Kernel/storage/descriptor.cpp

379 lines
8.3 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 <convert.h>
#include <stropts.h>
#include <task.hpp>
#include <printf.h>
#include <lock.hpp>
#include <cwalk.h>
#include "../kernel.h"
namespace vfs
{
int FileDescriptorTable::GetFlags(int FileDescriptor)
{
auto it = this->FileMap.find(FileDescriptor);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", FileDescriptor);
return it->second.Flags;
}
int FileDescriptorTable::SetFlags(int FileDescriptor, int Flags)
{
auto it = this->FileMap.find(FileDescriptor);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", FileDescriptor);
it->second.Flags = Flags;
return 0;
}
int FileDescriptorTable::AddFileDescriptor(const char *AbsolutePath,
mode_t Mode, int Flags)
{
Tasking::PCB *pcb = thisProcess;
auto ProbeMode = [](mode_t Mode, int Flags) -> int
{
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;
};
if (ProbeMode(Mode, Flags) < 0)
return -EACCES;
fixme("Do not follow symlinks when O_CREAT and O_EXCL are set");
if (Flags & O_CREAT)
{
FileNode *ret = fs->Create(pcb->CWD, AbsolutePath, Mode);
if (Flags & O_EXCL && ret == nullptr)
{
debug("%s: File already exists?, returning EEXIST",
AbsolutePath);
return -EEXIST;
}
}
if (Flags & O_CLOEXEC)
{
fixme("O_CLOEXEC");
}
FileNode *File = fs->GetByPath(AbsolutePath, pcb->CWD);
if (!File)
{
error("Failed to open file %s", AbsolutePath);
return -ENOENT;
}
if (Flags & O_TRUNC)
{
debug("Truncating file %s", AbsolutePath);
File->Truncate(0);
}
Fildes fd{};
if (Flags & O_APPEND)
{
debug("Appending to file %s", AbsolutePath);
struct kstat stat;
File->Stat(&stat);
fd.Offset = File->Seek(stat.Size);
}
fd.Mode = Mode;
fd.Flags = Flags;
fd.Node = File;
int fdn = this->GetFreeFileDescriptor();
if (fdn < 0)
return fdn;
this->FileMap.insert({fdn, fd});
char linkName[64];
snprintf(linkName, 64, "%d", fdn);
assert(fs->CreateLink(linkName, this->fdDir, AbsolutePath) != nullptr);
File->Open(Flags, Mode);
return fdn;
}
int FileDescriptorTable::RemoveFileDescriptor(int FileDescriptor)
{
auto it = this->FileMap.find(FileDescriptor);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", FileDescriptor);
fs->Remove(it->second.Node);
this->FileMap.erase(it);
return 0;
}
int FileDescriptorTable::GetFreeFileDescriptor()
{
Tasking::PCB *pcb = thisProcess;
for (size_t i = 0; i < pcb->SoftLimits.OpenFiles; i++)
{
auto it = this->FileMap.find(i);
if (it == this->FileMap.end())
return i;
}
return -EMFILE;
}
void FileDescriptorTable::Fork(FileDescriptorTable *Parent)
{
this->FileMap = Parent->FileMap;
for (const auto &fd : this->FileMap)
{
if (fd.second.Flags & O_CLOEXEC)
{
debug("O_CLOEXEC flag set, removing fd %d", fd.first);
this->FileMap.erase(fd.first);
}
}
}
int FileDescriptorTable::usr_open(const char *pathname, int flags, mode_t mode)
{
if (pathname == nullptr)
return -EFAULT;
return AddFileDescriptor(pathname, mode, flags);
}
int FileDescriptorTable::usr_creat(const char *pathname, mode_t mode)
{
return usr_open(pathname, O_WRONLY | O_CREAT | O_TRUNC, mode);
}
ssize_t FileDescriptorTable::usr_read(int fd, void *buf, size_t count)
{
auto it = this->FileMap.find(fd);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", fd);
return it->second.Node->Read(buf, count, it->second.Offset);
}
ssize_t FileDescriptorTable::usr_write(int fd, const void *buf, size_t count)
{
