Function ap_select_protocol

server/protocol.c:2444–2530

}

AP_DECLARE(const char *) ap_select_protocol(conn_rec *c, request_rec *r, 
                                            server_rec *s,
                                            const apr_array_header_t *choices)
{
    apr_pool_t *pool = r? r->pool : c->pool;
    core_server_config *conf;
    const char *protocol = NULL, *existing;
    apr_array_header_t *proposals;

    if (!s) {
        s = (r? r->server : c->base_server);
    }
    conf = ap_get_core_module_config(s->module_config);
    
    if (APLOGcdebug(c)) {
        const char *p = apr_array_pstrcat(pool, conf->protocols, ',');
        ap_log_cerror(APLOG_MARK, APLOG_DEBUG, 0, c, APLOGNO(03155) 
                      "select protocol from %s, choices=%s for server %s", 
                      p, apr_array_pstrcat(pool, choices, ','),
                      s->server_hostname);
    }

    if (conf->protocols->nelts <= 0) {
        /* nothing configured, by default, we only allow http/1.1 here.
         * For now...
         */
        if (ap_array_str_contains(choices, AP_PROTOCOL_HTTP1)) {
            return AP_PROTOCOL_HTTP1;
        }
        else {
            return NULL;
        }
    }

    proposals = apr_array_make(pool, choices->nelts + 1, sizeof(char *));
    ap_run_protocol_propose(c, r, s, choices, proposals);

    /* If the existing protocol has not been proposed, but is a choice,
     * add it to the proposals implicitly.
     */
    existing = ap_get_protocol(c);
    if (!ap_array_str_contains(proposals, existing)
        && ap_array_str_contains(choices, existing)) {
        APR_ARRAY_PUSH(proposals, const char*) = existing;
    }

    if (proposals->nelts > 0) {
        int i;
        const apr_array_header_t *prefs = NULL;

        /* Default for protocols_honor_order is 'on' or != 0 */
        if (conf->protocols_honor_order == 0 && choices->nelts > 0) {
            prefs = choices;
        }
        else {
            prefs = conf->protocols;
        }