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Kernel: Cleanup most of syscalls dealing with files

This commit is contained in:
Bananymous 2024-12-07 05:33:04 +02:00
parent 71a2d0971f
commit 2d0690ae2d
3 changed files with 94 additions and 125 deletions
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16
kernel/include/kernel/Process.h
View File

@ -103,7 +103,7 @@ namespace Kernel
BAN::ErrorOr<long> open_inode(VirtualFileSystem::File&&, int flags);
BAN::ErrorOr<void> create_file_or_dir(const VirtualFileSystem::File& parent, BAN::StringView path, mode_t mode) const;
BAN::ErrorOr<void> create_file_or_dir(int fd, const char* path, mode_t mode) const;
BAN::ErrorOr<long> sys_openat(int, const char* path, int, mode_t);
BAN::ErrorOr<long> sys_close(int fd);
BAN::ErrorOr<long> sys_read(int fd, void* buffer, size_t count);
@ -160,8 +160,6 @@ namespace Kernel
static BAN::ErrorOr<long> clean_poweroff(int command);
BAN::ErrorOr<long> sys_poweroff(int command);
BAN::ErrorOr<void> mount(BAN::StringView source, BAN::StringView target);
BAN::ErrorOr<long> sys_readdir(int fd, struct dirent* list, size_t list_len);
BAN::ErrorOr<long> sys_mmap(const sys_mmap_t*);
@ -212,6 +210,7 @@ namespace Kernel
// Return false if access was page violation (segfault)
BAN::ErrorOr<bool> allocate_page_for_demand_paging(vaddr_t addr, bool wants_write);
// FIXME: remove this API
BAN::ErrorOr<BAN::String> absolute_path_of(BAN::StringView) const;
// ONLY CALLED BY TIMER INTERRUPT
@ -223,8 +222,15 @@ namespace Kernel
Process(const Credentials&, pid_t pid, pid_t parent, pid_t sid, pid_t pgrp);
static Process* create_process(const Credentials&, pid_t parent, pid_t sid = 0, pid_t pgrp = 0);
BAN::ErrorOr<VirtualFileSystem::File> find_file(int fd, const char* path, int flags);
BAN::ErrorOr<VirtualFileSystem::File> find_parent(int fd, const char* path);
struct FileParent
{
VirtualFileSystem::File parent;
BAN::StringView file_name;
};
BAN::ErrorOr<VirtualFileSystem::File> find_file(int fd, const char* path, int flags) const;
BAN::ErrorOr<FileParent> find_parent_file(int fd, const char* path, int flags) const;
BAN::ErrorOr<VirtualFileSystem::File> find_relative_parent(int fd, const char* path) const;
BAN::ErrorOr<void> validate_string_access(const char*);
BAN::ErrorOr<void> validate_pointer_access_check(const void*, size_t, bool needs_write);

2
kernel/kernel/Networking/UNIX/Socket.cpp
View File

@ -208,7 +208,7 @@ namespace Kernel
auto parent_file = bind_path.front() == '/'
? VirtualFileSystem::get().root_file()
: TRY(Process::current().working_directory().clone());
if (auto ret = Process::current().create_file_or_dir(parent_file, bind_path, 0755 | S_IFSOCK); ret.is_error())
if (auto ret = Process::current().create_file_or_dir(AT_FDCWD, bind_path.data(), 0755 | S_IFSOCK); ret.is_error())
{
if (ret.error().get_error_code() == EEXIST)
return BAN::Error::from_errno(EADDRINUSE);

201
kernel/kernel/Process.cpp
View File

@ -119,8 +119,9 @@ namespace Kernel
TRY(process->m_cmdline.push_back({}));
TRY(process->m_cmdline.back().append(path));
auto absolute_path = TRY(process->absolute_path_of(path));
auto executable_inode = TRY(VirtualFileSystem::get().file_from_absolute_path(process->m_credentials, absolute_path, O_EXEC)).inode;
LockGuard _(process->m_process_lock);
auto executable_inode = TRY(process->find_file(AT_FDCWD, path.data(), O_EXEC)).inode;
auto executable = TRY(ELF::load_from_inode(executable_inode, process->m_credentials, process->page_table()));
