git.maemo.org Git - samba/blob - source/nsswitch/winbindd_dual.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    Winbind child daemons
   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  * We fork a child per domain to be able to act non-blocking in the main
  26  * winbind daemon. A domain controller thousands of miles away being being
  27  * slow replying with a 10.000 user list should not hold up netlogon calls
  28  * that can be handled locally.
  29  */
  30
  31 #include "includes.h"
  32 #include "winbindd.h"
  33
  34 #undef DBGC_CLASS
  35 #define DBGC_CLASS DBGC_WINBIND
  36
  37 /* Read some data from a client connection */
  38
  39 static void child_read_request(struct winbindd_cli_state *state)
  40 {
  41         ssize_t len;
  42
  43         /* Read data */
  44
  45         len = read_data(state->sock, (char *)&state->request,
  46                         sizeof(state->request));
  47
  48         if (len != sizeof(state->request)) {
  49                 DEBUG(0, ("Got invalid request length: %d\n", (int)len));
  50                 state->finished = True;
  51                 return;
  52         }
  53
  54         if (state->request.extra_len == 0) {
  55                 state->request.extra_data = NULL;
  56                 return;
  57         }
  58
  59         DEBUG(10, ("Need to read %d extra bytes\n", (int)state->request.extra_len));
  60
  61         state->request.extra_data =
  62                 SMB_MALLOC_ARRAY(char, state->request.extra_len + 1);
  63
  64         if (state->request.extra_data == NULL) {
  65                 DEBUG(0, ("malloc failed\n"));
  66                 state->finished = True;
  67                 return;
  68         }
  69
  70         /* Ensure null termination */
  71         state->request.extra_data[state->request.extra_len] = '\0';
  72
  73         len = read_data(state->sock, state->request.extra_data,
  74                         state->request.extra_len);
  75
  76         if (len != state->request.extra_len) {
  77                 DEBUG(0, ("Could not read extra data\n"));
  78                 state->finished = True;
  79                 return;
  80         }
  81 }
  82
  83 /*
  84  * Machinery for async requests sent to children. You set up a
  85  * winbindd_request, select a child to query, and issue a async_request
  86  * call. When the request is completed, the callback function you specified is
  87  * called back with the private pointer you gave to async_request.
  88  */
  89
  90 struct winbindd_async_request {
  91         struct winbindd_async_request *next, *prev;
  92         TALLOC_CTX *mem_ctx;
  93         struct winbindd_child *child;
  94         struct winbindd_request *request;
  95         struct winbindd_response *response;
  96         void (*continuation)(void *private_data, BOOL success);
  97         void *private_data;
  98 };
  99
 100 static void async_main_request_sent(void *private_data, BOOL success);
 101 static void async_request_sent(void *private_data, BOOL success);
 102 static void async_reply_recv(void *private_data, BOOL success);
 103 static void schedule_async_request(struct winbindd_child *child);
 104
 105 void async_request(TALLOC_CTX *mem_ctx, struct winbindd_child *child,
 106                    struct winbindd_request *request,
 107                    struct winbindd_response *response,
 108                    void (*continuation)(void *private_data, BOOL success),
 109                    void *private_data)
 110 {
 111         struct winbindd_async_request *state, *tmp;
 112
 113         SMB_ASSERT(continuation != NULL);
 114
 115         state = TALLOC_P(mem_ctx, struct winbindd_async_request);
 116
 117         if (state == NULL) {
 118                 DEBUG(0, ("talloc failed\n"));
 119                 continuation(private_data, False);
 120                 return;
 121         }
 122
 123         state->mem_ctx = mem_ctx;
 124         state->child = child;
 125         state->request = request;
 126         state->response = response;
 127         state->continuation = continuation;
 128         state->private_data = private_data;
