/* $NetBSD: client.c,v 1.5.4.2 2019/10/17 19:34:22 martin Exp $ */
/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#include <config.h>
#include <inttypes.h>
#include <stdbool.h>
#include <isc/aes.h>
#include <isc/formatcheck.h>
#include <isc/fuzz.h>
#include <isc/hmac.h>
#include <isc/mutex.h>
#include <isc/once.h>
#include <isc/nonce.h>
#include <isc/platform.h>
#include <isc/print.h>
#include <isc/queue.h>
#include <isc/random.h>
#include <isc/safe.h>
#include <isc/serial.h>
#include <isc/siphash.h>
#include <isc/stats.h>
#include <isc/stdio.h>
#include <isc/string.h>
#include <isc/task.h>
#include <isc/timer.h>
#include <isc/util.h>
#include <dns/adb.h>
#include <dns/badcache.h>
#include <dns/db.h>
#include <dns/dispatch.h>
#include <dns/dnstap.h>
#include <dns/cache.h>
#include <dns/edns.h>
#include <dns/events.h>
#include <dns/message.h>
#include <dns/peer.h>
#include <dns/rcode.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/resolver.h>
#include <dns/stats.h>
#include <dns/tsig.h>
#include <dns/view.h>
#include <dns/zone.h>
#include <ns/interfacemgr.h>
#include <ns/log.h>
#include <ns/notify.h>
#include <ns/server.h>
#include <ns/stats.h>
#include <ns/update.h>
/***
*** Client
***/
/*! \file
* Client Routines
*
* Important note!
*
* All client state changes, other than that from idle to listening, occur
* as a result of events. This guarantees serialization and avoids the
* need for locking.
*
* If a routine is ever created that allows someone other than the client's
* task to change the client, then the client will have to be locked.
*/
#define NS_CLIENT_TRACE
#ifdef NS_CLIENT_TRACE
#define CTRACE(m) ns_client_log(client, \
NS_LOGCATEGORY_CLIENT, \
NS_LOGMODULE_CLIENT, \
ISC_LOG_DEBUG(3), \
"%s", (m))
#define MTRACE(m) isc_log_write(ns_lctx, \
NS_LOGCATEGORY_CLIENT, \
NS_LOGMODULE_CLIENT, \
ISC_LOG_DEBUG(3), \
"clientmgr @%p: %s", manager, (m))
#else
#define CTRACE(m) ((void)(m))
#define MTRACE(m) ((void)(m))
#endif
#define TCP_CLIENT(c) (((c)->attributes & NS_CLIENTATTR_TCP) != 0)
#define TCP_BUFFER_SIZE (65535 + 2)
#define SEND_BUFFER_SIZE 4096
#define RECV_BUFFER_SIZE 4096
#define NMCTXS 100
/*%<
* Number of 'mctx pools' for clients. (Should this be configurable?)
* When enabling threads, we use a pool of memory contexts shared by
* client objects, since concurrent access to a shared context would cause
* heavy contentions. The above constant is expected to be enough for
* completely avoiding contentions among threads for an authoritative-only
* server.
*/
#define COOKIE_SIZE 24U /* 8 + 4 + 4 + 8 */
#define ECS_SIZE 20U /* 2 + 1 + 1 + [0..16] */
#define WANTNSID(x) (((x)->attributes & NS_CLIENTATTR_WANTNSID) != 0)
#define WANTEXPIRE(x) (((x)->attributes & NS_CLIENTATTR_WANTEXPIRE) != 0)
#define WANTPAD(x) (((x)->attributes & NS_CLIENTATTR_WANTPAD) != 0)
#define USEKEEPALIVE(x) (((x)->attributes & NS_CLIENTATTR_USEKEEPALIVE) != 0)
/*% nameserver client manager structure */
struct ns_clientmgr {
/* Unlocked. */
unsigned int magic;
/* The queue object has its own locks */
client_queue_t inactive; /*%< To be recycled */
isc_mem_t * mctx;
ns_server_t * sctx;
isc_taskmgr_t * taskmgr;
isc_timermgr_t * timermgr;
isc_task_t * excl;
/* Lock covers manager state. */
isc_mutex_t lock;
bool exiting;
/* Lock covers the clients list */
isc_mutex_t listlock;
client_list_t clients; /*%< All active clients */
/* Lock covers the recursing list */
isc_mutex_t reclock;
client_list_t recursing; /*%< Recursing clients */
#if NMCTXS > 0
/*%< mctx pool for clients. */
unsigned int nextmctx;
isc_mem_t * mctxpool[NMCTXS];
#endif
};
#define MANAGER_MAGIC ISC_MAGIC('N', 'S', 'C', 'm')
#define VALID_MANAGER(m) ISC_MAGIC_VALID(m, MANAGER_MAGIC)
/*!
* Client object states. Ordering is significant: higher-numbered
* states are generally "more active", meaning that the client can
* have more dynamically allocated data, outstanding events, etc.
* In the list below, any such properties listed for state N
* also apply to any state > N.
*
* To force the client into a less active state, set client->newstate
* to that state and call exit_check(). This will cause any
* activities defined for higher-numbered states to be aborted.
*/
#define NS_CLIENTSTATE_FREED 0
/*%<
* The client object no longer exists.
*/
#define NS_CLIENTSTATE_INACTIVE 1
/*%<
* The client object exists and has a task and timer.
* Its "query" struct and sendbuf are initialized.
* It is on the client manager's list of inactive clients.
* It has a message and OPT, both in the reset state.
*/
#define NS_CLIENTSTATE_READY 2
/*%<
* The client object is either a TCP or a UDP one, and
* it is associated with a network interface. It is on the
* client manager's list of active clients.
*
* If it is a TCP client object, it has a TCP listener socket
* and an outstanding TCP listen request.
*
* If it is a UDP client object, it has a UDP listener socket
* and an outstanding UDP receive request.
*/
#define NS_CLIENTSTATE_READING 3
/*%<
* The client object is a TCP client object that has received
* a connection. It has a tcpsocket, tcpmsg, TCP quota, and an
* outstanding TCP read request. This state is not used for
* UDP client objects.
*/
#define NS_CLIENTSTATE_WORKING 4
/*%<
* The client object has received a request and is working
* on it. It has a view, and it may have any of a non-reset OPT,
* recursion quota, and an outstanding write request.
*/
#define NS_CLIENTSTATE_RECURSING 5
/*%<
* The client object is recursing. It will be on the 'recursing'
* list.
*/
#define NS_CLIENTSTATE_MAX 9
/*%<
* Sentinel value used to indicate "no state". When client->newstate
* has this value, we are not attempting to exit the current state.
* Must be greater than any valid state.
*/
/*
* Enable ns_client_dropport() by default.
*/
#ifndef NS_CLIENT_DROPPORT
#define NS_CLIENT_DROPPORT 1
#endif
LIBNS_EXTERNAL_DATA unsigned int ns_client_requests;
static void read_settimeout(ns_client_t *client, bool newconn);
static void client_read(ns_client_t *client, bool newconn);
static void client_accept(ns_client_t *client);
static void client_udprecv(ns_client_t *client);
static void clientmgr_destroy(ns_clientmgr_t *manager);
static bool exit_check(ns_client_t *client);
static void ns_client_endrequest(ns_client_t *client);
static void client_start(isc_task_t *task, isc_event_t *event);
static void ns_client_dumpmessage(ns_client_t *client, const char *reason);
static isc_result_t get_client(ns_clientmgr_t *manager, ns_interface_t *ifp,
dns_dispatch_t *disp, bool tcp);
static isc_result_t get_worker(ns_clientmgr_t *manager, ns_interface_t *ifp,
isc_socket_t *sock, ns_client_t *oldclient);
static void compute_cookie(ns_client_t *client, uint32_t when,
uint32_t nonce, const unsigned char *secret,
isc_buffer_t *buf);
void
ns_client_recursing(ns_client_t *client) {
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(client->state == NS_CLIENTSTATE_WORKING);
LOCK(&client->manager->reclock);
client->newstate = client->state = NS_CLIENTSTATE_RECURSING;
ISC_LIST_APPEND(client->manager->recursing, client, rlink);
UNLOCK(&client->manager->reclock);
}
void
ns_client_killoldestquery(ns_client_t *client) {
ns_client_t *oldest;
REQUIRE(NS_CLIENT_VALID(client));
LOCK(&client->manager->reclock);
oldest = ISC_LIST_HEAD(client->manager->recursing);
if (oldest != NULL) {
ISC_LIST_UNLINK(client->manager->recursing, oldest, rlink);
UNLOCK(&client->manager->reclock);
ns_query_cancel(oldest);
} else
UNLOCK(&client->manager->reclock);
}
void
ns_client_settimeout(ns_client_t *client, unsigned int seconds) {
isc_result_t result;
isc_interval_t interval;
isc_interval_set(&interval, seconds, 0);
result = isc_timer_reset(client->timer, isc_timertype_once, NULL,
&interval, false);
client->timerset = true;
if (result != ISC_R_SUCCESS) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_ERROR,
"setting timeout: %s",
isc_result_totext(result));
/* Continue anyway. */
}
}
static void
read_settimeout(ns_client_t *client, bool newconn) {
isc_result_t result;
isc_interval_t interval;
unsigned int ds;
if (newconn)
ds = client->sctx->initialtimo;
else if (USEKEEPALIVE(client))
ds = client->sctx->keepalivetimo;
else
ds = client->sctx->idletimo;
isc_interval_set(&interval, ds / 10, 100000000 * (ds % 10));
result = isc_timer_reset(client->timer, isc_timertype_once, NULL,
&interval, false);
client->timerset = true;
if (result != ISC_R_SUCCESS) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_ERROR,
"setting timeout: %s",
isc_result_totext(result));
/* Continue anyway. */
}
}
/*%
* Allocate a reference-counted object that will maintain a single pointer to
* the (also reference-counted) TCP client quota, shared between all the
* clients processing queries on a single TCP connection, so that all
* clients sharing the one socket will together consume only one slot in
* the 'tcp-clients' quota.
*/
static isc_result_t
tcpconn_init(ns_client_t *client, bool force) {
isc_result_t result;
isc_quota_t *quota = NULL;
ns_tcpconn_t *tconn = NULL;
REQUIRE(client->tcpconn == NULL);
/*
* Try to attach to the quota first, so we won't pointlessly
* allocate memory for a tcpconn object if we can't get one.
*/
if (force) {
result = isc_quota_force(&client->sctx->tcpquota, "a);
} else {
result = isc_quota_attach(&client->sctx->tcpquota, "a);
}
if (result != ISC_R_SUCCESS) {
return (result);
}
/*
* A global memory context is used for the allocation as different
* client structures may have different memory contexts assigned and a
* reference counter allocated here might need to be freed by a
* different client. The performance impact caused by memory context
* contention here is expected to be negligible, given that this code
* is only executed for TCP connections.
*/
tconn = isc_mem_allocate(client->sctx->mctx, sizeof(*tconn));
isc_refcount_init(&tconn->refs, 1);
tconn->tcpquota = quota;
quota = NULL;
tconn->pipelined = false;
client->tcpconn = tconn;
return (ISC_R_SUCCESS);
}
/*%
* Increase the count of client structures sharing the TCP connection
* that 'source' is associated with; add a pointer to the same tcpconn
* to 'target', thus associating it with the same TCP connection.
*/
static void
tcpconn_attach(ns_client_t *source, ns_client_t *target) {
int old_refs;
REQUIRE(source->tcpconn != NULL);
REQUIRE(target->tcpconn == NULL);
REQUIRE(source->tcpconn->pipelined);
old_refs = isc_refcount_increment(&source->tcpconn->refs);
INSIST(old_refs > 0);
target->tcpconn = source->tcpconn;
}
/*%
* Decrease the count of client structures sharing the TCP connection that
* 'client' is associated with. If this is the last client using this TCP
* connection, we detach from the TCP quota and free the tcpconn
* object. Either way, client->tcpconn is set to NULL.
*/
static void
tcpconn_detach(ns_client_t *client) {
ns_tcpconn_t *tconn = NULL;
int old_refs;
REQUIRE(client->tcpconn != NULL);
tconn = client->tcpconn;
client->tcpconn = NULL;
old_refs = isc_refcount_decrement(&tconn->refs);
INSIST(old_refs > 0);
if (old_refs == 1) {
isc_quota_detach(&tconn->tcpquota);
isc_mem_free(client->sctx->mctx, tconn);
}
}
/*%
* Mark a client as active and increment the interface's 'ntcpactive'
* counter, as a signal that there is at least one client servicing
* TCP queries for the interface. If we reach the TCP client quota at
* some point, this will be used to determine whether a quota overrun
* should be permitted.
*
* Marking the client active with the 'tcpactive' flag ensures proper
* accounting, by preventing us from incrementing or decrementing
* 'ntcpactive' more than once per client.
*/
static void
mark_tcp_active(ns_client_t *client, bool active) {
if (active && !client->tcpactive) {
isc_refcount_increment0(&client->interface->ntcpactive);
client->tcpactive = active;
} else if (!active && client->tcpactive) {
uint32_t old =
isc_refcount_decrement(&client->interface->ntcpactive);
INSIST(old > 0);
client->tcpactive = active;
}
}
/*%
* Check for a deactivation or shutdown request and take appropriate
* action. Returns true if either is in progress; in this case
* the caller must no longer use the client object as it may have been
* freed.
*/
static bool
exit_check(ns_client_t *client) {
bool destroy_manager = false;
ns_clientmgr_t *manager = NULL;
REQUIRE(NS_CLIENT_VALID(client));
manager = client->manager;
if (client->state <= client->newstate)
return (false); /* Business as usual. */
INSIST(client->newstate < NS_CLIENTSTATE_RECURSING);
/*
* We need to detach from the view early when shutting down
* the server to break the following vicious circle:
*
* - The resolver will not shut down until the view refcount is zero
* - The view refcount does not go to zero until all clients detach
* - The client does not detach from the view until references is zero
* - references does not go to zero until the resolver has shut down
*
* Keep the view attached until any outstanding updates complete.
*/
if (client->nupdates == 0 &&
client->newstate == NS_CLIENTSTATE_FREED && client->view != NULL)
dns_view_detach(&client->view);
if (client->state == NS_CLIENTSTATE_WORKING ||
client->state == NS_CLIENTSTATE_RECURSING)
{
INSIST(client->newstate <= NS_CLIENTSTATE_READING);
/*
* Let the update processing complete.
*/
if (client->nupdates > 0)
return (true);
/*
* We are trying to abort request processing.
*/
if (client->nsends > 0) {
isc_socket_t *sock;
if (TCP_CLIENT(client))
sock = client->tcpsocket;
else
sock = client->udpsocket;
isc_socket_cancel(sock, client->task,
ISC_SOCKCANCEL_SEND);
}
if (! (client->nsends == 0 && client->nrecvs == 0 &&
client->references == 0))
{
/*
* Still waiting for I/O cancel completion.
* or lingering references.
*/
return (true);
}
/*
* I/O cancel is complete. Burn down all state
* related to the current request. Ensure that
* the client is no longer on the recursing list.
*
* We need to check whether the client is still linked,
* because it may already have been removed from the
* recursing list by ns_client_killoldestquery()
*/
if (client->state == NS_CLIENTSTATE_RECURSING) {
LOCK(&manager->reclock);
if (ISC_LINK_LINKED(client, rlink))
ISC_LIST_UNLINK(manager->recursing,
client, rlink);
UNLOCK(&manager->reclock);
}
ns_client_endrequest(client);
client->state = NS_CLIENTSTATE_READING;
INSIST(client->recursionquota == NULL);
if (NS_CLIENTSTATE_READING == client->newstate) {
INSIST(client->tcpconn != NULL);
if (!client->tcpconn->pipelined) {
client_read(client, false);
client->newstate = NS_CLIENTSTATE_MAX;
return (true); /* We're done. */
} else if (client->mortal) {
client->newstate = NS_CLIENTSTATE_INACTIVE;
} else
return (false);
}
}
if (client->state == NS_CLIENTSTATE_READING) {
/*
* We are trying to abort the current TCP connection,
* if any.
