LCOV - code coverage report
Current view: top level - source4/dns_server - dns_server.c (source / functions) Hit Total Coverage
Test: coverage report for master 2b515b7d Lines: 331 470 70.4 %
Date: 2024-02-28 12:06:22 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         138 : static void dns_tcp_terminate_connection(struct dns_tcp_connection *dnsconn, const char *reason)
      85             : {
      86         138 :         stream_terminate_connection(dnsconn->conn, reason);
      87         138 : }
      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             :         WERROR 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        4057 : 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           0 :         struct tevent_req *req, *subreq;
     125           0 :         struct dns_process_state *state;
     126           0 :         enum ndr_err_code ndr_err;
     127           0 :         WERROR ret;
     128        4057 :         const char **forwarder = lpcfg_dns_forwarder(dns->task->lp_ctx);
     129        4057 :         req = tevent_req_create(mem_ctx, &state, struct dns_process_state);
     130        4057 :         if (req == NULL) {
     131           0 :                 return NULL;
     132             :         }
     133        4057 :         state->state.mem_ctx = state;
     134        4057 :         state->in = in;
     135             : 
     136        4057 :         state->dns = dns;
     137             : 
     138        4057 :         if (in->length < 12) {
     139           0 :                 tevent_req_werror(req, WERR_INVALID_PARAMETER);
     140           0 :                 return tevent_req_post(req, ev);
     141             :         }
     142        4057 :         dump_data_dbgc(DBGC_DNS, 8, in->data, in->length);
     143             : 
     144        4057 :         ndr_err = ndr_pull_struct_blob(
     145        4057 :                 in, state, &state->in_packet,
     146             :                 (ndr_pull_flags_fn_t)ndr_pull_dns_name_packet);
     147             : 
     148        4057 :         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
     149           0 :                 DBG_NOTICE("ndr_pull_dns_name_packet() failed with %s\n",
     150             :                            ndr_map_error2string(ndr_err));
     151           0 :                 state->dns_err = DNS_ERR(FORMAT_ERROR);
     152           0 :                 tevent_req_done(req);
     153           0 :                 return tevent_req_post(req, ev);
     154             :         }
     155        4057 :         if (DEBUGLVLC(DBGC_DNS, 8)) {
     156           0 :                 NDR_PRINT_DEBUGC(DBGC_DNS, dns_name_packet, &state->in_packet);
     157             :         }
     158             : 
     159        4057 :         if (state->in_packet.operation & DNS_FLAG_REPLY) {
     160           4 :                 DBG_INFO("Won't reply to replies.\n");
     161           4 :                 tevent_req_werror(req, WERR_INVALID_PARAMETER);
     162           4 :                 return tevent_req_post(req, ev);
     163             :         }
     164             : 
     165        4053 :         state->state.flags = state->in_packet.operation;
     166        4053 :         state->state.flags |= DNS_FLAG_REPLY;
     167             : 
     168        4053 :         state->state.local_address = local_address;
     169        4053 :         state->state.remote_address = remote_address;
     170             : 
     171        4053 :         if (forwarder && *forwarder && **forwarder) {
     172        1368 :                 state->state.flags |= DNS_FLAG_RECURSION_AVAIL;
     173             :         }
     174             : 
     175        4053 :         state->out_packet = state->in_packet;
     176             : 
     177        4053 :         ret = dns_verify_tsig(dns, state, &state->state,
     178        4053 :                               &state->out_packet, in);
     179        4053 :         if (!W_ERROR_IS_OK(ret)) {
     180           4 :                 DBG_INFO("dns_verify_tsig() failed with %s\n",
     181             :                          win_errstr(ret));
     182           4 :                 state->dns_err = ret;
     183           4 :                 tevent_req_done(req);
     184           4 :                 return tevent_req_post(req, ev);
     185             :         }
     186             : 
     187        4049 :         switch (state->in_packet.operation & DNS_OPCODE) {
     188        2718 :         case DNS_OPCODE_QUERY:
     189        2718 :                 subreq = dns_server_process_query_send(
     190             :                         state, ev, dns,
     191        2718 :                         &state->state, &state->in_packet);
     192        2718 :                 if (tevent_req_nomem(subreq, req)) {
     193        2718 :                         return tevent_req_post(req, ev);
     194             :                 }
     195        2718 :                 tevent_req_set_callback(subreq, dns_process_done, req);
     196        2718 :                 return req;
     197        1331 :         case DNS_OPCODE_UPDATE:
     198        1331 :                 ret = dns_server_process_update(
     199        1331 :                         dns, &state->state, state, &state->in_packet,
     200        1331 :                         &state->out_packet.answers, &state->out_packet.ancount,
     201        1331 :                         &state->out_packet.nsrecs,  &state->out_packet.nscount,
     202        1331 :                         &state->out_packet.additional,
     203        1331 :                         &state->out_packet.arcount);
     204        1331 :                 DBG_DEBUG("dns_server_process_update(): %s\n",
     205             :                           win_errstr(ret));
     206        1331 :                 break;
     207           0 :         default:
     208           0 :                 ret = WERR_DNS_ERROR_RCODE_NOT_IMPLEMENTED;
     209           0 :                 DBG_NOTICE("OPCODE[0x%x]: %s\n",
     210             :                            (state->in_packet.operation & DNS_OPCODE),
     211             :                            win_errstr(ret));
     212             :         }
     213        1331 :         state->dns_err = ret;
     214        1331 :         tevent_req_done(req);
     215        1331 :         return tevent_req_post(req, ev);
