LCOV - code coverage report
Current view: top level - source4/dns_server - dns_server.c (source / functions) Hit Total Coverage
Test: coverage report for master 6248eab5 Lines: 302 413 73.1 %
Date: 2021-08-25 13:27:56 Functions: 18 20 90.0 %

          Line data    Source code
       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 "samba/service_task.h"
      24             : #include "samba/service.h"
      25             : #include "samba/service_stream.h"
      26             : #include "samba/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             : #include "librpc/gen_ndr/ndr_irpc.h"
      49             : #include "lib/messaging/irpc.h"
      50             : #include "libds/common/roles.h"
      51             : 
      52             : #undef DBGC_CLASS
      53             : #define DBGC_CLASS DBGC_DNS
      54             : 
      55             : NTSTATUS server_service_dns_init(TALLOC_CTX *);
      56             : 
      57             : /* hold information about one dns socket */
      58             : struct dns_socket {
      59             :         struct dns_server *dns;
      60             :         struct tsocket_address *local_address;
      61             : };
      62             : 
      63             : struct dns_udp_socket {
      64             :         struct dns_socket *dns_socket;
      65             :         struct tdgram_context *dgram;
      66             :         struct tevent_queue *send_queue;
      67             : };
      68             : 
      69             : /*
      70             :   state of an open tcp connection
      71             : */
      72             : struct dns_tcp_connection {
      73             :         /* stream connection we belong to */
      74             :         struct stream_connection *conn;
      75             : 
      76             :         /* the dns_server the connection belongs to */
      77             :         struct dns_socket *dns_socket;
      78             : 
      79             :         struct tstream_context *tstream;
      80             : 
      81             :         struct tevent_queue *send_queue;
      82             : };
      83             : 
      84         461 : static void dns_tcp_terminate_connection(struct dns_tcp_connection *dnsconn, const char *reason)
      85             : {
      86         461 :         stream_terminate_connection(dnsconn->conn, reason);
      87         461 : }
      88             : 
      89           0 : static void dns_tcp_recv(struct stream_connection *conn, uint16_t flags)
      90             : {
      91           0 :         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
      92             :                                                              struct dns_tcp_connection);
      93             :         /* this should never be triggered! */
      94           0 :         dns_tcp_terminate_connection(dnsconn, "dns_tcp_recv: called");
      95           0 : }
      96             : 
      97           0 : static void dns_tcp_send(struct stream_connection *conn, uint16_t flags)
      98             : {
      99           0 :         struct dns_tcp_connection *dnsconn = talloc_get_type(conn->private_data,
     100             :                                                              struct dns_tcp_connection);
     101             :         /* this should never be triggered! */
     102           0 :         dns_tcp_terminate_connection(dnsconn, "dns_tcp_send: called");
     103           0 : }
     104             : 
     105             : struct dns_process_state {
     106             :         DATA_BLOB *in;
     107             :         struct dns_server *dns;
     108             :         struct dns_name_packet in_packet;
     109             :         struct dns_request_state state;
     110             :         uint16_t dns_err;
     111             :         struct dns_name_packet out_packet;
     112             :         DATA_BLOB out;
     113             : };
     114             : 
     115             : static void dns_process_done(struct tevent_req *subreq);
     116             : 
     117       86588 : static struct tevent_req *dns_process_send(TALLOC_CTX *mem_ctx,
     118             :                                            struct tevent_context *ev,
     119             :                                            struct dns_server *dns,
     120             :                                            const struct tsocket_address *remote_address,
     121             :                                            const struct tsocket_address *local_address,
     122             :                                            DATA_BLOB *in)
     123             : {
     124             :         struct tevent_req *req, *subreq;
     125             :         struct dns_process_state *state;
     126             :         enum ndr_err_code ndr_err;
     127             :         WERROR ret;
     128       86588 :         const char **forwarder = lpcfg_dns_forwarder(dns->task->lp_ctx);
     129       86588 :         req = tevent_req_create(mem_ctx, &state, struct dns_process_state);
     130       86588 :         if (req == NULL) {
     131           0 :                 return NULL;
     132             :         }
     133       86588 :         state->state.mem_ctx = state;
     134       86588 :         state->in = in;
     135             : 
     136       86588 :         state->dns = dns;
     137             : 
     138       86588 :         if (in->length < 12) {
     139           0 :                 tevent_req_werror(req, WERR_INVALID_PARAMETER);
     140           0 :                 return tevent_req_post(req, ev);
     141             :         }
     142       86588 :         dump_data_dbgc(DBGC_DNS, 8, in->data, in->length);
     143             : 
     144       86588 :         ndr_err = ndr_pull_struct_blob(
     145       86588 :                 in, state, &state->in_packet,
     146             :                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
     147             : 
     148       86588 :         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
