unit-tests: Uninline dlopen() and friends, make more dynamic, fix dlerror()

As the error string contains a newline, we have to remove that before
returning the string.

src/libstrongswan/utils/windows.c

@@ -49,6 +49,130 @@ int usleep(useconds_t usec)
 	return 0;
 }
 
+/*
+ * See header.
+ */
+void *dlopen(const char *filename, int flag)
+{
+	return LoadLibrary(filename);
+}
+
+/**
+ * Load a symbol from known default libs (monolithic build)
+ */
+static void* dlsym_default(const char *name)
+{
+	const char *dlls[] = {
+		"libstrongswan-0.dll",
+		"libhydra-0.dll",
+		"libcharon-0.dll",
+		"libtnccs-0.dll",
+		NULL /* .exe */
+	};
+	HANDLE handle;
+	void *sym = NULL;
+	int i;
+
+	for (i = 0; i < countof(dlls); i++)
+	{
+		handle = GetModuleHandle(dlls[i]);
+		if (handle)
+		{
+			sym = GetProcAddress(handle, name);
+			if (sym)
+			{
+				break;
+			}
+		}
+	}
+	return sym;
+}
+
+/**
+ * Emulate RTLD_NEXT for some known symbols
+ */
+static void* dlsym_next(const char *name)
+{
+	struct {
+		const char *dll;
+		const char *syms[4];
+	} dlls[] = {
+		/* for leak detective */
+		{ "msvcrt",
+			{ "malloc", "calloc", "realloc", "free" }
+		},
+	};
+	HANDLE handle = NULL;
+	int i, j;
+
+	for (i = 0; i < countof(dlls); i++)
+	{
+		for (j = 0; j < countof(dlls[0].syms); j++)
+		{
+			if (dlls[i].syms[j] && streq(dlls[i].syms[j], name))
+			{
+				handle = GetModuleHandle(dlls[i].dll);
+				break;
+			}
+		}
+	}
+	if (handle)
+	{
+		return GetProcAddress(handle, name);
+	}
+	return handle;
+}
+
+/**
+ * See header.
+ */
+void* dlsym(void *handle, const char *symbol)
+{
+	if (handle == RTLD_DEFAULT)
+	{
+		return dlsym_default(symbol);
+	}
+	if (handle == RTLD_NEXT)
+	{
+		return dlsym_next(symbol);
+	}
+	return GetProcAddress((HMODULE)handle, symbol);
+}
+
+/**
+ * See header.
+ */
+char* dlerror(void)
+{
+	static char buf[128];
+	char *pos;
+	DWORD err;
+
+	err = GetLastError();
+	if (FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+					  NULL, err, 0, buf, sizeof(buf), NULL) > 0)
+	{
+		pos = strchr(buf, '\n');
+		if (pos)
+		{
+			*pos = '\0';
+		}
+	}
+	else
+	{
+		snprintf(buf, sizeof(buf), "(%u)", err);
+	}
+	return buf;
+}
+
+/**
+ * See header.
+ */
+int dlclose(void *handle)
+{
+	return FreeLibrary((HMODULE)handle);
+}
+
 /**
  * See header
  */

src/libstrongswan/utils/windows.h

@@ -203,39 +203,11 @@ static inline int setenv(const char *name, const char *value, int overwrite)
 	return 0;
 }
 
-/**
- * dlerror(3) from <dlfcn.h>, printing error to an alloca() buffer
- */
-#define dlerror() \
-({ \
-	char buf[128], *out;\
-	ssize_t len; \
-	DWORD err; \
-	err = GetLastError(); \
-	len = FormatMessage(0, NULL, err, 0, buf, sizeof(buf), NULL); \
-	if (len <= 0) \
-	{ \
-		len = snprintf(buf, sizeof(buf), "(%u)", err); \
-	} \
-	len++; \
-	out = alloca(len); \
-	memcpy(out, buf, len); \
-	out; \
-})
-
 /**
  * Lazy binding, ignored on Windows
  */
 #define RTLD_LAZY 1
 
-/**
- * dlopen(3) from <dlfcn.h>
- */
-static inline void *dlopen(const char *filename, int flag)
-{
-	return LoadLibrary(filename);
-}
-
 /**
  * Default handle targeting .exe
  */
@@ -246,43 +218,25 @@ static inline void *dlopen(const char *filename, int flag)
  */
 #define RTLD_NEXT ((void*)~(uintptr_t)0)
 
+/**
+ * dlopen(3) from <dlfcn.h>
+ */
+void* dlopen(const char *filename, int flag);
+
 /**
  * dlsym() from <dlfcn.h>
  */
-static inline void *dlsym(void *handle, const char *symbol)
-{
-	if (handle == RTLD_DEFAULT)
-	{
-		handle = GetModuleHandle(NULL);
-	}
-	else if (handle == RTLD_NEXT)
-	{
-		if (strcmp(symbol, "malloc") == 0 ||
-			strcmp(symbol, "realloc") == 0 ||
-			strcmp(symbol, "free") == 0)
-		{
-			/* for leak-detective */
-			handle = GetModuleHandle("msvcrt");
-		}
-		else
-		{
-			return NULL;
-		}
-	}
-	if (handle)
-	{
-		return GetProcAddress((HMODULE)handle, symbol);
-	}
-	return NULL;
-}
+void* dlsym(void *handle, const char *symbol);
+
+/**
+ * dlerror(3) from <dlfcn.h>, currently not thread save
+ */
+char* dlerror(void);
 
 /**
  * dlclose() from <dlfcn.h>
  */
-static inline int dlclose(void *handle)
-{
-	return FreeLibrary((HMODULE)handle);
-}
+int dlclose(void *handle);
 
 /**
  * socketpair(2) for SOCK_STREAM, uses TCP on loopback