libcli/nbt: fix wack timeout handling
[kai/samba-autobuild/.git] / libcli / nbt / nbtsocket.c
1 /*
2    Unix SMB/CIFS implementation.
3
4    low level socket handling for nbt requests
5
6    Copyright (C) Andrew Tridgell 2005
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 "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"
30
31 #define NBT_MAX_REPLIES 1000
32
33 /*
34   destroy a pending request
35 */
36 static int nbt_name_request_destructor(struct nbt_name_request *req)
37 {
38         if (req->state == NBT_REQUEST_SEND) {
39                 DLIST_REMOVE(req->nbtsock->send_queue, req);
40         }
41         if (req->state == NBT_REQUEST_WAIT) {
42                 req->nbtsock->num_pending--;
43         }
44         if (req->name_trn_id != 0 && !req->is_reply) {
45                 idr_remove(req->nbtsock->idr, req->name_trn_id);
46                 req->name_trn_id = 0;
47         }
48         if (req->te) {
49                 talloc_free(req->te);
50                 req->te = NULL;
51         }
52         if (req->nbtsock->send_queue == NULL) {
53                 EVENT_FD_NOT_WRITEABLE(req->nbtsock->fde);
54         }
55         if (req->nbtsock->num_pending == 0 &&
56             req->nbtsock->incoming.handler == NULL) {
57                 EVENT_FD_NOT_READABLE(req->nbtsock->fde);
58         }
59         return 0;
60 }
61
62
63 /*
64   handle send events on a nbt name socket
65 */
66 static void nbt_name_socket_send(struct nbt_name_socket *nbtsock)
67 {
68         struct nbt_name_request *req = nbtsock->send_queue;
69         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
70         NTSTATUS status;
71
72         while ((req = nbtsock->send_queue)) {
73                 size_t len;
74
75                 len = req->encoded.length;
76                 status = socket_sendto(nbtsock->sock, &req->encoded, &len,
77                                        req->dest);
78                 if (NT_STATUS_IS_ERR(status)) goto failed;
79
80                 if (!NT_STATUS_IS_OK(status)) {
81                         talloc_free(tmp_ctx);
82                         return;
83                 }
84
85                 DLIST_REMOVE(nbtsock->send_queue, req);
86                 req->state = NBT_REQUEST_WAIT;
87                 if (req->is_reply) {
88                         talloc_free(req);
89                 } else {
90                         EVENT_FD_READABLE(nbtsock->fde);
91                         nbtsock->num_pending++;
92                 }
93         }
94
95         EVENT_FD_NOT_WRITEABLE(nbtsock->fde);
96         talloc_free(tmp_ctx);
97         return;
98
99 failed:
100         DLIST_REMOVE(nbtsock->send_queue, req);
101         nbt_name_request_destructor(req);
102         req->status = status;
103         req->state = NBT_REQUEST_ERROR;
104         talloc_free(tmp_ctx);
105         if (req->async.fn) {
106                 req->async.fn(req);
107         } else if (req->is_reply) {
108                 talloc_free(req);
109         }
110         return;
111 }
112
113
114 /*
115   handle a request timeout
116 */
117 static void nbt_name_socket_timeout(struct tevent_context *ev, struct tevent_timer *te,
118                                     struct timeval t, void *private)
119 {
120         struct nbt_name_request *req = talloc_get_type(private,
121                                                        struct nbt_name_request);
122
123         if (req->num_retries != 0) {
124                 req->num_retries--;
125                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
126                                           timeval_add(&t, req->timeout, 0),
127                                           nbt_name_socket_timeout, req);
128                 if (req->state != NBT_REQUEST_SEND) {
129                         req->state = NBT_REQUEST_SEND;
130                         DLIST_ADD_END(req->nbtsock->send_queue, req,
131                                       struct nbt_name_request *);
132                 }
133                 EVENT_FD_WRITEABLE(req->nbtsock->fde);
134                 return;
135         }
136
137         nbt_name_request_destructor(req);
138         if (req->num_replies == 0) {
139                 req->state = NBT_REQUEST_TIMEOUT;
140                 req->status = NT_STATUS_IO_TIMEOUT;
141         } else {
142                 req->state = NBT_REQUEST_DONE;
143                 req->status = NT_STATUS_OK;
144         }
145         if (req->async.fn) {
146                 req->async.fn(req);
147         } else if (req->is_reply) {
148                 talloc_free(req);
