[libvirt] [PATCHv2] audit: Audit resources used by VirtIO RNG
Daniel P. Berrange
berrange at redhat.com
Tue Mar 12 18:02:28 UTC 2013
On Tue, Mar 12, 2013 at 04:11:15PM +0100, Peter Krempa wrote:
> This patch adds auditing of resources used by Virtio RNG devices. Only
> resources on the local filesystems are audited properly. For remote
> character device sources "remote" is logged as the path and "none"
> is logged for character device backends that don't have a source.
>
> The audit logs look like:
>
> For the 'random' backend:
> type=VIRT_RESOURCE msg=audit(1363099126.643:31): pid=995252 uid=0 auid=4294967295 ses=4294967295 msg='virt=kvm resrc=rng reason=start vm="qcow-test" uuid=118733ed-b658-3e22-a2cb-4fe5cb3ddf79 old-rng="?" new-rng="/dev/random": exe="/home/pipo/libvirt/daemon/.libs/libvirtd" hostname=? addr=? terminal=pts/0 res=success'
>
> For local character device source:
> type=VIRT_RESOURCE msg=audit(1363100164.240:96): pid=995252 uid=0 auid=4294967295 ses=4294967295 msg='virt=kvm resrc=rng reason=start vm="qcow-test" uuid=118733ed-b658-3e22-a2cb-4fe5cb3ddf79 old-rng="?" new-rng="/tmp/unix.sock": exe="/home/pipo/libvirt/daemon/.libs/libvirtd" hostname=? addr=? terminal=pts/0 res=success'
>
> For a remote character device source:
> type=VIRT_RESOURCE msg=audit(1363100291.450:127): pid=995252 uid=0 auid=4294967295 ses=4294967295 msg='virt=kvm resrc=rng reason=start vm="qcow-test" uuid=118733ed-b658-3e22-a2cb-4fe5cb3ddf79 old-rng="?" new-rng="remote": exe="/home/pipo/libvirt/daemon/.libs/libvirtd" hostname=? addr=? terminal=pts/0 res=success'
>
> And for character backends that don't have a source:
> type=VIRT_RESOURCE msg=audit(1363100520.513:158): pid=995252 uid=0 auid=4294967295 ses=4294967295 msg='virt=kvm resrc=rng reason=start vm="qcow-test" uuid=118733ed-b658-3e22-a2cb-4fe5cb3ddf79 old-rng="?" new-rng="none": exe="/home/pipo/libvirt/daemon/.libs/libvirtd" hostname=? addr=? terminal=pts/0 res=success'
For devices which don't touch any local resource, we should simply not emit any
audit record at all. So these last two examples should simply not exist.
> diff --git a/src/conf/domain_audit.c b/src/conf/domain_audit.c
> index 8cd522a..0f2cf4f 100644
> --- a/src/conf/domain_audit.c
> +++ b/src/conf/domain_audit.c
> @@ -57,6 +57,37 @@ virDomainAuditGetRdev(const char *path ATTRIBUTE_UNUSED)
> }
> #endif
>
> +static const char *
> +virDomainAuditChardev(virDomainChrSourceDefPtr chr)
> +{
> + if (!chr)
> + return "?";
> +
> + switch ((enum virDomainChrType) chr->type) {
> + case VIR_DOMAIN_CHR_TYPE_PTY:
> + case VIR_DOMAIN_CHR_TYPE_DEV:
> + case VIR_DOMAIN_CHR_TYPE_FILE:
> + case VIR_DOMAIN_CHR_TYPE_PIPE:
> + return chr->data.file.path;
> +
> + case VIR_DOMAIN_CHR_TYPE_UNIX:
> + return chr->data.nix.path;
> +
> + case VIR_DOMAIN_CHR_TYPE_TCP:
> + case VIR_DOMAIN_CHR_TYPE_UDP:
> + return "remote";
So return NULL here
> +
> + case VIR_DOMAIN_CHR_TYPE_NULL:
> + case VIR_DOMAIN_CHR_TYPE_VC:
> + case VIR_DOMAIN_CHR_TYPE_STDIO:
