server/mapping.c

   1 /*
   2  * Server-side file mapping management
   3  *
   4  * Copyright (C) 1999 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 #include <assert.h>
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <unistd.h>
  13
  14 #include "winnt.h"
  15 #include "winbase.h"
  16
  17 #include "handle.h"
  18 #include "thread.h"
  19 #include "request.h"
  20
  21 struct mapping
  22 {
  23     struct object   obj;             /* object header */
  24     int             size_high;       /* mapping size */
  25     int             size_low;        /* mapping size */
  26     int             protect;         /* protection flags */
  27     struct file    *file;            /* file mapped */
  28     int             header_size;     /* size of headers (for PE image mapping) */
  29     void           *base;            /* default base addr (for PE image mapping) */
  30     struct file    *shared_file;     /* temp file for shared PE mapping */
  31     int             shared_size;     /* shared mapping total size */
  32     struct mapping *shared_next;     /* next in shared PE mapping list */
  33     struct mapping *shared_prev;     /* prev in shared PE mapping list */
  34 };
  35
  36 static int mapping_get_fd( struct object *obj );
  37 static int mapping_get_info( struct object *obj, struct get_file_info_reply *reply );
  38 static void mapping_dump( struct object *obj, int verbose );
  39 static void mapping_destroy( struct object *obj );
  40
  41 static const struct object_ops mapping_ops =
  42 {
  43     sizeof(struct mapping),      /* size */
  44     mapping_dump,                /* dump */
  45     no_add_queue,                /* add_queue */
  46     NULL,                        /* remove_queue */
  47     NULL,                        /* signaled */
  48     NULL,                        /* satisfied */
  49     NULL,                        /* get_poll_events */
  50     NULL,                        /* poll_event */
  51     mapping_get_fd,              /* get_fd */
  52     no_flush,                    /* flush */
  53     mapping_get_info,            /* get_file_info */
  54     mapping_destroy              /* destroy */
  55 };
  56
  57 static struct mapping *shared_first;
  58
  59 #ifdef __i386__
  60
  61 /* These are always the same on an i386, and it will be faster this way */
  62 # define page_mask  0xfff
  63 # define page_shift 12
  64 # define init_page_size() do { /* nothing */ } while(0)
  65
  66 #else  /* __i386__ */
  67
  68 static int page_shift, page_mask;
  69
  70 static void init_page_size(void)
  71 {
  72     int page_size;
  73 # ifdef HAVE_GETPAGESIZE
  74     page_size = getpagesize();
  75 # else
  76 #  ifdef __svr4__
  77     page_size = sysconf(_SC_PAGESIZE);
  78 #  else
  79 #   error Cannot get the page size on this platform
  80 #  endif
  81 # endif
  82     page_mask = page_size - 1;
  83     /* Make sure we have a power of 2 */
  84     assert( !(page_size & page_mask) );
  85     page_shift = 0;
  86     while ((1 << page_shift) != page_size) page_shift++;
  87 }
  88 #endif  /* __i386__ */
  89
  90 #define ROUND_ADDR(addr) \
  91    ((int)(addr) & ~page_mask)
  92
  93 #define ROUND_SIZE(addr,size) \
  94    (((int)(size) + ((int)(addr) & page_mask) + page_mask) & ~page_mask)
  95
  96 /* get the fd to use for mmaping a file */
  97 inline static int get_mmap_fd( struct file *file )
  98 {
  99     struct object *obj;
 100     if (!(obj = (struct object *)file))
 101     {
 102         set_error( STATUS_INVALID_HANDLE );
 103         return -1;
 104     }
 105     return obj->ops->get_fd( obj );
 106 }
 107
