SysCalls.c revision 4fd606d1f5abe38e1f42c38de1d2e895166bd0f4
/** @file
EFI versions of NetBSD system calls.
Copyright (c) 2010 - 2011, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials are licensed and made available under
the terms and conditions of the BSD License that accompanies this distribution.
The full text of the license may be found at
http://opensource.org/licenses/bsd-license.
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include <Uefi.h>
#include <Library/UefiLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/BaseLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/ShellLib.h>
#include <LibConfig.h>
#include <sys/EfiCdefs.h>
#include <sys/ansi.h>
#include <errno.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <wchar.h>
#include <sys/poll.h>
#include <sys/fcntl.h>
#include <sys/stat.h>
#include <sys/syslimits.h>
#include <sys/filio.h>
#include <Efi/SysEfi.h>
#include <unistd.h>
#include <kfile.h>
#include <Device/Device.h>
#include <MainData.h>
#include <extern.h>
/* EFI versions of BSD system calls used in stdio */
/* Validate that fd refers to a valid file descriptor.
IsOpen is interpreted as follows:
- Positive fd must be OPEN
- Zero fd must be CLOSED
- Negative fd may be OPEN or CLOSED
@retval TRUE fd is VALID
@retval FALSE fd is INVALID
*/
BOOLEAN
ValidateFD( int fd, int IsOpen)
{
struct __filedes *filp;
BOOLEAN retval = FALSE;
if((fd >= 0) && (fd < OPEN_MAX)) {
filp = &gMD->fdarray[fd];
retval = TRUE;
if(IsOpen >= 0) {
retval = (BOOLEAN)((filp->f_iflags != 0) && // TRUE if OPEN
FILE_IS_USABLE(filp)); // and Usable (not Larval or Closing)
if(IsOpen == VALID_CLOSED) {
retval = (BOOLEAN)!retval; // We want TRUE if CLOSED
}
}
}
return retval;
}
/* Find and reserve a free File Descriptor.
Returns the first free File Descriptor greater than or equal to the,
already validated, fd specified by Minfd.
@return Returns -1 if there are no free FDs. Otherwise returns the
found fd.
*/
int
FindFreeFD( int MinFd )
{
struct __filedes *Mfd;
int i;
int fd = -1;
Mfd = gMD->fdarray;
// Get an available fd
for(i=MinFd; i < OPEN_MAX; ++i) {
if(Mfd[i].f_iflags == 0) {
Mfd[i].f_iflags = FIF_LARVAL; // Temporarily mark this fd as reserved
fd = i;
break;
}
}
return fd;
}
/* Mark that an open file is to be deleted when closed. */
int
DeleteOnClose(int fd)
{
int retval = 0;
if(ValidateFD( fd, VALID_OPEN)) {
gMD->fdarray[fd].f_iflags |= FIF_DELCLOSE;
}
else {
errno = EBADF;
retval = -1;
}
return retval;
}
/** The isatty() function tests whether fildes, an open file descriptor,
is associated with a terminal device.
@retval 1 fildes is associated with a terminal.
@retval 0 fildes is not associated with a terminal. errno is set to
EBADF if fildes is not a valid open FD.
**/
int
isatty (int fd)
{
int retval = 0;
struct __filedes *Fp;
if(ValidateFD( fd, VALID_OPEN)) {
Fp = &gMD->fdarray[fd];
retval = Fp->f_iflags & _S_ITTY;
}
else {
errno = EBADF;
}
return retval;
}
/** Determine if file descriptor fd is a duplicate of some other fd.
@param[in] fd The file descriptor to check.
@retval TRUE fd is a duplicate of another fd.
@retval FALSE fd is unique.
**/
static BOOLEAN
IsDupFd( int fd)
{
void * DevData;
const struct fileops *FileOps;
int i;
BOOLEAN Ret = FALSE;
if(ValidateFD( fd, VALID_OPEN )) {
FileOps = gMD->fdarray[fd].f_ops;
DevData = gMD->fdarray[fd].devdata;
for(i=0; i < OPEN_MAX; ++i) {
if(i == fd) continue;
if(ValidateFD( i, VALID_OPEN )) { // TRUE if fd is valid and OPEN
if((gMD->fdarray[i].f_ops == FileOps)
&&(gMD->fdarray[i].devdata == DevData )) {
Ret = TRUE;
break;
}
}
}
}
return Ret;
}
/** Close a file and set its fd to the specified state.