     216             : }
     217             : 
     218        2718 : static void dns_process_done(struct tevent_req *subreq)
     219             : {
     220        2718 :         struct tevent_req *req = tevent_req_callback_data(
     221             :                 subreq, struct tevent_req);
     222        2718 :         struct dns_process_state *state = tevent_req_data(
     223             :                 req, struct dns_process_state);
     224           0 :         WERROR ret;
     225             : 
     226        2718 :         ret = dns_server_process_query_recv(
     227             :                 subreq, state,
     228             :                 &state->out_packet.answers, &state->out_packet.ancount,
     229             :                 &state->out_packet.nsrecs,  &state->out_packet.nscount,
     230             :                 &state->out_packet.additional, &state->out_packet.arcount);
     231        2718 :         TALLOC_FREE(subreq);
     232             : 
     233        2718 :         DBG_DEBUG("dns_server_process_query_recv(): %s\n",
     234             :                   win_errstr(ret));
     235        2718 :         state->dns_err = ret;
     236        2718 :         tevent_req_done(req);
     237        2718 : }
     238             : 
     239        4057 : static WERROR dns_process_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx,
     240             :                                DATA_BLOB *out)
     241             : {
     242        4057 :         struct dns_process_state *state = tevent_req_data(
     243             :                 req, struct dns_process_state);
     244           0 :         enum ndr_err_code ndr_err;
     245           0 :         uint16_t dns_err;
     246           0 :         WERROR ret;
     247             : 
     248        4057 :         if (tevent_req_is_werror(req, &ret)) {
     249           4 :                 DBG_NOTICE("ERROR: %s from %s\n", win_errstr(ret),
     250             :                            tevent_req_print(state, req));
     251           4 :                 return ret;
     252             :         }
     253        4053 :         dns_err = werr_to_dns_err(state->dns_err);
     254        4053 :         if ((dns_err != DNS_RCODE_OK) &&
     255         185 :             (dns_err != DNS_RCODE_NXDOMAIN) &&
     256             :             (dns_err != DNS_RCODE_NOTAUTH))
     257             :         {
     258         181 :                 DBG_INFO("FAILURE: %s from %s\n",
     259             :                          win_errstr(state->dns_err),
     260             :                          tevent_req_print(state, req));
     261         181 :                 goto drop;
     262             :         }
     263        3872 :         if (dns_err != DNS_RCODE_OK) {
     264         123 :                 DBG_DEBUG("INFO: %s from %s\n",
     265             :                           win_errstr(state->dns_err),
     266             :                           tevent_req_print(state, req));
     267         123 :                 state->out_packet.operation |= dns_err;
     268             :         } else {
     269        3749 :                 DBG_DEBUG("OK: %s\n",
     270             :                           tevent_req_print(state, req));
     271             :         }
     272        3872 :         state->out_packet.operation |= state->state.flags;
     273             : 
     274        3872 :         if (state->state.sign) {
     275         134 :                 ret = dns_sign_tsig(state->dns, mem_ctx, &state->state,
     276             :                                     &state->out_packet, 0);
     277         134 :                 if (!W_ERROR_IS_OK(ret)) {
     278           0 :                         DBG_WARNING("dns_sign_tsig() failed %s\n",
     279             :                                     win_errstr(ret));
     280           0 :                         dns_err = DNS_RCODE_SERVFAIL;
     281           0 :                         goto drop;
     282             :                 }
     283             :         }
     284             : 
     285        3872 :         if (DEBUGLVLC(DBGC_DNS, 8)) {
     286           0 :                 NDR_PRINT_DEBUGC(DBGC_DNS, dns_name_packet, &state->out_packet);
     287             :         }
     288             : 
     289        3872 :         ndr_err = ndr_push_struct_blob(
     290        3872 :                 out, mem_ctx, &state->out_packet,
     291             :                 (ndr_push_flags_fn_t)ndr_push_dns_name_packet);
     292        3872 :         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
     293           4 :                 DBG_WARNING("Failed to push packet: %s!\n",
     294             :                             ndr_errstr(ndr_err));
     295           4 :                 dns_err = DNS_RCODE_SERVFAIL;
     296           4 :                 goto drop;
     297             :         }
     298        3868 :         return WERR_OK;
     299             : 
     300         185 : drop:
     301         185 :         *out = data_blob_talloc(mem_ctx, state->in->data, state->in->length);
     302         185 :         if (out->data == NULL) {
     303           0 :                 return WERR_NOT_ENOUGH_MEMORY;
     304             :         }
     305         185 :         out->data[2] |= 0x80; /* Toggle DNS_FLAG_REPLY */
     306         185 :         out->data[3] |= dns_err;
     307         185 :         return WERR_OK;
     308             : }
     309             : 
     310             : struct dns_tcp_call {
     311             :         struct dns_tcp_connection *dns_conn;
     312             :         DATA_BLOB in;
     313             :         DATA_BLOB out;
     314             :         uint8_t out_hdr[4];
     315             :         struct iovec out_iov[2];
     316             : };
     317             : 
     318             : static void dns_tcp_call_process_done(struct tevent_req *subreq);
     319             : static void dns_tcp_call_writev_done(struct tevent_req *subreq);
     320             : 
     321         356 : static void dns_tcp_call_loop(struct tevent_req *subreq)
     322             : {
     323         356 :         struct dns_tcp_connection *dns_conn = tevent_req_callback_data(subreq,
     324             :                                       struct dns_tcp_connection);
     325         356 :         struct dns_server *dns = dns_conn->dns_socket->dns;
