source3/smbd/scavenger.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    smbd scavenger daemon
   4
   5    Copyright (C) Gregor Beck                    2013
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include "includes.h"
  22 #include "messages.h"
  23 #include "serverid.h"
  24 #include "smbd/globals.h"
  25 #include "smbd/scavenger.h"
  26 #include "locking/proto.h"
  27 #include "lib/util/server_id.h"
  28 #include "lib/util/util_process.h"
  29 #include "lib/util/sys_rw_data.h"
  30
  31 #undef DBGC_CLASS
  32 #define DBGC_CLASS DBGC_SCAVENGER
  33
  34 struct smbd_scavenger_state {
  35         struct tevent_context *ev;
  36         struct messaging_context *msg;
  37         struct server_id parent_id;
  38         struct server_id *scavenger_id;
  39         bool am_scavenger;
  40 };
  41
  42 static struct smbd_scavenger_state *smbd_scavenger_state = NULL;
  43
  44 struct scavenger_message {
  45         struct file_id file_id;
  46         uint64_t open_persistent_id;
  47         NTTIME until;
  48 };
  49
  50 static int smbd_scavenger_main(struct smbd_scavenger_state *state)
  51 {
  52         struct server_id_buf tmp1, tmp2;
  53
  54         DEBUG(10, ("scavenger: %s started, parent: %s\n",
  55                    server_id_str_buf(*state->scavenger_id, &tmp1),
  56                    server_id_str_buf(state->parent_id, &tmp2)));
  57
  58         while (true) {
  59                 TALLOC_CTX *frame = talloc_stackframe();
  60                 int ret;
  61
  62                 ret = tevent_loop_once(state->ev);
  63                 if (ret != 0) {
  64                         DEBUG(2, ("tevent_loop_once failed: %s\n",
  65                                   strerror(errno)));
  66                         TALLOC_FREE(frame);
  67                         return 1;
  68                 }
  69
  70                 DEBUG(10, ("scavenger: %s event loop iteration\n",
  71                            server_id_str_buf(*state->scavenger_id, &tmp1)));
  72                 TALLOC_FREE(frame);
  73         }
  74
  75         return 0;
  76 }
  77
  78 static void smbd_scavenger_done(struct tevent_context *event_ctx, struct tevent_fd *fde,
  79                                 uint16_t flags, void *private_data)
  80 {
  81         struct smbd_scavenger_state *state = talloc_get_type_abort(
  82                 private_data, struct smbd_scavenger_state);
  83         struct server_id_buf tmp;
  84
  85         DEBUG(2, ("scavenger: %s died\n",
  86                   server_id_str_buf(*state->scavenger_id, &tmp)));
  87
  88         TALLOC_FREE(state->scavenger_id);
  89 }
  90
  91 static void smbd_scavenger_parent_dead(struct tevent_context *event_ctx,
  92                                        struct tevent_fd *fde,
  93                                        uint16_t flags, void *private_data)
  94 {
  95         struct smbd_scavenger_state *state = talloc_get_type_abort(
  96                 private_data, struct smbd_scavenger_state);
  97         struct server_id_buf tmp1, tmp2;
  98
  99         DEBUG(2, ("scavenger: %s parent %s died\n",
 100                   server_id_str_buf(*state->scavenger_id, &tmp1),
 101                   server_id_str_buf(state->parent_id, &tmp2)));
 102
 103         exit_server("smbd_scavenger_parent_dead");
 104 }
 105
 106 static void scavenger_sig_term_handler(struct tevent_context *ev,
 107                                        struct tevent_signal *se,
 108                                        int signum,
 109                                        int count,
 110                                        void *siginfo,
 111                                        void *private_data)
 112 {
 113         exit_server_cleanly("termination signal");
 114 }
 115
 116 static void scavenger_setup_sig_term_handler(struct tevent_context *ev_ctx)
 117 {
 118         struct tevent_signal *se;
 119
 120         se = tevent_add_signal(ev_ctx,
 121                                ev_ctx,
 122                                SIGTERM, 0,
