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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. #include <arch.h>
  30. #include <proc/task.h>
  31.  
  32. #include <errno.h>
  33. #include <mm/page.h>
  34. #include <memstr.h>
  35. #include <debug.h>
  36. #include <ipc/ipc.h>
  37. #include <ipc/sysipc.h>
  38.  
  39.  
  40. #include <print.h>
  41. #include <arch.h>
  42. #include <proc/thread.h>
  43.  
  44. /* TODO: multi-threaded connect-to-me can cause race condition
  45.  * on phone, add counter + thread_kill??
  46.  *
  47.  */
  48.  
  49. /** Return true if the method is a system method */
  50. static inline int is_system_method(__native method)
  51. {
  52.     if (method <= IPC_M_LAST_SYSTEM)
  53.         return 1;
  54.     return 0;
  55. }
  56.  
  57. /** Return true if the message with this method is forwardable
  58.  *
  59.  * - some system messages may be forwarded, for some of them
  60.  *   it is useless
  61.  */
  62. static inline int is_forwardable(__native method)
  63. {
  64.     return 1;
  65. }
  66.  
  67. /** Find call_t * in call table according to callid
  68.  *
  69.  * @return NULL on not found, otherwise pointer to call structure
  70.  */
  71. static inline call_t * get_call(__native callid)
  72. {
  73.     /* TODO: Traverse list of dispatched calls and find one */
  74.     /* TODO: locking of call, ripping it from dispatched calls etc.  */
  75.     return (call_t *) callid;
  76. }
  77.  
  78. /** Return pointer to phone identified by phoneid or NULL if non-existent */
  79. static phone_t * get_phone(__native phoneid)
  80. {
  81.     phone_t *phone;
  82.  
  83.     if (phoneid >= IPC_MAX_PHONES)
  84.         return NULL;
  85.  
  86.     phone = &TASK->phones[phoneid];
  87.     if (!phone->callee)
  88.         return NULL;
  89.     return phone;
  90. }
  91.  
  92. /** Allocate new phone slot in current TASK structure */
  93. static int phone_alloc(void)
  94. {
  95.     int i;
  96.  
  97.     spinlock_lock(&TASK->lock);
  98.    
  99.     for (i=0; i < IPC_MAX_PHONES; i++) {
  100.         if (!TASK->phones[i].busy) {
  101.             TASK->phones[i].busy = 1;
  102.             break;
  103.         }
  104.     }
  105.     spinlock_unlock(&TASK->lock);
  106.  
  107.     if (i >= IPC_MAX_PHONES)
  108.         return -1;
  109.     return i;
  110. }
  111.  
  112. /** Disconnect phone */
  113. static void phone_dealloc(int phoneid)
  114. {
  115.     spinlock_lock(&TASK->lock);
  116.  
  117.     ASSERT(TASK->phones[phoneid].busy);
  118.  
  119.     if (TASK->phones[phoneid].callee)
  120.         ipc_phone_destroy(&TASK->phones[phoneid]);
  121.  
  122.     TASK->phones[phoneid].busy = 0;
  123.     spinlock_unlock(&TASK->lock);
  124. }
  125.  
  126. static void phone_connect(int phoneid, answerbox_t *box)
  127. {
  128.     phone_t *phone = &TASK->phones[phoneid];
  129.    
  130.     ipc_phone_connect(phone, box);
  131. }
  132.  
  133. /****************************************************/
  134. /* Functions that preprocess answer before sending
  135.  * it to the recepient
  136.  */
  137.  
  138. /** Return true if the caller (ipc_answer) should save
  139.  * the old call contents and call answer_preprocess
  140.  */
  141. static inline int answer_will_preprocess(call_t *call)
  142. {
  143.     if (IPC_GET_METHOD(call->data) == IPC_M_CONNECTTOME)
  144.         return 1;
  145.     if (IPC_GET_METHOD(call->data) == IPC_M_CONNECTMETO)
  146.         return 1;
  147.     return 0;
  148. }
  149.  
  150. /** Interpret process answer as control information */
  151. static inline void answer_preprocess(call_t *answer, ipc_data_t *olddata)
  152. {
  153.     int phoneid;
  154.  