@param[in] fd The file descriptor to close.
@param[in] NewState State to set the fd to after the file is closed.
@retval 0 The operation completed successfully.
@retval -1 The operation failed. Further information is in errno.
**/
static int
_closeX (int fd, int NewState)
{
struct __filedes *Fp;
int retval = 0;
// Verify my pointers and get my FD.
if(ValidateFD( fd, VALID_OPEN )) {
Fp = &gMD->fdarray[fd];
// Check if there are other users of this FileHandle
if(Fp->RefCount == 1) { // There should be no other users
if(! IsDupFd(fd)) {
// Only do the close if no one else is using the FileHandle
if(Fp->f_iflags & FIF_DELCLOSE) {
/* Handle files marked "Delete on Close". */
if(Fp->f_ops->fo_delete != NULL) {
retval = Fp->f_ops->fo_delete(Fp);
}
}
else {
retval = Fp->f_ops->fo_close( Fp);
}
}
Fp->f_iflags = NewState; // Close this FD or reserve it
Fp->RefCount = 0; // No one using this FD
}
else {
--Fp->RefCount; /* One less user of this FD */
}
}
else {
// Bad FD
retval = -1;
errno = EBADF;
}
return retval;
}
/** The close() function deallocates the file descriptor indicated by fd.
To deallocate means to make the file descriptor available for return by
subsequent calls to open() or other functions that allocate file
descriptors. All outstanding record locks owned by the process on the file
associated with the file descriptor are removed (that is, unlocked).
@retval 0 Successful completion.
@retval -1 An error occurred and errno is set to identify the error.
**/
int
close (int fd)
{
return _closeX(fd, 0);
}
/**
**/
int
unlink (const char *path)
{
struct __filedes *Fp;
int fd;
int retval = -1;
EFIerrno = RETURN_SUCCESS;
fd = open(path, O_WRONLY, 0);
if(fd >= 0) {
Fp = &gMD->fdarray[fd];
if(Fp->f_ops->fo_delete != NULL) {
retval = Fp->f_ops->fo_delete(Fp);
}
Fp->f_iflags = 0; // Close this FD
Fp->RefCount = 0; // No one using this FD
}
return retval;
}
/** The fcntl() function shall perform the operations described below on open
files. The fildes argument is a file descriptor.
The available values for cmd are defined in <fcntl.h> and are as follows:
- F_DUPFD - Return a new file descriptor which shall be the lowest
numbered available (that is, not already open) file
descriptor greater than or equal to the third argument, arg,
taken as an integer of type int. The new file descriptor
shall refer to the same open file description as the original
file descriptor, and shall share any locks. The FD_CLOEXEC
flag associated with the new file descriptor shall be cleared
to keep the file open across calls to one of the exec functions.
- F_GETFD - Get the file descriptor flags defined in <fcntl.h> that are
associated with the file descriptor fildes. File descriptor
flags are associated with a single file descriptor and do not
affect other file descriptors that refer to the same file.
- F_SETFD - Set the file descriptor flags defined in <fcntl.h>, that are
associated with fildes, to the third argument, arg, taken
as type int. If the FD_CLOEXEC flag in the third argument
is 0, the file shall remain open across the exec
functions; otherwise, the file shall be closed upon
successful execution of one of the exec functions.
- F_GETFL - Get the file status flags and file access modes, defined in
<fcntl.h>, for the file description associated with fildes.
The file access modes can be extracted from the return
value using the mask O_ACCMODE, which is defined in
<fcntl.h>. File status flags and file access modes are
associated with the file description and do not affect
other file descriptors that refer to the same file with
different open file descriptions.
- F_SETFL - Set the file status flags, defined in <fcntl.h>, for the file
description associated with fildes from the corresponding
bits in the third argument, arg, taken as type int. Bits
corresponding to the file access mode and the file creation
flags, as defined in <fcntl.h>, that are set in arg shall
be ignored. If any bits in arg other than those mentioned
here are changed by the application, the result is unspecified.
- F_GETOWN - If fildes refers to a socket, get the process or process group
ID specified to receive SIGURG signals when out-of-band
data is available. Positive values indicate a process ID;
negative values, other than -1, indicate a process group
ID. If fildes does not refer to a socket, the results are
unspecified.
