socket.rs

use crate::vm::{builtins::PyModule, PyRef, VirtualMachine};
#[cfg(feature = "ssl")]
pub(super) use _socket::{sock_select, timeout_error_msg, PySocket, SelectKind};

pub fn make_module(vm: &VirtualMachine) -> PyRef<PyModule> {
    #[cfg(windows)]
    crate::vm::windows::init_winsock();
    _socket::make_module(vm)
}

#[pymodule]
mod _socket {
    use crate::common::lock::{PyMappedRwLockReadGuard, PyRwLock, PyRwLockReadGuard};
    use crate::vm::{
        builtins::{PyBaseExceptionRef, PyListRef, PyStrRef, PyTupleRef, PyTypeRef},
        common::os::ErrorExt,
        convert::{IntoPyException, ToPyObject, TryFromBorrowedObject, TryFromObject},
        function::{ArgBytesLike, ArgMemoryBuffer, Either, FsPath, OptionalArg, OptionalOption},
        types::{Constructor, DefaultConstructor, Initializer, Representable},
        utils::ToCString,
        AsObject, Py, PyObjectRef, PyPayload, PyRef, PyResult, VirtualMachine,
    };
    use crossbeam_utils::atomic::AtomicCell;
    use num_traits::ToPrimitive;
    use socket2::Socket;
    use std::{
        ffi,
        io::{self, Read, Write},
        mem::MaybeUninit,
        net::{self, Ipv4Addr, Ipv6Addr, Shutdown, SocketAddr, ToSocketAddrs},
        time::{Duration, Instant},
    };