  155.     if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECTTOME) {
  156.         phoneid = IPC_GET_ARG3(*olddata);
  157.         if (IPC_GET_RETVAL(answer->data)) {
  158.             /* The connection was not accepted */
  159.             phone_dealloc(phoneid);
  160.         } else {
  161.             /* The connection was accepted */
  162.             phone_connect(phoneid,&answer->sender->answerbox);
  163.         }
  164.     } else if (IPC_GET_METHOD(*olddata) == IPC_M_CONNECTMETO) {
  165.         /* If the users accepted call, connect */
  166.         if (!IPC_GET_RETVAL(answer->data)) {
  167.             ipc_phone_connect((phone_t *)IPC_GET_ARG3(*olddata),
  168.                       &TASK->answerbox);
  169.         }
  170.     }
  171. }
  172.  
  173. /****************************************************/
  174. /* Functions called to process received call/answer
  175.  * before passing to uspace
  176.  */
  177.  
  178. /** Do basic kernel processing of received call answer */
  179. static int process_answer(answerbox_t *box,call_t *call)
  180. {
  181.     return 0;
  182. }
  183.  
  184. /** Do basic kernel processing of received call request
  185.  *
  186.  * @return 0 - the call should be passed to userspace, 1 - ignore call
  187.  */
  188. static int process_request(answerbox_t *box,call_t *call)
  189. {
  190.     int phoneid;
  191.  
  192.     if (IPC_GET_METHOD(call->data) == IPC_M_CONNECTTOME) {
  193.         phoneid = phone_alloc();
  194.         if (phoneid < 0) { /* Failed to allocate phone */
  195.             IPC_SET_RETVAL(call->data, ELIMIT);
  196.             ipc_answer(box,call);
  197.             return -1;
  198.         }
  199.         IPC_SET_ARG3(call->data, phoneid);
  200.     }
  201.     return 0;
  202. }
  203.  
  204. /** Send a call over IPC, wait for reply, return to user
  205.  *
  206.  * @return Call identification, returns -1 on fatal error,
  207.            -2 on 'Too many async request, handle answers first
  208.  */
  209. __native sys_ipc_call_sync_fast(__native phoneid, __native method,
  210.                 __native arg1, __native *data)
  211. {
  212.     call_t call;
  213.     phone_t *phone;
  214.  
  215.     phone = get_phone(phoneid);
  216.     if (!phone)
  217.         return ENOENT;
  218.  
  219.     if (is_system_method(method))
  220.         return EPERM;
  221.  
  222.     ipc_call_init(&call);
  223.     IPC_SET_METHOD(call.data, method);
  224.     IPC_SET_ARG1(call.data, arg1);
  225.    
  226.     ipc_call_sync(phone, &call);
  227.  
  228.     copy_to_uspace(data, &call.data, sizeof(call.data));
  229.  
  230.     return 0;
  231. }
  232.  
  233. /** Synchronous IPC call allowing to send whole message */
  234. __native sys_ipc_call_sync(__native phoneid, __native *question,
  235.                __native *reply)
  236. {
  237.     call_t call;
  238.     phone_t *phone;
  239.  
  240.     phone = get_phone(phoneid);
  241.     if (!phone)
  242.         return ENOENT;
  243.  
  244.     ipc_call_init(&call);
  245.     copy_from_uspace(&call.data, question, sizeof(call.data));
  246.  
  247.     if (is_system_method(IPC_GET_METHOD(call.data)))
  248.         return EPERM;
  249.    
  250.     ipc_call_sync(phone, &call);
  251.  
  252.     copy_to_uspace(reply, &call.data, sizeof(call.data));
  253.  
  254.     return 0;
  255. }
  256.  
  257. /** Check that the task did not exceed allowed limit
  258.  *
  259.  * @return 0 - Limit OK,   -1 - limit exceeded
  260.  */
  261. static int check_call_limit(void)
  262. {
  263.     if (atomic_preinc(&TASK->active_calls) > IPC_MAX_ASYNC_CALLS) {
  264.         atomic_dec(&TASK->active_calls);
  265.         return -1;
  266.     }
  267.     return 0;
  268. }
  269.  
  270. /** Send an asynchronous call over ipc
  271.  *
  272.  * @return Call identification, returns -1 on fatal error,
  273.            -2 on 'Too many async request, handle answers first
  274.  */
  275. __native sys_ipc_call_async_fast(__native phoneid, __native method,
  276.                  __native arg1, __native arg2)
  277. {
  278.     call_t *call;
  279.     phone_t *phone;
  280.  
  281.     phone = get_phone(phoneid);
  282.     if (!phone)
  283.         return IPC_CALLRET_FATAL;
  284.  
  285.     if (is_system_method(method))
  286.         return IPC_CALLRET_FATAL;
  287.  
