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Code Issues Releases Wiki Activity

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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88
lib/isc/netmgr/tcp.c
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@@ -114,8 +114,10 @@ failed_accept_cb(isc_nmsocket_t *sock, isc_result_t eresult) {
}
static void
failed_connect_cb(isc_nmsocket_t *sock, isc_result_t eresult) {
isc__nm_uvreq_t *req;
failed_connect_cb(isc_nmsocket_t *sock, isc__nm_uvreq_t *req,
isc_result_t eresult) {
REQUIRE(VALID_NMSOCK(sock));
REQUIRE(VALID_UVREQ(req));
REQUIRE(sock->tid == isc_nm_tid());
if (sock->timer_running) {
@@ -129,8 +131,6 @@ failed_connect_cb(isc_nmsocket_t *sock, isc_result_t eresult) {
atomic_store(&sock->connecting, false);
req = uv_handle_get_data((uv_handle_t *)&sock->timer);
isc__nmsocket_clearcb(sock);
if (req->cb.connect != NULL) {
req->cb.connect(NULL, eresult, req->cbarg);
@@ -149,7 +149,7 @@ connecttimeout_cb(uv_timer_t *handle) {
REQUIRE(sock->tid == isc_nm_tid());
failed_connect_cb(sock, ISC_R_TIMEDOUT);
failed_connect_cb(sock, req, ISC_R_TIMEDOUT);
}
static int
@@ -162,20 +162,17 @@ tcp_connect_direct(isc_nmsocket_t *sock, isc__nm_uvreq_t *req) {
worker = &sock->mgr->workers[sock->tid];
if (!sock->timer_initialized) {
uv_timer_init(&worker->loop, &sock->timer);
uv_handle_set_data((uv_handle_t *)&sock->timer, req);
sock->timer_initialized = true;
}
atomic_store(&sock->connecting, true);
r = uv_tcp_init(&worker->loop, &sock->uv_handle.tcp);
if (r != 0) {
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_OPENFAIL]);
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);
}
@@ -186,14 +183,21 @@ tcp_connect_direct(isc_nmsocket_t *sock, isc__nm_uvreq_t *req) {
sock->statsindex[STATID_BINDFAIL]);
atomic_store(&sock->result, isc__nm_uverr2result(r));
atomic_store(&sock->connect_error, true);
failed_connect_cb(sock, isc__nm_uverr2result(-22));
tcp_close_direct(sock);
failed_connect_cb(sock, req, isc__nm_uverr2result(r));
atomic_store(&sock->active, false);
isc__nm_tcp_close(sock);
return (r);
}
}
uv_handle_set_data(&sock->uv_handle.handle, sock);
if (!sock->timer_initialized) {
uv_timer_init(&worker->loop, &sock->timer);
uv_handle_set_data((uv_handle_t *)&sock->timer, req);
sock->timer_initialized = true;
}
uv_handle_set_data(&sock->uv_handle.handle, sock);
uv_handle_set_data(&req->uv_req.handle, req);
r = uv_tcp_connect(&req->uv_req.connect, &sock->uv_handle.tcp,
&req->peer.type.sa, tcp_connect_cb);
if (r != 0) {
@@ -201,8 +205,9 @@ tcp_connect_direct(isc_nmsocket_t *sock, isc__nm_uvreq_t *req) {
sock->statsindex[STATID_CONNECTFAIL]);
atomic_store(&sock->result, isc__nm_uverr2result(r));
atomic_store(&sock->connect_error, true);
failed_connect_cb(sock, isc__nm_uverr2result(-22));
tcp_close_direct(sock);
failed_connect_cb(sock, req, isc__nm_uverr2result(r));
atomic_store(&sock->active, false);
isc__nm_tcp_close(sock);
return (r);
}
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_CONNECT]);
@@ -245,18 +250,14 @@ isc__nm_async_tcpconnect(isc__networker_t *worker, isc__netievent_t *ev0) {
static void
tcp_connect_cb(uv_connect_t *uvreq, int status) {
isc_result_t result;
isc__nm_uvreq_t *req = (isc__nm_uvreq_t *)uvreq->data;
isc__nm_uvreq_t *req = uv_handle_get_data((uv_handle_t *)uvreq);
isc_nmsocket_t *sock = uv_handle_get_data((uv_handle_t *)uvreq->handle);
struct sockaddr_storage ss;
isc_nmhandle_t *handle = NULL;
REQUIRE(VALID_NMSOCK(sock));
REQUIRE(sock->tid == isc_nm_tid());
if (status != 0) {
failed_connect_cb(sock, isc__nm_uverr2result(status));
return;
}
if (sock->timer_running) {
uv_timer_stop(&sock->timer);
sock->timer_running = false;
@@ -266,11 +267,14 @@ tcp_connect_cb(uv_connect_t *uvreq, int status) {
return;
}
atomic_store(&sock->connecting, false);
REQUIRE(VALID_UVREQ(req));
sock = uv_handle_get_data((uv_handle_t *)uvreq->handle);
if (status != 0) {
failed_connect_cb(sock, req, isc__nm_uverr2result(status));
return;
}
atomic_store(&sock->connecting, false);
isc__nm_incstats(sock->mgr, sock->statsindex[STATID_CONNECT]);
uv_tcp_getpeername(&sock->uv_handle.tcp, (struct sockaddr *)&ss,
@@ -1282,11 +1286,9 @@ tcp_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, tcp_close_cb);
uv_close(handle, tcp_close_cb);
}
static void
@@ -1308,7 +1310,13 @@ tcp_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, tcp_close_cb);
@@ -1321,6 +1329,11 @@ isc__nm_tcp_close(isc_nmsocket_t *sock) {
REQUIRE(sock->type == isc_nm_tcpsocket);
REQUIRE(!isc__nmsocket_active(sock));
if (!atomic_compare_exchange_strong(&sock->closing, &(bool){ false },
true)) {
return;
}
if (sock->tid == isc_nm_tid()) {
tcp_close_direct(sock);
} else {
@@ -1339,10 +1352,15 @@ isc__nm_tcp_close(isc_nmsocket_t *sock) {
void
isc__nm_async_tcpclose(isc__networker_t *worker, isc__netievent_t *ev0) {
isc__netievent_tcpclose_t *ievent = (isc__netievent_tcpclose_t *)ev0;
isc_nmsocket_t *sock = ievent->sock;
REQUIRE(worker->id == ievent->sock->tid);
REQUIRE(VALID_NMSOCK(sock));
tcp_close_direct(ievent->sock);
UNUSED(worker);
REQUIRE(sock->tid == isc_nm_tid());
tcp_close_direct(sock);
}
void
@@ -1355,7 +1373,11 @@ isc__nm_tcp_shutdown(isc_nmsocket_t *sock) {
}
if (atomic_load(&sock->connecting)) {
failed_connect_cb(sock, 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;
}