src/lib-http/http-server-request.c

	http-server-request.c revision e2a5de324df523512c42086d8422e4e41adf2c28
c25356d5978632df6203437e1953bcb29e0c736fTimo Sirainen/* Copyright (c) 2013-2017 Dovecot authors, see the included COPYING file */
c25356d5978632df6203437e1953bcb29e0c736fTimo Sirainen
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen#include "lib.h"
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen#include "ioloop.h"
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen#include "ostream.h"
031d075daf75b74b286711c1b6f64c3ae70e541bTimo Sirainen#include "istream-private.h"
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen#include "http-server-private.h"
6380f2bc729a03b328793e8ad6ba7587620fa184Timo Sirainen
6380f2bc729a03b328793e8ad6ba7587620fa184Timo Sirainen/*
37f96554a5734557cd454691d163e602d36384b4Timo Sirainen * Logging
6380f2bc729a03b328793e8ad6ba7587620fa184Timo Sirainen */
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainenstatic inline void
20b136f04257b0ba338e49f31a999c0d4b243647Timo Sirainenhttp_server_request_debug(struct http_server_request *req,
20b136f04257b0ba338e49f31a999c0d4b243647Timo Sirainen    const char *format, ...) ATTR_FORMAT(2, 3);
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainenstatic inline void
be044d4f3d08652d7332cdec5aaf8391474908bbTimo Sirainenhttp_server_request_debug(struct http_server_request *req,
be044d4f3d08652d7332cdec5aaf8391474908bbTimo Sirainen    const char *format, ...)
20b136f04257b0ba338e49f31a999c0d4b243647Timo Sirainen{
20b136f04257b0ba338e49f31a999c0d4b243647Timo Sirainen    struct http_server *server = req->server;
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen    va_list args;
57f4445a46726a17bfe78b0964dd301a6ccb40ecTimo Sirainen
    if (server->set.debug) {
        va_start(args, format);
        i_debug("http-server: request %s: %s",
            http_server_request_label(req),
            t_strdup_vprintf(format, args));
        va_end(args);
    }
}

static inline void
http_server_request_error(struct http_server_request *req,
    const char *format, ...) ATTR_FORMAT(2, 3);

static inline void
http_server_request_error(struct http_server_request *req,
    const char *format, ...)
{
    va_list args;

    va_start(args, format);
    i_error("http-server: request %s: %s",
        http_server_request_label(req),
        t_strdup_vprintf(format, args));
    va_end(args);
}

static inline void
http_server_request_client_error(struct http_server_request *req,
    const char *format, ...) ATTR_FORMAT(2, 3);

static inline void
http_server_request_client_error(struct http_server_request *req,
    const char *format, ...)
{
    va_list args;

    va_start(args, format);
    i_info("http-server: request %s: %s",
        http_server_request_label(req),
        t_strdup_vprintf(format, args));
    va_end(args);
}

/*
 * Request
 */

struct http_server_request *
http_server_request_new(struct http_server_connection *conn)
{
    static unsigned int id_counter = 0;
    pool_t pool;
    struct http_server_request *req;

    pool = pool_alloconly_create(MEMPOOL_GROWING"http_server_request", 4096);
    req = p_new(pool, struct http_server_request, 1);
    req->pool = pool;
    req->refcount = 1;
    req->conn = conn;
    req->server = conn->server;
    req->id = ++id_counter;

    http_server_connection_add_request(conn, req);
    return req;
}

void http_server_request_ref(struct http_server_request *req)
{
    i_assert(req->refcount > 0);
    req->refcount++;
}

bool http_server_request_unref(struct http_server_request **_req)
{
    struct http_server_request *req = *_req;
    struct http_server_connection *conn = req->conn;

    i_assert(req->refcount > 0);

    *_req = NULL;
    if (--req->refcount > 0)
        return TRUE;

    http_server_request_debug(req, "Free");

    if (req->state < HTTP_SERVER_REQUEST_STATE_FINISHED) {
        req->state = HTTP_SERVER_REQUEST_STATE_ABORTED;
        http_server_connection_remove_request(conn, req);
    }

    if (req->destroy_callback != NULL) {
        req->destroy_callback(req->destroy_context);
        req->destroy_callback = NULL;
    }

    if (req->response != NULL)
        http_server_response_free(req->response);
    pool_unref(&req->pool);
    return FALSE;
}

void http_server_request_destroy(struct http_server_request **_req)
{
    struct http_server_request *req = *_req;
    struct http_server *server = req->server;

    http_server_request_debug(req, "Destroy");

