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[libvirt] [PATCH] Added new attribute security_model to filesystem element
by Harsh Prateek Bora 08 Oct '10

08 Oct '10

This patch introduces new attribute to filesystem element to support customizable security_model for mount type. Valid security_model are: passthrough, mapped and none. Usage: <filesystem type='mount' security_model='passthrough'> <source dir='/export/to/guest'/> <target dir='mount_tag'/> </filesystem> Note: This patch is based on Daniel's patch to support 9pfs. It shall be applied after applying Daniel's patch to support 9pfs. Signed-off-by: Harsh Prateek Bora <harsh(a)linux.vnet.ibm.com> --- docs/schemas/domain.rng | 7 +++++++ src/conf/domain_conf.c | 30 ++++++++++++++++++++++++++++-- src/conf/domain_conf.h | 10 ++++++++++ src/qemu/qemu_conf.c | 11 +++++++++-- 4 files changed, 54 insertions(+), 4 deletions(-) diff --git a/docs/schemas/domain.rng b/docs/schemas/domain.rng index ccb8cf3..43a292d 100644 --- a/docs/schemas/domain.rng +++ b/docs/schemas/domain.rng @@ -761,6 +761,13 @@ </choice> <optional> <ref name="address"/> + <attribute name="security_model"> + <choice> + <value>passthrough</value> + <value>mapped</value> + <value>none</value> + </choice> + </attribute> </optional> </element> </define> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index e05d5d7..a9881d1 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -161,6 +161,12 @@ VIR_ENUM_IMPL(virDomainFS, VIR_DOMAIN_FS_TYPE_LAST, "file", "template") +VIR_ENUM_IMPL(virDomainFSSecurityModel, VIR_DOMAIN_FS_SECURITY_LAST, + "passthrough", + "mapped", + "none") + + VIR_ENUM_IMPL(virDomainNet, VIR_DOMAIN_NET_TYPE_LAST, "user", "ethernet", @@ -1847,6 +1853,7 @@ virDomainFSDefParseXML(xmlNodePtr node, char *type = NULL; char *source = NULL; char *target = NULL; + char *security_model; if (VIR_ALLOC(def) < 0) { virReportOOMError(); @@ -1864,6 +1871,17 @@ virDomainFSDefParseXML(xmlNodePtr node, def->type = VIR_DOMAIN_FS_TYPE_MOUNT; } + security_model = virXMLPropString(node, "security_model"); + if (security_model) { + if ((def->security_model = virDomainFSSecurityModelTypeFromString(security_model)) < 0) { + virDomainReportError(VIR_ERR_INTERNAL_ERROR, + _("unknown security model '%s'"), security_model); + goto error; + } + } else { + def->security_model = VIR_DOMAIN_FS_SECURITY_PASSTHROUGH; + } + cur = node->children; while (cur != NULL) { if (cur->type == XML_ELEMENT_NODE) { @@ -5602,6 +5620,7 @@ virDomainFSDefFormat(virBufferPtr buf, int flags) { const char *type = virDomainFSTypeToString(def->type); + const char *sec_model = virDomainFSSecurityModelTypeToString(def->security_model); if (!type) { virDomainReportError(VIR_ERR_INTERNAL_ERROR, @@ -5609,9 +5628,16 @@ virDomainFSDefFormat(virBufferPtr buf, return -1; } + if (!sec_model) { + virDomainReportError(VIR_ERR_INTERNAL_ERROR, + _("unexpected security model %d"), def->security_model); + return -1; + } + + virBufferVSprintf(buf, - " <filesystem type='%s'>\n", - type); + " <filesystem type='%s' security_model='%s'>\n", + type, sec_model); if (def->src) { switch (def->type) { diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 7195c04..6adf027 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -236,10 +236,20 @@ enum virDomainFSType { VIR_DOMAIN_FS_TYPE_LAST }; +/* Filesystem mount security model */ +enum virDomainFSSecurityModel { + VIR_DOMAIN_FS_SECURITY_PASSTHROUGH, + VIR_DOMAIN_FS_SECURITY_MAPPED, + VIR_DOMAIN_FS_SECURITY_NONE, + + VIR_DOMAIN_FS_SECURITY_LAST +}; + typedef struct _virDomainFSDef virDomainFSDef; typedef virDomainFSDef *virDomainFSDefPtr; struct _virDomainFSDef { int type; + int security_model; char *src; char *dst; unsigned int readonly : 1; diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index 18a302a..6b96d2f 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -2014,6 +2014,7 @@ qemuAssignDeviceAliases(virDomainDefPtr def, unsigned long long qemuCmdFlags) if (virAsprintf(&def->fss[i]->info.alias, "fs%d", i) < 0) goto no_memory; } + for (i = 0; i < def->nsounds ; i++) { if (virAsprintf(&def->sounds[i]->info.alias, "sound%d", i) < 0) goto no_memory; @@ -2783,11 +2784,17 @@ char *qemuBuildFSStr(virDomainFSDefPtr fs, if (fs->type != VIR_DOMAIN_FS_TYPE_MOUNT) { qemuReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s", - _("can only passthrough directories")); + _("only supports mount filesystem type")); goto error; } - virBufferAddLit(&opt, "local,security_model=passthrough"); + virBufferAddLit(&opt, "local"); + if (fs->security_model == VIR_DOMAIN_FS_SECURITY_PASSTHROUGH) + virBufferAddLit(&opt, ",security_model=passthrough"); + else if (fs->security_model == VIR_DOMAIN_FS_SECURITY_MAPPED) + virBufferAddLit(&opt, ",security_model=mapped"); + else if (fs->security_model == VIR_DOMAIN_FS_SECURITY_NONE) + virBufferAddLit(&opt, ",security_model=none"); virBufferVSprintf(&opt, ",id=%s%s", QEMU_FSDEV_HOST_PREFIX, fs->info.alias); virBufferVSprintf(&opt, ",path=%s", fs->src); -- 1.7.1.1

