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  1. /*
  2.  * Copyright (c) 2006 Ondrej Palkovsky
  3.  * All rights reserved.
  4.  *
  5.  * Redistribution and use in source and binary forms, with or without
  6.  * modification, are permitted provided that the following conditions
  7.  * are met:
  8.  *
  9.  * - Redistributions of source code must retain the above copyright
  10.  *   notice, this list of conditions and the following disclaimer.
  11.  * - Redistributions in binary form must reproduce the above copyright
  12.  *   notice, this list of conditions and the following disclaimer in the
  13.  *   documentation and/or other materials provided with the distribution.
  14.  * - The name of the author may not be used to endorse or promote products
  15.  *   derived from this software without specific prior written permission.
  16.  *
  17.  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18.  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20.  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21.  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22.  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23.  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24.  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25.  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26.  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27.  */
  28.  
  29. /** @addtogroup genericipc
  30.  * @{
  31.  */
  32. /** @file
  33.  */
  34.  
  35. #include <arch.h>
  36. #include <proc/task.h>
  37. #include <proc/thread.h>
  38. #include <errno.h>
  39. #include <memstr.h>
  40. #include <debug.h>
  41. #include <ipc/ipc.h>
  42. #include <ipc/sysipc.h>
  43. #include <ipc/irq.h>
  44. #include <ipc/ipcrsc.h>
  45. #include <arch/interrupt.h>
  46. #include <print.h>
  47. #include <syscall/copy.h>
  48. #include <security/cap.h>
  49. #include <mm/as.h>
  50. #include <print.h>
  51.  
  52. /**
  53.  * Maximum buffer size allowed for IPC_M_DATA_WRITE and IPC_M_DATA_READ
  54.  * requests.
  55.  */
  56. #define DATA_XFER_LIMIT     (64 * 1024)
  57.  
  58. #define GET_CHECK_PHONE(phone, phoneid, err) \
  59. { \
  60.     if (phoneid > IPC_MAX_PHONES) { \
  61.         err; \
  62.     } \
  63.     phone = &TASK->phones[phoneid]; \
  64. }
  65.  
  66. #define STRUCT_TO_USPACE(dst, src)  copy_to_uspace(dst, src, sizeof(*(src)))
  67.  
  68. /** Decide if the method is a system method.
  69.  *
  70.  * @param method    Method to be decided.
  71.  *
  72.  * @return      Return 1 if the method is a system method.
  73.  *          Otherwise return 0.
  74.  */
  75. static inline int method_is_system(unative_t method)
  76. {
  77.     if (method <= IPC_M_LAST_SYSTEM)
  78.         return 1;
  79.     return 0;
  80. }
  81.  
  82. /** Decide if the message with this method is forwardable.
  83.  *
  84.  * - some system messages may be forwarded, for some of them
  85.  *   it is useless
  86.  *
  87.  * @param method    Method to be decided.
  88.  *
  89.  * @return      Return 1 if the method is forwardable.
  90.  *          Otherwise return 0.
  91.  */
  92. static inline int method_is_forwardable(unative_t method)
  93. {
  94.     switch (method) {
  95.     case IPC_M_PHONE_HUNGUP:
  96.         /* This message is meant only for the original recipient. */
  97.         return 0;
  98.     default:
  99.         return 1;
  100.     }
  101. }
  102.  
  103. /** Decide if the message with this method is immutable on forward.
  104.  *
  105.  * - some system messages may be forwarded but their content cannot be altered
  106.  *
  107.  * @param method    Method to be decided.
  108.  *
  109.  * @return      Return 1 if the method is immutable on forward.
  110.  *          Otherwise return 0.
  111.  */
  112. static inline int method_is_immutable(unative_t method)
  113. {
  114.     switch (method) {
  115.     case IPC_M_SHARE_OUT:
  116.     case IPC_M_SHARE_IN:
  117.     case IPC_M_DATA_WRITE:
  118.     case IPC_M_DATA_READ:
  119.         return 1;
  120.         break;
  121.     default:
  122.         return 0;
  123.     }
  124. }
  125.  
  126.  
  127. /***********************************************************************
  128.  * Functions that preprocess answer before sending it to the recepient.
  129.  ***********************************************************************/
  130.  