149         }
150 }
151
152
153
154 /**
155   handle recv events on a nbt name socket
156 */
157 static void nbt_name_socket_recv(struct nbt_name_socket *nbtsock)
158 {
159         TALLOC_CTX *tmp_ctx = talloc_new(nbtsock);
160         NTSTATUS status;
161         enum ndr_err_code ndr_err;
162         struct socket_address *src;
163         DATA_BLOB blob;
164         size_t nread, dsize;
165         struct nbt_name_packet *packet;
166         struct nbt_name_request *req;
167
168         status = socket_pending(nbtsock->sock, &dsize);
169         if (!NT_STATUS_IS_OK(status)) {
170                 talloc_free(tmp_ctx);
171                 return;
172         }
173
174         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
175         if (blob.data == NULL) {
176                 talloc_free(tmp_ctx);
177                 return;
178         }
179
180         status = socket_recvfrom(nbtsock->sock, blob.data, blob.length, &nread,
181                                  tmp_ctx, &src);
182         if (!NT_STATUS_IS_OK(status)) {
183                 talloc_free(tmp_ctx);
184                 return;
185         }
186
187         packet = talloc(tmp_ctx, struct nbt_name_packet);
188         if (packet == NULL) {
189                 talloc_free(tmp_ctx);
190                 return;
191         }
192
193         /* parse the request */
194         ndr_err = ndr_pull_struct_blob(&blob, packet, nbtsock->iconv_convenience, packet,
195                                        (ndr_pull_flags_fn_t)ndr_pull_nbt_name_packet);
196         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
197                 status = ndr_map_error2ntstatus(ndr_err);
198                 DEBUG(2,("Failed to parse incoming NBT name packet - %s\n",
199                          nt_errstr(status)));
200                 talloc_free(tmp_ctx);
201                 return;
202         }
203
204         if (DEBUGLVL(10)) {
205                 DEBUG(10,("Received nbt packet of length %d from %s:%d\n",
206                           (int)blob.length, src->addr, src->port));
207                 NDR_PRINT_DEBUG(nbt_name_packet, packet);
208         }
209
210         /* if its not a reply then pass it off to the incoming request
211            handler, if any */
212         if (!(packet->operation & NBT_FLAG_REPLY)) {
213                 if (nbtsock->incoming.handler) {
214                         nbtsock->incoming.handler(nbtsock, packet, src);
215                 }
216                 talloc_free(tmp_ctx);
217                 return;
218         }
219
220         /* find the matching request */
221         req = (struct nbt_name_request *)idr_find(nbtsock->idr,
222                                                   packet->name_trn_id);
223         if (req == NULL) {
224                 if (nbtsock->unexpected.handler) {
225                         nbtsock->unexpected.handler(nbtsock, packet, src);
226                 } else {
227                         DEBUG(10,("Failed to match request for incoming name packet id 0x%04x on %p\n",
228                                  packet->name_trn_id, nbtsock));
229                 }
230                 talloc_free(tmp_ctx);
231                 return;
232         }
233
234         /* if this is a WACK response, this we need to go back to waiting,
235            but perhaps increase the timeout */
236         if ((packet->operation & NBT_OPCODE) == NBT_OPCODE_WACK) {
237                 uint32_t ttl;
238                 if (req->received_wack || packet->ancount < 1) {
239                         nbt_name_request_destructor(req);
240                         req->status = NT_STATUS_INVALID_NETWORK_RESPONSE;
241                         req->state  = NBT_REQUEST_ERROR;
242                         goto done;
243                 }
244                 talloc_free(req->te);
245                 /* we know we won't need any more retries - the server
246                    has received our request */
247                 req->num_retries   = 0;
248                 req->received_wack = true;
249                 /*
250                  * there is a timeout in the packet,
251                  * it is 5 + 4 * num_old_addresses
252                  *
253                  * although w2k3 screws it up
254                  * and uses num_old_addresses = 0
255                  *
256                  * so we better fallback to the maximum
257                  * of num_old_addresses = 25 if we got
258                  * a timeout of less than 9s (5 + 4*1)
259                  * or more than 105s (5 + 4*25).
