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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.  
  44. #define NAME    "NS"
  45.  
  46. #define NS_HASH_TABLE_CHAINS    20
  47.  
  48. extern int __DONT_OPEN_STDIO__=1;
  49.  
  50. static int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call);
  51. static int connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid);
  52.  
  53. /* Static functions implementing NS hash table operations. */
  54. static hash_index_t ns_hash(unsigned long *key);
  55. static int ns_compare(unsigned long *key, hash_count_t keys, link_t *item);
  56. static void ns_remove(link_t *item);
  57.  
  58. /** Operations for NS hash table. */
  59. static hash_table_operations_t ns_hash_table_ops = {
  60.     .hash = ns_hash,
  61.     .compare = ns_compare,
  62.     .remove_callback = ns_remove
  63. };
  64.  
  65. /** NS hash table structure. */
  66. static hash_table_t ns_hash_table;
  67.  
  68. /** NS hash table item. */
  69. typedef struct {
  70.     link_t link;
  71.     ipcarg_t service;       /**< Number of the service. */
  72.     ipcarg_t phone;         /**< Phone registered with the service. */
  73.     ipcarg_t in_phone_hash;     /**< Incoming phone hash. */
  74. } hashed_service_t;
  75.  
  76. int static ping_phone;
  77.  
  78. int main(int argc, char **argv)
  79. {
  80.     ipc_call_t call;
  81.     ipc_callid_t callid;
  82.     char *as_area;
  83.    
  84.     ipcarg_t retval, arg1, arg2;
  85.  
  86. //  printf("%s: Naming service started.\n", NAME);
  87.    
  88.     if (!hash_table_create(&ns_hash_table, NS_HASH_TABLE_CHAINS, 3, &ns_hash_table_ops)) {
  89. //      printf("%s: cannot create hash table\n", NAME);
  90.         return ENOMEM;
  91.     }
  92.        
  93.     while (1) {
  94.         callid = ipc_wait_for_call(&call, 0);
  95. //      printf("NS: Call in_phone_hash=%lX...", call.in_phone_hash);
  96.         switch (IPC_GET_METHOD(call)) {
  97.         case IPC_M_AS_AREA_SEND:
  98.             as_area = (char *)IPC_GET_ARG2(call);
  99. //          printf("Received as_area: %P, size:%d\n", as_area, IPC_GET_ARG3(call));
  100.             retval = ipc_answer_fast(callid, 0,(sysarg_t)(1024*1024), 0);
  101.             if (!retval) {
  102. //              printf("Reading shared memory...");
  103. //              printf("Text: %s", as_area);
  104.             } else
  105. //              printf("Failed answer: %d\n", retval);
  106.             continue;
  107.             break;
  108.         case IPC_M_INTERRUPT:
  109. //          printf("GOT INTERRUPT: %c\n", IPC_GET_ARG2(call));
  110.             break;
  111.         case IPC_M_PHONE_HUNGUP:
  112. //          printf("Phone hung up.\n");
  113.             retval = 0;
  114.             break;
  115.         case IPC_M_CONNECT_TO_ME:
  116.             /*
  117.              * Server requests service registration.
  118.              */
  119.             retval = register_service(IPC_GET_ARG1(call), IPC_GET_ARG3(call), &call);
  120.             ping_phone = IPC_GET_ARG3(call);
  121.             break;
  122.         case IPC_M_CONNECT_ME_TO:
  123.             /*
  124.              * Client requests to be connected to a service.
  125.              */
  126.             retval = connect_to_service(IPC_GET_ARG1(call), &call, callid);
  127.             break;
  128.         case NS_HANGUP:
  129. //          printf("Closing connection.\n");
  130.             retval = EHANGUP;
  131.             break;
  132.         case NS_PING:
  133. //          printf("Ping...%P %P\n", IPC_GET_ARG1(call),
  134. //                 IPC_GET_ARG2(call));
  135.             retval = 0;
  136.             arg1 = 0xdead;
  137.             arg2 = 0xbeef;
  138.             break;
  139.         case NS_PING_SVC:
  140. //          printf("NS:Pinging service %d\n", ping_phone);
  141.             ipc_call_sync(ping_phone, NS_PING, 0xbeef, 0);
  142. //          printf("NS:Got pong\n");
  143.             break;
  144.         default:
  145. //          printf("Unknown method: %zd\n", IPC_GET_METHOD(call));
  146.             retval = ENOENT;
  147.             break;
  148.         }
  149.         if (! (callid & IPC_CALLID_NOTIFICATION)) {
  150. //          printf("Answering.\n");
  151.             ipc_answer_fast(callid, retval, arg1, arg2);
  152.         }
  153.     }
  154. }
  155.  
