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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Singleton.h>
#include <AK/StringBuilder.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/FileSystem/VirtualFileSystem.h>
#include <Kernel/Net/LocalSocket.h>
#include <Kernel/Process.h>
#include <Kernel/StdLib.h>
#include <Kernel/UnixTypes.h>
#include <LibC/errno_numbers.h>
//#define DEBUG_LOCAL_SOCKET
namespace Kernel {
static AK::Singleton<Lockable<InlineLinkedList<LocalSocket>>> s_list;
Lockable<InlineLinkedList<LocalSocket>>& LocalSocket::all_sockets()
{
return *s_list;
}
void LocalSocket::for_each(Function<void(const LocalSocket&)> callback)
{
LOCKER(all_sockets().lock(), Lock::Mode::Shared);
for (auto& socket : all_sockets().resource())
callback(socket);
}
KResultOr<NonnullRefPtr<Socket>> LocalSocket::create(int type)
{
return adopt(*new LocalSocket(type));
}
LocalSocket::LocalSocket(int type)
: Socket(AF_LOCAL, type, 0)
{
LOCKER(all_sockets().lock());
all_sockets().resource().append(this);
auto current_process = Process::current();
m_prebind_uid = current_process->uid();
m_prebind_gid = current_process->gid();
m_prebind_mode = 0666;
m_for_client.set_unblock_callback([this]() {
evaluate_block_conditions();
});
m_for_server.set_unblock_callback([this]() {
evaluate_block_conditions();
});
#ifdef DEBUG_LOCAL_SOCKET
dbg() << "LocalSocket{" << this << "} created with type=" << type;
#endif
}
LocalSocket::~LocalSocket()
{
LOCKER(all_sockets().lock());
all_sockets().resource().remove(this);
}
void LocalSocket::get_local_address(sockaddr* address, socklen_t* address_size)
{
size_t bytes_to_copy = min(static_cast<size_t>(*address_size), sizeof(sockaddr_un));
memcpy(address, &m_address, 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);
}
KResult LocalSocket::bind(Userspace<const sockaddr*> user_address, socklen_t address_size)
{
ASSERT(setup_state() == SetupState::Unstarted);
if (address_size != sizeof(sockaddr_un))
return KResult(-EINVAL);
sockaddr_un address;
if (!copy_from_user(&address, user_address, sizeof(sockaddr_un)))
return KResult(-EFAULT);
if (address.sun_family != AF_LOCAL)
return KResult(-EINVAL);
auto path = String(address.sun_path, strnlen(address.sun_path, sizeof(address.sun_path)));
#ifdef DEBUG_LOCAL_SOCKET
dbg() << "LocalSocket{" << this << "} bind(" << path << ")";
#endif
mode_t mode = S_IFSOCK | (m_prebind_mode & 04777);
UidAndGid owner { m_prebind_uid, m_prebind_gid };
auto result = VFS::the().open(path, O_CREAT | O_EXCL | O_NOFOLLOW_NOERROR, mode, Process::current()->current_directory(), owner);
if (result.is_error()) {
if (result.error() == -EEXIST)
return KResult(-EADDRINUSE);
return result.error();
}
auto file = move(result.value());
ASSERT(file->inode());
if (!file->inode()->bind_socket(*this))
return KResult(-EADDRINUSE);
m_file = move(file);
m_address = address;
m_bound = true;
return KSuccess;
}
KResult LocalSocket::connect(FileDescription& description, Userspace<const sockaddr*> address, socklen_t address_size, ShouldBlock)
{
ASSERT(!m_bound);
if (address_size != sizeof(sockaddr_un))
return KResult(-EINVAL);
u16 sa_family_copy;
auto* user_address = reinterpret_cast<const sockaddr*>(address.unsafe_userspace_ptr());
if (!copy_from_user(&sa_family_copy, &user_address->sa_family, sizeof(u16)))
return KResult(-EFAULT);
if (sa_family_copy != AF_LOCAL)
return KResult(-EINVAL);
if (is_connected())
return KResult(-EISCONN);
const auto& local_address = *reinterpret_cast<const sockaddr_un*>(user_address);
char safe_address[sizeof(local_address.sun_path) + 1] = { 0 };
if (!copy_from_user(&safe_address[0], &local_address.sun_path[0], sizeof(safe_address) - 1))
return KResult(-EFAULT);
safe_address[sizeof(safe_address) - 1] = '\0';
#ifdef DEBUG_LOCAL_SOCKET
dbg() << "LocalSocket{" << this << "} connect(" << safe_address << ")";
