示例#1
0
static int rewrite_url(request_rec *r, proxy_worker *worker,
                        char **url)
{
    const char *scheme = strstr(*url, "://");
    const char *path = NULL;

    if (scheme)
        path = ap_strchr_c(scheme + 3, '/');

    /* we break the URL into host, port, uri */
    if (!worker) {
        return ap_proxyerror(r, HTTP_BAD_REQUEST, apr_pstrcat(r->pool,
                             "missing worker. URI cannot be parsed: ", *url,
                             NULL));
    }

    *url = apr_pstrcat(r->pool, worker->name, path, NULL);

    return OK;
}
PROXY_DECLARE(int) ap_proxy_pass_brigade(apr_bucket_alloc_t *bucket_alloc,
                                         request_rec *r, proxy_conn_rec *p_conn,
                                         conn_rec *origin, apr_bucket_brigade *bb,
                                         int flush)
{
    apr_status_t status;
    apr_off_t transferred;

    if (flush) {
        apr_bucket *e = apr_bucket_flush_create(bucket_alloc);
        APR_BRIGADE_INSERT_TAIL(bb, e);
    }
    apr_brigade_length(bb, 0, &transferred);
    if (transferred != -1)
        p_conn->worker->s->transferred += transferred;
    status = ap_pass_brigade(origin->output_filters, bb);
    if (status != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, "AH01084: "
                      "pass request body failed to %pI (%s)",
                      p_conn->addr, p_conn->hostname);
        if (origin->aborted) {
            const char *ssl_note;

            if (((ssl_note = apr_table_get(origin->notes, "SSL_connect_rv"))
                 != NULL) && (strcmp(ssl_note, "err") == 0)) {
                return ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
                                     "Error during SSL Handshake with"
                                     " remote server");
            }
            return APR_STATUS_IS_TIMEUP(status) ? HTTP_GATEWAY_TIME_OUT : HTTP_BAD_GATEWAY;
        }
        else {
            return HTTP_BAD_REQUEST;
        }
    }
    apr_brigade_cleanup(bb);
    return OK;
}
/* CONNECT handler */
static int proxy_connect_handler(request_rec *r, proxy_worker *worker,
                                 proxy_server_conf *conf,
                                 char *url, const char *proxyname,
                                 apr_port_t proxyport)
{
    apr_pool_t *p = r->pool;
    apr_socket_t *sock;
    apr_status_t err, rv;
    apr_size_t i, o, nbytes;
    char buffer[HUGE_STRING_LEN];
    apr_socket_t *client_socket = ap_get_module_config(r->connection->conn_config, &core_module);
    int failed;
    apr_pollset_t *pollset;
    apr_pollfd_t pollfd;
    const apr_pollfd_t *signalled;
    apr_int32_t pollcnt, pi;
    apr_int16_t pollevent;
    apr_sockaddr_t *uri_addr, *connect_addr;

    apr_uri_t uri;
    const char *connectname;
    int connectport = 0;

    /* is this for us? */
    if (r->method_number != M_CONNECT) {
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
             "proxy: CONNECT: declining URL %s", url);
    return DECLINED;
    }
    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
         "proxy: CONNECT: serving URL %s", url);


    /*
     * Step One: Determine Who To Connect To
     *
     * Break up the URL to determine the host to connect to
     */

    /* we break the URL into host, port, uri */
    if (APR_SUCCESS != apr_uri_parse_hostinfo(p, url, &uri)) {
    return ap_proxyerror(r, HTTP_BAD_REQUEST,
                 apr_pstrcat(p, "URI cannot be parsed: ", url, NULL));
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
         "proxy: CONNECT: connecting %s to %s:%d", url, uri.hostname, uri.port);

    /* do a DNS lookup for the destination host */
    err = apr_sockaddr_info_get(&uri_addr, uri.hostname, APR_UNSPEC, uri.port, 0, p);

    /* are we connecting directly, or via a proxy? */
    if (proxyname) {
    connectname = proxyname;
    connectport = proxyport;
        err = apr_sockaddr_info_get(&connect_addr, proxyname, APR_UNSPEC, proxyport, 0, p);
    }
    else {
    connectname = uri.hostname;
    connectport = uri.port;
    connect_addr = uri_addr;
    }
    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
         "proxy: CONNECT: connecting to remote proxy %s on port %d", connectname, connectport);

    /* check if ProxyBlock directive on this host */
    if (OK != ap_proxy_checkproxyblock(r, conf, uri_addr)) {
    return ap_proxyerror(r, HTTP_FORBIDDEN,
                 "Connect to remote machine blocked");
    }

    /* Check if it is an allowed port */
    if (conf->allowed_connect_ports->nelts == 0) {
    /* Default setting if not overridden by AllowCONNECT */
    switch (uri.port) {
        case APR_URI_HTTPS_DEFAULT_PORT:
        case APR_URI_SNEWS_DEFAULT_PORT:
        break;
        default:
                /* XXX can we call ap_proxyerror() here to get a nice log message? */
        return HTTP_FORBIDDEN;
    }
    } else if(!allowed_port(conf, uri.port)) {
        /* XXX can we call ap_proxyerror() here to get a nice log message? */
    return HTTP_FORBIDDEN;
    }

    /*
     * Step Two: Make the Connection
     *
     * We have determined who to connect to. Now make the connection.
     */

    /* get all the possible IP addresses for the destname and loop through them
     * until we get a successful connection
     */
    if (APR_SUCCESS != err) {
    return ap_proxyerror(r, HTTP_BAD_GATEWAY, apr_pstrcat(p,
                             "DNS lookup failure for: ",
                             connectname, NULL));
    }

