unix_efile.c

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/* ``The contents of this file are subject to the Erlang Public License,
 * Version 1.1, (the "License"); you may not use this file except in
 * compliance with the License. You should have received a copy of the
 * Erlang Public License along with this software. If not, it can be
 * retrieved via the world wide web at http://www.erlang.org/.
 * 
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 * 
 * The Initial Developer of the Original Code is Ericsson Utvecklings AB.
 * Portions created by Ericsson are Copyright 1999, Ericsson Utvecklings
 * AB. All Rights Reserved.''
 * 
 *     $Id$
 */
/*
 * Purpose: Provides file and directory operations for Unix.
 */
#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif
#include "sys.h"
#include "erl_driver.h"
#include "erl_efile.h"
#include <utime.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_UIO_H
#include <sys/types.h>
#include <sys/uio.h>
#endif

#ifdef _OSE_
#include "efs.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

#ifdef _OSE_SFK_
#include <string.h>
#endif
#endif /* _OSE_ */

#ifdef VXWORKS
#include <ioLib.h>
#include <dosFsLib.h>
#include <nfsLib.h>
#include <sys/stat.h>
/*
** Not nice to include usrLib.h as MANY normal variable names get reported
** as shadowing globals, like 'i' for example.
** Instead we declare the only function we use here
*/
/*
 * #include <usrLib.h>
 */
extern STATUS copy(char *, char *);
#include <errno.h>
#else /* UNIX */
#  if defined(HAVE_FCNTL_H) && defined(HAVE_F_DUPFD)
#    include <fcntl.h>
     static int try_dup = -1;
#    if defined(NO_SYSCONF)
#      include <sys/param.h>
#      define MAX_FILES()	NOFILE
#    else
#      define MAX_FILES()	sysconf(_SC_OPEN_MAX)
#    endif
#  endif
#endif /* !VXWORKS */

#ifdef SUNOS4
#  define getcwd(buf, size) getwd(buf)
#endif

/* Find a definition of MAXIOV, that is used in the code later. */
#if defined IOV_MAX
#define MAXIOV IOV_MAX
#elif defined UIO_MAXIOV
#define MAXIOV UIO_MAXIOV
#else
#define MAXIOV 16
#endif


/*
 * Macros for testing file types.
 */

#ifdef _OSE_

#define ISDIR(st) S_ISDIR(((st).st_mode))
#define ISREG(st) S_ISREG(((st).st_mode))
#define ISDEV(st) (S_ISCHR(((st).st_mode)) || S_ISBLK(((st).st_mode)))
#define ISLNK(st) S_ISLNK(((st).st_mode))
#ifdef NO_UMASK
#define FILE_MODE (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)
#define DIR_MODE  (S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH)
#else
#define FILE_MODE (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)
#define DIR_MODE  (S_IRUSR | S_IWUSR | S_IXUSR | S_IRGRP | S_IWGRP | S_IXGRP | S_IROTH | \
                   S_IWOTH | S_IXOTH)
#endif 

#else  /* !_OSE_ */

#define ISDIR(st) (((st).st_mode & S_IFMT) == S_IFDIR)
#define ISREG(st) (((st).st_mode & S_IFMT) == S_IFREG)
#define ISDEV(st) \
  (((st).st_mode&S_IFMT) == S_IFCHR || ((st).st_mode&S_IFMT) == S_IFBLK)
#define ISLNK(st) (((st).st_mode & S_IFLNK) == S_IFLNK)
#ifdef NO_UMASK
#define FILE_MODE 0644
#define DIR_MODE  0755
#else
#define FILE_MODE 0666
#define DIR_MODE  0777
#endif

#endif /* _OSE_ */

#ifdef VXWORKS /* Currently only used on vxworks */

#define EF_ALLOC(S)		driver_alloc((S))
#define EF_REALLOC(P, S)	driver_realloc((P), (S))
#define EF_SAFE_ALLOC(S)	ef_safe_alloc((S))
#define EF_SAFE_REALLOC(P, S)	ef_safe_realloc((P), (S))
#define EF_FREE(P)		do { if((P)) driver_free((P)); } while(0)

extern void erl_exit(int n, char *fmt, _DOTS_);

static void *ef_safe_alloc(Uint s)
{
    void *p = EF_ALLOC(s);
    if (!p) erl_exit(1,
		     "unix efile drv: Can't allocate %d bytes of memory\n",
		     s);
    return p;
}

#if 0 /* Currently not used */

static void *ef_safe_realloc(void *op, Uint s)
{
    void *p = EF_REALLOC(op, s);
    if (!p) erl_exit(1,
		     "unix efile drv: Can't reallocate %d bytes of memory\n",
		     s);
    return p;
}

