add functions for checking for config differences

diff --git a/config.c b/config.c
index 3dda5cf8505a5077dfbcf240ff863a5f751555ae..ff0410da10f44bf8a48a9aa16c96b3831a55b511 100644 (file)
--- a/config.c
+++ b/config.c
@@ -206,6 +206,74 @@ config_init_devices(void)
        }
 }
 
+bool
+config_diff(struct blob_attr **tb1, struct blob_attr **tb2,
+           const struct config_param_list *config, unsigned long *diff)
+{
+       bool ret = false;
+       int i;
+
+       for (i = 0; i < config->n_params; i++) {
+               if (!tb1[i] && !tb2[i])
+                       continue;
+
+               if (!!tb1[i] != !!tb2[i])
+                       goto mark;
+
+               if (blob_len(tb1[i]) != blob_len(tb2[i]))
+                       goto mark;
+
+               if (memcmp(tb1[i], tb2[i], blob_pad_len(tb1[i])) != 0)
+                       goto mark;
+
+               continue;
+
+mark:
+               ret = true;
+               if (diff)
+                       set_bit(diff, i);
+               else
+                       return ret;
+       }
+
+       return ret;
+}
+
+
+static bool
+__config_check_equal(struct blob_attr *c1, struct blob_attr *c2,
+                    const struct config_param_list *config)
+{
+       struct blob_attr **tb1, **tb2;
+
+       tb1 = alloca(config->n_params * sizeof(struct blob_attr *));
+       blobmsg_parse(config->params, config->n_params, tb1,
+               blob_data(c1), blob_len(c1));
+
+       tb2 = alloca(config->n_params * sizeof(struct blob_attr *));
+       blobmsg_parse(config->params, config->n_params, tb2,
+               blob_data(c2), blob_len(c2));
+
+       return !config_diff(tb1, tb2, config, NULL);
+}
+
+bool
+config_check_equal(struct blob_attr *c1, struct blob_attr *c2,
+                  const struct config_param_list *config)
+{
+       int i;
+
+       if (!__config_check_equal(c1, c2, config))
+               return false;
+
+       for (i = 0; i < config->n_next; i++) {
+               if (!__config_check_equal(c1, c2, config->next[i]))
+                       return false;
+       }
+
+       return true;
+}
+
 void
 config_init_interfaces(const char *name)
 {

diff --git a/config.h b/config.h
index df088edda631fe6dd74a4196f897965c8aa8f60e..6dfb236186b47c64d1a56bf62477c13d6ab082b4 100644 (file)
--- a/config.h
+++ b/config.h
@@ -25,6 +25,24 @@ struct config_param_list {
        const struct config_param_list *next[];
 };
 
+#ifndef BITS_PER_LONG
+#define BITS_PER_LONG (8 * sizeof(unsigned long))
+#endif
+
+static inline void set_bit(unsigned long *bits, int bit)
+{
+       bits[bit / BITS_PER_LONG] |= (1UL << (bit % BITS_PER_LONG));
+}
+
+static inline bool test_bit(unsigned long *bits, int bit)
+{
+       return !!(bits[bit / BITS_PER_LONG] & (1UL << (bit % BITS_PER_LONG)));
+}
+
 void config_init_interfaces(const char *name);
+bool config_check_equal(struct blob_attr *c1, struct blob_attr *c2,
+                       const struct config_param_list *config);
+bool config_diff(struct blob_attr **tb1, struct blob_attr **tb2,
+                const struct config_param_list *config, unsigned long *diff);
 
 #endif