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/*
* 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.
*/
#include <arch.h>
#include <proc/task.h>
#include <errno.h>
#include <mm/page.h>
#include <memstr.h>
#include <debug.h>
#include <ipc/ipc.h>
#include <ipc/sysipc.h>
#include <print.h>
/* TODO: multi-threaded connect-to-me can cause race condition
* on phone, add counter + thread_kill??
*
* - don't allow userspace app to send system messages
*/
/** Return pointer to phone identified by phoneid or NULL if non-existent */
static phone_t * get_phone(__native phoneid)
{
phone_t *phone;
if (phoneid >= IPC_MAX_PHONES)
return NULL;
phone = &TASK->phones[phoneid];
if (!phone->callee)
return NULL;
return phone;
}
/** Allocate new phone slot in current TASK structure */
static int phone_alloc(answerbox_t *callee)
{
int i;
spinlock_lock(&TASK->lock);
for (i=0; i < IPC_MAX_PHONES; i++) {
if (!TASK->phones[i].callee) {
TASK->phones[i].callee = callee;
break;
}
}
spinlock_unlock(&TASK->lock);
if (i >= IPC_MAX_PHONES)
return -1;
return i;
}
/** Disconnect phone */
static void phone_dealloc(int phoneid)
{
spinlock_lock(TASK->lock);
ASSERT(TASK->phones[phoneid].callee);
TASK->phones[phoneid].callee = NULL;
spinlock_unlock(TASK->lock);
}
/****************************************************/
/* Functions that preprocess answer before sending
* it to the recepient
*/
/** Return true if the caller (ipc_answer) should save
* the old call contents and call answer_preprocess
*/
static inline int answer_will_preprocess(call_t *call)
{
if (IPC_GET_METHOD(call->data) == IPC_M_CONNECTTOME)
return 1;
return 0;
}
/** Interpret process answer as control information */
static inline void answer_preprocess(call_t *answer, call_t *call)
{
int phoneid;
if (IPC_GET_METHOD(call->data) == IPC_M_CONNECTTOME) {
if (IPC_GET_RETVAL(answer->data)) {
/* The connection was not accepted */
/* TODO...race for multi-threaded process */
phoneid = IPC_GET_ARG3(call->data);
phone_dealloc(phoneid);
}
}
}
/****************************************************/
/* Functions called to process received call/answer
* before passing to uspace
*/
/** Do basic kernel processing of received call answer */
static int process_answer(answerbox_t *box,call_t *call)
{
return 0;
}
/** Do basic kernel processing of received call request
*
* @return 0 - the call should be passed to userspace, 1 - ignore call
*/
static int process_request(answerbox_t *box,call_t *call)
{
int phoneid;
if (IPC_GET_METHOD(call->data) == IPC_M_CONNECTTOME) {
phoneid = phone_alloc(&call->sender->answerbox);
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;
}
/** Send a call over IPC, wait for reply, return to user
*
* @return Call identification, returns -1 on fatal error,
-2 on 'Too many async request, handle answers first
*/
__native sys_ipc_call_sync_fast(__native phoneid, __native method,
__native arg1, __native *data)
{
call_t call;
phone_t *phone;
phone = get_phone(phoneid);
if (!phone)
return IPC_CALLRET_FATAL;
ipc_call_init(&call);
IPC_SET_METHOD(call.data, method);
IPC_SET_ARG1(call.data, arg1);
ipc_call_sync(phone, &call);
copy_to_uspace(data, &call.data, sizeof(call.data));
return 0;
}
/** Synchronous IPC call allowing to send whole message */
__native sys_ipc_call_sync(__native phoneid, __native *question,
__native *reply)
{
call_t call;
phone_t *phone;
phone = get_phone(phoneid);
if (!phone)
return IPC_CALLRET_FATAL;
ipc_call_init(&call);
copy_from_uspace(&call.data, question, sizeof(call.data));
ipc_call_sync(phone, &call);
copy_to_uspace(reply, &call.data, sizeof(call.data));
return 0;
}
/** Check that the task did not exceed allowed limit
*
* @return 0 - Limit OK, -1 - 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;
}
/** Send an asynchronous call over ipc
*