    /*
     * At this point we have a list of one or more IP addresses of
     * the machine to connect to. If configured, reorder this
     * list so that the "best candidate" is first try. "best
     * candidate" could mean the least loaded server, the fastest
     * responding server, whatever.
     *
     * For now we do nothing, ie we get DNS round robin.
     * XXX FIXME
     */
    failed = ap_proxy_connect_to_backend(&sock, "CONNECT", connect_addr,
                                         connectname, conf, r->server,
                                         r->pool);

    /* handle a permanent error from the above loop */
    if (failed) {
        if (proxyname) {
            return DECLINED;
        }
        else {
            return HTTP_BAD_GATEWAY;
        }
    }

    /*
     * Step Three: Send the Request
     *
     * Send the HTTP/1.1 CONNECT request to the remote server
     */

    /* we are acting as a tunnel - the output filter stack should
     * be completely empty, because when we are done here we are done completely.
     * We add the NULL filter to the stack to do this...
     */
    r->output_filters = NULL;
    r->connection->output_filters = NULL;


    /* If we are connecting through a remote proxy, we need to pass
     * the CONNECT request on to it.
     */
    if (proxyport) {
    /* FIXME: Error checking ignored.
     */
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
             "proxy: CONNECT: sending the CONNECT request to the remote proxy");
        nbytes = apr_snprintf(buffer, sizeof(buffer),
                  "CONNECT %s HTTP/1.0" CRLF, r->uri);
        apr_socket_send(sock, buffer, &nbytes);
        nbytes = apr_snprintf(buffer, sizeof(buffer),
                  "Proxy-agent: %s" CRLF CRLF, ap_get_server_banner());
        apr_socket_send(sock, buffer, &nbytes);
    }
    else {
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
             "proxy: CONNECT: Returning 200 OK Status");
        nbytes = apr_snprintf(buffer, sizeof(buffer),
                  "HTTP/1.0 200 Connection Established" CRLF);
        ap_xlate_proto_to_ascii(buffer, nbytes);
        apr_socket_send(client_socket, buffer, &nbytes);
        nbytes = apr_snprintf(buffer, sizeof(buffer),
                  "Proxy-agent: %s" CRLF CRLF, ap_get_server_banner());
        ap_xlate_proto_to_ascii(buffer, nbytes);
        apr_socket_send(client_socket, buffer, &nbytes);
#if 0
        /* This is safer code, but it doesn't work yet.  I'm leaving it
         * here so that I can fix it later.
         */
        r->status = HTTP_OK;
        r->header_only = 1;
        apr_table_set(r->headers_out, "Proxy-agent: %s", ap_get_server_banner());
        ap_rflush(r);
#endif
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
         "proxy: CONNECT: setting up poll()");

    /*
     * Step Four: Handle Data Transfer
     *
     * Handle two way transfer of data over the socket (this is a tunnel).
     */

/*    r->sent_bodyct = 1;*/

    if ((rv = apr_pollset_create(&pollset, 2, r->pool, 0)) != APR_SUCCESS)
    {
    apr_socket_close(sock);
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r,
            "proxy: CONNECT: error apr_pollset_create()");
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    /* Add client side to the poll */
    pollfd.p = r->pool;
    pollfd.desc_type = APR_POLL_SOCKET;
    pollfd.reqevents = APR_POLLIN;
    pollfd.desc.s = client_socket;
    pollfd.client_data = NULL;
    apr_pollset_add(pollset, &pollfd);

    /* Add the server side to the poll */
    pollfd.desc.s = sock;
    apr_pollset_add(pollset, &pollfd);

    while (1) { /* Infinite loop until error (one side closes the connection) */
        if ((rv = apr_pollset_poll(pollset, -1, &pollcnt, &signalled)) != APR_SUCCESS) {
        apr_socket_close(sock);
            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, "proxy: CONNECT: error apr_poll()");
            return HTTP_INTERNAL_SERVER_ERROR;
        }
#ifdef DEBUGGING
        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                     "proxy: CONNECT: woke from select(), i=%d", pollcnt);
#endif

        for (pi = 0; pi < pollcnt; pi++) {
            const apr_pollfd_t *cur = &signalled[pi];

            if (cur->desc.s == sock) {
                pollevent = cur->rtnevents;
                if (pollevent & APR_POLLIN) {
#ifdef DEBUGGING
                    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                                 "proxy: CONNECT: sock was set");
#endif
                    nbytes = sizeof(buffer);
                    rv = apr_socket_recv(sock, buffer, &nbytes);
                    if (rv == APR_SUCCESS) {
                        o = 0;
                        i = nbytes;
                        while(i > 0)
                        {
                            nbytes = i;
    /* This is just plain wrong.  No module should ever write directly
     * to the client.  For now, this works, but this is high on my list of
     * things to fix.  The correct line is:
     * if ((nbytes = ap_rwrite(buffer + o, nbytes, r)) < 0)
     * rbb
     */
                            rv = apr_socket_send(client_socket, buffer + o, &nbytes);
                            if (rv != APR_SUCCESS)
                                break;
                            o += nbytes;
                            i -= nbytes;
                        }
                    }
                    else
                        break;
                }
                else if ((pollevent & APR_POLLERR) || (pollevent & APR_POLLHUP))
                    break;
            }
            else if (cur->desc.s == client_socket) {
                pollevent = cur->rtnevents;
                if (pollevent & APR_POLLIN) {
#ifdef DEBUGGING
                    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                                 "proxy: CONNECT: client was set");
#endif
                    nbytes = sizeof(buffer);
                    rv = apr_socket_recv(client_socket, buffer, &nbytes);
                    if (rv == APR_SUCCESS) {
                        o = 0;
                        i = nbytes;
#ifdef DEBUGGING
                        ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
                                     "proxy: CONNECT: read %d from client", i);
#endif
                        while(i > 0)
                        {
                            nbytes = i;
                            rv = apr_socket_send(sock, buffer + o, &nbytes);
                            if (rv != APR_SUCCESS)
                                break;
                            o += nbytes;
                            i -= nbytes;
                        }
                    }
                    else
                        break;
                }
                else if ((pollevent & APR_POLLERR) || (pollevent & APR_POLLHUP)) {
                    rv = APR_EOF;
                    break;
                }
            }
            else
                break;
        }
        if (rv != APR_SUCCESS) {
            break;
        }
    }

    ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
         "proxy: CONNECT: finished with poll() - cleaning up");

    /*
     * Step Five: Clean Up
     *
     * Close the socket and clean up
     */

    apr_socket_close(sock);

    return OK;
}
示例#4
0
/* CONNECT handler */
static int proxy_connect_handler(request_rec *r, proxy_worker *worker,
                                 proxy_server_conf *conf,
                                 char *url, const char *proxyname,
                                 apr_port_t proxyport)
{
    connect_conf *c_conf =
        ap_get_module_config(r->server->module_config, &proxy_connect_module);

    apr_pool_t *p = r->pool;
    apr_socket_t *sock;
    conn_rec *c = r->connection;
    conn_rec *backconn;

    apr_bucket_brigade *bb = apr_brigade_create(p, c->bucket_alloc);
    apr_status_t rv;
    apr_size_t nbytes;
    char buffer[HUGE_STRING_LEN];
    apr_socket_t *client_socket = ap_get_conn_socket(c);
    int failed, rc;
    int client_error = 0;
    apr_pollset_t *pollset;
    apr_pollfd_t pollfd;
    const apr_pollfd_t *signalled;
    apr_int32_t pollcnt, pi;
    apr_int16_t pollevent;
    apr_sockaddr_t *nexthop;

    apr_uri_t uri;
    const char *connectname;
    int connectport = 0;

    /* is this for us? */
    if (r->method_number != M_CONNECT) {
        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "declining URL %s", url);
        return DECLINED;
    }
    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "serving URL %s", url);


    /*
     * Step One: Determine Who To Connect To
     *
     * Break up the URL to determine the host to connect to
     */

    /* we break the URL into host, port, uri */
    if (APR_SUCCESS != apr_uri_parse_hostinfo(p, url, &uri)) {
        return ap_proxyerror(r, HTTP_BAD_REQUEST,
                             apr_pstrcat(p, "URI cannot be parsed: ", url,
                                         NULL));
    }

    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01019)
                  "connecting %s to %s:%d", url, uri.hostname, uri.port);

    /* Determine host/port of next hop; from request URI or of a proxy. */
    connectname = proxyname ? proxyname : uri.hostname;
    connectport = proxyname ? proxyport : uri.port;

    /* Do a DNS lookup for the next hop */
    rv = apr_sockaddr_info_get(&nexthop, connectname, APR_UNSPEC, 
                               connectport, 0, p);
    if (rv != APR_SUCCESS) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(02327)
                      "failed to resolve hostname '%s'", connectname);
        return ap_proxyerror(r, HTTP_BAD_GATEWAY,
                             apr_pstrcat(p, "DNS lookup failure for: ",
                                         connectname, NULL));
    }

    /* Check ProxyBlock directive on the hostname/address.  */
    if (ap_proxy_checkproxyblock2(r, conf, uri.hostname, 
                                 proxyname ? NULL : nexthop) != OK) {
        return ap_proxyerror(r, HTTP_FORBIDDEN,
                             "Connect to remote machine blocked");
    }

    ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r,
                  "connecting to remote proxy %s on port %d",
                  connectname, connectport);

    /* Check if it is an allowed port */
    if(!allowed_port(c_conf, uri.port)) {
              return ap_proxyerror(r, HTTP_FORBIDDEN,
                                   "Connect to remote machine blocked");
    }

    /*
     * Step Two: Make the Connection
     *
     * We have determined who to connect to. Now make the connection.
     */

    /*
     * At this point we have a list of one or more IP addresses of
     * the machine to connect to. If configured, reorder this
     * list so that the "best candidate" is first try. "best
     * candidate" could mean the least loaded server, the fastest
     * responding server, whatever.
     *
     * For now we do nothing, ie we get DNS round robin.
     * XXX FIXME
     */
    failed = ap_proxy_connect_to_backend(&sock, "CONNECT", nexthop,
                                         connectname, conf, r);

    /* handle a permanent error from the above loop */
    if (failed) {
        if (proxyname) {
            return DECLINED;
        }
        else {
            return HTTP_SERVICE_UNAVAILABLE;
        }
    }

    /* setup polling for connection */
    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "setting up poll()");

    if ((rv = apr_pollset_create(&pollset, 2, r->pool, 0)) != APR_SUCCESS) {
        apr_socket_close(sock);
        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01020)
                      "error apr_pollset_create()");
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    /* Add client side to the poll */
    pollfd.p = r->pool;
    pollfd.desc_type = APR_POLL_SOCKET;
    pollfd.reqevents = APR_POLLIN;
    pollfd.desc.s = client_socket;
    pollfd.client_data = NULL;
    apr_pollset_add(pollset, &pollfd);

