source4/smbd/process_thread.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    thread model: standard (1 thread per client connection)
   4    Copyright (C) Andrew Tridgell 2003
   5    Copyright (C) James J Myers 2003 <myersjj@samba.org>
   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 2 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, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22 #include "includes.h"
  23 #include "pthread.h"
  24 #ifdef HAVE_BACKTRACE
  25 #include "execinfo.h"
  26 #endif
  27
  28 static void *connection_thread(void *thread_parm)
  29 {
  30         struct event_context *ev = thread_parm;
  31         /* wait for action */
  32         event_loop_wait(ev);
  33
  34 #if 0
  35         pthread_cleanup_pop(1);  /* will invoke terminate_mt_connection() */
  36 #endif
  37         return NULL;
  38 }
  39
  40 static int get_id(struct request_context *req)
  41 {
  42         return (int)pthread_self();
  43 }
  44
  45 /*
  46   called when a listening socket becomes readable
  47 */
  48 static void accept_connection(struct event_context *ev, struct fd_event *fde,
  49                               time_t t, uint16_t flags)
  50 {
  51         int accepted_fd, rc;
  52         struct sockaddr addr;
  53         socklen_t in_addrlen = sizeof(addr);
  54         pthread_t thread_id;
  55         pthread_attr_t thread_attr;
  56         struct model_ops *model_ops = fde->private;
  57
  58         /* accept an incoming connection */
  59         accepted_fd = accept(fde->fd,&addr,&in_addrlen);
  60
  61         if (accepted_fd == -1) {
  62                 DEBUG(0,("accept_connection_thread: accept: %s\n",
  63                          strerror(errno)));
  64                 return;
  65         }
  66
  67         /* create new detached thread for this connection.  The new
  68            thread gets a new event_context with a single fd_event for
  69            receiving from the new socket. We set that thread running
  70            with the main event loop, then return. When we return the
  71            main event_context is continued.
  72         */
  73         ev = event_context_init();
  74         MUTEX_LOCK_BY_ID(MUTEX_SMBD);
  75         init_smbsession(ev, model_ops, accepted_fd, smbd_read_handler);
  76         MUTEX_UNLOCK_BY_ID(MUTEX_SMBD);
  77
  78         pthread_attr_init(&thread_attr);
  79         pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);
  80         rc = pthread_create(&thread_id, &thread_attr, &connection_thread, ev);
  81         pthread_attr_destroy(&thread_attr);
  82         if (rc == 0) {
  83                 DEBUG(4,("accept_connection_thread: created thread_id=%lu for fd=%d\n",
  84                         (unsigned long int)thread_id, accepted_fd));
  85         } else {
  86                 DEBUG(0,("accept_connection_thread: thread create failed for fd=%d, rc=%d\n", accepted_fd, rc));
  87         }
  88 }
  89
  90
  91 /*
  92   called when a rpc listening socket becomes readable
  93 */
  94 static void accept_rpc_connection(struct event_context *ev, struct fd_event *fde, time_t t, uint16_t flags)
  95 {
  96         int accepted_fd, rc;
  97         struct sockaddr addr;
  98         socklen_t in_addrlen = sizeof(addr);
  99         pthread_t thread_id;
 100         pthread_attr_t thread_attr;
 101
 102         /* accept an incoming connection */
 103         accepted_fd = accept(fde->fd,&addr,&in_addrlen);
 104
 105         if (accepted_fd == -1) {
 106                 DEBUG(0,("accept_connection_thread: accept: %s\n",
 107                          strerror(errno)));
 108                 return;
 109         }
 110
 111         ev = event_context_init();
 112         MUTEX_LOCK_BY_ID(MUTEX_SMBD);
 113         init_rpc_session(ev, fde->private, accepted_fd);
 114         MUTEX_UNLOCK_BY_ID(MUTEX_SMBD);
