Commit 7536c40e authored by Nick Mathewson's avatar Nick Mathewson 🦀
Browse files

Implement option to turn off DNS cache modification by a client port 

(This is part 3 of making DNS cache use enabled/disabled on a
per-client port basis.  This implements the UseCacheIPv[46]DNS options)
parent f3348766

src/or/addressmap.c

+20 −9
Original line number Diff line number Diff line
@@ -594,13 +594,13 @@ client_dns_clear_failures(const char *address) 
 * <b>ttl</b>seconds; otherwise, we use the default.

 */

static void

client_dns_set_addressmap_impl(origin_circuit_t *on_circ,

client_dns_set_addressmap_impl(entry_connection_t *for_conn,

                               const char *address, const char *name,

                               const char *exitname,

                               int ttl)

{

  char *extendedaddress=NULL, *extendedval=NULL;

  (void)on_circ;

  (void)for_conn;



  tor_assert(address);

  tor_assert(name);
@@ -640,7 +640,7 @@ client_dns_set_addressmap_impl(origin_circuit_t *on_circ, 
 * <b>ttl</b>seconds; otherwise, we use the default.

 */

void

client_dns_set_addressmap(origin_circuit_t *on_circ,

client_dns_set_addressmap(entry_connection_t *for_conn,

                          const char *address,

                          const tor_addr_t *val,

                          const char *exitname,
@@ -655,14 +655,18 @@ client_dns_set_addressmap(origin_circuit_t *on_circ, 
  if (tor_addr_parse(&addr_tmp, address) >= 0)

    return; /* If address was an IP address already, don't add a mapping. */



  /* XXXXX For now, don't cache IPv6 addresses. */

  if (tor_addr_family(val) != AF_INET)

  if (tor_addr_family(val) == AF_INET) {

    if (! for_conn->cache_ipv4_answers)

      return;

  } else if (tor_addr_family(val) == AF_INET6) {

    if (! for_conn->cache_ipv6_answers)

      return;

  }



  if (! tor_addr_to_str(valbuf, val, sizeof(valbuf), 1))

    return;



  client_dns_set_addressmap_impl(on_circ, address, valbuf, exitname, ttl);

  client_dns_set_addressmap_impl(for_conn, address, valbuf, exitname, ttl);

}



/** Add a cache entry noting that <b>address</b> (ordinarily a dotted quad)
@@ -675,14 +679,21 @@ client_dns_set_addressmap(origin_circuit_t *on_circ, 
 * <b>ttl</b>seconds; otherwise, we use the default.

 */

void

client_dns_set_reverse_addressmap(origin_circuit_t *on_circ,

client_dns_set_reverse_addressmap(entry_connection_t *for_conn,

                                  const char *address, const char *v,

                                  const char *exitname,

                                  int ttl)

{

  char *s = NULL;

  {

    tor_addr_t tmp_addr;

    sa_family_t f = tor_addr_parse(&tmp_addr, address);

    if ((f == AF_INET && ! for_conn->cache_ipv4_answers) ||

        (f == AF_INET6 && ! for_conn->cache_ipv6_answers))

      return;

  }

  tor_asprintf(&s, "REVERSE[%s]", address);

  client_dns_set_addressmap_impl(on_circ, s, v, exitname, ttl);

  client_dns_set_addressmap_impl(for_conn, s, v, exitname, ttl);

  tor_free(s);

}

src/or/addressmap.h

+2 −2
Original line number Diff line number Diff line
@@ -31,7 +31,7 @@ int parse_virtual_addr_network(const char *val, int validate_only, 
                               char **msg);

int client_dns_incr_failures(const char *address);

void client_dns_clear_failures(const char *address);

void client_dns_set_addressmap(origin_circuit_t *on_circ,

void client_dns_set_addressmap(entry_connection_t *for_conn,

                               const char *address, const tor_addr_t *val,

                               const char *exitname, int ttl);

const char *addressmap_register_virtual_address(int type, char *new_address);
@@ -39,7 +39,7 @@ void addressmap_get_mappings(smartlist_t *sl, time_t min_expires, 
                             time_t max_expires, int want_expiry);

int address_is_in_virtual_range(const char *addr);

void clear_trackexithost_mappings(const char *exitname);

void client_dns_set_reverse_addressmap(origin_circuit_t *on_circ,

void client_dns_set_reverse_addressmap(entry_connection_t *for_conn,

                                       const char *address, const char *v,

                                       const char *exitname, int ttl);

src/or/connection_edge.c

+3 −3
Original line number Diff line number Diff line
@@ -2072,7 +2072,7 @@ connection_ap_handshake_socks_resolved(entry_connection_t *conn, 
      tor_addr_t a;

      tor_addr_from_ipv4n(&a, get_uint32(answer));

      if (! tor_addr_is_null(&a)) {

        client_dns_set_addressmap(origin_circ,

        client_dns_set_addressmap(conn,

                                  conn->socks_request->address, &a,

                                  conn->chosen_exit_name, ttl);

      }
@@ -2080,13 +2080,13 @@ connection_ap_handshake_socks_resolved(entry_connection_t *conn, 
      tor_addr_t a;

      tor_addr_from_ipv6_bytes(&a, (char*)answer);

      if (! tor_addr_is_null(&a)) {

        client_dns_set_addressmap(origin_circ,

        client_dns_set_addressmap(conn,

                                  conn->socks_request->address, &a,

                                  conn->chosen_exit_name, ttl);

      }

    } else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {

      char *cp = tor_strndup((char*)answer, answer_len);

      client_dns_set_reverse_addressmap(origin_circ,

      client_dns_set_reverse_addressmap(conn,

                                        conn->socks_request->address,

                                        cp,

                                        conn->chosen_exit_name, ttl);

src/or/relay.c

+2 −2
Original line number Diff line number Diff line
@@ -742,7 +742,7 @@ connection_ap_process_end_not_open( 
            return 0;

          }



          client_dns_set_addressmap(circ,

          client_dns_set_addressmap(conn,

                                    conn->socks_request->address, &addr,

                                    conn->chosen_exit_name, ttl);

        }
@@ -979,7 +979,7 @@ connection_edge_process_relay_cell_not_open( 
        return 0;

      }



      client_dns_set_addressmap(TO_ORIGIN_CIRCUIT(circ),

      client_dns_set_addressmap(entry_conn,

                                entry_conn->socks_request->address, &addr,

                                entry_conn->chosen_exit_name, ttl);