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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. /** @defgroup ns Naming Service
  30.  * @brief   Naming service for HelenOS IPC.
  31.  * @{
  32.  */
  33.  
  34. /**
  35.  * @file    ns.c
  36.  * @brief   Naming service for HelenOS IPC.
  37.  */
  38.  
  39.  
  40. #include <ipc/ipc.h>
  41. #include <ipc/ns.h>
  42. #include <ipc/services.h>
  43. #include <stdio.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 <ddi.h>
  52. #include <as.h>
  53.  
  54. #define NAME    "NS"
  55.  
  56. #define NS_HASH_TABLE_CHAINS    20
  57.  
  58. static int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call);
  59. static int connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid);
  60.  
  61. /* Static functions implementing NS hash table operations. */
  62. static hash_index_t ns_hash(unsigned long *key);
  63. static int ns_compare(unsigned long *key, hash_count_t keys, link_t *item);
  64. static void ns_remove(link_t *item);
  65.  
  66. /** Operations for NS hash table. */
  67. static hash_table_operations_t ns_hash_table_ops = {
  68.     .hash = ns_hash,
  69.     .compare = ns_compare,
  70.     .remove_callback = ns_remove
  71. };
  72.  
  73. /** NS hash table structure. */
  74. static hash_table_t ns_hash_table;
  75.  
  76. /** NS hash table item. */
  77. typedef struct {
  78.     link_t link;
  79.     ipcarg_t service;       /**< Number of the service. */
  80.     ipcarg_t phone;         /**< Phone registered with the service. */
  81.     ipcarg_t in_phone_hash;     /**< Incoming phone hash. */
  82. } hashed_service_t;
  83.  
  84. int static ping_phone;
  85.  
  86. static void *clockaddr = NULL;
  87. static void *klogaddr = NULL;
  88.  
  89. static void get_as(ipc_callid_t callid, ipc_call_t *call, char *name, void **addr)
  90. {
  91.     void *ph_addr;
  92.  
  93.     if (!*addr) {
  94.         ph_addr = (void *)sysinfo_value(name);
  95.         if (!ph_addr) {
  96.             ipc_answer_fast(callid, ENOENT, 0, 0);
  97.             return;
  98.         }
  99.         *addr = as_get_mappable_page(PAGE_SIZE);
  100.         map_physmem(ph_addr, *addr, 1, AS_AREA_READ | AS_AREA_CACHEABLE);
  101.     }
  102.     ipc_answer_fast(callid, 0, (ipcarg_t)*addr, AS_AREA_READ);
  103. }
  104.  
  105. int main(int argc, char **argv)
  106. {
  107.     ipc_call_t call;
  108.     ipc_callid_t callid;
  109.     char *as_area;
  110.    
  111.     ipcarg_t retval, arg1, arg2;
  112.  
  113.     if (!hash_table_create(&ns_hash_table, NS_HASH_TABLE_CHAINS, 3, &ns_hash_table_ops)) {
  114.         return ENOMEM;
  115.     }
  116.        
  117.     while (1) {
  118.         callid = ipc_wait_for_call(&call);
  119.         switch (IPC_GET_METHOD(call)) {
  120.         case IPC_M_AS_AREA_RECV:
  121.             switch (IPC_GET_ARG3(call)) {
  122.             case SERVICE_MEM_REALTIME:
  123.                 get_as(callid, &call, "clock.faddr", &clockaddr);
  124.                 break;
  125.             case SERVICE_MEM_KLOG:
  126.                 get_as(callid, &call, "klog.faddr", &klogaddr);
  127.                 break;
  128.             default:
  129.                 ipc_answer_fast(callid, ENOENT, 0, 0);
  130.             }
  131.             continue;
  132.         case IPC_M_PHONE_HUNGUP:
  133.             retval = 0;
  134.             break;
  135.         case IPC_M_CONNECT_TO_ME:
  136.             /*
  137.              * Server requests service registration.
  138.              */
  139.             retval = register_service(IPC_GET_ARG1(call), IPC_GET_ARG3(call), &call);
  140.             break;
  141.         case IPC_M_CONNECT_ME_TO:
  142.             /*
  143.              * Client requests to be connected to a service.