  131. /** Decide if the caller (e.g. ipc_answer()) should save the old call contents
  132.  * for answer_preprocess().
  133.  *
  134.  * @param call      Call structure to be decided.
  135.  *
  136.  * @return      Return 1 if the old call contents should be saved.
  137.  *          Return 0 otherwise.
  138.  */
  139. static inline int answer_need_old(call_t *call)
  140. {
  141.     switch (IPC_GET_METHOD(call->data)) {
  142.     case IPC_M_CONNECT_TO_ME:
  143.     case IPC_M_CONNECT_ME_TO:
  144.     case IPC_M_SHARE_OUT:
  145.     case IPC_M_SHARE_IN:
  146.     case IPC_M_DATA_WRITE:
  147.     case IPC_M_DATA_READ:
  148.         return 1;
  149.     default:
  150.         return 0;
  151.     }
  152. }
  153.  
  154. /** Interpret process answer as control information.
  155.  *
  156.  * This function is called directly after sys_ipc_answer().
  157.  *
  158.  * @param answer    Call structure with the answer.
  159.  * @param olddata   Saved data of the request.
  160.  *
  161.  * @return      Return 0 on success or an error code.
  162.  */
  163. static inline int answer_preprocess(call_t *answer, ipc_data_t *olddata)
  164. {
  165.     int phoneid;
  166.  
  167.     if ((native_t) IPC_GET_RETVAL(answer->data) == EHANGUP) {
  168.         /* In case of forward, hangup the forwared phone,
  169.          * not the originator
  170.          */
  171.         mutex_lock(&answer->data.phone->lock);
  172.         spinlock_lock(&TASK->answerbox.lock);
  173.         if (answer->data.phone->state == IPC_PHONE_CONNECTED) {
  174.             list_remove(&answer->data.phone->link);
  175.             answer->data.phone->state = IPC_PHONE_SLAMMED;
  176.         }
  177.         spinlock_unlock(&TASK->answerbox.lock);
  178.         mutex_unlock(&answer->data.phone->lock);
  179.     }
  180.  
  181.     if (!olddata)
  182.         return 0;
  183.  
  184.     if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECT_TO_ME) {
  185.         phoneid = IPC_GET_ARG5(*olddata);
  186.         if (IPC_GET_RETVAL(answer->data)) {
  187.             /* The connection was not accepted */
  188.             phone_dealloc(phoneid);
  189.         } else {
  190.             /* The connection was accepted */
  191.             phone_connect(phoneid, &answer->sender->answerbox);
  192.             /* Set 'phone hash' as arg5 of response */
  193.             IPC_SET_ARG5(answer->data,
  194.                 (unative_t) &TASK->phones[phoneid]);
  195.         }
  196.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECT_ME_TO) {
  197.         /* If the users accepted call, connect */
  198.         if (!IPC_GET_RETVAL(answer->data)) {
  199.             ipc_phone_connect((phone_t *) IPC_GET_ARG5(*olddata),
  200.                 &TASK->answerbox);
  201.         }
  202.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_SHARE_OUT) {
  203.         if (!IPC_GET_RETVAL(answer->data)) {
  204.             /* Accepted, handle as_area receipt */
  205.             ipl_t ipl;
  206.             int rc;
  207.             as_t *as;
  208.            
  209.             ipl = interrupts_disable();
  210.             spinlock_lock(&answer->sender->lock);
  211.             as = answer->sender->as;
  212.             spinlock_unlock(&answer->sender->lock);
  213.             interrupts_restore(ipl);
  214.            
  215.             rc = as_area_share(as, IPC_GET_ARG1(*olddata),
  216.                 IPC_GET_ARG2(*olddata), AS,
  217.                 IPC_GET_ARG1(answer->data), IPC_GET_ARG3(*olddata));
  218.             IPC_SET_RETVAL(answer->data, rc);
  219.             return rc;
  220.         }
  221.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_SHARE_IN) {
  222.         if (!IPC_GET_RETVAL(answer->data)) {
  223.             ipl_t ipl;
  224.             as_t *as;
  225.             int rc;
  226.            
  227.             ipl = interrupts_disable();
  228.             spinlock_lock(&answer->sender->lock);
  229.             as = answer->sender->as;
  230.             spinlock_unlock(&answer->sender->lock);
  231.             interrupts_restore(ipl);
  232.            
