tee-supplicant: add CFG_TEE_SUPP_PLUGINS to enable or not plugin support

This change allows optee_client configuration to enable or not supplicant
plugin support. The feature is enabled from switch CFG_TEE_SUPP_PLUGINS.
The configuration is default enable for backward compatibility purpose.

There are OSes where TEE supplicant plugin cannot be supported for
example when the OS does not enable dynamic/shared libraries. Such
systems should still be able to embed OP-TEE assuming the supplicant
plugin support is not embedded. Prior this change was optee_client
failing to build for such systems with a error message like the one
below reported by Buildroot CI build [1]:

/tmp/instance-2/output-1/build/optee-client-3.13.0/tee-supplicant/src/plugin.c:8:10: fatal error: dlfcn.h: No such file or directory
    8 | #include <dlfcn.h>
      |          ^~~~~~~~~

Link: [1] http://autobuild.buildroot.net/results/56d1ec172d0d857d6a968397b7785f961fad1043/
Signed-off-by: Etienne Carriere <etienne.carriere@linaro.org>
Acked-by: Jerome Forissier <jerome@forissier.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

Android.mk

@@ -11,6 +11,7 @@ CFG_TEE_SUPP_LOG_LEVEL ?= 2
 CFG_TEE_CLIENT_LOAD_PATH ?= /vendor/lib
 TEEC_TEST_LOAD_PATH ?= /data/vendor/tee
 CFG_TEE_FS_PARENT_PATH ?= /data/vendor/tee
+CFG_TEE_SUPP_PLUGINS ?= y
 ifneq ($(strip $($(combo_2nd_arch_prefix)TARGET_TOOLS_PREFIX)),)
 CFG_TEE_PLUGIN_LOAD_PATH ?= /vendor/lib64/tee-supplicant/plugins/
 else

config.mk

@@ -33,6 +33,10 @@ CFG_TEE_CLIENT_LOG_FILE ?= $(CFG_TEE_FS_PARENT_PATH)/teec.log
 #   The location of the client library file.
 CFG_TEE_CLIENT_LOAD_PATH ?= /lib
 
+# CFG_TEE_SUPP_PLUGINS
+#   Enable (y) or disable (n) TEE supplicant plugin support
+CFG_TEE_SUPP_PLUGINS ?= y
+
 # CFG_TEE_PLUGIN_LOAD_PATH
 #   The location of the user plugins
 CFG_TEE_PLUGIN_LOAD_PATH ?= /usr/lib/tee-supplicant/plugins/

tee-supplicant/CMakeLists.txt

@@ -7,6 +7,7 @@ option (CFG_TA_TEST_PATH "Enable tee-supplicant to load from test/debug path" OF
 option (RPMB_EMU "Enable tee-supplicant to emulate RPMB" ON)
 option (CFG_TA_GPROF_SUPPORT "Enable tee-supplicant support for TAs instrumented with gprof" ON)
 option (CFG_FTRACE_SUPPORT "Enable tee-supplicant support for TAs instrumented with ftrace" ON)
+option (CFG_TEE_SUPP_PLUGINS "Enable tee-supplicant plugin support" ON)
 
 set (CFG_TEE_SUPP_LOG_LEVEL "1" CACHE STRING "tee-supplicant log level")
 # FIXME: Question is, is this really needed? Should just use defaults from # GNUInstallDirs?
@@ -15,7 +16,10 @@ set (CFG_TEE_FS_PARENT_PATH "/data/tee" CACHE STRING "Location of TEE filesystem
 # FIXME: Why do we have if defined(CFG_GP_SOCKETS) && CFG_GP_SOCKETS == 1 in the c-file?
 set (CFG_GP_SOCKETS "1" CACHE STRING "Enable GlobalPlatform Socket API support")
 set (CFG_TEE_PLUGIN_LOAD_PATH "/usr/lib/tee-supplicant/plugins/" CACHE STRING "tee-supplicant's plugins path")
-set (CMAKE_INSTALL_RPATH "${CFG_TEE_PLUGIN_LOAD_PATH}")
+
+if (CFG_TEE_SUPP_PLUGINS)
+	set (CMAKE_INSTALL_RPATH "${CFG_TEE_PLUGIN_LOAD_PATH}")
+endif()
 
