From 93ccb3294bd2af4587d11e7306422a9aef83013c Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 24 Jun 2020 14:28:43 -0400
Subject: [PATCH 1/6] Make a bunch of networkstatus_t parameters constant.

This is part of refactoring our "notify the rest of the code that we
have a new consensus" code.
---
 src/core/or/channelpadding.c    | 2 +-
 src/core/or/channelpadding.h    | 3 +--
 src/core/or/circuitstats.c      | 4 ++--
 src/core/or/circuitstats.h      | 2 +-
 src/feature/nodelist/nodelist.c | 4 ++--
 src/feature/nodelist/nodelist.h | 4 ++--
 6 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/src/core/or/channelpadding.c b/src/core/or/channelpadding.c
index be2ce78a17..c754a58c42 100644
--- a/src/core/or/channelpadding.c
+++ b/src/core/or/channelpadding.c
@@ -90,7 +90,7 @@ static int consensus_nf_pad_single_onion;
  * for every single connection, every second.
  */
 void
-channelpadding_new_consensus_params(networkstatus_t *ns)
+channelpadding_new_consensus_params(const networkstatus_t *ns)
 {
 #define DFLT_NETFLOW_INACTIVE_KEEPALIVE_LOW 1500
 #define DFLT_NETFLOW_INACTIVE_KEEPALIVE_HIGH 9500
diff --git a/src/core/or/channelpadding.h b/src/core/or/channelpadding.h
index d1c7192ffd..9246988cdc 100644
--- a/src/core/or/channelpadding.h
+++ b/src/core/or/channelpadding.h
@@ -37,7 +37,6 @@ int channelpadding_send_enable_command(channel_t *chan, uint16_t low_timeout,
 
 int channelpadding_get_circuits_available_timeout(void);
 unsigned int channelpadding_get_channel_idle_timeout(const channel_t *, int);
-void channelpadding_new_consensus_params(networkstatus_t *ns);
+void channelpadding_new_consensus_params(const networkstatus_t *ns);
 
 #endif /* !defined(TOR_CHANNELPADDING_H) */
-
diff --git a/src/core/or/circuitstats.c b/src/core/or/circuitstats.c
index 6a9d84df99..bc6c263798 100644
--- a/src/core/or/circuitstats.c
+++ b/src/core/or/circuitstats.c
@@ -399,7 +399,7 @@ circuit_build_times_initial_timeout(void)
  * and learn a new timeout.
  */
 static int32_t
-circuit_build_times_recent_circuit_count(networkstatus_t *ns)
+circuit_build_times_recent_circuit_count(const networkstatus_t *ns)
 {
   int32_t num;
   num = networkstatus_get_param(ns, "cbtrecentcount",
@@ -425,7 +425,7 @@ circuit_build_times_recent_circuit_count(networkstatus_t *ns)
  */
 void
 circuit_build_times_new_consensus_params(circuit_build_times_t *cbt,
-                                         networkstatus_t *ns)
+                                         const networkstatus_t *ns)
 {
   int32_t num;
 
diff --git a/src/core/or/circuitstats.h b/src/core/or/circuitstats.h
index 317eeac202..930e0a9ba3 100644
--- a/src/core/or/circuitstats.h
+++ b/src/core/or/circuitstats.h
@@ -43,7 +43,7 @@ int circuit_build_times_needs_circuits_now(const circuit_build_times_t *cbt);
 void circuit_build_times_init(circuit_build_times_t *cbt);
 void circuit_build_times_free_timeouts(circuit_build_times_t *cbt);
 void circuit_build_times_new_consensus_params(circuit_build_times_t *cbt,
-                                              networkstatus_t *ns);
+                                              const networkstatus_t *ns);
 double circuit_build_times_timeout_rate(const circuit_build_times_t *cbt);
 double circuit_build_times_close_rate(const circuit_build_times_t *cbt);
 
