s4-auth: unconditionally set previous_ev
[kai/samba-autobuild/.git] / source4 / auth / kerberos / krb5_init_context.c
1 /*
2    Unix SMB/CIFS implementation.
3    Wrapper for krb5_init_context
4
5    Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
6    Copyright (C) Andrew Tridgell 2005
7    Copyright (C) Stefan Metzmacher 2004
8
9    This program is free software; you can redistribute it and/or modify
10    it under the terms of the GNU General Public License as published by
11    the Free Software Foundation; either version 3 of the License, or
12    (at your option) any later version.
13
14    This program is distributed in the hope that it will be useful,
15    but WITHOUT ANY WARRANTY; without even the implied warranty of
16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17    GNU General Public License for more details.
18
19    You should have received a copy of the GNU General Public License
20    along with this program.  If not, see <http://www.gnu.org/licenses/>.
21 */
22
23 #include "includes.h"
24 #include "system/kerberos.h"
25 #include <tevent.h>
26 #include "auth/kerberos/kerberos.h"
27 #include "lib/socket/socket.h"
28 #include "lib/stream/packet.h"
29 #include "system/network.h"
30 #include "param/param.h"
31 #include "libcli/resolve/resolve.h"
32
33 /*
34   context structure for operations on cldap packets
35 */
36 struct smb_krb5_socket {
37         struct socket_context *sock;
38
39         /* the fd event */
40         struct tevent_fd *fde;
41
42         NTSTATUS status;
43         DATA_BLOB request, reply;
44
45         struct packet_context *packet;
46
47         size_t partial_read;
48
49         krb5_krbhst_info *hi;
50 };
51
52 static krb5_error_code smb_krb5_context_destroy(struct smb_krb5_context *ctx)
53 {
54         /* Otherwise krb5_free_context will try and close what we have already free()ed */
55         krb5_set_warn_dest(ctx->krb5_context, NULL);
56         krb5_closelog(ctx->krb5_context, ctx->logf);
57         krb5_free_context(ctx->krb5_context);
58         return 0;
59 }
60
61 /* We never close down the DEBUG system, and no need to unreference the use */
62 static void smb_krb5_debug_close(void *private_data) {
63         return;
64 }
65
66 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private_data)
67 {
68         DEBUG(3, ("Kerberos: %s\n", msg));
69 }
70
71 /*
72   handle recv events on a smb_krb5 socket
73 */
74 static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
75 {
76         TALLOC_CTX *tmp_ctx = talloc_new(smb_krb5);
77         DATA_BLOB blob;
78         size_t nread, dsize;
79
80         smb_krb5->status = socket_pending(smb_krb5->sock, &dsize);
81         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
82                 talloc_free(tmp_ctx);
83                 return;
84         }
85
86         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
87         if (blob.data == NULL && dsize != 0) {
88                 smb_krb5->status = NT_STATUS_NO_MEMORY;
89                 talloc_free(tmp_ctx);
90                 return;
91         }
92
93         smb_krb5->status = socket_recv(smb_krb5->sock, blob.data, blob.length, &nread);
94         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
95                 talloc_free(tmp_ctx);
96                 return;
97         }
98         blob.length = nread;
99
100         if (nread == 0) {
101                 smb_krb5->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
102                 talloc_free(tmp_ctx);
103                 return;
104         }
105
106         DEBUG(2,("Received smb_krb5 packet of length %d\n",
107                  (int)blob.length));
108
109         talloc_steal(smb_krb5, blob.data);
110         smb_krb5->reply = blob;
111         talloc_free(tmp_ctx);
112 }
113
114 static NTSTATUS smb_krb5_full_packet(void *private_data, DATA_BLOB data)
115 {
116         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
117         talloc_steal(smb_krb5, data.data);
118         smb_krb5->reply = data;
119         smb_krb5->reply.length -= 4;
120         smb_krb5->reply.data += 4;
121         return NT_STATUS_OK;
122 }
123
124 /*
125   handle request timeouts
126 */
127 static void smb_krb5_request_timeout(struct tevent_context *event_ctx,
128                                   struct tevent_timer *te, struct timeval t,
129                                   void *private_data)
130 {
131         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
132         DEBUG(5,("Timed out smb_krb5 packet\n"));
133         smb_krb5->status = NT_STATUS_IO_TIMEOUT;
134 }
135
