WebSVN – HelenOS – Diff – /tags/0.2.0.5/kernel/generic/src/ipc/sysipc.c


/*
 * Copyright (c) 2006 Ondrej Palkovsky
 * 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 genericipc
 * @{
 */
/** @file
 */
 
#include <arch.h>
#include <proc/task.h>
#include <proc/thread.h>
#include <errno.h>
#include <memstr.h>
#include <debug.h>
#include <ipc/ipc.h>
#include <ipc/sysipc.h>
#include <ipc/irq.h>
#include <ipc/ipcrsc.h>
#include <arch/interrupt.h>
#include <print.h>
#include <syscall/copy.h>
#include <security/cap.h>
#include <mm/as.h>
#include <print.h>
 
#define GET_CHECK_PHONE(phone, phoneid, err) \
{ \
    if (phoneid > IPC_MAX_PHONES) { \
        err; \
    } \
    phone = &TASK->phones[phoneid]; \
}
 
#define STRUCT_TO_USPACE(dst, src)  copy_to_uspace(dst, src, sizeof(*(src)))
 
/** Decide if the method is a system method.
 *
 * @param method    Method to be decided.
 *
 * @return      Return 1 if the method is a system method.
 *          Otherwise return 0.
 */
static inline int is_system_method(unative_t method)
{
    if (method <= IPC_M_LAST_SYSTEM)
        return 1;
    return 0;
}
 
/** Decide if the message with this method is forwardable.
 *
 * - some system messages may be forwarded, for some of them
 *   it is useless
 *
 * @param method    Method to be decided.
 *
 * @return      Return 1 if the method is forwardable.
 *          Otherwise return 0.
 */
static inline int is_forwardable(unative_t method)
{
    if (method == IPC_M_PHONE_HUNGUP || method == IPC_M_AS_AREA_SEND ||
        method == IPC_M_AS_AREA_RECV)
        return 0; /* This message is meant only for the receiver */
    return 1;
}
 
 
/***********************************************************************
 * Functions that preprocess answer before sending it to the recepient.
 ***********************************************************************/
 
/** Decide if the caller (e.g. ipc_answer()) should save the old call contents
 * for answer_preprocess().
 *
 * @param call      Call structure to be decided.
 *
 * @return      Return 1 if the old call contents should be saved.
 *          Return 0 otherwise.
 */
static inline int answer_need_old(call_t *call)
{
    if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME)
        return 1;
    if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_ME_TO)
        return 1;
    if (IPC_GET_METHOD(call->data) == IPC_M_AS_AREA_SEND)
        return 1;
    if (IPC_GET_METHOD(call->data) == IPC_M_AS_AREA_RECV)
        return 1;
    return 0;
}
 
/** Interpret process answer as control information.
 *
 * This function is called directly after sys_ipc_answer().
 *
 * @param answer    Call structure with the answer.
 * @param olddata   Saved data of the request.
 *
 * @return      Return 0 on success or an error code.
 */
static inline int answer_preprocess(call_t *answer, ipc_data_t *olddata)
{
    int phoneid;
 
    if (IPC_GET_RETVAL(answer->data) == EHANGUP) {
        /* In case of forward, hangup the forwared phone,
         * not the originator
         */
        spinlock_lock(&answer->data.phone->lock);
        spinlock_lock(&TASK->answerbox.lock);
        if (answer->data.phone->state == IPC_PHONE_CONNECTED) {
            list_remove(&answer->data.phone->link);
            answer->data.phone->state = IPC_PHONE_SLAMMED;
        }
        spinlock_unlock(&TASK->answerbox.lock);
        spinlock_unlock(&answer->data.phone->lock);
    }
 
    if (!olddata)
        return 0;
 
    if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECT_TO_ME) {
        phoneid = IPC_GET_ARG3(*olddata);
        if (IPC_GET_RETVAL(answer->data)) {
            /* The connection was not accepted */
            phone_dealloc(phoneid);
        } else {
            /* The connection was accepted */
            phone_connect(phoneid, &answer->sender->answerbox);
            /* Set 'phone hash' as arg3 of response */
            IPC_SET_ARG3(answer->data,
                (unative_t) &TASK->phones[phoneid]);
        }
    } else if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECT_ME_TO) {
        /* If the users accepted call, connect */
        if (!IPC_GET_RETVAL(answer->data)) {
            ipc_phone_connect((phone_t *) IPC_GET_ARG3(*olddata),
                &TASK->answerbox);
        }
    } else if (IPC_GET_METHOD(*olddata) == IPC_M_AS_AREA_SEND) {
        if (!IPC_GET_RETVAL(answer->data)) {
            /* Accepted, handle as_area receipt */
            ipl_t ipl;
            int rc;
            as_t *as;
           
