mod_proxy_ajp.c

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/* Copyright 1999-2005 The Apache Software Foundation or its licensors, as
 * applicable.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* AJP routines for Apache proxy */

#include "mod_proxy.h"
#include "ajp.h"

module AP_MODULE_DECLARE_DATA proxy_ajp_module;

/*
 * Canonicalise http-like URLs.
 * scheme is the scheme for the URL
 * url is the URL starting with the first '/'
 * def_port is the default port for this scheme.
 */
static int proxy_ajp_canon(request_rec *r, char *url)
{
    char *host, *path, *search, sport[7];
    const char *err;
    apr_port_t port = AJP13_DEF_PORT;

    /* ap_port_of_scheme() */
    if (strncasecmp(url, "ajp:", 4) == 0) {
        url += 4;
    }
    else {
        return DECLINED;
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
             "proxy: AJP: canonicalising URL %s", url);

    /*
     * do syntactic check.
     * We break the URL into host, port, path, search
     */
    err = ap_proxy_canon_netloc(r->pool, &url, NULL, NULL, &host, &port);
    if (err) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r,
                      "error parsing URL %s: %s",
                      url, err);
        return HTTP_BAD_REQUEST;
    }

    /*
     * now parse path/search args, according to rfc1738
     *
     * N.B. if this isn't a true proxy request, then the URL _path_
     * has already been decoded.  True proxy requests have
     * r->uri == r->unparsed_uri, and no others have that property.
     */
    if (r->uri == r->unparsed_uri) {
        search = strchr(url, '?');
        if (search != NULL)
            *(search++) = '\0';
    }
    else
        search = r->args;

    /* process path */
    path = ap_proxy_canonenc(r->pool, url, strlen(url), enc_path, 0,
                             r->proxyreq);
    if (path == NULL)
        return HTTP_BAD_REQUEST;

    apr_snprintf(sport, sizeof(sport), ":%d", port);

    if (ap_strchr_c(host, ':')) {
        /* if literal IPv6 address */
        host = apr_pstrcat(r->pool, "[", host, "]", NULL);
    }
    r->filename = apr_pstrcat(r->pool, "proxy:ajp://", host, sport,
                              "/", path, (search) ? "?" : "",
                              (search) ? search : "", NULL);
    return OK;
}

/*
 * XXX: AJP Auto Flushing
 *
 * When processing CMD_AJP13_SEND_BODY_CHUNK AJP messages we will do a poll
 * with FLUSH_WAIT miliseconds timeout to determine if more data is currently
 * available at the backend. If there is no more data available, we flush
 * the data to the client by adding a flush bucket to the brigade we pass
 * up the filter chain.
 * This is only a bandaid to fix the AJP/1.3 protocol shortcoming of not
 * sending (actually not having defined) a flush message, when the data
 * should be flushed to the client. As soon as this protocol shortcoming is
 * fixed this code should be removed.
 *
 * For further discussion see PR37100.
 * http://issues.apache.org/bugzilla/show_bug.cgi?id=37100
 */

/*
 * process the request and write the response.
 */
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;
    char *buff;
    apr_uint16_t size;
    const char *tenc;
    int havebody = 1;
    int isok = 1;
    apr_off_t bb_len;
    int data_sent = 0;
    int rv = 0;
    apr_int32_t conn_poll_fd;
    apr_pollfd_t *conn_poll;

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

    /* send request headers */
    status = ajp_send_header(conn->sock, r, uri);
    if (status != APR_SUCCESS) {
        conn->close++;
        ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server,
                     "proxy: AJP: request failed to %pI (%s)",
                     conn->worker->cp->addr,
                     conn->worker->hostname);
        if (status == AJP_EOVERFLOW)
            return HTTP_BAD_REQUEST;
        else
            return HTTP_SERVICE_UNAVAILABLE;
    }

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

    /* read the first bloc of data */
    input_brigade = apr_brigade_create(p, r->connection->bucket_alloc);
    tenc = apr_table_get(r->headers_in, "Transfer-Encoding");
    if (tenc && (strcasecmp(tenc, "chunked") == 0)) {
        /* The AJP protocol does not want body data yet */
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                     "proxy: request is chunked");
    } else {
        status = ap_get_brigade(r->input_filters, input_brigade,
                                AP_MODE_READBYTES, APR_BLOCK_READ,
                                AJP13_MAX_SEND_BODY_SZ);

        if (status != APR_SUCCESS) {
            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                         "proxy: ap_get_brigade failed");
            apr_brigade_destroy(input_brigade);
            return HTTP_INTERNAL_SERVER_ERROR;
        }

        /* have something */
        if (APR_BUCKET_IS_EOS(APR_BRIGADE_LAST(input_brigade))) {
            ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                         "proxy: APR_BUCKET_IS_EOS");
        }

        /* Try to send something */
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                     "proxy: 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++;
            apr_brigade_destroy(input_brigade);
            ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server,
                         "proxy: apr_brigade_flatten");
            return HTTP_INTERNAL_SERVER_ERROR;
        }
        apr_brigade_cleanup(input_brigade);

        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                     "proxy: got %" APR_SIZE_T_FMT " bytes of data", bufsiz);
        if (bufsiz > 0) {
            status = ajp_send_data_msg(conn->sock, msg, bufsiz);
            if (status != APR_SUCCESS) {
                /* We had a failure: Close connection to backend */
                conn->close++;
                apr_brigade_destroy(input_brigade);
                ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server,
                             "proxy: send failed to %pI (%s)",
                             conn->worker->cp->addr,
                             conn->worker->hostname);
                return HTTP_SERVICE_UNAVAILABLE;
            }
            conn->worker->s->transferred += bufsiz;
        }
    }

    /* read the response */
    conn->data = NULL;
    status = ajp_read_header(conn->sock, r,
                             (ajp_msg_t **)&(conn->data));
    if (status != APR_SUCCESS) {
        /* We had a failure: Close connection to backend */
        conn->close++;
        apr_brigade_destroy(input_brigade);
        ap_log_error(APLOG_MARK, APLOG_ERR, status, r->server,
                     "proxy: read response failed from %pI (%s)",
                     conn->worker->cp->addr,
                     conn->worker->hostname);
        return HTTP_SERVICE_UNAVAILABLE;
    }
    /* parse the reponse */
    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 = AJP13_MAX_SEND_BODY_SZ;
    while (isok) {
        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_error(APLOG_MARK, APLOG_DEBUG, status, r->server,
                                     "proxy: APR_BUCKET_IS_EOS");
                    } else {
                        status = ap_get_brigade(r->input_filters, input_brigade,
                                                AP_MODE_READBYTES,
                                                APR_BLOCK_READ,
                                                AJP13_MAX_SEND_BODY_SZ);
                        if (status != APR_SUCCESS) {
                            ap_log_error(APLOG_MARK, APLOG_DEBUG, status,
                                         r->server,
                                         "ap_get_brigade failed");
                            break;
                        }
                        bufsiz = AJP13_MAX_SEND_BODY_SZ;
                        status = apr_brigade_flatten(input_brigade, buff,
                                                     &bufsiz);
                        apr_brigade_cleanup(input_brigade);
                        if (status != APR_SUCCESS) {
                            ap_log_error(APLOG_MARK, APLOG_DEBUG, status,
                                         r->server,