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(char *, 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 g_autofree gchar *emsg = g_win32_error_message(GetLastError()); 86 error_report("%s: VirtualProtect failed: %s", __func__, emsg); 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 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 static int qemu_open_cloexec(const char *name, int flags, mode_t mode) 283 { 284 int ret; 285 #ifdef O_CLOEXEC 286 ret = open(name, flags | O_CLOEXEC, mode); 287 #else 288 ret = open(name, flags, mode); 289 if (ret >= 0) { 290 qemu_set_cloexec(ret); 291 } 292 #endif 293 return ret; 294 } 295 296 /* 297 * Opens a file with FD_CLOEXEC set 298 */ 299 int qemu_open_old(const char *name, int flags, ...) 300 { 301 int ret; 302 int mode = 0; 303 304 #ifndef _WIN32 305 const char *fdset_id_str; 306 307 /* Attempt dup of fd from fd set */ 308 if (strstart(name, "/dev/fdset/", &fdset_id_str)) { 309 int64_t fdset_id; 310 int dupfd; 311 312 fdset_id = qemu_parse_fdset(fdset_id_str); 313 if (fdset_id == -1) { 314 errno = EINVAL; 315 return -1; 316 } 317 318 dupfd = monitor_fdset_dup_fd_add(fdset_id, flags); 319 if (dupfd == -1) { 320 return -1; 321 } 322 323 return dupfd; 324 } 325 #endif 326 327 if (flags & O_CREAT) { 328 va_list ap; 329 330 va_start(ap, flags); 331 mode = va_arg(ap, int); 332 va_end(ap); 333 } 334 335 ret = qemu_open_cloexec(name, flags, mode); 336 337 #ifdef O_DIRECT 338 if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) { 339 error_report("file system may not support O_DIRECT"); 340 errno = EINVAL; /* in case it was clobbered */ 341 } 342 #endif /* O_DIRECT */ 343 344 return ret; 345 } 346 347 int qemu_close(int fd) 348 { 349 int64_t fdset_id; 350 351 /* Close fd that was dup'd from an fdset */ 352 fdset_id = monitor_fdset_dup_fd_find(fd); 353 if (fdset_id != -1) { 354 int ret; 355 356 ret = close(fd); 357 if (ret == 0) { 358 monitor_fdset_dup_fd_remove(fd); 359 } 360 361 return ret; 362 } 363 364 return close(fd); 365 } 366 367 /* 368 * Delete a file from the filesystem, unless the filename is /dev/fdset/... 369 * 370 * Returns: On success, zero is returned. On error, -1 is returned, 371 * and errno is set appropriately. 372 */ 373 int qemu_unlink(const char *name) 374 { 375 if (g_str_has_prefix(name, "/dev/fdset/")) { 376 return 0; 377 } 378 379 return unlink(name); 380 } 381 382 /* 383 * A variant of write(2) which handles partial write. 384 * 385 * Return the number of bytes transferred. 386 * Set errno if fewer than `count' bytes are written. 387 * 388 * This function don't work with non-blocking fd's. 389 * Any of the possibilities with non-bloking fd's is bad: 390 * - return a short write (then name is wrong) 391 * - busy wait adding (errno == EAGAIN) to the loop 392 */ 393 ssize_t qemu_write_full(int fd, const void *buf, size_t count) 394 { 395 ssize_t ret = 0; 396 ssize_t total = 0; 397 398 while (count) { 399 ret = write(fd, buf, count); 400 if (ret < 0) { 401 if (errno == EINTR) 402 continue; 403 break; 404 } 405 406 count -= ret; 407 buf += ret; 408 total += ret; 409 } 410 411 return total; 412 } 413 414 /* 415 * Opens a socket with FD_CLOEXEC set 416 */ 417 int qemu_socket(int domain, int type, int protocol) 418 { 419 int ret; 420 421 #ifdef SOCK_CLOEXEC 422 ret = socket(domain, type | SOCK_CLOEXEC, protocol); 423 if (ret != -1 || errno != EINVAL) { 424 return ret; 425 } 426 #endif 427 ret = socket(domain, type, protocol); 428 if (ret >= 0) { 429 qemu_set_cloexec(ret); 430 } 431 432 return ret; 433 } 434 435 /* 436 * Accept a connection and set FD_CLOEXEC 437 */ 438 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen) 439 { 440 int ret; 441 442 #ifdef CONFIG_ACCEPT4 443 ret = accept4(s, addr, addrlen, SOCK_CLOEXEC); 444 if (ret != -1 || errno != ENOSYS) { 445 return ret; 446 } 447 #endif 448 ret = accept(s, addr, addrlen); 449 if (ret >= 0) { 450 qemu_set_cloexec(ret); 451 } 452 453 return ret; 454 } 455 456 void qemu_set_hw_version(const char *version) 457 { 458 hw_version = version; 459 } 460 461 const char *qemu_hw_version(void) 462 { 463 return hw_version; 464 } 465 466 void fips_set_state(bool requested) 467 { 468 #ifdef __linux__ 469 if (requested) { 470 FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r"); 471 if (fds != NULL) { 472 fips_enabled = (fgetc(fds) == '1'); 473 fclose(fds); 474 } 475 } 476 #else 477 fips_enabled = false; 478 #endif /* __linux__ */ 479 480 #ifdef _FIPS_DEBUG 481 fprintf(stderr, "FIPS mode %s (requested %s)\n", 482 (fips_enabled ? "enabled" : "disabled"), 483 (requested ? "enabled" : "disabled")); 484 #endif 485 } 486 487 bool fips_get_state(void) 488 { 489 return fips_enabled; 490 } 491 492 #ifdef _WIN32 493 static void socket_cleanup(void) 494 { 495 WSACleanup(); 496 } 497 #endif 498 499 int socket_init(void) 500 { 501 #ifdef _WIN32 502 WSADATA Data; 503 int ret, err; 504 505 ret = WSAStartup(MAKEWORD(2, 2), &Data); 506 if (ret != 0) { 507 err = WSAGetLastError(); 508 fprintf(stderr, "WSAStartup: %d\n", err); 509 return -1; 510 } 511 atexit(socket_cleanup); 512 #endif 513 return 0; 514 } 515 516 517 #ifndef CONFIG_IOVEC 518 /* helper function for iov_send_recv() */ 519 static ssize_t 520 readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write) 521 { 522 unsigned i = 0; 523 ssize_t ret = 0; 524 while (i < iov_cnt) { 525 ssize_t r = do_write 526 ? write(fd, iov[i].iov_base, iov[i].iov_len) 527 : read(fd, iov[i].iov_base, iov[i].iov_len); 528 if (r > 0) { 529 ret += r; 530 } else if (!r) { 531 break; 532 } else if (errno == EINTR) { 533 continue; 534 } else { 535 /* else it is some "other" error, 536 * only return if there was no data processed. */ 537 if (ret == 0) { 538 ret = -1; 539 } 540 break; 541 } 542 i++; 543 } 544 return ret; 545 } 546 547 ssize_t 548 readv(int fd, const struct iovec *iov, int iov_cnt) 549 { 550 return readv_writev(fd, iov, iov_cnt, false); 551 } 552 553 ssize_t 554 writev(int fd, const struct iovec *iov, int iov_cnt) 555 { 556 return readv_writev(fd, iov, iov_cnt, true); 557 } 558 #endif 559