wswrapper: interpose select/pselect. Cleaup.

Interpose on select/pselect so that WebSockets sockets are only
reported as ready if they have enough to actually decode at least
1 byte of real data. This prevents hanging in read/recv after
WebSocket is reported as ready but is not actually ready because empty
frames or less than four base64 bytes have been received.

Split defines and constant defintions into wswrapper.h.

Cleanup debug output and add TRACE for more detailed tracing debug
output.

Major TODO is that select needs to timeout if WebSocket socket keeps
reporting ready but actually isn't ready. That condition will
currently hang forever because the select timeout value is not
adjusted when looping.

utils/Makefile

@@ -6,6 +6,7 @@ all: $(TARGETS)
 wsproxy: wsproxy.o websocket.o md5.o
 	$(CC) $(LDFLAGS) $^ -lssl -lcrypto -lresolv -o $@
 
+wswrapper.o: wswrapper.h
 wswrapper.so: wswrapper.o md5.o
 	$(CC) $(LDFLAGS) $^ -shared -fPIC -ldl -lresolv -o $@
 

utils/wswrapper.h

+/*
+ * wswrap/wswrapper: Add WebSockets support to any service.
+ * Copyright 2010 Joel Martin
+ * Licensed under LGPL version 3 (see docs/LICENSE.LGPL-3)
+ *
+ * wswrapper.so is meant to be LD preloaded. Use wswrap to run a program using
+ * wswrapper.so.
+ */
+
+//#define DO_DEBUG 1
+//#define DO_TRACE 1
+
+#ifdef DO_DEBUG
+#define DEBUG(...) \
+    if (DO_DEBUG) { \
+        fprintf(stderr, "wswrapper: "); \
+        fprintf(stderr, __VA_ARGS__); \
+    }
+#else
+#define DEBUG(...)
+#endif
+
+#ifdef DO_TRACE
+#define TRACE(...) \
+    if (DO_TRACE) { \
+        fprintf(stderr, "wswrapper: "); \
+        fprintf(stderr, __VA_ARGS__); \
+    }
+#else
+#define TRACE(...)
+#endif
+
+#define MSG(...) \
+    fprintf(stderr, "wswrapper: "); \
+    fprintf(stderr, __VA_ARGS__);
+
+#define RET_ERROR(eno, ...) \
+    fprintf(stderr, "wswrapper error: "); \
+    fprintf(stderr, __VA_ARGS__); \
+    errno = eno; \
+    return -1;
+
+
+const char _WS_response[] = "\
+HTTP/1.1 101 Web Socket Protocol Handshake\r\n\
+Upgrade: WebSocket\r\n\
+Connection: Upgrade\r\n\
+%sWebSocket-Origin: %s\r\n\
+%sWebSocket-Location: %s://%s%s\r\n\
+%sWebSocket-Protocol: sample\r\n\
+\r\n%s";
+
+#define WS_BUFSIZE 65536
+#define WS_MAX_FDS 1024
+
+/* Buffers and state for each wrapped WebSocket connection */
+typedef struct {
+    char rbuf[WS_BUFSIZE];
+    char sbuf[WS_BUFSIZE];
+    int  rcarry_cnt;
+    char rcarry[3];
+    int  newframe;
+} _WS_connection;
+
+