 123                                scavenger_sig_term_handler,
 124                                NULL);
 125         if (se == NULL) {
 126                 exit_server("failed to setup SIGTERM handler");
 127         }
 128 }
 129
 130 static bool smbd_scavenger_running(struct smbd_scavenger_state *state)
 131 {
 132         if (state->scavenger_id == NULL) {
 133                 return false;
 134         }
 135
 136         return serverid_exists(state->scavenger_id);
 137 }
 138
 139 static int smbd_scavenger_server_id_destructor(struct server_id *id)
 140 {
 141         return 0;
 142 }
 143
 144 static bool scavenger_say_hello(int fd, struct server_id self)
 145 {
 146         ssize_t ret;
 147         struct server_id_buf tmp;
 148
 149         ret = write_data(fd, &self, sizeof(self));
 150         if (ret == -1) {
 151                 DEBUG(2, ("Failed to write to pipe: %s\n", strerror(errno)));
 152                 return false;
 153         }
 154         if (ret < sizeof(self)) {
 155                 DBG_WARNING("Could not write serverid\n");
 156                 return false;
 157         }
 158
 159         DEBUG(4, ("scavenger_say_hello: self[%s]\n",
 160                   server_id_str_buf(self, &tmp)));
 161         return true;
 162 }
 163
 164 static bool scavenger_wait_hello(int fd, struct server_id *child)
 165 {
 166         struct server_id_buf tmp;
 167         ssize_t ret;
 168
 169         ret = read_data(fd, child, sizeof(struct server_id));
 170         if (ret == -1) {
 171                 DEBUG(2, ("Failed to read from pipe: %s\n",
 172                           strerror(errno)));
 173                 return false;
 174         }
 175         if (ret < sizeof(struct server_id)) {
 176                 DBG_WARNING("Could not read serverid\n");
 177                 return false;
 178         }
 179
 180         DEBUG(4, ("scavenger_say_hello: child[%s]\n",
 181                   server_id_str_buf(*child, &tmp)));
 182         return true;
 183 }
 184
 185 static bool smbd_scavenger_start(struct smbd_scavenger_state *state)
 186 {
 187         struct server_id self = messaging_server_id(state->msg);
 188         struct tevent_fd *fde = NULL;
 189         int fds[2];
 190         int ret;
 191         bool ok;
 192
 193         SMB_ASSERT(server_id_equal(&state->parent_id, &self));
 194
 195         if (smbd_scavenger_running(state)) {
 196                 struct server_id_buf tmp;
 197                 DEBUG(10, ("scavenger %s already running\n",
 198                            server_id_str_buf(*state->scavenger_id,
 199                                              &tmp)));
 200                 return true;
 201         }
 202
 203         if (state->scavenger_id != NULL) {
 204                 struct server_id_buf tmp;
 205                 DEBUG(10, ("scavenger zombie %s, cleaning up\n",
 206                            server_id_str_buf(*state->scavenger_id,
 207                                              &tmp)));
 208                 TALLOC_FREE(state->scavenger_id);
 209         }
 210
 211         state->scavenger_id = talloc_zero(state, struct server_id);
 212         if (state->scavenger_id == NULL) {
 213                 DEBUG(2, ("Out of memory\n"));
 214                 goto fail;
 215         }
 216         talloc_set_destructor(state->scavenger_id,
 217                               smbd_scavenger_server_id_destructor);
 218
 219         ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
 220         if (ret == -1) {
 221                 DEBUG(2, ("socketpair failed: %s", strerror(errno)));
 222                 goto fail;
 223         }
 224
 225         smb_set_close_on_exec(fds[0]);
 226         smb_set_close_on_exec(fds[1]);
 227
 228         ret = fork();
 229         if (ret == -1) {
 230                 int err = errno;
 231                 close(fds[0]);
 232                 close(fds[1]);
 233                 DEBUG(0, ("fork failed: %s", strerror(err)));
 234                 goto fail;
 235         }
 236
 237         if (ret == 0) {
 238                 /* child */
 239
