1 /* dl_vms.xs 2 * 3 * Platform: OpenVMS, VAX or AXP 4 * Author: Charles Bailey bailey@newman.upenn.edu 5 * Revised: 12-Dec-1994 6 * 7 * Implementation Note 8 * This section is added as an aid to users and DynaLoader developers, in 9 * order to clarify the process of dynamic linking under VMS. 10 * dl_vms.xs uses the supported VMS dynamic linking call, which allows 11 * a running program to map an arbitrary file of executable code and call 12 * routines within that file. This is done via the VMS RTL routine 13 * lib$find_image_symbol, whose calling sequence is as follows: 14 * status = lib$find_image_symbol(imgname,symname,symval,defspec); 15 * where 16 * status = a standard VMS status value (unsigned long int) 17 * imgname = a fixed-length string descriptor, passed by 18 * reference, containing the NAME ONLY of the image 19 * file to be mapped. An attempt will be made to 20 * translate this string as a logical name, so it may 21 * not contain any characters which are not allowed in 22 * logical names. If no translation is found, imgname 23 * is used directly as the name of the image file. 24 * symname = a fixed-length string descriptor, passed by 25 * reference, containing the name of the routine 26 * to be located. 27 * symval = an unsigned long int, passed by reference, into 28 * which is written the entry point address of the 29 * routine whose name is specified in symname. 30 * defspec = a fixed-length string descriptor, passed by 31 * reference, containing a default file specification 32 * whichis used to fill in any missing parts of the 33 * image file specification after the imgname argument 34 * is processed. 35 * In order to accommodate the handling of the imgname argument, the routine 36 * dl_expandspec() is provided for use by perl code (e.g. dl_findfile) 37 * which wants to see what image file lib$find_image_symbol would use if 38 * it were passed a given file specification. The file specification passed 39 * to dl_expandspec() and dl_load_file() can be partial or complete, and can 40 * use VMS or Unix syntax; these routines perform the necessary conversions. 41 * In general, writers of perl extensions need only conform to the 42 * procedures set out in the DynaLoader documentation, and let the details 43 * be taken care of by the routines here and in DynaLoader.pm. If anyone 44 * comes across any incompatibilities, please let me know. Thanks. 45 * 46 */ 47 48 #include "EXTERN.h" 49 #include "perl.h" 50 #include "XSUB.h" 51 52 /* N.B.: 53 * dl_debug and dl_last_error are static vars; you'll need to deal 54 * with them appropriately if you need context independence 55 */ 56 57 #include <descrip.h> 58 #include <fscndef.h> 59 #include <lib$routines.h> 60 #include <rms.h> 61 #include <ssdef.h> 62 #include <starlet.h> 63 64 #if defined(VMS_WE_ARE_CASE_SENSITIVE) 65 #define DL_CASE_SENSITIVE 1<<4 66 #else 67 #define DL_CASE_SENSITIVE 0 68 #endif 69 70 typedef unsigned long int vmssts; 71 72 struct libref { 73 struct dsc$descriptor_s name; 74 struct dsc$descriptor_s defspec; 75 }; 76 77 typedef struct { 78 AV * x_require_symbols; 79 /* "Static" data for dl_expand_filespec() - This is static to save 80 * initialization on each call; if you need context-independence, 81 * just make these auto variables in dl_expandspec() and dl_load_file() 82 */ 83 char x_esa[NAM$C_MAXRSS]; 