#endif /* #if 0 */
#endif /* #ifdef VXWORKS */

#define IS_DOT_OR_DOTDOT(s) \
    (s[0] == '.' && (s[1] == '\0' || (s[1] == '.' && s[2] == '\0')))

#ifdef VXWORKS
static FUNCTION(int, vxworks_to_posix, (int vx_errno));
#endif

/*
** VxWorks (not) strikes again. Too long RESULTING paths
** may give the infamous bus error. Have to check ALL
** filenames and pathnames. No wonder the emulator is slow on
** these cards...
*/
#ifdef VXWORKS
#define CHECK_PATHLEN(Name, ErrInfo)		\
   if (path_size(Name) > PATH_MAX) {		\
       errno = ENAMETOOLONG;			\
       return check_error(-1, ErrInfo);		\
   }
#else
#define CHECK_PATHLEN(X,Y) /* Nothing */
#endif

static FUNCTION(int, check_error, (int result, Efile_error* errInfo));

static int
check_error(int result, Efile_error *errInfo)
{
    if (result < 0) {
#ifdef VXWORKS
	errInfo->posix_errno = errInfo->os_errno = vxworks_to_posix(errno);
#else
	errInfo->posix_errno = errInfo->os_errno = errno;
#endif
	return 0;
    }
    return 1;
}

#ifdef VXWORKS

/*
 * VxWorks has different error codes for different file systems.
 * We map those to POSIX ones.
 */
static int
vxworks_to_posix(int vx_errno)
{
    DEBUGF(("[vxworks_to_posix] vx_errno: %08x\n", vx_errno));
    switch (vx_errno) {
	/* dosFsLib mapping */
#ifdef S_dosFsLib_FILE_ALREADY_EXISTS    
    case S_dosFsLib_FILE_ALREADY_EXISTS: return EEXIST;
#else
    case S_dosFsLib_FILE_EXISTS: return EEXIST;
#endif
#ifdef S_dosFsLib_BAD_DISK
    case S_dosFsLib_BAD_DISK: return EIO;
#endif
#ifdef S_dosFsLib_CANT_CHANGE_ROOT
    case S_dosFsLib_CANT_CHANGE_ROOT: return EINVAL;
#endif
#ifdef S_dosFsLib_NO_BLOCK_DEVICE
    case S_dosFsLib_NO_BLOCK_DEVICE: return ENOTBLK;
#endif
#ifdef S_dosFsLib_BAD_SEEK
    case S_dosFsLib_BAD_SEEK: return ESPIPE;
#endif
    case S_dosFsLib_VOLUME_NOT_AVAILABLE: return ENXIO;
    case S_dosFsLib_DISK_FULL: return ENOSPC;
    case S_dosFsLib_FILE_NOT_FOUND: return ENOENT;
    case S_dosFsLib_NO_FREE_FILE_DESCRIPTORS: return ENFILE;
    case S_dosFsLib_INVALID_NUMBER_OF_BYTES: return EINVAL;
    case S_dosFsLib_ILLEGAL_NAME: return EINVAL;
    case S_dosFsLib_CANT_DEL_ROOT: return EACCES;
    case S_dosFsLib_NOT_FILE: return EISDIR;
    case S_dosFsLib_NOT_DIRECTORY: return ENOTDIR;
    case S_dosFsLib_NOT_SAME_VOLUME: return EXDEV;
    case S_dosFsLib_READ_ONLY: return EACCES;
    case S_dosFsLib_ROOT_DIR_FULL: return ENOSPC;
    case S_dosFsLib_DIR_NOT_EMPTY: return EEXIST;
    case S_dosFsLib_NO_LABEL: return ENXIO;
    case S_dosFsLib_INVALID_PARAMETER: return EINVAL;
    case S_dosFsLib_NO_CONTIG_SPACE: return ENOSPC;
    case S_dosFsLib_FD_OBSOLETE: return EBADF;
    case S_dosFsLib_DELETED: return EINVAL;
    case S_dosFsLib_INTERNAL_ERROR: return EIO;
    case S_dosFsLib_WRITE_ONLY: return EACCES;
	/* nfsLib mapping - is needed since Windriver has used */
	/* inconsistent error codes (errno.h/nfsLib.h). */
    case S_nfsLib_NFS_OK: return 0;
    case S_nfsLib_NFSERR_PERM: return EPERM;
    case S_nfsLib_NFSERR_NOENT: return ENOENT;
    case S_nfsLib_NFSERR_IO: return EIO;
    case S_nfsLib_NFSERR_NXIO: return ENXIO;
    case S_nfsLib_NFSERR_ACCES: return EACCES;
    case S_nfsLib_NFSERR_EXIST: return EEXIST;
    case S_nfsLib_NFSERR_NODEV: return ENODEV;
    case S_nfsLib_NFSERR_NOTDIR: return ENOTDIR;
    case S_nfsLib_NFSERR_ISDIR: return EISDIR;
    case S_nfsLib_NFSERR_FBIG: return EFBIG;
    case S_nfsLib_NFSERR_NOSPC: return ENOSPC;
    case S_nfsLib_NFSERR_ROFS: return EROFS;
    case S_nfsLib_NFSERR_NAMETOOLONG: return ENAMETOOLONG;
    case S_nfsLib_NFSERR_NOTEMPTY: return EEXIST;
    case S_nfsLib_NFSERR_DQUOT: return ENOSPC;
    case S_nfsLib_NFSERR_STALE: return EINVAL;
    case S_nfsLib_NFSERR_WFLUSH: return ENXIO;
	/* And sometimes (...) the error codes are from ioLib (as in the */
	/* case of the (for nfsLib) unimplemented rename function) */
    case S_ioLib_NO_DRIVER: return ENXIO;
    case S_ioLib_UNKNOWN_REQUEST: return ENOSYS;
    case S_ioLib_DEVICE_ERROR: return ENXIO;
    case  S_ioLib_DEVICE_TIMEOUT: return EIO;
    case S_ioLib_WRITE_PROTECTED: return EACCES;
    case  S_ioLib_DISK_NOT_PRESENT: return EIO;
    case S_ioLib_NO_FILENAME: return EINVAL;
    case S_ioLib_CANCELLED: return EINTR;
    case  S_ioLib_NO_DEVICE_NAME_IN_PATH: return EINVAL;
    case  S_ioLib_NAME_TOO_LONG: return ENAMETOOLONG;
#ifdef S_ioLib_UNFORMATED
	/* Added (VxWorks 5.2 -> 5.3.1) */
    case S_ioLib_UNFORMATED: return EIO;
#endif
#ifdef S_objLib_OBJ_UNAVAILABLE
    case S_objLib_OBJ_UNAVAILABLE: return ENOENT;
#endif

