dns_server: Remove parameter 'dns recursive queries' and base this on 'dns forwarder'
[nivanova/samba-autobuild/.git] / source4 / dns_server / dns_server.c
1 /*
2    Unix SMB/CIFS implementation.
3
4    DNS server startup
5
6    Copyright (C) 2010 Kai Blin  <kai@samba.org>
7
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3 of the License, or
11    (at your option) any later version.
12
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17
18    You should have received a copy of the GNU General Public License
19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include "includes.h"
23 #include "smbd/service_task.h"
24 #include "smbd/service.h"
25 #include "smbd/service_stream.h"
26 #include "smbd/process_model.h"
27 #include "lib/events/events.h"
28 #include "lib/socket/socket.h"
29 #include "lib/tsocket/tsocket.h"
30 #include "libcli/util/tstream.h"
31 #include "libcli/util/ntstatus.h"
32 #include "system/network.h"
33 #include "lib/stream/packet.h"
34 #include "lib/socket/netif.h"
35 #include "dns_server/dns_server.h"
36 #include "param/param.h"
37 #include "librpc/ndr/libndr.h"
38 #include "librpc/gen_ndr/ndr_dns.h"
39 #include "librpc/gen_ndr/ndr_dnsp.h"
40 #include <ldb.h>
41 #include "dsdb/samdb/samdb.h"
42 #include "dsdb/common/util.h"
43 #include "auth/session.h"
44 #include "lib/util/dlinklist.h"
45 #include "lib/util/tevent_werror.h"
46 #include "auth/auth.h"
47 #include "auth/credentials/credentials.h"
48
49 NTSTATUS server_service_dns_init(void);
50
51 /* hold information about one dns socket */
52 struct dns_socket {
53         struct dns_server *dns;
54         struct tsocket_address *local_address;
55 };
56
57 struct dns_udp_socket {
58         struct dns_socket *dns_socket;
59         struct tdgram_context *dgram;
60         struct tevent_queue *send_queue;
61 };
62
63 /*
64   state of an open tcp connection
65 */
66 struct dns_tcp_connection {
67         /* stream connection we belong to */
68         struct stream_connection *conn;
69
70         /* the dns_server the connection belongs to */
71         struct dns_socket *dns_socket;
72
73         struct tstream_context *tstream;
74
75         struct tevent_queue *send_queue;
76 };
77
78 static void dns_tcp_terminate_connection(struct dns_tcp_connection *dnsconn, const char *reason)
79 {
80         stream_terminate_connection(dnsconn->conn, reason);
81 }
82
83 static void dns_tcp_recv(struct stream_connection *conn, uint16_t flags)
84 {
85         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
86                                                              struct dns_tcp_connection);
87         /* this should never be triggered! */
88         dns_tcp_terminate_connection(dnsconn, "dns_tcp_recv: called");
89 }
90
91 static void dns_tcp_send(struct stream_connection *conn, uint16_t flags)
92 {
93         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
94                                                              struct dns_tcp_connection);
95         /* this should never be triggered! */
96         dns_tcp_terminate_connection(dnsconn, "dns_tcp_send: called");
97 }
98
99 struct dns_process_state {
100         DATA_BLOB *in;
101         struct dns_server *dns;
102         struct dns_name_packet in_packet;
103         struct dns_request_state state;
104         uint16_t dns_err;
105         struct dns_name_packet out_packet;
106         DATA_BLOB out;
107 };
108
109 static void dns_process_done(struct tevent_req *subreq);
110
111 static struct tevent_req *dns_process_send(TALLOC_CTX *mem_ctx,
112                                            struct tevent_context *ev,
113                                            struct dns_server *dns,
114                                            DATA_BLOB *in)
115 {
116         struct tevent_req *req, *subreq;
117         struct dns_process_state *state;
118         enum ndr_err_code ndr_err;
119         WERROR ret;
120         const char *forwarder = lpcfg_dns_forwarder(dns->task->lp_ctx);
121         req = tevent_req_create(mem_ctx, &state, struct dns_process_state);