> + case VIR_DOMAIN_CHR_TYPE_SPICEVMC:
> + case VIR_DOMAIN_CHR_TYPE_LAST:
> + return "none";
and return NULL here
> + }
> +
> + return "?";
> +}
> +
> void
> virDomainAuditDisk(virDomainObjPtr vm,
> const char *oldDef, const char *newDef,
> @@ -100,6 +131,89 @@ cleanup:
> }
>
>
> +static void
> +virDomainAuditRNG(virDomainObjPtr vm,
> + virDomainRNGDefPtr newDef, virDomainRNGDefPtr oldDef,
> + const char *reason, bool success)
> +{
> + char uuidstr[VIR_UUID_STRING_BUFLEN];
> + char *vmname;
> + const char *newsrcpath = NULL;
> + const char *oldsrcpath = NULL;
> + char *oldsrc = NULL;
> + char *newsrc = NULL;
> + const char *virt;
> +
> + virUUIDFormat(vm->def->uuid, uuidstr);
> + if (!(vmname = virAuditEncode("vm", vm->def->name)))
> + goto no_memory;
> +
> + if (!(virt = virDomainVirtTypeToString(vm->def->virtType))) {
> + VIR_WARN("Unexpected virt type %d while encoding audit message",
> + vm->def->virtType);
> + virt = "?";
> + }
> +
> + if (newDef) {
> + switch ((enum virDomainRNGBackend) newDef->backend) {
> + case VIR_DOMAIN_RNG_BACKEND_RANDOM:
> + if (newDef->source.file)
> + newsrcpath = newDef->source.file;
> + else
> + newsrcpath = "/dev/random";
> + break;
> +
> + case VIR_DOMAIN_RNG_BACKEND_EGD:
> + newsrcpath = virDomainAuditChardev(newDef->source.chardev);
> + break;
> +
> + case VIR_DOMAIN_RNG_BACKEND_LAST:
> + break;
> + }
> + }
> +
> + if (!(newsrc = virAuditEncode("new-rng", VIR_AUDIT_STR(newsrcpath))))
> + goto no_memory;
> +
> +
> + if (oldDef) {
> + switch ((enum virDomainRNGBackend) oldDef->backend) {
> + case VIR_DOMAIN_RNG_BACKEND_RANDOM:
> + if (oldDef->source.file)
> + oldsrcpath = oldDef->source.file;
> + else
> + oldsrcpath = "/dev/random";
> + break;
> +
> + case VIR_DOMAIN_RNG_BACKEND_EGD:
> + oldsrcpath = virDomainAuditChardev(oldDef->source.chardev);
> + break;
> +
> + case VIR_DOMAIN_RNG_BACKEND_LAST:
> + break;
> + }
> + }
And if both newsrcpath and oldsrcpath are NULL at this point, then jump
to the cleanup label
> +
> + if (!(oldsrc = virAuditEncode("old-rng", VIR_AUDIT_STR(oldsrcpath))))
> + goto no_memory;
> +
> + VIR_AUDIT(VIR_AUDIT_RECORD_RESOURCE, success,
> + "virt=%s resrc=rng reason=%s %s uuid=%s %s %s",
> + virt, reason, vmname, uuidstr,
> + oldsrc, newsrc);
> +
> +cleanup:
> + VIR_FREE(vmname);
> + VIR_FREE(oldsrc);
> + VIR_FREE(newsrc);
> + return;
> +
> +no_memory:
> + VIR_WARN("OOM while encoding audit message");
> + goto cleanup;
> +}
> +
> +
> void
> virDomainAuditFS(virDomainObjPtr vm,
> virDomainFSDefPtr oldDef, virDomainFSDefPtr newDef,
> @@ -641,6 +755,9 @@ virDomainAuditStart(virDomainObjPtr vm, const char *reason, bool success)
> virDomainAuditRedirdev(vm, redirdev, "start", true);
> }
>
> + if (vm->def->rng)
> + virDomainAuditRNG(vm, vm->def->rng, NULL, "start", true);
> +
> virDomainAuditMemory(vm, 0, vm->def->mem.cur_balloon, "start", true);
> virDomainAuditVcpu(vm, 0, vm->def->vcpus, "start", true);
Daniel
--
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