horok/bind9
1
0
Fork 0
Code Activity
bind9/lib/ns/client.c
Daniel Baumann f66ff7eae6
Adding upstream version 1:9.20.9. 
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
2025-06-21 13:32:37 +02:00

3124 lines
80 KiB
C
Raw Permalink Blame History

/*
* Copyright (C) Internet Systems Consortium, Inc. ("ISC")
*
* SPDX-License-Identifier: MPL-2.0
*
* 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 https://mozilla.org/MPL/2.0/.
*
* See the COPYRIGHT file distributed with this work for additional
* information regarding copyright ownership.
*/
#include <inttypes.h>
#include <limits.h>
#include <stdbool.h>
#include <isc/async.h>
#include <isc/atomic.h>
#include <isc/formatcheck.h>
#include <isc/fuzz.h>
#include <isc/hmac.h>
#include <isc/log.h>
#include <isc/mutex.h>
#include <isc/once.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/thread.h>
#include <isc/tid.h>
#include <isc/timer.h>
#include <isc/util.h>
#include <dns/adb.h>
#include <dns/badcache.h>
#include <dns/cache.h>
#include <dns/db.h>
#include <dns/dispatch.h>
#include <dns/dnstap.h>
#include <dns/edns.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/result.h>
#include <dns/stats.h>
#include <dns/tsig.h>
#include <dns/view.h>
#include <dns/zone.h>
#include <ns/client.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
* loop to change the client, then the client will have to be locked.
*/
#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 /* ifdef NS_CLIENT_TRACE */
#define CTRACE(m) ((void)(m))
#define MTRACE(m) ((void)(m))
#endif /* ifdef NS_CLIENT_TRACE */
#define TCP_CLIENT(c) (((c)->attributes & NS_CLIENTATTR_TCP) != 0)
#define COOKIE_SIZE 24U /* 8 + 4 + 4 + 8 */
#define ECS_SIZE 20U /* 2 + 1 + 1 + [0..16] */
#define TCPBUFFERS_FILLCOUNT 1U
#define TCPBUFFERS_FREEMAX 8U
#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)
#define MANAGER_MAGIC ISC_MAGIC('N', 'S', 'C', 'm')
#define VALID_MANAGER(m) ISC_MAGIC_VALID(m, MANAGER_MAGIC)
/*
* Enable ns_client_dropport() by default.
*/
#ifndef NS_CLIENT_DROPPORT
#define NS_CLIENT_DROPPORT 1
#endif /* ifndef NS_CLIENT_DROPPORT */
atomic_uint_fast64_t ns_client_requests = 0;
static atomic_uint_fast32_t last_sigchecks_quota_log = 0;
static bool
can_log_sigchecks_quota(void) {
isc_stdtime_t last;
isc_stdtime_t now = isc_stdtime_now();
last = atomic_exchange_relaxed(&last_sigchecks_quota_log, now);
if (now != last) {
return true;
}
return false;
}
static void
clientmgr_destroy_cb(void *arg);
static void
ns_client_dumpmessage(ns_client_t *client, const char *reason);
static void
ns_client_request_continue(void *arg);
static void
compute_cookie(ns_client_t *client, uint32_t when, const unsigned char *secret,
isc_buffer_t *buf);
#ifdef HAVE_DNSTAP
static dns_transport_type_t
ns_client_transport_type(const ns_client_t *client) {
/*
* Early escape hatch for libtest/ns.c
*
* When DoQ support this had to be removed to get correct DoQ entries.
*/
if (!TCP_CLIENT(client)) {
return DNS_TRANSPORT_UDP;
}
INSIST(client->handle != NULL);
switch (isc_nm_socket_type(client->handle)) {
case isc_nm_udpsocket:
case isc_nm_udplistener:
case isc_nm_proxyudpsocket:
case isc_nm_proxyudplistener:
return DNS_TRANSPORT_UDP;
case isc_nm_tlssocket:
case isc_nm_tlslistener:
return DNS_TRANSPORT_TLS;
case isc_nm_httpsocket:
case isc_nm_httplistener:
return DNS_TRANSPORT_HTTP;
case isc_nm_streamdnslistener:
case isc_nm_streamdnssocket:
case isc_nm_proxystreamlistener:
case isc_nm_proxystreamsocket:
/* If it isn't DoT, it is DNS-over-TCP */
if (isc_nm_has_encryption(client->handle)) {
return DNS_TRANSPORT_TLS;
}
FALLTHROUGH;
case isc_nm_tcpsocket:
case isc_nm_tcplistener:
return DNS_TRANSPORT_TCP;
case isc_nm_maxsocket:
case isc_nm_nonesocket:
UNREACHABLE();
}
return DNS_TRANSPORT_UDP;
}
#endif /* HAVE_DNSTAP */
void
ns_client_recursing(ns_client_t *client) {
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(client->state == NS_CLIENTSTATE_WORKING);
LOCK(&client->manager->reclock);
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);
ns_query_cancel(oldest);
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_reclimitdropped);
}
UNLOCK(&client->manager->reclock);
}
void
ns_client_settimeout(ns_client_t *client, unsigned int seconds) {
UNUSED(client);
UNUSED(seconds);
/* XXXWPK TODO use netmgr to set timeout */
}
static void
ns_client_endrequest(ns_client_t *client) {
INSIST(client->state == NS_CLIENTSTATE_WORKING ||
client->state == NS_CLIENTSTATE_RECURSING);
CTRACE("endrequest");
if (client->state == NS_CLIENTSTATE_RECURSING) {
LOCK(&client->manager->reclock);
if (ISC_LINK_LINKED(client, rlink)) {
ISC_LIST_UNLINK(client->manager->recursing, client,
rlink);
}
UNLOCK(&client->manager->reclock);
}
if (client->cleanup != NULL) {
(client->cleanup)(client);
client->cleanup = NULL;
}
if (client->view != NULL) {
#ifdef ENABLE_AFL
if (client->manager->sctx->fuzztype == isc_fuzz_resolver) {
dns_adb_t *adb = NULL;
dns_view_getadb(client->view, &adb);
if (adb != NULL) {
dns_adb_flush(adb);
dns_adb_detach(&adb);
}
}
#endif /* ifdef ENABLE_AFL */
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;
client->additionaldepth = 0;
dns_ecs_init(&client->ecs);
dns_message_reset(client->message, DNS_MESSAGE_INTENTPARSE);
/*
* Clear all client attributes that are specific to the request
*/
client->attributes = 0;
#ifdef ENABLE_AFL
if (client->manager->sctx->fuzznotify != NULL &&
(client->manager->sctx->fuzztype == isc_fuzz_client ||
client->manager->sctx->fuzztype == isc_fuzz_tcpclient ||
client->manager->sctx->fuzztype == isc_fuzz_resolver))
{
client->manager->sctx->fuzznotify();
}
#endif /* ENABLE_AFL */
}
void
ns_client_drop(ns_client_t *client, isc_result_t result) {
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(client->state == NS_CLIENTSTATE_WORKING ||
client->state == NS_CLIENTSTATE_RECURSING);
CTRACE("drop");
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));
}
}
static void
client_senddone(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) {
ns_client_t *client = cbarg;
REQUIRE(client->sendhandle == handle);
CTRACE("senddone");
/*
* Set sendhandle to NULL, but don't detach it immediately, in
* case we need to retry the send. If we do resend, then
* sendhandle will be reattached. Whether or not we resend,
* we will then detach the handle from *this* send by detaching
* 'handle' directly below.