diff --git a/src/feature/nodelist/nodelist.c b/src/feature/nodelist/nodelist.c
index 6b2c0d2016..dd6c65661a 100644
--- a/src/feature/nodelist/nodelist.c
+++ b/src/feature/nodelist/nodelist.c
@@ -621,7 +621,7 @@ get_estimated_address_per_node, (void))
  * and grab microdescriptors into nodes as appropriate.
  */
 void
-nodelist_set_consensus(networkstatus_t *ns)
+nodelist_set_consensus(const networkstatus_t *ns)
 {
   const or_options_t *options = get_options();
   int authdir = authdir_mode_v3(options);
@@ -952,7 +952,7 @@ nodelist_assert_ok(void)
 /** Ensure that the nodelist has been created with the most recent consensus.
  *  If that's not the case, make it so.  */
 void
-nodelist_ensure_freshness(networkstatus_t *ns)
+nodelist_ensure_freshness(const networkstatus_t *ns)
 {
   tor_assert(ns);
 
diff --git a/src/feature/nodelist/nodelist.h b/src/feature/nodelist/nodelist.h
index 4ba699d69d..826d1b957a 100644
--- a/src/feature/nodelist/nodelist.h
+++ b/src/feature/nodelist/nodelist.h
@@ -32,8 +32,8 @@ const node_t *node_get_by_hex_id(const char *identity_digest,
                                  unsigned flags);
 node_t *nodelist_set_routerinfo(routerinfo_t *ri, routerinfo_t **ri_old_out);
 node_t *nodelist_add_microdesc(microdesc_t *md);
-void nodelist_set_consensus(networkstatus_t *ns);
-void nodelist_ensure_freshness(networkstatus_t *ns);
+void nodelist_set_consensus(const networkstatus_t *ns);
+void nodelist_ensure_freshness(const networkstatus_t *ns);
 int nodelist_probably_contains_address(const tor_addr_t *addr);
 void nodelist_add_addr4_to_address_set(const uint32_t addr);
 void nodelist_add_addr6_to_address_set(const tor_addr_t *addr);

From 5c5fb0fcca504d319276a697fec43287e242765d Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 24 Jun 2020 14:30:05 -0400
Subject: [PATCH 2/6] Move code into notify_after_networkstatus_changes().

The purpose of having this function was to inform other code that
the consensus has changed, so it should go there.
---
 src/feature/nodelist/networkstatus.c | 50 +++++++++++++++-------------
 1 file changed, 27 insertions(+), 23 deletions(-)

diff --git a/src/feature/nodelist/networkstatus.c b/src/feature/nodelist/networkstatus.c
index e07d58c91c..010963cda4 100644
--- a/src/feature/nodelist/networkstatus.c
+++ b/src/feature/nodelist/networkstatus.c
@@ -1670,7 +1670,34 @@ notify_before_networkstatus_changes(const networkstatus_t *old_c,
 static void
 notify_after_networkstatus_changes(void)
 {
+  const networkstatus_t *c = networkstatus_get_latest_consensus();
+  const or_options_t *options = get_options();
+  const time_t now = approx_time();
+
   scheduler_notify_networkstatus_changed();
+
+  /* The "current" consensus has just been set and it is a usable flavor so
+   * the first thing we need to do is recalculate the voting schedule static
+   * object so we can use the timings in there needed by some subsystems
+   * such as hidden service and shared random. */
+  dirauth_sched_recalculate_timing(options, now);
+  reschedule_dirvote(options);
+
+  nodelist_set_consensus(c);
+
+  update_consensus_networkstatus_fetch_time(now);
+
+  /* Change the cell EWMA settings */
+  cmux_ewma_set_options(options, c);
+
+  /* XXXX this call might be unnecessary here: can changing the
+   * current consensus really alter our view of any OR's rate limits? */
+  connection_or_update_token_buckets(get_connection_array(), options);
+
+  circuit_build_times_new_consensus_params(
+                                 get_circuit_build_times_mutable(), c);
+  channelpadding_new_consensus_params(c);
+  circpad_new_consensus_params(c);
 }
 
 /** Copy all the ancillary information (like router download status and so on)
@@ -2115,29 +2142,6 @@ networkstatus_set_current_consensus(const char *consensus,
     /* Notify that we just changed the consensus so the current global value
      * can be looked at. */
     notify_after_networkstatus_changes();
-
-    /* The "current" consensus has just been set and it is a usable flavor so
-     * the first thing we need to do is recalculate the voting schedule static
-     * object so we can use the timings in there needed by some subsystems
-     * such as hidden service and shared random. */
-    dirauth_sched_recalculate_timing(options, now);
-    reschedule_dirvote(options);
-
-    nodelist_set_consensus(c);
-
-    update_consensus_networkstatus_fetch_time(now);
-
-    /* Change the cell EWMA settings */
-    cmux_ewma_set_options(options, c);
-
-    /* XXXX this call might be unnecessary here: can changing the
-     * current consensus really alter our view of any OR's rate limits? */
-    connection_or_update_token_buckets(get_connection_array(), options);
-
-    circuit_build_times_new_consensus_params(
-                               get_circuit_build_times_mutable(), c);
-    channelpadding_new_consensus_params(c);
-    circpad_new_consensus_params(c);
   }
 
