plugins: Minor interface improvement

Change the plugin compatibility check to make it more convenient to
define and check the major.minor Wireshark version.

Change-Id: I2a6d2a746682c29504311cce5c457e0a852c3daf
Reviewed-on: https://code.wireshark.org/review/29224
Petri-Dish: João Valverde <j@v6e.pt>
Tested-by: Petri Dish Buildbot
Reviewed-by: João Valverde <j@v6e.pt>

CMakeLists.txt

@@ -1418,12 +1418,13 @@ set_target_properties(version PROPERTIES FOLDER "Auxiliary")
 set( configure_input "Built with CMake ${CMAKE_VERSION}" )
 configure_file(${CMAKE_SOURCE_DIR}/cmakeconfig.h.in ${CMAKE_BINARY_DIR}/config.h)
 
+configure_file(${CMAKE_SOURCE_DIR}/ws_version.h.in ${CMAKE_BINARY_DIR}/ws_version.h)
+
 set( prefix "${CMAKE_INSTALL_PREFIX}" )
 set( exec_prefix "\${prefix}" )
 set( libdir "\${exec_prefix}/${CMAKE_INSTALL_LIBDIR}" )
 set( includedir  "\${prefix}/include" )
 set( plugindir "\${libdir}/wireshark/${PLUGIN_VERSION_DIR}" )
-set( VERSION_RELEASE "${PROJECT_RELEASE_VERSION}" )
 
 # Doxygen variables
 file(GLOB TOP_LEVEL_SOURCE_LIST *.c *.cpp *.h)
@@ -2825,6 +2826,7 @@ set(SHARK_PUBLIC_HEADERS
 	ws_diag_control.h
 	ws_symbol_export.h
 	version_info.h
+	${CMAKE_BINARY_DIR}/ws_version.h
 )
 
 if(NOT WIN32)

doc/plugins.example/CMakeLists.txt

@@ -20,7 +20,6 @@ pkg_check_modules(WIRESHARK REQUIRED wireshark>=2.5)
 ### CMake Bug: If you run into problems please use the "Unix Makefiles" generator.
 ### Ninja just wipes the pkg-config variables.
 # https://gitlab.kitware.com/cmake/cmake/issues/17531 (and probably others)
-pkg_get_variable(WIRESHARK_VERSION_RELEASE wireshark VERSION_RELEASE)
 pkg_get_variable(WIRESHARK_PLUGIN_DIR wireshark plugindir)
 
 set(PLUGIN_INSTALL_LIBDIR "${WIRESHARK_PLUGIN_DIR}/epan")
@@ -41,7 +40,7 @@ if (CMAKE_COMPILER_IS_GNUCC)
     set(CMAKE_C_FLAGS  "-Wall -Wextra ${CMAKE_C_FLAGS}")
 endif()
 
-add_definitions(-DHAVE_PLUGINS -DVERSION=\"${PROJECT_VERSION}\" -DVERSION_RELEASE=\"${WIRESHARK_VERSION_RELEASE}\")
+add_definitions(-DHAVE_PLUGINS -DVERSION=\"${PROJECT_VERSION}\")
 
 add_library(hello MODULE hello.c)
 set_target_properties(hello PROPERTIES PREFIX "" DEFINE_SYMBOL "")

doc/plugins.example/hello.c

@@ -14,6 +14,7 @@
 #include <epan/packet.h>
 #include <epan/proto.h>
 #include <ws_attributes.h>
+#include <ws_version.h>
 
 #ifndef VERSION
 #define VERSION "0.0.0"
@@ -22,7 +23,8 @@
 #define DLL_PUBLIC __attribute__((__visibility__("default")))
 
 DLL_PUBLIC const gchar plugin_version[] = VERSION;
-DLL_PUBLIC const gchar plugin_release[] = VERSION_RELEASE;
+DLL_PUBLIC const int plugin_want_major = WIRESHARK_VERSION_MAJOR;
+DLL_PUBLIC const int plugin_want_minor = WIRESHARK_VERSION_MINOR;
 
 DLL_PUBLIC void plugin_register(void);
 

plugins/epan/stats_tree/stats_tree_plugin.c

@@ -21,7 +21,8 @@
 #include "pinfo_stats_tree.h"
 