    /* just make sure the request ends in a proper state */
    if (req->state < HTTP_SERVER_REQUEST_STATE_FINISHED)
        req->state = HTTP_SERVER_REQUEST_STATE_ABORTED;

    if (server->ioloop != NULL)
        io_loop_stop(server->ioloop);

    if (req->delay_destroy) {
        req->destroy_pending = TRUE;
    } else if (req->destroy_callback != NULL) {
        void (*callback)(void *) = req->destroy_callback;

        req->destroy_callback = NULL;
        callback(req->destroy_context);
    }
    http_server_request_unref(_req);
}

#undef http_server_request_set_destroy_callback
void http_server_request_set_destroy_callback(struct http_server_request *req,
                          void (*callback)(void *),
                          void *context)
{
    req->destroy_callback = callback;
    req->destroy_context = context;
}

void http_server_request_abort(struct http_server_request **_req,
    const char *reason)
{
    struct http_server_request *req = *_req;
    struct http_server_connection *conn = req->conn;

    if (req->state >= HTTP_SERVER_REQUEST_STATE_FINISHED)
        return;

    http_server_request_debug(req, "Abort");

    req->conn = NULL;
    if (req->state < HTTP_SERVER_REQUEST_STATE_FINISHED) {
        if (conn != NULL) {
            http_server_connection_remove_request(conn, req);

            if (!conn->closed) {
                /* send best-effort response if appropriate */
                if (!conn->output_locked &&
                    req->state >= HTTP_SERVER_REQUEST_STATE_PROCESSING &&
                    req->state < HTTP_SERVER_REQUEST_STATE_SENT_RESPONSE) {
                    static const char *response =
                        "HTTP/1.1 500 Internal Server Error\r\n"
                        "Content-Length: 0\r\n"
                        "\r\n";

                    (void)o_stream_send(conn->conn.output,
                        response, strlen(response));
                }

                /* close the connection */
                http_server_connection_close(&conn, reason);
            }
        }

        req->state = HTTP_SERVER_REQUEST_STATE_ABORTED;
    }

    if (req->response != NULL &&
        !req->response->payload_blocking) {
        http_server_response_free(req->response);
        req->response = NULL;
    }

    http_server_request_destroy(_req);
}

const struct http_request *
http_server_request_get(struct http_server_request *req)
{
    return &req->req;
}

pool_t
http_server_request_get_pool(struct http_server_request *req)
{
    return req->pool;
}

struct http_server_response *
http_server_request_get_response(struct http_server_request *req)
{
    return req->response;
}

int http_server_request_get_auth(struct http_server_request *req,
    struct http_auth_credentials *credentials)
{
    const char *auth;

    auth = http_request_header_get(&req->req, "Authorization");
    if (auth == NULL)
        return 0;

    if (http_auth_parse_credentials
        ((const unsigned char *)auth, strlen(auth), credentials) < 0)
        return -1;

    return 1;
}

bool http_server_request_is_finished(struct http_server_request *req)
{
    return req->response != NULL ||
        req->state == HTTP_SERVER_REQUEST_STATE_ABORTED;
}

bool http_server_request_is_complete(struct http_server_request *req)
{
    return (req->failed || req->conn->input_broken ||
        (req->next != NULL && !http_server_request_is_new(req->next)) ||
        !http_server_connection_pending_payload(req->conn));
}

void http_server_request_halt_payload(struct http_server_request *req)
{
    i_assert(req->state <= HTTP_SERVER_REQUEST_STATE_QUEUED);
    req->payload_halted = TRUE;
}

void http_server_request_continue_payload(struct http_server_request *req)
{
    i_assert(req->state <= HTTP_SERVER_REQUEST_STATE_QUEUED);
    req->payload_halted = FALSE;
    if (req->req.expect_100_continue && !req->sent_100_continue)
        http_server_connection_trigger_responses(req->conn);
}

void http_server_request_ready_to_respond(struct http_server_request *req)
{
    http_server_request_debug(req, "Ready to respond");