  233.             rc = as_area_share(AS, IPC_GET_ARG1(answer->data),
  234.                 IPC_GET_ARG2(*olddata), as, IPC_GET_ARG1(*olddata),
  235.                 IPC_GET_ARG2(answer->data));
  236.             IPC_SET_RETVAL(answer->data, rc);
  237.         }
  238.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_DATA_READ) {
  239.         ASSERT(!answer->buffer);
  240.         if (!IPC_GET_RETVAL(answer->data)) {
  241.             /* The recipient agreed to send data. */
  242.             uintptr_t src = IPC_GET_ARG1(answer->data);
  243.             uintptr_t dst = IPC_GET_ARG1(*olddata);
  244.             size_t max_size = IPC_GET_ARG2(*olddata);
  245.             size_t size = IPC_GET_ARG2(answer->data);
  246.             if (size && size <= max_size) {
  247.                 /*
  248.                  * Copy the destination VA so that this piece of
  249.                  * information is not lost.
  250.                  */
  251.                 IPC_SET_ARG1(answer->data, dst);
  252.  
  253.                 answer->buffer = malloc(size, 0);
  254.                 int rc = copy_from_uspace(answer->buffer,
  255.                     (void *) src, size);
  256.                 if (rc) {
  257.                     IPC_SET_RETVAL(answer->data, rc);
  258.                     free(answer->buffer);
  259.                     answer->buffer = NULL;
  260.                 }
  261.             } else if (!size) {
  262.                 IPC_SET_RETVAL(answer->data, EOK);
  263.             } else {
  264.                 IPC_SET_RETVAL(answer->data, ELIMIT);
  265.             }
  266.         }
  267.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_DATA_WRITE) {
  268.         ASSERT(answer->buffer);
  269.         if (!IPC_GET_RETVAL(answer->data)) {
  270.             /* The recipient agreed to receive data. */
  271.             int rc;
  272.             uintptr_t dst;
  273.             size_t size;
  274.             size_t max_size;
  275.  
  276.             dst = (uintptr_t)IPC_GET_ARG1(answer->data);
  277.             size = (size_t)IPC_GET_ARG2(answer->data);
  278.             max_size = (size_t)IPC_GET_ARG2(*olddata);
  279.  
  280.             if (size <= max_size) {
  281.                 rc = copy_to_uspace((void *) dst,
  282.                     answer->buffer, size);
  283.                 if (rc)
  284.                     IPC_SET_RETVAL(answer->data, rc);
  285.             } else {
  286.                 IPC_SET_RETVAL(answer->data, ELIMIT);
  287.             }
  288.         }
  289.         free(answer->buffer);
  290.         answer->buffer = NULL;
  291.     }
  292.     return 0;
  293. }
  294.  
  295. /** Called before the request is sent.
  296.  *
  297.  * @param call      Call structure with the request.
  298.  *
  299.  * @return      Return 0 on success, ELIMIT or EPERM on error.
  300.  */
  301. static int request_preprocess(call_t *call)
  302. {
  303.     int newphid;
  304.     size_t size;
  305.     uintptr_t src;
  306.     int rc;
  307.  
  308.     switch (IPC_GET_METHOD(call->data)) {
  309.     case IPC_M_CONNECT_ME_TO:
  310.         newphid = phone_alloc();
  311.         if (newphid < 0)
  312.             return ELIMIT;
  313.         /* Set arg5 for server */
  314.         IPC_SET_ARG5(call->data, (unative_t) &TASK->phones[newphid]);
  315.         call->flags |= IPC_CALL_CONN_ME_TO;
  316.         call->priv = newphid;
  317.         break;
  318.     case IPC_M_SHARE_OUT:
  319.         size = as_area_get_size(IPC_GET_ARG1(call->data));
  320.         if (!size)
  321.             return EPERM;
  322.         IPC_SET_ARG2(call->data, size);
  323.         break;
  324.     case IPC_M_DATA_READ:
  325.         size = IPC_GET_ARG2(call->data);
  326.         if ((size <= 0 || (size > DATA_XFER_LIMIT)))
  327.             return ELIMIT;
  328.         break;
  329.     case IPC_M_DATA_WRITE:
  330.         src = IPC_GET_ARG1(call->data);
  331.         size = IPC_GET_ARG2(call->data);
  332.        
