source3/nsswitch/winbindd_dual.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Winbind background daemon
   5
   6    Copyright (C) Andrew Tridgell 2002
   7    Copyright (C) Volker Lendecke 2004,2005
   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 2 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, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22 */
  23
  24 /*
  25   the idea of the optional dual daemon mode is ot prevent slow domain
  26   responses from clagging up the rest of the system. When in dual
  27   daemon mode winbindd always responds to requests from cache if the
  28   request is in cache, and if the cached answer is stale then it asks
  29   the "dual daemon" to update the cache for that request
  30
  31  */
  32
  33 #include "includes.h"
  34 #include "winbindd.h"
  35
  36 #undef DBGC_CLASS
  37 #define DBGC_CLASS DBGC_WINBIND
  38
  39 /* Read some data from a client connection */
  40
  41 static void child_read_request(struct winbindd_cli_state *state)
  42 {
  43         ssize_t len;
  44
  45         /* Read data */
  46
  47         len = read_data(state->sock, (char *)&state->request,
  48                         sizeof(state->request));
  49
  50         if (len != sizeof(state->request)) {
  51                 DEBUG(0, ("Got invalid request length: %d\n", (int)len));
  52                 state->finished = True;
  53                 return;
  54         }
  55
  56         if (state->request.extra_len == 0) {
  57                 state->request.extra_data = NULL;
  58                 return;
  59         }
  60
  61         DEBUG(10, ("Need to read %d extra bytes\n", (int)state->request.extra_len));
  62
  63         state->request.extra_data =
  64                 SMB_MALLOC_ARRAY(char, state->request.extra_len + 1);
  65
  66         if (state->request.extra_data == NULL) {
  67                 DEBUG(0, ("malloc failed\n"));
  68                 state->finished = True;
  69                 return;
  70         }
  71
  72         /* Ensure null termination */
  73         state->request.extra_data[state->request.extra_len] = '\0';
  74
  75         len = read_data(state->sock, state->request.extra_data,
  76                         state->request.extra_len);
  77
  78         if (len != state->request.extra_len) {
  79                 DEBUG(0, ("Could not read extra data\n"));
  80                 state->finished = True;
  81                 return;
  82         }
  83 }
  84
  85 /*
  86  * Machinery for async requests sent to children. You set up a
  87  * winbindd_request, select a child to query, and issue a async_request
  88  * call. When the request is completed, the callback function you specified is
  89  * called back with the private pointer you gave to async_request.
  90  */
  91
  92 struct winbindd_async_request {
  93         struct winbindd_async_request *next, *prev;
  94         TALLOC_CTX *mem_ctx;
  95         struct winbindd_child *child;
  96         struct winbindd_request *request;
  97         struct winbindd_response *response;
  98         void (*continuation)(void *private_data, BOOL success);
  99         void *private_data;
 100 };
 101
 102 static void async_main_request_sent(void *private_data, BOOL success);
 103 static void async_request_sent(void *private_data, BOOL success);
 104 static void async_reply_recv(void *private_data, BOOL success);
 105 static void schedule_async_request(struct winbindd_child *child);
 106
 107 void async_request(TALLOC_CTX *mem_ctx, struct winbindd_child *child,
 108                    struct winbindd_request *request,
 109                    struct winbindd_response *response,
 110                    void (*continuation)(void *private_data, BOOL success),
 111                    void *private_data)
 112 {
 113         struct winbindd_async_request *state, *tmp;
 114
 115         SMB_ASSERT(continuation != NULL);
 116
 117         state = TALLOC_P(mem_ctx, struct winbindd_async_request);
 118
 119         if (state == NULL) {
 120                 DEBUG(0, ("talloc failed\n"));
 121                 continuation(private_data, False);
 122                 return;
 123         }
 124
