Improve NoAddrsAvail & co

diff --git a/server/dhcpv6.c b/server/dhcpv6.c
index f20f5db951e1f43d3b85182776ed97f25f387f57..4480e6cf492b471cab22dd0226a99150faf20c23 100644 (file)
--- a/server/dhcpv6.c
+++ b/server/dhcpv6.c
@@ -645,6 +645,12 @@ static const int required_opts[] = {
        D6O_PREFERENCE,
        0
 };
+static const int required_opts_NAA[] = {
+       D6O_CLIENTID,
+       D6O_SERVERID,
+       D6O_STATUS_CODE,
+       0
+};
 static const int required_opts_solicit[] = {
        D6O_CLIENTID,
        D6O_SERVERID,
@@ -1159,28 +1165,12 @@ lease_to_client(struct data_string *reply_ret,
         * the Reply message with no addresses in the IA and a Status
         * Code option in the IA containing status code NoAddrsAvail.
         *
-        * Section 18.2.3 (Renew):
-        *
-        * The server may choose to change the list of addresses and
-        * the lifetimes of addresses in IAs that are returned to the
-        * client.
-        *
-        * Section 18.2.4 (Rebind):
-        *
-        * Absolutely nothing.
+        * Section 18.1.8 (Client Behavior):
         *
-        * INTERPRETATION;
-        *
-        * Solicit and Request are fairly explicit; we send NoAddrsAvail.
-        * We handle SOLICIT here and REQUEST in the reply_process_ia_na()
-        * function (because SOLICIT only counts if we never get around to
-        * it).
-        *
-        * Renew and Rebind are totally undefined.  If we send a reply with
-        * empty IA's, however, the client will stop renewing or rebinding,
-        * and this is a problem if they could have gotten addressed from
-        * another server.  So we ignore client packets...they will eventually
-        * time out in the worst case.
+        * Leave unchanged any information about addresses the client has
+        * recorded in the IA but that were not included in the IA from
+        * the server.
+        * Sends a Renew/Rebind if the IA is not in the Reply message.
         */
        if (no_addrs_avail &&
            (reply.packet->dhcpv6_msg_type == DHCPV6_SOLICIT))
@@ -1198,7 +1188,7 @@ lease_to_client(struct data_string *reply_ret,
                reply.cursor = REPLY_OPTIONS_INDEX;
 
                /*
-                * Produce an advertise that includes;
+                * Produce an advertise that includes only:
                 *
                 * Status code.
                 * Server DUID.
@@ -1210,12 +1200,8 @@ lease_to_client(struct data_string *reply_ret,
                                               sizeof(reply.buf) -
                                                        reply.cursor,
                                               reply.opt_state, reply.packet,
-                                              required_opts,
+                                              required_opts_NAA,
                                               NULL);
-       } else if (no_addrs_avail &&
-                  (reply.packet->dhcpv6_msg_type != DHCPV6_REQUEST))
-       {
-               goto exit;
        } else {
                /*
                 * Having stored the client's IA_NA's, store any options that
@@ -1370,8 +1356,13 @@ reply_process_ia_na(struct reply_state *reply, struct option_cache *ia) {
        reply->cursor += 4;
 
        /* 
-        * For each address in this IA_NA, decide what to do about
-        * it.
+        * For each address in this IA_NA, decide what to do about it.
+        *
+        * Guidelines:
+        *
+        * The client leaves unchanged any infomation about addresses
+        * it has recorded but are not included ("cancel/break" below).
+        * A not included IA ("cleanup" below) could give a Renew/Rebind.
         */
        oc = lookup_option(&dhcpv6_universe, packet_ia, D6O_IAADDR);
        reply->valid = reply->prefer = 0xffffffff;
@@ -1405,10 +1396,9 @@ reply_process_ia_na(struct reply_state *reply, struct option_cache *ia) {
                        switch (reply->packet->dhcpv6_msg_type) {
                              case DHCPV6_SOLICIT:
                                /*
-                                * Solicit is handled by the caller, because
-                                * it has to be the sum of all the IA's.
+                                * No address for all the IA's is handled
+                                * by the caller.
                                 */
-                               goto cleanup;
 
                              case DHCPV6_REQUEST:
                                /* Section 18.2.1 (Request):
@@ -1460,10 +1450,7 @@ reply_process_ia_na(struct reply_state *reply, struct option_cache *ia) {
                                 *
                                 * We don't want to include the IA if we
                                 * provide zero addresses including zeroed
-                                * lifetimes...if we did, the client would
-                                * reset its renew/rebind behaviour.  If we do
-                                * not, the client may get a success off
-                                * another server.
+                                * lifetimes.
                                 */
                                if (reply->ia_addrs_included)
                                        status = ISC_R_SUCCESS;
@@ -1812,6 +1799,9 @@ reply_process_addr(struct reply_state *reply, struct option_cache *addr) {
                 * If the server cannot find a client entry for the IA the
                 * server returns the IA containing no addresses with a Status
                 * Code option set to NoBinding in the Reply message.
+                *
+                * On mismatch we (ab)use this pretending we have not the IA
+                * as soon as we have not an address.
                 */
                } else if (reply->packet->dhcpv6_msg_type == DHCPV6_RENEW) {
                        /* Rewind the IA_NA to empty. */