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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_fast(callid, ENOENT, 0, 0);
  96.             return;
  97.         }
  98.         *addr = as_get_mappable_page(PAGE_SIZE);
  99.         physmem_map(ph_addr, *addr, 1, AS_AREA_READ | AS_AREA_CACHEABLE);
  100.     }
  101.     ipc_answer_fast(callid, 0, (ipcarg_t) *addr, AS_AREA_READ);
  102. }
  103.  
  104. int main(int argc, char **argv)
  105. {
  106.     ipc_call_t call;
  107.     ipc_callid_t callid;
  108.    
  109.     ipcarg_t retval;
  110.  
  111.     if (!hash_table_create(&ns_hash_table, NS_HASH_TABLE_CHAINS, 3,
  112.         &ns_hash_table_ops)) {
  113.         return ENOMEM;
  114.     }
  115.        
  116.     while (1) {
  117.         callid = ipc_wait_for_call(&call);
  118.         switch (IPC_GET_METHOD(call)) {
  119.         case IPC_M_AS_AREA_RECV:
  120.             switch (IPC_GET_ARG3(call)) {
  121.             case SERVICE_MEM_REALTIME:
  122.                 get_as_area(callid, &call, "clock.faddr",
  123.                     &clockaddr);
  124.                 break;
  125.             case SERVICE_MEM_KLOG:
  126.                 get_as_area(callid, &call, "klog.faddr",
  127.                     &klogaddr);
  128.                 break;
  129.             default:
  130.                 ipc_answer_fast(callid, ENOENT, 0, 0);
  131.             }
  132.             continue;
  133.         case IPC_M_PHONE_HUNGUP:
  134.             retval = 0;
  135.             break;
  136.         case IPC_M_CONNECT_TO_ME:
  137.             /*
  138.              * Server requests service registration.
  139.              */
  140.             retval = register_service(IPC_GET_ARG1(call),
  141.                 IPC_GET_ARG3(call), &call);
  142.             break;
  143.         case IPC_M_CONNECT_ME_TO:
  144.             /*
  145.              * Client requests to be connected to a service.
  146.              */
  147.             retval = connect_to_service(IPC_GET_ARG1(call), &call,
  148.                 callid);
  149.             break;
  150.         default:
  151.             retval = ENOENT;
  152.             break;
  153.         }
  154.         if (!(callid & IPC_CALLID_NOTIFICATION)) {
  155.             ipc_answer_fast(callid, retval, 0, 0);
  156.         }
  157.     }
  158. }
  159.  
  160. /** Register service.
  161.  *
  162.  * @param service Service to be registered.
  163.  * @param phone Phone to be used for connections to the service.
  164.  * @param call Pointer to call structure.
  165.  *
  166.  * @return Zero on success or a value from @ref errno.h.
  167.  */
  168. int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call)
  169. {
  170.     unsigned long keys[3] = {
  171.         service,
  172.         call->in_phone_hash,
  173.         0
  174.     };
  175.     hashed_service_t *hs;
  176.            
  177.     if (hash_table_find(&ns_hash_table, keys)) {
  178.         return EEXISTS;
  179.     }
  180.            
  181.     hs = (hashed_service_t *) malloc(sizeof(hashed_service_t));
  182.     if (!hs) {
  183.         return ENOMEM;
  184.     }
  185.            
  186.     link_initialize(&hs->link);
  187.     hs->service = service;
  188.     hs->phone = phone;
  189.     hs->in_phone_hash = call->in_phone_hash;
  190.     hash_table_insert(&ns_hash_table, keys, &hs->link);
  191.            
  192.     return 0;
  193. }
  194.  
  195. /** Connect client to service.
  196.  *
  197.  * @param service Service to be connected to.
  198.  * @param call Pointer to call structure.
  199.  * @param callid Call ID of the request.
  200.  *
  201.  * @return Zero on success or a value from @ref errno.h.
  202.  */
  203. int connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid)
  204. {
  205.     unsigned long keys[3] = { service, 0, 0 };
  206.     link_t *hlp;
  207.     hashed_service_t *hs;
  208.            
  209.     hlp = hash_table_find(&ns_hash_table, keys);
  210.     if (!hlp) {
  211.         return ENOENT;
  212.     }
  213.     hs = hash_table_get_instance(hlp, hashed_service_t, link);
  214.     return ipc_forward_fast(callid, hs->phone, 0, 0);
  215. }
  216.  
  217. /** Compute hash index into NS hash table.
  218.  *
  219.  * @param key Pointer keys. However, only the first key (i.e. service number)
  220.  *        is used to compute the hash index.
  221.  * @return Hash index corresponding to key[0].
  222.  */
  223. hash_index_t ns_hash(unsigned long *key)
  224. {
  225.     assert(key);
  226.     return *key % NS_HASH_TABLE_CHAINS;
  227. }
  228.  
  229. /** Compare a key with hashed item.
  230.  *
  231.  * This compare function always ignores the third key.
  232.  * It exists only to make it possible to remove records
  233.  * originating from connection with key[1] in_phone_hash
  234.  * value. Note that this is close to being classified
  235.  * as a nasty hack.
  236.  *
  237.  * @param key Array of keys.
  238.  * @param keys Must be lesser or equal to 3.
  239.  * @param item Pointer to a hash table item.
  240.  * @return Non-zero if the key matches the item, zero otherwise.
  241.  */
  242. int ns_compare(unsigned long key[], hash_count_t keys, link_t *item)
  243. {
  244.     hashed_service_t *hs;
  245.  
  246.     assert(key);
  247.     assert(keys <= 3);
  248.     assert(item);
  249.    
  250.     hs = hash_table_get_instance(item, hashed_service_t, link);
  251.    
  252.     if (keys == 2)
  253.         return key[1] == hs->in_phone_hash;
  254.     else
  255.         return key[0] == hs->service;
  256. }
  257.  
  258. /** Perform actions after removal of item from the hash table.
  259.  *
  260.  * @param item Item that was removed from the hash table.
  261.  */
  262. void ns_remove(link_t *item)
  263. {
  264.     assert(item);
  265.     free(hash_table_get_instance(item, hashed_service_t, link));
  266. }
  267.  
  268. /**
  269.  * @}
  270.  */
  271.