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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 <bool.h>
  44. #include <unistd.h>
  45. #include <stdlib.h>
  46. #include <errno.h>
  47. #include <assert.h>
  48. #include <libadt/list.h>
  49. #include <libadt/hash_table.h>
  50. #include <sysinfo.h>
  51. #include <loader/loader.h>
  52. #include <ddi.h>
  53. #include <as.h>
  54.  
  55. #define NAME  "ns"
  56.  
  57. #define NS_HASH_TABLE_CHAINS  20
  58.  
  59. static int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call);
  60. static void connect_to_service(ipcarg_t service, ipc_call_t *call,
  61.     ipc_callid_t callid);
  62.  
  63. void register_clonable(ipcarg_t service, ipcarg_t phone, ipc_call_t *call,
  64.     ipc_callid_t callid);
  65. void connect_to_clonable(ipcarg_t service, ipc_call_t *call,
  66.     ipc_callid_t callid);
  67.  
  68.  
  69. /* Static functions implementing NS hash table operations. */
  70. static hash_index_t ns_hash(unsigned long *key);
  71. static int ns_compare(unsigned long *key, hash_count_t keys, link_t *item);
  72. static void ns_remove(link_t *item);
  73.  
  74. /** Operations for NS hash table. */
  75. static hash_table_operations_t ns_hash_table_ops = {
  76.     .hash = ns_hash,
  77.     .compare = ns_compare,
  78.     .remove_callback = ns_remove
  79. };
  80.  
  81. /** NS hash table structure. */
  82. static hash_table_t ns_hash_table;
  83.  
  84. /** NS hash table item. */
  85. typedef struct {
  86.     link_t link;
  87.     ipcarg_t service;        /**< Number of the service. */
  88.     ipcarg_t phone;          /**< Phone registered with the service. */
  89.     ipcarg_t in_phone_hash;  /**< Incoming phone hash. */
  90. } hashed_service_t;
  91.  
  92. /** Pending connection structure. */
  93. typedef struct {
  94.     link_t link;
  95.     ipcarg_t service;        /**< Number of the service. */
  96.     ipc_callid_t callid;     /**< Call ID waiting for the connection */
  97.     ipcarg_t arg2;           /**< Second argument */
  98.     ipcarg_t arg3;           /**< Third argument */
  99. } pending_req_t;
  100.  
  101. static link_t pending_req;
  102.  
  103. /** Request for connection to a clonable service. */
  104. typedef struct {
  105.     link_t link;
  106.     ipcarg_t service;
  107.     ipc_call_t call;
  108.     ipc_callid_t callid;
  109. } cs_req_t;
  110.  
  111. /** List of clonable-service connection requests. */
  112. static link_t cs_req;
  113.  
  114. static void *clockaddr = NULL;
  115. static void *klogaddr = NULL;
  116.  
  117. /** Return true if @a service is clonable. */
  118. static bool service_clonable(int service)
  119. {
  120.     return (service == SERVICE_LOAD);
  121. }
  122.  
  123. static void get_as_area(ipc_callid_t callid, ipc_call_t *call, char *name, void **addr)
  124. {
  125.     void *ph_addr;
  126.    
  127.     if (!*addr) {
  128.         ph_addr = (void *) sysinfo_value(name);
  129.         if (!ph_addr) {
  130.             ipc_answer_0(callid, ENOENT);
  131.             return;
  132.         }
  133.         *addr = as_get_mappable_page(PAGE_SIZE);
  134.         if (physmem_map(ph_addr, *addr, 1,
  135.             AS_AREA_READ | AS_AREA_CACHEABLE) != 0) {
  136.             ipc_answer_0(callid, ENOENT);
  137.             return;
  138.         }
  139.     }
  140.     ipc_answer_2(callid, EOK, (ipcarg_t) *addr, AS_AREA_READ);
  141. }
  142.  
  143. /** Process pending connection requests */
  144. static void process_pending_req()
  145. {
  146.     link_t *cur;
  147.    
  148. loop:
  149.     for (cur = pending_req.next; cur != &pending_req; cur = cur->next) {
  150.         pending_req_t *pr = list_get_instance(cur, pending_req_t, link);
  151.        
  152.         unsigned long keys[3] = {
  153.             pr->service,
  154.             0,
  155.             0
  156.         };
  157.        
  158.         link_t *link = hash_table_find(&ns_hash_table, keys);
  159.         if (!link)
  160.             continue;
  161.        
  162.         hashed_service_t *hs = hash_table_get_instance(link, hashed_service_t, link);
  163.         ipcarg_t retval = ipc_forward_fast(pr->callid, hs->phone,
  164.             pr->arg2, pr->arg3, 0, IPC_FF_NONE);
  165.        
  166.         if (!(pr->callid & IPC_CALLID_NOTIFICATION))
  167.             ipc_answer_0(pr->callid, retval);
  168.        
  169.         list_remove(cur);
  170.         free(pr);
  171.         goto loop;
  172.     }
  173. }
  174.  
  175. int main(int argc, char **argv)
  176. {
  177.     printf(NAME ": HelenOS IPC Naming Service\n");
  178.    