    #[cfg(unix)]
    use libc as c;
    #[cfg(windows)]
    mod c {
        pub use winapi::shared::netioapi::{if_indextoname, if_nametoindex};
        pub use winapi::shared::ws2def::{
            INADDR_ANY, INADDR_BROADCAST, INADDR_LOOPBACK, INADDR_NONE,
        };
        pub use winapi::um::winsock2::{
            getprotobyname, getservbyname, getservbyport, getsockopt, setsockopt,
            SO_EXCLUSIVEADDRUSE,
        };
        pub use winapi::um::ws2tcpip::{
            EAI_AGAIN, EAI_BADFLAGS, EAI_FAIL, EAI_FAMILY, EAI_MEMORY, EAI_NODATA, EAI_NONAME,
            EAI_SERVICE, EAI_SOCKTYPE,
        };
        pub use windows_sys::Win32::Networking::WinSock::{
            AF_DECnet, AF_APPLETALK, AF_IPX, AF_LINK, AI_ADDRCONFIG, AI_ALL, AI_CANONNAME,
            AI_NUMERICSERV, AI_V4MAPPED, IPPORT_RESERVED, IPPROTO_AH, IPPROTO_DSTOPTS, IPPROTO_EGP,
            IPPROTO_ESP, IPPROTO_FRAGMENT, IPPROTO_GGP, IPPROTO_HOPOPTS, IPPROTO_ICMP,
            IPPROTO_ICMPV6, IPPROTO_IDP, IPPROTO_IGMP, IPPROTO_IP, IPPROTO_IP as IPPROTO_IPIP,
            IPPROTO_IPV4, IPPROTO_IPV6, IPPROTO_ND, IPPROTO_NONE, IPPROTO_PIM, IPPROTO_PUP,
            IPPROTO_RAW, IPPROTO_ROUTING, IPPROTO_TCP, IPPROTO_UDP, IPV6_CHECKSUM, IPV6_DONTFRAG,
            IPV6_HOPLIMIT, IPV6_HOPOPTS, IPV6_JOIN_GROUP, IPV6_LEAVE_GROUP, IPV6_MULTICAST_HOPS,
            IPV6_MULTICAST_IF, IPV6_MULTICAST_LOOP, IPV6_PKTINFO, IPV6_RECVRTHDR, IPV6_RECVTCLASS,
            IPV6_RTHDR, IPV6_TCLASS, IPV6_UNICAST_HOPS, IPV6_V6ONLY, IP_ADD_MEMBERSHIP,
            IP_DROP_MEMBERSHIP, IP_HDRINCL, IP_MULTICAST_IF, IP_MULTICAST_LOOP, IP_MULTICAST_TTL,
            IP_OPTIONS, IP_RECVDSTADDR, IP_TOS, IP_TTL, MSG_BCAST, MSG_CTRUNC, MSG_DONTROUTE,
            MSG_MCAST, MSG_OOB, MSG_PEEK, MSG_TRUNC, MSG_WAITALL, NI_DGRAM, NI_MAXHOST, NI_MAXSERV,
            NI_NAMEREQD, NI_NOFQDN, NI_NUMERICHOST, NI_NUMERICSERV, RCVALL_IPLEVEL, RCVALL_OFF,
            RCVALL_ON, RCVALL_SOCKETLEVELONLY, SD_BOTH as SHUT_RDWR, SD_RECEIVE as SHUT_RD,
            SD_SEND as SHUT_WR, SIO_KEEPALIVE_VALS, SIO_LOOPBACK_FAST_PATH, SIO_RCVALL, SOCK_DGRAM,
            SOCK_RAW, SOCK_RDM, SOCK_SEQPACKET, SOCK_STREAM, SOL_SOCKET, SOMAXCONN, SO_BROADCAST,
            SO_ERROR, SO_LINGER, SO_OOBINLINE, SO_REUSEADDR, SO_TYPE, SO_USELOOPBACK, TCP_NODELAY,
            WSAEBADF, WSAECONNRESET, WSAENOTSOCK, WSAEWOULDBLOCK,
        };
        pub const IF_NAMESIZE: usize =
            windows_sys::Win32::NetworkManagement::Ndis::IF_MAX_STRING_SIZE as _;
        pub const AF_UNSPEC: i32 = windows_sys::Win32::Networking::WinSock::AF_UNSPEC as _;
        pub const AF_INET: i32 = windows_sys::Win32::Networking::WinSock::AF_INET as _;
        pub const AF_INET6: i32 = windows_sys::Win32::Networking::WinSock::AF_INET6 as _;
        pub const AI_PASSIVE: i32 = windows_sys::Win32::Networking::WinSock::AI_PASSIVE as _;
        pub const AI_NUMERICHOST: i32 =
            windows_sys::Win32::Networking::WinSock::AI_NUMERICHOST as _;
    }
    // constants
    #[pyattr(name = "has_ipv6")]
    const HAS_IPV6: bool = true;
    #[pyattr]
    // put IPPROTO_MAX later
    use c::{
        AF_INET, AF_INET6, AF_UNSPEC, INADDR_ANY, INADDR_LOOPBACK, INADDR_NONE, IPPROTO_ICMP,
        IPPROTO_ICMPV6, IPPROTO_IP, IPPROTO_IPV6, IPPROTO_TCP, IPPROTO_TCP as SOL_TCP, IPPROTO_UDP,
        MSG_CTRUNC, MSG_DONTROUTE, MSG_OOB, MSG_PEEK, MSG_TRUNC, MSG_WAITALL, NI_DGRAM, NI_MAXHOST,
        NI_NAMEREQD, NI_NOFQDN, NI_NUMERICHOST, NI_NUMERICSERV, SHUT_RD, SHUT_RDWR, SHUT_WR,
        SOCK_DGRAM, SOCK_STREAM, SOL_SOCKET, SO_BROADCAST, SO_ERROR, SO_LINGER, SO_OOBINLINE,
        SO_REUSEADDR, SO_TYPE, TCP_NODELAY,
    };

    #[cfg(not(target_os = "redox"))]
    #[pyattr]
    use c::{
        AF_DECnet, AF_APPLETALK, AF_IPX, IPPROTO_AH, IPPROTO_DSTOPTS, IPPROTO_EGP, IPPROTO_ESP,
        IPPROTO_FRAGMENT, IPPROTO_HOPOPTS, IPPROTO_IDP, IPPROTO_IGMP, IPPROTO_IPIP, IPPROTO_NONE,
        IPPROTO_PIM, IPPROTO_PUP, IPPROTO_RAW, IPPROTO_ROUTING,
    };

    #[cfg(unix)]
    #[pyattr]
    use c::{AF_UNIX, SO_REUSEPORT};

    #[pyattr]
    use c::{AI_ADDRCONFIG, AI_NUMERICHOST, AI_NUMERICSERV, AI_PASSIVE};

    #[cfg(not(target_os = "redox"))]
    #[pyattr]
    use c::{SOCK_RAW, SOCK_RDM, SOCK_SEQPACKET};

    #[cfg(target_os = "android")]
    #[pyattr]
    use c::{SOL_ATALK, SOL_AX25, SOL_IPX, SOL_NETROM, SOL_ROSE};

