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