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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. /**
  30.  * @file    ns.c
  31.  * @brief   Naming service for HelenOS IPC.
  32.  */
  33.  
  34. #include <ipc/ipc.h>
  35. #include <ipc/ns.h>
  36. #include <stdio.h>
  37. #include <unistd.h>
  38. #include <stdlib.h>
  39. #include <errno.h>
  40. #include <assert.h>
  41. #include <libadt/list.h>
  42. #include <libadt/hash_table.h>
  43. #include <sysinfo.h>
  44. #include <ddi.h>
  45. #include <as.h>
  46.  
  47. #define NAME    "NS"
  48.  
  49. #define NS_HASH_TABLE_CHAINS    20
  50.  
  51. static int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call);
  52. static int connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid);
  53.  
  54. /* Static functions implementing NS hash table operations. */
  55. static hash_index_t ns_hash(unsigned long *key);
  56. static int ns_compare(unsigned long *key, hash_count_t keys, link_t *item);
  57. static void ns_remove(link_t *item);
  58.  
  59. /** Operations for NS hash table. */
  60. static hash_table_operations_t ns_hash_table_ops = {
  61.     .hash = ns_hash,
  62.     .compare = ns_compare,
  63.     .remove_callback = ns_remove
  64. };
  65.  
  66. /** NS hash table structure. */
  67. static hash_table_t ns_hash_table;
  68.  
  69. /** NS hash table item. */
  70. typedef struct {
  71.     link_t link;
  72.     ipcarg_t service;       /**< Number of the service. */
  73.     ipcarg_t phone;         /**< Phone registered with the service. */
  74.     ipcarg_t in_phone_hash;     /**< Incoming phone hash. */
  75. } hashed_service_t;
  76.  
  77. int static ping_phone;
  78.  
  79. static void get_realtime_as(ipc_callid_t callid, ipc_call_t *call)
  80. {
  81.     static void *addr = NULL;
  82.     void *ph_addr;
  83.  
  84.     if (!addr) {
  85.         ph_addr = (void *)sysinfo_value("clock.faddr");
  86.         if (!ph_addr) {
  87.             ipc_answer_fast(callid, ENOENT, 0, 0);
  88.             return;
  89.         }
  90.         addr = as_get_mappable_page(PAGE_SIZE);
  91.         map_physmem(ph_addr, addr, 1, AS_AREA_READ | AS_AREA_CACHEABLE);
  92.     }
  93.     ipc_answer_fast(callid, 0, (ipcarg_t)addr, AS_AREA_READ);
  94. }
  95.  
  96. int main(int argc, char **argv)
  97. {
  98.     ipc_call_t call;
  99.     ipc_callid_t callid;
  100.     char *as_area;
  101.    
  102.     ipcarg_t retval, arg1, arg2;
  103.  
  104.     if (!hash_table_create(&ns_hash_table, NS_HASH_TABLE_CHAINS, 3, &ns_hash_table_ops)) {
  105.         return ENOMEM;
  106.     }
  107.        
  108.     while (1) {
  109.         callid = ipc_wait_for_call(&call);
  110.         switch (IPC_GET_METHOD(call)) {
  111.         case IPC_M_AS_AREA_RECV:
  112.             get_realtime_as(callid, &call);
  113.             continue;
  114.         case IPC_M_PHONE_HUNGUP:
  115.             retval = 0;
  116.             break;
  117.         case IPC_M_CONNECT_TO_ME:
  118.             /*
  119.              * Server requests service registration.
  120.              */
  121.             retval = register_service(IPC_GET_ARG1(call), IPC_GET_ARG3(call), &call);
  122.             break;
  123.         case IPC_M_CONNECT_ME_TO:
  124.             /*
  125.              * Client requests to be connected to a service.
