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 "system/gssapi.h"
  26 #include <tevent.h>
  27 #include "auth/kerberos/kerberos.h"
  28 #include "lib/socket/socket.h"
  29 #include "lib/stream/packet.h"
  30 #include "system/network.h"
  31 #include "param/param.h"
  32 #include "libcli/resolve/resolve.h"
  33 #include "../lib/tsocket/tsocket.h"
  34 #include "krb5_init_context.h"
  35 /*
  36   context structure for operations on cldap packets
  37 */
  38 struct smb_krb5_socket {
  39         struct socket_context *sock;
  40
  41         /* the fd event */
  42         struct tevent_fd *fde;
  43
  44         NTSTATUS status;
  45         DATA_BLOB request, reply;
  46
  47         struct packet_context *packet;
  48
  49         size_t partial_read;
  50 #ifdef SAMBA4_USES_HEIMDAL
  51         krb5_krbhst_info *hi;
  52 #endif
  53 };
  54
  55 static krb5_error_code smb_krb5_context_destroy(struct smb_krb5_context *ctx)
  56 {
  57 #ifdef SAMBA4_USES_HEIMDAL
  58         if (ctx->pvt_log_data) {
  59                 /* Otherwise krb5_free_context will try and close what we
  60                  * have already free()ed */
  61                 krb5_set_warn_dest(ctx->krb5_context, NULL);
  62                 krb5_closelog(ctx->krb5_context,
  63                                 (krb5_log_facility *)ctx->pvt_log_data);
  64         }
  65 #endif
  66         krb5_free_context(ctx->krb5_context);
  67         return 0;
  68 }
  69
  70 #ifdef SAMBA4_USES_HEIMDAL
  71 /* We never close down the DEBUG system, and no need to unreference the use */
  72 static void smb_krb5_debug_close(void *private_data) {
  73         return;
  74 }
  75 #endif
  76
  77 #ifdef SAMBA4_USES_HEIMDAL
  78 static void smb_krb5_debug_wrapper(const char *timestr, const char *msg, void *private_data)
  79 {
  80         DEBUGC(DBGC_KERBEROS, 3, ("Kerberos: %s\n", msg));
  81 }
  82 #endif
  83
  84 #ifdef SAMBA4_USES_HEIMDAL
  85 /*
  86   handle recv events on a smb_krb5 socket
  87 */
  88 static void smb_krb5_socket_recv(struct smb_krb5_socket *smb_krb5)
  89 {
  90         TALLOC_CTX *tmp_ctx = talloc_new(smb_krb5);
  91         DATA_BLOB blob;
  92         size_t nread, dsize;
  93
  94         smb_krb5->status = socket_pending(smb_krb5->sock, &dsize);
  95         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
  96                 talloc_free(tmp_ctx);
  97                 return;
  98         }
  99
 100         blob = data_blob_talloc(tmp_ctx, NULL, dsize);
 101         if (blob.data == NULL && dsize != 0) {
 102                 smb_krb5->status = NT_STATUS_NO_MEMORY;
 103                 talloc_free(tmp_ctx);
 104                 return;
 105         }
 106
 107         smb_krb5->status = socket_recv(smb_krb5->sock, blob.data, blob.length, &nread);
 108         if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 109                 talloc_free(tmp_ctx);
 110                 return;
 111         }
 112         blob.length = nread;
 113
 114         if (nread == 0) {
 115                 smb_krb5->status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
 116                 talloc_free(tmp_ctx);
 117                 return;
 118         }
 119
 120         DEBUG(4,("Received smb_krb5 packet of length %d\n",
 121                  (int)blob.length));
 122
 123         talloc_steal(smb_krb5, blob.data);
 124         smb_krb5->reply = blob;
 125         talloc_free(tmp_ctx);
 126 }
 127
 128 static NTSTATUS smb_krb5_full_packet(void *private_data, DATA_BLOB data)
 129 {
 130         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
 131         talloc_steal(smb_krb5, data.data);
 132         smb_krb5->reply = data;
 133         smb_krb5->reply.length -= 4;
 134         smb_krb5->reply.data += 4;
 135         return NT_STATUS_OK;
 136 }
 137
 138 /*
 139   handle request timeouts
 140 */
 141 static void smb_krb5_request_timeout(struct tevent_context *event_ctx,
 142                                   struct tevent_timer *te, struct timeval t,
 143                                   void *private_data)
 144 {
 145         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
 146         DEBUG(5,("Timed out smb_krb5 packet\n"));
 147         smb_krb5->status = NT_STATUS_IO_TIMEOUT;
 148 }
 149
 150 static void smb_krb5_error_handler(void *private_data, NTSTATUS status)
 151 {
 152         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
 153         smb_krb5->status = status;
 154 }
 155
 156 /*
 157   handle send events on a smb_krb5 socket
 158 */