 115
 116         pthread_attr_init(&thread_attr);
 117         pthread_attr_setdetachstate(&thread_attr, PTHREAD_CREATE_DETACHED);
 118         rc = pthread_create(&thread_id, &thread_attr, &connection_thread, ev);
 119         pthread_attr_destroy(&thread_attr);
 120         if (rc == 0) {
 121                 DEBUG(4,("accept_connection_thread: created thread_id=%lu for fd=%d\n",
 122                         (unsigned long int)thread_id, accepted_fd));
 123         } else {
 124                 DEBUG(0,("accept_connection_thread: thread create failed for fd=%d, rc=%d\n", accepted_fd, rc));
 125         }
 126 }
 127
 128 /* called when a SMB connection goes down */
 129 static void terminate_connection(struct server_context *server, const char *reason)
 130 {
 131         server_terminate(server);
 132
 133         /* terminate this thread */
 134         pthread_exit(NULL);  /* thread cleanup routine will do actual cleanup */
 135 }
 136
 137 /* called when a rpc connection goes down */
 138 static void terminate_rpc_connection(void *r, const char *reason)
 139 {
 140         rpc_server_terminate(r);
 141
 142         /* terminate this thread */
 143         pthread_exit(NULL);  /* thread cleanup routine will do actual cleanup */
 144 }
 145
 146 /*
 147   mutex init function for thread model
 148 */
 149 static int thread_mutex_init(smb_mutex_t *mutex, const char *name)
 150 {
 151         pthread_mutex_t m = PTHREAD_MUTEX_INITIALIZER;
 152         mutex->mutex = memdup(&m, sizeof(m));
 153         if (! mutex->mutex) {
 154                 errno = ENOMEM;
 155                 return -1;
 156         }
 157         return pthread_mutex_init((pthread_mutex_t *)mutex->mutex, NULL);
 158 }
 159
 160 /*
 161   mutex destroy function for thread model
 162 */
 163 static int thread_mutex_destroy(smb_mutex_t *mutex, const char *name)
 164 {
 165         return pthread_mutex_destroy((pthread_mutex_t *)mutex->mutex);
 166 }
 167
 168 static void mutex_start_timer(struct timeval *tp1)
 169 {
 170         gettimeofday(tp1,NULL);
 171 }
 172
 173 static double mutex_end_timer(struct timeval tp1)
 174 {
 175         struct timeval tp2;
 176         gettimeofday(&tp2,NULL);
 177         return((tp2.tv_sec - tp1.tv_sec) +
 178                (tp2.tv_usec - tp1.tv_usec)*1.0e-6);
 179 }
 180
 181 /*
 182   mutex lock function for thread model
 183 */
 184 static int thread_mutex_lock(smb_mutex_t *mutexP, const char *name)
 185 {
 186         pthread_mutex_t *mutex = (pthread_mutex_t *)mutexP->mutex;
 187         int rc;
 188         double t;
 189         struct timeval tp1;
 190         /* Test below is ONLY for debugging */
 191         if ((rc = pthread_mutex_trylock(mutex))) {
 192                 if (rc == EBUSY) {
 193                         mutex_start_timer(&tp1);
 194                         printf("mutex lock: thread %d, lock %s not available\n",
 195                                 (uint32_t)pthread_self(), name);
 196                         print_suspicious_usage("mutex_lock", name);
 197                         pthread_mutex_lock(mutex);
 198                         t = mutex_end_timer(tp1);
 199                         printf("mutex lock: thread %d, lock %s now available, waited %g seconds\n",
 200                                 (uint32_t)pthread_self(), name, t);
 201                         return 0;
 202                 }
 203                 printf("mutex lock: thread %d, lock %s failed rc=%d\n",
 204                                 (uint32_t)pthread_self(), name, rc);
 205                 SMB_ASSERT(errno == 0); /* force error */
 206         }
 207         return 0;
 208 }
 209
 210 /*
 211    mutex unlock for thread model
 212 */
 213 static int thread_mutex_unlock(smb_mutex_t *mutex, const char *name)
 214 {
 215         return pthread_mutex_unlock((pthread_mutex_t *)mutex->mutex);
