ladybird/Kernel/Net/LocalSocket.cpp
Andreas Kling 03cc45e5a2 Kernel: Use RefPtr instead of LockRefPtr for File and subclasses
This was mostly straightforward, as all the storage locations are
guarded by some related mutex.

The use of old-school associated mutexes instead of MutexProtected
is unfortunate, but the process to modernize such code is ongoing.
2023-03-10 13:15:44 +01:00

552 lines
17 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Singleton.h>
#include <AK/StringBuilder.h>
#include <Kernel/API/Ioctl.h>
#include <Kernel/API/POSIX/errno.h>
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Locking/Mutex.h>
#include <Kernel/Locking/MutexProtected.h>
#include <Kernel/Net/LocalSocket.h>
#include <Kernel/Process.h>
#include <Kernel/StdLib.h>
#include <Kernel/UnixTypes.h>
namespace Kernel {
static Singleton<MutexProtected<LocalSocket::List>> s_list;
static MutexProtected<LocalSocket::List>& all_sockets()
{
return *s_list;
}
void LocalSocket::for_each(Function<void(LocalSocket const&)> callback)
{
all_sockets().for_each_shared([&](auto const& socket) {
callback(socket);
});
}
ErrorOr<void> LocalSocket::try_for_each(Function<ErrorOr<void>(LocalSocket const&)> callback)
{
return all_sockets().with_shared([&](auto const& sockets) -> ErrorOr<void> {
for (auto& socket : sockets)
TRY(callback(socket));
return {};
});
}
ErrorOr<NonnullRefPtr<LocalSocket>> LocalSocket::try_create(int type)
{
auto client_buffer = TRY(DoubleBuffer::try_create("LocalSocket: Client buffer"sv));
auto server_buffer = TRY(DoubleBuffer::try_create("LocalSocket: Server buffer"sv));
return adopt_nonnull_ref_or_enomem(new (nothrow) LocalSocket(type, move(client_buffer), move(server_buffer)));
}
ErrorOr<SocketPair> LocalSocket::try_create_connected_pair(int type)
{
auto socket = TRY(LocalSocket::try_create(type));
auto description1 = TRY(OpenFileDescription::try_create(*socket));
TRY(socket->try_set_path("[socketpair]"sv));
socket->set_acceptor(Process::current());
socket->set_connected(true);
socket->set_connect_side_role(Role::Connected);
socket->set_role(Role::Accepted);
auto description2 = TRY(OpenFileDescription::try_create(*socket));
return SocketPair { move(description1), move(description2) };
}
LocalSocket::LocalSocket(int type, NonnullOwnPtr<DoubleBuffer> client_buffer, NonnullOwnPtr<DoubleBuffer> server_buffer)
: Socket(AF_LOCAL, type, 0)
, m_for_client(move(client_buffer))
, m_for_server(move(server_buffer))
{
auto& current_process = Process::current();
auto current_process_credentials = current_process.credentials();
m_prebind_uid = current_process_credentials->euid();
m_prebind_gid = current_process_credentials->egid();
m_prebind_mode = 0666;
m_for_client->set_unblock_callback([this]() {
evaluate_block_conditions();
});
m_for_server->set_unblock_callback([this]() {
evaluate_block_conditions();
});
all_sockets().with_exclusive([&](auto& list) {
list.append(*this);
});
dbgln_if(LOCAL_SOCKET_DEBUG, "LocalSocket({}) created with type={}", this, type);
}
LocalSocket::~LocalSocket()
{
all_sockets().with_exclusive([&](auto& list) {
list.remove(*this);
});
}
void LocalSocket::get_local_address(sockaddr* address, socklen_t* address_size)
{
auto& address_un = *reinterpret_cast<sockaddr_un*>(address);
address_un = {
.sun_family = AF_UNIX,
.sun_path = {},
};
if (!m_path || m_path->is_empty()) {
*address_size = sizeof(address_un.sun_family);
return;
}
size_t bytes_to_copy = min(m_path->length() + 1, min(static_cast<size_t>(*address_size), sizeof(address_un.sun_path)));
memcpy(address_un.sun_path, m_path->characters(), bytes_to_copy);
*address_size = sizeof(address_un.sun_family) + bytes_to_copy;
}
void LocalSocket::get_peer_address(sockaddr* address, socklen_t* address_size)
{
get_local_address(address, address_size);
}
ErrorOr<void> LocalSocket::bind(Credentials const& credentials, Userspace<sockaddr const*> user_address, socklen_t address_size)
{
VERIFY(setup_state() == SetupState::Unstarted);
if (address_size > sizeof(sockaddr_un))
