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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_AS_AREA_SEND:
  116.     case IPC_M_AS_AREA_RECV:
  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_AS_AREA_SEND:
  145.     case IPC_M_AS_AREA_RECV:
  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 (IPC_GET_RETVAL(answer->data) == EHANGUP) {
  168.         /* In case of forward, hangup the forwared phone,
  169.          * not the originator
  170.          */
  171.         spinlock_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.         spinlock_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_AS_AREA_SEND) {
  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_AS_AREA_RECV) {
  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_WRITE) {
  239.         if (!IPC_GET_RETVAL(answer->data)) {
  240.             int rc;
  241.             uintptr_t dst;
  242.             uintptr_t size;
  243.  
  244.             ASSERT(answer->buffer);
  245.  
  246.             dst = IPC_GET_ARG1(answer->data);
  247.             size = IPC_GET_ARG3(answer->data);
  248.  
  249.             rc = copy_to_uspace((void *) dst, answer->buffer, size);
  250.             if (rc != 0)
  251.                 IPC_SET_RETVAL(answer->data, rc);
  252.             free(answer->buffer);
  253.             answer->buffer = NULL;
  254.         }
  255.     }
  256.     return 0;
  257. }
  258.  
  259. /** Called before the request is sent.
  260.  *
  261.  * @param call      Call structure with the request.
  262.  *
  263.  * @return      Return 0 on success, ELIMIT or EPERM on error.
  264.  */
  265. static int request_preprocess(call_t *call)
  266. {
  267.     int newphid;
  268.     size_t size;
  269.     uintptr_t src;
  270.     int rc;
  271.  
  272.     switch (IPC_GET_METHOD(call->data)) {
  273.     case IPC_M_CONNECT_ME_TO:
  274.         newphid = phone_alloc();
  275.         if (newphid < 0)
  276.             return ELIMIT;
  277.         /* Set arg5 for server */
  278.         IPC_SET_ARG5(call->data, (unative_t) &TASK->phones[newphid]);
  279.         call->flags |= IPC_CALL_CONN_ME_TO;
  280.         call->priv = newphid;
  281.         break;
  282.     case IPC_M_AS_AREA_SEND:
  283.         size = as_area_get_size(IPC_GET_ARG1(call->data));
  284.         if (!size)
  285.             return EPERM;
  286.         IPC_SET_ARG2(call->data, size);
  287.         break;
  288.     case IPC_M_DATA_WRITE:
  289.         src = IPC_GET_ARG2(call->data);
  290.         size = IPC_GET_ARG3(call->data);
  291.        
  292.         if ((size <= 0) || (size > DATA_XFER_LIMIT))
  293.             return ELIMIT;
  294.        
  295.         call->buffer = (uint8_t *) malloc(size, 0);
  296.         rc = copy_from_uspace(call->buffer, (void *) src, size);
  297.         if (rc != 0) {
  298.             free(call->buffer);
  299.             return rc;
  300.         }
  301.         break;
  302.     default:
  303.         break;
  304.     }
  305.     return 0;
  306. }
  307.  
  308. /*******************************************************************************
  309.  * Functions called to process received call/answer before passing it to uspace.
  310.  *******************************************************************************/
  311.  
  312. /** Do basic kernel processing of received call answer.
  313.  *
  314.  * @param call      Call structure with the answer.
  315.  */
  316. static void process_answer(call_t *call)
  317. {
  318.     if (IPC_GET_RETVAL(call->data) == EHANGUP &&
  319.         (call->flags & IPC_CALL_FORWARDED))
  320.         IPC_SET_RETVAL(call->data, EFORWARD);
  321.  
  322.     if (call->flags & IPC_CALL_CONN_ME_TO) {
  323.         if (IPC_GET_RETVAL(call->data))
  324.             phone_dealloc(call->priv);
  325.         else
  326.             IPC_SET_ARG5(call->data, call->priv);
  327.     }
  328. }
  329.  
  330. /** Do basic kernel processing of received call request.
  331.  *
  332.  * @param box       Destination answerbox structure.
  333.  * @param call      Call structure with the request.
  334.  *
  335.  * @return      Return 0 if the call should be passed to userspace.
  336.  *          Return -1 if the call should be ignored.
  337.  */
  338. static int process_request(answerbox_t *box, call_t *call)
  339. {
  340.     int phoneid;
  341.  
  342.     if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME) {
  343.         phoneid = phone_alloc();
  344.         if (phoneid < 0) { /* Failed to allocate phone */
  345.             IPC_SET_RETVAL(call->data, ELIMIT);
  346.             ipc_answer(box, call);
  347.             return -1;
  348.         }
  349.         IPC_SET_ARG5(call->data, phoneid);
  350.     }
  351.     return 0;
  352. }
  353.  
