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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 ns
  30.  * @{
  31.  */
  32.  
  33. /**
  34.  * @file  ns.c
  35.  * @brief Naming service for HelenOS IPC.
  36.  */
  37.  
  38.  
  39. #include <ipc/ipc.h>
  40. #include <ipc/ns.h>
  41. #include <ipc/services.h>
  42. #include <stdio.h>
  43. #include <bool.h>
  44. #include <unistd.h>
  45. #include <stdlib.h>
  46. #include <errno.h>
  47. #include <assert.h>
  48. #include <libadt/list.h>
  49. #include <libadt/hash_table.h>
  50. #include <sysinfo.h>
  51. #include <loader/loader.h>
  52. #include <ddi.h>
  53. #include <as.h>
  54.  
  55. #define NAME  "ns"
  56.  
  57. #define NS_HASH_TABLE_CHAINS  20
  58.  
  59. static int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call);
  60. static void connect_to_service(ipcarg_t service, ipc_call_t *call,
  61.     ipc_callid_t callid);
  62.  
  63. void register_clonable(ipcarg_t service, ipcarg_t phone, ipc_call_t *call,
  64.     ipc_callid_t callid);
  65. void connect_to_clonable(ipcarg_t service, ipc_call_t *call,
  66.     ipc_callid_t callid);
  67.  
  68.  
  69. /* Static functions implementing NS hash table operations. */
  70. static hash_index_t ns_hash(unsigned long *key);
  71. static int ns_compare(unsigned long *key, hash_count_t keys, link_t *item);
  72. static void ns_remove(link_t *item);
  73.  
  74. /** Operations for NS hash table. */
  75. static hash_table_operations_t ns_hash_table_ops = {
  76.     .hash = ns_hash,
  77.     .compare = ns_compare,
  78.     .remove_callback = ns_remove
  79. };
  80.  
  81. /** NS hash table structure. */
  82. static hash_table_t ns_hash_table;
  83.  
  84. /** NS hash table item. */
  85. typedef struct {
  86.     link_t link;
  87.     ipcarg_t service;        /**< Number of the service. */
  88.     ipcarg_t phone;          /**< Phone registered with the service. */
  89.     ipcarg_t in_phone_hash;  /**< Incoming phone hash. */
  90. } hashed_service_t;
  91.  
  92. /** Pending connection structure. */
  93. typedef struct {
  94.     link_t link;
  95.     ipcarg_t service;        /**< Number of the service. */
  96.     ipc_callid_t callid;     /**< Call ID waiting for the connection */
  97.     ipcarg_t arg2;           /**< Second argument */
  98.     ipcarg_t arg3;           /**< Third argument */
  99. } pending_req_t;
  100.  
  101. static link_t pending_req;
  102.  
  103. /** Request for connection to a clonable service. */
  104. typedef struct {
  105.     link_t link;
  106.     ipcarg_t service;
  107.     ipc_call_t call;
  108.     ipc_callid_t callid;
  109. } cs_req_t;
  110.  
  111. /** List of clonable-service connection requests. */
  112. static link_t cs_req;
  113.  
  114. static void *clockaddr = NULL;
  115. static void *klogaddr = NULL;
  116.  
  117. /** Return true if @a service is clonable. */
  118. static bool service_clonable(int service)
  119. {
  120.     return (service == SERVICE_LOAD);
  121. }
  122.  
  123. static void get_as_area(ipc_callid_t callid, ipc_call_t *call, void *ph_addr, count_t pages, void **addr)
  124. {
  125.     if (ph_addr == NULL) {
  126.         ipc_answer_0(callid, ENOENT);
  127.         return;
  128.     }
  129.    
  130.     if (*addr == NULL) {
  131.         *addr = as_get_mappable_page(pages * PAGE_SIZE);
  132.        
  133.         if (*addr == NULL) {
  134.             ipc_answer_0(callid, ENOENT);
  135.             return;
  136.         }
  137.        
