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 #if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
  29 #include <sys/mman.h>
  30 #endif
  31
  32 #ifdef CONFIG_SOLARIS
  33 #include <sys/statvfs.h>
  34 /* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
  35    discussion about Solaris header problems */
  36 extern int madvise(caddr_t, size_t, int);
  37 #endif
  38
  39 #include "qemu-common.h"
  40 #include "qemu/sockets.h"
  41 #include "qemu/error-report.h"
  42 #include "monitor/monitor.h"
  43
  44 static bool fips_enabled = false;
  45
  46 /* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
  47  * instead of QEMU_VERSION, so setting hw_version on MachineClass
  48  * is no longer mandatory.
  49  *
  50  * Do NOT change this string, or it will break compatibility on all
  51  * machine classes that don't set hw_version.
  52  */
  53 static const char *hw_version = "2.5+";
  54
  55 int socket_set_cork(int fd, int v)
  56 {
  57 #if defined(SOL_TCP) && defined(TCP_CORK)
  58     return qemu_setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
  59 #else
  60     return 0;
  61 #endif
  62 }
  63
  64 int socket_set_nodelay(int fd)
  65 {
  66     int v = 1;
  67     return qemu_setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &v, sizeof(v));
  68 }
  69
  70 int qemu_madvise(void *addr, size_t len, int advice)
  71 {
  72     if (advice == QEMU_MADV_INVALID) {
  73         errno = EINVAL;
  74         return -1;
  75     }
  76 #if defined(CONFIG_MADVISE)
  77     return madvise(addr, len, advice);
  78 #elif defined(CONFIG_POSIX_MADVISE)
  79     return posix_madvise(addr, len, advice);
  80 #else
  81     errno = EINVAL;
  82     return -1;
  83 #endif
  84 }
  85
  86 #ifndef _WIN32
  87 /*
  88  * Dups an fd and sets the flags
  89  */
  90 static int qemu_dup_flags(int fd, int flags)
  91 {
  92     int ret;
  93     int serrno;
  94     int dup_flags;
  95
  96 #ifdef F_DUPFD_CLOEXEC
  97     ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
  98 #else
  99     ret = dup(fd);
 100     if (ret != -1) {
 101         qemu_set_cloexec(ret);
 102     }
 103 #endif
 104     if (ret == -1) {
 105         goto fail;
 106     }
 107
 108     dup_flags = fcntl(ret, F_GETFL);
 109     if (dup_flags == -1) {
 110         goto fail;
 111     }
 112
 113     if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
 114         errno = EINVAL;
 115         goto fail;
 116     }
 117
 118     /* Set/unset flags that we can with fcntl */
 119     if (fcntl(ret, F_SETFL, flags) == -1) {
 120         goto fail;
 121     }
 122
 123     /* Truncate the file in the cases that open() would truncate it */
 124     if (flags & O_TRUNC ||
 125             ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) {
 126         if (ftruncate(ret, 0) == -1) {
 127             goto fail;
 128         }
 129     }
 130
 131     return ret;
 132
 133 fail:
 134     serrno = errno;
 135     if (ret != -1) {
 136         close(ret);
 137     }
 138     errno = serrno;
 139     return -1;
 140 }
 141
 142 static int qemu_parse_fdset(const char *param)
 143 {
 144     return qemu_parse_fd(param);
 145 }
 146 #endif
 147
 148 /*
 149  * Opens a file with FD_CLOEXEC set
 150  */
 151 int qemu_open(const char *name, int flags, ...)
 152 {
 153     int ret;
 154     int mode = 0;
 155
 156 #ifndef _WIN32
 157     const char *fdset_id_str;
 158
 159     /* Attempt dup of fd from fd set */
 160     if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
 161         int64_t fdset_id;
 162         int fd, dupfd;
 163
 164         fdset_id = qemu_parse_fdset(fdset_id_str);
 165         if (fdset_id == -1) {
 166             errno = EINVAL;
 167             return -1;
 168         }
 169
 170         fd = monitor_fdset_get_fd(fdset_id, flags);
 171         if (fd == -1) {
 172             return -1;
 173         }
 174
 175         dupfd = qemu_dup_flags(fd, flags);
 176         if (dupfd == -1) {
 177             return -1;
 178         }
 179
 180         ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
 181         if (ret == -1) {
 182             close(dupfd);
 183             errno = EINVAL;
 184             return -1;
 185         }
 186
 187         return dupfd;
 188     }
 189 #endif
 190
 191     if (flags & O_CREAT) {
 192         va_list ap;
 193
 194         va_start(ap, flags);
 195         mode = va_arg(ap, int);
 196         va_end(ap);
 197     }
 198
 199 #ifdef O_CLOEXEC
 200     ret = open(name, flags | O_CLOEXEC, mode);
 201 #else
 202     ret = open(name, flags, mode);
 203     if (ret >= 0) {
 204         qemu_set_cloexec(ret);
 205     }
 206 #endif
 207
 208 #ifdef O_DIRECT
 209     if (ret == -1 && errno == EINVAL && (flags & O_DIRECT)) {
 210         error_report("file system may not support O_DIRECT");
 211         errno = EINVAL; /* in case it was clobbered */
 212     }
 213 #endif /* O_DIRECT */
 214
 215     return ret;
 216 }
 217
 218 int qemu_close(int fd)
 219 {
 220     int64_t fdset_id;
 221
 222     /* Close fd that was dup'd from an fdset */
 223     fdset_id = monitor_fdset_dup_fd_find(fd);
 224     if (fdset_id != -1) {
 225         int ret;
 226
 227         ret = close(fd);
 228         if (ret == 0) {
 229             monitor_fdset_dup_fd_remove(fd);
 230         }
 231
 232         return ret;
 233     }
 234
 235     return close(fd);
 236 }
 237
 238 /*
 239  * A variant of write(2) which handles partial write.