    #[cfg(target_os = "freebsd")]
    #[pyattr]
    use c::SO_SETFIB;

    #[cfg(target_os = "linux")]
    #[pyattr]
    use c::{
        CAN_BCM, CAN_EFF_FLAG, CAN_EFF_MASK, CAN_ERR_FLAG, CAN_ERR_MASK, CAN_ISOTP, CAN_J1939,
        CAN_RAW, CAN_RAW_ERR_FILTER, CAN_RAW_FD_FRAMES, CAN_RAW_FILTER, CAN_RAW_JOIN_FILTERS,
        CAN_RAW_LOOPBACK, CAN_RAW_RECV_OWN_MSGS, CAN_RTR_FLAG, CAN_SFF_MASK, IPPROTO_MPTCP,
        J1939_IDLE_ADDR, J1939_MAX_UNICAST_ADDR, J1939_NLA_BYTES_ACKED, J1939_NLA_PAD,
        J1939_NO_ADDR, J1939_NO_NAME, J1939_NO_PGN, J1939_PGN_ADDRESS_CLAIMED,
        J1939_PGN_ADDRESS_COMMANDED, J1939_PGN_MAX, J1939_PGN_PDU1_MAX, J1939_PGN_REQUEST,
        SCM_J1939_DEST_ADDR, SCM_J1939_DEST_NAME, SCM_J1939_ERRQUEUE, SCM_J1939_PRIO, SOL_CAN_BASE,
        SOL_CAN_RAW, SO_J1939_ERRQUEUE, SO_J1939_FILTER, SO_J1939_PROMISC, SO_J1939_SEND_PRIO,
    };

    #[cfg(all(target_os = "linux", target_env = "gnu"))]
    #[pyattr]
    use c::SOL_RDS;

    #[cfg(target_os = "netbsd")]
    #[pyattr]
    use c::IPPROTO_VRRP;

    #[cfg(target_vendor = "apple")]
    #[pyattr]
    use c::{AF_SYSTEM, PF_SYSTEM, SYSPROTO_CONTROL, TCP_KEEPALIVE};

    #[cfg(windows)]
    #[pyattr]
    use c::{
        IPPORT_RESERVED, IPPROTO_IPV4, RCVALL_IPLEVEL, RCVALL_OFF, RCVALL_ON,
        RCVALL_SOCKETLEVELONLY, SIO_KEEPALIVE_VALS, SIO_LOOPBACK_FAST_PATH, SIO_RCVALL,
        SO_EXCLUSIVEADDRUSE,
    };

    #[cfg(not(windows))]
    #[pyattr]
    const IPPORT_RESERVED: i32 = 1024;

    #[pyattr]
    const IPPORT_USERRESERVED: i32 = 5000;

    #[cfg(any(unix, target_os = "android"))]
    #[pyattr]
    use c::{
        EAI_SYSTEM, MSG_EOR, SO_ACCEPTCONN, SO_DEBUG, SO_DONTROUTE, SO_KEEPALIVE, SO_RCVBUF,
        SO_RCVLOWAT, SO_RCVTIMEO, SO_SNDBUF, SO_SNDLOWAT, SO_SNDTIMEO,
    };

    #[cfg(any(target_os = "android", target_os = "linux"))]
    #[pyattr]
    use c::{
        ALG_OP_DECRYPT, ALG_OP_ENCRYPT, ALG_SET_AEAD_ASSOCLEN, ALG_SET_AEAD_AUTHSIZE, ALG_SET_IV,
        ALG_SET_KEY, ALG_SET_OP, IPV6_DSTOPTS, IPV6_NEXTHOP, IPV6_PATHMTU, IPV6_RECVDSTOPTS,
        IPV6_RECVHOPLIMIT, IPV6_RECVHOPOPTS, IPV6_RECVPATHMTU, IPV6_RTHDRDSTOPTS,
        IP_DEFAULT_MULTICAST_LOOP, IP_RECVOPTS, IP_RETOPTS, NETLINK_CRYPTO, NETLINK_DNRTMSG,
        NETLINK_FIREWALL, NETLINK_IP6_FW, NETLINK_NFLOG, NETLINK_ROUTE, NETLINK_USERSOCK,
        NETLINK_XFRM, SOL_ALG, SO_PASSSEC, SO_PEERSEC,
    };

