#include <gsscon.h>
#include <tr_rp.h>
#include <tr_debug.h>
+#include <trp_rtable.h>
#include <trp_internal.h>
return result;
}
+/* get the currently selected route if available */
+TRP_RENTRY *trps_get_route(TRPS_INSTANCE *trps, TR_NAME *comm, TR_NAME *realm)
+{
+ return trp_rtable_get_selected_entry(trps->rtable, comm, realm);
+}
+
+/* mark a route as retracted */
+static TRP_RC trps_retract_route(TRPS_INSTANCE *trps, TRP_RENTRY *entry)
+{
+ trp_rentry_set_metric(entry, TRP_METRIC_INFINITY);
+}
+
+/* is this route retracted? */
+static int trps_route_retracted(TRPS_INSTANCE *trps, TRP_RENTRY *entry)
+{
+ return (trp_rentry_get_metric(entry)==TRP_METRIC_INFINITY);
+}
+
static TRP_RC trps_read_message(TRPS_INSTANCE *trps, TRP_CONNECTION *conn, TR_MSG **msg)
{
int err=0;
char *buf=NULL;
size_t buflen = 0;
+ TR_NAME *peer=NULL
tr_debug("trps_read_message: started");
if (err = gsscon_read_encrypted_token(trp_connection_get_fd(conn),
if (*msg==NULL)
return TRP_NOPARSE;
- /* fill in the next hop as the peer who just sent this to us */
- trp_inforec_set_next_hop(*msg, trp_connection_get_peer(conn));
+ peer=trp_connection_get_peer(conn);
+ /* verify we received a message we support, otherwise drop it now */
+ switch (tr_msg_get_msg_type(*msg)) {
+ case TRP_UPDATE:
+ trp_upd_set_peer(tr_msg_get_trp_upd(msg), tr_name_dup(peer));
+ break;
+
+ case TRP_REQUEST:
+ trp_req_set_peer(tr_msg_get_trp_req(msg), tr_name_dup(peer));
+ break;
+
+ default:
+ tr_debug("trps_read_message: received unsupported message from %.*s", peer->len, peer->buf);
+ tr_msg_free_decoded(*msg);
+ *msg=NULL;
+ return TRP_UNSUPPORTED;
+ }
+
return TRP_SUCCESS;
}
tr_debug("trps_handle_connection: connection closed.");
talloc_free(tmp_ctx);
}
+
+/* ensure that the update could be accepted if feasible */
+static TRP_RC trps_validate_inforec(TRPS_INSTANCE *trps, TRP_INFOREC *rec)
+{
+ switch(trp_inforec_get_type(rec)) {
+ case TRP_INFOREC_TYPE_ROUTE:
+ if ((trp_inforec_get_comm(rec)==NULL)
+ || (trp_inforec_get_realm(rec)==NULL)
+ || (trp_inforec_get_trust_router(rec)==NULL)
+ || (trp_inforec_get_next_hop(rec)==NULL))
+ tr_debug("trps_validate_inforec: missing record info.");
+ return TRP_ERROR;
+
+ /* check for valid metric */
+ if ((trp_inforec_get_metric(rec)==TRP_METRIC_INVALID)
+ || (trp_inforec_get_metric(rec)>TRP_METRIC_INFINITY)) {
+ tr_debug("trps_validate_inforec: invalid metric.");
+ return TRP_ERROR;
+ }
+
+ /* check for valid interval */
+ if (trp_inforec_get_interval(rec)==TRP_INTERVAL_INVALID) {
+ tr_debug("trps_validate_inforec: invalid interval.");
+ return TRP_ERROR;
+ }
+ break;
+
+ default:
+ return TRP_UNSUPPORTED;
+ }
+
+ return TRP_SUCCESS;
+}
+
+/* link cost to a peer */
+static unsigned int trps_cost(TRPS_INSTANCE *trps, TR_NAME *peer)
+{
+ return 1;
+}
+
+static unsigned int trps_advertised_metric(TRPS_INSTANCE *trps, TR_NAME *comm, TR_NAME *realm, TR_NAME *peer)
+{
+ TRP_RENTRY *entry=trp_rtable_get_entry(trps->rtable, comm, realm, peer);
+ if (entry==NULL)
+ return TRP_METRIC_INFINITY;
+ return trp_rentry_get_metric(entry) + trps_cost(trps, peer);
+}
+
+/* returns TRP_SUCCESS if route is feasible, TRP_ERROR otherwise */
+static TRP_RC trps_check_feasibility(TRPS_INSTANCE *trps, TRP_INFOREC *rec)
+{
+ unsigned int rec_metric=trp_inforec_get_metric(rec);
+ unsigned int new_metric=0;
+ unsigned int current_metric=0;
+
+ /* we check these in the validation stage, but just in case... */
+ if ((rec_metric==TRP_METRIC_INVALID) || (rec_metric>TRP_METRIC_INFINITY))
+ return TRP_ERROR;
+
+ /* retractions (aka infinite metrics) are always feasible */
+ if (rec_metric==TRP_METRIC_INFINITY)
+ return TRP_SUCCESS;
+
+ /* updates from our current next hop are always feasible*/
+ if (0==tr_name_cmp(trp_inforec_get_next_hop(rec),
+ trps_next_hop(trps,
+ trp_inforec_get_comm(rec),
+ trp_inforec_get_realm(rec)))) {
+ return TRP_SUCCESS;
+ }
+
+
+ /* compare the existing metric we advertise to what we would advertise
+ * if we accept this update */
+ current_metric=trps_advertised_metric(trps,
+ trp_inforec_get_comm(rec),
+ trp_inforec_get_realm(rec),
+ trp_inforec_get_next_hop(rec));
+ new_metric=rec_metric + trps_cost(trps, trp_inforec_get_next_hop(rec));