    /* Add the server side to the poll */
    pollfd.desc.s = sock;
    apr_pollset_add(pollset, &pollfd);

    /*
     * Step Three: Send the Request
     *
     * Send the HTTP/1.1 CONNECT request to the remote server
     */

    backconn = ap_run_create_connection(c->pool, r->server, sock,
                                        c->id, c->sbh, c->bucket_alloc);
    if (!backconn) {
        /* peer reset */
        ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(01021)
                      "an error occurred creating a new connection "
                      "to %pI (%s)", nexthop, connectname);
        apr_socket_close(sock);
        return HTTP_INTERNAL_SERVER_ERROR;
    }
    ap_proxy_ssl_disable(backconn);
    rc = ap_run_pre_connection(backconn, sock);
    if (rc != OK && rc != DONE) {
        backconn->aborted = 1;
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01022)
                      "pre_connection setup failed (%d)", rc);
        return HTTP_INTERNAL_SERVER_ERROR;
    }

    ap_log_rerror(APLOG_MARK, APLOG_TRACE3, 0, r,
                  "connection complete to %pI (%s)",
                  nexthop, connectname);
    apr_table_setn(r->notes, "proxy-source-port", apr_psprintf(r->pool, "%hu",
                   backconn->local_addr->port));

    /* If we are connecting through a remote proxy, we need to pass
     * the CONNECT request on to it.
     */
    if (proxyport) {
    /* FIXME: Error checking ignored.
     */
        ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
                      "sending the CONNECT request to the remote proxy");
        ap_fprintf(backconn->output_filters, bb,
                   "CONNECT %s HTTP/1.0" CRLF, r->uri);
        ap_fprintf(backconn->output_filters, bb,
                   "Proxy-agent: %s" CRLF CRLF, ap_get_server_banner());
        ap_fflush(backconn->output_filters, bb);
    }
    else {
        ap_log_rerror(APLOG_MARK, APLOG_TRACE1, 0, r, "Returning 200 OK");
        nbytes = apr_snprintf(buffer, sizeof(buffer),
                              "HTTP/1.0 200 Connection Established" CRLF);
        ap_xlate_proto_to_ascii(buffer, nbytes);
        ap_fwrite(c->output_filters, bb, buffer, nbytes);
        nbytes = apr_snprintf(buffer, sizeof(buffer),
                              "Proxy-agent: %s" CRLF CRLF,
                              ap_get_server_banner());
        ap_xlate_proto_to_ascii(buffer, nbytes);
        ap_fwrite(c->output_filters, bb, buffer, nbytes);
        ap_fflush(c->output_filters, bb);
#if 0
        /* This is safer code, but it doesn't work yet.  I'm leaving it
         * here so that I can fix it later.
         */
        r->status = HTTP_OK;
        r->header_only = 1;
        apr_table_set(r->headers_out, "Proxy-agent: %s", ap_get_server_banner());
        ap_rflush(r);
#endif
    }

    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r, "setting up poll()");

    /*
     * Step Four: Handle Data Transfer
     *
     * Handle two way transfer of data over the socket (this is a tunnel).
     */

    /* we are now acting as a tunnel - the input/output filter stacks should
     * not contain any non-connection filters.
     */
    r->output_filters = c->output_filters;
    r->proto_output_filters = c->output_filters;
    r->input_filters = c->input_filters;
    r->proto_input_filters = c->input_filters;
/*    r->sent_bodyct = 1;*/

    while (1) { /* Infinite loop until error (one side closes the connection) */
        if ((rv = apr_pollset_poll(pollset, -1, &pollcnt, &signalled))
            != APR_SUCCESS) {
            if (APR_STATUS_IS_EINTR(rv)) {
                continue;
            }
            apr_socket_close(sock);
            ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01023) "error apr_poll()");
            return HTTP_INTERNAL_SERVER_ERROR;
        }
#ifdef DEBUGGING
        ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01024)
                      "woke from poll(), i=%d", pollcnt);
#endif

        for (pi = 0; pi < pollcnt; pi++) {
            const apr_pollfd_t *cur = &signalled[pi];

            if (cur->desc.s == sock) {
                pollevent = cur->rtnevents;
                if (pollevent & APR_POLLIN) {
#ifdef DEBUGGING
                    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01025)
                                  "sock was readable");
#endif
                    rv = proxy_connect_transfer(r, backconn, c, bb, "sock");
                    }
                else if ((pollevent & APR_POLLERR)
                         || (pollevent & APR_POLLHUP)) {
                         rv = APR_EPIPE;
                         ap_log_rerror(APLOG_MARK, APLOG_NOTICE, 0, r, APLOGNO(01026)
                                       "err/hup on backconn");
                }
                if (rv != APR_SUCCESS)
                    client_error = 1;
            }
            else if (cur->desc.s == client_socket) {
                pollevent = cur->rtnevents;
                if (pollevent & APR_POLLIN) {
#ifdef DEBUGGING
                    ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(01027)
                                  "client was readable");
#endif
                    rv = proxy_connect_transfer(r, c, backconn, bb, "client");
                }
            }
            else {
                rv = APR_EBADF;
                ap_log_rerror(APLOG_MARK, APLOG_INFO, 0, r, APLOGNO(01028)
                              "unknown socket in pollset");
            }

        }
        if (rv != APR_SUCCESS) {
            break;
        }
    }

    ap_log_rerror(APLOG_MARK, APLOG_TRACE2, 0, r,
                  "finished with poll() - cleaning up");

