2 Unix SMB/CIFS implementation.
4 low level socket handling for nbt requests
6 Copyright (C) Andrew Tridgell 2005
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.
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.
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/>.
23 #include "lib/events/events.h"
24 #include "../lib/util/dlinklist.h"
25 #include "../libcli/nbt/libnbt.h"
26 #include "../libcli/nbt/nbt_proto.h"
27 #include "lib/socket/socket.h"
28 #include "librpc/gen_ndr/ndr_nbt.h"
29 #include "param/param.h"
31 #define NBT_MAX_REPLIES 1000
34 destroy a pending request
36 static int nbt_name_request_destructor(struct nbt_name_request
*req
)
38 if (req
->state
== NBT_REQUEST_SEND
) {
39 DLIST_REMOVE(req
->nbtsock
->send_queue
, req
);
41 if (req
->state
== NBT_REQUEST_WAIT
) {
42 req
->nbtsock
->num_pending
--;
44 if (req
->name_trn_id
!= 0 && !req
->is_reply
) {
45 idr_remove(req
->nbtsock
->idr
, req
->name_trn_id
);
49 if (req
->nbtsock
->send_queue
== NULL
) {
50 TEVENT_FD_NOT_WRITEABLE(req
->nbtsock
->fde
);
52 if (req
->nbtsock
->num_pending
== 0 &&
53 req
->nbtsock
->incoming
.handler
== NULL
) {
54 TEVENT_FD_NOT_READABLE(req
->nbtsock
->fde
);
61 handle send events on a nbt name socket
63 static void nbt_name_socket_send(struct nbt_name_socket
*nbtsock
)
65 struct nbt_name_request
*req
;
66 TALLOC_CTX
*tmp_ctx
= talloc_new(nbtsock
);
69 while ((req
= nbtsock
->send_queue
)) {
72 len
= req
->encoded
.length
;
73 status
= socket_sendto(nbtsock
->sock
, &req
->encoded
, &len
,
75 if (NT_STATUS_IS_ERR(status
)) goto failed
;
77 if (!NT_STATUS_IS_OK(status
)) {
82 DLIST_REMOVE(nbtsock
->send_queue
, req
);
83 req
->state
= NBT_REQUEST_WAIT
;
87 TEVENT_FD_READABLE(nbtsock
->fde
);
88 nbtsock
->num_pending
++;
92 TEVENT_FD_NOT_WRITEABLE(nbtsock
->fde
);
97 DLIST_REMOVE(nbtsock
->send_queue
, req
);
98 nbt_name_request_destructor(req
);
100 req
->state
= NBT_REQUEST_ERROR
;
101 talloc_free(tmp_ctx
);
104 } else if (req
->is_reply
) {
112 handle a request timeout
114 static void nbt_name_socket_timeout(struct tevent_context
*ev
, struct tevent_timer
*te
,
115 struct timeval t
, void *private_data
)
117 struct nbt_name_request
*req
= talloc_get_type(private_data
,
118 struct nbt_name_request
);
120 if (req
->num_retries
!= 0) {
122 req
->te
= tevent_add_timer(req
->nbtsock
->event_ctx
, req
,
123 timeval_add(&t
, req
->timeout
, 0),
124 nbt_name_socket_timeout
, req
);
125 if (req
->state
!= NBT_REQUEST_SEND
) {
126 req
->state
= NBT_REQUEST_SEND
;
127 DLIST_ADD_END(req
->nbtsock
->send_queue
, req
);
129 TEVENT_FD_WRITEABLE(req
->nbtsock
->fde
);
133 nbt_name_request_destructor(req
);
134 if (req
->num_replies
== 0) {
135 req
->state
= NBT_REQUEST_TIMEOUT
;
136 req
->status
= NT_STATUS_IO_TIMEOUT
;
138 req
->state
= NBT_REQUEST_DONE
;
139 req
->status
= NT_STATUS_OK
;
143 } else if (req
->is_reply
) {
151 handle recv events on a nbt name socket
153 static void nbt_name_socket_recv(struct nbt_name_socket
*nbtsock
)
155 TALLOC_CTX
*tmp_ctx
= talloc_new(nbtsock
);
157 enum ndr_err_code ndr_err
;
158 struct socket_address
*src
;
161 struct nbt_name_packet
*packet
;
162 struct nbt_name_request
*req
;
164 status
= socket_pending(nbtsock
->sock
, &dsize
);
165 if (!NT_STATUS_IS_OK(status
)) {
166 talloc_free(tmp_ctx
);
171 * Given a zero length, data_blob_talloc() returns the
172 * NULL blob {NULL, 0}.
