From 26c9d96ccb1ea3e97b3e7b937ddb4cfaee695217 Mon Sep 17 00:00:00 2001
From: Ryan Uber <ru@ryanuber.com>
Date: Fri, 23 Jan 2015 12:48:39 -0800
Subject: [PATCH] agent: error from KVS endpoint if incompatible flags are
 passed. Fixes #432

---
 command/agent/kvs_endpoint.go      | 25 ++++++++++++++++++
 command/agent/kvs_endpoint_test.go | 42 ++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)

diff --git a/command/agent/kvs_endpoint.go b/command/agent/kvs_endpoint.go
index 54f843c91..f632cfb2c 100644
--- a/command/agent/kvs_endpoint.go
+++ b/command/agent/kvs_endpoint.go
@@ -136,6 +136,9 @@ func (s *HTTPServer) KVSPut(resp http.ResponseWriter, req *http.Request, args *s
 	if missingKey(resp, args) {
 		return nil, nil
 	}
+	if conflictingFlags(resp, req, "cas", "acquire", "release") {
+		return nil, nil
+	}
 	applyReq := structs.KVSRequest{
 		Datacenter: args.Datacenter,
 		Op:         structs.KVSSet,
@@ -209,6 +212,9 @@ func (s *HTTPServer) KVSPut(resp http.ResponseWriter, req *http.Request, args *s
 
 // KVSPut handles a DELETE request
 func (s *HTTPServer) KVSDelete(resp http.ResponseWriter, req *http.Request, args *structs.KeyRequest) (interface{}, error) {
+	if conflictingFlags(resp, req, "recurse", "cas") {
+		return nil, nil
+	}
 	applyReq := structs.KVSRequest{
 		Datacenter: args.Datacenter,
 		Op:         structs.KVSDelete,
@@ -259,3 +265,22 @@ func missingKey(resp http.ResponseWriter, args *structs.KeyRequest) bool {
 	}
 	return false
 }
+
+// conflictingFlags determines if non-composable flags were passed in a request.
+func conflictingFlags(resp http.ResponseWriter, req *http.Request, flags ...string) bool {
+	params := req.URL.Query()
+
+	found := false
+	for _, conflict := range flags {
+		if _, ok := params[conflict]; ok {
+			if found {
+				resp.WriteHeader(400)
+				resp.Write([]byte("Conflicting flags: " + params.Encode()))
+				return true
+			}
+			found = true
+		}
+	}
+
+	return false
+}
diff --git a/command/agent/kvs_endpoint_test.go b/command/agent/kvs_endpoint_test.go
index 9e2b17416..ab6357ed1 100644
--- a/command/agent/kvs_endpoint_test.go
+++ b/command/agent/kvs_endpoint_test.go
@@ -531,3 +531,45 @@ func TestKVSEndpoint_GET_Raw(t *testing.T) {
 		}
 	})
 }
+
+func TestKVSEndpoint_PUT_ConflictingFlags(t *testing.T) {
+	httpTest(t, func(srv *HTTPServer) {
+		req, err := http.NewRequest("PUT", "/v1/kv/test?cas=0&acquire=xxx", nil)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		resp := httptest.NewRecorder()
+		if _, err := srv.KVSEndpoint(resp, req); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		if resp.Code != 400 {
+			t.Fatalf("expected 400, got %d", resp.Code)
+		}
+		if !bytes.Contains(resp.Body.Bytes(), []byte("Conflicting")) {
+			t.Fatalf("expected conflicting args error")
+		}
+	})
+}
+
+func TestKVSEndpoint_DELETE_ConflictingFlags(t *testing.T) {
+	httpTest(t, func(srv *HTTPServer) {
+		req, err := http.NewRequest("DELETE", "/v1/kv/test?recurse&cas=0", nil)
+		if err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		resp := httptest.NewRecorder()
+		if _, err := srv.KVSEndpoint(resp, req); err != nil {
+			t.Fatalf("err: %v", err)
+		}
+
+		if resp.Code != 400 {
+			t.Fatalf("expected 400, got %d", resp.Code)
+		}
+		if !bytes.Contains(resp.Body.Bytes(), []byte("Conflicting")) {
+			t.Fatalf("expected conflicting args error")
+		}
+	})
+}