source: branches/samba-3.2.x/source/libsmb/async_smb.c

Last change on this file was 232, checked in by Herwig Bauernfeind, 16 years ago

Update 3.2 branch to 3.2.8
File size: 11.6 KB
Line 
1/*
2 Unix SMB/CIFS implementation.
3 Infrastructure for async SMB client requests
4 Copyright (C) Volker Lendecke 2008
5
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
18*/
19
20#include "includes.h"
21
22/*
23 * Fetch an error out of a NBT packet
24 */
25
26NTSTATUS cli_pull_error(char *buf)
27{
28 uint32_t flags2 = SVAL(buf, smb_flg2);
29
30 if (flags2 & FLAGS2_32_BIT_ERROR_CODES) {
31 return NT_STATUS(IVAL(buf, smb_rcls));
32 }
33
34 /* if the client uses dos errors, but there is no error,
35 we should return no error here, otherwise it looks
36 like an unknown bad NT_STATUS. jmcd */
37 if (CVAL(buf, smb_rcls) == 0)
38 return NT_STATUS_OK;
39
40 return NT_STATUS_DOS(CVAL(buf, smb_rcls), SVAL(buf,smb_err));
41}
42
43/*
44 * Compatibility helper for the sync APIs: Fake NTSTATUS in cli->inbuf
45 */
46
47void cli_set_error(struct cli_state *cli, NTSTATUS status)
48{
49 uint32_t flags2 = SVAL(cli->inbuf, smb_flg2);
50
51 if (NT_STATUS_IS_DOS(status)) {
52 SSVAL(cli->inbuf, smb_flg2,
53 flags2 & ~FLAGS2_32_BIT_ERROR_CODES);
54 SCVAL(cli->inbuf, smb_rcls, NT_STATUS_DOS_CLASS(status));
55 SSVAL(cli->inbuf, smb_err, NT_STATUS_DOS_CODE(status));
56 return;
57 }
58
59 SSVAL(cli->inbuf, smb_flg2, flags2 | FLAGS2_32_BIT_ERROR_CODES);
60 SIVAL(cli->inbuf, smb_rcls, NT_STATUS_V(status));
61 return;
62}
63
64/*
65 * Allocate a new mid
66 */
67
68static uint16_t cli_new_mid(struct cli_state *cli)
69{
70 uint16_t result;
71 struct cli_request *req;
72
73 while (true) {
74 result = cli->mid++;
75 if (result == 0) {
76 continue;
77 }
78
79 for (req = cli->outstanding_requests; req; req = req->next) {
80 if (result == req->mid) {
81 break;
82 }
83 }
84
85 if (req == NULL) {
86 return result;
87 }
88 }
89}
90
91static char *cli_request_print(TALLOC_CTX *mem_ctx, struct async_req *req)
92{
93 char *result = async_req_print(mem_ctx, req);
94 struct cli_request *cli_req = cli_request_get(req);
95
96 if (result == NULL) {
97 return NULL;
98 }
99
100 return talloc_asprintf_append_buffer(
101 result, "mid=%d\n", cli_req->mid);
102}
103
104static int cli_request_destructor(struct cli_request *req)
105{
106 if (req->enc_state != NULL) {
107 common_free_enc_buffer(req->enc_state, req->outbuf);
108 }
109 DLIST_REMOVE(req->cli->outstanding_requests, req);
110 return 0;
111}
112
113/*
114 * Create a fresh async smb request
115 */
116
117struct async_req *cli_request_new(TALLOC_CTX *mem_ctx,
118 struct event_context *ev,
119 struct cli_state *cli,
120 uint8_t num_words, size_t num_bytes,
121 struct cli_request **preq)
122{
123 struct async_req *result;
124 struct cli_request *cli_req;
125 size_t bufsize = smb_size + num_words * 2 + num_bytes;
126
127 result = async_req_new(mem_ctx, ev);
128 if (result == NULL) {
129 return NULL;
130 }
131
132 cli_req = (struct cli_request *)talloc_size(