174 * We only want to error return here on a real out of memory condition
175 * (i.e. dsize != 0, so the UDP packet has data, but the return of the
176 * allocation failed, so blob.data==NULL).
178 * Given an actual zero length UDP packet having blob.data == NULL
179 * isn't an out of memory error condition, that's the defined semantics
180 * of data_blob_talloc() when asked for zero bytes.
182 * We still need to continue to do the zero-length socket_recvfrom()
183 * read in order to clear the "read pending" condition on the socket.
185 blob
= data_blob_talloc(tmp_ctx
, NULL
, dsize
);
186 if (blob
.data
== NULL
&& dsize
!= 0) {
187 talloc_free(tmp_ctx
);
191 status
= socket_recvfrom(nbtsock
->sock
, blob
.data
, blob
.length
, &nread
,
193 if (!NT_STATUS_IS_OK(status
)) {
194 talloc_free(tmp_ctx
);
198 packet
= talloc(tmp_ctx
, struct nbt_name_packet
);
199 if (packet
== NULL
) {
200 talloc_free(tmp_ctx
);
204 /* parse the request */
205 ndr_err
= ndr_pull_struct_blob(&blob
, packet
, packet
,
206 (ndr_pull_flags_fn_t
)ndr_pull_nbt_name_packet
);
207 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err
)) {
208 status
= ndr_map_error2ntstatus(ndr_err
);
209 DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
211 talloc_free(tmp_ctx
);
216 DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
217 (int)blob
.length
, src
->addr
, src
->port
));
218 NDR_PRINT_DEBUG(nbt_name_packet
, packet
);
221 /* if its not a reply then pass it off to the incoming request
223 if (!(packet
->operation
& NBT_FLAG_REPLY
)) {
224 if (nbtsock
->incoming
.handler
) {
225 nbtsock
->incoming
.handler(nbtsock
, packet
, src
);
227 talloc_free(tmp_ctx
);
231 /* find the matching request */
232 req
= (struct nbt_name_request
*)idr_find(nbtsock
->idr
,
233 packet
->name_trn_id
);
235 if (nbtsock
->unexpected
.handler
) {
236 nbtsock
->unexpected
.handler(nbtsock
, packet
, src
);
238 DEBUG(10,("Failed to match request for incoming name packet id 0x%04x on %p\n",
239 packet
->name_trn_id
, nbtsock
));
241 talloc_free(tmp_ctx
);
245 talloc_steal(req
, packet
);
246 talloc_steal(req
, src
);
247 talloc_free(tmp_ctx
);
248 nbt_name_socket_handle_response_packet(req
, packet
, src
);
251 void nbt_name_socket_handle_response_packet(struct nbt_name_request
*req
,
252 struct nbt_name_packet
*packet
,
253 struct socket_address
*src
)
255 /* if this is a WACK response, this we need to go back to waiting,
256 but perhaps increase the timeout */
257 if ((packet
->operation
& NBT_OPCODE
) == NBT_OPCODE_WACK
) {
259 if (req
->received_wack
|| packet
->ancount
< 1) {
260 nbt_name_request_destructor(req
);
261 req
->status
= NT_STATUS_INVALID_NETWORK_RESPONSE
;
262 req
->state
= NBT_REQUEST_ERROR
;
265 talloc_free(req
->te
);
266 /* we know we won't need any more retries - the server
267 has received our request */
268 req
->num_retries
= 0;
269 req
->received_wack
= true;
271 * there is a timeout in the packet,
272 * it is 5 + 4 * num_old_addresses
274 * although w2k3 screws it up
275 * and uses num_old_addresses = 0
277 * so we better fallback to the maximum
278 * of num_old_addresses = 25 if we got
279 * a timeout of less than 9s (5 + 4*1)
280 * or more than 105s (5 + 4*25).
