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                 state->am_scavenger = true;
 254                 *state->scavenger_id = messaging_server_id(state->msg);
 255
 256                 scavenger_setup_sig_term_handler(state->ev);
 257
 258                 ok = scavenger_say_hello(fds[1], *state->scavenger_id);
 259                 if (!ok) {
 260                         DEBUG(2, ("scavenger_say_hello failed\n"));
 261                         exit_server("scavenger_say_hello failed");
 262                         return false;
 263                 }
 264
 265                 fde = tevent_add_fd(state->ev, state->scavenger_id,
 266                                     fds[1], TEVENT_FD_READ,
 267                                     smbd_scavenger_parent_dead, state);
 268                 if (fde == NULL) {
 269                         DEBUG(2, ("tevent_add_fd(smbd_scavenger_parent_dead) "
 270                                   "failed\n"));
 271                         exit_server("tevent_add_fd(smbd_scavenger_parent_dead) "
 272                                     "failed");
 273                         return false;
 274                 }
 275                 tevent_fd_set_auto_close(fde);
 276
 277                 ret = smbd_scavenger_main(state);
 278
 279                 DEBUG(10, ("scavenger ended: %d\n", ret));
 280                 exit_server_cleanly("scavenger ended");
 281                 return false;
 282         }
 283
 284         /* parent */
 285         close(fds[1]);
 286
 287         ok = scavenger_wait_hello(fds[0], state->scavenger_id);
 288         if (!ok) {
 289                 close(fds[0]);
 290                 goto fail;
 291         }
 292
 293         fde = tevent_add_fd(state->ev, state->scavenger_id,
 294                             fds[0], TEVENT_FD_READ,
 295                             smbd_scavenger_done, state);
 296         if (fde == NULL) {
 297                 close(fds[0]);
 298                 goto fail;
 299         }
 300         tevent_fd_set_auto_close(fde);
 301
 302         return true;
 303 fail:
 304         TALLOC_FREE(state->scavenger_id);
 305         return false;
 306 }
 307
 308 static void scavenger_add_timer(struct smbd_scavenger_state *state,
 309                                 struct scavenger_message *msg);
 310
 311 static void smbd_scavenger_msg(struct messaging_context *msg_ctx,
 312                                void *private_data,
 313                                uint32_t msg_type,
 314                                struct server_id src,
 315                                DATA_BLOB *data)
 316 {
 317         struct smbd_scavenger_state *state =
 318                 talloc_get_type_abort(private_data,
 319                                       struct smbd_scavenger_state);
 320         TALLOC_CTX *frame = talloc_stackframe();
 321         struct server_id self = messaging_server_id(msg_ctx);
 322         struct scavenger_message *msg = NULL;
 323         struct server_id_buf tmp1, tmp2;
 324
 325         DEBUG(10, ("smbd_scavenger_msg: %s got message from %s\n",
 326                    server_id_str_buf(self, &tmp1),
 327                    server_id_str_buf(src, &tmp2)));
 328
 329         if (server_id_equal(&state->parent_id, &self)) {
 330                 NTSTATUS status;
 331
 332                 if (!smbd_scavenger_running(state) &&
 333                     !smbd_scavenger_start(state))
 334                 {
 335                         DEBUG(2, ("Failed to start scavenger\n"));
 336                         goto done;
 337                 }
 338                 DEBUG(10, ("forwarding message to scavenger\n"));
 339
 340                 status = messaging_send(msg_ctx,
 341                                         *state->scavenger_id, msg_type, data);
 342                 if (!NT_STATUS_IS_OK(status)) {
 343                         DEBUG(2, ("forwarding message to scavenger failed: "
 344                                   "%s\n", nt_errstr(status)));
 345                         goto done;
 346                 }
 347                 goto done;
 348         }
 349
 350         if (!state->am_scavenger) {
 351                 DEBUG(10, ("im not the scavenger: ignore message\n"));
 352                 goto done;
 353         }
 354
 355         if (!server_id_equal(&state->parent_id, &src)) {
 356                 DEBUG(10, ("scavenger: ignore spurious message\n"));
 357                 goto done;
 358         }
 359
 360         DEBUG(10, ("scavenger: got a message\n"));
 361         msg = (struct scavenger_message*)data->data;
 362         scavenger_add_timer(state, msg);
 363 done:
 364         talloc_free(frame);
 365 }
 366
 367 bool smbd_scavenger_init(TALLOC_CTX *mem_ctx,
 368                          struct messaging_context *msg,
 369                          struct tevent_context *ev)
 370 {
 371         struct smbd_scavenger_state *state;
 372         NTSTATUS status;
 373
 374         if (smbd_scavenger_state) {
 375                 DEBUG(10, ("smbd_scavenger_init called again\n"));
 376                 return true;
 377         }
 378
 379         state = talloc_zero(mem_ctx, struct smbd_scavenger_state);
 380         if (state == NULL) {
 381                 DEBUG(2, ("Out of memory\n"));
 382                 return false;
 383         }
 384
 385         state->msg = msg;
 386         state->ev = ev;
 387         state->parent_id = messaging_server_id(msg);
 388
 389         status = messaging_register(msg, state, MSG_SMB_SCAVENGER,
 390                                     smbd_scavenger_msg);
 391         if (!NT_STATUS_IS_OK(status)) {
 392                 DEBUG(2, ("failed to register message handler: %s\n",
 393                           nt_errstr(status)));
