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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 <udebug/udebug_ipc.h>
  46. #include <arch/interrupt.h>
  47. #include <print.h>
  48. #include <syscall/copy.h>
  49. #include <security/cap.h>
  50. #include <mm/as.h>
  51. #include <print.h>
  52.  
  53. /**
  54.  * Maximum buffer size allowed for IPC_M_DATA_WRITE and IPC_M_DATA_READ
  55.  * requests.
  56.  */
  57. #define DATA_XFER_LIMIT     (64 * 1024)
  58.  
  59. #define GET_CHECK_PHONE(phone, phoneid, err) \
  60. { \
  61.     if (phoneid > IPC_MAX_PHONES) { \
  62.         err; \
  63.     } \
  64.     phone = &TASK->phones[phoneid]; \
  65. }
  66.  
  67. #define STRUCT_TO_USPACE(dst, src)  copy_to_uspace(dst, src, sizeof(*(src)))
  68.  
  69. /** Decide if the method is a system method.
  70.  *
  71.  * @param method    Method to be decided.
  72.  *
  73.  * @return      Return 1 if the method is a system method.
  74.  *          Otherwise return 0.
  75.  */
  76. static inline int method_is_system(unative_t method)
  77. {
  78.     if (method <= IPC_M_LAST_SYSTEM)
  79.         return 1;
  80.     return 0;
  81. }
  82.  
  83. /** Decide if the message with this method is forwardable.
  84.  *
  85.  * - some system messages may be forwarded, for some of them
  86.  *   it is useless
  87.  *
  88.  * @param method    Method to be decided.
  89.  *
  90.  * @return      Return 1 if the method is forwardable.
  91.  *          Otherwise return 0.
  92.  */
  93. static inline int method_is_forwardable(unative_t method)
  94. {
  95.     switch (method) {
  96.     case IPC_M_PHONE_HUNGUP:
  97.         /* This message is meant only for the original recipient. */
  98.         return 0;
  99.     default:
  100.         return 1;
  101.     }
  102. }
  103.  
  104. /** Decide if the message with this method is immutable on forward.
  105.  *
  106.  * - some system messages may be forwarded but their content cannot be altered
  107.  *
  108.  * @param method    Method to be decided.
  109.  *
  110.  * @return      Return 1 if the method is immutable on forward.
  111.  *          Otherwise return 0.
  112.  */
  113. static inline int method_is_immutable(unative_t method)
  114. {
  115.     switch (method) {
  116.     case IPC_M_SHARE_OUT:
  117.     case IPC_M_SHARE_IN:
  118.     case IPC_M_DATA_WRITE:
  119.     case IPC_M_DATA_READ:
  120.         return 1;
  121.         break;
  122.     default:
  123.         return 0;
  124.     }
  125. }
  126.  
  127.  
  128. /***********************************************************************
  129.  * Functions that preprocess answer before sending it to the recepient.
  130.  ***********************************************************************/
  131.  
  132. /** Decide if the caller (e.g. ipc_answer()) should save the old call contents
  133.  * for answer_preprocess().
  134.  *
  135.  * @param call      Call structure to be decided.
  136.  *
  137.  * @return      Return 1 if the old call contents should be saved.
  138.  *          Return 0 otherwise.
  139.  */
  140. static inline int answer_need_old(call_t *call)
  141. {
  142.     switch (IPC_GET_METHOD(call->data)) {
  143.     case IPC_M_CONNECT_TO_ME:
  144.     case IPC_M_CONNECT_ME_TO:
  145.     case IPC_M_SHARE_OUT:
  146.     case IPC_M_SHARE_IN:
  147.     case IPC_M_DATA_WRITE:
  148.     case IPC_M_DATA_READ:
  149.         return 1;
  150.     default:
  151.         return 0;
  152.     }
  153. }
  154.  
  155. /** Interpret process answer as control information.
  156.  *
  157.  * This function is called directly after sys_ipc_answer().
  158.  *
  159.  * @param answer    Call structure with the answer.
  160.  * @param olddata   Saved data of the request.
