Merge remote-tracking branch 'dgoulet/ticket24902_029_05' into maint-0.2.9

src/or/command.c

@@ -46,6 +46,7 @@
 #include "config.h"
 #include "control.h"
 #include "cpuworker.h"
+#include "dos.h"
 #include "hibernate.h"
 #include "nodelist.h"
 #include "onion.h"
@@ -247,6 +248,11 @@ command_process_create_cell(cell_t *cell, channel_t *chan)
             (unsigned)cell->circ_id,
             U64_PRINTF_ARG(chan->global_identifier), chan);
 
+  /* First thing we do, even though the cell might be invalid, is inform the
+   * DoS mitigation subsystem layer of this event. Validation is done by this
+   * function. */
+  dos_cc_new_create_cell(chan);
+
   /* We check for the conditions that would make us drop the cell before
    * we check for the conditions that would make us send a DESTROY back,
    * since those conditions would make a DESTROY nonsensical. */
@@ -284,6 +290,13 @@ command_process_create_cell(cell_t *cell, channel_t *chan)
     return;
   }
 
+  /* Check if we should apply a defense for this channel. */
+  if (dos_cc_get_defense_type(chan) == DOS_CC_DEFENSE_REFUSE_CELL) {
+    channel_send_destroy(cell->circ_id, chan,
+                         END_CIRC_REASON_RESOURCELIMIT);
+    return;
+  }
+
   if (!server_mode(options) ||
       (!public_server_mode(options) && channel_is_outgoing(chan))) {
     log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,