  138.         if (physmem_map(ph_addr, *addr, pages,
  139.             AS_AREA_READ | AS_AREA_CACHEABLE) != 0) {
  140.             ipc_answer_0(callid, ENOENT);
  141.             return;
  142.         }
  143.     }
  144.    
  145.     ipc_answer_2(callid, EOK, (ipcarg_t) *addr, AS_AREA_READ);
  146. }
  147.  
  148. /** Process pending connection requests */
  149. static void process_pending_req()
  150. {
  151.     link_t *cur;
  152.    
  153. loop:
  154.     for (cur = pending_req.next; cur != &pending_req; cur = cur->next) {
  155.         pending_req_t *pr = list_get_instance(cur, pending_req_t, link);
  156.        
  157.         unsigned long keys[3] = {
  158.             pr->service,
  159.             0,
  160.             0
  161.         };
  162.        
  163.         link_t *link = hash_table_find(&ns_hash_table, keys);
  164.         if (!link)
  165.             continue;
  166.        
  167.         hashed_service_t *hs = hash_table_get_instance(link, hashed_service_t, link);
  168.         ipcarg_t retval = ipc_forward_fast(pr->callid, hs->phone,
  169.             pr->arg2, pr->arg3, 0, IPC_FF_NONE);
  170.        
  171.         if (!(pr->callid & IPC_CALLID_NOTIFICATION))
  172.             ipc_answer_0(pr->callid, retval);
  173.        
  174.         list_remove(cur);
  175.         free(pr);
  176.         goto loop;
  177.     }
  178. }
  179.  
  180. int main(int argc, char **argv)
  181. {
  182.     printf(NAME ": HelenOS IPC Naming Service\n");
  183.    
  184.     if (!hash_table_create(&ns_hash_table, NS_HASH_TABLE_CHAINS, 3,
  185.         &ns_hash_table_ops)) {
  186.         printf(NAME ": No memory available for services\n");
  187.         return ENOMEM;
  188.     }
  189.    
  190.     list_initialize(&pending_req);
  191.     list_initialize(&cs_req);
  192.    
  193.     printf(NAME ": Accepting connections\n");
  194.     while (true) {
  195.         process_pending_req();
  196.        
  197.         ipc_call_t call;
  198.         ipc_callid_t callid = ipc_wait_for_call(&call);
  199.         ipcarg_t retval;
  200.        
  201.         switch (IPC_GET_METHOD(call)) {
  202.         case IPC_M_SHARE_IN:
  203.             switch (IPC_GET_ARG3(call)) {
  204.             case SERVICE_MEM_REALTIME:
  205.                 get_as_area(callid, &call, sysinfo_value("clock.faddr"), 1, &clockaddr);
  206.                 break;
  207.             case SERVICE_MEM_KLOG:
  208.                 get_as_area(callid, &call, sysinfo_value("klog.faddr"), sysinfo_value("klog.pages"), &klogaddr);
  209.                 break;
  210.             default:
  211.                 ipc_answer_0(callid, ENOENT);
  212.             }
  213.             continue;
  214.         case IPC_M_PHONE_HUNGUP:
  215.             retval = EOK;
  216.             break;
  217.         case IPC_M_CONNECT_TO_ME:
  218.             /*
  219.              * Server requests service registration.
  220.              */
  221.             if (service_clonable(IPC_GET_ARG1(call))) {
  222.                 register_clonable(IPC_GET_ARG1(call),
  223.                     IPC_GET_ARG5(call), &call, callid);
  224.                 continue;
  225.             } else {
  226.                 retval = register_service(IPC_GET_ARG1(call),
  227.                     IPC_GET_ARG5(call), &call);
  228.             }
  229.             break;
  230.         case IPC_M_CONNECT_ME_TO:
  231.             /*
  232.              * Client requests to be connected to a service.