  161.  *
  162.  * @return      Return 0 on success or an error code.
  163.  */
  164. static inline int answer_preprocess(call_t *answer, ipc_data_t *olddata)
  165. {
  166.     int phoneid;
  167.  
  168.     if ((native_t) IPC_GET_RETVAL(answer->data) == EHANGUP) {
  169.         /* In case of forward, hangup the forwared phone,
  170.          * not the originator
  171.          */
  172.         spinlock_lock(&answer->data.phone->lock);
  173.         spinlock_lock(&TASK->answerbox.lock);
  174.         if (answer->data.phone->state == IPC_PHONE_CONNECTED) {
  175.             list_remove(&answer->data.phone->link);
  176.             answer->data.phone->state = IPC_PHONE_SLAMMED;
  177.         }
  178.         spinlock_unlock(&TASK->answerbox.lock);
  179.         spinlock_unlock(&answer->data.phone->lock);
  180.     }
  181.  
  182.     if (!olddata)
  183.         return 0;
  184.  
  185.     if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECT_TO_ME) {
  186.         phoneid = IPC_GET_ARG5(*olddata);
  187.         if (IPC_GET_RETVAL(answer->data)) {
  188.             /* The connection was not accepted */
  189.             phone_dealloc(phoneid);
  190.         } else {
  191.             /* The connection was accepted */
  192.             phone_connect(phoneid, &answer->sender->answerbox);
  193.             /* Set 'phone hash' as arg5 of response */
  194.             IPC_SET_ARG5(answer->data,
  195.                 (unative_t) &TASK->phones[phoneid]);
  196.         }
  197.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECT_ME_TO) {
  198.         /* If the users accepted call, connect */
  199.         if (!IPC_GET_RETVAL(answer->data)) {
  200.             ipc_phone_connect((phone_t *) IPC_GET_ARG5(*olddata),
  201.                 &TASK->answerbox);
  202.         }
  203.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_SHARE_OUT) {
  204.         if (!IPC_GET_RETVAL(answer->data)) {
  205.             /* Accepted, handle as_area receipt */
  206.             ipl_t ipl;
  207.             int rc;
  208.             as_t *as;
  209.            
  210.             ipl = interrupts_disable();
  211.             spinlock_lock(&answer->sender->lock);
  212.             as = answer->sender->as;
  213.             spinlock_unlock(&answer->sender->lock);
  214.             interrupts_restore(ipl);
  215.            
  216.             rc = as_area_share(as, IPC_GET_ARG1(*olddata),
  217.                 IPC_GET_ARG2(*olddata), AS,
  218.                 IPC_GET_ARG1(answer->data), IPC_GET_ARG3(*olddata));
  219.             IPC_SET_RETVAL(answer->data, rc);
  220.             return rc;
  221.         }
  222.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_SHARE_IN) {
  223.         if (!IPC_GET_RETVAL(answer->data)) {
  224.             ipl_t ipl;
  225.             as_t *as;
  226.             int rc;
  227.            
  228.             ipl = interrupts_disable();
  229.             spinlock_lock(&answer->sender->lock);
  230.             as = answer->sender->as;
  231.             spinlock_unlock(&answer->sender->lock);
  232.             interrupts_restore(ipl);
  233.            
  234.             rc = as_area_share(AS, IPC_GET_ARG1(answer->data),
  235.                 IPC_GET_ARG2(*olddata), as, IPC_GET_ARG1(*olddata),
  236.                 IPC_GET_ARG2(answer->data));
  237.             IPC_SET_RETVAL(answer->data, rc);
  238.         }
  239.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_DATA_READ) {
  240.         ASSERT(!answer->buffer);
  241.         if (!IPC_GET_RETVAL(answer->data)) {
  242.             /* The recipient agreed to send data. */
  243.             uintptr_t src = IPC_GET_ARG1(answer->data);
  244.             uintptr_t dst = IPC_GET_ARG1(*olddata);
  245.             size_t max_size = IPC_GET_ARG2(*olddata);
  246.             size_t size = IPC_GET_ARG2(answer->data);
  247.             if (size <= max_size) {
  248.                 /*
  249.                  * Copy the destination VA so that this piece of
  250.                  * information is not lost.
