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