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
  92 #ifdef F_DUPFD_CLOEXEC
  93     ret = fcntl(fd, F_DUPFD_CLOEXEC, 0);
  94 #else
  95     ret = dup(fd);
  96     if (ret != -1) {
  97         qemu_set_cloexec(ret);
  98     }
  99 #endif
 100     if (ret == -1) {
 101         goto fail;
 102     }
 103
 104     dup_flags = fcntl(ret, F_GETFL);
 105     if (dup_flags == -1) {
 106         goto fail;
 107     }
 108
 109     if ((flags & O_SYNC) != (dup_flags & O_SYNC)) {
 110         errno = EINVAL;
 111         goto fail;
 112     }
 113
 114     /* Set/unset flags that we can with fcntl */
 115     if (fcntl(ret, F_SETFL, flags) == -1) {
 116         goto fail;
 117     }
 118
 119     /* Truncate the file in the cases that open() would truncate it */
 120     if (flags & O_TRUNC ||
 121             ((flags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))) {
 122         if (ftruncate(ret, 0) == -1) {
 123             goto fail;
 124         }
 125     }
 126
 127     return ret;
 128
 129 fail:
 130     serrno = errno;
 131     if (ret != -1) {
 132         close(ret);
 133     }
 134     errno = serrno;
 135     return -1;
 136 }
 137 #endif
 138
 139 /*
 140  * Opens a file with FD_CLOEXEC set
 141  */
 142 int qemu_open(const char *name, int flags, ...)
 143 {
 144     int ret;
 145     int mode = 0;
 146
 147 #ifndef _WIN32
 148     const char *fdset_id_str;
 149
 150     /* Attempt dup of fd from fd set */
 151     if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
 152         int64_t fdset_id;
 153         int fd, dupfd;
 154
 155         fdset_id = qemu_parse_fdset(fdset_id_str);
 156         if (fdset_id == -1) {
 157             errno = EINVAL;
 158             return -1;
 159         }
 160
 161         fd = monitor_fdset_get_fd(fdset_id, flags);
 162         if (fd == -1) {
 163             return -1;
 164         }
 165
 166         dupfd = qemu_dup_flags(fd, flags);
 167         if (dupfd == -1) {
 168             return -1;
 169         }
 170
 171         ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
 172         if (ret == -1) {
 173             close(dupfd);
 174             errno = EINVAL;
 175             return -1;
 176         }
 177
 178         return dupfd;
 179     }
 180 #endif
 181
 182     if (flags & O_CREAT) {
 183         va_list ap;
 184
 185         va_start(ap, flags);
 186         mode = va_arg(ap, int);
 187         va_end(ap);
 188     }
 189
 190 #ifdef O_CLOEXEC
 191     ret = open(name, flags | O_CLOEXEC, mode);
 192 #else
 193     ret = open(name, flags, mode);
 194     if (ret >= 0) {
 195         qemu_set_cloexec(ret);
 196     }
 197 #endif
 198
 199     return ret;
 200 }
 201
 202 int qemu_close(int fd)
 203 {
 204     int64_t fdset_id;
 205
 206     /* Close fd that was dup'd from an fdset */
 207     fdset_id = monitor_fdset_dup_fd_find(fd);
 208     if (fdset_id != -1) {
 209         int ret;
 210
 211         ret = close(fd);
 212         if (ret == 0) {
 213             monitor_fdset_dup_fd_remove(fd);
 214         }
 215
 216         return ret;
 217     }
 218
 219     return close(fd);
 220 }
 221
 222 /*
 223  * A variant of write(2) which handles partial write.
 224  *
 225  * Return the number of bytes transferred.
 226  * Set errno if fewer than `count' bytes are written.
 227  *
 228  * This function don't work with non-blocking fd's.