  251.                  */
  252.                 IPC_SET_ARG1(answer->data, dst);
  253.  
  254.                 answer->buffer = malloc(size, 0);
  255.                 int rc = copy_from_uspace(answer->buffer,
  256.                     (void *) src, size);
  257.                 if (rc) {
  258.                     IPC_SET_RETVAL(answer->data, rc);
  259.                     free(answer->buffer);
  260.                     answer->buffer = NULL;
  261.                 }
  262.             } else {
  263.                 IPC_SET_RETVAL(answer->data, ELIMIT);
  264.             }
  265.         }
  266.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_DATA_WRITE) {
  267.         ASSERT(answer->buffer);
  268.         if (!IPC_GET_RETVAL(answer->data)) {
  269.             /* The recipient agreed to receive data. */
  270.             int rc;
  271.             uintptr_t dst;
  272.             uintptr_t size;
  273.             uintptr_t max_size;
  274.  
  275.             dst = IPC_GET_ARG1(answer->data);
  276.             size = IPC_GET_ARG2(answer->data);
  277.             max_size = IPC_GET_ARG2(*olddata);
  278.  
  279.             if (size <= max_size) {
  280.                 rc = copy_to_uspace((void *) dst,
  281.                     answer->buffer, size);
  282.                 if (rc)
  283.                     IPC_SET_RETVAL(answer->data, rc);
  284.             } else {
  285.                 IPC_SET_RETVAL(answer->data, ELIMIT);
  286.             }
  287.         }
  288.         free(answer->buffer);
  289.         answer->buffer = NULL;
  290.     }
  291.     return 0;
  292. }
  293.  
  294. /** Called before the request is sent.
  295.  *
  296.  * @param call      Call structure with the request.
  297.  * @param phone     Phone that the call will be sent through.
  298.  *
  299.  * @return      Return 0 on success, ELIMIT or EPERM on error.
  300.  */
  301. static int request_preprocess(call_t *call, phone_t *phone)
  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.     case IPC_M_DEBUG_ALL:
  344.         /* actually need possibility of backsend with 0 result code */
  345.         rc = udebug_request_preprocess(call, phone);
  346.         return rc;
  347.     default:
  348.         break;
  349.     }
  350.     return 0;
  351. }
  352.  
  353. /*******************************************************************************
  354.  * Functions called to process received call/answer before passing it to uspace.
  355.  *******************************************************************************/
  356.  
  357. /** Do basic kernel processing of received call answer.
  358.  *
  359.  * @param call      Call structure with the answer.
  360.  */
  361. static void process_answer(call_t *call)
  362. {
  363.     if (((native_t) IPC_GET_RETVAL(call->data) == EHANGUP) &&
  364.         (call->flags & IPC_CALL_FORWARDED))
  365.         IPC_SET_RETVAL(call->data, EFORWARD);
  366.  
  367.     if (call->flags & IPC_CALL_CONN_ME_TO) {
  368.         if (IPC_GET_RETVAL(call->data))
  369.             phone_dealloc(call->priv);
  370.         else
  371.             IPC_SET_ARG5(call->data, call->priv);
  372.     }
  373.  
  374.     if (call->buffer) {
  375.         /* This must be an affirmative answer to IPC_M_DATA_READ. */
  376.         /* or IPC_M_DEBUG_ALL/UDEBUG_M_MEM_READ... */
  377.         uintptr_t dst = IPC_GET_ARG1(call->data);
  378.         size_t size = IPC_GET_ARG2(call->data);
  379.         int rc = copy_to_uspace((void *) dst, call->buffer, size);
  380.         if (rc)
  381.             IPC_SET_RETVAL(call->data, rc);
  382.         free(call->buffer);
  383.         call->buffer = NULL;
  384.     }
  385. }
  386.  
  387. /** Do basic kernel processing of received call request.
  388.  *
  389.  * @param box       Destination answerbox structure.
