[or-cvs] r16943: {tor} (backport to 0.2.0.x) Fix for bug 797 (by arma, with tweaks) (in tor/branches/tor-0_2_0-patches: . doc src/or)

[nickm@xxxxxxxx]

Author: nickm
Date: 2008-09-23 16:13:43 -0400 (Tue, 23 Sep 2008)
New Revision: 16943

Modified:
   tor/branches/tor-0_2_0-patches/ChangeLog
   tor/branches/tor-0_2_0-patches/doc/tor.1.in
   tor/branches/tor-0_2_0-patches/src/or/circuitbuild.c
Log:
(backport to 0.2.0.x) Fix for bug 797 (by arma, with tweaks): always use create_fast for circuits where we do not know an onion key.

Modified: tor/branches/tor-0_2_0-patches/ChangeLog
===================================================================
--- tor/branches/tor-0_2_0-patches/ChangeLog	2008-09-23 20:13:23 UTC (rev 16942)
+++ tor/branches/tor-0_2_0-patches/ChangeLog	2008-09-23 20:13:43 UTC (rev 16943)
@@ -3,6 +3,9 @@
     - Fix several infrequent memory leaks spotted by Coverity.
     - When testing for libevent functions, set the LDFLAGS variable
       correctly.  (Found by Riastradh.)
+    - Avoid a bug where the FistFirstHopPK 0 option would keep Tor from
+      bootstrapping with tunneled directory connections.  Bugfix on
+      0.1.2.5-alpha.  Fixes bug 797.
 
 
 Changes in version 0.2.0.31 - 2008-09-03

Modified: tor/branches/tor-0_2_0-patches/doc/tor.1.in
===================================================================
--- tor/branches/tor-0_2_0-patches/doc/tor.1.in	2008-09-23 20:13:23 UTC (rev 16942)
+++ tor/branches/tor-0_2_0-patches/doc/tor.1.in	2008-09-23 20:13:43 UTC (rev 16943)
@@ -663,11 +663,14 @@
 .LP
 .TP
 \fBFastFirstHopPK \fR\fB0\fR|\fB1\fR\fP
-When this option is enabled and we aren't running as a server, Tor
-skips the public key step for the first hop of creating circuits.  This is
-safe since we have already used TLS to authenticate the server and to
-establish forward-secure keys.  Turning this option off makes circuit
-building slower.
+When this option is disabled, Tor uses the public key step for the first
+hop of creating circuits. Skipping it is generally safe since we have
+already used TLS to authenticate the relay and to establish forward-secure
+keys. Turning this option off makes circuit building slower.
+
+Note that Tor will always use the public key step for the first hop if
+it's operating as a relay, and it will never use the public key step if
+it doesn't yet know the onion key of the first hop.
 (Default: 1)
 .LP
 .TP

Modified: tor/branches/tor-0_2_0-patches/src/or/circuitbuild.c
===================================================================
--- tor/branches/tor-0_2_0-patches/src/or/circuitbuild.c	2008-09-23 20:13:23 UTC (rev 16942)
+++ tor/branches/tor-0_2_0-patches/src/or/circuitbuild.c	2008-09-23 20:13:43 UTC (rev 16943)
@@ -541,23 +541,20 @@
   return 1;
 }
 
-/** Return true iff we should send a create_fast cell to build a circuit
- * starting at <b>router</b>. (If <b>router</b> is NULL, we don't have
- * information on the router, so assume true.) */
+/** Return true iff we should send a create_fast cell to start building a given
+ * circuit */
 static INLINE int
-should_use_create_fast_for_router(routerinfo_t *router,
-                                  origin_circuit_t *circ)
+should_use_create_fast_for_circuit(origin_circuit_t *circ)
 {
   or_options_t *options = get_options();
+  tor_assert(circ->cpath);
+  tor_assert(circ->cpath->extend_info);
 
-  if (!options->FastFirstHopPK) /* create_fast is disabled */
-    return 0;
-  if (router && router->platform &&
-      !tor_version_as_new_as(router->platform, "0.1.0.6-rc")) {
-    /* known not to work */
-    return 0;
-  }
-  if (server_mode(options) && circ->cpath->extend_info->onion_key) {
+  if (!circ->cpath->extend_info->onion_key)
+    return 1; /* our hand is forced: only a create_fast will work. */
+  if (!options->FastFirstHopPK)
+    return 0; /* we prefer to avoid create_fast */
+  if (server_mode(options)) {
     /* We're a server, and we know an onion key. We can choose.
      * Prefer to blend in. */
     return 0;
@@ -593,14 +590,9 @@
     log_debug(LD_CIRC,"First skin; sending create cell.");
 
     router = router_get_by_digest(circ->_base.n_conn->identity_digest);
-    fast = should_use_create_fast_for_router(router, circ);
-    if (!fast && !circ->cpath->extend_info->onion_key) {
-      log_warn(LD_CIRC,
-               "Can't send create_fast, but have no onion key. Failing.");
-      return - END_CIRC_REASON_INTERNAL;
-    }
+    fast = should_use_create_fast_for_circuit(circ);
     if (!fast) {
-      /* We are an OR, or we are connecting to an old Tor: we should
+      /* We are an OR and we know the right onion key: we should
        * send an old slow create cell.
        */
       cell_type = CELL_CREATE;