process->m_mapped_regions = BAN::move(executable.regions);
@ -378,12 +379,61 @@ namespace Kernel
return read_from_vec_of_str(m_environ, offset, buffer);
}
BAN::ErrorOr<VirtualFileSystem::File> Process::find_parent(int fd, const char* path)
BAN::ErrorOr<VirtualFileSystem::File> Process::find_file(int fd, const char* path, int flags) const
{
ASSERT(m_process_lock.is_locked());
if (path)
TRY(validate_string_access(path));
auto parent_file = TRY(find_relative_parent(fd, path));
auto file = path
? TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags))
: BAN::move(parent_file);
return file;
}
BAN::ErrorOr<Process::FileParent> Process::find_parent_file(int fd, const char* path, int flags) const
{
ASSERT(m_process_lock.is_locked());
auto relative_parent = TRY(find_relative_parent(fd, path));
VirtualFileSystem::File parent;
BAN::StringView file_name;
auto path_sv = path ? BAN::StringView(path) : ""_sv;
while (!path_sv.empty() && path_sv.back() == '/')
path_sv = path_sv.substring(0, path_sv.size() - 1);
if (auto index = path_sv.rfind('/'); index.has_value())
{
parent = TRY(VirtualFileSystem::get().file_from_relative_path(relative_parent, m_credentials, path_sv.substring(0, index.value()), flags));
file_name = path_sv.substring(index.value() + 1);
}
else
{
parent = BAN::move(relative_parent);
file_name = path_sv;
}
if (!parent.inode->can_access(m_credentials, flags))
return BAN::Error::from_errno(EACCES);
if (!parent.inode->mode().ifdir())
return BAN::Error::from_errno(ENOTDIR);
while (!file_name.empty() && file_name.front() == '/')
file_name = file_name.substring(1);
while (!file_name.empty() && file_name.back() == '/')
file_name = file_name.substring(0, file_name.size() - 1);
return FileParent {
.parent = BAN::move(parent),
.file_name = file_name,
};
}
BAN::ErrorOr<VirtualFileSystem::File> Process::find_relative_parent(int fd, const char* path) const
{
ASSERT(m_process_lock.is_locked());
if (path && path[0] == '/')
return VirtualFileSystem::get().root_file();
@ -398,21 +448,6 @@ namespace Kernel
return TRY(m_open_file_descriptors.file_of(fd));
}
BAN::ErrorOr<VirtualFileSystem::File> Process::find_file(int fd, const char* path, int flags)
{
ASSERT(m_process_lock.is_locked());
if (path)
TRY(validate_string_access(path));
auto parent_file = TRY(find_parent(fd, path));
auto file = path
? TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags))
: BAN::move(parent_file);
return file;
}
BAN::ErrorOr<long> Process::sys_exit(int status)
{
ASSERT(this == &Process::current());
@ -521,8 +556,7 @@ namespace Kernel
TRY(validate_string_access(path));
auto absolute_path = TRY(absolute_path_of(path));
auto executable_file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_EXEC));
auto executable_file = TRY(find_file(AT_FDCWD, path, O_EXEC));
auto executable_inode = executable_file.inode;
BAN::Vector<BAN::String> str_argv;
@ -875,7 +909,7 @@ namespace Kernel
}
}
BAN::ErrorOr<void> Process::create_file_or_dir(const VirtualFileSystem::File& parent, BAN::StringView path, mode_t mode) const
BAN::ErrorOr<void> Process::create_file_or_dir(int fd, const char* path, mode_t mode) const
{
switch (mode & Inode::Mode::TYPE_MASK)
{
@ -889,26 +923,12 @@ namespace Kernel
return BAN::Error::from_errno(ENOTSUP);
}
BAN::RefPtr<Inode> parent_inode;
BAN::StringView file_name;
if (auto index = path.rfind('/'); index.has_value())
{
parent_inode = TRY(VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path.substring(0, index.value()), O_EXEC | O_WRONLY)).inode;
