server/process.c

   1 /*
   2  * Server-side process management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  */
   6
   7 #include <assert.h>
   8 #include <limits.h>
   9 #include <string.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <sys/time.h>
  13 #include <unistd.h>
  14
  15 #include "winerror.h"
  16 #include "winbase.h"
  17 #include "winnt.h"
  18
  19 #include "server.h"
  20 #include "server/thread.h"
  21
  22 /* reserved handle access rights */
  23 #define RESERVED_SHIFT         25
  24 #define RESERVED_INHERIT       (HANDLE_FLAG_INHERIT << RESERVED_SHIFT)
  25 #define RESERVED_CLOSE_PROTECT (HANDLE_FLAG_PROTECT_FROM_CLOSE << RESERVED_SHIFT)
  26 #define RESERVED_ALL           (RESERVED_INHERIT | RESERVED_CLOSE_PROTECT)
  27
  28 /* global handle macros */
  29 #define HANDLE_OBFUSCATOR         0x544a4def
  30 #define HANDLE_IS_GLOBAL(h)       (((h) ^ HANDLE_OBFUSCATOR) < 0x10000)
  31 #define HANDLE_LOCAL_TO_GLOBAL(h) ((h) ^ HANDLE_OBFUSCATOR)
  32 #define HANDLE_GLOBAL_TO_LOCAL(h) ((h) ^ HANDLE_OBFUSCATOR)
  33
  34 struct handle_entry
  35 {
  36     struct object *ptr;
  37     unsigned int   access;
  38 };
  39
  40 /* process structure; not much for now... */
  41
  42 struct process
  43 {
  44     struct object        obj;             /* object header */
  45     struct process      *next;            /* system-wide process list */
  46     struct process      *prev;
  47     struct thread       *thread_list;     /* head of the thread list */
  48     struct handle_entry *entries;         /* handle entry table */
  49     int                  handle_count;    /* nb of allocated handle entries */
  50     int                  handle_last;     /* last used handle entry */
  51     int                  exit_code;       /* process exit code */
  52     int                  running_threads; /* number of threads running in this process */
  53     struct timeval       start_time;      /* absolute time at process start */
  54     struct timeval       end_time;        /* absolute time at process end */
  55     int                  priority;        /* priority class */
  56     int                  affinity;        /* process affinity mask */
  57     struct object       *console_in;      /* console input */
  58     struct object       *console_out;     /* console output */
  59 };
  60
  61 static struct process *first_process;
  62 static struct process *initial_process;
  63
  64 #define MIN_HANDLE_ENTRIES  32
  65
  66 /* process operations */
  67
  68 static void process_dump( struct object *obj, int verbose );
  69 static int process_signaled( struct object *obj, struct thread *thread );
  70 static void process_destroy( struct object *obj );
  71 static void free_handles( struct process *process );
  72 static int copy_handle_table( struct process *process, struct process *parent );
  73
  74 static const struct object_ops process_ops =
  75 {
  76     process_dump,
  77     add_queue,
  78     remove_queue,
  79     process_signaled,
  80     no_satisfied,
  81     no_read_fd,
  82     no_write_fd,
  83     no_flush,
  84     no_get_file_info,
  85     process_destroy
  86 };
  87
  88 /* create a new process */
  89 struct process *create_process(void)
  90 {
  91     struct process *process, *parent;
  92
  93     if (!(process = mem_alloc( sizeof(*process) ))) return NULL;
  94
  95     parent = current ? current->process : NULL;
  96     if (!copy_handle_table( process, parent ))
  97     {
  98         free( process );
  99         return NULL;
 100     }
 101     init_object( &process->obj, &process_ops, NULL );
 102     process->next            = first_process;
 103     process->prev            = NULL;
 104     process->thread_list     = NULL;
 105     process->exit_code       = 0x103;  /* STILL_ACTIVE */
 106     process->running_threads = 0;
 107     process->priority        = NORMAL_PRIORITY_CLASS;
 108     process->affinity        = 1;
 109     process->console_in      = NULL;
 110     process->console_out     = NULL;
 111     if (parent)
 112     {