 108 /* find the shared PE mapping for a given mapping */
 109 static struct file *get_shared_file( struct mapping *mapping )
 110 {
 111     struct mapping *ptr;
 112
 113     for (ptr = shared_first; ptr; ptr = ptr->shared_next)
 114         if (is_same_file( ptr->file, mapping->file ))
 115             return (struct file *)grab_object( ptr->shared_file );
 116     return NULL;
 117 }
 118
 119 /* allocate and fill the temp file for a shared PE image mapping */
 120 static int build_shared_mapping( struct mapping *mapping, int fd,
 121                                  IMAGE_SECTION_HEADER *sec, int nb_sec )
 122 {
 123     int i, max_size, total_size, pos;
 124     char *buffer = NULL;
 125     int shared_fd;
 126     long toread;
 127
 128     /* compute the total size of the shared mapping */
 129
 130     total_size = max_size = 0;
 131     for (i = 0; i < nb_sec; i++)
 132     {
 133         if ((sec[i].Characteristics & IMAGE_SCN_MEM_SHARED) &&
 134             (sec[i].Characteristics & IMAGE_SCN_MEM_WRITE))
 135         {
 136             int size = ROUND_SIZE( 0, sec[i].Misc.VirtualSize );
 137             if (size > max_size) max_size = size;
 138             total_size += size;
 139         }
 140     }
 141     if (!(mapping->shared_size = total_size)) return 1;  /* nothing to do */
 142
 143     if ((mapping->shared_file = get_shared_file( mapping ))) return 1;
 144
 145     /* create a temp file for the mapping */
 146
 147     if (!(mapping->shared_file = create_temp_file( GENERIC_READ|GENERIC_WRITE ))) goto error;
 148     if (!grow_file( mapping->shared_file, 0, total_size )) goto error;
 149     if ((shared_fd = get_mmap_fd( mapping->shared_file )) == -1) goto error;
 150
 151     if (!(buffer = malloc( max_size ))) goto error;
 152
 153     /* copy the shared sections data into the temp file */
 154
 155     for (i = pos = 0; i < nb_sec; i++)
 156     {
 157         if (!(sec[i].Characteristics & IMAGE_SCN_MEM_SHARED)) continue;
 158         if (!(sec[i].Characteristics & IMAGE_SCN_MEM_WRITE)) continue;
 159         if (lseek( shared_fd, pos, SEEK_SET ) != pos) goto error;
 160         pos += ROUND_SIZE( 0, sec[i].Misc.VirtualSize );
 161         if (sec[i].Characteristics & IMAGE_SCN_CNT_UNINITIALIZED_DATA) continue;
 162         if (!sec[i].PointerToRawData || !sec[i].SizeOfRawData) continue;
 163         if (lseek( fd, sec[i].PointerToRawData, SEEK_SET ) != sec[i].PointerToRawData) goto error;
 164         toread = sec[i].SizeOfRawData;
 165         while (toread)
 166         {
 167             long res = read( fd, buffer + sec[i].SizeOfRawData - toread, toread );
 168             if (res <= 0) goto error;
 169             toread -= res;
 170         }
 171         if (write( shared_fd, buffer, sec[i].SizeOfRawData ) != sec[i].SizeOfRawData) goto error;
 172     }
 173     free( buffer );
 174     return 1;
 175
 176  error:
 177     if (buffer) free( buffer );
 178     return 0;
 179 }
 180
 181 /* retrieve the mapping parameters for an executable (PE) image */
 182 static int get_image_params( struct mapping *mapping )
 183 {
 184     IMAGE_DOS_HEADER dos;
 185     IMAGE_NT_HEADERS nt;
 186     IMAGE_SECTION_HEADER *sec = NULL;
 187     int fd, filepos, size;
 188
 189     /* load the headers */
 190
 191     if ((fd = get_mmap_fd( mapping->file )) == -1) return 0;
 192     filepos = lseek( fd, 0, SEEK_SET );
 193     if (read( fd, &dos, sizeof(dos) ) != sizeof(dos)) goto error;
 194     if (dos.e_magic != IMAGE_DOS_SIGNATURE) goto error;
 195     if (lseek( fd, dos.e_lfanew, SEEK_SET ) == -1) goto error;
 196     if (read( fd, &nt, sizeof(nt) ) != sizeof(nt)) goto error;
 197     if (nt.Signature != IMAGE_NT_SIGNATURE) goto error;
