Added <capabilities> in the <features> section of LXC domains
configuration. This section can contain elements named after the
capabilities like:
<mknod state="on"/>, keep CAP_MKNOD capability
<sys_chroot state="off"/> drop CAP_SYS_CHROOT capability
Users can restrict or give more capabilities than the default using
this mechanism.
---
docs/drvlxc.html.in | 47 +++++
docs/schemas/domaincommon.rng | 207 ++++++++++++++++++++
src/conf/domain_conf.c | 126 ++++++++++++-
src/conf/domain_conf.h | 56 ++++++
src/libvirt_private.syms | 3 +
src/lxc/lxc_cgroup.c | 8 +
src/lxc/lxc_container.c | 241 ++++++++++++++++++++++--
src/util/vircgroup.c | 57 +++++-
src/util/vircgroup.h | 2 +
tests/domainschemadata/domain-caps-features.xml | 28 +++
10 files changed, 755 insertions(+), 20 deletions(-)
create mode 100644 tests/domainschemadata/domain-caps-features.xml
diff --git a/docs/drvlxc.html.in b/docs/drvlxc.html.in
index fc4bc20..403ce24 100644
--- a/docs/drvlxc.html.in
+++ b/docs/drvlxc.html.in
@@ -540,6 +540,53 @@ debootstrap, whatever) under /opt/vm-1-root:
</domain>
</pre>
+<h2><a name="capabilities">Altering the available capabilities</a></h2>
+
+<p>
+By default the libvirt LXC driver drops some capabilities among which CAP_MKNOD.
+However <span class="since">since 1.2.6</span> libvirt can be told to keep or
+drop some capabilities using a domain configuration like the following:
+</p>
+<pre>
+...
+<features>
+ <capabilities policy='default'>
+ <mknod state='on'/>
+ <sys_chroot state='off'/>
+ </capabilities>
+</features>
+...
+</pre>
+<p>
+The capabilities children elements are named after the capabilities as defined in
+<code>man 7 capabilities</code>. An <code>off</code> state tells libvirt to drop the
+capability, while an <code>on</code> state will force to keep the capability even though
+this one is dropped by default.
+</p>
+<p>
+The <code>policy</code> attribute can be one of <code>default</code>, <code>allow</code>
+or <code>deny</code>. It defines the default rules for capabilities: either keep the
+default behavior that is dropping a few selected capabilities, or keep all capabilities
+or drop all capabilities. The interest of <code>allow</code> and <code>deny</code> is that
+they guarantee that all capabilities will be kept (or removed) even if new ones are added
+later.
+</p>
+<p>
+The following example, drops all capabilities but CAP_MKNOD:
+</p>
+<pre>
+...
+<features>
+ <capabilities policy='deny'>
+ <mknod state='on'/>
+ </capabilities>
+</features>
+...
+</pre>
+<p>
+Note that allowing capabilities that are normally dropped by default can seriously
+affect the security of the container and the host.
+</p>
<h2><a name="usage">Container usage / management</a></h2>
diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index 2caeef9..cf0a66d 100644
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -3798,6 +3798,9 @@
<empty/>
</element>
</optional>
+ <optional>
+ <ref name="capabilities"/>
+ </optional>
</interleave>
</element>
</optional>
@@ -4370,6 +4373,200 @@
</element>
</define>
+ <!-- Optional capabilities features -->
+ <define name="capabilities">
+ <element name="capabilities">
+ <ref name="capabilitiespolicy"/>
+ <interleave>
+ <optional>
