1 /* 2 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 3 * Use is subject to license terms. 4 */ 5 6 #pragma ident "%Z%%M% %I% %E% SMI" 7 8 /* 9 * k5-platform.h 10 * 11 * Copyright 2003, 2004 Massachusetts Institute of Technology. 12 * All Rights Reserved. 13 * 14 * Export of this software from the United States of America may 15 * require a specific license from the United States Government. 16 * It is the responsibility of any person or organization contemplating 17 * export to obtain such a license before exporting. 18 * 19 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and 20 * distribute this software and its documentation for any purpose and 21 * without fee is hereby granted, provided that the above copyright 22 * notice appear in all copies and that both that copyright notice and 23 * this permission notice appear in supporting documentation, and that 24 * the name of M.I.T. not be used in advertising or publicity pertaining 25 * to distribution of the software without specific, written prior 26 * permission. Furthermore if you modify this software you must label 27 * your software as modified software and not distribute it in such a 28 * fashion that it might be confused with the original M.I.T. software. 29 * M.I.T. makes no representations about the suitability of 30 * this software for any purpose. It is provided "as is" without express 31 * or implied warranty. 32 * 33 * 34 * Some platform-dependent definitions to sync up the C support level. 35 * Some to a C99-ish level, some related utility code. 36 * 37 * Currently: 38 * + make "static inline" work 39 * + 64-bit types and load/store code 40 * + SIZE_MAX 41 * + shared library init/fini hooks 42 */ 43 44 #ifndef K5_PLATFORM_H 45 #define K5_PLATFORM_H 46 47 #ifndef _KERNEL 48 #include "autoconf.h" 49 50 /* Initialization and finalization function support for libraries. 51 52 At top level, before the functions are defined or even declared: 53 MAKE_INIT_FUNCTION(init_fn); 54 MAKE_FINI_FUNCTION(fini_fn); 55 int init_fn(void) { ... } 56 void fini_fn(void) { if (INITIALIZER_RAN(init_fn)) ... } 57 58 In code, in the same file: 59 err = CALL_INIT_FUNCTION(init_fn); 60 61 To trigger or verify the initializer invocation from another file, 62 an additional function must be created. 63 64 The init_fn and fini_fn names should be chosen such that any 65 exported names staring with those names, and optionally followed by 66 additional characters, fits in with any namespace constraints on 67 the library in question. 68 69 70 Implementation outline: 71 72 Windows: MAKE_FINI_FUNCTION creates a symbol with a magic name that 73 is sought at library build time, and code is added to invoke the 74 function when the library is unloaded. MAKE_INIT_FUNCTION does 75 likewise, but the function is invoked when the library is loaded, 76 and an extra variable is declared to hold an error code and a "yes 77 the initializer ran" flag. CALL_INIT_FUNCTION blows up if the flag 78 isn't set, otherwise returns the error code. 79 80 UNIX: MAKE_INIT_FUNCTION creates and initializes a variable with a 81 name derived from the function name, containing a k5_once_t 82 (pthread_once_t or int), an error code, and a pointer to the 83 function. The function itself is declared static, but the 84 associated variable has external linkage. CALL_INIT_FUNCTION 85 ensures thath the function is called exactly once (pthread_once or 86 just check the flag) and returns the stored error code (or the 87 pthread_once error). 88 89 UNIX, with compiler support: MAKE_FINI_FUNCTION declares the 90 function as a destructor, and the run time linker support or 91 whatever will cause it to be invoked when the library is unloaded, 92 the program ends, etc. 93 94 UNIX, with linker support: MAKE_FINI_FUNCTION creates a symbol with 95 a magic name that is sought at library build time, and linker 96 options are used to mark it as a finalization function for the 97 library. The symbol must be exported. 