    req->state = HTTP_SERVER_REQUEST_STATE_READY_TO_RESPOND;
    http_server_connection_trigger_responses(req->conn);
}

void http_server_request_submit_response(struct http_server_request *req)
{
    struct http_server_connection *conn = req->conn;

    i_assert(conn != NULL && req->response != NULL && req->response->submitted);

    http_server_request_ref(req);

    if (conn->payload_handler != NULL && conn->payload_handler->req == req)
        http_server_payload_handler_destroy(&conn->payload_handler);

    switch (req->state) {
    case HTTP_SERVER_REQUEST_STATE_NEW:
    case HTTP_SERVER_REQUEST_STATE_QUEUED:
    case HTTP_SERVER_REQUEST_STATE_PAYLOAD_IN:
    case HTTP_SERVER_REQUEST_STATE_PROCESSING:
        if (!http_server_request_is_complete(req)) {
            http_server_request_debug(req, "Not ready to respond");
            req->state = HTTP_SERVER_REQUEST_STATE_SUBMITTED_RESPONSE;
            break;
        }
        http_server_request_ready_to_respond(req);
        break;
    case HTTP_SERVER_REQUEST_STATE_READY_TO_RESPOND:
        http_server_connection_trigger_responses(req->conn);
        break;
    case HTTP_SERVER_REQUEST_STATE_ABORTED:
        break;
    default:
        i_unreached();
    }

    http_server_request_unref(&req);
}

void http_server_request_finished(struct http_server_request *req)
{
    struct http_server_connection *conn = req->conn;
    struct http_server_response *resp = req->response;
    http_server_tunnel_callback_t tunnel_callback = resp->tunnel_callback;
    void *tunnel_context = resp->tunnel_context;

    http_server_request_debug(req, "Finished");

    i_assert(req->state < HTTP_SERVER_REQUEST_STATE_FINISHED);
    req->state = HTTP_SERVER_REQUEST_STATE_FINISHED;

    http_server_connection_remove_request(conn, req);
    conn->stats.response_count++;

    if (tunnel_callback == NULL) {
        if (resp->close) {
            http_server_connection_close(&conn,
                t_strdup_printf("Server closed connection: %u %s",
                    resp->status, resp->reason));
            http_server_request_destroy(&req);
            return;
        } else if (req->conn->input_broken) {
            http_server_connection_close(&conn,
                "Connection input is broken");
            http_server_request_destroy(&req);
            return;
        } else if (req->req.connection_close) {
            http_server_connection_close(&conn,
                "Client requested connection close");
            http_server_request_destroy(&req);
            return;
        }
    }

    http_server_request_destroy(&req);
    if (tunnel_callback != NULL) {
        http_server_connection_tunnel(&conn, tunnel_callback, tunnel_context);
        return;
    }

    http_server_connection_trigger_responses(conn);
}

static  struct http_server_response *
http_server_request_create_fail_response(struct http_server_request *req,
    unsigned int status, const char *reason)
{
    struct http_server_response *resp;

    req->failed = TRUE;

    i_assert(status / 100 != 1 && status != 204 && status != 304);

    resp = http_server_response_create(req, status, reason);
    if (!http_request_method_is(&req->req, "HEAD")) {
        http_server_response_add_header
            (resp, "Content-Type", "text/plain; charset=utf-8");
        reason = t_strconcat(reason, "\r\n", NULL);
        http_server_response_set_payload_data
            (resp, (const unsigned char *)reason, strlen(reason));
    }

    return resp;
}

static void
http_server_request_fail_full(struct http_server_request *req,
    unsigned int status, const char *reason, bool close)
{
    struct http_server_response *resp;

    req->failed = TRUE;
    resp = http_server_request_create_fail_response(req, status, reason);
    if (close)
        http_server_response_submit_close(resp);
    else
        http_server_response_submit(resp);
}

void http_server_request_fail(struct http_server_request *req,
    unsigned int status, const char *reason)
{
    http_server_request_fail_full(req, status, reason, FALSE);
}

void http_server_request_fail_close(struct http_server_request *req,
    unsigned int status, const char *reason)
{
    http_server_request_fail_full(req, status, reason, TRUE);
}

void http_server_request_fail_auth(struct http_server_request *req,
    const char *reason, const struct http_auth_challenge *chlng)
{
    struct http_server_response *resp;

    req->failed = TRUE;

    if (reason == NULL)
        reason = "Unauthenticated";

    resp = http_server_request_create_fail_response(req, 401, reason);
    http_server_response_add_auth(resp, chlng);
    http_server_response_submit(resp);
}

void http_server_request_fail_auth_basic(struct http_server_request *req,
    const char *reason, const char *realm)
{
    struct http_auth_challenge chlng;

    http_auth_basic_challenge_init(&chlng, realm);
    http_server_request_fail_auth(req, reason, &chlng);
}