  179.     if (!hash_table_create(&ns_hash_table, NS_HASH_TABLE_CHAINS, 3,
  180.         &ns_hash_table_ops)) {
  181.         printf(NAME ": No memory available for services\n");
  182.         return ENOMEM;
  183.     }
  184.    
  185.     list_initialize(&pending_req);
  186.     list_initialize(&cs_req);
  187.    
  188.     printf(NAME ": Accepting connections\n");
  189.     while (true) {
  190.         process_pending_req();
  191.        
  192.         ipc_call_t call;
  193.         ipc_callid_t callid = ipc_wait_for_call(&call);
  194.         ipcarg_t retval;
  195.        
  196.         switch (IPC_GET_METHOD(call)) {
  197.         case IPC_M_SHARE_IN:
  198.             switch (IPC_GET_ARG3(call)) {
  199.             case SERVICE_MEM_REALTIME:
  200.                 get_as_area(callid, &call, "clock.faddr", &clockaddr);
  201.                 break;
  202.             case SERVICE_MEM_KLOG:
  203.                 get_as_area(callid, &call, "klog.faddr", &klogaddr);
  204.                 break;
  205.             default:
  206.                 ipc_answer_0(callid, ENOENT);
  207.             }
  208.             continue;
  209.         case IPC_M_PHONE_HUNGUP:
  210.             retval = EOK;
  211.             break;
  212.         case IPC_M_CONNECT_TO_ME:
  213.             /*
  214.              * Server requests service registration.
  215.              */
  216.             if (service_clonable(IPC_GET_ARG1(call))) {
  217.                 register_clonable(IPC_GET_ARG1(call),
  218.                     IPC_GET_ARG5(call), &call, callid);
  219.                 continue;
  220.             } else {
  221.                 retval = register_service(IPC_GET_ARG1(call),
  222.                     IPC_GET_ARG5(call), &call);
  223.             }
  224.             break;
  225.         case IPC_M_CONNECT_ME_TO:
  226.             /*
  227.              * Client requests to be connected to a service.
  228.              */
  229.             if (service_clonable(IPC_GET_ARG1(call))) {
  230.                 connect_to_clonable(IPC_GET_ARG1(call),
  231.                     &call, callid);
  232.                 continue;
  233.             } else {
  234.                 connect_to_service(IPC_GET_ARG1(call), &call,
  235.                     callid);
  236.                 continue;
  237.             }
  238.             break;
  239.         default:
  240.             retval = ENOENT;
  241.             break;
  242.         }
  243.        
  244.         if (!(callid & IPC_CALLID_NOTIFICATION))
  245.             ipc_answer_0(callid, retval);
  246.     }
  247.    
  248.     /* Not reached */
  249.     return 0;
  250. }
  251.  
  252. /** Register service.
  253.  *
  254.  * @param service Service to be registered.
  255.  * @param phone   Phone to be used for connections to the service.
  256.  * @param call    Pointer to call structure.
  257.  *
  258.  * @return Zero on success or a value from @ref errno.h.
  259.  *
  260.  */
  261. int register_service(ipcarg_t service, ipcarg_t phone, ipc_call_t *call)
  262. {
  263.     unsigned long keys[3] = {
  264.         service,
  265.         call->in_phone_hash,
  266.         0
  267.     };
  268.    
  269.     if (hash_table_find(&ns_hash_table, keys))
  270.         return EEXISTS;
  271.    
  272.     hashed_service_t *hs = (hashed_service_t *) malloc(sizeof(hashed_service_t));
  273.     if (!hs)
  274.         return ENOMEM;
  275.    
  276.     link_initialize(&hs->link);
  277.     hs->service = service;
  278.     hs->phone = phone;
  279.     hs->in_phone_hash = call->in_phone_hash;
  280.     hash_table_insert(&ns_hash_table, keys, &hs->link);
  281.    
  282.     return 0;
  283. }
  284.  
  285. /** Connect client to service.
  286.  *
  287.  * @param service Service to be connected to.
  288.  * @param call    Pointer to call structure.
  289.  * @param callid  Call ID of the request.
  290.  *
  291.  * @return Zero on success or a value from @ref errno.h.
  292.  *
  293.  */
  294. void connect_to_service(ipcarg_t service, ipc_call_t *call, ipc_callid_t callid)
  295. {
  296.     ipcarg_t retval;
  297.     unsigned long keys[3] = {
  298.         service,
  299.         0,
  300.         0
  301.     };
  302.    
  303.     link_t *link = hash_table_find(&ns_hash_table, keys);
  304.     if (!link) {
  305.         if (IPC_GET_ARG4(*call) & IPC_FLAG_BLOCKING) {
  306.             /* Blocking connection, add to pending list */
  307.             pending_req_t *pr = (pending_req_t *) malloc(sizeof(pending_req_t));
  308.             if (!pr) {
  309.                 retval = ENOMEM;
  310.                 goto out;
  311.             }
  312.            
  313.             pr->service = service;
  314.             pr->callid = callid;
  315.             pr->arg2 = IPC_GET_ARG2(*call);
  316.             pr->arg3 = IPC_GET_ARG3(*call);
  317.             list_append(&pr->link, &pending_req);
  318.             return;
  319.         }
  320.         retval = ENOENT;
  321.         goto out;
  322.     }
  323.    