 129
 130         DLIST_ADD_END(child->requests, state, tmp);
 131
 132         schedule_async_request(child);
 133
 134         return;
 135 }
 136
 137 static void async_main_request_sent(void *private_data, BOOL success)
 138 {
 139         struct winbindd_async_request *state =
 140                 talloc_get_type_abort(private_data, struct winbindd_async_request);
 141
 142         if (!success) {
 143                 DEBUG(5, ("Could not send async request\n"));
 144
 145                 state->response->length = sizeof(struct winbindd_response);
 146                 state->response->result = WINBINDD_ERROR;
 147                 state->continuation(state->private_data, False);
 148                 return;
 149         }
 150
 151         if (state->request->extra_len == 0) {
 152                 async_request_sent(private_data, True);
 153                 return;
 154         }
 155
 156         setup_async_write(&state->child->event, state->request->extra_data,
 157                           state->request->extra_len,
 158                           async_request_sent, state);
 159 }
 160
 161 static void async_request_sent(void *private_data_data, BOOL success)
 162 {
 163         struct winbindd_async_request *state =
 164                 talloc_get_type_abort(private_data_data, struct winbindd_async_request);
 165
 166         if (!success) {
 167                 DEBUG(5, ("Could not send async request\n"));
 168
 169                 state->response->length = sizeof(struct winbindd_response);
 170                 state->response->result = WINBINDD_ERROR;
 171                 state->continuation(state->private_data, False);
 172                 return;
 173         }
 174
 175         /* Request successfully sent to the child, setup the wait for reply */
 176
 177         setup_async_read(&state->child->event,
 178                          &state->response->result,
 179                          sizeof(state->response->result),
 180                          async_reply_recv, state);
 181 }
 182
 183 static void async_reply_recv(void *private_data, BOOL success)
 184 {
 185         struct winbindd_async_request *state =
 186                 talloc_get_type_abort(private_data, struct winbindd_async_request);
 187         struct winbindd_child *child = state->child;
 188
 189         state->response->length = sizeof(struct winbindd_response);
 190
 191         if (!success) {
 192                 DEBUG(5, ("Could not receive async reply\n"));
 193                 state->response->result = WINBINDD_ERROR;
 194                 return;
 195         }
 196
 197         SMB_ASSERT(cache_retrieve_response(child->pid,
 198                                            state->response));
 199
 200         DLIST_REMOVE(child->requests, state);
 201
 202         schedule_async_request(child);
 203
 204         state->continuation(state->private_data, True);
 205 }
 206
 207 static BOOL fork_domain_child(struct winbindd_child *child);
 208
 209 static void schedule_async_request(struct winbindd_child *child)
 210 {
 211         struct winbindd_async_request *request = child->requests;
 212
 213         if (request == NULL) {
 214                 return;
 215         }
 216
 217         if (child->event.flags != 0) {
 218                 return;         /* Busy */
 219         }
 220
 221         if ((child->pid == 0) && (!fork_domain_child(child))) {
 222                 /* Cancel all outstanding requests */
 223
 224                 while (request != NULL) {
 225                         /* request might be free'd in the continuation */
 226                         struct winbindd_async_request *next = request->next;
 227                         request->continuation(request->private_data, False);
 228                         request = next;
 229                 }
 230                 return;
 231         }
 232
 233         setup_async_write(&child->event, request->request,
 234                           sizeof(*request->request),
 235                           async_main_request_sent, request);
 236         return;
 237 }
 238
 239 struct domain_request_state {