122         if (req == NULL) {
123                 return NULL;
124         }
125         state->in = in;
126
127         state->dns = dns;
128
129         if (in->length < 12) {
130                 tevent_req_werror(req, WERR_INVALID_PARAM);
131                 return tevent_req_post(req, ev);
132         }
133         dump_data(8, in->data, in->length);
134
135         ndr_err = ndr_pull_struct_blob(
136                 in, state, &state->in_packet,
137                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
138
139         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
140                 state->dns_err = DNS_RCODE_FORMERR;
141                 tevent_req_done(req);
142                 return tevent_req_post(req, ev);
143         }
144         if (DEBUGLVL(8)) {
145                 NDR_PRINT_DEBUG(dns_name_packet, &state->in_packet);
146         }
147
148         ret = dns_verify_tsig(dns, state, &state->state, &state->in_packet, in);
149         if (!W_ERROR_IS_OK(ret)) {
150                 DEBUG(1, ("Failed to verify TSIG!\n"));
151                 state->dns_err = werr_to_dns_err(ret);
152                 tevent_req_done(req);
153                 return tevent_req_post(req, ev);
154         }
155
156         state->state.flags = state->in_packet.operation;
157         state->state.flags |= DNS_FLAG_REPLY;
158
159         
160         if (forwarder && *forwarder) {
161                 state->state.flags |= DNS_FLAG_RECURSION_AVAIL;
162         }
163
164         state->out_packet = state->in_packet;
165
166         switch (state->in_packet.operation & DNS_OPCODE) {
167         case DNS_OPCODE_QUERY:
168                 subreq = dns_server_process_query_send(
169                         state, ev, dns, &state->state, &state->in_packet);
170                 if (tevent_req_nomem(subreq, req)) {
171                         return tevent_req_post(req, ev);
172                 }
173                 tevent_req_set_callback(subreq, dns_process_done, req);
174                 return req;
175         case DNS_OPCODE_UPDATE:
176                 ret = dns_server_process_update(
177                         dns, &state->state, state, &state->in_packet,
178                         &state->out_packet.answers, &state->out_packet.ancount,
179                         &state->out_packet.nsrecs,  &state->out_packet.nscount,
180                         &state->out_packet.additional,
181                         &state->out_packet.arcount);
182                 break;
183         default:
184                 ret = WERR_DNS_ERROR_RCODE_NOT_IMPLEMENTED;
185         }
186         if (!W_ERROR_IS_OK(ret)) {
187                 state->dns_err = werr_to_dns_err(ret);
188         }
189         tevent_req_done(req);
190         return tevent_req_post(req, ev);
191 }
192
193 static void dns_process_done(struct tevent_req *subreq)
194 {
195         struct tevent_req *req = tevent_req_callback_data(
196                 subreq, struct tevent_req);
197         struct dns_process_state *state = tevent_req_data(
198                 req, struct dns_process_state);
199         WERROR ret;
200
201         ret = dns_server_process_query_recv(
202                 subreq, state,
203                 &state->out_packet.answers, &state->out_packet.ancount,
204                 &state->out_packet.nsrecs,  &state->out_packet.nscount,
205                 &state->out_packet.additional, &state->out_packet.arcount);
206         TALLOC_FREE(subreq);
207
208         if (!W_ERROR_IS_OK(ret)) {
209                 state->dns_err = werr_to_dns_err(ret);
210         }
211         tevent_req_done(req);
212 }
213
214 static WERROR dns_process_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
215                                DATA_BLOB *out)
216 {
217         struct dns_process_state *state = tevent_req_data(
218                 req, struct dns_process_state);
219         enum ndr_err_code ndr_err;
220         WERROR ret;
221
222         if (tevent_req_is_werror(req, &ret)) {