260                  */
261                 ttl = packet->answers[0].ttl;
262                 if ((ttl < (5 + 4*1)) || (ttl > (5 + 4*25))) {
263                         ttl = 5 + 4*25;
264                 }
265                 req->timeout = ttl;
266                 req->te = event_add_timed(req->nbtsock->event_ctx, req,
267                                           timeval_current_ofs(req->timeout, 0),
268                                           nbt_name_socket_timeout, req);
269                 talloc_free(tmp_ctx);
270                 return;
271         }
272
273
274         req->replies = talloc_realloc(req, req->replies, struct nbt_name_reply, req->num_replies+1);
275         if (req->replies == NULL) {
276                 nbt_name_request_destructor(req);
277                 req->state  = NBT_REQUEST_ERROR;
278                 req->status = NT_STATUS_NO_MEMORY;
279                 goto done;
280         }
281
282         talloc_steal(req, src);
283         req->replies[req->num_replies].dest   = src;
284         talloc_steal(req, packet);
285         req->replies[req->num_replies].packet = packet;
286         req->num_replies++;
287
288         /* if we don't want multiple replies then we are done */
289         if (req->allow_multiple_replies &&
290             req->num_replies < NBT_MAX_REPLIES) {
291                 talloc_free(tmp_ctx);
292                 return;
293         }
294
295         nbt_name_request_destructor(req);
296         req->state  = NBT_REQUEST_DONE;
297         req->status = NT_STATUS_OK;
298
299 done:
300         talloc_free(tmp_ctx);
301         if (req->async.fn) {
302                 req->async.fn(req);
303         }
304 }
305
306 /*
307   handle fd events on a nbt_name_socket
308 */
309 static void nbt_name_socket_handler(struct tevent_context *ev, struct tevent_fd *fde,
310                                     uint16_t flags, void *private)
311 {
312         struct nbt_name_socket *nbtsock = talloc_get_type(private,
313                                                           struct nbt_name_socket);
314         if (flags & EVENT_FD_WRITE) {
315                 nbt_name_socket_send(nbtsock);
316         }
317         if (flags & EVENT_FD_READ) {
318                 nbt_name_socket_recv(nbtsock);
319         }
320 }
321
322
323 /*
324   initialise a nbt_name_socket. The event_ctx is optional, if provided
325   then operations will use that event context
326 */
327 _PUBLIC_ struct nbt_name_socket *nbt_name_socket_init(TALLOC_CTX *mem_ctx,
328                                              struct tevent_context *event_ctx,
329                                              struct smb_iconv_convenience *iconv_convenience)
330 {
331         struct nbt_name_socket *nbtsock;
332         NTSTATUS status;
333
334         nbtsock = talloc(mem_ctx, struct nbt_name_socket);
335         if (nbtsock == NULL) goto failed;
336
337         nbtsock->event_ctx = talloc_reference(nbtsock, event_ctx);
338         if (nbtsock->event_ctx == NULL) goto failed;
339
340         status = socket_create("ip", SOCKET_TYPE_DGRAM, &nbtsock->sock, 0);
341         if (!NT_STATUS_IS_OK(status)) goto failed;
342
343         socket_set_option(nbtsock->sock, "SO_BROADCAST", "1");
344
345         talloc_steal(nbtsock, nbtsock->sock);
346
347         nbtsock->idr = idr_init(nbtsock);
348         if (nbtsock->idr == NULL) goto failed;
349
350         nbtsock->send_queue = NULL;
351         nbtsock->num_pending = 0;
352         nbtsock->incoming.handler = NULL;
353         nbtsock->unexpected.handler = NULL;
354         nbtsock->iconv_convenience = iconv_convenience;
355
356         nbtsock->fde = event_add_fd(nbtsock->event_ctx, nbtsock,
357                                     socket_get_fd(nbtsock->sock), 0,
358                                     nbt_name_socket_handler, nbtsock);
359
360         return nbtsock;
361
362 failed:
363         talloc_free(nbtsock);
364         return NULL;
365 }
366
367 /*
368   send off a nbt name request
369 */
370 struct nbt_name_request *nbt_name_request_send(struct nbt_name_socket *nbtsock,
371                                                struct socket_address *dest,
372                                                struct nbt_name_packet *request,
373                                                int timeout, int retries,
374                                                bool allow_multiple_replies)
375 {
376         struct nbt_name_request *req;
377         int id;
378         enum ndr_err_code ndr_err;
379
380         req = talloc_zero(nbtsock, struct nbt_name_request);
381         if (req == NULL) goto failed;
382
383         req->nbtsock                = nbtsock;
384         req->allow_multiple_replies = allow_multiple_replies;
385         req->state                  = NBT_REQUEST_SEND;
386         req->is_reply               = false;
387         req->timeout                = timeout;
388         req->num_retries            = retries;
389         req->dest                   = dest;
390         if (talloc_reference(req, dest) == NULL) goto failed;
391
392         /* we select a random transaction id unless the user supplied one */
393         if (request->name_trn_id == 0) {
394                 id = idr_get_new_random(req->nbtsock->idr, req, UINT16_MAX);