 159 static void smb_krb5_socket_send(struct smb_krb5_socket *smb_krb5)
 160 {
 161         NTSTATUS status;
 162
 163         size_t len;
 164
 165         len = smb_krb5->request.length;
 166         status = socket_send(smb_krb5->sock, &smb_krb5->request, &len);
 167
 168         if (!NT_STATUS_IS_OK(status)) return;
 169
 170         TEVENT_FD_READABLE(smb_krb5->fde);
 171
 172         TEVENT_FD_NOT_WRITEABLE(smb_krb5->fde);
 173         return;
 174 }
 175
 176
 177 /*
 178   handle fd events on a smb_krb5_socket
 179 */
 180 static void smb_krb5_socket_handler(struct tevent_context *ev, struct tevent_fd *fde,
 181                                  uint16_t flags, void *private_data)
 182 {
 183         struct smb_krb5_socket *smb_krb5 = talloc_get_type(private_data, struct smb_krb5_socket);
 184         switch (smb_krb5->hi->proto) {
 185         case KRB5_KRBHST_UDP:
 186                 if (flags & TEVENT_FD_READ) {
 187                         smb_krb5_socket_recv(smb_krb5);
 188                         return;
 189                 }
 190                 if (flags & TEVENT_FD_WRITE) {
 191                         smb_krb5_socket_send(smb_krb5);
 192                         return;
 193                 }
 194                 /* not reached */
 195                 return;
 196         case KRB5_KRBHST_TCP:
 197                 if (flags & TEVENT_FD_READ) {
 198                         packet_recv(smb_krb5->packet);
 199                         return;
 200                 }
 201                 if (flags & TEVENT_FD_WRITE) {
 202                         packet_queue_run(smb_krb5->packet);
 203                         return;
 204                 }
 205                 /* not reached */
 206                 return;
 207         case KRB5_KRBHST_HTTP:
 208                 /* can't happen */
 209                 break;
 210         }
 211 }
 212
 213 static krb5_error_code smb_krb5_send_and_recv_func_int(krb5_context context,
 214                                                        struct tevent_context *ev,
 215                                                        krb5_krbhst_info *hi,
 216                                                        struct addrinfo *ai,
 217                                                        krb5_send_to_kdc_func func,
 218                                                        void *data,
 219                                                        time_t timeout,
 220                                                        const krb5_data *send_buf,
 221                                                        krb5_data *recv_buf)
 222 {
 223         krb5_error_code ret;
 224         NTSTATUS status;
 225         const char *name;
 226         struct addrinfo *a;
 227         struct smb_krb5_socket *smb_krb5;
 228
 229         DATA_BLOB send_blob;
 230
 231         TALLOC_CTX *frame = talloc_stackframe();
 232         if (frame == NULL) {
 233                 return ENOMEM;
 234         }
 235
 236         send_blob = data_blob_const(send_buf->data, send_buf->length);
 237
 238         for (a = ai; a; a = a->ai_next) {
 239                 struct socket_address *remote_addr;
 240                 smb_krb5 = talloc(frame, struct smb_krb5_socket);
 241                 if (!smb_krb5) {
 242                         TALLOC_FREE(frame);
 243                         return ENOMEM;
 244                 }
 245                 smb_krb5->hi = hi;
 246
 247                 switch (a->ai_family) {
 248                 case PF_INET:
 249                         name = "ipv4";
 250                         break;
 251 #ifdef HAVE_IPV6
 252                 case PF_INET6:
 253                         name = "ipv6";
 254                         break;
 255 #endif
 256                 default:
 257                         TALLOC_FREE(frame);
 258                         return EINVAL;
 259                 }
 260
 261                 status = NT_STATUS_INVALID_PARAMETER;
 262                 switch (hi->proto) {
 263                 case KRB5_KRBHST_UDP:
 264                         status = socket_create(smb_krb5, name,
 265                                                SOCKET_TYPE_DGRAM,
 266                                                &smb_krb5->sock, 0);
 267                         break;
 268                 case KRB5_KRBHST_TCP:
 269                         status = socket_create(smb_krb5, name,
 270                                                SOCKET_TYPE_STREAM,
 271                                                &smb_krb5->sock, 0);
 272                         break;
