ladybird/Kernel/Syscalls/socket.cpp
Andreas Kling 36d829b97c Kernel: Mark sys$listen() as not needing the big lock
This syscall already performs the necessary locking and so doesn't
need to rely on the process big lock.
2022-04-03 22:22:22 +02:00

397 lines
14 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/OpenFileDescription.h>
#include <Kernel/Net/LocalSocket.h>
#include <Kernel/Process.h>
#include <Kernel/UnixTypes.h>
namespace Kernel {
#define REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(domain) \
do { \
if (domain == AF_INET) \
TRY(require_promise(Pledge::inet)); \
else if (domain == AF_LOCAL) \
TRY(require_promise(Pledge::unix)); \
} while (0)
static void setup_socket_fd(Process::OpenFileDescriptions& fds, int fd, NonnullRefPtr<OpenFileDescription> description, int type)
{
description->set_readable(true);
description->set_writable(true);
unsigned flags = 0;
if (type & SOCK_CLOEXEC)
flags |= FD_CLOEXEC;
if (type & SOCK_NONBLOCK)
description->set_blocking(false);
fds[fd].set(*description, flags);
}
ErrorOr<FlatPtr> Process::sys$socket(int domain, int type, int protocol)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(domain);
if ((type & SOCK_TYPE_MASK) == SOCK_RAW && !is_superuser())
return EACCES;
return m_fds.with_exclusive([&](auto& fds) -> ErrorOr<FlatPtr> {
auto fd_allocation = TRY(fds.allocate());
auto socket = TRY(Socket::create(domain, type, protocol));
auto description = TRY(OpenFileDescription::try_create(socket));
setup_socket_fd(fds, fd_allocation.fd, move(description), type);
return fd_allocation.fd;
});
}
ErrorOr<FlatPtr> Process::sys$bind(int sockfd, Userspace<sockaddr const*> address, socklen_t address_length)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto description = TRY(open_file_description(sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
TRY(socket.bind(address, address_length));
return 0;
}
ErrorOr<FlatPtr> Process::sys$listen(int sockfd, int backlog)
{
VERIFY_NO_PROCESS_BIG_LOCK(this)
if (backlog < 0)
return EINVAL;
auto description = TRY(open_file_description(sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
if (socket.is_connected())
return EINVAL;
TRY(socket.listen(backlog));
return 0;
}
ErrorOr<FlatPtr> Process::sys$accept4(Userspace<Syscall::SC_accept4_params const*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
TRY(require_promise(Pledge::accept));
auto params = TRY(copy_typed_from_user(user_params));
int accepting_socket_fd = params.sockfd;
Userspace<sockaddr*> user_address((FlatPtr)params.addr);
Userspace<socklen_t*> user_address_size((FlatPtr)params.addrlen);
int flags = params.flags;
socklen_t address_size = 0;
if (user_address) {
TRY(copy_from_user(&address_size, static_ptr_cast<socklen_t const*>(user_address_size)));
}
ScopedDescriptionAllocation fd_allocation;
RefPtr<OpenFileDescription> accepting_socket_description;
TRY(m_fds.with_exclusive([&](auto& fds) -> ErrorOr<void> {
fd_allocation = TRY(fds.allocate());
accepting_socket_description = TRY(fds.open_file_description(accepting_socket_fd));
return {};
}));
if (!accepting_socket_description->is_socket())
return ENOTSOCK;
auto& socket = *accepting_socket_description->socket();
if (!socket.can_accept()) {
if (accepting_socket_description->is_blocking()) {
auto unblock_flags = Thread::FileBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::AcceptBlocker>({}, *accepting_socket_description, unblock_flags).was_interrupted())
return EINTR;
} else {
return EAGAIN;
}
}
auto accepted_socket = socket.accept();
VERIFY(accepted_socket);
if (user_address) {
sockaddr_un address_buffer {};
address_size = min(sizeof(sockaddr_un), static_cast<size_t>(address_size));
accepted_socket->get_peer_address((sockaddr*)&address_buffer, &address_size);
TRY(copy_to_user(user_address, &address_buffer, address_size));
TRY(copy_to_user(user_address_size, &address_size));
}
auto accepted_socket_description = TRY(OpenFileDescription::try_create(*accepted_socket));
accepted_socket_description->set_readable(true);
accepted_socket_description->set_writable(true);
if (flags & SOCK_NONBLOCK)
accepted_socket_description->set_blocking(false);
int fd_flags = 0;
if (flags & SOCK_CLOEXEC)
fd_flags |= FD_CLOEXEC;
TRY(m_fds.with_exclusive([&](auto& fds) -> ErrorOr<void> {
fds[fd_allocation.fd].set(move(accepted_socket_description), fd_flags);
return {};
}));
// NOTE: Moving this state to Completed is what causes connect() to unblock on the client side.
