sortix-mirror/sortix/fs/devfs.cpp

420 lines
8.4 KiB
C++

/******************************************************************************
COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2011.
This file is part of Sortix.
Sortix 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 3 of the License, or (at your option) any later
version.
Sortix 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 Sortix. If not, see <http://www.gnu.org/licenses/>.
fs/devfs.cpp
Provides access to various block, character, and other kinds of devices.
******************************************************************************/
#include "../platform.h"
#include <libmaxsi/error.h>
#include <libmaxsi/string.h>
#include <libmaxsi/memory.h>
#include "../filesystem.h"
#include "../directory.h"
#include "../stream.h"
#include "../terminal.h"
#include "../vga.h"
#include "../ata.h"
#include "devfs.h"
using namespace Maxsi;
namespace Sortix
{
class DevATA : public DevBuffer
{
public:
typedef DevBuffer BaseClass;
public:
DevATA(ATADrive* drive);
virtual ~DevATA();
private:
ATADrive* drive;
off_t offset;
public:
virtual ssize_t Read(byte* dest, size_t count);
virtual ssize_t Write(const byte* src, size_t count);
virtual bool IsReadable();
virtual bool IsWritable();
virtual size_t BlockSize();
virtual uintmax_t Size();
virtual uintmax_t Position();
virtual bool Seek(uintmax_t position);
virtual bool Resize(uintmax_t size);
};
DevATA::DevATA(ATADrive* drive)
{
this->drive = drive;
offset = 0;
}
DevATA::~DevATA()
{
}
ssize_t DevATA::Read(byte* dest, size_t count)
{
if ( SIZE_MAX < count ) { count = SIZE_MAX; }
if ( drive->GetSize() - offset < count ) { count = drive->GetSize() - offset; }
size_t amount = drive->Read(offset, dest, count);
if ( count && !amount ) { return -1; }
offset += amount;
return amount;
}
ssize_t DevATA::Write(const byte* src, size_t count)
{
if ( SIZE_MAX < count ) { count = SIZE_MAX; }
if ( drive->GetSize() <= offset && count ) { Error::Set(ENOSPC); return -1; }
if ( drive->GetSize() - offset < count ) { count = drive->GetSize() - offset; }
size_t amount = drive->Write(offset, src, count);
if ( count && !amount ) { return -1; }
offset += amount;
return amount;
}
bool DevATA::IsReadable()
{
return true;
}
bool DevATA::IsWritable()
{
return true;
}
size_t DevATA::BlockSize()
{
return drive->GetSectorSize();
}
uintmax_t DevATA::Size()
{
return drive->GetSize();
}
uintmax_t DevATA::Position()
{
return offset;
}
bool DevATA::Seek(uintmax_t position)
{
if ( drive->GetSize() <= position ) { Error::Set(ENOSPC); return false; }
offset = position;
return true;
}
bool DevATA::Resize(uintmax_t size)
{
Error::Set(EPERM);
return false;
}
const size_t NUM_ATAS = 4;
DevATA* atalist[NUM_ATAS];
void InitATADriveList()
{
for ( size_t i = 0; i < NUM_ATAS; i++ )
{
atalist[i] = NULL;
}
}
void RegisterATADrive(unsigned ataid, ATADrive* drive)
{
atalist[ataid] = new DevATA(drive);
atalist[ataid]->Refer();
}
// TODO: Remove this deprecated class!
class DevLogTTY : public DevTerminal
{
public:
typedef DevTerminal BaseClass;
public:
DevLogTTY();
virtual ~DevLogTTY();
public:
virtual ssize_t Read(byte* dest, size_t count);
virtual ssize_t Write(const byte* src, size_t count);
virtual bool IsReadable();
virtual bool IsWritable();
virtual bool SetMode(unsigned mode);
virtual bool SetWidth(unsigned width);
virtual bool SetHeight(unsigned height);
virtual unsigned GetMode() const;
virtual unsigned GetWidth() const;
virtual unsigned GetHeight() const;
};
DevLogTTY::DevLogTTY()
{
}
DevLogTTY::~DevLogTTY()
{
// TODO: Make an array of waiting threads on the keyboard..