     149           0 :                 state->dns_err = DNS_RCODE_FORMERR;
     150           0 :                 tevent_req_done(req);
     151           0 :                 return tevent_req_post(req, ev);
     152             :         }
     153       86588 :         if (DEBUGLVLC(DBGC_DNS, 8)) {
     154           0 :                 NDR_PRINT_DEBUGC(DBGC_DNS, dns_name_packet, &state->in_packet);
     155             :         }
     156             : 
     157       86588 :         if (state->in_packet.operation & DNS_FLAG_REPLY) {
     158           5 :                 DEBUG(1, ("Won't reply to replies.\n"));
     159           5 :                 tevent_req_werror(req, WERR_INVALID_PARAMETER);
     160           5 :                 return tevent_req_post(req, ev);
     161             :         }
     162             : 
     163       86515 :         state->state.flags = state->in_packet.operation;
     164       86583 :         state->state.flags |= DNS_FLAG_REPLY;
     165             : 
     166       86583 :         state->state.local_address = local_address;
     167       86583 :         state->state.remote_address = remote_address;
     168             : 
     169       86583 :         if (forwarder && *forwarder && **forwarder) {
     170        9781 :                 state->state.flags |= DNS_FLAG_RECURSION_AVAIL;
     171             :         }
     172             : 
     173       86583 :         state->out_packet = state->in_packet;
     174             : 
     175       86583 :         ret = dns_verify_tsig(dns, state, &state->state,
     176       86515 :                               &state->out_packet, in);
     177       86583 :         if (!W_ERROR_IS_OK(ret)) {
     178           2 :                 state->dns_err = werr_to_dns_err(ret);
     179           2 :                 tevent_req_done(req);
     180           2 :                 return tevent_req_post(req, ev);
     181             :         }
     182             : 
     183       86581 :         switch (state->in_packet.operation & DNS_OPCODE) {
     184       84574 :         case DNS_OPCODE_QUERY:
     185       84574 :                 subreq = dns_server_process_query_send(
     186             :                         state, ev, dns,
     187       84574 :                         &state->state, &state->in_packet);
     188       84574 :                 if (tevent_req_nomem(subreq, req)) {
     189           0 :                         return tevent_req_post(req, ev);
     190             :                 }
     191       84574 :                 tevent_req_set_callback(subreq, dns_process_done, req);
     192       84574 :                 return req;
     193        2007 :         case DNS_OPCODE_UPDATE:
     194       16056 :                 ret = dns_server_process_update(
     195        4014 :                         dns, &state->state, state, &state->in_packet,
     196        4014 :                         &state->out_packet.answers, &state->out_packet.ancount,
     197        4014 :                         &state->out_packet.nsrecs,  &state->out_packet.nscount,
     198        2007 :                         &state->out_packet.additional,
     199        2007 :                         &state->out_packet.arcount);
     200        2007 :                 break;
     201           0 :         default:
     202           0 :                 ret = WERR_DNS_ERROR_RCODE_NOT_IMPLEMENTED;
     203             :         }
     204        2007 :         if (!W_ERROR_IS_OK(ret)) {
     205         139 :                 state->dns_err = werr_to_dns_err(ret);
     206             :         }
     207        2007 :         tevent_req_done(req);
     208        2007 :         return tevent_req_post(req, ev);
     209             : }
     210             : 
     211       84574 : static void dns_process_done(struct tevent_req *subreq)
     212             : {
     213       84574 :         struct tevent_req *req = tevent_req_callback_data(
     214             :                 subreq, struct tevent_req);
     215       84574 :         struct dns_process_state *state = tevent_req_data(
     216             :                 req, struct dns_process_state);
     217             :         WERROR ret;
     218             : 
     219       84574 :         ret = dns_server_process_query_recv(
     220             :                 subreq, state,
     221             :                 &state->out_packet.answers, &state->out_packet.ancount,
     222             :                 &state->out_packet.nsrecs,  &state->out_packet.nscount,
     223             :                 &state->out_packet.additional, &state->out_packet.arcount);
     224       84574 :         TALLOC_FREE(subreq);
     225             : 
     226       84574 :         if (!W_ERROR_IS_OK(ret)) {
     227       69596 :                 state->dns_err = werr_to_dns_err(ret);
     228             :         }
     229       84574 :         tevent_req_done(req);
     230       84574 : }
     231             : 
     232       86588 : static WERROR dns_process_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
     233             :                                DATA_BLOB *out)
     234             : {
     235       86588 :         struct dns_process_state *state = tevent_req_data(
     236             :                 req, struct dns_process_state);
     237             :         enum ndr_err_code ndr_err;
     238             :         WERROR ret;
     239             : 
     240       86588 :         if (tevent_req_is_werror(req, &ret)) {
     241           5 :                 return ret;
     242             :         }
     243      156320 :         if ((state->dns_err != DNS_RCODE_OK) &&
     244       69897 :             (state->dns_err != DNS_RCODE_NXDOMAIN) &&
     245         160 :             (state->dns_err != DNS_RCODE_NOTAUTH))
     246             :         {
     247         158 :                 goto drop;
     248             :         }
     249       86425 :         if (state->dns_err != DNS_RCODE_OK) {
     250       69579 :                 state->out_packet.operation |= state->dns_err;
     251             :         }
