LXR qemu/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 <string.h>
  28#include <errno.h>
  29#include <unistd.h>
  30#include <fcntl.h>
  31
  32/* Needed early for CONFIG_BSD etc. */
  33#include "config-host.h"
  34
  35#if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)
  36#include <sys/mman.h>
  37#endif
  38
  39#ifdef CONFIG_SOLARIS
  40#include <sys/types.h>
  41#include <sys/statvfs.h>
  42/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for
  43   discussion about Solaris header problems */
  44extern int madvise(caddr_t, size_t, int);
  45#endif
  46
  47#include "qemu-common.h"
  48#include "trace.h"
  49#include "sysemu.h"
  50#include "qemu_socket.h"
  51
  52int qemu_madvise(void *addr, size_t len, int advice)
  53{
  54    if (advice == QEMU_MADV_INVALID) {
  55        errno = EINVAL;
  56        return -1;
  57    }
  58#if defined(CONFIG_MADVISE)
  59    return madvise(addr, len, advice);
  60#elif defined(CONFIG_POSIX_MADVISE)
  61    return posix_madvise(addr, len, advice);
  62#else
  63    errno = EINVAL;
  64    return -1;
  65#endif
  66}
  67
  68
  69/*
  70 * Opens a file with FD_CLOEXEC set
  71 */
  72int qemu_open(const char *name, int flags, ...)
  73{
  74    int ret;
  75    int mode = 0;
  76
  77    if (flags & O_CREAT) {
  78        va_list ap;
  79
  80        va_start(ap, flags);
  81        mode = va_arg(ap, int);
  82        va_end(ap);
  83    }
  84
  85#ifdef O_CLOEXEC
  86    ret = open(name, flags | O_CLOEXEC, mode);
  87#else
  88    ret = open(name, flags, mode);
  89    if (ret >= 0) {
  90        qemu_set_cloexec(ret);
  91    }
  92#endif
  93
  94    return ret;
  95}
  96
  97/*
  98 * A variant of write(2) which handles partial write.
  99 *
 100 * Return the number of bytes transferred.
 101 * Set errno if fewer than `count' bytes are written.
 102 *
 103 * This function don't work with non-blocking fd's.
 104 * Any of the possibilities with non-bloking fd's is bad:
 105 *   - return a short write (then name is wrong)
 106 *   - busy wait adding (errno == EAGAIN) to the loop
 107 */
 108ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 109{
 110    ssize_t ret = 0;
 111    ssize_t total = 0;
 112
 113    while (count) {
 114        ret = write(fd, buf, count);
 115        if (ret < 0) {
 116            if (errno == EINTR)
 117                continue;
 118            break;
 119        }
 120
 121        count -= ret;
 122        buf += ret;
 123        total += ret;
 124    }
 125
 126    return total;
 127}
 128
 129/*
 130 * Opens a socket with FD_CLOEXEC set
 131 */
 132int qemu_socket(int domain, int type, int protocol)
 133{
 134    int ret;
 135
 136#ifdef SOCK_CLOEXEC
 137    ret = socket(domain, type | SOCK_CLOEXEC, protocol);
 138    if (ret != -1 || errno != EINVAL) {
 139        return ret;
 140    }
 141#endif
 142    ret = socket(domain, type, protocol);
 143    if (ret >= 0) {
 144        qemu_set_cloexec(ret);
 145    }
 146
 147    return ret;
 148}
 149
 150/*
 151 * Accept a connection and set FD_CLOEXEC
 152 */
 153int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 154{
 155    int ret;
 156
 157#ifdef CONFIG_ACCEPT4
 158    ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
 159    if (ret != -1 || errno != ENOSYS) {
 160        return ret;
 161    }
 162#endif
 163    ret = accept(s, addr, addrlen);
 164    if (ret >= 0) {
 165        qemu_set_cloexec(ret);
 166    }
 167
 168    return ret;
 169}
 170