  233.              */
  234.             if (service_clonable(IPC_GET_ARG1(call))) {
  235.                 connect_to_clonable(IPC_GET_ARG1(call),
  236.                     &call, callid);
  237.                 continue;
  238.             } else {
  239.                 connect_to_service(IPC_GET_ARG1(call), &call,
  240.                     callid);
  241.                 continue;
  242.             }
  243.             break;
  244.         default:
  245.             retval = ENOENT;
  246.             break;
  247.         }
  248.        
  249.         if (!(callid & IPC_CALLID_NOTIFICATION))
  250.             ipc_answer_0(callid, retval);
  251.     }
  252.    
  253.     /* Not reached */
  254.     return 0;
  255. }
  256.  
  257. /** Register service.
  258.  *
  259.  * @param service Service to be registered.
  260.  * @param phone   Phone to be used for connections to the service.
  261.  * @param call    Pointer to call structure.
  262.  *
  263.  * @return Zero on success or a value from @ref errno.h.
  264.  *
  265.  */
  266. int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call)
  267. {
  268.     unsigned long keys[3] = {
  269.         service,
  270.         call->in_phone_hash,
  271.         0
  272.     };
  273.    
  274.     if (hash_table_find(&ns_hash_table, keys))
  275.         return EEXISTS;
  276.    
  277.     hashed_service_t *hs = (hashed_service_t *) malloc(sizeof(hashed_service_t));
  278.     if (!hs)
  279.         return ENOMEM;
  280.    
  281.     link_initialize(&hs->link);
  282.     hs->service = service;
  283.     hs->phone = phone;
  284.     hs->in_phone_hash = call->in_phone_hash;
  285.     hash_table_insert(&ns_hash_table, keys, &hs->link);
  286.    
  287.     return 0;
  288. }
  289.  
  290. /** Connect client to service.
  291.  *
  292.  * @param service Service to be connected to.
  293.  * @param call    Pointer to call structure.
  294.  * @param callid  Call ID of the request.
  295.  *
  296.  * @return Zero on success or a value from @ref errno.h.
  297.  *
  298.  */
  299. void connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid)
  300. {
  301.     ipcarg_t retval;
  302.     unsigned long keys[3] = {
  303.         service,
  304.         0,
  305.         0
  306.     };
  307.    
  308.     link_t *link = hash_table_find(&ns_hash_table, keys);
  309.     if (!link) {
  310.         if (IPC_GET_ARG4(*call) & IPC_FLAG_BLOCKING) {
  311.             /* Blocking connection, add to pending list */
  312.             pending_req_t *pr = (pending_req_t *) malloc(sizeof(pending_req_t));
  313.             if (!pr) {
  314.                 retval = ENOMEM;
  315.                 goto out;
  316.             }
  317.            
  318.             pr->service = service;
  319.             pr->callid = callid;
  320.             pr->arg2 = IPC_GET_ARG2(*call);
  321.             pr->arg3 = IPC_GET_ARG3(*call);
  322.             list_append(&pr->link, &pending_req);
  323.             return;
  324.         }
  325.         retval = ENOENT;
  326.         goto out;
  327.     }
  328.    
  329.     hashed_service_t *hs = hash_table_get_instance(link, hashed_service_t, link);
  330.     retval = ipc_forward_fast(callid, hs->phone, IPC_GET_ARG2(*call),
  331.         IPC_GET_ARG3(*call), 0, IPC_FF_NONE);
  332. out:
  333.     if (!(callid & IPC_CALLID_NOTIFICATION))
  334.         ipc_answer_0(callid, retval);
  335. }
  336.  
  337. /** Register clonable service.
  338.  *
  339.  * @param service Service to be registered.
  340.  * @param phone   Phone to be used for connections to the service.
  341.  * @param call    Pointer to call structure.
  342.  *
  343.  */
  344. void register_clonable(ipcarg_t service, ipcarg_t phone, ipc_call_t *call,
  345.     ipc_callid_t callid)
  346. {
  347.     if (list_empty(&cs_req)) {
  348.         /* There was no pending connection request. */
  349.         printf(NAME ": Unexpected clonable server.\n");
  350.         ipc_answer_0(callid, EBUSY);
  351.         return;
  352.     }
  353.    
