From: Joe Stringer <joestringer@nicira.com>
Date: Wed, 11 Nov 2015 19:39:49 +0000 (-0800)
Subject: ofproto-dpif: Reject partial ct_labels if unsupported.
X-Git-Tag: v2.5.0~213
X-Git-Url: http://git.cascardo.eti.br/?p=cascardo%2Fovs.git;a=commitdiff_plain;h=efba5ae4643c3806dabe4d0dff5494ddb6359b69

ofproto-dpif: Reject partial ct_labels if unsupported.

If only half of a ct_label is present in a miniflow/minimask (eg, only
matching on one specific bit), then rule_check() would allow the flow
even if ct_label was unsupported, because it required both 64-bit fields
that comprise the ct_label to be present in the miniflow before
performing the check.

Fix this by populating the stack copy of the label directly from the
miniflow fields if available (or zero each 64-bit word if unavailable).

Suggested-by: Jarno Rajahalme <jrajahalme@nicira.com>
Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Jarno Rajahalme <jarno@ovn.org>
---

diff --git a/lib/flow.h b/lib/flow.h
index 7be03adba..5d78615a4 100644
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -788,14 +788,12 @@ miniflow_get__(const struct miniflow *mf, size_t idx)
      [FLOW_U64_OFFREM(FIELD) / sizeof(TYPE)]                            \
      : 0)
 
-/* Get a pointer to the ovs_u128 value of struct flow 'FIELD' from miniflow
- * 'FLOW'. */
-#define MINIFLOW_GET_U128_PTR(FLOW, FIELD)                              \
-    ((MINIFLOW_IN_MAP(FLOW, FLOW_U64_OFFSET(FIELD))                     \
-      && (MINIFLOW_IN_MAP(FLOW, FLOW_U64_OFFSET(FIELD) + 1)))           \
-     ? &((OVS_FORCE const ovs_u128 *)miniflow_get__(FLOW, FLOW_U64_OFFSET(FIELD))) \
-     [FLOW_U64_OFFREM(FIELD) / sizeof(ovs_u128)]                        \
-     : NULL)
+#define MINIFLOW_GET_U128(FLOW, FIELD)                                  \
+    (ovs_u128) { .u64 = {                                               \
+            (MINIFLOW_IN_MAP(FLOW, FLOW_U64_OFFSET(FIELD)) ?            \
+             *miniflow_get__(FLOW, FLOW_U64_OFFSET(FIELD)) : 0),        \
+            (MINIFLOW_IN_MAP(FLOW, FLOW_U64_OFFSET(FIELD) + 1) ?        \
+             *miniflow_get__(FLOW, FLOW_U64_OFFSET(FIELD) + 1) : 0) } }
 
 #define MINIFLOW_GET_U8(FLOW, FIELD)            \
     MINIFLOW_GET_TYPE(FLOW, uint8_t, FIELD)
diff --git a/ofproto/ofproto-dpif.c b/ofproto/ofproto-dpif.c
index 3d41d11b4..37c5d5da0 100644
--- a/ofproto/ofproto-dpif.c
+++ b/ofproto/ofproto-dpif.c
@@ -4016,17 +4016,13 @@ static enum ofperr
 rule_check(struct rule *rule)
 {
     uint16_t ct_state, ct_zone;
-    const ovs_u128 *labelp;
-    ovs_u128 ct_label = { { 0, 0 } };
+    ovs_u128 ct_label;
     uint32_t ct_mark;
 
     ct_state = MINIFLOW_GET_U16(rule->cr.match.flow, ct_state);
     ct_zone = MINIFLOW_GET_U16(rule->cr.match.flow, ct_zone);
     ct_mark = MINIFLOW_GET_U32(rule->cr.match.flow, ct_mark);
-    labelp = MINIFLOW_GET_U128_PTR(rule->cr.match.flow, ct_label);
-    if (labelp) {
-        ct_label = *labelp;
-    }
+    ct_label = MINIFLOW_GET_U128(rule->cr.match.flow, ct_label);
 
     if (ct_state || ct_zone || ct_mark
         || !ovs_u128_is_zero(&ct_label)) {