* @return Call identification, returns -1 on fatal error,
-2 on 'Too many async request, handle answers first
*/
__native sys_ipc_call_async_fast(__native phoneid, __native method,
__native arg1, __native arg2)
{
call_t *call;
phone_t *phone;
phone = get_phone(phoneid);
if (!phone)
return IPC_CALLRET_FATAL;
if (check_call_limit())
return IPC_CALLRET_TEMPORARY;
call = ipc_call_alloc();
IPC_SET_METHOD(call->data, method);
IPC_SET_ARG1(call->data, arg1);
IPC_SET_ARG2(call->data, arg2);
ipc_call(phone, call);
return (__native) call;
}
/** Synchronous IPC call allowing to send whole message
*
* @return The same as sys_ipc_call_async
*/
__native sys_ipc_call_async(__native phoneid, __native *data)
{
call_t *call;
phone_t *phone;
phone = get_phone(phoneid);
if (!phone)
return IPC_CALLRET_FATAL;
if (check_call_limit())
return IPC_CALLRET_TEMPORARY;
call = ipc_call_alloc();
copy_from_uspace(&call->data, data, sizeof(call->data));
ipc_call(phone, call);
return (__native) call;
}
/** Send IPC answer */
__native sys_ipc_answer_fast(__native callid, __native retval,
__native arg1, __native arg2)
{
call_t *call;
call_t saved_call;
int preprocess = 0;
/* Check that the user is not sending us answer callid */
ASSERT(! (callid & 1));
/* TODO: Check that the callid is in the dispatch table */
call = (call_t *) callid;
if (answer_will_preprocess(call)) {
memcpy(&saved_call.data, &call->data, sizeof(call->data));
preprocess = 1;
}
IPC_SET_RETVAL(call->data, retval);
IPC_SET_ARG1(call->data, arg1);
IPC_SET_ARG2(call->data, arg2);
if (preprocess)
answer_preprocess(call, &saved_call);
ipc_answer(&TASK->answerbox, call);
return 0;
}
/** Send IPC answer */
inline __native sys_ipc_answer(__native callid, __native *data)
{
call_t *call;
call_t saved_call;
int preprocess = 0;
/* Check that the user is not sending us answer callid */
ASSERT(! (callid & 1));
/* TODO: Check that the callid is in the dispatch table */
call = (call_t *) callid;
if (answer_will_preprocess(call)) {
memcpy(&saved_call.data, &call->data, sizeof(call->data));
preprocess = 1;
}
copy_from_uspace(&call->data, data, sizeof(call->data));
if (preprocess)
answer_preprocess(call, &saved_call);
ipc_answer(&TASK->answerbox, call);
return 0;
}
/** Ask the other side of connection to do 'callback' connection
*
* @return 0 if no error, error otherwise
*/
__native sys_ipc_connect_to_me(__native phoneid, __native arg1,
__native arg2, task_id_t *taskid)
{
call_t call;
phone_t *phone;
phone = get_phone(phoneid);
if (!phone)
return IPC_CALLRET_FATAL;
ipc_call_init(&call);
IPC_SET_METHOD(call.data, IPC_M_CONNECTTOME);
IPC_SET_ARG1(call.data, arg1);
IPC_SET_ARG2(call.data, arg2);
ipc_call_sync(phone, &call);
if (!IPC_GET_RETVAL(call.data) && taskid)
copy_to_uspace(taskid,
&phone->callee->task->taskid,
sizeof(TASK->taskid));
return IPC_GET_RETVAL(call.data);
}
/** Wait for incoming ipc call or answer
*
* Generic function - can serve either as inkernel or userspace call
* - inside kernel does probably unnecessary copying of data (TODO)
*
* @param result
* @param taskid
* @param flags
* @return Callid, if callid & 1, then the call is answer
*/
inline __native sys_ipc_wait_for_call(ipc_data_t *calldata,
task_id_t *taskid,
__native flags)
{
call_t *call;
restart:
call = ipc_wait_for_call(&TASK->answerbox, flags);
if (call->flags & IPC_CALL_ANSWERED) {
if (process_answer(&TASK->answerbox, call))
goto restart;
copy_to_uspace(calldata, &call->data, sizeof(call->data));
atomic_dec(&TASK->active_calls);
ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
ipc_call_free(call);
return ((__native)call) | IPC_CALLID_ANSWERED;
}
if (process_request(&TASK->answerbox, call))
goto restart;
copy_to_uspace(calldata, &call->data, sizeof(call->data));
copy_to_uspace(taskid, (void *)&TASK->taskid, sizeof(TASK->taskid));
return (__native)call;
}