- F_SETOWN - If fildes refers to a socket, set the process or process
group ID specified to receive SIGURG signals when
out-of-band data is available, using the value of the third
argument, arg, taken as type int. Positive values indicate
a process ID; negative values, other than -1, indicate a
process group ID. If fildes does not refer to a socket, the
results are unspecified.
The fcntl() function shall fail if:
[EBADF] The fildes argument is not a valid open file descriptor.
[EINVAL] The cmd argument is invalid, or the cmd argument is F_DUPFD
and arg is negative or greater than or equal to {OPEN_MAX}.
[EMFILE] The argument cmd is F_DUPFD and {OPEN_MAX} file descriptors
are currently open in the calling process, or no file
descriptors greater than or equal to arg are available.
[EOVERFLOW] One of the values to be returned cannot be represented correctly.
@return Upon successful completion, the value returned shall depend on
cmd as follows:
- F_DUPFD - A new file descriptor.
- F_GETFD - Value of flags defined in <fcntl.h>. The return value
shall not be negative.
- F_SETFD - Value other than -1.
- F_GETFL - Value of file status flags and access modes. The return
value is not negative.
- F_SETFL - Value other than -1.
- F_GETOWN - Value of the socket owner process or process group;
this will not be -1.
- F_SETOWN - Value other than -1.
Otherwise, -1 shall be returned and errno set to indicate the error.
**/
int
fcntl (int fildes, int cmd, ...)
{
va_list p3;
struct __filedes *MyFd;
int retval = -1;
int temp;
//Print(L"%a( %d, %d, ...)\n", __func__, fildes, cmd);
va_start(p3, cmd);
if(ValidateFD( fildes, VALID_OPEN )) {
MyFd = &gMD->fdarray[fildes];
switch(cmd) {
case F_DUPFD:
temp = va_arg(p3, int);
if(ValidateFD( temp, VALID_DONT_CARE )) {
temp = FindFreeFD( temp );
if(temp < 0) {
errno = EMFILE;
break;
}
/* temp is now a valid fd reserved for further use
so copy fd into temp.
*/
(void)memcpy(&gMD->fdarray[temp], MyFd, sizeof(struct __filedes));
retval = temp;
}
else {
errno = EINVAL;
}
break;
case F_SETFL:
retval = MyFd->Oflags; // Get original value
temp = va_arg(p3, int);
temp &= O_SETMASK; // Only certain bits can be set
temp |= retval & O_SETMASK;
MyFd->Oflags = temp; // Set new value
break;
case F_SETFD:
retval = MyFd->f_iflags;
break;
//case F_SETOWN:
// retval = MyFd->SocProc;
// MyFd->SocProc = va_arg(p3, int);
// break;
case F_GETFD:
retval = MyFd->f_iflags;
break;
case F_GETFL:
retval = MyFd->Oflags;
break;
//case F_GETOWN:
// retval = MyFd->SocProc;
// break;
default:
errno = EINVAL;
break;
}
}
else {
// Bad FD
errno = EBADF;
}
va_end(p3);
return retval;;
}
/** The dup() function provides an alternative interface to the
service provided by fcntl() using the F_DUPFD command. The call:
- fid = dup(fildes);
shall be equivalent to:
- fid = fcntl(fildes, F_DUPFD, 0);
@return Upon successful completion a non-negative integer, namely the
file descriptor, shall be returned; otherwise, -1 shall be
returned and errno set to indicate the error.
**/
int
dup (int fildes)
{
return fcntl(fildes, F_DUPFD, 0);
}
/** The dup2() function provides an alternative interface to the
service provided by fcntl() using the F_DUPFD command. The call:
- fid = dup2(fildes, fildes2);
shall be equivalent to:
- close(fildes2);
- fid = fcntl(fildes, F_DUPFD, fildes2);
except for the following:
- If fildes2 is less than 0 or greater than or equal to {OPEN_MAX},
dup2() shall return -1 with errno set to [EBADF].
- If fildes is a valid file descriptor and is equal to fildes2, dup2()
shall return fildes2 without closing it.
- If fildes is not a valid file descriptor, dup2() shall return -1 and
shall not close fildes2.
- The value returned shall be equal to the value of fildes2 upon
successful completion, or -1 upon failure.
@return Upon successful completion a non-negative integer, namely
fildes2, shall be returned; otherwise, -1 shall be
returned and errno set to EBADF indicate the error.
