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netmgr: have a single source of truth for tcpdns callback

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We pass interface as an opaque argument to tcpdns listening socket.
If we stop listening on an interface but still have in-flight connections
the opaque 'interface' is not properly reference counted, and we might
hit a dead memory. We put just a single source of truth in a listening
socket and make the child sockets use that instead of copying the
value from listening socket. We clean the callback when we stop listening.
This commit is contained in:
Witold Kręcicki 2020-01-15 14:53:42 +01:00
parent 0d637b5985
commit eda4300bbb
3 changed files with 24 additions and 10 deletions
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3
lib/isc/netmgr/netmgr-int.h
View File

@ -347,7 +347,10 @@ struct isc_nmsocket {
int tid;
isc_nmsocket_type type;
isc_nm_t *mgr;
/*% Parent socket for multithreaded listeners */
isc_nmsocket_t *parent;
/*% Listener socket this connection was accepted on */
isc_nmsocket_t *listener;
/*%
* quota is the TCP client, attached when a TCP connection

26
lib/isc/netmgr/tcpdns.c
View File

@ -121,10 +121,8 @@ dnslisten_acceptcb(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
isc__nmsocket_init(dnssock, handle->sock->mgr,
isc_nm_tcpdnssocket, handle->sock->iface);
/* We need to copy read callbacks from outer socket */
dnssock->rcb.recv = dnslistensock->rcb.recv;
dnssock->rcbarg = dnslistensock->rcbarg;
dnssock->extrahandlesize = dnslistensock->extrahandlesize;
isc_nmsocket_attach(dnslistensock, &dnssock->listener);
isc_nmsocket_attach(handle->sock, &dnssock->outer);
dnssock->peer = handle->sock->peer;
dnssock->read_timeout = handle->sock->mgr->init;
@ -171,14 +169,17 @@ processbuffer(isc_nmsocket_t *dnssock, isc_nmhandle_t **handlep) {
*/
len = dnslen(dnssock->buf);
if (len <= dnssock->buf_len - 2) {
isc_nmhandle_t *dnshandle = NULL;
isc_region_t r2 = {
.base = dnssock->buf + 2,
.length = len
};
isc_nmhandle_t *dnshandle = isc__nmhandle_get(dnssock,
NULL, NULL);
isc_nmsocket_t *listener = dnssock->listener;
dnshandle = isc__nmhandle_get(dnssock, NULL, NULL);
dnssock->rcb.recv(dnshandle, &r2, dnssock->rcbarg);
if (listener != NULL && listener->rcb.recv != NULL) {
listener->rcb.recv(dnshandle,
&(isc_region_t){
.base = dnssock->buf + 2,
.length = len
}, listener->rcbarg);
}
len += 2;
dnssock->buf_len -= len;
@ -322,6 +323,8 @@ isc_nm_tcpdns_stoplistening(isc_nmsocket_t *sock) {
atomic_store(&sock->listening, false);
atomic_store(&sock->closed, true);
sock->rcb.recv = NULL;
sock->rcbarg = NULL;
if (sock->outer != NULL) {
isc_nm_tcp_stoplistening(sock->outer);
@ -502,6 +505,9 @@ tcpdns_close_direct(isc_nmsocket_t *sock) {
sock->outer->rcb.recv = NULL;
isc_nmsocket_detach(&sock->outer);
}
if (sock->listener != NULL) {
isc_nmsocket_detach(&sock->listener);
}
/* We don't need atomics here, it's all in single network thread */
if (sock->timer_initialized) {
sock->timer_initialized = false;

5
lib/ns/client.c
View File

@ -1625,6 +1625,11 @@ ns__client_request(isc_nmhandle_t *handle, isc_region_t *region, void *arg) {
ifp = (ns_interface_t *) arg;
mgr = ifp->clientmgr;
if (mgr == NULL) {
/* The interface was shut down in the meantime, just bail */
return;
}
REQUIRE(VALID_MANAGER(mgr));
client = isc_nmhandle_getdata(handle);