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