1 /* 2 * QEMU low level functions 3 * 4 * Copyright (c) 2003 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 #include "qemu/osdep.h" 25 26 /* Needed early for CONFIG_BSD etc. */ 27 28 #ifdef CONFIG_SOLARIS 29 #include <sys/statvfs.h> 30 /* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for 31 discussion about Solaris header problems */ 32 extern int madvise(caddr_t, size_t, int); 33 #endif 34 35 #include "qemu-common.h" 36 #include "qemu/cutils.h" 37 #include "qemu/sockets.h" 38 #include "qemu/error-report.h" 39 #include "monitor/monitor.h" 40 41 static bool fips_enabled = false; 42 43 static const char *hw_version = QEMU_HW_VERSION; 44 45 int socket_set_cork(int fd, int v) 46 { 47 #if defined(SOL_TCP) && defined(TCP_CORK) 48 return qemu_setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v)); 49 #else 50 return 0; 51 #endif 52 } 53 54 int socket_set_nodelay(int fd) 55 { 56 int v = 1; 57 return qemu_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v)); 58 } 59 60 int qemu_madvise(void *addr, size_t len, int advice) 61 { 62 if (advice == QEMU_MADV_INVALID) { 63 errno = EINVAL; 64 return -1; 65 } 66 #if defined(CONFIG_MADVISE) 67 return madvise(addr, len, advice); 68 #elif defined(CONFIG_POSIX_MADVISE) 69 return posix_madvise(addr, len, advice); 70 #else 71 errno = EINVAL; 72 return -1; 73 #endif 74 } 75 76 static int qemu_mprotect__osdep(void *addr, size_t size, int prot) 77 { 78 g_assert(!((uintptr_t)addr & ~qemu_real_host_page_mask)); 79 g_assert(!(size & ~qemu_real_host_page_mask)); 80 81 #ifdef _WIN32 82 DWORD old_protect; 83 84 if (!VirtualProtect(addr, size, prot, &old_protect)) { 85 error_report("%s: VirtualProtect failed with error code %ld", 86 __func__, GetLastError()); 87 return -1; 88 } 89 return 0; 90 #else 91 if (mprotect(addr, size, prot)) { 92 error_report("%s: mprotect failed: %s", __func__, strerror(errno)); 93 return -1; 94 } 95 return 0; 96 #endif 97 } 98 99 int qemu_mprotect_rwx(void *addr, size_t size) 100 { 101 #ifdef _WIN32 102 return qemu_mprotect__osdep(addr, size, PAGE_EXECUTE_READWRITE); 103 #else 104 return qemu_mprotect__osdep(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC); 105 #endif 106 } 107 108 int qemu_mprotect_none(void *addr, size_t size) 109 { 110 #ifdef _WIN32 111 return qemu_mprotect__osdep(addr, size, PAGE_NOACCESS); 112 #else 113 return qemu_mprotect__osdep(addr, size, PROT_NONE); 114 #endif 115 } 116 117 #ifndef _WIN32 118 119 static int fcntl_op_setlk = -1; 120 static int fcntl_op_getlk = -1; 121 122 /* 123 * Dups an fd and sets the flags 124 */ 125 static int qemu_dup_flags(int fd, int flags) 126 { 127 int ret; 128 int serrno; 129 int dup_flags; 130 131 ret = qemu_dup(fd); 132 if (ret == -1) { 133 goto fail; 134 } 135 136 dup_flags = fcntl(ret, F_GETFL); 137 if (dup_flags == -1) { 138 goto fail; 139 } 140 141 if ((flags & O_SYNC) != (dup_flags & O_SYNC)) { 142 errno = EINVAL; 143 goto fail; 144 } 145 146 /* Set/unset flags that we can with fcntl */ 147 if (fcntl(ret, F_SETFL, flags) == -1) { 148 goto fail; 149 } 150 151 /* Truncate the file in the cases that open() would truncate it */ 152 if (flags & O_TRUNC || 153 ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) { 154 if (ftruncate(ret, 0) == -1) { 155 goto fail; 156 } 157 } 158 159 return ret; 160 161 fail: 162 serrno = errno; 163 if (ret != -1) { 164 close(ret); 165 } 166 errno = serrno; 167 return -1; 168 } 169 170 int qemu_dup(int fd) 171 { 172 int ret; 173 #ifdef F_DUPFD_CLOEXEC 174 ret = fcntl(fd, F_DUPFD_CLOEXEC, 0); 175 #else 176 ret = dup(fd); 177 if (ret != -1) { 178 qemu_set_cloexec(ret); 179 } 180 #endif 181 return ret; 182 } 183 184 static int qemu_parse_fdset(const char *param) 185 { 186 return qemu_parse_fd(param); 187 } 