Merge branch 'bug5535_only_rebased'

6 files changed, 111 insertions, 44 deletions

diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index ba617ffa45..2a449b0cc0 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -3792,12 +3792,10 @@ onion_extend_cpath(origin_circuit_t *circ)
   } else if (cur_len == 0) { /* picking first node */
     const node_t *r = choose_good_entry_server(purpose, state);
     if (r) {
-      /* If we're extending to a bridge, use the preferred address
-         rather than the primary, for potentially extending to an IPv6
-         bridge.  */
-      int use_pref_addr = (r->ri != NULL &&
-                           r->ri->purpose == ROUTER_PURPOSE_BRIDGE);
-      info = extend_info_from_node(r, use_pref_addr);
+      /* If we're a client, use the preferred address rather than the
+         primary address, for potentially connecting to an IPv6 OR
+         port. */
+      info = extend_info_from_node(r, server_mode(get_options()) == 0);
       tor_assert(info);
     }
   } else {
@@ -3865,34 +3863,43 @@ extend_info_alloc(const char *nickname, const char *digest,
 
 /** Allocate and return a new extend_info that can be used to build a
  * circuit to or through the node <b>node</b>. Use the primary address
- * of the node unless <b>for_direct_connect</b> is true, in which case
- * the preferred address is used instead. May return NULL if there is
- * not enough info about <b>node</b> to extend to it--for example, if
- * there is no routerinfo_t or microdesc_t.
+ * of the node (i.e. its IPv4 address) unless
+ * <b>for_direct_connect</b> is true, in which case the preferred
+ * address is used instead. May return NULL if there is not enough
+ * info about <b>node</b> to extend to it--for example, if there is no
+ * routerinfo_t or microdesc_t.
  **/
 extend_info_t *
 extend_info_from_node(const node_t *node, int for_direct_connect)
 {
-  if (node->ri) {
-    const routerinfo_t *r = node->ri;
-    tor_addr_port_t ap;
-    if (for_direct_connect)
-      node_get_pref_orport(node, &ap);
-    else
-      node_get_prim_orport(node, &ap);
-    return extend_info_alloc(r->nickname, r->cache_info.identity_digest,
-                             r->onion_pkey, &ap.addr, ap.port);
-  } else if (node->rs && node->md) {
-    tor_addr_t addr;
-    tor_addr_from_ipv4h(&addr, node->rs->addr);
+  tor_addr_port_t ap;
+
+  if (node->ri == NULL && (node->rs == NULL || node->md == NULL))
+    return NULL;
+
+  if (for_direct_connect)
+    node_get_pref_orport(node, &ap);
+  else
+    node_get_prim_orport(node, &ap);
+
+  log_debug(LD_CIRC, "using %s:%d for %s",
+            fmt_and_decorate_addr(&ap.addr), ap.port,
+            node->ri ? node->ri->nickname : node->rs->nickname);
+
+  if (node->ri)
+    return extend_info_alloc(node->ri->nickname,
+                             node->identity,
+                             node->ri->onion_pkey,
+                             &ap.addr,
+                             ap.port);
+  else if (node->rs && node->md)
     return extend_info_alloc(node->rs->nickname,
                              node->identity,
                              node->md->onion_pkey,
-                             &addr,
-                             node->rs->or_port);
-  } else {
+                             &ap.addr,
+                             ap.port);
+  else
     return NULL;
-  }
 }
 
 /** Release storage held by an extend_info_t struct. */
@@ -5607,10 +5614,15 @@ rewrite_node_address_for_bridge(const bridge_info_t *bridge, node_t *node)
       }
     }
 
-    /* Indicate that we prefer connecting to this bridge over the
-       protocol that the bridge address indicates.  Last bridge
-       descriptor handled wins.  */
-    node->ipv6_preferred = tor_addr_family(&bridge->addr) == AF_INET6;
+    /* Mark bridge as preferably connected to over IPv6 if its IPv6
+       address is in a Bridge line and ClientPreferIPv6ORPort is
+       set. Unless both is true, a potential IPv6 OR port of this
+       bridge won't get selected.
+
+       XXX ipv6_preferred is never reset (#6757) */
+    if (get_options()->ClientPreferIPv6ORPort == 1 &&
+        tor_addr_family(&bridge->addr) == AF_INET6)
+      node->ipv6_preferred = 1;
 