136 static void smb_krb5_error_handler(void *private_data, NTSTATUS status)
137 {
138         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
139         smb_krb5->status = status;
140 }
141
142 /*
143   handle send events on a smb_krb5 socket
144 */
145 static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
146 {
147         NTSTATUS status;
148
149         size_t len;
150
151         len = smb_krb5->request.length;
152         status = socket_send(smb_krb5->sock, &smb_krb5->request, &len);
153
154         if (!NT_STATUS_IS_OK(status)) return;
155
156         TEVENT_FD_READABLE(smb_krb5->fde);
157
158         TEVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
159         return;
160 }
161
162
163 /*
164   handle fd events on a smb_krb5_socket
165 */
166 static void smb_krb5_socket_handler(struct tevent_context *ev, struct tevent_fd *fde,
167                                  uint16_t flags, void *private_data)
168 {
169         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
170         switch (smb_krb5->hi->proto) {
171         case KRB5_KRBHST_UDP:
172                 if (flags & TEVENT_FD_READ) {
173                         smb_krb5_socket_recv(smb_krb5);
174                         return;
175                 }
176                 if (flags & TEVENT_FD_WRITE) {
177                         smb_krb5_socket_send(smb_krb5);
178                         return;
179                 }
180                 /* not reached */
181                 return;
182         case KRB5_KRBHST_TCP:
183                 if (flags & TEVENT_FD_READ) {
184                         packet_recv(smb_krb5->packet);
185                         return;
186                 }
187                 if (flags & TEVENT_FD_WRITE) {
188                         packet_queue_run(smb_krb5->packet);
189                         return;
190                 }
191                 /* not reached */
192                 return;
193         case KRB5_KRBHST_HTTP:
194                 /* can't happen */
195                 break;
196         }
197 }
198
199
200 krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
201                                             void *data,
202                                             krb5_krbhst_info *hi,
203                                             time_t timeout,
204                                             const krb5_data *send_buf,
205                                             krb5_data *recv_buf)
206 {
207         krb5_error_code ret;
208         NTSTATUS status;
209         struct socket_address *remote_addr;
210         const char *name;
211         struct addrinfo *ai, *a;
212         struct smb_krb5_socket *smb_krb5;
213
214         DATA_BLOB send_blob;
215
216         struct tevent_context *ev;
217         TALLOC_CTX *tmp_ctx = talloc_new(NULL);
218         if (!tmp_ctx) {
219                 return ENOMEM;
220         }
221
222         if (!data) {
223                 /* If no event context was available, then create one for this loop */
224                 ev = tevent_context_init(tmp_ctx);
225                 if (!ev) {
226                         talloc_free(tmp_ctx);
227                         return ENOMEM;
228                 }
229         } else {
230                 ev = talloc_get_type_abort(data, struct tevent_context);
231         }
232
233         send_blob = data_blob_const(send_buf->data, send_buf->length);
234
235         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
236         if (ret) {
237                 talloc_free(tmp_ctx);
238                 return ret;
239         }
240
241         for (a = ai; a; a = ai->ai_next) {
242                 smb_krb5 = talloc(tmp_ctx, struct smb_krb5_socket);
243                 if (!smb_krb5) {
244                         talloc_free(tmp_ctx);
245                         return ENOMEM;
246                 }
247                 smb_krb5->hi = hi;
248
249                 switch (a->ai_family) {
250                 case PF_INET:
251                         name = "ipv4";
252                         break;
253 #ifdef HAVE_IPV6
254                 case PF_INET6:
255                         name = "ipv6";
256                         break;
257 #endif
258                 default:
259                         talloc_free(tmp_ctx);
260                         return EINVAL;
261                 }
262
263                 status = NT_STATUS_INVALID_PARAMETER;
264                 switch (hi->proto) {
265                 case KRB5_KRBHST_UDP:
266                         status = socket_create(name, SOCKET_TYPE_DGRAM, &smb_krb5->sock, 0);
267                         break;
