system.c

samba-3.0.22.tar.gz 编译smb服务器的源码

/* 
   Unix SMB/CIFS implementation.
   Samba system utilities
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Jeremy Allison  1998-2005
   Copyright (C) Timur Bakeyev        2005
   
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

/*
   The idea is that this file will eventually have wrappers around all
   important system calls in samba. The aims are:

   - to enable easier porting by putting OS dependent stuff in here

   - to allow for hooks into other "pseudo-filesystems"

   - to allow easier integration of things like the japanese extensions

   - to support the philosophy of Samba to expose the features of
     the OS within the SMB model. In general whatever file/printer/variable
     expansions/etc make sense to the OS should be acceptable to Samba.
*/



/*******************************************************************
 A wrapper for usleep in case we don't have one.
********************************************************************/

int sys_usleep(long usecs)
{
#ifndef HAVE_USLEEP
	struct timeval tval;
#endif

	/*
	 * We need this braindamage as the glibc usleep
	 * is not SPEC1170 complient... grumble... JRA.
	 */

	if(usecs < 0 || usecs > 1000000) {
		errno = EINVAL;
		return -1;
	}

#if HAVE_USLEEP
	usleep(usecs);
	return 0;
#else /* HAVE_USLEEP */
	/*
	 * Fake it with select...
	 */
	tval.tv_sec = 0;
	tval.tv_usec = usecs/1000;
	select(0,NULL,NULL,NULL,&tval);
	return 0;
#endif /* HAVE_USLEEP */
}

/*******************************************************************
A read wrapper that will deal with EINTR.
********************************************************************/

ssize_t sys_read(int fd, void *buf, size_t count)
{
	ssize_t ret;

	do {
		ret = read(fd, buf, count);
	} while (ret == -1 && errno == EINTR);
	return ret;
}

/*******************************************************************
A write wrapper that will deal with EINTR.
********************************************************************/

ssize_t sys_write(int fd, const void *buf, size_t count)
{
	ssize_t ret;

	do {
		ret = write(fd, buf, count);
	} while (ret == -1 && errno == EINTR);
	return ret;
}


/*******************************************************************
A pread wrapper that will deal with EINTR and 64-bit file offsets.
********************************************************************/

#if defined(HAVE_PREAD) || defined(HAVE_PREAD64)
ssize_t sys_pread(int fd, void *buf, size_t count, SMB_OFF_T off)
{
	ssize_t ret;

	do {
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_PREAD64)
		ret = pread64(fd, buf, count, off);
#else
		ret = pread(fd, buf, count, off);
#endif
	} while (ret == -1 && errno == EINTR);
	return ret;
}
#endif

/*******************************************************************
A write wrapper that will deal with EINTR and 64-bit file offsets.
********************************************************************/

#if defined(HAVE_PWRITE) || defined(HAVE_PWRITE64)
ssize_t sys_pwrite(int fd, const void *buf, size_t count, SMB_OFF_T off)
{
	ssize_t ret;

	do {
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_PWRITE64)
		ret = pwrite64(fd, buf, count, off);
#else
		ret = pwrite(fd, buf, count, off);
#endif
	} while (ret == -1 && errno == EINTR);
	return ret;
}
#endif

/*******************************************************************
A send wrapper that will deal with EINTR.
********************************************************************/

ssize_t sys_send(int s, const void *msg, size_t len, int flags)
{
	ssize_t ret;

	do {
		ret = send(s, msg, len, flags);
	} while (ret == -1 && errno == EINTR);
	return ret;
}

/*******************************************************************
A sendto wrapper that will deal with EINTR.
********************************************************************/

ssize_t sys_sendto(int s,  const void *msg, size_t len, int flags, const struct sockaddr *to, socklen_t tolen)
{
	ssize_t ret;

	do {
		ret = sendto(s, msg, len, flags, to, tolen);
	} while (ret == -1 && errno == EINTR);
	return ret;
}

/*******************************************************************
A recvfrom wrapper that will deal with EINTR.
********************************************************************/

ssize_t sys_recvfrom(int s, void *buf, size_t len, int flags, struct sockaddr *from, socklen_t *fromlen)
{
	ssize_t ret;

	do {
		ret = recvfrom(s, buf, len, flags, from, fromlen);
	} while (ret == -1 && errno == EINTR);
	return ret;
}

