struct Connection [src]

An interface to either a plain or TLS connection.

Fields

stream: net.Stream

tls_client: if (!disable_tls) *std.crypto.tls.Client else voidundefined unless protocol is tls.

protocol: ProtocolThe protocol that this connection is using.

host: []u8The host that this connection is connected to.

port: u16The port that this connection is connected to.

proxied: bool = falseWhether this connection is proxied and is not directly connected.

closing: bool = falseWhether this connection is closing when we're done with it.

read_start: BufferSize = 0

read_end: BufferSize = 0

write_end: BufferSize = 0

read_buf: [buffer_size]u8 = undefined

write_buf: [buffer_size]u8 = undefined

Members

allocWriteBuffer (Function)
buffer_size (Constant)
close (Function)
drop (Function)
fill (Function)
flush (Function)
peek (Function)
Protocol (enum)
read (Function)
reader (Function)
Reader (Type)
ReadError (Error Set)
readvDirect (Function)
readvDirectTls (Function)
write (Function)
writeAllDirect (Function)
writeAllDirectTls (Function)
WriteError (Error Set)
writer (Function)
Writer (Type)

Source

  pub const Connection = struct {
    stream: net.Stream,
    /// undefined unless protocol is tls.
    tls_client: if (!disable_tls) *std.crypto.tls.Client else void,

    /// The protocol that this connection is using.
    protocol: Protocol,

    /// The host that this connection is connected to.
    host: []u8,

    /// The port that this connection is connected to.
    port: u16,

    /// Whether this connection is proxied and is not directly connected.
    proxied: bool = false,

    /// Whether this connection is closing when we're done with it.
    closing: bool = false,

    read_start: BufferSize = 0,
    read_end: BufferSize = 0,
    write_end: BufferSize = 0,
    read_buf: [buffer_size]u8 = undefined,
    write_buf: [buffer_size]u8 = undefined,

    pub const buffer_size = std.crypto.tls.max_ciphertext_record_len;
    const BufferSize = std.math.IntFittingRange(0, buffer_size);

    pub const Protocol = enum { plain, tls };

    pub fn readvDirectTls(conn: *Connection, buffers: []std.posix.iovec) ReadError!usize {
        return conn.tls_client.readv(conn.stream, buffers) catch |err| {
            // https://github.com/ziglang/zig/issues/2473
            if (mem.startsWith(u8, @errorName(err), "TlsAlert")) return error.TlsAlert;

            switch (err) {
                error.TlsConnectionTruncated, error.TlsRecordOverflow, error.TlsDecodeError, error.TlsBadRecordMac, error.TlsBadLength, error.TlsIllegalParameter, error.TlsUnexpectedMessage => return error.TlsFailure,
                error.ConnectionTimedOut => return error.ConnectionTimedOut,
                error.ConnectionResetByPeer, error.BrokenPipe => return error.ConnectionResetByPeer,
                else => return error.UnexpectedReadFailure,
            }
        };
    }

    pub fn readvDirect(conn: *Connection, buffers: []std.posix.iovec) ReadError!usize {
        if (conn.protocol == .tls) {
            if (disable_tls) unreachable;

            return conn.readvDirectTls(buffers);
        }

        return conn.stream.readv(buffers) catch |err| switch (err) {
            error.ConnectionTimedOut => return error.ConnectionTimedOut,
            error.ConnectionResetByPeer, error.BrokenPipe => return error.ConnectionResetByPeer,
            else => return error.UnexpectedReadFailure,
        };
    }

    /// Refills the read buffer with data from the connection.
    pub fn fill(conn: *Connection) ReadError!void {
        if (conn.read_end != conn.read_start) return;

        var iovecs = [1]std.posix.iovec{
            .{ .base = &conn.read_buf, .len = conn.read_buf.len },
        };
        const nread = try conn.readvDirect(&iovecs);
        if (nread == 0) return error.EndOfStream;
        conn.read_start = 0;
        conn.read_end = @intCast(nread);
    }

    /// Returns the current slice of buffered data.
    pub fn peek(conn: *Connection) []const u8 {
        return conn.read_buf[conn.read_start..conn.read_end];
    }

    /// Discards the given number of bytes from the read buffer.
    pub fn drop(conn: *Connection, num: BufferSize) void {
        conn.read_start += num;
    }