   /* Reset the failure count only if this consensus is actually valid. */

From f9de0affd3f50d411e04bc1229525af2a14927fd Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 24 Jun 2020 14:39:01 -0400
Subject: [PATCH 3/6] Rename router_should_skip_orport_reachability_check.

This was supposed to happen in #40012, but the command line was wrong.

This is an automated commit, generated by this command:

./scripts/maint/rename_c_identifier.py \
        router_should_skip_orport_reachability_check router_all_orports_seem_reachable
---
 src/core/or/circuitbuild.c            | 2 +-
 src/core/or/circuituse.c              | 4 ++--
 src/feature/control/control_getinfo.c | 4 ++--
 src/feature/relay/router.c            | 2 +-
 src/feature/relay/selftest.c          | 2 +-
 src/feature/relay/selftest.h          | 4 ++--
 src/feature/stats/predict_ports.c     | 2 +-
 7 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/core/or/circuitbuild.c b/src/core/or/circuitbuild.c
index be8ec6f3cb..652d85b1c1 100644
--- a/src/core/or/circuitbuild.c
+++ b/src/core/or/circuitbuild.c
@@ -1055,7 +1055,7 @@ circuit_build_no_more_hops(origin_circuit_t *circ)
     control_event_client_status(LOG_NOTICE, "CIRCUIT_ESTABLISHED");
     clear_broken_connection_map(1);
     if (server_mode(options) &&
-        !router_should_skip_orport_reachability_check(options)) {
+        !router_all_orports_seem_reachable(options)) {
       inform_testing_reachability();
       router_do_reachability_checks(1, 1);
     }
diff --git a/src/core/or/circuituse.c b/src/core/or/circuituse.c
index 7358817531..f4cd4ced43 100644
--- a/src/core/or/circuituse.c
+++ b/src/core/or/circuituse.c
@@ -1642,7 +1642,7 @@ static void
 circuit_testing_opened(origin_circuit_t *circ)
 {
   if (have_performed_bandwidth_test ||
-      !router_should_skip_orport_reachability_check(get_options())) {
+      !router_all_orports_seem_reachable(get_options())) {
     /* either we've already done everything we want with testing circuits,
      * or this testing circuit became open due to a fluke, e.g. we picked
      * a last hop where we already had the connection open due to an
@@ -1661,7 +1661,7 @@ circuit_testing_failed(origin_circuit_t *circ, int at_last_hop)
 {
   const or_options_t *options = get_options();
   if (server_mode(options) &&
-      router_should_skip_orport_reachability_check(options))
+      router_all_orports_seem_reachable(options))
     return;
 