            ipl = interrupts_disable();
            spinlock_lock(&answer->sender->lock);
            as = answer->sender->as;
            spinlock_unlock(&answer->sender->lock);
            interrupts_restore(ipl);
           
            rc = as_area_share(as, IPC_GET_ARG1(*olddata),
                IPC_GET_ARG2(*olddata), AS,
                IPC_GET_ARG1(answer->data), IPC_GET_ARG3(*olddata));
            IPC_SET_RETVAL(answer->data, rc);
            return rc;
        }
    } else if (IPC_GET_METHOD(*olddata) == IPC_M_AS_AREA_RECV) {
        if (!IPC_GET_RETVAL(answer->data)) {
            ipl_t ipl;
            as_t *as;
            int rc;
           
            ipl = interrupts_disable();
            spinlock_lock(&answer->sender->lock);
            as = answer->sender->as;
            spinlock_unlock(&answer->sender->lock);
            interrupts_restore(ipl);
           
            rc = as_area_share(AS, IPC_GET_ARG1(answer->data),
                IPC_GET_ARG2(*olddata), as, IPC_GET_ARG1(*olddata),
                IPC_GET_ARG2(answer->data));
            IPC_SET_RETVAL(answer->data, rc);
        }
    }
    return 0;
}
 
/** Called before the request is sent.
 *
 * @param call      Call structure with the request.
 *
 * @return      Return 0 on success, ELIMIT or EPERM on error.
 */
static int request_preprocess(call_t *call)
{
    int newphid;
    size_t size;
 
    switch (IPC_GET_METHOD(call->data)) {
    case IPC_M_CONNECT_ME_TO:
        newphid = phone_alloc();
        if (newphid < 0)
            return ELIMIT;
        /* Set arg3 for server */
        IPC_SET_ARG3(call->data, (unative_t) &TASK->phones[newphid]);
        call->flags |= IPC_CALL_CONN_ME_TO;
        call->priv = newphid;
        break;
    case IPC_M_AS_AREA_SEND:
        size = as_get_size(IPC_GET_ARG1(call->data));
        if (!size)
            return EPERM;
        IPC_SET_ARG2(call->data, size);
        break;
    default:
        break;
    }
    return 0;
}
 
/*******************************************************************************
 * Functions called to process received call/answer before passing it to uspace.
 *******************************************************************************/
 
/** Do basic kernel processing of received call answer.
 *
 * @param call      Call structure with the answer.
 */
static void process_answer(call_t *call)
{
    if (IPC_GET_RETVAL(call->data) == EHANGUP &&
        (call->flags & IPC_CALL_FORWARDED))
        IPC_SET_RETVAL(call->data, EFORWARD);
 
    if (call->flags & IPC_CALL_CONN_ME_TO) {
        if (IPC_GET_RETVAL(call->data))
            phone_dealloc(call->priv);
        else
            IPC_SET_ARG3(call->data, call->priv);
    }
}
 
/** Do basic kernel processing of received call request.
 *
 * @param box       Destination answerbox structure.
 * @param call      Call structure with the request.
 *
 * @return      Return 0 if the call should be passed to userspace.
 *          Return -1 if the call should be ignored.
 */
static int process_request(answerbox_t *box, call_t *call)
{
    int phoneid;
 
    if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME) {
        phoneid = phone_alloc();
        if (phoneid < 0) { /* Failed to allocate phone */
            IPC_SET_RETVAL(call->data, ELIMIT);
            ipc_answer(box, call);
            return -1;
        }
        IPC_SET_ARG3(call->data, phoneid);
    }
    return 0;
}
 
