[s3]libsmbconf: add method is_writeable() and wrapper smbconf_is_writeable()

This allows for per-config-source checking of write support.

Michael

source3/lib/smbconf/smbconf.c

@@ -51,6 +51,14 @@ bool smbconf_backend_requires_messaging(struct smbconf_ctx *ctx)
 	return ctx->ops->requires_messaging(ctx);
 }
 
+/**
+ * Tell whether the source is writeable.
+ */
+bool smbconf_is_writeable(struct smbconf_ctx *ctx)
+{
+	return ctx->ops->is_writeable(ctx);
+}
+
 /**
  * Close the configuration.
  */

source3/lib/smbconf/smbconf.h

@@ -57,6 +57,7 @@ WERROR smbconf_init_txt(TALLOC_CTX *mem_ctx,
  * the smbconf API functions
  */
 bool smbconf_backend_requires_messaging(struct smbconf_ctx *ctx);
+bool smbconf_is_writeable(struct smbconf_ctx *ctx);
 void smbconf_shutdown(struct smbconf_ctx *ctx);
 bool smbconf_changed(struct smbconf_ctx *ctx, struct smbconf_csn *csn,
 		     const char *service, const char *param);

source3/lib/smbconf/smbconf_private.h

@@ -24,6 +24,7 @@ struct smbconf_ops {
 	WERROR (*init)(struct smbconf_ctx *ctx, const char *path);
 	int (*shutdown)(struct smbconf_ctx *ctx);
 	bool (*requires_messaging)(struct smbconf_ctx *ctx);
+	bool (*is_writeable)(struct smbconf_ctx *ctx);
 	WERROR (*open_conf)(struct smbconf_ctx *ctx);
 	int (*close_conf)(struct smbconf_ctx *ctx);
 	void (*get_csn)(struct smbconf_ctx *ctx, struct smbconf_csn *csn,

source3/lib/smbconf/smbconf_reg.c

@@ -652,6 +652,17 @@ static bool smbconf_reg_requires_messaging(struct smbconf_ctx *ctx)
 	return false;
 }
 
+static bool smbconf_reg_is_writeable(struct smbconf_ctx *ctx)
+{
+	/*
+	 * The backend has write support.
+	 *
+	 *  TODO: add access checks whether the concrete
+	 *  config source is really writeable by the calling user.
+	 */
+	return true;
+}
+
 static WERROR smbconf_reg_open(struct smbconf_ctx *ctx)
 {
 	WERROR werr;
@@ -1130,6 +1141,7 @@ struct smbconf_ops smbconf_ops_reg = {
 	.init			= smbconf_reg_init,
 	.shutdown		= smbconf_reg_shutdown,
 	.requires_messaging	= smbconf_reg_requires_messaging,
+	.is_writeable		= smbconf_reg_is_writeable,
 	.open_conf		= smbconf_reg_open,
 	.close_conf		= smbconf_reg_close,
 	.get_csn		= smbconf_reg_get_csn,

source3/lib/smbconf/smbconf_txt.c

@@ -248,6 +248,12 @@ static bool smbconf_txt_requires_messaging(struct smbconf_ctx *ctx)
 	return false;
 }
 
+static bool smbconf_txt_is_writeable(struct smbconf_ctx *ctx)
+{
+	/* no write support in this backend yet... */
+	return false;
+}
+
 static WERROR smbconf_txt_open(struct smbconf_ctx *ctx)
 {
 	return smbconf_txt_load_file(ctx);
@@ -610,6 +616,7 @@ static struct smbconf_ops smbconf_ops_txt = {
 	.init			= smbconf_txt_init,
 	.shutdown		= smbconf_txt_shutdown,
 	.requires_messaging	= smbconf_txt_requires_messaging,
+	.is_writeable		= smbconf_txt_is_writeable,
 	.open_conf		= smbconf_txt_open,
 	.close_conf		= smbconf_txt_close,
 	.get_csn		= smbconf_txt_get_csn,