**/
int
dup2 (int fildes, int fildes2)
{
int retval = -1;
if(ValidateFD( fildes, VALID_OPEN)) {
retval = fildes2;
if( fildes != fildes2) {
if(ValidateFD( fildes2, VALID_DONT_CARE)) {
gMD->fdarray[fildes2].f_iflags = FIF_LARVAL; // Mark the file closed, but reserved
(void)memcpy(&gMD->fdarray[fildes2], // Duplicate fildes into fildes2
&gMD->fdarray[fildes], sizeof(struct __filedes));
gMD->fdarray[fildes2].MyFD = (UINT16)fildes2;
}
else {
errno = EBADF;
retval = -1;
}
}
}
else {
errno = EBADF;
}
return retval;
}
/** Reposition a file's read/write offset.
The lseek() function repositions the offset of the file descriptor fildes
to the argument offset according to the directive how. The argument
fildes must be an open file descriptor. lseek() repositions the file
pointer fildes as follows:
If how is SEEK_SET, the offset is set to offset bytes.
If how is SEEK_CUR, the offset is set to its current location
plus offset bytes.
If how is SEEK_END, the offset is set to the size of the file
plus offset bytes.
The lseek() function allows the file offset to be set beyond the end of
the existing end-of-file of the file. If data is later written at this
point, subsequent reads of the data in the gap return bytes of zeros
(until data is actually written into the gap).
Some devices are incapable of seeking. The value of the pointer associ-
ated with such a device is undefined.
@return Upon successful completion, lseek() returns the resulting offset
location as measured in bytes from the beginning of the file.
Otherwise, a value of -1 is returned and errno is set to
indicate the error.
**/
__off_t
lseek (int fd, __off_t offset, int how)
{
__off_t CurPos = -1;
// RETURN_STATUS Status = RETURN_SUCCESS;
struct __filedes *filp;
EFIerrno = RETURN_SUCCESS; // In case of error without an EFI call
if( how == SEEK_SET || how == SEEK_CUR || how == SEEK_END) {
if(ValidateFD( fd, VALID_OPEN)) {
filp = &gMD->fdarray[fd];
// Both of our parameters have been verified as valid
CurPos = filp->f_ops->fo_lseek( filp, offset, how);
if(CurPos >= 0) {
filp->f_offset = CurPos;
}
}
else {
errno = EBADF; // Bad File Descriptor
}
}
else {
errno = EINVAL; // Invalid how argument
}
return CurPos;
}
/** The directory path is created with the access permissions specified by
perms.
The directory is closed after it is created.
@retval 0 The directory was created successfully.
@retval -1 An error occurred and error codes are stored in errno and EFIerrno.
**/
int
mkdir (const char *path, __mode_t perms)
{
wchar_t *NewPath;
DeviceNode *Node;
char *GenI;
RETURN_STATUS Status;
int Instance = 0;
int retval = 0;
Status = ParsePath(path, &NewPath, &Node, &Instance, NULL);
if(Status == RETURN_SUCCESS) {
GenI = Node->InstanceList;
if(GenI == NULL) {
errno = EPERM;
retval = -1;
}
else {
//GenI += (Instance * Node->InstanceSize);
retval = ((GenericInstance *)GenI)->Abstraction.fo_mkdir( path, perms);
}
free(NewPath);
}
else {
retval = -1;
}
return retval;
}
/** Open a file.
The EFI ShellOpenFileByName() function is used to perform the low-level
file open operation. The primary task of open() is to translate from the
flags used in the <stdio.h> environment to those used by the EFI function.
The only valid flag combinations for ShellOpenFileByName() are:
- Read
- Read/Write
- Create/Read/Write
The mode value is saved in the FD to indicate permissions for further operations.
O_RDONLY -- flags = EFI_FILE_MODE_READ -- this is always done
O_WRONLY -- flags |= EFI_FILE_MODE_WRITE
O_RDWR -- flags |= EFI_FILE_MODE_WRITE -- READ is already set
O_NONBLOCK -- ignored
O_APPEND -- Seek to EOF before every write
O_CREAT -- flags |= EFI_FILE_MODE_CREATE
O_TRUNC -- delete first then create new
O_EXCL -- if O_CREAT is also set, open will fail if the file already exists.
**/
int
open(
const char *path,
int oflags,
int mode
)
{
wchar_t *NewPath;
wchar_t *MPath;
DeviceNode *Node;
struct __filedes *filp;
int Instance = 0;
RETURN_STATUS Status;
UINT64 OpenMode;
int fd = -1;
int doresult;
Status = ParsePath(path, &NewPath, &Node, &Instance, &MPath);
if(Status == RETURN_SUCCESS) {
if((Node == NULL) ||
(Node->InstanceList == NULL)) {
errno = EPERM;
}
else {
// Could add a test to see if the file name begins with a period.