*/
client->sendhandle = NULL;
if (result != ISC_R_SUCCESS) {
if (!TCP_CLIENT(client) && result == ISC_R_MAXSIZE) {
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"send exceeded maximum size: truncating");
client->query.attributes &= ~NS_QUERYATTR_ANSWERED;
client->rcode_override = dns_rcode_noerror;
ns_client_error(client, ISC_R_MAXSIZE);
} else {
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"send failed: %s",
isc_result_totext(result));
isc_nm_bad_request(handle);
}
}
isc_nmhandle_detach(&handle);
}
static void
client_setup_tcp_buffer(ns_client_t *client) {
REQUIRE(client->tcpbuf == NULL);
client->tcpbuf = client->manager->tcp_buffer;
client->tcpbuf_size = NS_CLIENT_TCP_BUFFER_SIZE;
}
static void
client_put_tcp_buffer(ns_client_t *client) {
if (client->tcpbuf == NULL) {
return;
}
if (client->tcpbuf != client->manager->tcp_buffer) {
isc_mem_put(client->manager->mctx, client->tcpbuf,
client->tcpbuf_size);
}
client->tcpbuf = NULL;
client->tcpbuf_size = 0;
}
static void
client_allocsendbuf(ns_client_t *client, isc_buffer_t *buffer,
unsigned char **datap) {
unsigned char *data;
uint32_t bufsize;
REQUIRE(datap != NULL);
if (TCP_CLIENT(client)) {
client_setup_tcp_buffer(client);
data = client->tcpbuf;
isc_buffer_init(buffer, data, client->tcpbuf_size);
} else {
data = client->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 > NS_CLIENT_SEND_BUFFER_SIZE) {
bufsize = NS_CLIENT_SEND_BUFFER_SIZE;
}
isc_buffer_init(buffer, data, bufsize);
}
*datap = data;
}
static void
client_sendpkg(ns_client_t *client, isc_buffer_t *buffer) {
isc_result_t result;
isc_region_t r;
dns_ttl_t min_ttl = 0;
REQUIRE(client->sendhandle == NULL);
if (isc_buffer_base(buffer) == client->tcpbuf) {
size_t used = isc_buffer_usedlength(buffer);
INSIST(client->tcpbuf_size == NS_CLIENT_TCP_BUFFER_SIZE);
/*
* Copy the data into a smaller buffer before sending,
* and keep the original big TCP send buffer for reuse
* by other clients.
*/
if (used > NS_CLIENT_SEND_BUFFER_SIZE) {
/*
* We can save space by allocating a new buffer with a
* correct size and freeing the big buffer.
*/
unsigned char *new_tcpbuf =
isc_mem_get(client->manager->mctx, used);
memmove(new_tcpbuf, buffer->base, used);
/*
* Put the big buffer so we can replace the pointer
* and the size with the new ones.
*/
client_put_tcp_buffer(client);
/*
* Keep the new buffer's information so it can be freed.
*/
client->tcpbuf = new_tcpbuf;
client->tcpbuf_size = used;
r.base = new_tcpbuf;
} else {
/*
* The data fits in the available space in
* 'sendbuf', there is no need for a new buffer.
*/
memmove(client->sendbuf, buffer->base, used);
/*
* Put the big buffer, we don't need a dynamic buffer.