 113         if (parent->console_in) process->console_in = grab_object( parent->console_in );
 114         if (parent->console_out) process->console_out = grab_object( parent->console_out );
 115     }
 116
 117     if (first_process) first_process->prev = process;
 118     first_process = process;
 119     if (!initial_process)
 120     {
 121         initial_process = process;
 122         grab_object( initial_process ); /* so that we never free it */
 123     }
 124
 125     gettimeofday( &process->start_time, NULL );
 126     /* alloc a handle for the process itself */
 127     alloc_handle( process, process, PROCESS_ALL_ACCESS, 0 );
 128     return process;
 129 }
 130
 131 /* destroy a process when its refcount is 0 */
 132 static void process_destroy( struct object *obj )
 133 {
 134     struct process *process = (struct process *)obj;
 135     assert( obj->ops == &process_ops );
 136     assert( process != initial_process );
 137
 138     /* we can't have a thread remaining */
 139     assert( !process->thread_list );
 140     if (process->next) process->next->prev = process->prev;
 141     if (process->prev) process->prev->next = process->next;
 142     else first_process = process->next;
 143     free_console( process );
 144     free_handles( process );
 145     if (debug_level) memset( process, 0xbb, sizeof(process) );  /* catch errors */
 146     free( process );
 147 }
 148
 149 /* dump a process on stdout for debugging purposes */
 150 static void process_dump( struct object *obj, int verbose )
 151 {
 152     struct process *process = (struct process *)obj;
 153     assert( obj->ops == &process_ops );
 154
 155     printf( "Process next=%p prev=%p\n", process->next, process->prev );
 156 }
 157
 158 static int process_signaled( struct object *obj, struct thread *thread )
 159 {
 160     struct process *process = (struct process *)obj;
 161     return (process->running_threads > 0);
 162 }
 163
 164 /* get a process from an id (and increment the refcount) */
 165 struct process *get_process_from_id( void *id )
 166 {
 167     struct process *p = first_process;
 168     while (p && (p != id)) p = p->next;
 169     if (p) grab_object( p );
 170     else SET_ERROR( ERROR_INVALID_PARAMETER );
 171     return p;
 172 }
 173
 174 /* get a process from a handle (and increment the refcount) */
 175 struct process *get_process_from_handle( int handle, unsigned int access )
 176 {
 177     return (struct process *)get_handle_obj( current->process, handle,
 178                                              access, &process_ops );
 179 }
 180
 181 /* a process has been killed (i.e. its last thread died) */
 182 static void process_killed( struct process *process, int exit_code )
 183 {
 184     assert( !process->thread_list );
 185     process->exit_code = exit_code;
 186     gettimeofday( &process->end_time, NULL );
 187     wake_up( &process->obj, 0 );
 188     free_handles( process );
 189 }
 190
 191 /* free the process handle entries */
 192 static void free_handles( struct process *process )
 193 {
 194     struct handle_entry *entry;
 195     int handle;
 196
 197     if (!(entry = process->entries)) return;
 198     for (handle = 0; handle <= process->handle_last; handle++, entry++)
 199     {
 200         struct object *obj = entry->ptr;
 201         entry->ptr = NULL;
 202         if (obj) release_object( obj );
 203     }
 204     free( process->entries );
 205     process->handle_count = 0;
 206     process->handle_last  = -1;
 207     process->entries = NULL;
 208 }
 209
 210 /* add a thread to a process running threads list */
 211 void add_process_thread( struct process *process, struct thread *thread )
 212 {
 213     thread->proc_next = process->thread_list;
 214     thread->proc_prev = NULL;
 215     if (thread->proc_next) thread->proc_next->proc_prev = thread;
 216     process->thread_list = thread;
 217     process->running_threads++;
 218     grab_object( thread );
 219 }
 220
 221 /* remove a thread from a process running threads list */
 222 void remove_process_thread( struct process *process, struct thread *thread )
 223 {
 224     assert( process->running_threads > 0 );
