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
 138 static int qemu_parse_fdset(const char *param)
 139 {
 140     return qemu_parse_fd(param);
 141 }
 142 #endif
 143
 144 /*
 145  * Opens a file with FD_CLOEXEC set
 146  */
 147 int qemu_open(const char *name, int flags, ...)
 148 {
 149     int ret;
 150     int mode = 0;
 151
 152 #ifndef _WIN32
 153     const char *fdset_id_str;
 154
 155     /* Attempt dup of fd from fd set */
 156     if (strstart(name, "/dev/fdset/", &fdset_id_str)) {
 157         int64_t fdset_id;
 158         int fd, dupfd;
 159
 160         fdset_id = qemu_parse_fdset(fdset_id_str);
 161         if (fdset_id == -1) {
 162             errno = EINVAL;
 163             return -1;
 164         }
 165
 166         fd = monitor_fdset_get_fd(fdset_id, flags);
 167         if (fd == -1) {
 168             return -1;
 169         }
 170
 171         dupfd = qemu_dup_flags(fd, flags);
 172         if (dupfd == -1) {
 173             return -1;
 174         }
 175
 176         ret = monitor_fdset_dup_fd_add(fdset_id, dupfd);
 177         if (ret == -1) {
 178             close(dupfd);
 179             errno = EINVAL;
 180             return -1;
 181         }
 182
 183         return dupfd;
 184     }
 185 #endif
 186
 187     if (flags & O_CREAT) {
 188         va_list ap;
 189
 190         va_start(ap, flags);
 191         mode = va_arg(ap, int);
 192         va_end(ap);
 193     }
 194
 195 #ifdef O_CLOEXEC
 196     ret = open(name, flags | O_CLOEXEC, mode);
 197 #else
 198     ret = open(name, flags, mode);
 199     if (ret >= 0) {
 200         qemu_set_cloexec(ret);
 201     }
 202 #endif
 203
 204     return ret;
 205 }
 206
 207 int qemu_close(int fd)
 208 {
 209     int64_t fdset_id;
 210
 211     /* Close fd that was dup'd from an fdset */
 212     fdset_id = monitor_fdset_dup_fd_find(fd);
 213     if (fdset_id != -1) {
 214         int ret;
 215
 216         ret = close(fd);
 217         if (ret == 0) {
 218             monitor_fdset_dup_fd_remove(fd);
 219         }
 220
 221         return ret;
 222     }
 223
 224     return close(fd);
 225 }
 226
 227 /*
 228  * A variant of write(2) which handles partial write.
 229  *
 230  * Return the number of bytes transferred.
 231  * Set errno if fewer than `count' bytes are written.
 232  *
 233  * This function don't work with non-blocking fd's.
 234  * Any of the possibilities with non-bloking fd's is bad:
 235  *   - return a short write (then name is wrong)
 236  *   - busy wait adding (errno == EAGAIN) to the loop
 237  */
 238 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 239 {
 240     ssize_t ret = 0;
 241     ssize_t total = 0;
 242
 243     while (count) {
 244         ret = write(fd, buf, count);
 245         if (ret < 0) {
 246             if (errno == EINTR)
 247                 continue;
 248             break;
 249         }
 250
 251         count -= ret;
 252         buf += ret;
 253         total += ret;
 254     }
 255
 256     return total;
 257 }
 258
 259 /*
 260  * Opens a socket with FD_CLOEXEC set
 261  */
 262 int qemu_socket(int domain, int type, int protocol)
 263 {
 264     int ret;
 265
 266 #ifdef SOCK_CLOEXEC
 267     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
 268     if (ret != -1 || errno != EINVAL) {
 269         return ret;
 270     }
 271 #endif
 272     ret = socket(domain, type, protocol);
 273     if (ret >= 0) {
 274         qemu_set_cloexec(ret);
 275     }
 276
 277     return ret;
 278 }
 279
 280 /*
 281  * Accept a connection and set FD_CLOEXEC
 282  */
 283 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 284 {
 285     int ret;
 286
 287 #ifdef CONFIG_ACCEPT4
 288     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
 289     if (ret != -1 || errno != ENOSYS) {
 290         return ret;
 291     }
 292 #endif
 293     ret = accept(s, addr, addrlen);
 294     if (ret >= 0) {
 295         qemu_set_cloexec(ret);
 296     }
 297
 298     return ret;
 299 }
 300
 301 /*
 302  * A variant of send(2) which handles partial write.
 303  *
 304  * Return the number of bytes transferred, which is only
 305  * smaller than `count' if there is an error.
 306  *
 307  * This function won't work with non-blocking fd's.
 308  * Any of the possibilities with non-bloking fd's is bad:
 309  *   - return a short write (then name is wrong)
 310  *   - busy wait adding (errno == EAGAIN) to the loop
 311  */
 312 ssize_t qemu_send_full(int fd, const void *buf, size_t count, int flags)
 313 {
 314     ssize_t ret = 0;
 315     ssize_t total = 0;
 316
 317     while (count) {
 318         ret = send(fd, buf, count, flags);
 319         if (ret < 0) {
 320             if (errno == EINTR) {
 321                 continue;
 322             }
 323             break;
 324         }
 325
 326         count -= ret;
 327         buf += ret;
 328         total += ret;
 329     }
 330
 331     return total;
 332 }
 333
 334 /*
 335  * A variant of recv(2) which handles partial write.
 336  *
 337  * Return the number of bytes transferred, which is only
 338  * smaller than `count' if there is an error.
 339  *
 340  * This function won't work with non-blocking fd's.
 341  * Any of the possibilities with non-bloking fd's is bad:
 342  *   - return a short write (then name is wrong)
 343  *   - busy wait adding (errno == EAGAIN) to the loop
 344  */
 345 ssize_t qemu_recv_full(int fd, void *buf, size_t count, int flags)
 346 {
 347     ssize_t ret = 0;
 348     ssize_t total = 0;
 349
 350     while (count) {
 351         ret = qemu_recv(fd, buf, count, flags);
 352         if (ret <= 0) {
 353             if (ret < 0 && errno == EINTR) {
 354                 continue;
 355             }
 356             break;
 357         }
 358
 359         count -= ret;
 360         buf += ret;
 361         total += ret;
 362     }
 363
 364     return total;
 365 }
 366
 367 void qemu_set_version(const char *version)
 368 {
 369     qemu_version = version;
 370 }
 371
 372 const char *qemu_get_version(void)
 373 {
 374     return qemu_version;
 375 }
 376
 377 void fips_set_state(bool requested)
 378 {
 379 #ifdef __linux__
 380     if (requested) {
 381         FILE *fds = fopen("/proc/sys/crypto/fips_enabled", "r");
 382         if (fds != NULL) {
 383             fips_enabled = (fgetc(fds) == '1');
 384             fclose(fds);
 385         }
 386     }
 387 #else
 388     fips_enabled = false;
 389 #endif /* __linux__ */
 390
 391 #ifdef _FIPS_DEBUG
 392     fprintf(stderr, "FIPS mode %s (requested %s)\n",
 393             (fips_enabled ? "enabled" : "disabled"),
 394             (requested ? "enabled" : "disabled"));
 395 #endif
 396 }
 397
 398 bool fips_get_state(void)
 399 {
 400     return fips_enabled;
 401 }
 402