    /*
     * Step Five: Clean Up
     *
     * Close the socket and clean up
     */

    if (client_error)
        apr_socket_close(sock);
    else
        ap_lingering_close(backconn);

    c->aborted = 1;
    c->keepalive = AP_CONN_CLOSE;

    return OK;
}
示例#5
0
/*
 * This handles http:// URLs, and other URLs using a remote proxy over http
 * If proxyhost is NULL, then contact the server directly, otherwise
 * go via the proxy.
 * Note that if a proxy is used, then URLs other than http: can be accessed,
 * also, if we have trouble which is clearly specific to the proxy, then
 * we return DECLINED so that we can try another proxy. (Or the direct
 * route.)
 */
int ap_proxy_http_handler(request_rec *r, cache_req *c, char *url,
                              const char *proxyhost, int proxyport)
{
    const char *strp;
    char *strp2;
    const char *err, *desthost;
    int i, j, sock,/* len,*/ backasswards;
    table *req_hdrs, *resp_hdrs;
    array_header *reqhdrs_arr;
    table_entry *reqhdrs_elts;
    BUFF *f;
    char buffer[HUGE_STRING_LEN];
    char portstr[32];
    pool *p = r->pool;
    int chunked = 0, destport = 0;
    char *destportstr = NULL;
    const char *urlptr = NULL;
    const char *datestr, *urlstr;
    struct addrinfo hints, *res, *res0;
    int error;
    int result, major, minor;
    const char *content_length;
    const char *peer;
    int destportstrtonum;
    const char *errstr;

    void *sconf = r->server->module_config;
    proxy_server_conf *conf =
    (proxy_server_conf *)ap_get_module_config(sconf, &proxy_module);
    struct noproxy_entry *npent = (struct noproxy_entry *) conf->noproxies->elts;
    struct nocache_entry *ncent = (struct nocache_entry *) conf->nocaches->elts;
    int nocache = 0;

    if (conf->cache.root == NULL)
        nocache = 1;

    /* We break the URL into host, port, path-search */

    urlptr = strstr(url, "://");
    if (urlptr == NULL)
        return HTTP_BAD_REQUEST;
    destport = DEFAULT_HTTP_PORT;
    urlptr += 3;
    ap_hook_use("ap::mod_proxy::http::handler::set_destport", 
                AP_HOOK_SIG2(int,ptr), 
                AP_HOOK_TOPMOST,
                &destport, r);
    ap_snprintf(portstr, sizeof(portstr), "%d", destport);
    destportstr = portstr;
    strp = strchr(urlptr, '/');
    if (strp == NULL) {
        desthost = ap_pstrdup(p, urlptr);
        urlptr = "/";
    }
    else {
        char *q = ap_palloc(p, strp - urlptr + 1);
        memcpy(q, urlptr, strp - urlptr);
        q[strp - urlptr] = '\0';
        urlptr = strp;
        desthost = q;
    }
    if (*desthost == '['){
      char *u = strrchr(desthost+1, ']');
      if (u){
          desthost++;
          *u = '\0';
          if (*(u+1) == ':'){ /* [host]:xx */
              strp2 = u+1;
          }
          else if (*(u+1) == '\0'){   /* [host] */
              strp2 = NULL;
          }
          else
              return HTTP_BAD_REQUEST;
      }
      else
          return HTTP_BAD_REQUEST;
    }
    else
       strp2 = strrchr(desthost, ':');

    if (strp2 != NULL) {
        *(strp2++) = '\0';
        if (ap_isdigit(*strp2))
            destportstr = strp2;
    }

    /* Make sure peer is always set to prevent a segfault in the SSL handler */
    peer = desthost;

    memset(&hints, 0, sizeof(hints));
    hints.ai_family = PF_UNSPEC;
    hints.ai_socktype = SOCK_STREAM;
    hints.ai_protocol = IPPROTO_TCP;
    error = getaddrinfo(desthost, destportstr, &hints, &res0);
    if (error && proxyhost == NULL) {
      return ap_proxyerror(r, HTTP_INTERNAL_SERVER_ERROR,
                  gai_strerror(error));       /* give up */
     }
 
      /* check if ProxyBlock directive on this host */
      for (i = 0; i < conf->noproxies->nelts; i++) {
      int fail;
      struct sockaddr_in *sin;

      fail = 0;
      if (npent[i].name != NULL && strstr(desthost, npent[i].name))
          fail++;
      if (npent[i].name != NULL && strcmp(npent[i].name, "*") == 0)
          fail++;
      for (res = res0; res; res = res->ai_next) {
          switch (res->ai_family) {
          case AF_INET:
              sin = (struct sockaddr_in *)res->ai_addr;
              if (sin->sin_addr.s_addr == npent[i].addr.s_addr)
                  fail++;
              break;
		
          }
      }
      if (fail) {
          if (res0 != NULL)
              freeaddrinfo(res0);
          return ap_proxyerror(r, HTTP_FORBIDDEN,
                               "Connect to remote machine blocked");
      }
    }
    if (proxyhost != NULL) {
      char pbuf[10];

      if (res0 != NULL)
          freeaddrinfo(res0);

      ap_snprintf(pbuf, sizeof(pbuf), "%d", proxyport);
      memset(&hints, 0, sizeof(hints));
      hints.ai_family = PF_UNSPEC;
      hints.ai_socktype = SOCK_STREAM;
      hints.ai_protocol = IPPROTO_TCP;
      error = getaddrinfo(proxyhost, pbuf, &hints, &res0);
      if (error)
          return DECLINED;    /* try another */
    }

