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