ladybird/Kernel/Syscalls/socket.cpp
Daniel Bertalan b9f30c6f2a Everywhere: Fix some alignment issues
When creating uninitialized storage for variables, we need to make sure
that the alignment is correct. Fixes a KUBSAN failure when running
kernels compiled with Clang.

In `Syscalls/socket.cpp`, we can simply use local variables, as
`sockaddr_un` is a POD type.

Along with moving the `alignas` specifier to the correct member,
`AK::Optional`'s internal buffer has been made non-zeroed by default.
GCC emitted bogus uninitialized memory access warnings, so we now use
`__builtin_launder` to tell the compiler that we know what we are doing.
This might disable some optimizations, but judging by how GCC failed to
notice that the memory's initialization is dependent on `m_has_value`,
I'm not sure that's a bad thing.
2021-07-03 01:56:31 +04:30

423 lines
14 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/Net/IPv4Socket.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) \
REQUIRE_PROMISE(inet); \
else if (domain == AF_LOCAL) \
REQUIRE_PROMISE(unix); \
} while (0)
void Process::setup_socket_fd(int fd, NonnullRefPtr<FileDescription> 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);
m_fds[fd].set(*description, flags);
}
KResultOr<FlatPtr> Process::sys$socket(int domain, int type, int protocol)
{
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(domain);
if ((type & SOCK_TYPE_MASK) == SOCK_RAW && !is_superuser())
return EACCES;
int fd = m_fds.allocate();
if (fd < 0)
return fd;
auto result = Socket::create(domain, type, protocol);
if (result.is_error())
return result.error();
auto description_result = FileDescription::create(*result.value());
if (description_result.is_error())
return description_result.error();
setup_socket_fd(fd, description_result.value(), type);
return fd;
}
KResultOr<FlatPtr> Process::sys$bind(int sockfd, Userspace<const sockaddr*> address, socklen_t address_length)
{
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
return socket.bind(address, address_length);
}
KResultOr<FlatPtr> Process::sys$listen(int sockfd, int backlog)
{
if (backlog < 0)
return EINVAL;
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
if (socket.is_connected())
return EINVAL;
return socket.listen(backlog);
}
KResultOr<FlatPtr> Process::sys$accept4(Userspace<const Syscall::SC_accept4_params*> user_params)
{
REQUIRE_PROMISE(accept);
Syscall::SC_accept4_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
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 && !copy_from_user(&address_size, static_ptr_cast<const socklen_t*>(user_address_size)))
return EFAULT;
int accepted_socket_fd = m_fds.allocate();
if (accepted_socket_fd < 0)
return accepted_socket_fd;
auto accepting_socket_description = fds().file_description(accepting_socket_fd);
if (!accepting_socket_description)
return EBADF;
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);
if (!copy_to_user(user_address, &address_buffer, address_size))
return EFAULT;
if (!copy_to_user(user_address_size, &address_size))
return EFAULT;
}
auto accepted_socket_description_result = FileDescription::create(*accepted_socket);
if (accepted_socket_description_result.is_error())
return accepted_socket_description_result.error();
accepted_socket_description_result.value()->set_readable(true);
accepted_socket_description_result.value()->set_writable(true);
if (flags & SOCK_NONBLOCK)
accepted_socket_description_result.value()->set_blocking(false);
int fd_flags = 0;
if (flags & SOCK_CLOEXEC)
fd_flags |= FD_CLOEXEC;
m_fds[accepted_socket_fd].set(accepted_socket_description_result.release_value(), fd_flags);
// 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 accepted_socket_fd;
}
KResultOr<FlatPtr> Process::sys$connect(int sockfd, Userspace<const sockaddr*> user_address, socklen_t user_address_size)
{
int fd = m_fds.allocate();
if (fd < 0)
return fd;
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
return socket.connect(*description, user_address, user_address_size, description->is_blocking() ? ShouldBlock::Yes : ShouldBlock::No);
}
KResultOr<FlatPtr> Process::sys$shutdown(int sockfd, int how)
{
REQUIRE_PROMISE(stdio);
if (how & ~SHUT_RDWR)
return EINVAL;
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
return socket.shutdown(how);
}
KResultOr<FlatPtr> Process::sys$sendmsg(int sockfd, Userspace<const struct msghdr*> user_msg, int flags)
{
REQUIRE_PROMISE(stdio);
struct msghdr msg;
if (!copy_from_user(&msg, user_msg))
return EFAULT;
if (msg.msg_iovlen != 1)
return ENOTSUP; // FIXME: Support this :)
Vector<iovec, 1> iovs;
if (!iovs.try_resize(msg.msg_iovlen))
return ENOMEM;
if (!copy_n_from_user(iovs.data(), msg.msg_iov, msg.msg_iovlen))
return EFAULT;
if (iovs[0].iov_len > NumericLimits<ssize_t>::max())