 225     assert( process->thread_list );
 226
 227     if (thread->proc_next) thread->proc_next->proc_prev = thread->proc_prev;
 228     if (thread->proc_prev) thread->proc_prev->proc_next = thread->proc_next;
 229     else process->thread_list = thread->proc_next;
 230
 231     if (!--process->running_threads)
 232     {
 233         /* we have removed the last running thread, exit the process */
 234         process_killed( process, thread->exit_code );
 235     }
 236     release_object( thread );
 237 }
 238
 239 /* grow a handle table */
 240 /* return 1 if OK, 0 on error */
 241 static int grow_handle_table( struct process *process )
 242 {
 243     struct handle_entry *new_entries;
 244     int count = process->handle_count;
 245
 246     if (count >= INT_MAX / 2) return 0;
 247     count *= 2;
 248     if (!(new_entries = realloc( process->entries, count * sizeof(struct handle_entry) )))
 249     {
 250         SET_ERROR( ERROR_OUTOFMEMORY );
 251         return 0;
 252     }
 253     process->handle_count = count;
 254     process->entries      = new_entries;
 255     return 1;
 256 }
 257
 258 /* allocate a handle for an object, incrementing its refcount */
 259 /* return the handle, or -1 on error */
 260 int alloc_handle( struct process *process, void *obj, unsigned int access,
 261                   int inherit )
 262 {
 263     struct handle_entry *entry;
 264     int handle;
 265
 266     assert( !(access & RESERVED_ALL) );
 267     if (inherit) access |= RESERVED_INHERIT;
 268
 269     /* find the first free entry */
 270
 271     if (!(entry = process->entries)) return -1;
 272     for (handle = 0; handle <= process->handle_last; handle++, entry++)
 273         if (!entry->ptr) goto found;
 274
 275     if (handle >= process->handle_count)
 276     {
 277         if (!grow_handle_table( process )) return -1;
 278         entry = process->entries + handle;  /* the table may have moved */
 279     }
 280     process->handle_last = handle;
 281
 282  found:
 283     entry->ptr    = grab_object( obj );
 284     entry->access = access;
 285     return handle + 1;  /* avoid handle 0 */
 286 }
 287
 288 /* allocate a specific handle for an object, incrementing its refcount */
 289 static int alloc_specific_handle( struct process *process, void *obj, int handle,
 290                                   unsigned int access, int inherit )
 291 {
 292     struct handle_entry *entry;
 293     struct object *old;
 294
 295     if (handle == -1) return alloc_handle( process, obj, access, inherit );
 296
 297     assert( !(access & RESERVED_ALL) );
 298     if (inherit) access |= RESERVED_INHERIT;
 299
 300     handle--;  /* handles start at 1 */
 301     if ((handle < 0) || (handle > process->handle_last))
 302     {
 303         SET_ERROR( ERROR_INVALID_HANDLE );
 304         return -1;
 305     }
 306     entry = process->entries + handle;
 307
 308     old = entry->ptr;
 309     entry->ptr = grab_object( obj );
 310     entry->access = access;
 311     if (old) release_object( old );
 312     return handle + 1;
 313 }
 314
 315 /* return an handle entry, or NULL if the handle is invalid */
 316 static struct handle_entry *get_handle( struct process *process, int handle )
 317 {
 318     struct handle_entry *entry;
 319
 320     if (HANDLE_IS_GLOBAL(handle))
 321     {
 322         handle = HANDLE_GLOBAL_TO_LOCAL(handle);
 323         process = initial_process;
 324     }
 325     handle--;  /* handles start at 1 */
 326     if ((handle < 0) || (handle > process->handle_last)) goto error;
 327     entry = process->entries + handle;
 328     if (!entry->ptr) goto error;
 329     return entry;
 330
 331  error:
 332     SET_ERROR( ERROR_INVALID_HANDLE );
 333     return NULL;
 334 }
 335
 336 /* attempt to shrink a table */
 337 /* return 1 if OK, 0 on error */
 338 static int shrink_handle_table( struct process *process )
 339 {
 340     struct handle_entry *new_entries;
 341     struct handle_entry *entry = process->entries + process->handle_last;
 342     int count = process->handle_count;
 343
 344     while (process->handle_last >= 0)