*/
INSIST(client->recursionquota == NULL);
INSIST(client->newstate <= NS_CLIENTSTATE_READY);
if (client->nreads > 0) {
dns_tcpmsg_cancelread(&client->tcpmsg);
/* Still waiting for read cancel completion? */
if (client->nreads > 0) {
return (true);
}
}
if (client->tcpmsg_valid) {
dns_tcpmsg_invalidate(&client->tcpmsg);
client->tcpmsg_valid = false;
}
/*
* Soon the client will be ready to accept a new TCP
* connection or UDP request, but we may have enough
* clients doing that already. Check whether this client
* needs to remain active and allow it go inactive if
* not.
*
* UDP clients always go inactive at this point, but a TCP
* client may need to stay active and return to READY
* state if no other clients are available to listen
* for TCP requests on this interface.
*
* Regardless, if we're going to FREED state, that means
* the system is shutting down and we don't need to
* retain clients.
*/
if (client->mortal && TCP_CLIENT(client) &&
client->newstate != NS_CLIENTSTATE_FREED &&
(client->sctx->options & NS_SERVER_CLIENTTEST) == 0 &&
isc_refcount_current(&client->interface->ntcpaccepting) == 0)
{
/* Nobody else is accepting */
client->mortal = false;
client->newstate = NS_CLIENTSTATE_READY;
}
/*
* Detach from TCP connection and TCP client quota,
* if appropriate. If this is the last reference to
* the TCP connection in our pipeline group, the
* TCP quota slot will be released.
*/
if (client->tcpconn) {
tcpconn_detach(client);
}
if (client->tcpsocket != NULL) {
CTRACE("closetcp");
isc_socket_detach(&client->tcpsocket);
mark_tcp_active(client, false);
}
if (client->timerset) {
(void)isc_timer_reset(client->timer,
isc_timertype_inactive,
NULL, NULL, true);
client->timerset = false;
}
client->peeraddr_valid = false;
client->state = NS_CLIENTSTATE_READY;
/*
* We don't need the client; send it to the inactive
* queue for recycling.
*/
if (client->mortal) {
if (client->newstate > NS_CLIENTSTATE_INACTIVE) {
client->newstate = NS_CLIENTSTATE_INACTIVE;
}
}
if (NS_CLIENTSTATE_READY == client->newstate) {
if (TCP_CLIENT(client)) {
client_accept(client);
} else {
client_udprecv(client);
}
client->newstate = NS_CLIENTSTATE_MAX;
return (true);
}
}
if (client->state == NS_CLIENTSTATE_READY) {
INSIST(client->newstate <= NS_CLIENTSTATE_INACTIVE);
/*
* We are trying to enter the inactive state.
*/
if (client->naccepts > 0) {
isc_socket_cancel(client->tcplistener, client->task,
ISC_SOCKCANCEL_ACCEPT);
/* Still waiting for accept cancel completion? */
if (client->naccepts > 0) {
return (true);
}
}
/* Accept cancel is complete. */
if (client->nrecvs > 0) {
isc_socket_cancel(client->udpsocket, client->task,
ISC_SOCKCANCEL_RECV);
/* Still waiting for recv cancel completion? */
if (client->nrecvs > 0) {
return (true);
}
}
/* Still waiting for control event to be delivered */
if (client->nctls > 0) {
return (true);
}
INSIST(client->naccepts == 0);
INSIST(client->recursionquota == NULL);
if (client->tcplistener != NULL) {
isc_socket_detach(&client->tcplistener);
mark_tcp_active(client, false);
}
if (client->udpsocket != NULL) {
isc_socket_detach(&client->udpsocket);
}
/* Deactivate the client. */
if (client->interface != NULL) {
ns_interface_detach(&client->interface);
}
if (client->dispatch != NULL) {
dns_dispatch_detach(&client->dispatch);
}
client->attributes = 0;
client->mortal = false;
client->sendcb = NULL;
if (client->keytag != NULL) {
isc_mem_put(client->mctx, client->keytag,
client->keytag_len);
client->keytag_len = 0;
}
/*
* Put the client on the inactive list. If we are aiming for
* the "freed" state, it will be removed from the inactive
* list shortly, and we need to keep the manager locked until
* that has been done, lest the manager decide to reactivate
* the dying client inbetween.
*/
client->state = NS_CLIENTSTATE_INACTIVE;
INSIST(client->recursionquota == NULL);
if (client->state == client->newstate) {
client->newstate = NS_CLIENTSTATE_MAX;
if ((client->sctx->options &
NS_SERVER_CLIENTTEST) == 0 &&
manager != NULL && !manager->exiting)
{
ISC_QUEUE_PUSH(manager->inactive, client,
ilink);
}
if (client->needshutdown) {
isc_task_shutdown(client->task);
}
return (true);
}
}
if (client->state == NS_CLIENTSTATE_INACTIVE) {
INSIST(client->newstate == NS_CLIENTSTATE_FREED);
/*
* We are trying to free the client.
*
* When "shuttingdown" is true, either the task has received
* its shutdown event or no shutdown event has ever been
* set up. Thus, we have no outstanding shutdown
* event at this point.
*/
REQUIRE(client->state == NS_CLIENTSTATE_INACTIVE);
INSIST(client->recursionquota == NULL);
INSIST(!ISC_QLINK_LINKED(client, ilink));
if (manager != NULL) {
LOCK(&manager->listlock);
ISC_LIST_UNLINK(manager->clients, client, link);
LOCK(&manager->lock);
if (manager->exiting &&
ISC_LIST_EMPTY(manager->clients))
destroy_manager = true;
UNLOCK(&manager->lock);
UNLOCK(&manager->listlock);
}
ns_query_free(client);
isc_mem_put(client->mctx, client->recvbuf, RECV_BUFFER_SIZE);
isc_event_free((isc_event_t **)&client->sendevent);
isc_event_free((isc_event_t **)&client->recvevent);
isc_timer_detach(&client->timer);
if (client->delaytimer != NULL)
isc_timer_detach(&client->delaytimer);
if (client->tcpbuf != NULL)
isc_mem_put(client->mctx, client->tcpbuf,
TCP_BUFFER_SIZE);
if (client->opt != NULL) {
INSIST(dns_rdataset_isassociated(client->opt));
dns_rdataset_disassociate(client->opt);
dns_message_puttemprdataset(client->message,
&client->opt);
}
if (client->keytag != NULL) {
isc_mem_put(client->mctx, client->keytag,
client->keytag_len);
client->keytag_len = 0;
}
dns_message_destroy(&client->message);
/*
* Detaching the task must be done after unlinking from
* the manager's lists because the manager accesses
* client->task.
*/
if (client->task != NULL)
isc_task_detach(&client->task);
CTRACE("free");
client->magic = 0;
/*
* Check that there are no other external references to
* the memory context.
*/
if ((client->sctx->options & NS_SERVER_CLIENTTEST) != 0 &&
isc_mem_references(client->mctx) != 1)
{
isc_mem_stats(client->mctx, stderr);
INSIST(0);
ISC_UNREACHABLE();
}
/*
* Destroy the fetchlock mutex that was created in
* ns_query_init().
*/
isc_mutex_destroy(&client->query.fetchlock);
if (client->sctx != NULL)
ns_server_detach(&client->sctx);
isc_mem_putanddetach(&client->mctx, client, sizeof(*client));
}
if (destroy_manager && manager != NULL)
clientmgr_destroy(manager);
return (true);
}
/*%
* The client's task has received the client's control event
* as part of the startup process.
*/
static void
client_start(isc_task_t *task, isc_event_t *event) {
ns_client_t *client = (ns_client_t *) event->ev_arg;
INSIST(task == client->task);
UNUSED(task);
INSIST(client->nctls == 1);
client->nctls--;
if (exit_check(client))
return;
if (TCP_CLIENT(client)) {
if (client->tcpconn != NULL) {
client_read(client, false);
} else {
client_accept(client);
}
} else {
client_udprecv(client);
}
}
/*%
* The client's task has received a shutdown event.
*/
static void
client_shutdown(isc_task_t *task, isc_event_t *event) {
ns_client_t *client;
REQUIRE(event != NULL);
REQUIRE(event->ev_type == ISC_TASKEVENT_SHUTDOWN);
client = event->ev_arg;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(task == client->task);
UNUSED(task);
CTRACE("shutdown");
isc_event_free(&event);
if (client->shutdown != NULL) {
(client->shutdown)(client->shutdown_arg, ISC_R_SHUTTINGDOWN);
client->shutdown = NULL;
client->shutdown_arg = NULL;
}
if (ISC_QLINK_LINKED(client, ilink))
ISC_QUEUE_UNLINK(client->manager->inactive, client, ilink);
client->newstate = NS_CLIENTSTATE_FREED;
client->needshutdown = false;
(void)exit_check(client);
}
static void
ns_client_endrequest(ns_client_t *client) {
INSIST(client->naccepts == 0);
INSIST(client->nreads == 0);
INSIST(client->nsends == 0);
INSIST(client->nrecvs == 0);
INSIST(client->nupdates == 0);
INSIST(client->state == NS_CLIENTSTATE_WORKING ||
client->state == NS_CLIENTSTATE_RECURSING);
CTRACE("endrequest");
if (client->next != NULL) {
(client->next)(client);
client->next = NULL;
}
if (client->view != NULL) {
#ifdef ENABLE_AFL
if (client->sctx->fuzztype == isc_fuzz_resolver) {
dns_cache_clean(client->view->cache, INT_MAX);
dns_adb_flush(client->view->adb);
}
#endif
dns_view_detach(&client->view);
}
if (client->opt != NULL) {
INSIST(dns_rdataset_isassociated(client->opt));
dns_rdataset_disassociate(client->opt);
dns_message_puttemprdataset(client->message, &client->opt);
}
client->signer = NULL;
client->udpsize = 512;
client->extflags = 0;
client->ednsversion = -1;
dns_ecs_init(&client->ecs);
dns_message_reset(client->message, DNS_MESSAGE_INTENTPARSE);
if (client->recursionquota != NULL) {
isc_quota_detach(&client->recursionquota);
ns_stats_decrement(client->sctx->nsstats,
ns_statscounter_recursclients);
}
/*
* Clear all client attributes that are specific to
* the request; that's all except the TCP flag.
*/
client->attributes &= NS_CLIENTATTR_TCP;
#ifdef ENABLE_AFL
if (client->sctx->fuzznotify != NULL &&
(client->sctx->fuzztype == isc_fuzz_client ||
client->sctx->fuzztype == isc_fuzz_tcpclient ||
client->sctx->fuzztype == isc_fuzz_resolver))
{
client->sctx->fuzznotify();
}
#endif /* ENABLE_AFL */
}
void
ns_client_next(ns_client_t *client, isc_result_t result) {
int newstate;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(client->state == NS_CLIENTSTATE_WORKING ||
client->state == NS_CLIENTSTATE_RECURSING ||
client->state == NS_CLIENTSTATE_READING);
CTRACE("next");
if (result != ISC_R_SUCCESS)
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"request failed: %s", isc_result_totext(result));
/*
* An error processing a TCP request may have left
* the connection out of sync. To be safe, we always
* sever the connection when result != ISC_R_SUCCESS.
*/
if (result == ISC_R_SUCCESS && TCP_CLIENT(client))
newstate = NS_CLIENTSTATE_READING;
else
newstate = NS_CLIENTSTATE_READY;
if (client->newstate > newstate)
client->newstate = newstate;
(void)exit_check(client);
}
static void
client_senddone(isc_task_t *task, isc_event_t *event) {
ns_client_t *client;
isc_socketevent_t *sevent = (isc_socketevent_t *) event;
REQUIRE(sevent != NULL);
REQUIRE(sevent->ev_type == ISC_SOCKEVENT_SENDDONE);
client = sevent->ev_arg;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(task == client->task);
REQUIRE(sevent == client->sendevent);
UNUSED(task);
CTRACE("senddone");
if (sevent->result != ISC_R_SUCCESS)
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_WARNING,
"error sending response: %s",
isc_result_totext(sevent->result));
INSIST(client->nsends > 0);
client->nsends--;
if (client->tcpbuf != NULL) {
INSIST(TCP_CLIENT(client));
isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE);
client->tcpbuf = NULL;
}
ns_client_next(client, ISC_R_SUCCESS);
}
/*%
* We only want to fail with ISC_R_NOSPACE when called from
* ns_client_sendraw() and not when called from ns_client_send(),
* tcpbuffer is NULL when called from ns_client_sendraw() and
* length != 0. tcpbuffer != NULL when called from ns_client_send()
* and length == 0.
*/
static isc_result_t
client_allocsendbuf(ns_client_t *client, isc_buffer_t *buffer,
isc_buffer_t *tcpbuffer, uint32_t length,
unsigned char *sendbuf, unsigned char **datap)
{
unsigned char *data;
uint32_t bufsize;
isc_result_t result;
INSIST(datap != NULL);
INSIST((tcpbuffer == NULL && length != 0) ||
(tcpbuffer != NULL && length == 0));
if (TCP_CLIENT(client)) {
INSIST(client->tcpbuf == NULL);
if (length + 2 > TCP_BUFFER_SIZE) {
result = ISC_R_NOSPACE;
goto done;
}
client->tcpbuf = isc_mem_get(client->mctx, TCP_BUFFER_SIZE);
if (client->tcpbuf == NULL) {
result = ISC_R_NOMEMORY;
goto done;
}
data = client->tcpbuf;
if (tcpbuffer != NULL) {
isc_buffer_init(tcpbuffer, data, TCP_BUFFER_SIZE);
isc_buffer_init(buffer, data + 2, TCP_BUFFER_SIZE - 2);
} else {
isc_buffer_init(buffer, data, TCP_BUFFER_SIZE);
INSIST(length <= 0xffff);
isc_buffer_putuint16(buffer, (uint16_t)length);
}
} else {
data = sendbuf;
if ((client->attributes & NS_CLIENTATTR_HAVECOOKIE) == 0) {
if (client->view != NULL)
bufsize = client->view->nocookieudp;
else
bufsize = 512;
} else
bufsize = client->udpsize;
if (bufsize > client->udpsize)
bufsize = client->udpsize;
if (bufsize > SEND_BUFFER_SIZE)
bufsize = SEND_BUFFER_SIZE;
if (length > bufsize) {
result = ISC_R_NOSPACE;
goto done;
}
isc_buffer_init(buffer, data, bufsize);
}
*datap = data;
result = ISC_R_SUCCESS;
done:
return (result);
}
static isc_result_t
client_sendpkg(ns_client_t *client, isc_buffer_t *buffer) {
struct in6_pktinfo *pktinfo;
isc_result_t result;
isc_region_t r;
isc_sockaddr_t *address;
isc_socket_t *sock;
isc_netaddr_t netaddr;
int match;
unsigned int sockflags = ISC_SOCKFLAG_IMMEDIATE;
if (TCP_CLIENT(client)) {
sock = client->tcpsocket;
address = NULL;
} else {
dns_aclenv_t *env =
ns_interfacemgr_getaclenv(client->interface->mgr);
sock = client->udpsocket;
address = &client->peeraddr;
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
if (client->sctx->blackholeacl != NULL &&
(dns_acl_match(&netaddr, NULL, client->sctx->blackholeacl,
env, &match, NULL) == ISC_R_SUCCESS) &&
match > 0)
{
return (DNS_R_BLACKHOLED);
}
sockflags |= ISC_SOCKFLAG_NORETRY;
}
if ((client->attributes & NS_CLIENTATTR_PKTINFO) != 0 &&
(client->attributes & NS_CLIENTATTR_MULTICAST) == 0)
pktinfo = &client->pktinfo;
else
pktinfo = NULL;
if (client->dispatch != NULL) {
isc_dscp_t dscp = dns_dispatch_getdscp(client->dispatch);
if (dscp != -1) {
client->dscp = dscp;
}
}
if (client->dscp == -1) {
client->sendevent->attributes &= ~ISC_SOCKEVENTATTR_DSCP;
client->sendevent->dscp = 0;
} else {
client->sendevent->attributes |= ISC_SOCKEVENTATTR_DSCP;
client->sendevent->dscp = client->dscp;
}
isc_buffer_usedregion(buffer, &r);
/*
* If this is a UDP client and the IPv6 packet can't be
* encapsulated without generating a PTB on a 1500 octet
* MTU link force fragmentation at 1280 if it is a IPv6
* response.