    /* check if ProxyBlock directive on this host */
    for (i = 0; i < conf->noproxies->nelts; i++) {
	peer =  ap_psprintf(p, "%s:%s", desthost, destportstr);  
    }


    /*
     * we have worked out who exactly we are going to connect to, now make
     * that connection...
     */
     sock = i = -1;
     for (res = res0; res; res = res->ai_next) {
       sock = ap_psocket(p, res->ai_family, res->ai_socktype,
           res->ai_protocol);
       if (sock < 0)
           continue;

      if (conf->recv_buffer_size) {
          if (setsockopt(sock, SOL_SOCKET, SO_RCVBUF,
                         (const char *)&conf->recv_buffer_size, sizeof(int))
              == -1) {
              ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                            "setsockopt(SO_RCVBUF): Failed to set ProxyReceiveBufferSize, using default");
          }
      }

      i = ap_proxy_doconnect(sock, res->ai_addr, r);
      if (i == 0)
          break;
      ap_pclosesocket(p, sock);
    }
    freeaddrinfo(res0);

    if (i == -1) {
        if (proxyhost != NULL)
            return DECLINED;    /* try again another way */
        else
            return ap_proxyerror(r, HTTP_BAD_GATEWAY, ap_pstrcat(r->pool,
                                    "Could not connect to remote machine: ",
                                                    strerror(errno), NULL));
    }

    /* record request_time for HTTP/1.1 age calculation */
    c->req_time = time(NULL);

    /*
     * build upstream-request headers by stripping r->headers_in from
     * connection specific headers. We must not remove the Connection: header
     * from r->headers_in, we still have to react to Connection: close
     */
    req_hdrs = ap_copy_table(r->pool, r->headers_in);
    ap_proxy_clear_connection(r->pool, req_hdrs);

    /*
     * At this point, we start sending the HTTP/1.1 request to the remote
     * server (proxy or otherwise).
     */
    f = ap_bcreate(p, B_RDWR | B_SOCKET);
    ap_bpushfd(f, sock, sock);

    {
        char *errmsg = NULL;
        ap_hook_use("ap::mod_proxy::http::handler::new_connection", 
                    AP_HOOK_SIG4(ptr,ptr,ptr,ptr), 
                    AP_HOOK_DECLINE(NULL),
                    &errmsg, r, f, peer);
        if (errmsg != NULL)
            return ap_proxyerror(r, HTTP_BAD_GATEWAY, errmsg);
    }

    ap_hard_timeout("proxy send", r);
    ap_bvputs(f, r->method, " ", proxyhost ? url : urlptr, " HTTP/1.1" CRLF,
              NULL);
    {
	int rc = DECLINED;
	ap_hook_use("ap::mod_proxy::http::handler::write_host_header", 
		    AP_HOOK_SIG6(int,ptr,ptr,ptr,ptr,ptr), 
		    AP_HOOK_DECLINE(DECLINED),
		    &rc, r, f, desthost, destportstr, destportstr);
        if (rc == DECLINED) {
	    destportstrtonum = strtonum(destportstr, 0, 65535, &errstr);
	    if (errstr)
		errx(1, "The destination port is %s: %s", errstr, destportstr);

	    if (destportstr != NULL && destportstrtonum != destport)
		ap_bvputs(f, "Host: ", desthost, ":", destportstr, CRLF, NULL);
	    else
		ap_bvputs(f, "Host: ", desthost, CRLF, NULL);
        }
    }

    if (conf->viaopt == via_block) {
        /* Block all outgoing Via: headers */
        ap_table_unset(req_hdrs, "Via");
    }
    else if (conf->viaopt != via_off) {
        /* Create a "Via:" request header entry and merge it */
        i = ap_get_server_port(r);
        if (ap_is_default_port(i, r)) {
            strlcpy(portstr, "", sizeof(portstr));
        }
        else {
            ap_snprintf(portstr, sizeof portstr, ":%d", i);
        }
        /* Generate outgoing Via: header with/without server comment: */
        ap_table_mergen(req_hdrs, "Via",
                        (conf->viaopt == via_full)
                        ? ap_psprintf(p, "%d.%d %s%s (%s)",
                                      HTTP_VERSION_MAJOR(r->proto_num),
                                      HTTP_VERSION_MINOR(r->proto_num),
                                      ap_get_server_name(r), portstr,
                                      SERVER_BASEVERSION)
                        : ap_psprintf(p, "%d.%d %s%s",
                                      HTTP_VERSION_MAJOR(r->proto_num),
                                      HTTP_VERSION_MINOR(r->proto_num),
                                      ap_get_server_name(r), portstr)
            );
    }

    /* the X-* headers are only added if we are a reverse
     * proxy, otherwise we would be giving away private information.
     */
    if (r->proxyreq == PROXY_PASS) {
        const char *buf;

        /*
         * Add X-Forwarded-For: so that the upstream has a chance to determine,
         * where the original request came from.
         */
        ap_table_mergen(req_hdrs, "X-Forwarded-For", r->connection->remote_ip);

        /* Add X-Forwarded-Host: so that upstream knows what the
         * original request hostname was.
         */
        if ((buf = ap_table_get(r->headers_in, "Host"))) {
            ap_table_mergen(req_hdrs, "X-Forwarded-Host", buf);
        }

        /* Add X-Forwarded-Server: so that upstream knows what the
         * name of this proxy server is (if there are more than one)
         * XXX: This duplicates Via: - do we strictly need it?
         */
        ap_table_mergen(req_hdrs, "X-Forwarded-Server", r->server->server_hostname);
    } 