#endif
auto description_or_error = VFS::the().open(safe_address, O_RDWR, 0, Process::current()->current_directory());
if (description_or_error.is_error())
return KResult(-ECONNREFUSED);
m_file = move(description_or_error.value());
ASSERT(m_file->inode());
if (!m_file->inode()->socket())
return KResult(-ECONNREFUSED);
m_address.sun_family = sa_family_copy;
memcpy(m_address.sun_path, safe_address, sizeof(m_address.sun_path));
ASSERT(m_connect_side_fd == &description);
set_connect_side_role(Role::Connecting);
auto peer = m_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 KSuccess;
}
auto unblock_flags = Thread::FileDescriptionBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::ConnectBlocker>(nullptr, description, unblock_flags).was_interrupted()) {
set_connect_side_role(Role::None);
return KResult(-EINTR);
}
#ifdef DEBUG_LOCAL_SOCKET
dbg() << "LocalSocket{" << this << "} connect(" << safe_address << ") status is " << to_string(setup_state());
#endif
if (!((u32)unblock_flags & (u32)Thread::FileDescriptionBlocker::BlockFlags::Connect)) {
set_connect_side_role(Role::None);
return KResult(-ECONNREFUSED);
}
set_connect_side_role(Role::Connected);
return KSuccess;
}
KResult LocalSocket::listen(size_t backlog)
{
LOCKER(lock());
if (type() != SOCK_STREAM)
return KResult(-EOPNOTSUPP);
set_backlog(backlog);
auto previous_role = m_role;
m_role = Role::Listener;
set_connect_side_role(Role::Listener, previous_role != m_role);
#ifdef DEBUG_LOCAL_SOCKET
dbg() << "LocalSocket{" << this << "} listening with backlog=" << backlog;
#endif
return KSuccess;
}
void LocalSocket::attach(FileDescription& description)
{
ASSERT(!m_accept_side_fd_open);
if (m_connect_side_role == Role::None) {
ASSERT(m_connect_side_fd == nullptr);
m_connect_side_fd = &description;
} else {
ASSERT(m_connect_side_fd != &description);
m_accept_side_fd_open = true;
}
evaluate_block_conditions();
}
void LocalSocket::detach(FileDescription& description)
{
if (m_connect_side_fd == &description) {
m_connect_side_fd = nullptr;
} else {
ASSERT(m_accept_side_fd_open);
m_accept_side_fd_open = false;
}
evaluate_block_conditions();
}
bool LocalSocket::can_read(const FileDescription& 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 FileDescription& 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;
ASSERT_NOT_REACHED();
}
bool LocalSocket::can_write(const FileDescription& 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;
}
KResultOr<size_t> LocalSocket::sendto(FileDescription& description, const UserOrKernelBuffer& data, size_t data_size, int, Userspace<const sockaddr*>, socklen_t)
{
if (!has_attached_peer(description))
return KResult(-EPIPE);
ssize_t nwritten = send_buffer_for(description).write(data, data_size);
if (nwritten > 0)
Thread::current()->did_unix_socket_write(nwritten);
return nwritten;
}
DoubleBuffer& LocalSocket::receive_buffer_for(FileDescription& description)
{
auto role = this->role(description);
if (role == Role::Accepted)
return m_for_server;
if (role == Role::Connected)
return m_for_client;
ASSERT_NOT_REACHED();
}
DoubleBuffer& LocalSocket::send_buffer_for(FileDescription& description)
{
auto role = this->role(description);
if (role == Role::Connected)
return m_for_server;
if (role == Role::Accepted)
return m_for_client;
ASSERT_NOT_REACHED();
}
KResultOr<size_t> LocalSocket::recvfrom(FileDescription& description, UserOrKernelBuffer& buffer, size_t buffer_size, int, Userspace<sockaddr*>, Userspace<socklen_t*>, timeval&)
{
auto& buffer_for_me = receive_buffer_for(description);
if (!description.is_blocking()) {
if (buffer_for_me.is_empty()) {
if (!has_attached_peer(description))
return 0;
return KResult(-EAGAIN);
}
} else if (!can_read(description, 0)) {
auto unblock_flags = Thread::FileDescriptionBlocker::BlockFlags::None;
