static int ap_proxy_ajp_request()

in modules/proxy/mod_proxy_ajp.c [181:762]


static int ap_proxy_ajp_request(apr_pool_t *p, request_rec *r,
                                proxy_conn_rec *conn,
                                conn_rec *origin,
                                proxy_dir_conf *conf,
                                apr_uri_t *uri,
                                char *url, char *server_portstr)
{
    apr_status_t status;
    int result;
    apr_bucket *e;
    apr_bucket_brigade *input_brigade;
    apr_bucket_brigade *output_brigade;
    ajp_msg_t *msg;
    apr_size_t bufsiz = 0;
    char *buff;
    char *send_body_chunk_buff;
    apr_uint16_t size;
    apr_byte_t conn_reuse = 0;
    const char *tenc;
    int havebody = 1;
    int client_failed = 0;
    int backend_failed = 0;
    apr_off_t bb_len;
    int data_sent = 0;
    int request_ended = 0;
    int headers_sent = 0;
    int rv = OK;
    apr_int32_t conn_poll_fd;
    apr_pollfd_t *conn_poll;
    proxy_server_conf *psf =
    ap_get_module_config(r->server->module_config, &proxy_module);
    apr_size_t maxsize = AJP_MSG_BUFFER_SZ;
    int send_body = 0;
    apr_off_t content_length = 0;
    int original_status = r->status;
    const char *original_status_line = r->status_line;
    const char *secret = NULL;

    if (psf->io_buffer_size_set)
       maxsize = psf->io_buffer_size;
    /* Override with worker setting if present */
    if (conn->worker->s->io_buffer_size_set)
       maxsize = conn->worker->s->io_buffer_size;
    if (maxsize > AJP_MAX_BUFFER_SZ)
       maxsize = AJP_MAX_BUFFER_SZ;
    else if (maxsize < AJP_MSG_BUFFER_SZ)
       maxsize = AJP_MSG_BUFFER_SZ;
    maxsize = APR_ALIGN(maxsize, 1024);

    if (*conn->worker->s->secret)
        secret = conn->worker->s->secret;

    /*
     * Send the AJP request to the remote server
     */

    /* send request headers */
    status = ajp_send_header(conn->sock, r, maxsize, uri, secret);
    if (status != APR_SUCCESS) {
        conn->close = 1;
        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00868)
                      "request failed to %pI (%s:%hu)",
                      conn->addr, conn->hostname, conn->port);
        if (status == AJP_EOVERFLOW)
            return HTTP_BAD_REQUEST;
        else {
            /*
             * This is only non fatal when the method is idempotent. In this
             * case we can dare to retry it with a different worker if we are
             * a balancer member.
             */
            if (is_idempotent(r) == METHOD_IDEMPOTENT) {
                return HTTP_SERVICE_UNAVAILABLE;
            }
            return HTTP_INTERNAL_SERVER_ERROR;
        }
    }

    /* allocate an AJP message to store the data of the buckets */
    bufsiz = maxsize;
    status = ajp_alloc_data_msg(r->pool, &buff, &bufsiz, &msg);
    if (status != APR_SUCCESS) {
        /* We had a failure: Close connection to backend */
        conn->close = 1;
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00869)
                      "ajp_alloc_data_msg failed");
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    /* read the first block of data */
    input_brigade = apr_brigade_create(p, r->connection->bucket_alloc);
    tenc = apr_table_get(r->headers_in, "Transfer-Encoding");
    if (tenc) {
        if (ap_cstr_casecmp(tenc, "chunked") == 0) {
            /* The AJP protocol does not want body data yet */
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00870)
                          "request is chunked");
        }
        else {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(10396)
                          "%s Transfer-Encoding is not supported",
                          tenc);
            /* We had a failure: Close connection to backend */
            conn->close = 1;
            return HTTP_INTERNAL_SERVER_ERROR;
        }
    } else {
        /* Get client provided Content-Length header */
        content_length = get_content_length(r);
        if (content_length < 0) {
            status = APR_EINVAL;
        }
        else {
            status = ap_get_brigade(r->input_filters, input_brigade,
                                    AP_MODE_READBYTES, APR_BLOCK_READ,
                                    maxsize - AJP_HEADER_SZ);
        }
        if (status != APR_SUCCESS) {
            /* We had a failure: Close connection to backend */
            conn->close = 1;
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00871)
                          "ap_get_brigade failed");
            apr_brigade_destroy(input_brigade);
            return ap_map_http_request_error(status, HTTP_BAD_REQUEST);
        }