+ <element name="audit_control">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="audit_write">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="block_suspend">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="chown">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="dac_override">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="dac_read_search">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="fowner">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="fsetid">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="ipc_lock">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="ipc_owner">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="kill">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="lease">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="linux_immutable">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="mac_admin">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="mac_override">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="mknod">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="net_admin">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="net_bind_service">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="net_broadcast">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="net_raw">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="setgid">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="setfcap">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="setpcap">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="setuid">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_admin">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_boot">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_chroot">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_module">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_nice">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_pacct">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_ptrace">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_rawio">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_resource">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_time">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="sys_tty_config">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="syslog">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ <optional>
+ <element name="wake_alarm">
+ <ref name="featurestate"/>
+ </element>
+ </optional>
+ </interleave>
+ </element>
+ </define>
+
<define name="featurestate">
<attribute name="state">
<choice>
@@ -4379,6 +4576,16 @@
</attribute>
</define>
+ <define name="capabilitiespolicy">
+ <attribute name="policy">
+ <choice>
+ <value>default</value>
+ <value>allow</value>
+ <value>deny</value>
+ </choice>
+ </attribute>
+ </define>
+
<!--
Optional hypervisor extensions in their own namespace:
QEmu
diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index a1ef374..ed0bc92 100644
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -147,18 +147,63 @@ VIR_ENUM_IMPL(virDomainFeature, VIR_DOMAIN_FEATURE_LAST,
"viridian",
"privnet",
"hyperv",
- "pvspinlock")
+ "pvspinlock",
+ "capabilities")
VIR_ENUM_IMPL(virDomainFeatureState, VIR_DOMAIN_FEATURE_STATE_LAST,
"default",
"on",
"off")
