From: Jennifer Richards <jennifer@painless-security.com>
Date: Mon, 12 Jun 2017 20:14:21 +0000 (-0400)
Subject: Filter inbound TRP records (compiles but not tested)
X-Git-Tag: v3.0.0~18
X-Git-Url: http://www.project-moonshot.org/gitweb/?p=trust_router.git;a=commitdiff_plain;h=cda9bb642a88246313649e481c761602f874667d

Filter inbound TRP records (compiles but not tested)
---

diff --git a/tr/tr_trp.c b/tr/tr_trp.c
index 2b93969..5ad734d 100644
--- a/tr/tr_trp.c
+++ b/tr/tr_trp.c
@@ -237,6 +237,15 @@ static void tr_trps_print_route_table(TRPS_INSTANCE *trps, FILE *f)
   }
 }
 
+/**
+ * Event handler to process TRP messages from connection threads. These
+ * are added to the message queue (mq) in tr_trps_msg_handler(), which
+ * runs in the other threads.
+ *
+ * @param socket Ignored
+ * @param event Ignored
+ * @param arg Pointer to the TRPS_INSTANCE
+ */
 static void tr_trps_process_mq(int socket, short event, void *arg)
 {
   TRPS_INSTANCE *trps=talloc_get_type_abort(arg, TRPS_INSTANCE);
diff --git a/trp/trps.c b/trp/trps.c
index c706f72..6e7e56d 100644
--- a/trp/trps.c
+++ b/trp/trps.c
@@ -1003,6 +1003,43 @@ cleanup:
   return rc;
 }
 
+/**
+ * Apply applicable TRP_INBOUND filters to an inforec. Rejects everything if peer has no filters.
+ *
+ * @param trps Active TRPS instance
+ * @param peer_name Name of peer that sent this inforec
+ * @param rec Inforec to filter
+ * @return 1 if accepted by the filter, 0 otherwise
+ */
+static int trps_filter_inbound_inforec(TRPS_INSTANCE *trps, TR_NAME *peer_name, TRP_INFOREC *rec)
+{
+  TRP_PEER *peer=NULL;
+  TR_FILTER_ACTION action=TR_FILTER_ACTION_REJECT;
+
+  /* Look up the peer. For inbound messages, the peer is identified by its GSS name */
+  peer=trps_get_peer_by_gssname(trps, peer_name);
+  if (peer==NULL) {
+    tr_err("trps_filter_inbound_inforec: received inforec from unknown peer (%.*s), rejecting.",
+           peer_name->len,
+           peer_name->buf);
+    return 0;
+  }
+
+  /* tr_filter_apply() and tr_filter_set_get() handle null filter sets/filters by rejecting */
+  if ((TR_FILTER_NO_MATCH==tr_filter_apply(rec,
+                                           tr_filter_set_get(peer->filters, TR_FILTER_TYPE_TRP_INBOUND),
+                                           NULL,
+                                           &action))
+      || (action!=TR_FILTER_ACTION_ACCEPT)) {
+    /* either the filter did not match or it matched a reject rule */
+    return 0;
+  }
+
+  /* filter matched an accept rule */
+  return 1;
+}
+
+
 static TRP_RC trps_handle_update(TRPS_INSTANCE *trps, TRP_UPD *upd)
 {
   TRP_INFOREC *rec=NULL;
@@ -1021,6 +1058,11 @@ static TRP_RC trps_handle_update(TRPS_INSTANCE *trps, TRP_UPD *upd)
   }
 
   for (rec=trp_upd_get_inforec(upd); rec!=NULL; rec=trp_inforec_get_next(rec)) {
+    if (!trps_filter_inbound_inforec(trps, trp_upd_get_peer(upd), rec)) {
+      tr_debug("trps_handle_update: inforec rejected by filter.");
+      continue; /* just go on to the next record */
+    }
+
     switch (trp_inforec_get_type(rec)) {
     case TRP_INFOREC_TYPE_ROUTE:
       tr_debug("trps_handle_update: handling route inforec.");