// If it does, then add the HIDDEN flag to Attributes.
// Get an available fd
fd = FindFreeFD( VALID_CLOSED );
if( fd < 0 ) {
// All available FDs are in use
errno = EMFILE;
}
else {
filp = &gMD->fdarray[fd];
// Save the flags and mode in the File Descriptor
filp->Oflags = oflags;
filp->Omode = mode;
doresult = Node->OpenFunc(Node, filp, Instance, NewPath, MPath);
if(doresult < 0) {
filp->f_iflags = 0; // Release this FD
fd = -1; // Indicate an error
}
else {
// Re-use OpenMode in order to build our final f_iflags value
OpenMode = ( mode & S_ACC_READ ) ? S_ACC_READ : 0;
OpenMode |= ( mode & S_ACC_WRITE ) ? S_ACC_WRITE : 0;
filp->f_iflags |= (UINT32)OpenMode;
++filp->RefCount;
FILE_SET_MATURE(filp);
}
}
}
if(NewPath != NULL) {
free(NewPath);
}
}
if(MPath != NULL) {
free(MPath); // We don't need this any more.
}
// return the fd of our now open file
return fd;
}
/**
Poll a list of file descriptors.
The ::poll routine waits for up to timeout milliseconds for an event
to occur on one or more of the file descriptors listed. The event
types of interested are specified for each file descriptor in the events
field. The actual event detected is returned in the revents field of
the array. The
<a href="http://pubs.opengroup.org/onlinepubs/9699919799/functions/poll.html">POSIX</a>
documentation is available online.
@param [in] pfd Address of an array of pollfd structures.
@param [in] nfds Number of elements in the array of pollfd structures.
@param [in] timeout Length of time in milliseconds to wait for the event
@return The number of file descriptors with detected events. Zero
indicates that the call timed out and -1 indicates an error.
**/
int
poll (
struct pollfd * pfd,
nfds_t nfds,
int timeout
)
{
struct __filedes * pDescriptor;
struct pollfd * pEnd;
struct pollfd * pPollFD;
int SelectedFDs;
EFI_STATUS Status;
EFI_EVENT Timer;
UINT64 TimerTicks;
//
// Create the timer for the timeout
//
Timer = NULL;
Status = EFI_SUCCESS;
if ( INFTIM != timeout ) {
Status = gBS->CreateEvent ( EVT_TIMER,
TPL_NOTIFY,
NULL,
NULL,
&Timer );
if ( !EFI_ERROR ( Status )) {
//
// Start the timeout timer
//
TimerTicks = timeout;
TimerTicks *= 1000 * 10;
Status = gBS->SetTimer ( Timer,
TimerRelative,
TimerTicks );
}
else {
SelectedFDs = -1;
errno = ENOMEM;
}
}
if ( !EFI_ERROR ( Status )) {
//
// Poll until an event is detected or the timer fires
//
SelectedFDs = 0;
errno = 0;
do {
//
// Poll the list of file descriptors
//
pPollFD = pfd;
pEnd = &pPollFD [ nfds ];
while ( pEnd > pPollFD ) {
//
// Validate the file descriptor
//
if ( !ValidateFD ( pPollFD->fd, VALID_OPEN )) {
errno = EINVAL;
return -1;
}
//
// Poll the device or file
//
pDescriptor = &gMD->fdarray [ pPollFD->fd ];
pPollFD->revents = pDescriptor->f_ops->fo_poll ( pDescriptor,
pPollFD->events );
//
// Determine if this file descriptor detected an event
//
if ( 0 != pPollFD->revents ) {
//
// Select this descriptor
//
SelectedFDs += 1;
}
//
// Set the next file descriptor
//
pPollFD += 1;
}
//
// Check for timeout
//
if ( NULL != Timer ) {
Status = gBS->CheckEvent ( Timer );
if ( EFI_SUCCESS == Status ) {
//
// Timeout
//
break;
}
else if ( EFI_NOT_READY == Status ) {
Status = EFI_SUCCESS;
}
}
} while (( 0 == SelectedFDs )
&& ( EFI_SUCCESS == Status ));
//
// Stop the timer
//
if ( NULL != Timer ) {
gBS->SetTimer ( Timer,
TimerCancel,
0 );
}
}
else {
SelectedFDs = -1;
errno = EAGAIN;
}
//
// Release the timer
//
if ( NULL != Timer ) {
gBS->CloseEvent ( Timer );
}
//
// Return the number of selected file system descriptors
//
return SelectedFDs;
}
/** The rename() function changes the name of a file.