268                 case KRB5_KRBHST_TCP:
269                         status = socket_create(name, SOCKET_TYPE_STREAM, &smb_krb5->sock, 0);
270                         break;
271                 case KRB5_KRBHST_HTTP:
272                         talloc_free(tmp_ctx);
273                         return EINVAL;
274                 }
275                 if (!NT_STATUS_IS_OK(status)) {
276                         talloc_free(smb_krb5);
277                         continue;
278                 }
279
280                 talloc_steal(smb_krb5, smb_krb5->sock);
281
282                 remote_addr = socket_address_from_sockaddr(smb_krb5, a->ai_addr, a->ai_addrlen);
283                 if (!remote_addr) {
284                         talloc_free(smb_krb5);
285                         continue;
286                 }
287
288                 status = socket_connect_ev(smb_krb5->sock, NULL, remote_addr, 0, ev);
289                 if (!NT_STATUS_IS_OK(status)) {
290                         talloc_free(smb_krb5);
291                         continue;
292                 }
293                 talloc_free(remote_addr);
294
295                 /* Setup the FDE, start listening for read events
296                  * from the start (otherwise we may miss a socket
297                  * drop) and mark as AUTOCLOSE along with the fde */
298
299                 /* Ths is equivilant to EVENT_FD_READABLE(smb_krb5->fde) */
300                 smb_krb5->fde = tevent_add_fd(ev, smb_krb5->sock,
301                                               socket_get_fd(smb_krb5->sock),
302                                               TEVENT_FD_READ,
303                                               smb_krb5_socket_handler, smb_krb5);
304                 /* its now the job of the event layer to close the socket */
305                 tevent_fd_set_close_fn(smb_krb5->fde, socket_tevent_fd_close_fn);
306                 socket_set_flags(smb_krb5->sock, SOCKET_FLAG_NOCLOSE);
307
308                 tevent_add_timer(ev, smb_krb5,
309                                  timeval_current_ofs(timeout, 0),
310                                  smb_krb5_request_timeout, smb_krb5);
311
312                 smb_krb5->status = NT_STATUS_OK;
313                 smb_krb5->reply = data_blob(NULL, 0);
314
315                 switch (hi->proto) {
316                 case KRB5_KRBHST_UDP:
317                         TEVENT_FD_WRITEABLE(smb_krb5->fde);
318                         smb_krb5->request = send_blob;
319                         break;
320                 case KRB5_KRBHST_TCP:
321
322                         smb_krb5->packet = packet_init(smb_krb5);
323                         if (smb_krb5->packet == NULL) {
324                                 talloc_free(smb_krb5);
325                                 return ENOMEM;
326                         }
327                         packet_set_private(smb_krb5->packet, smb_krb5);
328                         packet_set_socket(smb_krb5->packet, smb_krb5->sock);
329                         packet_set_callback(smb_krb5->packet, smb_krb5_full_packet);
330                         packet_set_full_request(smb_krb5->packet, packet_full_request_u32);
331                         packet_set_error_handler(smb_krb5->packet, smb_krb5_error_handler);
332                         packet_set_event_context(smb_krb5->packet, ev);
333                         packet_set_fde(smb_krb5->packet, smb_krb5->fde);
334
335                         smb_krb5->request = data_blob_talloc(smb_krb5, NULL, send_blob.length + 4);
336                         RSIVAL(smb_krb5->request.data, 0, send_blob.length);
337                         memcpy(smb_krb5->request.data+4, send_blob.data, send_blob.length);
338                         packet_send(smb_krb5->packet, smb_krb5->request);
339                         break;
340                 case KRB5_KRBHST_HTTP:
341                         talloc_free(tmp_ctx);
342                         return EINVAL;
343                 }
344                 while ((NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
345                         if (tevent_loop_once(ev) != 0) {
346                                 talloc_free(tmp_ctx);
347                                 return EINVAL;
348                         }
349
350                         /* After each and every event loop, reset the
351                          * send_to_kdc pointers to what they were when
352                          * we entered this loop.  That way, if a
353                          * nested event has invalidated them, we put