   log_info(LD_GENERAL,
diff --git a/src/feature/control/control_getinfo.c b/src/feature/control/control_getinfo.c
index 8d6c314b43..47e0224a90 100644
--- a/src/feature/control/control_getinfo.c
+++ b/src/feature/control/control_getinfo.c
@@ -1279,7 +1279,7 @@ getinfo_helper_events(control_connection_t *control_conn,
                            ? "1" : "0");
     } else if (!strcmp(question, "status/reachability-succeeded/or")) {
       *answer = tor_strdup(
-                    router_should_skip_orport_reachability_check(options) ?
+                    router_all_orports_seem_reachable(options) ?
                     "1" : "0");
     } else if (!strcmp(question, "status/reachability-succeeded/dir")) {
       *answer = tor_strdup(
@@ -1288,7 +1288,7 @@ getinfo_helper_events(control_connection_t *control_conn,
     } else if (!strcmp(question, "status/reachability-succeeded")) {
       tor_asprintf(
           answer, "OR=%d DIR=%d",
-          router_should_skip_orport_reachability_check(options) ? 1 : 0,
+          router_all_orports_seem_reachable(options) ? 1 : 0,
           router_dirport_seems_reachable(options) ? 1 : 0);
     } else if (!strcmp(question, "status/bootstrap-phase")) {
       *answer = control_event_boot_last_msg();
diff --git a/src/feature/relay/router.c b/src/feature/relay/router.c
index 1691ac5f48..1933f61edb 100644
--- a/src/feature/relay/router.c
+++ b/src/feature/relay/router.c
@@ -1363,7 +1363,7 @@ decide_if_publishable_server(void)
     return 1;
   if (!router_get_advertised_or_port(options))
     return 0;
-  if (!router_should_skip_orport_reachability_check(options))
+  if (!router_all_orports_seem_reachable(options))
     return 0;
   if (router_have_consensus_path() == CONSENSUS_PATH_INTERNAL) {
     /* All set: there are no exits in the consensus (maybe this is a tiny
diff --git a/src/feature/relay/selftest.c b/src/feature/relay/selftest.c
index 71054e6e87..64b8578bac 100644
--- a/src/feature/relay/selftest.c
+++ b/src/feature/relay/selftest.c
@@ -408,7 +408,7 @@ ready_to_publish(const or_options_t *options)
 {
   return options->PublishServerDescriptor_ != NO_DIRINFO &&
     router_dirport_seems_reachable(options) &&
-    router_should_skip_orport_reachability_check(options);
+    router_all_orports_seem_reachable(options);
 }
 
 /** Annotate that we found our ORPort reachable with a given address
diff --git a/src/feature/relay/selftest.h b/src/feature/relay/selftest.h
index 9b7005db39..911d8bdc3f 100644
--- a/src/feature/relay/selftest.h
+++ b/src/feature/relay/selftest.h
@@ -15,7 +15,7 @@
 #ifdef HAVE_MODULE_RELAY
 
 struct or_options_t;
-#define router_should_skip_orport_reachability_check(opts) \
+#define router_all_orports_seem_reachable(opts) \
   router_orport_seems_reachable((opts),0)
 int router_orport_seems_reachable(
                                          const struct or_options_t *options,
@@ -34,7 +34,7 @@ void router_reset_reachability(void);
 
 #else /* !defined(HAVE_MODULE_RELAY) */
 
-#define router_should_skip_orport_reachability_check(opts)     \
+#define router_all_orports_seem_reachable(opts)     \
   ((void)(opts), 0)
 #define router_orport_seems_reachable(opts, fam)  \
   ((void)(opts), (void)(fam), 0)
diff --git a/src/feature/stats/predict_ports.c b/src/feature/stats/predict_ports.c
index 37f7f4c583..57463952e7 100644
--- a/src/feature/stats/predict_ports.c
+++ b/src/feature/stats/predict_ports.c
@@ -270,7 +270,7 @@ rep_hist_circbuilding_dormant(time_t now)
 
   /* see if we'll still need to build testing circuits */
   if (server_mode(options) &&
-      (!router_should_skip_orport_reachability_check(options) ||
+      (!router_all_orports_seem_reachable(options) ||
        !circuit_enough_testing_circs()))
     return 0;
   if (!router_dirport_seems_reachable(options))

From 6edf7f6710600962f95e7f5458787dbc5e5c7411 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 24 Jun 2020 14:52:44 -0400
Subject: [PATCH 4/6] Add two new networkstatus parameters to emulate
 AssumeReachable.

These parameters do not suppress checks, but they tell relays that
it's okay to publish even when those checks fail.

I have chosen lowercase hyphenated names, since these seem to be
more common in networkstatus params.

Closes #33224 and part of #34064.
---
 changes/ticket34064                  |  5 ++++
 src/feature/nodelist/networkstatus.c |  1 +
 src/feature/relay/router.c           | 43 ++++++++++++++++++++++++++--
 src/feature/relay/router.h           |  2 ++
 4 files changed, 49 insertions(+), 2 deletions(-)
 create mode 100644 changes/ticket34064

