util/osdep.c

   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 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  * Delete a file from the filesystem, unless the filename is /dev/fdset/...
 375  *
 376  * Returns: On success, zero is returned.  On error, -1 is returned,
 377  * and errno is set appropriately.
 378  */
 379 int qemu_unlink(const char *name)
 380 {
 381     if (g_str_has_prefix(name, "/dev/fdset/")) {
 382         return 0;
 383     }
 384
 385     return unlink(name);
 386 }
 387
 388 /*
 389  * A variant of write(2) which handles partial write.
 390  *
 391  * Return the number of bytes transferred.
 392  * Set errno if fewer than `count' bytes are written.
 393  *
 394  * This function don't work with non-blocking fd's.
 395  * Any of the possibilities with non-bloking fd's is bad:
 396  *   - return a short write (then name is wrong)
 397  *   - busy wait adding (errno == EAGAIN) to the loop
 398  */
 399 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 400 {
 401     ssize_t ret = 0;
 402     ssize_t total = 0;
 403
 404     while (count) {
 405         ret = write(fd, buf, count);
 406         if (ret < 0) {
 407             if (errno == EINTR)
 408                 continue;
 409             break;
 410         }
 411
 412         count -= ret;
 413         buf += ret;
 414         total += ret;
 415     }
 416
 417     return total;
 418 }
 419
 420 /*
 421  * Opens a socket with FD_CLOEXEC set
 422  */
 423 int qemu_socket(int domain, int type, int protocol)
 424 {
 425     int ret;
 426
 427 #ifdef SOCK_CLOEXEC
 428     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
 429     if (ret != -1 || errno != EINVAL) {
 430         return ret;
 431     }
 432 #endif
 433     ret = socket(domain, type, protocol);
 434     if (ret >= 0) {
 435         qemu_set_cloexec(ret);
 436     }
 437
 438     return ret;
 439 }
 440
 441 /*
 442  * Accept a connection and set FD_CLOEXEC
 443  */
 444 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 445 {
 446     int ret;
 447
 448 #ifdef CONFIG_ACCEPT4
 449     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
 450     if (ret != -1 || errno != ENOSYS) {
 451         return ret;
 452     }
 453 #endif
 454     ret = accept(s, addr, addrlen);
 455     if (ret >= 0) {
 456         qemu_set_cloexec(ret);
 457     }
 458
 459     return ret;
 460 }
 461
 462 void qemu_set_hw_version(const char *version)
 463 {
 464     hw_version = version;
 465 }
 466
 467 const char *qemu_hw_version(void)
 468 {
 469     return hw_version;
 470 }
 471
 472 void fips_set_state(bool requested)
 473 {
 474 #ifdef __linux__
 475     if (requested) {
 476         FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
 477         if (fds != NULL) {
 478             fips_enabled = (fgetc(fds) == '1');
 479             fclose(fds);
 480         }
 481     }
 482 #else
 483     fips_enabled = false;
 484 #endif /* __linux__ */
 485
 486 #ifdef _FIPS_DEBUG
 487     fprintf(stderr, "FIPS mode %s (requested %s)\n",
 488             (fips_enabled ? "enabled" : "disabled"),
 489             (requested ? "enabled" : "disabled"));
 490 #endif
 491 }
 492
 493 bool fips_get_state(void)
 494 {
 495     return fips_enabled;
 496 }
 497
 498 #ifdef _WIN32
 499 static void socket_cleanup(void)
 500 {
 501     WSACleanup();
 502 }
 503 #endif
 504
 505 int socket_init(void)
 506 {
 507 #ifdef _WIN32
 508     WSADATA Data;
 509     int ret, err;
 510
 511     ret = WSAStartup(MAKEWORD(2, 2), &Data);
 512     if (ret != 0) {
 513         err = WSAGetLastError();
 514         fprintf(stderr, "WSAStartup: %d\n", err);
 515         return -1;
 516     }
 517     atexit(socket_cleanup);
 518 #endif
 519     return 0;
 520 }
 521
 522
 523 #ifndef CONFIG_IOVEC
 524 /* helper function for iov_send_recv() */
 525 static ssize_t
 526 readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
 527 {
 528     unsigned i = 0;
 529     ssize_t ret = 0;
 530     while (i < iov_cnt) {
 531         ssize_t r = do_write
 532             ? write(fd, iov[i].iov_base, iov[i].iov_len)
 533             : read(fd, iov[i].iov_base, iov[i].iov_len);
 534         if (r > 0) {
 535             ret += r;
 536         } else if (!r) {
 537             break;
 538         } else if (errno == EINTR) {
 539             continue;
 540         } else {
 541             /* else it is some "other" error,
 542              * only return if there was no data processed. */
 543             if (ret == 0) {
 544                 ret = -1;
 545             }
 546             break;
 547         }
 548         i++;
 549     }
 550     return ret;
 551 }
 552
 553 ssize_t
 554 readv(int fd, const struct iovec *iov, int iov_cnt)
 555 {
 556     return readv_writev(fd, iov, iov_cnt, false);
 557 }
 558
 559 ssize_t
 560 writev(int fd, const struct iovec *iov, int iov_cnt)
 561 {
 562     return readv_writev(fd, iov, iov_cnt, true);
 563 }
 564 #endif