 198
 199     /* load the section headers */
 200
 201     size = sizeof(*sec) * nt.FileHeader.NumberOfSections;
 202     if (!(sec = malloc( size ))) goto error;
 203     if (read( fd, sec, size ) != size) goto error;
 204
 205     if (!build_shared_mapping( mapping, fd, sec, nt.FileHeader.NumberOfSections )) goto error;
 206
 207     if (mapping->shared_file)  /* link it in the list */
 208     {
 209         if ((mapping->shared_next = shared_first)) shared_first->shared_prev = mapping;
 210         mapping->shared_prev = NULL;
 211         shared_first = mapping;
 212     }
 213
 214     mapping->size_low    = ROUND_SIZE( 0, nt.OptionalHeader.SizeOfImage );
 215     mapping->size_high   = 0;
 216     mapping->base        = (void *)nt.OptionalHeader.ImageBase;
 217     mapping->header_size = ROUND_SIZE( mapping->base, nt.OptionalHeader.SizeOfHeaders );
 218     mapping->protect     = VPROT_IMAGE;
 219
 220     /* sanity check */
 221     if (mapping->header_size > mapping->size_low) goto error;
 222
 223     lseek( fd, filepos, SEEK_SET );
 224     free( sec );
 225     return 1;
 226
 227  error:
 228     lseek( fd, filepos, SEEK_SET );
 229     if (sec) free( sec );
 230     set_error( STATUS_INVALID_FILE_FOR_SECTION );
 231     return 0;
 232 }
 233
 234
 235 static struct object *create_mapping( int size_high, int size_low, int protect,
 236                                       handle_t handle, const WCHAR *name, size_t len )
 237 {
 238     struct mapping *mapping;
 239     int access = 0;
 240
 241     if (!page_mask) init_page_size();
 242
 243     if (!(mapping = create_named_object( &mapping_ops, name, len )))
 244         return NULL;
 245     if (get_error() == STATUS_OBJECT_NAME_COLLISION)
 246         return &mapping->obj;  /* Nothing else to do */
 247
 248     mapping->header_size = 0;
 249     mapping->base        = NULL;
 250     mapping->shared_file = NULL;
 251     mapping->shared_size = 0;
 252
 253     if (protect & VPROT_READ) access |= GENERIC_READ;
 254     if (protect & VPROT_WRITE) access |= GENERIC_WRITE;
 255
 256     if (handle)
 257     {
 258         if (!(mapping->file = get_file_obj( current->process, handle, access ))) goto error;
 259         if (protect & VPROT_IMAGE)
 260         {
 261             if (!get_image_params( mapping )) goto error;
 262             return &mapping->obj;
 263         }
 264         if (!size_high && !size_low)
 265         {
 266             struct get_file_info_reply reply;
 267             struct object *obj = (struct object *)mapping->file;
 268             obj->ops->get_file_info( obj, &reply );
 269             size_high = reply.size_high;
 270             size_low  = ROUND_SIZE( 0, reply.size_low );
 271         }
 272         else if (!grow_file( mapping->file, size_high, size_low )) goto error;
 273     }
 274     else  /* Anonymous mapping (no associated file) */
 275     {
 276         if ((!size_high && !size_low) || (protect & VPROT_IMAGE))
 277         {
 278             set_error( STATUS_INVALID_PARAMETER );
 279             mapping->file = NULL;
 280             goto error;
 281         }
 282         if (!(mapping->file = create_temp_file( access ))) goto error;
 283         if (!grow_file( mapping->file, size_high, size_low )) goto error;
 284     }
 285     mapping->size_high = size_high;
 286     mapping->size_low  = ROUND_SIZE( 0, size_low );
 287     mapping->protect   = protect;
 288     return &mapping->obj;
 289
 290  error:
 291     release_object( mapping );
 292     return NULL;
 293 }
 294
 295 static void mapping_dump( struct object *obj, int verbose )
 296 {
 297     struct mapping *mapping = (struct mapping *)obj;