file_name = path.substring(index.value() + 1);
}
else
{
parent_inode = parent.inode;
file_name = path;
if (!parent_inode->can_access(m_credentials, O_WRONLY))
return BAN::Error::from_errno(EACCES);
}
auto [parent, file_name] = TRY(find_parent_file(fd, path, O_EXEC | O_WRONLY));
if (Inode::Mode(mode).ifdir())
TRY(parent_inode->create_directory(file_name, mode, m_credentials.euid(), parent_inode->gid()));
TRY(parent.inode->create_directory(file_name, mode, m_credentials.euid(), parent.inode->gid()));
else
TRY(parent_inode->create_file(file_name, mode, m_credentials.euid(), parent_inode->gid()));
TRY(parent.inode->create_file(file_name, mode, m_credentials.euid(), parent.inode->gid()));
return {};
}
@ -952,8 +972,8 @@ namespace Kernel
TRY(validate_string_access(path));
auto parent_file = TRY(find_parent(fd, path));
auto file_or_error = VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags | O_NOFOLLOW);
auto [parent, file_name] = TRY(find_parent_file(fd, path, O_RDONLY));
auto file_or_error = VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, file_name, flags);
VirtualFileSystem::File file;
if (file_or_error.is_error())
@ -962,8 +982,8 @@ namespace Kernel
return file_or_error.release_error();
// FIXME: There is a race condition between next two lines
TRY(create_file_or_dir(parent_file, path, (mode & 0777) | Inode::Mode::IFREG));
file = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags & ~O_RDWR));
TRY(parent.inode->create_file(file_name, (mode & 0777) | Inode::Mode::IFREG, m_credentials.euid(), m_credentials.egid()));
file = TRY(VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, file_name, flags & ~O_RDWR));
}
else
{
@ -975,8 +995,6 @@ namespace Kernel
return BAN::Error::from_errno(EISDIR);
if (!file.inode->mode().ifdir() && (flags & O_DIRECTORY))
return BAN::Error::from_errno(ENOTDIR);
if (file.inode->mode().iflnk() && !(flags & O_NOFOLLOW))
file = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags));
}
auto inode = file.inode;
@ -1032,9 +1050,9 @@ namespace Kernel
credentials.set_euid(credentials.ruid());
credentials.set_egid(credentials.rgid());
auto absolute_path = TRY(absolute_path_of(path));
auto relative_parent = TRY(find_relative_parent(AT_FDCWD, path));
TRY(VirtualFileSystem::get().file_from_relative_path(relative_parent, credentials, path, flags));
TRY(VirtualFileSystem::get().file_from_absolute_path(credentials, absolute_path, flags));
return 0;
}
@ -1042,15 +1060,10 @@ namespace Kernel
{
LockGuard _(m_process_lock);
TRY(validate_string_access(path));
BAN::StringView path_sv(path);
if (!path_sv.empty() && path_sv.back() == '/')
path_sv = path_sv.substring(0, path_sv.size() - 1);
if (path_sv.empty())
return BAN::Error::from_errno(EINVAL);
if (path[0] == '/')
TRY(create_file_or_dir(VirtualFileSystem::get().root_file(), path_sv, Inode::Mode::IFDIR | mode));
else
TRY(create_file_or_dir(m_working_directory, path_sv, Inode::Mode::IFDIR | mode));
auto [parent, file_name] = TRY(find_parent_file(AT_FDCWD, path, O_WRONLY));
TRY(parent.inode->create_directory(file_name, (mode & 0777) | Inode::Mode::IFDIR, m_credentials.euid(), m_credentials.egid()));
return 0;
}
@ -1064,27 +1077,12 @@ namespace Kernel
if (inode->mode().ifdir())
return BAN::Error::from_errno(EISDIR);
auto parent = TRY(find_parent(fd2, path2));
auto [parent, file_name] = TRY(find_parent_file(fd2, path2, O_WRONLY));
if (!parent.inode->mode().ifdir())
return BAN::Error::from_errno(ENOTDIR);
