, BAD_CAST "dhcp")) { - if (virNetworkDHCPDefParseXML(networkName, cur, def) < 0) - goto cleanup; - } else if (cur->type == XML_ELEMENT_NODE && - xmlStrEqual(cur->name, BAD_CAST "tftp")) { - char *root; + if ((dhcp = virXPathNode("./dhcp[1]", ctxt)) && + virNetworkDHCPDefParseXML(networkName, dhcp, def) < 0) + goto cleanup; - if (!VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET)) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, - _("Unsupported <tftp> element in an IPv6 element in network '%s'"), - networkName); - goto cleanup; - } - if (!(root = virXMLPropString(cur, "root"))) { - cur = cur->next; - continue; - } - def->tftproot = (char *)root; + if (virXPathNode("./tftp[1]", ctxt)) { + if (!VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET)) { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Unsupported <tftp> element in an IPv6 element " + "in network '%s'"), + networkName); + goto cleanup; } - cur = cur->next; + + def->tftproot = virXPathString("string(./tftp[1]/@root)", ctxt); } result = 0; -- 2.11.0
The API creates PTR domain which corresponds to a given addr/prefix. Both IPv4 and IPv6 addresses are supported, but the prefix must be divisible by 8 for IPv4 and divisible by 4 for IPv6. The generated PTR domain has the following format IPv4: 1.2.3.4.in-addr.arpa IPv6: 0.1.2.3.4.5.6.7.8.9.a.b.c.d.e.f.0.1.2.3.4.5.6.7.8.9.a.b.c.d.e.f.ip6.arpa Signed-off-by: Jiri Denemark <jdenemar@redhat.com> --- src/libvirt_private.syms | 1 + src/util/virsocketaddr.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++ src/util/virsocketaddr.h | 9 +++++ 3 files changed, 95 insertions(+) diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index ffbf46c1a..27c1edaef 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -2391,6 +2391,7 @@ virSocketAddrParse; virSocketAddrParseIPv4; virSocketAddrParseIPv6; virSocketAddrPrefixToNetmask; +virSocketAddrPTRDomain; virSocketAddrSetIPv4Addr; virSocketAddrSetIPv4AddrNetOrder; virSocketAddrSetIPv6Addr; diff --git a/src/util/virsocketaddr.c b/src/util/virsocketaddr.c index 33b1e9e1f..41f75d5c2 100644 --- a/src/util/virsocketaddr.c +++ b/src/util/virsocketaddr.c @@ -27,6 +27,7 @@ #include "virerror.h" #include "virstring.h" #include "viralloc.h" +#include "virbuffer.h" #include <netdb.h> @@ -40,6 +41,8 @@ typedef unsigned char virSocketAddrIPv4[4]; typedef virSocketAddrIPv4 *virSocketAddrIPv4Ptr; typedef unsigned short virSocketAddrIPv6[8]; typedef virSocketAddrIPv6 *virSocketAddrIPv6Ptr; +typedef unsigned char virSocketAddrIPv6Nibbles[32]; +typedef virSocketAddrIPv6Nibbles *virSocketAddrIPv6NibblesPtr; static int virSocketAddrGetIPv4Addr(const virSocketAddr *addr, @@ -78,6 +81,23 @@ virSocketAddrGetIPv6Addr(const virSocketAddr *addr, virSocketAddrIPv6Ptr tab) } static int +virSocketAddrGetIPv6Nibbles(const virSocketAddr *addr, + virSocketAddrIPv6NibblesPtr tab) +{ + size_t i; + + if (!addr || !tab || addr->data.stor.ss_family != AF_INET6) + return -1; + + for (i = 0; i < 16; i++) { + (*tab)[2 * i] = addr->data.inet6.sin6_addr.s6_addr[i] >> 4; + (*tab)[2 * i + 1] = addr->data.inet6.sin6_addr.s6_addr[i] & 0xF; + } + + return 0; +} + +static int virSocketAddrParseInternal(struct addrinfo **res, const char *val, int family, @@ -1118,3 +1138,68 @@ virSocketAddrIsNumericLocalhost(const