84 char x_rsa[NAM$C_MAXRSS]; 85 struct FAB x_fab; 86 struct NAM x_nam; 87 } my_cxtx_t; /* this *must* be named my_cxtx_t */ 88 89 #define DL_CXT_EXTRA /* ask for dl_cxtx to be defined in dlutils.c */ 90 #include "dlutils.c" /* dl_debug, dl_last_error; SaveError not used */ 91 92 #define dl_require_symbols (dl_cxtx.x_require_symbols) 93 #define dl_esa (dl_cxtx.x_esa) 94 #define dl_rsa (dl_cxtx.x_rsa) 95 #define dl_fab (dl_cxtx.x_fab) 96 #define dl_nam (dl_cxtx.x_nam) 97 98 /* $PutMsg action routine - records error message in dl_last_error */ 99 static vmssts 100 copy_errmsg(msg,unused) 101 struct dsc$descriptor_s * msg; 102 vmssts unused; 103 { 104 dTHX; 105 dMY_CXT; 106 if (*(msg->dsc$a_pointer) == '%') { /* first line */ 107 if (dl_last_error) 108 strncpy((dl_last_error = saferealloc(dl_last_error,msg->dsc$w_length+1)), 109 msg->dsc$a_pointer, msg->dsc$w_length); 110 else 111 strncpy((dl_last_error = safemalloc(msg->dsc$w_length+1)), 112 msg->dsc$a_pointer, msg->dsc$w_length); 113 dl_last_error[msg->dsc$w_length] = '\0'; 114 } 115 else { /* continuation line */ 116 int errlen = strlen(dl_last_error); 117 dl_last_error = saferealloc(dl_last_error, errlen + msg->dsc$w_length + 2); 118 dl_last_error[errlen] = '\n'; dl_last_error[errlen+1] = '\0'; 119 strncat(dl_last_error, msg->dsc$a_pointer, msg->dsc$w_length); 120 dl_last_error[errlen+msg->dsc$w_length+1] = '\0'; 121 } 122 return 0; 123 } 124 125 /* Use $PutMsg to retrieve error message for failure status code */ 126 static void 127 dl_set_error(sts,stv) 128 vmssts sts; 129 vmssts stv; 130 { 131 vmssts vec[3]; 132 dTHX; 133 134 vec[0] = stv ? 2 : 1; 135 vec[1] = sts; vec[2] = stv; 136 _ckvmssts(sys$putmsg(vec,copy_errmsg,0,0)); 137 } 138 139 static unsigned int 140 findsym_handler(void *sig, void *mech) 141 { 142 dTHX; 143 unsigned long int myvec[8],args, *usig = (unsigned long int *) sig; 144 /* Be paranoid and assume signal vector passed in might be readonly */ 145 myvec[0] = args = usig[0] > 10 ? 9 : usig[0] - 1; 146 while (--args) myvec[args] = usig[args]; 147 _ckvmssts(sys$putmsg(myvec,copy_errmsg,0,0)); 148 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "findsym_handler: received\n\t%s\n",dl_last_error)); 149 return SS$_CONTINUE; 150 } 151 152 /* wrapper for lib$find_image_symbol, so signalled errors can be saved 153 * for dl_error and then returned */ 154 static unsigned long int 155 my_find_image_symbol(struct dsc$descriptor_s *imgname, 156 struct dsc$descriptor_s *symname, 157 void (**entry)(), 158 struct dsc$descriptor_s *defspec) 159 { 160 unsigned long int retsts; 161 VAXC$ESTABLISH(findsym_handler); 162 retsts = lib$find_image_symbol(imgname,symname,entry,defspec,DL_CASE_SENSITIVE); 163 return retsts; 164 } 165 166 167 static void 168 dl_private_init(pTHX) 169 { 170 dl_generic_private_init(aTHX); 171 { 172 dMY_CXT; 173 dl_require_symbols = get_av("DynaLoader::dl_require_symbols", 0x4); 174 /* Set up the static control blocks for dl_expand_filespec() */ 175 dl_fab = cc$rms_fab; 176 dl_nam = cc$rms_nam; 177 dl_fab.fab$l_nam = &dl_nam; 178 dl_nam.nam$l_esa = dl_esa; 179 dl_nam.nam$b_ess = sizeof dl_esa; 180 dl_nam.nam$l_rsa = dl_rsa; 181 dl_nam.nam$b_rss = sizeof dl_rsa; 182 } 183 } 184 MODULE = DynaLoader PACKAGE = DynaLoader 185 186 BOOT: 187 (void)dl_private_init(aTHX); 188 189 void 190 dl_expandspec(filespec) 