 298     assert( obj->ops == &mapping_ops );
 299     fprintf( stderr, "Mapping size=%08x%08x prot=%08x file=%p header_size=%08x base=%p "
 300              "shared_file=%p shared_size=%08x ",
 301              mapping->size_high, mapping->size_low, mapping->protect, mapping->file,
 302              mapping->header_size, mapping->base, mapping->shared_file, mapping->shared_size );
 303     dump_object_name( &mapping->obj );
 304     fputc( '\n', stderr );
 305 }
 306
 307 static int mapping_get_fd( struct object *obj )
 308 {
 309     struct mapping *mapping = (struct mapping *)obj;
 310     assert( obj->ops == &mapping_ops );
 311     return get_mmap_fd( mapping->file );
 312 }
 313
 314 static int mapping_get_info( struct object *obj, struct get_file_info_reply *reply )
 315 {
 316     struct mapping *mapping = (struct mapping *)obj;
 317     struct object *file = (struct object *)mapping->file;
 318
 319     assert( obj->ops == &mapping_ops );
 320     assert( file );
 321     return file->ops->get_file_info( file, reply );
 322 }
 323
 324 static void mapping_destroy( struct object *obj )
 325 {
 326     struct mapping *mapping = (struct mapping *)obj;
 327     assert( obj->ops == &mapping_ops );
 328     if (mapping->file) release_object( mapping->file );
 329     if (mapping->shared_file)
 330     {
 331         release_object( mapping->shared_file );
 332         if (mapping->shared_next) mapping->shared_next->shared_prev = mapping->shared_prev;
 333         if (mapping->shared_prev) mapping->shared_prev->shared_next = mapping->shared_next;
 334         else shared_first = mapping->shared_next;
 335     }
 336 }
 337
 338 int get_page_size(void)
 339 {
 340     if (!page_mask) init_page_size();
 341     return page_mask + 1;
 342 }
 343
 344 /* create a file mapping */
 345 DECL_HANDLER(create_mapping)
 346 {
 347     struct object *obj;
 348
 349     reply->handle = 0;
 350     if ((obj = create_mapping( req->size_high, req->size_low,
 351                                req->protect, req->file_handle,
 352                                get_req_data(), get_req_data_size() )))
 353     {
 354         int access = FILE_MAP_ALL_ACCESS;
 355         if (!(req->protect & VPROT_WRITE)) access &= ~FILE_MAP_WRITE;
 356         reply->handle = alloc_handle( current->process, obj, access, req->inherit );
 357         release_object( obj );
 358     }
 359 }
 360
 361 /* open a handle to a mapping */
 362 DECL_HANDLER(open_mapping)
 363 {
 364     reply->handle = open_object( get_req_data(), get_req_data_size(),
 365                                  &mapping_ops, req->access, req->inherit );
 366 }
 367
 368 /* get a mapping information */
 369 DECL_HANDLER(get_mapping_info)
 370 {
 371     struct mapping *mapping;
 372
 373     if ((mapping = (struct mapping *)get_handle_obj( current->process, req->handle,
 374                                                      0, &mapping_ops )))
 375     {
 376         reply->size_high   = mapping->size_high;
 377         reply->size_low    = mapping->size_low;
 378         reply->protect     = mapping->protect;
 379         reply->header_size = mapping->header_size;
 380         reply->base        = mapping->base;
 381         reply->shared_file = 0;
 382         reply->shared_size = mapping->shared_size;
 383         reply->drive_type  = get_file_drive_type( mapping->file );
 384         if (mapping->shared_file)
 385             reply->shared_file = alloc_handle( current->process, mapping->shared_file,
 386                                                GENERIC_READ|GENERIC_WRITE, 0 );
 387         release_object( mapping );
 388     }
 389 }