  288.     if (check_call_limit())
  289.         return IPC_CALLRET_TEMPORARY;
  290.  
  291.     call = ipc_call_alloc();
  292.     IPC_SET_METHOD(call->data, method);
  293.     IPC_SET_ARG1(call->data, arg1);
  294.     IPC_SET_ARG2(call->data, arg2);
  295.  
  296.     ipc_call(phone, call);
  297.  
  298.     return (__native) call;
  299. }
  300.  
  301. /** Synchronous IPC call allowing to send whole message
  302.  *
  303.  * @return The same as sys_ipc_call_async
  304.  */
  305. __native sys_ipc_call_async(__native phoneid, __native *data)
  306. {
  307.     call_t *call;
  308.     phone_t *phone;
  309.  
  310.     phone = get_phone(phoneid);
  311.     if (!phone)
  312.         return IPC_CALLRET_FATAL;
  313.  
  314.     if (check_call_limit())
  315.         return IPC_CALLRET_TEMPORARY;
  316.  
  317.     call = ipc_call_alloc();
  318.     copy_from_uspace(&call->data, data, sizeof(call->data));
  319.  
  320.     if (is_system_method(IPC_GET_METHOD(call->data))) {
  321.         ipc_call_free(call);
  322.         return EPERM;
  323.     }
  324.    
  325.     ipc_call(phone, call);
  326.  
  327.     return (__native) call;
  328. }
  329.  
  330. /** Forward received call to another destination
  331.  *
  332.  * The arg1 and arg2 are changed in the forwarded message
  333.  *
  334.  * Warning: If implementing non-fast version, make sure that
  335.  *          arg3 is not rewritten for certain system IPC
  336.  */
  337. __native sys_ipc_forward_fast(__native callid, __native phoneid,
  338.                   __native method, __native arg1)
  339. {
  340.     call_t *call;
  341.     phone_t *phone;
  342.  
  343.     call = get_call(callid);
  344.     if (!call)
  345.         return ENOENT;
  346.  
  347.     phone = get_phone(phoneid);
  348.     if (!phone) {
  349.         IPC_SET_RETVAL(call->data, EFORWARD);
  350.         ipc_answer(&TASK->answerbox, call);
  351.         return ENOENT;
  352.     }
  353.  
  354.     if (!is_forwardable(IPC_GET_METHOD(call->data))) {
  355.         IPC_SET_RETVAL(call->data, EFORWARD);
  356.         ipc_answer(&TASK->answerbox, call);
  357.         return EPERM;
  358.     }
  359.  
  360.     /* Userspace is not allowed to change method of system methods
  361.      * on forward, allow changing ARG1 and ARG2 by means of method and arg1
  362.      */
  363.     if (is_system_method(IPC_GET_METHOD(call->data))) {
  364.         IPC_SET_ARG1(call->data, method);
  365.         IPC_SET_ARG2(call->data, arg1);
  366.     } else {
  367.         IPC_SET_METHOD(call->data, method);
  368.         IPC_SET_ARG1(call->data, arg1);
  369.     }
  370.  
  371.     ipc_forward(call, phone->callee, &TASK->answerbox);
  372.  
  373.     return 0;
  374. }
  375.  
  376. /** Send IPC answer */
  377. __native sys_ipc_answer_fast(__native callid, __native retval,
  378.                  __native arg1, __native arg2)
  379. {
  380.     call_t *call;
  381.     ipc_data_t saved_data;
  382.     int preprocess = 0;
  383.  
  384.     call = get_call(callid);
  385.     if (!call)
  386.         return ENOENT;
  387.  
  388.     if (answer_will_preprocess(call)) {
  389.         memcpy(&saved_data, &call->data, sizeof(call->data));
  390.         preprocess = 1;
  391.     }
  392.  
  393.     IPC_SET_RETVAL(call->data, retval);
  394.     IPC_SET_ARG1(call->data, arg1);
  395.     IPC_SET_ARG2(call->data, arg2);
  396.  
  397.     if (preprocess)
  398.         answer_preprocess(call, &saved_data);
  399.  
  400.     ipc_answer(&TASK->answerbox, call);
  401.     return 0;
  402. }
  403.  
  404. /** Send IPC answer */
  405. inline __native sys_ipc_answer(__native callid, __native *data)
  406. {
  407.     call_t *call;
  408.     ipc_data_t saved_data;
  409.     int preprocess = 0;
  410.  
  411.     call = get_call(callid);
  412.     if (!call)
  413.         return ENOENT;
  414.  