*/
client->sendevent->attributes &= ~ISC_SOCKEVENTATTR_USEMINMTU;
if (!TCP_CLIENT(client) && r.length > 1432)
client->sendevent->attributes |= ISC_SOCKEVENTATTR_USEMINMTU;
CTRACE("sendto");
result = isc_socket_sendto2(sock, &r, client->task,
address, pktinfo,
client->sendevent, sockflags);
if (result == ISC_R_SUCCESS || result == ISC_R_INPROGRESS) {
client->nsends++;
if (result == ISC_R_SUCCESS)
client_senddone(client->task,
(isc_event_t *)client->sendevent);
result = ISC_R_SUCCESS;
}
return (result);
}
void
ns_client_sendraw(ns_client_t *client, dns_message_t *message) {
isc_result_t result;
unsigned char *data;
isc_buffer_t buffer;
isc_region_t r;
isc_region_t *mr;
unsigned char sendbuf[SEND_BUFFER_SIZE];
REQUIRE(NS_CLIENT_VALID(client));
CTRACE("sendraw");
mr = dns_message_getrawmessage(message);
if (mr == NULL) {
result = ISC_R_UNEXPECTEDEND;
goto done;
}
result = client_allocsendbuf(client, &buffer, NULL, mr->length,
sendbuf, &data);
if (result != ISC_R_SUCCESS)
goto done;
/*
* Copy message to buffer and fixup id.
*/
isc_buffer_availableregion(&buffer, &r);
result = isc_buffer_copyregion(&buffer, mr);
if (result != ISC_R_SUCCESS)
goto done;
r.base[0] = (client->message->id >> 8) & 0xff;
r.base[1] = client->message->id & 0xff;
result = client_sendpkg(client, &buffer);
if (result == ISC_R_SUCCESS)
return;
done:
if (client->tcpbuf != NULL) {
isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE);
client->tcpbuf = NULL;
}
ns_client_next(client, result);
}
static void
client_send(ns_client_t *client) {
isc_result_t result;
unsigned char *data;
isc_buffer_t buffer;
isc_buffer_t tcpbuffer;
isc_region_t r;
dns_compress_t cctx;
bool cleanup_cctx = false;
unsigned char sendbuf[SEND_BUFFER_SIZE];
unsigned int render_opts;
unsigned int preferred_glue;
bool opt_included = false;
size_t respsize;
dns_aclenv_t *env = ns_interfacemgr_getaclenv(client->interface->mgr);
#ifdef HAVE_DNSTAP
unsigned char zone[DNS_NAME_MAXWIRE];
dns_dtmsgtype_t dtmsgtype;
isc_region_t zr;
#endif /* HAVE_DNSTAP */
REQUIRE(NS_CLIENT_VALID(client));
CTRACE("send");
if (client->message->opcode == dns_opcode_query &&
(client->attributes & NS_CLIENTATTR_RA) != 0)
client->message->flags |= DNS_MESSAGEFLAG_RA;
if ((client->attributes & NS_CLIENTATTR_WANTDNSSEC) != 0)
render_opts = 0;
else
render_opts = DNS_MESSAGERENDER_OMITDNSSEC;
preferred_glue = 0;
if (client->view != NULL) {
if (client->view->preferred_glue == dns_rdatatype_a)
preferred_glue = DNS_MESSAGERENDER_PREFER_A;
else if (client->view->preferred_glue == dns_rdatatype_aaaa)
preferred_glue = DNS_MESSAGERENDER_PREFER_AAAA;
}
if (preferred_glue == 0) {
if (isc_sockaddr_pf(&client->peeraddr) == AF_INET)
preferred_glue = DNS_MESSAGERENDER_PREFER_A;
else
preferred_glue = DNS_MESSAGERENDER_PREFER_AAAA;
}
/*
* Create an OPT for our reply.
*/
if ((client->attributes & NS_CLIENTATTR_WANTOPT) != 0) {
result = ns_client_addopt(client, client->message,
&client->opt);
if (result != ISC_R_SUCCESS)
goto done;
}
/*
* XXXRTH The following doesn't deal with TCP buffer resizing.
*/
result = client_allocsendbuf(client, &buffer, &tcpbuffer, 0,
sendbuf, &data);
if (result != ISC_R_SUCCESS)
goto done;
result = dns_compress_init(&cctx, -1, client->mctx);
if (result != ISC_R_SUCCESS)
goto done;
if (client->peeraddr_valid && client->view != NULL) {
isc_netaddr_t netaddr;
dns_name_t *name = NULL;
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
if (client->message->tsigkey != NULL)
name = &client->message->tsigkey->name;
if (client->view->nocasecompress == NULL ||
!dns_acl_allowed(&netaddr, name,
client->view->nocasecompress, env))
{
dns_compress_setsensitive(&cctx, true);
}
if (client->view->msgcompression == false) {
dns_compress_disable(&cctx);
}
}
cleanup_cctx = true;
result = dns_message_renderbegin(client->message, &cctx, &buffer);
if (result != ISC_R_SUCCESS)
goto done;
if (client->opt != NULL) {
result = dns_message_setopt(client->message, client->opt);
opt_included = true;
client->opt = NULL;
if (result != ISC_R_SUCCESS)
goto done;
}
result = dns_message_rendersection(client->message,
DNS_SECTION_QUESTION, 0);
if (result == ISC_R_NOSPACE) {
client->message->flags |= DNS_MESSAGEFLAG_TC;
goto renderend;
}
if (result != ISC_R_SUCCESS)
goto done;
/*
* Stop after the question if TC was set for rate limiting.
*/
if ((client->message->flags & DNS_MESSAGEFLAG_TC) != 0)
goto renderend;
result = dns_message_rendersection(client->message,
DNS_SECTION_ANSWER,
DNS_MESSAGERENDER_PARTIAL |
render_opts);
if (result == ISC_R_NOSPACE) {
client->message->flags |= DNS_MESSAGEFLAG_TC;
goto renderend;
}
if (result != ISC_R_SUCCESS)
goto done;
result = dns_message_rendersection(client->message,
DNS_SECTION_AUTHORITY,
DNS_MESSAGERENDER_PARTIAL |
render_opts);
if (result == ISC_R_NOSPACE) {
client->message->flags |= DNS_MESSAGEFLAG_TC;
goto renderend;
}
if (result != ISC_R_SUCCESS)
goto done;
result = dns_message_rendersection(client->message,
DNS_SECTION_ADDITIONAL,
preferred_glue | render_opts);
if (result != ISC_R_SUCCESS && result != ISC_R_NOSPACE)
goto done;
renderend:
result = dns_message_renderend(client->message);
if (result != ISC_R_SUCCESS)
goto done;
#ifdef HAVE_DNSTAP
memset(&zr, 0, sizeof(zr));
if (((client->message->flags & DNS_MESSAGEFLAG_AA) != 0) &&
(client->query.authzone != NULL))
{
isc_buffer_t b;
dns_name_t *zo =
dns_zone_getorigin(client->query.authzone);
isc_buffer_init(&b, zone, sizeof(zone));
dns_compress_setmethods(&cctx, DNS_COMPRESS_NONE);
result = dns_name_towire(zo, &cctx, &b);
if (result == ISC_R_SUCCESS)
isc_buffer_usedregion(&b, &zr);
}
if (client->message->opcode == dns_opcode_update) {
dtmsgtype = DNS_DTTYPE_UR;
} else if ((client->message->flags & DNS_MESSAGEFLAG_RD) != 0) {
dtmsgtype = DNS_DTTYPE_CR;
} else {
dtmsgtype = DNS_DTTYPE_AR;
}
#endif /* HAVE_DNSTAP */
if (cleanup_cctx) {
dns_compress_invalidate(&cctx);
cleanup_cctx = false;
}
if (client->sendcb != NULL) {
client->sendcb(&buffer);
} else if (TCP_CLIENT(client)) {
isc_buffer_usedregion(&buffer, &r);
isc_buffer_putuint16(&tcpbuffer, (uint16_t) r.length);
isc_buffer_add(&tcpbuffer, r.length);
#ifdef HAVE_DNSTAP
if (client->view != NULL) {
dns_dt_send(client->view, dtmsgtype,
&client->peeraddr, &client->destsockaddr,
true, &zr, &client->requesttime, NULL,
&buffer);
}
#endif /* HAVE_DNSTAP */
/* don't count the 2-octet length header */
respsize = isc_buffer_usedlength(&tcpbuffer) - 2;
result = client_sendpkg(client, &tcpbuffer);
switch (isc_sockaddr_pf(&client->peeraddr)) {
case AF_INET:
isc_stats_increment(client->sctx->tcpoutstats4,
ISC_MIN((int)respsize / 16, 256));
break;
case AF_INET6:
isc_stats_increment(client->sctx->tcpoutstats6,
ISC_MIN((int)respsize / 16, 256));
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
} else {
#ifdef HAVE_DNSTAP
/*
* Log dnstap data first, because client_sendpkg() may
* leave client->view set to NULL.
*/
if (client->view != NULL) {
dns_dt_send(client->view, dtmsgtype,
&client->peeraddr,
&client->destsockaddr,
false, &zr,
&client->requesttime, NULL, &buffer);
}
#endif /* HAVE_DNSTAP */
respsize = isc_buffer_usedlength(&buffer);
result = client_sendpkg(client, &buffer);
switch (isc_sockaddr_pf(&client->peeraddr)) {
case AF_INET:
isc_stats_increment(client->sctx->udpoutstats4,
ISC_MIN((int)respsize / 16, 256));
break;
case AF_INET6:
isc_stats_increment(client->sctx->udpoutstats6,
ISC_MIN((int)respsize / 16, 256));
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
}
/* update statistics (XXXJT: is it okay to access message->xxxkey?) */
ns_stats_increment(client->sctx->nsstats, ns_statscounter_response);
dns_rcodestats_increment(client->sctx->rcodestats,
client->message->rcode);
if (opt_included) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_edns0out);
}
if (client->message->tsigkey != NULL) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_tsigout);
}
if (client->message->sig0key != NULL) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_sig0out);
}
if ((client->message->flags & DNS_MESSAGEFLAG_TC) != 0)
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_truncatedresp);
if (result == ISC_R_SUCCESS)
return;
done:
if (client->tcpbuf != NULL) {
isc_mem_put(client->mctx, client->tcpbuf, TCP_BUFFER_SIZE);
client->tcpbuf = NULL;
}
if (cleanup_cctx)
dns_compress_invalidate(&cctx);
ns_client_next(client, result);
}
/*
* Completes the sending of a delayed client response.
*/
static void
client_delay(isc_task_t *task, isc_event_t *event) {
ns_client_t *client;
REQUIRE(event != NULL);
REQUIRE(event->ev_type == ISC_TIMEREVENT_LIFE ||
event->ev_type == ISC_TIMEREVENT_IDLE);
client = event->ev_arg;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(task == client->task);
REQUIRE(client->delaytimer != NULL);
UNUSED(task);
CTRACE("client_delay");
isc_event_free(&event);
isc_timer_detach(&client->delaytimer);
client_send(client);
ns_client_detach(&client);
}
void
ns_client_send(ns_client_t *client) {
/*
* Delay the response according to the -T delay option
*/
if (client->sctx->delay != 0) {
ns_client_t *dummy = NULL;
isc_result_t result;
isc_interval_t interval;
/*
* Replace ourselves if we have not already been replaced.
*/
if (!client->mortal) {
result = ns_client_replace(client);
if (result != ISC_R_SUCCESS)
goto nodelay;
}
ns_client_attach(client, &dummy);
if (client->sctx->delay >= 1000)
isc_interval_set(&interval, client->sctx->delay / 1000,
(client->sctx->delay % 1000) * 1000000);
else
isc_interval_set(&interval, 0,
client->sctx->delay * 1000000);
result = isc_timer_create(client->manager->timermgr,
isc_timertype_once, NULL, &interval,
client->task, client_delay,
client, &client->delaytimer);
if (result == ISC_R_SUCCESS)
return;
ns_client_detach(&dummy);
}
nodelay:
client_send(client);
}
#if NS_CLIENT_DROPPORT
#define DROPPORT_NO 0
#define DROPPORT_REQUEST 1
#define DROPPORT_RESPONSE 2
/*%
* ns_client_dropport determines if certain requests / responses
* should be dropped based on the port number.
*
* Returns:
* \li 0: Don't drop.
* \li 1: Drop request.
* \li 2: Drop (error) response.
*/
static int
ns_client_dropport(in_port_t port) {
switch (port) {
case 7: /* echo */
case 13: /* daytime */
case 19: /* chargen */
case 37: /* time */
return (DROPPORT_REQUEST);
case 464: /* kpasswd */
return (DROPPORT_RESPONSE);
}
return (DROPPORT_NO);
}
#endif
void
ns_client_error(ns_client_t *client, isc_result_t result) {
dns_rcode_t rcode;
dns_message_t *message;
REQUIRE(NS_CLIENT_VALID(client));
CTRACE("error");
message = client->message;
if (client->rcode_override == -1) {
rcode = dns_result_torcode(result);
} else {
rcode = (dns_rcode_t)(client->rcode_override & 0xfff);
}
#if NS_CLIENT_DROPPORT
/*
* Don't send FORMERR to ports on the drop port list.
*/
if (rcode == dns_rcode_formerr &&
ns_client_dropport(isc_sockaddr_getport(&client->peeraddr)) !=
DROPPORT_NO)
{
char buf[64];
isc_buffer_t b;
isc_buffer_init(&b, buf, sizeof(buf) - 1);
if (dns_rcode_totext(rcode, &b) != ISC_R_SUCCESS) {
isc_buffer_putstr(&b, "UNKNOWN RCODE");
}
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"dropped error (%.*s) response: suspicious port",
(int)isc_buffer_usedlength(&b), buf);
ns_client_next(client, ISC_R_SUCCESS);
return;
}
#endif
/*
* Try to rate limit error responses.
*/
if (client->view != NULL && client->view->rrl != NULL) {
bool wouldlog;
char log_buf[DNS_RRL_LOG_BUF_LEN];
dns_rrl_result_t rrl_result;
int loglevel;
INSIST(rcode != dns_rcode_noerror &&
rcode != dns_rcode_nxdomain);
if ((client->sctx->options & NS_SERVER_LOGQUERIES) != 0) {
loglevel = DNS_RRL_LOG_DROP;
} else {
loglevel = ISC_LOG_DEBUG(1);
}
wouldlog = isc_log_wouldlog(ns_lctx, loglevel);
rrl_result = dns_rrl(client->view, &client->peeraddr,
TCP_CLIENT(client),
dns_rdataclass_in, dns_rdatatype_none,
NULL, result, client->now,
wouldlog, log_buf, sizeof(log_buf));
if (rrl_result != DNS_RRL_RESULT_OK) {
/*
* Log dropped errors in the query category
* so that they are not lost in silence.
* Starts of rate-limited bursts are logged in
* NS_LOGCATEGORY_RRL.
*/
if (wouldlog) {
ns_client_log(client,
NS_LOGCATEGORY_QUERY_ERRORS,
NS_LOGMODULE_CLIENT,
loglevel,
"%s", log_buf);
}
/*
* Some error responses cannot be 'slipped',
* so don't try to slip any error responses.
*/
if (!client->view->rrl->log_only) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_ratedropped);
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_dropped);
ns_client_next(client, DNS_R_DROP);
return;
}
}
}
/*
* Message may be an in-progress reply that we had trouble
* with, in which case QR will be set. We need to clear QR before
* calling dns_message_reply() to avoid triggering an assertion.
*/
message->flags &= ~DNS_MESSAGEFLAG_QR;
/*
* AA and AD shouldn't be set.
*/
message->flags &= ~(DNS_MESSAGEFLAG_AA | DNS_MESSAGEFLAG_AD);
result = dns_message_reply(message, true);
if (result != ISC_R_SUCCESS) {
/*
* It could be that we've got a query with a good header,
* but a bad question section, so we try again with
* want_question_section set to false.
*/
result = dns_message_reply(message, false);
if (result != ISC_R_SUCCESS) {
ns_client_next(client, result);
return;
}
}
message->rcode = rcode;
if (rcode == dns_rcode_formerr) {
/*
* FORMERR loop avoidance: If we sent a FORMERR message
* with the same ID to the same client less than two
* seconds ago, assume that we are in an infinite error
* packet dialog with a server for some protocol whose
* error responses look enough like DNS queries to
* elicit a FORMERR response. Drop a packet to break
* the loop.