return EINVAL;
Userspace<const sockaddr*> user_addr((FlatPtr)msg.msg_name);
socklen_t addr_length = msg.msg_namelen;
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
if (socket.is_shut_down_for_writing())
return EPIPE;
auto data_buffer = UserOrKernelBuffer::for_user_buffer((u8*)iovs[0].iov_base, iovs[0].iov_len);
if (!data_buffer.has_value())
return EFAULT;
auto result = socket.sendto(*description, data_buffer.value(), iovs[0].iov_len, flags, user_addr, addr_length);
if (result.is_error())
return result.error();
else
return result.release_value();
}
KResultOr<FlatPtr> Process::sys$recvmsg(int sockfd, Userspace<struct msghdr*> user_msg, int flags)
{
REQUIRE_PROMISE(stdio);
struct msghdr msg;
if (!copy_from_user(&msg, user_msg))
return EFAULT;
if (msg.msg_iovlen != 1)
return ENOTSUP; // FIXME: Support this :)
Vector<iovec, 1> iovs;
if (!iovs.try_resize(msg.msg_iovlen))
return ENOMEM;
if (!copy_n_from_user(iovs.data(), msg.msg_iov, msg.msg_iovlen))
return EFAULT;
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 = fds().file_description(sockfd);
if (!description)
return EBADF;
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 = UserOrKernelBuffer::for_user_buffer((u8*)iovs[0].iov_base, iovs[0].iov_len);
if (!data_buffer.has_value())
return EFAULT;
Time timestamp {};
auto result = socket.recvfrom(*description, data_buffer.value(), 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.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() };
if (!copy_to_user(msg.msg_control, &cmsg_timestamp, control_length))
return EFAULT;
}
if (!copy_to_user(&user_msg.unsafe_userspace_ptr()->msg_controllen, &control_length))
return EFAULT;
}
if (!copy_to_user(&user_msg.unsafe_userspace_ptr()->msg_flags, &msg_flags))
return EFAULT;
return result.value();
}
template<bool sockname, typename Params>
int Process::get_sock_or_peer_name(const Params& params)
{
socklen_t addrlen_value;
if (!copy_from_user(&addrlen_value, params.addrlen, sizeof(socklen_t)))
return EFAULT;
if (addrlen_value <= 0)
return EINVAL;
auto description = fds().file_description(params.sockfd);
if (!description)
return EBADF;
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);
if (!copy_to_user(params.addr, &address_buffer, addrlen_value))
return EFAULT;
if (!copy_to_user(params.addrlen, &addrlen_value))
return EFAULT;
return 0;
}
KResultOr<FlatPtr> Process::sys$getsockname(Userspace<const Syscall::SC_getsockname_params*> user_params)
{
Syscall::SC_getsockname_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
return get_sock_or_peer_name<true>(params);
}
KResultOr<FlatPtr> Process::sys$getpeername(Userspace<const Syscall::SC_getpeername_params*> user_params)
{
Syscall::SC_getpeername_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
return get_sock_or_peer_name<false>(params);
}
KResultOr<FlatPtr> Process::sys$getsockopt(Userspace<const Syscall::SC_getsockopt_params*> user_params)
{
Syscall::SC_getsockopt_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
int sockfd = params.sockfd;
int level = params.level;
int option = params.option;
Userspace<void*> user_value((FlatPtr)params.value);
Userspace<socklen_t*> user_value_size((FlatPtr)params.value_size);
socklen_t value_size;
if (!copy_from_user(&value_size, params.value_size, sizeof(socklen_t)))
return EFAULT;
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
return socket.getsockopt(*description, level, option, user_value, user_value_size);
}
KResultOr<FlatPtr> Process::sys$setsockopt(Userspace<const Syscall::SC_setsockopt_params*> user_params)
{
Syscall::SC_setsockopt_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
Userspace<const void*> user_value((FlatPtr)params.value);
auto description = fds().file_description(params.sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
return socket.setsockopt(params.level, params.option, user_value, params.value_size);
}
KResultOr<FlatPtr> Process::sys$socketpair(Userspace<const Syscall::SC_socketpair_params*> user_params)
{
Syscall::SC_socketpair_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
if (params.domain != AF_LOCAL)
return EINVAL;
if (params.protocol != 0 && params.protocol != PF_LOCAL)
return EINVAL;
auto result = LocalSocket::create_connected_pair(params.type & SOCK_TYPE_MASK);
if (result.is_error())
return result.error();
auto pair = result.value();
int fds[2];
fds[0] = m_fds.allocate();
if (fds[0] < 0)
return ENFILE;
setup_socket_fd(fds[0], pair.description1, params.type);
fds[1] = m_fds.allocate();
if (fds[1] < 0) {
// FIXME: This leaks fds[0]
return ENFILE;
}
setup_socket_fd(fds[1], pair.description2, params.type);
if (!copy_to_user(params.sv, fds, sizeof(fds))) {
// FIXME: This leaks both file descriptors
return EFAULT;
}
return KSuccess;
}
}