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[libvirt] [PATCH v3] nwfilter: resolve deadlock between VM operations and filter update
by Stefan Berger 08 Oct '10

08 Oct '10

V3: - removed debugging code - I looked through existing code and I could not find any other instances where the filter and domain_lock were locked without a preceding qemu/uml_driver lock. So the 2nd assumption seems to hold and no further changes should be required for this issue. V2: - remove the locks from qemudVMFilterRebuild & umlVMFilterRebuild This is from a bug report and conversation on IRC where Soren reported that while a filter update is occurring on one or more VMs (due to a rule having been edited for example), a deadlock can occur when a VM referencing a filter is started. The problem is caused by the two locking sequences of qemu driver, qemu domain, filter # for the VM start operation filter, qemu_driver, qemu_domain # for the filter update operation that obviously don't lock in the same order. The problem is the 2nd lock sequence. Here the qemu_driver lock is being grabbed in qemu_driver:qemudVMFilterRebuild() The following solution is based on the idea of trying to re-arrange the 2nd sequence of locks as follows: qemu_driver, filter, qemu_driver, qemu_domain and making the qemu driver recursively lockable so that a second lock can occur, this would then lead to the following net-locking sequence qemu_driver, filter, qemu_domain where the 2nd qemu_driver lock has been ( logically ) eliminated. The 2nd part of the idea is that the sequence of locks (filter, qemu_domain) and (qemu_domain, filter) becomes interchangeable if all code paths where filter AND qemu_domain are locked have a preceding qemu_domain lock that basically blocks their concurrent execution So, the following code paths exist towards qemu_driver:qemudVMFilterRebuild where we now want to put a qemu_driver lock in front of the filter lock. -> nwfilterUndefine() [ locks the filter ] -> virNWFilterTestUnassignDef() -> virNWFilterTriggerVMFilterRebuild() -> qemudVMFilterRebuild() -> nwfilterDefine() -> virNWFilterPoolAssignDef() [ locks the filter ] -> virNWFilterTriggerVMFilterRebuild() -> qemudVMFilterRebuild() -> nwfilterDriverReload() -> virNWFilterPoolLoadAllConfigs() ->virNWFilterPoolObjLoad() -> virNWFilterPoolAssignDef() [ locks the filter ] -> virNWFilterTriggerVMFilterRebuild() -> qemudVMFilterRebuild() -> nwfilterDriverStartup() -> virNWFilterPoolLoadAllConfigs() ->virNWFilterPoolObjLoad() -> virNWFilterPoolAssignDef() [ locks the filter ] -> virNWFilterTriggerVMFilterRebuild() -> qemudVMFilterRebuild() Qemu is not the only driver using the nwfilter driver, but also the UML driver calls into it. Therefore qemuVMFilterRebuild() can be exchanged with umlVMFilterRebuild() along with the driver lock of qemu_driver that can now be a uml_driver. Further, since UML and Qemu domains can be running on the same machine, the triggering of a rebuild of the filter can touch both types of drivers and their domains. In the patch below I am now extending each nwfilter callback driver with functions for locking and unlocking the (VM) driver (UML, QEMU) and introduce new functions for locking all registered callback drivers and unlocking them. Then I am distributing the lock-all-cbdrivers/unlock-all-cbdrivers call into the above call paths. The last shown callpath starting with nwfilterDriverStart() is problematic since it is initialize before the Qemu and UML drives are and thus a lock in the path would result in a NULL pointer attempted to be locked -- the call to virNWFilterTriggerVMFilterRebuild() is never called, so we never lock either the qemu_driver or the uml_driver in that path. Therefore, only the first 3 paths now receive calls to lock and unlock all callback drivers. Now that the locks are distributed where it matters I can remove the qemu_driver and uml_driver lock from qemudVMFilterRebuild() and umlVMFilterRebuild() and not requiring the recursive locks. For now I want to put this out as an RFC patch. I have tested it by 'stretching' the critical section after the define/undefine functions each lock the filter so I can (easily) concurrently execute another VM operation (suspend,start). That code is in this patch and if you want you can de-activate it. It seems to work ok and operations are being blocked while the update is being done. I still also want to verify the other assumption above that locking filter and qemu_domain always has a preceding qemu_driver lock. Signed-off-by: Stefan Berger <stefanb(a)us.ibm.com> --- src/conf/nwfilter_conf.c | 18 ++++++++++++++++++ src/conf/nwfilter_conf.h | 6 ++++++ src/libvirt_private.syms | 2 ++ src/nwfilter/nwfilter_driver.c | 13 +++++++++++++ src/qemu/qemu_driver.c | 19 +++++++++++++++---- src/uml/uml_driver.c | 18 ++++++++++++++---- 6 files changed, 68 insertions(+), 8 deletions(-) Index: libvirt-acl/src/conf/nwfilter_conf.h =================================================================== --- libvirt-acl.orig/src/conf/nwfilter_conf.h +++ libvirt-acl/src/conf/nwfilter_conf.h @@ -658,6 +658,8 @@ void virNWFilterConfLayerShutdown(void); typedef int (*virNWFilterRebuild)(virConnectPtr conn, virHashIterator, void *data); +typedef void (*virNWFilterVoidCall)(void); + typedef struct _virNWFilterCallbackDriver virNWFilterCallbackDriver; typedef virNWFilterCallbackDriver *virNWFilterCallbackDriverPtr; @@ -665,9 +667,13 @@ struct _virNWFilterCallbackDriver { const char *name; virNWFilterRebuild vmFilterRebuild; + virNWFilterVoidCall vmDriverLock; + virNWFilterVoidCall vmDriverUnlock; }; void virNWFilterRegisterCallbackDriver(virNWFilterCallbackDriverPtr); +void virNWFilterCallbackDriversLock(void); +void virNWFilterCallbackDriversUnlock(void); VIR_ENUM_DECL(virNWFilterRuleAction); Index: libvirt-acl/src/qemu/qemu_driver.c =================================================================== --- libvirt-acl.orig/src/qemu/qemu_driver.c +++ libvirt-acl/src/qemu/qemu_driver.c @@ -12725,11 +12725,7 @@ static int qemudVMFilterRebuild(virConnectPtr conn ATTRIBUTE_UNUSED, virHashIterator iter, void *data) { - struct qemud_driver *driver = qemu_driver; - - qemuDriverLock(driver); virHashForEach(qemu_driver->domains.objs, iter, data); - qemuDriverUnlock(driver); return 0; } @@ -12757,9 +12753,24 @@ qemudVMFiltersInstantiate(virConnectPtr return err; } + +static void +qemudVMDriverLock(void) { + qemuDriverLock(qemu_driver); +}; + + +static void +qemudVMDriverUnlock(void) { + qemuDriverUnlock(qemu_driver); +}; + + static virNWFilterCallbackDriver qemuCallbackDriver = { .name = "QEMU", .vmFilterRebuild = qemudVMFilterRebuild, + .vmDriverLock = qemudVMDriverLock, + .vmDriverUnlock = qemudVMDriverUnlock, }; int qemuRegister(void) { Index: libvirt-acl/src/uml/uml_driver.c =================================================================== --- libvirt-acl.orig/src/uml/uml_driver.c +++ libvirt-acl/src/uml/uml_driver.c @@ -2202,11 +2202,7 @@ static int umlVMFilterRebuild(virConnectPtr conn ATTRIBUTE_UNUSED, virHashIterator iter, void *data) { - struct uml_driver *driver = uml_driver; - - umlDriverLock(driver); virHashForEach(uml_driver->domains.objs, iter, data); - umlDriverUnlock(driver); return 0; } @@ -2219,9 +2215,23 @@ static virStateDriver umlStateDriver = { .active = umlActive, }; +static void +umlVMDriverLock(void) +{ + umlDriverLock(uml_driver); +} + +static void +umlVMDriverUnlock(void) +{ + umlDriverUnlock(uml_driver); +} + static virNWFilterCallbackDriver umlCallbackDriver = { .name = "UML", .vmFilterRebuild = umlVMFilterRebuild, + .vmDriverLock = umlVMDriverLock, + .vmDriverUnlock = umlVMDriverUnlock, }; int umlRegister(void) { Index: libvirt-acl/src/conf/nwfilter_conf.c =================================================================== --- libvirt-acl.orig/src/conf/nwfilter_conf.c +++ libvirt-acl/src/conf/nwfilter_conf.c @@ -2303,6 +2303,24 @@ virNWFilterRegisterCallbackDriver(virNWF } } +void +virNWFilterCallbackDriversLock(void) +{ + int i; + + for (i = 0; i < nCallbackDriver; i++) + callbackDrvArray[i]->vmDriverLock(); +} + +void +virNWFilterCallbackDriversUnlock(void) +{ + int i; + + for (i = 0; i < nCallbackDriver; i++) + callbackDrvArray[i]->vmDriverUnlock(); +} + static virHashIterator virNWFilterDomainFWUpdateCB; Index: libvirt-acl/src/libvirt_private.syms =================================================================== --- libvirt-acl.orig/src/libvirt_private.syms +++ libvirt-acl/src/libvirt_private.syms @@ -535,6 +535,8 @@ virNWFilterConfLayerShutdown; virNWFilterLockFilterUpdates; virNWFilterUnlockFilterUpdates; virNWFilterPrintStateMatchFlags; +virNWFilterCallbackDriversLock; +virNWFilterCallbackDriversUnlock; # nwfilter_params.h Index: libvirt-acl/src/nwfilter/nwfilter_driver.c =================================================================== --- libvirt-acl.orig/src/nwfilter/nwfilter_driver.c +++ libvirt-acl/src/nwfilter/nwfilter_driver.c @@ -34,6 +34,7 @@ #include "memory.h" #include "domain_conf.h" #include "domain_nwfilter.h" +#include "nwfilter_conf.h" #include "nwfilter_driver.h" #include "nwfilter_gentech_driver.h" @@ -152,9 +153,13 @@ nwfilterDriverReload(void) { virNWFilterLearnThreadsTerminate(true); nwfilterDriverLock(driverState); + virNWFilterCallbackDriversLock(); + virNWFilterPoolLoadAllConfigs(conn, &driverState->pools, driverState->configDir); + + virNWFilterCallbackDriversUnlock(); nwfilterDriverUnlock(driverState); virConnectClose(conn); @@ -328,6 +333,8 @@ nwfilterDefine(virConnectPtr conn, virNWFilterPtr ret = NULL; nwfilterDriverLock(driver); + virNWFilterCallbackDriversLock(); + if (!(def = virNWFilterDefParseString(conn, xml))) goto cleanup; @@ -347,6 +354,8 @@ cleanup: virNWFilterDefFree(def); if (pool) virNWFilterPoolObjUnlock(pool); + + virNWFilterCallbackDriversUnlock(); nwfilterDriverUnlock(driver); return ret; } @@ -359,6 +368,8 @@ nwfilterUndefine(virNWFilterPtr obj) { int ret = -1; nwfilterDriverLock(driver); + virNWFilterCallbackDriversLock(); + pool = virNWFilterPoolObjFindByUUID(&driver->pools, obj->uuid); if (!pool) { virNWFilterReportError(VIR_ERR_INVALID_NWFILTER, @@ -385,6 +396,8 @@ nwfilterUndefine(virNWFilterPtr obj) { cleanup: if (pool) virNWFilterPoolObjUnlock(pool); + + virNWFilterCallbackDriversUnlock(); nwfilterDriverUnlock(driver); return ret; }