*/
if (isc_sockaddr_equal(&client->peeraddr,
&client->formerrcache.addr) &&
message->id == client->formerrcache.id &&
(isc_time_seconds(&client->requesttime) -
client->formerrcache.time) < 2)
{
/* Drop packet. */
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
"possible error packet loop, "
"FORMERR dropped");
ns_client_next(client, result);
return;
}
client->formerrcache.addr = client->peeraddr;
client->formerrcache.time =
isc_time_seconds(&client->requesttime);
client->formerrcache.id = message->id;
} else if (rcode == dns_rcode_servfail && client->query.qname != NULL &&
client->view != NULL && client->view->fail_ttl != 0 &&
((client->attributes & NS_CLIENTATTR_NOSETFC) == 0))
{
/*
* SERVFAIL caching: store qname/qtype of failed queries
*/
isc_time_t expire;
isc_interval_t i;
uint32_t flags = 0;
if ((message->flags & DNS_MESSAGEFLAG_CD) != 0)
flags = NS_FAILCACHE_CD;
isc_interval_set(&i, client->view->fail_ttl, 0);
result = isc_time_nowplusinterval(&expire, &i);
if (result == ISC_R_SUCCESS) {
dns_badcache_add(client->view->failcache,
client->query.qname,
client->query.qtype,
true, flags, &expire);
}
}
ns_client_send(client);
}
isc_result_t
ns_client_addopt(ns_client_t *client, dns_message_t *message,
dns_rdataset_t **opt)
{
unsigned char ecs[ECS_SIZE];
char nsid[BUFSIZ], *nsidp;
unsigned char cookie[COOKIE_SIZE];
isc_result_t result;
dns_view_t *view;
dns_resolver_t *resolver;
uint16_t udpsize;
dns_ednsopt_t ednsopts[DNS_EDNSOPTIONS];
int count = 0;
unsigned int flags;
unsigned char expire[4];
unsigned char advtimo[2];
dns_aclenv_t *env = ns_interfacemgr_getaclenv(client->interface->mgr);
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(opt != NULL && *opt == NULL);
REQUIRE(message != NULL);
view = client->view;
resolver = (view != NULL) ? view->resolver : NULL;
if (resolver != NULL)
udpsize = dns_resolver_getudpsize(resolver);
else
udpsize = client->sctx->udpsize;
flags = client->extflags & DNS_MESSAGEEXTFLAG_REPLYPRESERVE;
/* Set EDNS options if applicable */
if (WANTNSID(client)) {
if (client->sctx->server_id != NULL) {
nsidp = client->sctx->server_id;
} else if (client->sctx->gethostname != NULL) {
result = client->sctx->gethostname(nsid, sizeof(nsid));
if (result != ISC_R_SUCCESS) {
goto no_nsid;
}
nsidp = nsid;
} else {
goto no_nsid;
}
INSIST(count < DNS_EDNSOPTIONS);
ednsopts[count].code = DNS_OPT_NSID;
ednsopts[count].length = (uint16_t)strlen(nsidp);
ednsopts[count].value = (unsigned char *)nsidp;
count++;
}
no_nsid:
if ((client->attributes & NS_CLIENTATTR_WANTCOOKIE) != 0) {
isc_buffer_t buf;
isc_stdtime_t now;
uint32_t nonce;
isc_buffer_init(&buf, cookie, sizeof(cookie));
isc_stdtime_get(&now);
isc_random_buf(&nonce, sizeof(nonce));
compute_cookie(client, now, nonce, client->sctx->secret, &buf);
INSIST(count < DNS_EDNSOPTIONS);
ednsopts[count].code = DNS_OPT_COOKIE;
ednsopts[count].length = COOKIE_SIZE;
ednsopts[count].value = cookie;
count++;
}
if ((client->attributes & NS_CLIENTATTR_HAVEEXPIRE) != 0) {
isc_buffer_t buf;
INSIST(count < DNS_EDNSOPTIONS);
isc_buffer_init(&buf, expire, sizeof(expire));
isc_buffer_putuint32(&buf, client->expire);
ednsopts[count].code = DNS_OPT_EXPIRE;
ednsopts[count].length = 4;
ednsopts[count].value = expire;
count++;
}
if (((client->attributes & NS_CLIENTATTR_HAVEECS) != 0) &&
(client->ecs.addr.family == AF_INET ||
client->ecs.addr.family == AF_INET6 ||
client->ecs.addr.family == AF_UNSPEC))
{
isc_buffer_t buf;
uint8_t addr[16];
uint32_t plen, addrl;
uint16_t family = 0;
/* Add CLIENT-SUBNET option. */
plen = client->ecs.source;
/* Round up prefix len to a multiple of 8 */
addrl = (plen + 7) / 8;
switch (client->ecs.addr.family) {
case AF_UNSPEC:
INSIST(plen == 0);
family = 0;
break;
case AF_INET:
INSIST(plen <= 32);
family = 1;
memmove(addr, &client->ecs.addr.type, addrl);
break;
case AF_INET6:
INSIST(plen <= 128);
family = 2;
memmove(addr, &client->ecs.addr.type, addrl);
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
isc_buffer_init(&buf, ecs, sizeof(ecs));
/* family */
isc_buffer_putuint16(&buf, family);
/* source prefix-length */
isc_buffer_putuint8(&buf, client->ecs.source);
/* scope prefix-length */
isc_buffer_putuint8(&buf, client->ecs.scope);
/* address */
if (addrl > 0) {
/* Mask off last address byte */
if ((plen % 8) != 0)
addr[addrl - 1] &=
~0U << (8 - (plen % 8));
isc_buffer_putmem(&buf, addr,
(unsigned) addrl);
}
ednsopts[count].code = DNS_OPT_CLIENT_SUBNET;
ednsopts[count].length = addrl + 4;
ednsopts[count].value = ecs;
count++;
}
if (TCP_CLIENT(client) && USEKEEPALIVE(client)) {
isc_buffer_t buf;
INSIST(count < DNS_EDNSOPTIONS);
isc_buffer_init(&buf, advtimo, sizeof(advtimo));
isc_buffer_putuint16(&buf,
(uint16_t) client->sctx->advertisedtimo);
ednsopts[count].code = DNS_OPT_TCP_KEEPALIVE;
ednsopts[count].length = 2;
ednsopts[count].value = advtimo;
count++;
}
/* Padding must be added last */
if ((view != NULL) && (view->padding > 0) && WANTPAD(client) &&
(TCP_CLIENT(client) ||
((client->attributes & NS_CLIENTATTR_HAVECOOKIE) != 0)))
{
isc_netaddr_t netaddr;
int match;
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
result = dns_acl_match(&netaddr, NULL, view->pad_acl,
env, &match, NULL);
if (result == ISC_R_SUCCESS && match > 0) {
INSIST(count < DNS_EDNSOPTIONS);
ednsopts[count].code = DNS_OPT_PAD;
ednsopts[count].length = 0;
ednsopts[count].value = NULL;
count++;
dns_message_setpadding(message, view->padding);
}
}
result = dns_message_buildopt(message, opt, 0, udpsize, flags,
ednsopts, count);
return (result);
}
static void
compute_cookie(ns_client_t *client, uint32_t when, uint32_t nonce,
const unsigned char *secret, isc_buffer_t *buf)
{
unsigned char digest[ISC_MAX_MD_SIZE] ISC_NONSTRING = { 0 };
STATIC_ASSERT(ISC_MAX_MD_SIZE >= ISC_SIPHASH24_TAG_LENGTH,
"You need to increase the digest buffer.");
STATIC_ASSERT(ISC_MAX_MD_SIZE >= ISC_AES_BLOCK_LENGTH,
"You need to increase the digest buffer.");
switch (client->sctx->cookiealg) {
case ns_cookiealg_siphash24: {
unsigned char input[16 + 16] ISC_NONSTRING = { 0 };
size_t inputlen = 0;
isc_netaddr_t netaddr;
unsigned char *cp;
cp = isc_buffer_used(buf);
isc_buffer_putmem(buf, client->cookie, 8);
isc_buffer_putuint8(buf, NS_COOKIE_VERSION_1);
isc_buffer_putuint24(buf, 0); /* Reserved */
isc_buffer_putuint32(buf, when);
memmove(input, cp, 16);
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
switch (netaddr.family) {
case AF_INET:
cp = (unsigned char *)&netaddr.type.in;
memmove(input + 16, cp, 4);
inputlen = 20;
break;
case AF_INET6:
cp = (unsigned char *)&netaddr.type.in6;
memmove(input + 16, cp, 16);
inputlen = 32;
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
isc_siphash24(secret, input, inputlen, digest);
isc_buffer_putmem(buf, digest, 8);
break;
}
case ns_cookiealg_aes: {
unsigned char input[4 + 4 + 16] ISC_NONSTRING = { 0 };
isc_netaddr_t netaddr;
unsigned char *cp;
unsigned int i;
cp = isc_buffer_used(buf);
isc_buffer_putmem(buf, client->cookie, 8);
isc_buffer_putuint32(buf, nonce);
isc_buffer_putuint32(buf, when);
memmove(input, cp, 16);
isc_aes128_crypt(secret, input, digest);
for (i = 0; i < 8; i++) {
input[i] = digest[i] ^ digest[i + 8];
}
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
switch (netaddr.family) {
case AF_INET:
cp = (unsigned char *)&netaddr.type.in;
memmove(input + 8, cp, 4);
memset(input + 12, 0, 4);
isc_aes128_crypt(secret, input, digest);
break;
case AF_INET6:
cp = (unsigned char *)&netaddr.type.in6;
memmove(input + 8, cp, 16);
isc_aes128_crypt(secret, input, digest);
for (i = 0; i < 8; i++) {
input[i + 8] = digest[i] ^ digest[i + 8];
}
isc_aes128_crypt(client->sctx->secret, input + 8,
digest);
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
for (i = 0; i < 8; i++) {
digest[i] ^= digest[i + 8];
}
isc_buffer_putmem(buf, digest, 8);
break;
}
case ns_cookiealg_sha1:
case ns_cookiealg_sha256: {
unsigned char input[8 + 4 + 4 + 16];
isc_netaddr_t netaddr;
unsigned char *cp;
unsigned int length = 0;
isc_md_type_t md_type =
(client->sctx->cookiealg == ns_cookiealg_sha1)
? ISC_MD_SHA1
: ISC_MD_SHA256;
unsigned int secret_len = isc_md_type_get_size(md_type);
cp = isc_buffer_used(buf);
isc_buffer_putmem(buf, client->cookie, 8);
isc_buffer_putuint32(buf, nonce);
isc_buffer_putuint32(buf, when);
memmove(input, cp, 16);
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
switch (netaddr.family) {
case AF_INET:
memmove(input + 16,
(unsigned char *)&netaddr.type.in, 4);
length = 16 + 4;
break;
case AF_INET6:
memmove(input + 16,
(unsigned char *)&netaddr.type.in6, 16);
length = 16 + 16;
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
/*
* XXXOND: Feels wrong to assert on cookie calculation failure
*/
RUNTIME_CHECK(isc_hmac(md_type, secret, secret_len,
input, length,
digest, NULL) == ISC_R_SUCCESS);
isc_buffer_putmem(buf, digest, 8);
break;
}
default:
INSIST(0);
ISC_UNREACHABLE();
}
}
static void
process_cookie(ns_client_t *client, isc_buffer_t *buf, size_t optlen) {
ns_altsecret_t *altsecret;
unsigned char dbuf[COOKIE_SIZE];
unsigned char *old;
isc_stdtime_t now;
uint32_t when;
uint32_t nonce;
isc_buffer_t db;
/*
* If we have already seen a cookie option skip this cookie option.
*/
if ((!client->sctx->answercookie) ||
(client->attributes & NS_CLIENTATTR_WANTCOOKIE) != 0)
{
isc_buffer_forward(buf, (unsigned int)optlen);
return;
}
client->attributes |= NS_CLIENTATTR_WANTCOOKIE;
ns_stats_increment(client->sctx->nsstats, ns_statscounter_cookiein);
if (optlen != COOKIE_SIZE) {
/*
* Not our token.
*/
INSIST(optlen >= 8U);
memmove(client->cookie, isc_buffer_current(buf), 8);
isc_buffer_forward(buf, (unsigned int)optlen);
if (optlen == 8U)
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_cookienew);
else
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_cookiebadsize);
return;
}
/*
* Process all of the incoming buffer.
*/
old = isc_buffer_current(buf);
memmove(client->cookie, old, 8);
isc_buffer_forward(buf, 8);
nonce = isc_buffer_getuint32(buf);
when = isc_buffer_getuint32(buf);
isc_buffer_forward(buf, 8);
/*
* Allow for a 5 minute clock skew between servers sharing a secret.
* Only accept COOKIE if we have talked to the client in the last hour.
*/
isc_stdtime_get(&now);
if (isc_serial_gt(when, (now + 300)) || /* In the future. */
isc_serial_lt(when, (now - 3600))) { /* In the past. */
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_cookiebadtime);
return;
}
isc_buffer_init(&db, dbuf, sizeof(dbuf));
compute_cookie(client, when, nonce, client->sctx->secret, &db);
if (isc_safe_memequal(old, dbuf, COOKIE_SIZE)) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_cookiematch);
client->attributes |= NS_CLIENTATTR_HAVECOOKIE;
return;
}
for (altsecret = ISC_LIST_HEAD(client->sctx->altsecrets);
altsecret != NULL;
altsecret = ISC_LIST_NEXT(altsecret, link))
{
isc_buffer_init(&db, dbuf, sizeof(dbuf));
compute_cookie(client, when, nonce, altsecret->secret, &db);
if (isc_safe_memequal(old, dbuf, COOKIE_SIZE)) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_cookiematch);
client->attributes |= NS_CLIENTATTR_HAVECOOKIE;
return;
}
}
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_cookienomatch);
}
static isc_result_t
process_ecs(ns_client_t *client, isc_buffer_t *buf, size_t optlen) {
uint16_t family;
uint8_t addrlen, addrbytes, scope, *paddr;
isc_netaddr_t caddr;
/*
* If we have already seen a ECS option skip this ECS option.
*/
if ((client->attributes & NS_CLIENTATTR_HAVEECS) != 0) {
isc_buffer_forward(buf, (unsigned int)optlen);
return (ISC_R_SUCCESS);
}
/*
* XXXMUKS: Is there any need to repeat these checks here
* (except query's scope length) when they are done in the OPT
* RDATA fromwire code?
*/
if (optlen < 4U) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
"EDNS client-subnet option too short");
return (DNS_R_FORMERR);
}
family = isc_buffer_getuint16(buf);
addrlen = isc_buffer_getuint8(buf);
scope = isc_buffer_getuint8(buf);
optlen -= 4;
if (scope != 0U) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
"EDNS client-subnet option: invalid scope");
return (DNS_R_OPTERR);
}
memset(&caddr, 0, sizeof(caddr));
switch (family) {
case 0:
/*
* XXXMUKS: In queries, if FAMILY is set to 0, SOURCE
* PREFIX-LENGTH must be 0 and ADDRESS should not be
* present as the address and prefix lengths don't make
* sense because the family is unknown.
