ComputerSurge/bind9
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Have the dns_client hold a .references until all external references are removed

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so that cleanup can all be done in dns_client_destroy().
This commit is contained in:
Ondřej Surý
2019-08-06 17:35:20 +02:00
parent be8af3afb7
commit e80c4c3431
1 changed files with 56 additions and 65 deletions
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121
lib/dns/client.c
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@@ -19,6 +19,7 @@
#include <isc/mem.h>
#include <isc/mutex.h>
#include <isc/portset.h>
#include <isc/refcount.h>
#include <isc/safe.h>
#include <isc/sockaddr.h>
#include <isc/socket.h>
@@ -94,8 +95,9 @@ struct dns_client {
unsigned int find_timeout;
unsigned int find_udpretries;
isc_refcount_t references;
/* Locked */
unsigned int references;
dns_viewlist_t viewlist;
ISC_LIST(struct resctx) resctxs;
ISC_LIST(struct reqctx) reqctxs;
@@ -508,8 +510,7 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx,
result = isc_mutex_init(&client->lock);
if (result != ISC_R_SUCCESS) {
isc_mem_put(mctx, client, sizeof(*client));
return (result);
goto cleanup_client;
}
client->actx = actx;
@@ -519,12 +520,14 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx,
client->task = NULL;
result = isc_task_create(client->taskmgr, 0, &client->task);
if (result != ISC_R_SUCCESS)
goto cleanup;
if (result != ISC_R_SUCCESS) {
goto cleanup_lock;
}
result = dns_dispatchmgr_create(mctx, NULL, &dispatchmgr);
if (result != ISC_R_SUCCESS)
goto cleanup;
if (result != ISC_R_SUCCESS) {
goto cleanup_task;
}
client->dispatchmgr = dispatchmgr;
(void)setsourceports(mctx, dispatchmgr);
@@ -537,8 +540,9 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx,
result = getudpdispatch(AF_INET, dispatchmgr, socketmgr,
taskmgr, true,
&dispatchv4, localaddr4);
if (result == ISC_R_SUCCESS)
if (result == ISC_R_SUCCESS) {
client->dispatchv4 = dispatchv4;
}
}
client->dispatchv6 = NULL;
@@ -546,22 +550,30 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx,
result = getudpdispatch(AF_INET6, dispatchmgr, socketmgr,
taskmgr, true,
&dispatchv6, localaddr6);
if (result == ISC_R_SUCCESS)
if (result == ISC_R_SUCCESS) {
client->dispatchv6 = dispatchv6;
}
}
/* We need at least one of the dispatchers */
if (dispatchv4 == NULL && dispatchv6 == NULL) {
INSIST(result != ISC_R_SUCCESS);
goto cleanup;
goto cleanup_dispatchmgr;
}
result = isc_refcount_init(&client->references, 1);
if (result != ISC_R_SUCCESS) {
goto cleanup_dispatches;
}
/* Create the default view for class IN */
result = createview(mctx, dns_rdataclass_in, options, taskmgr,
RESOLVER_NTASKS, socketmgr, timermgr,
dispatchmgr, dispatchv4, dispatchv6, &view);
if (result != ISC_R_SUCCESS)
goto cleanup;
if (result != ISC_R_SUCCESS) {
goto cleanup_references;
}
ISC_LIST_INIT(client->viewlist);
ISC_LIST_APPEND(client->viewlist, view, link);
@@ -581,32 +593,38 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx,
client->find_udpretries = DEF_FIND_UDPRETRIES;
client->attributes = 0;
client->references = 1;
client->magic = DNS_CLIENT_MAGIC;
*clientp = client;
return (ISC_R_SUCCESS);
cleanup:
cleanup_references:
isc_refcount_decrement(&client->references, NULL);
isc_refcount_destroy(&client->references);
cleanup_dispatches:
if (dispatchv4 != NULL)
dns_dispatch_detach(&dispatchv4);
if (dispatchv6 != NULL)
dns_dispatch_detach(&dispatchv6);
if (dispatchmgr != NULL)
dns_dispatchmgr_destroy(&dispatchmgr);
if (client->task != NULL)
isc_task_detach(&client->task);
cleanup_dispatchmgr:
dns_dispatchmgr_destroy(&dispatchmgr);
cleanup_task:
isc_task_detach(&client->task);
cleanup_lock:
DESTROYLOCK(&client->lock);
cleanup_client:
isc_mem_put(mctx, client, sizeof(*client));
return (result);
}
static void
destroyclient(dns_client_t **clientp) {
dns_client_t *client = *clientp;
destroyclient(dns_client_t *client) {
dns_view_t *view;
isc_refcount_destroy(&client->references);
while ((view = ISC_LIST_HEAD(client->viewlist)) != NULL) {
ISC_LIST_UNLINK(client->viewlist, view, link);
dns_view_detach(&view);
@@ -638,32 +656,22 @@ destroyclient(dns_client_t **clientp) {
client->magic = 0;
isc_mem_putanddetach(&client->mctx, client, sizeof(*client));
*clientp = NULL;
}
void
dns_client_destroy(dns_client_t **clientp) {
dns_client_t *client;
bool destroyok = false;
uint32_t references;
REQUIRE(clientp != NULL);
client = *clientp;
*clientp = NULL;
REQUIRE(DNS_CLIENT_VALID(client));