 125         state->mem_ctx = mem_ctx;
 126         state->child = child;
 127         state->request = request;
 128         state->response = response;
 129         state->continuation = continuation;
 130         state->private_data = private_data;
 131
 132         DLIST_ADD_END(child->requests, state, tmp);
 133
 134         schedule_async_request(child);
 135
 136         return;
 137 }
 138
 139 static void async_main_request_sent(void *private_data, BOOL success)
 140 {
 141         struct winbindd_async_request *state =
 142                 talloc_get_type_abort(private_data, struct winbindd_async_request);
 143
 144         if (!success) {
 145                 DEBUG(5, ("Could not send async request\n"));
 146
 147                 state->response->length = sizeof(struct winbindd_response);
 148                 state->response->result = WINBINDD_ERROR;
 149                 state->continuation(state->private_data, False);
 150                 return;
 151         }
 152
 153         if (state->request->extra_len == 0) {
 154                 async_request_sent(private_data, True);
 155                 return;
 156         }
 157
 158         setup_async_write(&state->child->event, state->request->extra_data,
 159                           state->request->extra_len,
 160                           async_request_sent, state);
 161 }
 162
 163 static void async_request_sent(void *private_data_data, BOOL success)
 164 {
 165         struct winbindd_async_request *state =
 166                 talloc_get_type_abort(private_data_data, struct winbindd_async_request);
 167
 168         if (!success) {
 169                 DEBUG(5, ("Could not send async request\n"));
 170
 171                 state->response->length = sizeof(struct winbindd_response);
 172                 state->response->result = WINBINDD_ERROR;
 173                 state->continuation(state->private_data, False);
 174                 return;
 175         }
 176
 177         /* Request successfully sent to the child, setup the wait for reply */
 178
 179         setup_async_read(&state->child->event,
 180                          &state->response->result,
 181                          sizeof(state->response->result),
 182                          async_reply_recv, state);
 183 }
 184
 185 static void async_reply_recv(void *private_data, BOOL success)
 186 {
 187         struct winbindd_async_request *state =
 188                 talloc_get_type_abort(private_data, struct winbindd_async_request);
 189         struct winbindd_child *child = state->child;
 190
 191         state->response->length = sizeof(struct winbindd_response);
 192
 193         if (!success) {
 194                 DEBUG(5, ("Could not receive async reply\n"));
 195                 state->response->result = WINBINDD_ERROR;
 196                 return;
 197         }
 198
 199         SMB_ASSERT(cache_retrieve_response(child->pid,
 200                                            state->response));
 201
 202         DLIST_REMOVE(child->requests, state);
 203
 204         schedule_async_request(child);
 205
 206         state->continuation(state->private_data, True);
 207 }
 208
 209 static BOOL fork_domain_child(struct winbindd_child *child);
 210
 211 static void schedule_async_request(struct winbindd_child *child)
 212 {
 213         struct winbindd_async_request *request = child->requests;
 214
 215         if (request == NULL) {
 216                 return;
 217         }
 218
 219         if (child->event.flags != 0) {
 220                 return;         /* Busy */
 221         }
 222
 223         if ((child->pid == 0) && (!fork_domain_child(child))) {
 224                 /* Cancel all outstanding requests */
 225
 226                 while (request != NULL) {
 227                         /* request might be free'd in the continuation */
 228                         struct winbindd_async_request *next = request->next;
 229                         request->continuation(request->private_data, False);
 230                         request = next;
 231                 }
 232                 return;
 233         }
 234
 235         setup_async_write(&child->event, request->request,