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[libvirt] [PATCH v2 0/5] nwfilter: Support comment attribute in filter rule descriptions
by Stefan Berger 07 Oct '10

07 Oct '10

V2: - work on the iptables instantiation patch (2/5) - work on the parser patch (1/5) - small changes to the test cases (5/5) The following patch series adds support for a comment node to the XML attributes of all protocols. If possible, as for example in case of iptables, the comments are instantiated (iptables ... -m comment --comment ...). The patches do the following: - extend the parser and XML generator to parse and create XML with the comment attribute - instantiate the comment in case of ip(6)tables - extend the nwfilter.rng schema with the comment attribute - add the information to the web docs - add a test case for the XML parser/generator to be run during 'make check' Regards, Stefan

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[libvirt] [TCK][PATCH] nwfilter: implement support for --force flag
by Stefan Berger 07 Oct '10

07 Oct '10

Implement support for the --force command line option to delete existing VMs and nwfilters starting with 'tck'. Fix how the --no-attach flag is handled. Signed-off-by: Stefan Berger <stefanb(a)us.ibm.com> diff --git a/scripts/nwfilter/nwfilter2vmtest.sh b/scripts/nwfilter/nwfilter2vmtest.sh index b527ee8..496c220 100644 --- a/scripts/nwfilter/nwfilter2vmtest.sh +++ b/scripts/nwfilter/nwfilter2vmtest.sh @@ -23,6 +23,7 @@ FLAG_ATTACH="$((1<<1))" FLAG_VERBOSE="$((1<<2))" FLAG_LIBVIRT_TEST="$((1<<3))" FLAG_TAP_TEST="$((1<<4))" +FLAG_FORCE_CLEAN="$((1<<5))" failctr=0 passctr=0 @@ -47,6 +48,8 @@ Options: --verbose : Verbose output --libvirt-test : Use the libvirt test output format --tap-test : TAP format output + --force : Allow the automatic cleaning of VMs and nwfilters + previously created by the TCK test suite This test will create two virtual machines. The one virtual machine will use a filter called '${TESTFILTERNAME}', and reference the filter @@ -498,11 +501,12 @@ function main() { while [ $# -ne 0 ]; do case "$1" in --help|-h|-\?) usage ${prgname}; exit 0;; - --noattach) ((flags ^= FLAG_ATTACH ));; + --noattach) ((flags &= ~FLAG_ATTACH ));; --wait) ((flags |= FLAG_WAIT ));; --verbose) ((flags |= FLAG_VERBOSE ));; --libvirt-test) ((flags |= FLAG_LIBVIRT_TEST ));; --tap-test) ((flags |= FLAG_TAP_TEST ));; + --force) ((flags |= FLAG_FORCE_CLEAN ));; *) usage ${prgname}; exit 1;; esac shift 1 @@ -523,12 +527,14 @@ function main() { exit 0 fi - for name in `virsh nwfilter-list | awk '{print $2}'` + for name in `virsh list | awk '{print $2}'` do case ${name} in tck*) - if [ "x${LIBVIRT_TCK_AUTOCLEAN}" == "x1" ]; then - res=$(virsh nwfilter-undefine ${name} 2>&1) + if [ "x${LIBVIRT_TCK_AUTOCLEAN}" == "x1" -o \ + $((flags & FLAG_FORCE_CLEAN)) -ne 0 ]; then + res=$(virsh destroy ${name} 2>&1) + res=$(virsh undefine ${name} 2>&1) if [ $? -ne 0 ]; then echo "Bail out! Could not undefine nwfiler ${name}: ${res}" exit 0 @@ -544,8 +550,9 @@ function main() { do case ${name} in tck*) - if [ "x${LIBVIRT_TCK_AUTOCLEAN}" == "x1" ]; then - res=$(virsh undefine ${name} 2>&1) + if [ "x${LIBVIRT_TCK_AUTOCLEAN}" == "x1" -o \ + $((flags & FLAG_FORCE_CLEAN)) -ne 0 ]; then + res=$(virsh nwfilter-undefine ${name} 2>&1) if [ $? -ne 0 ]; then echo "Bail out! Could not undefine domain ${name}: ${res}" exit 1

