add ipv6 address check for dhcpconfirm

src/dhcp6.c

@@ -397,6 +397,34 @@ struct dhcp_config *config_find_by_address6(struct dhcp_config *configs, struct
   return NULL;
 }
 
+int is_invalid_address_from_static_range(struct dhcp_context *context, struct in6_addr *taddr)
+{
+    struct dhcp_context *c;
+    struct dhcp_config *config;
+    int    range_matched = 0;
+    for (c = context; c; c = c->current) {
+        if (!is_same_net6(&c->start6, taddr, c->prefix)) {
+            continue;
+        }
+
+        range_matched = 1;
+        if (c->flags & (CONTEXT_STATIC)) {
+            config = config_find_by_address6(daemon->dhcp_conf, &c->start6, c->prefix, addr6part(taddr));
+            if (config) {
+                return 1;
+            }
+        } 
+    }
+
+    /* return fail only when target address match static dhcp range, but it's not static configed */
+    if (range_matched) {
+        return 0;
+    } else {
+        return 1;
+    }
+}
+
+
 struct dhcp_context *address6_allocate(struct dhcp_context *context,  unsigned char *clid, int clid_len, int temp_addr,
 				       int iaid, int serial, struct dhcp_netid *netids, int plain_range, struct in6_addr *ans)   
 {

src/dnsmasq.h

@@ -1412,6 +1412,7 @@ int get_incoming_mark(union mysockaddr *peer_addr, struct all_addr *local_addr,
 #ifdef HAVE_DHCP6
 void dhcp6_init(void);
 void dhcp6_packet(time_t now);
+int  is_invalid_address_from_static_range(struct dhcp_context *context, struct in6_addr *taddr);
 struct dhcp_context *address6_allocate(struct dhcp_context *context,  unsigned char *clid, int clid_len, int temp_addr,
 				       int iaid, int serial, struct dhcp_netid *netids, int plain_range, struct in6_addr *ans);
 int config_valid(struct dhcp_config *config, struct dhcp_context *context, struct in6_addr *addr);

src/rfc3315.c

@@ -1098,6 +1098,14 @@ static int dhcp6_no_relay(struct state *state, int msg_type, void *inbuff, size_
 		    return 1;
 		  }
 
+                if (!is_invalid_address_from_static_range(state->context, req_addr)) {
+                    o1 = new_opt6(OPTION6_STATUS_CODE);
+                    put_opt6_short(DHCP6NOTONLINK);
+                    put_opt6_string(_("confirm failed"));
+                    end_opt6(o1);
+                    return 1;
+                }
+
 		good_addr = 1;
 		log6_quiet(state, "DHCPREPLY", req_addr, state->hostname);
 	      }