return set_so_error(EINVAL);
sockaddr_un address = {};
SOCKET_TRY(copy_from_user(&address, user_address, address_size));
if (address.sun_family != AF_LOCAL)
return set_so_error(EINVAL);
auto path = SOCKET_TRY(KString::try_create(StringView { address.sun_path, strnlen(address.sun_path, sizeof(address.sun_path)) }));
dbgln_if(LOCAL_SOCKET_DEBUG, "LocalSocket({}) bind({})", this, path);
mode_t mode = S_IFSOCK | (m_prebind_mode & 0777);
UidAndGid owner { m_prebind_uid, m_prebind_gid };
auto result = VirtualFileSystem::the().open(credentials, path->view(), O_CREAT | O_EXCL | O_NOFOLLOW_NOERROR, mode, Process::current().current_directory(), owner);
if (result.is_error()) {
if (result.error().code() == EEXIST)
return set_so_error(EADDRINUSE);
return result.release_error();
}
auto file = move(result.value());
auto inode = file->inode();
VERIFY(inode);
if (!inode->bind_socket(*this))
return set_so_error(EADDRINUSE);
m_inode = inode;
m_path = move(path);
m_bound = true;
return {};
}
ErrorOr<void> LocalSocket::connect(Credentials const& credentials, OpenFileDescription& description, Userspace<sockaddr const*> user_address, socklen_t address_size)
{
VERIFY(!m_bound);
if (address_size > sizeof(sockaddr_un))
return set_so_error(EINVAL);
sockaddr_un address = {};
SOCKET_TRY(copy_from_user(&address, user_address, address_size));
if (address.sun_family != AF_LOCAL)
return set_so_error(EINVAL);
if (is_connected())
return set_so_error(EISCONN);
auto path = SOCKET_TRY(KString::try_create(StringView { address.sun_path, strnlen(address.sun_path, sizeof(address.sun_path)) }));
dbgln_if(LOCAL_SOCKET_DEBUG, "LocalSocket({}) connect({})", this, *path);
auto file = SOCKET_TRY(VirtualFileSystem::the().open(credentials, path->view(), O_RDWR, 0, Process::current().current_directory()));
auto inode = file->inode();
m_inode = inode;
VERIFY(inode);
auto peer = inode->bound_socket();
if (!peer)
return set_so_error(ECONNREFUSED);
m_path = move(path);
VERIFY(m_connect_side_fd == &description);
set_connect_side_role(Role::Connecting);
auto result = peer->queue_connection_from(*this);
if (result.is_error()) {
set_connect_side_role(Role::None);
return result;
}
if (is_connected()) {
set_connect_side_role(Role::Connected);
return {};
}
auto unblock_flags = Thread::OpenFileDescriptionBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::ConnectBlocker>({}, description, unblock_flags).was_interrupted()) {
set_connect_side_role(Role::None);
return set_so_error(EINTR);
}
dbgln_if(LOCAL_SOCKET_DEBUG, "LocalSocket({}) connect({}) status is {}", this, *m_path, to_string(setup_state()));
if (!has_flag(unblock_flags, Thread::OpenFileDescriptionBlocker::BlockFlags::Connect)) {
set_connect_side_role(Role::None);
return set_so_error(ECONNREFUSED);
}
set_connect_side_role(Role::Connected);
return {};
}
ErrorOr<void> LocalSocket::listen(size_t backlog)
{
MutexLocker locker(mutex());
if (type() != SOCK_STREAM)
return set_so_error(EOPNOTSUPP);
set_backlog(backlog);
auto previous_role = m_role;
set_role(Role::Listener);
set_connect_side_role(Role::Listener, previous_role != m_role);
dbgln_if(LOCAL_SOCKET_DEBUG, "LocalSocket({}) listening with backlog={}", this, backlog);
return {};
}
ErrorOr<void> LocalSocket::attach(OpenFileDescription& description)
{
VERIFY(!m_accept_side_fd_open);
if (m_connect_side_role == Role::None) {
VERIFY(m_connect_side_fd == nullptr);
m_connect_side_fd = &description;
} else {
VERIFY(m_connect_side_fd != &description);
m_accept_side_fd_open = true;
}
evaluate_block_conditions();
return {};
}
void LocalSocket::detach(OpenFileDescription& description)
{
if (m_connect_side_fd == &description) {
m_connect_side_fd = nullptr;
} else {
VERIFY(m_accept_side_fd_open);
m_accept_side_fd_open = false;
if (m_bound) {
if (m_inode)
m_inode->unbind_socket();
}
}
evaluate_block_conditions();
}
bool LocalSocket::can_read(OpenFileDescription const& description, u64) const
{
auto role = this->role(description);
if (role == Role::Listener)
return can_accept();