LOCK(&client->lock);
client->references--;
if (client->references == 0 && ISC_LIST_EMPTY(client->resctxs) &&
ISC_LIST_EMPTY(client->reqctxs) &&
ISC_LIST_EMPTY(client->updatectxs)) {
destroyok = true;
isc_refcount_decrement(&client->references, &references);
if (references == 0U) {
destroyclient(client);
}
UNLOCK(&client->lock);
if (destroyok)
destroyclient(&client);
*clientp = NULL;
}
isc_result_t
@@ -1459,6 +1467,7 @@ dns_client_startresolve(dns_client_t *client, dns_name_t *name,
rctx->event = event;
rctx->magic = RCTX_MAGIC;
isc_refcount_increment(&client->references, NULL);
LOCK(&client->lock);
ISC_LIST_APPEND(client->resctxs, rctx, link);
@@ -1529,10 +1538,10 @@ dns_client_destroyrestrans(dns_clientrestrans_t **transp) {
resctx_t *rctx;
isc_mem_t *mctx;
dns_client_t *client;
bool need_destroyclient = false;
REQUIRE(transp != NULL);
rctx = (resctx_t *)*transp;
*transp = NULL;
REQUIRE(RCTX_VALID(rctx));
REQUIRE(rctx->fetch == NULL);
REQUIRE(rctx->event == NULL);
@@ -1554,11 +1563,6 @@ dns_client_destroyrestrans(dns_clientrestrans_t **transp) {
INSIST(ISC_LINK_LINKED(rctx, link));
ISC_LIST_UNLINK(client->resctxs, rctx, link);
if (client->references == 0 && ISC_LIST_EMPTY(client->resctxs) &&
ISC_LIST_EMPTY(client->reqctxs) &&
ISC_LIST_EMPTY(client->updatectxs))
need_destroyclient = true;
UNLOCK(&client->lock);
INSIST(ISC_LIST_EMPTY(rctx->namelist));
@@ -1568,10 +1572,8 @@ dns_client_destroyrestrans(dns_clientrestrans_t **transp) {
isc_mem_put(mctx, rctx, sizeof(*rctx));
if (need_destroyclient)
destroyclient(&client);
dns_client_destroy(&client);
*transp = NULL;
}
isc_result_t
@@ -1845,6 +1847,7 @@ dns_client_startrequest(dns_client_t *client, dns_message_t *qmessage,
LOCK(&client->lock);
ISC_LIST_APPEND(client->reqctxs, ctx, link);
isc_refcount_increment(&client->references, NULL);
UNLOCK(&client->lock);
ctx->request = NULL;
@@ -1859,6 +1862,8 @@ dns_client_startrequest(dns_client_t *client, dns_message_t *qmessage,
return (ISC_R_SUCCESS);
}
isc_refcount_decrement(&client->references, NULL);
cleanup:
if (ctx != NULL) {
LOCK(&client->lock);
@@ -1899,10 +1904,10 @@ dns_client_destroyreqtrans(dns_clientreqtrans_t **transp) {
reqctx_t *ctx;
isc_mem_t *mctx;
dns_client_t *client;
bool need_destroyclient = false;
REQUIRE(transp != NULL);
ctx = (reqctx_t *)*transp;
*transp = NULL;
REQUIRE(REQCTX_VALID(ctx));
client = ctx->client;
REQUIRE(DNS_CLIENT_VALID(client));
@@ -1917,12 +1922,6 @@ dns_client_destroyreqtrans(dns_clientreqtrans_t **transp) {
INSIST(ISC_LINK_LINKED(ctx, link));
ISC_LIST_UNLINK(client->reqctxs, ctx, link);
if (client->references == 0 && ISC_LIST_EMPTY(client->resctxs) &&
ISC_LIST_EMPTY(client->reqctxs) &&
ISC_LIST_EMPTY(client->updatectxs)) {
need_destroyclient = true;
}
UNLOCK(&client->lock);
DESTROYLOCK(&ctx->lock);
@@ -1930,10 +1929,7 @@ dns_client_destroyreqtrans(dns_clientreqtrans_t **transp) {
isc_mem_put(mctx, ctx, sizeof(*ctx));
if (need_destroyclient)
destroyclient(&client);
*transp = NULL;
dns_client_destroy(&client);
}
/*%
@@ -3023,6 +3019,7 @@ dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass,
LOCK(&client->lock);
ISC_LIST_APPEND(client->updatectxs, uctx, link);
isc_refcount_increment(&client->references, NULL);
UNLOCK(&client->lock);
*transp = (dns_clientupdatetrans_t *)uctx;
@@ -3041,6 +3038,8 @@ dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass,
}
if (result == ISC_R_SUCCESS)
return (result);
isc_refcount_decrement(&client->references, NULL);
*transp = NULL;
fail:
@@ -3098,11 +3097,11 @@ dns_client_destroyupdatetrans(dns_clientupdatetrans_t **transp) {
updatectx_t *uctx;
isc_mem_t *mctx;
dns_client_t *client;
bool need_destroyclient = false;
isc_sockaddr_t *sa;
REQUIRE(transp != NULL);
uctx = (updatectx_t *)*transp;
*transp = NULL;
REQUIRE(UCTX_VALID(uctx));
client = uctx->client;
REQUIRE(DNS_CLIENT_VALID(client));
@@ -3123,11 +3122,6 @@ dns_client_destroyupdatetrans(dns_clientupdatetrans_t **transp) {
INSIST(ISC_LINK_LINKED(uctx, link));
ISC_LIST_UNLINK(client->updatectxs, uctx, link);
if (client->references == 0 && ISC_LIST_EMPTY(client->resctxs) &&
ISC_LIST_EMPTY(client->reqctxs) &&
ISC_LIST_EMPTY(client->updatectxs))
need_destroyclient = true;
UNLOCK(&client->lock);
DESTROYLOCK(&uctx->lock);
@@ -3135,10 +3129,7 @@ dns_client_destroyupdatetrans(dns_clientupdatetrans_t **transp) {
isc_mem_put(mctx, uctx, sizeof(*uctx));
if (need_destroyclient)
destroyclient(&client);
*transp = NULL;
dns_client_destroy(&client);
}
isc_mem_t *