*/
if (addrlen != 0U) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
"EDNS client-subnet option: invalid "
"address length (%u) for FAMILY=0",
addrlen);
return (DNS_R_OPTERR);
}
caddr.family = AF_UNSPEC;
break;
case 1:
if (addrlen > 32U) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
"EDNS client-subnet option: invalid "
"address length (%u) for IPv4",
addrlen);
return (DNS_R_OPTERR);
}
caddr.family = AF_INET;
break;
case 2:
if (addrlen > 128U) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
"EDNS client-subnet option: invalid "
"address length (%u) for IPv6",
addrlen);
return (DNS_R_OPTERR);
}
caddr.family = AF_INET6;
break;
default:
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
"EDNS client-subnet option: invalid family");
return (DNS_R_OPTERR);
}
addrbytes = (addrlen + 7) / 8;
if (isc_buffer_remaininglength(buf) < addrbytes) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
"EDNS client-subnet option: address too short");
return (DNS_R_OPTERR);
}
paddr = (uint8_t *) &caddr.type;
if (addrbytes != 0U) {
memmove(paddr, isc_buffer_current(buf), addrbytes);
isc_buffer_forward(buf, addrbytes);
optlen -= addrbytes;
if ((addrlen % 8) != 0) {
uint8_t bits = ~0U << (8 - (addrlen % 8));
bits &= paddr[addrbytes - 1];
if (bits != paddr[addrbytes - 1])
return (DNS_R_OPTERR);
}
}
memmove(&client->ecs.addr, &caddr, sizeof(caddr));
client->ecs.source = addrlen;
client->ecs.scope = 0;
client->attributes |= NS_CLIENTATTR_HAVEECS;
isc_buffer_forward(buf, (unsigned int)optlen);
return (ISC_R_SUCCESS);
}
static isc_result_t
process_keytag(ns_client_t *client, isc_buffer_t *buf, size_t optlen) {
if (optlen == 0 || (optlen % 2) != 0) {
isc_buffer_forward(buf, (unsigned int)optlen);
return (DNS_R_OPTERR);
}
/* Silently drop additional keytag options. */
if (client->keytag != NULL) {
isc_buffer_forward(buf, (unsigned int)optlen);
return (ISC_R_SUCCESS);
}
client->keytag = isc_mem_get(client->mctx, optlen);
if (client->keytag != NULL) {
client->keytag_len = (uint16_t)optlen;
memmove(client->keytag, isc_buffer_current(buf), optlen);
}
isc_buffer_forward(buf, (unsigned int)optlen);
return (ISC_R_SUCCESS);
}
static isc_result_t
process_opt(ns_client_t *client, dns_rdataset_t *opt) {
dns_rdata_t rdata;
isc_buffer_t optbuf;
isc_result_t result;
uint16_t optcode;
uint16_t optlen;
/*
* Set the client's UDP buffer size.
*/
client->udpsize = opt->rdclass;
/*
* If the requested UDP buffer size is less than 512,
* ignore it and use 512.
*/
if (client->udpsize < 512)
client->udpsize = 512;
/*
* Get the flags out of the OPT record.
*/
client->extflags = (uint16_t)(opt->ttl & 0xFFFF);
/*
* Do we understand this version of EDNS?
*
* XXXRTH need library support for this!
*/
client->ednsversion = (opt->ttl & 0x00FF0000) >> 16;
if (client->ednsversion > DNS_EDNS_VERSION) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_badednsver);
result = ns_client_addopt(client, client->message,
&client->opt);
if (result == ISC_R_SUCCESS)
result = DNS_R_BADVERS;
ns_client_error(client, result);
return (result);
}
/* Check for NSID request */
result = dns_rdataset_first(opt);
if (result == ISC_R_SUCCESS) {
dns_rdata_init(&rdata);
dns_rdataset_current(opt, &rdata);
isc_buffer_init(&optbuf, rdata.data, rdata.length);
isc_buffer_add(&optbuf, rdata.length);
while (isc_buffer_remaininglength(&optbuf) >= 4) {
optcode = isc_buffer_getuint16(&optbuf);
optlen = isc_buffer_getuint16(&optbuf);
switch (optcode) {
case DNS_OPT_NSID:
if (!WANTNSID(client))
ns_stats_increment(
client->sctx->nsstats,
ns_statscounter_nsidopt);
client->attributes |= NS_CLIENTATTR_WANTNSID;
isc_buffer_forward(&optbuf, optlen);
break;
case DNS_OPT_COOKIE:
process_cookie(client, &optbuf, optlen);
break;
case DNS_OPT_EXPIRE:
if (!WANTEXPIRE(client))
ns_stats_increment(
client->sctx->nsstats,
ns_statscounter_expireopt);
client->attributes |= NS_CLIENTATTR_WANTEXPIRE;
isc_buffer_forward(&optbuf, optlen);
break;
case DNS_OPT_CLIENT_SUBNET:
result = process_ecs(client, &optbuf, optlen);
if (result != ISC_R_SUCCESS) {
ns_client_error(client, result);
return (result);
}
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_ecsopt);
break;
case DNS_OPT_TCP_KEEPALIVE:
if (!USEKEEPALIVE(client))
ns_stats_increment(
client->sctx->nsstats,
ns_statscounter_keepaliveopt);
client->attributes |=
NS_CLIENTATTR_USEKEEPALIVE;
isc_buffer_forward(&optbuf, optlen);
break;
case DNS_OPT_PAD:
client->attributes |= NS_CLIENTATTR_WANTPAD;
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_padopt);
isc_buffer_forward(&optbuf, optlen);
break;
case DNS_OPT_KEY_TAG:
result = process_keytag(client, &optbuf,
optlen);
if (result != ISC_R_SUCCESS) {
ns_client_error(client, result);
return (result);
}
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_keytagopt);
break;
default:
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_otheropt);
isc_buffer_forward(&optbuf, optlen);
break;
}
}
}
ns_stats_increment(client->sctx->nsstats, ns_statscounter_edns0in);
client->attributes |= NS_CLIENTATTR_WANTOPT;
return (result);
}
/*
* Handle an incoming request event from the socket (UDP case)
* or tcpmsg (TCP case).
*/
void
ns__client_request(isc_task_t *task, isc_event_t *event) {
ns_client_t *client;
isc_socketevent_t *sevent;
isc_result_t result;
isc_result_t sigresult = ISC_R_SUCCESS;
isc_buffer_t *buffer;
isc_buffer_t tbuffer;
dns_rdataset_t *opt;
const dns_name_t *signame;
bool ra; /* Recursion available. */
isc_netaddr_t netaddr;
int match;
dns_messageid_t id;
unsigned int flags;
bool notimp;
size_t reqsize;
dns_aclenv_t *env;
#ifdef HAVE_DNSTAP
dns_dtmsgtype_t dtmsgtype;
#endif
REQUIRE(event != NULL);
client = event->ev_arg;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(task == client->task);
INSIST(client->recursionquota == NULL);
INSIST(client->state == (TCP_CLIENT(client) ?
NS_CLIENTSTATE_READING :
NS_CLIENTSTATE_READY));
ns_client_requests++;
if (event->ev_type == ISC_SOCKEVENT_RECVDONE) {
INSIST(!TCP_CLIENT(client));
sevent = (isc_socketevent_t *)event;
REQUIRE(sevent == client->recvevent);
isc_buffer_init(&tbuffer, sevent->region.base, sevent->n);
isc_buffer_add(&tbuffer, sevent->n);
buffer = &tbuffer;
result = sevent->result;
if (result == ISC_R_SUCCESS) {
client->peeraddr = sevent->address;
client->peeraddr_valid = true;
}
if ((sevent->attributes & ISC_SOCKEVENTATTR_DSCP) != 0) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(90),
"received DSCP %d", sevent->dscp);
if (client->dscp == -1)
client->dscp = sevent->dscp;
}
if ((sevent->attributes & ISC_SOCKEVENTATTR_PKTINFO) != 0) {
client->attributes |= NS_CLIENTATTR_PKTINFO;
client->pktinfo = sevent->pktinfo;
}
if ((sevent->attributes & ISC_SOCKEVENTATTR_MULTICAST) != 0)
client->attributes |= NS_CLIENTATTR_MULTICAST;
client->nrecvs--;
} else {
INSIST(TCP_CLIENT(client));
INSIST(client->tcpconn != NULL);
REQUIRE(event->ev_type == DNS_EVENT_TCPMSG);
REQUIRE(event->ev_sender == &client->tcpmsg);
buffer = &client->tcpmsg.buffer;
result = client->tcpmsg.result;
INSIST(client->nreads == 1);
/*
* client->peeraddr was set when the connection was accepted.
*/
client->nreads--;
}
reqsize = isc_buffer_usedlength(buffer);
/* don't count the length header */
if (TCP_CLIENT(client))
reqsize -= 2;
if (exit_check(client)) {
return;
}
client->state = client->newstate = NS_CLIENTSTATE_WORKING;
isc_task_getcurrenttimex(task, &client->requesttime);
client->tnow = client->requesttime;
client->now = isc_time_seconds(&client->tnow);
if (result != ISC_R_SUCCESS) {
if (TCP_CLIENT(client)) {
ns_client_next(client, result);
} else {
if (result != ISC_R_CANCELED)
isc_log_write(ns_lctx, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT,
ISC_LOG_ERROR,
"UDP client handler shutting "
"down due to fatal receive "
"error: %s",
isc_result_totext(result));
isc_task_shutdown(client->task);
}
return;
}
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
#if NS_CLIENT_DROPPORT
if (ns_client_dropport(isc_sockaddr_getport(&client->peeraddr)) ==
DROPPORT_REQUEST) {
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"dropped request: suspicious port");
ns_client_next(client, ISC_R_SUCCESS);
return;
}
#endif
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"%s request",
TCP_CLIENT(client) ? "TCP" : "UDP");
/*
* Check the blackhole ACL for UDP only, since TCP is done in
* client_newconn.
*/
env = ns_interfacemgr_getaclenv(client->interface->mgr);
if (!TCP_CLIENT(client)) {
if (client->sctx->blackholeacl != NULL &&
(dns_acl_match(&netaddr, NULL, client->sctx->blackholeacl,
env, &match, NULL) == ISC_R_SUCCESS) &&
match > 0)
{
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"blackholed UDP datagram");
ns_client_next(client, ISC_R_SUCCESS);
return;
}
}
/*
* Silently drop multicast requests for the present.
* XXXMPA revisit this as mDNS spec was published.
*/
if ((client->attributes & NS_CLIENTATTR_MULTICAST) != 0) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(2),
"dropping multicast request");
ns_client_next(client, DNS_R_REFUSED);
return;
}
result = dns_message_peekheader(buffer, &id, &flags);
if (result != ISC_R_SUCCESS) {
/*
* There isn't enough header to determine whether
* this was a request or a response. Drop it.
*/
ns_client_next(client, result);
return;
}
/*
* The client object handles requests, not responses.
* If this is a UDP response, forward it to the dispatcher.
* If it's a TCP response, discard it here.
*/
if ((flags & DNS_MESSAGEFLAG_QR) != 0) {
if (TCP_CLIENT(client)) {
CTRACE("unexpected response");
ns_client_next(client, DNS_R_FORMERR);
return;
} else {
dns_dispatch_importrecv(client->dispatch, event);
ns_client_next(client, ISC_R_SUCCESS);
return;
}
}
/*
* Update some statistics counters. Don't count responses.
*/
if (isc_sockaddr_pf(&client->peeraddr) == PF_INET) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_requestv4);
} else {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_requestv6);
}
if (TCP_CLIENT(client)) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_requesttcp);
switch (isc_sockaddr_pf(&client->peeraddr)) {
case AF_INET:
isc_stats_increment(client->sctx->tcpinstats4,
ISC_MIN((int)reqsize / 16, 18));
break;
case AF_INET6:
isc_stats_increment(client->sctx->tcpinstats6,
ISC_MIN((int)reqsize / 16, 18));
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
} else {
switch (isc_sockaddr_pf(&client->peeraddr)) {
case AF_INET:
isc_stats_increment(client->sctx->udpinstats4,
ISC_MIN((int)reqsize / 16, 18));
break;
case AF_INET6:
isc_stats_increment(client->sctx->udpinstats6,
ISC_MIN((int)reqsize / 16, 18));
break;
default:
INSIST(0);
ISC_UNREACHABLE();
}
}
/*
* It's a request. Parse it.
*/
result = dns_message_parse(client->message, buffer, 0);
if (result != ISC_R_SUCCESS) {
/*
* Parsing the request failed. Send a response
* (typically FORMERR or SERVFAIL).
*/
if (result == DNS_R_OPTERR) {
(void)ns_client_addopt(client, client->message,
&client->opt);
}
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
"message parsing failed: %s",
isc_result_totext(result));
if (result == ISC_R_NOSPACE) {
result = DNS_R_FORMERR;
}
ns_client_error(client, result);
return;
}
/*
* Pipeline TCP query processing.
*/
if (TCP_CLIENT(client) &&
client->message->opcode != dns_opcode_query)
{
client->tcpconn->pipelined = false;
}
if (TCP_CLIENT(client) && client->tcpconn->pipelined) {
/*
* We're pipelining. Replace the client; the
* replacement can read the TCP socket looking
* for new messages and this one can process the
* current message asynchronously.
*
* There will now be at least three clients using this
* TCP socket - one accepting new connections,
* one reading an existing connection to get new
* messages, and one answering the message already
* received.
*/
result = ns_client_replace(client);
if (result != ISC_R_SUCCESS) {
client->tcpconn->pipelined = false;
}
}
dns_opcodestats_increment(client->sctx->opcodestats,
client->message->opcode);
switch (client->message->opcode) {
case dns_opcode_query:
case dns_opcode_update:
case dns_opcode_notify:
notimp = false;
break;
case dns_opcode_iquery:
default:
notimp = true;
break;
}
client->message->rcode = dns_rcode_noerror;
/* RFC1123 section 6.1.3.2 */
if ((client->attributes & NS_CLIENTATTR_MULTICAST) != 0)
client->message->flags &= ~DNS_MESSAGEFLAG_RD;
/*
* Deal with EDNS.
*/
if ((client->sctx->options & NS_SERVER_NOEDNS) != 0)
opt = NULL;
else
opt = dns_message_getopt(client->message);
client->ecs.source = 0;
client->ecs.scope = 0;
if (opt != NULL) {
/*
* Are returning FORMERR to all EDNS queries?
* Simulate a STD13 compliant server.
*/
if ((client->sctx->options & NS_SERVER_EDNSFORMERR) != 0) {
ns_client_error(client, DNS_R_FORMERR);
return;
}
/*
* Are returning NOTIMP to all EDNS queries?
*/
if ((client->sctx->options & NS_SERVER_EDNSNOTIMP) != 0) {
ns_client_error(client, DNS_R_NOTIMP);
return;
}
/*
* Are returning REFUSED to all EDNS queries?
*/
if ((client->sctx->options & NS_SERVER_EDNSREFUSED) != 0) {
ns_client_error(client, DNS_R_REFUSED);
return;
}
/*
* Are we dropping all EDNS queries?
*/
if ((client->sctx->options & NS_SERVER_DROPEDNS) != 0) {
ns_client_next(client, ISC_R_SUCCESS);
return;
}
result = process_opt(client, opt);
if (result != ISC_R_SUCCESS)
return;
}
if (client->message->rdclass == 0) {
if ((client->attributes & NS_CLIENTATTR_WANTCOOKIE) != 0 &&
client->message->opcode == dns_opcode_query &&
client->message->counts[DNS_SECTION_QUESTION] == 0U)
{
result = dns_message_reply(client->message, true);
if (result != ISC_R_SUCCESS) {
ns_client_error(client, result);
return;
}
if (notimp)
client->message->rcode = dns_rcode_notimp;
ns_client_send(client);
return;
}
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
"message class could not be determined");
ns_client_dumpmessage(client,
"message class could not be determined");
ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_FORMERR);
return;
}
/*
* Determine the destination address. If the receiving interface is
* bound to a specific address, we simply use it regardless of the
* address family. All IPv4 queries should fall into this case.
* Otherwise, if this is a TCP query, get the address from the
* receiving socket (this needs a system call and can be heavy).
* For IPv6 UDP queries, we get this from the pktinfo structure (if
* supported).
* If all the attempts fail (this can happen due to memory shortage,
* etc), we regard this as an error for safety.
*/
if ((client->interface->flags & NS_INTERFACEFLAG_ANYADDR) == 0)
isc_netaddr_fromsockaddr(&client->destaddr,
&client->interface->addr);
else {
isc_sockaddr_t sockaddr;
result = ISC_R_FAILURE;
if (TCP_CLIENT(client))
result = isc_socket_getsockname(client->tcpsocket,
&sockaddr);
if (result == ISC_R_SUCCESS)
isc_netaddr_fromsockaddr(&client->destaddr, &sockaddr);
if (result != ISC_R_SUCCESS &&
client->interface->addr.type.sa.sa_family == AF_INET6 &&
(client->attributes & NS_CLIENTATTR_PKTINFO) != 0) {
/*
* XXXJT technically, we should convert the receiving
* interface ID to a proper scope zone ID. However,
* due to the fact there is no standard API for this,
* we only handle link-local addresses and use the
* interface index as link ID. Despite the assumption,
* it should cover most typical cases.