/*
 * Payload input stream
 */

struct http_server_istream {
    struct istream_private istream;

    struct http_server_request *req;

    ssize_t read_status;
};

static void
http_server_istream_switch_ioloop(struct istream_private *stream)
{
    struct http_server_istream *hsristream =
        (struct http_server_istream *)stream;

    if (hsristream->istream.istream.blocking)
        return;

    http_server_connection_switch_ioloop(hsristream->req->conn);
}

static void
http_server_istream_read_any(struct http_server_istream *hsristream)
{
    struct istream_private *stream = &hsristream->istream;
    struct http_server *server = hsristream->req->server;
    ssize_t ret;

    if ((ret=i_stream_read_copy_from_parent
        (&stream->istream)) > 0) {
        hsristream->read_status = ret;
        io_loop_stop(server->ioloop);
    }
}

static ssize_t
http_server_istream_read(struct istream_private *stream)
{
    struct http_server_istream *hsristream =
        (struct http_server_istream *)stream;
    struct http_server_request *req = hsristream->req;
    struct http_server *server;
    struct http_server_connection *conn;
    bool blocking = stream->istream.blocking;
    ssize_t ret;

    if (req == NULL) {
        /* request already gone (we shouldn't get here) */
        stream->istream.stream_errno = EINVAL;
        return -1;
    }

    i_stream_seek(stream->parent, stream->parent_start_offset +
              stream->istream.v_offset);

    server = hsristream->req->server;
    conn = hsristream->req->conn;

    ret = i_stream_read_copy_from_parent(&stream->istream);
    if (ret == 0 && blocking) {
        struct ioloop *prev_ioloop = current_ioloop;
        struct io *io;

        http_server_connection_ref(conn);
        http_server_request_ref(req);

        i_assert(server->ioloop == NULL);
        server->ioloop = io_loop_create();
        http_server_connection_switch_ioloop(conn);

        if (blocking && req->req.expect_100_continue &&
            !req->sent_100_continue)
            http_server_connection_trigger_responses(conn);

        hsristream->read_status = 0;
        io = io_add_istream(&stream->istream,
            http_server_istream_read_any, hsristream);
        while (req->state < HTTP_SERVER_REQUEST_STATE_FINISHED &&
            hsristream->read_status == 0) {
            io_loop_run(server->ioloop);
        }
        io_remove(&io);

        io_loop_set_current(prev_ioloop);
        http_server_connection_switch_ioloop(conn);
        io_loop_set_current(server->ioloop);
        io_loop_destroy(&server->ioloop);

        ret = hsristream->read_status;

        if (!http_server_request_unref(&req))
            hsristream->req = NULL;
        http_server_connection_unref(&conn);
    }

    return ret;
}

static void
http_server_istream_destroy(struct iostream_private *stream)
{
    struct http_server_istream *hsristream =
        (struct http_server_istream *)stream;
    uoff_t v_offset;

    v_offset = hsristream->istream.parent_start_offset +
        hsristream->istream.istream.v_offset;
    if (hsristream->istream.parent->seekable ||
        v_offset > hsristream->istream.parent->v_offset) {
        /* get to same position in parent stream */
        i_stream_seek(hsristream->istream.parent, v_offset);
    }
}

struct istream *
http_server_request_get_payload_input(struct http_server_request *req,
    bool blocking)
{
    struct http_server_istream *hsristream;
    struct istream *payload = req->req.payload;

    i_assert(req->payload_input == NULL);

    hsristream = i_new(struct http_server_istream, 1);
    hsristream->req = req;
    hsristream->istream.max_buffer_size =
        payload->real_stream->max_buffer_size;
    hsristream->istream.stream_size_passthrough = TRUE;

    hsristream->istream.read = http_server_istream_read;
    hsristream->istream.switch_ioloop = http_server_istream_switch_ioloop;
    hsristream->istream.iostream.destroy = http_server_istream_destroy;

    hsristream->istream.istream.readable_fd = FALSE;
    hsristream->istream.istream.blocking = blocking;
    hsristream->istream.istream.seekable = FALSE;

    req->payload_input = i_stream_create
        (&hsristream->istream, payload, i_stream_get_fd(payload));
    i_stream_unref(&req->req.payload);
    return req->payload_input;
}

