Name

Post Read Request

Synopsis

static int module_post_read_request(request_rec *pReq)

This function is called immediately after the request headers have been read or, in the case of an internal redirect, synthesized. It is not called for subrequests. It can return OK, DECLINED, or a status code. If something other than DECLINED is returned, no further modules are called. This can be used to make decisions based purely on the header content. Currently, the only standard Apache module to use this hook is the proxy module.

See Example 21-12 for an excerpt from mod_proxy.c.

Example

Example 21-12. mod_proxy.c

static int proxy_detect(request_rec *r)
{
    void *sconf = r->server->module_config;
    proxy_server_conf *conf;

    conf = (proxy_server_conf *) ap_get_module_config(sconf, &proxy_module);

    if (conf->req && r->parsed_uri.scheme) {
        /* but it might be something vhosted */
       if (!(r->parsed_uri.hostname
            && !strcasecmp(r->parsed_uri.scheme, ap_http_method(r))
            && ap_matches_request_vhost(r, r->parsed_uri.hostname,
               r->parsed_uri.port_str ? r->parsed_uri.port : ap_default_port(r)))) {
            r->proxyreq = STD_PROXY;
            r->uri = r->unparsed_uri;
            r->filename = ap_pstrcat(r->pool, "proxy:", r->uri, NULL);
            r->handler = "proxy-server";
        }
    }
    /* We need special treatment for CONNECT proxying: it has no scheme part */
    else if (conf->req && r->method_number == M_CONNECT
             && r->parsed_uri.hostname
             && r->parsed_uri.port_str) {
            r->proxyreq = STD_PROXY;
            r->uri = r->unparsed_uri;
            r->filename = ap_pstrcat(r->pool, "proxy:", r->uri, NULL);
            r->handler = "proxy-server";
    }
    return DECLINED;
}

This code checks for a request that includes a hostname that does not match the current virtual host (which, since it will have been chosen on the basis of the hostname in the request, means it doesn’t match any virtual host) or a CONNECT method (which only proxies use). If either of these conditions are true, the handler is set to proxy-server, and the filename is set to proxy: uri so that the later phases will be handled by the proxy module.

Apart from minor differences in naming of constants, this function is identical in 2.0.