accepted_socket->set_setup_state(Socket::SetupState::Completed);
return fd_allocation.fd;
}
ErrorOr<FlatPtr> Process::sys$connect(int sockfd, Userspace<sockaddr const*> user_address, socklen_t user_address_size)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto description = TRY(open_file_description(sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
TRY(socket.connect(*description, user_address, user_address_size, description->is_blocking() ? ShouldBlock::Yes : ShouldBlock::No));
return 0;
}
ErrorOr<FlatPtr> Process::sys$shutdown(int sockfd, int how)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
TRY(require_promise(Pledge::stdio));
if (how & ~SHUT_RDWR)
return EINVAL;
auto description = TRY(open_file_description(sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
TRY(socket.shutdown(how));
return 0;
}
ErrorOr<FlatPtr> Process::sys$sendmsg(int sockfd, Userspace<const struct msghdr*> user_msg, int flags)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
TRY(require_promise(Pledge::stdio));
auto msg = TRY(copy_typed_from_user(user_msg));
if (msg.msg_iovlen != 1)
return ENOTSUP; // FIXME: Support this :)
Vector<iovec, 1> iovs;
TRY(iovs.try_resize(msg.msg_iovlen));
TRY(copy_n_from_user(iovs.data(), msg.msg_iov, msg.msg_iovlen));
if (iovs[0].iov_len > NumericLimits<ssize_t>::max())
return EINVAL;
Userspace<sockaddr const*> user_addr((FlatPtr)msg.msg_name);
socklen_t addr_length = msg.msg_namelen;
auto description = TRY(open_file_description(sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
if (socket.is_shut_down_for_writing())
return EPIPE;
auto data_buffer = TRY(UserOrKernelBuffer::for_user_buffer((u8*)iovs[0].iov_base, iovs[0].iov_len));
while (true) {
while (!description->can_write()) {
if (!description->is_blocking()) {
return EAGAIN;
}
auto unblock_flags = Thread::FileBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::WriteBlocker>({}, *description, unblock_flags).was_interrupted()) {
return EINTR;
}
// TODO: handle exceptions in unblock_flags
}
auto bytes_sent = TRY(socket.sendto(*description, data_buffer, iovs[0].iov_len, flags, user_addr, addr_length));
if (bytes_sent > 0)
return bytes_sent;
}
}
ErrorOr<FlatPtr> Process::sys$recvmsg(int sockfd, Userspace<struct msghdr*> user_msg, int flags)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
TRY(require_promise(Pledge::stdio));
struct msghdr msg;
TRY(copy_from_user(&msg, user_msg));
if (msg.msg_iovlen != 1)
return ENOTSUP; // FIXME: Support this :)
Vector<iovec, 1> iovs;
TRY(iovs.try_resize(msg.msg_iovlen));
TRY(copy_n_from_user(iovs.data(), msg.msg_iov, msg.msg_iovlen));
Userspace<sockaddr*> user_addr((FlatPtr)msg.msg_name);
Userspace<socklen_t*> user_addr_length(msg.msg_name ? (FlatPtr)&user_msg.unsafe_userspace_ptr()->msg_namelen : 0);
auto description = TRY(open_file_description(sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
if (socket.is_shut_down_for_reading())
return 0;
bool original_blocking = description->is_blocking();
if (flags & MSG_DONTWAIT)
description->set_blocking(false);
auto data_buffer = TRY(UserOrKernelBuffer::for_user_buffer((u8*)iovs[0].iov_base, iovs[0].iov_len));
Time timestamp {};
auto result = socket.recvfrom(*description, data_buffer, iovs[0].iov_len, flags, user_addr, user_addr_length, timestamp);
if (flags & MSG_DONTWAIT)
description->set_blocking(original_blocking);
if (result.is_error())
return result.release_error();
int msg_flags = 0;
if (result.value() > iovs[0].iov_len) {
VERIFY(socket.type() != SOCK_STREAM);
msg_flags |= MSG_TRUNC;
}
if (socket.wants_timestamp()) {
struct {
cmsghdr cmsg;
timeval timestamp;
} cmsg_timestamp;
socklen_t control_length = sizeof(cmsg_timestamp);
if (msg.msg_controllen < control_length) {
msg_flags |= MSG_CTRUNC;
} else {
