ladybird/Kernel/Syscalls/socket.cpp
Brian Gianforcaro 4b2651ddab Kernel: Track allocated FileDescriptionAndFlag elements in each Process
The way the Process::FileDescriptions::allocate() API works today means
that two callers who allocate back to back without associating a
FileDescription with the allocated FD, will receive the same FD and thus
one will stomp over the other.

Naively tracking which FileDescriptions are allocated and moving onto
the next would introduce other bugs however, as now if you "allocate"
a fd and then return early further down the control flow of the syscall
you would leak that fd.

This change modifies this behavior by tracking which descriptions are
allocated and then having an RAII type to "deallocate" the fd if the
association is not setup the end of it's scope.
2021-07-28 19:07:00 +02:00

434 lines
15 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$socket(int domain, int type, int protocol)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(domain);
if ((type & SOCK_TYPE_MASK) == SOCK_RAW && !is_superuser())
return EACCES;
auto fd_or_error = m_fds.allocate();
if (fd_or_error.is_error())
return fd_or_error.error();
auto socket_fd = fd_or_error.release_value();
auto result = Socket::create(domain, type, protocol);
if (result.is_error())
return result.error();
auto description_result = FileDescription::create(*result.value());
if (description_result.is_error())
return description_result.error();
setup_socket_fd(socket_fd.fd, description_result.value(), type);
return socket_fd.fd;
}
KResultOr<FlatPtr> Process::sys$bind(int sockfd, Userspace<const sockaddr*> address, socklen_t address_length)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
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$listen(int sockfd, int backlog)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
if (backlog < 0)
return EINVAL;
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
if (socket.is_connected())
return EINVAL;
return socket.listen(backlog);
}
KResultOr<FlatPtr> Process::sys$accept4(Userspace<const Syscall::SC_accept4_params*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
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;
auto accepted_socket_fd_or_error = m_fds.allocate();
if (accepted_socket_fd_or_error.is_error())
return accepted_socket_fd_or_error.error();
auto accepted_socket_fd = accepted_socket_fd_or_error.release_value();
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.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.fd;
}
KResultOr<FlatPtr> Process::sys$connect(int sockfd, Userspace<const sockaddr*> user_address, socklen_t user_address_size)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
return socket.connect(*description, user_address, user_address_size, description->is_blocking() ? ShouldBlock::Yes : ShouldBlock::No);
}
KResultOr<FlatPtr> Process::sys$shutdown(int sockfd, int how)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
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$sendmsg(int sockfd, Userspace<const struct msghdr*> user_msg, int flags)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
REQUIRE_PROMISE(stdio);
struct msghdr msg;
if (!copy_from_user(&msg, user_msg))
return EFAULT;
if (msg.msg_iovlen != 1)
return ENOTSUP; // FIXME: Support this :)
Vector<iovec, 1> iovs;
if (!iovs.try_resize(msg.msg_iovlen))
return ENOMEM;
if (!copy_n_from_user(iovs.data(), msg.msg_iov, msg.msg_iovlen))
return EFAULT;
if (iovs[0].iov_len > NumericLimits<ssize_t>::max())
return EINVAL;
Userspace<const sockaddr*> user_addr((FlatPtr)msg.msg_name);
socklen_t addr_length = msg.msg_namelen;
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
if (socket.is_shut_down_for_writing())
return EPIPE;
auto data_buffer = UserOrKernelBuffer::for_user_buffer((u8*)iovs[0].iov_base, iovs[0].iov_len);
if (!data_buffer.has_value())
return EFAULT;
auto result = socket.sendto(*description, data_buffer.value(), iovs[0].iov_len, flags, user_addr, addr_length);
if (result.is_error())
return result.error();
else
return result.release_value();
}
KResultOr<FlatPtr> Process::sys$recvmsg(int sockfd, Userspace<struct msghdr*> user_msg, int flags)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
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$getsockname(Userspace<const Syscall::SC_getsockname_params*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
Syscall::SC_getsockname_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
return get_sock_or_peer_name<true>(params);
}
KResultOr<FlatPtr> Process::sys$getpeername(Userspace<const Syscall::SC_getpeername_params*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
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$getsockopt(Userspace<const Syscall::SC_getsockopt_params*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
Syscall::SC_getsockopt_params params;
if (!copy_from_user(&params, user_params))
return EFAULT;
int sockfd = params.sockfd;
int level = params.level;
int option = params.option;
Userspace<void*> user_value((FlatPtr)params.value);
Userspace<socklen_t*> user_value_size((FlatPtr)params.value_size);
socklen_t value_size;
if (!copy_from_user(&value_size, params.value_size, sizeof(socklen_t)))
return EFAULT;
auto description = fds().file_description(sockfd);
if (!description)
return EBADF;
if (!description->is_socket())
return ENOTSOCK;
auto& socket = *description->socket();
REQUIRE_PROMISE_FOR_SOCKET_DOMAIN(socket.domain());
return socket.getsockopt(*description, level, option, user_value, user_value_size);
}
KResultOr<FlatPtr> Process::sys$setsockopt(Userspace<const Syscall::SC_setsockopt_params*> user_params)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
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)
{
VERIFY_PROCESS_BIG_LOCK_ACQUIRED(this)
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];
auto fd1_or_error = m_fds.allocate();
if (fd1_or_error.is_error())
return fd1_or_error.error();
fds[0] = fd1_or_error.value().fd;
setup_socket_fd(fds[0], pair.description1, params.type);
auto fd2_or_error = m_fds.allocate();
if (fd2_or_error.is_error())
return fd2_or_error.error();
fds[1] = fd2_or_error.value().fd;
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;
}
}