Partial Write

[PengZheng]

evt__tls__op failed to deal with partial write of evt__send_pending, which makes the whole library unusable.

[dlmeetei]

Can you elaborate or some test case to reproduce?

[PengZheng]

Can you elaborate or some test case to reproduce?

        case EVT_TLS_OP_WRITE: {
            assert( sz > 0 && "number of bytes to write should be positive");
            r = SSL_write(conn->ssl, buf, sz);
            if ( 0 == r) goto handle_shutdown;
            bytes = evt__send_pending(conn);
            if ( r > 0 && conn->write_cb) {
                conn->write_cb(conn, r);
            }
            break;
        }

evt__tls__op does not use return value bytes, i.e. the API doesn't keep track of how much data has been actually sent, which becomes conn->writer's responsibility. The reference implementation given by uv_tls_writer fails to do that.

int uv_tls_writer(evt_tls_t *t, void *bfr, int sz) {
    int rv = 0;
    uv_buf_t b;
    b.base = bfr;
    b.len = sz;
    uv_tls_t *uvt = t->data;
    if(uv_is_writable((uv_stream_t*)(uvt->tcp_hdl)) ) {
        rv = uv_try_write((uv_stream_t*)(uvt->tcp_hdl), &b, 1);
    }
    return rv;
}

When conn->write_cb invoked, it's possible that data has not been actually written into the underlying socket. At its best, the API is very awkward to use.