133 result, sizeof(*cli_req) + bufsize);
134 if (cli_req == NULL) {
135 TALLOC_FREE(result);
136 return NULL;
137 }
138 talloc_set_name_const(cli_req, "struct cli_request");
139 result->private_data = cli_req;
140 result->print = cli_request_print;
141
142 cli_req->async = result;
143 cli_req->cli = cli;
144 cli_req->outbuf = ((char *)cli_req + sizeof(*cli_req));
145 cli_req->sent = 0;
146 cli_req->mid = cli_new_mid(cli);
147 cli_req->inbuf = NULL;
148 cli_req->enc_state = NULL;
149
150 SCVAL(cli_req->outbuf, smb_wct, num_words);
151 SSVAL(cli_req->outbuf, smb_vwv + num_words * 2, num_bytes);
152
153 DLIST_ADD_END(cli->outstanding_requests, cli_req,
154 struct cli_request *);
155 talloc_set_destructor(cli_req, cli_request_destructor);
156
157 DEBUG(10, ("cli_request_new: mid=%d\n", cli_req->mid));
158
159 *preq = cli_req;
160 return result;
161}
162
163/*
164 * Convenience function to get the SMB part out of an async_req
165 */
166
167struct cli_request *cli_request_get(struct async_req *req)
168{
169 if (req == NULL) {
170 return NULL;
171 }
172 return talloc_get_type_abort(req->private_data, struct cli_request);
173}
174
175/*
176 * A PDU has arrived on cli->evt_inbuf
177 */
178
179static void handle_incoming_pdu(struct cli_state *cli)
180{
181 struct cli_request *req;
182 uint16_t mid;
183 size_t raw_pdu_len, buf_len, pdu_len, rest_len;
184 char *pdu;
185 NTSTATUS status;
186
187 /*
188 * The encrypted PDU len might differ from the unencrypted one
189 */
190 raw_pdu_len = smb_len(cli->evt_inbuf) + 4;
191 buf_len = talloc_get_size(cli->evt_inbuf);
192 rest_len = buf_len - raw_pdu_len;
193
194 if (buf_len == raw_pdu_len) {
195 /*
196 * Optimal case: Exactly one PDU was in the socket buffer
197 */
198 pdu = cli->evt_inbuf;
199 cli->evt_inbuf = NULL;
200 }
201 else {
202 DEBUG(11, ("buf_len = %d, raw_pdu_len = %d, splitting "
203 "buffer\n", (int)buf_len, (int)raw_pdu_len));
204
205 if (raw_pdu_len < rest_len) {
206 /*
207 * The PDU is shorter, talloc_memdup that one.
208 */
209 pdu = (char *)talloc_memdup(
210 cli, cli->evt_inbuf, raw_pdu_len);
211
212 memmove(cli->evt_inbuf, cli->evt_inbuf + raw_pdu_len,
213 buf_len - raw_pdu_len);
214
215 cli->evt_inbuf = TALLOC_REALLOC_ARRAY(
216 NULL, cli->evt_inbuf, char, rest_len);
217
218 if (pdu == NULL) {
219 status = NT_STATUS_NO_MEMORY;
220 goto invalidate_requests;
221 }
222 }
223 else {
224 /*
225 * The PDU is larger than the rest, talloc_memdup the
226 * rest
227 */
228 pdu = cli->evt_inbuf;
229
230 cli->evt_inbuf = (char *)talloc_memdup(
231 cli, pdu + raw_pdu_len, rest_len);
232
233 if (cli->evt_inbuf == NULL) {
234 status = NT_STATUS_NO_MEMORY;
235 goto invalidate_requests;
236 }
237 }
238
239 }
240
241 /*
242 * TODO: Handle oplock break requests
243 */
244
245 if (cli_encryption_on(cli) && CVAL(pdu, 0) == 0) {
246 uint16_t enc_ctx_num;
247
248 status = get_enc_ctx_num((uint8_t *)pdu, &enc_ctx_num);
249 if (!NT_STATUS_IS_OK(status)) {