*/
client_put_tcp_buffer(client);
r.base = client->sendbuf;
}
r.length = used;
} else {
isc_buffer_usedregion(buffer, &r);
}
isc_nmhandle_attach(client->handle, &client->sendhandle);
if (isc_nm_is_http_handle(client->handle)) {
result = dns_message_response_minttl(client->message, &min_ttl);
if (result == ISC_R_SUCCESS) {
isc_nm_set_maxage(client->handle, min_ttl);
}
}
isc_nm_send(client->handle, &r, client_senddone, client);
}
void
ns_client_sendraw(ns_client_t *client, dns_message_t *message) {
isc_result_t result;
unsigned char *data = NULL;
isc_buffer_t buffer;
isc_region_t r;
isc_region_t *mr = NULL;
#ifdef HAVE_DNSTAP
dns_transport_type_t transport_type;
dns_dtmsgtype_t dtmsgtype;
#endif
REQUIRE(NS_CLIENT_VALID(client));
CTRACE("sendraw");
mr = dns_message_getrawmessage(message);
if (mr == NULL) {
result = ISC_R_UNEXPECTEDEND;
goto done;
}
client_allocsendbuf(client, &buffer, &data);
if (mr->length > isc_buffer_length(&buffer)) {
result = ISC_R_NOSPACE;
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;
#ifdef HAVE_DNSTAP
if (client->view != NULL) {
transport_type = ns_client_transport_type(client);
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;
}
dns_dt_send(client->view, dtmsgtype, &client->peeraddr,
&client->destsockaddr, transport_type, NULL,
&client->requesttime, NULL, &buffer);
}
#endif
client_sendpkg(client, &buffer);
return;
done:
if (client->tcpbuf != NULL) {
client_put_tcp_buffer(client);
}
ns_client_drop(client, result);
}
void
ns_client_send(ns_client_t *client) {
isc_result_t result;
unsigned char *data = NULL;
isc_buffer_t buffer = { .magic = 0 };
isc_region_t r;
dns_compress_t cctx;
unsigned int compflags;
bool cleanup_cctx = false;
unsigned int render_opts;
unsigned int preferred_glue;
bool opt_included = false;
size_t respsize;
dns_aclenv_t *env = NULL;
#ifdef HAVE_DNSTAP
unsigned char zone[DNS_NAME_MAXWIRE];
dns_transport_type_t transport_type;
dns_dtmsgtype_t dtmsgtype;
isc_region_t zr;
#endif /* HAVE_DNSTAP */
REQUIRE(NS_CLIENT_VALID(client));
if ((client->query.attributes & NS_QUERYATTR_ANSWERED) != 0) {
return;
}
/*
* XXXWPK TODO
* Delay the response according to the -T delay option
*/
env = client->manager->aclenv;
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 cleanup;
}
}
client_allocsendbuf(client, &buffer, &data);
compflags = 0;
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))
{
compflags |= DNS_COMPRESS_CASE;
}
if (!client->view->msgcompression) {
compflags = DNS_COMPRESS_DISABLED;
}
}
dns_compress_init(&cctx, client->manager->mctx, compflags);
cleanup_cctx = true;
result = dns_message_renderbegin(client->message, &cctx, &buffer);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
if (client->opt != NULL) {
result = dns_message_setopt(client->message, client->opt);
opt_included = true;
client->opt = NULL;
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
}
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 cleanup;
}
/*
* 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 cleanup;
}
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 cleanup;
}
result = dns_message_rendersection(client->message,
DNS_SECTION_ADDITIONAL,
preferred_glue | render_opts);
if (result != ISC_R_SUCCESS && result != ISC_R_NOSPACE) {
goto cleanup;
}
renderend:
result = dns_message_renderend(client->message);
if (result != ISC_R_SUCCESS) {
goto cleanup;
}
#ifdef HAVE_DNSTAP
memset(&zr, 0, sizeof(zr));
if (((client->message->flags & DNS_MESSAGEFLAG_AA) != 0) &&
(client->query.authzone != NULL))
{
isc_result_t eresult;
isc_buffer_t b;
dns_name_t *zo = dns_zone_getorigin(client->query.authzone);
isc_buffer_init(&b, zone, sizeof(zone));
dns_compress_setpermitted(&cctx, false);
eresult = dns_name_towire(zo, &cctx, &b, NULL);
if (eresult == 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;
}
transport_type = ns_client_transport_type(client);
#endif /* HAVE_DNSTAP */
if (cleanup_cctx) {
dns_compress_invalidate(&cctx);
}
if (client->sendcb != NULL) {
client->sendcb(&buffer);
} else if (TCP_CLIENT(client)) {
isc_buffer_usedregion(&buffer, &r);
#ifdef HAVE_DNSTAP
if (client->view != NULL) {
dns_dt_send(client->view, dtmsgtype, &client->peeraddr,
&client->destsockaddr, transport_type, &zr,
&client->requesttime, NULL, &buffer);
}
#endif /* HAVE_DNSTAP */
respsize = isc_buffer_usedlength(&buffer);
client_sendpkg(client, &buffer);
switch (isc_sockaddr_pf(&client->peeraddr)) {
case AF_INET:
isc_histomulti_inc(client->manager->sctx->tcpoutstats4,
DNS_SIZEHISTO_BUCKETOUT(respsize));
break;
case AF_INET6:
isc_histomulti_inc(client->manager->sctx->tcpoutstats6,
DNS_SIZEHISTO_BUCKETOUT(respsize));
break;
default:
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, transport_type, &zr,
&client->requesttime, NULL, &buffer);
}
#endif /* HAVE_DNSTAP */
respsize = isc_buffer_usedlength(&buffer);
client_sendpkg(client, &buffer);
switch (isc_sockaddr_pf(&client->peeraddr)) {
case AF_INET:
isc_histomulti_inc(client->manager->sctx->udpoutstats4,
DNS_SIZEHISTO_BUCKETOUT(respsize));
break;
case AF_INET6:
isc_histomulti_inc(client->manager->sctx->udpoutstats6,
DNS_SIZEHISTO_BUCKETOUT(respsize));
break;
default:
UNREACHABLE();
}
}
/* update statistics (XXXJT: is it okay to access message->xxxkey?) */
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_response);
dns_rcodestats_increment(client->manager->sctx->rcodestats,
client->message->rcode);
if (opt_included) {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_edns0out);
}
if (client->message->tsigkey != NULL) {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_tsigout);
}
if (client->message->sig0key != NULL) {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_sig0out);
}
if ((client->message->flags & DNS_MESSAGEFLAG_TC) != 0) {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_truncatedresp);
}
client->query.attributes |= NS_QUERYATTR_ANSWERED;
return;
cleanup:
if (client->tcpbuf != NULL) {
client_put_tcp_buffer(client);
}
if (cleanup_cctx) {
dns_compress_invalidate(&cctx);
}
}
#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 /* if NS_CLIENT_DROPPORT */
void
ns_client_error(ns_client_t *client, isc_result_t result) {
dns_message_t *message = NULL;
dns_rcode_t rcode;
bool trunc = false;
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 (result == ISC_R_MAXSIZE) {
trunc = true;
}
#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_drop(client, ISC_R_SUCCESS);
return;
}
#endif /* if NS_CLIENT_DROPPORT */
/*
* 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;
if ((client->manager->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, NULL, &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->manager->sctx->nsstats,
ns_statscounter_ratedropped);
ns_stats_increment(
client->manager->sctx->nsstats,
ns_statscounter_dropped);
ns_client_drop(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_drop(client, result);
return;
}
}
message->rcode = rcode;