*/
isc_netaddr_fromin6(&client->destaddr,
&client->pktinfo.ipi6_addr);
if (IN6_IS_ADDR_LINKLOCAL(&client->pktinfo.ipi6_addr))
isc_netaddr_setzone(&client->destaddr,
client->pktinfo.ipi6_ifindex);
result = ISC_R_SUCCESS;
}
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"failed to get request's "
"destination: %s",
isc_result_totext(result));
ns_client_next(client, ISC_R_SUCCESS);
return;
}
}
isc_sockaddr_fromnetaddr(&client->destsockaddr, &client->destaddr, 0);
result = client->sctx->matchingview(&netaddr, &client->destaddr,
client->message, env,
&sigresult, &client->view);
if (result != ISC_R_SUCCESS) {
char classname[DNS_RDATACLASS_FORMATSIZE];
/*
* Do a dummy TSIG verification attempt so that the
* response will have a TSIG if the query did, as
* required by RFC2845.
*/
isc_buffer_t b;
isc_region_t *r;
dns_message_resetsig(client->message);
r = dns_message_getrawmessage(client->message);
isc_buffer_init(&b, r->base, r->length);
isc_buffer_add(&b, r->length);
(void)dns_tsig_verify(&b, client->message, NULL, NULL);
dns_rdataclass_format(client->message->rdclass, classname,
sizeof(classname));
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
"no matching view in class '%s'", classname);
ns_client_dumpmessage(client, "no matching view in class");
ns_client_error(client, notimp ? DNS_R_NOTIMP : DNS_R_REFUSED);
return;
}
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(5),
"using view '%s'", client->view->name);
/*
* Check for a signature. We log bad signatures regardless of
* whether they ultimately cause the request to be rejected or
* not. We do not log the lack of a signature unless we are
* debugging.
*/
client->signer = NULL;
dns_name_init(&client->signername, NULL);
result = dns_message_signer(client->message, &client->signername);
if (result != ISC_R_NOTFOUND) {
signame = NULL;
if (dns_message_gettsig(client->message, &signame) != NULL) {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_tsigin);
} else {
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_sig0in);
}
}
if (result == ISC_R_SUCCESS) {
char namebuf[DNS_NAME_FORMATSIZE];
dns_name_format(&client->signername, namebuf, sizeof(namebuf));
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"request has valid signature: %s", namebuf);
client->signer = &client->signername;
} else if (result == ISC_R_NOTFOUND) {
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"request is not signed");
} else if (result == DNS_R_NOIDENTITY) {
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"request is signed by a nonauthoritative key");
} else {
char tsigrcode[64];
isc_buffer_t b;
dns_rcode_t status;
isc_result_t tresult;
/* There is a signature, but it is bad. */
ns_stats_increment(client->sctx->nsstats,
ns_statscounter_invalidsig);
signame = NULL;
if (dns_message_gettsig(client->message, &signame) != NULL) {
char namebuf[DNS_NAME_FORMATSIZE];
char cnamebuf[DNS_NAME_FORMATSIZE];
dns_name_format(signame, namebuf, sizeof(namebuf));
status = client->message->tsigstatus;
isc_buffer_init(&b, tsigrcode, sizeof(tsigrcode) - 1);
tresult = dns_tsigrcode_totext(status, &b);
INSIST(tresult == ISC_R_SUCCESS);
tsigrcode[isc_buffer_usedlength(&b)] = '\0';
if (client->message->tsigkey->generated) {
dns_name_format(client->message->tsigkey->creator,
cnamebuf, sizeof(cnamebuf));
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT,
ISC_LOG_ERROR,
"request has invalid signature: "
"TSIG %s (%s): %s (%s)", namebuf,
cnamebuf,
isc_result_totext(result),
tsigrcode);
} else {
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT,
ISC_LOG_ERROR,
"request has invalid signature: "
"TSIG %s: %s (%s)", namebuf,
isc_result_totext(result),
tsigrcode);
}
} else {
status = client->message->sig0status;
isc_buffer_init(&b, tsigrcode, sizeof(tsigrcode) - 1);
tresult = dns_tsigrcode_totext(status, &b);
INSIST(tresult == ISC_R_SUCCESS);
tsigrcode[isc_buffer_usedlength(&b)] = '\0';
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_ERROR,
"request has invalid signature: %s (%s)",
isc_result_totext(result), tsigrcode);
}
/*
* Accept update messages signed by unknown keys so that
* update forwarding works transparently through slaves
* that don't have all the same keys as the master.
*/
if (!(client->message->tsigstatus == dns_tsigerror_badkey &&
client->message->opcode == dns_opcode_update)) {
ns_client_error(client, sigresult);
return;
}
}
/*
* Decide whether recursive service is available to this client.
* We do this here rather than in the query code so that we can
* set the RA bit correctly on all kinds of responses, not just
* responses to ordinary queries. Note if you can't query the
* cache there is no point in setting RA.
*/
ra = false;
if (client->view->resolver != NULL &&
client->view->recursion == true &&
ns_client_checkaclsilent(client, NULL,
client->view->recursionacl,
true) == ISC_R_SUCCESS &&
ns_client_checkaclsilent(client, NULL,
client->view->cacheacl,
true) == ISC_R_SUCCESS &&
ns_client_checkaclsilent(client, &client->destaddr,
client->view->recursiononacl,
true) == ISC_R_SUCCESS &&
ns_client_checkaclsilent(client, &client->destaddr,
client->view->cacheonacl,
true) == ISC_R_SUCCESS)
ra = true;
if (ra == true) {
client->attributes |= NS_CLIENTATTR_RA;
}
ns_client_log(client, DNS_LOGCATEGORY_SECURITY, NS_LOGMODULE_CLIENT,
ISC_LOG_DEBUG(3), ra ? "recursion available" :
"recursion not available");
/*
* Adjust maximum UDP response size for this client.
*/
if (client->udpsize > 512) {
dns_peer_t *peer = NULL;
uint16_t udpsize = client->view->maxudp;
(void) dns_peerlist_peerbyaddr(client->view->peers,
&netaddr, &peer);
if (peer != NULL)
dns_peer_getmaxudp(peer, &udpsize);
if (client->udpsize > udpsize)
client->udpsize = udpsize;
}
/*
* Dispatch the request.
*/
switch (client->message->opcode) {
case dns_opcode_query:
CTRACE("query");
#ifdef HAVE_DNSTAP
if (ra && (client->message->flags & DNS_MESSAGEFLAG_RD) != 0) {
dtmsgtype = DNS_DTTYPE_CQ;
} else {
dtmsgtype = DNS_DTTYPE_AQ;
}
dns_dt_send(client->view, dtmsgtype, &client->peeraddr,
&client->destsockaddr, TCP_CLIENT(client), NULL,
&client->requesttime, NULL, buffer);
#endif /* HAVE_DNSTAP */
ns_query_start(client);
break;
case dns_opcode_update:
CTRACE("update");
#ifdef HAVE_DNSTAP
dns_dt_send(client->view, DNS_DTTYPE_UQ, &client->peeraddr,
&client->destsockaddr, TCP_CLIENT(client), NULL,
&client->requesttime, NULL, buffer);
#endif /* HAVE_DNSTAP */
ns_client_settimeout(client, 60);
ns_update_start(client, sigresult);
break;
case dns_opcode_notify:
CTRACE("notify");
ns_client_settimeout(client, 60);
ns_notify_start(client);
break;
case dns_opcode_iquery:
CTRACE("iquery");
ns_client_error(client, DNS_R_NOTIMP);
break;
default:
CTRACE("unknown opcode");
ns_client_error(client, DNS_R_NOTIMP);
}
}
static void
client_timeout(isc_task_t *task, isc_event_t *event) {
ns_client_t *client;
REQUIRE(event != NULL);
REQUIRE(event->ev_type == ISC_TIMEREVENT_LIFE ||
event->ev_type == ISC_TIMEREVENT_IDLE);
client = event->ev_arg;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(task == client->task);
REQUIRE(client->timer != NULL);
UNUSED(task);
CTRACE("timeout");
isc_event_free(&event);
if (client->shutdown != NULL) {
(client->shutdown)(client->shutdown_arg, ISC_R_TIMEDOUT);
client->shutdown = NULL;
client->shutdown_arg = NULL;
}
if (client->newstate > NS_CLIENTSTATE_READY)
client->newstate = NS_CLIENTSTATE_READY;
(void)exit_check(client);
}
static isc_result_t
get_clientmctx(ns_clientmgr_t *manager, isc_mem_t **mctxp) {
isc_mem_t *clientmctx;
isc_result_t result;
#if NMCTXS > 0
unsigned int nextmctx;
#endif
MTRACE("clientmctx");
/*
* Caller must be holding the manager lock.
*/
if ((manager->sctx->options & NS_SERVER_CLIENTTEST) != 0) {
result = isc_mem_create(0, 0, mctxp);
if (result == ISC_R_SUCCESS)
isc_mem_setname(*mctxp, "client", NULL);
return (result);
}
#if NMCTXS > 0
nextmctx = manager->nextmctx++;
if (manager->nextmctx == NMCTXS)
manager->nextmctx = 0;
INSIST(nextmctx < NMCTXS);
clientmctx = manager->mctxpool[nextmctx];
if (clientmctx == NULL) {
result = isc_mem_create(0, 0, &clientmctx);
if (result != ISC_R_SUCCESS)
return (result);
isc_mem_setname(clientmctx, "client", NULL);
manager->mctxpool[nextmctx] = clientmctx;
}
#else
clientmctx = manager->mctx;
#endif
isc_mem_attach(clientmctx, mctxp);
return (ISC_R_SUCCESS);
}
static isc_result_t
client_create(ns_clientmgr_t *manager, ns_client_t **clientp) {
ns_client_t *client;
isc_result_t result;
isc_mem_t *mctx = NULL;
/*
* Caller must be holding the manager lock.
*
* Note: creating a client does not add the client to the
* manager's client list or set the client's manager pointer.
* The caller is responsible for that.
*/
REQUIRE(clientp != NULL && *clientp == NULL);
result = get_clientmctx(manager, &mctx);
if (result != ISC_R_SUCCESS)
return (result);
client = isc_mem_get(mctx, sizeof(*client));
if (client == NULL) {
isc_mem_detach(&mctx);
return (ISC_R_NOMEMORY);
}
client->mctx = mctx;
client->sctx = NULL;
ns_server_attach(manager->sctx, &client->sctx);
client->task = NULL;
result = isc_task_create(manager->taskmgr, 0, &client->task);
if (result != ISC_R_SUCCESS)
goto cleanup_client;
isc_task_setname(client->task, "client", client);
client->timer = NULL;
result = isc_timer_create(manager->timermgr, isc_timertype_inactive,
NULL, NULL, client->task, client_timeout,
client, &client->timer);
if (result != ISC_R_SUCCESS)
goto cleanup_task;
client->timerset = false;
client->delaytimer = NULL;
client->message = NULL;
result = dns_message_create(client->mctx, DNS_MESSAGE_INTENTPARSE,
&client->message);
if (result != ISC_R_SUCCESS)
goto cleanup_timer;
/* XXXRTH Hardwired constants */
client->sendevent = isc_socket_socketevent(client->mctx, client,
ISC_SOCKEVENT_SENDDONE,
client_senddone, client);
if (client->sendevent == NULL) {
result = ISC_R_NOMEMORY;
goto cleanup_message;
}
client->recvbuf = isc_mem_get(client->mctx, RECV_BUFFER_SIZE);
if (client->recvbuf == NULL) {
result = ISC_R_NOMEMORY;
goto cleanup_sendevent;
}
client->recvevent = isc_socket_socketevent(client->mctx, client,
ISC_SOCKEVENT_RECVDONE,
ns__client_request, client);
if (client->recvevent == NULL) {
result = ISC_R_NOMEMORY;
goto cleanup_recvbuf;
}
client->magic = NS_CLIENT_MAGIC;
client->manager = NULL;
client->state = NS_CLIENTSTATE_INACTIVE;
client->newstate = NS_CLIENTSTATE_MAX;
client->naccepts = 0;
client->nreads = 0;
client->nsends = 0;
client->nrecvs = 0;
client->nupdates = 0;
client->nctls = 0;
client->references = 0;
client->attributes = 0;
client->view = NULL;
client->dispatch = NULL;
client->udpsocket = NULL;
client->tcplistener = NULL;
client->tcpsocket = NULL;
client->tcpmsg_valid = false;
client->tcpbuf = NULL;
client->opt = NULL;
client->udpsize = 512;
client->dscp = -1;
client->extflags = 0;
client->ednsversion = -1;
client->next = NULL;
client->shutdown = NULL;
client->shutdown_arg = NULL;
client->signer = NULL;
dns_name_init(&client->signername, NULL);
client->mortal = false;
client->sendcb = NULL;
client->tcpconn = NULL;
client->recursionquota = NULL;
client->interface = NULL;
client->peeraddr_valid = false;
dns_ecs_init(&client->ecs);
client->needshutdown = ((client->sctx->options &
NS_SERVER_CLIENTTEST) != 0);
client->tcpactive = false;
ISC_EVENT_INIT(&client->ctlevent, sizeof(client->ctlevent), 0, NULL,
NS_EVENT_CLIENTCONTROL, client_start, client, client,
NULL, NULL);
/*
* Initialize FORMERR cache to sentinel value that will not match
* any actual FORMERR response.
*/
isc_sockaddr_any(&client->formerrcache.addr);
client->formerrcache.time = 0;
client->formerrcache.id = 0;
ISC_LINK_INIT(client, link);
ISC_LINK_INIT(client, rlink);
ISC_QLINK_INIT(client, ilink);
client->keytag = NULL;
client->keytag_len = 0;
client->rcode_override = -1; /* not set */
/*
* We call the init routines for the various kinds of client here,
* after we have created an otherwise valid client, because some
* of them call routines that REQUIRE(NS_CLIENT_VALID(client)).
*/
result = ns_query_init(client);
if (result != ISC_R_SUCCESS)
goto cleanup_recvevent;
result = isc_task_onshutdown(client->task, client_shutdown, client);
if (result != ISC_R_SUCCESS)
goto cleanup_query;
CTRACE("create");
*clientp = client;
return (ISC_R_SUCCESS);
cleanup_query:
ns_query_free(client);
cleanup_recvevent:
isc_event_free((isc_event_t **)&client->recvevent);
cleanup_recvbuf:
isc_mem_put(client->mctx, client->recvbuf, RECV_BUFFER_SIZE);
cleanup_sendevent:
isc_event_free((isc_event_t **)&client->sendevent);
client->magic = 0;
cleanup_message:
dns_message_destroy(&client->message);
cleanup_timer:
isc_timer_detach(&client->timer);
cleanup_task:
isc_task_detach(&client->task);
cleanup_client:
if (client->sctx != NULL)
ns_server_detach(&client->sctx);
isc_mem_putanddetach(&client->mctx, client, sizeof(*client));
return (result);
}
static void
client_read(ns_client_t *client, bool newconn) {
isc_result_t result;
CTRACE("read");
result = dns_tcpmsg_readmessage(&client->tcpmsg, client->task,
ns__client_request, client);
if (result != ISC_R_SUCCESS)
goto fail;
/*
* Set a timeout to limit the amount of time we will wait
* for a request on this TCP connection.
*/
read_settimeout(client, newconn);
client->state = client->newstate = NS_CLIENTSTATE_READING;
INSIST(client->nreads == 0);
INSIST(client->recursionquota == NULL);
client->nreads++;
return;
fail:
ns_client_next(client, result);
}
static void
client_newconn(isc_task_t *task, isc_event_t *event) {
isc_result_t result;
ns_client_t *client = event->ev_arg;
isc_socket_newconnev_t *nevent = (isc_socket_newconnev_t *)event;
dns_aclenv_t *env = ns_interfacemgr_getaclenv(client->interface->mgr);
uint32_t old;
REQUIRE(event->ev_type == ISC_SOCKEVENT_NEWCONN);
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(client->task == task);
UNUSED(task);
INSIST(client->state == NS_CLIENTSTATE_READY);
/*
* The accept() was successful and we're now establishing a new
* connection. We need to make note of it in the client and
* interface objects so client objects can do the right thing
* when going inactive in exit_check() (see comments in
* client_accept() for details).
