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/process.h"
  21 #include "server/thread.h"
  22
  23 /* reserved handle access rights */
  24 #define RESERVED_SHIFT         25
  25 #define RESERVED_INHERIT       (HANDLE_FLAG_INHERIT << RESERVED_SHIFT)
  26 #define RESERVED_CLOSE_PROTECT (HANDLE_FLAG_PROTECT_FROM_CLOSE << RESERVED_SHIFT)
  27 #define RESERVED_ALL           (RESERVED_INHERIT | RESERVED_CLOSE_PROTECT)
  28
  29 /* global handle macros */
  30 #define HANDLE_OBFUSCATOR         0x544a4def
  31 #define HANDLE_IS_GLOBAL(h)       (((h) ^ HANDLE_OBFUSCATOR) < 0x10000)
  32 #define HANDLE_LOCAL_TO_GLOBAL(h) ((h) ^ HANDLE_OBFUSCATOR)
  33 #define HANDLE_GLOBAL_TO_LOCAL(h) ((h) ^ HANDLE_OBFUSCATOR)
  34
  35 struct handle_entry
  36 {
  37     struct object *ptr;
  38     unsigned int   access;
  39 };
  40
  41 /* process structure; not much for now... */
  42
  43 struct process
  44 {
  45     struct object        obj;             /* object header */
  46     struct process      *next;            /* system-wide process list */
  47     struct process      *prev;
  48     struct thread       *thread_list;     /* head of the thread list */
  49     struct handle_entry *entries;         /* handle entry table */
  50     int                  handle_count;    /* nb of allocated handle entries */
  51     int                  handle_last;     /* last used handle entry */
  52     int                  exit_code;       /* process exit code */
  53     int                  running_threads; /* number of threads running in this process */
  54     struct timeval       start_time;      /* absolute time at process start */
  55     struct timeval       end_time;        /* absolute time at process end */
  56     int                  priority;        /* priority class */
  57     int                  affinity;        /* process affinity mask */
  58     struct object       *console_in;      /* console input */
  59     struct object       *console_out;     /* console output */
  60 };
  61
  62 static struct process *first_process;
  63 static struct process *initial_process;
  64 static int running_processes;
  65
  66 #define MIN_HANDLE_ENTRIES  32
  67
  68 /* process operations */
  69
  70 static void process_dump( struct object *obj, int verbose );
  71 static int process_signaled( struct object *obj, struct thread *thread );
  72 static void process_destroy( struct object *obj );
  73 static void free_handles( struct process *process );
  74 static int copy_handle_table( struct process *process, struct process *parent );
  75
  76 static const struct object_ops process_ops =
  77 {
  78     process_dump,
  79     add_queue,
  80     remove_queue,
  81     process_signaled,
  82     no_satisfied,
  83     no_read_fd,
  84     no_write_fd,
  85     no_flush,
  86     no_get_file_info,
  87     process_destroy
  88 };
  89
  90 /* create a new process */
  91 struct process *create_process(void)
  92 {
  93     struct process *process, *parent;
  94
  95     if (!(process = mem_alloc( sizeof(*process) ))) return NULL;
  96
  97     parent = current ? current->process : NULL;
  98     if (!copy_handle_table( process, parent ))
  99     {
 100         free( process );
 101         return NULL;
 102     }
 103     init_object( &process->obj, &process_ops, NULL );
 104     process->next            = first_process;
 105     process->prev            = NULL;
 106     process->thread_list     = NULL;
 107     process->exit_code       = 0x103;  /* STILL_ACTIVE */
 108     process->running_threads = 0;
 109     process->priority        = NORMAL_PRIORITY_CLASS;
 110     process->affinity        = 1;
 111     process->console_in      = NULL;
 112     process->console_out     = NULL;
 113     if (parent)
 114     {
 115         if (parent->console_in) process->console_in = grab_object( parent->console_in );
 116         if (parent->console_out) process->console_out = grab_object( parent->console_out );
 117     }
 118
 119     if (first_process) first_process->prev = process;
