source: mainline/uspace/srv/ns/clonable.c@ 40313e4

/*
 * Copyright (c) 2009 Martin Decky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup ns
 * @{
 */

#include <ipc/ipc.h>
#include <ipc/services.h>
#include <libadt/list.h>
#include <bool.h>
#include <errno.h>
#include <assert.h>
#include <stdio.h>
#include <malloc.h>
#include "clonable.h"
#include "ns.h"

/** Request for connection to a clonable service. */
typedef struct {
        link_t link;
        ipcarg_t service;
        ipc_call_t call;
        ipc_callid_t callid;
} cs_req_t;

/** List of clonable-service connection requests. */
static link_t cs_req;

int clonable_init(void)
{
        list_initialize(&cs_req);
        return EOK;
}

/** Return true if @a service is clonable. */
bool service_clonable(int service)
{
        return (service == SERVICE_LOAD);
}

/** Register clonable service.
 *
 * @param service Service to be registered.
 * @param phone   Phone to be used for connections to the service.
 * @param call    Pointer to call structure.
 *
 */
void register_clonable(ipcarg_t service, ipcarg_t phone, ipc_call_t *call,
    ipc_callid_t callid)
{
        if (list_empty(&cs_req)) {
                /* There was no pending connection request. */
                printf(NAME ": Unexpected clonable server.\n");
                ipc_answer_0(callid, EBUSY);
                return;
        }
        
        cs_req_t *csr = list_get_instance(cs_req.next, cs_req_t, link);
        list_remove(&csr->link);
        
        /* Currently we can only handle a single type of clonable service. */
        assert(csr->service == SERVICE_LOAD);
        
        ipc_answer_0(callid, EOK);
        
        ipc_forward_fast(csr->callid, phone, IPC_GET_ARG2(csr->call),
                IPC_GET_ARG3(csr->call), 0, IPC_FF_NONE);
        
        free(csr);
        ipc_hangup(phone);
}

/** Connect client to clonable service.
 *
 * @param service Service to be connected to.
 * @param call    Pointer to call structure.
 * @param callid  Call ID of the request.
 *
 * @return Zero on success or a value from @ref errno.h.
 *
 */
void connect_to_clonable(ipcarg_t service, ipc_call_t *call,
    ipc_callid_t callid)
{
        assert(service == SERVICE_LOAD);
        
        cs_req_t *csr = malloc(sizeof(cs_req_t));
        if (csr == NULL) {
                ipc_answer_0(callid, ENOMEM);
                return;
        }
        
        /* Spawn a loader. */
        int rc = loader_spawn("loader");
        
        if (rc < 0) {
                free(csr);
                ipc_answer_0(callid, rc);
                return;
        }
        
        csr->service = service;
        csr->call = *call;
        csr->callid = callid;
        
        /*
         * We can forward the call only after the server we spawned connects
         * to us. Meanwhile we might need to service more connection requests.
         * Thus we store the call in a queue.
         */
        list_append(&csr->link, &cs_req);
}

/**
 * @}
 */