*/
INSIST(client->naccepts == 1);
client->naccepts--;
old = isc_refcount_decrement(&client->interface->ntcpaccepting);
INSIST(old > 0);
/*
* We must take ownership of the new socket before the exit
* check to make sure it gets destroyed if we decide to exit.
*/
if (nevent->result == ISC_R_SUCCESS) {
client->tcpsocket = nevent->newsocket;
isc_socket_setname(client->tcpsocket, "client-tcp", NULL);
client->state = NS_CLIENTSTATE_READING;
INSIST(client->recursionquota == NULL);
(void)isc_socket_getpeername(client->tcpsocket,
&client->peeraddr);
client->peeraddr_valid = true;
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"new TCP connection");
} else {
/*
* XXXRTH What should we do? We're trying to accept but
* it didn't work. If we just give up, then TCP
* service may eventually stop.
*
* For now, we just go idle.
*
* Going idle is probably the right thing if the
* I/O was canceled.
*/
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"accept failed: %s",
isc_result_totext(nevent->result));
tcpconn_detach(client);
}
if (exit_check(client))
goto freeevent;
if (nevent->result == ISC_R_SUCCESS) {
int match;
isc_netaddr_t netaddr;
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
if (client->sctx->blackholeacl != NULL &&
(dns_acl_match(&netaddr, NULL, client->sctx->blackholeacl,
env, &match, NULL) == ISC_R_SUCCESS) &&
match > 0)
{
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"blackholed connection attempt");
client->newstate = NS_CLIENTSTATE_READY;
(void)exit_check(client);
goto freeevent;
}
INSIST(client->tcpmsg_valid == false);
dns_tcpmsg_init(client->mctx, client->tcpsocket,
&client->tcpmsg);
client->tcpmsg_valid = true;
/*
* Let a new client take our place immediately, before
* we wait for a request packet. If we don't,
* telnetting to port 53 (once per CPU) will
* deny service to legitimate TCP clients.
*/
result = ns_client_replace(client);
if (result == ISC_R_SUCCESS &&
(client->sctx->keepresporder == NULL ||
!dns_acl_allowed(&netaddr, NULL,
client->sctx->keepresporder, env)))
{
client->tcpconn->pipelined = true;
}
client_read(client, true);
}
freeevent:
isc_event_free(&event);
}
static void
client_accept(ns_client_t *client) {
isc_result_t result;
CTRACE("accept");
/*
* Set up a new TCP connection. This means try to attach to the
* TCP client quota (tcp-clients), but fail if we're over quota.
*/
result = tcpconn_init(client, false);
if (result != ISC_R_SUCCESS) {
bool exit;
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_WARNING,
"TCP client quota reached: %s",
isc_result_totext(result));
/*
* We have exceeded the system-wide TCP client quota. But,
* we can't just block this accept in all cases, because if
* we did, a heavy TCP load on other interfaces might cause
* this interface to be starved, with no clients able to
* accept new connections.
*
* So, we check here to see if any other clients are
* already servicing TCP queries on this interface (whether
* accepting, reading, or processing). If we find that at
* least one client other than this one is active, then
* it's okay *not* to call accept - we can let this
* client go inactive and another will take over when it's
* done.
*
* If there aren't enough active clients on the interface,
* then we can be a little bit flexible about the quota.
* We'll allow *one* extra client through to ensure we're
* listening on every interface; we do this by setting the
* 'force' option to tcpconn_init().
*
* (Note: In practice this means that the real TCP client
* quota is tcp-clients plus the number of listening
* interfaces plus 1.)
*/
exit = (isc_refcount_current(&client->interface->ntcpactive) >
(client->tcpactive ? 1U : 0U));
if (exit) {
client->newstate = NS_CLIENTSTATE_INACTIVE;
(void)exit_check(client);
return;
}
result = tcpconn_init(client, true);
RUNTIME_CHECK(result == ISC_R_SUCCESS);
}
/*
* If this client was set up using get_client() or get_worker(),
* then TCP is already marked active. However, if it was restarted
* from exit_check(), it might not be, so we take care of it now.
*/
mark_tcp_active(client, true);
result = isc_socket_accept(client->tcplistener, client->task,
client_newconn, client);
if (result != ISC_R_SUCCESS) {
/*
* XXXRTH What should we do? We're trying to accept but
* it didn't work. If we just give up, then TCP
* service may eventually stop.
*
* For now, we just go idle.
*/
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_socket_accept() failed: %s",
isc_result_totext(result));
tcpconn_detach(client);
mark_tcp_active(client, false);
return;
}
/*
* The client's 'naccepts' counter indicates that this client has
* called accept() and is waiting for a new connection. It should
* never exceed 1.
*/
INSIST(client->naccepts == 0);
client->naccepts++;
/*
* The interface's 'ntcpaccepting' counter is incremented when
* any client calls accept(), and decremented in client_newconn()
* once the connection is established.
*
* When the client object is shutting down after handling a TCP
* request (see exit_check()), if this value is at least one, that
* means another client has called accept() and is waiting to
* establish the next connection. That means the client may be
* be free to become inactive; otherwise it may need to start
* listening for connections itself to prevent the interface
* going dead.
*/
isc_refcount_increment0(&client->interface->ntcpaccepting);
}
static void
client_udprecv(ns_client_t *client) {
isc_result_t result;
isc_region_t r;
CTRACE("udprecv");
r.base = client->recvbuf;
r.length = RECV_BUFFER_SIZE;
result = isc_socket_recv2(client->udpsocket, &r, 1,
client->task, client->recvevent, 0);
if (result != ISC_R_SUCCESS) {
UNEXPECTED_ERROR(__FILE__, __LINE__,
"isc_socket_recv2() failed: %s",
isc_result_totext(result));
/*
* This cannot happen in the current implementation, since
* isc_socket_recv2() cannot fail if flags == 0.
*
* If this does fail, we just go idle.
*/
return;
}
INSIST(client->nrecvs == 0);
client->nrecvs++;
}
void
ns_client_attach(ns_client_t *source, ns_client_t **targetp) {
REQUIRE(NS_CLIENT_VALID(source));
REQUIRE(targetp != NULL && *targetp == NULL);
source->references++;
ns_client_log(source, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"ns_client_attach: ref = %d", source->references);
*targetp = source;
}
void
ns_client_detach(ns_client_t **clientp) {
ns_client_t *client = *clientp;
client->references--;
INSIST(client->references >= 0);
*clientp = NULL;
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"ns_client_detach: ref = %d", client->references);
(void)exit_check(client);
}
bool
ns_client_shuttingdown(ns_client_t *client) {
return (client->newstate == NS_CLIENTSTATE_FREED);
}
isc_result_t
ns_client_replace(ns_client_t *client) {
isc_result_t result;
bool tcp;
CTRACE("replace");
REQUIRE(client != NULL);
REQUIRE(client->manager != NULL);
tcp = TCP_CLIENT(client);
if (tcp && client->tcpconn != NULL && client->tcpconn->pipelined) {
result = get_worker(client->manager, client->interface,
client->tcpsocket, client);
} else {
result = get_client(client->manager, client->interface,
client->dispatch, tcp);
}
if (result != ISC_R_SUCCESS) {
return (result);
}
/*
* The responsibility for listening for new requests is hereby
* transferred to the new client. Therefore, the old client
* should refrain from listening for any more requests.
*/
client->mortal = true;
return (ISC_R_SUCCESS);
}
/***
*** Client Manager
***/
static void
clientmgr_destroy(ns_clientmgr_t *manager) {
#if NMCTXS > 0
int i;
#endif
REQUIRE(ISC_LIST_EMPTY(manager->clients));
MTRACE("clientmgr_destroy");
#if NMCTXS > 0
for (i = 0; i < NMCTXS; i++) {
if (manager->mctxpool[i] != NULL)
isc_mem_detach(&manager->mctxpool[i]);
}
#endif
ISC_QUEUE_DESTROY(manager->inactive);
isc_mutex_destroy(&manager->lock);
isc_mutex_destroy(&manager->listlock);
isc_mutex_destroy(&manager->reclock);
if (manager->excl != NULL)
isc_task_detach(&manager->excl);
ns_server_detach(&manager->sctx);
manager->magic = 0;
isc_mem_put(manager->mctx, manager, sizeof(*manager));
}
isc_result_t
ns_clientmgr_create(isc_mem_t *mctx, ns_server_t *sctx, isc_taskmgr_t *taskmgr,
isc_timermgr_t *timermgr, ns_clientmgr_t **managerp)
{
ns_clientmgr_t *manager;
isc_result_t result;
#if NMCTXS > 0
int i;
#endif
manager = isc_mem_get(mctx, sizeof(*manager));
if (manager == NULL)
return (ISC_R_NOMEMORY);
isc_mutex_init(&manager->lock);
isc_mutex_init(&manager->listlock);
isc_mutex_init(&manager->reclock);
manager->excl = NULL;
result = isc_taskmgr_excltask(taskmgr, &manager->excl);
if (result != ISC_R_SUCCESS) {
goto cleanup_reclock;
}
manager->mctx = mctx;
manager->taskmgr = taskmgr;
manager->timermgr = timermgr;
manager->exiting = false;
manager->sctx = NULL;
ns_server_attach(sctx, &manager->sctx);
ISC_LIST_INIT(manager->clients);
ISC_LIST_INIT(manager->recursing);
ISC_QUEUE_INIT(manager->inactive, ilink);
#if NMCTXS > 0
manager->nextmctx = 0;
for (i = 0; i < NMCTXS; i++)
manager->mctxpool[i] = NULL; /* will be created on-demand */
#endif
manager->magic = MANAGER_MAGIC;
MTRACE("create");
*managerp = manager;
return (ISC_R_SUCCESS);
cleanup_reclock:
isc_mutex_destroy(&manager->reclock);
isc_mutex_destroy(&manager->listlock);
isc_mutex_destroy(&manager->lock);
isc_mem_put(manager->mctx, manager, sizeof(*manager));
return (result);
}
void
ns_clientmgr_destroy(ns_clientmgr_t **managerp) {
isc_result_t result;
ns_clientmgr_t *manager;
ns_client_t *client;
bool need_destroy = false, unlock = false;
REQUIRE(managerp != NULL);
manager = *managerp;
REQUIRE(VALID_MANAGER(manager));
MTRACE("destroy");
/*
* Check for success because we may already be task-exclusive
* at this point. Only if we succeed at obtaining an exclusive
* lock now will we need to relinquish it later.
*/
result = isc_task_beginexclusive(manager->excl);
if (result == ISC_R_SUCCESS)
unlock = true;
manager->exiting = true;
for (client = ISC_LIST_HEAD(manager->clients);
client != NULL;
client = ISC_LIST_NEXT(client, link))
isc_task_shutdown(client->task);
if (ISC_LIST_EMPTY(manager->clients))
need_destroy = true;
if (unlock)
isc_task_endexclusive(manager->excl);
if (need_destroy)
clientmgr_destroy(manager);
*managerp = NULL;
}
static isc_result_t
get_client(ns_clientmgr_t *manager, ns_interface_t *ifp,
dns_dispatch_t *disp, bool tcp)
{
isc_result_t result = ISC_R_SUCCESS;
isc_event_t *ev;
ns_client_t *client;
MTRACE("get client");
REQUIRE(manager != NULL);
if (manager->exiting)
return (ISC_R_SHUTTINGDOWN);
/*
* Allocate a client. First try to get a recycled one;
* if that fails, make a new one.
*/
client = NULL;
if ((manager->sctx->options & NS_SERVER_CLIENTTEST) == 0) {
ISC_QUEUE_POP(manager->inactive, ilink, client);
}
if (client != NULL) {
MTRACE("recycle");
} else {
MTRACE("create new");
LOCK(&manager->lock);
result = client_create(manager, &client);
UNLOCK(&manager->lock);
if (result != ISC_R_SUCCESS)
return (result);
LOCK(&manager->listlock);
ISC_LIST_APPEND(manager->clients, client, link);
UNLOCK(&manager->listlock);
}
client->manager = manager;
ns_interface_attach(ifp, &client->interface);
client->state = NS_CLIENTSTATE_READY;
client->sctx = manager->sctx;
INSIST(client->recursionquota == NULL);
client->dscp = ifp->dscp;
client->rcode_override = -1; /* not set */
if (tcp) {
mark_tcp_active(client, true);
client->attributes |= NS_CLIENTATTR_TCP;
isc_socket_attach(ifp->tcpsocket,
&client->tcplistener);
} else {
isc_socket_t *sock;
dns_dispatch_attach(disp, &client->dispatch);
sock = dns_dispatch_getsocket(client->dispatch);
isc_socket_attach(sock, &client->udpsocket);
}
INSIST(client->nctls == 0);
client->nctls++;
ev = &client->ctlevent;
isc_task_send(client->task, &ev);
return (result);
}
static isc_result_t
get_worker(ns_clientmgr_t *manager, ns_interface_t *ifp, isc_socket_t *sock,
ns_client_t *oldclient)
{
isc_result_t result = ISC_R_SUCCESS;
isc_event_t *ev;
ns_client_t *client;
MTRACE("get worker");
REQUIRE(manager != NULL);
REQUIRE(oldclient != NULL);
if (manager->exiting)
return (ISC_R_SHUTTINGDOWN);
/*
* Allocate a client. First try to get a recycled one;
* if that fails, make a new one.