 ################################################################################
 # Source files
@@ -28,7 +32,6 @@ set (SRC
 	src/tee_supp_fs.c
 	src/tee_supplicant.c
 	src/teec_ta_load.c
-	src/plugin.c
 )
 
 if (CFG_GP_SOCKETS)
@@ -39,6 +42,10 @@ if (CFG_TA_GPROF_SUPPORT OR CFG_FTRACE_SUPPORT)
 	set (SRC ${SRC} src/prof.c)
 endif()
 
+if (CFG_TEE_SUPP_PLUGINS)
+	set (SRC ${SRC} src/plugin.c)
+endif()
+
 ################################################################################
 # Built binary
 ################################################################################
@@ -52,7 +59,6 @@ target_compile_definitions (${PROJECT_NAME}
 	PRIVATE -DTEEC_LOAD_PATH="${CFG_TEE_CLIENT_LOAD_PATH}"
 	PRIVATE -DTEE_FS_PARENT_PATH="${CFG_TEE_FS_PARENT_PATH}"
 	PRIVATE -DBINARY_PREFIX="TSUP"
-	PRIVATE -DTEE_PLUGIN_LOAD_PATH="${CFG_TEE_PLUGIN_LOAD_PATH}"
 )
 
 ################################################################################
@@ -83,6 +89,13 @@ if (CFG_FTRACE_SUPPORT)
 		PRIVATE -DCFG_FTRACE_SUPPORT)
 endif()
 
+if (CFG_TEE_SUPP_PLUGINS)
+	target_compile_definitions (${PROJECT_NAME}
+		PRIVATE -DTEE_SUPP_PLUGINS
+		PRIVATE -DTEE_PLUGIN_LOAD_PATH="${CFG_TEE_PLUGIN_LOAD_PATH}"
+	)
+endif()
+
 ################################################################################
 # Public and private header and library dependencies
 ################################################################################
@@ -91,7 +104,13 @@ target_include_directories(${PROJECT_NAME} PRIVATE src)
 target_link_libraries (${PROJECT_NAME}
 	PRIVATE teec
 	PRIVATE optee-client-headers
-	PRIVATE dl)
+)
+
+if (CFG_TEE_SUPP_PLUGINS)
+	target_link_libraries (${PROJECT_NAME}
+		PRIVATE dl
+	)
+endif()
 
 ################################################################################
 # Install targets

tee-supplicant/Makefile

@@ -18,9 +18,7 @@ TEES_SRCS	:= tee_supplicant.c \
 		   teec_ta_load.c \
 		   tee_supp_fs.c \
 		   rpmb.c \
-		   handle.c \
-		   plugin.c
-
+		   handle.c
 
 ifeq ($(CFG_GP_SOCKETS),y)
 TEES_SRCS 	+= tee_socket.c
@@ -33,6 +31,10 @@ ifneq (,$(filter y,$(CFG_TA_GPROF_SUPPORT) $(CFG_FTRACE_SUPPORT)))
 TEES_SRCS	+= prof.c
 endif
 
+ifeq ($(CFG_TEE_SUPP_PLUGINS),y)
+TEES_SRCS 	+= plugin.c
+endif
+
 TEES_SRC_DIR	:= src
 TEES_OBJ_DIR	:= $(OUT_DIR)
 TEES_OBJS 	:= $(patsubst %.c,$(TEES_OBJ_DIR)/%.o, $(TEES_SRCS))
@@ -45,7 +47,6 @@ TEES_CFLAGS	:= $(addprefix -I, $(TEES_INCLUDES)) $(CFLAGS) \
 		   -DBINARY_PREFIX=\"TEES\" \
 		   -DTEE_FS_PARENT_PATH=\"$(CFG_TEE_FS_PARENT_PATH)\" \
 		   -DTEEC_LOAD_PATH=\"$(CFG_TEE_CLIENT_LOAD_PATH)\" \
-		   -DTEE_PLUGIN_LOAD_PATH=\"$(CFG_TEE_PLUGIN_LOAD_PATH)\"
 
 ifeq ($(CFG_GP_SOCKETS),y)
 TEES_CFLAGS	+= -DCFG_GP_SOCKETS=1
@@ -67,13 +68,21 @@ ifeq ($(CFG_FTRACE_SUPPORT),y)
 TEES_CFLAGS	+= -DCFG_FTRACE_SUPPORT
 endif
 