223                 return ret;
224         }
225         if (state->dns_err != DNS_RCODE_OK) {
226                 goto drop;
227         }
228         state->out_packet.operation |= state->state.flags;
229
230         if (state->state.sign) {
231                 ret = dns_sign_tsig(state->dns, mem_ctx, &state->state,
232                                     &state->out_packet, 0);
233                 if (!W_ERROR_IS_OK(ret)) {
234                         state->dns_err = DNS_RCODE_SERVFAIL;
235                         goto drop;
236                 }
237         }
238
239         ndr_err = ndr_push_struct_blob(
240                 out, mem_ctx, &state->out_packet,
241                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
242         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
243                 DEBUG(1, ("Failed to push packet: %s!\n",
244                           ndr_errstr(ndr_err)));
245                 state->dns_err = DNS_RCODE_SERVFAIL;
246                 goto drop;
247         }
248         return WERR_OK;
249
250 drop:
251         *out = data_blob_talloc(mem_ctx, state->in->data, state->in->length);
252         if (out->data == NULL) {
253                 return WERR_NOMEM;
254         }
255         out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
256         out->data[3] |= state->dns_err;
257         return WERR_OK;
258 }
259
260 struct dns_tcp_call {
261         struct dns_tcp_connection *dns_conn;
262         DATA_BLOB in;
263         DATA_BLOB out;
264         uint8_t out_hdr[4];
265         struct iovec out_iov[2];
266 };
267
268 static void dns_tcp_call_process_done(struct tevent_req *subreq);
269 static void dns_tcp_call_writev_done(struct tevent_req *subreq);
270
271 static void dns_tcp_call_loop(struct tevent_req *subreq)
272 {
273         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
274                                       struct dns_tcp_connection);
275         struct dns_server *dns = dns_conn->dns_socket->dns;
276         struct dns_tcp_call *call;
277         NTSTATUS status;
278
279         call = talloc(dns_conn, struct dns_tcp_call);
280         if (call == NULL) {
281                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
282                                 "no memory for dns_tcp_call");
283                 return;
284         }
285         call->dns_conn = dns_conn;
286
287         status = tstream_read_pdu_blob_recv(subreq,
288                                             call,
289                                             &call->in);
290         TALLOC_FREE(subreq);
291         if (!NT_STATUS_IS_OK(status)) {
292                 const char *reason;
293
294                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
295                                          "tstream_read_pdu_blob_recv() - %s",
296                                          nt_errstr(status));
297                 if (!reason) {
298                         reason = nt_errstr(status);
299                 }
300
301                 dns_tcp_terminate_connection(dns_conn, reason);
302                 return;
303         }
304
305         DEBUG(10,("Received DNS TCP packet of length %lu from %s\n",
306                  (long) call->in.length,
307                  tsocket_address_string(dns_conn->conn->remote_address, call)));
308
309         /* skip length header */
310         call->in.data += 2;
311         call->in.length -= 2;
312
313         subreq = dns_process_send(call, dns->task->event_ctx, dns,
314                                   &call->in);
315         if (subreq == NULL) {
316                 dns_tcp_terminate_connection(
317                         dns_conn, "dns_tcp_call_loop: dns_process_send "
318                         "failed\n");
319                 return;
320         }
321         tevent_req_set_callback(subreq, dns_tcp_call_process_done, call);
322
323         /*
324          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
325          * packet_full_request_u16 provides the pdu length then.