 240                 NTSTATUS status;
 241
 242                 close(fds[0]);
 243
 244                 status = smbd_reinit_after_fork(state->msg, state->ev,
 245                                                 true, "smbd-scavenger");
 246                 if (!NT_STATUS_IS_OK(status)) {
 247                         DEBUG(2, ("reinit_after_fork failed: %s\n",
 248                                   nt_errstr(status)));
 249                         exit_server("reinit_after_fork failed");
 250                         return false;
 251                 }
 252
 253                 reopen_logs();
 254
 255                 state->am_scavenger = true;
 256                 *state->scavenger_id = messaging_server_id(state->msg);
 257
 258                 scavenger_setup_sig_term_handler(state->ev);
 259
 260                 ok = scavenger_say_hello(fds[1], *state->scavenger_id);
 261                 if (!ok) {
 262                         DEBUG(2, ("scavenger_say_hello failed\n"));
 263                         exit_server("scavenger_say_hello failed");
 264                         return false;
 265                 }
 266
 267                 fde = tevent_add_fd(state->ev, state->scavenger_id,
 268                                     fds[1], TEVENT_FD_READ,
 269                                     smbd_scavenger_parent_dead, state);
 270                 if (fde == NULL) {
 271                         DEBUG(2, ("tevent_add_fd(smbd_scavenger_parent_dead) "
 272                                   "failed\n"));
 273                         exit_server("tevent_add_fd(smbd_scavenger_parent_dead) "
 274                                     "failed");
 275                         return false;
 276                 }
 277                 tevent_fd_set_auto_close(fde);
 278
 279                 ret = smbd_scavenger_main(state);
 280
 281                 DEBUG(10, ("scavenger ended: %d\n", ret));
 282                 exit_server_cleanly("scavenger ended");
 283                 return false;
 284         }
 285
 286         /* parent */
 287         close(fds[1]);
 288
 289         ok = scavenger_wait_hello(fds[0], state->scavenger_id);
 290         if (!ok) {
 291                 close(fds[0]);
 292                 goto fail;
 293         }
 294
 295         fde = tevent_add_fd(state->ev, state->scavenger_id,
 296                             fds[0], TEVENT_FD_READ,
 297                             smbd_scavenger_done, state);
 298         if (fde == NULL) {
 299                 close(fds[0]);
 300                 goto fail;
 301         }
 302         tevent_fd_set_auto_close(fde);
 303
 304         return true;
 305 fail:
 306         TALLOC_FREE(state->scavenger_id);
 307         return false;
 308 }
 309
 310 static void scavenger_add_timer(struct smbd_scavenger_state *state,
 311                                 struct scavenger_message *msg);
 312
 313 static void smbd_scavenger_msg(struct messaging_context *msg_ctx,
 314                                void *private_data,
 315                                uint32_t msg_type,
 316                                struct server_id src,
 317                                DATA_BLOB *data)
 318 {
 319         struct smbd_scavenger_state *state =
 320                 talloc_get_type_abort(private_data,
 321                                       struct smbd_scavenger_state);
 322         TALLOC_CTX *frame = talloc_stackframe();
 323         struct server_id self = messaging_server_id(msg_ctx);
 324         struct scavenger_message *msg = NULL;
 325         struct server_id_buf tmp1, tmp2;
 326
 327         DEBUG(10, ("smbd_scavenger_msg: %s got message from %s\n",
 328                    server_id_str_buf(self, &tmp1),
 329                    server_id_str_buf(src, &tmp2)));
 330
 331         if (server_id_equal(&state->parent_id, &self)) {
 332                 NTSTATUS status;
 333
 334                 if (!smbd_scavenger_running(state) &&
 335                     !smbd_scavenger_start(state))
 336                 {
 337                         DEBUG(2, ("Failed to start scavenger\n"));