  144.              */
  145.             retval = connect_to_service(IPC_GET_ARG1(call), &call, callid);
  146.             break;
  147.         default:
  148.             retval = ENOENT;
  149.             break;
  150.         }
  151.         if (! (callid & IPC_CALLID_NOTIFICATION)) {
  152.             ipc_answer_fast(callid, retval, arg1, arg2);
  153.         }
  154.     }
  155. }
  156.  
  157. /** Register service.
  158.  *
  159.  * @param service Service to be registered.
  160.  * @param phone phone Phone to be used for connections to the service.
  161.  * @param call Pointer to call structure.
  162.  *
  163.  * @return Zero on success or a value from @ref errno.h.
  164.  */
  165. int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call)
  166. {
  167.     unsigned long keys[3] = { service, call->in_phone_hash, 0 };
  168.     hashed_service_t *hs;
  169.            
  170.     if (hash_table_find(&ns_hash_table, keys)) {
  171.         return EEXISTS;
  172.     }
  173.            
  174.     hs = (hashed_service_t *) malloc(sizeof(hashed_service_t));
  175.     if (!hs) {
  176.         return ENOMEM;
  177.     }
  178.            
  179.     link_initialize(&hs->link);
  180.     hs->service = service;
  181.     hs->phone = phone;
  182.     hs->in_phone_hash = call->in_phone_hash;
  183.     hash_table_insert(&ns_hash_table, keys, &hs->link);
  184.            
  185.     return 0;
  186. }
  187.  
  188. /** Connect client to service.
  189.  *
  190.  * @param service Service to be connected to.
  191.  * @param call Pointer to call structure.
  192.  * @param callid Call ID of the request.
  193.  *
  194.  * @return Zero on success or a value from @ref errno.h.
  195.  */
  196. int connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid)
  197. {
  198.     unsigned long keys[3] = { service, 0, 0 };
  199.     link_t *hlp;
  200.     hashed_service_t *hs;
  201.            
  202.     hlp = hash_table_find(&ns_hash_table, keys);
  203.     if (!hlp) {
  204.         return ENOENT;
  205.     }
  206.     hs = hash_table_get_instance(hlp, hashed_service_t, link);
  207.     return ipc_forward_fast(callid, hs->phone, 0, 0);
  208. }
  209.  
  210. /** Compute hash index into NS hash table.
  211.  *
  212.  * @param key Pointer keys. However, only the first key (i.e. service number)
  213.  *        is used to compute the hash index.
  214.  * @return Hash index corresponding to key[0].
  215.  */
  216. hash_index_t ns_hash(unsigned long *key)
  217. {
  218.     assert(key);
  219.     return *key % NS_HASH_TABLE_CHAINS;
  220. }
  221.  
  222. /** Compare a key with hashed item.
  223.  *
  224.  * This compare function always ignores the third key.
  225.  * It exists only to make it possible to remove records
  226.  * originating from connection with key[1] in_phone_hash
  227.  * value. Note that this is close to being classified
  228.  * as a nasty hack.
  229.  *
  230.  * @param key Array of keys.
  231.  * @param keys Must be lesser or equal to 3.
  232.  * @param item Pointer to a hash table item.
  233.  * @return Non-zero if the key matches the item, zero otherwise.
  234.  */
  235. int ns_compare(unsigned long key[], hash_count_t keys, link_t *item)
  236. {
  237.     hashed_service_t *hs;
  238.  
  239.     assert(key);
  240.     assert(keys <= 3);
  241.     assert(item);
  242.    
  243.     hs = hash_table_get_instance(item, hashed_service_t, link);
  244.    
  245.     if (keys == 2)
  246.         return key[1] == hs->in_phone_hash;
  247.     else
  248.         return key[0] == hs->service;
  249. }
  250.  
  251. /** Perform actions after removal of item from the hash table.
  252.  *
  253.  * @param item Item that was removed from the hash table.
  254.  */
  255. void ns_remove(link_t *item)
  256. {
  257.     assert(item);
  258.     free(hash_table_get_instance(item, hashed_service_t, link));
  259. }
  260. /**
  261.  * @}
  262.  */
  263.