rdoff/rdoff.c

   1 /* rdoff.c      library of routines for manipulating rdoff files
   2  *
   3  * The Netwide Assembler is copyright (C) 1996 Simon Tatham and
   4  * Julian Hall. All rights reserved. The software is
   5  * redistributable under the licence given in the file "Licence"
   6  * distributed in the NASM archive.
   7  *
   8  * Permission to use this file in your own projects is granted, as long
   9  * as acknowledgement is given in an appropriate manner to its authors,
  10  * with instructions of how to obtain a copy via ftp.
  11  */
  12
  13 /* TODO:        The functions in this module assume they are running
  14  *              on a little-endian machine. This should be fixed to
  15  *              make it portable.
  16  */
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <string.h>
  21 #include <errno.h>
  22
  23 #include "multboot.h"
  24 #include "rdoff.h"
  25
  26 #define newstr(str) strcpy(malloc(strlen(str) + 1),str)
  27 #define newstrcat(s1,s2) strcat(strcpy(malloc(strlen(s1) + strlen(s2) + 1), \
  28                                        s1),s2)
  29
  30 /*
  31  * Comment this out to allow the module to read & write header record types
  32  * that it isn't aware of. With this defined, unrecognised header records
  33  * will generate error number 8, reported as 'unknown extended header record'.
  34  */
  35
  36 #define STRICT_ERRORS
  37
  38 /* ========================================================================
  39  * Code for memory buffers (for delayed writing of header until we know
  40  * how long it is).
  41  * ======================================================================== */
  42
  43
  44 memorybuffer * newmembuf()
  45 {
  46     memorybuffer * t;
  47
  48     t = malloc(sizeof(memorybuffer));
  49     if (!t) return NULL;
  50
  51     t->length = 0;
  52     t->next = NULL;
  53     return t;
  54 }
  55
  56 void membufwrite(memorybuffer *const b, void *data, int bytes)
  57 {
  58     int16 w;
  59     long l;
  60
  61     if (b->next) {        /* memory buffer full - use next buffer */
  62         membufwrite(b->next,data,bytes);
  63         return;
  64     }
  65
  66     if ((bytes < 0 && b->length - bytes > BUF_BLOCK_LEN)
  67         || (bytes > 0 && b->length + bytes > BUF_BLOCK_LEN))
  68     {
  69
  70         /* buffer full and no next allocated... allocate and initialise next
  71          * buffer */
  72         b->next = newmembuf();
  73         membufwrite(b->next,data,bytes);
  74         return;
  75     }
  76
  77     switch(bytes) {
  78     case -4:              /* convert to little-endian */
  79         l = * (long *) data ;
  80         b->buffer[b->length++] = l & 0xFF;
  81         l >>= 8 ;
  82         b->buffer[b->length++] = l & 0xFF;
  83         l >>= 8 ;
  84         b->buffer[b->length++] = l & 0xFF;
  85         l >>= 8 ;
  86         b->buffer[b->length++] = l & 0xFF;
  87         break;
  88
  89     case -2:
  90         w = * (int16 *) data ;
  91         b->buffer[b->length++] = w & 0xFF;
  92         w >>= 8 ;
  93         b->buffer[b->length++] = w & 0xFF;
  94         break;
  95
  96     default:
  97         while(bytes--) {
  98             b->buffer[b->length++] = *(* (unsigned char **) &data);
  99
 100             (* (unsigned char **) &data)++ ;
 101         }
 102         break;
 103     }
 104 }
 105
 106 void membufdump(memorybuffer *b,FILE *fp)
 107 {
 108     if (!b) return;
 109
 110     fwrite (b->buffer, 1, b->length, fp);
 111
 112     membufdump(b->next,fp);
 113 }
 114
 115 int membuflength(memorybuffer *b)
 116 {
 117     if (!b) return 0;
 118     return b->length + membuflength(b->next);
 119 }
 120
 121 void freemembuf(memorybuffer *b)
 122 {
 123     if (!b) return;