     326           0 :         struct dns_tcp_call *call;
     327           0 :         NTSTATUS status;
     328             : 
     329         356 :         call = talloc(dns_conn, struct dns_tcp_call);
     330         356 :         if (call == NULL) {
     331           0 :                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
     332             :                                 "no memory for dns_tcp_call");
     333         134 :                 return;
     334             :         }
     335         356 :         call->dns_conn = dns_conn;
     336             : 
     337         356 :         status = tstream_read_pdu_blob_recv(subreq,
     338             :                                             call,
     339             :                                             &call->in);
     340         356 :         TALLOC_FREE(subreq);
     341         356 :         if (!NT_STATUS_IS_OK(status)) {
     342           0 :                 const char *reason;
     343             : 
     344         134 :                 reason = talloc_asprintf(call, "dns_tcp_call_loop: "
     345             :                                          "tstream_read_pdu_blob_recv() - %s",
     346             :                                          nt_errstr(status));
     347         134 :                 if (!reason) {
     348           0 :                         reason = nt_errstr(status);
     349             :                 }
     350             : 
     351         134 :                 dns_tcp_terminate_connection(dns_conn, reason);
     352         134 :                 return;
     353             :         }
     354             : 
     355         222 :         DEBUG(10,("Received DNS TCP packet of length %lu from %s\n",
     356             :                  (long) call->in.length,
     357             :                  tsocket_address_string(dns_conn->conn->remote_address, call)));
     358             : 
     359             :         /* skip length header */
     360         222 :         call->in.data += 2;
     361         222 :         call->in.length -= 2;
     362             : 
     363         222 :         subreq = dns_process_send(call, dns->task->event_ctx, dns,
     364         222 :                                   dns_conn->conn->remote_address,
     365         222 :                                   dns_conn->conn->local_address,
     366             :                                   &call->in);
     367         222 :         if (subreq == NULL) {
     368           0 :                 dns_tcp_terminate_connection(
     369             :                         dns_conn, "dns_tcp_call_loop: dns_process_send "
     370             :                         "failed\n");
     371           0 :                 return;
     372             :         }
     373         222 :         tevent_req_set_callback(subreq, dns_tcp_call_process_done, call);
     374             : 
     375             :         /*
     376             :          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
     377             :          * tstream_full_request_u16 provides the pdu length then.
     378             :          */
     379         222 :         subreq = tstream_read_pdu_blob_send(dns_conn,
     380         222 :                                             dns_conn->conn->event.ctx,
     381             :                                             dns_conn->tstream,
     382             :                                             2, /* initial_read_size */
     383             :                                             tstream_full_request_u16,
     384             :                                             dns_conn);
     385         222 :         if (subreq == NULL) {
     386           0 :                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
     387             :                                 "no memory for tstream_read_pdu_blob_send");
     388           0 :                 return;
     389             :         }
     390         222 :         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
     391             : }
     392             : 
     393         222 : static void dns_tcp_call_process_done(struct tevent_req *subreq)
     394             : {
     395         222 :         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
     396             :                         struct dns_tcp_call);
     397         222 :         struct dns_tcp_connection *dns_conn = call->dns_conn;
     398           0 :         WERROR err;
     399             : 
     400         222 :         err = dns_process_recv(subreq, call, &call->out);
     401         222 :         TALLOC_FREE(subreq);
     402         222 :         if (!W_ERROR_IS_OK(err)) {
     403           4 :                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
     404           4 :                 dns_tcp_terminate_connection(dns_conn,
     405             :                                 "dns_tcp_call_loop: process function failed");
     406           4 :                 return;
     407             :         }
     408             : 
     409             :         /* First add the length of the out buffer */
     410         218 :         RSSVAL(call->out_hdr, 0, call->out.length);
     411         218 :         call->out_iov[0].iov_base = (char *) call->out_hdr;
     412         218 :         call->out_iov[0].iov_len = 2;
     413             : 
     414         218 :         call->out_iov[1].iov_base = (char *) call->out.data;
     415         218 :         call->out_iov[1].iov_len = call->out.length;
     416             : 
     417         218 :         subreq = tstream_writev_queue_send(call,
     418         218 :                                            dns_conn->conn->event.ctx,
     419             :                                            dns_conn->tstream,
     420             :                                            dns_conn->send_queue,
     421         218 :                                            call->out_iov, 2);
     422         218 :         if (subreq == NULL) {
     423           0 :                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_call_loop: "
     424             :                                 "no memory for tstream_writev_queue_send");
     425           0 :                 return;
     426             :         }
