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Fix more races between connect and shutdown

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There were more races that could happen while connecting to a
socket while closing or shutting down the same socket.  This
commit introduces a .closing flag to guard the socket from
being closed twice.
This commit is contained in:
Ondřej Surý
2020-10-29 12:04:00 +01:00
committed by Ondřej Surý
parent 6cfadf9db0
commit ed3ab63f74
4 changed files with 99 additions and 50 deletions
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56
lib/isc/netmgr/udp.c
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@@ -217,8 +217,9 @@ isc__nm_async_udplisten(isc__networker_t *worker, isc__netievent_t *ev0) {
static void
udp_stop_cb(uv_handle_t *handle) {
isc_nmsocket_t *sock = uv_handle_get_data(handle);
atomic_store(&sock->closed, true);
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_CLOSE]);
atomic_store(&sock->closed, true);
isc__nmsocket_detach((isc_nmsocket_t **)&sock->uv_handle.udp.data);
}
@@ -229,9 +230,12 @@ stop_udp_child(isc_nmsocket_t *sock) {
uv_udp_recv_stop(&sock->uv_handle.udp);
uv_close((uv_handle_t *)&sock->uv_handle.udp, udp_stop_cb);
if (!atomic_compare_exchange_strong(&sock->closing, &(bool){ false },
true)) {
return;
}
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_CLOSE]);
uv_close(&sock->uv_handle.handle, udp_stop_cb);
LOCK(&sock->parent->lock);
atomic_fetch_sub(&sock->parent->rchildren, 1);
@@ -630,19 +634,24 @@ udp_connect_direct(isc_nmsocket_t *sock, isc__nm_uvreq_t *req) {
r = uv_udp_init(&worker->loop, &sock->uv_handle.udp);
if (r != 0) {
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_OPENFAIL]);
/* Socket was never opened; no need for udp_close_direct() */
/* Socket was never opened; no need for isc__nm_udp_close() */
atomic_store(&sock->closing, true);
atomic_store(&sock->closed, true);
atomic_store(&sock->result, isc__nm_uverr2result(r));
atomic_store(&sock->connect_error, true);
failed_connect_cb(sock, req, isc__nm_uverr2result(r));
atomic_store(&sock->active, false);
return (r);
}
r = uv_udp_open(&sock->uv_handle.udp, sock->fd);
if (r != 0) {
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_OPENFAIL]);
atomic_store(&sock->closed, true);
atomic_store(&sock->connect_error, true);
atomic_store(&sock->result, isc__nm_uverr2result(r));
failed_connect_cb(sock, req, isc__nm_uverr2result(r));
atomic_store(&sock->active, false);
isc__nm_udp_close(sock);
return (r);
}
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_OPEN]);
@@ -657,7 +666,9 @@ udp_connect_direct(isc_nmsocket_t *sock, isc__nm_uvreq_t *req) {
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_BINDFAIL]);
atomic_store(&sock->connect_error, true);
atomic_store(&sock->result, isc__nm_uverr2result(r));
udp_close_direct(sock);
failed_connect_cb(sock, req, isc__nm_uverr2result(r));
atomic_store(&sock->active, false);
isc__nm_udp_close(sock);
return (r);
}
@@ -669,7 +680,9 @@ udp_connect_direct(isc_nmsocket_t *sock, isc__nm_uvreq_t *req) {
sock->statsindex[STATID_CONNECTFAIL]);
atomic_store(&sock->connect_error, true);
atomic_store(&sock->result, isc__nm_uverr2result(r));
udp_close_direct(sock);
failed_connect_cb(sock, req, isc__nm_uverr2result(r));
atomic_store(&sock->active, false);
isc__nm_udp_close(sock);
return (r);
}
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_CONNECT]);
@@ -714,7 +727,6 @@ isc__nm_async_udpconnect(isc__networker_t *worker, isc__netievent_t *ev0) {
r = udp_connect_direct(sock, req);
if (r != 0) {
failed_connect_cb(sock, req, isc__nm_uverr2result(r));
LOCK(&sock->lock);
SIGNAL(&sock->cond);
UNLOCK(&sock->lock);
@@ -977,11 +989,9 @@ udp_close_cb(uv_handle_t *uvhandle) {
static void
timer_close_cb(uv_handle_t *uvhandle) {
isc_nmsocket_t *sock = uv_handle_get_data(uvhandle);
uv_handle_t *handle = uv_handle_get_data(uvhandle);
REQUIRE(VALID_NMSOCK(sock));
uv_close(&sock->uv_handle.handle, udp_close_cb);
uv_close(handle, udp_close_cb);
}
static void
@@ -995,7 +1005,13 @@ udp_close_direct(isc_nmsocket_t *sock) {
if (sock->timer_initialized) {
sock->timer_initialized = false;
uv_handle_set_data((uv_handle_t *)&sock->timer, sock);
/*
* The read and timer is stopped and the socket will be
* scheduled to be closed, so we can override the data that the
* timer handle holds.
*/
uv_handle_set_data((uv_handle_t *)&sock->timer,
&sock->uv_handle.handle);
uv_close((uv_handle_t *)&sock->timer, timer_close_cb);
} else {
uv_close(&sock->uv_handle.handle, udp_close_cb);
@@ -1016,9 +1032,13 @@ void
isc__nm_udp_close(isc_nmsocket_t *sock) {
REQUIRE(VALID_NMSOCK(sock));
REQUIRE(sock->type == isc_nm_udpsocket);
REQUIRE(!isc__nmsocket_active(sock));
if (!atomic_compare_exchange_strong(&sock->closing, &(bool){ false },
true)) {
return;
}
if (sock->tid == isc_nm_tid()) {
udp_close_direct(sock);
} else {
@@ -1048,8 +1068,6 @@ failed_connect_cb(isc_nmsocket_t *sock, isc__nm_uvreq_t *req,
INSIST(req != NULL);
req = uv_handle_get_data((uv_handle_t *)&sock->timer);
isc__nmsocket_clearcb(sock);
if (req->cb.connect != NULL) {
@@ -1071,7 +1089,11 @@ isc__nm_udp_shutdown(isc_nmsocket_t *sock) {
}
if (atomic_load(&sock->connecting)) {
failed_connect_cb(sock, NULL, ISC_R_CANCELED);
if (sock->timer_initialized) {
isc__nm_uvreq_t *req =
uv_handle_get_data((uv_handle_t *)&sock->timer);
failed_connect_cb(sock, req, ISC_R_CANCELED);
}
return;
}