 240         TALLOC_CTX *mem_ctx;
 241         struct winbindd_domain *domain;
 242         struct winbindd_request *request;
 243         struct winbindd_response *response;
 244         void (*continuation)(void *private_data_data, BOOL success);
 245         void *private_data_data;
 246 };
 247
 248 static void domain_init_recv(void *private_data_data, BOOL success);
 249
 250 void async_domain_request(TALLOC_CTX *mem_ctx,
 251                           struct winbindd_domain *domain,
 252                           struct winbindd_request *request,
 253                           struct winbindd_response *response,
 254                           void (*continuation)(void *private_data_data, BOOL success),
 255                           void *private_data_data)
 256 {
 257         struct domain_request_state *state;
 258
 259         if (domain->initialized) {
 260                 async_request(mem_ctx, &domain->child, request, response,
 261                               continuation, private_data_data);
 262                 return;
 263         }
 264
 265         state = TALLOC_P(mem_ctx, struct domain_request_state);
 266         if (state == NULL) {
 267                 DEBUG(0, ("talloc failed\n"));
 268                 continuation(private_data_data, False);
 269                 return;
 270         }
 271
 272         state->mem_ctx = mem_ctx;
 273         state->domain = domain;
 274         state->request = request;
 275         state->response = response;
 276         state->continuation = continuation;
 277         state->private_data_data = private_data_data;
 278
 279         init_child_connection(domain, domain_init_recv, state);
 280 }
 281
 282 static void recvfrom_child(void *private_data_data, BOOL success)
 283 {
 284         struct winbindd_cli_state *state =
 285                 talloc_get_type_abort(private_data_data, struct winbindd_cli_state);
 286         enum winbindd_result result = state->response.result;
 287
 288         /* This is an optimization: The child has written directly to the
 289          * response buffer. The request itself is still in pending state,
 290          * state that in the result code. */
 291
 292         state->response.result = WINBINDD_PENDING;
 293
 294         if ((!success) || (result != WINBINDD_OK)) {
 295                 request_error(state);
 296                 return;
 297         }
 298
 299         request_ok(state);
 300 }
 301
 302 void sendto_child(struct winbindd_cli_state *state,
 303                   struct winbindd_child *child)
 304 {
 305         async_request(state->mem_ctx, child, &state->request,
 306                       &state->response, recvfrom_child, state);
 307 }
 308
 309 void sendto_domain(struct winbindd_cli_state *state,
 310                    struct winbindd_domain *domain)
 311 {
 312         async_domain_request(state->mem_ctx, domain,
 313                              &state->request, &state->response,
 314                              recvfrom_child, state);
 315 }
 316
 317 static void domain_init_recv(void *private_data_data, BOOL success)
 318 {
 319         struct domain_request_state *state =
 320                 talloc_get_type_abort(private_data_data, struct domain_request_state);
 321
 322         if (!success) {
 323                 DEBUG(5, ("Domain init returned an error\n"));
 324                 state->continuation(state->private_data_data, False);
 325                 return;
 326         }
 327
 328         async_request(state->mem_ctx, &state->domain->child,
 329                       state->request, state->response,
 330                       state->continuation, state->private_data_data);
 331 }
 332
 333 struct winbindd_child_dispatch_table {
 334         enum winbindd_cmd cmd;
 335         enum winbindd_result (*fn)(struct winbindd_domain *domain,
 336                                    struct winbindd_cli_state *state);
 337         const char *winbindd_cmd_name;
 338 };
 339
 340 static struct winbindd_child_dispatch_table child_dispatch_table[] = {
 341
 342         { WINBINDD_LOOKUPSID,            winbindd_dual_lookupsid,             "LOOKUPSID" },