 240  *
 241  * Return the number of bytes transferred.
 242  * Set errno if fewer than `count' bytes are written.
 243  *
 244  * This function don't work with non-blocking fd's.
 245  * Any of the possibilities with non-bloking fd's is bad:
 246  *   - return a short write (then name is wrong)
 247  *   - busy wait adding (errno == EAGAIN) to the loop
 248  */
 249 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 250 {
 251     ssize_t ret = 0;
 252     ssize_t total = 0;
 253
 254     while (count) {
 255         ret = write(fd, buf, count);
 256         if (ret < 0) {
 257             if (errno == EINTR)
 258                 continue;
 259             break;
 260         }
 261
 262         count -= ret;
 263         buf += ret;
 264         total += ret;
 265     }
 266
 267     return total;
 268 }
 269
 270 /*
 271  * Opens a socket with FD_CLOEXEC set
 272  */
 273 int qemu_socket(int domain, int type, int protocol)
 274 {
 275     int ret;
 276
 277 #ifdef SOCK_CLOEXEC
 278     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
 279     if (ret != -1 || errno != EINVAL) {
 280         return ret;
 281     }
 282 #endif
 283     ret = socket(domain, type, protocol);
 284     if (ret >= 0) {
 285         qemu_set_cloexec(ret);
 286     }
 287
 288     return ret;
 289 }
 290
 291 /*
 292  * Accept a connection and set FD_CLOEXEC
 293  */
 294 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 295 {
 296     int ret;
 297
 298 #ifdef CONFIG_ACCEPT4
 299     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
 300     if (ret != -1 || errno != ENOSYS) {
 301         return ret;
 302     }
 303 #endif
 304     ret = accept(s, addr, addrlen);
 305     if (ret >= 0) {
 306         qemu_set_cloexec(ret);
 307     }
 308
 309     return ret;
 310 }
 311
 312 void qemu_set_hw_version(const char *version)
 313 {
 314     hw_version = version;
 315 }
 316
 317 const char *qemu_hw_version(void)
 318 {
 319     return hw_version;
 320 }
 321
 322 void fips_set_state(bool requested)
 323 {
 324 #ifdef __linux__
 325     if (requested) {
 326         FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
 327         if (fds != NULL) {
 328             fips_enabled = (fgetc(fds) == '1');
 329             fclose(fds);
 330         }
 331     }
 332 #else
 333     fips_enabled = false;
 334 #endif /* __linux__ */
 335
 336 #ifdef _FIPS_DEBUG
 337     fprintf(stderr, "FIPS mode %s (requested %s)\n",
 338             (fips_enabled ? "enabled" : "disabled"),
 339             (requested ? "enabled" : "disabled"));
 340 #endif
 341 }
 342
 343 bool fips_get_state(void)
 344 {
 345     return fips_enabled;
 346 }
 347
 348 #ifdef _WIN32
 349 static void socket_cleanup(void)
 350 {
 351     WSACleanup();
 352 }
 353 #endif
 354
 355 int socket_init(void)
 356 {
 357 #ifdef _WIN32
 358     WSADATA Data;
 359     int ret, err;
 360
 361     ret = WSAStartup(MAKEWORD(2, 2), &Data);
 362     if (ret != 0) {
 363         err = WSAGetLastError();
 364         fprintf(stderr, "WSAStartup: %d\n", err);
 365         return -1;
 366     }
 367     atexit(socket_cleanup);
 368 #endif
 369     return 0;
 370 }
 371
 372 #if !GLIB_CHECK_VERSION(2, 31, 0)
 373 /* Ensure that glib is running in multi-threaded mode
 374  * Old versions of glib require explicit initialization.  Failure to do
 375  * this results in the single-threaded code paths being taken inside
 376  * glib.  For example, the g_slice allocator will not be thread-safe
 377  * and cause crashes.
 378  */
 379 static void __attribute__((constructor)) thread_init(void)
 380 {
 381     if (!g_thread_supported()) {
 382        g_thread_init(NULL);
 383     }
 384 }
 385 #endif
 386
 387 #ifndef CONFIG_IOVEC
 388 /* helper function for iov_send_recv() */
 389 static ssize_t
 390 readv_writev(int fd, const struct iovec *iov, int iov_cnt, bool do_write)
 391 {
 392     unsigned i = 0;
 393     ssize_t ret = 0;
 394     while (i < iov_cnt) {
 395         ssize_t r = do_write
 396             ? write(fd, iov[i].iov_base, iov[i].iov_len)
 397             : read(fd, iov[i].iov_base, iov[i].iov_len);
 398         if (r > 0) {
 399             ret += r;
 400         } else if (!r) {
 401             break;
 402         } else if (errno == EINTR) {
 403             continue;
 404         } else {
 405             /* else it is some "other" error,
 406              * only return if there was no data processed. */
 407             if (ret == 0) {
 408                 ret = -1;
 409             }
 410             break;
 411         }
 412         i++;
 413     }
 414     return ret;
 415 }
 416
 417 ssize_t
 418 readv(int fd, const struct iovec *iov, int iov_cnt)
 419 {
 420     return readv_writev(fd, iov, iov_cnt, false);
 421 }
 422
 423 ssize_t
 424 writev(int fd, const struct iovec *iov, int iov_cnt)
 425 {
 426     return readv_writev(fd, iov, iov_cnt, true);
 427 }
 428 #endif