+VIR_ENUM_IMPL(virDomainCapabilitiesPolicy, VIR_DOMAIN_CAPABILITIES_POLICY_LAST,
+ "default",
+ "allow",
+ "deny")
+
VIR_ENUM_IMPL(virDomainHyperv, VIR_DOMAIN_HYPERV_LAST,
"relaxed",
"vapic",
"spinlocks")
+VIR_ENUM_IMPL(virDomainCapsFeature, VIR_DOMAIN_CAPS_FEATURE_LAST,
+ "audit_control",
+ "audit_write",
+ "block_suspend",
+ "chown",
+ "dac_override",
+ "dac_read_search",
+ "fowner",
+ "fsetid",
+ "ipc_lock",
+ "ipc_owner",
+ "kill",
+ "lease",
+ "linux_immutable",
+ "mac_admin",
+ "mac_override",
+ "mknod",
+ "net_admin",
+ "net_bind_service",
+ "net_broadcast",
+ "net_raw",
+ "setgid",
+ "setfcap",
+ "setpcap",
+ "setuid",
+ "sys_admin",
+ "sys_boot",
+ "sys_chroot",
+ "sys_module",
+ "sys_nice",
+ "sys_pacct",
+ "sys_ptrace",
+ "sys_rawio",
+ "sys_resource",
+ "sys_time",
+ "sys_tty_config",
+ "syslog",
+ "wake_alarm")
+
VIR_ENUM_IMPL(virDomainLifecycle, VIR_DOMAIN_LIFECYCLE_LAST,
"destroy",
"restart",
@@ -11847,6 +11892,22 @@ virDomainDefParseXML(xmlDocPtr xml,
def->features[val] = VIR_DOMAIN_FEATURE_STATE_ON;
break;
+ case VIR_DOMAIN_FEATURE_CAPABILITIES:
+ node = ctxt->node;
+ ctxt->node = nodes[i];
+ if ((tmp = virXPathString("string(./@policy)", ctxt))) {
+ if ((def->features[val] = virDomainCapabilitiesPolicyTypeFromString(tmp)) == -1) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("unknown state attribute '%s' of feature '%s'"),
+ tmp, virDomainFeatureTypeToString(val));
+ goto error;
+ }
+ VIR_FREE(tmp);
+ } else {
+ def->features[val] = VIR_DOMAIN_FEATURE_STATE_DEFAULT;
+ }
+ ctxt->node = node;
+ break;
case VIR_DOMAIN_FEATURE_PVSPINLOCK:
node = ctxt->node;
ctxt->node = nodes[i];
@@ -11955,6 +12016,37 @@ virDomainDefParseXML(xmlDocPtr xml,
ctxt->node = node;
}
+ if ((n = virXPathNodeSet("./features/capabilities/*", ctxt, &nodes)) < 0)
+ goto error;
+
+ for (i = 0; i < n; i++) {
+ int val = virDomainCapsFeatureTypeFromString((const char *)nodes[i]->name);
+ if (val < 0) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("unexpected capability feature '%s'"), nodes[i]->name);
+ goto error;
+ }
+
+ if (val >= 0 && val < VIR_DOMAIN_CAPS_FEATURE_LAST) {
+ node = ctxt->node;
+ ctxt->node = nodes[i];
+
+ if ((tmp = virXPathString("string(./@state)", ctxt))) {
+ if ((def->caps_features[val] = virDomainFeatureStateTypeFromString(tmp)) == -1) {
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("unknown state attribute '%s' of feature capability '%s'"),
+ tmp, virDomainFeatureTypeToString(val));
+ goto error;
+ }
+ VIR_FREE(tmp);
+ } else {
+ def->caps_features[val] = VIR_DOMAIN_FEATURE_STATE_ON;
+ }
+ ctxt->node = node;
+ }
+ }
+ VIR_FREE(nodes);
+
if (virDomainEventActionParseXML(ctxt, "on_reboot",
"string(./on_reboot[1])",
&def->onReboot,
@@ -17148,6 +17240,19 @@ verify(((VIR_DOMAIN_XML_INTERNAL_STATUS |
VIR_DOMAIN_XML_INTERNAL_CLOCK_ADJUST)
& DUMPXML_FLAGS) == 0);
+static bool
+virDomainDefHasCapabilitiesFeatures(virDomainDefPtr def)
+{
+ size_t i;
+
+ for (i = 0; i < VIR_DOMAIN_CAPS_FEATURE_LAST; i++) {
+ if (def->caps_features[i] != VIR_DOMAIN_FEATURE_STATE_DEFAULT)
+ return true;
+ }
+
+ return false;
+}
+
/* This internal version can accept VIR_DOMAIN_XML_INTERNAL_*,
* whereas the public version cannot. Also, it appends to an existing
