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 CONFIG_EVENTFD
  48 #include <sys/eventfd.h>
  49 #endif
  50
  51 #ifdef _WIN32
  52 #include <windows.h>
  53 #elif defined(CONFIG_BSD)
  54 #include <stdlib.h>
  55 #else
  56 #include <malloc.h>
  57 #endif
  58
  59 #include "qemu-common.h"
  60 #include "trace.h"
  61 #include "sysemu.h"
  62 #include "qemu_socket.h"
  63
  64 int qemu_madvise(void *addr, size_t len, int advice)
  65 {
  66     if (advice == QEMU_MADV_INVALID) {
  67         errno = EINVAL;
  68         return -1;
  69     }
  70 #if defined(CONFIG_MADVISE)
  71     return madvise(addr, len, advice);
  72 #elif defined(CONFIG_POSIX_MADVISE)
  73     return posix_madvise(addr, len, advice);
  74 #else
  75     errno = EINVAL;
  76     return -1;
  77 #endif
  78 }
  79
  80 int qemu_create_pidfile(const char *filename)
  81 {
  82     char buffer[128];
  83     int len;
  84 #ifndef _WIN32
  85     int fd;
  86
  87     fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);
  88     if (fd == -1)
  89         return -1;
  90
  91     if (lockf(fd, F_TLOCK, 0) == -1)
  92         return -1;
  93
  94     len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
  95     if (write(fd, buffer, len) != len)
  96         return -1;
  97 #else
  98     HANDLE file;
  99     OVERLAPPED overlap;
 100     BOOL ret;
 101     memset(&overlap, 0, sizeof(overlap));
 102
 103     file = CreateFile(filename, GENERIC_WRITE, FILE_SHARE_READ, NULL,
 104                       OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
 105
 106     if (file == INVALID_HANDLE_VALUE)
 107       return -1;
 108
 109     len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());
 110     ret = WriteFileEx(file, (LPCVOID)buffer, (DWORD)len,
 111                       &overlap, NULL);
 112     if (ret == 0)
 113       return -1;
 114 #endif
 115     return 0;
 116 }
 117
 118 #ifdef _WIN32
 119
 120 /* mingw32 needs ffs for compilations without optimization. */
 121 int ffs(int i)
 122 {
 123     /* Use gcc's builtin ffs. */
 124     return __builtin_ffs(i);
 125 }
 126
 127 /* Offset between 1/1/1601 and 1/1/1970 in 100 nanosec units */
 128 #define _W32_FT_OFFSET (116444736000000000ULL)
 129
 130 int qemu_gettimeofday(qemu_timeval *tp)
 131 {
 132   union {
 133     unsigned long long ns100; /*time since 1 Jan 1601 in 100ns units */
 134     FILETIME ft;
 135   }  _now;
 136
 137   if(tp)
 138     {
 139       GetSystemTimeAsFileTime (&_now.ft);
 140       tp->tv_usec=(long)((_now.ns100 / 10ULL) % 1000000ULL );
 141       tp->tv_sec= (long)((_now.ns100 - _W32_FT_OFFSET) / 10000000ULL);
 142     }
 143   /* Always return 0 as per Open Group Base Specifications Issue 6.
 144      Do not set errno on error.  */
 145   return 0;
 146 }
 147 #endif /* _WIN32 */
 148
 149
 150 /*
 151  * Opens a file with FD_CLOEXEC set
 152  */
 153 int qemu_open(const char *name, int flags, ...)
 154 {
 155     int ret;
 156     int mode = 0;
 157
 158     if (flags & O_CREAT) {
 159         va_list ap;
 160
 161         va_start(ap, flags);
 162         mode = va_arg(ap, int);
 163         va_end(ap);
 164     }
 165
 166 #ifdef O_CLOEXEC
 167     ret = open(name, flags | O_CLOEXEC, mode);
 168 #else
 169     ret = open(name, flags, mode);
 170     if (ret >= 0) {
 171         qemu_set_cloexec(ret);
 172     }
 173 #endif
 174
 175     return ret;
 176 }
 177
 178 /*
 179  * A variant of write(2) which handles partial write.
 180  *
 181  * Return the number of bytes transferred.
 182  * Set errno if fewer than `count' bytes are written.
 183  *
 184  * This function don't work with non-blocking fd's.
 185  * Any of the possibilities with non-bloking fd's is bad:
 186  *   - return a short write (then name is wrong)
 187  *   - busy wait adding (errno == EAGAIN) to the loop
 188  */
 189 ssize_t qemu_write_full(int fd, const void *buf, size_t count)
 190 {
 191     ssize_t ret = 0;
 192     ssize_t total = 0;
 193
 194     while (count) {
 195         ret = write(fd, buf, count);
 196         if (ret < 0) {
 197             if (errno == EINTR)
 198                 continue;
 199             break;
 200         }
 201
 202         count -= ret;
 203         buf += ret;
 204         total += ret;
 205     }
 206
 207     return total;
 208 }
 209
 210 #ifndef _WIN32
 211 /*
 212  * Creates an eventfd that looks like a pipe and has EFD_CLOEXEC set.
 213  */
 214 int qemu_eventfd(int fds[2])
 215 {
 216 #ifdef CONFIG_EVENTFD
 217     int ret;
 218
 219     ret = eventfd(0, 0);
 220     if (ret >= 0) {
 221         fds[0] = ret;
 222         qemu_set_cloexec(ret);
 223         if ((fds[1] = dup(ret)) == -1) {
 224             close(ret);
 225             return -1;
 226         }
 227         qemu_set_cloexec(fds[1]);
 228         return 0;
 229     }
 230
 231     if (errno != ENOSYS) {
 232         return -1;
 233     }
 234 #endif
 235
 236     return qemu_pipe(fds);
 237 }
 238 #endif
 239
 240 /*
 241  * Opens a socket with FD_CLOEXEC set
 242  */
 243 int qemu_socket(int domain, int type, int protocol)
 244 {
 245     int ret;
 246
 247 #ifdef SOCK_CLOEXEC
 248     ret = socket(domain, type | SOCK_CLOEXEC, protocol);
 249     if (ret != -1 || errno != EINVAL) {
 250         return ret;
 251     }
 252 #endif
 253     ret = socket(domain, type, protocol);
 254     if (ret >= 0) {
 255         qemu_set_cloexec(ret);
 256     }
 257
 258     return ret;
 259 }
 260
 261 /*
 262  * Accept a connection and set FD_CLOEXEC
 263  */
 264 int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)
 265 {
 266     int ret;
 267
 268 #ifdef CONFIG_ACCEPT4
 269     ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);
 270     if (ret != -1 || errno != ENOSYS) {
 271         return ret;
 272     }
 273 #endif
 274     ret = accept(s, addr, addrlen);
 275     if (ret >= 0) {
 276         qemu_set_cloexec(ret);
 277     }
 278
 279     return ret;
 280 }