diff --git a/changes/ticket34064 b/changes/ticket34064
new file mode 100644
index 0000000000..13ed70c8f6
--- /dev/null
+++ b/changes/ticket34064
@@ -0,0 +1,5 @@
+  o Minor features (relay, ipv6):
+    - Add new "assume-reachable" and "assume-reachable-ipv6" parameters
+      to be used in an emergency to tell relays that they should publish
+      even if they cannot complete their ORPort self-checks.
+      Closes ticket 34064 and part of 33224.
diff --git a/src/feature/nodelist/networkstatus.c b/src/feature/nodelist/networkstatus.c
index 010963cda4..f63d598ef7 100644
--- a/src/feature/nodelist/networkstatus.c
+++ b/src/feature/nodelist/networkstatus.c
@@ -1698,6 +1698,7 @@ notify_after_networkstatus_changes(void)
                                  get_circuit_build_times_mutable(), c);
   channelpadding_new_consensus_params(c);
   circpad_new_consensus_params(c);
+  router_new_consensus_params(c);
 }
 
 /** Copy all the ancillary information (like router download status and so on)
diff --git a/src/feature/relay/router.c b/src/feature/relay/router.c
index 1933f61edb..97b630add7 100644
--- a/src/feature/relay/router.c
+++ b/src/feature/relay/router.c
@@ -1335,6 +1335,17 @@ should_refuse_unknown_exits(const or_options_t *options)
   }
 }
 
+/**
+ * If true, then we will publish our descriptor even if our own IPv4 ORPort
+ * seems to be unreachable.
+ **/
+static bool publish_even_when_ipv4_orport_unreachable = false;
+/**
+ * If true, then we will publish our descriptor even if our own IPv6 ORPort
+ * seems to be unreachable.
+ **/
+static bool publish_even_when_ipv6_orport_unreachable = false;
+
 /** Decide if we're a publishable server. We are a publishable server if:
  * - We don't have the ClientOnly option set
  * and
@@ -1363,8 +1374,18 @@ decide_if_publishable_server(void)
     return 1;
   if (!router_get_advertised_or_port(options))
     return 0;
-  if (!router_all_orports_seem_reachable(options))
-    return 0;
+  if (!router_orport_seems_reachable(AF_INET)) {
+    // We have an ipv4 orport, and it doesn't seem reachable.
+    if (!publish_even_when_ipv4_orport_unreachable) {
+      return 0;
+    }
+  }
+  if (!router_orport_seems_reachable(AF_INET6)) {
+    // We have an ipv6 orport, and it doesn't seem reachable.
+    if (!publish_even_when_ipv6_orport_unreachable) {
+      return 0;
+    }
+  }
   if (router_have_consensus_path() == CONSENSUS_PATH_INTERNAL) {
     /* All set: there are no exits in the consensus (maybe this is a tiny
      * test network), so we can't check our DirPort reachability. */
@@ -2388,6 +2409,24 @@ router_rebuild_descriptor(int force)
   return 0;
 }
 
+/** Called when we have a new set of consensus parameters. */
+void
+router_new_consensus_params(const networkstatus_t *ns)
+{
+  const int32_t DEFAULT_ASSUME_REACHABLE = 0;
+  const int32_t DEFAULT_ASSUME_REACHABLE_IPV6 = 0;
+  int ar, ar6;
+  ar = networkstatus_get_param(ns,
+                               "assume-reachable",
+                               DEFAULT_ASSUME_REACHABLE, 0, 1);
+  ar6 = networkstatus_get_param(ns,
+                                "assume-reachable-ipv6",
+                                DEFAULT_ASSUME_REACHABLE_IPV6, 0, 1);
+
+  publish_even_when_ipv4_orport_unreachable = ar;
+  publish_even_when_ipv6_orport_unreachable = ar || ar6;
+}
+
 /** If our router descriptor ever goes this long without being regenerated
  * because something changed, we force an immediate regenerate-and-upload. */
 #define FORCE_REGENERATE_DESCRIPTOR_INTERVAL (18*60*60)
diff --git a/src/feature/relay/router.h b/src/feature/relay/router.h
index 50790a73dd..b1f90699a2 100644
--- a/src/feature/relay/router.h
+++ b/src/feature/relay/router.h
@@ -34,6 +34,7 @@ void set_server_identity_key(crypto_pk_t *k);
 MOCK_DECL(crypto_pk_t *,get_server_identity_key,(void));
 #else
 #define get_server_identity_key() (tor_abort_(),NULL)
+#define router_new_consensus_params(c) ((void)(c))
 #endif
 int server_identity_key_is_set(void);
 void set_client_identity_key(crypto_pk_t *k);
@@ -81,6 +82,7 @@ int router_should_advertise_dirport(const or_options_t *options,
 void consider_publishable_server(int force);
 int should_refuse_unknown_exits(const or_options_t *options);
 