 343         { WINBINDD_LOOKUPNAME,           winbindd_dual_lookupname,            "LOOKUPNAME" },
 344         { WINBINDD_LIST_TRUSTDOM,        winbindd_dual_list_trusted_domains,  "LIST_TRUSTDOM" },
 345         { WINBINDD_INIT_CONNECTION,      winbindd_dual_init_connection,       "INIT_CONNECTION" },
 346         { WINBINDD_GETDCNAME,            winbindd_dual_getdcname,             "GETDCNAME" },
 347         { WINBINDD_SHOW_SEQUENCE,        winbindd_dual_show_sequence,         "SHOW_SEQUENCE" },
 348         { WINBINDD_PAM_AUTH,             winbindd_dual_pam_auth,              "PAM_AUTH" },
 349         { WINBINDD_PAM_AUTH_CRAP,        winbindd_dual_pam_auth_crap,         "AUTH_CRAP" },
 350         { WINBINDD_CHECK_MACHACC,        winbindd_dual_check_machine_acct,    "CHECK_MACHACC" },
 351         { WINBINDD_DUAL_SID2UID,         winbindd_dual_sid2uid,               "DUAL_SID2UID" },
 352         { WINBINDD_DUAL_SID2GID,         winbindd_dual_sid2gid,               "DUAL_SID2GID" },
 353         { WINBINDD_DUAL_UID2NAME,        winbindd_dual_uid2name,              "DUAL_UID2NAME" },
 354         { WINBINDD_DUAL_NAME2UID,        winbindd_dual_name2uid,              "DUAL_NAME2UID" },
 355         { WINBINDD_DUAL_GID2NAME,        winbindd_dual_gid2name,              "DUAL_GID2NAME" },
 356         { WINBINDD_DUAL_NAME2GID,        winbindd_dual_name2gid,              "DUAL_NAME2GID" },
 357         { WINBINDD_DUAL_IDMAPSET,        winbindd_dual_idmapset,              "DUAL_IDMAPSET" },
 358         { WINBINDD_DUAL_USERINFO,        winbindd_dual_userinfo,              "DUAL_USERINFO" },
 359         { WINBINDD_ALLOCATE_RID,         winbindd_dual_allocate_rid,          "ALLOCATE_RID" },
 360         { WINBINDD_ALLOCATE_RID_AND_GID, winbindd_dual_allocate_rid_and_gid,  "ALLOCATE_RID_AND_GID" },
 361         { WINBINDD_GETUSERDOMGROUPS,     winbindd_dual_getuserdomgroups,      "GETUSERDOMGROUPS" },
 362         { WINBINDD_DUAL_GETSIDALIASES,   winbindd_dual_getsidaliases,         "GETSIDALIASES" },
 363         /* End of list */
 364
 365         { WINBINDD_NUM_CMDS, NULL, "NONE" }
 366 };
 367
 368 static void child_process_request(struct winbindd_domain *domain,
 369                                   struct winbindd_cli_state *state)
 370 {
 371         struct winbindd_child_dispatch_table *table;
 372
 373         /* Free response data - we may be interrupted and receive another
 374            command before being able to send this data off. */
 375
 376         state->response.result = WINBINDD_ERROR;
 377         state->response.length = sizeof(struct winbindd_response);
 378
 379         state->mem_ctx = talloc_init("winbind request");
 380         if (state->mem_ctx == NULL)
 381                 return;
 382
 383         /* Process command */
 384
 385         for (table = child_dispatch_table; table->fn; table++) {
 386                 if (state->request.cmd == table->cmd) {
 387                         DEBUG(10,("process_request: request fn %s\n",
 388                                   table->winbindd_cmd_name ));
 389                         state->response.result = table->fn(domain, state);
 390                         break;
 391                 }
 392         }
 393
 394         if (!table->fn) {
 395                 DEBUG(10,("process_request: unknown request fn number %d\n",
 396                           (int)state->request.cmd ));
 397                 state->response.result = WINBINDD_ERROR;
 398         }
 399
 400         talloc_destroy(state->mem_ctx);
 401 }
 402
 403 void setup_domain_child(struct winbindd_domain *domain,
 404                         struct winbindd_child *child,
 405                         const char *explicit_logfile)
 406 {
 407         if (explicit_logfile != NULL) {
 408                 pstr_sprintf(child->logfilename, "%s/log.winbindd-%s",
 409                              dyn_LOGFILEBASE, explicit_logfile);
 410         } else if (domain != NULL) {
 411                 pstr_sprintf(child->logfilename, "%s/log.wb-%s",
 412                              dyn_LOGFILEBASE, domain->name);