The old argument points to the pathname of the file to be renamed. The new
argument points to the new pathname of the file.
If the old argument points to the pathname of a file that is not a
directory, the new argument shall not point to the pathname of a
directory. If the file named by the new argument exists, it shall be
removed and old renamed to new. Write access permission is required for
both the directory containing old and the directory containing new.
If the old argument points to the pathname of a directory, the new
argument shall not point to the pathname of a file that is not a
directory. If the directory named by the new argument exists, it shall be
removed and old renamed to new.
The new pathname shall not contain a path prefix that names old. Write
access permission is required for the directory containing old and the
directory containing new. If the old argument points to the pathname of a
directory, write access permission may be required for the directory named
by old, and, if it exists, the directory named by new.
If the rename() function fails for any reason other than [EIO], any file
named by new shall be unaffected.
@return Upon successful completion, rename() shall return 0; otherwise,
-1 shall be returned, errno shall be set to indicate the error,
and neither the file named by old nor the file named by new
shall be changed or created.
**/
int
rename(
const char *from,
const char *to
)
{
wchar_t *FromPath;
DeviceNode *FromNode;
char *GenI;
int Instance = 0;
RETURN_STATUS Status;
int retval = -1;
Status = ParsePath(from, &FromPath, &FromNode, &Instance, NULL);
if(Status == RETURN_SUCCESS) {
GenI = FromNode->InstanceList;
if(GenI == NULL) {
errno = EPERM;
retval = -1;
}
else {
//GenI += (Instance * FromNode->InstanceSize);
retval = ((GenericInstance *)GenI)->Abstraction.fo_rename( from, to);
}
free(FromPath);
}
return retval;
}
/**
**/
int
rmdir(
const char *path
)
{
struct __filedes *filp;
int fd;
int retval = -1;
fd = open(path, O_RDWR, 0);
if(fd >= 0) {
filp = &gMD->fdarray[fd];
retval = filp->f_ops->fo_rmdir(filp);
filp->f_iflags = 0; // Close this FD
filp->RefCount = 0; // No one using this FD
}
return retval;
}
/** The fstat() function obtains information about an open file associated
with the file descriptor fildes, and shall write it to the area pointed to
by buf.
The buf argument is a pointer to a stat structure, as defined
in <sys/stat.h>, into which information is placed concerning the file.
The structure members st_mode, st_ino, st_dev, st_uid, st_gid, st_atime,
st_ctime, and st_mtime shall have meaningful values. The value of the
member st_nlink shall be set to the number of links to the file.
The fstat() function shall update any time-related fields before writing
into the stat structure.
The fstat() function is implemented using the ShellGetFileInfo()
function.
The stat structure members which don't have direct analogs to EFI file
information are filled in as follows:
- st_mode Populated with information from fildes
- st_ino Set to zero. (inode)
- st_dev Set to zero.
- st_uid Set to zero.
- st_gid Set to zero.
- st_nlink Set to one.
@param[in] fd File descriptor as returned from open().
@param[out] statbuf Buffer in which the file status is put.
@retval 0 Successful Completion.
@retval -1 An error has occurred and errno has been set to
identify the error.
**/
int
fstat (int fd, struct stat *statbuf)
{
int retval = -1;
struct __filedes *filp;
if(ValidateFD( fd, VALID_OPEN)) {
filp = &gMD->fdarray[fd];
retval = filp->f_ops->fo_stat(filp, statbuf, NULL);
}
else {
errno = EBADF;
}
return retval;
}
/** Obtains information about the file pointed to by path.
Opens the file pointed to by path, calls _EFI_FileInfo with the file's handle,
then closes the file.
@retval 0 Successful Completion.
@retval -1 An error has occurred and errno has been set to
identify the error.
