interface tcp { use wasi:io/streams@0.2.0.{input-stream, output-stream}; use wasi:io/poll@0.2.0.{pollable}; use wasi:clocks/monotonic-clock@0.2.0.{duration}; use network.{network, error-code, ip-socket-address, ip-address-family}; enum shutdown-type { /// Similar to `SHUT_RD` in POSIX. receive, /// Similar to `SHUT_WR` in POSIX. send, /// Similar to `SHUT_RDWR` in POSIX. both, } /// A TCP socket resource. /// /// The socket can be in one of the following states: /// - `unbound` /// - `bind-in-progress` /// - `bound` (See note below) /// - `listen-in-progress` /// - `listening` /// - `connect-in-progress` /// - `connected` /// - `closed` /// See /// for a more information. /// /// Note: Except where explicitly mentioned, whenever this documentation uses /// the term "bound" without backticks it actually means: in the `bound` state *or higher*. /// (i.e. `bound`, `listen-in-progress`, `listening`, `connect-in-progress` or `connected`) /// /// In addition to the general error codes documented on the /// `network::error-code` type, TCP socket methods may always return /// `error(invalid-state)` when in the `closed` state. resource tcp-socket { /// Bind the socket to a specific network on the provided IP address and port. /// /// If the IP address is zero (`0.0.0.0` in IPv4, `::` in IPv6), it is left to the implementation to decide which /// network interface(s) to bind to. /// If the TCP/UDP port is zero, the socket will be bound to a random free port. /// /// Bind can be attempted multiple times on the same socket, even with /// different arguments on each iteration. But never concurrently and /// only as long as the previous bind failed. Once a bind succeeds, the /// binding can't be changed anymore. /// /// # Typical errors /// - `invalid-argument`: The `local-address` has the wrong address family. (EAFNOSUPPORT, EFAULT on Windows) /// - `invalid-argument`: `local-address` is not a unicast address. (EINVAL) /// - `invalid-argument`: `local-address` is an IPv4-mapped IPv6 address. (EINVAL) /// - `invalid-state`: The socket is already bound. (EINVAL) /// - `address-in-use`: No ephemeral ports available. (EADDRINUSE, ENOBUFS on Windows) /// - `address-in-use`: Address is already in use. (EADDRINUSE) /// - `address-not-bindable`: `local-address` is not an address that the `network` can bind to. (EADDRNOTAVAIL) /// - `not-in-progress`: A `bind` operation is not in progress. /// - `would-block`: Can't finish the operation, it is still in progress. (EWOULDBLOCK, EAGAIN) /// /// # Implementors note /// When binding to a non-zero port, this bind operation shouldn't be affected by the TIME_WAIT /// state of a recently closed socket on the same local address. In practice this means that the SO_REUSEADDR /// socket option should be set implicitly on all platforms, except on Windows where this is the default behavior /// and SO_REUSEADDR performs something different entirely. /// /// Unlike in POSIX, in WASI the bind operation is async. This enables /// interactive WASI hosts to inject permission prompts. Runtimes that /// don't want to make use of this ability can simply call the native /// `bind` as part of either `start-bind` or `finish-bind`. /// /// # References /// - /// - /// - /// - start-bind: func(network: borrow, local-address: ip-socket-address) -> result<_, error-code>; finish-bind: func() -> result<_, error-code>; /// Connect to a remote endpoint. /// /// On success: /// - the socket is transitioned into the `connection` state. /// - a pair of streams is returned that can be used to read & write to the connection /// /// After a failed connection attempt, the socket will be in the `closed` /// state and the only valid action left is to `drop` the socket. A single /// socket can not be used to connect more than once. /// /// # Typical errors /// - `invalid-argument`: The `remote-address` has the wrong address family. (EAFNOSUPPORT) /// - `invalid-argument`: `remote-address` is not a unicast address. (EINVAL, ENETUNREACH on Linux, EAFNOSUPPORT on MacOS) /// - `invalid-argument`: `remote-address` is an IPv4-mapped IPv6 address. (EINVAL, EADDRNOTAVAIL on Illumos) /// - `invalid-argument`: The IP address in `remote-address` is set to INADDR_ANY (`0.0.0.0` / `::`). (EADDRNOTAVAIL on Windows) /// - `invalid-argument`: The port in `remote-address` is set to 0. (EADDRNOTAVAIL on Windows) /// - `invalid-argument`: The socket is already attached to a different network. The `network` passed to `connect` must be identical to the one passed to `bind`. /// - `invalid-state`: The socket is already in the `connected` state. (EISCONN) /// - `invalid-state`: The socket is already in the `listening` state. (EOPNOTSUPP, EINVAL on Windows) /// - `timeout`: Connection timed out. (ETIMEDOUT) /// - `connection-refused`: The connection was forcefully rejected. (ECONNREFUSED) /// - `connection-reset`: The connection was reset. (ECONNRESET) /// - `connection-aborted`: The connection was