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 <stdlib.h>
  25 #include <stdio.h>
  26 #include <stdarg.h>
  27 #include <stdbool.h>
  28 #include <string.h>
  29 #include <errno.h>
  30 #include <unistd.h>
  31 #include <fcntl.h>
  32
  33 /* Needed early for CONFIG_BSD etc. */
  34 #include "config-host.h"
  35
  36 #if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
  37 #include <sys/mman.h>
  38 #endif
  39
  40 #ifdef CONFIG_SOLARIS
  41 #include <sys/types.h>
  42 #include <sys/statvfs.h>
  43 /* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
  44    discussion about Solaris header problems */
  45 extern int madvise(caddr_t, size_t, int);
  46 #endif
  47
  48 #include "qemu-common.h"
  49 #include "trace.h"
  50 #include "qemu_socket.h"
  51 #include "monitor.h"
  52
  53 static bool fips_enabled = false;
  54
  55 static const char *qemu_version = QEMU_VERSION;
  56
  57 int socket_set_cork(int fd, int v)
  58 {
  59 #if defined(SOL_TCP) && defined(TCP_CORK)
  60     return setsockopt(fd, SOL_TCP, TCP_CORK, &v, sizeof(v));
  61 #else
  62     return 0;
  63 #endif
  64 }
  65
  66 int qemu_madvise(void *addr, size_t len, int advice)
  67 {
  68     if (advice == QEMU_MADV_INVALID) {
  69         errno = EINVAL;
  70         return -1;
  71     }
  72 #if defined(CONFIG_MADVISE)
  73     return madvise(addr, len, advice);
  74 #elif defined(CONFIG_POSIX_MADVISE)
  75     return posix_madvise(addr, len, advice);
  76 #else
  77     errno = EINVAL;
  78     return -1;
  79 #endif
  80 }
  81
  82 #ifndef _WIN32
  83 /*
  84  * Dups an fd and sets the flags
  85  */
  86 static int qemu_dup_flags(int fd, int flags)
  87 {
  88     int ret;
  89     int serrno;
  90     int dup_flags;
  91     int setfl_flags;
  92
  93 #ifdef F_DUPFD_CLOEXEC
  94     ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
  95 #else
  96     ret = dup(fd);
  97     if (ret != -1) {
  98         qemu_set_cloexec(ret);
  99     }
 100 #endif
 101     if (ret == -1) {
 102         goto fail;
 103     }
 104
 105     dup_flags = fcntl(ret, F_GETFL);
 106     if (dup_flags == -1) {
 107         goto fail;
 108     }
 109
 110     if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
 111         errno = EINVAL;
 112         goto fail;
 113     }
 114
 115     /* Set/unset flags that we can with fcntl */
 116     setfl_flags = O_APPEND | O_ASYNC | O_DIRECT | O_NOATIME | O_NONBLOCK;
 117     dup_flags &= ~setfl_flags;
 118     dup_flags |= (flags & setfl_flags);
 119     if (fcntl(ret, F_SETFL, dup_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 #endif
 142
 143 /*
 144  * Opens a file with FD_CLOEXEC set
 145  */
 146 int qemu_open(const char *name, int flags, ...)
 147 {
 148     int ret;
 149     int mode = 0;
 150
 151 #ifndef _WIN32
 152     const char *fdset_id_str;
 153
 154     /* Attempt dup of fd from fd set */
 155     if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
 156         int64_t fdset_id;
 157         int fd, dupfd;
 158
 159         fdset_id = qemu_parse_fdset(fdset_id_str);
 160         if (fdset_id == -1) {
 161             errno = EINVAL;
 162             return -1;
 163         }
 164
 165         fd = monitor_fdset_get_fd(fdset_id, flags);
 166         if (fd == -1) {
 167             return -1;
 168         }
 169
 170         dupfd = qemu_dup_flags(fd, flags);
 171         if (dupfd == -1) {
 172             return -1;
 173         }
 174
 175         ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
 176         if (ret == -1) {
 177             close(dupfd);
 178             errno = EINVAL;
 179             return -1;
 180         }
 181
 182         return dupfd;
 183     }
 184 #endif
 185
 186     if (flags & O_CREAT) {
 187         va_list ap;
 188
 189         va_start(ap, flags);
 190         mode = va_arg(ap, int);
 191         va_end(ap);
 192     }
 193
 194 #ifdef O_CLOEXEC
 195     ret = open(name, flags | O_CLOEXEC, mode);
 196 #else
 197     ret = open(name, flags, mode);
 198     if (ret >= 0) {
 199         qemu_set_cloexec(ret);
 200     }
 201 #endif
 202
 203     return ret;
 204 }
 205
 206 int qemu_close(int fd)
 207 {
 208     int64_t fdset_id;
 209
 210     /* Close fd that was dup'd from an fdset */
 211     fdset_id = monitor_fdset_dup_fd_find(fd);
 212     if (fdset_id != -1) {
 213         int ret;
 214
 215         ret = close(fd);
 216         if (ret == 0) {
 217             monitor_fdset_dup_fd_remove(fd);
 218         }
 219
 220         return ret;
 221     }
 222
 223     return close(fd);
 224 }
 225
 226 /*
 227  * A variant of write(2) which handles partial write.