 345     {
 346         if (entry->ptr) break;
 347         process->handle_last--;
 348         entry--;
 349     }
 350     if (process->handle_last >= count / 4) return 1;  /* no need to shrink */
 351     if (count < MIN_HANDLE_ENTRIES * 2) return 1;  /* too small to shrink */
 352     count /= 2;
 353     if (!(new_entries = realloc( process->entries,
 354                                  count * sizeof(struct handle_entry) )))
 355         return 0;
 356     process->handle_count = count;
 357     process->entries      = new_entries;
 358     return 1;
 359 }
 360
 361 /* copy the handle table of the parent process */
 362 /* return 1 if OK, 0 on error */
 363 static int copy_handle_table( struct process *process, struct process *parent )
 364 {
 365     struct handle_entry *ptr;
 366     int i, count, last;
 367
 368     if (!parent)  /* first process */
 369     {
 370         count = MIN_HANDLE_ENTRIES;
 371         last  = -1;
 372     }
 373     else
 374     {
 375         assert( parent->entries );
 376         count = parent->handle_count;
 377         last  = parent->handle_last;
 378     }
 379
 380     if (!(ptr = mem_alloc( count * sizeof(struct handle_entry)))) return 0;
 381     process->entries      = ptr;
 382     process->handle_count = count;
 383     process->handle_last  = last;
 384
 385     if (last >= 0)
 386     {
 387         memcpy( ptr, parent->entries, (last + 1) * sizeof(struct handle_entry) );
 388         for (i = 0; i <= last; i++, ptr++)
 389         {
 390             if (!ptr->ptr) continue;
 391             if (ptr->access & RESERVED_INHERIT) grab_object( ptr->ptr );
 392             else ptr->ptr = NULL; /* don't inherit this entry */
 393         }
 394     }
 395     /* attempt to shrink the table */
 396     shrink_handle_table( process );
 397     return 1;
 398 }
 399
 400 /* close a handle and decrement the refcount of the associated object */
 401 /* return 1 if OK, 0 on error */
 402 int close_handle( struct process *process, int handle )
 403 {
 404     struct handle_entry *entry;
 405     struct object *obj;
 406
 407     if (HANDLE_IS_GLOBAL(handle))
 408     {
 409         handle = HANDLE_GLOBAL_TO_LOCAL(handle);
 410         process = initial_process;
 411     }
 412     if (!(entry = get_handle( process, handle ))) return 0;
 413     if (entry->access & RESERVED_CLOSE_PROTECT) return 0;  /* FIXME: error code */
 414     obj = entry->ptr;
 415     entry->ptr = NULL;
 416     if (handle-1 == process->handle_last) shrink_handle_table( process );
 417     release_object( obj );
 418     return 1;
 419 }
 420
 421 /* retrieve the object corresponding to a handle, incrementing its refcount */
 422 struct object *get_handle_obj( struct process *process, int handle,
 423                                unsigned int access, const struct object_ops *ops )
 424 {
 425     struct handle_entry *entry;
 426     struct object *obj;
 427
 428     switch( handle )
 429     {
 430     case 0xfffffffe:  /* current thread pseudo-handle */
 431         obj = &current->obj;
 432         break;
 433     case 0x7fffffff:  /* current process pseudo-handle */
 434         obj = (struct object *)current->process;
 435         break;
 436     default:
 437         if (!(entry = get_handle( process, handle ))) return NULL;
 438         if ((entry->access & access) != access)
 439         {
 440             SET_ERROR( ERROR_ACCESS_DENIED );
 441             return NULL;
 442         }
 443         obj = entry->ptr;
 444         break;
 445     }
 446     if (ops && (obj->ops != ops))
 447     {
 448         SET_ERROR( ERROR_INVALID_HANDLE );  /* not the right type */
 449         return NULL;
 450     }
 451     return grab_object( obj );
 452 }
 453
 454 /* get/set the handle reserved flags */
 455 /* return the new flags (or -1 on error) */
 456 int set_handle_info( struct process *process, int handle, int mask, int flags )
 457 {
 458     struct handle_entry *entry;
 459
 460     if (!(entry = get_handle( process, handle ))) return -1;
 461     mask  = (mask << RESERVED_SHIFT) & RESERVED_ALL;