  390.  * @param call      Call structure with the request.
  391.  *
  392.  * @return      Return 0 if the call should be passed to userspace.
  393.  *          Return -1 if the call should be ignored.
  394.  */
  395. static int process_request(answerbox_t *box, call_t *call)
  396. {
  397.     int phoneid;
  398.  
  399.     if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME) {
  400.         phoneid = phone_alloc();
  401.         if (phoneid < 0) { /* Failed to allocate phone */
  402.             IPC_SET_RETVAL(call->data, ELIMIT);
  403.             ipc_answer(box, call);
  404.             return -1;
  405.         }
  406.         IPC_SET_ARG5(call->data, phoneid);
  407.     }
  408.     switch (IPC_GET_METHOD(call->data)) {
  409.     case IPC_M_DEBUG_ALL:
  410.         return -1;
  411.     default:
  412.         break;
  413.     }
  414.     return 0;
  415. }
  416.  
  417. /** Make a fast call over IPC, wait for reply and return to user.
  418.  *
  419.  * This function can handle only three arguments of payload, but is faster than
  420.  * the generic function (i.e. sys_ipc_call_sync_slow()).
  421.  *
  422.  * @param phoneid   Phone handle for the call.
  423.  * @param method    Method of the call.
  424.  * @param arg1      Service-defined payload argument.
  425.  * @param arg2      Service-defined payload argument.
  426.  * @param arg3      Service-defined payload argument.
  427.  * @param data      Address of userspace structure where the reply call will
  428.  *          be stored.
  429.  *
  430.  * @return      Returns 0 on success.
  431.  *          Return ENOENT if there is no such phone handle.
  432.  */
  433. unative_t sys_ipc_call_sync_fast(unative_t phoneid, unative_t method,
  434.     unative_t arg1, unative_t arg2, unative_t arg3, ipc_data_t *data)
  435. {
  436.     call_t call;
  437.     phone_t *phone;
  438.     int res;
  439.     int rc;
  440.  
  441.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  442.  
  443.     ipc_call_static_init(&call);
  444.     IPC_SET_METHOD(call.data, method);
  445.     IPC_SET_ARG1(call.data, arg1);
  446.     IPC_SET_ARG2(call.data, arg2);
  447.     IPC_SET_ARG3(call.data, arg3);
  448.     /*
  449.      * To achieve deterministic behavior, zero out arguments that are beyond
  450.      * the limits of the fast version.
  451.      */
  452.     IPC_SET_ARG4(call.data, 0);
  453.     IPC_SET_ARG5(call.data, 0);
  454.  
  455.     if (!(res = request_preprocess(&call, phone))) {
  456.         ipc_call_sync(phone, &call);
  457.         process_answer(&call);
  458.     } else {
  459.         IPC_SET_RETVAL(call.data, res);
  460.     }
  461.     rc = STRUCT_TO_USPACE(&data->args, &call.data.args);
  462.     if (rc != 0)
  463.         return rc;
  464.  
  465.     return 0;
  466. }
  467.  
  468. /** Make a synchronous IPC call allowing to transmit the entire payload.
  469.  *
  470.  * @param phoneid   Phone handle for the call.
  471.  * @param question  Userspace address of call data with the request.
  472.  * @param reply     Userspace address of call data where to store the
  473.  *          answer.
  474.  *
  475.  * @return      Zero on success or an error code.
  476.  */
  477. unative_t sys_ipc_call_sync_slow(unative_t phoneid, ipc_data_t *question,
  478.     ipc_data_t *reply)
  479. {
  480.     call_t call;
  481.     phone_t *phone;
  482.     int res;
  483.     int rc;
  484.  
  485.     ipc_call_static_init(&call);
  486.     rc = copy_from_uspace(&call.data.args, &question->args,
  487.         sizeof(call.data.args));
  488.     if (rc != 0)
  489.         return (unative_t) rc;
  490.  
  491.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  492.  
  493.     if (!(res = request_preprocess(&call, phone))) {
  494.         ipc_call_sync(phone, &call);
  495.         process_answer(&call);
  496.     } else
  497.         IPC_SET_RETVAL(call.data, res);
  498.  