  333.         if ((size <= 0) || (size > DATA_XFER_LIMIT))
  334.             return ELIMIT;
  335.        
  336.         call->buffer = (uint8_t *) malloc(size, 0);
  337.         rc = copy_from_uspace(call->buffer, (void *) src, size);
  338.         if (rc != 0) {
  339.             free(call->buffer);
  340.             return rc;
  341.         }
  342.         break;
  343.     default:
  344.         break;
  345.     }
  346.     return 0;
  347. }
  348.  
  349. /*******************************************************************************
  350.  * Functions called to process received call/answer before passing it to uspace.
  351.  *******************************************************************************/
  352.  
  353. /** Do basic kernel processing of received call answer.
  354.  *
  355.  * @param call      Call structure with the answer.
  356.  */
  357. static void process_answer(call_t *call)
  358. {
  359.     if (((native_t) IPC_GET_RETVAL(call->data) == EHANGUP) &&
  360.         (call->flags & IPC_CALL_FORWARDED))
  361.         IPC_SET_RETVAL(call->data, EFORWARD);
  362.  
  363.     if (call->flags & IPC_CALL_CONN_ME_TO) {
  364.         if (IPC_GET_RETVAL(call->data))
  365.             phone_dealloc(call->priv);
  366.         else
  367.             IPC_SET_ARG5(call->data, call->priv);
  368.     }
  369.  
  370.     if (call->buffer) {
  371.         /* This must be an affirmative answer to IPC_M_DATA_READ. */
  372.         uintptr_t dst = IPC_GET_ARG1(call->data);
  373.         size_t size = IPC_GET_ARG2(call->data);
  374.         int rc = copy_to_uspace((void *) dst, call->buffer, size);
  375.         if (rc)
  376.             IPC_SET_RETVAL(call->data, rc);
  377.         free(call->buffer);
  378.         call->buffer = NULL;
  379.     }
  380. }
  381.  
  382. /** Do basic kernel processing of received call request.
  383.  *
  384.  * @param box       Destination answerbox structure.
  385.  * @param call      Call structure with the request.
  386.  *
  387.  * @return      Return 0 if the call should be passed to userspace.
  388.  *          Return -1 if the call should be ignored.
  389.  */
  390. static int process_request(answerbox_t *box, call_t *call)
  391. {
  392.     int phoneid;
  393.  
  394.     if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME) {
  395.         phoneid = phone_alloc();
  396.         if (phoneid < 0) { /* Failed to allocate phone */
  397.             IPC_SET_RETVAL(call->data, ELIMIT);
  398.             ipc_answer(box, call);
  399.             return -1;
  400.         }
  401.         IPC_SET_ARG5(call->data, phoneid);
  402.     }
  403.     return 0;
  404. }
  405.  
  406. /** Make a fast call over IPC, wait for reply and return to user.
  407.  *
  408.  * This function can handle only three arguments of payload, but is faster than
  409.  * the generic function (i.e. sys_ipc_call_sync_slow()).
  410.  *
  411.  * @param phoneid   Phone handle for the call.
  412.  * @param method    Method of the call.
  413.  * @param arg1      Service-defined payload argument.
  414.  * @param arg2      Service-defined payload argument.
  415.  * @param arg3      Service-defined payload argument.
  416.  * @param data      Address of userspace structure where the reply call will
  417.  *          be stored.
  418.  *
  419.  * @return      Returns 0 on success.
  420.  *          Return ENOENT if there is no such phone handle.
  421.  */
  422. unative_t sys_ipc_call_sync_fast(unative_t phoneid, unative_t method,
  423.     unative_t arg1, unative_t arg2, unative_t arg3, ipc_data_t *data)
  424. {
  425.     call_t call;
  426.     phone_t *phone;
  427.     int res;
  428.     int rc;
  429.    
  430.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  431.  
  432.     ipc_call_static_init(&call);
  433.     IPC_SET_METHOD(call.data, method);
  434.     IPC_SET_ARG1(call.data, arg1);
  435.     IPC_SET_ARG2(call.data, arg2);
  436.     IPC_SET_ARG3(call.data, arg3);
  437.     /*
  438.      * To achieve deterministic behavior, zero out arguments that are beyond
  439.      * the limits of the fast version.