 413         } else {
 414                 smb_panic("Internal error: domain == NULL && "
 415                           "explicit_logfile == NULL");
 416         }
 417
 418         child->domain = domain;
 419 }
 420
 421 struct winbindd_child *children = NULL;
 422
 423 void winbind_child_died(pid_t pid)
 424 {
 425         struct winbindd_child *child;
 426
 427         for (child = children; child != NULL; child = child->next) {
 428                 if (child->pid == pid) {
 429                         break;
 430                 }
 431         }
 432
 433         if (child == NULL) {
 434                 DEBUG(0, ("Unknown child %d died!\n", pid));
 435                 return;
 436         }
 437
 438         remove_fd_event(&child->event);
 439         close(child->event.fd);
 440         child->event.fd = 0;
 441         child->event.flags = 0;
 442         child->pid = 0;
 443
 444         schedule_async_request(child);
 445 }
 446
 447 static BOOL fork_domain_child(struct winbindd_child *child)
 448 {
 449         int fdpair[2];
 450         struct winbindd_cli_state state;
 451         extern BOOL override_logfile;
 452
 453         if (socketpair(AF_UNIX, SOCK_STREAM, 0, fdpair) != 0) {
 454                 DEBUG(0, ("Could not open child pipe: %s\n",
 455                           strerror(errno)));
 456                 return False;
 457         }
 458
 459         ZERO_STRUCT(state);
 460         state.pid = getpid();
 461
 462         child->pid = sys_fork();
 463
 464         if (child->pid == -1) {
 465                 DEBUG(0, ("Could not fork: %s\n", strerror(errno)));
 466                 return False;
 467         }
 468
 469         if (child->pid != 0) {
 470                 /* Parent */
 471                 close(fdpair[0]);
 472                 child->next = child->prev = NULL;
 473                 DLIST_ADD(children, child);
 474                 child->event.fd = fdpair[1];
 475                 child->event.flags = 0;
 476                 child->requests = NULL;
 477                 add_fd_event(&child->event);
 478                 return True;
 479         }
 480
 481         /* Child */
 482
 483         state.sock = fdpair[0];
 484         close(fdpair[1]);
 485
 486         /* tdb needs special fork handling */
 487         if (tdb_reopen_all() == -1) {
 488                 DEBUG(0,("tdb_reopen_all failed.\n"));
 489                 _exit(0);
 490         }
 491
 492         close_conns_after_fork();
 493
 494         if (!override_logfile) {
 495                 lp_set_logfile(child->logfilename);
 496                 reopen_logs();
 497         }
 498
 499         while (1) {
 500                 /* free up any talloc memory */
 501                 lp_talloc_free();
 502                 main_loop_talloc_free();
 503
 504                 /* fetch a request from the main daemon */
 505                 child_read_request(&state);
 506
 507                 if (state.finished) {
 508                         /* we lost contact with our parent */
 509                         exit(0);
 510                 }
 511
 512                 DEBUG(4,("child daemon request %d\n", (int)state.request.cmd));
 513
 514                 ZERO_STRUCT(state.response);
 515                 state.request.null_term = '\0';
 516                 child_process_request(child->domain, &state);
 517
 518                 SAFE_FREE(state.request.extra_data);
 519
 520                 cache_store_response(sys_getpid(), &state.response);
 521
 522                 SAFE_FREE(state.response.extra_data);
 523
 524                 /* We just send the result code back, the result
 525                  * structure needs to be fetched via the
 526                  * winbindd_cache. Hmm. That needs fixing... */
 527
 528                 if (write_data(state.sock, (void *)&state.response.result,
 529                                sizeof(state.response.result)) !=
 530                     sizeof(state.response.result)) {
 531                         DEBUG(0, ("Could not write result\n"));
 532                         exit(1);
 533                 }
 534         }
 535 }