 124     freemembuf(b->next);
 125     free(b);
 126 }
 127
 128 /* =========================================================================
 129    General purpose routines and variables used by the library functions
 130    ========================================================================= */
 131
 132 /*
 133  * translatelong() and translateshort()
 134  *
 135  * translate from little endian to local representation
 136  */
 137 long translatelong(long in)
 138 {
 139     long r;
 140     unsigned char *i;
 141
 142     i = (unsigned char *)&in;
 143     r = i[3];
 144     r = (r << 8) + i[2];
 145     r = (r << 8) + i[1];
 146     r = (r << 8) + *i;
 147
 148     return r;
 149 }
 150
 151 int16 translateshort(int16 in)
 152 {
 153     int16 r;
 154     unsigned char * i;
 155
 156     i = (unsigned char *)&in;
 157     r = (i[1] << 8) + i[0];
 158
 159     return r;
 160 }
 161
 162 const char *RDOFFId = "RDOFF2"; /* written to the start of RDOFF files */
 163
 164 const char *rdf_errors[11] = {
 165   "no error occurred","could not open file","invalid file format",
 166   "error reading file","unknown error","header not read",
 167   "out of memory", "RDOFF v1 not supported",
 168   "unknown extended header record",
 169   "header record of known type but unknown length",
 170   "no such segment"};
 171
 172 int rdf_errno = 0;
 173
 174 /* ========================================================================
 175    The library functions
 176    ======================================================================== */
 177
 178 int rdfopen(rdffile *f, const char *name)
 179 {
 180     FILE * fp;
 181
 182     fp = fopen(name,"rb");
 183     if (!fp) return rdf_errno = 1;              /* error 1: file open error */
 184
 185     return rdfopenhere(f,fp,NULL,name);
 186 }
 187
 188 int rdfopenhere(rdffile *f, FILE *fp, int *refcount, const char *name)
 189 {
 190   char buf[8];
 191   long initpos;
 192   long l;
 193   int16 s;
 194
 195   if (translatelong(0x01020304) != 0x01020304)
 196   {                                     /* fix this to be portable! */
 197     fputs("*** this program requires a little endian machine\n",stderr);
 198     fprintf(stderr,"01020304h = %08lxh\n",translatelong(0x01020304));
 199     exit(3);
 200   }
 201
 202   f->fp = fp;
 203   initpos = ftell(fp);
 204
 205   fread(buf,6,1,f->fp);         /* read header */
 206   buf[6] = 0;
 207
 208   if (strcmp(buf,RDOFFId)) {
 209     fclose(f->fp);
 210     if (!strcmp(buf,"RDOFF1"))
 211         return rdf_errno = 7;   /* error 7: RDOFF 1 not supported */
 212     return rdf_errno = 2;       /* error 2: invalid file format */
 213   }
 214
 215   if (fread(&l,1,4,f->fp) != 4 ||
 216       fread(&f->header_len,1,4,f->fp) != 4) {
 217     fclose(f->fp);
 218     return rdf_errno = 3;       /* error 3: file read error */
 219   }
 220
 221   f->header_ofs = ftell(f->fp);
 222   f->eof_offset = f->header_ofs + translatelong(l) - 4;
 223
 224   if (fseek(f->fp,f->header_len,SEEK_CUR)) {
 225     fclose(f->fp);
 226     return rdf_errno = 2;       /* seek past end of file...? */
 227   }
 228
 229   if (fread(&s,1,2,f->fp) != 2) {
 230       fclose(f->fp);
 231       return rdf_errno = 3;
 232   }
 233
 234   f->nsegs = 0;
 235
 236   while (s != 0)
 237   {
 238       f->seg[f->nsegs].type = s;
 239       if (fread(&f->seg[f->nsegs].number,1,2,f->fp) != 2 ||
 240           fread(&f->seg[f->nsegs].reserved,1,2,f->fp) != 2 ||
 241           fread(&f->seg[f->nsegs].length,1,4,f->fp) != 4)
 242       {
 243           fclose(f->fp);
 244           return rdf_errno = 3;
 245       }
 246
 247       f->seg[f->nsegs].offset = ftell(f->fp);
 248       if (fseek(f->fp,f->seg[f->nsegs].length,SEEK_CUR)) {
 249           fclose(f->fp);