354                          * it back before we return to the heimdal
355                          * code */
356                         ret = krb5_set_send_to_kdc_func(context,
357                                                         smb_krb5_send_and_recv_func,
358                                                         data);
359                         if (ret != 0) {
360                                 talloc_free(tmp_ctx);
361                                 return ret;
362                         }
363                 }
364                 if (NT_STATUS_EQUAL(smb_krb5->status, NT_STATUS_IO_TIMEOUT)) {
365                         talloc_free(smb_krb5);
366                         continue;
367                 }
368
369                 if (!NT_STATUS_IS_OK(smb_krb5->status)) {
370                         DEBUG(2,("Error reading smb_krb5 reply packet: %s\n", nt_errstr(smb_krb5->status)));
371                         talloc_free(smb_krb5);
372                         continue;
373                 }
374
375                 ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
376                 if (ret) {
377                         talloc_free(tmp_ctx);
378                         return ret;
379                 }
380                 talloc_free(smb_krb5);
381
382                 break;
383         }
384         talloc_free(tmp_ctx);
385         if (a) {
386                 return 0;
387         }
388         return KRB5_KDC_UNREACH;
389 }
390
391 krb5_error_code
392 smb_krb5_init_context_basic(TALLOC_CTX *tmp_ctx,
393                             struct loadparm_context *lp_ctx,
394                             krb5_context *_krb5_context)
395 {
396         krb5_error_code ret;
397         char **config_files;
398         const char *config_file, *realm;
399         krb5_context krb5_ctx;
400
401         initialize_krb5_error_table();
402
403         ret = krb5_init_context(&krb5_ctx);
404         if (ret) {
405                 DEBUG(1,("krb5_init_context failed (%s)\n",
406                          error_message(ret)));
407                 return ret;
408         }
409
410         config_file = config_path(tmp_ctx, lp_ctx, "krb5.conf");
411         if (!config_file) {
412                 krb5_free_context(krb5_ctx);
413                 return ENOMEM;
414         }
415
416         /* Use our local krb5.conf file by default */
417         ret = krb5_prepend_config_files_default(config_file == NULL?"":config_file, &config_files);
418         if (ret) {
419                 DEBUG(1,("krb5_prepend_config_files_default failed (%s)\n",
420                          smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
421                 krb5_free_context(krb5_ctx);
422                 return ret;
423         }
424
425         ret = krb5_set_config_files(krb5_ctx, config_files);
426         krb5_free_config_files(config_files);
427         if (ret) {
428                 DEBUG(1,("krb5_set_config_files failed (%s)\n",
429                          smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
430                 krb5_free_context(krb5_ctx);
431                 return ret;
432         }
433
434         realm = lpcfg_realm(lp_ctx);
435         if (realm != NULL) {
436                 ret = krb5_set_default_realm(krb5_ctx, realm);
437                 if (ret) {
438                         DEBUG(1,("krb5_set_default_realm failed (%s)\n",
439                                  smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
440                         krb5_free_context(krb5_ctx);
441                         return ret;
442                 }
443         }
444
445         *_krb5_context = krb5_ctx;
446         return 0;
447 }
448
449 krb5_error_code smb_krb5_init_context(void *parent_ctx,
450                                       struct tevent_context *ev,
451                                       struct loadparm_context *lp_ctx,
452                                       struct smb_krb5_context **smb_krb5_context)
453 {
454         krb5_error_code ret;
455         TALLOC_CTX *tmp_ctx;
456
457         initialize_krb5_error_table();
458
459         tmp_ctx = talloc_new(parent_ctx);
460         *smb_krb5_context = talloc_zero(tmp_ctx, struct smb_krb5_context);
461
462         if (!*smb_krb5_context || !tmp_ctx) {
463                 talloc_free(tmp_ctx);
464                 return ENOMEM;
465         }
466
467         ret = smb_krb5_init_context_basic(tmp_ctx, lp_ctx,
468                                           &(*smb_krb5_context)->krb5_context);
469         if (ret) {
470                 DEBUG(1,("smb_krb5_context_init_basic failed (%s)\n",