  156. /** Register service.
  157.  *
  158.  * @param service Service to be registered.
  159.  * @param phone phone Phone to be used for connections to the service.
  160.  * @param call Pointer to call structure.
  161.  *
  162.  * @return Zero on success or a value from @ref errno.h.
  163.  */
  164. int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call)
  165. {
  166.     unsigned long keys[3] = { service, call->in_phone_hash, 0 };
  167.     hashed_service_t *hs;
  168.            
  169. //  printf("Registering service %d on phone %d...", service, phone);
  170.  
  171.     if (hash_table_find(&ns_hash_table, keys)) {
  172. //      printf("Service %d already registered.\n", service);
  173.         return EEXISTS;
  174.     }
  175.            
  176.     hs = (hashed_service_t *) malloc(sizeof(hashed_service_t));
  177.     if (!hs) {
  178. //      printf("Failed to register service %d.\n", service);
  179.         return ENOMEM;
  180.     }
  181.            
  182.     link_initialize(&hs->link);
  183.     hs->service = service;
  184.     hs->phone = phone;
  185.     hs->in_phone_hash = call->in_phone_hash;
  186.     hash_table_insert(&ns_hash_table, keys, &hs->link);
  187.            
  188.     return 0;
  189. }
  190.  
  191. /** Connect client to service.
  192.  *
  193.  * @param service Service to be connected to.
  194.  * @param call Pointer to call structure.
  195.  * @param callid Call ID of the request.
  196.  *
  197.  * @return Zero on success or a value from @ref errno.h.
  198.  */
  199. int connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid)
  200. {
  201.     unsigned long keys[3] = { service, 0, 0 };
  202.     link_t *hlp;
  203.     hashed_service_t *hs;
  204.            
  205.     hlp = hash_table_find(&ns_hash_table, keys);
  206.     if (!hlp) {
  207. //      printf("Service %d not registered.\n", service);
  208.         return ENOENT;
  209.     }
  210.     hs = hash_table_get_instance(hlp, hashed_service_t, link);
  211. //  printf("Connecting in_phone_hash=%lX to service at phone %d...", call->in_phone_hash, hs->phone);
  212.     return ipc_forward_fast(callid, hs->phone, 0, 0);
  213. }
  214.  
  215. /** Compute hash index into NS hash table.
  216.  *
  217.  * @param key Pointer keys. However, only the first key (i.e. service number)
  218.  *        is used to compute the hash index.
  219.  * @return Hash index corresponding to key[0].
  220.  */
  221. hash_index_t ns_hash(unsigned long *key)
  222. {
  223.     assert(key);
  224.     return *key % NS_HASH_TABLE_CHAINS;
  225. }
  226.  
  227. /** Compare a key with hashed item.
  228.  *
  229.  * This compare function always ignores the third key.
  230.  * It exists only to make it possible to remove records
  231.  * originating from connection with key[1] in_phone_hash
  232.  * value. Note that this is close to being classified
  233.  * as a nasty hack.
  234.  *
  235.  * @param key Array of keys.
  236.  * @param keys Must be lesser or equal to 3.
  237.  * @param item Pointer to a hash table item.
  238.  * @return Non-zero if the key matches the item, zero otherwise.
  239.  */
  240. int ns_compare(unsigned long key[], hash_count_t keys, link_t *item)
  241. {
  242.     hashed_service_t *hs;
  243.  
  244.     assert(key);
  245.     assert(keys <= 3);
  246.     assert(item);
  247.    
  248.     hs = hash_table_get_instance(item, hashed_service_t, link);
  249.    
  250.     if (keys == 2)
  251.         return key[1] == hs->in_phone_hash;
  252.     else
  253.         return key[0] == hs->service;
  254. }
  255.  
  256. /** Perform actions after removal of item from the hash table.
  257.  *
  258.  * @param item Item that was removed from the hash table.
  259.  */
  260. void ns_remove(link_t *item)
  261. {
  262.     assert(item);
  263.     free(hash_table_get_instance(item, hashed_service_t, link));
  264. }
  265.