  354.     cs_req_t *csr = list_get_instance(cs_req.next, cs_req_t, link);
  355.     list_remove(&csr->link);
  356.    
  357.     /* Currently we can only handle a single type of clonable service. */
  358.     assert(csr->service == SERVICE_LOAD);
  359.    
  360.     ipc_answer_0(callid, EOK);
  361.    
  362.     int rc = ipc_forward_fast(csr->callid, phone, IPC_GET_ARG2(csr->call),
  363.         IPC_GET_ARG3(csr->call), 0, IPC_FF_NONE);
  364.  
  365.     free(csr);
  366.     ipc_hangup(phone);
  367. }
  368.  
  369. /** Connect client to clonable service.
  370.  *
  371.  * @param service Service to be connected to.
  372.  * @param call    Pointer to call structure.
  373.  * @param callid  Call ID of the request.
  374.  *
  375.  * @return Zero on success or a value from @ref errno.h.
  376.  *
  377.  */
  378. void connect_to_clonable(ipcarg_t service, ipc_call_t *call,
  379.     ipc_callid_t callid)
  380. {
  381.     assert(service == SERVICE_LOAD);
  382.    
  383.     cs_req_t *csr = malloc(sizeof(cs_req_t));
  384.     if (csr == NULL) {
  385.         ipc_answer_0(callid, ENOMEM);
  386.         return;
  387.     }
  388.    
  389.     /* Spawn a loader. */
  390.     int rc = loader_spawn("loader");
  391.    
  392.     if (rc < 0) {
  393.         free(csr);
  394.         ipc_answer_0(callid, rc);
  395.         return;
  396.     }
  397.    
  398.     csr->service = service;
  399.     csr->call = *call;
  400.     csr->callid = callid;
  401.    
  402.     /*
  403.      * We can forward the call only after the server we spawned connects
  404.      * to us. Meanwhile we might need to service more connection requests.
  405.      * Thus we store the call in a queue.
  406.      */
  407.     list_append(&csr->link, &cs_req);
  408. }
  409.  
  410. /** Compute hash index into NS hash table.
  411.  *
  412.  * @param key Pointer keys. However, only the first key (i.e. service number)
  413.  *            is used to compute the hash index.
  414.  *
  415.  * @return Hash index corresponding to key[0].
  416.  *
  417.  */
  418. hash_index_t ns_hash(unsigned long *key)
  419. {
  420.     assert(key);
  421.     return (*key % NS_HASH_TABLE_CHAINS);
  422. }
  423.  
  424. /** Compare a key with hashed item.
  425.  *
  426.  * This compare function always ignores the third key.
  427.  * It exists only to make it possible to remove records
  428.  * originating from connection with key[1] in_phone_hash
  429.  * value. Note that this is close to being classified
  430.  * as a nasty hack.
  431.  *
  432.  * @param key  Array of keys.
  433.  * @param keys Must be lesser or equal to 3.
  434.  * @param item Pointer to a hash table item.
  435.  *
  436.  * @return Non-zero if the key matches the item, zero otherwise.
  437.  *
  438.  */
  439. int ns_compare(unsigned long key[], hash_count_t keys, link_t *item)
  440. {
  441.     assert(key);
  442.     assert(keys <= 3);
  443.     assert(item);
  444.    
  445.     hashed_service_t *hs = hash_table_get_instance(item, hashed_service_t, link);
  446.    
  447.     if (keys == 2)
  448.         return key[1] == hs->in_phone_hash;
  449.     else
  450.         return key[0] == hs->service;
  451. }
  452.  
  453. /** Perform actions after removal of item from the hash table.
  454.  *
  455.  * @param item Item that was removed from the hash table.
  456.  *
  457.  */
  458. void ns_remove(link_t *item)
  459. {
  460.     assert(item);
  461.     free(hash_table_get_instance(item, hashed_service_t, link));
  462. }
  463.  
  464. /**
  465.  * @}
  466.  */
  467.