  324.     hashed_service_t *hs = hash_table_get_instance(link, hashed_service_t, link);
  325.     retval = ipc_forward_fast(callid, hs->phone, IPC_GET_ARG2(*call),
  326.         IPC_GET_ARG3(*call), 0, IPC_FF_NONE);
  327.    
  328. out:
  329.     if (!(callid & IPC_CALLID_NOTIFICATION))
  330.         ipc_answer_0(callid, retval);
  331. }
  332.  
  333. /** Register clonable service.
  334.  *
  335.  * @param service Service to be registered.
  336.  * @param phone   Phone to be used for connections to the service.
  337.  * @param call    Pointer to call structure.
  338.  *
  339.  */
  340. void register_clonable(ipcarg_t service, ipcarg_t phone, ipc_call_t *call,
  341.     ipc_callid_t callid)
  342. {
  343.     if (list_empty(&cs_req)) {
  344.         /* There was no pending connection request. */
  345.         printf(NAME ": Unexpected clonable server.\n");
  346.         ipc_answer_0(callid, EBUSY);
  347.         return;
  348.     }
  349.    
  350.     cs_req_t *csr = list_get_instance(cs_req.next, cs_req_t, link);
  351.     list_remove(&csr->link);
  352.    
  353.     /* Currently we can only handle a single type of clonable service. */
  354.     assert(csr->service == SERVICE_LOAD);
  355.    
  356.     ipc_answer_0(callid, EOK);
  357.    
  358.     int rc = ipc_forward_fast(csr->callid, phone, IPC_GET_ARG2(csr->call),
  359.         IPC_GET_ARG3(csr->call), 0, IPC_FF_NONE);
  360.    
  361.     free(csr);
  362. }
  363.  
  364. /** Connect client to clonable service.
  365.  *
  366.  * @param service Service to be connected to.
  367.  * @param call    Pointer to call structure.
  368.  * @param callid  Call ID of the request.
  369.  *
  370.  * @return Zero on success or a value from @ref errno.h.
  371.  *
  372.  */
  373. void connect_to_clonable(ipcarg_t service, ipc_call_t *call,
  374.     ipc_callid_t callid)
  375. {
  376.     assert(service == SERVICE_LOAD);
  377.    
  378.     cs_req_t *csr = malloc(sizeof(cs_req_t));
  379.     if (csr == NULL) {
  380.         ipc_answer_0(callid, ENOMEM);
  381.         return;
  382.     }
  383.    
  384.     /* Spawn a loader. */
  385.     int rc = loader_spawn("loader");
  386.    
  387.     if (rc < 0) {
  388.         free(csr);
  389.         ipc_answer_0(callid, rc);
  390.         return;
  391.     }
  392.    
  393.     csr->service = service;
  394.     csr->call = *call;
  395.     csr->callid = callid;
  396.    
  397.     /*
  398.      * We can forward the call only after the server we spawned connects
  399.      * to us. Meanwhile we might need to service more connection requests.
  400.      * Thus we store the call in a queue.
  401.      */
  402.     list_append(&csr->link, &cs_req);
  403. }
  404.  
  405. /** Compute hash index into NS hash table.
  406.  *
  407.  * @param key Pointer keys. However, only the first key (i.e. service number)
  408.  *            is used to compute the hash index.
  409.  *
  410.  * @return Hash index corresponding to key[0].
  411.  *
  412.  */
  413. hash_index_t ns_hash(unsigned long *key)
  414. {
  415.     assert(key);
  416.     return (*key % NS_HASH_TABLE_CHAINS);
  417. }
  418.  
  419. /** Compare a key with hashed item.
  420.  *
  421.  * This compare function always ignores the third key.
  422.  * It exists only to make it possible to remove records
  423.  * originating from connection with key[1] in_phone_hash
  424.  * value. Note that this is close to being classified
  425.  * as a nasty hack.
  426.  *
  427.  * @param key  Array of keys.
  428.  * @param keys Must be lesser or equal to 3.
  429.  * @param item Pointer to a hash table item.
  430.  *
  431.  * @return Non-zero if the key matches the item, zero otherwise.
  432.  *
  433.  */
  434. int ns_compare(unsigned long key[], hash_count_t keys, link_t *item)
  435. {
  436.     assert(key);
  437.     assert(keys <= 3);
  438.     assert(item);
  439.    
  440.     hashed_service_t *hs = hash_table_get_instance(item, hashed_service_t, link);
  441.    
  442.     if (keys == 2)
  443.         return key[1] == hs->in_phone_hash;
  444.     else
  445.         return key[0] == hs->service;
  446. }
  447.  
  448. /** Perform actions after removal of item from the hash table.
  449.  *
  450.  * @param item Item that was removed from the hash table.
  451.  *
  452.  */
  453. void ns_remove(link_t *item)
  454. {
  455.     assert(item);
  456.     free(hash_table_get_instance(item, hashed_service_t, link));
  457. }
  458.  
  459. /**
  460.  * @}
  461.  */
  462.