 250           return rdf_errno = 2;
 251       }
 252       f->nsegs++;
 253
 254       if (fread(&s,1,2,f->fp) != 2) {
 255           fclose(f->fp);
 256           return rdf_errno = 3;
 257       }
 258   }
 259
 260   if (f->eof_offset != ftell(f->fp) + 8)  /* +8 = skip null segment header */
 261   {
 262       fprintf(stderr, "warning: eof_offset [%ld] and actual eof offset "
 263               "[%ld] don't match\n", f->eof_offset, ftell(f->fp) + 8);
 264   }
 265   fseek(f->fp,initpos,SEEK_SET);
 266   f->header_loc = NULL;
 267
 268   f->name = newstr(name);
 269   f->refcount = refcount;
 270   if (refcount) (*refcount)++;
 271   return 0;
 272 }
 273
 274 int rdfclose(rdffile *f)
 275 {
 276     if (! f->refcount || ! --(*f->refcount))
 277      {
 278       fclose(f->fp);
 279       f->fp = NULL;
 280      }
 281     free(f->name);
 282
 283     return 0;
 284 }
 285
 286 void rdfperror(const char *app,const char *name)
 287 {
 288   fprintf(stderr,"%s:%s: %s\n",app,name,rdf_errors[rdf_errno]);
 289   if (rdf_errno == 1 || rdf_errno == 3)
 290   {
 291       perror(app);
 292   }
 293
 294 }
 295
 296 int rdffindsegment(rdffile * f, int segno)
 297 {
 298     int i;
 299     for (i = 0; i < f->nsegs; i++)
 300         if (f->seg[i].number == segno) return i;
 301     return -1;
 302 }
 303
 304 int rdfloadseg(rdffile *f,int segment,void *buffer)
 305 {
 306   long fpos;
 307   long slen;
 308
 309   switch(segment) {
 310   case RDOFF_HEADER:
 311       fpos = f->header_ofs;
 312       slen = f->header_len;
 313       f->header_loc = (byte *)buffer;
 314       f->header_fp = 0;
 315       break;
 316   default:
 317       if (segment < f->nsegs) {
 318           fpos = f->seg[segment].offset;
 319           slen = f->seg[segment].length;
 320           f->seg[segment].data = (byte *)buffer;
 321       }
 322       else {
 323           return rdf_errno = 10; /* no such segment */
 324       }
 325   }
 326
 327   if (fseek(f->fp,fpos,SEEK_SET))
 328     return rdf_errno = 4;
 329
 330   if (fread(buffer,1,slen,f->fp) != slen)
 331     return rdf_errno = 3;
 332
 333   return 0;
 334 }
 335
 336 /* Macros for reading integers from header in memory */
 337
 338 #define RI8(v) v = f->header_loc[f->header_fp++]
 339 #define RI16(v) { v = (f->header_loc[f->header_fp] + \
 340                        (f->header_loc[f->header_fp+1] << 8)); \
 341                   f->header_fp += 2; }
 342
 343 #define RI32(v) { v = (f->header_loc[f->header_fp] + \
 344                        (f->header_loc[f->header_fp+1] << 8) + \
 345                        (f->header_loc[f->header_fp+2] << 16) + \
 346                        (f->header_loc[f->header_fp+3] << 24)); \
 347                   f->header_fp += 4; }
 348
 349 #define RS(str,max) { for(i=0;i<max;i++){\
 350   RI8(str[i]); if (!str[i]) break;} str[i]=0; }
 351
 352 rdfheaderrec *rdfgetheaderrec(rdffile *f)
 353 {
 354   static rdfheaderrec r;
 355   int i;
 356
 357   if (!f->header_loc) {
 358     rdf_errno = 5;
 359     return NULL;
 360   }
 361
 362   if (f->header_fp >= f->header_len) return 0;
 363
 364   RI8(r.type);
 365   RI8(r.g.reclen);
 366
 367   switch(r.type) {
 368   case 1:       /* Relocation record */
 369   case 6:
 370       if (r.r.reclen != 8) {
 371           rdf_errno = 9;
 372           return NULL;
 373       }
 374     RI8(r.r.segment);
 375     RI32(r.r.offset);
 376     RI8(r.r.length);
 377     RI16(r.r.refseg);
 378     break;
 379
 380   case 2:       /* Imported symbol record */
 381   case 7:
 382     RI16(r.i.segment);
 383     RS(r.i.label,32);
 384     break;
 385
 386   case 3:       /* Exported symbol record */
 387     RI8(r.e.flags);
 388     RI8(r.e.segment);
 389     RI32(r.e.offset);
 390     RS(r.e.label,32);
 391     break;
 392
