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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,
  59.     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_area(ipc_callid_t callid, ipc_call_t *call, char *name,
  88.     void **addr)
  89. {
  90.     void *ph_addr;
  91.  
  92.     if (!*addr) {
  93.         ph_addr = (void *) sysinfo_value(name);
  94.         if (!ph_addr) {
  95.             ipc_answer_0(callid, ENOENT);
  96.             return;
  97.         }
  98.         *addr = as_get_mappable_page(PAGE_SIZE);
  99.         physmem_map(ph_addr, *addr, 1,
  100.             AS_AREA_READ | AS_AREA_CACHEABLE);
  101.     }
  102.     ipc_answer_2(callid, EOK, (ipcarg_t) *addr, AS_AREA_READ);
  103. }
  104.  
  105. int main(int argc, char **argv)
  106. {
  107.     printf(NAME ": HelenOS IPC Naming Service\n");
  108.    
  109.     ipc_call_t call;
  110.     ipc_callid_t callid;
  111.    
  112.     ipcarg_t retval;
  113.  
  114.     if (!hash_table_create(&ns_hash_table, NS_HASH_TABLE_CHAINS, 3,
  115.         &ns_hash_table_ops)) {
  116.         printf(NAME ": No memory available\n");
  117.         return ENOMEM;
  118.     }
  119.    
  120.     printf(NAME ": Accepting connections\n");
  121.     while (1) {
  122.         callid = ipc_wait_for_call(&call);
  123.         switch (IPC_GET_METHOD(call)) {
  124.         case IPC_M_SHARE_IN:
  125.             switch (IPC_GET_ARG3(call)) {
  126.             case SERVICE_MEM_REALTIME:
  127.                 get_as_area(callid, &call, "clock.faddr",
  128.                     &clockaddr);
  129.                 break;
  130.             case SERVICE_MEM_KLOG:
  131.                 get_as_area(callid, &call, "klog.faddr",
  132.                     &klogaddr);
  133.                 break;
  134.             default:
  135.                 ipc_answer_0(callid, ENOENT);
  136.             }
  137.             continue;
  138.         case IPC_M_PHONE_HUNGUP:
  139.             retval = EOK;
  140.             break;
  141.         case IPC_M_CONNECT_TO_ME:
  142.             /*
  143.              * Server requests service registration.
  144.              */
  145.             retval = register_service(IPC_GET_ARG1(call),
  146.                 IPC_GET_ARG5(call), &call);
  147.             break;
  148.         case IPC_M_CONNECT_ME_TO:
  149.             /*
  150.              * Client requests to be connected to a service.
  151.              */
  152.             retval = connect_to_service(IPC_GET_ARG1(call), &call,
  153.                 callid);
  154.             break;
  155.         default:
  156.             retval = ENOENT;
  157.             break;
  158.         }
  159.         if (!(callid & IPC_CALLID_NOTIFICATION)) {
  160.             ipc_answer_0(callid, retval);
  161.         }
  162.     }
  163.    
  164.     /* Not reached */
  165.     return 0;
  166. }
  167.  
  168. /** Register service.
  169.  *
  170.  * @param service Service to be registered.
  171.  * @param phone Phone to be used for connections to the service.
  172.  * @param call Pointer to call structure.
  173.  *
  174.  * @return Zero on success or a value from @ref errno.h.
  175.  */
  176. int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call)
  177. {
  178.     unsigned long keys[3] = {
  179.         service,
  180.         call->in_phone_hash,
  181.         0
  182.     };
  183.     hashed_service_t *hs;
  184.            
  185.     if (hash_table_find(&ns_hash_table, keys)) {
  186.         return EEXISTS;
  187.     }
  188.            
  189.     hs = (hashed_service_t *) malloc(sizeof(hashed_service_t));
  190.     if (!hs) {
  191.         return ENOMEM;
  192.     }
  193.            
  194.     link_initialize(&hs->link);
  195.     hs->service = service;
  196.     hs->phone = phone;
  197.     hs->in_phone_hash = call->in_phone_hash;
  198.     hash_table_insert(&ns_hash_table, keys, &hs->link);
  199.            
  200.     return 0;
  201. }
  202.  
  203. /** Connect client to service.
  204.  *
  205.  * @param service Service to be connected to.
  206.  * @param call Pointer to call structure.
  207.  * @param callid Call ID of the request.
  208.  *
  209.  * @return Zero on success or a value from @ref errno.h.
  210.  */
  211. int connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid)
  212. {
  213.     unsigned long keys[3] = { service, 0, 0 };
  214.     link_t *hlp;
  215.     hashed_service_t *hs;
  216.            
  217.     hlp = hash_table_find(&ns_hash_table, keys);
  218.     if (!hlp) {
  219.         return ENOENT;
  220.     }
  221.     hs = hash_table_get_instance(hlp, hashed_service_t, link);
  222.     return ipc_forward_fast(callid, hs->phone, IPC_GET_ARG2(*call),
  223.         IPC_GET_ARG3(*call), 0, IPC_FF_NONE);
  224. }
  225.  
  226. /** Compute hash index into NS hash table.
  227.  *
  228.  * @param key Pointer keys. However, only the first key (i.e. service number)
  229.  *        is used to compute the hash index.
  230.  * @return Hash index corresponding to key[0].
  231.  */
  232. hash_index_t ns_hash(unsigned long *key)
  233. {
  234.     assert(key);
  235.     return *key % NS_HASH_TABLE_CHAINS;
  236. }
  237.  
  238. /** Compare a key with hashed item.
  239.  *
  240.  * This compare function always ignores the third key.
  241.  * It exists only to make it possible to remove records
  242.  * originating from connection with key[1] in_phone_hash
  243.  * value. Note that this is close to being classified
  244.  * as a nasty hack.
  245.  *
  246.  * @param key Array of keys.
  247.  * @param keys Must be lesser or equal to 3.
  248.  * @param item Pointer to a hash table item.
  249.  * @return Non-zero if the key matches the item, zero otherwise.
  250.  */
  251. int ns_compare(unsigned long key[], hash_count_t keys, link_t *item)
  252. {
  253.     hashed_service_t *hs;
  254.  
  255.     assert(key);
  256.     assert(keys <= 3);
  257.     assert(item);
  258.    
  259.     hs = hash_table_get_instance(item, hashed_service_t, link);
  260.    
  261.     if (keys == 2)
  262.         return key[1] == hs->in_phone_hash;
  263.     else
  264.         return key[0] == hs->service;
  265. }
  266.  
  267. /** Perform actions after removal of item from the hash table.
  268.  *
  269.  * @param item Item that was removed from the hash table.
  270.  */
  271. void ns_remove(link_t *item)
  272. {
  273.     assert(item);
  274.     free(hash_table_get_instance(item, hashed_service_t, link));
  275. }
  276.  
  277. /**
  278.  * @}
  279.  */
  280.