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[libvirt] Using -netdev with qemu/kvm rather than old style
by Pete Ashdown 07 Oct '10

07 Oct '10

I have 0.8.3 installed and my net devices are still being defined via -net rather than -netdev. I have found that using the latter allows my ethernet to properly offload and gives a 35% performance gain. Looking through the libvirt code I find in qemu_conf.c: /* Possible combinations * * 1. Old way: -net nic,model=e1000,vlan=1 -net tap,vlan=1 * 2. Semi-new: -device e1000,vlan=1 -net tap,vlan=1 * 3. Best way: -netdev type=tap,id=netdev1 -device e1000,id=netdev1 * * NB, no support for -netdev without use of -device */ How do I convince virsh/libvirt to use #3, the "Best way"?

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[libvirt] [PATCH] [DOCS] nwfilter: Add 2nd example to the html docs
by Stefan Berger 07 Oct '10

07 Oct '10

This patch adds another example to the nwfilter html page and provides 2 solutions for how to write a filter meeting the given requirements using newly added features. Signed-off-by: Stefan Berger <stefanb(a)us.ibm.com> --- docs/formatnwfilter.html.in | 180 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 179 insertions(+), 1 deletion(-) Index: libvirt-acl/docs/formatnwfilter.html.in =================================================================== --- libvirt-acl.orig/docs/formatnwfilter.html.in +++ libvirt-acl/docs/formatnwfilter.html.in @@ -1468,7 +1468,8 @@ <li>prevents a VM's interface from MAC, IP and ARP spoofing</li> <li>opens only TCP ports 22 and 80 of a VM's interface</li> <li>allows the VM to send ping traffic from an interface - but no let the VM be pinged on the interface</li> + but not let the VM be pinged on the interface</li> + <li>allows the VM to do DNS lookups (UDP towards port 53)</li> </ul> <p> The requirement to prevent spoofing is fulfilled by the existing @@ -1510,6 +1511,11 @@ <icmp/> </rule> +  + <rule action='accept' direction='out'> + <udp dstportstart='53'/> + </rule> +  <rule action='drop' direction='inout'> <all/> @@ -1556,6 +1562,178 @@ </rule> </pre> + <h3><a name="nwfwriteexample2nd">Second example custom filter</a></h3> + <p> + In this example we now want to build a similar filter as in the + example above, but extend the list of requirements with an + ftp server located inside the VM. Further, we will be using features + that have been added in <span class="since">version 0.8.5</span>. + The requirements for this filter shall be: + </p> + <ul> + <li>prevents a VM's interface from MAC, IP and ARP spoofing</li> + <li>opens only TCP ports 22 and 80 of a VM's interface</li> + <li>allows the VM to send ping traffic from an interface + but not let the VM be pinged on the interface</li> + <li>allows the VM to do DNS lookups (UDP towards port 53)</li> + <li>enable an ftp server (in active mode) to be run inside the VM + </ul> + <p> + The additional requirement of allowing an ftp server to be run inside + the VM maps into the requirement of allowing port 21 to be reachable + for ftp control traffic as well as enabling the VM to establish an + outgoing tcp connection originating from the VM's TCP port 20 back to + the ftp client (ftp active mode). There are several ways of how this + filter can be written and we present 2 solutions. + <br><br> + The 1st solution makes use of the <code>state</code> attribute of + the TCP protocol that gives us a hook into the connection tracking + framework of the Linux host. For the VM-initiated ftp data connection + (ftp active mode) we use the <code>RELATED</code> state that allows + us to detect that the VM-initated ftp data connection is a consequence of + ( or 'has a relationship with' ) an existing ftp control connection, + thus we want to allow it to let packets + pass the firewall. The <code>RELATED</code> state, however, is only + valid for the very first packet of the outgoing TCP connection for the + ftp data path. Afterwards, the state to compare against is + <code>ESTABLISHED</code>, which then applies equally + to the incoming and outgoing direction. All this is related to the ftp + data traffic origination from TCP port 20 of the VM. This then leads to + the following solution + <span class="since">(since 0.8.5 (Qemu, KVM, UML))</span>: + </p> +<pre> +<filter name='test-eth0'> +  + <filterref filter='clean-traffic'/> + +  + <rule action='accept' direction='in'> + <tcp dstportstart='21'/> + </rule> + +  + <rule action='accept' direction='out'> + <tcp srcportstart='20' state='RELATED,ESTABLISHED'/> + </rule> + +  + <rule action='accept' direction='in'> + <tcp dstportstart='20' state='ESTABLISHED'/> + </rule> + +  + <rule action='accept' direction='in'> + <tcp dstportstart='22'/> + </rule> + + <rule action='accept' direction='in'> + <tcp dstportstart='80'/> + </rule> + +  + <rule action='accept' direction='out'> + <icmp/> + </rule> + +  + <rule action='accept' direction='out'> + <udp dstportstart='53'/> + </rule> + +  + <rule action='drop' direction='inout'> + <all/> + </rule> + +</filter> +</pre> + <p> + Before trying out a filter using the <code>RELATED</code> state, + you have to make sure that the approriate connection tracking module + has been loaded into the host's kernel. Depending on the version of the + kernel, you must run either one of the following two commands before + the ftp connection with the VM is established. + </p> +<pre> + modprobe nf_conntrack_ftp # where available or + + modprobe ip_conntrack_ftp # if above is not available +</pre> + <p> + If other protocols than ftp are to be used in conjunction with the + <code>RELATED</code> state, their corresponding module must be loaded. + Modules exist at least for the protocols ftp, tftp, irc, sip, + sctp, and amanda. + </p> + <p> + The 2nd solution makes uses the state flags of connections more + than the previous solution did. + In this solution we take advantage of the fact that the + <code>NEW</code> state of a connection is valid when the very + first packet of a traffic flow is seen. Subsequently, if the very first + packet of a flow is accepted, the flow becomes a connection and enters + the <code>ESTABLISHED</code> state. This allows us to write a general + rule for allowing packets of <code>ESTABLISHED</code> connections to + reach the VM or be sent by the VM. + We write specific rules for the very first packets identified by the + <code>NEW</code> state and for which ports they are acceptable. All + packets for ports that are not explicitly accepted will be dropped and + therefore the connection will not go into the <code>ESTABLISHED</code> + state and any subsequent packets be dropped. + </p> + +<pre> +<filter name='test-eth0'> +  + <filterref filter='clean-traffic'/> + +  + <rule action='accept' direction='in'> + <all state='ESTABLISHED'/> + </rule> + +  + <rule action='accept' direction='out'> + <all state='ESTABLISHED,RELATED'/> + </rule> + +  + <rule action='accept' direction='in'> + <tcp dstportstart='21' dstportend='22' state='NEW'/> + </rule> + + <rule action='accept' direction='in'> + <tcp dstportstart='80' state='NEW'/> + </rule> + +  + <rule action='accept' direction='out'> + <icmp state='NEW'/> + </rule> + +  + <rule action='accept' direction='out'> + <udp dstportstart='53' state='NEW'/> + </rule> + +  + <rule action='drop' direction='inout'> + <all/> + </rule> + +</filter> + +</pre> <h2><a name="nwflimits">Limitations</a></h2> <p>