        /* have something */
        if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00872) "APR_BUCKET_IS_EOS");
        }

        /* Try to send something */
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00873)
                      "data to read (max %" APR_SIZE_T_FMT
                      " at %" APR_SIZE_T_FMT ")", bufsiz, msg->pos);

        status = apr_brigade_flatten(input_brigade, buff, &bufsiz);
        if (status != APR_SUCCESS) {
            /* We had a failure: Close connection to backend */
            conn->close = 1;
            apr_brigade_destroy(input_brigade);
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00874)
                          "apr_brigade_flatten");
            return HTTP_INTERNAL_SERVER_ERROR;
        }
        apr_brigade_cleanup(input_brigade);

        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00875)
                      "got %" APR_SIZE_T_FMT " bytes of data", bufsiz);
        if (bufsiz > 0) {
            status = ajp_send_data_msg(conn->sock, msg, bufsiz);
            ajp_msg_log(r, msg, "First ajp_send_data_msg: ajp_ilink_send packet dump");
            if (status != APR_SUCCESS) {
                /* We had a failure: Close connection to backend */
                conn->close = 1;
                apr_brigade_destroy(input_brigade);
                ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00876)
                              "send failed to %pI (%s:%hu)",
                              conn->addr, conn->hostname, conn->port);
                /*
                 * It is fatal when we failed to send a (part) of the request
                 * body.
                 */
                return HTTP_INTERNAL_SERVER_ERROR;
            }
            conn->worker->s->transferred += bufsiz;
            send_body = 1;
        }
        else if (content_length > 0) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00877)
                          "read zero bytes, expecting"
                          " %" APR_OFF_T_FMT " bytes",
                          content_length);
            /*
             * We can only get here if the client closed the connection
             * to us without sending the body.
             * Now the connection is in the wrong state on the backend.
             * Sending an empty data msg doesn't help either as it does
             * not move this connection to the correct state on the backend
             * for later resusage by the next request again.
             * Close it to clean things up.
             */
            conn->close = 1;
            apr_brigade_destroy(input_brigade);
            return HTTP_BAD_REQUEST;
        }
    }

    /* read the response */
    conn->data = NULL;
    status = ajp_read_header(conn->sock, r, maxsize,
                             (ajp_msg_t **)&(conn->data));
    if (status != APR_SUCCESS) {
        /* We had a failure: Close connection to backend */
        conn->close = 1;
        apr_brigade_destroy(input_brigade);
        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00878)
                      "read response failed from %pI (%s:%hu)",
                      conn->addr, conn->hostname, conn->port);

        /* If we had a successful cping/cpong and then a timeout
         * we assume it is a request that cause a back-end timeout,
         * but doesn't affect the whole worker.
         */
        if (APR_STATUS_IS_TIMEUP(status) &&
                conn->worker->s->ping_timeout_set) {
            apr_table_setn(r->notes, "proxy_timedout", "1");
            return HTTP_GATEWAY_TIME_OUT;
        }

        /*
         * This is only non fatal when we have not sent (parts) of a possible
         * request body so far (we do not store it and thus cannot send it
         * again) and the method is idempotent. In this case we can dare to
         * retry it with a different worker if we are a balancer member.
         */
        if (!send_body && (is_idempotent(r) == METHOD_IDEMPOTENT)) {
            return HTTP_SERVICE_UNAVAILABLE;
        }
        return HTTP_INTERNAL_SERVER_ERROR;
    }
    /* parse the response */
    result = ajp_parse_type(r, conn->data);
    output_brigade = apr_brigade_create(p, r->connection->bucket_alloc);