  440.      */
  441.     IPC_SET_ARG4(call.data, 0);
  442.     IPC_SET_ARG5(call.data, 0);
  443.  
  444.     if (!(res = request_preprocess(&call))) {
  445.         rc = ipc_call_sync(phone, &call);
  446.         if (rc != EOK)
  447.             return rc;
  448.         process_answer(&call);
  449.     } else {
  450.         IPC_SET_RETVAL(call.data, res);
  451.     }
  452.     rc = STRUCT_TO_USPACE(&data->args, &call.data.args);
  453.     if (rc != 0)
  454.         return rc;
  455.  
  456.     return 0;
  457. }
  458.  
  459. /** Make a synchronous IPC call allowing to transmit the entire payload.
  460.  *
  461.  * @param phoneid   Phone handle for the call.
  462.  * @param question  Userspace address of call data with the request.
  463.  * @param reply     Userspace address of call data where to store the
  464.  *          answer.
  465.  *
  466.  * @return      Zero on success or an error code.
  467.  */
  468. unative_t sys_ipc_call_sync_slow(unative_t phoneid, ipc_data_t *question,
  469.     ipc_data_t *reply)
  470. {
  471.     call_t call;
  472.     phone_t *phone;
  473.     int res;
  474.     int rc;
  475.  
  476.     ipc_call_static_init(&call);
  477.     rc = copy_from_uspace(&call.data.args, &question->args,
  478.         sizeof(call.data.args));
  479.     if (rc != 0)
  480.         return (unative_t) rc;
  481.  
  482.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  483.  
  484.     if (!(res = request_preprocess(&call))) {
  485.         rc = ipc_call_sync(phone, &call);
  486.         if (rc != EOK)
  487.             return rc;
  488.         process_answer(&call);
  489.     } else
  490.         IPC_SET_RETVAL(call.data, res);
  491.  
  492.     rc = STRUCT_TO_USPACE(&reply->args, &call.data.args);
  493.     if (rc != 0)
  494.         return rc;
  495.  
  496.     return 0;
  497. }
  498.  
  499. /** Check that the task did not exceed the allowed limit of asynchronous calls.
  500.  *
  501.  * @return      Return 0 if limit not reached or -1 if limit exceeded.
  502.  */
  503. static int check_call_limit(void)
  504. {
  505.     if (atomic_preinc(&TASK->active_calls) > IPC_MAX_ASYNC_CALLS) {
  506.         atomic_dec(&TASK->active_calls);
  507.         return -1;
  508.     }
  509.     return 0;
  510. }
  511.  
  512. /** Make a fast asynchronous call over IPC.
  513.  *
  514.  * This function can only handle four arguments of payload, but is faster than
  515.  * the generic function sys_ipc_call_async_slow().
  516.  *
  517.  * @param phoneid   Phone handle for the call.
  518.  * @param method    Method of the call.
  519.  * @param arg1      Service-defined payload argument.
  520.  * @param arg2      Service-defined payload argument.
  521.  * @param arg3      Service-defined payload argument.
  522.  * @param arg4      Service-defined payload argument.
  523.  *
  524.  * @return      Return call hash on success.
  525.  *          Return IPC_CALLRET_FATAL in case of a fatal error and
  526.  *          IPC_CALLRET_TEMPORARY if there are too many pending
  527.  *          asynchronous requests; answers should be handled first.
  528.  */
  529. unative_t sys_ipc_call_async_fast(unative_t phoneid, unative_t method,
  530.     unative_t arg1, unative_t arg2, unative_t arg3, unative_t arg4)
  531. {
  532.     call_t *call;
  533.     phone_t *phone;
  534.     int res;
  535.  
  536.     if (check_call_limit())
  537.         return IPC_CALLRET_TEMPORARY;
  538.  
  539.     GET_CHECK_PHONE(phone, phoneid, return IPC_CALLRET_FATAL);
  540.  
  541.     call = ipc_call_alloc(0);
  542.     IPC_SET_METHOD(call->data, method);
  543.     IPC_SET_ARG1(call->data, arg1);
  544.     IPC_SET_ARG2(call->data, arg2);
  545.     IPC_SET_ARG3(call->data, arg3);
  546.     IPC_SET_ARG4(call->data, arg4);
  547.     /*
  548.      * To achieve deterministic behavior, zero out arguments that are beyond
  549.      * the limits of the fast version.
