ladybird/Kernel/Net/LocalSocket.cpp
Andreas Kling 79fa9765ca Kernel: Replace KResult and KResultOr<T> with Error and ErrorOr<T>
We now use AK::Error and AK::ErrorOr<T> in both kernel and userspace!
This was a slightly tedious refactoring that took a long time, so it's
not unlikely that some bugs crept in.

Nevertheless, it does pass basic functionality testing, and it's just
real nice to finally see the same pattern in all contexts. :^)
2021-11-08 01:10:53 +01:00

516 lines
16 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/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>
#include <LibC/errno_numbers.h>
#include <LibC/sys/ioctl_numbers.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(const LocalSocket&)> callback)
{
all_sockets().for_each_shared([&](const auto& socket) {
callback(socket);
});
}
ErrorOr<NonnullRefPtr<LocalSocket>> LocalSocket::try_create(int type)
{
auto client_buffer = TRY(DoubleBuffer::try_create());
auto server_buffer = TRY(DoubleBuffer::try_create());
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();
m_prebind_uid = current_process.euid();
m_prebind_gid = current_process.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)
{
if (!m_path || m_path->is_empty()) {
size_t bytes_to_copy = min(static_cast<size_t>(*address_size), sizeof(sockaddr_un));
memset(address, 0, bytes_to_copy);
} else {
size_t bytes_to_copy = min(m_path->length(), min(static_cast<size_t>(*address_size), sizeof(sockaddr_un)));
memcpy(address, m_path->characters(), bytes_to_copy);
}
*address_size = sizeof(sockaddr_un);
}
void LocalSocket::get_peer_address(sockaddr* address, socklen_t* address_size)
{
get_local_address(address, address_size);
}
ErrorOr<void> LocalSocket::bind(Userspace<const sockaddr*> 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, sizeof(sockaddr_un)));
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(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(OpenFileDescription& description, Userspace<const sockaddr*> address, socklen_t address_size, ShouldBlock)
{
VERIFY(!m_bound);
if (address_size != sizeof(sockaddr_un))
return set_so_error(EINVAL);
u16 sa_family_copy;
auto* user_address = reinterpret_cast<const sockaddr*>(address.unsafe_userspace_ptr());
SOCKET_TRY(copy_from_user(&sa_family_copy, &user_address->sa_family, sizeof(u16)));
if (sa_family_copy != AF_LOCAL)
return set_so_error(EINVAL);
if (is_connected())
return set_so_error(EISCONN);
OwnPtr<KString> maybe_path;
{
auto const& local_address = *reinterpret_cast<sockaddr_un const*>(user_address);
char safe_address[sizeof(local_address.sun_path) + 1] = { 0 };
SOCKET_TRY(copy_from_user(&safe_address[0], &local_address.sun_path[0], sizeof(safe_address) - 1));
safe_address[sizeof(safe_address) - 1] = '\0';
maybe_path = SOCKET_TRY(KString::try_create(safe_address));
}
auto path = maybe_path.release_nonnull();
dbgln_if(LOCAL_SOCKET_DEBUG, "LocalSocket({}) connect({})", this, *path);
auto file = SOCKET_TRY(VirtualFileSystem::the().open(path->view(), O_RDWR, 0, Process::current().current_directory()));
auto inode = file->inode();
m_inode = inode;
VERIFY(inode);
if (!inode->socket())
return set_so_error(ECONNREFUSED);
m_path = move(path);
VERIFY(m_connect_side_fd == &description);
set_connect_side_role(Role::Connecting);
auto peer = file->inode()->socket();
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) {
auto inode = m_inode.strong_ref();
if (inode)
inode->unbind_socket();
}
}
evaluate_block_conditions();
}
bool LocalSocket::can_read(const OpenFileDescription& description, size_t) 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(const OpenFileDescription& 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(const OpenFileDescription& description, size_t) 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, const UserOrKernelBuffer& data, size_t data_size, int, Userspace<const sockaddr*>, 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&)
{
auto* socket_buffer = receive_buffer_for(description);
if (!socket_buffer)
return set_so_error(EINVAL);
if (!description.is_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(const OpenFileDescription& description) const
{
StringBuilder builder;
builder.append("socket:");
builder.append(socket_path());
switch (role(description)) {
case Role::Listener:
builder.append(" (listening)");
break;
case Role::Accepted:
builder.appendff(" (accepted from pid {})", origin_pid());
break;
case Role::Connected:
builder.appendff(" (connected to pid {})", acceptor_pid());
break;
case Role::Connecting:
builder.append(" (connecting)");
break;
default:
break;
}
return KString::try_create(builder.to_string());
}
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);
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(Userspace<int*>(arg), &readable);
}
}
return ENOTTY;
}
ErrorOr<void> LocalSocket::chmod(OpenFileDescription&, mode_t mode)
{
auto inode = m_inode.strong_ref();
if (inode)
return inode->chmod(mode);
m_prebind_mode = mode & 0777;
return {};
}
ErrorOr<void> LocalSocket::chown(OpenFileDescription&, UserID uid, GroupID gid)
{
auto inode = m_inode.strong_ref();
if (inode)
return inode->chown(uid, gid);
auto& current_process = Process::current();
if (!current_process.is_superuser() && (current_process.euid() != uid || !current_process.in_group(gid)))
return set_so_error(EPERM);
m_prebind_uid = uid;
m_prebind_gid = gid;
return {};
}
NonnullRefPtrVector<OpenFileDescription>& LocalSocket::recvfd_queue_for(const OpenFileDescription& description)
{
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();
}
NonnullRefPtrVector<OpenFileDescription>& LocalSocket::sendfd_queue_for(const OpenFileDescription& description)
{
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);
if (!queue.try_append(move(passing_description)))
return set_so_error(ENOMEM);
return {};
}
ErrorOr<NonnullRefPtr<OpenFileDescription>> LocalSocket::recvfd(const OpenFileDescription& 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<void> LocalSocket::try_set_path(StringView path)
{
m_path = TRY(KString::try_create(path));
return {};
}
}