282 ttl
= packet
->answers
[0].ttl
;
283 if ((ttl
< (5 + 4*1)) || (ttl
> (5 + 4*25))) {
287 req
->te
= tevent_add_timer(req
->nbtsock
->event_ctx
, req
,
288 timeval_current_ofs(req
->timeout
, 0),
289 nbt_name_socket_timeout
, req
);
294 req
->replies
= talloc_realloc(req
, req
->replies
, struct nbt_name_reply
, req
->num_replies
+1);
295 if (req
->replies
== NULL
) {
296 nbt_name_request_destructor(req
);
297 req
->state
= NBT_REQUEST_ERROR
;
298 req
->status
= NT_STATUS_NO_MEMORY
;
302 talloc_steal(req
, src
);
303 req
->replies
[req
->num_replies
].dest
= src
;
304 talloc_steal(req
, packet
);
305 req
->replies
[req
->num_replies
].packet
= packet
;
308 /* if we don't want multiple replies then we are done */
309 if (req
->allow_multiple_replies
&&
310 req
->num_replies
< NBT_MAX_REPLIES
) {
314 nbt_name_request_destructor(req
);
315 req
->state
= NBT_REQUEST_DONE
;
316 req
->status
= NT_STATUS_OK
;
325 handle fd events on a nbt_name_socket
327 static void nbt_name_socket_handler(struct tevent_context
*ev
, struct tevent_fd
*fde
,
328 uint16_t flags
, void *private_data
)
330 struct nbt_name_socket
*nbtsock
= talloc_get_type(private_data
,
331 struct nbt_name_socket
);
332 if (flags
& TEVENT_FD_WRITE
) {
333 nbt_name_socket_send(nbtsock
);
335 if (flags
& TEVENT_FD_READ
) {
336 nbt_name_socket_recv(nbtsock
);
342 initialise a nbt_name_socket. The event_ctx is optional, if provided
343 then operations will use that event context
345 _PUBLIC_
struct nbt_name_socket
*nbt_name_socket_init(TALLOC_CTX
*mem_ctx
,
346 struct tevent_context
*event_ctx
)
348 struct nbt_name_socket
*nbtsock
;
351 nbtsock
= talloc(mem_ctx
, struct nbt_name_socket
);
352 if (nbtsock
== NULL
) goto failed
;
354 nbtsock
->event_ctx
= event_ctx
;
355 if (nbtsock
->event_ctx
== NULL
) goto failed
;
357 status
= socket_create(nbtsock
, "ip", SOCKET_TYPE_DGRAM
,
359 if (!NT_STATUS_IS_OK(status
)) goto failed
;
361 socket_set_option(nbtsock
->sock
, "SO_BROADCAST", "1");
363 nbtsock
->idr
= idr_init(nbtsock
);
364 if (nbtsock
->idr
== NULL
) goto failed
;
366 nbtsock
->send_queue
= NULL
;
367 nbtsock
->num_pending
= 0;
368 nbtsock
->incoming
.handler
= NULL
;
369 nbtsock
->unexpected
.handler
= NULL
;
371 nbtsock
->fde
= tevent_add_fd(nbtsock
->event_ctx
, nbtsock
,
372 socket_get_fd(nbtsock
->sock
), 0,
373 nbt_name_socket_handler
, nbtsock
);
378 talloc_free(nbtsock
);
383 send off a nbt name request
385 struct nbt_name_request
*nbt_name_request_send(TALLOC_CTX
*mem_ctx
,
386 struct nbt_name_socket
*nbtsock
,
387 struct socket_address
*dest
,
388 struct nbt_name_packet
*request
,
389 int timeout
, int retries
,
390 bool allow_multiple_replies
)
392 struct nbt_name_request
*req
;
394 enum ndr_err_code ndr_err
;
396 req
= talloc_zero(mem_ctx
, struct nbt_name_request
);
397 if (req
== NULL
) goto failed
;
399 req
->nbtsock
= nbtsock
;
400 req
->allow_multiple_replies
= allow_multiple_replies
;
401 req
->state
= NBT_REQUEST_SEND
;
402 req
->is_reply
= false;
403 req
->timeout
= timeout
;
404 req
->num_retries
= retries
;
405 req
->dest
= socket_address_copy(req
, dest
);
406 if (req
->dest
== NULL
) goto failed
;
408 /* we select a random transaction id unless the user supplied one */
409 if (request
->name_trn_id
== 0) {
410 id
= idr_get_new_random(req
->nbtsock
->idr
, req
, UINT16_MAX
);
412 if (idr_find(req
->nbtsock
->idr
, request
->name_trn_id
)) goto failed
;
413 id
= idr_get_new_above(req
->nbtsock
->idr
, req