  354. /** Make a fast call over IPC, wait for reply and return to user.
  355.  *
  356.  * This function can handle only three arguments of payload, but is faster than
  357.  * the generic function (i.e. sys_ipc_call_sync_slow()).
  358.  *
  359.  * @param phoneid   Phone handle for the call.
  360.  * @param method    Method of the call.
  361.  * @param arg1      Service-defined payload argument.
  362.  * @param arg2      Service-defined payload argument.
  363.  * @param arg3      Service-defined payload argument.
  364.  * @param data      Address of userspace structure where the reply call will
  365.  *          be stored.
  366.  *
  367.  * @return      Returns 0 on success.
  368.  *          Return ENOENT if there is no such phone handle.
  369.  */
  370. unative_t sys_ipc_call_sync_fast(unative_t phoneid, unative_t method,
  371.     unative_t arg1, unative_t arg2, unative_t arg3, ipc_data_t *data)
  372. {
  373.     call_t call;
  374.     phone_t *phone;
  375.     int res;
  376.     int rc;
  377.  
  378.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  379.  
  380.     ipc_call_static_init(&call);
  381.     IPC_SET_METHOD(call.data, method);
  382.     IPC_SET_ARG1(call.data, arg1);
  383.     IPC_SET_ARG2(call.data, arg2);
  384.     IPC_SET_ARG3(call.data, arg3);
  385.     /*
  386.      * To achieve deterministic behavior, zero out arguments that are beyond
  387.      * the limits of the fast version.
  388.      */
  389.     IPC_SET_ARG4(call.data, 0);
  390.     IPC_SET_ARG5(call.data, 0);
  391.  
  392.     if (!(res = request_preprocess(&call))) {
  393.         ipc_call_sync(phone, &call);
  394.         process_answer(&call);
  395.     } else {
  396.         IPC_SET_RETVAL(call.data, res);
  397.     }
  398.     rc = STRUCT_TO_USPACE(&data->args, &call.data.args);
  399.     if (rc != 0)
  400.         return rc;
  401.  
  402.     return 0;
  403. }
  404.  
  405. /** Make a synchronous IPC call allowing to transmit the entire payload.
  406.  *
  407.  * @param phoneid   Phone handle for the call.
  408.  * @param question  Userspace address of call data with the request.
  409.  * @param reply     Userspace address of call data where to store the
  410.  *          answer.
  411.  *
  412.  * @return      Zero on success or an error code.
  413.  */
  414. unative_t sys_ipc_call_sync_slow(unative_t phoneid, ipc_data_t *question,
  415.     ipc_data_t *reply)
  416. {
  417.     call_t call;
  418.     phone_t *phone;
  419.     int res;
  420.     int rc;
  421.  
  422.     ipc_call_static_init(&call);
  423.     rc = copy_from_uspace(&call.data.args, &question->args,
  424.         sizeof(call.data.args));
  425.     if (rc != 0)
  426.         return (unative_t) rc;
  427.  
  428.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  429.  
  430.     if (!(res = request_preprocess(&call))) {
  431.         ipc_call_sync(phone, &call);
  432.         process_answer(&call);
  433.     } else
  434.         IPC_SET_RETVAL(call.data, res);
  435.  
  436.     rc = STRUCT_TO_USPACE(&reply->args, &call.data.args);
  437.     if (rc != 0)
  438.         return rc;
  439.  
  440.     return 0;
  441. }
  442.  
  443. /** Check that the task did not exceed the allowed limit of asynchronous calls.
  444.  *
  445.  * @return      Return 0 if limit not reached or -1 if limit exceeded.
  446.  */
  447. static int check_call_limit(void)
  448. {
  449.     if (atomic_preinc(&TASK->active_calls) > IPC_MAX_ASYNC_CALLS) {
  450.         atomic_dec(&TASK->active_calls);
  451.         return -1;
  452.     }
  453.     return 0;
  454. }
  455.  
  456. /** Make a fast asynchronous call over IPC.
  457.  *
  458.  * This function can only handle four arguments of payload, but is faster than
  459.  * the generic function sys_ipc_call_async_slow().
  460.  *
  461.  * @param phoneid   Phone handle for the call.
  462.  * @param method    Method of the call.
  463.  * @param arg1      Service-defined payload argument.
  464.  * @param arg2      Service-defined payload argument.
  465.  * @param arg3      Service-defined payload argument.
  466.  * @param arg4      Service-defined payload argument.
  467.  *
  468.  * @return      Return call hash on success.