 236                           sizeof(*request->request),
 237                           async_main_request_sent, request);
 238         return;
 239 }
 240
 241 struct domain_request_state {
 242         TALLOC_CTX *mem_ctx;
 243         struct winbindd_domain *domain;
 244         struct winbindd_request *request;
 245         struct winbindd_response *response;
 246         void (*continuation)(void *private_data_data, BOOL success);
 247         void *private_data_data;
 248 };
 249
 250 static void domain_init_recv(void *private_data_data, BOOL success);
 251
 252 void async_domain_request(TALLOC_CTX *mem_ctx,
 253                           struct winbindd_domain *domain,
 254                           struct winbindd_request *request,
 255                           struct winbindd_response *response,
 256                           void (*continuation)(void *private_data_data, BOOL success),
 257                           void *private_data_data)
 258 {
 259         struct domain_request_state *state;
 260
 261         if (domain->initialized) {
 262                 async_request(mem_ctx, &domain->child, request, response,
 263                               continuation, private_data_data);
 264                 return;
 265         }
 266
 267         state = TALLOC_P(mem_ctx, struct domain_request_state);
 268         if (state == NULL) {
 269                 DEBUG(0, ("talloc failed\n"));
 270                 continuation(private_data_data, False);
 271                 return;
 272         }
 273
 274         state->mem_ctx = mem_ctx;
 275         state->domain = domain;
 276         state->request = request;
 277         state->response = response;
 278         state->continuation = continuation;
 279         state->private_data_data = private_data_data;
 280
 281         init_child_connection(domain, domain_init_recv, state);
 282 }
 283
 284 static void recvfrom_child(void *private_data_data, BOOL success)
 285 {
 286         struct winbindd_cli_state *state =
 287                 talloc_get_type_abort(private_data_data, struct winbindd_cli_state);
 288         enum winbindd_result result = state->response.result;
 289
 290         /* This is an optimization: The child has written directly to the
 291          * response buffer. The request itself is still in pending state,
 292          * state that in the result code. */
 293
 294         state->response.result = WINBINDD_PENDING;
 295
 296         if ((!success) || (result != WINBINDD_OK)) {
 297                 request_error(state);
 298                 return;
 299         }
 300
 301         request_ok(state);
 302 }
 303
 304 void sendto_child(struct winbindd_cli_state *state,
 305                   struct winbindd_child *child)
 306 {
 307         async_request(state->mem_ctx, child, &state->request,
 308                       &state->response, recvfrom_child, state);
 309 }
 310
 311 void sendto_domain(struct winbindd_cli_state *state,
 312                    struct winbindd_domain *domain)
 313 {
 314         async_domain_request(state->mem_ctx, domain,
 315                              &state->request, &state->response,
 316                              recvfrom_child, state);
 317 }
 318
 319 static void domain_init_recv(void *private_data_data, BOOL success)
 320 {
 321         struct domain_request_state *state =
 322                 talloc_get_type_abort(private_data_data, struct domain_request_state);
 323
 324         if (!success) {
 325                 DEBUG(5, ("Domain init returned an error\n"));
 326                 state->continuation(state->private_data_data, False);
 327                 return;
 328         }
 329
 330         async_request(state->mem_ctx, &state->domain->child,
 331                       state->request, state->response,
 332                       state->continuation, state->private_data_data);
 333 }
 334
 335 struct winbindd_child_dispatch_table {
 336         enum winbindd_cmd cmd;
 337         enum winbindd_result (*fn)(struct winbindd_domain *domain,
 338                                    struct winbindd_cli_state *state);
 339         const char *winbindd_cmd_name;
 340 };
 341