* buffer (possibly with auto-indent), rather than flattening to string.
@@ -17645,6 +17750,25 @@ virDomainDefFormatInternal(virDomainDefPtr def,
virBufferAddLit(buf, "</hyperv>\n");
break;
+ case VIR_DOMAIN_FEATURE_CAPABILITIES:
+ if (def->features[i] == VIR_DOMAIN_CAPABILITIES_POLICY_DEFAULT &&
+ !virDomainDefHasCapabilitiesFeatures(def))
+ break;
+
+ virBufferAsprintf(buf, "<capabilities policy='%s'>\n",
+ virDomainCapabilitiesPolicyTypeToString(def->features[i]));
+ virBufferAdjustIndent(buf, 2);
+ for (j = 0; j < VIR_DOMAIN_CAPS_FEATURE_LAST; j++) {
+ if (def->caps_features[j] != VIR_DOMAIN_FEATURE_STATE_DEFAULT)
+ virBufferAsprintf(buf, "<%s state='%s'/>\n",
+ virDomainCapsFeatureTypeToString(j),
+ virDomainFeatureStateTypeToString(
+ def->caps_features[j]));
+ }
+ virBufferAdjustIndent(buf, -2);
+ virBufferAddLit(buf, "</capabilities>\n");
+ break;
+
case VIR_DOMAIN_FEATURE_LAST:
break;
}
diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index e4d7988..d99a943 100644
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1534,6 +1534,7 @@ typedef enum {
VIR_DOMAIN_FEATURE_PRIVNET,
VIR_DOMAIN_FEATURE_HYPERV,
VIR_DOMAIN_FEATURE_PVSPINLOCK,
+ VIR_DOMAIN_FEATURE_CAPABILITIES,
VIR_DOMAIN_FEATURE_LAST
} virDomainFeature;
@@ -1555,6 +1556,56 @@ typedef enum {
} virDomainHyperv;
typedef enum {
+ VIR_DOMAIN_CAPABILITIES_POLICY_DEFAULT = 0,
+ VIR_DOMAIN_CAPABILITIES_POLICY_ALLOW,
+ VIR_DOMAIN_CAPABILITIES_POLICY_DENY,
+
+ VIR_DOMAIN_CAPABILITIES_POLICY_LAST
+} virDomainCapabilitiesPolicy;
+
+/* The capabilities are ordered alphabetically to help check for new ones */
+typedef enum {
+ VIR_DOMAIN_CAPS_FEATURE_AUDIT_CONTROL = 0,
+ VIR_DOMAIN_CAPS_FEATURE_AUDIT_WRITE,
+ VIR_DOMAIN_CAPS_FEATURE_BLOCK_SUSPEND,
+ VIR_DOMAIN_CAPS_FEATURE_CHOWN,
+ VIR_DOMAIN_CAPS_FEATURE_DAC_OVERRIDE,
+ VIR_DOMAIN_CAPS_FEATURE_DAC_READ_SEARCH,
+ VIR_DOMAIN_CAPS_FEATURE_FOWNER,
+ VIR_DOMAIN_CAPS_FEATURE_FSETID,
+ VIR_DOMAIN_CAPS_FEATURE_IPC_LOCK,
+ VIR_DOMAIN_CAPS_FEATURE_IPC_OWNER,
+ VIR_DOMAIN_CAPS_FEATURE_KILL,
+ VIR_DOMAIN_CAPS_FEATURE_LEASE,
+ VIR_DOMAIN_CAPS_FEATURE_LINUX_IMMUTABLE,
+ VIR_DOMAIN_CAPS_FEATURE_MAC_ADMIN,
+ VIR_DOMAIN_CAPS_FEATURE_MAC_OVERRIDE,
+ VIR_DOMAIN_CAPS_FEATURE_MKNOD,
+ VIR_DOMAIN_CAPS_FEATURE_NET_ADMIN,
+ VIR_DOMAIN_CAPS_FEATURE_NET_BIND_SERVICE,
+ VIR_DOMAIN_CAPS_FEATURE_NET_BROADCAST,
+ VIR_DOMAIN_CAPS_FEATURE_NET_RAW,
+ VIR_DOMAIN_CAPS_FEATURE_SETGID,
+ VIR_DOMAIN_CAPS_FEATURE_SETFCAP,
+ VIR_DOMAIN_CAPS_FEATURE_SETPCAP,
+ VIR_DOMAIN_CAPS_FEATURE_SETUID,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_ADMIN,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_BOOT,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_CHROOT,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_MODULE,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_NICE,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_PACCT,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_PTRACE,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_RAWIO,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_RESOURCE,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_TIME,
+ VIR_DOMAIN_CAPS_FEATURE_SYS_TTY_CONFIG,
+ VIR_DOMAIN_CAPS_FEATURE_SYSLOG,
+ VIR_DOMAIN_CAPS_FEATURE_WAKE_ALARM,
+ VIR_DOMAIN_CAPS_FEATURE_LAST
+} virDomainCapsFeature;