cmsg_timestamp = { { control_length, SOL_SOCKET, SCM_TIMESTAMP }, timestamp.to_timeval() };
TRY(copy_to_user(msg.msg_control, &cmsg_timestamp, control_length));
}
TRY(copy_to_user(&user_msg.unsafe_userspace_ptr()->msg_controllen, &control_length));
}
TRY(copy_to_user(&user_msg.unsafe_userspace_ptr()->msg_flags, &msg_flags));
return result.value();
}
template<bool sockname, typename Params>
ErrorOr<void> Process::get_sock_or_peer_name(Params const& params)
{
socklen_t addrlen_value;
TRY(copy_from_user(&addrlen_value, params.addrlen, sizeof(socklen_t)));
if (addrlen_value <= 0)
return EINVAL;
auto description = TRY(open_file_description(params.sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
sockaddr_un address_buffer {};
addrlen_value = min(sizeof(sockaddr_un), static_cast<size_t>(addrlen_value));
if constexpr (sockname)
socket.get_local_address((sockaddr*)&address_buffer, &addrlen_value);
else
socket.get_peer_address((sockaddr*)&address_buffer, &addrlen_value);
TRY(copy_to_user(params.addr, &address_buffer, addrlen_value));
return copy_to_user(params.addrlen, &addrlen_value);
}
ErrorOr<FlatPtr> Process::sys$getsockname(Userspace<Syscall::SC_getsockname_params const*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto params = TRY(copy_typed_from_user(user_params));
TRY(get_sock_or_peer_name<true>(params));
return 0;
}
ErrorOr<FlatPtr> Process::sys$getpeername(Userspace<Syscall::SC_getpeername_params const*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto params = TRY(copy_typed_from_user(user_params));
TRY(get_sock_or_peer_name<false>(params));
return 0;
}
ErrorOr<FlatPtr> Process::sys$getsockopt(Userspace<Syscall::SC_getsockopt_params const*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto params = TRY(copy_typed_from_user(user_params));
int sockfd = params.sockfd;
int level = params.level;
int option = params.option;
Userspace<void*> user_value((FlatPtr)params.value);
Userspace<socklen_t*> user_value_size((FlatPtr)params.value_size);
socklen_t value_size;
TRY(copy_from_user(&value_size, params.value_size, sizeof(socklen_t)));
auto description = TRY(open_file_description(sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
TRY(socket.getsockopt(*description, level, option, user_value, user_value_size));
return 0;
}
ErrorOr<FlatPtr> Process::sys$setsockopt(Userspace<Syscall::SC_setsockopt_params const*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto params = TRY(copy_typed_from_user(user_params));
Userspace<void const*> user_value((FlatPtr)params.value);
auto description = TRY(open_file_description(params.sockfd));
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
TRY(socket.setsockopt(params.level, params.option, user_value, params.value_size));
return 0;
}
ErrorOr<FlatPtr> Process::sys$socketpair(Userspace<Syscall::SC_socketpair_params const*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto params = TRY(copy_typed_from_user(user_params));
if (params.domain != AF_LOCAL)
return EINVAL;
if (params.protocol != 0 && params.protocol != PF_LOCAL)
return EINVAL;
auto pair = TRY(LocalSocket::try_create_connected_pair(params.type & SOCK_TYPE_MASK));
return m_fds.with_exclusive([&](auto& fds) -> ErrorOr<FlatPtr> {
auto fd_allocation0 = TRY(fds.allocate());
auto fd_allocation1 = TRY(fds.allocate());
int allocated_fds[2];
allocated_fds[0] = fd_allocation0.fd;
allocated_fds[1] = fd_allocation1.fd;
setup_socket_fd(fds, allocated_fds[0], pair.description0, params.type);
setup_socket_fd(fds, allocated_fds[1], pair.description1, params.type);
if (copy_to_user(params.sv, allocated_fds, sizeof(allocated_fds)).is_error()) {
// Avoid leaking both file descriptors on error.
fds[allocated_fds[0]] = {};
fds[allocated_fds[1]] = {};
return EFAULT;
}
return 0;
});
}
}