Avoid updating too often if ISP spams RAs

[odhcp6c.git] / src / odhcp6c.c

diff --git a/src/odhcp6c.c b/src/odhcp6c.c
index 5c433af31e7c90b1fcad9746be36d29734cc6aab..e81b15f92a5bcfc0a8b54895a336cdf46a8d6ace 100644 (file)
--- a/src/odhcp6c.c
+++ b/src/odhcp6c.c
@@ -463,17 +463,23 @@ struct odhcp6c_entry* odhcp6c_find_entry(enum odhcp6c_state state, const struct
 }
 
 
-void odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
+bool odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *new, uint32_t safe)
 {
        size_t len;
        struct odhcp6c_entry *x = odhcp6c_find_entry(state, new);
        struct odhcp6c_entry *start = odhcp6c_get_state(state, &len);
+       bool changed = true;
 
        if (x && x->valid > new->valid && new->valid < safe)
                new->valid = safe;
 
        if (new->valid > 0) {
                if (x) {
+                       if (new->valid >= x->valid && new->valid - x->valid < 60 &&
+                                       new->preferred >= x->preferred &&
+                                       new->preferred - x->preferred < 60 &&
+                                       x->class == new->class)
+                               changed = false;
                        x->valid = new->valid;
                        x->preferred = new->preferred;
                        x->class = new->class;
@@ -483,12 +489,13 @@ void odhcp6c_update_entry_safe(enum odhcp6c_state state, struct odhcp6c_entry *n
        } else if (x) {
                odhcp6c_remove_state(state, (x - start) * sizeof(*x), sizeof(*x));
        }
+       return changed;
 }
 
 
-void odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
+bool odhcp6c_update_entry(enum odhcp6c_state state, struct odhcp6c_entry *new)
 {
-       odhcp6c_update_entry_safe(state, new, 0);
+       return odhcp6c_update_entry_safe(state, new, 0);
 }