     /* XXXipv6 we lack support for falling back to another address for
        the same relay, warn the user */
diff --git a/src/or/config.c b/src/or/config.c
index a5a8fec507..f21016d48f 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -225,8 +225,10 @@ static config_var_t _option_vars[] = {
   V(CircuitPriorityHalflife,     DOUBLE,  "-100.0"), /*negative:'Use default'*/
   V(ClientDNSRejectInternalAddresses, BOOL,"1"),
   V(ClientOnly,                  BOOL,     "0"),
+  V(ClientPreferIPv6ORPort,      BOOL,     "0"),
   V(ClientRejectInternalAddresses, BOOL,   "1"),
   V(ClientTransportPlugin,       LINELIST, NULL),
+  V(ClientUseIPv6,               BOOL,     "0"),
   V(ConsensusParams,             STRING,   NULL),
   V(ConnLimit,                   UINT,     "1000"),
   V(ConnDirectionStatistics,     BOOL,     "0"),
diff --git a/src/or/nodelist.c b/src/or/nodelist.c
index 9d0247f4ea..e35039bdb8 100644
--- a/src/or/nodelist.c
+++ b/src/or/nodelist.c
@@ -206,6 +206,7 @@ nodelist_set_consensus(networkstatus_t *ns)
 {
   const or_options_t *options = get_options();
   int authdir = authdir_mode_v2(options) || authdir_mode_v3(options);
+  int client = !server_mode(options);
 
   init_nodelist();
   if (ns->flavor == FLAV_MICRODESC)
@@ -242,6 +243,11 @@ nodelist_set_consensus(networkstatus_t *ns)
       node->is_bad_directory = rs->is_bad_directory;
       node->is_bad_exit = rs->is_bad_exit;
       node->is_hs_dir = rs->is_hs_dir;
+      node->ipv6_preferred = 0;
+      if (client && options->ClientPreferIPv6ORPort == 1 &&
+          (tor_addr_is_null(&rs->ipv6_addr) == 0 ||
+           (node->md && tor_addr_is_null(&node->md->ipv6_addr) == 0)))
+        node->ipv6_preferred = 1;
     }
 
   } SMARTLIST_FOREACH_END(rs);
@@ -815,31 +821,44 @@ node_get_declared_family(const node_t *node)
 int
 node_ipv6_preferred(const node_t *node)
 {
+  tor_addr_port_t ipv4_addr;
   node_assert_ok(node);
-  if (node->ri)
-    return (!tor_addr_is_null(&node->ri->ipv6_addr)
-            && (node->ipv6_preferred || node->ri->addr == 0));
-  if (node->rs)
-    return (!tor_addr_is_null(&node->rs->ipv6_addr)
-            && (node->ipv6_preferred || node->rs->addr == 0));
+
+  if (node->ipv6_preferred || node_get_prim_orport(node, &ipv4_addr)) {
+    if (node->ri)
+      return !tor_addr_is_null(&node->ri->ipv6_addr);
+    if (node->md)
+      return !tor_addr_is_null(&node->md->ipv6_addr);
+    if (node->rs)
+      return !tor_addr_is_null(&node->rs->ipv6_addr);
+  }
   return 0;
 }
 
 /** Copy the primary (IPv4) OR port (IP address and TCP port) for
- * <b>node</b> into *<b>ap_out</b>. */
-void
+ * <b>node</b> into *<b>ap_out</b>. Return 0 if a valid address and
+ * port was copied, else return non-zero.*/
+int
 node_get_prim_orport(const node_t *node, tor_addr_port_t *ap_out)
 {
   node_assert_ok(node);
   tor_assert(ap_out);
 
   if (node->ri) {
+    if (node->ri->addr == 0 || node->ri->or_port == 0)
+      return -1;
     tor_addr_from_ipv4h(&ap_out->addr, node->ri->addr);
     ap_out->port = node->ri->or_port;
-  } else if (node->rs) {
+    return 0;
+  }
+  if (node->rs) {
+    if (node->rs->addr == 0 || node->rs->or_port == 0)
+      return -1;
     tor_addr_from_ipv4h(&ap_out->addr, node->rs->addr);
     ap_out->port = node->rs->or_port;
+    return 0;
   }
+  return -1;
 }
 
 /** Copy the preferred OR port (IP address and TCP port) for
@@ -849,7 +868,13 @@ node_get_pref_orport(const node_t *node, tor_addr_port_t *ap_out)
 {
   tor_assert(ap_out);
 
-  if (node_ipv6_preferred(node))
+  /* Cheap implementation of config option ClientUseIPv6 -- simply
+     don't prefer IPv6 when ClientUseIPv6 is not set. (See #4455 for
+     more on this subject.) Note that this filter is too strict since
+     we're hindering not only clients! Erring on the safe side
+     shouldn't be a problem though. XXX move this check to where
+     outgoing connections are made? -LN */
+  if (get_options()->ClientUseIPv6 == 1 && node_ipv6_preferred(node))
     node_get_pref_ipv6_orport(node, ap_out);
   else
     node_get_prim_orport(node, ap_out);
@@ -863,9 +888,17 @@ node_get_pref_ipv6_orport(const node_t *node, tor_addr_port_t *ap_out)
   node_assert_ok(node);
   tor_assert(ap_out);
 