 216 }
 217
 218 /*****************************************************************
 219  Read/write lock routines.
 220 *****************************************************************/
 221 /*
 222   rwlock init function for thread model
 223 */
 224 static int thread_rwlock_init(smb_rwlock_t *rwlock, const char *name)
 225 {
 226         pthread_rwlock_t m = PTHREAD_RWLOCK_INITIALIZER;
 227         rwlock->rwlock = memdup(&m, sizeof(m));
 228         if (! rwlock->rwlock) {
 229                 errno = ENOMEM;
 230                 return -1;
 231         }
 232         return pthread_rwlock_init((pthread_rwlock_t *)rwlock->rwlock, NULL);
 233 }
 234
 235 /*
 236   rwlock destroy function for thread model
 237 */
 238 static int thread_rwlock_destroy(smb_rwlock_t *rwlock, const char *name)
 239 {
 240         return pthread_rwlock_destroy((pthread_rwlock_t *)rwlock->rwlock);
 241 }
 242
 243 /*
 244   rwlock lock for read function for thread model
 245 */
 246 static int thread_rwlock_lock_read(smb_rwlock_t *rwlockP, const char *name)
 247 {
 248         pthread_rwlock_t *rwlock = (pthread_rwlock_t *)rwlockP->rwlock;
 249         int rc;
 250         double t;
 251         struct timeval tp1;
 252         /* Test below is ONLY for debugging */
 253         if ((rc = pthread_rwlock_tryrdlock(rwlock))) {
 254                 if (rc == EBUSY) {
 255                         mutex_start_timer(&tp1);
 256                         printf("rwlock lock_read: thread %d, lock %s not available\n",
 257                                 (uint32_t)pthread_self(), name);
 258                         print_suspicious_usage("rwlock_lock_read", name);
 259                         pthread_rwlock_rdlock(rwlock);
 260                         t = mutex_end_timer(tp1);
 261                         printf("rwlock lock_read: thread %d, lock %s now available, waited %g seconds\n",
 262                                 (uint32_t)pthread_self(), name, t);
 263                         return 0;
 264                 }
 265                 printf("rwlock lock_read: thread %d, lock %s failed rc=%d\n",
 266                                 (uint32_t)pthread_self(), name, rc);
 267                 SMB_ASSERT(errno == 0); /* force error */
 268         }
 269         return 0;
 270 }
 271
 272 /*
 273   rwlock lock for write function for thread model
 274 */
 275 static int thread_rwlock_lock_write(smb_rwlock_t *rwlockP, const char *name)
 276 {
 277         pthread_rwlock_t *rwlock = (pthread_rwlock_t *)rwlockP->rwlock;
 278         int rc;
 279         double t;
 280         struct timeval tp1;
 281         /* Test below is ONLY for debugging */
 282         if ((rc = pthread_rwlock_trywrlock(rwlock))) {
 283                 if (rc == EBUSY) {
 284                         mutex_start_timer(&tp1);
 285                         printf("rwlock lock_write: thread %d, lock %s not available\n",
 286                                 (uint32_t)pthread_self(), name);
 287                         print_suspicious_usage("rwlock_lock_write", name);
 288                         pthread_rwlock_wrlock(rwlock);
 289                         t = mutex_end_timer(tp1);
 290                         printf("rwlock lock_write: thread %d, lock %s now available, waited %g seconds\n",
 291                                 (uint32_t)pthread_self(), name, t);
 292                         return 0;
 293                 }
 294                 printf("rwlock lock_write: thread %d, lock %s failed rc=%d\n",
 295                                 (uint32_t)pthread_self(), name, rc);
 296                 SMB_ASSERT(errno == 0); /* force error */
 297         }
 298         return 0;
 299 }
 300
 301
 302 /*
 303    rwlock unlock for thread model
 304 */
 305 static int thread_rwlock_unlock(smb_rwlock_t *rwlock, const char *name)
 306 {
 307         return pthread_rwlock_unlock((pthread_rwlock_t *)rwlock->rwlock);