     427         218 :         tevent_req_set_callback(subreq, dns_tcp_call_writev_done, call);
     428             : }
     429             : 
     430         218 : static void dns_tcp_call_writev_done(struct tevent_req *subreq)
     431             : {
     432         218 :         struct dns_tcp_call *call = tevent_req_callback_data(subreq,
     433             :                         struct dns_tcp_call);
     434           0 :         int sys_errno;
     435           0 :         int rc;
     436             : 
     437         218 :         rc = tstream_writev_queue_recv(subreq, &sys_errno);
     438         218 :         TALLOC_FREE(subreq);
     439         218 :         if (rc == -1) {
     440           0 :                 const char *reason;
     441             : 
     442           0 :                 reason = talloc_asprintf(call, "dns_tcp_call_writev_done: "
     443             :                                          "tstream_writev_queue_recv() - %d:%s",
     444             :                                          sys_errno, strerror(sys_errno));
     445           0 :                 if (!reason) {
     446           0 :                         reason = "dns_tcp_call_writev_done: tstream_writev_queue_recv() failed";
     447             :                 }
     448             : 
     449           0 :                 dns_tcp_terminate_connection(call->dns_conn, reason);
     450           0 :                 return;
     451             :         }
     452             : 
     453             :         /* We don't care about errors */
     454             : 
     455         218 :         talloc_free(call);
     456             : }
     457             : 
     458             : /*
     459             :   called when we get a new connection
     460             : */
     461         138 : static void dns_tcp_accept(struct stream_connection *conn)
     462             : {
     463           0 :         struct dns_socket *dns_socket;
     464           0 :         struct dns_tcp_connection *dns_conn;
     465           0 :         struct tevent_req *subreq;
     466           0 :         int rc;
     467             : 
     468         138 :         dns_conn = talloc_zero(conn, struct dns_tcp_connection);
     469         138 :         if (dns_conn == NULL) {
     470           0 :                 stream_terminate_connection(conn,
     471             :                                 "dns_tcp_accept: out of memory");
     472           0 :                 return;
     473             :         }
     474             : 
     475         138 :         dns_conn->send_queue = tevent_queue_create(conn, "dns_tcp_accept");
     476         138 :         if (dns_conn->send_queue == NULL) {
     477           0 :                 stream_terminate_connection(conn,
     478             :                                 "dns_tcp_accept: out of memory");
     479           0 :                 return;
     480             :         }
     481             : 
     482         138 :         dns_socket = talloc_get_type(conn->private_data, struct dns_socket);
     483             : 
     484         138 :         TALLOC_FREE(conn->event.fde);
     485             : 
     486         138 :         rc = tstream_bsd_existing_socket(dns_conn,
     487             :                         socket_get_fd(conn->socket),
     488             :                         &dns_conn->tstream);
     489         138 :         if (rc < 0) {
     490           0 :                 stream_terminate_connection(conn,
     491             :                                 "dns_tcp_accept: out of memory");
     492           0 :                 return;
     493             :         }
     494             :         /* as server we want to fail early */
     495         138 :         tstream_bsd_fail_readv_first_error(dns_conn->tstream, true);
     496             : 
     497         138 :         dns_conn->conn = conn;
     498         138 :         dns_conn->dns_socket = dns_socket;
     499         138 :         conn->private_data = dns_conn;
     500             : 
     501             :         /*
     502             :          * The dns tcp pdu's has the length as 2 byte (initial_read_size),
     503             :          * tstream_full_request_u16 provides the pdu length then.
     504             :          */
     505         138 :         subreq = tstream_read_pdu_blob_send(dns_conn,
     506         138 :                                             dns_conn->conn->event.ctx,
     507             :                                             dns_conn->tstream,
     508             :                                             2, /* initial_read_size */
     509             :                                             tstream_full_request_u16,
     510             :                                             dns_conn);
     511         138 :         if (subreq == NULL) {
     512           0 :                 dns_tcp_terminate_connection(dns_conn, "dns_tcp_accept: "
     513             :                                 "no memory for tstream_read_pdu_blob_send");
     514           0 :                 return;
     515             :         }
     516         138 :         tevent_req_set_callback(subreq, dns_tcp_call_loop, dns_conn);
     517             : }
     518             : 
     519             : static const struct stream_server_ops dns_tcp_stream_ops = {
     520             :         .name                   = "dns_tcp",
     521             :         .accept_connection      = dns_tcp_accept,
     522             :         .recv_handler           = dns_tcp_recv,
     523             :         .send_handler           = dns_tcp_send
     524             : };
     525             : 
     526             : struct dns_udp_call {
     527             :         struct dns_udp_socket *sock;
     528             :         struct tsocket_address *src;
     529             :         DATA_BLOB in;
     530             :         DATA_BLOB out;
     531             : };
     532             : 
     533             : static void dns_udp_call_process_done(struct tevent_req *subreq);
     534             : static void dns_udp_call_sendto_done(struct tevent_req *subreq);
     535             : 
     536        3841 : static void dns_udp_call_loop(struct tevent_req *subreq)
     537             : {
     538        3841 :         struct dns_udp_socket *sock = tevent_req_callback_data(subreq,
     539             :                                       struct dns_udp_socket);