      /* Temporary workaround for a weird error in passFs 
	 (VxWorks Simsparc only). File operation fails because of
	 ENOENT, but errno is not set. */
#ifdef SIMSPARCSOLARIS
    case 0: return ENOENT;
#endif

    }
    /* If the error code matches none of the above, assume */
    /* it is a POSIX one already. The upper bits (>=16) are */
    /* cleared since VxWorks uses those bits to indicate in */
    /* what module the error occured. */
    return vx_errno & 0xffff;
}

static int 
vxworks_enotsup(Efile_error *errInfo) 
{
    errInfo->posix_errno = errInfo->os_errno = ENOTSUP;
    return 0;
}

static int 
count_path_length(char *pathname, char *pathname2)
{
    static int stack[PATH_MAX / 2 + 1];
    int sp = 0;
    char *tmp;
    char *cpy = NULL;
    int i;
    int sum;
    for(i = 0;i < 2;++i) {
	if (!i) {
	    cpy = EF_SAFE_ALLOC(strlen(pathname)+1);
	    strcpy(cpy, pathname);
	} else if (pathname2 != NULL) {
	    EF_FREE(cpy);
	    cpy = EF_SAFE_ALLOC(strlen(pathname2)+1);
	    strcpy(cpy, pathname2);
	} else 
	    break;
	    
	for (tmp = strtok(cpy,"/"); tmp != NULL; tmp = strtok(NULL,"/")) {
	    if (!strcmp(tmp,"..") && sp > 0)
		--sp;
	    else if (strcmp(tmp,".")) 
		stack[sp++] = strlen(tmp);
	}
    }
    if (cpy != NULL)
	EF_FREE(cpy);
    sum = 0;
    for(i = 0;i < sp; ++i)
	sum += stack[i]+1;
    return (sum) ? sum : 1;
}

static int 
path_size(char *pathname) 
{
    static char currdir[PATH_MAX+2];
    if (*pathname == '/') 
	return count_path_length(pathname,NULL);
    ioDefPathGet(currdir);
    strcat(currdir,"/");
    return count_path_length(currdir,pathname);
}
    