    /*
     * Prepare apr_pollfd_t struct for possible later check if there is currently
     * data available from the backend (do not flush response to client)
     * or not (flush response to client)
     */
    conn_poll = apr_pcalloc(p, sizeof(apr_pollfd_t));
    conn_poll->reqevents = APR_POLLIN;
    conn_poll->desc_type = APR_POLL_SOCKET;
    conn_poll->desc.s = conn->sock;

    bufsiz = maxsize;
    for (;;) {
        switch (result) {
            case CMD_AJP13_GET_BODY_CHUNK:
                if (havebody) {
                    if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
                        /* This is the end */
                        bufsiz = 0;
                        havebody = 0;
                        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00879)
                                      "APR_BUCKET_IS_EOS");
                    } else {
                        status = ap_get_brigade(r->input_filters, input_brigade,
                                                AP_MODE_READBYTES,
                                                APR_BLOCK_READ,
                                                maxsize - AJP_HEADER_SZ);
                        if (status != APR_SUCCESS) {
                            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00880)
                                          "ap_get_brigade failed");
                            if (APR_STATUS_IS_TIMEUP(status)) {
                                rv = HTTP_REQUEST_TIME_OUT;
                            }
                            else if (status == AP_FILTER_ERROR) {
                                rv = AP_FILTER_ERROR;
                            }
                            client_failed = 1;
                            break;
                        }
                        bufsiz = maxsize;
                        status = apr_brigade_flatten(input_brigade, buff,
                                                     &bufsiz);
                        apr_brigade_cleanup(input_brigade);
                        if (status != APR_SUCCESS) {
                            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00881)
                                         "apr_brigade_flatten failed");
                            rv = HTTP_INTERNAL_SERVER_ERROR;
                            client_failed = 1;
                            break;
                        }
                    }

                    ajp_msg_reset(msg);
                    /* will go in ajp_send_data_msg */
                    status = ajp_send_data_msg(conn->sock, msg, bufsiz);
                    ajp_msg_log(r, msg, "ajp_send_data_msg after CMD_AJP13_GET_BODY_CHUNK: ajp_ilink_send packet dump");
                    if (status != APR_SUCCESS) {
                        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00882)
                                      "ajp_send_data_msg failed");
                        backend_failed = 1;
                        break;
                    }
                    conn->worker->s->transferred += bufsiz;
                } else {
                    /*
                     * something is wrong TC asks for more body but we are
                     * already at the end of the body data
                     */
                    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00883)
                                  "ap_proxy_ajp_request error read after end");
                    backend_failed = 1;
                }
                break;
            case CMD_AJP13_SEND_HEADERS:
                if (headers_sent) {
                    /* Do not send anything to the client.
                     * Backend already send us the headers.
                     */
                    backend_failed = 1;
                    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00884)
                                  "Backend sent headers twice.");
                    break;
                }
                /* AJP13_SEND_HEADERS: process them */
                status = ajp_parse_header(r, conf, conn->data);
                if (status != APR_SUCCESS) {
                    backend_failed = 1;
                }
                else if ((r->status == 401) && conf->error_override) {
                    const char *buf;
                    const char *wa = "WWW-Authenticate";
                    if ((buf = apr_table_get(r->headers_out, wa))) {
                        apr_table_set(r->err_headers_out, wa, buf);
                    } else {
                        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00885)
                                      "ap_proxy_ajp_request: origin server "
                                      "sent 401 without WWW-Authenticate header");
                    }
                }
                headers_sent = 1;
                break;
            case CMD_AJP13_SEND_BODY_CHUNK:
                /* AJP13_SEND_BODY_CHUNK: piece of data */
                status = ajp_parse_data(r, conn->data, &size, &send_body_chunk_buff);
                if (status == APR_SUCCESS) {
                    /* If we are overriding the errors, we can't put the content
                     * of the page into the brigade.
                     */
                    if (!ap_proxy_should_override(conf, r->status)) {
                        /* AJP13_SEND_BODY_CHUNK with zero length
                         * is explicit flush message
                         */
                        if (size == 0) {
                            if (headers_sent) {
                                e = apr_bucket_flush_create(r->connection->bucket_alloc);
                                APR_BRIGADE_INSERT_TAIL(output_brigade, e);
                            }
                            else {
                                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00886)
                                              "Ignoring flush message "
                                              "received before headers");
                            }
                        }
                        else {
                            apr_status_t rv;