if (Thread::current()->block<Thread::ReadBlocker>(nullptr, description, unblock_flags).was_interrupted())
return KResult(-EINTR);
}
if (!has_attached_peer(description) && buffer_for_me.is_empty())
return 0;
ASSERT(!buffer_for_me.is_empty());
int nread = buffer_for_me.read(buffer, buffer_size);
if (nread > 0)
Thread::current()->did_unix_socket_read(nread);
return nread;
}
StringView LocalSocket::socket_path() const
{
size_t len = strnlen(m_address.sun_path, sizeof(m_address.sun_path));
return { m_address.sun_path, len };
}
String LocalSocket::absolute_path(const FileDescription& 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.appendf(" (accepted from pid %d)", origin_pid());
break;
case Role::Connected:
builder.appendf(" (connected to pid %d)", acceptor_pid());
break;
case Role::Connecting:
builder.append(" (connecting)");
break;
default:
break;
}
return builder.to_string();
}
KResult LocalSocket::getsockopt(FileDescription& 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;
if (!copy_from_user(&size, value_size.unsafe_userspace_ptr()))
return KResult(-EFAULT);
switch (option) {
case SO_PEERCRED: {
if (size < sizeof(ucred))
return KResult(-EINVAL);
switch (role(description)) {
case Role::Accepted:
if (!copy_to_user(static_ptr_cast<ucred*>(value), &m_origin))
return KResult(-EFAULT);
size = sizeof(ucred);
if (!copy_to_user(value_size, &size))
return KResult(-EFAULT);
return KSuccess;
case Role::Connected:
if (!copy_to_user(static_ptr_cast<ucred*>(value), &m_acceptor))
return KResult(-EFAULT);
size = sizeof(ucred);
if (!copy_to_user(value_size, &size))
return KResult(-EFAULT);
return KSuccess;
case Role::Connecting:
return KResult(-ENOTCONN);
default:
return KResult(-EINVAL);
}
break;
}
default:
return Socket::getsockopt(description, level, option, value, value_size);
}
}
KResult LocalSocket::chmod(FileDescription&, mode_t mode)
{
if (m_file)
return m_file->chmod(mode);
m_prebind_mode = mode & 04777;
return KSuccess;
}
KResult LocalSocket::chown(FileDescription&, uid_t uid, gid_t gid)
{
if (m_file)
return m_file->chown(uid, gid);
auto current_process = Process::current();
if (!current_process->is_superuser() && (current_process->euid() != uid || !current_process->in_group(gid)))
return KResult(-EPERM);
m_prebind_uid = uid;
m_prebind_gid = gid;
return KSuccess;
}
NonnullRefPtrVector<FileDescription>& LocalSocket::recvfd_queue_for(const FileDescription& description)
{
auto role = this->role(description);
if (role == Role::Connected)
return m_fds_for_client;
if (role == Role::Accepted)
return m_fds_for_server;
ASSERT_NOT_REACHED();
}
NonnullRefPtrVector<FileDescription>& LocalSocket::sendfd_queue_for(const FileDescription& description)
{
auto role = this->role(description);
if (role == Role::Connected)
return m_fds_for_server;
if (role == Role::Accepted)
return m_fds_for_client;
ASSERT_NOT_REACHED();
}
KResult LocalSocket::sendfd(const FileDescription& socket_description, FileDescription& passing_description)
{
LOCKER(lock());
auto role = this->role(socket_description);
if (role != Role::Connected && role != Role::Accepted)
return KResult(-EINVAL);
auto& queue = sendfd_queue_for(socket_description);
// FIXME: Figure out how we should limit this properly.
if (queue.size() > 16)
return KResult(-EBUSY);
queue.append(move(passing_description));
return KSuccess;
}
KResultOr<NonnullRefPtr<FileDescription>> LocalSocket::recvfd(const FileDescription& socket_description)
{
LOCKER(lock());
auto role = this->role(socket_description);
if (role != Role::Connected && role != Role::Accepted)
return KResult(-EINVAL);
auto& queue = recvfd_queue_for(socket_description);
if (queue.is_empty()) {
// FIXME: Figure out the perfect error code for this.
return KResult(-EAGAIN);
}
return queue.take_first();
}
}
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