Try rebinding new listener after closing old one if first bind failed with EADDRINUSE

This commit is contained in:
rl1987 2018-04-25 16:17:11 +02:00 committed by Nick Mathewson
parent ed0ee340d4
commit c99bb8b6ea

View File

@ -137,7 +137,11 @@ static connection_t *connection_listener_new(
const struct sockaddr *listensockaddr,
socklen_t listensocklen, int type,
const char *address,
const port_cfg_t *portcfg);
const port_cfg_t *portcfg,
int *addr_in_use);
static connection_t *connection_listener_new_for_port(
const port_cfg_t *port,
int *defer, int *addr_in_use);
static void connection_init(time_t now, connection_t *conn, int type,
int socket_family);
static int connection_handle_listener_read(connection_t *conn, int new_type);
@ -1188,7 +1192,8 @@ static connection_t *
connection_listener_new(const struct sockaddr *listensockaddr,
socklen_t socklen,
int type, const char *address,
const port_cfg_t *port_cfg)
const port_cfg_t *port_cfg,
int *addr_in_use)
{
listener_connection_t *lis_conn;
connection_t *conn = NULL;
@ -1204,6 +1209,8 @@ connection_listener_new(const struct sockaddr *listensockaddr,
tor_addr_t addr;
int exhaustion = 0;
if (addr_in_use) *addr_in_use = 0;
if (listensockaddr->sa_family == AF_INET ||
listensockaddr->sa_family == AF_INET6) {
int is_stream = (type != CONN_TYPE_AP_DNS_LISTENER);
@ -1282,8 +1289,10 @@ connection_listener_new(const struct sockaddr *listensockaddr,
if (bind(s,listensockaddr,socklen) < 0) {
const char *helpfulhint = "";
int e = tor_socket_errno(s);
if (ERRNO_IS_EADDRINUSE(e))
if (ERRNO_IS_EADDRINUSE(e)) {
helpfulhint = ". Is Tor already running?";
if (addr_in_use) *addr_in_use = 1;
}
log_warn(LD_NET, "Could not bind to %s:%u: %s%s", address, usePort,
tor_socket_strerror(e), helpfulhint);
goto err;
@ -1487,8 +1496,15 @@ connection_listener_new(const struct sockaddr *listensockaddr,
return NULL;
}
/**
* Create a new listener connection for a given <b>port</b>. In case we
* for a reason that is not an error condition, set <b>defer</b>
* to true. If we cannot bind listening socket because address is already
* in use, set <b>addr_in_use</b> to true.
*/
static connection_t *
connection_listener_new_for_port(const port_cfg_t *port, int *defer)
connection_listener_new_for_port(const port_cfg_t *port,
int *defer, int *addr_in_use)
{
connection_t *conn;
struct sockaddr *listensockaddr;
@ -1531,7 +1547,8 @@ connection_listener_new_for_port(const port_cfg_t *port, int *defer)
if (listensockaddr) {
conn = connection_listener_new(listensockaddr, listensocklen,
port->type, address, port);
port->type, address, port,
addr_in_use);
tor_free(listensockaddr);
tor_free(address);
} else {
@ -2651,16 +2668,26 @@ connection_read_proxy_handshake(connection_t *conn)
return ret;
}
struct replacement_s
{
connection_t *old_conn;
port_cfg_t *new_port;
};
/** Given a list of listener connections in <b>old_conns</b>, and list of
* port_cfg_t entries in <b>ports</b>, open a new listener for every port in
* <b>ports</b> that does not already have a listener in <b>old_conns</b>.
*
* Remove from <b>old_conns</b> every connection that has a corresponding
* entry in <b>ports</b>. Add to <b>new_conns</b> new every connection we
* launch.
* launch. If we may need to perform socket rebind when creating new
* listener that replaces old one, create a <b>replacement_s</b> struct