if (role == Role::Accepted)
return !has_attached_peer(description) || !m_for_server->is_empty();
if (role == Role::Connected)
return !has_attached_peer(description) || !m_for_client->is_empty();
return false;
}
bool LocalSocket::has_attached_peer(OpenFileDescription const& description) const
{
auto role = this->role(description);
if (role == Role::Accepted)
return m_connect_side_fd != nullptr;
if (role == Role::Connected)
return m_accept_side_fd_open;
return false;
}
bool LocalSocket::can_write(OpenFileDescription const& description, u64) const
{
auto role = this->role(description);
if (role == Role::Accepted)
return !has_attached_peer(description) || m_for_client->space_for_writing();
if (role == Role::Connected)
return !has_attached_peer(description) || m_for_server->space_for_writing();
return false;
}
ErrorOr<size_t> LocalSocket::sendto(OpenFileDescription& description, UserOrKernelBuffer const& data, size_t data_size, int, Userspace<sockaddr const*>, socklen_t)
{
if (!has_attached_peer(description))
return set_so_error(EPIPE);
auto* socket_buffer = send_buffer_for(description);
if (!socket_buffer)
return set_so_error(EINVAL);
auto nwritten_or_error = socket_buffer->write(data, data_size);
if (!nwritten_or_error.is_error() && nwritten_or_error.value() > 0)
Thread::current()->did_unix_socket_write(nwritten_or_error.value());
return nwritten_or_error;
}
DoubleBuffer* LocalSocket::receive_buffer_for(OpenFileDescription& description)
{
auto role = this->role(description);
if (role == Role::Accepted)
return m_for_server.ptr();
if (role == Role::Connected)
return m_for_client.ptr();
return nullptr;
}
DoubleBuffer* LocalSocket::send_buffer_for(OpenFileDescription& description)
{
auto role = this->role(description);
if (role == Role::Connected)
return m_for_server.ptr();
if (role == Role::Accepted)
return m_for_client.ptr();
return nullptr;
}
ErrorOr<size_t> LocalSocket::recvfrom(OpenFileDescription& description, UserOrKernelBuffer& buffer, size_t buffer_size, int, Userspace<sockaddr*>, Userspace<socklen_t*>, Time&, bool blocking)
{
auto* socket_buffer = receive_buffer_for(description);
if (!socket_buffer)
return set_so_error(EINVAL);
if (!blocking) {
if (socket_buffer->is_empty()) {
if (!has_attached_peer(description))
return 0;
return set_so_error(EAGAIN);
}
} else if (!can_read(description, 0)) {
auto unblock_flags = Thread::OpenFileDescriptionBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::ReadBlocker>({}, description, unblock_flags).was_interrupted())
return set_so_error(EINTR);
}
if (!has_attached_peer(description) && socket_buffer->is_empty())
return 0;
VERIFY(!socket_buffer->is_empty());
auto nread_or_error = socket_buffer->read(buffer, buffer_size);
if (!nread_or_error.is_error() && nread_or_error.value() > 0)
Thread::current()->did_unix_socket_read(nread_or_error.value());
return nread_or_error;
}
StringView LocalSocket::socket_path() const
{
if (!m_path)
return {};
return m_path->view();
}
ErrorOr<NonnullOwnPtr<KString>> LocalSocket::pseudo_path(OpenFileDescription const& description) const
{
StringBuilder builder;
TRY(builder.try_append("socket:"sv));
TRY(builder.try_append(socket_path()));
switch (role(description)) {
case Role::Listener:
TRY(builder.try_append(" (listening)"sv));
break;
case Role::Accepted:
TRY(builder.try_appendff(" (accepted from pid {})", origin_pid()));
break;
case Role::Connected:
TRY(builder.try_appendff(" (connected to pid {})", acceptor_pid()));
break;
case Role::Connecting:
TRY(builder.try_append(" (connecting)"sv));
break;
default:
break;
}
return KString::try_create(builder.string_view());
}
ErrorOr<void> LocalSocket::getsockopt(OpenFileDescription& description, int level, int option, Userspace<void*> value, Userspace<socklen_t*> value_size)
{
if (level != SOL_SOCKET)
return Socket::getsockopt(description, level, option, value, value_size);
MutexLocker locker(mutex());
socklen_t size;
TRY(copy_from_user(&size, value_size.unsafe_userspace_ptr()));
switch (option) {
