[libvirt] [PATCH 1/6] security: Add check for valid security model

[Erik Skultety]

We do have a check for valid per-domain security model, however we still
do permit an invalid security model for a <disk> type device.
This patch introduces a new function virSecurityStackCheckDiskLabels
which compares user specified security model against currently
registered security drivers. That being said, it also permits 'none'
being specified as a device security model.

Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1165485
---
 src/security/security_manager.c |  5 +++++
 src/security/security_manager.h |  1 +
 src/security/security_stack.c   | 48 +++++++++++++++++++++++++++++++++++++++--
 3 files changed, 52 insertions(+), 2 deletions(-)

diff --git a/src/security/security_manager.c b/src/security/security_manager.c
index 302f54d..8eacf0c 100644
--- a/src/security/security_manager.c
+++ b/src/security/security_manager.c
@@ -262,6 +262,11 @@ virSecurityManagerGetDriver(virSecurityManagerPtr mgr)
     return mgr->virtDriver;
 }
 
+const char *
+virSecurityManagerGetDriverName(virSecurityManagerPtr mgr)
+{
+    return mgr->drv->name;
+}
 
 const char *
 virSecurityManagerGetDOI(virSecurityManagerPtr mgr)
diff --git a/src/security/security_manager.h b/src/security/security_manager.h
index 156f882..4626c4b 100644
--- a/src/security/security_manager.h
+++ b/src/security/security_manager.h
@@ -70,6 +70,7 @@ void virSecurityManagerPostFork(virSecurityManagerPtr mgr);
 void *virSecurityManagerGetPrivateData(virSecurityManagerPtr mgr);
 
 const char *virSecurityManagerGetDriver(virSecurityManagerPtr mgr);
+const char *virSecurityManagerGetDriverName(virSecurityManagerPtr mgr);
 const char *virSecurityManagerGetDOI(virSecurityManagerPtr mgr);
 const char *virSecurityManagerGetModel(virSecurityManagerPtr mgr);
 const char *virSecurityManagerGetBaseLabel(virSecurityManagerPtr mgr, int virtType);
diff --git a/src/security/security_stack.c b/src/security/security_stack.c
index 1ded57b..75d8b96 100644
--- a/src/security/security_stack.c
+++ b/src/security/security_stack.c
@@ -301,7 +301,46 @@ virSecurityStackRestoreSecurityHostdevLabel(virSecurityManagerPtr mgr,
     return rc;
 }
 
+static int
+virSecurityStackCheckSecurityDiskLabels(virSecurityManagerPtr mgr,
+                                        virDomainDefPtr vm)
+{
+    virSecurityStackDataPtr priv = virSecurityManagerGetPrivateData(mgr);
+    virSecurityStackItemPtr item = priv->itemsHead;
+    size_t i, j;
+    bool sec_model_valid = false;
+
+    for (i = 0; i < vm->ndisks; i++) {
+        virStorageSourcePtr src = vm->disks[i]->src;
+        for (j = 0; j < src->nseclabels; j++) {
+            const char *sec_model = src->seclabels[j]->model;
+
+            if (STREQ_NULLABLE(sec_model, "none")) {
+                sec_model_valid = true;
+                continue;
+            }
+
+            sec_model_valid = false;
+            for (; item; item = item->next) {
+                const char *drv_name = virSecurityManagerGetDriverName(mgr);
+
+                if (STREQ_NULLABLE(sec_model, drv_name)) {
+                    sec_model_valid = true;
+                    break;
+                }
+            }
+            if (!sec_model_valid) {
+                virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
+                               _("No security driver matches security model "
+                                 "'%s'"),
+                               sec_model);
+                return -1;
+            }
+        }
+    }
 
+    return 0;
+}
 static int
 virSecurityStackSetSecurityAllLabel(virSecurityManagerPtr mgr,
                                     virDomainDefPtr vm,
@@ -309,13 +348,18 @@ virSecurityStackSetSecurityAllLabel(virSecurityManagerPtr mgr,
 {
     virSecurityStackDataPtr priv = virSecurityManagerGetPrivateData(mgr);
     virSecurityStackItemPtr item = priv->itemsHead;
-    int rc = 0;
+    int rc = -1;
+
+    if (virSecurityStackCheckSecurityDiskLabels(mgr, vm) < 0)
+        goto error;
 
     for (; item; item = item->next) {
         if (virSecurityManagerSetAllLabel(item->securityManager, vm, stdin_path) < 0)
-            rc = -1;
+            goto error;
     }
+    rc = 0;
 
+ error:
     return rc;
 }
 
-- 
1.9.3