* for affected pair and add it to <b>replacements</b>. For more
* information, see ticket #17873.
*
* If <b>control_listeners_only</b> is true, then we only open control
* listeners, and we do not remove any noncontrol listeners from old_conns.
* listeners, and we do not remove any noncontrol listeners from
* old_conns.
*
* Return 0 on success, -1 on failure.
**/
@ -2668,8 +2695,10 @@ static int
retry_listener_ports(smartlist_t *old_conns,
const smartlist_t *ports,
smartlist_t *new_conns,
smartlist_t *replacements,
int control_listeners_only)
{
smartlist_t *launch = smartlist_new();
int r = 0;
@ -2705,16 +2734,31 @@ retry_listener_ports(smartlist_t *old_conns,
break;
}
} else {
int port_matches;
if (wanted->port == CFG_AUTO_PORT) {
port_matches = 1;
} else {
port_matches = (wanted->port == conn->port);
}
/* Numeric values of old and new port match exactly. */
const int port_matches_exact = (wanted->port == conn->port);
/* Ports match semantically - either their specific values
match exactly, or new port is 'auto'.
*/
const int port_matches = (wanted->port == CFG_AUTO_PORT ||
port_matches_exact);
if (port_matches && tor_addr_eq(&wanted->addr, &conn->addr)) {
found_port = wanted;
break;
}
const int may_need_rebind =
port_matches_exact && bool_neq(tor_addr_is_null(&wanted->addr),
tor_addr_is_null(&conn->addr));
if (replacements && may_need_rebind) {
struct replacement_s *replacement =
tor_malloc(sizeof(struct replacement_s));
replacement->old_conn = conn;
replacement->new_port = (port_cfg_t *)wanted;
smartlist_add(replacements, replacement);
SMARTLIST_DEL_CURRENT(launch, wanted);
}
}
} SMARTLIST_FOREACH_END(wanted);
@ -2731,7 +2775,7 @@ retry_listener_ports(smartlist_t *old_conns,
/* Now open all the listeners that are configured but not opened. */
SMARTLIST_FOREACH_BEGIN(launch, const port_cfg_t *, port) {
int skip = 0;
connection_t *conn = connection_listener_new_for_port(port, &skip);
connection_t *conn = connection_listener_new_for_port(port, &skip, NULL);
if (conn && new_conns)
smartlist_add(new_conns, conn);
@ -2759,6 +2803,7 @@ retry_all_listeners(smartlist_t *replaced_conns,
smartlist_t *new_conns, int close_all_noncontrol)
{
smartlist_t *listeners = smartlist_new();
smartlist_t *replacements = smartlist_new();
const or_options_t *options = get_options();
int retval = 0;
const uint16_t old_or_port = router_get_advertised_or_port(options);
@ -2774,9 +2819,42 @@ retry_all_listeners(smartlist_t *replaced_conns,
if (retry_listener_ports(listeners,
get_configured_ports(),
new_conns,
replacements,
close_all_noncontrol) < 0)
retval = -1;
SMARTLIST_FOREACH_BEGIN(replacements, struct replacement_s *, r) {
int addr_in_use = 0;
int skip = 0;
tor_assert(r->new_port);
tor_assert(r->old_conn);
connection_t *new_conn =
connection_listener_new_for_port(r->new_port, &skip, &addr_in_use);
connection_t *old_conn = r->old_conn;
if (skip)
continue;
// XXX: replaced_conns
connection_close_immediate(r->old_conn);
connection_mark_for_close(r->old_conn);
if (addr_in_use) {
new_conn = connection_listener_new_for_port(r->new_port,
&skip, &addr_in_use);
}
tor_assert(new_conn);
smartlist_add(new_conns, new_conn);
tor_free(r);
SMARTLIST_DEL_CURRENT(replacements, r);
} SMARTLIST_FOREACH_END(r);
/* Any members that were still in 'listeners' don't correspond to
* any configured port. Kill 'em. */
SMARTLIST_FOREACH_BEGIN(listeners, connection_t *, conn) {