auto it = this->FileMap.find(fd);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", fd);
return it->second.Node->Write(buf, count, it->second.Offset);
}
int FileDescriptorTable::usr_close(int fd)
{
auto it = this->FileMap.find(fd);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", fd);
return RemoveFileDescriptor(fd);
}
off_t FileDescriptorTable::usr_lseek(int fd, off_t offset, int whence)
{
auto it = this->FileMap.find(fd);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", fd);
off_t &newOffset = it->second.Offset;
switch (whence)
{
case SEEK_SET:
{
newOffset = it->second.Node->Seek(offset);
break;
}
case SEEK_CUR:
{
newOffset = it->second.Node->Seek(newOffset + offset);
break;
}
case SEEK_END:
{
struct kstat stat
{
};
it->second.Node->Stat(&stat);
newOffset = it->second.Node->Seek(stat.Size + offset);
break;
}
default:
return -EINVAL;
}
return newOffset;
}
int FileDescriptorTable::usr_stat(const char *pathname,
struct kstat *statbuf)
{
FileNode *node = fs->GetByPath(pathname, nullptr);
if (node == nullptr)
ReturnLogError(-ENOENT, "Failed to find %s", pathname);
if (node->IsSymbolicLink())
{
std::unique_ptr<char[]> buffer(new char[1024]);
ssize_t ret = node->ReadLink(buffer.get(), 1024);
if (ret < 0)
return ret;
FileNode *target = fs->GetByPath(buffer.get(), nullptr);
if (target == nullptr)
return -ENOENT;
return target->Stat(statbuf);
}
return node->Stat(statbuf);
}
int FileDescriptorTable::usr_fstat(int fd, struct kstat *statbuf)
{
auto it = this->FileMap.find(fd);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", fd);
vfs::FileDescriptorTable::Fildes &fildes = it->second;
return fildes.Node->Stat(statbuf);
}
int FileDescriptorTable::usr_lstat(const char *pathname,
struct kstat *statbuf)
{
FileNode *node = fs->GetByPath(pathname, nullptr);
if (node == nullptr)
ReturnLogError(-ENOENT, "Failed to find %s", pathname);
return node->Stat(statbuf);
}
int FileDescriptorTable::usr_dup(int oldfd)
{
auto it = this->FileMap.find(oldfd);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", oldfd);
int newfd = this->GetFreeFileDescriptor();
if (newfd < 0)
return -EMFILE;
Fildes new_dfd{};
new_dfd.Node = it->second.Node;
new_dfd.Mode = it->second.Mode;
this->FileMap.insert({newfd, new_dfd});
debug("Duplicated file descriptor %d to %d", oldfd, newfd);
return newfd;
}
int FileDescriptorTable::usr_dup2(int oldfd, int newfd)
{
if (newfd < 0)
ReturnLogError(-EBADF, "Invalid newfd %d", newfd);
auto it = this->FileMap.find(oldfd);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid oldfd %d", oldfd);
if (newfd == oldfd)
return newfd;
/* Even if it's not valid we ignore it. */
this->usr_close(newfd);
Fildes new_dfd{};
new_dfd.Node = it->second.Node;
new_dfd.Mode = it->second.Mode;
this->FileMap.insert({newfd, new_dfd});
debug("Duplicated file descriptor %d to %d", oldfd, newfd);
return newfd;
}
int FileDescriptorTable::usr_ioctl(int fd, unsigned long request, void *argp)
{
auto it = this->FileMap.find(fd);
if (it == this->FileMap.end())
ReturnLogError(-EBADF, "Invalid fd %d", fd);
return it->second.Node->Ioctl(request, argp);
}
FileDescriptorTable::FileDescriptorTable(void *_Owner)
: Owner(_Owner)
{
debug("+ %#lx", this);
mode_t Mode = S_IXOTH | S_IROTH |
S_IXGRP | S_IRGRP |
S_IXUSR | S_IRUSR |
S_IFDIR;
this->fdDir = fs->Create(((Tasking::PCB *)_Owner)->ProcDirectory, "fd", Mode);
}
}