Rename files with reference and descriptor code

storage/descriptor.cpp

@@ -0,0 +1,655 @@
+/*
+	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 <stropts.h>
+#include <task.hpp>
+#include <printf.h>
+#include <lock.hpp>
+#include <cwalk.h>
+
+#include "../kernel.h"
+
+namespace vfs
+{
+	// ReadFSFunction(fd_Read)
+	// {
+	// 	if (Size <= 0)
+	// 		Size = node->Length;
+
+	// 	if (RefOffset > node->Length)
+	// 		return 0;
+
+	// 	if ((node->Length - RefOffset) == 0)
+	// 		return 0; /* EOF */
+
+	// 	if (RefOffset + (off_t)Size > node->Length)
+	// 		Size = node->Length;
+
+	// 	memcpy(Buffer, (uint8_t *)(node->Address + RefOffset), Size);
+	// 	return Size;
+	// }
+
+	// WriteFSFunction(fd_Write)
+	// {
+	// 	if (Size <= 0)
+	// 		Size = node->Length;
+
+	// 	if (RefOffset > node->Length)
+	// 		return 0;
+
+	// 	if (RefOffset + (off_t)Size > node->Length)
+	// 		Size = node->Length;
+
+	// 	memcpy((uint8_t *)(node->Address + RefOffset), Buffer, Size);
+	// 	return Size;
+	// }
+
+	// vfs::FileSystemOperations fd_op = {
+	// 	.Name = "fd",
+	// 	// .Read = fd_Read,
+	// 	// .Write = fd_Write,
+	// };
+
+	FileDescriptorTable::Fildes &
+	FileDescriptorTable::GetFileDescriptor(int FileDescriptor)
+	{
+		foreach (auto &fd in FileDescriptors)
+		{
+			if (fd.Descriptor == FileDescriptor)
+			{
+				// debug("Found file descriptor %d", FileDescriptor);
+				return fd;
+			}
+		}
+		return nullfd;
+	}
+
+	FileDescriptorTable::Fildes &
+	FileDescriptorTable::GetDupFildes(int FileDescriptor)
+	{
+		foreach (auto &fd in FildesDuplicates)
+		{
+			if (fd.Descriptor == FileDescriptor)
+			{
+				debug("Found duplicated file descriptor %d", FileDescriptor);
+				return fd;
+			}
+		}
+		return nullfd;
+	}
+
+	FileDescriptorTable::Fildes &
+	FileDescriptorTable::GetDescriptor(int FileDescriptor)
+	{
+		Fildes &fd = this->GetFileDescriptor(FileDescriptor);
+		Fildes &dfd = this->GetDupFildes(FileDescriptor);
+
+		if (fd.Descriptor == -1 &&
+			dfd.Descriptor == -1)
+			return nullfd;
+
+		if (fd.Descriptor != -1)
+			return fd;
+		else
+			return dfd;
+	}
+
+	int FileDescriptorTable::GetFlags(int FileDescriptor)
+	{
+		Fildes &fd = this->GetDescriptor(FileDescriptor);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", FileDescriptor);
+			return -EBADF;
+		}
+
+		return fd.Flags;
+	}
+
+	int FileDescriptorTable::SetFlags(int FileDescriptor, int Flags)
+	{
+		Fildes &fd = this->GetDescriptor(FileDescriptor);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", FileDescriptor);
+			return -EBADF;
+		}
+
+		fd.Flags = Flags;
+		return 0;
+	}
+
+	int FileDescriptorTable::ProbeMode(mode_t Mode, int Flags)
+	{
+		if (!(Flags & O_CREAT))
+			return 0;
+
+		if (Flags & O_RDONLY)
+		{
+			if (!(Mode & S_IRUSR))
+			{
+				debug("No read permission (%d)", Mode);
+				return -EACCES;
+			}
+		}
+
+		if (Flags & O_WRONLY)
+		{
+			if (!(Mode & S_IWUSR))
+			{
+				debug("No write permission (%d)", Mode);
+				return -EACCES;
+			}
+		}
+
+		if (Flags & O_RDWR)
+		{
+			if (!(Mode & S_IRUSR) ||
+				!(Mode & S_IWUSR))
+			{
+				debug("No read/write permission (%d)", Mode);
+				return -EACCES;
+			}
+		}
+
+		return 0;
+	}
+