    #[cfg(any(target_os = "android", target_vendor = "apple"))]
    #[pyattr]
    use c::{AI_DEFAULT, AI_MASK, AI_V4MAPPED_CFG};

    #[cfg(any(target_os = "freebsd", target_os = "netbsd"))]
    #[pyattr]
    use c::MSG_NOTIFICATION;

    #[cfg(any(target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    use c::TCP_USER_TIMEOUT;

    #[cfg(any(unix, target_os = "android", windows))]
    #[pyattr]
    use c::{
        INADDR_BROADCAST, IPV6_MULTICAST_HOPS, IPV6_MULTICAST_IF, IPV6_MULTICAST_LOOP,
        IPV6_UNICAST_HOPS, IPV6_V6ONLY, IP_ADD_MEMBERSHIP, IP_DROP_MEMBERSHIP, IP_MULTICAST_IF,
        IP_MULTICAST_LOOP, IP_MULTICAST_TTL, IP_TTL,
    };

    #[cfg(any(unix, target_os = "android", windows))]
    #[pyattr]
    const INADDR_UNSPEC_GROUP: u32 = 0xe0000000;

    #[cfg(any(unix, target_os = "android", windows))]
    #[pyattr]
    const INADDR_ALLHOSTS_GROUP: u32 = 0xe0000001;

    #[cfg(any(unix, target_os = "android", windows))]
    #[pyattr]
    const INADDR_MAX_LOCAL_GROUP: u32 = 0xe00000ff;

    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    use c::{
        AF_ALG, AF_ASH, AF_ATMPVC, AF_ATMSVC, AF_AX25, AF_BRIDGE, AF_CAN, AF_ECONET, AF_IRDA,
        AF_LLC, AF_NETBEUI, AF_NETLINK, AF_NETROM, AF_PACKET, AF_PPPOX, AF_RDS, AF_SECURITY,
        AF_TIPC, AF_VSOCK, AF_WANPIPE, AF_X25, IP_TRANSPARENT, MSG_CONFIRM, MSG_ERRQUEUE,
        MSG_FASTOPEN, MSG_MORE, PF_CAN, PF_PACKET, PF_RDS, SCM_CREDENTIALS, SOL_IP, SOL_TIPC,
        SOL_UDP, SO_BINDTODEVICE, SO_MARK, TCP_CORK, TCP_DEFER_ACCEPT, TCP_LINGER2, TCP_QUICKACK,
        TCP_SYNCNT, TCP_WINDOW_CLAMP,
    };

    // gated on presence of AF_VSOCK:
    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    const SO_VM_SOCKETS_BUFFER_SIZE: u32 = 0;

    // gated on presence of AF_VSOCK:
    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    const SO_VM_SOCKETS_BUFFER_MIN_SIZE: u32 = 1;

    // gated on presence of AF_VSOCK:
    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    const SO_VM_SOCKETS_BUFFER_MAX_SIZE: u32 = 2;

    // gated on presence of AF_VSOCK:
    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    const VMADDR_CID_ANY: u32 = 0xffffffff; // 0xffffffff

    // gated on presence of AF_VSOCK:
    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    const VMADDR_PORT_ANY: u32 = 0xffffffff; // 0xffffffff

    // gated on presence of AF_VSOCK:
    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    const VMADDR_CID_HOST: u32 = 2;

    // gated on presence of AF_VSOCK:
    #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    #[pyattr]
    const VM_SOCKETS_INVALID_VERSION: u32 = 0xffffffff; // 0xffffffff

    // TODO: gated on https://github.com/rust-lang/libc/pull/1662
    // // gated on presence of AF_VSOCK:
    // #[cfg(any(target_os = "android", target_os = "fuchsia", target_os = "linux"))]
    // #[pyattr(name = "IOCTL_VM_SOCKETS_GET_LOCAL_CID", once)]
    // fn ioctl_vm_sockets_get_local_cid(_vm: &VirtualMachine) -> i32 {
    //     c::_IO(7, 0xb9)
    // }

    #[cfg(not(any(target_os = "android", target_os = "fuchsia", target_os = "linux")))]
    #[pyattr]
    const SOL_IP: i32 = 0;

    #[cfg(not(any(target_os = "android", target_os = "fuchsia", target_os = "linux")))]
    #[pyattr]
    const SOL_UDP: i32 = 17;