/** Make a fast call over IPC, wait for reply and return to user.
 *
 * This function can handle only one argument of payload, but is faster than
 * the generic function (i.e. sys_ipc_call_sync()).
 *
 * @param phoneid   Phone handle for the call.
 * @param method    Method of the call.
 * @param arg1      Service-defined payload argument.
 * @param data      Address of userspace structure where the reply call will
 *          be stored.
 *
 * @return      Returns 0 on success.
 *          Return ENOENT if there is no such phone handle.
 */
unative_t sys_ipc_call_sync_fast(unative_t phoneid, unative_t method,
    unative_t arg1, ipc_data_t *data)
{
    call_t call;
    phone_t *phone;
    int res;
 
    GET_CHECK_PHONE(phone, phoneid, return ENOENT);
 
    ipc_call_static_init(&call);
    IPC_SET_METHOD(call.data, method);
    IPC_SET_ARG1(call.data, arg1);
 
    if (!(res = request_preprocess(&call))) {
        ipc_call_sync(phone, &call);
        process_answer(&call);
    } else {
        IPC_SET_RETVAL(call.data, res);
    }
    STRUCT_TO_USPACE(&data->args, &call.data.args);
 
    return 0;
}
 
/** Make a synchronous IPC call allowing to transmit the entire payload.
 *
 * @param phoneid   Phone handle for the call.
 * @param question  Userspace address of call data with the request.
 * @param reply     Userspace address of call data where to store the answer.
 *
 * @return      Zero on success or an error code.
 */
unative_t sys_ipc_call_sync(unative_t phoneid, ipc_data_t *question,
    ipc_data_t *reply)
{
    call_t call;
    phone_t *phone;
    int res;
    int rc;
 
    ipc_call_static_init(&call);
    rc = copy_from_uspace(&call.data.args, &question->args,
        sizeof(call.data.args));
    if (rc != 0)
        return (unative_t) rc;
 
    GET_CHECK_PHONE(phone, phoneid, return ENOENT);
 
    if (!(res = request_preprocess(&call))) {
        ipc_call_sync(phone, &call);
        process_answer(&call);
    } else
        IPC_SET_RETVAL(call.data, res);
 
    rc = STRUCT_TO_USPACE(&reply->args, &call.data.args);
    if (rc != 0)
        return rc;
 
    return 0;
}
 
/** Check that the task did not exceed the allowed limit of asynchronous calls.
 *
 * @return      Return 0 if limit not reached or -1 if limit exceeded.
 */
static int check_call_limit(void)
{
    if (atomic_preinc(&TASK->active_calls) > IPC_MAX_ASYNC_CALLS) {
        atomic_dec(&TASK->active_calls);
        return -1;
    }
    return 0;
}
 
/** Make a fast asynchronous call over IPC.
 *
 * This function can only handle two arguments of payload, but is faster than
 * the generic function sys_ipc_call_async().
 *
 * @param phoneid   Phone handle for the call.
 * @param method    Method of the call.
 * @param arg1      Service-defined payload argument.
 * @param arg2      Service-defined payload argument.
 *
 * @return      Return call hash on success.
 *          Return IPC_CALLRET_FATAL in case of a fatal error and
 *          IPC_CALLRET_TEMPORARY if there are too many pending
 *          asynchronous requests; answers should be handled first.
 */
unative_t sys_ipc_call_async_fast(unative_t phoneid, unative_t method,
    unative_t arg1, unative_t arg2)
{
    call_t *call;
    phone_t *phone;
    int res;
 
    if (check_call_limit())
        return IPC_CALLRET_TEMPORARY;
 
    GET_CHECK_PHONE(phone, phoneid, return IPC_CALLRET_FATAL);
 
    call = ipc_call_alloc(0);
    IPC_SET_METHOD(call->data, method);
    IPC_SET_ARG1(call->data, arg1);
    IPC_SET_ARG2(call->data, arg2);
    IPC_SET_ARG3(call->data, 0);
 
    if (!(res = request_preprocess(call)))
        ipc_call(phone, call);
    else
        ipc_backsend_err(phone, call, res);
 
    return (unative_t) call;
}
 
/** Make an asynchronous IPC call allowing to transmit the entire payload.
 *
 * @param phoneid   Phone handle for the call.
 * @param data      Userspace address of call data with the request.
 *
 * @return      See sys_ipc_call_async_fast().
 */
unative_t sys_ipc_call_async(unative_t phoneid, ipc_data_t *data)
{
    call_t *call;
    phone_t *phone;
    int res;
    int rc;
 
    if (check_call_limit())
        return IPC_CALLRET_TEMPORARY;
 