     252       86425 :         state->out_packet.operation |= state->state.flags;
     253             : 
     254       86425 :         if (state->state.sign) {
     255         449 :                 ret = dns_sign_tsig(state->dns, mem_ctx, &state->state,
     256             :                                     &state->out_packet, 0);
     257         449 :                 if (!W_ERROR_IS_OK(ret)) {
     258           0 :                         state->dns_err = DNS_RCODE_SERVFAIL;
     259           0 :                         goto drop;
     260             :                 }
     261             :         }
     262             : 
     263       86425 :         if (DEBUGLVLC(DBGC_DNS, 8)) {
     264           0 :                 NDR_PRINT_DEBUGC(DBGC_DNS, dns_name_packet, &state->out_packet);
     265             :         }
     266             : 
     267       86425 :         ndr_err = ndr_push_struct_blob(
     268       86425 :                 out, mem_ctx, &state->out_packet,
     269             :                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
     270       86425 :         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
     271           4 :                 DEBUG(1, ("Failed to push packet: %s!\n",
     272             :                           ndr_errstr(ndr_err)));
     273           4 :                 state->dns_err = DNS_RCODE_SERVFAIL;
     274           4 :                 goto drop;
     275             :         }
     276       86421 :         return WERR_OK;
     277             : 
     278         162 : drop:
     279         162 :         *out = data_blob_talloc(mem_ctx, state->in->data, state->in->length);
     280         162 :         if (out->data == NULL) {
     281           0 :                 return WERR_NOT_ENOUGH_MEMORY;
     282             :         }
     283         162 :         out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
     284         162 :         out->data[3] |= state->dns_err;
     285         162 :         return WERR_OK;
     286             : }
     287             : 
     288             : struct dns_tcp_call {
     289             :         struct dns_tcp_connection *dns_conn;
     290             :         DATA_BLOB in;
     291             :         DATA_BLOB out;
     292             :         uint8_t out_hdr[4];
     293             :         struct iovec out_iov[2];
     294             : };
     295             : 
     296             : static void dns_tcp_call_process_done(struct tevent_req *subreq);
     297             : static void dns_tcp_call_writev_done(struct tevent_req *subreq);
     298             : 
     299         969 : static void dns_tcp_call_loop(struct tevent_req *subreq)
     300             : {
     301         969 :         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
     302             :                                       struct dns_tcp_connection);
     303         969 :         struct dns_server *dns = dns_conn->dns_socket->dns;
     304             :         struct dns_tcp_call *call;
     305             :         NTSTATUS status;
     306             : 
     307         969 :         call = talloc(dns_conn, struct dns_tcp_call);
     308         969 :         if (call == NULL) {
     309           0 :                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
     310             :                                 "no memory for dns_tcp_call");
     311           0 :                 return;
     312             :         }
     313         969 :         call->dns_conn = dns_conn;
     314             : 
     315         969 :         status = tstream_read_pdu_blob_recv(subreq,
     316             :                                             call,
     317             :                                             &call->in);
     318         969 :         TALLOC_FREE(subreq);
     319         969 :         if (!NT_STATUS_IS_OK(status)) {
     320             :                 const char *reason;
     321             : 
     322         456 :                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
     323             :                                          "tstream_read_pdu_blob_recv() - %s",
     324             :                                          nt_errstr(status));
     325         456 :                 if (!reason) {
     326           0 :                         reason = nt_errstr(status);
     327             :                 }
     328             : 
     329         456 :                 dns_tcp_terminate_connection(dns_conn, reason);
     330         456 :                 return;
     331             :         }
     332             : 
     333         513 :         DEBUG(10,("Received DNS TCP packet of length %lu from %s\n",
     334             :                  (long) call->in.length,
     335             :                  tsocket_address_string(dns_conn->conn->remote_address, call)));
     336             : 
     337             :         /* skip length header */
     338         513 :         call->in.data += 2;
     339         513 :         call->in.length -= 2;
     340             : 
     341        1026 :         subreq = dns_process_send(call, dns->task->event_ctx, dns,
     342         513 :                                   dns_conn->conn->remote_address,
     343         513 :                                   dns_conn->conn->local_address,
     344             :                                   &call->in);
     345         513 :         if (subreq == NULL) {
     346           0 :                 dns_tcp_terminate_connection(
     347             :                         dns_conn, "dns_tcp_call_loop: dns_process_send "
     348             :                         "failed\n");
     349           0 :                 return;
     350             :         }
     351         513 :         tevent_req_set_callback(subreq, dns_tcp_call_process_done, call);
     352             : 
     353             :         /*
     354             :          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
     355             :          * packet_full_request_u16 provides the pdu length then.