    #[cfg(any(target_os = "android", target_os = "linux", windows))]
    #[pyattr]
    use c::{IPV6_HOPOPTS, IPV6_RECVRTHDR, IPV6_RTHDR, IP_OPTIONS};

    #[cfg(any(
        target_os = "dragonfly",
        target_os = "freebsd",
        target_vendor = "apple"
    ))]
    #[pyattr]
    use c::{IPPROTO_HELLO, IPPROTO_XTP, LOCAL_PEERCRED, MSG_EOF};

    #[cfg(any(target_os = "netbsd", target_os = "openbsd", windows))]
    #[pyattr]
    use c::{MSG_BCAST, MSG_MCAST};

    #[cfg(any(
        target_os = "android",
        target_os = "fuchsia",
        target_os = "freebsd",
        target_os = "linux"
    ))]
    #[pyattr]
    use c::{IPPROTO_UDPLITE, TCP_CONGESTION};

    #[cfg(any(
        target_os = "android",
        target_os = "fuchsia",
        target_os = "freebsd",
        target_os = "linux"
    ))]
    #[pyattr]
    const UDPLITE_SEND_CSCOV: i32 = 10;

    #[cfg(any(
        target_os = "android",
        target_os = "fuchsia",
        target_os = "freebsd",
        target_os = "linux"
    ))]
    #[pyattr]
    const UDPLITE_RECV_CSCOV: i32 = 11;

    #[cfg(any(
        target_os = "android",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "openbsd"
    ))]
    #[pyattr]
    use c::AF_KEY;

    #[cfg(any(
        target_os = "android",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "redox"
    ))]
    #[pyattr]
    use c::SO_DOMAIN;

    #[cfg(any(
        target_os = "android",
        target_os = "fuchsia",
        all(
            target_os = "linux",
            any(
                target_arch = "aarch64",
                target_arch = "x86",
                target_arch = "loongarch64",
                target_arch = "mips",
                target_arch = "powerpc",
                target_arch = "powerpc64",
                target_arch = "riscv64",
                target_arch = "s390x",
                target_arch = "x86_64"
            )
        ),
        target_os = "redox"
    ))]
    #[pyattr]
    use c::SO_PRIORITY;

    #[cfg(any(
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "netbsd",
        target_os = "openbsd"
    ))]
    #[pyattr]
    use c::IPPROTO_MOBILE;

    #[cfg(any(
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "netbsd",
        target_vendor = "apple"
    ))]
    #[pyattr]
    use c::SCM_CREDS;

    #[cfg(any(
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_vendor = "apple"
    ))]
    #[pyattr]
    use c::TCP_FASTOPEN;

    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        all(
            target_os = "linux",
            any(
                target_arch = "aarch64",
                target_arch = "x86",
                target_arch = "loongarch64",
                target_arch = "mips",
                target_arch = "powerpc",
                target_arch = "powerpc64",
                target_arch = "riscv64",
                target_arch = "s390x",
                target_arch = "x86_64"
            )
        ),
        target_os = "redox"
    ))]
    #[pyattr]
    use c::SO_PROTOCOL;

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "linux",
        windows
    ))]
    #[pyattr]
    use c::IPV6_DONTFRAG;

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "redox"
    ))]
    #[pyattr]
    use c::{SO_PASSCRED, SO_PEERCRED};

    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd"
    ))]
    #[pyattr]
    use c::TCP_INFO;

    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_vendor = "apple"
    ))]
    #[pyattr]
    use c::IP_RECVTOS;

    #[cfg(any(
        target_os = "android",
        target_os = "netbsd",
        target_os = "redox",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::NI_MAXSERV;

    #[cfg(any(
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "netbsd",
        target_os = "openbsd",
        target_vendor = "apple"
    ))]
    #[pyattr]
    use c::{IPPROTO_EON, IPPROTO_IPCOMP};

    #[cfg(any(
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "netbsd",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::IPPROTO_ND;

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "linux",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::{IPV6_CHECKSUM, IPV6_HOPLIMIT};

    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd"
    ))]
    #[pyattr]
    use c::IPPROTO_SCTP; // also in windows

    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::{AI_ALL, AI_V4MAPPED};

    #[cfg(any(
        target_os = "android",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::EAI_NODATA;

    #[cfg(any(
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "netbsd",
        target_os = "openbsd",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::{
        AF_LINK, IPPROTO_GGP, IPV6_JOIN_GROUP, IPV6_LEAVE_GROUP, IP_RECVDSTADDR, SO_USELOOPBACK,
    };