 273                 case KRB5_KRBHST_HTTP:
 274                         TALLOC_FREE(frame);
 275                         return EINVAL;
 276                 }
 277                 if (!NT_STATUS_IS_OK(status)) {
 278                         talloc_free(smb_krb5);
 279                         continue;
 280                 }
 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
 294                 /* Setup the FDE, start listening for read events
 295                  * from the start (otherwise we may miss a socket
 296                  * drop) and mark as AUTOCLOSE along with the fde */
 297
 298                 /* Ths is equivilant to EVENT_FD_READABLE(smb_krb5->fde) */
 299                 smb_krb5->fde = tevent_add_fd(ev, smb_krb5->sock,
 300                                               socket_get_fd(smb_krb5->sock),
 301                                               TEVENT_FD_READ,
 302                                               smb_krb5_socket_handler, smb_krb5);
 303                 /* its now the job of the event layer to close the socket */
 304                 tevent_fd_set_close_fn(smb_krb5->fde, socket_tevent_fd_close_fn);
 305                 socket_set_flags(smb_krb5->sock, SOCKET_FLAG_NOCLOSE);
 306
 307                 tevent_add_timer(ev, smb_krb5,
 308                                  timeval_current_ofs(timeout, 0),
 309                                  smb_krb5_request_timeout, smb_krb5);
 310
 311                 smb_krb5->status = NT_STATUS_OK;
 312                 smb_krb5->reply = data_blob(NULL, 0);
 313
 314                 switch (hi->proto) {
 315                 case KRB5_KRBHST_UDP:
 316                         TEVENT_FD_WRITEABLE(smb_krb5->fde);
 317                         smb_krb5->request = send_blob;
 318                         break;
 319                 case KRB5_KRBHST_TCP:
 320
 321                         smb_krb5->packet = packet_init(smb_krb5);
 322                         if (smb_krb5->packet == NULL) {
 323                                 talloc_free(smb_krb5);
 324                                 return ENOMEM;
 325                         }
 326                         packet_set_private(smb_krb5->packet, smb_krb5);
 327                         packet_set_socket(smb_krb5->packet, smb_krb5->sock);
 328                         packet_set_callback(smb_krb5->packet, smb_krb5_full_packet);
 329                         packet_set_full_request(smb_krb5->packet, packet_full_request_u32);
 330                         packet_set_error_handler(smb_krb5->packet, smb_krb5_error_handler);
 331                         packet_set_event_context(smb_krb5->packet, ev);
 332                         packet_set_fde(smb_krb5->packet, smb_krb5->fde);
 333
 334                         smb_krb5->request = data_blob_talloc(smb_krb5, NULL, send_blob.length + 4);
 335                         RSIVAL(smb_krb5->request.data, 0, send_blob.length);
 336                         memcpy(smb_krb5->request.data+4, send_blob.data, send_blob.length);
 337                         packet_send(smb_krb5->packet, smb_krb5->request);
 338                         break;
 339                 case KRB5_KRBHST_HTTP:
 340                         TALLOC_FREE(frame);
 341                         return EINVAL;
 342                 }
 343                 while ((NT_STATUS_IS_OK(smb_krb5->status)) && !smb_krb5->reply.length) {
 344                         if (tevent_loop_once(ev) != 0) {
 345                                 TALLOC_FREE(frame);
 346                                 return EINVAL;
 347                         }
 348
 349                         if (func) {
 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                                                                 func,
 358                                                                 data);
 359                                 if (ret != 0) {
 360                                         TALLOC_FREE(frame);
 361                                         return ret;
 362                                 }
 363                         }
 364                 }
 365                 if (NT_STATUS_EQUAL(smb_krb5->status, NT_STATUS_IO_TIMEOUT)) {
 366                         talloc_free(smb_krb5);
 367                         continue;
 368                 }
 369
 370                 if (!NT_STATUS_IS_OK(smb_krb5->status)) {
 371                         struct tsocket_address *addr = socket_address_to_tsocket_address(smb_krb5, remote_addr);
 372                         const char *addr_string = NULL;