     356             :          */
     357        1026 :         subreq = tstream_read_pdu_blob_send(dns_conn,
     358         513 :                                             dns_conn->conn->event.ctx,
     359             :                                             dns_conn->tstream,
     360             :                                             2, /* initial_read_size */
     361             :                                             packet_full_request_u16,
     362             :                                             dns_conn);
     363         513 :         if (subreq == NULL) {
     364           0 :                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
     365             :                                 "no memory for tstream_read_pdu_blob_send");
     366           0 :                 return;
     367             :         }
     368         513 :         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
     369             : }
     370             : 
     371         513 : static void dns_tcp_call_process_done(struct tevent_req *subreq)
     372             : {
     373         513 :         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
     374             :                         struct dns_tcp_call);
     375         513 :         struct dns_tcp_connection *dns_conn = call->dns_conn;
     376             :         WERROR err;
     377             : 
     378         513 :         err = dns_process_recv(subreq, call, &call->out);
     379         513 :         TALLOC_FREE(subreq);
     380         513 :         if (!W_ERROR_IS_OK(err)) {
     381           5 :                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
     382           5 :                 dns_tcp_terminate_connection(dns_conn,
     383             :                                 "dns_tcp_call_loop: process function failed");
     384           5 :                 return;
     385             :         }
     386             : 
     387             :         /* First add the length of the out buffer */
     388         508 :         RSSVAL(call->out_hdr, 0, call->out.length);
     389         508 :         call->out_iov[0].iov_base = (char *) call->out_hdr;
     390         508 :         call->out_iov[0].iov_len = 2;
     391             : 
     392         508 :         call->out_iov[1].iov_base = (char *) call->out.data;
     393         508 :         call->out_iov[1].iov_len = call->out.length;
     394             : 
     395        1016 :         subreq = tstream_writev_queue_send(call,
     396         508 :                                            dns_conn->conn->event.ctx,
     397             :                                            dns_conn->tstream,
     398             :                                            dns_conn->send_queue,
     399         508 :                                            call->out_iov, 2);
     400         508 :         if (subreq == NULL) {
     401           0 :                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
     402             :                                 "no memory for tstream_writev_queue_send");
     403           0 :                 return;
     404             :         }
     405         508 :         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
     406             : }
     407             : 
     408         508 : static void dns_tcp_call_writev_done(struct tevent_req *subreq)
     409             : {
     410         508 :         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
     411             :                         struct dns_tcp_call);
     412             :         int sys_errno;
     413             :         int rc;
     414             : 
     415         508 :         rc = tstream_writev_queue_recv(subreq, &sys_errno);
     416         508 :         TALLOC_FREE(subreq);
     417         508 :         if (rc == -1) {
     418             :                 const char *reason;
     419             : 
     420           0 :                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
     421             :                                          "tstream_writev_queue_recv() - %d:%s",
     422             :                                          sys_errno, strerror(sys_errno));
     423           0 :                 if (!reason) {
     424           0 :                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
     425             :                 }
     426             : 
     427           0 :                 dns_tcp_terminate_connection(call->dns_conn, reason);
     428           0 :                 return;
     429             :         }
     430             : 
     431             :         /* We don't care about errors */
     432             : 
     433         508 :         talloc_free(call);
     434             : }
     435             : 
     436             : /*
     437             :   called when we get a new connection
     438             : */
     439         461 : static void dns_tcp_accept(struct stream_connection *conn)
     440             : {
     441             :         struct dns_socket *dns_socket;
     442             :         struct dns_tcp_connection *dns_conn;
     443             :         struct tevent_req *subreq;
     444             :         int rc;
     445             : 
     446         461 :         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
     447         461 :         if (dns_conn == NULL) {
     448           0 :                 stream_terminate_connection(conn,
     449             :                                 "dns_tcp_accept: out of memory");
     450           0 :                 return;
     451             :         }
     452             : 
     453         461 :         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
     454         461 :         if (dns_conn->send_queue == NULL) {
     455           0 :                 stream_terminate_connection(conn,
     456             :                                 "dns_tcp_accept: out of memory");
     457           0 :                 return;
     458             :         }
     459             : 
     460         461 :         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
     461             : 
     462         461 :         TALLOC_FREE(conn->event.fde);
     463             : 
     464         461 :         rc = tstream_bsd_existing_socket(dns_conn,
     465             :                         socket_get_fd(conn->socket),
     466             :                         &dns_conn->tstream);
     467         461 :         if (rc < 0) {
     468           0 :                 stream_terminate_connection(conn,
     469             :                                 "dns_tcp_accept: out of memory");
     470           0 :                 return;
     471             :         }
     472             : 
     473         461 :         dns_conn->conn = conn;
     474         461 :         dns_conn->dns_socket = dns_socket;
     475         461 :         conn->private_data = dns_conn;
     476             : 
     477             :         /*
     478             :          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
     479             :          * packet_full_request_u16 provides the pdu length then.