 338                         goto done;
 339                 }
 340                 DEBUG(10, ("forwarding message to scavenger\n"));
 341
 342                 status = messaging_send(msg_ctx,
 343                                         *state->scavenger_id, msg_type, data);
 344                 if (!NT_STATUS_IS_OK(status)) {
 345                         DEBUG(2, ("forwarding message to scavenger failed: "
 346                                   "%s\n", nt_errstr(status)));
 347                         goto done;
 348                 }
 349                 goto done;
 350         }
 351
 352         if (!state->am_scavenger) {
 353                 DEBUG(10, ("im not the scavenger: ignore message\n"));
 354                 goto done;
 355         }
 356
 357         if (!server_id_equal(&state->parent_id, &src)) {
 358                 DEBUG(10, ("scavenger: ignore spurious message\n"));
 359                 goto done;
 360         }
 361
 362         DEBUG(10, ("scavenger: got a message\n"));
 363         msg = (struct scavenger_message*)data->data;
 364         scavenger_add_timer(state, msg);
 365 done:
 366         talloc_free(frame);
 367 }
 368
 369 bool smbd_scavenger_init(TALLOC_CTX *mem_ctx,
 370                          struct messaging_context *msg,
 371                          struct tevent_context *ev)
 372 {
 373         struct smbd_scavenger_state *state;
 374         NTSTATUS status;
 375
 376         if (smbd_scavenger_state) {
 377                 DEBUG(10, ("smbd_scavenger_init called again\n"));
 378                 return true;
 379         }
 380
 381         state = talloc_zero(mem_ctx, struct smbd_scavenger_state);
 382         if (state == NULL) {
 383                 DEBUG(2, ("Out of memory\n"));
 384                 return false;
 385         }
 386
 387         state->msg = msg;
 388         state->ev = ev;
 389         state->parent_id = messaging_server_id(msg);
 390
 391         status = messaging_register(msg, state, MSG_SMB_SCAVENGER,
 392                                     smbd_scavenger_msg);
 393         if (!NT_STATUS_IS_OK(status)) {
 394                 DEBUG(2, ("failed to register message handler: %s\n",
 395                           nt_errstr(status)));
 396                 goto fail;
 397         }
 398
 399         smbd_scavenger_state = state;
 400         return true;
 401 fail:
 402         talloc_free(state);
 403         return false;
 404 }
 405
 406 void scavenger_schedule_disconnected(struct files_struct *fsp)
 407 {
 408         NTSTATUS status;
 409         struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
 410         struct timeval disconnect_time, until;
 411         uint64_t timeout_usec;
 412         struct scavenger_message msg;
 413         DATA_BLOB msg_blob;
 414         struct server_id_buf tmp;
 415         struct file_id_buf idbuf;
 416
 417         if (fsp->op == NULL) {
 418                 return;
 419         }
 420         nttime_to_timeval(&disconnect_time, fsp->op->global->disconnect_time);
 421         timeout_usec = 1000 * fsp->op->global->durable_timeout_msec;
 422         until = timeval_add(&disconnect_time,
 423                             timeout_usec / 1000000,
 424                             timeout_usec % 1000000);
 425
 426         ZERO_STRUCT(msg);
 427         msg.file_id = fsp->file_id;
 428         msg.open_persistent_id = fsp->op->global->open_persistent_id;
 429         msg.until = timeval_to_nttime(&until);
 430
 431         DEBUG(10, ("smbd: %s mark file %s as disconnected at %s with timeout "
 432                    "at %s in %fs\n",
 433                    server_id_str_buf(self, &tmp),
 434                    file_id_str_buf(fsp->file_id, &idbuf),
 435                    timeval_string(talloc_tos(), &disconnect_time, true),
 436                    timeval_string(talloc_tos(), &until, true),
 437                    fsp->op->global->durable_timeout_msec/1000.0));
 438
 439         SMB_ASSERT(server_id_is_disconnected(&fsp->op->global->server_id));
