Luna/kernel/src/fs/FileDescriptor.cpp
apio 44815b08c7 Kernel: Use copy_from_user() and copy_to_user() in read/write
This is huge. Finally, we can do proper reads/writes with invalid addresses, or big buffers.
2022-11-06 15:19:23 +01:00

96 lines
2.6 KiB
C++

#include "fs/FileDescriptor.h"
#include "std/errno.h"
#include "std/stdlib.h"
#include "sys/UserMemory.h"
Descriptor::Descriptor() : m_is_open(false)
{
}
Descriptor::Descriptor(const Descriptor& other)
: m_is_open(other.m_is_open), m_can_read(other.m_can_read), m_can_write(other.m_can_write),
m_able_to_block(other.m_able_to_block), m_close_on_exec(other.m_close_on_exec), m_node(other.m_node),
m_offset(other.m_offset)
{
}
void Descriptor::open(VFS::Node* node, bool can_read, bool can_write, bool able_to_block, bool close_on_exec)
{
m_can_read = can_read;
m_can_write = can_write;
m_able_to_block = able_to_block;
m_close_on_exec = close_on_exec;
m_node = node;
m_offset = 0;
m_is_open = true;
}
ssize_t Descriptor::read(size_t size, char* buffer)
{
ssize_t result = VFS::read(m_node, m_offset, size, buffer);
m_offset += result;
return result;
}
ssize_t Descriptor::write(size_t size, const char* buffer)
{
ssize_t result = VFS::write(m_node, m_offset, size, buffer);
m_offset += result;
return result;
}
ssize_t Descriptor::user_read(size_t size, char* buffer)
{
char* buf = (char*)kmalloc(size);
if (!buf) return -ENOMEM;
ssize_t result = read(size, buf);
if (!copy_to_user(buffer, buf, size)) result = -EFAULT;
kfree(buf);
return result;
}
ssize_t Descriptor::user_write(size_t size, const char* buffer)
{
char* buf = (char*)kmalloc(size);
if (!buf) return -ENOMEM;
ssize_t result;
if (!copy_from_user(buffer, buf, size)) result = -EFAULT;
else
result = write(size, buf);
kfree(buf);
return result;
}
#define MAP_FAIL(errno) 0xffffffffffffff00 | (unsigned char)(errno)
uintptr_t Descriptor::mmap(uintptr_t addr, size_t size, int prot, off_t offset)
{
if (!m_node->mmap_func) return MAP_FAIL(ENOTSUP);
return m_node->mmap_func(m_node, addr, size, prot, offset);
}
long Descriptor::ioctl(int cmd, uintptr_t arg)
{
if (!m_node->ioctl_func) return MAP_FAIL(ENOTSUP);
return m_node->ioctl_func(m_node, cmd, arg);
}
int Descriptor::seek(long offset)
{
if (m_node->type == VFS_FILE && (uint64_t)offset > m_node->length)
return -EINVAL; // FIXME: Support seeking beyond the current file's length.
m_offset = (uint64_t)offset;
return 0;
}
const Descriptor& Descriptor::operator=(const Descriptor& other)
{
m_is_open = other.m_is_open;
m_can_read = other.m_can_read;
m_can_write = other.m_can_write;
m_offset = other.m_offset;
m_node = other.m_node;
m_able_to_block = other.m_able_to_block;
m_close_on_exec = other.m_close_on_exec;
return other;
}