     480             :          */
     481         922 :         subreq = tstream_read_pdu_blob_send(dns_conn,
     482         461 :                                             dns_conn->conn->event.ctx,
     483             :                                             dns_conn->tstream,
     484             :                                             2, /* initial_read_size */
     485             :                                             packet_full_request_u16,
     486             :                                             dns_conn);
     487         461 :         if (subreq == NULL) {
     488           0 :                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
     489             :                                 "no memory for tstream_read_pdu_blob_send");
     490           0 :                 return;
     491             :         }
     492         461 :         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
     493             : }
     494             : 
     495             : static const struct stream_server_ops dns_tcp_stream_ops = {
     496             :         .name                   = "dns_tcp",
     497             :         .accept_connection      = dns_tcp_accept,
     498             :         .recv_handler           = dns_tcp_recv,
     499             :         .send_handler           = dns_tcp_send
     500             : };
     501             : 
     502             : struct dns_udp_call {
     503             :         struct dns_udp_socket *sock;
     504             :         struct tsocket_address *src;
     505             :         DATA_BLOB in;
     506             :         DATA_BLOB out;
     507             : };
     508             : 
     509             : static void dns_udp_call_process_done(struct tevent_req *subreq);
     510             : static void dns_udp_call_sendto_done(struct tevent_req *subreq);
     511             : 
     512       86082 : static void dns_udp_call_loop(struct tevent_req *subreq)
     513             : {
     514       86082 :         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
     515             :                                       struct dns_udp_socket);
     516       86082 :         struct dns_server *dns = sock->dns_socket->dns;
     517             :         struct dns_udp_call *call;
     518             :         uint8_t *buf;
     519             :         ssize_t len;
     520             :         int sys_errno;
     521             : 
     522       86082 :         call = talloc(sock, struct dns_udp_call);
     523       86082 :         if (call == NULL) {
     524           0 :                 talloc_free(call);
     525           0 :                 goto done;
     526             :         }
     527       86082 :         call->sock = sock;
     528             : 
     529       86082 :         len = tdgram_recvfrom_recv(subreq, &sys_errno,
     530             :                                    call, &buf, &call->src);
     531       86082 :         TALLOC_FREE(subreq);
     532       86082 :         if (len == -1) {
     533           7 :                 talloc_free(call);
     534           7 :                 goto done;
     535             :         }
     536             : 
     537       86075 :         call->in.data = buf;
     538       86075 :         call->in.length = len;
     539             : 
     540       86075 :         DEBUG(10,("Received DNS UDP packet of length %lu from %s\n",
     541             :                  (long)call->in.length,
     542             :                  tsocket_address_string(call->src, call)));
     543             : 
     544      172150 :         subreq = dns_process_send(call, dns->task->event_ctx, dns,
     545       86075 :                                   call->src,
     546       86075 :                                   sock->dns_socket->local_address,
     547             :                                   &call->in);
     548       86075 :         if (subreq == NULL) {
     549           0 :                 TALLOC_FREE(call);
     550           0 :                 goto done;
     551             :         }
     552       86075 :         tevent_req_set_callback(subreq, dns_udp_call_process_done, call);
     553             : 
     554       86082 : done:
     555      172164 :         subreq = tdgram_recvfrom_send(sock,
     556       86082 :                                       sock->dns_socket->dns->task->event_ctx,
     557             :                                       sock->dgram);
     558       86082 :         if (subreq == NULL) {
     559           0 :                 task_server_terminate(sock->dns_socket->dns->task,
     560             :                                       "no memory for tdgram_recvfrom_send",
     561             :                                       true);
     562           0 :                 return;
     563             :         }
     564       86082 :         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
     565             : }
     566             : 
     567       86075 : static void dns_udp_call_process_done(struct tevent_req *subreq)
     568             : {
     569       86075 :         struct dns_udp_call *call = tevent_req_callback_data(
     570             :                 subreq, struct dns_udp_call);
     571       86075 :         struct dns_udp_socket *sock = call->sock;
     572       86075 :         struct dns_server *dns = sock->dns_socket->dns;
     573             :         WERROR err;
     574             : 
     575       86075 :         err = dns_process_recv(subreq, call, &call->out);
     576       86075 :         TALLOC_FREE(subreq);
     577       86075 :         if (!W_ERROR_IS_OK(err)) {
     578           0 :                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
     579           0 :                 TALLOC_FREE(call);
     580           0 :                 return;
     581             :         }
     582             : 
     583      258225 :         subreq = tdgram_sendto_queue_send(call,
     584       86075 :                                           dns->task->event_ctx,
     585             :                                           sock->dgram,
     586             :                                           sock->send_queue,
     587       86075 :                                           call->out.data,
     588             :                                           call->out.length,
     589             :                                           call->src);
     590       86075 :         if (subreq == NULL) {
     591           0 :                 talloc_free(call);
     592           0 :                 return;
     593             :         }
     594       86075 :         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
     595             : 
     596             : }
     597       86075 : static void dns_udp_call_sendto_done(struct tevent_req *subreq)
     598             : {
