Fix for WebSocket payload length using 8 bytes

The 8-byte conversion macros were incorrect, and could be replaced with
standard methods instead. This also adds a test to cover this case.

src/websocket.c

@@ -29,18 +29,6 @@ ws_schedule_write(struct ws_client *ws);
  * A copy is available at http://www.rfc-editor.org/rfc/rfc6455.txt
  */
 
-/* custom 64-bit encoding functions to avoid portability issues */
-#define webdis_ntohl64(p) \
-	((((uint64_t)((p)[0])) <<  0) + (((uint64_t)((p)[1])) <<  8) +\
-	 (((uint64_t)((p)[2])) << 16) + (((uint64_t)((p)[3])) << 24) +\
-	 (((uint64_t)((p)[4])) << 32) + (((uint64_t)((p)[5])) << 40) +\
-	 (((uint64_t)((p)[6])) << 48) + (((uint64_t)((p)[7])) << 56))
-
-#define webdis_htonl64(p) {\
-	(char)(((p & ((uint64_t)0xff <<  0)) >>  0) & 0xff), (char)(((p & ((uint64_t)0xff <<  8)) >>  8) & 0xff), \
-	(char)(((p & ((uint64_t)0xff << 16)) >> 16) & 0xff), (char)(((p & ((uint64_t)0xff << 24)) >> 24) & 0xff), \
-	(char)(((p & ((uint64_t)0xff << 32)) >> 32) & 0xff), (char)(((p & ((uint64_t)0xff << 40)) >> 40) & 0xff), \
-	(char)(((p & ((uint64_t)0xff << 48)) >> 48) & 0xff), (char)(((p & ((uint64_t)0xff << 56)) >> 56) & 0xff) }
 static int
 ws_compute_handshake(struct http_client *c, char *out, size_t *out_sz) {
 
@@ -411,7 +399,7 @@ ws_peek_data(struct ws_client *ws, struct ws_msg **out_msg) {
 		p = frame + 4 + (has_mask ? 4 : 0);
 		if(has_mask) memcpy(&mask, frame + 4, sizeof(mask));
 	} else if(len == 127) {
-		len = webdis_ntohl64(frame+2);
+		len = ntohll(*(uint64_t*)(frame+2));
 		p = frame + 10 + (has_mask ? 4 : 0);
 		if(has_mask) memcpy(&mask, frame + 10, sizeof(mask));
 	} else {
@@ -532,7 +520,9 @@ ws_frame_and_send_response(struct ws_client *ws, enum ws_frame_type frame_type,
 		memcpy(frame + 4, p, sz);
 		frame_sz = sz + 4;
 	} else { /* sz > 65536 */
-		char sz64[8] = webdis_htonl64(sz);
+		uint64_t sz_be = htonll(sz);
+		char sz64[8];
+		memcpy(sz64, &sz_be, 8);
 		frame[1] = 127;
 		memcpy(frame + 2, sz64, 8);
 		memcpy(frame + 10, p, sz);
@@ -577,7 +567,12 @@ ws_can_read(int fd, short event, void *p) {
 	} else if(ws->close_after_events) {
 		ws_close_if_able(ws);
 	} else {
-		ws_process_read_data(ws, NULL);
+		enum ws_state state = ws_process_read_data(ws, NULL);
+		if(state == WS_READING) { /* need more data, schedule new read */
+			ws_monitor_input(ws);
+		} else if(state == WS_ERROR) {
+			ws_close_if_able(ws);
+		}
 	}
 }
 

tests/ws-tests.py

@@ -167,5 +167,29 @@ class TestPubSub(unittest.TestCase):
                                  f'In {channel}: expected at offset {i} was "{expected}", actual was: "{received_per_channel[channel][i]}"')
 
 
+class TestFrameSizes(TestWebdis):
+    def format(self):
+        return 'json'
+
+    def serialize(self, cmd, *args):
+        return json.dumps([cmd] + list(args))
+
+    def deserialize(self, response):
+        return json.loads(response)
+
+    def test_length_126(self):
+        key = str(uuid.uuid4())
+        value = 'A' * 1024  # this will require 2 bytes to encode the length
+        self.assertEqual(self.exec('SET', key, value), {'SET': [True, 'OK']})
+        self.exec('DEL', key)
+
+    def test_length_127(self):
+        key = str(uuid.uuid4())
+        value = 'A' * (2 ** 18)  # this will require more than 2 bytes to encode the length (actually using 8)
+        self.assertEqual(self.exec('SET', key, value), {'SET': [True, 'OK']})
+        self.exec('DEL', key)
+
+
+
 if __name__ == '__main__':
     unittest.main()