if (trunc) {
message->flags |= DNS_MESSAGEFLAG_TC;
}
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_drop(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, flags,
isc_time_seconds(&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[_POSIX_HOST_NAME_MAX + 1], *nsidp = NULL;
unsigned char cookie[COOKIE_SIZE];
isc_result_t result;
dns_view_t *view = NULL;
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 = NULL;
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(opt != NULL && *opt == NULL);
REQUIRE(message != NULL);
env = client->manager->aclenv;
view = client->view;
if (view != NULL) {
udpsize = dns_view_getudpsize(view);
} else {
udpsize = client->manager->sctx->udpsize;
}
flags = client->extflags & DNS_MESSAGEEXTFLAG_REPLYPRESERVE;
/* Set EDNS options if applicable */
if (WANTNSID(client)) {
if (client->manager->sctx->server_id != NULL) {
nsidp = client->manager->sctx->server_id;
} else if (client->manager->sctx->usehostname) {
if (gethostname(nsid, sizeof(nsid)) != 0) {
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 = isc_stdtime_now();
isc_buffer_init(&buf, cookie, sizeof(cookie));
compute_cookie(client, now, client->manager->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:
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 int)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;
uint32_t adv;
INSIST(count < DNS_EDNSOPTIONS);
isc_nm_gettimeouts(isc_nmhandle_netmgr(client->handle), NULL,
NULL, NULL, &adv);
adv /= 100; /* units of 100 milliseconds */
isc_buffer_init(&buf, advtimo, sizeof(advtimo));
isc_buffer_putuint16(&buf, (uint16_t)adv);
ednsopts[count].code = DNS_OPT_TCP_KEEPALIVE;
ednsopts[count].length = 2;
ednsopts[count].value = advtimo;
count++;
}
for (size_t i = 0; i < DNS_EDE_MAX_ERRORS; i++) {
dns_ednsopt_t *ede = client->edectx.ede[i];
if (ede == NULL) {
break;
}
INSIST(count < DNS_EDNSOPTIONS);
ednsopts[count].code = DNS_OPT_EDE;
ednsopts[count].length = ede->length;
ednsopts[count].value = ede->value;
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, 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.");
switch (client->manager->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;
isc_buffer_putmem(buf, client->cookie, 8);
isc_buffer_putuint8(buf, NS_COOKIE_VERSION_1);
isc_buffer_putuint8(buf, 0); /* Reserved */
isc_buffer_putuint16(buf, 0); /* Reserved */
isc_buffer_putuint32(buf, when);
memmove(input, (unsigned char *)isc_buffer_used(buf) - 16, 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:
UNREACHABLE();
}
isc_siphash24(secret, input, inputlen, true, digest);
isc_buffer_putmem(buf, digest, 8);
break;
}
default:
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;
isc_buffer_t db;
bool alwaysvalid;
/*
* If we have already seen a cookie option skip this cookie option.
*/
if ((!client->manager->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->manager->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->manager->sctx->nsstats,
ns_statscounter_cookienew);
} else {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_cookiebadsize);
client->attributes |= NS_CLIENTATTR_BADCOOKIE;
}
return;
}
/*
* Process all of the incoming buffer.
*/
old = isc_buffer_current(buf);
memmove(client->cookie, old, 8);
isc_buffer_forward(buf, 8);
isc_buffer_forward(buf, 4); /* version + reserved */
when = isc_buffer_getuint32(buf);
isc_buffer_forward(buf, 8);
/*
* For '-T cookiealwaysvalid' still process everything to not skew any
* performance tests involving cookies, but make sure that the cookie
* check passes in the end, given the cookie was structurally correct.
*/
alwaysvalid = ns_server_getoption(client->manager->sctx,
NS_SERVER_COOKIEALWAYSVALID);
/*
* 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.
*/
now = isc_stdtime_now();
if (alwaysvalid) {
now = when;
}
if (isc_serial_gt(when, (now + 300)) /* In the future. */ ||
isc_serial_lt(when, (now - 3600)) /* In the past. */)
{
client->attributes |= NS_CLIENTATTR_BADCOOKIE;
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_cookiebadtime);
return;
}
isc_buffer_init(&db, dbuf, sizeof(dbuf));
compute_cookie(client, when, client->manager->sctx->secret, &db);
if (isc_safe_memequal(old, dbuf, COOKIE_SIZE) || alwaysvalid) {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_cookiematch);
client->attributes |= NS_CLIENTATTR_HAVECOOKIE;
return;
}
for (altsecret = ISC_LIST_HEAD(client->manager->sctx->altsecrets);
altsecret != NULL; altsecret = ISC_LIST_NEXT(altsecret, link))
{
isc_buffer_init(&db, dbuf, sizeof(dbuf));
compute_cookie(client, when, altsecret->secret, &db);
if (isc_safe_memequal(old, dbuf, COOKIE_SIZE)) {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_cookiematch);
client->attributes |= NS_CLIENTATTR_HAVECOOKIE;
return;
}
}
client->attributes |= NS_CLIENTATTR_BADCOOKIE;
ns_stats_increment(client->manager->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->manager->mctx, optlen);
{
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;
/* 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);
/*
* When returning BADVERSION, only process
* DNS_OPT_NSID or DNS_OPT_COOKIE options.
*/
if (client->ednsversion > DNS_EDNS_VERSION &&
optcode != DNS_OPT_NSID &&
optcode != DNS_OPT_COOKIE)
{
isc_buffer_forward(&optbuf, optlen);
continue;
}
switch (optcode) {
case DNS_OPT_NSID:
if (!WANTNSID(client)) {
ns_stats_increment(
client->manager->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->manager->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->manager->sctx->nsstats,
ns_statscounter_ecsopt);
break;
case DNS_OPT_TCP_KEEPALIVE:
if (!USEKEEPALIVE(client)) {
ns_stats_increment(
client->manager->sctx->nsstats,
ns_statscounter_keepaliveopt);
}
client->attributes |=
NS_CLIENTATTR_USEKEEPALIVE;
isc_nmhandle_keepalive(client->handle, true);
isc_buffer_forward(&optbuf, optlen);
break;
case DNS_OPT_PAD:
client->attributes |= NS_CLIENTATTR_WANTPAD;
ns_stats_increment(
client->manager->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->manager->sctx->nsstats,
ns_statscounter_keytagopt);
break;
default:
ns_stats_increment(
client->manager->sctx->nsstats,
ns_statscounter_otheropt);
isc_buffer_forward(&optbuf, optlen);
break;
}
}
}
if (client->ednsversion > DNS_EDNS_VERSION) {
ns_stats_increment(client->manager->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;
}
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_edns0in);
client->attributes |= NS_CLIENTATTR_WANTOPT;
return result;
}
static void
ns_client_async_reset(ns_client_t *client) {
if (client->async) {
client->async = false;
if (client->handle != NULL) {
isc_nmhandle_unref(client->handle);
}
}
}
void
ns__client_reset_cb(void *client0) {
ns_client_t *client = client0;
ns_client_log(client, DNS_LOGCATEGORY_SECURITY, NS_LOGMODULE_CLIENT,
ISC_LOG_DEBUG(3), "reset client");
/*
* We never started processing this client, possible if we're
* shutting down, just exit.