#endif /* VXWORKS */

#ifdef _OSE_
static int 
ose_enotsup(Efile_error *errInfo) 
{
    errInfo->posix_errno = errInfo->os_errno = ENOTSUP;
    return 0;
}
#endif /* _OSE_ */

int
efile_mkdir(Efile_error* errInfo,	/* Where to return error codes. */
	    char* name)			/* Name of directory to create. */
{
    CHECK_PATHLEN(name,errInfo);
#ifdef NO_MKDIR_MODE
#ifdef VXWORKS
	/* This is a VxWorks/nfs workaround for erl_tar to create
	 * non-existant directories. (of some reason (...) VxWorks
	 * returns, the *non-module-prefixed*, 0xd code when
	 * trying to create a directory in a directory that doesn't exist).
	 * (see efile_openfile)
	 */
    if (mkdir(name) < 0) {
	struct stat sb;
	if (name[0] == '\0') {
	/* Return the correct error code enoent */ 
	    errno = S_nfsLib_NFSERR_NOENT;
	} else if (stat(name, &sb) == OK) {
	    errno = S_nfsLib_NFSERR_EXIST;
	} else if((strchr(name, '/') != NULL) && (errno == 0xd)) {
	/* Return the correct error code enoent */ 
	    errno = S_nfsLib_NFSERR_NOENT;
	}
	return check_error(-1, errInfo);
    } else return 1;
#else
    return check_error(mkdir(name), errInfo);
#endif
#else
    return check_error(mkdir(name, DIR_MODE), errInfo);
#endif
}

int
efile_rmdir(Efile_error* errInfo,	/* Where to return error codes. */
	    char* name)			/* Name of directory to delete. */
{
    CHECK_PATHLEN(name, errInfo);
    if (rmdir(name) == 0) {
	return 1;
    }
#ifdef VXWORKS
    if (name[0] == '\0') {
	/* Return the correct error code enoent */ 
	errno = S_nfsLib_NFSERR_NOENT;
    }
#else
    if (errno == ENOTEMPTY) {
	errno = EEXIST;
    }
    if (errno == EEXIST) {
	int saved_errno = errno;
	struct stat file_stat;
	struct stat cwd_stat;

	/*
	 *  The error code might be wrong if this is the current directory.
	 */

	if (stat(name, &file_stat) == 0 && stat(".", &cwd_stat) == 0 &&
	    file_stat.st_ino == cwd_stat.st_ino &&
	    file_stat.st_dev == cwd_stat.st_dev) {
	    saved_errno = EINVAL;
	}
	errno = saved_errno;
    }
#endif
    return check_error(-1, errInfo);
}

int
efile_delete_file(Efile_error* errInfo,	/* Where to return error codes. */
		  char* name)		/* Name of file to delete. */
{
    CHECK_PATHLEN(name,errInfo);
#ifdef _OSE_
    if (remove(name) == 0) {
	return 1;
    }
#else
    if (unlink(name) == 0) {
	return 1;
    }
    if (errno == EISDIR) {	/* Linux sets the wrong error code. */
	errno = EPERM;
    }
#endif
    return check_error(-1, errInfo);
}

/*
 *---------------------------------------------------------------------------
 *
 *      Changes the name of an existing file or directory, from src to dst.
 *	If src and dst refer to the same file or directory, does nothing
 *	and returns success.  Otherwise if dst already exists, it will be
 *	deleted and replaced by src subject to the following conditions:
 *	    If src is a directory, dst may be an empty directory.
 *	    If src is a file, dst may be a file.
 *	In any other situation where dst already exists, the rename will
 *	fail.  
 *
 * Results:
 *	If the directory was successfully created, returns 1.
 *	Otherwise the return value is 0 and errno is set to
 *	indicate the error.  Some possible values for errno are:
 *
 *	EACCES:     src or dst parent directory can't be read and/or written.
 *	EEXIST:	    dst is a non-empty directory.
 *	EINVAL:	    src is a root directory or dst is a subdirectory of src.
 *	EISDIR:	    dst is a directory, but src is not.
 *	ENOENT:	    src doesn't exist, or src or dst is "".
 *	ENOTDIR:    src is a directory, but dst is not.  
 *	EXDEV:	    src and dst are on different filesystems.
 *	
 * Side effects:
 *	The implementation of rename may allow cross-filesystem renames,
 *	but the caller should be prepared to emulate it with copy and
 *	delete if errno is EXDEV.
 *
 *---------------------------------------------------------------------------
 */

int
efile_rename(Efile_error* errInfo,	/* Where to return error codes. */
	     char* src,		        /* Original name. */
	     char* dst)			/* New name. */
{
    CHECK_PATHLEN(src,errInfo);
    CHECK_PATHLEN(dst,errInfo);
#ifdef VXWORKS
	
    /* First check if src == dst, if so, just return. */
    /* VxWorks dos file system destroys the file otherwise, */
    /* VxWorks nfs file system rename doesn't work at all. */
    if(strcmp(src, dst) == 0)
	return 1;
#endif
    if (rename(src, dst) == 0) {