+
+typedef enum {
VIR_DOMAIN_LIFECYCLE_DESTROY,
VIR_DOMAIN_LIFECYCLE_RESTART,
VIR_DOMAIN_LIFECYCLE_RESTART_RENAME,
@@ -1921,6 +1972,9 @@ struct _virDomainDef {
int hyperv_features[VIR_DOMAIN_HYPERV_LAST];
unsigned int hyperv_spinlocks;
+ /* This options are of type virDomainFeatureState: ON = keep, OFF = drop */
+ int caps_features[VIR_DOMAIN_CAPS_FEATURE_LAST];
+
virDomainClockDef clock;
size_t ngraphics;
@@ -2538,6 +2592,8 @@ VIR_ENUM_DECL(virDomainBoot)
VIR_ENUM_DECL(virDomainBootMenu)
VIR_ENUM_DECL(virDomainFeature)
VIR_ENUM_DECL(virDomainFeatureState)
+VIR_ENUM_DECL(virDomainCapabilitiesPolicy)
+VIR_ENUM_DECL(virDomainCapsFeature)
VIR_ENUM_DECL(virDomainLifecycle)
VIR_ENUM_DECL(virDomainLifecycleCrash)
VIR_ENUM_DECL(virDomainPMState)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 8d3671c..e014f5a 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -147,6 +147,8 @@ virDomainBlockedReasonTypeFromString;
virDomainBlockedReasonTypeToString;
virDomainBootMenuTypeFromString;
virDomainBootMenuTypeToString;
+virDomainCapabilitiesPolicyTypeToString;
+virDomainCapsFeatureTypeToString;
virDomainChrConsoleTargetTypeFromString;
virDomainChrConsoleTargetTypeToString;
virDomainChrDefForeach;
@@ -1060,6 +1062,7 @@ virBufferVasprintf;
# util/vircgroup.h
virCgroupAddTask;
virCgroupAddTaskController;
+virCgroupAllowAllDevices;
virCgroupAllowDevice;
virCgroupAllowDeviceMajor;
virCgroupAllowDevicePath;
diff --git a/src/lxc/lxc_cgroup.c b/src/lxc/lxc_cgroup.c
index 395ea05..572caca 100644
--- a/src/lxc/lxc_cgroup.c
+++ b/src/lxc/lxc_cgroup.c
@@ -353,6 +353,14 @@ static int virLXCCgroupSetupDeviceACL(virDomainDefPtr def,
if (virCgroupDenyAllDevices(cgroup) < 0)
goto cleanup;
+ /* white list mknod if CAP_MKNOD has to be kept */
+ int capMknod = def->caps_features[VIR_DOMAIN_CAPS_FEATURE_MKNOD];
+ if (capMknod == VIR_DOMAIN_FEATURE_STATE_ON) {
+ if (virCgroupAllowAllDevices(cgroup,
+ VIR_CGROUP_DEVICE_MKNOD) < 0)
+ goto cleanup;
+ }
+
for (i = 0; devices[i].type != 0; i++) {
virLXCCgroupDevicePolicyPtr dev = &devices[i];
if (virCgroupAllowDevice(cgroup,
diff --git a/src/lxc/lxc_container.c b/src/lxc/lxc_container.c
index 4d89677..e00af55 100644
--- a/src/lxc/lxc_container.c
+++ b/src/lxc/lxc_container.c
@@ -1732,25 +1732,233 @@ static int lxcContainerResolveSymlinks(virDomainDefPtr vmDef)
* host system, since they are not currently "containerized"
*/
#if WITH_CAPNG
-static int lxcContainerDropCapabilities(bool keepReboot)
+
+/* Define capabilities to -1 if those aren't defined in the kernel:
+ * this will help us ignore them. */
+# ifndef CAP_AUDIT_CONTROL
+# define CAP_AUDIT_CONTROL -1
+# endif
+# ifndef CAP_AUDIT_WRITE
+# define CAP_AUDIT_WRITE -1
+# endif
+# ifndef CAP_BLOCK_SUSPEND
+# define CAP_BLOCK_SUSPEND -1
+# endif
+# ifndef CAP_CHOWN
+# define CAP_CHOWN -1
+# endif
+# ifndef CAP_DAC_OVERRIDE
+# define CAP_DAC_OVERRIDE -1
+# endif
+# ifndef CAP_DAC_READ_SEARCH
+# define CAP_DAC_READ_SEARCH -1
+# endif
+# ifndef CAP_FOWNER
+# define CAP_FOWNER -1
+# endif
+# ifndef CAP_FSETID
+# define CAP_FSETID -1
+# endif
+# ifndef CAP_IPC_LOCK
+# define CAP_IPC_LOCK -1
+# endif
+# ifndef CAP_IPC_OWNER
+# define CAP_IPC_OWNER -1
+# endif
+# ifndef CAP_KILL
+# define CAP_KILL -1