 373                         if (addr) {
 374                                 addr_string = tsocket_address_inet_addr_string(addr, smb_krb5);
 375                         } else {
 376                                 addr_string = NULL;
 377                         }
 378                         DEBUG(2,("Error reading smb_krb5 reply packet: %s from %s\n", nt_errstr(smb_krb5->status),
 379                                  addr_string));
 380                         talloc_free(smb_krb5);
 381                         continue;
 382                 }
 383
 384                 ret = krb5_data_copy(recv_buf, smb_krb5->reply.data, smb_krb5->reply.length);
 385                 if (ret) {
 386                         TALLOC_FREE(frame);
 387                         return ret;
 388                 }
 389                 talloc_free(smb_krb5);
 390
 391                 break;
 392         }
 393         TALLOC_FREE(frame);
 394         if (a) {
 395                 return 0;
 396         }
 397         return KRB5_KDC_UNREACH;
 398 }
 399
 400 krb5_error_code smb_krb5_send_and_recv_func(krb5_context context,
 401                                             void *data,
 402                                             krb5_krbhst_info *hi,
 403                                             time_t timeout,
 404                                             const krb5_data *send_buf,
 405                                             krb5_data *recv_buf)
 406 {
 407         krb5_error_code ret;
 408         struct addrinfo *ai;
 409
 410         struct tevent_context *ev;
 411         TALLOC_CTX *frame = talloc_stackframe();
 412         if (frame == NULL) {
 413                 return ENOMEM;
 414         }
 415
 416         if (data == NULL) {
 417                 /* If no event context was available, then create one for this loop */
 418                 ev = samba_tevent_context_init(frame);
 419                 if (ev == NULL) {
 420                         TALLOC_FREE(frame);
 421                         return ENOMEM;
 422                 }
 423         } else {
 424                 ev = talloc_get_type_abort(data, struct tevent_context);
 425         }
 426
 427         ret = krb5_krbhst_get_addrinfo(context, hi, &ai);
 428         if (ret) {
 429                 TALLOC_FREE(frame);
 430                 return ret;
 431         }
 432
 433         ret = smb_krb5_send_and_recv_func_int(context, ev, hi, ai, smb_krb5_send_and_recv_func, data, timeout, send_buf, recv_buf);
 434         TALLOC_FREE(frame);
 435         return ret;
 436 }
 437
 438 krb5_error_code smb_krb5_send_and_recv_func_forced(krb5_context context,
 439                                                    void *data, /* struct addrinfo */
 440                                                    krb5_krbhst_info *hi,
 441                                                    time_t timeout,
 442                                                    const krb5_data *send_buf,
 443                                                    krb5_data *recv_buf)
 444 {
 445         krb5_error_code k5ret;
 446         struct addrinfo *ai = data;
 447
 448         struct tevent_context *ev;
 449         TALLOC_CTX *frame = talloc_stackframe();
 450         if (frame == NULL) {
 451                 return ENOMEM;
 452         }
 453
 454         /* no event context is passed in, create one for this loop */
 455         ev = samba_tevent_context_init(frame);
 456         if (ev == NULL) {
 457                 TALLOC_FREE(frame);
 458                 return ENOMEM;
 459         }
 460
 461         /* No need to pass in send_and_recv functions, we won't nest on this private event loop */
 462         k5ret = smb_krb5_send_and_recv_func_int(context, ev, hi, ai, NULL, NULL,
 463                                                 timeout, send_buf, recv_buf);
 464         TALLOC_FREE(frame);
 465         return k5ret;
 466 }
 467 #endif
 468
 469 krb5_error_code
 470 smb_krb5_init_context_basic(TALLOC_CTX *tmp_ctx,
 471                             struct loadparm_context *lp_ctx,
 472                             krb5_context *_krb5_context)
 473 {
 474         krb5_error_code ret;
 475 #ifdef SAMBA4_USES_HEIMDAL
 476         char **config_files;
 477         const char *config_file, *realm;
 478 #endif
 479         krb5_context krb5_ctx;
 480
 481         ret = smb_krb5_init_context_common(&krb5_ctx);
 482         if (ret) {
 483                 return ret;
 484         }
 485
 486         /* The MIT Kerberos build relies on using the system krb5.conf file.