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd"
    ))]
    #[pyattr]
    use c::{MSG_CMSG_CLOEXEC, MSG_NOSIGNAL};

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "redox"
    ))]
    #[pyattr]
    use c::TCP_KEEPIDLE;

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd",
        target_vendor = "apple"
    ))]
    #[pyattr]
    use c::{TCP_KEEPCNT, TCP_KEEPINTVL};

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
        target_os = "redox"
    ))]
    #[pyattr]
    use c::{SOCK_CLOEXEC, SOCK_NONBLOCK};

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
        target_vendor = "apple"
    ))]
    #[pyattr]
    use c::{
        AF_ROUTE, AF_SNA, EAI_OVERFLOW, IPPROTO_GRE, IPPROTO_RSVP, IPPROTO_TP, IPV6_RECVPKTINFO,
        MSG_DONTWAIT, SCM_RIGHTS, TCP_MAXSEG,
    };

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::IPV6_PKTINFO;

    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::AI_CANONNAME;

    #[cfg(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
        target_vendor = "apple",
        windows
    ))]
    #[pyattr]
    use c::{
        EAI_AGAIN, EAI_BADFLAGS, EAI_FAIL, EAI_FAMILY, EAI_MEMORY, EAI_NONAME, EAI_SERVICE,
        EAI_SOCKTYPE, IPV6_RECVTCLASS, IPV6_TCLASS, IP_HDRINCL, IP_TOS, SOMAXCONN,
    };

    #[cfg(not(any(
        target_os = "android",
        target_os = "dragonfly",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "netbsd",
        target_os = "openbsd",
        target_vendor = "apple",
        windows
    )))]
    #[pyattr]
    const SOMAXCONN: i32 = 5; // Common value

    // HERE IS WHERE THE BLUETOOTH CONSTANTS START
    // TODO: there should be a more intelligent way of detecting bluetooth on a platform.
    //       CPython uses header-detection, but blocks NetBSD and DragonFly BSD
    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "openbsd"
    ))]
    #[pyattr]
    use c::AF_BLUETOOTH;

    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "openbsd"
    ))]
    #[pyattr]
    const BDADDR_ANY: &str = "00:00:00:00:00:00";
    #[cfg(any(
        target_os = "android",
        target_os = "freebsd",
        target_os = "fuchsia",
        target_os = "linux",
        target_os = "openbsd"
    ))]
    #[pyattr]
    const BDADDR_LOCAL: &str = "00:00:00:FF:FF:FF";
    // HERE IS WHERE THE BLUETOOTH CONSTANTS END

    #[cfg(windows)]
    #[pyattr]
    use windows_sys::Win32::Networking::WinSock::{
        IPPROTO_CBT, IPPROTO_ICLFXBM, IPPROTO_IGP, IPPROTO_L2TP, IPPROTO_PGM, IPPROTO_RDP,
        IPPROTO_SCTP, IPPROTO_ST,
    };

    #[pyattr]
    fn error(vm: &VirtualMachine) -> PyTypeRef {
        vm.ctx.exceptions.os_error.to_owned()
    }

    #[pyattr]
    fn timeout(vm: &VirtualMachine) -> PyTypeRef {
        vm.ctx.exceptions.timeout_error.to_owned()
    }

    #[pyattr(once)]
    fn herror(vm: &VirtualMachine) -> PyTypeRef {
        vm.ctx.new_exception_type(
            "socket",
            "herror",
            Some(vec![vm.ctx.exceptions.os_error.to_owned()]),
        )
    }
    #[pyattr(once)]
    fn gaierror(vm: &VirtualMachine) -> PyTypeRef {
        vm.ctx.new_exception_type(
            "socket",
            "gaierror",
            Some(vec![vm.ctx.exceptions.os_error.to_owned()]),
        )
    }

    #[pyfunction]
    fn htonl(x: u32) -> u32 {
        u32::to_be(x)
    }
    #[pyfunction]
    fn htons(x: u16) -> u16 {
        u16::to_be(x)
    }
    #[pyfunction]
    fn ntohl(x: u32) -> u32 {
        u32::from_be(x)
    }
    #[pyfunction]
    fn ntohs(x: u16) -> u16 {
        u16::from_be(x)
    }