*/
if (client->state == NS_CLIENTSTATE_READY) {
return;
}
ns_client_endrequest(client);
if (client->tcpbuf != NULL) {
client_put_tcp_buffer(client);
}
if (client->keytag != NULL) {
isc_mem_put(client->manager->mctx, client->keytag,
client->keytag_len);
client->keytag_len = 0;
}
ns_client_async_reset(client);
client->state = NS_CLIENTSTATE_READY;
#ifdef WANT_SINGLETRACE
isc_log_setforcelog(false);
#endif /* WANT_SINGLETRACE */
}
void
ns__client_put_cb(void *client0) {
ns_client_t *client = client0;
ns_clientmgr_t *manager = NULL;
REQUIRE(NS_CLIENT_VALID(client));
manager = client->manager;
ns_client_log(client, DNS_LOGCATEGORY_SECURITY, NS_LOGMODULE_CLIENT,
ISC_LOG_DEBUG(3), "freeing client");
/*
* Call this first because it requires a valid client.
*/
ns_query_free(client);
dns_ede_invalidate(&client->edectx);
client->magic = 0;
if (client->opt != NULL) {
INSIST(dns_rdataset_isassociated(client->opt));
dns_rdataset_disassociate(client->opt);
dns_message_puttemprdataset(client->message, &client->opt);
}
ns_client_async_reset(client);
dns_message_detach(&client->message);
/*
* Destroy the fetchlock mutex that was created in
* ns_query_init().
*/
isc_mutex_destroy(&client->query.fetchlock);
isc_mem_put(manager->mctx, client, sizeof(*client));
ns_clientmgr_detach(&manager);
}
static isc_result_t
ns_client_setup_view(ns_client_t *client, isc_netaddr_t *netaddr) {
isc_result_t result;
client->sigresult = client->viewmatchresult = ISC_R_UNSET;
if (client->async) {
isc_nmhandle_ref(client->handle);
}
result = client->manager->sctx->matchingview(
netaddr, &client->destaddr, client->message,
client->manager->aclenv, client->manager->sctx,
client->async ? client->manager->loop : NULL,
ns_client_request_continue, client, &client->sigresult,
&client->viewmatchresult, &client->view);
/* Async mode. */
if (result == DNS_R_WAIT) {
INSIST(client->async == true);
return DNS_R_WAIT;
}
/*
* matchingview() returning anything other than DNS_R_WAIT means it's
* not running in async mode, in which case 'result' must be equal to
* 'client->viewmatchresult'.
*/
INSIST(result == client->viewmatchresult);
/* Non-async mode. */
ns_client_async_reset(client);
return result;
}
/*
* Handle an incoming request event from the socket (UDP case)
* or tcpmsg (TCP case).
*/
void
ns_client_request(isc_nmhandle_t *handle, isc_result_t eresult,
isc_region_t *region, void *arg) {
ns_client_t *client = NULL;
isc_result_t result;
dns_rdataset_t *opt = NULL;
isc_netaddr_t netaddr;
int match;
dns_messageid_t id;
unsigned int flags;
bool notimp;
size_t reqsize;
dns_aclenv_t *env = NULL;
if (eresult != ISC_R_SUCCESS) {
return;
}
client = isc_nmhandle_getdata(handle);
if (client == NULL) {
ns_interface_t *ifp = (ns_interface_t *)arg;
ns_clientmgr_t *clientmgr =
ns_interfacemgr_getclientmgr(ifp->mgr);
INSIST(VALID_MANAGER(clientmgr));
INSIST(clientmgr->tid == isc_tid());
client = isc_mem_get(clientmgr->mctx, sizeof(*client));
ns__client_setup(client, clientmgr, true);
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(3),
"allocate new client");
} else {
ns__client_setup(client, NULL, false);
}
client->state = NS_CLIENTSTATE_READY;
if (client->handle == NULL) {
isc_nmhandle_setdata(handle, client, ns__client_reset_cb,
ns__client_put_cb);
client->handle = handle;
}
if (isc_nmhandle_is_stream(handle)) {
client->attributes |= NS_CLIENTATTR_TCP;
}
INSIST(client->state == NS_CLIENTSTATE_READY);
(void)atomic_fetch_add_relaxed(&ns_client_requests, 1);
isc_buffer_init(&client->tbuffer, region->base, region->length);
isc_buffer_add(&client->tbuffer, region->length);
client->buffer = &client->tbuffer;
client->peeraddr = isc_nmhandle_peeraddr(handle);
client->peeraddr_valid = true;
reqsize = isc_buffer_usedlength(client->buffer);
client->state = NS_CLIENTSTATE_WORKING;
client->requesttime = isc_time_now();
client->tnow = client->requesttime;
client->now = isc_time_seconds(&client->tnow);
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");
isc_nm_bad_request(handle);
return;
}
#endif /* if NS_CLIENT_DROPPORT */
env = client->manager->aclenv;
if (client->manager->sctx->blackholeacl != NULL &&
(dns_acl_match(&netaddr, NULL, client->manager->sctx->blackholeacl,
env, &match, NULL) == ISC_R_SUCCESS) &&
match > 0)
{
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"dropped request: blackholed peer");
isc_nm_bad_request(handle);
return;
}
ns_client_log(client, NS_LOGCATEGORY_CLIENT, NS_LOGMODULE_CLIENT,
ISC_LOG_DEBUG(3), "%s request",
TCP_CLIENT(client) ? "TCP" : "UDP");
result = dns_message_peekheader(client->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_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"dropped request: invalid message header");
isc_nm_bad_request(handle);
return;
}
#ifdef WANT_SINGLETRACE
if (id == 0) {
isc_log_setforcelog(true);
}
#endif /* WANT_SINGLETRACE */
/*
* 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) {
ns_client_log(client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(10),
"dropped request: unexpected response");
isc_nm_bad_request(handle);
return;
}
/*
* Update some statistics counters. Don't count responses.