    /* we don't yet support keepalives - but we will soon, I promise! */
    ap_table_set(req_hdrs, "Connection", "close");

    reqhdrs_arr = ap_table_elts(req_hdrs);
    reqhdrs_elts = (table_entry *)reqhdrs_arr->elts;
    for (i = 0; i < reqhdrs_arr->nelts; i++) {
        if (reqhdrs_elts[i].key == NULL || reqhdrs_elts[i].val == NULL

        /*
         * Clear out hop-by-hop request headers not to send: RFC2616 13.5.1
         * says we should strip these headers:
         */
            || !strcasecmp(reqhdrs_elts[i].key, "Host") /* Already sent */
            || !strcasecmp(reqhdrs_elts[i].key, "Keep-Alive")
            || !strcasecmp(reqhdrs_elts[i].key, "TE")
            || !strcasecmp(reqhdrs_elts[i].key, "Trailer")
            || !strcasecmp(reqhdrs_elts[i].key, "Transfer-Encoding")
            || !strcasecmp(reqhdrs_elts[i].key, "Upgrade")
        /*
         * XXX: @@@ FIXME: "Proxy-Authorization" should *only* be suppressed
         * if THIS server requested the authentication, not when a frontend
         * proxy requested it!
         * 
         * The solution to this problem is probably to strip out the
         * Proxy-Authorisation header in the authorisation code itself, not
         * here. This saves us having to signal somehow whether this request
         * was authenticated or not.
         */
            || !strcasecmp(reqhdrs_elts[i].key, "Proxy-Authorization"))
            continue;
        ap_bvputs(f, reqhdrs_elts[i].key, ": ", reqhdrs_elts[i].val, CRLF, NULL);
    }

    /* the obligatory empty line to mark the end of the headers */
    ap_bputs(CRLF, f);

    /* and flush the above away */
    ap_bflush(f);

    /* and kill the send timeout */
    ap_kill_timeout(r);


    /* read the request data, and pass it to the backend.
     * we might encounter a stray 100-continue reponse from a PUT or POST,
     * if this happens we ignore the 100 continue status line and read the
     * response again.
     */
    {
        /* send the request data, if any. */
        ap_hard_timeout("proxy receive request data", r);
        if (ap_should_client_block(r)) {
            while ((i = ap_get_client_block(r, buffer, sizeof buffer)) > 0) {
                ap_reset_timeout(r);
                ap_bwrite(f, buffer, i);
            }
        }
        ap_bflush(f);
        ap_kill_timeout(r);


        /* then, read a response line */
        ap_hard_timeout("proxy receive response status line", r);
        result = ap_proxy_read_response_line(f, r, buffer, sizeof(buffer)-1, &backasswards, &major, &minor);
        ap_kill_timeout(r);

        /* trap any errors */
        if (result != OK) {
            ap_bclose(f);
            return result;
        }

        /* if this response was 100-continue, a stray response has been caught.
         * read the line again for the real response
         */
        if (r->status == 100) {
            ap_hard_timeout("proxy receive response status line", r);
            result = ap_proxy_read_response_line(f, r, buffer, sizeof(buffer)-1, &backasswards, &major, &minor);
            ap_kill_timeout(r);

            /* trap any errors */
            if (result != OK) {
                ap_bclose(f);
                return result;
            }
        }
    }


    /*
     * We have our response status line from the convoluted code above,
     * now we read the headers to continue.
     */
    ap_hard_timeout("proxy receive response headers", r);

    /*
     * Is it an HTTP/1 response? Do some sanity checks on the response. (This
     * is buggy if we ever see an HTTP/1.10)
     */
    if (backasswards == 0) {

        /* read the response headers. */
        /* N.B. for HTTP/1.0 clients, we have to fold line-wrapped headers */
        /* Also, take care with headers with multiple occurences. */

        resp_hdrs = ap_proxy_read_headers(r, buffer, sizeof(buffer), f);
        if (resp_hdrs == NULL) {
            ap_log_error(APLOG_MARK, APLOG_WARNING | APLOG_NOERRNO, r->server,
                         "proxy: Bad HTTP/%d.%d header returned by %s (%s)",
                         major, minor, r->uri, r->method);
            resp_hdrs = ap_make_table(p, 20);
            nocache = 1;        /* do not cache this broken file */
        }

        /* handle Via header in the response */
        if (conf->viaopt != via_off && conf->viaopt != via_block) {
            /* Create a "Via:" response header entry and merge it */
            i = ap_get_server_port(r);
            if (ap_is_default_port(i, r)) {
                strlcpy(portstr, "", sizeof(portstr));
            }
            else {
                ap_snprintf(portstr, sizeof portstr, ":%d", i);
            }
            ap_table_mergen((table *)resp_hdrs, "Via",
                            (conf->viaopt == via_full)
                            ? ap_psprintf(p, "%d.%d %s%s (%s)",
                                          major, minor,
                                          ap_get_server_name(r), portstr,
                                          SERVER_BASEVERSION)
                            : ap_psprintf(p, "%d.%d %s%s",
                                          major, minor,
                                          ap_get_server_name(r), portstr)
                );
        }

        /* is this content chunked? */
        chunked = ap_find_last_token(r->pool,
                                     ap_table_get(resp_hdrs, "Transfer-Encoding"),
                                     "chunked");