char *addr) return false; } + + +/** + * virSocketAddrPTRDomain: + * + * Create PTR domain which corresponds to @addr/@prefix. Both IPv4 and IPv6 + * addresses are supported, but @prefix must be divisible by 8 for IPv4 and + * divisible by 4 for IPv6, otherwise -2 will be returned. + * + * Returns -2 if the PTR record cannot be automatically created, + * -1 on error, + * 0 on success. + */ +int +virSocketAddrPTRDomain(const virSocketAddr *addr, + unsigned int prefix, + char **ptr) +{ + virBuffer buf = VIR_BUFFER_INITIALIZER; + size_t i; + int ret = -1; + + if (VIR_SOCKET_ADDR_IS_FAMILY(addr, AF_INET)) { + virSocketAddrIPv4 ip; + + if (prefix == 0 || prefix >= 32 || prefix % 8 != 0) + goto unsupported; + + if (virSocketAddrGetIPv4Addr(addr, &ip) < 0) + goto cleanup; + + for (i = prefix / 8; i > 0; i--) + virBufferAsprintf(&buf, "%u.", ip[i - 1]); + + virBufferAddLit(&buf, VIR_SOCKET_ADDR_IPV4_ARPA); + } else if (VIR_SOCKET_ADDR_IS_FAMILY(addr, AF_INET6)) { + virSocketAddrIPv6Nibbles ip; + + if (prefix == 0 || prefix >= 128 || prefix % 4 != 0) + goto unsupported; + + if (virSocketAddrGetIPv6Nibbles(addr, &ip) < 0) + goto cleanup; + + for (i = prefix / 4; i > 0; i--) + virBufferAsprintf(&buf, "%x.", ip[i - 1]); + + virBufferAddLit(&buf, VIR_SOCKET_ADDR_IPV6_ARPA); + } else { + goto unsupported; + } + + if (!(*ptr = virBufferContentAndReset(&buf))) + goto cleanup; + + ret = 0; + + cleanup: + virBufferFreeAndReset(&buf); + return ret; + + unsupported: + ret = -2; + goto cleanup; +} diff --git a/src/util/virsocketaddr.h b/src/util/virsocketaddr.h index 7ee993b1a..43a370620 100644 --- a/src/util/virsocketaddr.h +++ b/src/util/virsocketaddr.h @@ -57,6 +57,9 @@ typedef struct { # define VIR_SOCKET_ADDR_IPV4_ALL "0.0.0.0" # define VIR_SOCKET_ADDR_IPV6_ALL "::" +# define VIR_SOCKET_ADDR_IPV4_ARPA "in-addr.arpa" +# define VIR_SOCKET_ADDR_IPV6_ARPA "ip6.arpa" + typedef virSocketAddr *virSocketAddrPtr; typedef struct _virSocketAddrRange virSocketAddrRange; @@ -136,4 +139,10 @@ bool virSocketAddrIsWildcard(const virSocketAddr *addr); int virSocketAddrNumericFamily(const char *address); bool virSocketAddrIsNumericLocalhost(const char *addr); + +int virSocketAddrPTRDomain(const virSocketAddr *addr, + unsigned int prefix, + char **ptr) + ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(3); + #endif /* __VIR_SOCKETADDR_H__ */ -- 2.11.0
Similarly to localOnly DNS domain, local PTR domains can be used to tell the DNS server not to forward reverse lookups for unknown IPs which belong to the virtual network. Signed-off-by: Jiri Denemark <jdenemar@redhat.com> --- docs/formatnetwork.html.in | 37 ++++++++++--- src/conf/network_conf.c | 72 ++++++++++++++++++++++++- src/conf/network_conf.h | 4 ++ src/network/bridge_driver.c | 47 ++++++++++++++++ tests/networkxml2confdata/ptr-domains-auto.conf | 20 +++++++ tests/networkxml2confdata/ptr-domains-auto.xml | 21 ++++++++ tests/networkxml2confdata/ptr-domains.conf | 24 +++++++++ tests/networkxml2confdata/ptr-domains.xml | 24 +++++++++ tests/networkxml2conftest.c | 2 + 9 files changed, 244 insertions(+), 7 deletions(-) create mode 100644 tests/networkxml2confdata/ptr-domains-auto.conf create mode 100644 tests/networkxml2confdata/ptr-domains-auto.xml create mode 100644 tests/networkxml2confdata/ptr-domains.conf