  550.      */
  551.     IPC_SET_ARG5(call->data, 0);
  552.  
  553.     if (!(res = request_preprocess(call)))
  554.         ipc_call(phone, call);
  555.     else
  556.         ipc_backsend_err(phone, call, res);
  557.  
  558.     return (unative_t) call;
  559. }
  560.  
  561. /** Make an asynchronous IPC call allowing to transmit the entire payload.
  562.  *
  563.  * @param phoneid   Phone handle for the call.
  564.  * @param data      Userspace address of call data with the request.
  565.  *
  566.  * @return      See sys_ipc_call_async_fast().
  567.  */
  568. unative_t sys_ipc_call_async_slow(unative_t phoneid, ipc_data_t *data)
  569. {
  570.     call_t *call;
  571.     phone_t *phone;
  572.     int res;
  573.     int rc;
  574.  
  575.     if (check_call_limit())
  576.         return IPC_CALLRET_TEMPORARY;
  577.  
  578.     GET_CHECK_PHONE(phone, phoneid, return IPC_CALLRET_FATAL);
  579.  
  580.     call = ipc_call_alloc(0);
  581.     rc = copy_from_uspace(&call->data.args, &data->args,
  582.         sizeof(call->data.args));
  583.     if (rc != 0) {
  584.         ipc_call_free(call);
  585.         return (unative_t) rc;
  586.     }
  587.     if (!(res = request_preprocess(call)))
  588.         ipc_call(phone, call);
  589.     else
  590.         ipc_backsend_err(phone, call, res);
  591.  
  592.     return (unative_t) call;
  593. }
  594.  
  595. /** Forward a received call to another destination.
  596.  *
  597.  * @param callid    Hash of the call to forward.
  598.  * @param phoneid   Phone handle to use for forwarding.
  599.  * @param method    New method to use for the forwarded call.
  600.  * @param arg1      New value of the first argument for the forwarded call.
  601.  * @param arg2      New value of the second argument for the forwarded call.
  602.  * @param mode      Flags that specify mode of the forward operation.
  603.  *
  604.  * @return      Return 0 on succes, otherwise return an error code.
  605.  *
  606.  * In case the original method is a system method, ARG1, ARG2 and ARG3 are
  607.  * overwritten in the forwarded message with the new method and the new arg1 and
  608.  * arg2, respectively. Otherwise the METHOD, ARG1 and ARG2 are rewritten with
  609.  * the new method, arg1 and arg2, respectively. Also note there is a set of
  610.  * immutable methods, for which the new method and argument is not set and
  611.  * these values are ignored.
  612.  *
  613.  * Warning: When implementing support for changing additional payload
  614.  *      arguments, make sure that ARG5 is not rewritten for certain
  615.  *      system IPC
  616.  */
  617. unative_t sys_ipc_forward_fast(unative_t callid, unative_t phoneid,
  618.     unative_t method, unative_t arg1, unative_t arg2, int mode)
  619. {
  620.     call_t *call;
  621.     phone_t *phone;
  622.  
  623.     call = get_call(callid);
  624.     if (!call)
  625.         return ENOENT;
  626.  
  627.     call->flags |= IPC_CALL_FORWARDED;
  628.  
  629.     GET_CHECK_PHONE(phone, phoneid, {
  630.         IPC_SET_RETVAL(call->data, EFORWARD);
  631.         ipc_answer(&TASK->answerbox, call);
  632.         return ENOENT;
  633.     });
  634.  
  635.     if (!method_is_forwardable(IPC_GET_METHOD(call->data))) {
  636.         IPC_SET_RETVAL(call->data, EFORWARD);
  637.         ipc_answer(&TASK->answerbox, call);
  638.         return EPERM;
  639.     }
  640.  
  641.     /*
  642.      * Userspace is not allowed to change method of system methods on
  643.      * forward, allow changing ARG1, ARG2 and ARG3 by means of method,
  644.      * arg1 and arg2.
  645.      * If the method is immutable, don't change anything.
