test: add linker wrap for mocking

test/CMakeLists.txt

@@ -60,6 +60,11 @@ include_directories(
 
 find_package(re CONFIG REQUIRED HINTS ../cmake)
 
+if(CMAKE_C_COMPILER_ID MATCHES "Clang" OR CMAKE_C_COMPILER_ID MATCHES "GNU")
+  set(HAVE_WRAP TRUE)
+  list(APPEND RE_DEFINITIONS HAVE_WRAP)
+endif()
+
 ##############################################################################
 #
 # Source/Header section
@@ -143,6 +148,14 @@ set(SRCS
   websock.c
 )
 
+if(HAVE_WRAP)
+  list(APPEND SRCS
+      wrap/wrap.c
+      wrap/epoll.c
+      wrap/getaddrinfo.c
+  )
+endif()
+
 if(USE_OPENSSL)
   list(APPEND SRCS
     tls.c
@@ -175,6 +188,16 @@ set_property(TARGET ${PROJECT_NAME} PROPERTY ENABLE_EXPORTS 1)
 target_link_libraries(${PROJECT_NAME} PRIVATE ${LINKLIBS})
 target_compile_definitions(${PROJECT_NAME} PRIVATE ${RE_DEFINITIONS})
 
+if(HAVE_WRAP)
+  target_link_options(${PROJECT_NAME} PRIVATE
+    -Wl,
+    --wrap=epoll_create,
+    --wrap=epoll_ctl,
+    --wrap=getaddrinfo,
+    --wrap=freeaddrinfo
+  )
+endif()
+
 if(USE_OPENSSL)
   target_include_directories(${PROJECT_NAME} PRIVATE ${OPENSSL_INCLUDE_DIR})
 endif()

test/test.h

@@ -547,3 +547,12 @@ int dns_server_add_srv(struct dns_server *srv, const char *name,
 		       uint16_t pri, uint16_t weight, uint16_t port,
 		       const char *target);
 void dns_server_flush(struct dns_server *srv);
+
+
+/*
+ * Wrap functions
+ */
+int wrap_will_return_int(const char *func, int ret);
+int wrap_will_return_data(const char *func, void *data);
+int wrap_return_int(const char *func, int *ret);
+void *wrap_return_data(const char *func);

test/wrap/epoll.c

@@ -0,0 +1,30 @@
+#include <sys/epoll.h>
+
+#include <re.h>
+#include "test.h"
+
+
+int __wrap_epoll_create(int size);
+int __real_epoll_create(int size);
+
+int __wrap_epoll_create(int size)
+{
+	int ret;
+
+	int err = wrap_return_int("epoll_create", &ret);
+
+	return err ? __real_epoll_create(size) : ret;
+}
+
+
+int __wrap_epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);
+int __real_epoll_ctl(int epfd, int op, int fd, struct epoll_event *event);
+
+int __wrap_epoll_ctl(int epfd, int op, int fd, struct epoll_event *event)
+{
+	int ret;
+
+	int err = wrap_return_int("epoll_create", &ret);
+
+	return err ? __real_epoll_ctl(epfd, op, fd, event) : ret;
+}

test/wrap/getaddrinfo.c

@@ -0,0 +1,26 @@
+#include <netdb.h>
+
+#include <re.h>
+#include "test.h"
+
+
+int __wrap_getaddrinfo(const char *restrict node, const char *restrict service,
+		       const struct addrinfo *restrict hints,
+		       struct addrinfo **restrict res);
+int __real_getaddrinfo(const char *restrict node, const char *restrict service,
+		       const struct addrinfo *restrict hints,
+		       struct addrinfo **restrict res);
+int __wrap_getaddrinfo(const char *restrict node, const char *restrict service,
+		       const struct addrinfo *restrict hints,
+		       struct addrinfo **restrict res)
+{
+	return __real_getaddrinfo(node, service, hints, res);
+}
+
+
+void __wrap_freeaddrinfo(struct addrinfo *res);
+void __real_freeaddrinfo(struct addrinfo *res);
+void __wrap_freeaddrinfo(struct addrinfo *res)
+{
+	__real_freeaddrinfo(res);
+}

test/wrap/wrap.c

@@ -0,0 +1,129 @@
+#include <re.h>
+#include "test.h"
+
+enum wrap_type {
+	WRAP_INT,
+	WRAP_DATA
+};
+
+struct wrap_entry {
+	struct le le;
+	char func[64];
+	enum wrap_type type;
+	union {
+		int ret_int;
+		void *ret_data;
+	} u;
+};
+
+static struct list wrapl = LIST_INIT;
+
+
+static void entry_destruct(void *arg)
+{
+	struct wrap_entry *e = arg;
+	list_unlink(&e->le);
+}
+
+
+static struct wrap_entry *wrap_entry_alloc(const char *func)
+{
+	struct wrap_entry *e;
+
+	e = mem_alloc(sizeof(struct wrap_entry), entry_destruct);
+	if (!e)
+		return NULL;
+
+	str_ncpy(e->func, func, sizeof(e->func));
+
+	list_append(&wrapl, &e->le, e);
+
+	return e;
+}
+
+
+int wrap_will_return_int(const char *func, int ret)
+{
+	struct wrap_entry *e;
+
+	if (!func)
+		return EINVAL;
+
+	e = wrap_entry_alloc(func);
+	if (!e)
+		return ENOMEM;
+
+	e->type = WRAP_INT;
+	e->u.ret_int = ret;
+
+	return 0;
+}
+
+
+int wrap_will_return_data(const char *func, void *data)
+{
+	struct wrap_entry *e;
+
+	if (!func)
+		return EINVAL;
+
+	e = wrap_entry_alloc(func);
+	if (!e)
+		return ENOMEM;
+
+	e->type = WRAP_DATA;
+	e->u.ret_data = data;
+
+	return 0;
+}
+
+
+int wrap_return_int(const char *func, int *ret)
+{
+	struct le *le;
+
+	if (!func)
+		return EINVAL;
+
+	LIST_FOREACH(&wrapl, le)
+	{
+		struct wrap_entry *e = le->data;
+
+		if (e->type != WRAP_INT)
+			continue;
+
+		if (0 == str_casecmp(e->func, func)) {
+			*ret = e->u.ret_int;
+			mem_deref(e);
+			return 0;
+		}
+	}
+
+	return ENODATA;
+}
+
+
+void *wrap_return_data(const char *func)
+{
+	struct le *le;
+	void *data;
+
+	if (!func)
+		return NULL;
+
+	LIST_FOREACH(&wrapl, le)
+	{
+		struct wrap_entry *e = le->data;
+
+		if (e->type != WRAP_DATA)
+			continue;
+
+		if (0 == str_casecmp(e->func, func)) {
+			data = e->u.ret_data;
+			mem_deref(e);
+			return data;
+		}
+	}
+
+	return NULL;
+}