98 99 UNIX, no library finalization support: The finalization function 100 never runs, and we leak memory. Tough. 101 102 103 104 For maximum flexibility in defining the macros, the function name 105 parameter should be a simple name, not even a macro defined as 106 another name. The function should have a unique name, and should 107 conform to whatever namespace is used by the library in question. 108 109 If the macro expansion needs the function to have been declared, it 110 must include a declaration. If it is not necessary for the symbol 111 name to be exported from the object file, the macro should declare 112 it as "static". Hence the signature must exactly match "void 113 foo(void)". (ANSI C allows a static declaration followed by a 114 non-static one; the result is internal linkage.) The macro 115 expansion has to come before the function, because gcc apparently 116 won't act on "__attribute__((constructor))" if it comes after the 117 function definition. 118 119 This is going to be compiler- and environment-specific, and may 120 require some support at library build time, and/or "asm" 121 statements. 122 123 It's okay for this code to require that the library be built 124 with the same compiler and compiler options throughout, but 125 we shouldn't require that the library and application use the 126 same compiler. 127 128 For static libraries, we don't really care about cleanup too much, 129 since it's all memory handling and mutex allocation which will all 130 be cleaned up when the program exits. Thus, it's okay if gcc-built 131 static libraries don't play nicely with cc-built executables when 132 it comes to static constructors, just as long as it doesn't cause 133 linking to fail. 134 135 For dynamic libraries on UNIX, we'll use pthread_once-type support 136 to do delayed initialization, so if finalization can't be made to 137 work, we'll only have memory leaks in a load/use/unload cycle. If 138 anyone (like, say, the OS vendor) complains about this, they can 139 tell us how to get a shared library finalization function invoked 140 automatically. */ 141 142 /* Helper macros. */ 143 144 # define JOIN__2_2(A,B) A ## _ ## _ ## B 145 # define JOIN__2(A,B) JOIN__2_2(A,B) 146 147 /* XXX Should test USE_LINKER_INIT_OPTION early, and if it's set, 148 always provide a function by the expected name, even if we're 149 delaying initialization. */ 150 151 #if defined(DELAY_INITIALIZER) 152 153 /* Run the initialization code during program execution, at the latest 154 possible moment. This means multiple threads may be active. */ 155 # include "k5-thread.h" 156 typedef struct { k5_once_t once; int error, did_run; void (*fn)(void); } k5_init_t; 157 # ifdef USE_LINKER_INIT_OPTION 158 # define MAYBE_DUMMY_INIT(NAME) \ 159 void JOIN__2(NAME, auxinit) () { } 160 # else 161 # define MAYBE_DUMMY_INIT(NAME) 162 # endif 163 # define MAKE_INIT_FUNCTION(NAME) \ 164 static int NAME(void); \ 165 MAYBE_DUMMY_INIT(NAME) \ 166 /* forward declaration for use in initializer */ \ 167 static void JOIN__2(NAME, aux) (void); \ 168 static k5_init_t JOIN__2(NAME, once) = \ 169 { K5_ONCE_INIT, 0, 0, JOIN__2(NAME, aux) }; \ 170 static void JOIN__2(NAME, aux) (void) \ 171 { \ 172 JOIN__2(NAME, once).did_run = 1; \ 173 JOIN__2(NAME, once).error = NAME(); \ 174 } \ 175 /* so ';' following macro use won't get error */ \ 176 static int NAME(void) 177 # define CALL_INIT_FUNCTION(NAME) \ 178 k5_call_init_function(& JOIN__2(NAME, once)) 179 # ifdef __GNUC__ 180 /* Do it in macro form so we get the file/line of the invocation if 181 the assertion fails. */ 182 # define k5_call_init_function(I) \ 183 (__extension__ ({ \ 184 k5_init_t *k5int_i = (I); \ 185 int k5int_err = k5_once(&k5int_i->once, k5int_i->fn); \ 186 (k5int_err \ 187 ? k5int_err \ 188 : (assert(k5int_i->did_run != 0), k5int_i->error)); \ 189 })) 190 # else /* __GNUC__ */ 191 static int k5_call_init_function(k5_init_t *i) 192 { 193 int err; 194 err = k5_once(&i->once, i->fn); 195 if (err) 196 return err; 197 assert (i->did_run != 0); 198 return i->error; 199 } 200 # endif /* __GNUC__ */ 201 /* This should be called in finalization only, so we shouldn't have 202 multiple active threads mucking around in our library at this 203 point. So ignore the once_t object and just look at the flag. 204 205 XXX Could we have problems with memory coherence between 206 processors if we don't invoke mutex/once routines? */ 207 # define INITIALIZER_RAN(NAME) \ 208 (JOIN__2(NAME, once).did_run && JOIN__2(NAME, once).error == 0) 209 210 # define PROGRAM_EXITING() (0) 211 212 #elif defined(__GNUC__) && !defined(_WIN32) && defined(CONSTRUCTOR_ATTR_WORKS) 213 214 /* Run initializer at load time, via GCC/C++ hook magic. */ 215 216 # ifdef USE_LINKER_INIT_OPTION 217 # define MAYBE_DUMMY_INIT(NAME) \ 218 void JOIN__2(NAME, auxinit) () { } 219 # else 220 # define MAYBE_DUMMY_INIT(NAME) 221 # endif 222 223 typedef struct { int error; unsigned char did_run; } k5_init_t; 224 # define MAKE_INIT_FUNCTION(NAME) \ 225 MAYBE_DUMMY_INIT(NAME) \ 226 static k5_init_t JOIN__2(NAME, ran) \ 227 = { 0, 2 }; \ 228 static void JOIN__2(NAME, aux)(void) \ 229 __attribute__((constructor)); \ 230 static int NAME(void); \ 231 static void JOIN__2(NAME, aux)(void) \ 232 { \ 233 JOIN__2(NAME, ran).error = NAME(); \ 234 JOIN__2(NAME, ran).did_run = 3; \ 235 } \ 236 static int NAME(void) 237 # define CALL_INIT_FUNCTION(NAME) \ 238 (JOIN__2(NAME, ran).did_run == 3 \ 239 ? JOIN__2(NAME, ran).error \ 240 : (abort(),0)) 241 # define INITIALIZER_RAN(NAME) (JOIN__2(NAME,ran).did_run == 3 && JOIN__2(NAME, ran).error == 0) 242 243 #elif defined(USE_LINKER_INIT_OPTION) || defined(_WIN32) 244 245 /* Run initializer at load time, via linker magic, or in the 246 case of WIN32, win_glue.c hard-coded knowledge. */ 247 typedef struct { int error; unsigned char did_run; } k5_init_t; 248 # define MAKE_INIT_FUNCTION(NAME) \ 249 static k5_init_t JOIN__2(NAME, ran) \ 250 = { 0, 2 }; \ 251 static int NAME(void); \ 252 void JOIN__2(NAME, auxinit)() \ 253 { \ 254 JOIN__2(NAME, ran).error = NAME(); \ 255 JOIN__2(NAME, ran).did_run = 3; \ 256 } \ 257 static int NAME(void) 258 # define CALL_INIT_FUNCTION(NAME) \ 259 (JOIN__2(NAME, ran).did_run == 3 \ 260 ? JOIN__2(NAME, ran).error \ 261 : (abort(),0)) 262 # define INITIALIZER_RAN(NAME) \ 263 (JOIN__2(NAME, ran).error == 0) 264 265 # define PROGRAM_EXITING() (0) 266 267 #else 268 269 # error "Don't know how to do load-time initializers for this configuration." 270 271 # define PROGRAM_EXITING() (0) 272 273 #endif 274 275 276 277 #if defined(USE_LINKER_FINI_OPTION) || defined(_WIN32) 278 /* If we're told the linker option will be used, it doesn't really 279 matter what compiler we're using. Do it the same way 280 regardless. */ 281 282 # define MAKE_FINI_FUNCTION(NAME) \ 283 void NAME(void) 284 285 #elif defined(__GNUC__) && defined(DESTRUCTOR_ATTR_WORKS) 286 /* If we're using gcc, if the C++ support works, the compiler should 287 build executables and shared libraries that support the use of 288 static constructors and destructors. The C compiler supports a 289 function attribute that makes use of the same facility as C++. 290 291 XXX How do we know if the C++ support actually works? */ 292 # define MAKE_FINI_FUNCTION(NAME) \ 293 static void NAME(void) __attribute__((destructor)) 294 295 #elif !defined(SHARED) 296 297 /* In this case, we just don't care about finalization. 298 299 The code will still define the function, but we won't do anything 300 with it. Annoying: This may generate unused-function warnings. */ 301 302 # define MAKE_FINI_FUNCTION(NAME) \ 303 static void NAME(void) 304 305 #else /* DELAY_INITIALIZER */ 306 307 # error "Don't know how to do unload-time finalization for this configuration." 308 309 #endif /* DELAY_INITIALIZER */ 310 311 #endif /* !_KERNEL */ 312 313 314 /* 64-bit support: krb5_ui_8 and krb5_int64. 