 393   case 4:       /* DLL record */
 394     RS(r.d.libname,127);
 395     break;
 396
 397   case 5:       /* BSS reservation record */
 398       if (r.r.reclen != 4) {
 399           rdf_errno = 9;
 400           return NULL;
 401       }
 402     RI32(r.b.amount);
 403     break;
 404
 405   case 8:       /* Module name record */
 406     RS(r.m.modname,127);
 407     break;
 408
 409   default:
 410 #ifdef STRICT_ERRORS
 411     rdf_errno = 8; /* unknown header record */
 412     return NULL;
 413 #else
 414     for (i = 0; i < r.g.reclen; i++)
 415         RI8(r.g.data[i]);
 416 #endif
 417   }
 418   return &r;
 419 }
 420
 421 void rdfheaderrewind(rdffile *f)
 422 {
 423   f->header_fp = 0;
 424 }
 425
 426
 427 rdf_headerbuf * rdfnewheader(void)
 428 {
 429     rdf_headerbuf * hb = malloc(sizeof(rdf_headerbuf));
 430     if (hb == NULL) return NULL;
 431
 432     hb->buf = newmembuf();
 433     hb->nsegments = 0;
 434     hb->seglength = 0;
 435
 436     return hb;
 437 }
 438
 439 int rdfaddheader(rdf_headerbuf * h, rdfheaderrec * r)
 440 {
 441 #ifndef STRICT_ERRORS
 442     int i;
 443 #endif
 444     membufwrite(h->buf,&r->type,1);
 445     membufwrite(h->buf,&r->g.reclen,1);
 446
 447     switch (r->type)
 448     {
 449     case 1:
 450     case 6:
 451         membufwrite(h->buf,&r->r.segment,1);
 452         membufwrite(h->buf,&r->r.offset,-4);
 453         membufwrite(h->buf,&r->r.length,1);
 454         membufwrite(h->buf,&r->r.refseg,-2);    /* 9 bytes written */
 455         break;
 456
 457     case 2:                             /* import */
 458     case 7:
 459         membufwrite(h->buf,&r->i.segment,-2);
 460         membufwrite(h->buf,&r->i.label,strlen(r->i.label) + 1);
 461         break ;
 462
 463     case 3:                             /* export */
 464         membufwrite(h->buf,&r->e.flags,1);
 465         membufwrite(h->buf,&r->e.segment,1);
 466         membufwrite(h->buf,&r->e.offset,-4);
 467         membufwrite(h->buf,&r->e.label,strlen(r->e.label) + 1);
 468         break ;
 469
 470     case 4:                             /* DLL */
 471         membufwrite(h->buf,&r->d.libname,strlen(r->d.libname) + 1);
 472         break ;
 473
 474     case 5:                             /* BSS */
 475         membufwrite(h->buf,&r->b.amount,-4);
 476         break ;
 477
 478     case 8:                             /* Module name */
 479         membufwrite(h->buf,&r->m.modname,strlen(r->m.modname) + 1);
 480         break ;
 481
 482 #ifdef _MULTBOOT_H
 483     case 9:                             /* MultiBoot header */
 484         membufwrite(h->buf,&r->mbh.mb,sizeof(struct tMultiBootHeader)+RDFLDRMOVER_SIZE);
 485         break ;
 486 #endif
 487
 488     default:
 489 #ifdef STRICT_ERRORS
 490         return (rdf_errno = 8);
 491 #else
 492         for (i = 0; i < r->g.reclen; i++)
 493             membufwrite(h->buf, r->g.data[i], 1);
 494 #endif
 495     }
 496     return 0;
 497 }
 498
 499 int rdfaddsegment(rdf_headerbuf *h, long seglength)
 500 {
 501     h->nsegments ++;
 502     h->seglength += seglength;
 503     return 0;
 504 }
 505
 506 int rdfwriteheader(FILE * fp, rdf_headerbuf * h)
 507 {
 508     long                l, l2;
 509
 510     fwrite (RDOFFId, 1, strlen(RDOFFId), fp) ;
 511
 512     l = membuflength (h->buf);
 513     l2 = l + 14 + 10*h->nsegments + h->seglength;
 514     l = translatelong(l);
 515     l2 = translatelong(l2);
 516     fwrite (&l2, 4, 1, fp);     /* object length */
 517     fwrite (&l, 4, 1, fp);      /* header length */
 518
 519     membufdump(h->buf, fp);
 520
 521     return 0;           /* no error handling in here... CHANGE THIS! */
 522 }
 523
 524 void rdfdoneheader(rdf_headerbuf * h)
 525 {
 526     freemembuf(h->buf);
 527     free(h);
 528 }
 529