     599       86075 :         struct dns_udp_call *call = tevent_req_callback_data(subreq,
     600             :                                        struct dns_udp_call);
     601             :         int sys_errno;
     602             : 
     603       86075 :         tdgram_sendto_queue_recv(subreq, &sys_errno);
     604             : 
     605             :         /* We don't care about errors */
     606             : 
     607       86075 :         talloc_free(call);
     608       86075 : }
     609             : 
     610             : /*
     611             :   start listening on the given address
     612             : */
     613         114 : static NTSTATUS dns_add_socket(struct dns_server *dns,
     614             :                                const struct model_ops *model_ops,
     615             :                                const char *name,
     616             :                                const char *address,
     617             :                                uint16_t port)
     618             : {
     619             :         struct dns_socket *dns_socket;
     620             :         struct dns_udp_socket *dns_udp_socket;
     621             :         struct tevent_req *udpsubreq;
     622             :         NTSTATUS status;
     623             :         int ret;
     624             : 
     625         114 :         dns_socket = talloc(dns, struct dns_socket);
     626         114 :         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
     627             : 
     628         114 :         dns_socket->dns = dns;
     629             : 
     630         114 :         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
     631             :                                                 address, port,
     632             :                                                 &dns_socket->local_address);
     633         114 :         if (ret != 0) {
     634           0 :                 status = map_nt_error_from_unix_common(errno);
     635           0 :                 return status;
     636             :         }
     637             : 
     638         448 :         status = stream_setup_socket(dns->task,
     639         110 :                                      dns->task->event_ctx,
     640         114 :                                      dns->task->lp_ctx,
     641             :                                      model_ops,
     642             :                                      &dns_tcp_stream_ops,
     643             :                                      "ip", address, &port,
     644         110 :                                      lpcfg_socket_options(dns->task->lp_ctx),
     645             :                                      dns_socket,
     646         114 :                                      dns->task->process_context);
     647         114 :         if (!NT_STATUS_IS_OK(status)) {
     648           0 :                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
     649             :                          address, port, nt_errstr(status)));
     650           0 :                 talloc_free(dns_socket);
     651           0 :                 return status;
     652             :         }
     653             : 
     654         114 :         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
     655         114 :         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
     656             : 
     657         114 :         dns_udp_socket->dns_socket = dns_socket;
     658             : 
     659         114 :         ret = tdgram_inet_udp_socket(dns_socket->local_address,
     660             :                                      NULL,
     661             :                                      dns_udp_socket,
     662             :                                      &dns_udp_socket->dgram);
     663         114 :         if (ret != 0) {
     664           0 :                 status = map_nt_error_from_unix_common(errno);
     665           0 :                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
     666             :                          address, port, nt_errstr(status)));
     667           0 :                 return status;
     668             :         }
     669             : 
     670         114 :         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
     671             :                                                          "dns_udp_send_queue");
     672         114 :         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
     673             : 
     674         228 :         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
     675         114 :                                          dns->task->event_ctx,
     676             :                                          dns_udp_socket->dgram);
     677         114 :         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
     678         114 :         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
     679             : 
     680         114 :         return NT_STATUS_OK;
     681             : }
     682             : 
     683             : /*
     684             :   setup our listening sockets on the configured network interfaces
     685             : */
     686          57 : static NTSTATUS dns_startup_interfaces(struct dns_server *dns,
     687             :                                        struct interface *ifaces,
     688             :                                        const struct model_ops *model_ops)
     689             : {
     690             :         size_t num_interfaces;
     691          57 :         TALLOC_CTX *tmp_ctx = talloc_new(dns);
     692             :         NTSTATUS status;
     693             :         int i;
     694             : 
     695          57 :         if (ifaces != NULL) {
     696           0 :                 num_interfaces = iface_list_count(ifaces);
     697             : 
     698           0 :                 for (i=0; i<num_interfaces; i++) {
     699           0 :                         const char *address = talloc_strdup(tmp_ctx,
     700             :                                                             iface_list_n_ip(ifaces, i));
     701             : 
     702           0 :                         status = dns_add_socket(dns, model_ops, "dns", address,
     703             :                                                 DNS_SERVICE_PORT);
     704           0 :                         NT_STATUS_NOT_OK_RETURN(status);
     705             :                 }
     706             :         } else {
     707          57 :                 size_t num_binds = 0;
     708             :                 char **wcard;
     709          57 :                 wcard = iface_list_wildcard(tmp_ctx);
     710          57 :                 if (wcard == NULL) {
     711           0 :                         DEBUG(0, ("No wildcard address available\n"));