**/
int
stat (const char *path, struct stat *statbuf)
{
int fd;
int retval = -1;
struct __filedes *filp;
fd = open(path, O_RDONLY, 0);
if(fd >= 0) {
filp = &gMD->fdarray[fd];
retval = filp->f_ops->fo_stat( filp, statbuf, NULL);
close(fd);
}
return retval;
}
/** Same as stat since EFI doesn't have symbolic links. **/
int
lstat (const char *path, struct stat *statbuf)
{
return stat(path, statbuf);
}
/** Control a device.
**/
int
ioctl(
int fd,
unsigned long request,
...
)
{
int retval = -1;
struct __filedes *filp;
va_list argp;
va_start(argp, request);
if(ValidateFD( fd, VALID_OPEN)) {
filp = &gMD->fdarray[fd];
if(request == FIODLEX) {
/* set Delete-on-Close */
filp->f_iflags |= FIF_DELCLOSE;
retval = 0;
}
else if(request == FIONDLEX) {
/* clear Delete-on-Close */
filp->f_iflags &= ~FIF_DELCLOSE;
retval = 0;
}
else {
/* All other requests. */
retval = filp->f_ops->fo_ioctl(filp, request, argp);
}
}
else {
errno = EBADF;
}
va_end(argp);
return retval;
}
/** Read from a file.
The read() function shall attempt to read nbyte bytes from the file
associated with the open file descriptor, fildes, into the buffer pointed
to by buf.
Before any action described below is taken, and if nbyte is zero, the
read() function may detect and return errors as described below. In the
absence of errors, or if error detection is not performed, the read()
function shall return zero and have no other results.
On files that support seeking (for example, a regular file), the read()
shall start at a position in the file given by the file offset associated
with fildes. The file offset shall be incremented by the number of bytes
actually read.
Files that do not support seeking - for example, terminals - always read
from the current position. The value of a file offset associated with
such a file is undefined.
No data transfer shall occur past the current end-of-file. If the
starting position is at or after the end-of-file, 0 shall be returned.
The read() function reads data previously written to a file. If any
portion of a regular file prior to the end-of-file has not been written,
read() shall return bytes with value 0. For example, lseek() allows the
file offset to be set beyond the end of existing data in the file. If data
is later written at this point, subsequent reads in the gap between the
previous end of data and the newly written data shall return bytes with
value 0 until data is written into the gap.
Upon successful completion, where nbyte is greater than 0, read() shall
mark for update the st_atime field of the file, and shall return the
number of bytes read. This number shall never be greater than nbyte. The
value returned may be less than nbyte if the number of bytes left in the
file is less than nbyte, if the read() request was interrupted by a
signal, or if the file is a pipe or FIFO or special file and has fewer
than nbyte bytes immediately available for reading. For example, a read()
from a file associated with a terminal may return one typed line of data.
If fildes does not refer to a directory, the function reads the requested
number of bytes from the file at the file's current position and returns
them in buf. If the read goes beyond the end of the file, the read
length is truncated to the end of the file. The file's current position is
increased by the number of bytes returned.
If fildes refers to a directory, the function reads the directory entry at
the file's current position and returns the entry in buf. If buf
is not large enough to hold the current directory entry, then
errno is set to EBUFSIZE, EFIerrno is set to EFI_BUFFER_TOO_SMALL, and the
current file position is not updated. The size of the buffer needed to read
the entry will be returned as a negative number. On success, the current
position is updated to the next directory entry. If there are no more
directory entries, the read returns a zero-length buffer.
EFI_FILE_INFO is the structure returned as the directory entry.
@return Upon successful completion, read() returns a non-negative integer
indicating the number of bytes actually read. Otherwise, the
functions return a negative value and sets errno to indicate the
error. If errno is EBUFSIZE, the absolute value of the
return value indicates the size of the buffer needed to read
the directory entry.
**/
ssize_t
read (int fildes, void *buf, size_t nbyte)
{
struct __filedes *filp;
ssize_t BufSize;
BufSize = (ssize_t)nbyte;
if(ValidateFD( fildes, VALID_OPEN)) {
filp = &gMD->fdarray[fildes];
BufSize = filp->f_ops->fo_read(filp, &filp->f_offset, nbyte, buf);
}
else {
errno = EBADF;
BufSize = -EBADF;
}
return BufSize;
}
/** Write data to a file.
This function writes the specified number of bytes to the file at the current
file position. The current file position is advanced the actual number of bytes
written, which is returned in BufferSize. Partial writes only occur when there
has been a data error during the write attempt (such as "volume space full").
The file is automatically grown to hold the data if required. Direct writes to
opened directories are not supported.