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[libvirt] [patch 0/5] nwfilter: add a 'state' attribute to protocols
by Stefan Berger 07 Oct '10

07 Oct '10

The following patch series introduces an attribute 'state' for iptables- supported protocols. This gives the user more control over the 'state match' of the underlying ip(6)tables implementation and allows to create filtering rules that are more efficient to evaluate. TCK test cases will be posted later. Each rule containing a state attribute with either one of the values NEW, ESTABLISHED, RELATED, INVALID or NONE, gets one iptables rule created for the direction of the rule. The keyword 'NONE' does the same, but doesn't generate a rule with the 'state match'. If no state attribute is used, a symmetric rule in the incoming and outgoing direction is generated (as was done previously). The patches do the following: - extend the parser and XML generator to parse and create XML with the state attribute - instantiate the state in case of ip(6)tables - extend the nwfilter.rng schema with the state attribute's possible values - add information about the new state attribute to the web docs - add a test case for the XML parser/generator to be run during 'make check' I valgrind'ed this patch and it looks all memory is freed appropriately. Regards, Stefan

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[libvirt] [PATCH] document authentication with PolicyKit-1
by Gerd v. Egidy 07 Oct '10

07 Oct '10

Hi, I just encountered the same problem with the newer PolicyKit as discussed e.g. in this thread: http://lists.fedoraproject.org/pipermail/virt/2010-June/002081.html I solved it and thought updating the documentation for PolicyKit 1 would be nice. Patch attached. Kind regards, Gerd -- Address (better: trap) for people I really don't want to get mail from: jonas(a)cactusamerica.com