  646.      */
  647.     if (!method_is_immutable(IPC_GET_METHOD(call->data))) {
  648.         if (method_is_system(IPC_GET_METHOD(call->data))) {
  649.             if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME)
  650.                 phone_dealloc(IPC_GET_ARG5(call->data));
  651.  
  652.             IPC_SET_ARG1(call->data, method);
  653.             IPC_SET_ARG2(call->data, arg1);
  654.             IPC_SET_ARG3(call->data, arg2);
  655.         } else {
  656.             IPC_SET_METHOD(call->data, method);
  657.             IPC_SET_ARG1(call->data, arg1);
  658.             IPC_SET_ARG2(call->data, arg2);
  659.         }
  660.     }
  661.  
  662.     return ipc_forward(call, phone, &TASK->answerbox, mode);
  663. }
  664.  
  665. /** Answer an IPC call - fast version.
  666.  *
  667.  * This function can handle only two return arguments of payload, but is faster
  668.  * than the generic sys_ipc_answer().
  669.  *
  670.  * @param callid    Hash of the call to be answered.
  671.  * @param retval    Return value of the answer.
  672.  * @param arg1      Service-defined return value.
  673.  * @param arg2      Service-defined return value.
  674.  * @param arg3      Service-defined return value.
  675.  * @param arg4      Service-defined return value.
  676.  *
  677.  * @return      Return 0 on success, otherwise return an error code.   
  678.  */
  679. unative_t sys_ipc_answer_fast(unative_t callid, unative_t retval,
  680.     unative_t arg1, unative_t arg2, unative_t arg3, unative_t arg4)
  681. {
  682.     call_t *call;
  683.     ipc_data_t saved_data;
  684.     int saveddata = 0;
  685.     int rc;
  686.  
  687.     /* Do not answer notification callids */
  688.     if (callid & IPC_CALLID_NOTIFICATION)
  689.         return 0;
  690.  
  691.     call = get_call(callid);
  692.     if (!call)
  693.         return ENOENT;
  694.  
  695.     if (answer_need_old(call)) {
  696.         memcpy(&saved_data, &call->data, sizeof(call->data));
  697.         saveddata = 1;
  698.     }
  699.  
  700.     IPC_SET_RETVAL(call->data, retval);
  701.     IPC_SET_ARG1(call->data, arg1);
  702.     IPC_SET_ARG2(call->data, arg2);
  703.     IPC_SET_ARG3(call->data, arg3);
  704.     IPC_SET_ARG4(call->data, arg4);
  705.     /*
  706.      * To achieve deterministic behavior, zero out arguments that are beyond
  707.      * the limits of the fast version.
  708.      */
  709.     IPC_SET_ARG5(call->data, 0);
  710.     rc = answer_preprocess(call, saveddata ? &saved_data : NULL);
  711.  
  712.     ipc_answer(&TASK->answerbox, call);
  713.     return rc;
  714. }
  715.  
  716. /** Answer an IPC call.
  717.  *
  718.  * @param callid    Hash of the call to be answered.
  719.  * @param data      Userspace address of call data with the answer.
  720.  *
  721.  * @return      Return 0 on success, otherwise return an error code.
  722.  */
  723. unative_t sys_ipc_answer_slow(unative_t callid, ipc_data_t *data)
  724. {
  725.     call_t *call;
  726.     ipc_data_t saved_data;
  727.     int saveddata = 0;
  728.     int rc;
  729.  
  730.     /* Do not answer notification callids */
  731.     if (callid & IPC_CALLID_NOTIFICATION)
  732.         return 0;
  733.  
  734.     call = get_call(callid);
  735.     if (!call)
  736.         return ENOENT;
  737.  
  738.     if (answer_need_old(call)) {
  739.         memcpy(&saved_data, &call->data, sizeof(call->data));
  740.         saveddata = 1;
  741.     }
  742.     rc = copy_from_uspace(&call->data.args, &data->args,
  743.         sizeof(call->data.args));
  744.     if (rc != 0)
  745.         return rc;
  746.  
  747.     rc = answer_preprocess(call, saveddata ? &saved_data : NULL);
  748.    
  749.     ipc_answer(&TASK->answerbox, call);
  750.  
  751.     return rc;
  752. }
  753.  
  754. /** Hang up a phone.
  755.  *
  756.  * @param       Phone handle of the phone to be hung up.