395         } else {
396                 if (idr_find(req->nbtsock->idr, request->name_trn_id)) goto failed;
397                 id = idr_get_new_above(req->nbtsock->idr, req, request->name_trn_id,
398                                        UINT16_MAX);
399         }
400         if (id == -1) goto failed;
401
402         request->name_trn_id = id;
403         req->name_trn_id     = id;
404
405         req->te = event_add_timed(nbtsock->event_ctx, req,
406                                   timeval_current_ofs(req->timeout, 0),
407                                   nbt_name_socket_timeout, req);
408
409         talloc_set_destructor(req, nbt_name_request_destructor);
410
411         ndr_err = ndr_push_struct_blob(&req->encoded, req,
412                                        req->nbtsock->iconv_convenience,
413                                        request,
414                                        (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
415         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) goto failed;
416
417         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
418
419         if (DEBUGLVL(10)) {
420                 DEBUG(10,("Queueing nbt packet to %s:%d\n",
421                           req->dest->addr, req->dest->port));
422                 NDR_PRINT_DEBUG(nbt_name_packet, request);
423         }
424
425         EVENT_FD_WRITEABLE(nbtsock->fde);
426
427         return req;
428
429 failed:
430         talloc_free(req);
431         return NULL;
432 }
433
434
435 /*
436   send off a nbt name reply
437 */
438 _PUBLIC_ NTSTATUS nbt_name_reply_send(struct nbt_name_socket *nbtsock,
439                              struct socket_address *dest,
440                              struct nbt_name_packet *request)
441 {
442         struct nbt_name_request *req;
443         enum ndr_err_code ndr_err;
444
445         req = talloc_zero(nbtsock, struct nbt_name_request);
446         NT_STATUS_HAVE_NO_MEMORY(req);
447
448         req->nbtsock   = nbtsock;
449         req->dest = dest;
450         if (talloc_reference(req, dest) == NULL) goto failed;
451         req->state     = NBT_REQUEST_SEND;
452         req->is_reply = true;
453
454         talloc_set_destructor(req, nbt_name_request_destructor);
455
456         if (DEBUGLVL(10)) {
457                 NDR_PRINT_DEBUG(nbt_name_packet, request);
458         }
459
460         ndr_err = ndr_push_struct_blob(&req->encoded, req,
461                                        req->nbtsock->iconv_convenience,
462                                        request,
463                                        (ndr_push_flags_fn_t)ndr_push_nbt_name_packet);
464         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
465                 talloc_free(req);
466                 return ndr_map_error2ntstatus(ndr_err);
467         }
468
469         DLIST_ADD_END(nbtsock->send_queue, req, struct nbt_name_request *);
470
471         EVENT_FD_WRITEABLE(nbtsock->fde);
472
473         return NT_STATUS_OK;
474
475 failed:
476         talloc_free(req);
477         return NT_STATUS_NO_MEMORY;
478 }
479
480 /*
481   wait for a nbt request to complete
482 */
483 NTSTATUS nbt_name_request_recv(struct nbt_name_request *req)
484 {
485         if (!req) return NT_STATUS_NO_MEMORY;
486
487         while (req->state < NBT_REQUEST_DONE) {
488                 if (event_loop_once(req->nbtsock->event_ctx) != 0) {
489                         req->state = NBT_REQUEST_ERROR;
490                         req->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
491                         break;
492                 }
493         }
494         return req->status;
495 }
496
497
498 /*
499   setup a handler for incoming requests
500 */
501 _PUBLIC_ NTSTATUS nbt_set_incoming_handler(struct nbt_name_socket *nbtsock,
502                                   void (*handler)(struct nbt_name_socket *, struct nbt_name_packet *,
503                                                   struct socket_address *),
504                                   void *private)
505 {
506         nbtsock->incoming.handler = handler;
507         nbtsock->incoming.private_data = private;
508         EVENT_FD_READABLE(nbtsock->fde);
509         return NT_STATUS_OK;
510 }
511
512
513 /*
514   turn a NBT rcode into a NTSTATUS
515 */
516 _PUBLIC_ NTSTATUS nbt_rcode_to_ntstatus(uint8_t rcode)
517 {
518         int i;
519         struct {
520                 enum nbt_rcode rcode;
521                 NTSTATUS status;
522         } map[] = {
523                 { NBT_RCODE_FMT, NT_STATUS_INVALID_PARAMETER },
524                 { NBT_RCODE_SVR, NT_STATUS_SERVER_DISABLED },
525                 { NBT_RCODE_NAM, NT_STATUS_OBJECT_NAME_NOT_FOUND },
526                 { NBT_RCODE_IMP, NT_STATUS_NOT_SUPPORTED },
527                 { NBT_RCODE_RFS, NT_STATUS_ACCESS_DENIED },
528                 { NBT_RCODE_ACT, NT_STATUS_ADDRESS_ALREADY_EXISTS },
529                 { NBT_RCODE_CFT, NT_STATUS_CONFLICTING_ADDRESSES }
530         };
531         for (i=0;i<ARRAY_SIZE(map);i++) {
532                 if (map[i].rcode == rcode) {
533                         return map[i].status;
534                 }
535         }
536         return NT_STATUS_UNSUCCESSFUL;
537 }