+	int FileDescriptorTable::AddFileDescriptor(const char *AbsolutePath,
+											   mode_t Mode, int Flags)
+	{
+		Tasking::PCB *pcb = thisProcess;
+
+		if (ProbeMode(Mode, Flags) < 0)
+			return -EACCES;
+
+		if (Flags & O_CREAT)
+		{
+			int ret;
+			bool absolute = cwk_path_is_absolute(AbsolutePath);
+			new Node(pcb->CurrentWorkingDirectory,
+					 AbsolutePath, NodeType::FILE,
+					 absolute, fs, &ret);
+
+			if (ret == -EEXIST)
+			{
+				debug("%s: File already exists, continuing...",
+					  AbsolutePath);
+			}
+			else if (Flags & O_EXCL)
+			{
+				debug("%s: File already exists, returning EEXIST",
+					  AbsolutePath);
+				return -EEXIST;
+			}
+			else if (ret < 0)
+			{
+				error("Failed to create file %s: %d",
+					  AbsolutePath, ret);
+				assert(ret < 0);
+			}
+		}
+
+		if (Flags & O_TRUNC)
+		{
+			fixme("O_TRUNC");
+		}
+
+		if (Flags & O_CLOEXEC)
+		{
+			fixme("O_CLOEXEC");
+		}
+
+		RefNode *File = fs->Open(AbsolutePath,
+								 pcb->CurrentWorkingDirectory);
+
+		if (!File)
+		{
+			error("Failed to open file %s",
+				  AbsolutePath);
+			return -ENOENT;
+		}
+
+		if (Flags & O_APPEND)
+		{
+			debug("Appending to file %s", AbsolutePath);
+			File->seek(0, SEEK_END);
+		}
+
+		Fildes fd = {.Descriptor = GetFreeFileDescriptor()};
+
+		if (fd.Descriptor < 0)
+			return -EMFILE;
+
+		fd.Mode = Mode;
+		fd.Flags = Flags;
+		fd.Handle = File;
+
+		FileDescriptors.push_back(fd);
+
+		char FileName[64];
+		itoa(fd.Descriptor, FileName, 10);
+		assert(fs->CreateLink(FileName, AbsolutePath, this->fdDir) != nullptr);
+
+		int rfd = File->node->open(Flags, Mode);
+		if (rfd <= 0)
+			return fd.Descriptor;
+		else
+			return rfd;
+	}
+
+	int FileDescriptorTable::RemoveFileDescriptor(int FileDescriptor)
+	{
+		forItr(itr, FileDescriptors)
+		{
+			if (itr->Descriptor == FileDescriptor)
+			{
+				FileDescriptors.erase(itr);
+
+				char FileName[64];
+				itoa(FileDescriptor, FileName, 10);
+				fs->Delete(FileName, false, this->fdDir);
+				return 0;
+			}
+		}
+
+		forItr(itr, FildesDuplicates)
+		{
+			if (itr->Descriptor == FileDescriptor)
+			{
+				FildesDuplicates.erase(itr);
+
+				char FileName[64];
+				itoa(FileDescriptor, FileName, 10);
+				fs->Delete(FileName, false, this->fdDir);
+				return 0;
+			}
+		}
+
+		return -EBADF;
+	}
+
+	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)
+			{
+				foreach (auto fd in FildesDuplicates)
+				{
+					if (fd.Descriptor == i)
+					{
+						Found = true;
+						break;
+					}
+				}
+			}
+
+			if (!Found)
+				return i;
+			i++;
+		}
+
+		return -EMFILE;
+	}
+
+	const char *FileDescriptorTable::GetAbsolutePath(int FileDescriptor)
+	{
+		Fildes &fd = this->GetDescriptor(FileDescriptor);
+		if (fd == nullfd)
+			return "";
+
+		Node *node = fd.Handle->node;
+		const char *path = new char[strlen(node->FullPath) + 1];
+		strcpy((char *)path, node->FullPath);
+		return path;
+	}
+
+	RefNode *FileDescriptorTable::GetRefNode(int FileDescriptor)
+	{
+		Fildes &fd = this->GetDescriptor(FileDescriptor);
+		if (fd == nullfd)
+			return nullptr;
+
+		return fd.Handle;
+	}
+
+	void FileDescriptorTable::Fork(FileDescriptorTable *Parent)
+	{
+		foreach (auto &fd in Parent->FileDescriptors)
+		{