+  /* We prefer the microdesc over a potential routerstatus here. They
+     are not being synchronised atm so there might be a chance that
+     they differ at some point, f.ex. when flipping
+     UseMicrodescriptors? -LN */
+
   if (node->ri) {
     tor_addr_copy(&ap_out->addr, &node->ri->ipv6_addr);
     ap_out->port = node->ri->ipv6_orport;
+  } else if (node->md) {
+    tor_addr_copy(&ap_out->addr, &node->md->ipv6_addr);
+    ap_out->port = node->md->ipv6_orport;
   } else if (node->rs) {
     tor_addr_copy(&ap_out->addr, &node->rs->ipv6_addr);
     ap_out->port = node->rs->ipv6_orport;
diff --git a/src/or/nodelist.h b/src/or/nodelist.h
index 5558827961..fb65fa5483 100644
--- a/src/or/nodelist.h
+++ b/src/or/nodelist.h
@@ -42,18 +42,18 @@ int node_get_purpose(const node_t *node);
 int node_is_me(const node_t *node);
 int node_exit_policy_rejects_all(const node_t *node);
 smartlist_t *node_get_all_orports(const node_t *node);
-void node_get_prim_orport(const node_t *node, tor_addr_port_t *ap_out);
-void node_get_pref_orport(const node_t *node, tor_addr_port_t *ap_out);
-void node_get_pref_ipv6_orport(const node_t *node, tor_addr_port_t *ap_out);
-uint32_t node_get_prim_addr_ipv4h(const node_t *node);
 int node_allows_single_hop_exits(const node_t *node);
 const char *node_get_nickname(const node_t *node);
 const char *node_get_platform(const node_t *node);
+uint32_t node_get_prim_addr_ipv4h(const node_t *node);
 void node_get_address_string(const node_t *node, char *cp, size_t len);
 long node_get_declared_uptime(const node_t *node);
 time_t node_get_published_on(const node_t *node);
 const smartlist_t *node_get_declared_family(const node_t *node);
 int node_ipv6_preferred(const node_t *node);
+int node_get_prim_orport(const node_t *node, tor_addr_port_t *ap_out);
+void node_get_pref_orport(const node_t *node, tor_addr_port_t *ap_out);
+void node_get_pref_ipv6_orport(const node_t *node, tor_addr_port_t *ap_out);
 
 smartlist_t *nodelist_get_list(void);
 
diff --git a/src/or/or.h b/src/or/or.h
index 00a359c533..4bf99e2eaa 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -1960,6 +1960,10 @@ typedef struct microdesc_t {
 
   /** As routerinfo_t.onion_pkey */
   crypto_pk_t *onion_pkey;
+  /** As routerinfo_t.ipv6_add */
+  tor_addr_t ipv6_addr;
+  /** As routerinfo_t.ipv6_orport */
+  uint16_t ipv6_orport;
   /** As routerinfo_t.family */
   smartlist_t *family;
   /** Exit policy summary */
@@ -3487,6 +3491,13 @@ typedef struct {
    * over randomly chosen exits. */
   int ClientRejectInternalAddresses;
 
+  /** If true, clients may connect over IPv6. XXX we don't really
+      enforce this -- clients _may_ set up outgoing IPv6 connections
+      even when this option is not set. */
+  int ClientUseIPv6;
+  /** If true, prefer an IPv6 OR port over an IPv4 one. */
+  int ClientPreferIPv6ORPort;
+
   /** The length of time that we think a consensus should be fresh. */
   int V3AuthVotingInterval;
   /** The length of time we think it will take to distribute votes. */
diff --git a/src/or/routerparse.c b/src/or/routerparse.c
index cda1c00664..7bee08434f 100644
--- a/src/or/routerparse.c
+++ b/src/or/routerparse.c
@@ -524,6 +524,7 @@ static token_rule_t networkstatus_detached_signature_token_table[] = {
 /** List of tokens recognized in microdescriptors */
 static token_rule_t microdesc_token_table[] = {
   T1_START("onion-key",        K_ONION_KEY,        NO_ARGS,     NEED_KEY_1024),
+  T0N("a",                     K_A,                GE(1),       NO_OBJ ),
   T01("family",                K_FAMILY,           ARGS,        NO_OBJ ),
   T01("p",                     K_P,                CONCAT_ARGS, NO_OBJ ),
   A01("@last-listed",          A_LAST_LISTED,      CONCAT_ARGS, NO_OBJ ),
@@ -4454,6 +4455,14 @@ microdescs_parse_from_string(const char *s, const char *eos,
     md->onion_pkey = tok->key;
     tok->key = NULL;
 
+    {
+      smartlist_t *a_lines = find_all_by_keyword(tokens, K_A);
+      if (a_lines) {
+        find_single_ipv6_orport(a_lines, &md->ipv6_addr, &md->ipv6_orport);
+        smartlist_free(a_lines);
+      }
+    }
+
     if ((tok = find_opt_by_keyword(tokens, K_FAMILY))) {
       int i;
       md->family = smartlist_new();