326          */
327         subreq = tstream_read_pdu_blob_send(dns_conn,
328                                             dns_conn->conn->event.ctx,
329                                             dns_conn->tstream,
330                                             2, /* initial_read_size */
331                                             packet_full_request_u16,
332                                             dns_conn);
333         if (subreq == NULL) {
334                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
335                                 "no memory for tstream_read_pdu_blob_send");
336                 return;
337         }
338         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
339 }
340
341 static void dns_tcp_call_process_done(struct tevent_req *subreq)
342 {
343         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
344                         struct dns_tcp_call);
345         struct dns_tcp_connection *dns_conn = call->dns_conn;
346         WERROR err;
347
348         err = dns_process_recv(subreq, call, &call->out);
349         TALLOC_FREE(subreq);
350         if (!W_ERROR_IS_OK(err)) {
351                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
352                 dns_tcp_terminate_connection(dns_conn,
353                                 "dns_tcp_call_loop: process function failed");
354                 return;
355         }
356
357         /* First add the length of the out buffer */
358         RSSVAL(call->out_hdr, 0, call->out.length);
359         call->out_iov[0].iov_base = (char *) call->out_hdr;
360         call->out_iov[0].iov_len = 2;
361
362         call->out_iov[1].iov_base = (char *) call->out.data;
363         call->out_iov[1].iov_len = call->out.length;
364
365         subreq = tstream_writev_queue_send(call,
366                                            dns_conn->conn->event.ctx,
367                                            dns_conn->tstream,
368                                            dns_conn->send_queue,
369                                            call->out_iov, 2);
370         if (subreq == NULL) {
371                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
372                                 "no memory for tstream_writev_queue_send");
373                 return;
374         }
375         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
376 }
377
378 static void dns_tcp_call_writev_done(struct tevent_req *subreq)
379 {
380         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
381                         struct dns_tcp_call);
382         int sys_errno;
383         int rc;
384
385         rc = tstream_writev_queue_recv(subreq, &sys_errno);
386         TALLOC_FREE(subreq);
387         if (rc == -1) {
388                 const char *reason;
389
390                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
391                                          "tstream_writev_queue_recv() - %d:%s",
392                                          sys_errno, strerror(sys_errno));
393                 if (!reason) {
394                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
395                 }
396
397                 dns_tcp_terminate_connection(call->dns_conn, reason);
398                 return;
399         }
400
401         /* We don't care about errors */
402
403         talloc_free(call);
404 }
405
406 /*
407   called when we get a new connection
408 */
409 static void dns_tcp_accept(struct stream_connection *conn)
410 {
411         struct dns_socket *dns_socket;
412         struct dns_tcp_connection *dns_conn;
413         struct tevent_req *subreq;
414         int rc;
415
416         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
417         if (dns_conn == NULL) {
418                 stream_terminate_connection(conn,
419                                 "dns_tcp_accept: out of memory");
420                 return;
421         }
422
423         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
424         if (dns_conn->send_queue == NULL) {
425                 stream_terminate_connection(conn,
426                                 "dns_tcp_accept: out of memory");
427                 return;
428         }
429
430         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
431
432         TALLOC_FREE(conn->event.fde);
433
434         rc = tstream_bsd_existing_socket(dns_conn,
435                         socket_get_fd(conn->socket),
436                         &dns_conn->tstream);
437         if (rc < 0) {
438                 stream_terminate_connection(conn,
439                                 "dns_tcp_accept: out of memory");
440                 return;
441         }
442
443         dns_conn->conn = conn;
444         dns_conn->dns_socket = dns_socket;
445         conn->private_data = dns_conn;
446
447         /*
448          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
449          * packet_full_request_u16 provides the pdu length then.