*/
if (isc_sockaddr_pf(&client->peeraddr) == PF_INET) {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_requestv4);
} else {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_requestv6);
}
if (TCP_CLIENT(client)) {
ns_stats_increment(client->manager->sctx->nsstats,
ns_statscounter_requesttcp);
switch (isc_sockaddr_pf(&client->peeraddr)) {
case AF_INET:
isc_histomulti_inc(client->manager->sctx->tcpinstats4,
DNS_SIZEHISTO_BUCKETIN(reqsize));
break;
case AF_INET6:
isc_histomulti_inc(client->manager->sctx->tcpinstats6,
DNS_SIZEHISTO_BUCKETIN(reqsize));
break;
default:
UNREACHABLE();
}
} else {
switch (isc_sockaddr_pf(&client->peeraddr)) {
case AF_INET:
isc_histomulti_inc(client->manager->sctx->udpinstats4,
DNS_SIZEHISTO_BUCKETIN(reqsize));
break;
case AF_INET6:
isc_histomulti_inc(client->manager->sctx->udpinstats6,
DNS_SIZEHISTO_BUCKETIN(reqsize));
break;
default:
UNREACHABLE();
}
}
/*
* It's a request. Parse it.
*/
result = dns_message_parse(client->message, client->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_BADTSIG) {
result = DNS_R_FORMERR;
}
ns_client_error(client, result);
return;
}
dns_opcodestats_increment(client->manager->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;
/*
* Deal with EDNS.
*/
if ((client->manager->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->manager->sctx->options & NS_SERVER_EDNSFORMERR) !=
0)
{
ns_client_error(client, DNS_R_FORMERR);
return;
}
/*
* Are returning NOTIMP to all EDNS queries?
*/
if ((client->manager->sctx->options & NS_SERVER_EDNSNOTIMP) !=
0)
{
ns_client_error(client, DNS_R_NOTIMP);
return;
}
/*
* Are returning REFUSED to all EDNS queries?
*/
if ((client->manager->sctx->options & NS_SERVER_EDNSREFUSED) !=
0)
{
ns_client_error(client, DNS_R_REFUSED);
return;
}
/*
* Are we dropping all EDNS queries?
*/
if ((client->manager->sctx->options & NS_SERVER_DROPEDNS) != 0)
{
ns_client_drop(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;
}
client->destsockaddr = isc_nmhandle_localaddr(handle);
isc_netaddr_fromsockaddr(&client->destaddr, &client->destsockaddr);
/*
* Offload view matching only if we are going to check a SIG(0)
* signature.
*/
client->async = (client->message->tsigkey == NULL &&
client->message->tsig == NULL &&
client->message->sig0 != NULL);
result = ns_client_setup_view(client, &netaddr);
if (result == DNS_R_WAIT) {
return;
}
ns_client_request_continue(client);
}
static void
ns_client_request_continue(void *arg) {
ns_client_t *client = arg;
const dns_name_t *signame = NULL;
bool ra; /* Recursion available. */
isc_result_t result = ISC_R_UNSET;
static const char *ra_reasons[] = {
"ACLs not processed yet",
"no resolver in view",
"recursion not enabled for view",
"allow-recursion did not match",
"allow-query-cache did not match",
"allow-recursion-on did not match",
"allow-query-cache-on did not match",
};
enum refusal_reasons {
INVALID,
NO_RESOLVER,
RECURSION_DISABLED,
ALLOW_RECURSION,
ALLOW_QUERY_CACHE,
ALLOW_RECURSION_ON,
ALLOW_QUERY_CACHE_ON
} ra_refusal_reason = INVALID;
#ifdef HAVE_DNSTAP
dns_transport_type_t transport_type;
dns_dtmsgtype_t dtmsgtype;
#endif /* ifdef HAVE_DNSTAP */
INSIST(client->viewmatchresult != ISC_R_UNSET);
/*
* This function could be running asynchronously, in which case update
* the current 'now' for correct timekeeping.
*/
if (client->async) {
client->tnow = isc_time_now();
client->now = isc_time_seconds(&client->tnow);
}
if (client->viewmatchresult != ISC_R_SUCCESS) {
isc_buffer_t b;
isc_region_t *r;
/*
* Do a dummy TSIG verification attempt so that the
* response will have a TSIG if the query did, as
* required by RFC2845.