  415.     if (answer_will_preprocess(call)) {
  416.         memcpy(&saved_data, &call->data, sizeof(call->data));
  417.         preprocess = 1;
  418.     }
  419.     copy_from_uspace(&call->data, data, sizeof(call->data));
  420.  
  421.     if (preprocess)
  422.         answer_preprocess(call, &saved_data);
  423.    
  424.     ipc_answer(&TASK->answerbox, call);
  425.  
  426.     return 0;
  427. }
  428.  
  429. /** Ask the other side of connection to do 'callback' connection
  430.  *
  431.  * @return 0 if no error, error otherwise
  432.  */
  433. __native sys_ipc_connect_to_me(__native phoneid, __native arg1,
  434.                    __native arg2, task_id_t *taskid)
  435. {
  436.     call_t call;
  437.     phone_t *phone;
  438.  
  439.     phone = get_phone(phoneid);
  440.     if (!phone)
  441.         return ENOENT;
  442.  
  443.     ipc_call_init(&call);
  444.     IPC_SET_METHOD(call.data, IPC_M_CONNECTTOME);
  445.     IPC_SET_ARG1(call.data, arg1);
  446.     IPC_SET_ARG2(call.data, arg2);
  447.    
  448.     ipc_call_sync(phone, &call);
  449.  
  450.     if (!IPC_GET_RETVAL(call.data) && taskid)
  451.         copy_to_uspace(taskid,
  452.                    &phone->callee->task->taskid,
  453.                    sizeof(TASK->taskid));
  454.  
  455.     return IPC_GET_RETVAL(call.data);
  456. }
  457.  
  458. /** Ask target process to connect me somewhere
  459.  *
  460.  * @return phoneid - on success, error otherwise
  461.  */
  462. __native sys_ipc_connect_me_to(__native phoneid, __native arg1,
  463.                    __native arg2)
  464. {
  465.     call_t call;
  466.     phone_t *phone;
  467.     int newphid;
  468.  
  469.     phone = get_phone(phoneid);
  470.     if (!phone)
  471.         return ENOENT;
  472.  
  473.     newphid = phone_alloc();
  474.     if (newphid < 0)
  475.         return ELIMIT;
  476.  
  477.     ipc_call_init(&call);
  478.     IPC_SET_METHOD(call.data, IPC_M_CONNECTMETO);
  479.     IPC_SET_ARG1(call.data, arg1);
  480.     IPC_SET_ARG2(call.data, arg2);
  481.     IPC_SET_ARG3(call.data, (__native)&TASK->phones[newphid]);
  482.  
  483.     ipc_call_sync(phone, &call);
  484.  
  485.     if (IPC_GET_RETVAL(call.data)) { /* Connection failed */
  486.         phone_dealloc(newphid);
  487.         return IPC_GET_RETVAL(call.data);
  488.     }
  489.  
  490.     return newphid;
  491. }
  492.  
  493. /** Wait for incoming ipc call or answer
  494.  *
  495.  * Generic function - can serve either as inkernel or userspace call
  496.  * - inside kernel does probably unnecessary copying of data (TODO)
  497.  *
  498.  * @param result
  499.  * @param taskid
  500.  * @param flags
  501.  * @return Callid, if callid & 1, then the call is answer
  502.  */
  503. inline __native sys_ipc_wait_for_call(ipc_data_t *calldata,
  504.                       task_id_t *taskid,
  505.                       __native flags)
  506.                          
  507. {
  508.     call_t *call;
  509.  
  510. restart:   
  511.     call = ipc_wait_for_call(&TASK->answerbox, flags);
  512.  
  513.     if (call->flags & IPC_CALL_ANSWERED) {
  514.         if (process_answer(&TASK->answerbox, call))
  515.             goto restart;
  516.  
  517.         copy_to_uspace(calldata, &call->data, sizeof(call->data));
  518.         atomic_dec(&TASK->active_calls);
  519.         ASSERT(! (call->flags & IPC_CALL_STATIC_ALLOC));
  520.         ipc_call_free(call);
  521.  
  522.         return ((__native)call) | IPC_CALLID_ANSWERED;
  523.     }
  524.     if (process_request(&TASK->answerbox, call))
  525.         goto restart;
  526.     copy_to_uspace(calldata, &call->data, sizeof(call->data));
  527.     copy_to_uspace(taskid, (void *)&TASK->taskid, sizeof(TASK->taskid));
  528.     return (__native)call;
  529. }
  530.  
  531.