191 char * filespec 192 CODE: 193 char vmsspec[NAM$C_MAXRSS], defspec[NAM$C_MAXRSS]; 194 size_t deflen; 195 vmssts sts; 196 dMY_CXT; 197 198 tovmsspec(filespec,vmsspec); 199 dl_fab.fab$l_fna = vmsspec; 200 dl_fab.fab$b_fns = strlen(vmsspec); 201 dl_fab.fab$l_dna = 0; 202 dl_fab.fab$b_dns = 0; 203 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_expand_filespec(%s):\n",vmsspec)); 204 /* On the first pass, just parse the specification string */ 205 dl_nam.nam$b_nop = NAM$M_SYNCHK; 206 sts = sys$parse(&dl_fab); 207 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tSYNCHK sys$parse = %d\n",sts)); 208 if (!(sts & 1)) { 209 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv); 210 ST(0) = &PL_sv_undef; 211 } 212 else { 213 /* Now set up a default spec - everything but the name */ 214 deflen = dl_nam.nam$l_name - dl_esa; 215 memcpy(defspec,dl_esa,deflen); 216 memcpy(defspec+deflen,dl_nam.nam$l_type, 217 dl_nam.nam$b_type + dl_nam.nam$b_ver); 218 deflen += dl_nam.nam$b_type + dl_nam.nam$b_ver; 219 memcpy(vmsspec,dl_nam.nam$l_name,dl_nam.nam$b_name); 220 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsplit filespec: name = %.*s, default = %.*s\n", 221 dl_nam.nam$b_name,vmsspec,deflen,defspec)); 222 /* . . . and go back to expand it */ 223 dl_nam.nam$b_nop = 0; 224 dl_fab.fab$l_dna = defspec; 225 dl_fab.fab$b_dns = deflen; 226 dl_fab.fab$b_fns = dl_nam.nam$b_name; 227 sts = sys$parse(&dl_fab); 228 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tname/default sys$parse = %d\n",sts)); 229 if (!(sts & 1)) { 230 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv); 231 ST(0) = &PL_sv_undef; 232 } 233 else { 234 /* Now find the actual file */ 235 sts = sys$search(&dl_fab); 236 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsys$search = %d\n",sts)); 237 if (!(sts & 1)) { 238 dl_set_error(dl_fab.fab$l_sts,dl_fab.fab$l_stv); 239 ST(0) = &PL_sv_undef; 240 } 241 else { 242 ST(0) = sv_2mortal(newSVpvn(dl_nam.nam$l_rsa,dl_nam.nam$b_rsl)); 243 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "\tresult = \\%.*s\\\n", 244 dl_nam.nam$b_rsl,dl_nam.nam$l_rsa)); 245 } 246 } 247 } 248 249 void 250 dl_load_file(filespec, flags) 251 char * filespec 252 int flags 253 PREINIT: 254 dTHX; 255 dMY_CXT; 256 char vmsspec[NAM$C_MAXRSS]; 257 SV *reqSV, **reqSVhndl; 258 STRLEN deflen; 259 struct dsc$descriptor_s 260 specdsc = {0, DSC$K_DTYPE_T, DSC$K_CLASS_S, 0}, 261 symdsc = {0, DSC$K_DTYPE_T, DSC$K_CLASS_S, 0}; 262 struct fscnlst { 263 unsigned short int len; 264 unsigned short int code; 265 char *string; 266 } namlst[2] = {{0,FSCN$_NAME,0},{0,0,0}}; 267 struct libref *dlptr; 268 vmssts sts, failed = 0; 269 void (*entry)(); 270 CODE: 271 272 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_load_file(%s,%x):\n", filespec,flags)); 273 specdsc.dsc$a_pointer = tovmsspec(filespec,vmsspec); 274 specdsc.dsc$w_length = strlen(specdsc.dsc$a_pointer); 275 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tVMS-ified filespec is %s\n", 276 specdsc.dsc$a_pointer)); 277 Newx(dlptr,1,struct libref); 278 dlptr->name.dsc$b_dtype = dlptr->defspec.dsc$b_dtype = DSC$K_DTYPE_T; 279 dlptr->name.dsc$b_class = dlptr->defspec.dsc$b_class = DSC$K_CLASS_S; 280 sts = sys$filescan(&specdsc,namlst,0); 281 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tsys$filescan: returns %d, name is %.