*/
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);
if (client->viewmatchresult == ISC_R_QUOTA) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_DEBUG(5),
"SIG(0) checks quota reached");
if (can_log_sigchecks_quota()) {
ns_client_log(client, NS_LOGCATEGORY_CLIENT,
NS_LOGMODULE_CLIENT, ISC_LOG_INFO,
"SIG(0) checks quota reached");
ns_client_dumpmessage(
client, "SIG(0) checks quota reached");
}
} else {
char classname[DNS_RDATACLASS_FORMATSIZE];
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");
}
dns_ede_add(&client->edectx, DNS_EDE_PROHIBITED, NULL);
ns_client_error(client, DNS_R_REFUSED);
goto cleanup;
}
if (isc_nm_is_proxy_handle(client->handle)) {
char fmtbuf[ISC_SOCKADDR_FORMATSIZE] = { 0 };
isc_netaddr_t real_local_addr, real_peer_addr;
isc_sockaddr_t real_local, real_peer;
int log_level = ISC_LOG_DEBUG(10);
real_peer = isc_nmhandle_real_peeraddr(client->handle);
isc_netaddr_fromsockaddr(&real_peer_addr, &real_peer);
real_local = isc_nmhandle_real_localaddr(client->handle);
isc_netaddr_fromsockaddr(&real_local_addr, &real_local);
/* do not allow by default */
if (ns_client_checkaclsilent(client, &real_peer_addr,
client->view->proxyacl,
false) != ISC_R_SUCCESS)
{
if (isc_log_wouldlog(ns_lctx, log_level)) {
isc_sockaddr_format(&real_peer, fmtbuf,
sizeof(fmtbuf));
ns_client_log(
client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, log_level,
"dropped request: PROXY is not allowed "
"for that client (real client address: "
"%s). Rejected by the 'allow-proxy' "
"ACL",
fmtbuf);
}
isc_nm_bad_request(client->handle);
goto cleanup;
}
/* allow by default */
if (ns_client_checkaclsilent(client, &real_local_addr,
client->view->proxyonacl,
true) != ISC_R_SUCCESS)
{
if (isc_log_wouldlog(ns_lctx, log_level)) {
isc_sockaddr_format(&real_local, fmtbuf,
sizeof(fmtbuf));
ns_client_log(
client, DNS_LOGCATEGORY_SECURITY,
NS_LOGMODULE_CLIENT, log_level,
"dropped request: PROXY is not allowed "
"on the interface (real interface "
"address: %s). Rejected by the "
"'allow-proxy-on' ACL",
fmtbuf);
}
isc_nm_bad_request(client->handle);
goto cleanup;
}
}
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->manager->sctx->nsstats,
ns_statscounter_tsigin);
} else {
ns_stats_increment(client->manager->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->manager->sctx->nsstats,
ns_statscounter_invalidsig);
signame = NULL;
if (dns_message_gettsig(client->message, &signame) != NULL) {
char namebuf[DNS_NAME_FORMATSIZE];
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,
namebuf, sizeof(namebuf));
} else {
dns_name_format(signame, namebuf,
sizeof(namebuf));
}
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 primary.
*/
if (!(client->message->tsigstatus == dns_tsigerror_badkey &&
client->message->opcode == dns_opcode_update))
{
ns_client_error(client, client->sigresult);
goto cleanup;
}
}
/*
* 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;
/* must be initialized before ns_client_log uses it as index */
if (client->view->resolver == NULL) {
ra_refusal_reason = NO_RESOLVER;
} else if (!client->view->recursion) {
ra_refusal_reason = RECURSION_DISABLED;
} else if (ns_client_checkaclsilent(client, NULL,
client->view->recursionacl,
true) != ISC_R_SUCCESS)
{
ra_refusal_reason = ALLOW_RECURSION;
} else if (ns_client_checkaclsilent(client, NULL,
client->view->cacheacl,
true) != ISC_R_SUCCESS)
{
ra_refusal_reason = ALLOW_QUERY_CACHE;
} else if (ns_client_checkaclsilent(client, &client->destaddr,
client->view->recursiononacl,
true) != ISC_R_SUCCESS)
{
ra_refusal_reason = ALLOW_RECURSION_ON;
} else if (ns_client_checkaclsilent(client, &client->destaddr,
client->view->cacheonacl,
true) != ISC_R_SUCCESS)
{
ra_refusal_reason = ALLOW_QUERY_CACHE_ON;
} else {
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 (%s)",
ra_reasons[ra_refusal_reason]);
/*
* Adjust maximum UDP response size for this client.
*/
if (client->udpsize > 512) {
dns_peer_t *peer = NULL;
uint16_t udpsize = client->view->maxudp;
isc_netaddr_t netaddr;
isc_netaddr_fromsockaddr(&netaddr, &client->peeraddr);
(void)dns_peerlist_peerbyaddr(client->view->peers, &netaddr,
&peer);
if (peer != NULL) {
dns_peer_getmaxudp(peer, &udpsize);
}
if (client->udpsize > udpsize) {
client->udpsize = udpsize;
}
}
#ifdef HAVE_DNSTAP
transport_type = ns_client_transport_type(client);
#endif /* HAVE_DNSTAP */
/*
* 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, transport_type, NULL,
&client->requesttime, NULL, client->buffer);
#endif /* HAVE_DNSTAP */
ns_query_start(client, client->handle);
break;
case dns_opcode_update:
CTRACE("update");
#ifdef HAVE_DNSTAP
dns_dt_send(client->view, DNS_DTTYPE_UQ, &client->peeraddr,
&client->destsockaddr, transport_type, NULL,
&client->requesttime, NULL, client->buffer);
#endif /* HAVE_DNSTAP */
ns_client_settimeout(client, 60);
ns_update_start(client, client->handle, client->sigresult);
break;
case dns_opcode_notify:
CTRACE("notify");
ns_client_settimeout(client, 60);
ns_notify_start(client, client->handle);
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);
}
cleanup:
ns_client_async_reset(client);
}
isc_result_t
ns__client_tcpconn(isc_nmhandle_t *handle, isc_result_t result, void *arg) {
ns_interface_t *ifp = (ns_interface_t *)arg;
dns_aclenv_t *env = ns_interfacemgr_getaclenv(ifp->mgr);
ns_server_t *sctx = ns_interfacemgr_getserver(ifp->mgr);
unsigned int tcpquota;
isc_sockaddr_t peeraddr;
isc_netaddr_t netaddr;
int match;
if (result != ISC_R_SUCCESS) {
return result;
}
if (handle != NULL) {
peeraddr = isc_nmhandle_peeraddr(handle);
isc_netaddr_fromsockaddr(&netaddr, &peeraddr);
if (sctx->blackholeacl != NULL &&
(dns_acl_match(&netaddr, NULL, sctx->blackholeacl, env,
&match, NULL) == ISC_R_SUCCESS) &&
match > 0)
{
return ISC_R_CONNREFUSED;
}
}
tcpquota = isc_quota_getused(&sctx->tcpquota);
ns_stats_update_if_greater(sctx->nsstats, ns_statscounter_tcphighwater,
tcpquota);
return ISC_R_SUCCESS;
}
void
ns__client_setup(ns_client_t *client, ns_clientmgr_t *mgr, bool new) {
/*
* Note: creating a client does not add the client to the
* manager's client list, the caller is responsible for that.
