Add a new family-specific syntax for tor_addr_parse_mask_ports

By default, "*" means "All IPv4 addresses" with
tor_addr_parse_mask_ports, so I won't break anything.  But if the new
EXTENDED_STAR flag is provided, then * means "any address", *4 means
"any IPv4 address" (that is, 0.0.0.0/0), and "*6" means "any IPv6
address" (that is, [::]/0).

This is going to let us have a syntax for specifying exit policies in
torrc that won't drive people mad.

Also, add a bunch of unit tests for tor_addr_parse_mask_ports to test
these new features, and to increase coverage.

src/or/config.c

@@ -276,6 +276,7 @@ static config_var_t option_vars_[] = {
   V(HTTPProxyAuthenticator,      STRING,   NULL),
   V(HTTPSProxy,                  STRING,   NULL),
   V(HTTPSProxyAuthenticator,     STRING,   NULL),
+  //  V(IPv6EXit,                    BOOL,     "0"),
   VAR("ServerTransportPlugin",   LINELIST, ServerTransportPlugin,  NULL),
   V(Socks4Proxy,                 STRING,   NULL),
   V(Socks5Proxy,                 STRING,   NULL),

src/or/policies.c

@@ -87,7 +87,8 @@ policy_expand_private(smartlist_t **policy)
        memcpy(&newpolicy, p, sizeof(addr_policy_t));
        newpolicy.is_private = 0;
        newpolicy.is_canonical = 0;
-       if (tor_addr_parse_mask_ports(private_nets[i], &newpolicy.addr,
+       if (tor_addr_parse_mask_ports(private_nets[i], 0,
+                               &newpolicy.addr,
                                &newpolicy.maskbits, &port_min, &port_max)<0) {
          tor_assert(0);
        }
@@ -1192,8 +1193,8 @@ policy_summary_add_item(smartlist_t *summary, addr_policy_t *p)
      for (i = 0; private_nets[i]; ++i) {
        tor_addr_t addr;
        maskbits_t maskbits;
-       if (tor_addr_parse_mask_ports(private_nets[i], &addr,
-                                  &maskbits, NULL, NULL)<0) {
+       if (tor_addr_parse_mask_ports(private_nets[i], 0, &addr,
+                                     &maskbits, NULL, NULL)<0) {
          tor_assert(0);
        }
        if (tor_addr_compare(&p->addr, &addr, CMP_EXACT) == 0 &&

src/or/routerparse.c

@@ -1280,7 +1280,8 @@ find_single_ipv6_orport(const smartlist_t *list,
     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,
+    if (tor_addr_parse_mask_ports(t->args[0], 0,
+                                  &a, &bits, &port_min,
                                   &port_max) == AF_INET6 &&
         bits == 128 &&
         port_min == port_max) {
@@ -3737,7 +3738,7 @@ router_parse_addr_policy(directory_token_t *tok)
   else
     newe.policy_type = ADDR_POLICY_ACCEPT;
 
-  if (tor_addr_parse_mask_ports(arg, &newe.addr, &newe.maskbits,
+  if (tor_addr_parse_mask_ports(arg, 0, &newe.addr, &newe.maskbits,
                                 &newe.prt_min, &newe.prt_max) < 0) {
     log_warn(LD_DIR,"Couldn't parse line %s. Dropping", escaped(arg));
     return NULL;