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         serverid_deregister(*id);
 142         return 0;
 143 }
 144
 145 static bool scavenger_say_hello(int fd, struct server_id self)
 146 {
 147         ssize_t ret;
 148         struct server_id_buf tmp;
 149
 150         ret = write_data(fd, &self, sizeof(self));
 151         if (ret == -1) {
 152                 DEBUG(2, ("Failed to write to pipe: %s\n", strerror(errno)));
 153                 return false;
 154         }
 155         if (ret < sizeof(self)) {
 156                 DBG_WARNING("Could not write serverid\n");
 157                 return false;
 158         }
 159
 160         DEBUG(4, ("scavenger_say_hello: self[%s]\n",
 161                   server_id_str_buf(self, &tmp)));
 162         return true;
 163 }
 164
 165 static bool scavenger_wait_hello(int fd, struct server_id *child)
 166 {
 167         struct server_id_buf tmp;
 168         ssize_t ret;
 169
 170         ret = read_data(fd, child, sizeof(struct server_id));
 171         if (ret == -1) {
 172                 DEBUG(2, ("Failed to read from pipe: %s\n",
 173                           strerror(errno)));
 174                 return false;
 175         }
 176         if (ret < sizeof(struct server_id)) {
 177                 DBG_WARNING("Could not read serverid\n");
 178                 return false;
 179         }
 180
 181         DEBUG(4, ("scavenger_say_hello: child[%s]\n",
 182                   server_id_str_buf(*child, &tmp)));
 183         return true;
 184 }
 185
 186 static bool smbd_scavenger_start(struct smbd_scavenger_state *state)
 187 {
 188         struct server_id self = messaging_server_id(state->msg);
 189         struct tevent_fd *fde = NULL;
 190         int fds[2];
 191         int ret;
 192         bool ok;
 193
 194         SMB_ASSERT(server_id_equal(&state->parent_id, &self));
 195
 196         if (smbd_scavenger_running(state)) {
 197                 struct server_id_buf tmp;
 198                 DEBUG(10, ("scavenger %s already running\n",
 199                            server_id_str_buf(*state->scavenger_id,
 200                                              &tmp)));
 201                 return true;
 202         }
 203
 204         if (state->scavenger_id != NULL) {
 205                 struct server_id_buf tmp;
 206                 DEBUG(10, ("scavenger zombie %s, cleaning up\n",
 207                            server_id_str_buf(*state->scavenger_id,
 208                                              &tmp)));
 209                 TALLOC_FREE(state->scavenger_id);
 210         }
 211
 212         state->scavenger_id = talloc_zero(state, struct server_id);
 213         if (state->scavenger_id == NULL) {
 214                 DEBUG(2, ("Out of memory\n"));
 215                 goto fail;
 216         }
 217         talloc_set_destructor(state->scavenger_id,
 218                               smbd_scavenger_server_id_destructor);
 219
 220         ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
 221         if (ret == -1) {
 222                 DEBUG(2, ("socketpair failed: %s", strerror(errno)));
 223                 goto fail;
 224         }
 225
 226         smb_set_close_on_exec(fds[0]);
 227         smb_set_close_on_exec(fds[1]);
 228
 229         ret = fork();
 230         if (ret == -1) {
 231                 int err = errno;
 232                 close(fds[0]);
 233                 close(fds[1]);
 234                 DEBUG(0, ("fork failed: %s", strerror(err)));
 235                 goto fail;
 236         }
 237
 238         if (ret == 0) {
 239                 /* child */
 240
 241                 NTSTATUS status;
 242
 243                 close(fds[0]);
 244
 245                 status = smbd_reinit_after_fork(state->msg, state->ev,
 246                                                 true, "smbd-scavenger");
 247                 if (!NT_STATUS_IS_OK(status)) {
 248                         DEBUG(2, ("reinit_after_fork failed: %s\n",
 249                                   nt_errstr(status)));
 250                         exit_server("reinit_after_fork failed");
 251                         return false;
 252                 }
 253
 254                 state->am_scavenger = true;
 255                 *state->scavenger_id = messaging_server_id(state->msg);
 256
 257                 scavenger_setup_sig_term_handler(state->ev);
 258
 259                 if (!serverid_register(*state->scavenger_id,
 260                                        FLAG_MSG_GENERAL)) {
 261                         DBG_WARNING("serverid_register failed");
 262                         exit_server("serverid_register failed");
 263                         return false;
 264                 }
 265
 266                 ok = scavenger_say_hello(fds[1], *state->scavenger_id);
 267                 if (!ok) {
 268                         DEBUG(2, ("scavenger_say_hello failed\n"));
 269                         exit_server("scavenger_say_hello failed");
 270                         return false;
 271                 }
 272
 273                 fde = tevent_add_fd(state->ev, state->scavenger_id,
 274                                     fds[1], TEVENT_FD_READ,
 275                                     smbd_scavenger_parent_dead, state);
 276                 if (fde == NULL) {