4 4

[libvirt] bug: network lock-out
by Zdenek Styblik 07 Oct '10

07 Oct '10

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hello, I'm sorry to report this, but network should start or stop regardless iptables status. virsh # net-start default error: Failed to start network default error: internal error '/usr/sbin/iptables --table filter --delete INPUT - --in-interface virbr0 --protocol udp --destination-port 69 --jump ACCEPT' exited with non-zero status 1 and signal 0: iptables: Bad rule (does a matching rule exist in that chain?). Ok, so I'm going to create this rule to make you happy. virsh # net-start default error: Failed to start network default error: internal error '/usr/sbin/iptables --table mangle --delete POSTROUTING --out-interface virbr0 --protocol udp --destination-port 68 - --jump CHECKSUM --checksum-fill' exited with non-zero status 2 and signal 0: iptables v1.4.7: unknown option `--checksum-fill' Try `iptables -h' or 'iptables --help' for more information. And Oops, because I don't have CHECKSUM support. And to note, it's not even in kernel. Rely on such features is unfriendly and bellow belt :) Once again, I'm locked by hard-coded features :( That's why I "fight" against these. btw it's strange to me that libvirt is deleting rules that shouldn't be present since I want to start network, not to stop it. Let's dump all nwfilters and hope for miracle...and nothing. Same errors, although nwfilter rules are gone. What the ...? :| libvirt-0.8.4 Regards, Zdenek - -- Zdenek Styblik Net/Linux admin OS TurnovFree.net email: stybla(a)turnovfree.net jabber: stybla(a)jabber.turnovfree.net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAkyrezwACgkQ8MreUbSH7ikbpQCdEDtbwG+PV6u0yvUZYzXlQas9 ohEAoIyy/HPZwtWlaOAgtx6jnOEFashR =u7st -----END PGP SIGNATURE-----

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[libvirt] libvirt and nested pagind
by Eduardo 07 Oct '10