aborted. (ECONNABORTED) /// - `remote-unreachable`: The remote address is not reachable. (EHOSTUNREACH, EHOSTDOWN, ENETUNREACH, ENETDOWN, ENONET) /// - `address-in-use`: Tried to perform an implicit bind, but there were no ephemeral ports available. (EADDRINUSE, EADDRNOTAVAIL on Linux, EAGAIN on BSD) /// - `not-in-progress`: A connect operation is not in progress. /// - `would-block`: Can't finish the operation, it is still in progress. (EWOULDBLOCK, EAGAIN) /// /// # Implementors note /// The POSIX equivalent of `start-connect` is the regular `connect` syscall. /// Because all WASI sockets are non-blocking this is expected to return /// EINPROGRESS, which should be translated to `ok()` in WASI. /// /// The POSIX equivalent of `finish-connect` is a `poll` for event `POLLOUT` /// with a timeout of 0 on the socket descriptor. Followed by a check for /// the `SO_ERROR` socket option, in case the poll signaled readiness. /// /// # References /// - /// - /// - /// - start-connect: func(network: borrow, remote-address: ip-socket-address) -> result<_, error-code>; finish-connect: func() -> result, error-code>; /// Start listening for new connections. /// /// Transitions the socket into the `listening` state. /// /// Unlike POSIX, the socket must already be explicitly bound. /// /// # Typical errors /// - `invalid-state`: The socket is not bound to any local address. (EDESTADDRREQ) /// - `invalid-state`: The socket is already in the `connected` state. (EISCONN, EINVAL on BSD) /// - `invalid-state`: The socket is already in the `listening` state. /// - `address-in-use`: Tried to perform an implicit bind, but there were no ephemeral ports available. (EADDRINUSE) /// - `not-in-progress`: A listen operation is not in progress. /// - `would-block`: Can't finish the operation, it is still in progress. (EWOULDBLOCK, EAGAIN) /// /// # Implementors note /// Unlike in POSIX, in WASI the listen operation is async. This enables /// interactive WASI hosts to inject permission prompts. Runtimes that /// don't want to make use of this ability can simply call the native /// `listen` as part of either `start-listen` or `finish-listen`. /// /// # References /// - /// - /// - /// - start-listen: func() -> result<_, error-code>; finish-listen: func() -> result<_, error-code>; /// Accept a new client socket. /// /// The returned socket is bound and in the `connected` state. The following properties are inherited from the listener socket: /// - `address-family` /// - `keep-alive-enabled` /// - `keep-alive-idle-time` /// - `keep-alive-interval` /// - `keep-alive-count` /// - `hop-limit` /// - `receive-buffer-size` /// - `send-buffer-size` /// /// On success, this function returns the newly accepted client socket along with /// a pair of streams that can be used to read & write to the connection. /// /// # Typical errors /// - `invalid-state`: Socket is not in the `listening` state. (EINVAL) /// - `would-block`: No pending connections at the moment. (EWOULDBLOCK, EAGAIN) /// - `connection-aborted`: An incoming connection was pending, but was terminated by the client before this listener could accept it. (ECONNABORTED) /// - `new-socket-limit`: The new socket resource could not be created because of a system limit. (EMFILE, ENFILE) /// /// # References /// - /// - /// - /// - accept: func() -> result, error-code>; /// Get the bound local address. /// /// POSIX mentions: /// > If the socket has not been bound to a local name, the value /// > stored in the object pointed to by `address` is unspecified. /// /// WASI is stricter and requires `local-address` to return `invalid-state` when the socket hasn't been bound yet. /// /// # Typical errors /// - `invalid-state`: The socket is not bound to any local address. /// /// # References /// - /// - /// - /// - local-address: func() -> result; /// Get the remote address. /// /// # Typical errors /// - `invalid-state`: The socket is not connected to a remote address. (ENOTCONN) /// /// # References /// - /// - /// - /// - remote-address: func() -> result; /// Whether the socket is in the `listening` state. /// /// Equivalent to the SO_ACCEPTCONN socket option. is-listening: func() -> bool; /// Whether this is a IPv4 or IPv6 socket. /// /// Equivalent to the SO_DOMAIN socket option. address-family: func() -> ip-address-family; /// Hints the desired listen queue size. Implementations are free to ignore this. /// /// If the provided value is 0, an `invalid-argument` error is returned. /// Any other value will never cause an error, but it might be silently clamped and/or rounded. /// /// # Typical errors /// - `not-supported`: (set) The platform does not support changing the backlog size after the initial listen. /// - `invalid-argument`: (set) The provided value was 0. /// - `invalid-state`: (set) The socket is in the `connect-in-progress` or `connected` state. set-listen-backlog-size: func(value: u64) -> result<_, error-code>; /// Enables or disables keepalive. /// /// The