                            /* Handle the case where the error document is itself reverse
                             * proxied and was successful. We must maintain any previous
                             * error status so that an underlying error (eg HTTP_NOT_FOUND)
                             * doesn't become an HTTP_OK.
                             */
                            if (ap_proxy_should_override(conf, original_status)) {
                                r->status = original_status;
                                r->status_line = original_status_line;
                            }

                            e = apr_bucket_transient_create(send_body_chunk_buff, size,
                                                        r->connection->bucket_alloc);
                            APR_BRIGADE_INSERT_TAIL(output_brigade, e);

                            if ((conn->worker->s->flush_packets == flush_on) ||
                                ((conn->worker->s->flush_packets == flush_auto) &&
                                ((rv = apr_poll(conn_poll, 1, &conn_poll_fd,
                                                 conn->worker->s->flush_wait))
                                                 != APR_SUCCESS) &&
                                  APR_STATUS_IS_TIMEUP(rv))) {
                                e = apr_bucket_flush_create(r->connection->bucket_alloc);
                                APR_BRIGADE_INSERT_TAIL(output_brigade, e);
                            }
                            apr_brigade_length(output_brigade, 0, &bb_len);
                            if (bb_len != -1)
                                conn->worker->s->read += bb_len;
                        }
                        if (headers_sent) {
                            if (ap_pass_brigade(r->output_filters,
                                                output_brigade) != APR_SUCCESS) {
                                ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00887)
                                              "error processing body.%s",
                                              r->connection->aborted ?
                                              " Client aborted connection." : "");
                                client_failed = 1;
                            }
                            data_sent = 1;
                            apr_brigade_cleanup(output_brigade);
                        }
                    }
                }
                else {
                    backend_failed = 1;
                }
                break;
            case CMD_AJP13_END_RESPONSE:
                /* If we are overriding the errors, we must not send anything to
                 * the client, especially as the brigade already contains headers.
                 * So do nothing here, and it will be cleaned up below.
                 */
                status = ajp_parse_reuse(r, conn->data, &conn_reuse);
                if (status != APR_SUCCESS) {
                    backend_failed = 1;
                }
                if (!ap_proxy_should_override(conf, r->status)) {
                    e = apr_bucket_eos_create(r->connection->bucket_alloc);
                    APR_BRIGADE_INSERT_TAIL(output_brigade, e);
                    if (ap_pass_brigade(r->output_filters,
                                        output_brigade) != APR_SUCCESS) {
                        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00888)
                                      "error processing end");
                        client_failed = 1;
                    }
                    /* XXX: what about flush here? See mod_jk */
                    data_sent = 1;
                }
                request_ended = 1;
                break;
            default:
                backend_failed = 1;
                break;
        }

        /*
         * If connection has been aborted by client: Stop working.
         * Pretend we are done (data_sent) to avoid further processing.
         */
        if (r->connection->aborted) {
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(02821)
                          "client connection aborted");
            /* no response yet (or ever), set status for access log */
            if (!headers_sent) {
                r->status = HTTP_BAD_REQUEST;
            }
            client_failed = 1;
            /* return DONE */
            data_sent = 1;
            break;
        }

        /*
         * We either have finished successfully or we failed.
         * So bail out
         */
        if ((result == CMD_AJP13_END_RESPONSE)
                || backend_failed || client_failed)
            break;

        /* read the response */
        status = ajp_read_header(conn->sock, r, maxsize,
                                 (ajp_msg_t **)&(conn->data));
        if (status != APR_SUCCESS) {
            backend_failed = 1;
            ap_log_rerror(APLOG_MARK, APLOG_DEBUG, status, r, APLOGNO(00889)
                          "ajp_read_header failed");
            break;
        }
        result = ajp_parse_type(r, conn->data);
    }
    apr_brigade_destroy(input_brigade);

