Log an audit message with the LXC init pid

Currently the LXC driver logs audit messages when a container
is started or stopped. These audit messages, however, contain
the PID of the libvirt_lxc supervisor process. To enable
sysadmins to correlate with audit messages generated by
processes /inside/ the container, we need to include the
container init process PID.

We can't do this in the main 'start' audit message, since
the init PID is not available at that point. Instead we output
a completely new audit record, that lists both PIDs.

type=VIRT_CONTROL msg=audit(1353433750.071:363): pid=20180 uid=0 auid=501 ses=3 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 msg='virt=lxc op=init vm="busy" uuid=dda7b947-0846-1759-2873-0f375df7d7eb vm-pid=20371 init-pid=20372 exe="/home/berrange/src/virt/libvirt/daemon/.libs/lt-libvirtd" hostname=? addr=? terminal=pts/6 res=success'

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>

src/conf/domain_audit.c

@@ -605,6 +605,32 @@ virDomainAuditStart(virDomainObjPtr vm, const char *reason, bool success)
     virDomainAuditLifecycle(vm, "start", reason, success);
 }
 
+void
+virDomainAuditInit(virDomainObjPtr vm,
+                   pid_t initpid)
+{
+    char uuidstr[VIR_UUID_STRING_BUFLEN];
+    char *vmname;
+    const char *virt;
+
+    virUUIDFormat(vm->def->uuid, uuidstr);
+
+    if (!(vmname = virAuditEncode("vm", vm->def->name))) {
+        VIR_WARN("OOM while encoding audit message");
+        return;
+    }
+
+    if (!(virt = virDomainVirtTypeToString(vm->def->virtType))) {
+        VIR_WARN("Unexpected virt type %d while encoding audit message", vm->def->virtType);
+        virt = "?";
+    }
+
+    VIR_AUDIT(VIR_AUDIT_RECORD_MACHINE_CONTROL, true,
+              "virt=%s op=init %s uuid=%s vm-pid=%lld init-pid=%lld",
+              virt, vmname, uuidstr, (long long)vm->pid, (long long)initpid);
+
+    VIR_FREE(vmname);
+}
 
 void
 virDomainAuditStop(virDomainObjPtr vm, const char *reason)

src/conf/domain_audit.h

@@ -31,6 +31,9 @@ void virDomainAuditStart(virDomainObjPtr vm,
                          const char *reason,
                          bool success)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
+void virDomainAuditInit(virDomainObjPtr vm,
+                        pid_t pid)
+    ATTRIBUTE_NONNULL(1);
 void virDomainAuditStop(virDomainObjPtr vm,
                         const char *reason)
     ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);

src/libvirt_private.syms

@@ -258,6 +258,7 @@ virDomainAuditCgroupPath;
 virDomainAuditDisk;
 virDomainAuditFS;
 virDomainAuditHostdev;
+virDomainAuditInit;
 virDomainAuditMemory;
 virDomainAuditNet;
 virDomainAuditNetDevice;

src/lxc/lxc_controller.c

@@ -125,6 +125,7 @@ struct _virLXCController {
 
     /* Server socket */
     virNetServerPtr server;
+    bool firstClient;
     virNetServerClientPtr client;
     virNetServerProgramPtr prog;
     bool inShutdown;
@@ -134,6 +135,8 @@ struct _virLXCController {
 #include "lxc_controller_dispatch.h"
 
 static void virLXCControllerFree(virLXCControllerPtr ctrl);
+static int virLXCControllerEventSendInit(virLXCControllerPtr ctrl,
+                                         pid_t initpid);
 
 static void virLXCControllerQuitTimer(int timer ATTRIBUTE_UNUSED, void *opaque)
 {
@@ -154,6 +157,7 @@ static virLXCControllerPtr virLXCControllerNew(const char *name)
         goto no_memory;
 
     ctrl->timerShutdown = -1;
+    ctrl->firstClient = true;
 
     if (!(ctrl->name = strdup(name)))
         goto no_memory;
@@ -591,6 +595,11 @@ static void *virLXCControllerClientPrivateNew(virNetServerClientPtr client,
     virNetServerClientSetCloseHook(client, virLXCControllerClientCloseHook);
     VIR_DEBUG("Got new client %p", client);
     ctrl->client = client;
+
+    if (ctrl->initpid && ctrl->firstClient)
+        virLXCControllerEventSendInit(ctrl, ctrl->initpid);
+    ctrl->firstClient = false;
+
     return dummy;
 }
 
@@ -1278,8 +1287,10 @@ virLXCControllerEventSend(virLXCControllerPtr ctrl,
 {
     virNetMessagePtr msg;
 
-    if (!ctrl->client)
+    if (!ctrl->client) {
+        VIR_WARN("Dropping event %d becuase libvirtd is not connected", procnr);
         return;
+    }
 
     VIR_DEBUG("Send event %d client=%p", procnr, ctrl->client);
     if (!(msg = virNetMessageNew(false)))
@@ -1346,6 +1357,24 @@ virLXCControllerEventSendExit(virLXCControllerPtr ctrl,
 }
 