471                          error_message(ret)));
472                 talloc_free(tmp_ctx);
473                 return ret;
474         }
475
476         /* TODO: Should we have a different name here? */
477         ret = krb5_initlog((*smb_krb5_context)->krb5_context, "Samba", &(*smb_krb5_context)->logf);
478
479         if (ret) {
480                 DEBUG(1,("krb5_initlog failed (%s)\n",
481                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
482                 krb5_free_context((*smb_krb5_context)->krb5_context);
483                 talloc_free(tmp_ctx);
484                 return ret;
485         }
486
487         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy);
488
489         ret = krb5_addlog_func((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf, 0 /* min */, -1 /* max */,
490                                smb_krb5_debug_wrapper, smb_krb5_debug_close, NULL);
491         if (ret) {
492                 DEBUG(1,("krb5_addlog_func failed (%s)\n",
493                          smb_get_krb5_error_message((*smb_krb5_context)->krb5_context, ret, tmp_ctx)));
494                 talloc_free(tmp_ctx);
495                 return ret;
496         }
497         krb5_set_warn_dest((*smb_krb5_context)->krb5_context, (*smb_krb5_context)->logf);
498
499         /* Set use of our socket lib */
500         if (ev) {
501                 struct tevent_context *previous_ev;
502                 ret = smb_krb5_context_set_event_ctx(*smb_krb5_context,
503                                                      ev, &previous_ev);
504                 if (ret) {
505                         talloc_free(tmp_ctx);
506                         return ret;
507                 }
508         }
509
510         talloc_steal(parent_ctx, *smb_krb5_context);
511         talloc_free(tmp_ctx);
512
513         /* Set options in kerberos */
514
515         krb5_set_dns_canonicalize_hostname((*smb_krb5_context)->krb5_context,
516                                            lpcfg_parm_bool(lp_ctx, NULL, "krb5", "set_dns_canonicalize", false));
517
518         return 0;
519 }
520
521 krb5_error_code smb_krb5_context_set_event_ctx(struct smb_krb5_context *smb_krb5_context,
522                                                struct tevent_context *ev,
523                                                struct tevent_context **previous_ev)
524 {
525         int ret;
526         if (!ev) {
527                 return EINVAL;
528         }
529
530         *previous_ev = smb_krb5_context->current_ev;
531
532         smb_krb5_context->current_ev = talloc_reference(smb_krb5_context, ev);
533         if (!smb_krb5_context->current_ev) {
534                 return ENOMEM;
535         }
536
537         /* Set use of our socket lib */
538         ret = krb5_set_send_to_kdc_func(smb_krb5_context->krb5_context,
539                                         smb_krb5_send_and_recv_func,
540                                         ev);
541         if (ret) {
542                 TALLOC_CTX *tmp_ctx = talloc_new(NULL);
543                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
544                          smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, tmp_ctx)));
545                 talloc_free(tmp_ctx);
546                 talloc_unlink(smb_krb5_context, smb_krb5_context->current_ev);
547                 smb_krb5_context->current_ev = NULL;
548                 return ret;
549         }
550         return 0;
551 }
552
553 krb5_error_code smb_krb5_context_remove_event_ctx(struct smb_krb5_context *smb_krb5_context,
554                                                   struct tevent_context *previous_ev,
555                                                   struct tevent_context *ev)
556 {
557         int ret;
558         talloc_unlink(smb_krb5_context, ev);
559         /* If there was a mismatch with things happening on a stack, then don't wipe things */
560         smb_krb5_context->current_ev = previous_ev;
561         /* Set use of our socket lib */
562         ret = krb5_set_send_to_kdc_func(smb_krb5_context->krb5_context,
563                                         smb_krb5_send_and_recv_func,
564                                         previous_ev);
565         if (ret) {
566                 TALLOC_CTX *tmp_ctx = talloc_new(NULL);
567                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
568                          smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, tmp_ctx)));
569                 talloc_free(tmp_ctx);
570                 return ret;
571         }
572         return 0;
573 }