/*
 * Payload handling
 */

static void
http_server_payload_handler_init(
    struct http_server_payload_handler *handler ,
    struct http_server_request *req)
{
    struct http_server_connection *conn = req->conn;

    i_assert(conn->payload_handler == NULL);
    i_assert(conn->in_req_callback);

    conn->payload_handler = handler;

    handler->req = req;
}

void http_server_payload_handler_destroy(
    struct http_server_payload_handler **_handler)
{
    struct http_server_payload_handler *handler = *_handler;
    struct http_server_connection *conn = handler->req->conn;

    if (handler->in_callback) {
        /* don't destroy handler while in callback */
        return;
    }

    *_handler = NULL;
    i_assert(conn->payload_handler == NULL);

    if (handler->destroy != NULL)
        handler->destroy(handler);
}

void http_server_payload_handler_switch_ioloop(
    struct http_server_payload_handler *handler)
{
    if (handler->switch_ioloop != NULL)
        handler->switch_ioloop(handler);
}

/* pump-based */

struct http_server_payload_handler_pump {
    struct http_server_payload_handler handler;

    struct iostream_pump *pump;

    void (*callback)(void *);
    void *context;
};

static void
payload_handler_pump_destroy(
    struct http_server_payload_handler *handler)
{
    struct http_server_payload_handler_pump *phandler =
        (struct http_server_payload_handler_pump *)handler;

    iostream_pump_unref(&phandler->pump);
}

static void
payload_handler_pump_switch_ioloop(
    struct http_server_payload_handler *handler)
{
    struct http_server_payload_handler_pump *phandler =
        (struct http_server_payload_handler_pump *)handler;

    iostream_pump_switch_ioloop(phandler->pump);
}

static void
payload_handler_pump_callback(bool success,
    struct http_server_payload_handler_pump *phandler)
{
    struct http_server_payload_handler *handler = &phandler->handler;
    struct http_server_request *req = handler->req;
    struct http_server_connection *conn = req->conn;
    struct istream *input = iostream_pump_get_input(phandler->pump);
    struct ostream *output = iostream_pump_get_output(phandler->pump);

    if (success) {
        if (!i_stream_is_eof(conn->incoming_payload)) {
            http_server_request_fail_close(req,
                413, "Payload Too Large");
        } else {
            unsigned int old_refcount = req->refcount;

            handler->in_callback = TRUE;
            phandler->callback(phandler->context);
            req->callback_refcount += req->refcount - old_refcount;
            handler->in_callback = FALSE;

            i_assert(req->callback_refcount > 0 ||
                (req->response != NULL && req->response->submitted));
        }
    } else if (input->stream_errno != 0) {
        http_server_request_client_error(req,
            "iostream_pump: read(%s) failed: %s",
            i_stream_get_name(input),
            i_stream_get_error(input));
        http_server_request_fail_close(req,
            400, "Bad Request");
    } else {
        if (output->stream_errno != 0) {
            http_server_request_error(req,
                "iostream_pump: write(%s) failed: %s",
                o_stream_get_name(output),
                o_stream_get_error(output));
        }
        http_server_request_fail_close(req,
            500, "Internal Server Error");
    }

    if (conn->payload_handler != NULL)
        http_server_payload_handler_destroy(&conn->payload_handler);
}