450          */
451         subreq = tstream_read_pdu_blob_send(dns_conn,
452                                             dns_conn->conn->event.ctx,
453                                             dns_conn->tstream,
454                                             2, /* initial_read_size */
455                                             packet_full_request_u16,
456                                             dns_conn);
457         if (subreq == NULL) {
458                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
459                                 "no memory for tstream_read_pdu_blob_send");
460                 return;
461         }
462         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
463 }
464
465 static const struct stream_server_ops dns_tcp_stream_ops = {
466         .name                   = "dns_tcp",
467         .accept_connection      = dns_tcp_accept,
468         .recv_handler           = dns_tcp_recv,
469         .send_handler           = dns_tcp_send
470 };
471
472 struct dns_udp_call {
473         struct dns_udp_socket *sock;
474         struct tsocket_address *src;
475         DATA_BLOB in;
476         DATA_BLOB out;
477 };
478
479 static void dns_udp_call_process_done(struct tevent_req *subreq);
480 static void dns_udp_call_sendto_done(struct tevent_req *subreq);
481
482 static void dns_udp_call_loop(struct tevent_req *subreq)
483 {
484         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
485                                       struct dns_udp_socket);
486         struct dns_server *dns = sock->dns_socket->dns;
487         struct dns_udp_call *call;
488         uint8_t *buf;
489         ssize_t len;
490         int sys_errno;
491
492         call = talloc(sock, struct dns_udp_call);
493         if (call == NULL) {
494                 talloc_free(call);
495                 goto done;
496         }
497         call->sock = sock;
498
499         len = tdgram_recvfrom_recv(subreq, &sys_errno,
500                                    call, &buf, &call->src);
501         TALLOC_FREE(subreq);
502         if (len == -1) {
503                 talloc_free(call);
504                 goto done;
505         }
506
507         call->in.data = buf;
508         call->in.length = len;
509
510         DEBUG(10,("Received DNS UDP packet of length %lu from %s\n",
511                  (long)call->in.length,
512                  tsocket_address_string(call->src, call)));
513
514         subreq = dns_process_send(call, dns->task->event_ctx, dns,
515                                   &call->in);
516         if (subreq == NULL) {
517                 TALLOC_FREE(call);
518                 goto done;
519         }
520         tevent_req_set_callback(subreq, dns_udp_call_process_done, call);
521
522 done:
523         subreq = tdgram_recvfrom_send(sock,
524                                       sock->dns_socket->dns->task->event_ctx,
525                                       sock->dgram);
526         if (subreq == NULL) {
527                 task_server_terminate(sock->dns_socket->dns->task,
528                                       "no memory for tdgram_recvfrom_send",
529                                       true);
530                 return;
531         }
532         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
533 }
534
535 static void dns_udp_call_process_done(struct tevent_req *subreq)
536 {
537         struct dns_udp_call *call = tevent_req_callback_data(
538                 subreq, struct dns_udp_call);
539         struct dns_udp_socket *sock = call->sock;
540         struct dns_server *dns = sock->dns_socket->dns;
541         WERROR err;
542
543         err = dns_process_recv(subreq, call, &call->out);
544         TALLOC_FREE(subreq);
545         if (!W_ERROR_IS_OK(err)) {
546                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
547                 TALLOC_FREE(call);
548                 return;
549         }
550
551         subreq = tdgram_sendto_queue_send(call,
552                                           dns->task->event_ctx,
553                                           sock->dgram,
554                                           sock->send_queue,
555                                           call->out.data,
556                                           call->out.length,
557                                           call->src);
558         if (subreq == NULL) {
559                 talloc_free(call);
560                 return;
561         }
562         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
563
564 }
565 static void dns_udp_call_sendto_done(struct tevent_req *subreq)
566 {
567         struct dns_udp_call *call = tevent_req_callback_data(subreq,
568                                        struct dns_udp_call);
569         ssize_t ret;
570         int sys_errno;
571
572         ret = tdgram_sendto_queue_recv(subreq, &sys_errno);
573
574         /* We don't care about errors */
575
576         talloc_free(call);
577 }
578