  469.  *          Return IPC_CALLRET_FATAL in case of a fatal error and
  470.  *          IPC_CALLRET_TEMPORARY if there are too many pending
  471.  *          asynchronous requests; answers should be handled first.
  472.  */
  473. unative_t sys_ipc_call_async_fast(unative_t phoneid, unative_t method,
  474.     unative_t arg1, unative_t arg2, unative_t arg3, unative_t arg4)
  475. {
  476.     call_t *call;
  477.     phone_t *phone;
  478.     int res;
  479.  
  480.     if (check_call_limit())
  481.         return IPC_CALLRET_TEMPORARY;
  482.  
  483.     GET_CHECK_PHONE(phone, phoneid, return IPC_CALLRET_FATAL);
  484.  
  485.     call = ipc_call_alloc(0);
  486.     IPC_SET_METHOD(call->data, method);
  487.     IPC_SET_ARG1(call->data, arg1);
  488.     IPC_SET_ARG2(call->data, arg2);
  489.     IPC_SET_ARG3(call->data, arg3);
  490.     IPC_SET_ARG4(call->data, arg4);
  491.     /*
  492.      * To achieve deterministic behavior, zero out arguments that are beyond
  493.      * the limits of the fast version.
  494.      */
  495.     IPC_SET_ARG5(call->data, 0);
  496.  
  497.     if (!(res = request_preprocess(call)))
  498.         ipc_call(phone, call);
  499.     else
  500.         ipc_backsend_err(phone, call, res);
  501.  
  502.     return (unative_t) call;
  503. }
  504.  
  505. /** Make an asynchronous IPC call allowing to transmit the entire payload.
  506.  *
  507.  * @param phoneid   Phone handle for the call.
  508.  * @param data      Userspace address of call data with the request.
  509.  *
  510.  * @return      See sys_ipc_call_async_fast().
  511.  */
  512. unative_t sys_ipc_call_async_slow(unative_t phoneid, ipc_data_t *data)
  513. {
  514.     call_t *call;
  515.     phone_t *phone;
  516.     int res;
  517.     int rc;
  518.  
  519.     if (check_call_limit())
  520.         return IPC_CALLRET_TEMPORARY;
  521.  
  522.     GET_CHECK_PHONE(phone, phoneid, return IPC_CALLRET_FATAL);
  523.  
  524.     call = ipc_call_alloc(0);
  525.     rc = copy_from_uspace(&call->data.args, &data->args,
  526.         sizeof(call->data.args));
  527.     if (rc != 0) {
  528.         ipc_call_free(call);
  529.         return (unative_t) rc;
  530.     }
  531.     if (!(res = request_preprocess(call)))
  532.         ipc_call(phone, call);
  533.     else
  534.         ipc_backsend_err(phone, call, res);
  535.  
  536.     return (unative_t) call;
  537. }
  538.  
  539. /** Forward a received call to another destination.
  540.  *
  541.  * @param callid    Hash of the call to forward.
  542.  * @param phoneid   Phone handle to use for forwarding.
  543.  * @param method    New method to use for the forwarded call.
  544.  * @param arg1      New value of the first argument for the forwarded call.
  545.  * @param arg2      New value of the second argument for the forwarded call.
  546.  * @param mode      Flags that specify mode of the forward operation.
  547.  *
  548.  * @return      Return 0 on succes, otherwise return an error code.
  549.  *
  550.  * In case the original method is a system method, ARG1, ARG2 and ARG3 are
  551.  * overwritten in the forwarded message with the new method and the new arg1 and
  552.  * arg2, respectively. Otherwise the METHOD, ARG1 and ARG2 are rewritten with
  553.  * the new method, arg1 and arg2, respectively. Also note there is a set of
  554.  * immutable methods, for which the new method and argument is not set and
  555.  * these values are ignored.
  556.  *
  557.  * Warning: When implementing support for changing additional payload
  558.  *      arguments, make sure that ARG5 is not rewritten for certain
  559.  *      system IPC
  560.  */
  561. unative_t sys_ipc_forward_fast(unative_t callid, unative_t phoneid,
  562.     unative_t method, unative_t arg1, unative_t arg2, int mode)
  563. {
  564.     call_t *call;
  565.     phone_t *phone;
  566.  
  567.     call = get_call(callid);
  568.     if (!call)
  569.         return ENOENT;
  570.  
  571.     call->flags |= IPC_CALL_FORWARDED;
  572.  
  573.     GET_CHECK_PHONE(phone, phoneid, {
  574.         IPC_SET_RETVAL(call->data, EFORWARD);
  575.         ipc_answer(&TASK->answerbox, call);
  576.         return ENOENT;
  577.     });    
  578.  