 487          * If you really want to use another file please set KRB5_CONFIG
 488          * accordingly. */
 489 #ifdef SAMBA4_USES_HEIMDAL
 490         config_file = lpcfg_config_path(tmp_ctx, lp_ctx, "krb5.conf");
 491         if (!config_file) {
 492                 krb5_free_context(krb5_ctx);
 493                 return ENOMEM;
 494         }
 495
 496         /* Use our local krb5.conf file by default */
 497         ret = krb5_prepend_config_files_default(config_file, &config_files);
 498         if (ret) {
 499                 DEBUG(1,("krb5_prepend_config_files_default failed (%s)\n",
 500                          smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
 501                 krb5_free_context(krb5_ctx);
 502                 return ret;
 503         }
 504
 505         ret = krb5_set_config_files(krb5_ctx, config_files);
 506         krb5_free_config_files(config_files);
 507         if (ret) {
 508                 DEBUG(1,("krb5_set_config_files failed (%s)\n",
 509                          smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
 510                 krb5_free_context(krb5_ctx);
 511                 return ret;
 512         }
 513
 514         realm = lpcfg_realm(lp_ctx);
 515         if (realm != NULL) {
 516                 ret = krb5_set_default_realm(krb5_ctx, realm);
 517                 if (ret) {
 518                         DEBUG(1,("krb5_set_default_realm failed (%s)\n",
 519                                  smb_get_krb5_error_message(krb5_ctx, ret, tmp_ctx)));
 520                         krb5_free_context(krb5_ctx);
 521                         return ret;
 522                 }
 523         }
 524 #endif
 525         *_krb5_context = krb5_ctx;
 526         return 0;
 527 }
 528
 529 krb5_error_code smb_krb5_init_context(void *parent_ctx,
 530                                       struct loadparm_context *lp_ctx,
 531                                       struct smb_krb5_context **smb_krb5_context)
 532 {
 533         krb5_error_code ret;
 534         TALLOC_CTX *tmp_ctx;
 535         krb5_context kctx;
 536 #ifdef SAMBA4_USES_HEIMDAL
 537         krb5_log_facility *logf;
 538 #endif
 539
 540         tmp_ctx = talloc_new(parent_ctx);
 541         *smb_krb5_context = talloc_zero(tmp_ctx, struct smb_krb5_context);
 542
 543         if (!*smb_krb5_context || !tmp_ctx) {
 544                 talloc_free(tmp_ctx);
 545                 return ENOMEM;
 546         }
 547
 548         ret = smb_krb5_init_context_basic(tmp_ctx, lp_ctx, &kctx);
 549         if (ret) {
 550                 DEBUG(1,("smb_krb5_context_init_basic failed (%s)\n",
 551                          error_message(ret)));
 552                 talloc_free(tmp_ctx);
 553                 return ret;
 554         }
 555         (*smb_krb5_context)->krb5_context = kctx;
 556
 557         talloc_set_destructor(*smb_krb5_context, smb_krb5_context_destroy);
 558
 559 #ifdef SAMBA4_USES_HEIMDAL
 560         /* TODO: Should we have a different name here? */
 561         ret = krb5_initlog(kctx, "Samba", &logf);
 562
 563         if (ret) {
 564                 DEBUG(1,("krb5_initlog failed (%s)\n",
 565                          smb_get_krb5_error_message(kctx, ret, tmp_ctx)));
 566                 talloc_free(tmp_ctx);
 567                 return ret;
 568         }
 569         (*smb_krb5_context)->pvt_log_data = logf;
 570
 571         ret = krb5_addlog_func(kctx, logf, 0 /* min */, -1 /* max */,