*s\n", 282 sts,namlst[0].len,namlst[0].string)); 283 if (!(sts & 1)) { 284 failed = 1; 285 dl_set_error(sts,0); 286 } 287 else { 288 dlptr->name.dsc$w_length = namlst[0].len; 289 dlptr->name.dsc$a_pointer = savepvn(namlst[0].string,namlst[0].len); 290 dlptr->defspec.dsc$w_length = specdsc.dsc$w_length - namlst[0].len; 291 Newx(dlptr->defspec.dsc$a_pointer, dlptr->defspec.dsc$w_length + 1, char); 292 deflen = namlst[0].string - specdsc.dsc$a_pointer; 293 memcpy(dlptr->defspec.dsc$a_pointer,specdsc.dsc$a_pointer,deflen); 294 memcpy(dlptr->defspec.dsc$a_pointer + deflen, 295 namlst[0].string + namlst[0].len, 296 dlptr->defspec.dsc$w_length - deflen); 297 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlibref = name: %s, defspec: %.*s\n", 298 dlptr->name.dsc$a_pointer, 299 dlptr->defspec.dsc$w_length, 300 dlptr->defspec.dsc$a_pointer)); 301 if (!(reqSVhndl = av_fetch(dl_require_symbols,0,FALSE)) || !(reqSV = *reqSVhndl)) { 302 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\t@dl_require_symbols empty, returning untested libref\n")); 303 } 304 else { 305 symdsc.dsc$w_length = SvCUR(reqSV); 306 symdsc.dsc$a_pointer = SvPVX(reqSV); 307 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\t$dl_require_symbols[0] = %.*s\n", 308 symdsc.dsc$w_length, symdsc.dsc$a_pointer)); 309 sts = my_find_image_symbol(&(dlptr->name),&symdsc, 310 &entry,&(dlptr->defspec)); 311 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlib$find_image_symbol returns %d\n",sts)); 312 if (!(sts&1)) { 313 failed = 1; 314 dl_set_error(sts,0); 315 } 316 } 317 } 318 319 if (failed) { 320 Safefree(dlptr->name.dsc$a_pointer); 321 Safefree(dlptr->defspec.dsc$a_pointer); 322 Safefree(dlptr); 323 ST(0) = &PL_sv_undef; 324 } 325 else { 326 ST(0) = sv_2mortal(newSViv(PTR2IV(dlptr))); 327 } 328 329 330 void 331 dl_find_symbol(librefptr,symname) 332 void * librefptr 333 SV * symname 334 CODE: 335 struct libref thislib = *((struct libref *)librefptr); 336 struct dsc$descriptor_s 337 symdsc = {SvCUR(symname),DSC$K_DTYPE_T,DSC$K_CLASS_S,SvPVX(symname)}; 338 void (*entry)(); 339 vmssts sts; 340 341 DLDEBUG(1,PerlIO_printf(Perl_debug_log, "dl_find_dymbol(%.*s,%.*s):\n", 342 thislib.name.dsc$w_length, thislib.name.dsc$a_pointer, 343 symdsc.dsc$w_length,symdsc.dsc$a_pointer)); 344 sts = my_find_image_symbol(&(thislib.name),&symdsc, 345 &entry,&(thislib.defspec)); 346 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tlib$find_image_symbol returns %d\n",sts)); 347 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "\tentry point is %d\n", 348 (unsigned long int) entry)); 349 if (!(sts & 1)) { 350 /* error message already saved by findsym_handler */ 351 ST(0) = &PL_sv_undef; 352 } 353 else ST(0) = sv_2mortal(newSViv(PTR2IV(entry))); 354 355 356 void 357 dl_undef_symbols() 358 PPCODE: 359 360 361 # These functions should not need changing on any platform: 362 363 void 364 dl_install_xsub(perl_name, symref, filename="$Package") 365 char * perl_name 366 void * symref 367 char * filename 368 CODE: 369 DLDEBUG(2,PerlIO_printf(Perl_debug_log, "dl_install_xsub(name=%s, symref=%x)\n", 370 perl_name, symref)); 371 ST(0) = sv_2mortal(newRV((SV*)newXS(perl_name, 372 (void(*)(pTHX_ CV *))symref, 373 filename))); 374 375 376 char * 377 dl_error() 378 CODE: 379 dMY_CXT; 380 RETVAL = dl_last_error ; 381 OUTPUT: 382 RETVAL 383 384 # end. 385