 277                         DEBUG(2, ("tevent_add_fd(smbd_scavenger_parent_dead) "
 278                                   "failed\n"));
 279                         exit_server("tevent_add_fd(smbd_scavenger_parent_dead) "
 280                                     "failed");
 281                         return false;
 282                 }
 283                 tevent_fd_set_auto_close(fde);
 284
 285                 ret = smbd_scavenger_main(state);
 286
 287                 DEBUG(10, ("scavenger ended: %d\n", ret));
 288                 exit_server_cleanly("scavenger ended");
 289                 return false;
 290         }
 291
 292         /* parent */
 293         close(fds[1]);
 294
 295         ok = scavenger_wait_hello(fds[0], state->scavenger_id);
 296         if (!ok) {
 297                 close(fds[0]);
 298                 goto fail;
 299         }
 300
 301         fde = tevent_add_fd(state->ev, state->scavenger_id,
 302                             fds[0], TEVENT_FD_READ,
 303                             smbd_scavenger_done, state);
 304         if (fde == NULL) {
 305                 close(fds[0]);
 306                 goto fail;
 307         }
 308         tevent_fd_set_auto_close(fde);
 309
 310         return true;
 311 fail:
 312         TALLOC_FREE(state->scavenger_id);
 313         return false;
 314 }
 315
 316 static void scavenger_add_timer(struct smbd_scavenger_state *state,
 317                                 struct scavenger_message *msg);
 318
 319 static void smbd_scavenger_msg(struct messaging_context *msg_ctx,
 320                                void *private_data,
 321                                uint32_t msg_type,
 322                                struct server_id src,
 323                                DATA_BLOB *data)
 324 {
 325         struct smbd_scavenger_state *state =
 326                 talloc_get_type_abort(private_data,
 327                                       struct smbd_scavenger_state);
 328         TALLOC_CTX *frame = talloc_stackframe();
 329         struct server_id self = messaging_server_id(msg_ctx);
 330         struct scavenger_message *msg = NULL;
 331         struct server_id_buf tmp1, tmp2;
 332
 333         DEBUG(10, ("smbd_scavenger_msg: %s got message from %s\n",
 334                    server_id_str_buf(self, &tmp1),
 335                    server_id_str_buf(src, &tmp2)));
 336
 337         if (server_id_equal(&state->parent_id, &self)) {
 338                 NTSTATUS status;
 339
 340                 if (!smbd_scavenger_running(state) &&
 341                     !smbd_scavenger_start(state))
 342                 {
 343                         DEBUG(2, ("Failed to start scavenger\n"));
 344                         goto done;
 345                 }
 346                 DEBUG(10, ("forwarding message to scavenger\n"));
 347
 348                 status = messaging_send(msg_ctx,
 349                                         *state->scavenger_id, msg_type, data);
 350                 if (!NT_STATUS_IS_OK(status)) {
 351                         DEBUG(2, ("forwarding message to scavenger failed: "
 352                                   "%s\n", nt_errstr(status)));
 353                         goto done;
 354                 }
 355                 goto done;
 356         }
 357
 358         if (!state->am_scavenger) {
 359                 DEBUG(10, ("im not the scavenger: ignore message\n"));
 360                 goto done;
 361         }
 362
 363         if (!server_id_equal(&state->parent_id, &src)) {
 364                 DEBUG(10, ("scavenger: ignore spurious message\n"));
 365                 goto done;
 366         }
 367
 368         DEBUG(10, ("scavenger: got a message\n"));
 369         msg = (struct scavenger_message*)data->data;
 370         scavenger_add_timer(state, msg);
 371 done:
 372         talloc_free(frame);
 373 }
 374
 375 bool smbd_scavenger_init(TALLOC_CTX *mem_ctx,
 376                          struct messaging_context *msg,
 377                          struct tevent_context *ev)
 378 {
 379         struct smbd_scavenger_state *state;
 380         NTSTATUS status;
 381
 382         if (smbd_scavenger_state) {
 383                 DEBUG(10, ("smbd_scavenger_init called again\n"));
 384                 return true;
 385         }
 386
 387         state = talloc_zero(mem_ctx, struct smbd_scavenger_state);
 388         if (state == NULL) {
 389                 DEBUG(2, ("Out of memory\n"));
 390                 return false;
 391         }
 392
 393         state->msg = msg;
 394         state->ev = ev;
 395         state->parent_id = messaging_server_id(msg);
 396
 397         status = messaging_register(msg, state, MSG_SMB_SCAVENGER,
 398                                     smbd_scavenger_msg);
 399         if (!NT_STATUS_IS_OK(status)) {
 400                 DEBUG(2, ("failed to register message handler: %s\n",
 401                           nt_errstr(status)));
 402                 goto fail;
 403         }
 404
 405         smbd_scavenger_state = state;
 406         return true;
 407 fail:
 408         talloc_free(state);
 409         return false;
 410 }
 411
 412 void scavenger_schedule_disconnected(struct files_struct *fsp)
 413 {
 414         NTSTATUS status;
 415         struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
 416         struct timeval disconnect_time, until;