07 Oct '10

Good afternoon! Searching on the web, I joint some codes and produced those patches. Now I have a server running perfectly with the following scenario: AMD Phenom 8400 x3; Slackware64 13.1 on a slim and custom 2.6.35.2 Linux; qemu-kvm 0.12.5; libvirt 0.8.4. Patch of libvirt 0.8.3: diff -Naur ../libvirt-0.8.3//docs/schemas/domain.rng ./docs/schemas/domain.rng --- ../libvirt-0.8.3//docs/schemas/domain.rng 2010-07-29 06:48:30.000000000 -0300 +++ ./docs/schemas/domain.rng 2010-09-01 16:51:57.710851479 -0300 @@ -1595,6 +1595,11 @@ <empty/> </element> </optional> + <optional> + <element name="nesting"> + <empty/> + </element> + </optional> </interleave> </element> </optional> diff -Naur ../libvirt-0.8.3//src/conf/domain_conf.c ./src/conf/domain_conf.c --- ../libvirt-0.8.3//src/conf/domain_conf.c 2010-08-02 16:16:42.000000000 -0300 +++ ./src/conf/domain_conf.c 2010-09-01 16:51:57.710851479 -0300 @@ -75,7 +75,8 @@ VIR_ENUM_IMPL(virDomainFeature, VIR_DOMAIN_FEATURE_LAST, "acpi", "apic", - "pae") + "pae", + "nesting") VIR_ENUM_IMPL(virDomainLifecycle, VIR_DOMAIN_LIFECYCLE_LAST, "destroy", diff -Naur ../libvirt-0.8.3//src/conf/domain_conf.h ./src/conf/domain_conf.h --- ../libvirt-0.8.3//src/conf/domain_conf.h 2010-07-29 06:48:30.000000000 -0300 +++ ./src/conf/domain_conf.h 2010-09-01 16:51:57.710851479 -0300 @@ -649,6 +649,7 @@ VIR_DOMAIN_FEATURE_ACPI, VIR_DOMAIN_FEATURE_APIC, VIR_DOMAIN_FEATURE_PAE, + VIR_DOMAIN_FEATURE_NESTING, VIR_DOMAIN_FEATURE_LAST }; diff -Naur ../libvirt-0.8.3//src/qemu/qemu_conf.c ./src/qemu/qemu_conf.c --- ../libvirt-0.8.3//src/qemu/qemu_conf.c 2010-08-04 09:21:27.000000000 -0300 +++ ./src/qemu/qemu_conf.c 2010-09-01 16:57:47.485469640 -0300 @@ -1190,6 +1190,8 @@ flags |= QEMUD_CMD_FLAG_MEM_PATH; if (strstr(help, "-chardev")) flags |= QEMUD_CMD_FLAG_CHARDEV; + if (strstr(help, "-enable-nesting")) + flags |= QEMUD_CMD_FLAG_NESTING; if (strstr(help, "-balloon")) flags |= QEMUD_CMD_FLAG_BALLOON; if (strstr(help, "-device")) @@ -3907,6 +3909,9 @@ goto error; } } + if ((qemuCmdFlags & QEMUD_CMD_FLAG_NESTING) && + (def->features & (1 << VIR_DOMAIN_FEATURE_NESTING))) + ADD_ARG_LIT("-enable-nesting"); /* * NB, -nographic *MUST* come before any serial, or monitor @@ -6265,6 +6270,8 @@ fullscreen = 1; } else if (STREQ(arg, "-localtime")) { def->clock.offset = VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME; + } else if (STREQ(arg, "-enable-nesting")) { + def->features |= (1 << VIR_DOMAIN_FEATURE_NESTING); } else if (STREQ(arg, "-kernel")) { WANT_VALUE(); if (!(def->os.kernel = strdup(val))) diff -Naur ../libvirt-0.8.3//src/qemu/qemu_conf.h ./src/qemu/qemu_conf.h --- ../libvirt-0.8.3//src/qemu/qemu_conf.h 2010-07-28 11:18:15.000000000 -0300 +++ ./src/qemu/qemu_conf.h 2010-09-01 16:58:29.900876561 -0300 @@ -92,6 +92,7 @@ QEMUD_CMD_FLAG_PCI_CONFIGFD = (1LL << 36), /* pci-assign.configfd */ QEMUD_CMD_FLAG_NODEFCONFIG = (1LL << 37), /* -nodefconfig */ QEMUD_CMD_FLAG_BOOT_MENU = (1LL << 38), /* -boot menu=on support */ + QEMUD_CMD_FLAG_NESTING = (1LL << 39), /* Is the -enable-nesting flag available */ }; /* Main driver state */ Patch of libvirt 0.8.4: diff -Naur libvirt-0.8.4/docs/schemas/domain.rng libvirt-0.8.4.edu/docs/schemas/domain.rng --- libvirt-0.8.4/docs/schemas/domain.rng 2010-08-31 10:44:13.000000000 -0300 +++ libvirt-0.8.4.edu/docs/schemas/domain.rng 2010-09-28 14:34:40.626234752 -0300 @@ -1619,6 +1619,11 @@ <empty/> </element> </optional> + <optional> + <element name="nesting"> + <empty/> + </element> + </optional> </interleave> </element> </optional> diff -Naur libvirt-0.8.4/src/conf/domain_conf.c libvirt-0.8.4.edu/src/conf/domain_conf.c --- libvirt-0.8.4/src/conf/domain_conf.c 2010-08-31 10:44:13.000000000 -0300 +++ libvirt-0.8.4.edu/src/conf/domain_conf.c 2010-09-28 14:35:36.069149447 -0300 @@ -75,7 +75,8 @@ VIR_ENUM_IMPL(virDomainFeature, VIR_DOMAIN_FEATURE_LAST, "acpi", "apic", - "pae") + "pae", + "nesting") VIR_ENUM_IMPL(virDomainLifecycle, VIR_DOMAIN_LIFECYCLE_LAST, "destroy", diff -Naur libvirt-0.8.4/src/conf/domain_conf.h libvirt-0.8.4.edu/src/conf/domain_conf.h --- libvirt-0.8.4/src/conf/domain_conf.h 2010-08-31 10:44:13.000000000 -0300 +++ libvirt-0.8.4.edu/src/conf/domain_conf.h 2010-09-28 14:36:11.931054102 -0300 @@ -650,6 +650,7 @@ VIR_DOMAIN_FEATURE_ACPI, VIR_DOMAIN_FEATURE_APIC, VIR_DOMAIN_FEATURE_PAE, + VIR_DOMAIN_FEATURE_NESTING, VIR_DOMAIN_FEATURE_LAST }; diff -Naur libvirt-0.8.4/src/qemu/qemu_conf.c libvirt-0.8.4.edu/src/qemu/qemu_conf.c --- libvirt-0.8.4/src/qemu/qemu_conf.c 2010-09-10 09:38:13.000000000 -0300 +++ libvirt-0.8.4.edu/src/qemu/qemu_conf.c 2010-09-28 14:38:36.218612249 -0300 @@ -1192,6 +1192,8 @@ flags |= QEMUD_CMD_FLAG_MEM_PATH; if (strstr(help, "-chardev")) flags |= QEMUD_CMD_FLAG_CHARDEV; + if (strstr(help, "-enable-nesting")) + flags |= QEMUD_CMD_FLAG_NESTING; if (strstr(help, "-balloon")) flags |= QEMUD_CMD_FLAG_BALLOON; if (strstr(help, "-device")) @@ -3944,6 +3946,9 @@ goto error; } } + if ((qemuCmdFlags & QEMUD_CMD_FLAG_NESTING) && + (def->features & (1 << VIR_DOMAIN_FEATURE_NESTING))) + ADD_ARG_LIT("-enable-nesting"); /* * NB, -nographic *MUST* come before any serial, or monitor @@ -6303,6 +6308,8 @@ fullscreen = 1; } else if (STREQ(arg, "-localtime")) { def->clock.offset = VIR_DOMAIN_CLOCK_OFFSET_LOCALTIME; + } else if (STREQ(arg, "-enable-nesting")) { + def->features |= (1 << VIR_DOMAIN_FEATURE_NESTING); } else if (STREQ(arg, "-kernel")) { WANT_VALUE(); if (!(def->os.kernel = strdup(val))) diff -Naur libvirt-0.8.4/src/qemu/qemu_conf.h libvirt-0.8.4.edu/src/qemu/qemu_conf.h --- libvirt-0.8.4/src/qemu/qemu_conf.h 2010-08-31 10:44:13.000000000 -0300 +++ libvirt-0.8.4.edu/src/qemu/qemu_conf.h 2010-09-28 14:38:58.739788135 -0300 @@ -93,6 +93,8 @@ QEMUD_CMD_FLAG_NODEFCONFIG = (1LL << 37), /* -nodefconfig */ QEMUD_CMD_FLAG_BOOT_MENU = (1LL << 38), /* -boot menu=on support */ QEMUD_CMD_FLAG_ENABLE_KQEMU = (1LL << 39), /* -enable-kqemu flag */ + QEMUD_CMD_FLAG_NESTING = (1LL << 39), /* Is the -enable-nesting flag available */ + }; /* Main driver state */ -- *Eduardo Ramos* www.freedominterface.org +55 12 91051687 exten=>eduardo,1,hangup()

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