+			debug("Forking fd: %d", fd.Descriptor);
+			RefNode *node = fs->Open(fd.Handle->node->FullPath,
+									 thisProcess->CurrentWorkingDirectory);
+			assert(node != nullptr);
+
+			Fildes new_fd;
+			new_fd.Descriptor = fd.Descriptor;
+			new_fd.Flags = fd.Flags;
+			new_fd.Mode = fd.Mode;
+			new_fd.Handle = node;
+			this->FileDescriptors.push_back(new_fd);
+		}
+
+		foreach (auto &fd in Parent->FildesDuplicates)
+		{
+			debug("Forking duplicated fd: %d", fd.Descriptor);
+			RefNode *node = fs->Open(fd.Handle->node->FullPath,
+									 thisProcess->CurrentWorkingDirectory);
+			assert(node != nullptr);
+
+			Fildes new_fd;
+			new_fd.Descriptor = fd.Descriptor;
+			new_fd.Flags = fd.Flags;
+			new_fd.Mode = fd.Mode;
+			new_fd.Handle = node;
+			this->FildesDuplicates.push_back(new_fd);
+		}
+	}
+
+	int FileDescriptorTable::_open(const char *pathname, int flags,
+								   mode_t mode)
+	{
+		if (pathname == nullptr)
+			return -EFAULT;
+
+		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)
+	{
+		Fildes &fd = this->GetDescriptor(_fd);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", _fd);
+			return -EBADF;
+		}
+
+		return fd.Handle->read((uint8_t *)buf, count);
+	}
+
+	ssize_t FileDescriptorTable::_write(int _fd, const void *buf,
+										size_t count)
+	{
+		Fildes &fd = this->GetDescriptor(_fd);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", _fd);
+			return -EBADF;
+		}
+
+		return fd.Handle->write((uint8_t *)buf, count);
+	}
+
+	int FileDescriptorTable::_close(int _fd)
+	{
+		Fildes &fd = this->GetDescriptor(_fd);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", _fd);
+			return -EBADF;
+		}
+
+		if (RemoveFileDescriptor(_fd) < 0)
+		{
+			debug("invalid fd %d", _fd);
+			return -EBADF;
+		}
+
+		bool Found = false;
+		foreach (auto dfd in FileDescriptors)
+		{
+			if (dfd.Handle == fd.Handle)
+			{
+				Found = true;
+				break;
+			}
+		}
+
+		if (!Found)
+			foreach (auto dfd in FildesDuplicates)
+			{
+				if (dfd.Handle == fd.Handle)
+				{
+					Found = true;
+					break;
+				}
+			}
+
+		/* If the file descriptor is a duplicate,
+			we don't need to close the handle,
+			because it's a duplicate of another
+			file descriptor. */
+		if (!Found)
+			delete fd.Handle;
+		return 0;
+	}
+
+	off_t FileDescriptorTable::_lseek(int _fd, off_t offset, int whence)
+	{
+		Fildes &fd = this->GetDescriptor(_fd);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", _fd);
+			return -EBADF;
+		}
+
+		return fd.Handle->seek(offset, whence);
+	}
+
+	int FileDescriptorTable::_stat(const char *pathname,
+								   struct stat *statbuf)
+	{
+		if (pathname == nullptr)
+			return -EINVAL;
+
+		RefNode *file = fs->Open(pathname,
+								 thisProcess->CurrentWorkingDirectory);
+
+		if (!file)
+		{
+			error("Failed to open file %s",
+				  pathname);
+			return -ENOENT;
+		}
+
+		Node *node = file->node;
+		statbuf->st_dev = 0; /* FIXME: stub */
+		statbuf->st_ino = node->IndexNode;
+		statbuf->st_mode = node->Type | (node->Mode & ~S_IFMT);
+		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->Size;
+		statbuf->st_atime = node->AccessTime;
+		statbuf->st_mtime = node->ModifyTime;
+		statbuf->st_ctime = node->ChangeTime;