    #[cfg(unix)]
    type RawSocket = std::os::unix::io::RawFd;
    #[cfg(windows)]
    type RawSocket = std::os::windows::raw::SOCKET;

    #[cfg(unix)]
    macro_rules! errcode {
        ($e:ident) => {
            c::$e
        };
    }
    #[cfg(windows)]
    macro_rules! errcode {
    ($e:ident) => {
        paste::paste!(c::[<WSA $e>])
    };
}

    #[cfg(windows)]
    use winapi::shared::netioapi;

    fn get_raw_sock(obj: PyObjectRef, vm: &VirtualMachine) -> PyResult<RawSocket> {
        #[cfg(unix)]
        type CastFrom = libc::c_long;
        #[cfg(windows)]
        type CastFrom = libc::c_longlong;

        // should really just be to_index() but test_socket tests the error messages explicitly
        if obj.fast_isinstance(vm.ctx.types.float_type) {
            return Err(vm.new_type_error("integer argument expected, got float".to_owned()));
        }
        let int = obj
            .try_index_opt(vm)
            .unwrap_or_else(|| Err(vm.new_type_error("an integer is required".to_owned())))?;
        int.try_to_primitive::<CastFrom>(vm)
            .map(|sock| sock as RawSocket)
    }

    #[pyattr(name = "socket")]
    #[pyattr(name = "SocketType")]
    #[pyclass(name = "socket")]
    #[derive(Debug, PyPayload)]
    pub struct PySocket {
        kind: AtomicCell<i32>,
        family: AtomicCell<i32>,
        proto: AtomicCell<i32>,
        pub(crate) timeout: AtomicCell<f64>,
        sock: PyRwLock<Option<Socket>>,
    }

    const _: () = assert!(std::mem::size_of::<Option<Socket>>() == std::mem::size_of::<Socket>());

    impl Default for PySocket {
        fn default() -> Self {
            PySocket {
                kind: AtomicCell::default(),
                family: AtomicCell::default(),
                proto: AtomicCell::default(),
                timeout: AtomicCell::new(-1.0),
                sock: PyRwLock::new(None),
            }
        }
    }

    #[cfg(windows)]
    const CLOSED_ERR: i32 = c::WSAENOTSOCK;
    #[cfg(unix)]
    const CLOSED_ERR: i32 = c::EBADF;

    impl Read for &PySocket {
        fn read(&mut self, buf: &mut [u8]) -> std::io::Result<usize> {
            (&mut &*self.sock()?).read(buf)
        }
    }
    impl Write for &PySocket {
        fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
            (&mut &*self.sock()?).write(buf)
        }

        fn flush(&mut self) -> std::io::Result<()> {
            (&mut &*self.sock()?).flush()
        }
    }

    impl PySocket {
        pub fn sock_opt(&self) -> Option<PyMappedRwLockReadGuard<'_, Socket>> {
            let sock = PyRwLockReadGuard::try_map(self.sock.read(), |sock| sock.as_ref());
            sock.ok()
        }

        pub fn sock(&self) -> io::Result<PyMappedRwLockReadGuard<'_, Socket>> {
            self.sock_opt()
                .ok_or_else(|| io::Error::from_raw_os_error(CLOSED_ERR))
        }

        fn init_inner(
            &self,
            family: i32,
            socket_kind: i32,
            proto: i32,
            sock: Socket,
        ) -> io::Result<()> {
            self.family.store(family);
            self.kind.store(socket_kind);
            self.proto.store(proto);
            let mut s = self.sock.write();
            let sock = s.insert(sock);
            let timeout = DEFAULT_TIMEOUT.load();
            self.timeout.store(timeout);
            if timeout >= 0.0 {
                sock.set_nonblocking(true)?;
            }
            Ok(())
        }

        /// returns Err(blocking)
        pub fn get_timeout(&self) -> Result<Duration, bool> {
            let timeout = self.timeout.load();
            if timeout > 0.0 {
                Ok(Duration::from_secs_f64(timeout))
            } else {
                Err(timeout != 0.0)
            }
        }

        fn sock_op<F, R>(
            &self,
            vm: &VirtualMachine,
            select: SelectKind,
            f: F,
        ) -> Result<R, IoOrPyException>
        where
            F: FnMut() -> io::Result<R>,
        {
            let timeout = self.get_timeout().ok();
            self.sock_op_timeout_err(vm, select, timeout, f)
        }