+ifeq ($(CFG_TEE_SUPP_PLUGINS),y)
+TEES_CFLAGS	+= -DTEE_SUPP_PLUGINS \
+		   -DTEE_PLUGIN_LOAD_PATH=\"$(CFG_TEE_PLUGIN_LOAD_PATH)\"
+endif
+
 TEES_LFLAGS	+= -lpthread
 # Needed to get clock_gettime() for for glibc versions before 2.17
 TEES_LFLAGS	+= -lrt
+
+ifeq ($(CFG_TEE_SUPP_PLUGINS),y)
 # Needed to dynamically load user plugins
 TEES_LFLAGS	+= -ldl
 # Needed for dlopen()
-TEES_LFLAGS += -Wl,-rpath=$(CFG_TEE_PLUGIN_LOAD_PATH)
+TEES_LFLAGS 	+= -Wl,-rpath=$(CFG_TEE_PLUGIN_LOAD_PATH)
+endif
 
 tee-supplicant: $(TEES_FILE)
 

tee-supplicant/src/plugin.h

@@ -19,6 +19,7 @@ struct plugin {
 	struct plugin *next;
 };
 
+#ifdef TEE_SUPP_PLUGINS
 /*
  * Loads all shared objects from 'CFG_TEE_PLUGIN_LOAD_PATH'
  * and binds all functions.
@@ -29,6 +30,21 @@ TEEC_Result plugin_load_all(void);
 
 /* Plugin RPC handler */
 TEEC_Result plugin_process(size_t num_params, struct tee_ioctl_param *params);
+#else
+static inline TEEC_Result plugin_load_all(void)
+{
+	return TEEC_SUCCESS;
+}
+
+static inline TEEC_Result plugin_process(size_t num_params,
+					 struct tee_ioctl_param *params)
+{
+	(void)num_params;
+	(void)params;
+
+	return TEEC_ERROR_NOT_SUPPORTED;
+}
+#endif /*TEE_SUPP_PLUGINS*/
 
 #endif /* PLUGIN_H */
 

tee-supplicant/tee_supplicant_android.mk

@@ -9,8 +9,7 @@ LOCAL_CFLAGS += $(optee_CFLAGS)
 LOCAL_CFLAGS += -DDEBUGLEVEL_$(CFG_TEE_SUPP_LOG_LEVEL) \
 		-DBINARY_PREFIX=\"TEES\" \
 		-DTEE_FS_PARENT_PATH=\"$(CFG_TEE_FS_PARENT_PATH)\" \
-		-DTEEC_LOAD_PATH=\"$(CFG_TEE_CLIENT_LOAD_PATH)\" \
-		-DTEE_PLUGIN_LOAD_PATH=\"$(CFG_TEE_PLUGIN_LOAD_PATH)\"
+		-DTEEC_LOAD_PATH=\"$(CFG_TEE_CLIENT_LOAD_PATH)\"
 
 ifneq ($(TEEC_TEST_LOAD_PATH),)
 LOCAL_CFLAGS += -DTEEC_TEST_LOAD_PATH=\"$(TEEC_TEST_LOAD_PATH)\"
@@ -24,8 +23,7 @@ LOCAL_SRC_FILES += src/tee_supplicant.c \
 		   src/teec_ta_load.c \
 		   src/tee_supp_fs.c \
 		   src/rpmb.c \
-		   src/handle.c \
-		   src/plugin.c
+		   src/handle.c
 
 ifeq ($(CFG_GP_SOCKETS),y)
 LOCAL_SRC_FILES += src/tee_socket.c
@@ -46,11 +44,19 @@ ifeq ($(CFG_TA_GPROF_SUPPORT),y)
 LOCAL_CFLAGS += -DCFG_TA_GPROF_SUPPORT
 endif
 
-LOCAL_CFLAGS += -pthread
+ifeq ($(CFG_TEE_SUPP_PLUGINS),y)
+LOCAL_SRC_FILES += src/plugin.c
+
+LOCAL_CFLAGS += -DTEE_SUPP_PLUGINS \
+		-DTEE_PLUGIN_LOAD_PATH=\"$(CFG_TEE_PLUGIN_LOAD_PATH)\"
+
 # Needed to dynamically load user plugins
 LOCAL_LDFLAGS += -ldl
 # Needed for dlopen()
 LOCAL_LDFLAGS += -Wl,-rpath=$(CFG_TEE_PLUGIN_LOAD_PATH)
+endif
+
+LOCAL_CFLAGS += -pthread
 
 ifeq ($(CFG_FTRACE_SUPPORT),y)
 LOCAL_CFLAGS += -DCFG_FTRACE_SUPPORT