  126.              */
  127.             retval = connect_to_service(IPC_GET_ARG1(call), &call, callid);
  128.             break;
  129.         default:
  130.             retval = ENOENT;
  131.             break;
  132.         }
  133.         if (! (callid & IPC_CALLID_NOTIFICATION)) {
  134.             ipc_answer_fast(callid, retval, arg1, arg2);
  135.         }
  136.     }
  137. }
  138.  
  139. /** Register service.
  140.  *
  141.  * @param service Service to be registered.
  142.  * @param phone phone Phone to be used for connections to the service.
  143.  * @param call Pointer to call structure.
  144.  *
  145.  * @return Zero on success or a value from @ref errno.h.
  146.  */
  147. int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call)
  148. {
  149.     unsigned long keys[3] = { service, call->in_phone_hash, 0 };
  150.     hashed_service_t *hs;
  151.            
  152.     if (hash_table_find(&ns_hash_table, keys)) {
  153.         return EEXISTS;
  154.     }
  155.            
  156.     hs = (hashed_service_t *) malloc(sizeof(hashed_service_t));
  157.     if (!hs) {
  158.         return ENOMEM;
  159.     }
  160.            
  161.     link_initialize(&hs->link);
  162.     hs->service = service;
  163.     hs->phone = phone;
  164.     hs->in_phone_hash = call->in_phone_hash;
  165.     hash_table_insert(&ns_hash_table, keys, &hs->link);
  166.            
  167.     return 0;
  168. }
  169.  
  170. /** Connect client to service.
  171.  *
  172.  * @param service Service to be connected to.
  173.  * @param call Pointer to call structure.
  174.  * @param callid Call ID of the request.
  175.  *
  176.  * @return Zero on success or a value from @ref errno.h.
  177.  */
  178. int connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid)
  179. {
  180.     unsigned long keys[3] = { service, 0, 0 };
  181.     link_t *hlp;
  182.     hashed_service_t *hs;
  183.            
  184.     hlp = hash_table_find(&ns_hash_table, keys);
  185.     if (!hlp) {
  186.         return ENOENT;
  187.     }
  188.     hs = hash_table_get_instance(hlp, hashed_service_t, link);
  189.     return ipc_forward_fast(callid, hs->phone, 0, 0);
  190. }
  191.  
  192. /** Compute hash index into NS hash table.
  193.  *
  194.  * @param key Pointer keys. However, only the first key (i.e. service number)
  195.  *        is used to compute the hash index.
  196.  * @return Hash index corresponding to key[0].
  197.  */
  198. hash_index_t ns_hash(unsigned long *key)
  199. {
  200.     assert(key);
  201.     return *key % NS_HASH_TABLE_CHAINS;
  202. }
  203.  
  204. /** Compare a key with hashed item.
  205.  *
  206.  * This compare function always ignores the third key.
  207.  * It exists only to make it possible to remove records
  208.  * originating from connection with key[1] in_phone_hash
  209.  * value. Note that this is close to being classified
  210.  * as a nasty hack.
  211.  *
  212.  * @param key Array of keys.
  213.  * @param keys Must be lesser or equal to 3.
  214.  * @param item Pointer to a hash table item.
  215.  * @return Non-zero if the key matches the item, zero otherwise.
  216.  */
  217. int ns_compare(unsigned long key[], hash_count_t keys, link_t *item)
  218. {
  219.     hashed_service_t *hs;
  220.  
  221.     assert(key);
  222.     assert(keys <= 3);
  223.     assert(item);
  224.    
  225.     hs = hash_table_get_instance(item, hashed_service_t, link);
  226.    
  227.     if (keys == 2)
  228.         return key[1] == hs->in_phone_hash;
  229.     else
  230.         return key[0] == hs->service;
  231. }
  232.  
  233. /** Perform actions after removal of item from the hash table.
  234.  *
  235.  * @param item Item that was removed from the hash table.
  236.  */
  237. void ns_remove(link_t *item)
  238. {
  239.     assert(item);
  240.     free(hash_table_get_instance(item, hashed_service_t, link));
  241. }
  242.