     712           0 :                         return NT_STATUS_INTERNAL_ERROR;
     713             :                 }
     714         169 :                 for (i = 0; wcard[i] != NULL; i++) {
     715         114 :                         status = dns_add_socket(dns, model_ops, "dns", wcard[i],
     716             :                                                 DNS_SERVICE_PORT);
     717         114 :                         if (NT_STATUS_IS_OK(status)) {
     718         114 :                                 num_binds++;
     719             :                         }
     720             :                 }
     721          57 :                 if (num_binds == 0) {
     722           0 :                         talloc_free(tmp_ctx);
     723           0 :                         return NT_STATUS_INVALID_PARAMETER_MIX;
     724             :                 }
     725             :         }
     726             : 
     727          57 :         talloc_free(tmp_ctx);
     728             : 
     729          57 :         return NT_STATUS_OK;
     730             : }
     731             : 
     732          57 : static struct dns_server_tkey_store *tkey_store_init(TALLOC_CTX *mem_ctx,
     733             :                                                      uint16_t size)
     734             : {
     735          57 :         struct dns_server_tkey_store *buffer = talloc_zero(mem_ctx,
     736             :                                                 struct dns_server_tkey_store);
     737             : 
     738          57 :         if (buffer == NULL) {
     739           0 :                 return NULL;
     740             :         }
     741             : 
     742          57 :         buffer->size = size;
     743          57 :         buffer->next_idx = 0;
     744             : 
     745          57 :         buffer->tkeys = talloc_zero_array(buffer, struct dns_server_tkey *, size);
     746          57 :         if (buffer->tkeys == NULL) {
     747           0 :                 TALLOC_FREE(buffer);
     748             :         }
     749             : 
     750          55 :         return buffer;
     751             : }
     752             : 
     753        1769 : static NTSTATUS dns_server_reload_zones(struct dns_server *dns)
     754             : {
     755             :         NTSTATUS status;
     756        1769 :         struct dns_server_zone *new_list = NULL;
     757        1769 :         struct dns_server_zone *old_list = dns->zones;
     758             :         struct dns_server_zone *old_zone;
     759        1769 :         status = dns_common_zones(dns->samdb, dns, NULL, &new_list);
     760        1769 :         if (!NT_STATUS_IS_OK(status)) {
     761           0 :                 return status;
     762             :         }
     763        1769 :         dns->zones = new_list;
     764        8643 :         while ((old_zone = DLIST_TAIL(old_list)) != NULL) {
     765        5105 :                 DLIST_REMOVE(old_list, old_zone);
     766        5105 :                 talloc_free(old_zone);
     767             :         }
     768             : 
     769        1769 :         return NT_STATUS_OK;
     770             : }
     771             : 
     772             : /**
     773             :  * Called when the internal DNS server should reload the zones from DB, for
     774             :  * example, when zones are added or deleted through RPC or replicated by
     775             :  * inbound DRS.
     776             :  */
     777        1712 : static NTSTATUS dns_reload_zones(struct irpc_message *msg,
     778             :                                  struct dnssrv_reload_dns_zones *r)
     779             : {
     780             :         struct dns_server *dns;
     781             : 
     782        1712 :         dns = talloc_get_type(msg->private_data, struct dns_server);
     783        1712 :         if (dns == NULL) {
     784           0 :                 r->out.result = NT_STATUS_INTERNAL_ERROR;
     785           0 :                 return NT_STATUS_INTERNAL_ERROR;
     786             :         }
     787             : 
     788        1712 :         r->out.result = dns_server_reload_zones(dns);
     789             : 
     790        1712 :         return NT_STATUS_OK;
     791             : }
     792             : 
     793          63 : static NTSTATUS dns_task_init(struct task_server *task)
     794             : {
     795             :         struct dns_server *dns;
     796             :         NTSTATUS status;
     797          63 :         struct interface *ifaces = NULL;
     798             :         int ret;
     799             :         static const char * const attrs_none[] = { NULL};
     800             :         struct ldb_message *dns_acc;
     801             :         char *hostname_lower;
     802             :         char *dns_spn;
     803             :         bool ok;
     804             : 
     805          63 :         switch (lpcfg_server_role(task->lp_ctx)) {
     806           0 :         case ROLE_STANDALONE:
     807           0 :                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
     808           0 :                 return NT_STATUS_INVALID_DOMAIN_ROLE;
     809           6 :         case ROLE_DOMAIN_MEMBER:
     810           6 :                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
     811           0 :                 return NT_STATUS_INVALID_DOMAIN_ROLE;
     812          55 :         case ROLE_ACTIVE_DIRECTORY_DC:
     813             :                 /* Yes, we want a DNS */
     814          55 :                 break;
     815             :         }
     816             : 
     817          57 :         if (lpcfg_interfaces(task->lp_ctx) && lpcfg_bind_interfaces_only(task->lp_ctx)) {
     818           0 :                 load_interface_list(task, task->lp_ctx, &ifaces);
     819             : 
     820           0 :                 if (iface_list_count(ifaces) == 0) {
     821           0 :                         task_server_terminate(task, "dns: no network interfaces configured", false);
     822           0 :                         return NT_STATUS_UNSUCCESSFUL;
     823             :                 }
     824             :         }
     825             : 
     826          57 :         task_server_set_title(task, "task[dns]");
     827             : 
     828          57 :         dns = talloc_zero(task, struct dns_server);
     829          57 :         if (dns == NULL) {
     830           0 :                 task_server_terminate(task, "dns: out of memory", true);
     831           0 :                 return NT_STATUS_NO_MEMORY;
     832             :         }
     833             : 
     834          57 :         dns->task = task;
     835             : 
     836          57 :         dns->server_credentials = cli_credentials_init(dns);
     837          57 :         if (!dns->server_credentials) {