keepalive behavior can be adjusted using: /// - `keep-alive-idle-time` /// - `keep-alive-interval` /// - `keep-alive-count` /// These properties can be configured while `keep-alive-enabled` is false, but only come into effect when `keep-alive-enabled` is true. /// /// Equivalent to the SO_KEEPALIVE socket option. keep-alive-enabled: func() -> result; set-keep-alive-enabled: func(value: bool) -> result<_, error-code>; /// Amount of time the connection has to be idle before TCP starts sending keepalive packets. /// /// If the provided value is 0, an `invalid-argument` error is returned. /// Any other value will never cause an error, but it might be silently clamped and/or rounded. /// I.e. after setting a value, reading the same setting back may return a different value. /// /// Equivalent to the TCP_KEEPIDLE socket option. (TCP_KEEPALIVE on MacOS) /// /// # Typical errors /// - `invalid-argument`: (set) The provided value was 0. keep-alive-idle-time: func() -> result; set-keep-alive-idle-time: func(value: duration) -> result<_, error-code>; /// The time between keepalive packets. /// /// If the provided value is 0, an `invalid-argument` error is returned. /// Any other value will never cause an error, but it might be silently clamped and/or rounded. /// I.e. after setting a value, reading the same setting back may return a different value. /// /// Equivalent to the TCP_KEEPINTVL socket option. /// /// # Typical errors /// - `invalid-argument`: (set) The provided value was 0. keep-alive-interval: func() -> result; set-keep-alive-interval: func(value: duration) -> result<_, error-code>; /// The maximum amount of keepalive packets TCP should send before aborting the connection. /// /// If the provided value is 0, an `invalid-argument` error is returned. /// Any other value will never cause an error, but it might be silently clamped and/or rounded. /// I.e. after setting a value, reading the same setting back may return a different value. /// /// Equivalent to the TCP_KEEPCNT socket option. /// /// # Typical errors /// - `invalid-argument`: (set) The provided value was 0. keep-alive-count: func() -> result; set-keep-alive-count: func(value: u32) -> result<_, error-code>; /// Equivalent to the IP_TTL & IPV6_UNICAST_HOPS socket options. /// /// If the provided value is 0, an `invalid-argument` error is returned. /// /// # Typical errors /// - `invalid-argument`: (set) The TTL value must be 1 or higher. hop-limit: func() -> result; set-hop-limit: func(value: u8) -> result<_, error-code>; /// The kernel buffer space reserved for sends/receives on this socket. /// /// If the provided value is 0, an `invalid-argument` error is returned. /// Any other value will never cause an error, but it might be silently clamped and/or rounded. /// I.e. after setting a value, reading the same setting back may return a different value. /// /// Equivalent to the SO_RCVBUF and SO_SNDBUF socket options. /// /// # Typical errors /// - `invalid-argument`: (set) The provided value was 0. receive-buffer-size: func() -> result; set-receive-buffer-size: func(value: u64) -> result<_, error-code>; send-buffer-size: func() -> result; set-send-buffer-size: func(value: u64) -> result<_, error-code>; /// Create a `pollable` which can be used to poll for, or block on, /// completion of any of the asynchronous operations of this socket. /// /// When `finish-bind`, `finish-listen`, `finish-connect` or `accept` /// return `error(would-block)`, this pollable can be used to wait for /// their success or failure, after which the method can be retried. /// /// The pollable is not limited to the async operation that happens to be /// in progress at the time of calling `subscribe` (if any). Theoretically, /// `subscribe` only has to be called once per socket and can then be /// (re)used for the remainder of the socket's lifetime. /// /// See /// for a more information. /// /// Note: this function is here for WASI Preview2 only. /// It's planned to be removed when `future` is natively supported in Preview3. subscribe: func() -> pollable; /// Initiate a graceful shutdown. /// /// - `receive`: The socket is not expecting to receive any data from /// the peer. The `input-stream` associated with this socket will be /// closed. Any data still in the receive queue at time of calling /// this method will be discarded. /// - `send`: The socket has no more data to send to the peer. The `output-stream` /// associated with this socket will be closed and a FIN packet will be sent. /// - `both`: Same effect as `receive` & `send` combined. /// /// This function is idempotent. Shutting a down a direction more than once /// has no effect and returns `ok`. /// /// The shutdown function does not close (drop) the socket. /// /// # Typical errors /// - `invalid-state`: The socket is not in the `connected` state. (ENOTCONN) /// /// # References /// - /// - /// - /// - shutdown: func(shutdown-type: shutdown-type) -> result<_, error-code>; } }