server/mapping.c

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