If fildes refers to a terminal device, isatty() returns TRUE, a partial write
will occur if a NULL or EOF character is encountered before n characters have
been written. Characters inserted due to line-end translations will not be
counted. Unconvertable characters are translated into the UEFI character
BLOCKELEMENT_LIGHT_SHADE.
Since the UEFI console device works on wide characters, the buffer is assumed
to contain a single-byte character stream which is then translated to wide
characters using the btowc() functions. The resulting wide character stream
is what is actually sent to the UEFI console.
QUESTION: Should writes to stdout or stderr always succeed?
**/
ssize_t
write (int fd, const void *buf, size_t nbyte)
{
struct __filedes *filp;
ssize_t BufSize;
// EFI_FILE_HANDLE FileHandle;
// RETURN_STATUS Status = RETURN_SUCCESS;
BufSize = (ssize_t)nbyte;
if(ValidateFD( fd, VALID_OPEN)) {
filp = &gMD->fdarray[fd];
BufSize = filp->f_ops->fo_write(filp, &filp->f_offset, nbyte, buf);
}
else {
errno = EBADF;
BufSize = -EBADF;
}
return BufSize;
}
/** Gets the current working directory.
The getcwd() function shall place an absolute pathname of the current
working directory in the array pointed to by buf, and return buf.The
size argument is the size in bytes of the character array pointed to
by the buf argument.
@param[in,out] buf The buffer to fill.
@param[in] size The number of bytes in buffer.
@retval NULL The function failed. The value in errno provides
further information about the cause of the failure.
Values for errno are:
- EINVAL: buf is NULL or size is zero.
- ENOENT: directory does not exist.
- ERANGE: buf size is too small to hold CWD
@retval buf The function completed successfully.
**/
char
*getcwd (char *buf, size_t size)
{
CONST CHAR16 *Cwd;
if (size == 0 || buf == NULL) {
errno = EINVAL;
return NULL;
}
Cwd = ShellGetCurrentDir(NULL);
if (Cwd == NULL) {
errno = ENOENT;
return NULL;
}
if (size < ((StrLen (Cwd) + 1) * sizeof (CHAR8))) {
errno = ERANGE;
return (NULL);
}
return (UnicodeStrToAsciiStr(Cwd, buf));
}
/** Change the current working directory.
The chdir() function shall cause the directory named by the pathname
pointed to by the path argument to become the current working directory;
that is, the starting point for path searches for pathnames not beginning
with '/'.
@param[in] path The new path to set.
@retval 0 Operation completed successfully.
@retval -1 Function failed. The value in errno provides more
information on the cause of failure:
- EPERM: Operation not supported with this Shell version.
- ENOMEM: Unable to allocate memory.
- ENOENT: Target directory does not exist.
@todo Add non-NEW-shell CWD changing.
**/
int
chdir (const char *path)
{
CONST CHAR16 *Cwd;
EFI_STATUS Status;
CHAR16 *UnicodePath;
/* Old Shell does not support Set Current Dir. */
if(gEfiShellProtocol != NULL) {
Cwd = ShellGetCurrentDir(NULL);
if (Cwd != NULL) {
/* We have shell support */
UnicodePath = AllocatePool(((AsciiStrLen (path) + 1) * sizeof (CHAR16)));
if (UnicodePath == NULL) {
errno = ENOMEM;
return -1;
}
AsciiStrToUnicodeStr(path, UnicodePath);
Status = gEfiShellProtocol->SetCurDir(NULL, UnicodePath);
FreePool(UnicodePath);
if (EFI_ERROR(Status)) {
errno = ENOENT;
return -1;
} else {
return 0;
}
}
}
/* Add here for non-shell */
errno = EPERM;
return -1;
}
pid_t tcgetpgrp (int x)
{
return ((pid_t)(UINTN)(gImageHandle));
}
pid_t getpgrp(void)
{
return ((pid_t)(UINTN)(gImageHandle));
}
/** Set file access and modification times.
@param[in] path
@param[in] times
@return
**/
int
utimes(
const char *path,
const struct timeval *times
)
{
struct __filedes *filp;
va_list ap;
int fd;
int retval = -1;
va_start(ap, path);
fd = open(path, O_RDWR, 0);
if(fd >= 0) {
filp = &gMD->fdarray[fd];
retval = filp->f_ops->fo_ioctl( filp, FIOSETIME, ap);
close(fd);
}
va_end(ap);
return retval;
}