 394                 goto fail;
 395         }
 396
 397         smbd_scavenger_state = state;
 398         return true;
 399 fail:
 400         talloc_free(state);
 401         return false;
 402 }
 403
 404 void scavenger_schedule_disconnected(struct files_struct *fsp)
 405 {
 406         NTSTATUS status;
 407         struct server_id self = messaging_server_id(fsp->conn->sconn->msg_ctx);
 408         struct timeval disconnect_time, until;
 409         uint64_t timeout_usec;
 410         struct scavenger_message msg;
 411         DATA_BLOB msg_blob;
 412         struct server_id_buf tmp;
 413
 414         if (fsp->op == NULL) {
 415                 return;
 416         }
 417         nttime_to_timeval(&disconnect_time, fsp->op->global->disconnect_time);
 418         timeout_usec = 1000 * fsp->op->global->durable_timeout_msec;
 419         until = timeval_add(&disconnect_time,
 420                             timeout_usec / 1000000,
 421                             timeout_usec % 1000000);
 422
 423         ZERO_STRUCT(msg);
 424         msg.file_id = fsp->file_id;
 425         msg.open_persistent_id = fsp->op->global->open_persistent_id;
 426         msg.until = timeval_to_nttime(&until);
 427
 428         DEBUG(10, ("smbd: %s mark file %s as disconnected at %s with timeout "
 429                    "at %s in %fs\n",
 430                    server_id_str_buf(self, &tmp),
 431                    file_id_string_tos(&fsp->file_id),
 432                    timeval_string(talloc_tos(), &disconnect_time, true),
 433                    timeval_string(talloc_tos(), &until, true),
 434                    fsp->op->global->durable_timeout_msec/1000.0));
 435
 436         SMB_ASSERT(server_id_is_disconnected(&fsp->op->global->server_id));
 437         SMB_ASSERT(!server_id_equal(&self, &smbd_scavenger_state->parent_id));
 438         SMB_ASSERT(!smbd_scavenger_state->am_scavenger);
 439
 440         msg_blob = data_blob_const(&msg, sizeof(msg));
 441         DEBUG(10, ("send message to scavenger\n"));
 442
 443         status = messaging_send(smbd_scavenger_state->msg,
 444                                 smbd_scavenger_state->parent_id,
 445                                 MSG_SMB_SCAVENGER,
 446                                 &msg_blob);
 447         if (!NT_STATUS_IS_OK(status)) {
 448                 struct server_id_buf tmp1, tmp2;
 449                 DEBUG(2, ("Failed to send message to parent smbd %s "
 450                           "from %s: %s\n",
 451                           server_id_str_buf(smbd_scavenger_state->parent_id,
 452                                             &tmp1),
 453                           server_id_str_buf(self, &tmp2),
 454                           nt_errstr(status)));
 455         }
 456 }
 457
 458 struct scavenger_timer_context {
 459         struct smbd_scavenger_state *state;
 460         struct scavenger_message msg;
 461 };
 462
 463 static void scavenger_timer(struct tevent_context *ev,
 464                             struct tevent_timer *te,
 465                             struct timeval t, void *data)
 466 {
 467         struct scavenger_timer_context *ctx =
 468                 talloc_get_type_abort(data, struct scavenger_timer_context);
 469         NTSTATUS status;
 470         bool ok;
 471
 472         DEBUG(10, ("scavenger: do cleanup for file %s at %s\n",
 473                   file_id_string_tos(&ctx->msg.file_id),
 474                   timeval_string(talloc_tos(), &t, true)));
 475
 476         ok = share_mode_cleanup_disconnected(ctx->msg.file_id,
 477                                              ctx->msg.open_persistent_id);
 478         if (!ok) {
 479                 DEBUG(2, ("Failed to cleanup share modes and byte range locks "
 480                           "for file %s open %llu\n",
 481                           file_id_string_tos(&ctx->msg.file_id),
 482                           (unsigned long long)ctx->msg.open_persistent_id));
 483         }
 484
 485         status = smbXsrv_open_cleanup(ctx->msg.open_persistent_id);
 486         if (!NT_STATUS_IS_OK(status)) {
 487                 DEBUG(2, ("Failed to cleanup open global for file %s open %llu:"
 488                           " %s\n", file_id_string_tos(&ctx->msg.file_id),
 489                           (unsigned long long)ctx->msg.open_persistent_id,
 490                           nt_errstr(status)));
 491         }
 492 }
 493
 494 static void scavenger_add_timer(struct smbd_scavenger_state *state,
 495                                 struct scavenger_message *msg)
 496 {
 497         struct tevent_timer *te;
 498         struct scavenger_timer_context *ctx;
 499         struct timeval until;
 500
 501         nttime_to_timeval(&until, msg->until);
 502
 503         DEBUG(10, ("scavenger: schedule file %s for cleanup at %s\n",
 504                    file_id_string_tos(&msg->file_id),
 505                    timeval_string(talloc_tos(), &until, true)));
 506
 507         ctx = talloc_zero(state, struct scavenger_timer_context);
 508         if (ctx == NULL) {
 509                 DEBUG(2, ("Failed to talloc_zero(scavenger_timer_context)\n"));
 510                 return;
 511         }
 512
 513         ctx->state = state;
 514         ctx->msg = *msg;
 515
 516         te = tevent_add_timer(state->ev,
 517                               state,
 518                               until,
 519                               scavenger_timer,
 520                               ctx);
 521         if (te == NULL) {
 522                 DEBUG(2, ("Failed to add scavenger_timer event\n"));
 523                 talloc_free(ctx);
 524                 return;
 525         }
 526
 527         /* delete context after handler was running */
 528         talloc_steal(te, ctx);
 529 }