*/
client = NULL;
if ((manager->sctx->options & NS_SERVER_CLIENTTEST) == 0)
ISC_QUEUE_POP(manager->inactive, ilink, client);
if (client != NULL)
MTRACE("recycle");
else {
MTRACE("create new");
LOCK(&manager->lock);
result = client_create(manager, &client);
UNLOCK(&manager->lock);
if (result != ISC_R_SUCCESS)
return (result);
LOCK(&manager->listlock);
ISC_LIST_APPEND(manager->clients, client, link);
UNLOCK(&manager->listlock);
}
client->manager = manager;
ns_interface_attach(ifp, &client->interface);
client->newstate = client->state = NS_CLIENTSTATE_WORKING;
INSIST(client->recursionquota == NULL);
client->sctx = manager->sctx;
client->dscp = ifp->dscp;
client->attributes |= NS_CLIENTATTR_TCP;
client->mortal = true;
client->sendcb = NULL;
client->rcode_override = -1; /* not set */
tcpconn_attach(oldclient, client);
mark_tcp_active(client, true);
isc_socket_attach(ifp->tcpsocket, &client->tcplistener);
isc_socket_attach(sock, &client->tcpsocket);
isc_socket_setname(client->tcpsocket, "worker-tcp", NULL);
(void)isc_socket_getpeername(client->tcpsocket, &client->peeraddr);
client->peeraddr_valid = true;
INSIST(client->tcpmsg_valid == false);
dns_tcpmsg_init(client->mctx, client->tcpsocket, &client->tcpmsg);
client->tcpmsg_valid = true;
INSIST(client->nctls == 0);
client->nctls++;
ev = &client->ctlevent;
isc_task_send(client->task, &ev);
return (result);
}
isc_result_t
ns__clientmgr_getclient(ns_clientmgr_t *manager, ns_interface_t *ifp,
bool tcp, ns_client_t **clientp)
{
isc_result_t result = ISC_R_SUCCESS;
ns_client_t *client;
MTRACE("getclient");
REQUIRE(VALID_MANAGER(manager));
REQUIRE(clientp != NULL && *clientp == NULL);
if (manager->exiting)
return (ISC_R_SHUTTINGDOWN);
client = NULL;
ISC_QUEUE_POP(manager->inactive, ilink, client);
if (client != NULL)
MTRACE("getclient (recycle)");
else {
MTRACE("getclient (create)");
LOCK(&manager->lock);
result = client_create(manager, &client);
UNLOCK(&manager->lock);
if (result != ISC_R_SUCCESS)
return (result);
LOCK(&manager->listlock);
ISC_LIST_APPEND(manager->clients, client, link);
UNLOCK(&manager->listlock);
}
client->manager = manager;
ns_interface_attach(ifp, &client->interface);
client->state = NS_CLIENTSTATE_READY;
INSIST(client->recursionquota == NULL);
client->dscp = ifp->dscp;
client->references++;
if (tcp) {
client->attributes |= NS_CLIENTATTR_TCP;
}
*clientp = client;
return (result);
}
isc_result_t
ns_clientmgr_createclients(ns_clientmgr_t *manager, unsigned int n,
ns_interface_t *ifp, bool tcp)
{
isc_result_t result = ISC_R_SUCCESS;
unsigned int disp;
REQUIRE(VALID_MANAGER(manager));
REQUIRE(n > 0);
MTRACE("createclients");
for (disp = 0; disp < n; disp++) {
result = get_client(manager, ifp, ifp->udpdispatch[disp], tcp);
if (result != ISC_R_SUCCESS)
break;
}
return (result);
}
isc_sockaddr_t *
ns_client_getsockaddr(ns_client_t *client) {
return (&client->peeraddr);
}
isc_sockaddr_t *
ns_client_getdestaddr(ns_client_t *client) {
return (&client->destsockaddr);
}
isc_result_t
ns_client_checkaclsilent(ns_client_t *client, isc_netaddr_t *netaddr,
dns_acl_t *acl, bool default_allow)
{
isc_result_t result;
dns_aclenv_t *env = ns_interfacemgr_getaclenv(client->interface->mgr);
isc_netaddr_t tmpnetaddr;
int match;
if (acl == NULL) {
if (default_allow)
goto allow;
else
goto deny;
}
if (netaddr == NULL) {
isc_netaddr_fromsockaddr(&tmpnetaddr, &client->peeraddr);
netaddr = &tmpnetaddr;
}
result = dns_acl_match(netaddr, client->signer, acl,
env, &match, NULL);
if (result != ISC_R_SUCCESS)
goto deny; /* Internal error, already logged. */
if (match > 0)
goto allow;
goto deny; /* Negative match or no match. */
allow:
return (ISC_R_SUCCESS);
deny:
return (DNS_R_REFUSED);
}
isc_result_t
ns_client_checkacl(ns_client_t *client, isc_sockaddr_t *sockaddr,
const char *opname, dns_acl_t *acl,
bool default_allow, int log_level)
{
isc_result_t result;
isc_netaddr_t netaddr;
if (sockaddr != NULL)
isc_netaddr_fromsockaddr(&netaddr, sockaddr);
result = ns_client_checkaclsilent(client, sockaddr ? &netaddr : NULL,
acl, default_allow);
if (result == ISC_R_SUCCESS)
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"%s approved", opname);
else
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT,
log_level, "%s denied", opname);
return (result);
}
static void
ns_client_name(ns_client_t *client, char *peerbuf, size_t len) {
if (client->peeraddr_valid)
isc_sockaddr_format(&client->peeraddr, peerbuf,
(unsigned int)len);
else
snprintf(peerbuf, len, "@%p", client);
}
void
ns_client_logv(ns_client_t *client, isc_logcategory_t *category,
isc_logmodule_t *module, int level, const char *fmt, va_list ap)
{
char msgbuf[4096];
char signerbuf[DNS_NAME_FORMATSIZE], qnamebuf[DNS_NAME_FORMATSIZE];
char peerbuf[ISC_SOCKADDR_FORMATSIZE];
const char *viewname = "";
const char *sep1 = "", *sep2 = "", *sep3 = "", *sep4 = "";
const char *signer = "", *qname = "";
dns_name_t *q = NULL;
REQUIRE(client != NULL);
vsnprintf(msgbuf, sizeof(msgbuf), fmt, ap);
if (client->signer != NULL) {
dns_name_format(client->signer, signerbuf, sizeof(signerbuf));
sep1 = "/key ";
signer = signerbuf;
}
q = client->query.origqname != NULL
? client->query.origqname : client->query.qname;
if (q != NULL) {
dns_name_format(q, qnamebuf, sizeof(qnamebuf));
sep2 = " (";
sep3 = ")";
qname = qnamebuf;
}
if (client->view != NULL && strcmp(client->view->name, "_bind") != 0 &&
strcmp(client->view->name, "_default") != 0) {
sep4 = ": view ";
viewname = client->view->name;
}
if (client->peeraddr_valid) {
isc_sockaddr_format(&client->peeraddr,
peerbuf, sizeof(peerbuf));
} else {
snprintf(peerbuf, sizeof(peerbuf), "(no-peer)");
}
isc_log_write(ns_lctx, category, module, level,
"client @%p %s%s%s%s%s%s%s%s: %s",
client, peerbuf, sep1, signer, sep2, qname, sep3,
sep4, viewname, msgbuf);
}
void
ns_client_log(ns_client_t *client, isc_logcategory_t *category,
isc_logmodule_t *module, int level, const char *fmt, ...)
{
va_list ap;
if (! isc_log_wouldlog(ns_lctx, level))
return;
va_start(ap, fmt);
ns_client_logv(client, category, module, level, fmt, ap);
va_end(ap);
}
void
ns_client_aclmsg(const char *msg, const dns_name_t *name, dns_rdatatype_t type,
dns_rdataclass_t rdclass, char *buf, size_t len)
{
char namebuf[DNS_NAME_FORMATSIZE];
char typebuf[DNS_RDATATYPE_FORMATSIZE];
char classbuf[DNS_RDATACLASS_FORMATSIZE];
dns_name_format(name, namebuf, sizeof(namebuf));
dns_rdatatype_format(type, typebuf, sizeof(typebuf));
dns_rdataclass_format(rdclass, classbuf, sizeof(classbuf));
(void)snprintf(buf, len, "%s '%s/%s/%s'", msg, namebuf, typebuf,
classbuf);
}
static void
ns_client_dumpmessage(ns_client_t *client, const char *reason) {
isc_buffer_t buffer;
char *buf = NULL;
int len = 1024;
isc_result_t result;
if (!isc_log_wouldlog(ns_lctx, ISC_LOG_DEBUG(1)))
return;
/*
* Note that these are multiline debug messages. We want a newline
* to appear in the log after each message.
*/
do {
buf = isc_mem_get(client->mctx, len);
if (buf == NULL)
break;
isc_buffer_init(&buffer, buf, len);
result = dns_message_totext(client->message,
&dns_master_style_debug,
0, &buffer);
if (result == ISC_R_NOSPACE) {
isc_mem_put(client->mctx, buf, len);
len += 1024;
} else if (result == ISC_R_SUCCESS)
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(1),
"%s\n%.*s", reason,
(int)isc_buffer_usedlength(&buffer),
buf);
} while (result == ISC_R_NOSPACE);
if (buf != NULL)
isc_mem_put(client->mctx, buf, len);
}
void
ns_client_dumprecursing(FILE *f, ns_clientmgr_t *manager) {
ns_client_t *client;
char namebuf[DNS_NAME_FORMATSIZE];
char original[DNS_NAME_FORMATSIZE];
char peerbuf[ISC_SOCKADDR_FORMATSIZE];
char typebuf[DNS_RDATATYPE_FORMATSIZE];
char classbuf[DNS_RDATACLASS_FORMATSIZE];
const char *name;
const char *sep;
const char *origfor;
dns_rdataset_t *rdataset;
REQUIRE(VALID_MANAGER(manager));
LOCK(&manager->reclock);
client = ISC_LIST_HEAD(manager->recursing);
while (client != NULL) {
INSIST(client->state == NS_CLIENTSTATE_RECURSING);
ns_client_name(client, peerbuf, sizeof(peerbuf));
if (client->view != NULL &&
strcmp(client->view->name, "_bind") != 0 &&
strcmp(client->view->name, "_default") != 0) {
name = client->view->name;
sep = ": view ";
} else {
name = "";
sep = "";
}
LOCK(&client->query.fetchlock);
INSIST(client->query.qname != NULL);
dns_name_format(client->query.qname, namebuf, sizeof(namebuf));
if (client->query.qname != client->query.origqname &&
client->query.origqname != NULL) {
origfor = " for ";
dns_name_format(client->query.origqname, original,
sizeof(original));
} else {
origfor = "";
original[0] = '\0';
}
rdataset = ISC_LIST_HEAD(client->query.qname->list);
if (rdataset == NULL && client->query.origqname != NULL)
rdataset = ISC_LIST_HEAD(client->query.origqname->list);
if (rdataset != NULL) {
dns_rdatatype_format(rdataset->type, typebuf,
sizeof(typebuf));
dns_rdataclass_format(rdataset->rdclass, classbuf,
sizeof(classbuf));
} else {
strlcpy(typebuf, "-", sizeof(typebuf));
strlcpy(classbuf, "-", sizeof(classbuf));
}
UNLOCK(&client->query.fetchlock);
fprintf(f, "; client %s%s%s: id %u '%s/%s/%s'%s%s "
"requesttime %u\n", peerbuf, sep, name,
client->message->id, namebuf, typebuf, classbuf,
origfor, original,
isc_time_seconds(&client->requesttime));
client = ISC_LIST_NEXT(client, rlink);
}
UNLOCK(&manager->reclock);
}
void
ns_client_qnamereplace(ns_client_t *client, dns_name_t *name) {
LOCK(&client->query.fetchlock);
if (client->query.restarts > 0) {
/*
* client->query.qname was dynamically allocated.
*/
dns_message_puttempname(client->message,
&client->query.qname);
}
client->query.qname = name;
client->query.attributes &= ~NS_QUERYATTR_REDIRECT;
UNLOCK(&client->query.fetchlock);
}
isc_result_t
ns_client_sourceip(dns_clientinfo_t *ci, isc_sockaddr_t **addrp) {
ns_client_t *client = (ns_client_t *) ci->data;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(addrp != NULL);
*addrp = &client->peeraddr;
return (ISC_R_SUCCESS);
}
dns_rdataset_t *
ns_client_newrdataset(ns_client_t *client) {
dns_rdataset_t *rdataset;
isc_result_t result;
REQUIRE(NS_CLIENT_VALID(client));
rdataset = NULL;
result = dns_message_gettemprdataset(client->message, &rdataset);
if (result != ISC_R_SUCCESS) {
return (NULL);
}
return (rdataset);
}
void
ns_client_putrdataset(ns_client_t *client, dns_rdataset_t **rdatasetp) {
dns_rdataset_t *rdataset;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(rdatasetp != NULL);
rdataset = *rdatasetp;
if (rdataset != NULL) {
if (dns_rdataset_isassociated(rdataset)) {
dns_rdataset_disassociate(rdataset);
}
dns_message_puttemprdataset(client->message, rdatasetp);
}
}
isc_result_t
ns_client_newnamebuf(ns_client_t *client) {
isc_buffer_t *dbuf;
isc_result_t result;
CTRACE("ns_client_newnamebuf");
dbuf = NULL;
result = isc_buffer_allocate(client->mctx, &dbuf, 1024);
if (result != ISC_R_SUCCESS) {
CTRACE("ns_client_newnamebuf: "
"isc_buffer_allocate failed: done");
return (result);
}
ISC_LIST_APPEND(client->query.namebufs, dbuf, link);
CTRACE("ns_client_newnamebuf: done");
return (ISC_R_SUCCESS);
}
dns_name_t *
ns_client_newname(ns_client_t *client, isc_buffer_t *dbuf, isc_buffer_t *nbuf) {
dns_name_t *name;
isc_region_t r;
isc_result_t result;
REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) == 0);
CTRACE("ns_client_newname");
name = NULL;
result = dns_message_gettempname(client->message, &name);
if (result != ISC_R_SUCCESS) {
CTRACE("ns_client_newname: "
"dns_message_gettempname failed: done");
return (NULL);
}
isc_buffer_availableregion(dbuf, &r);
isc_buffer_init(nbuf, r.base, r.length);
dns_name_init(name, NULL);
dns_name_setbuffer(name, nbuf);
client->query.attributes |= NS_QUERYATTR_NAMEBUFUSED;
CTRACE("ns_client_newname: done");
return (name);
}
isc_buffer_t *
ns_client_getnamebuf(ns_client_t *client) {
isc_buffer_t *dbuf;
isc_result_t result;
isc_region_t r;
CTRACE("ns_client_getnamebuf");
/*%
* Return a name buffer with space for a maximal name, allocating
* a new one if necessary.
*/
if (ISC_LIST_EMPTY(client->query.namebufs)) {
result = ns_client_newnamebuf(client);
if (result != ISC_R_SUCCESS) {
CTRACE("ns_client_getnamebuf: "
"ns_client_newnamebuf failed: done");
return (NULL);
}
}
dbuf = ISC_LIST_TAIL(client->query.namebufs);
INSIST(dbuf != NULL);
isc_buffer_availableregion(dbuf, &r);
if (r.length < DNS_NAME_MAXWIRE) {
result = ns_client_newnamebuf(client);
if (result != ISC_R_SUCCESS) {
CTRACE("ns_client_getnamebuf: "
"ns_client_newnamebuf failed: done");
return (NULL);
}
dbuf = ISC_LIST_TAIL(client->query.namebufs);
isc_buffer_availableregion(dbuf, &r);
INSIST(r.length >= 255);
}
CTRACE("ns_client_getnamebuf: done");
return (dbuf);
}
void
ns_client_keepname(ns_client_t *client, dns_name_t *name, isc_buffer_t *dbuf) {
isc_region_t r;
CTRACE("ns_client_keepname");
/*%
* 'name' is using space in 'dbuf', but 'dbuf' has not yet been
* adjusted to take account of that. We do the adjustment.
*/
REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) != 0);
dns_name_toregion(name, &r);
isc_buffer_add(dbuf, r.length);
dns_name_setbuffer(name, NULL);
client->query.attributes &= ~NS_QUERYATTR_NAMEBUFUSED;
}
void
ns_client_releasename(ns_client_t *client, dns_name_t **namep) {
dns_name_t *name = *namep;
/*%
* 'name' is no longer needed. Return it to our pool of temporary
* names. If it is using a name buffer, relinquish its exclusive
* rights on the buffer.
*/
CTRACE("ns_client_releasename");
if (dns_name_hasbuffer(name)) {
INSIST((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED)
!= 0);
client->query.attributes &= ~NS_QUERYATTR_NAMEBUFUSED;
}
dns_message_puttempname(client->message, namep);
CTRACE("ns_client_releasename: done");
}
isc_result_t
ns_client_newdbversion(ns_client_t *client, unsigned int n) {
unsigned int i;
ns_dbversion_t *dbversion;
for (i = 0; i < n; i++) {
dbversion = isc_mem_get(client->mctx, sizeof(*dbversion));
if (dbversion != NULL) {
dbversion->db = NULL;
dbversion->version = NULL;
ISC_LIST_INITANDAPPEND(client->query.freeversions,
dbversion, link);
} else {
/*
* We only return ISC_R_NOMEMORY if we couldn't
* allocate anything.
*/
if (i == 0) {
return (ISC_R_NOMEMORY);
} else {
return (ISC_R_SUCCESS);
}
}
}
return (ISC_R_SUCCESS);
}
static inline ns_dbversion_t *
client_getdbversion(ns_client_t *client) {
isc_result_t result;
ns_dbversion_t *dbversion;
if (ISC_LIST_EMPTY(client->query.freeversions)) {
result = ns_client_newdbversion(client, 1);
if (result != ISC_R_SUCCESS) {
return (NULL);
}
}
dbversion = ISC_LIST_HEAD(client->query.freeversions);
INSIST(dbversion != NULL);
ISC_LIST_UNLINK(client->query.freeversions, dbversion, link);
return (dbversion);
}
ns_dbversion_t *
ns_client_findversion(ns_client_t *client, dns_db_t *db) {
ns_dbversion_t *dbversion;
for (dbversion = ISC_LIST_HEAD(client->query.activeversions);
dbversion != NULL;
dbversion = ISC_LIST_NEXT(dbversion, link))
{
if (dbversion->db == db) {
break;
}
}
if (dbversion == NULL) {
/*
* This is a new zone for this query. Add it to
* the active list.
*/
dbversion = client_getdbversion(client);
if (dbversion == NULL) {
return (NULL);
}
dns_db_attach(db, &dbversion->db);
dns_db_currentversion(db, &dbversion->version);
dbversion->acl_checked = false;
dbversion->queryok = false;
ISC_LIST_APPEND(client->query.activeversions,
dbversion, link);
}
return (dbversion);
}