     540        3841 :         struct dns_server *dns = sock->dns_socket->dns;
     541           0 :         struct dns_udp_call *call;
     542           0 :         uint8_t *buf;
     543           0 :         ssize_t len;
     544           0 :         int sys_errno;
     545             : 
     546        3841 :         call = talloc(sock, struct dns_udp_call);
     547        3841 :         if (call == NULL) {
     548           0 :                 talloc_free(call);
     549           0 :                 goto done;
     550             :         }
     551        3841 :         call->sock = sock;
     552             : 
     553        3841 :         len = tdgram_recvfrom_recv(subreq, &sys_errno,
     554             :                                    call, &buf, &call->src);
     555        3841 :         TALLOC_FREE(subreq);
     556        3841 :         if (len == -1) {
     557           6 :                 talloc_free(call);
     558           6 :                 goto done;
     559             :         }
     560             : 
     561        3835 :         call->in.data = buf;
     562        3835 :         call->in.length = len;
     563             : 
     564        3835 :         DEBUG(10,("Received DNS UDP packet of length %lu from %s\n",
     565             :                  (long)call->in.length,
     566             :                  tsocket_address_string(call->src, call)));
     567             : 
     568        3835 :         subreq = dns_process_send(call, dns->task->event_ctx, dns,
     569        3835 :                                   call->src,
     570        3835 :                                   sock->dns_socket->local_address,
     571             :                                   &call->in);
     572        3835 :         if (subreq == NULL) {
     573           0 :                 TALLOC_FREE(call);
     574           0 :                 goto done;
     575             :         }
     576        3835 :         tevent_req_set_callback(subreq, dns_udp_call_process_done, call);
     577             : 
     578        3841 : done:
     579        3841 :         subreq = tdgram_recvfrom_send(sock,
     580        3841 :                                       sock->dns_socket->dns->task->event_ctx,
     581             :                                       sock->dgram);
     582        3841 :         if (subreq == NULL) {
     583           0 :                 task_server_terminate(sock->dns_socket->dns->task,
     584             :                                       "no memory for tdgram_recvfrom_send",
     585             :                                       true);
     586           0 :                 return;
     587             :         }
     588        3841 :         tevent_req_set_callback(subreq, dns_udp_call_loop, sock);
     589             : }
     590             : 
     591        3835 : static void dns_udp_call_process_done(struct tevent_req *subreq)
     592             : {
     593        3835 :         struct dns_udp_call *call = tevent_req_callback_data(
     594             :                 subreq, struct dns_udp_call);
     595        3835 :         struct dns_udp_socket *sock = call->sock;
     596        3835 :         struct dns_server *dns = sock->dns_socket->dns;
     597           0 :         WERROR err;
     598             : 
     599        3835 :         err = dns_process_recv(subreq, call, &call->out);
     600        3835 :         TALLOC_FREE(subreq);
     601        3835 :         if (!W_ERROR_IS_OK(err)) {
     602           0 :                 DEBUG(1, ("dns_process returned %s\n", win_errstr(err)));
     603           0 :                 TALLOC_FREE(call);
     604           0 :                 return;
     605             :         }
     606             : 
     607        3835 :         subreq = tdgram_sendto_queue_send(call,
     608        3835 :                                           dns->task->event_ctx,
     609             :                                           sock->dgram,
     610             :                                           sock->send_queue,
     611        3835 :                                           call->out.data,
     612             :                                           call->out.length,
     613             :                                           call->src);
     614        3835 :         if (subreq == NULL) {
     615           0 :                 talloc_free(call);
     616           0 :                 return;
     617             :         }
     618        3835 :         tevent_req_set_callback(subreq, dns_udp_call_sendto_done, call);
     619             : 
     620             : }
     621        3835 : static void dns_udp_call_sendto_done(struct tevent_req *subreq)
     622             : {
     623        3835 :         struct dns_udp_call *call = tevent_req_callback_data(subreq,
     624             :                                        struct dns_udp_call);
     625           0 :         int sys_errno;
     626             : 
     627        3835 :         tdgram_sendto_queue_recv(subreq, &sys_errno);
     628             : 
     629             :         /* We don't care about errors */
     630             : 
     631        3835 :         talloc_free(call);
     632        3835 : }
     633             : 
     634             : /*
     635             :   start listening on the given address
     636             : */
     637         118 : static NTSTATUS dns_add_socket(struct dns_server *dns,
     638             :                                const struct model_ops *model_ops,
     639             :                                const char *name,
     640             :                                const char *address,
     641             :                                uint16_t port)
     642             : {
     643           4 :         struct dns_socket *dns_socket;
     644           4 :         struct dns_udp_socket *dns_udp_socket;
     645           4 :         struct tevent_req *udpsubreq;
     646           4 :         NTSTATUS status;
     647           4 :         int ret;
     648             : 
     649         118 :         dns_socket = talloc(dns, struct dns_socket);
     650         118 :         NT_STATUS_HAVE_NO_MEMORY(dns_socket);
     651             : 
     652         118 :         dns_socket->dns = dns;
     653             : 