 308 }
 309
 310 /*****************************************************************
 311  Log suspicious usage (primarily for possible thread-unsafe behavior.
 312 *****************************************************************/
 313 static void thread_log_suspicious_usage(const char* from, const char* info)
 314 {
 315         DEBUG(1,("log_suspicious_usage: from %s info='%s'\n", from, info));
 316 #ifdef HAVE_BACKTRACE
 317         {
 318                 void *addresses[10];
 319                 int num_addresses = backtrace(addresses, 8);
 320                 char **bt_symbols = backtrace_symbols(addresses, num_addresses);
 321                 int i;
 322
 323                 if (bt_symbols) {
 324                         for (i=0; i<num_addresses; i++) {
 325                                 DEBUG(1,("log_suspicious_usage: %s%s\n", DEBUGTAB(1), bt_symbols[i]));
 326                         }
 327                         free(bt_symbols);
 328                 }
 329         }
 330 #endif
 331 }
 332
 333 /*****************************************************************
 334  Log suspicious usage to stdout (primarily for possible thread-unsafe behavior.
 335  Used in mutex code where DEBUG calls would cause recursion.
 336 *****************************************************************/
 337 static void thread_print_suspicious_usage(const char* from, const char* info)
 338 {
 339         printf("log_suspicious_usage: from %s info='%s'\n", from, info);
 340 #ifdef HAVE_BACKTRACE
 341         {
 342                 void *addresses[10];
 343                 int num_addresses = backtrace(addresses, 8);
 344                 char **bt_symbols = backtrace_symbols(addresses, num_addresses);
 345                 int i;
 346
 347                 if (bt_symbols) {
 348                         for (i=0; i<num_addresses; i++) {
 349                                 printf("log_suspicious_usage: %s%s\n", DEBUGTAB(1), bt_symbols[i]);
 350                         }
 351                         free(bt_symbols);
 352                 }
 353         }
 354 #endif
 355 }
 356
 357 static uint32_t thread_get_task_id(void)
 358 {
 359         return (uint32_t)pthread_self();
 360 }
 361
 362 static void thread_log_task_id(int fd)
 363 {
 364         char *s;
 365
 366         asprintf(&s, "thread %u: ", (uint32_t)pthread_self());
 367         write(fd, s, strlen(s));
 368         free(s);
 369 }
 370 /****************************************************************************
 371 catch serious errors
 372 ****************************************************************************/
 373 static void thread_sig_fault(int sig)
 374 {
 375         DEBUG(0,("===============================================================\n"));
 376         DEBUG(0,("TERMINAL ERROR: Recursive signal %d in thread %lu (%s)\n",sig,(unsigned long int)pthread_self(),SAMBA_VERSION_STRING));
 377         DEBUG(0,("===============================================================\n"));
 378         exit(1); /* kill the whole server for now */
 379 }
 380
 381 /*******************************************************************
 382 setup our recursive fault handlers
 383 ********************************************************************/
 384 static void thread_fault_setup(void)
 385 {
 386 #ifdef SIGSEGV
 387         CatchSignal(SIGSEGV,SIGNAL_CAST thread_sig_fault);
 388 #endif
 389 #ifdef SIGBUS
 390         CatchSignal(SIGBUS,SIGNAL_CAST thread_sig_fault);
 391 #endif
 392 #ifdef SIGABRT
 393         CatchSignal(SIGABRT,SIGNAL_CAST thread_sig_fault);
 394 #endif
 395 }
 396
 397 /*******************************************************************
 398 report a fault in a thread
 399 ********************************************************************/
 400 static void thread_fault_handler(int sig)
 401 {
 402         static int counter;