/*******************************************************************
A fcntl wrapper that will deal with EINTR.
********************************************************************/

int sys_fcntl_ptr(int fd, int cmd, void *arg)
{
	int ret;

	do {
		ret = fcntl(fd, cmd, arg);
	} while (ret == -1 && errno == EINTR);
	return ret;
}

/*******************************************************************
A fcntl wrapper that will deal with EINTR.
********************************************************************/

int sys_fcntl_long(int fd, int cmd, long arg)
{
	int ret;

	do {
		ret = fcntl(fd, cmd, arg);
	} while (ret == -1 && errno == EINTR);
	return ret;
}

/*******************************************************************
A stat() wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_stat(const char *fname,SMB_STRUCT_STAT *sbuf)
{
	int ret;
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_STAT64)
	ret = stat64(fname, sbuf);
#else
	ret = stat(fname, sbuf);
#endif
	/* we always want directories to appear zero size */
	if (ret == 0 && S_ISDIR(sbuf->st_mode)) sbuf->st_size = 0;
	return ret;
}

/*******************************************************************
 An fstat() wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_fstat(int fd,SMB_STRUCT_STAT *sbuf)
{
	int ret;
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_FSTAT64)
	ret = fstat64(fd, sbuf);
#else
	ret = fstat(fd, sbuf);
#endif
	/* we always want directories to appear zero size */
	if (ret == 0 && S_ISDIR(sbuf->st_mode)) sbuf->st_size = 0;
	return ret;
}

/*******************************************************************
 An lstat() wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_lstat(const char *fname,SMB_STRUCT_STAT *sbuf)
{
	int ret;
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_LSTAT64)
	ret = lstat64(fname, sbuf);
#else
	ret = lstat(fname, sbuf);
#endif
	/* we always want directories to appear zero size */
	if (ret == 0 && S_ISDIR(sbuf->st_mode)) sbuf->st_size = 0;
	return ret;
}

/*******************************************************************
 An ftruncate() wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_ftruncate(int fd, SMB_OFF_T offset)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_FTRUNCATE64)
	return ftruncate64(fd, offset);
#else
	return ftruncate(fd, offset);
#endif
}

/*******************************************************************
 An lseek() wrapper that will deal with 64 bit filesizes.
********************************************************************/

SMB_OFF_T sys_lseek(int fd, SMB_OFF_T offset, int whence)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OFF64_T) && defined(HAVE_LSEEK64)
	return lseek64(fd, offset, whence);
#else
	return lseek(fd, offset, whence);
#endif
}

/*******************************************************************
 An fseek() wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_fseek(FILE *fp, SMB_OFF_T offset, int whence)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(LARGE_SMB_OFF_T) && defined(HAVE_FSEEK64)
	return fseek64(fp, offset, whence);
#elif defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(LARGE_SMB_OFF_T) && defined(HAVE_FSEEKO64)
	return fseeko64(fp, offset, whence);
#else
	return fseek(fp, offset, whence);
#endif
}

/*******************************************************************
 An ftell() wrapper that will deal with 64 bit filesizes.
********************************************************************/

SMB_OFF_T sys_ftell(FILE *fp)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(LARGE_SMB_OFF_T) && defined(HAVE_FTELL64)
	return (SMB_OFF_T)ftell64(fp);
#elif defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(LARGE_SMB_OFF_T) && defined(HAVE_FTELLO64)
	return (SMB_OFF_T)ftello64(fp);
#else
	return (SMB_OFF_T)ftell(fp);
#endif
}

/*******************************************************************
 A creat() wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_creat(const char *path, mode_t mode)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_CREAT64)
	return creat64(path, mode);
#else
	/*
	 * If creat64 isn't defined then ensure we call a potential open64.
	 * JRA.
	 */
	return sys_open(path, O_WRONLY | O_CREAT | O_TRUNC, mode);
#endif
}

/*******************************************************************
 An open() wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_open(const char *path, int oflag, mode_t mode)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OPEN64)
	return open64(path, oflag, mode);
#else
	return open(path, oflag, mode);
#endif
}

