Function connect [src]

Initiate a connection on a socket. If sockfd is opened in non blocking mode, the function will return error.WouldBlock when EAGAIN or EINPROGRESS is received.

Prototype

pub fn connect(sock: socket_t, sock_addr: *const sockaddr, len: socklen_t) ConnectError!void

Parameters

sock: socket_tsock_addr: *const sockaddrlen: socklen_t

Possible Errors

AccessDenied

For UNIX domain sockets, which are identified by pathname: Write permission is denied on the socket file, or search permission is denied for one of the directories in the path prefix. or The user tried to connect to a broadcast address without having the socket broadcast flag enabled or the connection request failed because of a local firewall rule.

AddressFamilyNotSupported

The passed address didn't have the correct address family in its sa_family field.

AddressInUse

Local address is already in use.

AddressNotAvailable

(Internet domain sockets) The socket referred to by sockfd had not previously been bound to an address and, upon attempting to bind it to an ephemeral port, it was determined that all port numbers in the ephemeral port range are currently in use. See the discussion of /proc/sys/net/ipv4/ip_local_port_range in ip(7).

ConnectionPending

Socket is non-blocking and already has a pending connection in progress.

ConnectionRefused

A connect() on a stream socket found no one listening on the remote address.

ConnectionResetByPeer

Connection was reset by peer before connect could complete.

ConnectionTimedOut

Timeout while attempting connection. The server may be too busy to accept new connections. Note that for IP sockets the timeout may be very long when syncookies are enabled on the server.

FileNotFound

The given path for the unix socket does not exist.

NetworkUnreachable

Network is unreachable.

PermissionDenied

See AccessDenied

SystemResources

Insufficient entries in the routing cache.

Unexpected UnexpectedError

The Operating System returned an undocumented error code.

This error is in theory not possible, but it would be better to handle this error than to invoke undefined behavior.

When this error code is observed, it usually means the Zig Standard Library needs a small patch to add the error code to the error set for the respective function.

WouldBlock

This error occurs when no global event loop is configured, and connecting to the socket would block.

Source

  pub fn connect(sock: socket_t, sock_addr: *const sockaddr, len: socklen_t) ConnectError!void {
    if (native_os == .windows) {
        const rc = windows.ws2_32.connect(sock, sock_addr, @intCast(len));
        if (rc == 0) return;
        switch (windows.ws2_32.WSAGetLastError()) {
            .WSAEADDRINUSE => return error.AddressInUse,
            .WSAEADDRNOTAVAIL => return error.AddressNotAvailable,
            .WSAECONNREFUSED => return error.ConnectionRefused,
            .WSAECONNRESET => return error.ConnectionResetByPeer,
            .WSAETIMEDOUT => return error.ConnectionTimedOut,
            .WSAEHOSTUNREACH, // TODO: should we return NetworkUnreachable in this case as well?
            .WSAENETUNREACH,
            => return error.NetworkUnreachable,
            .WSAEFAULT => unreachable,
            .WSAEINVAL => unreachable,
            .WSAEISCONN => unreachable,
            .WSAENOTSOCK => unreachable,
            .WSAEWOULDBLOCK => return error.WouldBlock,
            .WSAEACCES => unreachable,
            .WSAENOBUFS => return error.SystemResources,
            .WSAEAFNOSUPPORT => return error.AddressFamilyNotSupported,
            else => |err| return windows.unexpectedWSAError(err),
        }
        return;
    }

    while (true) {
        switch (errno(system.connect(sock, sock_addr, len))) {
            .SUCCESS => return,
            .ACCES => return error.AccessDenied,
            .PERM => return error.PermissionDenied,
            .ADDRINUSE => return error.AddressInUse,
            .ADDRNOTAVAIL => return error.AddressNotAvailable,
            .AFNOSUPPORT => return error.AddressFamilyNotSupported,
            .AGAIN, .INPROGRESS => return error.WouldBlock,
            .ALREADY => return error.ConnectionPending,
            .BADF => unreachable, // sockfd is not a valid open file descriptor.
            .CONNREFUSED => return error.ConnectionRefused,
            .CONNRESET => return error.ConnectionResetByPeer,
            .FAULT => unreachable, // The socket structure address is outside the user's address space.
            .INTR => continue,
            .ISCONN => unreachable, // The socket is already connected.
            .HOSTUNREACH => return error.NetworkUnreachable,
            .NETUNREACH => return error.NetworkUnreachable,
            .NOTSOCK => unreachable, // The file descriptor sockfd does not refer to a socket.
            .PROTOTYPE => unreachable, // The socket type does not support the requested communications protocol.
            .TIMEDOUT => return error.ConnectionTimedOut,
            .NOENT => return error.FileNotFound, // Returned when socket is AF.UNIX and the given path does not exist.
            .CONNABORTED => unreachable, // Tried to reuse socket that previously received error.ConnectionRefused.
            else => |err| return unexpectedErrno(err),
        }
    }
}  