+		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)
+	{
+		Fildes &fd = this->GetDescriptor(_fd);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", _fd);
+			return -EBADF;
+		}
+
+		Node *node = fd.Handle->node;
+		statbuf->st_dev = 0; /* FIXME: stub */
+		statbuf->st_ino = node->IndexNode;
+		statbuf->st_mode = node->Type | (node->Mode & ~S_IFMT);
+		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->Size;
+		statbuf->st_atime = node->AccessTime;
+		statbuf->st_mtime = node->ModifyTime;
+		statbuf->st_ctime = node->ChangeTime;
+		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)
+			return -EINVAL;
+
+		RefNode *file = fs->Open(pathname,
+								 thisProcess->CurrentWorkingDirectory);
+
+		if (!file)
+		{
+			error("Failed to open file %s",
+				  pathname);
+			return -ENOENT;
+		}
+
+		Node *node = file->node;
+		statbuf->st_dev = 0; /* FIXME: stub */
+		statbuf->st_ino = node->IndexNode;
+		statbuf->st_mode = node->Type | (node->Mode & ~S_IFMT);
+		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->Size;
+		statbuf->st_atime = node->AccessTime;
+		statbuf->st_mtime = node->ModifyTime;
+		statbuf->st_ctime = node->ChangeTime;
+		statbuf->st_blksize = 0; /* FIXME: stub */
+		statbuf->st_blocks = 0;	 /* FIXME: stub */
+		statbuf->st_attr = 0;	 /* FIXME: stub */
+		return 0;
+	}
+
+	int FileDescriptorTable::_dup(int oldfd)
+	{
+		Fildes &fd = this->GetDescriptor(oldfd);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", oldfd);
+			return -EBADF;
+		}
+
+		int newfd = this->GetFreeFileDescriptor();
+		if (newfd < 0)
+			return -EMFILE;
+
+		Fildes new_dfd{};
+		new_dfd.Handle = fd.Handle;
+		new_dfd.Mode = fd.Mode;
+
+		new_dfd.Descriptor = newfd;
+		this->FildesDuplicates.push_back(new_dfd);
+		debug("Duplicated file descriptor %d to %d",
+			  oldfd, newfd);
+		return newfd;
+	}
+
+	int FileDescriptorTable::_dup2(int oldfd, int newfd)
+	{
+		Fildes &fd = this->GetDescriptor(oldfd);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", oldfd);
+			return -EBADF;
+		}
+
+		if (newfd < 0)
+		{
+			debug("invalid fd %d", newfd);
+			return -EBADF;
+		}
+
+		if (newfd == oldfd)
+			return newfd;
+
+		/* Even if it's not valid
+			we ignore it. */
+		this->_close(newfd);
+
+		Fildes new_dfd{};
+		new_dfd.Handle = fd.Handle;
+		new_dfd.Mode = fd.Mode;
+
+		new_dfd.Descriptor = newfd;
+		this->FildesDuplicates.push_back(new_dfd);
+		debug("Duplicated file descriptor %d to %d",
+			  oldfd, newfd);
+		return newfd;
+	}
+
+	int FileDescriptorTable::_ioctl(int _fd, unsigned long request, void *argp)
+	{
+		Fildes &fd = this->GetDescriptor(_fd);
+		if (fd == nullfd)
+		{
+			debug("invalid fd %d", _fd);
+			return -EBADF;
+		}
+
+		return fd.Handle->ioctl(request, argp);
+	}
+
+	FileDescriptorTable::FileDescriptorTable(void *Owner)
+	{
+		debug("+ %#lx", this);
+		this->fdDir = fs->Create("fd", vfs::NodeType::DIRECTORY,
+								 ((Tasking::PCB *)Owner));
+	}
+
+	FileDescriptorTable::~FileDescriptorTable()
+	{
+		debug("- %#lx", this);
+		foreach (auto &fd in FileDescriptors)
+		{
+			debug("Removing fd: %d", fd.Descriptor);
+			this->RemoveFileDescriptor(fd.Descriptor);
+			delete fd.Handle;
+		}
+	}
+}