 229  * Any of the possibilities with non-bloking fd's is bad:
 230  *   - return a short write (then name is wrong)
 231  *   - busy wait adding (errno == EAGAIN) to the loop
 232  */
 233 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 234 {
 235     ssize_t ret = 0;
 236     ssize_t total = 0;
 237
 238     while (count) {
 239         ret = write(fd, buf, count);
 240         if (ret < 0) {
 241             if (errno == EINTR)
 242                 continue;
 243             break;
 244         }
 245
 246         count -= ret;
 247         buf += ret;
 248         total += ret;
 249     }
 250
 251     return total;
 252 }
 253
 254 /*
 255  * Opens a socket with FD_CLOEXEC set
 256  */
 257 int qemu_socket(int domain, int type, int protocol)
 258 {
 259     int ret;
 260
 261 #ifdef SOCK_CLOEXEC
 262     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
 263     if (ret != -1 || errno != EINVAL) {
 264         return ret;
 265     }
 266 #endif
 267     ret = socket(domain, type, protocol);
 268     if (ret >= 0) {
 269         qemu_set_cloexec(ret);
 270     }
 271
 272     return ret;
 273 }
 274
 275 /*
 276  * Accept a connection and set FD_CLOEXEC
 277  */
 278 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 279 {
 280     int ret;
 281
 282 #ifdef CONFIG_ACCEPT4
 283     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
 284     if (ret != -1 || errno != ENOSYS) {
 285         return ret;
 286     }
 287 #endif
 288     ret = accept(s, addr, addrlen);
 289     if (ret >= 0) {
 290         qemu_set_cloexec(ret);
 291     }
 292
 293     return ret;
 294 }
 295
 296 /*
 297  * A variant of send(2) which handles partial write.
 298  *
 299  * Return the number of bytes transferred, which is only
 300  * smaller than `count' if there is an error.
 301  *
 302  * This function won't work with non-blocking fd's.
 303  * Any of the possibilities with non-bloking fd's is bad:
 304  *   - return a short write (then name is wrong)
 305  *   - busy wait adding (errno == EAGAIN) to the loop
 306  */
 307 ssize_t qemu_send_full(int fd, const void *buf, size_t count, int flags)
 308 {
 309     ssize_t ret = 0;
 310     ssize_t total = 0;
 311
 312     while (count) {
 313         ret = send(fd, buf, count, flags);
 314         if (ret < 0) {
 315             if (errno == EINTR) {
 316                 continue;
 317             }
 318             break;
 319         }
 320
 321         count -= ret;
 322         buf += ret;
 323         total += ret;
 324     }
 325
 326     return total;
 327 }
 328
 329 /*
 330  * A variant of recv(2) which handles partial write.
 331  *
 332  * Return the number of bytes transferred, which is only
 333  * smaller than `count' if there is an error.
 334  *
 335  * This function won't work with non-blocking fd's.
 336  * Any of the possibilities with non-bloking fd's is bad:
 337  *   - return a short write (then name is wrong)
 338  *   - busy wait adding (errno == EAGAIN) to the loop
 339  */
 340 ssize_t qemu_recv_full(int fd, void *buf, size_t count, int flags)
 341 {
 342     ssize_t ret = 0;
 343     ssize_t total = 0;
 344
 345     while (count) {
 346         ret = qemu_recv(fd, buf, count, flags);
 347         if (ret <= 0) {
 348             if (ret < 0 && errno == EINTR) {
 349                 continue;
 350             }
 351             break;
 352         }
 353
 354         count -= ret;
 355         buf += ret;
 356         total += ret;
 357     }
 358
 359     return total;
 360 }
 361
 362 void qemu_set_version(const char *version)
 363 {
 364     qemu_version = version;
 365 }
 366
 367 const char *qemu_get_version(void)
 368 {
 369     return qemu_version;
 370 }
 371
 372 void fips_set_state(bool requested)
 373 {
 374 #ifdef __linux__
 375     if (requested) {
 376         FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
 377         if (fds != NULL) {
 378             fips_enabled = (fgetc(fds) == '1');
 379             fclose(fds);
 380         }
 381     }
 382 #else
 383     fips_enabled = false;
 384 #endif /* __linux__ */
 385
 386 #ifdef _FIPS_DEBUG
 387     fprintf(stderr, "FIPS mode %s (requested %s)\n",
 388             (fips_enabled ? "enabled" : "disabled"),
 389             (requested ? "enabled" : "disabled"));
 390 #endif
 391 }
 392
 393 bool fips_get_state(void)
 394 {
 395     return fips_enabled;
 396 }