[libvirt] [PATCH 09/17] libvirt-lxc: add virDomainLxcEnterCGroup API

[Daniel P. Berrange]

Add the virDomainLxcEnterCGroup API to the libvirt-lxc.so
file. This method moves the calling process into the cgroups
associated with the container.

Signed-off-by: Daniel P. Berrange <berrange at redhat.com>
---
 include/libvirt/libvirt-lxc.h |  2 ++
 src/libvirt-lxc.c             | 47 +++++++++++++++++++++++++++++++++++++++++++
 src/libvirt_lxc.syms          |  5 +++++
 3 files changed, 54 insertions(+)

diff --git a/include/libvirt/libvirt-lxc.h b/include/libvirt/libvirt-lxc.h
index 1901fce..0d16a5c 100644
--- a/include/libvirt/libvirt-lxc.h
+++ b/include/libvirt/libvirt-lxc.h
@@ -46,6 +46,8 @@ int virDomainLxcEnterSecurityLabel(virSecurityModelPtr model,
                                    virSecurityLabelPtr label,
                                    virSecurityLabelPtr oldlabel,
                                    unsigned int flags);
+int virDomainLxcEnterCGroup(virDomainPtr domain,
+                            unsigned int flags);
 
 # ifdef __cplusplus
 }
diff --git a/src/libvirt-lxc.c b/src/libvirt-lxc.c
index 8553570..16e08e9 100644
--- a/src/libvirt-lxc.c
+++ b/src/libvirt-lxc.c
@@ -36,6 +36,7 @@
 #ifdef WITH_APPARMOR
 # include <sys/apparmor.h>
 #endif
+#include "vircgroup.h"
 
 #define VIR_FROM_THIS VIR_FROM_NONE
 
@@ -269,3 +270,49 @@ virDomainLxcEnterSecurityLabel(virSecurityModelPtr model,
     virDispatchError(NULL);
     return -1;
 }
+
+
+/**
+ * virDomainLxcEnterCGroup:
+ * @domain: a domain object
+ * @flags: currently unused, pass 0
+ *
+ * This API is LXC specific, so it will only work with hypervisor
+ * connections to the LXC driver.
+ *
+ * Attaches the process to the control cgroups associated
+ * with the container @domain.
+ *
+ * Returns 0 on success, -1 on error
+ */
+int virDomainLxcEnterCGroup(virDomainPtr domain,
+                            unsigned int flags)
+{
+    virConnectPtr conn;
+    virCgroupPtr cgroup = NULL;
+
+    VIR_DOMAIN_DEBUG(domain, "flags=%x", flags);
+
+    virResetLastError();
+
+    virCheckDomainReturn(domain, -1);
+    conn = domain->conn;
+
+    virCheckReadOnlyGoto(conn->flags, error);
+    virCheckFlagsGoto(0, error);
+
+    if (virCgroupNewDetect(domain->id, -1, &cgroup) < 0)
+        goto error;
+
+    if (virCgroupAddTask(cgroup, getpid()) < 0)
+        goto error;
+
+    virCgroupFree(&cgroup);
+
+    return 0;
+
+ error:
+    virDispatchError(NULL);
+    virCgroupFree(&cgroup);
+    return -1;
+}
diff --git a/src/libvirt_lxc.syms b/src/libvirt_lxc.syms
index ccf1be9..061152a 100644
--- a/src/libvirt_lxc.syms
+++ b/src/libvirt_lxc.syms
@@ -20,3 +20,8 @@ LIBVIRT_LXC_1.0.4 {
     global:
         virDomainLxcEnterSecurityLabel;
 } LIBVIRT_LXC_1.0.2;
+
+LIBVIRT_LXC_1.3.4 {
+    global:
+        virDomainLxcEnterCGroup;
+} LIBVIRT_LXC_1.0.4;
-- 
2.5.5