 572                                smb_krb5_debug_wrapper,
 573                                 smb_krb5_debug_close, NULL);
 574         if (ret) {
 575                 DEBUG(1,("krb5_addlog_func failed (%s)\n",
 576                          smb_get_krb5_error_message(kctx, ret, tmp_ctx)));
 577                 talloc_free(tmp_ctx);
 578                 return ret;
 579         }
 580         krb5_set_warn_dest(kctx, logf);
 581
 582         /* Set options in kerberos */
 583
 584         krb5_set_dns_canonicalize_hostname(kctx,
 585                         lpcfg_parm_bool(lp_ctx, NULL, "krb5",
 586                                         "set_dns_canonicalize", false));
 587 #endif
 588         talloc_steal(parent_ctx, *smb_krb5_context);
 589         talloc_free(tmp_ctx);
 590
 591         return 0;
 592 }
 593
 594 #ifdef SAMBA4_USES_HEIMDAL
 595 krb5_error_code smb_krb5_context_set_event_ctx(struct smb_krb5_context *smb_krb5_context,
 596                                                struct tevent_context *ev,
 597                                                struct tevent_context **previous_ev)
 598 {
 599         int ret;
 600         if (!ev) {
 601                 return EINVAL;
 602         }
 603
 604         *previous_ev = smb_krb5_context->current_ev;
 605
 606         smb_krb5_context->current_ev = talloc_reference(smb_krb5_context, ev);
 607         if (!smb_krb5_context->current_ev) {
 608                 return ENOMEM;
 609         }
 610
 611         /* Set use of our socket lib */
 612         ret = krb5_set_send_to_kdc_func(smb_krb5_context->krb5_context,
 613                                         smb_krb5_send_and_recv_func,
 614                                         ev);
 615         if (ret) {
 616                 TALLOC_CTX *tmp_ctx = talloc_new(NULL);
 617                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
 618                          smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, tmp_ctx)));
 619                 talloc_free(tmp_ctx);
 620                 talloc_unlink(smb_krb5_context, smb_krb5_context->current_ev);
 621                 smb_krb5_context->current_ev = NULL;
 622                 return ret;
 623         }
 624         return 0;
 625 }
 626
 627 krb5_error_code smb_krb5_context_remove_event_ctx(struct smb_krb5_context *smb_krb5_context,
 628                                                   struct tevent_context *previous_ev,
 629                                                   struct tevent_context *ev)
 630 {
 631         int ret;
 632         talloc_unlink(smb_krb5_context, ev);
 633         /* If there was a mismatch with things happening on a stack, then don't wipe things */
 634         smb_krb5_context->current_ev = previous_ev;
 635         /* Set use of our socket lib */
 636         ret = krb5_set_send_to_kdc_func(smb_krb5_context->krb5_context,
 637                                         smb_krb5_send_and_recv_func,
 638                                         previous_ev);
 639         if (ret) {
 640                 TALLOC_CTX *tmp_ctx = talloc_new(NULL);
 641                 DEBUG(1,("krb5_set_send_recv_func failed (%s)\n",
 642                          smb_get_krb5_error_message(smb_krb5_context->krb5_context, ret, tmp_ctx)));
 643                 talloc_free(tmp_ctx);
 644                 return ret;
 645         }
 646         return 0;
 647 }
 648 #endif