 120     first_process = process;
 121     if (!initial_process)
 122     {
 123         initial_process = process;
 124         grab_object( initial_process ); /* so that we never free it */
 125     }
 126
 127     gettimeofday( &process->start_time, NULL );
 128     /* alloc a handle for the process itself */
 129     alloc_handle( process, process, PROCESS_ALL_ACCESS, 0 );
 130     return process;
 131 }
 132
 133 /* destroy a process when its refcount is 0 */
 134 static void process_destroy( struct object *obj )
 135 {
 136     struct process *process = (struct process *)obj;
 137     assert( obj->ops == &process_ops );
 138     assert( process != initial_process );
 139
 140     /* we can't have a thread remaining */
 141     assert( !process->thread_list );
 142     if (process->next) process->next->prev = process->prev;
 143     if (process->prev) process->prev->next = process->next;
 144     else first_process = process->next;
 145     free_console( process );
 146     free_handles( process );
 147     if (debug_level) memset( process, 0xbb, sizeof(process) );  /* catch errors */
 148     free( process );
 149 }
 150
 151 /* dump a process on stdout for debugging purposes */
 152 static void process_dump( struct object *obj, int verbose )
 153 {
 154     struct process *process = (struct process *)obj;
 155     assert( obj->ops == &process_ops );
 156
 157     printf( "Process next=%p prev=%p\n", process->next, process->prev );
 158 }
 159
 160 static int process_signaled( struct object *obj, struct thread *thread )
 161 {
 162     struct process *process = (struct process *)obj;
 163     return !process->running_threads;
 164 }
 165
 166 /* get a process from an id (and increment the refcount) */
 167 struct process *get_process_from_id( void *id )
 168 {
 169     struct process *p = first_process;
 170     while (p && (p != id)) p = p->next;
 171     if (p) grab_object( p );
 172     else SET_ERROR( ERROR_INVALID_PARAMETER );
 173     return p;
 174 }
 175
 176 /* get a process from a handle (and increment the refcount) */
 177 struct process *get_process_from_handle( int handle, unsigned int access )
 178 {
 179     return (struct process *)get_handle_obj( current->process, handle,
 180                                              access, &process_ops );
 181 }
 182
 183 /* a process has been killed (i.e. its last thread died) */
 184 static void process_killed( struct process *process, int exit_code )
 185 {
 186     assert( !process->thread_list );
 187     process->exit_code = exit_code;
 188     gettimeofday( &process->end_time, NULL );
 189     wake_up( &process->obj, 0 );
 190     free_handles( process );
 191 }
 192
 193 /* free the process handle entries */
 194 static void free_handles( struct process *process )
 195 {
 196     struct handle_entry *entry;
 197     int handle;
 198
 199     if (!(entry = process->entries)) return;
 200     for (handle = 0; handle <= process->handle_last; handle++, entry++)
 201     {
 202         struct object *obj = entry->ptr;
 203         entry->ptr = NULL;
 204         if (obj) release_object( obj );
 205     }
 206     free( process->entries );
 207     process->handle_count = 0;
 208     process->handle_last  = -1;
 209     process->entries = NULL;
 210 }
 211
 212 /* add a thread to a process running threads list */
 213 void add_process_thread( struct process *process, struct thread *thread )
 214 {
 215     thread->proc_next = process->thread_list;
 216     thread->proc_prev = NULL;
 217     if (thread->proc_next) thread->proc_next->proc_prev = thread;
 218     process->thread_list = thread;
 219     if (!process->running_threads++) running_processes++;
 220     grab_object( thread );
 221 }
 222
 223 /* remove a thread from a process running threads list */
 224 void remove_process_thread( struct process *process, struct thread *thread )
 225 {
 226     assert( process->running_threads > 0 );
 227     assert( process->thread_list );
 228
 229     if (thread->proc_next) thread->proc_next->proc_prev = thread->proc_prev;