, request
->name_trn_id
,
416 if (id
== -1) goto failed
;
418 request
->name_trn_id
= id
;
419 req
->name_trn_id
= id
;
421 req
->te
= tevent_add_timer(nbtsock
->event_ctx
, req
,
422 timeval_current_ofs(req
->timeout
, 0),
423 nbt_name_socket_timeout
, req
);
425 talloc_set_destructor(req
, nbt_name_request_destructor
);
427 ndr_err
= ndr_push_struct_blob(&req
->encoded
, req
,
429 (ndr_push_flags_fn_t
)ndr_push_nbt_name_packet
);
430 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err
)) goto failed
;
432 DLIST_ADD_END(nbtsock
->send_queue
, req
);
435 DEBUG(10,("Queueing nbt packet to %s:%d\n",
436 req
->dest
->addr
, req
->dest
->port
));
437 NDR_PRINT_DEBUG(nbt_name_packet
, request
);
440 TEVENT_FD_WRITEABLE(nbtsock
->fde
);
451 send off a nbt name reply
453 _PUBLIC_ NTSTATUS
nbt_name_reply_send(struct nbt_name_socket
*nbtsock
,
454 struct socket_address
*dest
,
455 struct nbt_name_packet
*request
)
457 struct nbt_name_request
*req
;
458 enum ndr_err_code ndr_err
;
460 req
= talloc_zero(nbtsock
, struct nbt_name_request
);
461 NT_STATUS_HAVE_NO_MEMORY(req
);
463 req
->nbtsock
= nbtsock
;
464 req
->dest
= socket_address_copy(req
, dest
);
465 if (req
->dest
== NULL
) goto failed
;
466 req
->state
= NBT_REQUEST_SEND
;
467 req
->is_reply
= true;
469 talloc_set_destructor(req
, nbt_name_request_destructor
);
472 NDR_PRINT_DEBUG(nbt_name_packet
, request
);
475 ndr_err
= ndr_push_struct_blob(&req
->encoded
, req
,
477 (ndr_push_flags_fn_t
)ndr_push_nbt_name_packet
);
478 if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err
)) {
480 return ndr_map_error2ntstatus(ndr_err
);
483 DLIST_ADD_END(nbtsock
->send_queue
, req
);
485 TEVENT_FD_WRITEABLE(nbtsock
->fde
);
491 return NT_STATUS_NO_MEMORY
;
495 wait for a nbt request to complete
497 NTSTATUS
nbt_name_request_recv(struct nbt_name_request
*req
)
499 if (!req
) return NT_STATUS_NO_MEMORY
;
501 while (req
->state
< NBT_REQUEST_DONE
) {
502 if (tevent_loop_once(req
->nbtsock
->event_ctx
) != 0) {
503 req
->state
= NBT_REQUEST_ERROR
;
504 req
->status
= NT_STATUS_UNEXPECTED_NETWORK_ERROR
;
513 setup a handler for incoming requests
515 _PUBLIC_ NTSTATUS
nbt_set_incoming_handler(struct nbt_name_socket
*nbtsock
,
516 void (*handler
)(struct nbt_name_socket
*, struct nbt_name_packet
*,
517 struct socket_address
*),
520 nbtsock
->incoming
.handler
= handler
;
521 nbtsock
->incoming
.private_data
= private_data
;
522 TEVENT_FD_READABLE(nbtsock
->fde
);
527 setup a handler for unexpected requests
529 NTSTATUS
nbt_set_unexpected_handler(struct nbt_name_socket
*nbtsock
,
530 void (*handler
)(struct nbt_name_socket
*, struct nbt_name_packet
*,
531 struct socket_address
*),
534 nbtsock
->unexpected
.handler
= handler
;
535 nbtsock
->unexpected
.private_data
= private_data
;
536 TEVENT_FD_READABLE(nbtsock
->fde
);
541 turn a NBT rcode into a NTSTATUS
543 _PUBLIC_ NTSTATUS
nbt_rcode_to_ntstatus(uint8_t rcode
)
547 enum nbt_rcode rcode
;
550 { NBT_RCODE_FMT
, NT_STATUS_INVALID_PARAMETER
},
551 { NBT_RCODE_SVR
, NT_STATUS_SERVER_DISABLED
},
552 { NBT_RCODE_NAM
, NT_STATUS_OBJECT_NAME_NOT_FOUND
},
553 { NBT_RCODE_IMP
, NT_STATUS_NOT_SUPPORTED
},
554 { NBT_RCODE_RFS
, NT_STATUS_ACCESS_DENIED
},
555 { NBT_RCODE_ACT
, NT_STATUS_ADDRESS_ALREADY_EXISTS
},
556 { NBT_RCODE_CFT
, NT_STATUS_CONFLICTING_ADDRESSES
}
558 for (i
=0;i
<ARRAY_SIZE(map
);i
++) {
559 if (map
[i
].rcode
== rcode
) {
560 return map
[i
].status
;
563 return NT_STATUS_UNSUCCESSFUL
;