[vlc-devel] [PATCH 2/6] modules: check plugin version

[Steve Lhomme]

On 2019-07-18 21:29, Rémi Denis-Courmont wrote:
> ---
>   src/modules/bank.c | 59 +++++++++++++++++++++++++++++++++++-----------
>   1 file changed, 45 insertions(+), 14 deletions(-)
> 
> diff --git a/src/modules/bank.c b/src/modules/bank.c
> index 0b551a91bc..f6f5ae1a85 100644
> --- a/src/modules/bank.c
> +++ b/src/modules/bank.c
> @@ -193,6 +193,49 @@ static void module_InitStaticModules(void) { }
>   #endif
>   
>   #ifdef HAVE_DYNAMIC_PLUGINS
> +static const char *module_GetVersion(void *handle)
> +{
> +    const char *(*get_api_version)(void);
> +
> +    get_api_version = vlc_dlsym(handle, "vlc_entry_api_version");
> +    if (get_api_version == NULL)
> +        return NULL;
> +
> +    return get_api_version();
> +}
> +
> +static void *module_Open(struct vlc_logger *log,
> +                         const char *path, bool fast)
> +{
> +    void *handle = vlc_dlopen(path, fast);
> +    if (handle == NULL)
> +    {
> +        char *errmsg = vlc_dlerror();
> +
> +        vlc_error(log, "cannot load plug-in %s: %s", path,
> +                  errmsg ? errmsg : "unknown error");
> +        free(errmsg);
> +        return NULL;
> +    }
> +
> +    const char *str = module_GetVersion(handle);
> +    if (str == NULL) {
> +        vlc_error(log, "cannot load plug-in %s: %s", path,
> +                  "unknown version or not a plug-in");
> +error:
> +        vlc_dlclose(handle);
> +        return NULL;
> +    }
> +
> +    if (strcmp(str, VLC_API_VERSION_STRING)) {

Couldn't we use an integer ? Speed-wise this is going backward from have 
no extra check needed because the name we loaded already had the proper 
version, which was a feature not a bug.

> +        vlc_error(log, "cannot load plug-in %s: unsupported version %s", path,
> +                  str);
> +        goto error;
> +    }
> +
> +    return handle;
> +}
> +
>   static const char vlc_entry_name[] = "vlc_entry" MODULE_SUFFIX;
>   
>   /**
> @@ -207,15 +250,9 @@ static const char vlc_entry_name[] = "vlc_entry" MODULE_SUFFIX;
>   static vlc_plugin_t *module_InitDynamic(vlc_object_t *obj, const char *path,
>                                           bool fast)
>   {
> -    void *handle = vlc_dlopen(path, fast);
> +    void *handle = module_Open(obj->logger, path, fast);
>       if (handle == NULL)
> -    {
> -        char *errmsg = vlc_dlerror();
> -        msg_Err(obj, "cannot load plug-in %s: %s", path,
> -                errmsg ? errmsg : "unknown error");
> -        free(errmsg);
>           return NULL;
> -    }
>   
>       /* Try to resolve the symbol */
>       vlc_plugin_cb entry = vlc_dlsym(handle, vlc_entry_name);
> @@ -507,15 +544,9 @@ int module_Map(struct vlc_logger *log, vlc_plugin_t *plugin)
>       /* Try to load the plug-in (without locks, so read-only) */
>       assert(plugin->abspath != NULL);
>   
> -    void *handle = vlc_dlopen(plugin->abspath, false);
> +    void *handle = module_Open(log, plugin->abspath, false);
>       if (handle == NULL)
> -    {
> -        char *errmsg = vlc_dlerror();
> -        vlc_error(log, "cannot load plug-in %s: %s",
> -                  plugin->abspath, errmsg ? errmsg : "unknown error");
> -        free(errmsg);
>           return -1;
> -    }
>   
>       vlc_plugin_cb entry = vlc_dlsym(handle, vlc_entry_name);
>       if (entry == NULL)
> -- 
> 2.22.0
> 
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel
>