Archipelago » qemu

/*

 * QEMU low level functions

 *

 * Copyright (c) 2003 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <stdlib.h>

#include <stdio.h>

#include <stdarg.h>

#include <string.h>

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

/* Needed early for CONFIG_BSD etc. */

#include "config-host.h"

#if defined(CONFIG_MADVISE) || defined(CONFIG_POSIX_MADVISE)

#include <sys/mman.h>

#endif

#ifdef CONFIG_SOLARIS

#include <sys/types.h>

#include <sys/statvfs.h>

/* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for

   discussion about Solaris header problems */

extern int madvise(caddr_t, size_t, int);

#endif

#ifdef _WIN32

#include <windows.h>

#elif defined(CONFIG_BSD)

#include <stdlib.h>

#else

#include <malloc.h>

#endif

#include "qemu-common.h"

#include "trace.h"

#include "sysemu.h"

#include "qemu_socket.h"

int qemu_madvise(void *addr, size_t len, int advice)

{

    if (advice == QEMU_MADV_INVALID) {

        errno = EINVAL;

        return -1;

    }

#if defined(CONFIG_MADVISE)

    return madvise(addr, len, advice);

#elif defined(CONFIG_POSIX_MADVISE)

    return posix_madvise(addr, len, advice);

#else

    errno = EINVAL;

    return -1;

#endif

}

int qemu_create_pidfile(const char *filename)

{

    char buffer[128];

    int len;

#ifndef _WIN32

    int fd;

    fd = qemu_open(filename, O_RDWR | O_CREAT, 0600);

    if (fd == -1)

        return -1;

    if (lockf(fd, F_TLOCK, 0) == -1)

        return -1;

    len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());

    if (write(fd, buffer, len) != len)

        return -1;

#else

    HANDLE file;

    OVERLAPPED overlap;

    BOOL ret;

    memset(&overlap, 0, sizeof(overlap));

    file = CreateFile(filename, GENERIC_WRITE, FILE_SHARE_READ, NULL,

                      OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);

    if (file == INVALID_HANDLE_VALUE)

      return -1;

    len = snprintf(buffer, sizeof(buffer), "%ld\n", (long)getpid());

    ret = WriteFileEx(file, (LPCVOID)buffer, (DWORD)len,

                      &overlap, NULL);

    if (ret == 0)

      return -1;

#endif

    return 0;

}

/*

 * Opens a file with FD_CLOEXEC set

 */

int qemu_open(const char *name, int flags, ...)

{

    int ret;

    int mode = 0;

    if (flags & O_CREAT) {

        va_list ap;

        va_start(ap, flags);

        mode = va_arg(ap, int);

        va_end(ap);

    }

#ifdef O_CLOEXEC

    ret = open(name, flags | O_CLOEXEC, mode);

#else

    ret = open(name, flags, mode);

    if (ret >= 0) {

        qemu_set_cloexec(ret);

    }

#endif

    return ret;

}

/*

 * A variant of write(2) which handles partial write.

 *

 * Return the number of bytes transferred.

 * Set errno if fewer than `count' bytes are written.

 *

 * This function don't work with non-blocking fd's.

 * Any of the possibilities with non-bloking fd's is bad:

 *   - return a short write (then name is wrong)

 *   - busy wait adding (errno == EAGAIN) to the loop

 */

ssize_t qemu_write_full(int fd, const void *buf, size_t count)

{

    ssize_t ret = 0;

    ssize_t total = 0;

    while (count) {

        ret = write(fd, buf, count);

        if (ret < 0) {

            if (errno == EINTR)

                continue;

            break;

        }

        count -= ret;

        buf += ret;

        total += ret;

    }

    return total;

}

/*

 * Opens a socket with FD_CLOEXEC set

 */

int qemu_socket(int domain, int type, int protocol)

{

    int ret;

#ifdef SOCK_CLOEXEC

    ret = socket(domain, type | SOCK_CLOEXEC, protocol);

    if (ret != -1 || errno != EINVAL) {

        return ret;

    }

#endif

    ret = socket(domain, type, protocol);

    if (ret >= 0) {

        qemu_set_cloexec(ret);

    }

    return ret;

}

/*

 * Accept a connection and set FD_CLOEXEC

 */

int qemu_accept(int s, struct sockaddr *addr, socklen_t *addrlen)

{

    int ret;

#ifdef CONFIG_ACCEPT4

    ret = accept4(s, addr, addrlen, SOCK_CLOEXEC);

    if (ret != -1 || errno != ENOSYS) {

        return ret;

    }

#endif

    ret = accept(s, addr, addrlen);

    if (ret >= 0) {

        qemu_set_cloexec(ret);

    }

    return ret;

}