 462     flags = (flags << RESERVED_SHIFT) & mask;
 463     entry->access = (entry->access & ~mask) | flags;
 464     return (entry->access & RESERVED_ALL) >> RESERVED_SHIFT;
 465 }
 466
 467 /* duplicate a handle */
 468 int duplicate_handle( struct process *src, int src_handle, struct process *dst,
 469                       int dst_handle, unsigned int access, int inherit, int options )
 470 {
 471     int res;
 472     struct handle_entry *entry = get_handle( src, src_handle );
 473     if (!entry) return -1;
 474
 475     if (options & DUP_HANDLE_SAME_ACCESS) access = entry->access;
 476     if (options & DUP_HANDLE_MAKE_GLOBAL) dst = initial_process;
 477     access &= ~RESERVED_ALL;
 478     res = alloc_specific_handle( dst, entry->ptr, dst_handle, access, inherit );
 479     if (options & DUP_HANDLE_MAKE_GLOBAL) res = HANDLE_LOCAL_TO_GLOBAL(res);
 480     return res;
 481 }
 482
 483 /* open a new handle to an existing object */
 484 int open_object( const char *name, const struct object_ops *ops,
 485                  unsigned int access, int inherit )
 486 {
 487     struct object *obj = find_object( name );
 488     if (!obj) return -1;  /* FIXME: set error code */
 489     if (ops && obj->ops != ops)
 490     {
 491         release_object( obj );
 492         return -1;  /* FIXME: set error code */
 493     }
 494     return alloc_handle( current->process, obj, access, inherit );
 495 }
 496
 497 /* dump a handle table on stdout */
 498 void dump_handles( struct process *process )
 499 {
 500     struct handle_entry *entry;
 501     int i;
 502
 503     if (!process->entries) return;
 504     entry = process->entries;
 505     for (i = 0; i <= process->handle_last; i++, entry++)
 506     {
 507         if (!entry->ptr) continue;
 508         printf( "%5d: %p %08x ", i + 1, entry->ptr, entry->access );
 509         entry->ptr->ops->dump( entry->ptr, 0 );
 510     }
 511 }
 512
 513 /* kill a process on the spot */
 514 void kill_process( struct process *process, int exit_code )
 515 {
 516     while (process->thread_list)
 517         kill_thread( process->thread_list, exit_code );
 518 }
 519
 520 /* get all information about a process */
 521 void get_process_info( struct process *process,
 522                        struct get_process_info_reply *reply )
 523 {
 524     reply->pid              = process;
 525     reply->exit_code        = process->exit_code;
 526     reply->priority         = process->priority;
 527     reply->process_affinity = process->affinity;
 528     reply->system_affinity  = 1;
 529 }
 530
 531 /* set all information about a process */
 532 void set_process_info( struct process *process,
 533                        struct set_process_info_request *req )
 534 {
 535     if (req->mask & SET_PROCESS_INFO_PRIORITY)
 536         process->priority = req->priority;
 537     if (req->mask & SET_PROCESS_INFO_AFFINITY)
 538     {
 539         if (req->affinity != 1) SET_ERROR( ERROR_INVALID_PARAMETER );
 540         else process->affinity = req->affinity;
 541     }
 542 }
 543
 544 /* allocate a console for this process */
 545 int alloc_console( struct process *process )
 546 {
 547     struct object *obj[2];
 548     if (process->console_in || process->console_out)
 549     {
 550         SET_ERROR( ERROR_ACCESS_DENIED );
 551         return 0;
 552     }
 553     if (!create_console( -1, obj )) return 0;
 554     process->console_in  = obj[0];
 555     process->console_out = obj[1];
 556     return 1;
 557 }
 558
 559 /* free the console for this process */
 560 int free_console( struct process *process )
 561 {
 562     if (process->console_in) release_object( process->console_in );
 563     if (process->console_out) release_object( process->console_out );
 564     process->console_in = process->console_out = NULL;
 565     return 1;
 566 }
 567
 568 /* get the process console */
 569 struct object *get_console( struct process *process, int output )
 570 {
 571     struct object *obj;
 572     if (!(obj = output ? process->console_out : process->console_in))
 573         return NULL;
 574     return grab_object( obj );
 575 }