msg/Pipe: work around incorrect features reported by earlier versions

If we see a peer reporting features ~0ull, we know they are deluded in a
particular way and should infer what features they *actually* have.  Do
this right when the features come over the wire to catch all users.

Fixes: #5655
Signed-off-by: Samuel Just <sam.just@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>

2 files changed, 35 insertions, 5 deletions

diff --git a/src/include/ceph_features.h b/src/include/ceph_features.h
index f72e1028898..362a459bde6 100644
--- a/src/include/ceph_features.h
+++ b/src/include/ceph_features.h
@@ -41,6 +41,28 @@
 #define CEPH_FEATURE_OSD_PACKED_RECOVERY (1ULL<<34)
 
 /*
+ * The introduction of CEPH_FEATURE_OSD_SNAPMAPPER caused the feature
+ * vector to evaluate to 64 bit ~0.  To cope, we designate 1ULL << 63
+ * to mean 33 bit ~0, and introduce a helper below to do the
+ * translation.
+ *
+ * This was introduced by commit
+ *   9ea02b84104045c2ffd7e7f4e7af512953855ecd v0.58-657-g9ea02b8
+ * and fixed by commit
+ *   4255b5c2fb54ae40c53284b3ab700fdfc7e61748 v0.65-263-g4255b5c
+ */
+#define CEPH_FEATURE_RESERVED (1ULL<<63)
+
+static inline unsigned long long ceph_sanitize_features(unsigned long long f) {
+	if (f & CEPH_FEATURE_RESERVED) {
+		/* everything through OSD_SNAPMAPPER */
+		return 0x1ffffffffull;
+	} else {
+		return f;
+	}
+}
+
+/*
  * Features supported.  Should be everything above.
  */
 #define CEPH_FEATURES_ALL		 \
diff --git a/src/msg/Pipe.cc b/src/msg/Pipe.cc
index 03ee79a15c2..6f271c812f3 100644
--- a/src/msg/Pipe.cc
+++ b/src/msg/Pipe.cc
@@ -313,6 +313,9 @@ int Pipe::accept()
       goto fail_unlocked;
     }
 
+    // sanitize features
+    connect.features = ceph_sanitize_features(connect.features);
+
     authorizer.clear();
     if (connect.authorizer_len) {
       bp = buffer::create(connect.authorizer_len);
@@ -920,12 +923,17 @@ int Pipe::connect()
       ldout(msgr->cct,2) << "connect read reply " << strerror_r(errno, buf, sizeof(buf)) << dendl;
       goto fail;
     }
+
+    // sanitize features
+    reply.features = ceph_sanitize_features(reply.features);
+
     ldout(msgr->cct,20) << "connect got reply tag " << (int)reply.tag
-	     << " connect_seq " << reply.connect_seq
-	     << " global_seq " << reply.global_seq
-	     << " proto " << reply.protocol_version
-	     << " flags " << (int)reply.flags
-	     << dendl;
+			<< " connect_seq " << reply.connect_seq
+			<< " global_seq " << reply.global_seq
+			<< " proto " << reply.protocol_version
+			<< " flags " << (int)reply.flags
+			<< " features " << reply.features
+			<< dendl;
 
     authorizer_reply.clear();