/*******************************************************************
 An fopen() wrapper that will deal with 64 bit filesizes.
********************************************************************/

FILE *sys_fopen(const char *path, const char *type)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_FOPEN64)
	return fopen64(path, type);
#else
	return fopen(path, type);
#endif
}

/*******************************************************************
 An opendir wrapper that will deal with 64 bit filesizes.
********************************************************************/

SMB_STRUCT_DIR *sys_opendir(const char *name)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_OPENDIR64)
	return opendir64(name);
#else
	return opendir(name);
#endif
}

/*******************************************************************
 A readdir wrapper that will deal with 64 bit filesizes.
********************************************************************/

SMB_STRUCT_DIRENT *sys_readdir(SMB_STRUCT_DIR *dirp)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_READDIR64)
	return readdir64(dirp);
#else
	return readdir(dirp);
#endif
}

/*******************************************************************
 A seekdir wrapper that will deal with 64 bit filesizes.
********************************************************************/

void sys_seekdir(SMB_STRUCT_DIR *dirp, long offset)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_SEEKDIR64)
	seekdir64(dirp, offset);
#else
	seekdir(dirp, offset);
#endif
}

/*******************************************************************
 A telldir wrapper that will deal with 64 bit filesizes.
********************************************************************/

long sys_telldir(SMB_STRUCT_DIR *dirp)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_TELLDIR64)
	return (long)telldir64(dirp);
#else
	return (long)telldir(dirp);
#endif
}

/*******************************************************************
 A rewinddir wrapper that will deal with 64 bit filesizes.
********************************************************************/

void sys_rewinddir(SMB_STRUCT_DIR *dirp)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_REWINDDIR64)
	rewinddir64(dirp);
#else
	rewinddir(dirp);
#endif
}

/*******************************************************************
 A close wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_closedir(SMB_STRUCT_DIR *dirp)
{
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_CLOSEDIR64)
	return closedir64(dirp);
#else
	return closedir(dirp);
#endif
}

/*******************************************************************
 An mknod() wrapper that will deal with 64 bit filesizes.
********************************************************************/

int sys_mknod(const char *path, mode_t mode, SMB_DEV_T dev)
{
#if defined(HAVE_MKNOD) || defined(HAVE_MKNOD64)
#if defined(HAVE_EXPLICIT_LARGEFILE_SUPPORT) && defined(HAVE_MKNOD64) && defined(HAVE_DEV64_T)
	return mknod64(path, mode, dev);
#else
	return mknod(path, mode, dev);
#endif
#else
	/* No mknod system call. */
	errno = ENOSYS;
	return -1;
#endif
}

/*******************************************************************
 Wrapper for realpath.
********************************************************************/

char *sys_realpath(const char *path, char *resolved_path)
{
#if defined(HAVE_REALPATH)
	return realpath(path, resolved_path);
#else
	/* As realpath is not a system call we can't return ENOSYS. */
	errno = EINVAL;
	return NULL;
#endif
}

/*******************************************************************
The wait() calls vary between systems
********************************************************************/

int sys_waitpid(pid_t pid,int *status,int options)
{
#ifdef HAVE_WAITPID
	return waitpid(pid,status,options);
#else /* HAVE_WAITPID */
	return wait4(pid, status, options, NULL);
#endif /* HAVE_WAITPID */
}

/*******************************************************************
 System wrapper for getwd
********************************************************************/

char *sys_getwd(char *s)
{
	char *wd;
#ifdef HAVE_GETCWD
	wd = (char *)getcwd(s, sizeof (pstring));
#else
	wd = (char *)getwd(s);
#endif
	return wd;
}

/*******************************************************************
system wrapper for symlink
********************************************************************/

int sys_symlink(const char *oldpath, const char *newpath)
{
#ifndef HAVE_SYMLINK
	errno = ENOSYS;
	return -1;
#else
	return symlink(oldpath, newpath);
#endif
}

/*******************************************************************
system wrapper for readlink
********************************************************************/

int sys_readlink(const char *path, char *buf, size_t bufsiz)
{
#ifndef HAVE_READLINK