Have directory authorities vote on IPv6 OR ports according to the spec

Define new new consensus method 14 adding "a" lines to vote and
consensus documents.

From proposal 186:

  As with other data in the vote derived from the descriptor, the
  consensus will include whichever set of "a" lines are given by the
  most authorities who voted for the descriptor digest that will be
  used for the router.

This patch implements this.

1 files changed, 48 insertions, 15 deletions

diff --git a/src/or/routerparse.c b/src/or/routerparse.c
index 60a2eae75f..cda1c00664 100644
--- a/src/or/routerparse.c
+++ b/src/or/routerparse.c
@@ -67,6 +67,7 @@ typedef enum {
   K_OR_ADDRESS,
   K_P,
   K_R,
+  K_A,
   K_S,
   K_V,
   K_W,
@@ -338,6 +339,7 @@ static token_rule_t extrainfo_token_table[] = {
 static token_rule_t rtrstatus_token_table[] = {
   T01("p",                   K_P,               CONCAT_ARGS, NO_OBJ ),
   T1( "r",                   K_R,                   GE(7),   NO_OBJ ),
+  T0N("a",                   K_A,                   GE(1),   NO_OBJ ),
   T1( "s",                   K_S,                   ARGS,    NO_OBJ ),
   T01("v",                   K_V,               CONCAT_ARGS, NO_OBJ ),
   T01("w",                   K_W,                   ARGS,    NO_OBJ ),
@@ -1257,6 +1259,42 @@ dump_distinct_digest_count(int severity)
 #endif
 }
 
+/** Try to find an IPv6 OR port in <b>list</b> of directory_token_t's
+ * with at least one argument (use GE(1) in setup). If found, store
+ * address and port number to <b>addr_out</b> and
+ * <b>port_out</b>. Return number of OR ports found. */
+static int
+find_single_ipv6_orport(const smartlist_t *list,
+                        tor_addr_t *addr_out,
+                        uint16_t *port_out)
+{
+  int ret = 0;
+  tor_assert(list != NULL);
+  tor_assert(addr_out != NULL);
+  tor_assert(port_out != NULL);
+
+  SMARTLIST_FOREACH_BEGIN(list, directory_token_t *, t) {
+    tor_addr_t a;
+    maskbits_t bits;
+    uint16_t port_min, port_max;
+    tor_assert(t->n_args >= 1);
+    /* XXXX Prop186 the full spec allows much more than this. */
+    if (tor_addr_parse_mask_ports(t->args[0], &a, &bits, &port_min,
+                                  &port_max) == AF_INET6 &&
+        bits == 128 &&
+        port_min == port_max) {
+      /* Okay, this is one we can understand. Use it and ignore
+         any potential more addresses in list. */
+      tor_addr_copy(addr_out, &a);
+      *port_out = port_min;
+      ret = 1;
+      break;
+    }
+  } SMARTLIST_FOREACH_END(t);
+
+  return ret;
+}
+
 /** Helper function: reads a single router entry from *<b>s</b> ...
  * *<b>end</b>.  Mallocs a new router and returns it if all goes well, else
  * returns NULL.  If <b>cache_copy</b> is true, duplicate the contents of
@@ -1513,21 +1551,8 @@ router_parse_entry_from_string(const char *s, const char *end,
   {
     smartlist_t *or_addresses = find_all_by_keyword(tokens, K_OR_ADDRESS);
     if (or_addresses) {
-      SMARTLIST_FOREACH_BEGIN(or_addresses, directory_token_t *, t) {
-        tor_addr_t a;
-        maskbits_t bits;
-        uint16_t port_min, port_max;
-        /* XXXX Prop186 the full spec allows much more than this. */
-        if (tor_addr_parse_mask_ports(t->args[0], &a, &bits, &port_min,
-                                      &port_max) == AF_INET6 &&
-            bits == 128 &&
-            port_min == port_max) {
-          /* Okay, this is one we can understand. */
-          tor_addr_copy(&router->ipv6_addr, &a);
-          router->ipv6_orport = port_min;
-          break;
-        }
-      } SMARTLIST_FOREACH_END(t);
+      find_single_ipv6_orport(or_addresses, &router->ipv6_addr,
+                              &router->ipv6_orport);
       smartlist_free(or_addresses);
     }
   }
@@ -2060,6 +2085,14 @@ routerstatus_parse_entry_from_string(memarea_t *area,
   rs->dir_port = (uint16_t) tor_parse_long(tok->args[7+offset],
                                            10,0,65535,NULL,NULL);
 
+  {
+    smartlist_t *a_lines = find_all_by_keyword(tokens, K_A);
+    if (a_lines) {
+      find_single_ipv6_orport(a_lines, &rs->ipv6_addr, &rs->ipv6_orport);
+      smartlist_free(a_lines);
+    }
+  }
+
   tok = find_opt_by_keyword(tokens, K_S);
   if (tok && vote) {
     int i;