+# endif
+# ifndef CAP_LEASE
+# define CAP_LEASE -1
+# endif
+# ifndef CAP_LINUX_IMMUTABLE
+# define CAP_LINUX_IMMUTABLE -1
+# endif
+# ifndef CAP_MAC_ADMIN
+# define CAP_MAC_ADMIN -1
+# endif
+# ifndef CAP_MAC_OVERRIDE
+# define CAP_MAC_OVERRIDE -1
+# endif
+# ifndef CAP_MKNOD
+# define CAP_MKNOD -1
+# endif
+# ifndef CAP_NET_ADMIN
+# define CAP_NET_ADMIN -1
+# endif
+# ifndef CAP_NET_BIND_SERVICE
+# define CAP_NET_BIND_SERVICE -1
+# endif
+# ifndef CAP_NET_BROADCAST
+# define CAP_NET_BROADCAST -1
+# endif
+# ifndef CAP_NET_RAW
+# define CAP_NET_RAW -1
+# endif
+# ifndef CAP_SETGID
+# define CAP_SETGID -1
+# endif
+# ifndef CAP_SETFCAP
+# define CAP_SETFCAP -1
+# endif
+# ifndef CAP_SETPCAP
+# define CAP_SETPCAP -1
+# endif
+# ifndef CAP_SETUID
+# define CAP_SETUID -1
+# endif
+# ifndef CAP_SYS_ADMIN
+# define CAP_SYS_ADMIN -1
+# endif
+# ifndef CAP_SYS_BOOT
+# define CAP_SYS_BOOT -1
+# endif
+# ifndef CAP_SYS_CHROOT
+# define CAP_SYS_CHROOT -1
+# endif
+# ifndef CAP_SYS_MODULE
+# define CAP_SYS_MODULE -1
+# endif
+# ifndef CAP_SYS_NICE
+# define CAP_SYS_NICE -1
+# endif
+# ifndef CAP_SYS_PACCT
+# define CAP_SYS_PACCT -1
+# endif
+# ifndef CAP_SYS_PTRACE
+# define CAP_SYS_PTRACE -1
+# endif
+# ifndef CAP_SYS_RAWIO
+# define CAP_SYS_RAWIO -1
+# endif
+# ifndef CAP_SYS_RESOURCE
+# define CAP_SYS_RESOURCE -1
+# endif
+# ifndef CAP_SYS_TIME
+# define CAP_SYS_TIME -1
+# endif
+# ifndef CAP_SYS_TTY_CONFIG
+# define CAP_SYS_TTY_CONFIG -1
+# endif
+# ifndef CAP_SYSLOG
+# define CAP_SYSLOG -1
+# endif
+# ifndef CAP_WAKE_ALARM
+# define CAP_WAKE_ALARM -1
+# endif
+
+static int lxcContainerDropCapabilities(virDomainDefPtr def,
+ bool keepReboot)
{
int ret;
+ size_t i;
+ int policy = def->features[VIR_DOMAIN_FEATURE_CAPABILITIES];
+
+ /* Maps virDomainCapsFeature to CAPS_* */
+ static unsigned int capsMapping[] = {CAP_AUDIT_CONTROL,
+ CAP_AUDIT_WRITE,
+ CAP_BLOCK_SUSPEND,
+ CAP_CHOWN,
+ CAP_DAC_OVERRIDE,
+ CAP_DAC_READ_SEARCH,
+ CAP_FOWNER,
+ CAP_FSETID,
+ CAP_IPC_LOCK,
+ CAP_IPC_OWNER,
+ CAP_KILL,
+ CAP_LEASE,
+ CAP_LINUX_IMMUTABLE,
+ CAP_MAC_ADMIN,
+ CAP_MAC_OVERRIDE,
+ CAP_MKNOD,
+ CAP_NET_ADMIN,
+ CAP_NET_BIND_SERVICE,
+ CAP_NET_BROADCAST,
+ CAP_NET_RAW,
+ CAP_SETGID,
+ CAP_SETFCAP,
+ CAP_SETPCAP,
+ CAP_SETUID,
+ CAP_SYS_ADMIN,
+ CAP_SYS_BOOT,
+ CAP_SYS_CHROOT,
+ CAP_SYS_MODULE,
+ CAP_SYS_NICE,
+ CAP_SYS_PACCT,
+ CAP_SYS_PTRACE,
+ CAP_SYS_RAWIO,
+ CAP_SYS_RESOURCE,
+ CAP_SYS_TIME,
+ CAP_SYS_TTY_CONFIG,
+ CAP_SYSLOG,
+ CAP_WAKE_ALARM};
capng_get_caps_process();
- if ((ret = capng_updatev(CAPNG_DROP,
- CAPNG_EFFECTIVE | CAPNG_PERMITTED |
- CAPNG_INHERITABLE | CAPNG_BOUNDING_SET,
- CAP_SYS_MODULE, /* No kernel module loading */
- CAP_SYS_TIME, /* No changing the clock */
- CAP_MKNOD, /* No creating device nodes */
- CAP_AUDIT_CONTROL, /* No messing with auditing status */
- CAP_MAC_ADMIN, /* No messing with LSM config */
- keepReboot ? -1 : CAP_SYS_BOOT, /* No use of reboot */
- -1)) < 0) {
- virReportError(VIR_ERR_INTERNAL_ERROR,
- _("Failed to remove capabilities: %d"), ret);
- return -1;
+ /* Make sure we drop everything if required by the user */
+ if (policy == VIR_DOMAIN_CAPABILITIES_POLICY_DENY)
+ capng_clear(CAPNG_SELECT_BOTH);
+
+ /* Apply all single capabilities changes */