 403
 404         /* try to catch recursive faults */
 405         thread_fault_setup();
 406
 407         counter++;      /* count number of faults that have occurred */
 408
 409         DEBUG(0,("===============================================================\n"));
 410         DEBUG(0,("INTERNAL ERROR: Signal %d in thread %lu (%s)\n",sig,(unsigned long int)pthread_self(),SAMBA_VERSION_STRING));
 411         DEBUG(0,("Please read the file BUGS.txt in the distribution\n"));
 412         DEBUG(0,("===============================================================\n"));
 413 #ifdef HAVE_BACKTRACE
 414         {
 415                 void *addresses[10];
 416                 int num_addresses = backtrace(addresses, 8);
 417                 char **bt_symbols = backtrace_symbols(addresses, num_addresses);
 418                 int i;
 419
 420                 if (bt_symbols) {
 421                         for (i=0; i<num_addresses; i++) {
 422                                 DEBUG(1,("fault_report: %s%s\n", DEBUGTAB(1), bt_symbols[i]));
 423                         }
 424                         free(bt_symbols);
 425                 }
 426         }
 427 #endif
 428         pthread_exit(NULL); /* terminate failing thread only */
 429 }
 430
 431 /*
 432   called when the process model is selected
 433 */
 434 static void model_startup(void)
 435 {
 436         struct mutex_ops m_ops;
 437         struct debug_ops d_ops;
 438
 439         ZERO_STRUCT(m_ops);
 440         ZERO_STRUCT(d_ops);
 441
 442         smbd_process_init();
 443
 444         /* register mutex/rwlock handlers */
 445         m_ops.mutex_init = thread_mutex_init;
 446         m_ops.mutex_lock = thread_mutex_lock;
 447         m_ops.mutex_unlock = thread_mutex_unlock;
 448         m_ops.mutex_destroy = thread_mutex_destroy;
 449
 450         m_ops.rwlock_init = thread_rwlock_init;
 451         m_ops.rwlock_lock_write = thread_rwlock_lock_write;
 452         m_ops.rwlock_lock_read = thread_rwlock_lock_read;
 453         m_ops.rwlock_unlock = thread_rwlock_unlock;
 454         m_ops.rwlock_destroy = thread_rwlock_destroy;
 455
 456         register_mutex_handlers("thread", &m_ops);
 457
 458         register_fault_handler("thread", thread_fault_handler);
 459
 460         d_ops.log_suspicious_usage = thread_log_suspicious_usage;
 461         d_ops.print_suspicious_usage = thread_print_suspicious_usage;
 462         d_ops.get_task_id = thread_get_task_id;
 463         d_ops.log_task_id = thread_log_task_id;
 464
 465         register_debug_handlers("thread", &d_ops);
 466 }
 467
 468 static void thread_exit_server(struct server_context *smb, const char *reason)
 469 {
 470         DEBUG(1,("thread_exit_server: reason[%s]\n",reason));
 471 }
 472
 473 /*
 474   initialise the thread process model, registering ourselves with the model subsystem
 475  */
 476 NTSTATUS process_model_thread_init(void)
 477 {
 478         NTSTATUS ret;
 479         struct model_ops ops;
 480
 481         ZERO_STRUCT(ops);
 482
 483         /* fill in our name */
 484         ops.name = "thread";
 485
 486         /* fill in all the operations */
 487         ops.model_startup = model_startup;
 488         ops.accept_connection = accept_connection;
 489         ops.accept_rpc_connection = accept_rpc_connection;
 490         ops.terminate_connection = terminate_connection;
 491         ops.terminate_rpc_connection = terminate_rpc_connection;
 492         ops.exit_server = thread_exit_server;
 493         ops.get_id = get_id;
 494
 495         /* register ourselves with the PROCESS_MODEL subsystem. */
 496         ret = register_backend("process_model", &ops);
 497         if (!NT_STATUS_IS_OK(ret)) {
 498                 DEBUG(0,("Failed to register process_model 'thread'!\n"));
 499                 return ret;
 500         }
 501
 502         return ret;
 503 }