Merge branch 'maint-0.4.5'

changes/ticket40106

@@ -1,5 +1,6 @@
   o Minor bugfixes (config, bridge):
-    - Really fix the case where torrc has a missing ClientTransportPlugin but
-      configured with a Bridge line and UseBridges. Previously, we failed to
-      also look at the managed proxy list and thus it would fail for the
-      "exec" case. Fixes bug 40106; bugfix on 0.4.5.1-alpha.
+    - Don't initiate a connection to a bridge without a corresponding
+      transport. Fixes bug 40106; bugfix on 0.4.5.1-alpha.
+    - This also reverts an earlier fix we did for this that would validate
+      configuration to avoid such situation but turns out it wouldn't work for
+      a DisableNetwork thus the new approach.

src/app/config/config.c

@@ -2189,23 +2189,6 @@ options_act,(const or_options_t *old_options))
     }
   }
 
-  /* Validate that we actually have a configured transport for a Bridge line
-   * that has one.  This is done here because we require the bridge and
-   * transport to be added to the global list before doing the validation.
-   *
-   * In an ideal world, pt_parse_transport_line() would actually return a
-   * transport_t object so we could inspect it and thus do this step at
-   * validation time. */
-  SMARTLIST_FOREACH_BEGIN(bridge_list_get(), const bridge_info_t *, bi) {
-    const char *bi_transport_name = bridget_get_transport_name(bi);
-    if (bi_transport_name && (!transport_get_by_name(bi_transport_name) &&
-                          !managed_proxy_has_transport(bi_transport_name))) {
-      log_warn(LD_CONFIG, "Bridge line with transport %s is missing a "
-                          "ClientTransportPlugin line", bi_transport_name);
-      return -1;
-    }
-  } SMARTLIST_FOREACH_END(bi);
-
   if (options_act_server_transport(old_options) < 0)
     return -1;
 

src/feature/client/bridges.c

@@ -175,6 +175,17 @@ bridget_get_transport_name(const bridge_info_t *bridge)
   return bridge->transport_name;
 }
 
+/**
+ * Return true if @a bridge has a transport name for which we don't actually
+ * know a transport.
+ */
+bool
+bridge_has_invalid_transport(const bridge_info_t *bridge)
+{
+  const char *tname = bridget_get_transport_name(bridge);
+  return tname && transport_get_by_name(tname) == NULL;
+}
+
 /** If we have a bridge configured whose digest matches <b>digest</b>, or a
  * bridge with no known digest whose address matches any of the
  * tor_addr_port_t's in <b>orports</b>, return that bridge.  Else return
@@ -656,6 +667,15 @@ launch_direct_bridge_descriptor_fetch(bridge_info_t *bridge)
       DIR_PURPOSE_FETCH_SERVERDESC))
     return; /* it's already on the way */
 
+  if (bridge_has_invalid_transport(bridge)) {
+    download_status_mark_impossible(&bridge->fetch_status);
+    log_warn(LD_CONFIG, "Can't use bridge at %s: there is no configured "
+             "transport called \"%s\".",
+             safe_str_client(fmt_and_decorate_addr(&bridge->addr)),
+             bridget_get_transport_name(bridge));
+    return; /* Can't use this bridge; it has not */
+  }
+
   if (routerset_contains_bridge(options->ExcludeNodes, bridge)) {
     download_status_mark_impossible(&bridge->fetch_status);
     log_warn(LD_APP, "Not using bridge at %s: it is in ExcludeNodes.",

src/feature/client/bridges.h

@@ -24,6 +24,7 @@ const smartlist_t *bridge_list_get(void);
 const uint8_t *bridge_get_rsa_id_digest(const bridge_info_t *bridge);
 const tor_addr_port_t * bridge_get_addr_port(const bridge_info_t *bridge);
 const char *bridget_get_transport_name(const bridge_info_t *bridge);
+bool bridge_has_invalid_transport(const bridge_info_t *bridge);
 bridge_info_t *get_configured_bridge_by_addr_port_digest(
                                           const tor_addr_t *addr,
                                           uint16_t port,

src/feature/client/entrynodes.c

@@ -804,6 +804,9 @@ get_sampled_guard_for_bridge(guard_selection_t *gs,
   entry_guard_t *guard;
   if (BUG(!addrport))
     return NULL; // LCOV_EXCL_LINE
+  if (bridge_has_invalid_transport(bridge)) {
+    return NULL;
+  }
   guard = get_sampled_guard_by_bridge_addr(gs, addrport);
   if (! guard || (id && tor_memneq(id, guard->identity, DIGEST_LEN)))
     return NULL;