579 /*
580   start listening on the given address
581 */
582 static NTSTATUS dns_add_socket(struct dns_server *dns,
583                                const struct model_ops *model_ops,
584                                const char *name,
585                                const char *address,
586                                uint16_t port)
587 {
588         struct dns_socket *dns_socket;
589         struct dns_udp_socket *dns_udp_socket;
590         struct tevent_req *udpsubreq;
591         NTSTATUS status;
592         int ret;
593
594         dns_socket = talloc(dns, struct dns_socket);
595         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
596
597         dns_socket->dns = dns;
598
599         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
600                                                 address, port,
601                                                 &dns_socket->local_address);
602         if (ret != 0) {
603                 status = map_nt_error_from_unix_common(errno);
604                 return status;
605         }
606
607         status = stream_setup_socket(dns->task,
608                                      dns->task->event_ctx,
609                                      dns->task->lp_ctx,
610                                      model_ops,
611                                      &dns_tcp_stream_ops,
612                                      "ip", address, &port,
613                                      lpcfg_socket_options(dns->task->lp_ctx),
614                                      dns_socket);
615         if (!NT_STATUS_IS_OK(status)) {
616                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
617                          address, port, nt_errstr(status)));
618                 talloc_free(dns_socket);
619                 return status;
620         }
621
622         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
623         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
624
625         dns_udp_socket->dns_socket = dns_socket;
626
627         ret = tdgram_inet_udp_socket(dns_socket->local_address,
628                                      NULL,
629                                      dns_udp_socket,
630                                      &dns_udp_socket->dgram);
631         if (ret != 0) {
632                 status = map_nt_error_from_unix_common(errno);
633                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
634                          address, port, nt_errstr(status)));
635                 return status;
636         }
637
638         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
639                                                          "dns_udp_send_queue");
640         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
641
642         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
643                                          dns->task->event_ctx,
644                                          dns_udp_socket->dgram);
645         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
646         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
647
648         return NT_STATUS_OK;
649 }
650
651 /*
652   setup our listening sockets on the configured network interfaces
653 */
654 static NTSTATUS dns_startup_interfaces(struct dns_server *dns, struct loadparm_context *lp_ctx,
655                                        struct interface *ifaces)
656 {
657         const struct model_ops *model_ops;
658         int num_interfaces;
659         TALLOC_CTX *tmp_ctx = talloc_new(dns);
660         NTSTATUS status;
661         int i;
662
663         /* within the dns task we want to be a single process, so
664            ask for the single process model ops and pass these to the
665            stream_setup_socket() call. */
666         model_ops = process_model_startup("single");
667         if (!model_ops) {
668                 DEBUG(0,("Can't find 'single' process model_ops\n"));
669                 return NT_STATUS_INTERNAL_ERROR;
670         }
671
672         num_interfaces = iface_list_count(ifaces);
673
674         for (i=0; i<num_interfaces; i++) {
675                 const char *address = talloc_strdup(tmp_ctx, iface_list_n_ip(ifaces, i));
676
677                 status = dns_add_socket(dns, model_ops, "dns", address, DNS_SERVICE_PORT);
678                 NT_STATUS_NOT_OK_RETURN(status);
679         }
680
681         talloc_free(tmp_ctx);
682
683         return NT_STATUS_OK;
684 }
685
686 static int dns_server_sort_zones(struct ldb_message **m1, struct ldb_message **m2)
687 {
688         const char *n1, *n2;
689         size_t l1, l2;
690
691         n1 = ldb_msg_find_attr_as_string(*m1, "name", NULL);
692         n2 = ldb_msg_find_attr_as_string(*m2, "name", NULL);
693
694         l1 = strlen(n1);
695         l2 = strlen(n2);
696
697         /* If the string lengths are not equal just sort by length */
698         if (l1 != l2) {
699                 /* If m1 is the larger zone name, return it first */