188 189 static void qemu_probe_lock_ops(void) 190 { 191 if (fcntl_op_setlk == -1) { 192 #ifdef F_OFD_SETLK 193 int fd; 194 int ret; 195 struct flock fl = { 196 .l_whence = SEEK_SET, 197 .l_start = 0, 198 .l_len = 0, 199 .l_type = F_WRLCK, 200 }; 201 202 fd = open("/dev/null", O_RDWR); 203 if (fd < 0) { 204 fprintf(stderr, 205 "Failed to open /dev/null for OFD lock probing: %s\n", 206 strerror(errno)); 207 fcntl_op_setlk = F_SETLK; 208 fcntl_op_getlk = F_GETLK; 209 return; 210 } 211 ret = fcntl(fd, F_OFD_GETLK, &fl); 212 close(fd); 213 if (!ret) { 214 fcntl_op_setlk = F_OFD_SETLK; 215 fcntl_op_getlk = F_OFD_GETLK; 216 } else { 217 fcntl_op_setlk = F_SETLK; 218 fcntl_op_getlk = F_GETLK; 219 } 220 #else 221 fcntl_op_setlk = F_SETLK; 222 fcntl_op_getlk = F_GETLK; 223 #endif 224 } 225 } 226 227 bool qemu_has_ofd_lock(void) 228 { 229 qemu_probe_lock_ops(); 230 #ifdef F_OFD_SETLK 231 return fcntl_op_setlk == F_OFD_SETLK; 232 #else 233 return false; 234 #endif 235 } 236 237 static int qemu_lock_fcntl(int fd, int64_t start, int64_t len, int fl_type) 238 { 239 int ret; 240 struct flock fl = { 241 .l_whence = SEEK_SET, 242 .l_start = start, 243 .l_len = len, 244 .l_type = fl_type, 245 }; 246 qemu_probe_lock_ops(); 247 do { 248 ret = fcntl(fd, fcntl_op_setlk, &fl); 249 } while (ret == -1 && errno == EINTR); 250 return ret == -1 ? -errno : 0; 251 } 252 253 int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive) 254 { 255 return qemu_lock_fcntl(fd, start, len, exclusive ? F_WRLCK : F_RDLCK); 256 } 257 258 int qemu_unlock_fd(int fd, int64_t start, int64_t len) 259 { 260 return qemu_lock_fcntl(fd, start, len, F_UNLCK); 261 } 262 263 int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive) 264 { 265 int ret; 266 struct flock fl = { 267 .l_whence = SEEK_SET, 268 .l_start = start, 269 .l_len = len, 270 .l_type = exclusive ? F_WRLCK : F_RDLCK, 271 }; 272 qemu_probe_lock_ops(); 273 ret = fcntl(fd, fcntl_op_getlk, &fl); 274 if (ret == -1) { 275 return -errno; 276 } else { 277 return fl.l_type == F_UNLCK ? 0 : -EAGAIN; 278 } 279 } 280 #endif 281 282 /* 283 * Opens a file with FD_CLOEXEC set 284 */ 285 int qemu_open(const char *name, int flags, ...) 286 { 287 int ret; 288 int mode = 0; 289 290 #ifndef _WIN32 291 const char *fdset_id_str; 292 293 /* Attempt dup of fd from fd set */ 294 if (strstart(name, "/dev/fdset/", &fdset_id_str)) { 295 int64_t fdset_id; 296 int fd, dupfd; 297 298 fdset_id = qemu_parse_fdset(fdset_id_str); 299 if (fdset_id == -1) { 300 errno = EINVAL; 301 return -1; 302 } 303 304 fd = monitor_fdset_get_fd(fdset_id, flags); 305 if (fd < 0) { 306 errno = -fd; 307 return -1; 308 } 309 310 dupfd = qemu_dup_flags(fd, flags); 311 if (dupfd == -1) { 312 return -1; 313 } 314 315 ret = monitor_fdset_dup_fd_add(fdset_id, dupfd); 316 if (ret == -1) { 317 close(dupfd); 318 errno = EINVAL; 319 return -1; 320 } 321 322 return dupfd; 323 } 324 #endif 325 326 if (flags & O_CREAT) { 327 va_list ap; 328 329 va_start(ap, flags); 330 mode = va_arg(ap, int); 331 va_end(ap); 332 } 333 334 #ifdef O_CLOEXEC 335 ret = open(name, flags | O_CLOEXEC, mode); 336 #else 337 ret = open(name, flags, mode); 338 if (ret >= 0) { 339 qemu_set_cloexec(ret); 340 } 341 #endif 342 343 #ifdef O_DIRECT 344 if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) { 345 error_report("file system may not support O_DIRECT"); 346 errno = EINVAL; /* in case it was clobbered */ 347 } 348 #endif /* O_DIRECT */ 349 350 return ret; 351 } 352 353 int qemu_close(int fd) 354 { 355 int64_t fdset_id; 356 357 /* Close fd that was dup'd from an fdset */ 358 fdset_id = monitor_fdset_dup_fd_find(fd); 359 if (fdset_id != -1) { 360 int ret; 361 362 ret = close(fd); 363 if (ret == 0) { 364 monitor_fdset_dup_fd_remove(fd); 365 } 366 367 return ret; 368 } 369 370 return close(fd); 371 } 372 373 /* 374 * A variant of write(2) which handles partial write. 