  579.     if (!method_is_forwardable(IPC_GET_METHOD(call->data))) {
  580.         IPC_SET_RETVAL(call->data, EFORWARD);
  581.         ipc_answer(&TASK->answerbox, call);
  582.         return EPERM;
  583.     }
  584.  
  585.     /*
  586.      * Userspace is not allowed to change method of system methods on
  587.      * forward, allow changing ARG1, ARG2 and ARG3 by means of method,
  588.      * arg1 and arg2.
  589.      * If the method is immutable, don't change anything.
  590.      */
  591.     if (!method_is_immutable(IPC_GET_METHOD(call->data))) {
  592.         if (method_is_system(IPC_GET_METHOD(call->data))) {
  593.             if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME)
  594.                 phone_dealloc(IPC_GET_ARG5(call->data));
  595.  
  596.             IPC_SET_ARG1(call->data, method);
  597.             IPC_SET_ARG2(call->data, arg1);
  598.             IPC_SET_ARG3(call->data, arg2);
  599.         } else {
  600.             IPC_SET_METHOD(call->data, method);
  601.             IPC_SET_ARG1(call->data, arg1);
  602.             IPC_SET_ARG2(call->data, arg2);
  603.         }
  604.     }
  605.  
  606.     return ipc_forward(call, phone, &TASK->answerbox, mode);
  607. }
  608.  
  609. /** Answer an IPC call - fast version.
  610.  *
  611.  * This function can handle only two return arguments of payload, but is faster
  612.  * than the generic sys_ipc_answer().
  613.  *
  614.  * @param callid    Hash of the call to be answered.
  615.  * @param retval    Return value of the answer.
  616.  * @param arg1      Service-defined return value.
  617.  * @param arg2      Service-defined return value.
  618.  * @param arg3      Service-defined return value.
  619.  * @param arg4      Service-defined return value.
  620.  *
  621.  * @return      Return 0 on success, otherwise return an error code.   
  622.  */
  623. unative_t sys_ipc_answer_fast(unative_t callid, unative_t retval,
  624.     unative_t arg1, unative_t arg2, unative_t arg3, unative_t arg4)
  625. {
  626.     call_t *call;
  627.     ipc_data_t saved_data;
  628.     int saveddata = 0;
  629.     int rc;
  630.  
  631.     /* Do not answer notification callids */
  632.     if (callid & IPC_CALLID_NOTIFICATION)
  633.         return 0;
  634.  
  635.     call = get_call(callid);
  636.     if (!call)
  637.         return ENOENT;
  638.  
  639.     if (answer_need_old(call)) {
  640.         memcpy(&saved_data, &call->data, sizeof(call->data));
  641.         saveddata = 1;
  642.     }
  643.  
  644.     IPC_SET_RETVAL(call->data, retval);
  645.     IPC_SET_ARG1(call->data, arg1);
  646.     IPC_SET_ARG2(call->data, arg2);
  647.     IPC_SET_ARG3(call->data, arg3);
  648.     IPC_SET_ARG4(call->data, arg4);
  649.     /*
  650.      * To achieve deterministic behavior, zero out arguments that are beyond
  651.      * the limits of the fast version.
  652.      */
  653.     IPC_SET_ARG5(call->data, 0);
  654.     rc = answer_preprocess(call, saveddata ? &saved_data : NULL);
  655.  
  656.     ipc_answer(&TASK->answerbox, call);
  657.     return rc;
  658. }
  659.  
  660. /** Answer an IPC call.
  661.  *
  662.  * @param callid    Hash of the call to be answered.
  663.  * @param data      Userspace address of call data with the answer.
  664.  *
  665.  * @return      Return 0 on success, otherwise return an error code.
  666.  */
  667. unative_t sys_ipc_answer_slow(unative_t callid, ipc_data_t *data)
  668. {
  669.     call_t *call;
  670.     ipc_data_t saved_data;
  671.     int saveddata = 0;
  672.     int rc;
  673.  
  674.     /* Do not answer notification callids */
  675.     if (callid & IPC_CALLID_NOTIFICATION)
  676.         return 0;
  677.  
  678.     call = get_call(callid);
  679.     if (!call)
  680.         return ENOENT;
  681.  
  682.     if (answer_need_old(call)) {
  683.         memcpy(&saved_data, &call->data, sizeof(call->data));
  684.         saveddata = 1;
  685.     }
  686.     rc = copy_from_uspace(&call->data.args, &data->args,
  687.         sizeof(call->data.args));
  688.     if (rc != 0)
  689.         return rc;
  690.  