 WS_DLL_PUBLIC_DEF const gchar plugin_version[] = PLUGIN_VERSION;
-WS_DLL_PUBLIC_DEF const gchar plugin_release[] = VERSION_RELEASE;
+WS_DLL_PUBLIC_DEF const int plugin_want_major = VERSION_MAJOR;
+WS_DLL_PUBLIC_DEF const int plugin_want_minor = VERSION_MINOR;
 
 WS_DLL_PUBLIC void plugin_register(void);
 

tools/make-plugin-reg.py

@@ -130,7 +130,8 @@ for symbol in regs['codec_register']:
 
 reg_code += """
 WS_DLL_PUBLIC_DEF const gchar plugin_version[] = PLUGIN_VERSION;
-WS_DLL_PUBLIC_DEF const gchar plugin_release[] = VERSION_RELEASE;
+WS_DLL_PUBLIC_DEF const int plugin_want_major = VERSION_MAJOR;
+WS_DLL_PUBLIC_DEF const int plugin_want_minor = VERSION_MINOR;
 
 WS_DLL_PUBLIC void plugin_register(void);
 

wireshark.pc.in

@@ -4,7 +4,6 @@ libdir=@libdir@
 includedir=@includedir@
 sharedlibdir=${libdir}
 plugindir=@plugindir@
-VERSION_RELEASE=@VERSION_RELEASE@
 
 Name: Wireshark
 Description: Network Packet Dissection Library

ws_version.h.in

@@ -0,0 +1,10 @@
+/* ws_version.h.in */
+
+#ifndef __WS_VERSION_H__
+#define __WS_VERSION_H__
+
+#define WIRESHARK_VERSION_MAJOR @PROJECT_MAJOR_VERSION@
+#define WIRESHARK_VERSION_MINOR @PROJECT_MINOR_VERSION@
+#define WIRESHARK_VERSION_MICRO @PROJECT_PATCH_VERSION@
+
+#endif /* __WS_VERSION_H__ */

wsutil/plugins.c

@@ -96,6 +96,33 @@ compare_plugins(gconstpointer a, gconstpointer b)
     return g_strcmp0((*(plugin *const *)a)->name, (*(plugin *const *)b)->name);
 }
 
+static gboolean
+pass_plugin_version_compatibility(GModule *handle, const char *name)
+{
+    gpointer symb;
+    int major, minor;
+
+    if(!g_module_symbol(handle, "plugin_want_major", &symb)) {
+        report_failure("The plugin '%s' has no \"plugin_want_major\" symbol", name);
+        return FALSE;
+    }
+    major = *(int *)symb;
+
+    if(!g_module_symbol(handle, "plugin_want_minor", &symb)) {
+        report_failure("The plugin '%s' has no \"plugin_want_minor\" symbol", name);
+        return FALSE;
+    }
+    minor = *(int *)symb;
+
+    if (major != VERSION_MAJOR || minor != VERSION_MINOR) {
+        report_failure("The plugin '%s' was compiled for Wireshark version %d.%d",
+                            name, major, minor);
+        return FALSE;
+    }
+
+    return TRUE;
+}
+
 static void
 scan_plugins_dir(GHashTable *plugins_module, const char *dirpath, plugin_type_e type, gboolean append_type)
 {
@@ -105,7 +132,7 @@ scan_plugins_dir(GHashTable *plugins_module, const char *dirpath, plugin_type_e
     gchar         *plugin_file;     /* current file full path */
     GModule       *handle;          /* handle returned by g_module_open */
     gpointer       symbol;
-    const char    *plug_version, *plug_release;
+    const char    *plug_version;
     plugin        *new_plug;
 
     if (append_type)
@@ -152,15 +179,7 @@ scan_plugins_dir(GHashTable *plugins_module, const char *dirpath, plugin_type_e
         }
         plug_version = (const char *)symbol;
 
-        if (!g_module_symbol(handle, "plugin_release", &symbol))
-        {
-            report_failure("The plugin '%s' has no \"plugin_release\" symbol", name);
-            g_module_close(handle);
-            continue;
-        }
-        plug_release = (const char *)symbol;
-        if (strcmp(plug_release, VERSION_RELEASE) != 0) {
-            report_failure("The plugin '%s' was compiled for Wireshark version %s", name, plug_release);
+        if (!pass_plugin_version_compatibility(handle, name)) {
             g_module_close(handle);
             continue;
         }