}
ssize_t DevLogTTY::Read(byte* /*dest*/, size_t /*count*/)
{
// TODO: Read from keyboard.
return 0;
}
ssize_t DevLogTTY::Write(const byte* src, size_t count)
{
if ( SSIZE_MAX < count ) { count = SSIZE_MAX; }
return Log::deviceCallback(Log::devicePointer, (char*) src, count);
}
bool DevLogTTY::IsReadable()
{
return true;
}
bool DevLogTTY::IsWritable()
{
return true;
}
bool DevLogTTY::SetMode(unsigned mode)
{
if ( mode ) { Error::Set(ENOSYS); return false; }
return true;
}
bool DevLogTTY::SetWidth(unsigned width)
{
if ( width != GetWidth() ) { Error::Set(ENOTSUP); return false; }
return true;
}
bool DevLogTTY::SetHeight(unsigned height)
{
if ( height != GetHeight() ) { Error::Set(ENOTSUP); return false; }
return true;
}
unsigned DevLogTTY::GetMode() const
{
return 0;
}
unsigned DevLogTTY::GetWidth() const
{
return 25;
}
unsigned DevLogTTY::GetHeight() const
{
return 80;
}
class DevNull : public DevStream
{
public:
typedef DevStream BaseClass;
public:
DevNull();
virtual ~DevNull();
public:
virtual ssize_t Read(byte* dest, size_t count);
virtual ssize_t Write(const byte* src, size_t count);
virtual bool IsReadable();
virtual bool IsWritable();
};
DevNull::DevNull()
{
}
DevNull::~DevNull()
{
}
ssize_t DevNull::Read(byte* /*dest*/, size_t /*count*/)
{
return 0; // Return EOF
}
ssize_t DevNull::Write(const byte* /*src*/, size_t count)
{
if ( SSIZE_MAX < count ) { count = SSIZE_MAX; }
// O' glorious bitbucket in the sky, I hereby sacrifice to You, my holy
// data in trust You will keep it safe. That You will store it for all
// eternity, until the day You will return to User-Land to rule the land
// and preserve data-integrity for all eternity. Amen.
return count;
}
bool DevNull::IsReadable()
{
return true;
}
bool DevNull::IsWritable()
{
return true;
}
class DevDevFSDir : public DevDirectory
{
public:
typedef Device DevDirectory;
public:
DevDevFSDir();
virtual ~DevDevFSDir();
public:
size_t position;
public:
virtual void Rewind();
virtual int Read(sortix_dirent* dirent, size_t available);
};
DevDevFSDir::DevDevFSDir()
{
position = 0;
}
DevDevFSDir::~DevDevFSDir()
{
}
void DevDevFSDir::Rewind()
{
position = 0;
}
int DevDevFSDir::Read(sortix_dirent* dirent, size_t available)
{
const char* names[] = { "null", "tty", "vga", "ata0", "ata1", "ata2", "ata3" };
const size_t nameslength = 7;
if ( available <= sizeof(sortix_dirent) ) { return -1; }
if ( nameslength <= position )
{
dirent->d_namelen = 0;
dirent->d_name[0] = 0;
return 0;
}
const char* name = names[position];
size_t namelen = String::Length(name);
size_t needed = sizeof(sortix_dirent) + namelen + 1;
if ( name[0] == 'a' && name[1] == 't' && name[2] == 'a' )
{
if ( !atalist[name[3]-'0'] )
{
position++;
return Read(dirent, available);
}
}
if ( available < needed )
{
dirent->d_namelen = needed;
Error::Set(ERANGE);
return -1;
}
Memory::Copy(dirent->d_name, name, namelen + 1);
dirent->d_namelen = namelen;
position++;
return 0;
}
DevDevFS::DevDevFS()
{
}
DevDevFS::~DevDevFS()
{
}
Device* DevDevFS::Open(const char* path, int flags, mode_t mode)
{
if ( (flags & O_LOWERFLAGS) == O_SEARCH )
{
if ( path[0] == 0 || (path[0] == '/' && path[1] == 0) ) { return new DevDevFSDir(); }
Error::Set(ENOTDIR);
return NULL;
}
if ( String::Compare(path, "/null") == 0 ) { return new DevNull; }
if ( String::Compare(path, "/tty") == 0 ) { return new DevLogTTY; }
if ( String::Compare(path, "/vga") == 0 ) { return new DevVGA; }
if ( path[0] == '/' && path[1] == 'a' && path[2] == 't' && path[3] == 'a' && path[4] && !path[5] )
{
if ( '0' <= path[4] && path[4] <= '9' )
{
size_t index = path[4] - '0';
if ( index <= NUM_ATAS && atalist[index] )
{
bool write = flags & O_WRONLY; // TODO: HACK: O_RDWD != O_WRONLY | O_RDONLY
if ( write && !ENABLE_DISKWRITE )
{
Error::Set(EPERM);
return false;
}
return new DevFileWrapper(atalist[index], flags);
}
}
}
Error::Set(flags & O_CREAT ? EPERM : ENOENT);
return NULL;
}
bool DevDevFS::Unlink(const char* path)
{
if ( *path == '\0' || ( *path++ == '/' && *path == '\0' ) )
{
Error::Set(EISDIR);
return false;
}
Error::Set(EPERM);
return false;
}
}