#undef http_server_request_forward_payload
void http_server_request_forward_payload(struct http_server_request *req,
    struct ostream *output, uoff_t max_size,
    void (*callback)(void *), void *context)
{
    struct http_server_connection *conn = req->conn;
    struct istream *input = conn->incoming_payload;
    struct http_server_payload_handler_pump *phandler;
    uoff_t payload_size;
    int ret;

    i_assert(req->req.payload != NULL);

    if (max_size == (uoff_t)-1) {
        i_stream_ref(input);
    } else {
        if ((ret = i_stream_get_size(input, TRUE, &payload_size)) != 0) {
            if (ret < 0) {
                http_server_request_error(req,
                    "i_stream_get_size(%s) failed: %s",
                    i_stream_get_name(input), i_stream_get_error(input));
                http_server_request_fail_close(req,
                    500, "Internal Server Error");
                return;
            }
            if (payload_size > max_size) {
                http_server_request_fail_close(req,
                    413, "Payload Too Large");
                return;
            }
        }
        input = i_stream_create_limit(input, max_size);
    }

    phandler = p_new(req->pool, struct http_server_payload_handler_pump, 1);
    http_server_payload_handler_init(&phandler->handler, req);
    phandler->handler.switch_ioloop = payload_handler_pump_switch_ioloop;
    phandler->handler.destroy = payload_handler_pump_destroy;
    phandler->callback = callback;
    phandler->context = context;

    phandler->pump = iostream_pump_create(input, output);
    iostream_pump_set_completion_callback(phandler->pump,
        payload_handler_pump_callback, phandler);
    iostream_pump_start(phandler->pump);
    i_stream_unref(&input);
}

#undef http_server_request_buffer_payload
void http_server_request_buffer_payload(struct http_server_request *req,
    buffer_t *buffer, uoff_t max_size,
    void (*callback)(void *), void *context)
{
    struct ostream *output;

    output = o_stream_create_buffer(buffer);
    http_server_request_forward_payload(req,
        output, max_size, callback, context);
    o_stream_unref(&output);
}

/* raw */

struct http_server_payload_handler_raw {
    struct http_server_payload_handler handler;

    struct io *io;

    void (*callback)(void *context);
    void *context;
};

static void
payload_handler_raw_destroy(
    struct http_server_payload_handler *handler)
{
    struct http_server_payload_handler_raw *rhandler =
        (struct http_server_payload_handler_raw *)handler;

    io_remove(&rhandler->io);
}

static void
payload_handler_raw_switch_ioloop(
    struct http_server_payload_handler *handler)
{
    struct http_server_payload_handler_raw *rhandler =
        (struct http_server_payload_handler_raw *)handler;

    rhandler->io = io_loop_move_io(&rhandler->io);
}

static void
payload_handler_raw_input(
    struct http_server_payload_handler_raw *rhandler)
{
    struct http_server_payload_handler *handler = &rhandler->handler;
    struct http_server_request *req = handler->req;
    struct http_server_connection *conn = req->conn;
    struct istream *input = conn->incoming_payload;
    unsigned int old_refcount = req->refcount;

    handler->in_callback = TRUE;
    rhandler->callback(rhandler->context);
    req->callback_refcount += req->refcount - old_refcount;
    handler->in_callback = FALSE;

    if (input != NULL && input->stream_errno != 0) {
        if (req->response == NULL) {
            http_server_request_client_error(req,
                "read(%s) failed: %s",
                i_stream_get_name(input),
                i_stream_get_error(input));
            http_server_request_fail_close(req,
                400, "Bad Request");
        }
    } else if (input == NULL ||
        !i_stream_have_bytes_left(input)) {
        i_assert(req->callback_refcount > 0 ||
            (req->response != NULL && req->response->submitted));
    } else {
        return;
    }

    if (conn->payload_handler != NULL)
        http_server_payload_handler_destroy(&conn->payload_handler);

}

#undef http_server_request_handle_payload
void http_server_request_handle_payload(struct http_server_request *req,
    void (*callback)(void *context), void *context)
{
    struct http_server_payload_handler_raw *rhandler;
    struct http_server_connection *conn = req->conn;

    rhandler = p_new(req->pool, struct http_server_payload_handler_raw, 1);
    http_server_payload_handler_init(&rhandler->handler, req);
    rhandler->handler.switch_ioloop = payload_handler_raw_switch_ioloop;
    rhandler->handler.destroy = payload_handler_raw_destroy;
    rhandler->callback = callback;
    rhandler->context = context;

    rhandler->io = io_add_istream(conn->incoming_payload,
        payload_handler_raw_input, rhandler);
    i_stream_set_input_pending(conn->incoming_payload, TRUE);
}