 
+static int
+virLXCControllerEventSendInit(virLXCControllerPtr ctrl,
+                              pid_t initpid)
+{
+    virLXCProtocolInitEventMsg msg;
+
+    VIR_DEBUG("Init pid %llu", (unsigned long long)initpid);
+    memset(&msg, 0, sizeof(msg));
+    msg.initpid = initpid;
+
+    virLXCControllerEventSend(ctrl,
+                              VIR_LXC_PROTOCOL_PROC_INIT_EVENT,
+                              (xdrproc_t)xdr_virLXCProtocolInitEventMsg,
+                              (void*)&msg);
+    return 0;
+}
+
+
 static int
 virLXCControllerRun(virLXCControllerPtr ctrl)
 {

src/lxc/lxc_monitor.c

@@ -65,12 +65,20 @@ static void
 virLXCMonitorHandleEventExit(virNetClientProgramPtr prog,
                              virNetClientPtr client,
                              void *evdata, void *opaque);
+static void
+virLXCMonitorHandleEventInit(virNetClientProgramPtr prog,
+                             virNetClientPtr client,
+                             void *evdata, void *opaque);
 
 static virNetClientProgramEvent virLXCProtocolEvents[] = {
     { VIR_LXC_PROTOCOL_PROC_EXIT_EVENT,
       virLXCMonitorHandleEventExit,
       sizeof(virLXCProtocolExitEventMsg),
       (xdrproc_t)xdr_virLXCProtocolExitEventMsg },
+    { VIR_LXC_PROTOCOL_PROC_INIT_EVENT,
+      virLXCMonitorHandleEventInit,
+      sizeof(virLXCProtocolInitEventMsg),
+      (xdrproc_t)xdr_virLXCProtocolInitEventMsg },
 };
 
 
@@ -88,6 +96,21 @@ virLXCMonitorHandleEventExit(virNetClientProgramPtr prog ATTRIBUTE_UNUSED,
 }
 
 
+static void
+virLXCMonitorHandleEventInit(virNetClientProgramPtr prog ATTRIBUTE_UNUSED,
+                             virNetClientPtr client ATTRIBUTE_UNUSED,
+                             void *evdata, void *opaque)
+{
+    virLXCMonitorPtr mon = opaque;
+    virLXCProtocolInitEventMsg *msg = evdata;
+
+    VIR_DEBUG("Event init %llu",
+              (unsigned long long)msg->initpid);
+    if (mon->cb.initNotify)
+        mon->cb.initNotify(mon, (pid_t)msg->initpid, mon->vm);
+}
+
+
 static void virLXCMonitorEOFNotify(virNetClientPtr client ATTRIBUTE_UNUSED,
                                    int reason ATTRIBUTE_UNUSED,
                                    void *opaque)

src/lxc/lxc_monitor.h

@@ -40,10 +40,15 @@ typedef void (*virLXCMonitorCallbackExitNotify)(virLXCMonitorPtr mon,
                                                 virLXCProtocolExitStatus status,
                                                 virDomainObjPtr vm);
 
+typedef void (*virLXCMonitorCallbackInitNotify)(virLXCMonitorPtr mon,
+                                                pid_t pid,
+                                                virDomainObjPtr vm);
+
 struct _virLXCMonitorCallbacks {
     virLXCMonitorCallbackDestroy destroy;
     virLXCMonitorCallbackEOFNotify eofNotify;
     virLXCMonitorCallbackExitNotify exitNotify;
+    virLXCMonitorCallbackInitNotify initNotify;
 };
 
 virLXCMonitorPtr virLXCMonitorNew(virDomainObjPtr vm,

src/lxc/lxc_process.c

@@ -637,9 +637,17 @@ static void virLXCProcessMonitorExitNotify(virLXCMonitorPtr mon ATTRIBUTE_UNUSED
               priv->stopReason, status);
 }
 
+static void virLXCProcessMonitorInitNotify(virLXCMonitorPtr mon ATTRIBUTE_UNUSED,
+                                           pid_t initpid,
+                                           virDomainObjPtr vm)
+{
+    virDomainAuditInit(vm, initpid);
+}
+
 static virLXCMonitorCallbacks monitorCallbacks = {
     .eofNotify = virLXCProcessMonitorEOFNotify,
     .exitNotify = virLXCProcessMonitorExitNotify,
+    .initNotify = virLXCProcessMonitorInitNotify,
 };
 
 

src/lxc/lxc_protocol.x

@@ -14,9 +14,14 @@ struct virLXCProtocolExitEventMsg {
     enum virLXCProtocolExitStatus status;
 };
 
+struct virLXCProtocolInitEventMsg {
+    unsigned hyper initpid;
+};
+
 const VIR_LXC_PROTOCOL_PROGRAM = 0x12341234;
 const VIR_LXC_PROTOCOL_PROGRAM_VERSION = 1;
 
 enum virLXCProtocolProcedure {
-    VIR_LXC_PROTOCOL_PROC_EXIT_EVENT = 1 /* skipgen skipgen */
+    VIR_LXC_PROTOCOL_PROC_EXIT_EVENT = 1, /* skipgen skipgen */
+    VIR_LXC_PROTOCOL_PROC_INIT_EVENT = 2 /* skipgen skipgen */
 };