Luna/kernel/src/sys/stat.cpp
apio e2a77bb3da
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kernel+libc: Add pledge support
2023-08-12 21:38:25 +02:00

92 lines
2.7 KiB
C++

#include "Pledge.h"
#include "memory/MemoryManager.h"
#include "sys/Syscall.h"
#include "thread/Scheduler.h"
#include <bits/access.h>
#include <bits/atfile.h>
#include <bits/modes.h>
#include <bits/struct_stat.h>
static mode_t make_mode(mode_t mode, VFS::InodeType type)
{
mode_t result = mode;
switch (type)
{
case VFS::InodeType::RegularFile: result |= S_IFREG; break;
case VFS::InodeType::Directory: result |= S_IFDIR; break;
case VFS::InodeType::CharacterDevice: result |= S_IFCHR; break;
case VFS::InodeType::BlockDevice: result |= S_IFBLK; break;
case VFS::InodeType::Symlink: result |= S_IFLNK; break;
case VFS::InodeType::FIFO: result |= S_IFIFO; break;
case VFS::InodeType::Socket: result |= S_IFSOCK; break;
default: break;
}
return result;
}
Result<u64> sys_fstatat(Registers*, SyscallArgs args)
{
int dirfd = (int)args[0];
auto path = TRY(MemoryManager::strdup_from_user(args[1]));
stat* st = (stat*)args[2];
int flags = (int)args[3];
Thread* current = Scheduler::current();
TRY(check_pledge(current, Promise::p_rpath));
auto inode = TRY(current->resolve_atfile(dirfd, path, flags & AT_EMPTY_PATH, !(flags & AT_SYMLINK_NOFOLLOW)));
stat kstat;
const auto& metadata = inode->metadata();
kstat.st_ino = metadata.inum;
kstat.st_mode = make_mode(metadata.mode, inode->type());
kstat.st_nlink = metadata.nlinks;
kstat.st_uid = metadata.uid;
kstat.st_gid = metadata.gid;
kstat.st_size = metadata.size;
kstat.st_dev = inode->fs() ? inode->fs()->host_device_id() : 0;
kstat.st_rdev = metadata.devid;
kstat.st_atim = metadata.atime;
kstat.st_mtim = metadata.mtime;
kstat.st_ctim = metadata.ctime;
if (!MemoryManager::copy_to_user_typed(st, &kstat)) return err(EFAULT);
return 0;
}
Result<u64> sys_faccessat(Registers*, SyscallArgs args)
{
int dirfd = (int)args[0];
auto path = TRY(MemoryManager::strdup_from_user(args[1]));
int amode = (int)args[2];
int flags = (int)args[3];
Credentials creds;
auto* current = Scheduler::current();
TRY(check_pledge(current, Promise::p_rpath));
if (flags & AT_EACCESS) creds = current->auth;
else
{
auto auth = current->auth;
creds.euid = auth.uid;
creds.egid = auth.gid;
}
auto inode = TRY(current->resolve_atfile(dirfd, path, false, true));
if ((amode & R_OK) && !VFS::can_read(inode, creds)) return err(EACCES);
if ((amode & W_OK) && !VFS::can_write(inode, creds)) return err(EACCES);
if ((amode & X_OK) && !VFS::can_execute(inode, creds)) return err(EACCES);
// Either all checks succeeded, or amode == F_OK and the file exists, since resolve_atfile() would have failed
// otherwise.
return 0;
}