315 316 This should move to krb5.h eventually, but without the namespace 317 pollution from the autoconf macros. */ 318 #if defined(HAVE_STDINT_H) || defined(HAVE_INTTYPES_H) 319 # ifdef HAVE_STDINT_H 320 # include <stdint.h> 321 # endif 322 # ifdef HAVE_INTTYPES_H 323 # include <inttypes.h> 324 # endif 325 # define INT64_TYPE int64_t 326 # define UINT64_TYPE uint64_t 327 #elif defined(_WIN32) 328 # define INT64_TYPE signed __int64 329 # define UINT64_TYPE unsigned __int64 330 #else /* not Windows, and neither stdint.h nor inttypes.h */ 331 # define INT64_TYPE signed long long 332 # define UINT64_TYPE unsigned long long 333 #endif 334 335 #ifndef _KERNEL 336 #include <limits.h> 337 #endif /* !_KERNEL */ 338 #ifndef SIZE_MAX 339 # define SIZE_MAX ((size_t)((size_t)0 - 1)) 340 #endif 341 342 343 /* Read and write integer values as (unaligned) octet strings in 344 specific byte orders. 345 346 Add per-platform optimizations later if needed. (E.g., maybe x86 347 unaligned word stores and gcc/asm instructions for byte swaps, 348 etc.) */ 349 350 static void 351 store_16_be (unsigned int val, unsigned char *p) 352 { 353 p[0] = (val >> 8) & 0xff; 354 p[1] = (val ) & 0xff; 355 } 356 static void 357 store_16_le (unsigned int val, unsigned char *p) 358 { 359 p[1] = (val >> 8) & 0xff; 360 p[0] = (val ) & 0xff; 361 } 362 static void 363 store_32_be (unsigned int val, unsigned char *p) 364 { 365 p[0] = (val >> 24) & 0xff; 366 p[1] = (val >> 16) & 0xff; 367 p[2] = (val >> 8) & 0xff; 368 p[3] = (val ) & 0xff; 369 } 370 static void 371 store_32_le (unsigned int val, unsigned char *p) 372 { 373 p[3] = (val >> 24) & 0xff; 374 p[2] = (val >> 16) & 0xff; 375 p[1] = (val >> 8) & 0xff; 376 p[0] = (val ) & 0xff; 377 } 378 static void 379 store_64_be (UINT64_TYPE val, unsigned char *p) 380 { 381 p[0] = (unsigned char)((val >> 56) & 0xff); 382 p[1] = (unsigned char)((val >> 48) & 0xff); 383 p[2] = (unsigned char)((val >> 40) & 0xff); 384 p[3] = (unsigned char)((val >> 32) & 0xff); 385 p[4] = (unsigned char)((val >> 24) & 0xff); 386 p[5] = (unsigned char)((val >> 16) & 0xff); 387 p[6] = (unsigned char)((val >> 8) & 0xff); 388 p[7] = (unsigned char)((val ) & 0xff); 389 } 390 static void 391 store_64_le (UINT64_TYPE val, unsigned char *p) 392 { 393 p[7] = (unsigned char)((val >> 56) & 0xff); 394 p[6] = (unsigned char)((val >> 48) & 0xff); 395 p[5] = (unsigned char)((val >> 40) & 0xff); 396 p[4] = (unsigned char)((val >> 32) & 0xff); 397 p[3] = (unsigned char)((val >> 24) & 0xff); 398 p[2] = (unsigned char)((val >> 16) & 0xff); 399 p[1] = (unsigned char)((val >> 8) & 0xff); 400 p[0] = (unsigned char)((val ) & 0xff); 401 } 402 static unsigned short 403 load_16_be (unsigned char *p) 404 { 405 return (p[1] | (p[0] << 8)); 406 } 407 static unsigned short 408 load_16_le (unsigned char *p) 409 { 410 return (p[0] | (p[1] << 8)); 411 } 412 static unsigned int 413 load_32_be (unsigned char *p) 414 { 415 return (p[3] | (p[2] << 8) | (p[1] << 16) | (p[0] << 24)); 416 } 417 static unsigned int 418 load_32_le (unsigned char *p) 419 { 420 return (p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24)); 421 } 422 static UINT64_TYPE 423 load_64_be (unsigned char *p) 424 { 425 return ((UINT64_TYPE)load_32_be(p) << 32) | load_32_be(p+4); 426 } 427 static UINT64_TYPE 428 load_64_le (unsigned char *p) 429 { 430 return ((UINT64_TYPE)load_32_le(p+4) << 32) | load_32_le(p); 431 } 432 433 434 /* Make the interfaces to getpwnam and getpwuid consistent. 435 Model the wrappers on the POSIX thread-safe versions, but 436 use the unsafe system versions if the safe ones don't exist 437 or we can't figure out their interfaces. */ 438 /* SUNW15resync - just have Solaris relevant ones */ 439 440 #define k5_getpwnam_r(NAME, REC, BUF, BUFSIZE, OUT) \ 441 (*(OUT) = getpwnam_r(NAME,REC,BUF,BUFSIZE), *(OUT) == NULL ? -1 : 0) 442 443 #define k5_getpwuid_r(UID, REC, BUF, BUFSIZE, OUT) \ 444 (*(OUT) = getpwuid_r(UID,REC,BUF,BUFSIZE), *(OUT) == NULL ? -1 : 0) 445 446 447 #endif /* K5_PLATFORM_H */ 448