     838           0 :                 task_server_terminate(task, "Failed to init server credentials\n", true);
     839           0 :                 return NT_STATUS_UNSUCCESSFUL;
     840             :         }
     841             : 
     842         169 :         dns->samdb = samdb_connect(dns,
     843          55 :                                    dns->task->event_ctx,
     844          57 :                                    dns->task->lp_ctx,
     845          57 :                                    system_session(dns->task->lp_ctx),
     846             :                                    NULL,
     847             :                                    0);
     848          57 :         if (!dns->samdb) {
     849           0 :                 task_server_terminate(task, "dns: samdb_connect failed", true);
     850           0 :                 return NT_STATUS_UNSUCCESSFUL;
     851             :         }
     852             : 
     853          57 :         ok = cli_credentials_set_conf(dns->server_credentials, task->lp_ctx);
     854          57 :         if (!ok) {
     855           0 :                 task_server_terminate(task,
     856             :                                       "dns: failed to load smb.conf",
     857             :                                       true);
     858           0 :                 return NT_STATUS_UNSUCCESSFUL;
     859             :         }
     860             : 
     861          57 :         hostname_lower = strlower_talloc(dns, lpcfg_netbios_name(task->lp_ctx));
     862          57 :         dns_spn = talloc_asprintf(dns, "DNS/%s.%s",
     863             :                                   hostname_lower,
     864             :                                   lpcfg_dnsdomain(task->lp_ctx));
     865          57 :         TALLOC_FREE(hostname_lower);
     866             : 
     867          57 :         ret = dsdb_search_one(dns->samdb, dns, &dns_acc,
     868             :                               ldb_get_default_basedn(dns->samdb), LDB_SCOPE_SUBTREE,
     869             :                               attrs_none, 0, "(servicePrincipalName=%s)",
     870             :                               dns_spn);
     871          57 :         if (ret == LDB_SUCCESS) {
     872           2 :                 TALLOC_FREE(dns_acc);
     873           2 :                 if (!dns_spn) {
     874           0 :                         task_server_terminate(task, "dns: talloc_asprintf failed", true);
     875           0 :                         return NT_STATUS_UNSUCCESSFUL;
     876             :                 }
     877           2 :                 status = cli_credentials_set_stored_principal(dns->server_credentials, task->lp_ctx, dns_spn);
     878           2 :                 if (!NT_STATUS_IS_OK(status)) {
     879           0 :                         task_server_terminate(task,
     880           0 :                                               talloc_asprintf(task, "Failed to obtain server credentials for DNS, "
     881             :                                                               "despite finding it in the samdb! %s\n",
     882             :                                                               nt_errstr(status)),
     883             :                                               true);
     884           0 :                         return status;
     885             :                 }
     886             :         } else {
     887          55 :                 TALLOC_FREE(dns_spn);
     888          55 :                 status = cli_credentials_set_machine_account(dns->server_credentials, task->lp_ctx);
     889          55 :                 if (!NT_STATUS_IS_OK(status)) {
     890           0 :                         task_server_terminate(task,
     891           0 :                                               talloc_asprintf(task, "Failed to obtain server credentials, perhaps a standalone server?: %s\n",
     892             :                                                               nt_errstr(status)),
     893             :                                               true);
     894           0 :                         return status;
     895             :                 }
     896             :         }
     897             : 
     898          57 :         dns->tkeys = tkey_store_init(dns, TKEY_BUFFER_SIZE);
     899          57 :         if (!dns->tkeys) {
     900           0 :                 task_server_terminate(task, "Failed to allocate tkey storage\n", true);
     901           0 :                 return NT_STATUS_NO_MEMORY;
     902             :         }
     903             : 
     904          57 :         status = dns_server_reload_zones(dns);
     905          57 :         if (!NT_STATUS_IS_OK(status)) {
     906           0 :                 task_server_terminate(task, "dns: failed to load DNS zones", true);
     907           0 :                 return status;
     908             :         }
     909             : 
     910          57 :         status = dns_startup_interfaces(dns, ifaces, task->model_ops);
     911          57 :         if (!NT_STATUS_IS_OK(status)) {
     912           0 :                 task_server_terminate(task, "dns failed to setup interfaces", true);
     913           0 :                 return status;
     914             :         }
     915             : 
     916             :         /* Setup the IRPC interface and register handlers */
     917          57 :         status = irpc_add_name(task->msg_ctx, "dnssrv");
     918          57 :         if (!NT_STATUS_IS_OK(status)) {
     919           0 :                 task_server_terminate(task, "dns: failed to register IRPC name", true);
     920           0 :                 return status;
     921             :         }
     922             : 
     923          57 :         status = IRPC_REGISTER(task->msg_ctx, irpc, DNSSRV_RELOAD_DNS_ZONES,
     924             :                                dns_reload_zones, dns);
     925          57 :         if (!NT_STATUS_IS_OK(status)) {
     926           0 :                 task_server_terminate(task, "dns: failed to setup reload handler", true);
     927           0 :                 return status;
     928             :         }
     929          57 :         return NT_STATUS_OK;
     930             : }
     931             : 
     932          64 : NTSTATUS server_service_dns_init(TALLOC_CTX *ctx)
     933             : {
     934             :         static const struct service_details details = {
     935             :                 .inhibit_fork_on_accept = true,
     936             :                 .inhibit_pre_fork = true,
     937             :                 .task_init = dns_task_init,
     938             :                 .post_fork = NULL
     939             :         };
     940          64 :         return register_server_service(ctx, "dns", &details);
     941             : }

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