 230     if (thread->proc_prev) thread->proc_prev->proc_next = thread->proc_next;
 231     else process->thread_list = thread->proc_next;
 232
 233     if (!--process->running_threads)
 234     {
 235         /* we have removed the last running thread, exit the process */
 236         running_processes--;
 237         process_killed( process, thread->exit_code );
 238     }
 239     release_object( thread );
 240 }
 241
 242 /* grow a handle table */
 243 /* return 1 if OK, 0 on error */
 244 static int grow_handle_table( struct process *process )
 245 {
 246     struct handle_entry *new_entries;
 247     int count = process->handle_count;
 248
 249     if (count >= INT_MAX / 2) return 0;
 250     count *= 2;
 251     if (!(new_entries = realloc( process->entries, count * sizeof(struct handle_entry) )))
 252     {
 253         SET_ERROR( ERROR_OUTOFMEMORY );
 254         return 0;
 255     }
 256     process->handle_count = count;
 257     process->entries      = new_entries;
 258     return 1;
 259 }
 260
 261 /* allocate a handle for an object, incrementing its refcount */
 262 /* return the handle, or -1 on error */
 263 int alloc_handle( struct process *process, void *obj, unsigned int access,
 264                   int inherit )
 265 {
 266     struct handle_entry *entry;
 267     int handle;
 268
 269     assert( !(access & RESERVED_ALL) );
 270     if (inherit) access |= RESERVED_INHERIT;
 271
 272     /* find the first free entry */
 273
 274     if (!(entry = process->entries)) return -1;
 275     for (handle = 0; handle <= process->handle_last; handle++, entry++)
 276         if (!entry->ptr) goto found;
 277
 278     if (handle >= process->handle_count)
 279     {
 280         if (!grow_handle_table( process )) return -1;
 281         entry = process->entries + handle;  /* the table may have moved */
 282     }
 283     process->handle_last = handle;
 284
 285  found:
 286     entry->ptr    = grab_object( obj );
 287     entry->access = access;
 288     return handle + 1;  /* avoid handle 0 */
 289 }
 290
 291 /* return an handle entry, or NULL if the handle is invalid */
 292 static struct handle_entry *get_handle( struct process *process, int handle )
 293 {
 294     struct handle_entry *entry;
 295
 296     if (HANDLE_IS_GLOBAL(handle))
 297     {
 298         handle = HANDLE_GLOBAL_TO_LOCAL(handle);
 299         process = initial_process;
 300     }
 301     handle--;  /* handles start at 1 */
 302     if ((handle < 0) || (handle > process->handle_last)) goto error;
 303     entry = process->entries + handle;
 304     if (!entry->ptr) goto error;
 305     return entry;
 306
 307  error:
 308     SET_ERROR( ERROR_INVALID_HANDLE );
 309     return NULL;
 310 }
 311
 312 /* attempt to shrink a table */
 313 /* return 1 if OK, 0 on error */
 314 static int shrink_handle_table( struct process *process )
 315 {
 316     struct handle_entry *new_entries;
 317     struct handle_entry *entry = process->entries + process->handle_last;
 318     int count = process->handle_count;
 319
 320     while (process->handle_last >= 0)
 321     {
 322         if (entry->ptr) break;
 323         process->handle_last--;
 324         entry--;
 325     }
 326     if (process->handle_last >= count / 4) return 1;  /* no need to shrink */
 327     if (count < MIN_HANDLE_ENTRIES * 2) return 1;  /* too small to shrink */
 328     count /= 2;
 329     if (!(new_entries = realloc( process->entries,
 330                                  count * sizeof(struct handle_entry) )))
 331         return 0;
 332     process->handle_count = count;
 333     process->entries      = new_entries;
 334     return 1;
 335 }
 336
 337 /* copy the handle table of the parent process */
 338 /* return 1 if OK, 0 on error */
 339 static int copy_handle_table( struct process *process, struct process *parent )
 340 {
 341     struct handle_entry *ptr;
 342     int i, count, last;
 343
 344     if (!parent)  /* first process */
 345     {
 346         count = MIN_HANDLE_ENTRIES;
 347         last  = -1;
 348     }
 349     else
 350     {