    /*
     * Clear output_brigade to remove possible buckets that remained there
     * after an error.
     */
    apr_brigade_cleanup(output_brigade);

    if (backend_failed || client_failed) {
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00890)
                      "Processing of request failed backend: %i, client: %i",
                      backend_failed, client_failed);
        /* We had a failure: Close connection to backend */
        conn->close = 1;
        if (data_sent) {
            /* Return DONE to avoid error messages being added to the stream */
            rv = DONE;
        }
    }
    else if (!request_ended) {
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00891)
                      "Processing of request didn't terminate cleanly");
        /* We had a failure: Close connection to backend */
        conn->close = 1;
        backend_failed = 1;
        if (data_sent) {
            /* Return DONE to avoid error messages being added to the stream */
            rv = DONE;
        }
    }
    else if (!conn_reuse) {
        /* Our backend signalled connection close */
        conn->close = 1;
    }
    else {
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(00892)
                      "got response from %pI (%s:%hu)",
                      conn->addr, conn->hostname, conn->port);

        if (ap_proxy_should_override(conf, r->status)) {
            /* clear r->status for override error, otherwise ErrorDocument
             * thinks that this is a recursive error, and doesn't find the
             * custom error page
             */
            rv = r->status;
            r->status = HTTP_OK;
            /*
             * prevent proxy_handler() from treating this as an
             * internal error.
             */
            apr_table_setn(r->notes, "proxy-error-override", "1");
        }
        else {
            rv = OK;
        }
    }

    if (backend_failed) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(00893)
                      "dialog to %pI (%s:%hu) failed",
                      conn->addr, conn->hostname, conn->port);
        /*
         * If we already send data, signal a broken backend connection
         * upwards in the chain.
         */
        if (data_sent) {
            ap_proxy_fill_error_brigade(r, HTTP_BAD_GATEWAY, output_brigade, -1);
        } else if (!send_body && (is_idempotent(r) == METHOD_IDEMPOTENT)) {
            /*
             * This is only non fatal when we have not send (parts) of a possible
             * request body so far (we do not store it and thus cannot send it
             * again) and the method is idempotent. In this case we can dare to
             * retry it with a different worker if we are a balancer member.
             */
            rv = HTTP_SERVICE_UNAVAILABLE;
        } else {
            /* If we had a successful cping/cpong and then a timeout
             * we assume it is a request that cause a back-end timeout,
             * but doesn't affect the whole worker.
             */
            if (APR_STATUS_IS_TIMEUP(status) &&
                    conn->worker->s->ping_timeout_set) {
                apr_table_setn(r->notes, "proxy_timedout", "1");
                rv = HTTP_GATEWAY_TIME_OUT;
            }
            else {
                rv = HTTP_INTERNAL_SERVER_ERROR;
            }
        }
    }
    else if (client_failed) {
        int level = (r->connection->aborted) ? APLOG_DEBUG : APLOG_ERR;
        ap_log_rerror(APLOG_MARK, level, status, r, APLOGNO(02822)
                      "dialog with client %pI failed",
                      r->connection->client_addr);
        if (rv == OK) {
            rv = HTTP_BAD_REQUEST;
        }
    }

    /*
     * Ensure that we sent an EOS bucket thru the filter chain, if we already
     * have sent some data.
     */
    if (data_sent && !r->eos_sent && !r->connection->aborted) {
        e = apr_bucket_eos_create(r->connection->bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(output_brigade, e);
    }

    /* If we have added something to the brigade above, send it */
    if (!APR_BRIGADE_EMPTY(output_brigade)
        && ap_pass_brigade(r->output_filters, output_brigade) != APR_SUCCESS) {
        rv = AP_FILTER_ERROR;
    }

    apr_brigade_destroy(output_brigade);

    if (apr_table_get(r->subprocess_env, "proxy-nokeepalive")) {
        conn->close = 1;
    }

    return rv;
}