+ for (i = 0; i < VIR_DOMAIN_CAPS_FEATURE_LAST; i++) {
+ bool toDrop = false;
+ int state = def->caps_features[i];
+
+ if (!cap_valid(capsMapping[i]))
+ continue;
+
+ switch ((virDomainCapabilitiesPolicy) policy) {
+
+ case VIR_DOMAIN_CAPABILITIES_POLICY_DENY:
+ if (state == VIR_DOMAIN_FEATURE_STATE_ON &&
+ (ret = capng_update(CAPNG_ADD,
+ CAPNG_EFFECTIVE | CAPNG_PERMITTED |
+ CAPNG_INHERITABLE | CAPNG_BOUNDING_SET,
+ capsMapping[i])) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Failed to add capability %s: %d"),
+ virDomainCapsFeatureTypeToString(i), ret);
+ return -1;
+ }
+ break;
+
+ case VIR_DOMAIN_CAPABILITIES_POLICY_DEFAULT:
+ switch ((virDomainCapsFeature) i) {
+ case VIR_DOMAIN_CAPS_FEATURE_SYS_BOOT: /* No use of reboot */
+ toDrop = !keepReboot && (state != VIR_DOMAIN_FEATURE_STATE_ON);
+ break;
+ case VIR_DOMAIN_CAPS_FEATURE_SYS_MODULE: /* No kernel module loading */
+ case VIR_DOMAIN_CAPS_FEATURE_SYS_TIME: /* No changing the clock */
+ case VIR_DOMAIN_CAPS_FEATURE_MKNOD: /* No creating device nodes */
+ case VIR_DOMAIN_CAPS_FEATURE_AUDIT_CONTROL: /* No messing with auditing status */
+ case VIR_DOMAIN_CAPS_FEATURE_MAC_ADMIN: /* No messing with LSM config */
+ toDrop = (state != VIR_DOMAIN_FEATURE_STATE_ON);
+ break;
+ default: /* User specified capabilities to drop */
+ toDrop = (state == VIR_DOMAIN_FEATURE_STATE_OFF);
+ }
+ /* Fallthrough */
+
+ case VIR_DOMAIN_CAPABILITIES_POLICY_ALLOW:
+ if (policy == VIR_DOMAIN_CAPABILITIES_POLICY_ALLOW)
+ toDrop = state == VIR_DOMAIN_FEATURE_STATE_OFF;
+
+ if (toDrop && (ret = capng_update(CAPNG_DROP,
+ CAPNG_EFFECTIVE | CAPNG_PERMITTED |
+ CAPNG_INHERITABLE | CAPNG_BOUNDING_SET,
+ capsMapping[i])) < 0) {
+ virReportError(VIR_ERR_INTERNAL_ERROR,
+ _("Failed to remove capability %s: %d"),
+ virDomainCapsFeatureTypeToString(i), ret);
+ return -1;
+ }
+ break;
+
+ default:
+ virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+ _("Unsupported capabilities policy: %s"),
+ virDomainCapabilitiesPolicyTypeToString(policy));
+ }
}
if ((ret = capng_apply(CAPNG_SELECT_BOTH)) < 0) {
@@ -1768,7 +1976,8 @@ static int lxcContainerDropCapabilities(bool keepReboot)
return 0;
}
#else
-static int lxcContainerDropCapabilities(bool keepReboot ATTRIBUTE_UNUSED)
+static int lxcContainerDropCapabilities(virDomainDefPtr def ATTRIBUTE_UNUSED,
+ bool keepReboot ATTRIBUTE_UNUSED)
{
VIR_WARN("libcap-ng support not compiled in, unable to clear capabilities");
return 0;
@@ -1874,7 +2083,7 @@ static int lxcContainerChild(void *data)
}
/* drop a set of root capabilities */
- if (lxcContainerDropCapabilities(!!hasReboot) < 0)
+ if (lxcContainerDropCapabilities(vmDef, !!hasReboot) < 0)
goto cleanup;
if (lxcContainerSendContinue(argv->handshakefd) < 0) {
diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
index 1ec12ac..8b554a9 100644
--- a/src/util/vircgroup.c
+++ b/src/util/vircgroup.c
@@ -2660,14 +2660,45 @@ virCgroupDenyAllDevices(virCgroupPtr group)
"a");
}
+/**
+ * virCgroupAllowAllDevices:
+ *
+ * Allows the permissiong for all devices by setting lines similar
+ * to these ones (obviously the 'm' permission is an example):
+ *
+ * 'b *:* m'
+ * 'c *:* m'
+ *
+ * @group: The cgroup to allow devices for
+ * @perms: Bitwise or of VIR_CGROUP_DEVICE permission bits to allow