+ if (new_metric <= current_metric)
+ return TRP_SUCCESS;
+ else
+ return TRP_ERROR;
+}
+
+/* uses memory pointed to by *ts, also returns that value */
+static void trps_compute_expiry(unsigned int interval, struct timespec *ts)
+{
+ const unsigned int small_factor=3; /* how many intervals we wait before expiring */
+ if (0!=clock_gettime(CLOCK_REALTIME, ts)) {
+ tr_error("trps_compute_expiry: could not read realtime clock.");
+ ts->tv_sec=0;
+ ts->tv_nsec=0;
+ return NULL;
+ }
+ ts->tv_sec += small_factor*interval;
+ return ts;
+}
+
+static TRP_RC trps_accept_update(TRPS_INSTANCE *trps, TRP_INFOREC *rec)
+{
+ TRP_RENTRY *entry=NULL;
+
+ entry=trp_rtable_get_entry(trps->rtable,
+ trp_inforec_get_comm(rec),
+ trp_inforec_get_realm(rec),
+ trp_inforec_get_next_hop(rec));
+ if (entry==NULL) {
+ entry=trp_rentry_new(NULL);
+ if (entry==NULL) {
+ tr_error("trps_accept_update: unable to allocate new entry.");
+ return TRP_NOMEM;
+ }
+
+ trp_rentry_set_apc(entry, tr_dup_name(trp_inforec_get_comm(rec)));
+ trp_rentry_set_realm(entry, tr_dup_name(trp_inforec_get_realm(rec)));
+ trp_rentry_set_peer(entry, tr_dup_name(trp_inforec_get_next_hop(rec)));
+ trp_rentry_set_trust_router(entry, tr_dup_name(trp_inforec_get_trust_router(rec)));
+ trp_rentry_set_next_hop(entry, tr_dup_name(trp_inforec_get_next_hop(rec)));
+ if ((trp_rentry_get_apc(entry)==NULL)
+ ||(trp_rentry_get_realm(entry)==NULL)
+ ||(trp_rentry_get_peer(entry)==NULL)
+ ||(trp_rentry_get_trust_router(entry)==NULL)
+ ||(trp_rentry_next_hop(entry)==NULL)) {
+ /* at least one field could not be allocated */
+ tr_error("trps_accept_update: unable to allocate all fields for entry.");
+ trp_rentry_free(entry);
+ return TRP_NOMEM;
+ }
+ trp_rtable_add(trps->rtable, entry);
+ }
+
+ /* We now have an entry in the table, whether it's new or not. Update metric and expiry, unless
+ * the metric is infinity. An infinite metric can only occur here if we just retracted an existing
+ * route (we never accept retractions as new routes), so there is no risk of leaving the expiry
+ * time unset on a new route entry. */
+ trp_rentry_set_metric(entry, trp_inforec_get_metric(rec));
+ if (!trps_route_retracted(trps, entry))
+ trp_rentry_set_expiry(entry, trps_compute_expiry(trps, trp_inforec_get_interval(rec)));
+ return TRP_SUCCESS;
+}
+
+/* TODO: handle community updates */
+static TRP_RC trps_handle_update(TRPS_INSTANCE *trps, TRP_UPD *upd)
+{
+ unsigned int feas=0;
+ TRP_INFOREC *rec=trp_upd_get_inforec(upd);
+ TRP_RENTRY *route=NULL;
+
+ if (rec==NULL) {
+ tr_notice("trps_handle_update: received TRP update with no info records.");
+ return TRP_ERROR;
+ }
+
+ for (;rec!=NULL; rec=trp_inforec_get_next(rec)) {
+ /* validate/sanity check the update */
+ if (trps_validate_inforec(trps, upd) != TRP_SUCCESS) {
+ tr_notice("trps_handle_update: invalid record in TRP update.");
+ continue;
+ }
+
+ /* determine feasibility */
+ feas=trps_check_feasibility(trps, rec);
+
+ /* do we have an existing route? */
+ route=trps_get_route(trps, trp_inforec_get_comm(rec), trp_inforec_get_realm(rec));
+ if (route!=NULL) {
+ /* there was a route table entry already */
+ if (feas) {
+ /* Update is feasible. Accept it. */
+ trps_accept_update(trps, rec);
+ } else {
+ /* Update is infeasible. Ignore it unless the trust router has changed. */
+ if (0!=tr_name_cmp(trp_rentry_get_trust_router(route),
+ trp_inforec_get_trust_router(rec))) {
+ /* the trust router associated with the route has changed, treat update as a retraction */
+ trps_retract_route(trps, route);
+ }
+ }
+ } else {
+ /* No existing route table entry. Ignore it unless it is feasible and not a retraction. */
+ if (feas && (trp_inforec_get_metric != TRP_METRIC_INFINITY))
+ trps_accept_update(trps, rec);
+ }
+ }
+ return TRP_SUCCESS;
+}
+
+TRP_RC trps_handle_tr_msg(TRPS_INSTANCE *trps, TR_MSG *tr_msg)
+{
+ switch (tr_msg_get_msg_type(tr_msg)) {
+ case TRP_UPDATE:
+ return trps_handle_update(TRPS_INSTANCE *trps, tr_msg_get_trp_upd(tr_msg));
+
+ case TRP_REQUEST:
+ return TRP_UNSUPPORTED;
+
+ default:
+ /* unknown error or one we don't care about (e.g., TID messages) */
+ return TRP_ERROR;
+ }
+}
projects / trust_router.git / commitdiff