  499.     rc = STRUCT_TO_USPACE(&reply->args, &call.data.args);
  500.     if (rc != 0)
  501.         return rc;
  502.  
  503.     return 0;
  504. }
  505.  
  506. /** Check that the task did not exceed the allowed limit of asynchronous calls.
  507.  *
  508.  * @return      Return 0 if limit not reached or -1 if limit exceeded.
  509.  */
  510. static int check_call_limit(void)
  511. {
  512.     if (atomic_preinc(&TASK->active_calls) > IPC_MAX_ASYNC_CALLS) {
  513.         atomic_dec(&TASK->active_calls);
  514.         return -1;
  515.     }
  516.     return 0;
  517. }
  518.  
  519. /** Make a fast asynchronous call over IPC.
  520.  *
  521.  * This function can only handle four arguments of payload, but is faster than
  522.  * the generic function sys_ipc_call_async_slow().
  523.  *
  524.  * @param phoneid   Phone handle for the call.
  525.  * @param method    Method of the call.
  526.  * @param arg1      Service-defined payload argument.
  527.  * @param arg2      Service-defined payload argument.
  528.  * @param arg3      Service-defined payload argument.
  529.  * @param arg4      Service-defined payload argument.
  530.  *
  531.  * @return      Return call hash on success.
  532.  *          Return IPC_CALLRET_FATAL in case of a fatal error and
  533.  *          IPC_CALLRET_TEMPORARY if there are too many pending
  534.  *          asynchronous requests; answers should be handled first.
  535.  */
  536. unative_t sys_ipc_call_async_fast(unative_t phoneid, unative_t method,
  537.     unative_t arg1, unative_t arg2, unative_t arg3, unative_t arg4)
  538. {
  539.     call_t *call;
  540.     phone_t *phone;
  541.     int res;
  542.  
  543.     if (check_call_limit())
  544.         return IPC_CALLRET_TEMPORARY;
  545.  
  546.     GET_CHECK_PHONE(phone, phoneid, return IPC_CALLRET_FATAL);
  547.  
  548.     call = ipc_call_alloc(0);
  549.     IPC_SET_METHOD(call->data, method);
  550.     IPC_SET_ARG1(call->data, arg1);
  551.     IPC_SET_ARG2(call->data, arg2);
  552.     IPC_SET_ARG3(call->data, arg3);
  553.     IPC_SET_ARG4(call->data, arg4);
  554.     /*
  555.      * To achieve deterministic behavior, zero out arguments that are beyond
  556.      * the limits of the fast version.
  557.      */
  558.     IPC_SET_ARG5(call->data, 0);
  559.  
  560.     if (!(res = request_preprocess(call, phone)))
  561.         ipc_call(phone, call);
  562.     else
  563.         ipc_backsend_err(phone, call, res);
  564.  
  565.     return (unative_t) call;
  566. }
  567.  
  568. /** Make an asynchronous IPC call allowing to transmit the entire payload.
  569.  *
  570.  * @param phoneid   Phone handle for the call.
  571.  * @param data      Userspace address of call data with the request.
  572.  *
  573.  * @return      See sys_ipc_call_async_fast().
  574.  */
  575. unative_t sys_ipc_call_async_slow(unative_t phoneid, ipc_data_t *data)
  576. {
  577.     call_t *call;
  578.     phone_t *phone;
  579.     int res;
  580.     int rc;
  581.  
  582.     if (check_call_limit())
  583.         return IPC_CALLRET_TEMPORARY;
  584.  
  585.     GET_CHECK_PHONE(phone, phoneid, return IPC_CALLRET_FATAL);
  586.  
  587.     call = ipc_call_alloc(0);
  588.     rc = copy_from_uspace(&call->data.args, &data->args,
  589.         sizeof(call->data.args));
  590.     if (rc != 0) {
  591.         ipc_call_free(call);
  592.         return (unative_t) rc;
  593.     }
  594.     if (!(res = request_preprocess(call, phone)))
  595.         ipc_call(phone, call);
  596.     else
  597.         ipc_backsend_err(phone, call, res);
  598.  