+ *
+ * Returns: 0 on success
+ */
+int
+virCgroupAllowAllDevices(virCgroupPtr group, int perms)
+{
+ int ret = -1;
+
+ if (virCgroupAllowDevice(group, 'b', -1, -1, perms) < 0)
+ goto cleanup;
+
+ if (virCgroupAllowDevice(group, 'c', -1, -1, perms) < 0)
+ goto cleanup;
+
+ ret = 0;
+
+ cleanup:
+ return ret;
+}
+
/**
* virCgroupAllowDevice:
*
* @group: The cgroup to allow a device for
* @type: The device type (i.e., 'c' or 'b')
- * @major: The major number of the device
- * @minor: The minor number of the device
+ * @major: The major number of the device, a negative value means '*'
+ * @minor: The minor number of the device, a negative value means '*'
* @perms: Bitwise or of VIR_CGROUP_DEVICE permission bits to allow
*
* Returns: 0 on success
@@ -2678,8 +2709,18 @@ virCgroupAllowDevice(virCgroupPtr group, char type, int major, int minor,
{
int ret = -1;
char *devstr = NULL;
+ char *majorstr = NULL;
+ char *minorstr = NULL;
- if (virAsprintf(&devstr, "%c %i:%i %s", type, major, minor,
+ if ((major < 0 && VIR_STRDUP(majorstr, "*") < 0) ||
+ virAsprintf(&majorstr, "%i", major) < 0)
+ goto cleanup;
+
+ if ((minor < 0 && VIR_STRDUP(minorstr, "*") < 0) ||
+ virAsprintf(&minorstr, "%i", minor) < 0)
+ goto cleanup;
+
+ if (virAsprintf(&devstr, "%c %s:%s %s", type, majorstr, minorstr,
virCgroupGetDevicePermsString(perms)) < 0)
goto cleanup;
@@ -2693,6 +2734,8 @@ virCgroupAllowDevice(virCgroupPtr group, char type, int major, int minor,
cleanup:
VIR_FREE(devstr);
+ VIR_FREE(majorstr);
+ VIR_FREE(minorstr);
return ret;
}
@@ -4232,6 +4275,14 @@ virCgroupGetCpusetCpus(virCgroupPtr group ATTRIBUTE_UNUSED,
return -1;
}
+int
+virCgroupAllowAllDevices(virCgroupPtr group ATTRIBUTE_UNUSED,
+ int perms ATTRIBUTE_UNUSED)
+{
+ virReportSystemError(ENOSYS, "%s",
+ _("Control groups not supported on this platform"));
+ return -1;
+}
int
virCgroupDenyAllDevices(virCgroupPtr group ATTRIBUTE_UNUSED)
diff --git a/src/util/vircgroup.h b/src/util/vircgroup.h
index 3ab9f1c..90b41f7 100644
--- a/src/util/vircgroup.h
+++ b/src/util/vircgroup.h
@@ -177,6 +177,8 @@ const char *virCgroupGetDevicePermsString(int perms);
int virCgroupDenyAllDevices(virCgroupPtr group);
+int virCgroupAllowAllDevices(virCgroupPtr group, int perms);
+
int virCgroupAllowDevice(virCgroupPtr group,
char type,
int major,
diff --git a/tests/domainschemadata/domain-caps-features.xml b/tests/domainschemadata/domain-caps-features.xml
new file mode 100644
index 0000000..4f118b2
--- /dev/null
+++ b/tests/domainschemadata/domain-caps-features.xml
@@ -0,0 +1,28 @@
+<domain type='lxc'>
+ <name>demo</name>
+ <uuid>8369f1ac-7e46-e869-4ca5-759d51478066</uuid>
+ <os>
+ <type>exe</type>
+ <init>/sh</init>
+ </os>
+ <features>
+ <capabilities policy="deny">
+ <mknod state="on"/>
+ </capabilities>
+ </features>
+ <resource>
+ <partition>/virtualmachines</partition>
+ </resource>
+ <memory unit='KiB'>500000</memory>
+ <devices>
+ <filesystem type='mount'>
+ <source dir='/root/container'/>
+ <target dir='/'/>
+ </filesystem>
+ <filesystem type='mount'>
+ <source dir='/home'/>
+ <target dir='/home'/>
+ </filesystem>
+ <console type='pty'/>
+ </devices>
+</domain>
--
1.8.4.5
--
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