BAN::RefPtr<Inode> parent_inode;
BAN::StringView file_name;
TRY(parent.inode->link_inode(file_name, inode));
BAN::StringView path2_sv = path2;
if (auto index = path2_sv.rfind('/'); index.has_value())
{
parent_inode = TRY(VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path2_sv.substring(0, index.value()), O_EXEC | O_WRONLY)).inode;
file_name = path2_sv.substring(index.value() + 1);
}
else
{
parent_inode = parent.inode;
file_name = path2_sv;
if (!parent_inode->can_access(m_credentials, O_WRONLY))
return BAN::Error::from_errno(EACCES);
}
ASSERT(parent_inode->mode().ifdir());
TRY(parent_inode->link_inode(file_name, inode));
return 0;
}
@ -1093,17 +1091,8 @@ namespace Kernel
LockGuard _(m_process_lock);
TRY(validate_string_access(path));
auto absolute_path = TRY(absolute_path_of(path));
size_t index = absolute_path.size();
for (; index > 0; index--)
if (absolute_path[index - 1] == '/')
break;
auto directory = absolute_path.sv().substring(0, index);
auto file_name = absolute_path.sv().substring(index);
auto parent = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, directory, O_EXEC | O_WRONLY)).inode;
TRY(parent->unlink(file_name));
auto [parent, file_name] = TRY(find_parent_file(AT_FDCWD, path, O_WRONLY));
TRY(parent.inode->unlink(file_name));
return 0;
}
@ -1130,14 +1119,12 @@ namespace Kernel
TRY(validate_string_access(path1));
TRY(validate_string_access(path2));
auto parent_file = TRY(find_parent(fd, path2));
auto file_or_error = VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path2, O_NOFOLLOW);
if (!file_or_error.is_error())
if (!find_file(fd, path2, O_NOFOLLOW).is_error())
return BAN::Error::from_errno(EEXIST);
TRY(create_file_or_dir(parent_file, path2, 0777 | Inode::Mode::IFLNK));
TRY(create_file_or_dir(fd, path2, 0777 | Inode::Mode::IFLNK));
auto symlink = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path2, O_NOFOLLOW));
auto symlink = TRY(find_file(fd, path2, O_NOFOLLOW));
TRY(symlink.inode->set_link_target(path1));
return 0;
@ -1522,18 +1509,6 @@ namespace Kernel
return 0;
}
BAN::ErrorOr<void> Process::mount(BAN::StringView source, BAN::StringView target)
{
BAN::String absolute_source, absolute_target;
{
LockGuard _(m_process_lock);
TRY(absolute_source.append(TRY(absolute_path_of(source))));
TRY(absolute_target.append(TRY(absolute_path_of(target))));
}
TRY(VirtualFileSystem::get().mount(m_credentials, absolute_source, absolute_target));
return {};
}
BAN::ErrorOr<long> Process::sys_fstatat(int fd, const char* path, struct stat* buf, int flag)
{
if (flag & ~AT_SYMLINK_NOFOLLOW)
@ -1597,9 +1572,7 @@ namespace Kernel
TRY(validate_string_access(path));
TRY(validate_pointer_access(buffer, PATH_MAX, true));
auto absolute_path = TRY(absolute_path_of(path));
auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_RDONLY));
auto file = TRY(find_file(AT_FDCWD, path, O_RDONLY));
if (file.canonical_path.size() >= PATH_MAX)
return BAN::Error::from_errno(ENAMETOOLONG);
@ -1654,19 +1627,9 @@ namespace Kernel
BAN::ErrorOr<long> Process::sys_setpwd(const char* path)
{
BAN::String absolute_path;
{
LockGuard _(m_process_lock);
TRY(validate_string_access(path));
absolute_path = TRY(absolute_path_of(path));
}
auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_SEARCH));
if (!file.inode->mode().ifdir())
return BAN::Error::from_errno(ENOTDIR);
LockGuard _(m_process_lock);
auto file = TRY(find_file(AT_FDCWD, path, O_SEARCH));
m_working_directory = BAN::move(file);
return 0;