     654         118 :         ret = tsocket_address_inet_from_strings(dns_socket, "ip",
     655             :                                                 address, port,
     656             :                                                 &dns_socket->local_address);
     657         118 :         if (ret != 0) {
     658           0 :                 status = map_nt_error_from_unix_common(errno);
     659           0 :                 return status;
     660             :         }
     661             : 
     662         236 :         status = stream_setup_socket(dns->task,
     663         114 :                                      dns->task->event_ctx,
     664         118 :                                      dns->task->lp_ctx,
     665             :                                      model_ops,
     666             :                                      &dns_tcp_stream_ops,
     667             :                                      "ip", address, &port,
     668         114 :                                      lpcfg_socket_options(dns->task->lp_ctx),
     669             :                                      dns_socket,
     670         118 :                                      dns->task->process_context);
     671         118 :         if (!NT_STATUS_IS_OK(status)) {
     672           0 :                 DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
     673             :                          address, port, nt_errstr(status)));
     674           0 :                 talloc_free(dns_socket);
     675           0 :                 return status;
     676             :         }
     677             : 
     678         118 :         dns_udp_socket = talloc(dns_socket, struct dns_udp_socket);
     679         118 :         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket);
     680             : 
     681         118 :         dns_udp_socket->dns_socket = dns_socket;
     682             : 
     683         118 :         ret = tdgram_inet_udp_socket(dns_socket->local_address,
     684             :                                      NULL,
     685             :                                      dns_udp_socket,
     686             :                                      &dns_udp_socket->dgram);
     687         118 :         if (ret != 0) {
     688           0 :                 status = map_nt_error_from_unix_common(errno);
     689           0 :                 DEBUG(0,("Failed to bind to %s:%u UDP - %s\n",
     690             :                          address, port, nt_errstr(status)));
     691           0 :                 return status;
     692             :         }
     693             : 
     694         118 :         dns_udp_socket->send_queue = tevent_queue_create(dns_udp_socket,
     695             :                                                          "dns_udp_send_queue");
     696         118 :         NT_STATUS_HAVE_NO_MEMORY(dns_udp_socket->send_queue);
     697             : 
     698         122 :         udpsubreq = tdgram_recvfrom_send(dns_udp_socket,
     699         118 :                                          dns->task->event_ctx,
     700             :                                          dns_udp_socket->dgram);
     701         118 :         NT_STATUS_HAVE_NO_MEMORY(udpsubreq);
     702         118 :         tevent_req_set_callback(udpsubreq, dns_udp_call_loop, dns_udp_socket);
     703             : 
     704         118 :         return NT_STATUS_OK;
     705             : }
     706             : 
     707             : /*
     708             :   setup our listening sockets on the configured network interfaces
     709             : */
     710          59 : static NTSTATUS dns_startup_interfaces(struct dns_server *dns,
     711             :                                        struct interface *ifaces,
     712             :                                        const struct model_ops *model_ops)
     713             : {
     714           2 :         size_t num_interfaces;
     715          59 :         TALLOC_CTX *tmp_ctx = talloc_new(dns);
     716           2 :         NTSTATUS status;
     717           2 :         int i;
     718             : 
     719          59 :         if (ifaces != NULL) {
     720           0 :                 num_interfaces = iface_list_count(ifaces);
     721             : 
     722           0 :                 for (i=0; i<num_interfaces; i++) {
     723           0 :                         const char *address = talloc_strdup(tmp_ctx,
     724             :                                                             iface_list_n_ip(ifaces, i));
     725             : 
     726           0 :                         status = dns_add_socket(dns, model_ops, "dns", address,
     727           0 :                                                 lpcfg_dns_port(dns->task->lp_ctx));
     728           0 :                         NT_STATUS_NOT_OK_RETURN(status);
     729             :                 }
     730             :         } else {
     731          59 :                 size_t num_binds = 0;
     732           2 :                 char **wcard;
     733          59 :                 wcard = iface_list_wildcard(tmp_ctx);
     734          59 :                 if (wcard == NULL) {
     735           0 :                         DEBUG(0, ("No wildcard address available\n"));
     736           0 :                         return NT_STATUS_INTERNAL_ERROR;
     737             :                 }
     738         177 :                 for (i = 0; wcard[i] != NULL; i++) {
     739         118 :                         status = dns_add_socket(dns, model_ops, "dns", wcard[i],
     740         118 :                                                 lpcfg_dns_port(dns->task->lp_ctx));
     741         118 :                         if (NT_STATUS_IS_OK(status)) {
     742         118 :                                 num_binds++;
     743             :                         }
     744             :                 }
     745          59 :                 if (num_binds == 0) {
     746           0 :                         talloc_free(tmp_ctx);
     747           0 :                         return NT_STATUS_INVALID_PARAMETER_MIX;
     748             :                 }
     749             :         }
     750             : 
     751          59 :         talloc_free(tmp_ctx);
     752             : 
     753          59 :         return NT_STATUS_OK;
     754             : }
     755             : 
