Kernel/FileSystem/FileDescriptor.cpp
2023-08-06 04:53:14 +03:00

435 lines
8.8 KiB
C++

/*
This file is part of Fennix Kernel.
Fennix Kernel 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.
Fennix Kernel 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 Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/
#include <filesystem.hpp>
#include <smart_ptr.hpp>
#include <convert.h>
#include <task.hpp>
#include <printf.h>
#include <lock.hpp>
#include <cwalk.h>
#include "../kernel.h"
namespace VirtualFileSystem
{
ReadFSFunction(fd_Read)
{
if (!Size)
Size = node->Length;
if (RefOffset > node->Length)
return 0;
if (RefOffset + (off_t)Size > node->Length)
Size = node->Length - RefOffset;
memcpy(Buffer, (uint8_t *)(node->Address + RefOffset), Size);
return Size;
}
WriteFSFunction(fd_Write)
{
if (!Size)
Size = node->Length;
if (RefOffset > node->Length)
return 0;
if (RefOffset + (off_t)Size > node->Length)
Size = node->Length - RefOffset;
memcpy((uint8_t *)(node->Address + RefOffset), Buffer, Size);
return Size;
}
VirtualFileSystem::FileSystemOperations fd_op = {
.Name = "fd",
// .Read = fd_Read,
// .Write = fd_Write,
};
FileDescriptorTable::FileDescriptor
FileDescriptorTable::GetFileDescriptor(int FileDescriptor)
{
foreach (auto fd in FileDescriptors)
{
if (fd.Descriptor == FileDescriptor)
return fd;
}
return {.Descriptor = -1};
}
int FileDescriptorTable::ProbeMode(mode_t Mode, int Flags)
{
if (Flags & O_RDONLY)
{
if (!(Mode & S_IRUSR))
return -EACCES;
}
if (Flags & O_WRONLY)
{
if (!(Mode & S_IWUSR))
return -EACCES;
}
if (Flags & O_RDWR)
{
if (!(Mode & S_IRUSR) ||
!(Mode & S_IWUSR))
return -EACCES;
}
return 0;
}
int FileDescriptorTable::AddFileDescriptor(const char *AbsolutePath,
mode_t Mode, int Flags)
{
Tasking::PCB *pcb = thisProcess;
if (ProbeMode(Mode, Flags) < 0)
{
errno = EACCES;
return -1;
}
if (Flags & O_CREAT)
{
Node *n = vfs->Create(AbsolutePath,
NodeFlags::FILE,
pcb->CurrentWorkingDirectory);
if (!n)
{
error("Failed to create file %s: %d",
AbsolutePath, errno);
return -1;
}
}
if (Flags & O_EXCL)
{
RefNode *File = vfs->Open(AbsolutePath,
pcb->CurrentWorkingDirectory);
if (!File)
{
errno = EEXIST;
return -1;
}
}
if (Flags & O_TRUNC)
{
fixme("Implement O_TRUNC");
}
if (Flags & O_APPEND)
{
fixme("Implement O_APPEND");
}
if (Flags & O_CLOEXEC)
{
fixme("Implement O_CLOEXEC");
}
RefNode *File = vfs->Open(AbsolutePath,
pcb->CurrentWorkingDirectory);
if (!File)
{
error("Failed to open file %s: %d",
AbsolutePath, errno);
return -1;
}
FileDescriptorTable::FileDescriptor fd;
fd.Descriptor = GetFreeFileDescriptor();
if (fd.Descriptor < 0)
{
errno = EMFILE;
return -1;
}
fd.Mode = Mode;
fd.Flags = Flags;
fd.Handle = File;
FileDescriptors.push_back(fd);
char FileName[64];
sprintf(FileName, "%d", fd.Descriptor);
VirtualFileSystem::Node *n = vfs->Create(FileName, VirtualFileSystem::NodeFlags::FILE, this->fdDir);
if (n)
{
/* FIXME: Implement proper file descriptors */
n->Address = (uintptr_t)0xdeadbeef;
n->Length = File->FileSize;
n->Operator = &fd_op;
}
return fd.Descriptor;
}
int FileDescriptorTable::RemoveFileDescriptor(int FileDescriptor)
{
forItr(itr, FileDescriptors)
{
if (itr->Descriptor == FileDescriptor)
{
FileDescriptors.erase(itr);
char FileName[64];
sprintf(FileName, "%d", FileDescriptor);
vfs->Delete(FileName, false, this->fdDir);
return 0;
}
}
errno = EBADF;
return -1;
}
int FileDescriptorTable::GetFreeFileDescriptor()
{
int i = 0;
while (true)
{
bool Found = false;
foreach (auto fd in FileDescriptors)
{
if (fd.Descriptor == i)
{
Found = true;
break;
}
}
if (!Found)
return i;
i++;
}
errno = EMFILE;
return -1;
}
std::string FileDescriptorTable::GetAbsolutePath(int FileDescriptor)
{
FileDescriptorTable::FileDescriptor fd =
this->GetFileDescriptor(FileDescriptor);
if (fd.Descriptor == -1)
return "";
Node *node = fd.Handle->node;
std::string absolutePath = vfs->GetPathFromNode(node);
