1 /*************************************************************************** 2 * Copyright (c) 2024 Microsoft Corporation 3 * 4 * This program and the accompanying materials are made available under the 5 * terms of the MIT License which is available at 6 * https://opensource.org/licenses/MIT. 7 * 8 * SPDX-License-Identifier: MIT 9 **************************************************************************/ 10 /**************************************************************************/ 11 /**************************************************************************/ 12 /** */ 13 /** NetX Component */ 14 /** */ 15 /** Internet Protocol version 6 Default Router Table (IPv6 router) */ 16 /** */ 17 /**************************************************************************/ 18 /**************************************************************************/ 19 #define NX_SOURCE_CODE 20 21 22 /* Include necessary system files. */ 23 24 #include "nx_api.h" 25 #include "nx_ipv6.h" 26 #include "nx_nd_cache.h" 27 28 29 #ifdef FEATURE_NX_IPV6 30 /**************************************************************************/ 31 /* */ 32 /* FUNCTION RELEASE */ 33 /* */ 34 /* _nxd_ipv6_find_default_router_from_address PORTABLE C */ 35 /* 6.1 */ 36 /* AUTHOR */ 37 /* */ 38 /* Yuxin Zhou, Microsoft Corporation */ 39 /* */ 40 /* DESCRIPTION */ 41 /* */ 42 /* This function finds the specific IPv6 default router. */ 43 /* */ 44 /* INPUT */ 45 /* */ 46 /* ip_ptr IP instance pointer */ 47 /* router_address The specific gateway address */ 48 /* to search for. */ 49 /* */ 50 /* OUTPUT */ 51 /* */ 52 /* default router entry Pointer to the default router */ 53 /* entry. */ 54 /* CALLS */ 55 /* */ 56 /* tx_mutex_get Obtain IP protection mutex */ 57 /* tx_mutex_put Release IP protection mutex */ 58 /* */ 59 /* CALLED BY */ 60 /* */ 61 /* _nxd_icmpv6_process_na */ 62 /* */ 63 /* NOTE */ 64 /* */ 65 /* This function acquires the nx_ipv6_protection mutex. */ 66 /* Make sure the mutex is not locked before entering this function. */ 67 /* */ 68 /* This function cannot be called from ISR. */ 69 /* */ 70 /* RELEASE HISTORY */ 71 /* */ 72 /* DATE NAME DESCRIPTION */ 73 /* */ 74 /* 05-19-2020 Yuxin Zhou Initial Version 6.0 */ 75 /* 09-30-2020 Yuxin Zhou Modified comment(s), */ 76 /* resulting in version 6.1 */ 77 /* */ 78 /**************************************************************************/ _nxd_ipv6_find_default_router_from_address(NX_IP * ip_ptr,ULONG * router_address)79NX_IPV6_DEFAULT_ROUTER_ENTRY *_nxd_ipv6_find_default_router_from_address(NX_IP *ip_ptr, ULONG *router_address) 80 { 81 82 INT i; 83 NX_IPV6_DEFAULT_ROUTER_ENTRY *rt_entry; 84 85 86 /* Get exclusive access to the IP task lock. */ 87 tx_mutex_get(&(ip_ptr -> nx_ip_protection), TX_WAIT_FOREVER); 88 89 /* Start the search at the top of the list...*/ 90 i = 0; 91 92 /* And go through the entire table or until a match is found. */ 93 while (i < NX_IPV6_DEFAULT_ROUTER_TABLE_SIZE) 94 { 95 96 /* Local pointer to table entry. */ 97 rt_entry = &ip_ptr -> nx_ipv6_default_router_table[i]; 98 99 /* Does this slot contain a valid router? */ 100 if (rt_entry -> nx_ipv6_default_router_entry_flag) 101 { 102 103 /* Yes, check if it matches the specified router address. */ 104 if (CHECK_IPV6_ADDRESSES_SAME(router_address, rt_entry -> nx_ipv6_default_router_entry_router_address)) 105 { 106 107 108 /* Yes it does, we can release the IP protection. */ 109 tx_mutex_put(&(ip_ptr -> nx_ip_protection)); 110 111 /* Return the pointer to this router entry. */ 112 return(rt_entry); 113 } 114 } 115 116 i++; 117 } 118 119 /* Release the lock. */ 120 tx_mutex_put(&(ip_ptr -> nx_ip_protection)); 121 122 /* Return a null pointer indicating no matching router found. */ 123 return(NX_NULL); 124 } 125 126 #endif /* FEATURE_NX_IPV6 */ 127 128
