[tor-commits] [stegotorus/master] Don't allow connection count to grow without limit in HTTP steg.

[zwol at torproject.org]

commit 83648b9054337c6276077a342c7d7653a9daafca
Author: Zack Weinberg <zackw at cmu.edu>
Date:   Mon Jul 16 15:04:12 2012 -0700

    Don't allow connection count to grow without limit in HTTP steg.
    
    The fix involves two complementary changes: (1) restore the upper
    limit of 64 outstanding downstream connections per circuit; (2) HTTP
    steg needs to call ->cease_transmission() and ->expect_close() on its
    connections at the right times (for now, unconditionally; in the
    future, paying attention to the HTTP "Connection:" header).
---
 src/protocol/chop.cc |    3 ++-
 src/steg/http.cc     |   13 ++++++++++++-
 src/steg/jsSteg.cc   |    2 --
 src/steg/pdfSteg.cc  |    2 --
 src/steg/swfSteg.cc  |    3 ---
 5 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/src/protocol/chop.cc b/src/protocol/chop.cc
index bb4a95c..3059c1b 100644
--- a/src/protocol/chop.cc
+++ b/src/protocol/chop.cc
@@ -479,7 +479,8 @@ chop_circuit_t::send()
     // reopening new connections.  If we're the server, we have to
     // just twiddle our thumbs and hope the client does that.
     if (no_target_connection) {
-      if (config->mode != LSN_SIMPLE_SERVER)
+      if (config->mode != LSN_SIMPLE_SERVER &&
+          downstreams.size() < 64)
         circuit_reopen_downstreams(this);
       else
         circuit_arm_axe_timer(this, axe_interval());
diff --git a/src/steg/http.cc b/src/steg/http.cc
index 7caf2e7..381258c 100644
--- a/src/steg/http.cc
+++ b/src/steg/http.cc
@@ -588,7 +588,13 @@ http_steg_t::transmit(struct evbuffer *source)
       break;
     }
 
-    if (rval == 0) have_transmitted = 1;
+    if (rval == 0) {
+      have_transmitted = 1;
+      // FIXME: should decide whether or not to do this based on the
+      // Connection: header.  (Needs additional changes elsewhere, esp.
+      // in transmit_room.)
+      conn->cease_transmission();
+    }
     return rval;
   }
 }
@@ -671,6 +677,11 @@ http_server_receive(http_steg_t *s, conn_t *conn, struct evbuffer *dest, struct
   s->have_received = 1;
   s->type = type;
 
+  // FIXME: should decide whether or not to do this based on the
+  // Connection: header.  (Needs additional changes elsewhere, esp.
+  // in transmit_room.)
+  conn->expect_close();
+
   conn->transmit_soon(100);
   return RECV_GOOD;
 }
diff --git a/src/steg/jsSteg.cc b/src/steg/jsSteg.cc
index dbe4431..3954829 100644
--- a/src/steg/jsSteg.cc
+++ b/src/steg/jsSteg.cc
@@ -893,8 +893,6 @@ http_server_JS_transmit (payloads& pl, struct evbuffer *source, conn_t *conn,
   evbuffer_drain(source, sbuflen);
 
   free(outbuf2);
-  conn->cease_transmission();
-  //  downcast_steg(s)->have_transmitted = 1;
   return 0;
 }
 
diff --git a/src/steg/pdfSteg.cc b/src/steg/pdfSteg.cc
index f76da99..8bff423 100644
--- a/src/steg/pdfSteg.cc
+++ b/src/steg/pdfSteg.cc
@@ -464,8 +464,6 @@ http_server_PDF_transmit(payloads &pl, struct evbuffer *source,
   }
 
   evbuffer_drain(source, sbuflen);
-
-  conn->cease_transmission();
   return 0;
 }
 
diff --git a/src/steg/swfSteg.cc b/src/steg/swfSteg.cc
index 8fb29ee..8e12d21 100644
--- a/src/steg/swfSteg.cc
+++ b/src/steg/swfSteg.cc
@@ -152,9 +152,6 @@ http_server_SWF_transmit(payloads& pl, struct evbuffer *source, conn_t *conn)
     return -1;
   }
 
-    
-  conn->cease_transmission();
-
   free(inbuf);
   free(outbuf);
   return 0;