     756          59 : static struct dns_server_tkey_store *tkey_store_init(TALLOC_CTX *mem_ctx,
     757             :                                                      uint16_t size)
     758             : {
     759          59 :         struct dns_server_tkey_store *buffer = talloc_zero(mem_ctx,
     760             :                                                 struct dns_server_tkey_store);
     761             : 
     762          59 :         if (buffer == NULL) {
     763           0 :                 return NULL;
     764             :         }
     765             : 
     766          59 :         buffer->size = size;
     767          59 :         buffer->next_idx = 0;
     768             : 
     769          59 :         buffer->tkeys = talloc_zero_array(buffer, struct dns_server_tkey *, size);
     770          59 :         if (buffer->tkeys == NULL) {
     771           0 :                 TALLOC_FREE(buffer);
     772             :         }
     773             : 
     774          57 :         return buffer;
     775             : }
     776             : 
     777        1283 : static NTSTATUS dns_server_reload_zones(struct dns_server *dns)
     778             : {
     779           2 :         NTSTATUS status;
     780        1283 :         struct dns_server_zone *new_list = NULL;
     781        1283 :         struct dns_server_zone *old_list = dns->zones;
     782           2 :         struct dns_server_zone *old_zone;
     783        1283 :         status = dns_common_zones(dns->samdb, dns, NULL, &new_list);
     784        1283 :         if (!NT_STATUS_IS_OK(status)) {
     785           0 :                 return status;
     786             :         }
     787        1283 :         dns->zones = new_list;
     788        4941 :         while ((old_zone = DLIST_TAIL(old_list)) != NULL) {
     789        3658 :                 DLIST_REMOVE(old_list, old_zone);
     790        3658 :                 talloc_free(old_zone);
     791             :         }
     792             : 
     793        1283 :         return NT_STATUS_OK;
     794             : }
     795             : 
     796             : /**
     797             :  * Called when the internal DNS server should reload the zones from DB, for
     798             :  * example, when zones are added or deleted through RPC or replicated by
     799             :  * inbound DRS.
     800             :  */
     801        1224 : static NTSTATUS dns_reload_zones(struct irpc_message *msg,
     802             :                                  struct dnssrv_reload_dns_zones *r)
     803             : {
     804           0 :         struct dns_server *dns;
     805             : 
     806        1224 :         dns = talloc_get_type(msg->private_data, struct dns_server);
     807        1224 :         if (dns == NULL) {
     808           0 :                 r->out.result = NT_STATUS_INTERNAL_ERROR;
     809           0 :                 return NT_STATUS_INTERNAL_ERROR;
     810             :         }
     811             : 
     812        1224 :         r->out.result = dns_server_reload_zones(dns);
     813             : 
     814        1224 :         return NT_STATUS_OK;
     815             : }
     816             : 
     817          65 : static NTSTATUS dns_task_init(struct task_server *task)
     818             : {
     819           2 :         struct dns_server *dns;
     820           2 :         NTSTATUS status;
     821          65 :         struct interface *ifaces = NULL;
     822           2 :         int ret;
     823           2 :         static const char * const attrs_none[] = { NULL};
     824           2 :         struct ldb_message *dns_acc;
     825           2 :         char *hostname_lower;
     826           2 :         char *dns_spn;
     827           2 :         bool ok;
     828             : 
     829          65 :         switch (lpcfg_server_role(task->lp_ctx)) {
     830           0 :         case ROLE_STANDALONE:
     831           0 :                 task_server_terminate(task, "dns: no DNS required in standalone configuration", false);
     832           0 :                 return NT_STATUS_INVALID_DOMAIN_ROLE;
     833           6 :         case ROLE_DOMAIN_MEMBER:
     834           6 :                 task_server_terminate(task, "dns: no DNS required in member server configuration", false);
     835           0 :                 return NT_STATUS_INVALID_DOMAIN_ROLE;
     836          57 :         case ROLE_ACTIVE_DIRECTORY_DC:
     837             :                 /* Yes, we want a DNS */
     838          57 :                 break;
     839             :         }
     840             : 
     841          59 :         if (lpcfg_interfaces(task->lp_ctx) && lpcfg_bind_interfaces_only(task->lp_ctx)) {
     842           0 :                 load_interface_list(task, task->lp_ctx, &ifaces);
     843             : 
     844           0 :                 if (iface_list_count(ifaces) == 0) {
     845           0 :                         task_server_terminate(task, "dns: no network interfaces configured", false);
     846           0 :                         return NT_STATUS_UNSUCCESSFUL;
     847             :                 }
     848             :         }
     849             : 
     850          59 :         task_server_set_title(task, "task[dns]");
     851             : 
     852          59 :         dns = talloc_zero(task, struct dns_server);
     853          59 :         if (dns == NULL) {
     854           0 :                 task_server_terminate(task, "dns: out of memory", true);
     855           0 :                 return NT_STATUS_NO_MEMORY;
     856             :         }
     857             : 
     858          59 :         dns->task = task;
     859             : 
     860          59 :         dns->server_credentials = cli_credentials_init(dns);
     861          59 :         if (!dns->server_credentials) {
     862           0 :                 task_server_terminate(task, "Failed to init server credentials\n", true);
     863           0 :                 return NT_STATUS_UNSUCCESSFUL;
     864             :         }
     865             : 
     866         177 :         dns->samdb = samdb_connect(dns,
     867          57 :                                    dns->task->event_ctx,
     868          59 :                                    dns->task->lp_ctx,
     869          59 :                                    system_session(dns->task->lp_ctx),