  599.     return (unative_t) call;
  600. }
  601.  
  602. /** Forward a received call to another destination.
  603.  *
  604.  * @param callid    Hash of the call to forward.
  605.  * @param phoneid   Phone handle to use for forwarding.
  606.  * @param method    New method to use for the forwarded call.
  607.  * @param arg1      New value of the first argument for the forwarded call.
  608.  * @param arg2      New value of the second argument for the forwarded call.
  609.  * @param mode      Flags that specify mode of the forward operation.
  610.  *
  611.  * @return      Return 0 on succes, otherwise return an error code.
  612.  *
  613.  * In case the original method is a system method, ARG1, ARG2 and ARG3 are
  614.  * overwritten in the forwarded message with the new method and the new arg1 and
  615.  * arg2, respectively. Otherwise the METHOD, ARG1 and ARG2 are rewritten with
  616.  * the new method, arg1 and arg2, respectively. Also note there is a set of
  617.  * immutable methods, for which the new method and argument is not set and
  618.  * these values are ignored.
  619.  *
  620.  * Warning: When implementing support for changing additional payload
  621.  *      arguments, make sure that ARG5 is not rewritten for certain
  622.  *      system IPC
  623.  */
  624. unative_t sys_ipc_forward_fast(unative_t callid, unative_t phoneid,
  625.     unative_t method, unative_t arg1, unative_t arg2, int mode)
  626. {
  627.     call_t *call;
  628.     phone_t *phone;
  629.  
  630.     call = get_call(callid);
  631.     if (!call)
  632.         return ENOENT;
  633.  
  634.     call->flags |= IPC_CALL_FORWARDED;
  635.  
  636.     GET_CHECK_PHONE(phone, phoneid, {
  637.         IPC_SET_RETVAL(call->data, EFORWARD);
  638.         ipc_answer(&TASK->answerbox, call);
  639.         return ENOENT;
  640.     });    
  641.  
  642.     if (!method_is_forwardable(IPC_GET_METHOD(call->data))) {
  643.         IPC_SET_RETVAL(call->data, EFORWARD);
  644.         ipc_answer(&TASK->answerbox, call);
  645.         return EPERM;
  646.     }
  647.  
  648.     /*
  649.      * Userspace is not allowed to change method of system methods on
  650.      * forward, allow changing ARG1, ARG2 and ARG3 by means of method,
  651.      * arg1 and arg2.
  652.      * If the method is immutable, don't change anything.
  653.      */
  654.     if (!method_is_immutable(IPC_GET_METHOD(call->data))) {
  655.         if (method_is_system(IPC_GET_METHOD(call->data))) {
  656.             if (IPC_GET_METHOD(call->data) == IPC_M_CONNECT_TO_ME)
  657.                 phone_dealloc(IPC_GET_ARG5(call->data));
  658.  
  659.             IPC_SET_ARG1(call->data, method);
  660.             IPC_SET_ARG2(call->data, arg1);
  661.             IPC_SET_ARG3(call->data, arg2);
  662.         } else {
  663.             IPC_SET_METHOD(call->data, method);
  664.             IPC_SET_ARG1(call->data, arg1);
  665.             IPC_SET_ARG2(call->data, arg2);
  666.         }
  667.     }
  668.  
  669.     return ipc_forward(call, phone, &TASK->answerbox, mode);
  670. }
  671.  
  672. /** Answer an IPC call - fast version.
  673.  *
  674.  * This function can handle only two return arguments of payload, but is faster
  675.  * than the generic sys_ipc_answer().
  676.  *
  677.  * @param callid    Hash of the call to be answered.
  678.  * @param retval    Return value of the answer.
  679.  * @param arg1      Service-defined return value.
  680.  * @param arg2      Service-defined return value.
  681.  * @param arg3      Service-defined return value.
  682.  * @param arg4      Service-defined return value.
  683.  *
  684.  * @return      Return 0 on success, otherwise return an error code.   