 342 static struct winbindd_child_dispatch_table child_dispatch_table[] = {
 343
 344         { WINBINDD_LOOKUPSID,            winbindd_dual_lookupsid,             "LOOKUPSID" },
 345         { WINBINDD_LOOKUPNAME,           winbindd_dual_lookupname,            "LOOKUPNAME" },
 346         { WINBINDD_LIST_TRUSTDOM,        winbindd_dual_list_trusted_domains,  "LIST_TRUSTDOM" },
 347         { WINBINDD_INIT_CONNECTION,      winbindd_dual_init_connection,       "INIT_CONNECTION" },
 348         { WINBINDD_GETDCNAME,            winbindd_dual_getdcname,             "GETDCNAME" },
 349         { WINBINDD_SHOW_SEQUENCE,        winbindd_dual_show_sequence,         "SHOW_SEQUENCE" },
 350         { WINBINDD_PAM_AUTH,             winbindd_dual_pam_auth,              "PAM_AUTH" },
 351         { WINBINDD_PAM_AUTH_CRAP,        winbindd_dual_pam_auth_crap,         "AUTH_CRAP" },
 352         { WINBINDD_CHECK_MACHACC,        winbindd_dual_check_machine_acct,    "CHECK_MACHACC" },
 353         { WINBINDD_DUAL_SID2UID,         winbindd_dual_sid2uid,               "DUAL_SID2UID" },
 354         { WINBINDD_DUAL_SID2GID,         winbindd_dual_sid2gid,               "DUAL_SID2GID" },
 355         { WINBINDD_DUAL_UID2NAME,        winbindd_dual_uid2name,              "DUAL_UID2NAME" },
 356         { WINBINDD_DUAL_NAME2UID,        winbindd_dual_name2uid,              "DUAL_NAME2UID" },
 357         { WINBINDD_DUAL_GID2NAME,        winbindd_dual_gid2name,              "DUAL_GID2NAME" },
 358         { WINBINDD_DUAL_NAME2GID,        winbindd_dual_name2gid,              "DUAL_NAME2GID" },
 359         { WINBINDD_DUAL_IDMAPSET,        winbindd_dual_idmapset,              "DUAL_IDMAPSET" },
 360         { WINBINDD_DUAL_USERINFO,        winbindd_dual_userinfo,              "DUAL_USERINFO" },
 361         { WINBINDD_ALLOCATE_RID,         winbindd_dual_allocate_rid,          "ALLOCATE_RID" },
 362         { WINBINDD_ALLOCATE_RID_AND_GID, winbindd_dual_allocate_rid_and_gid,  "ALLOCATE_RID_AND_GID" },
 363         { WINBINDD_GETUSERDOMGROUPS,     winbindd_dual_getuserdomgroups,      "GETUSERDOMGROUPS" },
 364         { WINBINDD_DUAL_GETSIDALIASES,   winbindd_dual_getsidaliases,         "GETSIDALIASES" },
 365         /* End of list */
 366
 367         { WINBINDD_NUM_CMDS, NULL, "NONE" }
 368 };
 369
 370 static void child_process_request(struct winbindd_domain *domain,
 371                                   struct winbindd_cli_state *state)
 372 {
 373         struct winbindd_child_dispatch_table *table;
 374
 375         /* Free response data - we may be interrupted and receive another
 376            command before being able to send this data off. */
 377
 378         state->response.result = WINBINDD_ERROR;
 379         state->response.length = sizeof(struct winbindd_response);
 380
 381         state->mem_ctx = talloc_init("winbind request");
 382         if (state->mem_ctx == NULL)
 383                 return;
 384
 385         /* Process command */
 386
 387         for (table = child_dispatch_table; table->fn; table++) {
 388                 if (state->request.cmd == table->cmd) {
 389                         DEBUG(10,("process_request: request fn %s\n",
 390                                   table->winbindd_cmd_name ));
 391                         state->response.result = table->fn(domain, state);
 392                         break;
 393                 }
 394         }
 395
 396         if (!table->fn) {
 397                 DEBUG(10,("process_request: unknown request fn number %d\n",
 398                           (int)state->request.cmd ));
 399                 state->response.result = WINBINDD_ERROR;
 400         }
 401
 402         talloc_destroy(state->mem_ctx);
 403 }
 404
 405 void setup_domain_child(struct winbindd_domain *domain,
 406                         struct winbindd_child *child,
 407                         const char *explicit_logfile)
 408 {
 409         if (explicit_logfile != NULL) {
 410                 pstr_sprintf(child->logfilename, "%s/log.winbindd-%s",
 411                              dyn_LOGFILEBASE, explicit_logfile);
 412         } else if (domain != NULL) {
 413                 pstr_sprintf(child->logfilename, "%s/log.wb-%s",
