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 */
  44 extern int madvise(caddr_t, size_t, int);
  45 #endif
  46
  47 #ifdef _WIN32
  48 #include <windows.h>
  49 #elif defined(CONFIG_BSD)
  50 #include <stdlib.h>
  51 #else
  52 #include <malloc.h>
  53 #endif
  54
  55 #include "qemu-common.h"
  56 #include "trace.h"
  57 #include "sysemu.h"
  58 #include "qemu_socket.h"
  59
  60 int qemu_madvise(void *addr, size_t len, int advice)
  61 {
  62     if (advice == QEMU_MADV_INVALID) {
  63         errno = EINVAL;
  64         return -1;
  65     }
  66 #if defined(CONFIG_MADVISE)
  67     return madvise(addr, len, advice);
  68 #elif defined(CONFIG_POSIX_MADVISE)
  69     return posix_madvise(addr, len, advice);
  70 #else
  71     errno = EINVAL;
  72     return -1;
  73 #endif
  74 }
  75
  76
  77 /*
  78  * Opens a file with FD_CLOEXEC set
  79  */
  80 int qemu_open(const char *name, int flags, ...)
  81 {
  82     int ret;
  83     int mode = 0;
  84
  85     if (flags & O_CREAT) {
  86         va_list ap;
  87
  88         va_start(ap, flags);
  89         mode = va_arg(ap, int);
  90         va_end(ap);
  91     }
  92
  93 #ifdef O_CLOEXEC
  94     ret = open(name, flags | O_CLOEXEC, mode);
  95 #else
  96     ret = open(name, flags, mode);
  97     if (ret >= 0) {
  98         qemu_set_cloexec(ret);
  99     }
 100 #endif
 101
 102     return ret;
 103 }
 104
 105 /*
 106  * A variant of write(2) which handles partial write.
 107  *
 108  * Return the number of bytes transferred.
 109  * Set errno if fewer than `count' bytes are written.
 110  *
 111  * This function don't work with non-blocking fd's.
 112  * Any of the possibilities with non-bloking fd's is bad:
 113  *   - return a short write (then name is wrong)
 114  *   - busy wait adding (errno == EAGAIN) to the loop
 115  */
 116 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 117 {
 118     ssize_t ret = 0;
 119     ssize_t total = 0;
 120
 121     while (count) {
 122         ret = write(fd, buf, count);
 123         if (ret < 0) {
 124             if (errno == EINTR)
 125                 continue;
 126             break;
 127         }
 128
 129         count -= ret;
 130         buf += ret;
 131         total += ret;
 132     }
 133
 134     return total;
 135 }
 136
 137 /*
 138  * Opens a socket with FD_CLOEXEC set
 139  */
 140 int qemu_socket(int domain, int type, int protocol)
 141 {
 142     int ret;
 143
 144 #ifdef SOCK_CLOEXEC
 145     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
 146     if (ret != -1 || errno != EINVAL) {
 147         return ret;
 148     }
 149 #endif
 150     ret = socket(domain, type, protocol);
 151     if (ret >= 0) {
 152         qemu_set_cloexec(ret);
 153     }
 154
 155     return ret;
 156 }
 157
 158 /*
 159  * Accept a connection and set FD_CLOEXEC
 160  */
 161 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 162 {
 163     int ret;
 164
 165 #ifdef CONFIG_ACCEPT4
 166     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
 167     if (ret != -1 || errno != ENOSYS) {
 168         return ret;
 169     }
 170 #endif
 171     ret = accept(s, addr, addrlen);
 172     if (ret >= 0) {
 173         qemu_set_cloexec(ret);
 174     }
 175
 176     return ret;
 177 }