  691.     rc = answer_preprocess(call, saveddata ? &saved_data : NULL);
  692.    
  693.     ipc_answer(&TASK->answerbox, call);
  694.  
  695.     return rc;
  696. }
  697.  
  698. /** Hang up a phone.
  699.  *
  700.  * @param       Phone handle of the phone to be hung up.
  701.  *
  702.  * @return      Return 0 on success or an error code.
  703.  */
  704. unative_t sys_ipc_hangup(int phoneid)
  705. {
  706.     phone_t *phone;
  707.  
  708.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  709.  
  710.     if (ipc_phone_hangup(phone))
  711.         return -1;
  712.  
  713.     return 0;
  714. }
  715.  
  716. /** Wait for an incoming IPC call or an answer.
  717.  *
  718.  * @param calldata  Pointer to buffer where the call/answer data is stored.
  719.  * @param usec      Timeout. See waitq_sleep_timeout() for explanation.
  720.  * @param flags     Select mode of sleep operation. See waitq_sleep_timeout()
  721.  *          for explanation.
  722.  *
  723.  * @return      Hash of the call.
  724.  *          If IPC_CALLID_NOTIFICATION bit is set in the hash, the
  725.  *          call is a notification. IPC_CALLID_ANSWERED denotes an
  726.  *          answer.
  727.  */
  728. unative_t sys_ipc_wait_for_call(ipc_data_t *calldata, uint32_t usec, int flags)
  729. {
  730.     call_t *call;
  731.  
  732. restart:   
  733.     call = ipc_wait_for_call(&TASK->answerbox, usec,
  734.         flags | SYNCH_FLAGS_INTERRUPTIBLE);
  735.     if (!call)
  736.         return 0;
  737.  
  738.     if (call->flags & IPC_CALL_NOTIF) {
  739.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  740.  
  741.         /* Set in_phone_hash to the interrupt counter */
  742.         call->data.phone = (void *) call->priv;
  743.        
  744.         STRUCT_TO_USPACE(calldata, &call->data);
  745.  
  746.         ipc_call_free(call);
  747.        
  748.         return ((unative_t) call) | IPC_CALLID_NOTIFICATION;
  749.     }
  750.  
  751.     if (call->flags & IPC_CALL_ANSWERED) {
  752.         process_answer(call);
  753.  
  754.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  755.  
  756.         atomic_dec(&TASK->active_calls);
  757.  
  758.         if (call->flags & IPC_CALL_DISCARD_ANSWER) {
  759.             ipc_call_free(call);
  760.             goto restart;
  761.         }
  762.  
  763.         STRUCT_TO_USPACE(&calldata->args, &call->data.args);
  764.         ipc_call_free(call);
  765.  
  766.         return ((unative_t) call) | IPC_CALLID_ANSWERED;
  767.     }
  768.  
  769.     if (process_request(&TASK->answerbox, call))
  770.         goto restart;
  771.  
  772.     /* Include phone address('id') of the caller in the request,
  773.      * copy whole call->data, not only call->data.args */
  774.     if (STRUCT_TO_USPACE(calldata, &call->data)) {
  775.         return 0;
  776.     }
  777.     return (unative_t)call;
  778. }
  779.  
  780. /** Connect an IRQ handler to a task.
  781.  *
  782.  * @param inr       IRQ number.
  783.  * @param devno     Device number.
  784.  * @param method    Method to be associated with the notification.
  785.  * @param ucode     Uspace pointer to the top-half pseudocode.
  786.  *
  787.  * @return      EPERM or a return code returned by ipc_irq_register().
  788.  */
  789. unative_t sys_ipc_register_irq(inr_t inr, devno_t devno, unative_t method,
  790.     irq_code_t *ucode)
  791. {
  792.     if (!(cap_get(TASK) & CAP_IRQ_REG))
  793.         return EPERM;
  794.  
  795.     return ipc_irq_register(&TASK->answerbox, inr, devno, method, ucode);
  796. }
  797.  
  798. /** Disconnect an IRQ handler from a task.
  799.  *
  800.  * @param inr       IRQ number.
  801.  * @param devno     Device number.
  802.  *
  803.  * @return      Zero on success or EPERM on error..
  804.  */
  805. unative_t sys_ipc_unregister_irq(inr_t inr, devno_t devno)
  806. {
  807.     if (!(cap_get(TASK) & CAP_IRQ_REG))
  808.         return EPERM;
  809.  
  810.     ipc_irq_unregister(&TASK->answerbox, inr, devno);
  811.  
  812.     return 0;
  813. }
  814.  
  815. /** @}
  816.  */
  817.