xsm, argo: XSM control for argo message send operation

Default policy: allow. Signed-off-by: Christopher Clark <[email protected]> Reviewed-by: Paul Durrant <[email protected]> Acked-by: Daniel De Graaf <[email protected]> v3 Daniel/Jan: add to the default xsm policy for the send op v3 Add Daniel's Acked-by v2: reordered commit sequence to after sendv implementation v1 feedback Jan #16: apply const to function signatures v1 version was: Reviewed-by: Paul Durrant <[email protected]>
andyhhp · Jan 15, 2019 · 6da973f · 6da973f
1 parent 3f2d1da
commit 6da973f
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Showing 7 changed files with 34 additions and 3 deletions.
diff --git a/tools/flask/policy/modules/guest_features.te b/tools/flask/policy/modules/guest_features.te
@@ -6,10 +6,11 @@ allow domain_type xen_t:xen tmem_op;
 allow domain_type xen_t:xen2 pmu_use;
 
 # Allow all domains:
-# to register single-sender (unicast) rings to partner with any domain; and
-# to register any-sender (wildcard) rings that can be sent to by any domain.
+# to register single-sender (unicast) rings to partner with any domain;
+# to register any-sender (wildcard) rings that can be sent to by any domain;
+# and send messages to rings.
 allow domain_type xen_t:argo { register_any_source };
-allow domain_type domain_type:argo { register_single_source };
+allow domain_type domain_type:argo { send register_single_source };
 
 # Allow guest console output to the serial console.  This is used by PV Linux
 # and stub domains for early boot output, so don't audit even when we deny it.

diff --git a/xen/common/argo.c b/xen/common/argo.c
@@ -1943,6 +1943,14 @@ sendv(struct domain *src_d, const xen_argo_addr_t *src_addr,
         goto out_unlock;
     }
 
+    ret = xsm_argo_send(src_d, dst_d);
+    if ( ret )
+    {
+        gprintk(XENLOG_ERR, "argo: XSM REJECTED %i -> %i\n",
+                src_addr->domain_id, dst_addr->domain_id);
+        goto out_unlock;
+    }
+
     read_lock(&dst_d->argo->rings_L2_rwlock);
 
     ring_info = find_ring_info_by_match(dst_d, dst_addr->aport,

diff --git a/xen/include/xsm/dummy.h b/xen/include/xsm/dummy.h
@@ -732,6 +732,12 @@ static XSM_INLINE int xsm_argo_register_any_source(struct domain *d)
     return 0;
 }
 
+static XSM_INLINE int xsm_argo_send(const struct domain *d,
+                                    const struct domain *t)
+{
+    return 0;
+}
+
 #endif /* CONFIG_ARGO */
 
 #include <public/version.h>

diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h
@@ -185,6 +185,7 @@ struct xsm_operations {
     int (*argo_register_single_source) (const struct domain *d,
                                         const struct domain *t);
     int (*argo_register_any_source) (const struct domain *d);
+    int (*argo_send) (const struct domain *d, const struct domain *t);
 #endif
 };
 
@@ -715,6 +716,11 @@ static inline xsm_argo_register_any_source(const struct domain *d)
     return xsm_ops->argo_register_any_source(d);
 }
 
+static inline int xsm_argo_send(const struct domain *d, const struct domain *t)
+{
+    return xsm_ops->argo_send(d, t);
+}
+
 #endif /* CONFIG_ARGO */
 
 #endif /* XSM_NO_WRAPPERS */

diff --git a/xen/xsm/dummy.c b/xen/xsm/dummy.c
@@ -155,5 +155,6 @@ void __init xsm_fixup_ops (struct xsm_operations *ops)
 #ifdef CONFIG_ARGO
     set_to_dummy_if_null(ops, argo_register_single_source);
     set_to_dummy_if_null(ops, argo_register_any_source);
+    set_to_dummy_if_null(ops, argo_send);
 #endif
 }
diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
@@ -1732,6 +1732,12 @@ static int flask_argo_register_any_source(const struct domain *d)
     return avc_has_perm(domain_sid(d), SECINITSID_XEN, SECCLASS_ARGO,
                         ARGO__REGISTER_ANY_SOURCE, NULL);
 }
+
+static int flask_argo_send(const struct domain *d, const struct domain *t)
+{
+    return domain_has_perm(d, t, SECCLASS_ARGO, ARGO__SEND);
+}
+
 #endif
 
 long do_flask_op(XEN_GUEST_HANDLE_PARAM(xsm_op_t) u_flask_op);
@@ -1871,6 +1877,7 @@ static struct xsm_operations flask_ops = {
 #ifdef CONFIG_ARGO
     .argo_register_single_source = flask_argo_register_single_source,
     .argo_register_any_source = flask_argo_register_any_source,
+    .argo_send = flask_argo_send,
 #endif
 };
 

diff --git a/xen/xsm/flask/policy/access_vectors b/xen/xsm/flask/policy/access_vectors
@@ -541,4 +541,6 @@ class argo
     # Domain requesting registration of a communication ring
     # to receive messages from any other domain.
     register_any_source
+    # Domain sending a message to another domain.
+    send
 }