env: add check/apply logic to himport_r()
Change hashtable so that a callback function will decide whether a
variable can be overwritten, and possibly apply the changes.
So add a new field to struct hsearch_data:
o "apply" callback function to check whether a variable can be
overwritten, and possibly immediately apply the changes;
when NULL, no check is performed.
And a new argument to himport_r():
o "do_apply": whether to call the apply callback function
NOTE: This patch does not change the current behavior.
Signed-off-by: Gerlando Falauto <gerlando.falauto@keymile.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/include/environment.h b/include/environment.h
index ae3f7b6..90fb130 100644
--- a/include/environment.h
+++ b/include/environment.h
@@ -184,6 +184,15 @@
/* Import from binary representation into hash table */
int env_import(const char *buf, int check);
+/*
+ * Check if variable "name" can be changed from oldval to newval,
+ * and if so, apply the changes (e.g. baudrate).
+ * When (flag & H_FORCE) is set, it does not print out any error
+ * message and forces overwriting of write-once variables.
+ */
+int env_check_apply(const char *name, const char *oldval,
+ const char *newval, int flag);
+
#endif /* DO_DEPS_ONLY */
#endif /* _ENVIRONMENT_H_ */