WebSVN – HelenOS – Diff – /trunk/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.
  */
 #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 true if the method is a system method */
+static inline int is_system_method(__native method)
+{
+    if (method <= IPC_M_LAST_SYSTEM)
+        return 1;
+    return 0;
+}
+/** Return true if the message with this method is forwardable
+ *
+ * - some system messages may be forwarded, for some of them
+ *   it is useless
+ */
+static inline int is_forwardable(__native method)
+{
+    return 1;
+}
+/** Find call_t * in call table according to callid
+ *
+ * @return NULL on not found, otherwise pointer to call structure
+ */
+static inline call_t * get_call(__native callid)
+{
+    /* TODO: Traverse list of dispatched calls and find one */
+    /* TODO: locking of call, ripping it from dispatched calls etc.  */
+    return (call_t *) callid;
+}
 /** 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)
+static int phone_alloc(void)
+{
     int i;
     spinlock_lock(&TASK->lock);
     for (i=0; i < IPC_MAX_PHONES; i++) {
-        if (!TASK->phones[i].callee) {
+        if (!TASK->phones[i].busy) {
-            TASK->phones[i].callee = callee;
+            TASK->phones[i].busy = 1;
             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);
+    ASSERT(TASK->phones[phoneid].busy);
+    if (TASK->phones[phoneid].callee)
+        ipc_phone_destroy(&TASK->phones[phoneid]);
-    TASK->phones[phoneid].callee = NULL;
+    TASK->phones[phoneid].busy = 0;
     spinlock_unlock(&TASK->lock);
+}
+static void phone_connect(int phoneid, answerbox_t *box)
+{
+    phone_t *phone = &TASK->phones[phoneid];
+    ipc_phone_connect(phone, box);
+}
 /****************************************************/
 /* 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)
+static inline void answer_preprocess(call_t *answer, ipc_data_t *olddata)
+{
     int phoneid;
-    if (IPC_GET_METHOD(call->data) == IPC_M_CONNECTTOME) {
+    if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECTTOME) {
+        phoneid = IPC_GET_ARG3(*olddata);
         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);
+        } else {
+            /* The connection was accepted */
+            phone_connect(phoneid,&answer->sender->answerbox);
+        }
+    }
+}
 /****************************************************/
 /* 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);
+        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;
+}
 /** 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;
+        return ENOENT;
+    if (is_system_method(method))
+        return EPERM;
     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;
+        return ENOENT;
     ipc_call_init(&call);
     copy_from_uspace(&call.data, question, sizeof(call.data));
+    if (is_system_method(IPC_GET_METHOD(call.data)))
+        return EPERM;
     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 (is_system_method(method))
+        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));
+    if (is_system_method(IPC_GET_METHOD(call->data))) {
+        ipc_call_free(call);
+        return EPERM;
+    }
     ipc_call(phone, call);
     return (__native) call;
+}
+/** Forward received call to another destination
+ *
+ * The arg1 and arg2 are changed in the forwarded message
+ */
+__native sys_ipc_forward_fast(__native callid, __native phoneid,
+                  __native method, __native arg1)
+{
+    call_t *call;
+    phone_t *phone;
+    call = get_call(callid);
+    if (!call)
+        return ENOENT;
+    phone = get_phone(phoneid);
+    if (!phone) {
+        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))) {
+        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);
+    }
+    ipc_forward(call, phone->callee, &TASK->answerbox);
+    return 0;
+}
 /** Send IPC answer */
 __native sys_ipc_answer_fast(__native callid, __native retval,
                  __native arg1, __native arg2)
+{
     call_t *call;
-    call_t saved_call;
+    ipc_data_t saved_data;
     int preprocess = 0;
-    /* Check that the user is not sending us answer callid */
+    call = get_call(callid);
-    ASSERT(! (callid & 1));
+    if (!call)
-    /* TODO: Check that the callid is in the dispatch table */
-    call = (call_t *) callid;
+        return ENOENT;
     if (answer_will_preprocess(call)) {
-        memcpy(&saved_call.data, &call->data, sizeof(call->data));
+        memcpy(&saved_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);
+        answer_preprocess(call, &saved_data);
     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;
+    ipc_data_t saved_data;
     int preprocess = 0;
-    /* Check that the user is not sending us answer callid */
+    call = get_call(callid);
-    ASSERT(! (callid & 1));
+    if (!call)
-    /* TODO: Check that the callid is in the dispatch table */
-    call = (call_t *) callid;
+        return ENOENT;
     if (answer_will_preprocess(call)) {
-        memcpy(&saved_call.data, &call->data, sizeof(call->data));
+        memcpy(&saved_data, &call->data, sizeof(call->data));
         preprocess = 1;
+    }
     copy_from_uspace(&call->data, data, sizeof(call->data));
     if (preprocess)
-        answer_preprocess(call, &saved_call);
+        answer_preprocess(call, &saved_data);
     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;
+        return ENOENT;
     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);
+}
+/** Ask target process to connect me somewhere
+ *
+ * @return phoneid - on success, error otherwise
+ */
+__native sys_ipc_connect_me_to(__native phoneid, __native arg1,
+                   __native arg2)
+{
+    call_t call;
+    phone_t *phone;
+    phone = get_phone(phoneid);
+    if (!phone)
+        return ENOENT;
+    ipc_call_init(&call);
+    IPC_SET_METHOD(call.data, IPC_M_CONNECTMETO);
+    IPC_SET_ARG1(call.data, arg1);
+    IPC_SET_ARG2(call.data, arg2);
+    ipc_call_sync(phone, &call);
+    if (!IPC_GET_RETVAL(call.data)) {
+        /* Everybody accepted, we should be connected by now */
+    }
+    return 0;
+}
 /** 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);
+    printf("Received call %P from sender: %P\n", call, call->sender);
     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;
+}

Subversion Repositories HelenOS

(root)/trunk/kernel/generic/src/ipc/sysipc.c @ 2471 – Rev 1029 → 1040