std::string path = absolutePath.c_str();
return path;
}
int FileDescriptorTable::_open(const char *pathname, int flags,
mode_t mode)
{
if (pathname == nullptr)
{
errno = EFAULT;
return -1;
}
return AddFileDescriptor(pathname, mode, flags);
}
int FileDescriptorTable::_creat(const char *pathname, mode_t mode)
{
return _open(pathname, O_WRONLY | O_CREAT | O_TRUNC, mode);
}
ssize_t FileDescriptorTable::_read(int fd, void *buf, size_t count)
{
FileDescriptor fdesc;
fdesc = this->GetFileDescriptor(fd);
if (fdesc.Descriptor < 0)
{
errno = EBADF;
return -1;
}
return fdesc.Handle->Read((uint8_t *)buf, count);
}
ssize_t FileDescriptorTable::_write(int fd, const void *buf,
size_t count)
{
FileDescriptor fdesc;
fdesc = this->GetFileDescriptor(fd);
if (fdesc.Descriptor < 0)
return -1;
return fdesc.Handle->Write((uint8_t *)buf, count);
}
int FileDescriptorTable::_close(int fd)
{
FileDescriptor fdesc;
fdesc = this->GetFileDescriptor(fd);
if (fdesc.Descriptor < 0)
{
errno = EBADF;
return -1;
}
if (RemoveFileDescriptor(fd) < 0)
{
errno = EBADF;
return -1;
}
delete fdesc.Handle;
return 0;
}
off_t FileDescriptorTable::_lseek(int fd, off_t offset, int whence)
{
FileDescriptor fdesc;
fdesc = this->GetFileDescriptor(fd);
if (fdesc.Descriptor < 0)
{
errno = EBADF;
return -1;
}
return fdesc.Handle->Seek(offset, whence);
}
int FileDescriptorTable::_stat(const char *pathname,
struct stat *statbuf)
{
if (pathname == nullptr)
{
errno = EINVAL;
return -1;
}
RefNode *file = vfs->Open(pathname,
thisProcess->CurrentWorkingDirectory);
if (!file)
{
error("Failed to open file %s: %d",
pathname, errno);
return -1;
}
Node *node = file->node;
statbuf->st_dev = 0; /* FIXME: stub */
statbuf->st_ino = node->IndexNode;
statbuf->st_mode = node->Flags | node->Mode;
statbuf->st_nlink = 0; /* FIXME: stub */
statbuf->st_uid = node->UserIdentifier;
statbuf->st_gid = node->GroupIdentifier;
statbuf->st_rdev = 0; /* FIXME: stub */
statbuf->st_size = node->Length;
statbuf->st_blksize = 0; /* FIXME: stub */
statbuf->st_blocks = 0; /* FIXME: stub */
statbuf->st_attr = 0; /* FIXME: stub */
return 0;
}
int FileDescriptorTable::_fstat(int fd, struct stat *statbuf)
{
FileDescriptor fdesc;
fdesc = this->GetFileDescriptor(fd);
if (fdesc.Descriptor < 0)
{
errno = EBADF;
return -1;
}
Node *node = fdesc.Handle->node;
statbuf->st_dev = 0; /* FIXME: stub */
statbuf->st_ino = node->IndexNode;
statbuf->st_mode = node->Flags | node->Mode;
statbuf->st_nlink = 0; /* FIXME: stub */
statbuf->st_uid = node->UserIdentifier;
statbuf->st_gid = node->GroupIdentifier;
statbuf->st_rdev = 0; /* FIXME: stub */
statbuf->st_size = node->Length;
statbuf->st_blksize = 0; /* FIXME: stub */
statbuf->st_blocks = 0; /* FIXME: stub */
statbuf->st_attr = 0; /* FIXME: stub */
return 0;
}
int FileDescriptorTable::_lstat(const char *pathname,
struct stat *statbuf)
{
if (pathname == nullptr)
{
errno = EINVAL;
return -1;
}
RefNode *file = vfs->Open(pathname,
thisProcess->CurrentWorkingDirectory);
if (!file)
{
error("Failed to open file %s: %d",
pathname, errno);
return -1;
}
Node *node = file->node;
statbuf->st_dev = 0; /* FIXME: stub */
statbuf->st_ino = node->IndexNode;
statbuf->st_mode = node->Flags | node->Mode;
statbuf->st_nlink = 0; /* FIXME: stub */
statbuf->st_uid = node->UserIdentifier;
statbuf->st_gid = node->GroupIdentifier;
statbuf->st_rdev = 0; /* FIXME: stub */
statbuf->st_size = node->Length;
statbuf->st_blksize = 0; /* FIXME: stub */
statbuf->st_blocks = 0; /* FIXME: stub */
statbuf->st_attr = 0; /* FIXME: stub */
return 0;
}
FileDescriptorTable::FileDescriptorTable(void *Owner)
{
this->fdDir = vfs->Create("fd", VirtualFileSystem::NodeFlags::DIRECTORY,
((Tasking::PCB *)Owner)->ProcessDirectory);
}
FileDescriptorTable::~FileDescriptorTable()
{
foreach (auto var in FileDescriptors)
{
this->RemoveFileDescriptor(var.Descriptor);
delete var.Handle;
}
}
}