    /// Reads data from the connection into the given buffer.
    pub fn read(conn: *Connection, buffer: []u8) ReadError!usize {
        const available_read = conn.read_end - conn.read_start;
        const available_buffer = buffer.len;

        if (available_read > available_buffer) { // partially read buffered data
            @memcpy(buffer[0..available_buffer], conn.read_buf[conn.read_start..conn.read_end][0..available_buffer]);
            conn.read_start += @intCast(available_buffer);

            return available_buffer;
        } else if (available_read > 0) { // fully read buffered data
            @memcpy(buffer[0..available_read], conn.read_buf[conn.read_start..conn.read_end]);
            conn.read_start += available_read;

            return available_read;
        }

        var iovecs = [2]std.posix.iovec{
            .{ .base = buffer.ptr, .len = buffer.len },
            .{ .base = &conn.read_buf, .len = conn.read_buf.len },
        };
        const nread = try conn.readvDirect(&iovecs);

        if (nread > buffer.len) {
            conn.read_start = 0;
            conn.read_end = @intCast(nread - buffer.len);
            return buffer.len;
        }

        return nread;
    }

    pub const ReadError = error{
        TlsFailure,
        TlsAlert,
        ConnectionTimedOut,
        ConnectionResetByPeer,
        UnexpectedReadFailure,
        EndOfStream,
    };

    pub const Reader = std.io.Reader(*Connection, ReadError, read);

    pub fn reader(conn: *Connection) Reader {
        return Reader{ .context = conn };
    }

    pub fn writeAllDirectTls(conn: *Connection, buffer: []const u8) WriteError!void {
        return conn.tls_client.writeAll(conn.stream, buffer) catch |err| switch (err) {
            error.BrokenPipe, error.ConnectionResetByPeer => return error.ConnectionResetByPeer,
            else => return error.UnexpectedWriteFailure,
        };
    }

    pub fn writeAllDirect(conn: *Connection, buffer: []const u8) WriteError!void {
        if (conn.protocol == .tls) {
            if (disable_tls) unreachable;

            return conn.writeAllDirectTls(buffer);
        }

        return conn.stream.writeAll(buffer) catch |err| switch (err) {
            error.BrokenPipe, error.ConnectionResetByPeer => return error.ConnectionResetByPeer,
            else => return error.UnexpectedWriteFailure,
        };
    }

    /// Writes the given buffer to the connection.
    pub fn write(conn: *Connection, buffer: []const u8) WriteError!usize {
        if (conn.write_buf.len - conn.write_end < buffer.len) {
            try conn.flush();

            if (buffer.len > conn.write_buf.len) {
                try conn.writeAllDirect(buffer);
                return buffer.len;
            }
        }

        @memcpy(conn.write_buf[conn.write_end..][0..buffer.len], buffer);
        conn.write_end += @intCast(buffer.len);

        return buffer.len;
    }

    /// Returns a buffer to be filled with exactly len bytes to write to the connection.
    pub fn allocWriteBuffer(conn: *Connection, len: BufferSize) WriteError![]u8 {
        if (conn.write_buf.len - conn.write_end < len) try conn.flush();
        defer conn.write_end += len;
        return conn.write_buf[conn.write_end..][0..len];
    }

    /// Flushes the write buffer to the connection.
    pub fn flush(conn: *Connection) WriteError!void {
        if (conn.write_end == 0) return;

        try conn.writeAllDirect(conn.write_buf[0..conn.write_end]);
        conn.write_end = 0;
    }

    pub const WriteError = error{
        ConnectionResetByPeer,
        UnexpectedWriteFailure,
    };

    pub const Writer = std.io.Writer(*Connection, WriteError, write);

    pub fn writer(conn: *Connection) Writer {
        return Writer{ .context = conn };
    }

    /// Closes the connection.
    pub fn close(conn: *Connection, allocator: Allocator) void {
        if (conn.protocol == .tls) {
            if (disable_tls) unreachable;

            // try to cleanly close the TLS connection, for any server that cares.
            _ = conn.tls_client.writeEnd(conn.stream, "", true) catch {};
            if (conn.tls_client.ssl_key_log) |key_log| key_log.file.close();
            allocator.destroy(conn.tls_client);
        }

        conn.stream.close();
        allocator.free(conn.host);
    }
}  