250 DEBUG(10, ("get_enc_ctx_num returned %s\n",
251 nt_errstr(status)));
252 goto invalidate_requests;
253 }
254
255 if (enc_ctx_num != cli->trans_enc_state->enc_ctx_num) {
256 DEBUG(10, ("wrong enc_ctx %d, expected %d\n",
257 enc_ctx_num,
258 cli->trans_enc_state->enc_ctx_num));
259 status = NT_STATUS_INVALID_HANDLE;
260 goto invalidate_requests;
261 }
262
263 status = common_decrypt_buffer(cli->trans_enc_state,
264 pdu);
265 if (!NT_STATUS_IS_OK(status)) {
266 DEBUG(10, ("common_decrypt_buffer returned %s\n",
267 nt_errstr(status)));
268 goto invalidate_requests;
269 }
270 }
271
272 if (!cli_check_sign_mac(cli, pdu)) {
273 DEBUG(10, ("cli_check_sign_mac failed\n"));
274 status = NT_STATUS_ACCESS_DENIED;
275 goto invalidate_requests;
276 }
277
278 mid = SVAL(pdu, smb_mid);
279
280 DEBUG(10, ("handle_incoming_pdu: got mid %d\n", mid));
281
282 for (req = cli->outstanding_requests; req; req = req->next) {
283 if (req->mid == mid) {
284 break;
285 }
286 }
287
288 pdu_len = smb_len(pdu) + 4;
289
290 if (req == NULL) {
291 DEBUG(3, ("Request for mid %d not found, dumping PDU\n", mid));
292
293 TALLOC_FREE(pdu);
294 return;
295 }
296
297 req->inbuf = talloc_move(req, &pdu);
298
299 async_req_done(req->async);
300 return;
301
302 invalidate_requests:
303
304 DEBUG(10, ("handle_incoming_pdu: Aborting with %s\n",
305 nt_errstr(status)));
306
307 for (req = cli->outstanding_requests; req; req = req->next) {
308 async_req_error(req->async, status);
309 }
310 return;
311}
312
313/*
314 * fd event callback. This is the basic connection to the socket
315 */
316
317static void cli_state_handler(struct event_context *event_ctx,
318 struct fd_event *event, uint16 flags, void *p)
319{
320 struct cli_state *cli = (struct cli_state *)p;
321 struct cli_request *req, *next;
322 NTSTATUS status;
323
324 DEBUG(11, ("cli_state_handler called with flags %d\n", flags));
325
326 if (flags & EVENT_FD_READ) {
327 int res, available;
328 size_t old_size, new_size;
329 char *tmp;
330
331 res = ioctl(cli->fd, FIONREAD, &available);
332 if (res == -1) {
333 DEBUG(10, ("ioctl(FIONREAD) failed: %s\n",
334 strerror(errno)));
335 status = map_nt_error_from_unix(errno);
336 goto sock_error;
337 }
338
339 if (available == 0) {
340 /* EOF */
341 status = NT_STATUS_END_OF_FILE;
342 goto sock_error;
343 }
344
345 old_size = talloc_get_size(cli->evt_inbuf);
346 new_size = old_size + available;
347
348 if (new_size < old_size) {
349 /* wrap */
350 status = NT_STATUS_UNEXPECTED_IO_ERROR;
351 goto sock_error;
352 }
353
354 tmp = TALLOC_REALLOC_ARRAY(cli, cli->evt_inbuf, char,
355 new_size);
356 if (tmp == NULL) {
357 /* nomem */
358 status = NT_STATUS_NO_MEMORY;
359 goto sock_error;
360 }
361 cli->evt_inbuf = tmp;
362
363 res = recv(cli->fd, cli->evt_inbuf + old_size, available, 0);
364 if (res == -1) {
365 DEBUG(10, ("recv failed: %s\n", strerror(errno)));
366 status = map_nt_error_from_unix(errno);
367 goto sock_error;
368 }
369
370 DEBUG(11, ("cli_state_handler: received %d bytes, "