*/
if (new) {
REQUIRE(VALID_MANAGER(mgr));
REQUIRE(client != NULL);
REQUIRE(mgr->tid == isc_tid());
*client = (ns_client_t){ .magic = 0 };
ns_clientmgr_attach(mgr, &client->manager);
dns_message_create(client->manager->mctx,
client->manager->namepool,
client->manager->rdspool,
DNS_MESSAGE_INTENTPARSE, &client->message);
/*
* Set magic earlier than usual because ns_query_init()
* and the functions it calls will require it.
*/
client->magic = NS_CLIENT_MAGIC;
ns_query_init(client);
dns_ede_init(client->manager->mctx, &client->edectx);
} else {
REQUIRE(NS_CLIENT_VALID(client));
REQUIRE(client->manager->tid == isc_tid());
/*
* Retain these values from the existing client, but
* zero every thing else.
*/
*client = (ns_client_t){
.magic = 0,
.manager = client->manager,
.message = client->message,
.edectx = client->edectx,
.query = client->query,
};
dns_ede_reset(&client->edectx);
}
client->query.attributes &= ~NS_QUERYATTR_ANSWERED;
client->state = NS_CLIENTSTATE_INACTIVE;
client->udpsize = 512;
client->ednsversion = -1;
dns_name_init(&client->signername, NULL);
dns_ecs_init(&client->ecs);
isc_sockaddr_any(&client->formerrcache.addr);
client->formerrcache.time = 0;
client->formerrcache.id = 0;
ISC_LINK_INIT(client, rlink);
client->rcode_override = -1; /* not set */
client->magic = NS_CLIENT_MAGIC;
CTRACE("client_setup");
}
/***
*** Client Manager
***/
static void
clientmgr_destroy_cb(void *arg) {
ns_clientmgr_t *manager = (ns_clientmgr_t *)arg;
MTRACE("clientmgr_destroy");
manager->magic = 0;
isc_loop_detach(&manager->loop);
dns_aclenv_detach(&manager->aclenv);
isc_mutex_destroy(&manager->reclock);
ns_server_detach(&manager->sctx);
dns_message_destroypools(&manager->rdspool, &manager->namepool);
isc_mem_putanddetach(&manager->mctx, manager, sizeof(*manager));
}
static void
clientmgr_destroy(ns_clientmgr_t *mgr) {
isc_async_run(mgr->loop, clientmgr_destroy_cb, mgr);
}
ISC_REFCOUNT_IMPL(ns_clientmgr, clientmgr_destroy);
isc_result_t
ns_clientmgr_create(ns_server_t *sctx, isc_loopmgr_t *loopmgr,
dns_aclenv_t *aclenv, int tid, ns_clientmgr_t **managerp) {
ns_clientmgr_t *manager = NULL;
isc_mem_t *mctx = NULL;
isc_mem_create(&mctx);
isc_mem_setname(mctx, "clientmgr");
manager = isc_mem_get(mctx, sizeof(*manager));
*manager = (ns_clientmgr_t){
.magic = 0,
.mctx = mctx,
.tid = tid,
.recursing = ISC_LIST_INITIALIZER,
};
isc_loop_attach(isc_loop_get(loopmgr, tid), &manager->loop);
isc_mutex_init(&manager->reclock);
dns_aclenv_attach(aclenv, &manager->aclenv);
isc_refcount_init(&manager->references, 1);
ns_server_attach(sctx, &manager->sctx);
dns_message_createpools(mctx, &manager->namepool, &manager->rdspool);
manager->magic = MANAGER_MAGIC;
MTRACE("create");
*managerp = manager;
return ISC_R_SUCCESS;
}
void
ns_clientmgr_shutdown(ns_clientmgr_t *manager) {
ns_client_t *client;
REQUIRE(VALID_MANAGER(manager));
MTRACE("destroy");
LOCK(&manager->reclock);
for (client = ISC_LIST_HEAD(manager->recursing); client != NULL;
client = ISC_LIST_NEXT(client, rlink))
{
ns_query_cancel(client);
}
UNLOCK(&manager->reclock);
}
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 = client->manager->aclenv;
isc_netaddr_t tmpnetaddr;
int match;
isc_sockaddr_t local;
if (acl == NULL) {
if (default_allow) {
goto allow;
} else {
goto deny;
}
}
if (netaddr == NULL) {
isc_netaddr_fromsockaddr(&tmpnetaddr, &client->peeraddr);
netaddr = &tmpnetaddr;
}
local = isc_nmhandle_localaddr(client->handle);
result = dns_acl_match_port_transport(
netaddr, isc_sockaddr_getport(&local),
isc_nm_socket_type(client->handle),
isc_nm_has_encryption(client->handle), 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 {
dns_ede_add(&client->edectx, DNS_EDE_PROHIBITED, NULL);
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->manager->mctx, len);
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->manager->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->manager->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;
REQUIRE(NS_CLIENT_VALID(client));
rdataset = NULL;
dns_message_gettemprdataset(client->message, &rdataset);
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 = NULL;
CTRACE("ns_client_newnamebuf");
isc_buffer_allocate(client->manager->mctx, &dbuf, 1024);
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 = NULL;
isc_region_t r;
REQUIRE((client->query.attributes & NS_QUERYATTR_NAMEBUFUSED) == 0);
CTRACE("ns_client_newname");
dns_message_gettempname(client->message, &name);
isc_buffer_availableregion(dbuf, &r);
isc_buffer_init(nbuf, r.base, r.length);
dns_name_setbuffer(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_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)) {
ns_client_newnamebuf(client);
}
dbuf = ISC_LIST_TAIL(client->query.namebufs);
INSIST(dbuf != NULL);
isc_buffer_availableregion(dbuf, &r);
if (r.length < DNS_NAME_MAXWIRE) {
ns_client_newnamebuf(client);
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) {
/*%
* '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");
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 = NULL;
for (i = 0; i < n; i++) {
dbversion = isc_mem_get(client->manager->mctx,
sizeof(*dbversion));
*dbversion = (ns_dbversion_t){ 0 };
ISC_LIST_INITANDAPPEND(client->query.freeversions, dbversion,
link);
}
return ISC_R_SUCCESS;
}
static ns_dbversion_t *
client_getdbversion(ns_client_t *client) {
ns_dbversion_t *dbversion = NULL;
if (ISC_LIST_EMPTY(client->query.freeversions)) {
ns_client_newdbversion(client, 1);
}
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;
}
View git blame Copy permalink