create mode 100644 tests/networkxml2confdata/ptr-domains.xml diff --git a/docs/formatnetwork.html.in b/docs/formatnetwork.html.in index 9cf940052..3c9414779 100644 --- a/docs/formatnetwork.html.in +++ b/docs/formatnetwork.html.in @@ -855,7 +855,7 @@ <hostname>myhostalias</hostname> </host> </dns> -<ip address="192.168.122.1" netmask="255.255.255.0"> +<ip address="192.168.122.1" netmask="255.255.255.0" localPtr="yes"> <dhcp> <range start="192.168.122.100" end="192.168.122.254"/> <host mac="00:16:3e:77:e2:ed" name="foo.example.com" ip="192.168.122.10"/> @@ -863,6 +863,10 @@ </dhcp> </ip> <ip family="ipv6" address="2001:db8:ca2:2::1" prefix="64"/> +<ip family="ipv6" address="fec0::1" prefix="31" localPtr="yes"> + <ptr domain="0.0.0.0.0.c.e.f.ip6.arpa"/> + <ptr domain="1.0.0.0.0.c.e.f.ip6.arpa"/> +</ip> <route family="ipv6" address="2001:db9:ca1:1::" prefix="64" gateway="2001:db8:ca2:2::2"/> </pre> @@ -983,11 +987,20 @@ to specify the type of address — <code>ipv4</code> or <code>ipv6</code>; if no <code>family</code> is given, <code>ipv4</code> is assumed. More than one address of each family can - be defined for a network. The <code>ip</code> element is supported - <span class="since">since 0.3.0</span>. IPv6, multiple addresses on a - single network, <code>family</code>, and <code>prefix</code> are - supported <span class="since">since 0.8.7</span>. The <code>ip</code> - element may contain the following elements: + be defined for a network. The optional <code>localPtr</code> attribute + (<span class="since">since 3.0.0</span>) configures the DNS server not + to forward any reverse DNS requests for IP addresses from the network + configured by the <code>address</code> and + <code>netmask</code>/<code>prefix</code> attributes. For some unusual + network prefixes (not divisible by 8 for IPv4 or not divisible by 4 for + IPv6) libvirt may be unable to compute the PTR domain automatically, + in which case the domain has to be specified explicitly by the + <code>ptr</code> element described below. The <code>ip</code> element + is supported <span class="since">since 0.3.0</span>. IPv6, multiple + addresses on a single network, <code>family</code>, and + <code>prefix</code> are supported <span class="since">since + 0.8.7</span>. The <code>ip</code> element may contain the following + elements: <dl> <dt><code>tftp</code></dt> @@ -1051,6 +1064,18 @@ </dd> </dl> </dd> + + <dt><code>ptr</code></dt> + <dd>The <code>domain</code> attribute of the optional + <code>ptr</code> element specifies the PTR domain used for reverse + DNS lookups. The domain has to end with ".in-addr.arpa" for IPv4 + and ".ip6.arpa" for IPv6. Each <code>ip</code> element may contain + zero or more <code>ptr</code> elements. When + <code>localPtr='yes'</code> attribute is set in the parent + <code>ip</code> element the DNS server for this network will be + configured not to forward any reverse lookups within the specified + domains. <span class="since">Since 3.0.0</span> + </dd> </dl> </dd> </dl> diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c index b6849ceab..ce0bd0260 100644 --- a/src/conf/network_conf.c +++ b/src/conf/network_conf.c @@ -315,6 +315,10 @@ static void virNetworkIPDefClear(virNetworkIPDefPtr def) { VIR_FREE(def->family); + + virStringListFreeCount(def->ptrs, def->nptrs); + def->ptrs = NULL; + VIR_FREE(def->ranges); while (def->nhosts) @@ -1507,6 +1511,10 @@ virNetworkIPDefParseXML(const char *networkName, unsigned long prefix = 0; int prefixRc; int result = -1; + char *localPtr = NULL; + xmlNodePtr *nodes = NULL; + size_t i; + int n; save = ctxt->node; ctxt->node = node; @@ -1549,6 +1557,17 @@ virNetworkIPDefParseXML(const char *networkName, else def->prefix = prefix; + localPtr = virXPathString("string(./@localPtr)", ctxt); + if (localPtr) { + def->localPTR = virTristateBoolTypeFromString(localPtr); + if (def->localPTR <= 0) { + virReportError(VIR_ERR_XML_ERROR, + _("Invalid localPtr value '%s' in network '%s'"), + localPtr, networkName); + goto cleanup; + } + } + /* validate address, etc. for each family */ if ((def->family == NULL) || (STREQ(def->family, "ipv4"))) { if (!(VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET) || @@ -1604,6 +1623,46 @@ virNetworkIPDefParseXML(const char *networkName, goto cleanup; } + if ((n = virXPathNodeSet("./ptr", ctxt, &nodes)) < 0) + goto cleanup; + + if (n > 0) { + if (VIR_ALLOC_N(def->ptrs, n) < 0) + goto cleanup; + def->nptrs = n; + } + for (i = 0; i < n; i++) { + char *domain; + const char *suffix; + size_t len; + size_t suflen; + + if (!(domain = virXMLPropString(nodes[i], "domain"))) { + virReportError(VIR_ERR_XML_ERROR, + _("Missing PTR domain in network '%s'"), + networkName); + goto cleanup; + } + + if (VIR_SOCKET_ADDR_IS_FAMILY(&def->address, AF_INET)) + suffix = VIR_SOCKET_ADDR_IPV4_ARPA; + else + suffix = VIR_SOCKET_ADDR_IPV6_ARPA; + + len = strlen(domain); + suflen = strlen(suffix); + if (len <= suflen || + STRNEQ(domain + len - suflen, suffix) || + domain[len - suflen - 1] != '.') { + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("Invalid PTR domain '%s' in network '%s'"), + domain, networkName); + VIR_FREE(domain); + goto cleanup; + } + def->ptrs[i] = domain; + } + if ((dhcp = virXPathNode("./dhcp[1]", ctxt)) && virNetworkDHCPDefParseXML(networkName, dhcp, def) < 0) goto cleanup; @@ -1627,6 +1686,8 @@ virNetworkIPDefParseXML(const char *networkName, virNetworkIPDefClear(def); VIR_FREE(address); VIR_FREE(netmask); + VIR_FREE(localPtr); + VIR_FREE(nodes); ctxt->node = save; return result; @@ -2630,6 +2691,7 @@ static int virNetworkIPDefFormat(virBufferPtr buf, const virNetworkIPDef *def) { + size_t i; int result = -1; virBufferAddLit(buf, "<ip"); @@ -2652,15 +2714,23 @@ virNetworkIPDefFormat(virBufferPtr buf, } if (def->prefix > 0) virBufferAsprintf(buf, " prefix='%u'", def->prefix); + + if (def->localPTR) { + virBufferAsprintf(buf, " localPtr='%s'", + virTristateBoolTypeToString(def->localPTR)); + } + virBufferAddLit(buf, ">\n"); virBufferAdjustIndent(buf, 2); + for (i = 0; i < def->nptrs; i++) + virBufferAsprintf(buf, "<ptr domain='%s'/>\n", def->ptrs[i]); + if (def->tftproot) { virBufferEscapeString(buf, "<tftp root='%s'/>\n", def->tftproot); } if ((def->nranges || def->nhosts)) { - size_t i; virBufferAddLit(buf, "<dhcp>\n"); virBufferAdjustIndent(buf, 2); diff --git a/src/conf/network_conf.h b/src/conf/network_conf.h index 09e091616..edf1a1abd 100644 --- a/src/conf/network_conf.h +++ b/src/conf/network_conf.h @@ -162,6 +162,10 @@ struct _virNetworkIPDef { unsigned int prefix; /* ipv6 - only prefix allowed */ virSocketAddr netmask; /* ipv4 - either netmask or prefix specified */ + int localPTR; /* virTristateBool */ + size_t nptrs; + char **ptrs; + size_t nranges; /* Zero or more dhcp ranges */ virSocketAddrRangePtr ranges; diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c index ae1589d8c..49753737f 100644 --- a/src/network/bridge_driver.c +++ b/src/network/bridge_driver.c @@ -994,6 +994,49 @@ networkBuildDnsmasqHostsList(dnsmasqContext *dctx, } +static int +networkDnsmasqConfLocalPTRs(virBufferPtr buf, + virNetworkDefPtr def) +{ + virNetworkIPDefPtr ip; + size_t i, j; + char *ptr = NULL; + int rc; + + for (i = 0; i < def->nips; i++) { + ip = def->ips + i; + + if (ip->localPTR != VIR_TRISTATE_BOOL_YES) + continue; + + for (j = 0; j < ip->nptrs; j++) + virBufferAsprintf(buf, "local=/%s/\n", ip->ptrs[j]); + + if (ip->nptrs > 0) + continue; + + if ((rc = virSocketAddrPTRDomain(&ip->address, + virNetworkIPDefPrefix(ip), + &ptr)) < 0) { + if (rc == -2) { + int family = VIR_SOCKET_ADDR_FAMILY(&ip->address); + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, + _("PTR domain for %s network with prefix %u " + "cannot be automatically created"), + (family == AF_INET) ? "IPv4" : "IPv6", + virNetworkIPDefPrefix(ip)); + } + return -1; + } + + virBufferAsprintf(buf, "local=/%s/\n", ptr); + VIR_FREE(ptr); + } + + return 0; +} + + int networkDnsmasqConfContents(virNetworkObjPtr network, const char *pidfile, @@ -1079,6 +1122,10 @@ networkDnsmasqConfContents(virNetworkObjPtr network, network->def->domain); } + if (wantDNS && + networkDnsmasqConfLocalPTRs(&configbuf, network->def) < 0) + goto cleanup; + if (wantDNS && network->def->dns.forwardPlainNames == VIR_TRISTATE_BOOL_NO) { virBufferAddLit(&configbuf, "domain-needed\n"); /* need to specify local=// whether or not a domain is diff --git a/tests/networkxml2confdata/ptr-domains-auto.conf b/tests/networkxml2confdata/ptr-domains-auto.conf new file mode 100644 index 000000000..7f1a393dd --- /dev/null +++ b/tests/networkxml2confdata/ptr-domains-auto.conf @@ -0,0 +1,20 @@ +##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 +local=/122.168.192.in-addr.arpa/ +local=/1.0.e.f.0.1.c.a.8.b.d.0.1.0.0.2.ip6.arpa/ +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-range=2001:db8:ac10:fe01::1,ra-only +dhcp-range=2001:db8:ac10:fd01::1,ra-only diff --git a/tests/networkxml2confdata/ptr-domains-auto.xml b/tests/networkxml2confdata/ptr-domains-auto.xml new file mode 100644 index 000000000..7fe12dc67 --- /dev/null +++ b/tests/networkxml2confdata/ptr-domains-auto.xml @@ -0,0 +1,21 @@ +<network> + <name>default</name> + <uuid>81ff0d90-c91e-6742-64da-4a736edb9a9b</uuid> + <forward dev='eth1' mode='nat'/> + <bridge name='virbr0' stp='on' delay='0'/> + <ip address='192.168.122.1' netmask='255.255.255.0' localPtr='yes'> + <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' localPtr='no'> + </ip> + <ip family='ipv6' address='2001:db8:ac10:fe01::1' prefix='64' localPtr='yes'> + </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/networkxml2confdata/ptr-domains.conf b/tests/networkxml2confdata/ptr-domains.conf new file mode 100644 index 000000000..2900eebce --- /dev/null +++ b/tests/networkxml2confdata/ptr-domains.conf @@ -0,0 +1,24 @@ +##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 test +## or other application using the libvirt API. +## +## dnsmasq conf file created by libvirt +strict-order +local=/30.20.10.in-addr.arpa/ +local=/31.20.10.in-addr.arpa/ +local=/2.0.0.0.0.c.e.f.ip6.arpa/ +local=/0.0.0.0.0.c.e.f.ip6.arpa/ +local=/1.0.0.0.0.c.e.f.ip6.arpa/ +local=/1.0.f.e.d.c.b.a.4.0.0.0.0.c.e.f.ip6.arpa/ +except-interface=lo +bind-dynamic +interface=virbr2 +dhcp-range=10.20.30.1,static +dhcp-no-override +dhcp-authoritative +dhcp-hostsfile=/var/lib/libvirt/dnsmasq/test.hostsfile +addn-hosts=/var/lib/libvirt/dnsmasq/test.addnhosts +dhcp-range=fec0:2::1,ra-only +dhcp-range=fec0::1,ra-only +dhcp-range=fec0:4:abcd:ef01::1,ra-only diff --git a/tests/networkxml2confdata/ptr-domains.xml b/tests/networkxml2confdata/ptr-domains.xml new file mode 100644 index 000000000..64a329676 --- /dev/null +++ b/tests/networkxml2confdata/ptr-domains.xml @@ -0,0 +1,24 @@ +<network> + <name>test</name> + <uuid>cafecafe-cafe-cafe-cafe-cafecafecafe</uuid> + <forward mode='nat'/> + <bridge name='virbr2' stp='on' delay='0'/> + <mac address='52:54:00:eb:c2:e8'/> + <ip address='10.20.30.1' prefix='23' localPtr='yes'> + <ptr domain='30.20.10.in-addr.arpa'/> + <ptr domain='31.20.10.in-addr.arpa'/> + <dhcp> + <host mac='ca:fe:ca:fe:ca:fe' name='ble' ip='10.20.30.2'/> + <host mac='ca:fe:ca:fe:ca:fe' name='bla' ip='10.20.30.3'/> + <host mac='52:54:00:16:c6:1a' name='pxe' ip='10.20.30.4'/> + </dhcp> + </ip> + <ip family='ipv6' address='fec0:2::1' prefix='32' localPtr='yes'> + </ip> + <ip family='ipv6' address='fec0::1' prefix='31' localPtr='yes'> + <ptr domain='0.0.0.0.0.c.e.f.ip6.arpa'/> + <ptr domain='1.0.0.0.0.c.e.f.ip6.arpa'/> + </ip> + <ip family='ipv6' address='fec0:4:abcd:ef01::1' prefix='64' localPtr='yes'> + </ip> +</network> diff --git a/tests/networkxml2conftest.c b/tests/networkxml2conftest.c index 65a0e3218..b6c967c45 100644 --- a/tests/networkxml2conftest.c +++ b/tests/networkxml2conftest.c @@ -129,6 +129,8 @@ mymain(void) DO_TEST("dhcp6-network", dhcpv6); DO_TEST("dhcp6-nat-network", dhcpv6); DO_TEST("dhcp6host-routed-network", dhcpv6); + DO_TEST("ptr-domains", dhcpv6); + DO_TEST("ptr-domains-auto", dhcpv6); virObjectUnref(dhcpv6); virObjectUnref(full); -- 2.11.0
On Tue, Dec 13, 2016 at 13:28:04 +0100, Jiri Denemark wrote:
I run a system dnsmasq to be able to forward specific DNS requests to specific servers. And I have it configured for both forward and reverse lookups. Another dnsmasq is started for a virtual network with domain "virt". The system dnsmasq knows it needs to forward any requests for the "virt" domain and corresponding PTR domain to the dnsmasq started by libvirt. The problem is dnsmasq forwards queries for unknown names to the upstream name server (which is the system instance in my case). One can get nice endless loops of DNS requests pretty easily. Forward loops can be avoided by specifying localOnly='yes', but there was no way to avoid reverse lookup loops. And this is what I'm trying to address in the following patches.
Jiri Denemark (3): conf: Make virNetworkIPDefParseXML a little bit saner util: Introduce virSocketAddrPTRDomain network: Add support for local PTR domains
Oops, RNG schema update is missing, v2 comming soon :-) Jirka
participants (1)
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Jiri Denemark