 228  *
 229  * Return the number of bytes transferred.
 230  * Set errno if fewer than `count' bytes are written.
 231  *
 232  * This function don't work with non-blocking fd's.
 233  * Any of the possibilities with non-bloking fd's is bad:
 234  *   - return a short write (then name is wrong)
 235  *   - busy wait adding (errno == EAGAIN) to the loop
 236  */
 237 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 238 {
 239     ssize_t ret = 0;
 240     ssize_t total = 0;
 241
 242     while (count) {
 243         ret = write(fd, buf, count);
 244         if (ret < 0) {
 245             if (errno == EINTR)
 246                 continue;
 247             break;
 248         }
 249
 250         count -= ret;
 251         buf += ret;
 252         total += ret;
 253     }
 254
 255     return total;
 256 }
 257
 258 /*
 259  * Opens a socket with FD_CLOEXEC set
 260  */
 261 int qemu_socket(int domain, int type, int protocol)
 262 {
 263     int ret;
 264
 265 #ifdef SOCK_CLOEXEC
 266     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
 267     if (ret != -1 || errno != EINVAL) {
 268         return ret;
 269     }
 270 #endif
 271     ret = socket(domain, type, protocol);
 272     if (ret >= 0) {
 273         qemu_set_cloexec(ret);
 274     }
 275
 276     return ret;
 277 }
 278
 279 /*
 280  * Accept a connection and set FD_CLOEXEC
 281  */
 282 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 283 {
 284     int ret;
 285
 286 #ifdef CONFIG_ACCEPT4
 287     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
 288     if (ret != -1 || errno != ENOSYS) {
 289         return ret;
 290     }
 291 #endif
 292     ret = accept(s, addr, addrlen);
 293     if (ret >= 0) {
 294         qemu_set_cloexec(ret);
 295     }
 296
 297     return ret;
 298 }
 299
 300 /*
 301  * A variant of send(2) which handles partial write.
 302  *
 303  * Return the number of bytes transferred, which is only
 304  * smaller than `count' if there is an error.
 305  *
 306  * This function won't work with non-blocking fd's.
 307  * Any of the possibilities with non-bloking fd's is bad:
 308  *   - return a short write (then name is wrong)
 309  *   - busy wait adding (errno == EAGAIN) to the loop
 310  */
 311 ssize_t qemu_send_full(int fd, const void *buf, size_t count, int flags)
 312 {
 313     ssize_t ret = 0;
 314     ssize_t total = 0;
 315
 316     while (count) {
 317         ret = send(fd, buf, count, flags);
 318         if (ret < 0) {
 319             if (errno == EINTR) {
 320                 continue;
 321             }
 322             break;
 323         }
 324
 325         count -= ret;
 326         buf += ret;
 327         total += ret;
 328     }
 329
 330     return total;
 331 }
 332
 333 /*
 334  * A variant of recv(2) which handles partial write.
 335  *
 336  * Return the number of bytes transferred, which is only
 337  * smaller than `count' if there is an error.
 338  *
 339  * This function won't work with non-blocking fd's.
 340  * Any of the possibilities with non-bloking fd's is bad:
 341  *   - return a short write (then name is wrong)
 342  *   - busy wait adding (errno == EAGAIN) to the loop
 343  */
 344 ssize_t qemu_recv_full(int fd, void *buf, size_t count, int flags)
 345 {
 346     ssize_t ret = 0;
 347     ssize_t total = 0;
 348
 349     while (count) {
 350         ret = qemu_recv(fd, buf, count, flags);
 351         if (ret <= 0) {
 352             if (ret < 0 && errno == EINTR) {
 353                 continue;
 354             }
 355             break;
 356         }
 357
 358         count -= ret;
 359         buf += ret;
 360         total += ret;
 361     }
 362
 363     return total;
 364 }
 365
 366 void qemu_set_version(const char *version)
 367 {
 368     qemu_version = version;
 369 }
 370
 371 const char *qemu_get_version(void)
 372 {
 373     return qemu_version;
 374 }
 375
 376 void fips_set_state(bool requested)
 377 {
 378 #ifdef __linux__
 379     if (requested) {
 380         FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
 381         if (fds != NULL) {
 382             fips_enabled = (fgetc(fds) == '1');
 383             fclose(fds);
 384         }
 385     }
 386 #else
 387     fips_enabled = false;
 388 #endif /* __linux__ */
 389
 390 #ifdef _FIPS_DEBUG
 391     fprintf(stderr, "FIPS mode %s (requested %s)\n",
 392             (fips_enabled ? "enabled" : "disabled"),
 393             (requested ? "enabled" : "disabled"));
 394 #endif
 395 }
 396
 397 bool fips_get_state(void)
 398 {
 399     return fips_enabled;
 400 }