case SO_SNDBUF:
return ENOTSUP;
case SO_RCVBUF:
return ENOTSUP;
case SO_PEERCRED: {
if (size < sizeof(ucred))
return EINVAL;
switch (role(description)) {
case Role::Accepted:
TRY(copy_to_user(static_ptr_cast<ucred*>(value), &m_origin));
size = sizeof(ucred);
TRY(copy_to_user(value_size, &size));
return {};
case Role::Connected:
TRY(copy_to_user(static_ptr_cast<ucred*>(value), &m_acceptor));
size = sizeof(ucred);
TRY(copy_to_user(value_size, &size));
return {};
case Role::Connecting:
return ENOTCONN;
default:
return EINVAL;
}
VERIFY_NOT_REACHED();
}
default:
return Socket::getsockopt(description, level, option, value, value_size);
}
}
ErrorOr<void> LocalSocket::ioctl(OpenFileDescription& description, unsigned request, Userspace<void*> arg)
{
switch (request) {
case FIONREAD: {
int readable = receive_buffer_for(description)->immediately_readable();
return copy_to_user(static_ptr_cast<int*>(arg), &readable);
}
}
return EINVAL;
}
ErrorOr<void> LocalSocket::chmod(Credentials const& credentials, OpenFileDescription& description, mode_t mode)
{
if (m_inode) {
if (auto custody = description.custody())
return VirtualFileSystem::the().chmod(credentials, *custody, mode);
VERIFY_NOT_REACHED();
}
m_prebind_mode = mode & 0777;
return {};
}
ErrorOr<void> LocalSocket::chown(Credentials const& credentials, OpenFileDescription& description, UserID uid, GroupID gid)
{
if (m_inode) {
if (auto custody = description.custody())
return VirtualFileSystem::the().chown(credentials, *custody, uid, gid);
VERIFY_NOT_REACHED();
}
if (!credentials.is_superuser() && (credentials.euid() != uid || !credentials.in_group(gid)))
return set_so_error(EPERM);
m_prebind_uid = uid;
m_prebind_gid = gid;
return {};
}
Vector<NonnullRefPtr<OpenFileDescription>>& LocalSocket::recvfd_queue_for(OpenFileDescription const& description)
{
VERIFY(mutex().is_exclusively_locked_by_current_thread());
auto role = this->role(description);
if (role == Role::Connected)
return m_fds_for_client;
if (role == Role::Accepted)
return m_fds_for_server;
VERIFY_NOT_REACHED();
}
Vector<NonnullRefPtr<OpenFileDescription>>& LocalSocket::sendfd_queue_for(OpenFileDescription const& description)
{
VERIFY(mutex().is_exclusively_locked_by_current_thread());
auto role = this->role(description);
if (role == Role::Connected)
return m_fds_for_server;
if (role == Role::Accepted)
return m_fds_for_client;
VERIFY_NOT_REACHED();
}
ErrorOr<void> LocalSocket::sendfd(OpenFileDescription const& socket_description, NonnullRefPtr<OpenFileDescription> passing_description)
{
MutexLocker locker(mutex());
auto role = this->role(socket_description);
if (role != Role::Connected && role != Role::Accepted)
return set_so_error(EINVAL);
auto& queue = sendfd_queue_for(socket_description);
// FIXME: Figure out how we should limit this properly.
if (queue.size() > 128)
return set_so_error(EBUSY);
SOCKET_TRY(queue.try_append(move(passing_description)));
return {};
}
ErrorOr<NonnullRefPtr<OpenFileDescription>> LocalSocket::recvfd(OpenFileDescription const& socket_description)
{
MutexLocker locker(mutex());
auto role = this->role(socket_description);
if (role != Role::Connected && role != Role::Accepted)
return set_so_error(EINVAL);
auto& queue = recvfd_queue_for(socket_description);
if (queue.is_empty()) {
// FIXME: Figure out the perfect error code for this.
return set_so_error(EAGAIN);
}
return queue.take_first();
}
ErrorOr<Vector<NonnullRefPtr<OpenFileDescription>>> LocalSocket::recvfds(OpenFileDescription const& socket_description, int n)
{
MutexLocker locker(mutex());
Vector<NonnullRefPtr<OpenFileDescription>> fds;
auto role = this->role(socket_description);
if (role != Role::Connected && role != Role::Accepted)
return set_so_error(EINVAL);
auto& queue = recvfd_queue_for(socket_description);
for (int i = 0; i < n; ++i) {
if (queue.is_empty())
break;
fds.append(queue.take_first());
}
return fds;
}
ErrorOr<void> LocalSocket::try_set_path(StringView path)
{
m_path = TRY(KString::try_create(path));
return {};
}
}