375 * 376 * Return the number of bytes transferred. 377 * Set errno if fewer than `count' bytes are written. 378 * 379 * This function don't work with non-blocking fd's. 380 * Any of the possibilities with non-bloking fd's is bad: 381 * - return a short write (then name is wrong) 382 * - busy wait adding (errno == EAGAIN) to the loop 383 */ 384 ssize_t qemu_write_full(int fd, const void *buf, size_t count) 385 { 386 ssize_t ret = 0; 387 ssize_t total = 0; 388 389 while (count) { 390 ret = write(fd, buf, count); 391 if (ret < 0) { 392 if (errno == EINTR) 393 continue; 394 break; 395 } 396 397 count -= ret; 398 buf += ret; 399 total += ret; 400 } 401 402 return total; 403 } 404 405 /* 406 * Opens a socket with FD_CLOEXEC set 407 */ 408 int qemu_socket(int domain, int type, int protocol) 409 { 410 int ret; 411 412 #ifdef SOCK_CLOEXEC 413 ret = socket(domain, type | SOCK_CLOEXEC, protocol); 414 if (ret != -1 || errno != EINVAL) { 415 return ret; 416 } 417 #endif 418 ret = socket(domain, type, protocol); 419 if (ret >= 0) { 420 qemu_set_cloexec(ret); 421 } 422 423 return ret; 424 } 425 426 /* 427 * Accept a connection and set FD_CLOEXEC 428 */ 429 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen) 430 { 431 int ret; 432 433 #ifdef CONFIG_ACCEPT4 434 ret = accept4(s, addr, addrlen, SOCK_CLOEXEC); 435 if (ret != -1 || errno != ENOSYS) { 436 return ret; 437 } 438 #endif 439 ret = accept(s, addr, addrlen); 440 if (ret >= 0) { 441 qemu_set_cloexec(ret); 442 } 443 444 return ret; 445 } 446 447 void qemu_set_hw_version(const char *version) 448 { 449 hw_version = version; 450 } 451 452 const char *qemu_hw_version(void) 453 { 454 return hw_version; 455 } 456 457 void fips_set_state(bool requested) 458 { 459 #ifdef __linux__ 460 if (requested) { 461 FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r"); 462 if (fds != NULL) { 463 fips_enabled = (fgetc(fds) == '1'); 464 fclose(fds); 465 } 466 } 467 #else 468 fips_enabled = false; 469 #endif /* __linux__ */ 470 471 #ifdef _FIPS_DEBUG 472 fprintf(stderr, "FIPS mode %s (requested %s)\n", 473 (fips_enabled ? "enabled" : "disabled"), 474 (requested ? "enabled" : "disabled")); 475 #endif 476 } 477 478 bool fips_get_state(void) 479 { 480 return fips_enabled; 481 } 482 483 #ifdef _WIN32 484 static void socket_cleanup(void) 485 { 486 WSACleanup(); 487 } 488 #endif 489 490 int socket_init(void) 491 { 492 #ifdef _WIN32 493 WSADATA Data; 494 int ret, err; 495 496 ret = WSAStartup(MAKEWORD(2, 2), &Data); 497 if (ret != 0) { 498 err = WSAGetLastError(); 499 fprintf(stderr, "WSAStartup: %d\n", err); 500 return -1; 501 } 502 atexit(socket_cleanup); 503 #endif 504 return 0; 505 } 506 507 508 #ifndef CONFIG_IOVEC 509 /* helper function for iov_send_recv() */ 510 static ssize_t 511 readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write) 512 { 513 unsigned i = 0; 514 ssize_t ret = 0; 515 while (i < iov_cnt) { 516 ssize_t r = do_write 517 ? write(fd, iov[i].iov_base, iov[i].iov_len) 518 : read(fd, iov[i].iov_base, iov[i].iov_len); 519 if (r > 0) { 520 ret += r; 521 } else if (!r) { 522 break; 523 } else if (errno == EINTR) { 524 continue; 525 } else { 526 /* else it is some "other" error, 527 * only return if there was no data processed. */ 528 if (ret == 0) { 529 ret = -1; 530 } 531 break; 532 } 533 i++; 534 } 535 return ret; 536 } 537 538 ssize_t 539 readv(int fd, const struct iovec *iov, int iov_cnt) 540 { 541 return readv_writev(fd, iov, iov_cnt, false); 542 } 543 544 ssize_t 545 writev(int fd, const struct iovec *iov, int iov_cnt) 546 { 547 return readv_writev(fd, iov, iov_cnt, true); 548 } 549 #endif 550