  757.  *
  758.  * @return      Return 0 on success or an error code.
  759.  */
  760. unative_t sys_ipc_hangup(int phoneid)
  761. {
  762.     phone_t *phone;
  763.  
  764.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  765.  
  766.     if (ipc_phone_hangup(phone))
  767.         return -1;
  768.  
  769.     return 0;
  770. }
  771.  
  772. /** Wait for an incoming IPC call or an answer.
  773.  *
  774.  * @param calldata  Pointer to buffer where the call/answer data is stored.
  775.  * @param usec      Timeout. See waitq_sleep_timeout() for explanation.
  776.  * @param flags     Select mode of sleep operation. See waitq_sleep_timeout()
  777.  *          for explanation.
  778.  *
  779.  * @return      Hash of the call.
  780.  *          If IPC_CALLID_NOTIFICATION bit is set in the hash, the
  781.  *          call is a notification. IPC_CALLID_ANSWERED denotes an
  782.  *          answer.
  783.  */
  784. unative_t sys_ipc_wait_for_call(ipc_data_t *calldata, uint32_t usec, int flags)
  785. {
  786.     call_t *call;
  787.  
  788. restart:   
  789.     call = ipc_wait_for_call(&TASK->answerbox, usec,
  790.         flags | SYNCH_FLAGS_INTERRUPTIBLE);
  791.     if (!call)
  792.         return 0;
  793.  
  794.     if (call->flags & IPC_CALL_NOTIF) {
  795.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  796.  
  797.         /* Set in_phone_hash to the interrupt counter */
  798.         call->data.phone = (void *) call->priv;
  799.        
  800.         STRUCT_TO_USPACE(calldata, &call->data);
  801.  
  802.         ipc_call_free(call);
  803.        
  804.         return ((unative_t) call) | IPC_CALLID_NOTIFICATION;
  805.     }
  806.  
  807.     if (call->flags & IPC_CALL_ANSWERED) {
  808.         process_answer(call);
  809.  
  810.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  811.  
  812.         atomic_dec(&TASK->active_calls);
  813.  
  814.         if (call->flags & IPC_CALL_DISCARD_ANSWER) {
  815.             ipc_call_free(call);
  816.             goto restart;
  817.         }
  818.  
  819.         STRUCT_TO_USPACE(&calldata->args, &call->data.args);
  820.         ipc_call_free(call);
  821.  
  822.         return ((unative_t) call) | IPC_CALLID_ANSWERED;
  823.     }
  824.  
  825.     if (process_request(&TASK->answerbox, call))
  826.         goto restart;
  827.  
  828.     /* Include phone address('id') of the caller in the request,
  829.      * copy whole call->data, not only call->data.args */
  830.     if (STRUCT_TO_USPACE(calldata, &call->data)) {
  831.         return 0;
  832.     }
  833.     return (unative_t)call;
  834. }
  835.  
  836. /** Connect an IRQ handler to a task.
  837.  *
  838.  * @param inr       IRQ number.
  839.  * @param devno     Device number.
  840.  * @param method    Method to be associated with the notification.
  841.  * @param ucode     Uspace pointer to the top-half pseudocode.
  842.  *
  843.  * @return      EPERM or a return code returned by ipc_irq_register().
  844.  */
  845. unative_t sys_ipc_register_irq(inr_t inr, devno_t devno, unative_t method,
  846.     irq_code_t *ucode)
  847. {
  848.     if (!(cap_get(TASK) & CAP_IRQ_REG))
  849.         return EPERM;
  850.  
  851.     return ipc_irq_register(&TASK->answerbox, inr, devno, method, ucode);
  852. }
  853.  
  854. /** Disconnect an IRQ handler from a task.
  855.  *
  856.  * @param inr       IRQ number.
  857.  * @param devno     Device number.
  858.  *
  859.  * @return      Zero on success or EPERM on error..
  860.  */
  861. unative_t sys_ipc_unregister_irq(inr_t inr, devno_t devno)
  862. {
  863.     if (!(cap_get(TASK) & CAP_IRQ_REG))
  864.         return EPERM;
  865.  
  866.     ipc_irq_unregister(&TASK->answerbox, inr, devno);
  867.  
  868.     return 0;
  869. }
  870.  
  871. /** @}
  872.  */
  873.