371 "smb_len(evt_inbuf) = %d\n", (int)res,
372 smb_len(cli->evt_inbuf)));
373
374 /* recv *might* have returned less than announced */
375 new_size = old_size + res;
376
377 /* shrink, so I don't expect errors here */
378 cli->evt_inbuf = TALLOC_REALLOC_ARRAY(cli, cli->evt_inbuf,
379 char, new_size);
380
381 while ((cli->evt_inbuf != NULL)
382 && ((smb_len(cli->evt_inbuf) + 4) <= new_size)) {
383 /*
384 * we've got a complete NBT level PDU in evt_inbuf
385 */
386 handle_incoming_pdu(cli);
387 new_size = talloc_get_size(cli->evt_inbuf);
388 }
389 }
390
391 if (flags & EVENT_FD_WRITE) {
392 size_t to_send;
393 ssize_t sent;
394
395 for (req = cli->outstanding_requests; req; req = req->next) {
396 to_send = smb_len(req->outbuf)+4;
397 if (to_send > req->sent) {
398 break;
399 }
400 }
401
402 if (req == NULL) {
403 event_fd_set_not_writeable(event);
404 return;
405 }
406
407 sent = send(cli->fd, req->outbuf + req->sent,
408 to_send - req->sent, 0);
409
410 if (sent < 0) {
411 status = map_nt_error_from_unix(errno);
412 goto sock_error;
413 }
414
415 req->sent += sent;
416
417 if (req->sent == to_send) {
418 return;
419 }
420 }
421 return;
422
423 sock_error:
424 for (req = cli->outstanding_requests; req; req = next) {
425 next = req;
426 async_req_error(req->async, status);
427 }
428 TALLOC_FREE(cli->fd_event);
429 close(cli->fd);
430 cli->fd = -1;
431}
432
433/*
434 * Holder for a talloc_destructor, we need to zero out the pointers in cli
435 * when deleting
436 */
437struct cli_tmp_event {
438 struct cli_state *cli;
439};
440
441static int cli_tmp_event_destructor(struct cli_tmp_event *e)
442{
443 TALLOC_FREE(e->cli->fd_event);
444 TALLOC_FREE(e->cli->event_ctx);
445 return 0;
446}
447
448/*
449 * Create a temporary event context for use in the sync helper functions
450 */
451
452struct cli_tmp_event *cli_tmp_event_ctx(TALLOC_CTX *mem_ctx,
453 struct cli_state *cli)
454{
455 struct cli_tmp_event *state;
456
457 if (cli->event_ctx != NULL) {
458 return NULL;
459 }
460
461 state = talloc(mem_ctx, struct cli_tmp_event);
462 if (state == NULL) {
463 return NULL;
464 }
465 state->cli = cli;
466 talloc_set_destructor(state, cli_tmp_event_destructor);
467
468 cli->event_ctx = event_context_init(state);
469 if (cli->event_ctx == NULL) {
470 TALLOC_FREE(state);
471 return NULL;
472 }
473
474 cli->fd_event = event_add_fd(cli->event_ctx, state, cli->fd,
475 EVENT_FD_READ, cli_state_handler, cli);
476 if (cli->fd_event == NULL) {
477 TALLOC_FREE(state);
478 return NULL;
479 }
480 return state;
481}
482
483/*
484 * Attach an event context permanently to a cli_struct
485 */
486
487NTSTATUS cli_add_event_ctx(struct cli_state *cli,
488 struct event_context *event_ctx)
489{
490 cli->event_ctx = event_ctx;
491 cli->fd_event = event_add_fd(event_ctx, cli, cli->fd, EVENT_FD_READ,
492 cli_state_handler, cli);
493 if (cli->fd_event == NULL) {
494 return NT_STATUS_NO_MEMORY;
495 }
496 return NT_STATUS_OK;
497}
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