    GET_CHECK_PHONE(phone, phoneid, return IPC_CALLRET_FATAL);
 
    call = ipc_call_alloc(0);
    rc = copy_from_uspace(&call->data.args, &data->args,
        sizeof(call->data.args));
    if (rc != 0) {
        ipc_call_free(call);
        return (unative_t) rc;
    }
    if (!(res = request_preprocess(call)))
        ipc_call(phone, call);
    else
        ipc_backsend_err(phone, call, res);
 
    return (unative_t) call;
}
 
/** Forward a received call to another destination.
 *
 * @param callid    Hash of the call to forward.
 * @param phoneid   Phone handle to use for forwarding.
 * @param method    New method to use for the forwarded call.
 * @param arg1      New value of the first argument for the forwarded call.
 *
 * @return      Return 0 on succes, otherwise return an error code.
 *
 * In case the original method is a system method, ARG1 and ARG2 are overwritten
 * in the forwarded message with the new method and the new arg1, respectively.
 * Otherwise the METHOD and ARG1 are rewritten with the new method and arg1,
 * respectively.
 *
 * Warning: If implementing non-fast version, make sure that
 *          ARG3 is not rewritten for certain system IPC
 */
unative_t sys_ipc_forward_fast(unative_t callid, unative_t phoneid,
    unative_t method, unative_t arg1)
{
    call_t *call;
    phone_t *phone;
 
    call = get_call(callid);
    if (!call)
        return ENOENT;
 
    call->flags |= IPC_CALL_FORWARDED;
 
    GET_CHECK_PHONE(phone, phoneid, {
        IPC_SET_RETVAL(call->data, EFORWARD);
        ipc_answer(&TASK->answerbox, call);
        return ENOENT;
    });    
 
    if (!is_forwardable(IPC_GET_METHOD(call->data))) {
        IPC_SET_RETVAL(call->data, EFORWARD);
        ipc_answer(&TASK->answerbox, call);
        return EPERM;
    }
 
    /* Userspace is not allowed to change method of system methods
     * on forward, allow changing ARG1 and ARG2 by means of method and arg1
     */
    if (is_system_method(IPC_GET_METHOD(call->data))) {
        if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME)
            phone_dealloc(IPC_GET_ARG3(call->data));
 
        IPC_SET_ARG1(call->data, method);
        IPC_SET_ARG2(call->data, arg1);
    } else {
        IPC_SET_METHOD(call->data, method);
        IPC_SET_ARG1(call->data, arg1);
    }
 
    return ipc_forward(call, phone, &TASK->answerbox);
}
 
/** Answer an IPC call - fast version.
 *
 * This function can handle only two return arguments of payload, but is faster
 * than the generic sys_ipc_answer().
 *
 * @param callid    Hash of the call to be answered.
 * @param retval    Return value of the answer.
 * @param arg1      Service-defined return value.
 * @param arg2      Service-defined return value.
 *
 * @return      Return 0 on success, otherwise return an error code.   
 */
unative_t sys_ipc_answer_fast(unative_t callid, unative_t retval,
    unative_t arg1, unative_t arg2)
{
    call_t *call;
    ipc_data_t saved_data;
    int saveddata = 0;
    int rc;
 
    /* Do not answer notification callids */
    if (callid & IPC_CALLID_NOTIFICATION)
        return 0;
 
    call = get_call(callid);
    if (!call)
        return ENOENT;
 
    if (answer_need_old(call)) {
        memcpy(&saved_data, &call->data, sizeof(call->data));
        saveddata = 1;
    }
 
    IPC_SET_RETVAL(call->data, retval);
    IPC_SET_ARG1(call->data, arg1);
    IPC_SET_ARG2(call->data, arg2);
    rc = answer_preprocess(call, saveddata ? &saved_data : NULL);
 
    ipc_answer(&TASK->answerbox, call);
    return rc;
}
 
/** Answer an IPC call.
 *
 * @param callid    Hash of the call to be answered.
 * @param data      Userspace address of call data with the answer.
 *
 * @return      Return 0 on success, otherwise return an error code.
 */
unative_t sys_ipc_answer(unative_t callid, ipc_data_t *data)
{
    call_t *call;
    ipc_data_t saved_data;
    int saveddata = 0;
    int rc;
 