        /* strip hop-by-hop headers defined by Connection and RFC2616 */
        ap_proxy_clear_connection(p, resp_hdrs);

        content_length = ap_table_get(resp_hdrs, "Content-Length");
        if (content_length != NULL) {
            c->len = ap_strtol(content_length, NULL, 10);

	    if (c->len < 0) {
		ap_kill_timeout(r);
		return ap_proxyerror(r, HTTP_BAD_GATEWAY, ap_pstrcat(r->pool,
				     "Invalid Content-Length from remote server",
                                      NULL));
	    }
        }

    }
    else {
        /* an http/0.9 response */

        /* no headers */
        resp_hdrs = ap_make_table(p, 20);
    }

    ap_kill_timeout(r);

    /*
     * HTTP/1.1 requires us to accept 3 types of dates, but only generate one
     * type
     */
    /*
     * we SET the dates here, obliterating possible multiple dates, as only
     * one of each date makes sense in each response.
     */
    if ((datestr = ap_table_get(resp_hdrs, "Date")) != NULL)
        ap_table_set(resp_hdrs, "Date", ap_proxy_date_canon(p, datestr));
    if ((datestr = ap_table_get(resp_hdrs, "Last-Modified")) != NULL)
        ap_table_set(resp_hdrs, "Last-Modified", ap_proxy_date_canon(p, datestr));
    if ((datestr = ap_table_get(resp_hdrs, "Expires")) != NULL)
        ap_table_set(resp_hdrs, "Expires", ap_proxy_date_canon(p, datestr));

    /* handle the ProxyPassReverse mappings */
    if ((urlstr = ap_table_get(resp_hdrs, "Location")) != NULL)
        ap_table_set(resp_hdrs, "Location", proxy_location_reverse_map(r, urlstr));
    if ((urlstr = ap_table_get(resp_hdrs, "URI")) != NULL)
        ap_table_set(resp_hdrs, "URI", proxy_location_reverse_map(r, urlstr));
    if ((urlstr = ap_table_get(resp_hdrs, "Content-Location")) != NULL)
        ap_table_set(resp_hdrs, "Content-Location", proxy_location_reverse_map(r, urlstr));

/* check if NoCache directive on this host */
  {
    struct sockaddr_in *sin;
    struct sockaddr_in6 *sin6;

    if (nocache == 0) {
	for (i = 0; i < conf->nocaches->nelts; i++) {
	    if (ncent[i].name != NULL && 
		(ncent[i].name[0] == '*' ||
		 strstr(desthost, ncent[i].name) != NULL)) {
		nocache = 1;
		break;
	    }
	    switch (res->ai_addr->sa_family) {
	    case AF_INET:
		sin = (struct sockaddr_in *)res->ai_addr;
		if (sin->sin_addr.s_addr == ncent[i].addr.s_addr) {
		    nocache = 1;
		    break;
		}
	    }
	}

        /* update the cache file, possibly even fulfilling the request if
         * it turns out a conditional allowed us to serve the object from the
         * cache...
         */
        i = ap_proxy_cache_update(c, resp_hdrs, !backasswards, nocache);
        if (i != DECLINED) {
            ap_bclose(f);
            return i;
        }

        /* write status line and headers to the cache file */
        ap_proxy_write_headers(c, ap_pstrcat(p, "HTTP/1.1 ", r->status_line, NULL), resp_hdrs);
    }
  }

    /* Setup the headers for our client from upstreams response-headers */
    ap_proxy_table_replace(r->headers_out, resp_hdrs);
    /* Add X-Cache header - be careful not to obliterate any upstream headers */
    ap_table_mergen(r->headers_out, "X-Cache",
                    ap_pstrcat(r->pool, "MISS from ",
                               ap_get_server_name(r), NULL));
    /* The Content-Type of this response is the upstream one. */
    r->content_type = ap_table_get(r->headers_out, "Content-Type");
    ap_log_error(APLOG_MARK, APLOG_DEBUG | APLOG_NOERRNO, r->server, "Content-Type: %s", r->content_type);

    /* finally output the headers to the client */
    ap_send_http_header(r);

    /*
     * Is it an HTTP/0.9 respose? If so, send the extra data we read from
     * upstream as the start of the reponse to client
     */
/* FIXME: This code is broken: we try and write a buffer and length that
 * were never intelligently initialised. Rather have a bit of broken protocol
 * handling for now than broken code.
 */
/*
    if (backasswards) {
        ap_hard_timeout("proxy send assbackward", r);

        ap_bwrite(r->connection->client, buffer, len);
        if (c != NULL && c->fp != NULL && ap_bwrite(c->fp, buffer, len) != len) {
            ap_log_rerror(APLOG_MARK, APLOG_ERR, c->req,
                      "proxy: error writing extra data to %s", c->tempfile);
            c = ap_proxy_cache_error(c);
        }
        ap_kill_timeout(r);
    }
*/

/* send body */
/* if header only, then cache will be NULL */
/* HTTP/1.0 tells us to read to EOF, rather than content-length bytes */
/* XXX CHANGEME: We want to eventually support keepalives, which means
 * we must read content-length bytes... */
    if (!r->header_only) {
/* we need to set this for ap_proxy_send_fb()... */
        c->cache_completion = conf->cache.cache_completion;

/* XXX CHECKME: c->len should be the expected content length, or -1 if the
 * content length is not known. We need to make 100% sure c->len is always
 * set correctly before we get here to correctly do keepalive.
 */
        ap_proxy_send_fb(f, r, c, c->len, 0, chunked, conf->io_buffer_size);
    }

    /* ap_proxy_send_fb() closes the socket f for us */

    ap_proxy_cache_tidy(c);

    ap_proxy_garbage_coll(r);
    return OK;
}