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Code Issues Releases Wiki Activity

properly lock the setting/unsetting of callbacks in isc_nmsocket_t

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changes to socket callback functions were not thread safe.
This commit is contained in:
Ondřej Surý
2020-09-11 10:53:31 +02:00
committed by Evan Hunt
parent 57b4dde974
commit 89c534d3b9
5 changed files with 122 additions and 61 deletions
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50
lib/isc/netmgr/tcpdns.c
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@@ -109,6 +109,8 @@ dnslisten_acceptcb(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
isc_nmsocket_t *dnslistensock = (isc_nmsocket_t *)cbarg;
isc_nmsocket_t *dnssock = NULL;
isc_nmhandle_t *readhandle = NULL;
isc_nm_accept_cb_t accept_cb;
void *accept_cbarg;
REQUIRE(VALID_NMSOCK(dnslistensock));
REQUIRE(dnslistensock->type == isc_nm_tcpdnslistener);
@@ -117,9 +119,13 @@ dnslisten_acceptcb(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
return (result);
}
if (dnslistensock->accept_cb.accept != NULL) {
result = dnslistensock->accept_cb.accept(
handle, ISC_R_SUCCESS, dnslistensock->accept_cbarg);
LOCK(&dnslistensock->lock);
accept_cb = dnslistensock->accept_cb;
accept_cbarg = dnslistensock->accept_cbarg;
UNLOCK(&dnslistensock->lock);
if (accept_cb != NULL) {
result = accept_cb(handle, ISC_R_SUCCESS, accept_cbarg);
if (result != ISC_R_SUCCESS) {
return (result);
}
@@ -196,6 +202,8 @@ processbuffer(isc_nmsocket_t *dnssock, isc_nmhandle_t **handlep) {
if (len <= dnssock->buf_len - 2) {
isc_nmhandle_t *dnshandle = NULL;
isc_nmsocket_t *listener = NULL;
isc_nm_recv_cb_t cb = NULL;
void *cbarg = NULL;
if (atomic_load(&dnssock->client) &&
dnssock->statichandle != NULL) {
@@ -205,22 +213,25 @@ processbuffer(isc_nmsocket_t *dnssock, isc_nmhandle_t **handlep) {
}
listener = dnssock->listener;
if (listener != NULL && listener->rcb.recv != NULL) {
listener->rcb.recv(
dnshandle, ISC_R_SUCCESS,
&(isc_region_t){ .base = dnssock->buf + 2,
.length = len },
listener->rcbarg);
} else if (dnssock->rcb.recv != NULL) {
isc_nm_recv_cb_t cb = dnssock->rcb.recv;
void *cbarg = dnssock->rcbarg;
if (listener != NULL) {
LOCK(&listener->lock);
cb = listener->recv_cb;
cbarg = listener->recv_cbarg;
UNLOCK(&listener->lock);
} else if (dnssock->recv_cb != NULL) {
LOCK(&dnssock->lock);
cb = dnssock->recv_cb;
cbarg = dnssock->recv_cbarg;
/*
* We need to clear the read callback *before*
* calling it, because it might make another
* call to isc_nm_read() and set up a new callback.
*/
isc__nmsocket_clearcb(dnssock);
UNLOCK(&dnssock->lock);
}
if (cb != NULL) {
cb(dnshandle, ISC_R_SUCCESS,
&(isc_region_t){ .base = dnssock->buf + 2,
.length = len },
@@ -303,8 +314,10 @@ dnslisten_readcb(isc_nmhandle_t *handle, isc_result_t eresult,
uv_timer_stop(&dnssock->timer);
}
LOCK(&dnssock->lock);
if (atomic_load(&dnssock->sequential) ||
dnssock->rcb.recv == NULL) {
dnssock->recv_cb == NULL) {
UNLOCK(&dnssock->lock);
/*
* There are two reasons we might want to pause here:
* - We're in sequential mode and we've received
@@ -315,6 +328,7 @@ dnslisten_readcb(isc_nmhandle_t *handle, isc_result_t eresult,
isc_nm_pauseread(dnssock->outerhandle);
done = true;
} else {
UNLOCK(&dnssock->lock);
/*
* We're pipelining, so we now resume processing
* packets until the clients-per-connection limit
@@ -350,10 +364,12 @@ isc_nm_listentcpdns(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb,
REQUIRE(VALID_NM(mgr));
isc__nmsocket_init(dnslistensock, mgr, isc_nm_tcpdnslistener, iface);
dnslistensock->rcb.recv = cb;
dnslistensock->rcbarg = cbarg;
dnslistensock->accept_cb.accept = accept_cb;
LOCK(&dnslistensock->lock);
dnslistensock->recv_cb = cb;
dnslistensock->recv_cbarg = cbarg;
dnslistensock->accept_cb = accept_cb;
dnslistensock->accept_cbarg = accept_cbarg;
UNLOCK(&dnslistensock->lock);
dnslistensock->extrahandlesize = extrahandlesize;
/*