  685.  */
  686. unative_t sys_ipc_answer_fast(unative_t callid, unative_t retval,
  687.     unative_t arg1, unative_t arg2, unative_t arg3, unative_t arg4)
  688. {
  689.     call_t *call;
  690.     ipc_data_t saved_data;
  691.     int saveddata = 0;
  692.     int rc;
  693.  
  694.     /* Do not answer notification callids */
  695.     if (callid & IPC_CALLID_NOTIFICATION)
  696.         return 0;
  697.  
  698.     call = get_call(callid);
  699.     if (!call)
  700.         return ENOENT;
  701.  
  702.     if (answer_need_old(call)) {
  703.         memcpy(&saved_data, &call->data, sizeof(call->data));
  704.         saveddata = 1;
  705.     }
  706.  
  707.     IPC_SET_RETVAL(call->data, retval);
  708.     IPC_SET_ARG1(call->data, arg1);
  709.     IPC_SET_ARG2(call->data, arg2);
  710.     IPC_SET_ARG3(call->data, arg3);
  711.     IPC_SET_ARG4(call->data, arg4);
  712.     /*
  713.      * To achieve deterministic behavior, zero out arguments that are beyond
  714.      * the limits of the fast version.
  715.      */
  716.     IPC_SET_ARG5(call->data, 0);
  717.     rc = answer_preprocess(call, saveddata ? &saved_data : NULL);
  718.  
  719.     ipc_answer(&TASK->answerbox, call);
  720.     return rc;
  721. }
  722.  
  723. /** Answer an IPC call.
  724.  *
  725.  * @param callid    Hash of the call to be answered.
  726.  * @param data      Userspace address of call data with the answer.
  727.  *
  728.  * @return      Return 0 on success, otherwise return an error code.
  729.  */
  730. unative_t sys_ipc_answer_slow(unative_t callid, ipc_data_t *data)
  731. {
  732.     call_t *call;
  733.     ipc_data_t saved_data;
  734.     int saveddata = 0;
  735.     int rc;
  736.  
  737.     /* Do not answer notification callids */
  738.     if (callid & IPC_CALLID_NOTIFICATION)
  739.         return 0;
  740.  
  741.     call = get_call(callid);
  742.     if (!call)
  743.         return ENOENT;
  744.  
  745.     if (answer_need_old(call)) {
  746.         memcpy(&saved_data, &call->data, sizeof(call->data));
  747.         saveddata = 1;
  748.     }
  749.     rc = copy_from_uspace(&call->data.args, &data->args,
  750.         sizeof(call->data.args));
  751.     if (rc != 0)
  752.         return rc;
  753.  
  754.     rc = answer_preprocess(call, saveddata ? &saved_data : NULL);
  755.    
  756.     ipc_answer(&TASK->answerbox, call);
  757.  
  758.     return rc;
  759. }
  760.  
  761. /** Hang up a phone.
  762.  *
  763.  * @param       Phone handle of the phone to be hung up.
  764.  *
  765.  * @return      Return 0 on success or an error code.
  766.  */
  767. unative_t sys_ipc_hangup(int phoneid)
  768. {
  769.     phone_t *phone;
  770.  
  771.     GET_CHECK_PHONE(phone, phoneid, return ENOENT);
  772.  
  773.     if (ipc_phone_hangup(phone))
  774.         return -1;
  775.  
  776.     return 0;
  777. }
  778.  
  779. /** Wait for an incoming IPC call or an answer.
  780.  *
  781.  * @param calldata  Pointer to buffer where the call/answer data is stored.
  782.  * @param usec      Timeout. See waitq_sleep_timeout() for explanation.
  783.  * @param flags     Select mode of sleep operation. See waitq_sleep_timeout()
  784.  *          for explanation.
  785.  *
  786.  * @return      Hash of the call.
  787.  *          If IPC_CALLID_NOTIFICATION bit is set in the hash, the
  788.  *          call is a notification. IPC_CALLID_ANSWERED denotes an
  789.  *          answer.