+void router_new_consensus_params(const networkstatus_t *);
 void router_upload_dir_desc_to_dirservers(int force);
 void mark_my_descriptor_dirty_if_too_old(time_t now);
 void mark_my_descriptor_dirty(const char *reason);

From edb023b1e74dd3b900af399126bd985fc4064857 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Wed, 24 Jun 2020 15:12:57 -0400
Subject: [PATCH 5/6] Add an AssumeReachableIPv6 autobool option.

This option tells Tor that our IPv6 orport is reachable, and doesn't
need to be checked.

Closes the rest of 33224.
---
 changes/ticket33224            |  3 +++
 doc/tor.1.txt                  |  7 ++++++-
 src/app/config/config.c        |  5 +++++
 src/app/config/or_options_st.h |  9 ++++++++-
 src/feature/relay/router.c     |  4 ++--
 src/feature/relay/selftest.c   | 12 ++++++++----
 6 files changed, 32 insertions(+), 8 deletions(-)
 create mode 100644 changes/ticket33224

diff --git a/changes/ticket33224 b/changes/ticket33224
new file mode 100644
index 0000000000..3fdab7dc53
--- /dev/null
+++ b/changes/ticket33224
@@ -0,0 +1,3 @@
+  o Minor features (relay, IPv6):
+    - Add an AssumeReachableIPv6 option to disable self-checking IPv6
+      reachability. Closes part of ticket 33224.
diff --git a/doc/tor.1.txt b/doc/tor.1.txt
index 15d5775e2c..7ff31fa007 100644
--- a/doc/tor.1.txt
+++ b/doc/tor.1.txt
@@ -2146,7 +2146,12 @@ is non-zero):
     don't do self-reachability testing; just upload your server descriptor
     immediately. If **AuthoritativeDirectory** is also set, this option
     instructs the dirserver to bypass remote reachability testing too and list
-    all connected servers as running.
+    all connected servers as running. (Default: 0)
+
+[[AssumeReachableIPv6]] **AssumeReachableIPv6** **0**|**1**|**auto**::
+    Like **AssumeReachable**, but affects only the relay's own IPv6 ORPort.
+    If this value is set to "auto", then Tor will look at **AssumeReachable**
+    instead. (Default: auto)
 
 [[BridgeRelay]] **BridgeRelay** **0**|**1**::
     Sets the relay to act as a "bridge" with respect to relaying connections
diff --git a/src/app/config/config.c b/src/app/config/config.c
index 286cd9304a..7878fa9de0 100644
--- a/src/app/config/config.c
+++ b/src/app/config/config.c
@@ -323,6 +323,7 @@ static const config_var_t option_vars_[] = {
   V(AlternateDirAuthority,       LINELIST, NULL),
   OBSOLETE("AlternateHSAuthority"),
   V(AssumeReachable,             BOOL,     "0"),
+  V(AssumeReachableIPv6,         AUTOBOOL, "auto"),
   OBSOLETE("AuthDirBadDir"),
   OBSOLETE("AuthDirBadDirCCs"),
   V(AuthDirBadExit,              LINELIST, NULL),
@@ -3229,6 +3230,10 @@ options_validate_cb(const void *old_options_, void *options_, char **msg)
     REJECT("TokenBucketRefillInterval must be between 1 and 1000 inclusive.");
   }
 
+  if (options->AssumeReachable && options->AssumeReachableIPv6 == 0) {
+    REJECT("Cannot set AssumeReachable 1 and AssumeReachableIPv6 0.");
+  }
+
   if (options->ExcludeExitNodes || options->ExcludeNodes) {
     options->ExcludeExitNodesUnion_ = routerset_new();
     routerset_union(options->ExcludeExitNodesUnion_,options->ExcludeExitNodes);
diff --git a/src/app/config/or_options_st.h b/src/app/config/or_options_st.h
index 2f375f5d9b..07126cc6ce 100644
--- a/src/app/config/or_options_st.h
+++ b/src/app/config/or_options_st.h
@@ -195,7 +195,14 @@ struct or_options_t {
   unsigned int HTTPTunnelPort_set : 1;
   /**@}*/
 