 414                              dyn_LOGFILEBASE, domain->name);
 415         } else {
 416                 smb_panic("Internal error: domain == NULL && "
 417                           "explicit_logfile == NULL");
 418         }
 419
 420         child->domain = domain;
 421 }
 422
 423 struct winbindd_child *children = NULL;
 424
 425 void winbind_child_died(pid_t pid)
 426 {
 427         struct winbindd_child *child;
 428
 429         for (child = children; child != NULL; child = child->next) {
 430                 if (child->pid == pid) {
 431                         break;
 432                 }
 433         }
 434
 435         if (child == NULL) {
 436                 DEBUG(0, ("Unknown child %d died!\n", pid));
 437                 return;
 438         }
 439
 440         remove_fd_event(&child->event);
 441         close(child->event.fd);
 442         child->event.fd = 0;
 443         child->event.flags = 0;
 444         child->pid = 0;
 445
 446         schedule_async_request(child);
 447 }
 448
 449 static BOOL fork_domain_child(struct winbindd_child *child)
 450 {
 451         int fdpair[2];
 452         struct winbindd_cli_state state;
 453         extern BOOL override_logfile;
 454
 455         if (socketpair(AF_UNIX, SOCK_STREAM, 0, fdpair) != 0) {
 456                 DEBUG(0, ("Could not open child pipe: %s\n",
 457                           strerror(errno)));
 458                 return False;
 459         }
 460
 461         ZERO_STRUCT(state);
 462         state.pid = getpid();
 463
 464         child->pid = sys_fork();
 465
 466         if (child->pid == -1) {
 467                 DEBUG(0, ("Could not fork: %s\n", strerror(errno)));
 468                 return False;
 469         }
 470
 471         if (child->pid != 0) {
 472                 /* Parent */
 473                 close(fdpair[0]);
 474                 child->next = child->prev = NULL;
 475                 DLIST_ADD(children, child);
 476                 child->event.fd = fdpair[1];
 477                 child->event.flags = 0;
 478                 child->requests = NULL;
 479                 add_fd_event(&child->event);
 480                 return True;
 481         }
 482
 483         /* Child */
 484
 485         state.sock = fdpair[0];
 486         close(fdpair[1]);
 487
 488         /* tdb needs special fork handling */
 489         if (tdb_reopen_all() == -1) {
 490                 DEBUG(0,("tdb_reopen_all failed.\n"));
 491                 _exit(0);
 492         }
 493
 494         close_conns_after_fork();
 495
 496         if (!override_logfile) {
 497                 lp_set_logfile(child->logfilename);
 498                 reopen_logs();
 499         }
 500
 501         while (1) {
 502                 /* free up any talloc memory */
 503                 lp_talloc_free();
 504                 main_loop_talloc_free();
 505
 506                 /* fetch a request from the main daemon */
 507                 child_read_request(&state);
 508
 509                 if (state.finished) {
 510                         /* we lost contact with our parent */
 511                         exit(0);
 512                 }
 513
 514                 DEBUG(4,("child daemon request %d\n", (int)state.request.cmd));
 515
 516                 ZERO_STRUCT(state.response);
 517                 state.request.null_term = '\0';
 518                 child_process_request(child->domain, &state);
 519
 520                 SAFE_FREE(state.request.extra_data);
 521
 522                 cache_store_response(sys_getpid(), &state.response);
 523
 524                 SAFE_FREE(state.response.extra_data);
 525
 526                 /* We just send the result code back, the result
 527                  * structure needs to be fetched via the
 528                  * winbindd_cache. Hmm. That needs fixing... */
 529
 530                 if (write_data(state.sock, (void *)&state.response.result,
 531                                sizeof(state.response.result)) !=
 532                     sizeof(state.response.result)) {
 533                         DEBUG(0, ("Could not write result\n"));
 534                         exit(1);
 535                 }
 536         }
 537 }