     870             :                                    NULL,
     871             :                                    0);
     872          59 :         if (!dns->samdb) {
     873           0 :                 task_server_terminate(task, "dns: samdb_connect failed", true);
     874           0 :                 return NT_STATUS_UNSUCCESSFUL;
     875             :         }
     876             : 
     877          59 :         ok = cli_credentials_set_conf(dns->server_credentials, task->lp_ctx);
     878          59 :         if (!ok) {
     879           0 :                 task_server_terminate(task,
     880             :                                       "dns: failed to load smb.conf",
     881             :                                       true);
     882           0 :                 return NT_STATUS_UNSUCCESSFUL;
     883             :         }
     884             : 
     885          59 :         hostname_lower = strlower_talloc(dns, lpcfg_netbios_name(task->lp_ctx));
     886          59 :         dns_spn = talloc_asprintf(dns, "DNS/%s.%s",
     887             :                                   hostname_lower,
     888             :                                   lpcfg_dnsdomain(task->lp_ctx));
     889          59 :         TALLOC_FREE(hostname_lower);
     890             : 
     891          59 :         ret = dsdb_search_one(dns->samdb, dns, &dns_acc,
     892             :                               ldb_get_default_basedn(dns->samdb), LDB_SCOPE_SUBTREE,
     893             :                               attrs_none, 0, "(servicePrincipalName=%s)",
     894             :                               dns_spn);
     895          59 :         if (ret == LDB_SUCCESS) {
     896           2 :                 TALLOC_FREE(dns_acc);
     897           2 :                 if (!dns_spn) {
     898           0 :                         task_server_terminate(task, "dns: talloc_asprintf failed", true);
     899           0 :                         return NT_STATUS_UNSUCCESSFUL;
     900             :                 }
     901           2 :                 status = cli_credentials_set_stored_principal(dns->server_credentials, task->lp_ctx, dns_spn);
     902           2 :                 if (!NT_STATUS_IS_OK(status)) {
     903           0 :                         task_server_terminate(task,
     904           0 :                                               talloc_asprintf(task, "Failed to obtain server credentials for DNS, "
     905             :                                                               "despite finding it in the samdb! %s\n",
     906             :                                                               nt_errstr(status)),
     907             :                                               true);
     908           0 :                         return status;
     909             :                 }
     910             :         } else {
     911          57 :                 TALLOC_FREE(dns_spn);
     912          57 :                 status = cli_credentials_set_machine_account(dns->server_credentials, task->lp_ctx);
     913          57 :                 if (!NT_STATUS_IS_OK(status)) {
     914           0 :                         task_server_terminate(task,
     915           0 :                                               talloc_asprintf(task, "Failed to obtain server credentials, perhaps a standalone server?: %s\n",
     916             :                                                               nt_errstr(status)),
     917             :                                               true);
     918           0 :                         return status;
     919             :                 }
     920             :         }
     921             : 
     922          59 :         dns->tkeys = tkey_store_init(dns, TKEY_BUFFER_SIZE);
     923          59 :         if (!dns->tkeys) {
     924           0 :                 task_server_terminate(task, "Failed to allocate tkey storage\n", true);
     925           0 :                 return NT_STATUS_NO_MEMORY;
     926             :         }
     927             : 
     928          59 :         status = dns_server_reload_zones(dns);
     929          59 :         if (!NT_STATUS_IS_OK(status)) {
     930           0 :                 task_server_terminate(task, "dns: failed to load DNS zones", true);
     931           0 :                 return status;
     932             :         }
     933             : 
     934          59 :         status = dns_startup_interfaces(dns, ifaces, task->model_ops);
     935          59 :         if (!NT_STATUS_IS_OK(status)) {
     936           0 :                 task_server_terminate(task, "dns failed to setup interfaces", true);
     937           0 :                 return status;
     938             :         }
     939             : 
     940             :         /* Setup the IRPC interface and register handlers */
     941          59 :         status = irpc_add_name(task->msg_ctx, "dnssrv");
     942          59 :         if (!NT_STATUS_IS_OK(status)) {
     943           0 :                 task_server_terminate(task, "dns: failed to register IRPC name", true);
     944           0 :                 return status;
     945             :         }
     946             : 
     947          59 :         status = IRPC_REGISTER(task->msg_ctx, irpc, DNSSRV_RELOAD_DNS_ZONES,
     948             :                                dns_reload_zones, dns);
     949          59 :         if (!NT_STATUS_IS_OK(status)) {
     950           0 :                 task_server_terminate(task, "dns: failed to setup reload handler", true);
     951           0 :                 return status;
     952             :         }
     953          59 :         return NT_STATUS_OK;
     954             : }
     955             : 
     956          66 : NTSTATUS server_service_dns_init(TALLOC_CTX *ctx)
     957             : {
     958           3 :         static const struct service_details details = {
     959             :                 .inhibit_fork_on_accept = true,
     960             :                 .inhibit_pre_fork = true,
     961             :                 .task_init = dns_task_init,
     962             :                 .post_fork = NULL
     963             :         };
     964          66 :         return register_server_service(ctx, "dns", &details);
     965             : }

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