 351         assert( parent->entries );
 352         count = parent->handle_count;
 353         last  = parent->handle_last;
 354     }
 355
 356     if (!(ptr = mem_alloc( count * sizeof(struct handle_entry)))) return 0;
 357     process->entries      = ptr;
 358     process->handle_count = count;
 359     process->handle_last  = last;
 360
 361     if (last >= 0)
 362     {
 363         memcpy( ptr, parent->entries, (last + 1) * sizeof(struct handle_entry) );
 364         for (i = 0; i <= last; i++, ptr++)
 365         {
 366             if (!ptr->ptr) continue;
 367             if (ptr->access & RESERVED_INHERIT) grab_object( ptr->ptr );
 368             else ptr->ptr = NULL; /* don't inherit this entry */
 369         }
 370     }
 371     /* attempt to shrink the table */
 372     shrink_handle_table( process );
 373     return 1;
 374 }
 375
 376 /* close a handle and decrement the refcount of the associated object */
 377 /* return 1 if OK, 0 on error */
 378 int close_handle( struct process *process, int handle )
 379 {
 380     struct handle_entry *entry;
 381     struct object *obj;
 382
 383     if (HANDLE_IS_GLOBAL(handle))
 384     {
 385         handle = HANDLE_GLOBAL_TO_LOCAL(handle);
 386         process = initial_process;
 387     }
 388     if (!(entry = get_handle( process, handle ))) return 0;
 389     if (entry->access & RESERVED_CLOSE_PROTECT) return 0;  /* FIXME: error code */
 390     obj = entry->ptr;
 391     entry->ptr = NULL;
 392     if (handle-1 == process->handle_last) shrink_handle_table( process );
 393     release_object( obj );
 394     return 1;
 395 }
 396
 397 /* retrieve the object corresponding to a handle, incrementing its refcount */
 398 struct object *get_handle_obj( struct process *process, int handle,
 399                                unsigned int access, const struct object_ops *ops )
 400 {
 401     struct handle_entry *entry;
 402     struct object *obj;
 403
 404     switch( handle )
 405     {
 406     case 0xfffffffe:  /* current thread pseudo-handle */
 407         obj = &current->obj;
 408         break;
 409     case 0x7fffffff:  /* current process pseudo-handle */
 410         obj = (struct object *)current->process;
 411         break;
 412     default:
 413         if (!(entry = get_handle( process, handle ))) return NULL;
 414         if ((entry->access & access) != access)
 415         {
 416             SET_ERROR( ERROR_ACCESS_DENIED );
 417             return NULL;
 418         }
 419         obj = entry->ptr;
 420         break;
 421     }
 422     if (ops && (obj->ops != ops))
 423     {
 424         SET_ERROR( ERROR_INVALID_HANDLE );  /* not the right type */
 425         return NULL;
 426     }
 427     return grab_object( obj );
 428 }
 429
 430 /* get/set the handle reserved flags */
 431 /* return the new flags (or -1 on error) */
 432 int set_handle_info( struct process *process, int handle, int mask, int flags )
 433 {
 434     struct handle_entry *entry;
 435
 436     if (!(entry = get_handle( process, handle ))) return -1;
 437     mask  = (mask << RESERVED_SHIFT) & RESERVED_ALL;
 438     flags = (flags << RESERVED_SHIFT) & mask;
 439     entry->access = (entry->access & ~mask) | flags;
 440     return (entry->access & RESERVED_ALL) >> RESERVED_SHIFT;
 441 }
 442
 443 /* duplicate a handle */
 444 int duplicate_handle( struct process *src, int src_handle, struct process *dst,
 445                       unsigned int access, int inherit, int options )
 446 {
 447     int res;
 448     struct handle_entry *entry = get_handle( src, src_handle );
 449     if (!entry) return -1;
 450
 451     if (options & DUP_HANDLE_SAME_ACCESS) access = entry->access;
 452     if (options & DUP_HANDLE_MAKE_GLOBAL) dst = initial_process;
 453     access &= ~RESERVED_ALL;
 454     res = alloc_handle( dst, entry->ptr, access, inherit );
 455     if (options & DUP_HANDLE_MAKE_GLOBAL) res = HANDLE_LOCAL_TO_GLOBAL(res);
 456     return res;
 457 }
 458
 459 /* open a new handle to an existing object */
 460 int open_object( const char *name, const struct object_ops *ops,