-  int AssumeReachable; /**< Whether to publish our descriptor regardless. */
+  /** Whether to publish our descriptor regardless of all our self-tests
+   */
+  int AssumeReachable;
+  /** Whether to publish our descriptor regardless of IPv6 self-tests.
+   *
+   * This is an autobool; when set to AUTO, it uses AssumeReachable.
+   **/
+  int AssumeReachableIPv6;
   int AuthoritativeDir; /**< Boolean: is this an authoritative directory? */
   int V3AuthoritativeDir; /**< Boolean: is this an authoritative directory
                            * for version 3 directories? */
diff --git a/src/feature/relay/router.c b/src/feature/relay/router.c
index 97b630add7..d32d03fc1c 100644
--- a/src/feature/relay/router.c
+++ b/src/feature/relay/router.c
@@ -1374,13 +1374,13 @@ decide_if_publishable_server(void)
     return 1;
   if (!router_get_advertised_or_port(options))
     return 0;
-  if (!router_orport_seems_reachable(AF_INET)) {
+  if (!router_orport_seems_reachable(options, AF_INET)) {
     // We have an ipv4 orport, and it doesn't seem reachable.
     if (!publish_even_when_ipv4_orport_unreachable) {
       return 0;
     }
   }
-  if (!router_orport_seems_reachable(AF_INET6)) {
+  if (!router_orport_seems_reachable(options, AF_INET6)) {
     // We have an ipv6 orport, and it doesn't seem reachable.
     if (!publish_even_when_ipv6_orport_unreachable) {
       return 0;
diff --git a/src/feature/relay/selftest.c b/src/feature/relay/selftest.c
index 64b8578bac..ae24a04401 100644
--- a/src/feature/relay/selftest.c
+++ b/src/feature/relay/selftest.c
@@ -86,9 +86,8 @@ router_reachability_checks_disabled(const or_options_t *options)
  * orport checks.
  */
 int
-router_orport_seems_reachable(
-                                                const or_options_t *options,
-                                                int family)
+router_orport_seems_reachable(const or_options_t *options,
+                              int family)
 {
   tor_assert_nonfatal(family == AF_INET || family == AF_INET6 || family == 0);
   int reach_checks_disabled = router_reachability_checks_disabled(options);
@@ -96,6 +95,11 @@ router_orport_seems_reachable(
     return true;
   }
 
+  // Note that we do a == 1 here, not just a boolean check.  This value
+  // is also an autobool, so CFG_AUTO does not mean that we should
+  // assume IPv6 ports are reachable.
+  const bool ipv6_assume_reachable = (options->AssumeReachableIPv6 == 1);
+
   // Which reachability flags should we look at?
   const bool checking_ipv4 = (family == AF_INET || family == 0);
   const bool checking_ipv6 = (family == AF_INET6 || family == 0);
@@ -105,7 +109,7 @@ router_orport_seems_reachable(
       return false;
     }
   }
-  if (checking_ipv6) {
+  if (checking_ipv6 && !ipv6_assume_reachable) {
     if (have_orport_for_family(AF_INET6) && !can_reach_or_port_ipv6) {
       return false;
     }

From cb25f5772441e6caed4ae8b84300f32de078fe62 Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Fri, 26 Jun 2020 08:32:33 -0400
Subject: [PATCH 6/6] Remove stub macro for router_new_consensus_params()

I had incorrectly believed that the router.c file was disabled when
we were building with relay mode disabled.
---
 src/feature/relay/router.h | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/feature/relay/router.h b/src/feature/relay/router.h
index b1f90699a2..4c557b8d0d 100644
--- a/src/feature/relay/router.h
+++ b/src/feature/relay/router.h
@@ -34,7 +34,6 @@ void set_server_identity_key(crypto_pk_t *k);
 MOCK_DECL(crypto_pk_t *,get_server_identity_key,(void));
 #else
 #define get_server_identity_key() (tor_abort_(),NULL)
-#define router_new_consensus_params(c) ((void)(c))
 #endif
 int server_identity_key_is_set(void);
 void set_client_identity_key(crypto_pk_t *k);