        fn sock_op_timeout_err<F, R>(
            &self,
            vm: &VirtualMachine,
            select: SelectKind,
            timeout: Option<Duration>,
            mut f: F,
        ) -> Result<R, IoOrPyException>
        where
            F: FnMut() -> io::Result<R>,
        {
            let deadline = timeout.map(Deadline::new);

            loop {
                if deadline.is_some() || matches!(select, SelectKind::Connect) {
                    let interval = deadline.as_ref().map(|d| d.time_until()).transpose()?;
                    let res = sock_select(&*self.sock()?, select, interval);
                    match res {
                        Ok(true) => return Err(IoOrPyException::Timeout),
                        Err(e) if e.kind() == io::ErrorKind::Interrupted => {
                            vm.check_signals()?;
                            continue;
                        }
                        Err(e) => return Err(e.into()),
                        Ok(false) => {} // no timeout, continue as normal
                    }
                }

                let err = loop {
                    // loop on interrupt
                    match f() {
                        Ok(x) => return Ok(x),
                        Err(e) if e.kind() == io::ErrorKind::Interrupted => vm.check_signals()?,
                        Err(e) => break e,
                    }
                };
                if timeout.is_some() && err.kind() == io::ErrorKind::WouldBlock {
                    continue;
                }
                return Err(err.into());
            }
        }

        fn extract_address(
            &self,
            addr: PyObjectRef,
            caller: &str,
            vm: &VirtualMachine,
        ) -> Result<socket2::SockAddr, IoOrPyException> {
            let family = self.family.load();
            match family {
                #[cfg(unix)]
                c::AF_UNIX => {
                    use std::os::unix::ffi::OsStrExt;
                    let buf = crate::vm::function::ArgStrOrBytesLike::try_from_object(vm, addr)?;
                    let path = &*buf.borrow_bytes();
                    socket2::SockAddr::unix(ffi::OsStr::from_bytes(path))
                        .map_err(|_| vm.new_os_error("AF_UNIX path too long".to_owned()).into())
                }
                c::AF_INET => {
                    let tuple: PyTupleRef = addr.downcast().map_err(|obj| {
                        vm.new_type_error(format!(
                            "{}(): AF_INET address must be tuple, not {}",
                            caller,
                            obj.class().name()
                        ))
                    })?;
                    if tuple.len() != 2 {
                        return Err(vm
                            .new_type_error(
                                "AF_INET address must be a pair (host, post)".to_owned(),
                            )
                            .into());
                    }
                    let addr = Address::from_tuple(&tuple, vm)?;
                    let mut addr4 = get_addr(vm, addr.host, c::AF_INET)?;
                    match &mut addr4 {
                        SocketAddr::V4(addr4) => {
                            addr4.set_port(addr.port);
                        }
                        SocketAddr::V6(_) => unreachable!(),
                    }
                    Ok(addr4.into())
                }
                c::AF_INET6 => {
                    let tuple: PyTupleRef = addr.downcast().map_err(|obj| {
                        vm.new_type_error(format!(
                            "{}(): AF_INET6 address must be tuple, not {}",
                            caller,
                            obj.class().name()
                        ))
                    })?;
                    match tuple.len() {
                        2..=4 => {}
                        _ => return Err(vm.new_type_error(
                            "AF_INET6 address must be a tuple (host, port[, flowinfo[, scopeid]])"
                                .to_owned(),
                        ).into()),
                    }
                    let (addr, flowinfo, scopeid) = Address::from_tuple_ipv6(&tuple, vm)?;
                    let mut addr6 = get_addr(vm, addr.host, c::AF_INET6)?;
                    match &mut addr6 {
                        SocketAddr::V6(addr6) => {
                            addr6.set_port(addr.port);
                            addr6.set_flowinfo(flowinfo);
                            addr6.set_scope_id(scopeid);
                        }
                        SocketAddr::V4(_) => unreachable!(),
                    }
                    Ok(addr6.into())
                }
                _ => Err(vm.new_os_error(format!("{caller}(): bad family")).into()),
            }
        }

        fn connect_inner(
            &self,
            address: PyObjectRef,
            caller: &str,
            vm: &VirtualMachine,
        ) -> Result<(), IoOrPyException> {
            let sock_addr = self.extract_address(address, caller, vm)?;

            let err = match self.sock()?.connect(&sock_addr) {
                Ok(()) => return Ok(()),
                Err(e) => e,
            };