 440         SMB_ASSERT(!server_id_equal(&self, &smbd_scavenger_state->parent_id));
 441         SMB_ASSERT(!smbd_scavenger_state->am_scavenger);
 442
 443         msg_blob = data_blob_const(&msg, sizeof(msg));
 444         DEBUG(10, ("send message to scavenger\n"));
 445
 446         status = messaging_send(smbd_scavenger_state->msg,
 447                                 smbd_scavenger_state->parent_id,
 448                                 MSG_SMB_SCAVENGER,
 449                                 &msg_blob);
 450         if (!NT_STATUS_IS_OK(status)) {
 451                 struct server_id_buf tmp1, tmp2;
 452                 DEBUG(2, ("Failed to send message to parent smbd %s "
 453                           "from %s: %s\n",
 454                           server_id_str_buf(smbd_scavenger_state->parent_id,
 455                                             &tmp1),
 456                           server_id_str_buf(self, &tmp2),
 457                           nt_errstr(status)));
 458         }
 459 }
 460
 461 struct scavenger_timer_context {
 462         struct smbd_scavenger_state *state;
 463         struct scavenger_message msg;
 464 };
 465
 466 static void scavenger_timer(struct tevent_context *ev,
 467                             struct tevent_timer *te,
 468                             struct timeval t, void *data)
 469 {
 470         struct scavenger_timer_context *ctx =
 471                 talloc_get_type_abort(data, struct scavenger_timer_context);
 472         struct file_id_buf idbuf;
 473         NTSTATUS status;
 474         bool ok;
 475
 476         DBG_DEBUG("do cleanup for file %s at %s\n",
 477                   file_id_str_buf(ctx->msg.file_id, &idbuf),
 478                   timeval_string(talloc_tos(), &t, true));
 479
 480         ok = share_mode_cleanup_disconnected(ctx->msg.file_id,
 481                                              ctx->msg.open_persistent_id);
 482         if (!ok) {
 483                 DBG_WARNING("Failed to cleanup share modes and byte range "
 484                             "locks for file %s open %"PRIu64"\n",
 485                             file_id_str_buf(ctx->msg.file_id, &idbuf),
 486                             ctx->msg.open_persistent_id);
 487         }
 488
 489         status = smbXsrv_open_cleanup(ctx->msg.open_persistent_id);
 490         if (!NT_STATUS_IS_OK(status)) {
 491                 DBG_WARNING("Failed to cleanup open global for file %s open "
 492                             "%"PRIu64": %s\n",
 493                             file_id_str_buf(ctx->msg.file_id, &idbuf),
 494                             ctx->msg.open_persistent_id,
 495                             nt_errstr(status));
 496         }
 497 }
 498
 499 static void scavenger_add_timer(struct smbd_scavenger_state *state,
 500                                 struct scavenger_message *msg)
 501 {
 502         struct tevent_timer *te;
 503         struct scavenger_timer_context *ctx;
 504         struct timeval until;
 505         struct file_id_buf idbuf;
 506
 507         nttime_to_timeval(&until, msg->until);
 508
 509         DBG_DEBUG("schedule file %s for cleanup at %s\n",
 510                   file_id_str_buf(msg->file_id, &idbuf),
 511                   timeval_string(talloc_tos(), &until, true));
 512
 513         ctx = talloc_zero(state, struct scavenger_timer_context);
 514         if (ctx == NULL) {
 515                 DEBUG(2, ("Failed to talloc_zero(scavenger_timer_context)\n"));
 516                 return;
 517         }
 518
 519         ctx->state = state;
 520         ctx->msg = *msg;
 521
 522         te = tevent_add_timer(state->ev,
 523                               state,
 524                               until,
 525                               scavenger_timer,
 526                               ctx);
 527         if (te == NULL) {
 528                 DEBUG(2, ("Failed to add scavenger_timer event\n"));
 529                 talloc_free(ctx);
 530                 return;
 531         }
 532
 533         /* delete context after handler was running */
 534         talloc_steal(te, ctx);
 535 }