700                 return l2 - l1;
701         }
702
703         /*TODO: We need to compare DNs here, we want the DomainDNSZones first */
704         return 0;
705 }
706
707 static struct dns_server_tkey_store *tkey_store_init(TALLOC_CTX *mem_ctx,
708                                                      uint16_t size)
709 {
710         struct dns_server_tkey_store *buffer = talloc_zero(mem_ctx,
711                                                 struct dns_server_tkey_store);
712
713         if (buffer == NULL) {
714                 return NULL;
715         }
716
717         buffer->size = size;
718         buffer->next_idx = 0;
719
720         buffer->tkeys = talloc_zero_array(buffer, struct dns_server_tkey *, size);
721         if (buffer->tkeys == NULL) {
722                 TALLOC_FREE(buffer);
723         }
724
725         return buffer;
726 }
727
728 static void dns_task_init(struct task_server *task)
729 {
730         struct dns_server *dns;
731         NTSTATUS status;
732         struct interface *ifaces;
733         int ret;
734         struct ldb_result *res;
735         static const char * const attrs[] = { "name", NULL};
736         unsigned int i;
737
738         switch (lpcfg_server_role(task->lp_ctx)) {
739         case ROLE_STANDALONE:
740                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
741                 return;
742         case ROLE_DOMAIN_MEMBER:
743                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
744                 return;
745         case ROLE_ACTIVE_DIRECTORY_DC:
746                 /* Yes, we want a DNS */
747                 break;
748         }
749
750         load_interface_list(task, task->lp_ctx, &ifaces);
751
752         if (iface_list_count(ifaces) == 0) {
753                 task_server_terminate(task, "dns: no network interfaces configured", false);
754                 return;
755         }
756
757         task_server_set_title(task, "task[dns]");
758
759         dns = talloc_zero(task, struct dns_server);
760         if (dns == NULL) {
761                 task_server_terminate(task, "dns: out of memory", true);
762                 return;
763         }
764
765         dns->task = task;
766
767         dns->server_credentials = cli_credentials_init(dns);
768         if (!dns->server_credentials) {
769                 task_server_terminate(task, "Failed to init server credentials\n", true);
770                 return;
771         }
772
773         cli_credentials_set_conf(dns->server_credentials, task->lp_ctx);
774         status = cli_credentials_set_machine_account(dns->server_credentials, task->lp_ctx);
775         if (!NT_STATUS_IS_OK(status)) {
776                 task_server_terminate(task,
777                         talloc_asprintf(task, "Failed to obtain server credentials, perhaps a standalone server?: %s\n",
778                                         nt_errstr(status)),
779                         true);
780                 return;
781         }
782
783         dns->tkeys = tkey_store_init(dns, TKEY_BUFFER_SIZE);
784         if (!dns->tkeys) {
785                 task_server_terminate(task, "Failed to allocate tkey storage\n", true);
786                 return;
787         }
788
789         dns->samdb = samdb_connect(dns, dns->task->event_ctx, dns->task->lp_ctx,
790                               system_session(dns->task->lp_ctx), 0);
791         if (!dns->samdb) {
792                 task_server_terminate(task, "dns: samdb_connect failed", true);
793                 return;
794         }
795
796         // TODO: this search does not work against windows
797         ret = dsdb_search(dns->samdb, dns, &res, NULL, LDB_SCOPE_SUBTREE,
798                           attrs, DSDB_SEARCH_SEARCH_ALL_PARTITIONS, "(objectClass=dnsZone)");
799         if (ret != LDB_SUCCESS) {
800                 task_server_terminate(task,
801                                       "dns: failed to look up root DNS zones",
802                                       true);
803                 return;
804         }
805
806         TYPESAFE_QSORT(res->msgs, res->count, dns_server_sort_zones);
807
808         for (i=0; i < res->count; i++) {
809                 struct dns_server_zone *z;
810
811                 z = talloc_zero(dns, struct dns_server_zone);
812                 if (z == NULL) {
813                 }
814
815                 z->name = ldb_msg_find_attr_as_string(res->msgs[i], "name", NULL);
816                 z->dn = talloc_move(z, &res->msgs[i]->dn);
817
818                 DLIST_ADD_END(dns->zones, z, NULL);
819         }
820
821         status = dns_startup_interfaces(dns, task->lp_ctx, ifaces);
822         if (!NT_STATUS_IS_OK(status)) {
823                 task_server_terminate(task, "dns failed to setup interfaces", true);
824                 return;
825         }
826 }
827
828 NTSTATUS server_service_dns_init(void)
829 {
830         return register_server_service("dns", dns_task_init);
831 }