    /* Do not answer notification callids */
    if (callid & IPC_CALLID_NOTIFICATION)
        return 0;
 
    call = get_call(callid);
    if (!call)
        return ENOENT;
 
    if (answer_need_old(call)) {
        memcpy(&saved_data, &call->data, sizeof(call->data));
        saveddata = 1;
    }
    rc = copy_from_uspace(&call->data.args, &data->args,
        sizeof(call->data.args));
    if (rc != 0)
        return rc;
 
    rc = answer_preprocess(call, saveddata ? &saved_data : NULL);
   
    ipc_answer(&TASK->answerbox, call);
 
    return rc;
}
 
/** Hang up a phone.
 *
 * @param       Phone handle of the phone to be hung up.
 *
 * @return      Return 0 on success or an error code.
 */
unative_t sys_ipc_hangup(int phoneid)
{
    phone_t *phone;
 
    GET_CHECK_PHONE(phone, phoneid, return ENOENT);
 
    if (ipc_phone_hangup(phone))
        return -1;
 
    return 0;
}
 
/** Wait for an incoming IPC call or an answer.
 *
 * @param calldata  Pointer to buffer where the call/answer data is stored.
 * @param usec      Timeout. See waitq_sleep_timeout() for explanation.
 * @param flags     Select mode of sleep operation. See waitq_sleep_timeout()
 *          for explanation.
 *
 * @return      Hash of the call.
 *          If IPC_CALLID_NOTIFICATION bit is set in the hash, the
 *          call is a notification. IPC_CALLID_ANSWERED denotes an
 *          answer.
 */
unative_t sys_ipc_wait_for_call(ipc_data_t *calldata, uint32_t usec, int flags)
{
    call_t *call;
 
restart:   
    call = ipc_wait_for_call(&TASK->answerbox, usec,
        flags | SYNCH_FLAGS_INTERRUPTIBLE);
    if (!call)
        return 0;
 
    if (call->flags & IPC_CALL_NOTIF) {
        ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
 
        /* Set in_phone_hash to the interrupt counter */
        call->data.phone = (void *) call->priv;
       
        STRUCT_TO_USPACE(calldata, &call->data);
 
        ipc_call_free(call);
       
        return ((unative_t) call) | IPC_CALLID_NOTIFICATION;
    }
 
    if (call->flags & IPC_CALL_ANSWERED) {
        process_answer(call);
 
        ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
 
        atomic_dec(&TASK->active_calls);
 
        if (call->flags & IPC_CALL_DISCARD_ANSWER) {
            ipc_call_free(call);
            goto restart;
        }
 
        STRUCT_TO_USPACE(&calldata->args, &call->data.args);
        ipc_call_free(call);
 
        return ((unative_t) call) | IPC_CALLID_ANSWERED;
    }
 
    if (process_request(&TASK->answerbox, call))
        goto restart;
 
    /* Include phone address('id') of the caller in the request,
     * copy whole call->data, not only call->data.args */
    if (STRUCT_TO_USPACE(calldata, &call->data)) {
        return 0;
    }
    return (unative_t)call;
}
 
/** Connect an IRQ handler to a task.
 *
 * @param inr       IRQ number.
 * @param devno     Device number.
 * @param method    Method to be associated with the notification.
 * @param ucode     Uspace pointer to the top-half pseudocode.
 *
 * @return      EPERM or a return code returned by ipc_irq_register().
 */
unative_t sys_ipc_register_irq(inr_t inr, devno_t devno, unative_t method,
    irq_code_t *ucode)
{
    if (!(cap_get(TASK) & CAP_IRQ_REG))
        return EPERM;
 
    return ipc_irq_register(&TASK->answerbox, inr, devno, method, ucode);
}
 
/** Disconnect an IRQ handler from a task.
 *
 * @param inr       IRQ number.
 * @param devno     Device number.
 *
 * @return      Zero on success or EPERM on error..
 */
unative_t sys_ipc_unregister_irq(inr_t inr, devno_t devno)
{
    if (!(cap_get(TASK) & CAP_IRQ_REG))
        return EPERM;
 
    ipc_irq_unregister(&TASK->answerbox, inr, devno);
 
    return 0;
}
 
/** @}
 */
 
Subversion Repositories HelenOS

(root)/tags/0.2.0.5/kernel/generic/src/ipc/sysipc.c – Rev 2471 → 2474
