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