  790.  */
  791. unative_t sys_ipc_wait_for_call(ipc_data_t *calldata, uint32_t usec, int flags)
  792. {
  793.     call_t *call;
  794.  
  795. restart:   
  796.     call = ipc_wait_for_call(&TASK->answerbox, usec,
  797.         flags | SYNCH_FLAGS_INTERRUPTIBLE);
  798.     if (!call)
  799.         return 0;
  800.  
  801.     if (call->flags & IPC_CALL_NOTIF) {
  802.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  803.  
  804.         /* Set in_phone_hash to the interrupt counter */
  805.         call->data.phone = (void *) call->priv;
  806.        
  807.         STRUCT_TO_USPACE(calldata, &call->data);
  808.  
  809.         ipc_call_free(call);
  810.        
  811.         return ((unative_t) call) | IPC_CALLID_NOTIFICATION;
  812.     }
  813.  
  814.     if (call->flags & IPC_CALL_ANSWERED) {
  815.         process_answer(call);
  816.  
  817.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  818.  
  819.         atomic_dec(&TASK->active_calls);
  820.  
  821.         if (call->flags & IPC_CALL_DISCARD_ANSWER) {
  822.             ipc_call_free(call);
  823.             goto restart;
  824.         }
  825.  
  826.         STRUCT_TO_USPACE(&calldata->args, &call->data.args);
  827.         ipc_call_free(call);
  828.  
  829.         return ((unative_t) call) | IPC_CALLID_ANSWERED;
  830.     }
  831.  
  832.     if (process_request(&TASK->answerbox, call))
  833.         goto restart;
  834.  
  835.     /* Include phone address('id') of the caller in the request,
  836.      * copy whole call->data, not only call->data.args */
  837.     if (STRUCT_TO_USPACE(calldata, &call->data)) {
  838.         return 0;
  839.     }
  840.     return (unative_t)call;
  841. }
  842.  
  843. /** Connect an IRQ handler to a task.
  844.  *
  845.  * @param inr       IRQ number.
  846.  * @param devno     Device number.
  847.  * @param method    Method to be associated with the notification.
  848.  * @param ucode     Uspace pointer to the top-half pseudocode.
  849.  *
  850.  * @return      EPERM or a return code returned by ipc_irq_register().
  851.  */
  852. unative_t sys_ipc_register_irq(inr_t inr, devno_t devno, unative_t method,
  853.     irq_code_t *ucode)
  854. {
  855.     if (!(cap_get(TASK) & CAP_IRQ_REG))
  856.         return EPERM;
  857.  
  858.     return ipc_irq_register(&TASK->answerbox, inr, devno, method, ucode);
  859. }
  860.  
  861. /** Disconnect an IRQ handler from a task.
  862.  *
  863.  * @param inr       IRQ number.
  864.  * @param devno     Device number.
  865.  *
  866.  * @return      Zero on success or EPERM on error..
  867.  */
  868. unative_t sys_ipc_unregister_irq(inr_t inr, devno_t devno)
  869. {
  870.     if (!(cap_get(TASK) & CAP_IRQ_REG))
  871.         return EPERM;
  872.  
  873.     ipc_irq_unregister(&TASK->answerbox, inr, devno);
  874.  
  875.     return 0;
  876. }
  877.  
  878. #include <console/klog.h>
  879.  
  880. /**
  881.  * Syscall connect to a task by id.
  882.  *
  883.  * @return      Phone id on success, or negative error code.
  884.  */
  885. unative_t sys_ipc_connect_kbox(sysarg64_t *uspace_taskid_arg)
  886. {
  887.     sysarg64_t taskid_arg;
  888.     int rc;
  889.    
  890.     rc = copy_from_uspace(&taskid_arg, uspace_taskid_arg, sizeof(sysarg64_t));
  891.     if (rc != 0)
  892.         return (unative_t) rc;
  893.  
  894.     klog_printf("sys_ipc_connect_kbox(%lld, %d)", taskid_arg.value);
  895.  
  896.     return ipc_connect_kbox(taskid_arg.value);
  897. }
  898.  
  899. /** @}
  900.  */
  901.