 417         uint64_t timeout_usec;
 418         struct scavenger_message msg;
 419         DATA_BLOB msg_blob;
 420         struct server_id_buf tmp;
 421
 422         if (fsp->op == NULL) {
 423                 return;
 424         }
 425         nttime_to_timeval(&disconnect_time, fsp->op->global->disconnect_time);
 426         timeout_usec = 1000 * fsp->op->global->durable_timeout_msec;
 427         until = timeval_add(&disconnect_time,
 428                             timeout_usec / 1000000,
 429                             timeout_usec % 1000000);
 430
 431         ZERO_STRUCT(msg);
 432         msg.file_id = fsp->file_id;
 433         msg.open_persistent_id = fsp->op->global->open_persistent_id;
 434         msg.until = timeval_to_nttime(&until);
 435
 436         DEBUG(10, ("smbd: %s mark file %s as disconnected at %s with timeout "
 437                    "at %s in %fs\n",
 438                    server_id_str_buf(self, &tmp),
 439                    file_id_string_tos(&fsp->file_id),
 440                    timeval_string(talloc_tos(), &disconnect_time, true),
 441                    timeval_string(talloc_tos(), &until, true),
 442                    fsp->op->global->durable_timeout_msec/1000.0));
 443
 444         SMB_ASSERT(server_id_is_disconnected(&fsp->op->global->server_id));
 445         SMB_ASSERT(!server_id_equal(&self, &smbd_scavenger_state->parent_id));
 446         SMB_ASSERT(!smbd_scavenger_state->am_scavenger);
 447
 448         msg_blob = data_blob_const(&msg, sizeof(msg));
 449         DEBUG(10, ("send message to scavenger\n"));
 450
 451         status = messaging_send(smbd_scavenger_state->msg,
 452                                 smbd_scavenger_state->parent_id,
 453                                 MSG_SMB_SCAVENGER,
 454                                 &msg_blob);
 455         if (!NT_STATUS_IS_OK(status)) {
 456                 struct server_id_buf tmp1, tmp2;
 457                 DEBUG(2, ("Failed to send message to parent smbd %s "
 458                           "from %s: %s\n",
 459                           server_id_str_buf(smbd_scavenger_state->parent_id,
 460                                             &tmp1),
 461                           server_id_str_buf(self, &tmp2),
 462                           nt_errstr(status)));
 463         }
 464 }
 465
 466 struct scavenger_timer_context {
 467         struct smbd_scavenger_state *state;
 468         struct scavenger_message msg;
 469 };
 470
 471 static void scavenger_timer(struct tevent_context *ev,
 472                             struct tevent_timer *te,
 473                             struct timeval t, void *data)
 474 {
 475         struct scavenger_timer_context *ctx =
 476                 talloc_get_type_abort(data, struct scavenger_timer_context);
 477         NTSTATUS status;
 478         bool ok;
 479
 480         DEBUG(10, ("scavenger: do cleanup for file %s at %s\n",
 481                   file_id_string_tos(&ctx->msg.file_id),
 482                   timeval_string(talloc_tos(), &t, true)));
 483
 484         ok = share_mode_cleanup_disconnected(ctx->msg.file_id,
 485                                              ctx->msg.open_persistent_id);
 486         if (!ok) {
 487                 DEBUG(2, ("Failed to cleanup share modes and byte range locks "
 488                           "for file %s open %llu\n",
 489                           file_id_string_tos(&ctx->msg.file_id),
 490                           (unsigned long long)ctx->msg.open_persistent_id));
 491         }
 492
 493         status = smbXsrv_open_cleanup(ctx->msg.open_persistent_id);
 494         if (!NT_STATUS_IS_OK(status)) {
 495                 DEBUG(2, ("Failed to cleanup open global for file %s open %llu:"
 496                           " %s\n", file_id_string_tos(&ctx->msg.file_id),
 497                           (unsigned long long)ctx->msg.open_persistent_id,
 498                           nt_errstr(status)));
 499         }
 500 }
 501
 502 static void scavenger_add_timer(struct smbd_scavenger_state *state,
 503                                 struct scavenger_message *msg)
 504 {
 505         struct tevent_timer *te;
 506         struct scavenger_timer_context *ctx;
 507         struct timeval until;
 508
 509         nttime_to_timeval(&until, msg->until);
 510
 511         DEBUG(10, ("scavenger: schedule file %s for cleanup at %s\n",
 512                    file_id_string_tos(&msg->file_id),
 513                    timeval_string(talloc_tos(), &until, true)));
 514
 515         ctx = talloc_zero(state, struct scavenger_timer_context);
 516         if (ctx == NULL) {
 517                 DEBUG(2, ("Failed to talloc_zero(scavenger_timer_context)\n"));
 518                 return;
 519         }
 520
 521         ctx->state = state;
 522         ctx->msg = *msg;
 523
 524         te = tevent_add_timer(state->ev,
 525                               state,
 526                               until,
 527                               scavenger_timer,
 528                               ctx);
 529         if (te == NULL) {
 530                 DEBUG(2, ("Failed to add scavenger_timer event\n"));
 531                 talloc_free(ctx);
 532                 return;
 533         }
 534
 535         /* delete context after handler was running */
 536         talloc_steal(te, ctx);
 537 }