 461                  unsigned int access, int inherit )
 462 {
 463     struct object *obj = find_object( name );
 464     if (!obj)
 465     {
 466         SET_ERROR( ERROR_FILE_NOT_FOUND );
 467         return -1;
 468     }
 469     if (ops && obj->ops != ops)
 470     {
 471         release_object( obj );
 472         SET_ERROR( ERROR_INVALID_HANDLE );  /* FIXME: not the right type */
 473         return -1;
 474     }
 475     return alloc_handle( current->process, obj, access, inherit );
 476 }
 477
 478 /* dump a handle table on stdout */
 479 void dump_handles( struct process *process )
 480 {
 481     struct handle_entry *entry;
 482     int i;
 483
 484     if (!process->entries) return;
 485     entry = process->entries;
 486     for (i = 0; i <= process->handle_last; i++, entry++)
 487     {
 488         if (!entry->ptr) continue;
 489         printf( "%5d: %p %08x ", i + 1, entry->ptr, entry->access );
 490         entry->ptr->ops->dump( entry->ptr, 0 );
 491     }
 492 }
 493
 494 /* kill a process on the spot */
 495 void kill_process( struct process *process, int exit_code )
 496 {
 497     while (process->thread_list)
 498         kill_thread( process->thread_list, exit_code );
 499 }
 500
 501 /* get all information about a process */
 502 void get_process_info( struct process *process,
 503                        struct get_process_info_reply *reply )
 504 {
 505     reply->pid              = process;
 506     reply->exit_code        = process->exit_code;
 507     reply->priority         = process->priority;
 508     reply->process_affinity = process->affinity;
 509     reply->system_affinity  = 1;
 510 }
 511
 512 /* set all information about a process */
 513 void set_process_info( struct process *process,
 514                        struct set_process_info_request *req )
 515 {
 516     if (req->mask & SET_PROCESS_INFO_PRIORITY)
 517         process->priority = req->priority;
 518     if (req->mask & SET_PROCESS_INFO_AFFINITY)
 519     {
 520         if (req->affinity != 1) SET_ERROR( ERROR_INVALID_PARAMETER );
 521         else process->affinity = req->affinity;
 522     }
 523 }
 524
 525 /* allocate a console for this process */
 526 int alloc_console( struct process *process )
 527 {
 528     struct object *obj[2];
 529     if (process->console_in || process->console_out)
 530     {
 531         SET_ERROR( ERROR_ACCESS_DENIED );
 532         return 0;
 533     }
 534     if (!create_console( -1, obj )) return 0;
 535     process->console_in  = obj[0];
 536     process->console_out = obj[1];
 537     return 1;
 538 }
 539
 540 /* free the console for this process */
 541 int free_console( struct process *process )
 542 {
 543     if (process->console_in) release_object( process->console_in );
 544     if (process->console_out) release_object( process->console_out );
 545     process->console_in = process->console_out = NULL;
 546     return 1;
 547 }
 548
 549 /* get the process console */
 550 struct object *get_console( struct process *process, int output )
 551 {
 552     struct object *obj;
 553     if (!(obj = output ? process->console_out : process->console_in))
 554         return NULL;
 555     return grab_object( obj );
 556 }
 557
 558 /* take a snapshot of currently running processes */
 559 struct process_snapshot *process_snap( int *count )
 560 {
 561     struct process_snapshot *snapshot, *ptr;
 562     struct process *process;
 563     if (!running_processes) return NULL;
 564     if (!(snapshot = mem_alloc( sizeof(*snapshot) * running_processes )))
 565         return NULL;
 566     ptr = snapshot;
 567     for (process = first_process; process; process = process->next)
 568     {
 569         if (!process->running_threads) continue;
 570         ptr->process  = process;
 571         ptr->threads  = process->running_threads;
 572         ptr->priority = process->priority;
 573         grab_object( process );
 574         ptr++;
 575     }
 576     *count = running_processes;
 577     return snapshot;
 578 }