1 /**************************************************************************/ 2 /* */ 3 /* Copyright (c) Microsoft Corporation. All rights reserved. */ 4 /* */ 5 /* This software is licensed under the Microsoft Software License */ 6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */ 7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */ 8 /* and in the root directory of this software. */ 9 /* */ 10 /**************************************************************************/ 11 12 13 /**************************************************************************/ 14 /**************************************************************************/ 15 /** */ 16 /** NetX Component */ 17 /** */ 18 /** Neighbor Discovery Cache */ 19 /** */ 20 /**************************************************************************/ 21 /**************************************************************************/ 22 23 #define NX_SOURCE_CODE 24 25 26 /* Include necessary system files. */ 27 28 #include "nx_api.h" 29 #include "nx_ipv6.h" 30 #include "nx_nd_cache.h" 31 32 #ifdef FEATURE_NX_IPV6 33 34 35 /**************************************************************************/ 36 /* */ 37 /* FUNCTION RELEASE */ 38 /* */ 39 /* nx_nd_cache_find_entry PORTABLE C */ 40 /* 6.1 */ 41 /* AUTHOR */ 42 /* */ 43 /* Yuxin Zhou, Microsoft Corporation */ 44 /* */ 45 /* DESCRIPTION */ 46 /* */ 47 /* This internal function finds an entry in the ND cache that is */ 48 /* mapped to the specified IPv6 address. */ 49 /* */ 50 /* INPUT */ 51 /* */ 52 /* ip_ptr IP instance pointer */ 53 /* dest_ip The IP address to match */ 54 /* nd_cache_entry User specified storage space of pointer to */ 55 /* the corresponding ND cache. */ 56 /* */ 57 /* OUTPUT */ 58 /* */ 59 /* status NX_SUCCESS: The ND cache entry is located. */ 60 /* nd_cache_entry contains valid value. */ 61 /* NX_NOT_SUCCESSFUL: The ND cache entry */ 62 /* cannot be found, or nd_cache_entry is */ 63 /* NULL. */ 64 /* */ 65 /* CALLS */ 66 /* */ 67 /* None */ 68 /* */ 69 /* CALLED BY */ 70 /* */ 71 /* Application Code */ 72 /* */ 73 /* RELEASE HISTORY */ 74 /* */ 75 /* DATE NAME DESCRIPTION */ 76 /* */ 77 /* 05-19-2020 Yuxin Zhou Initial Version 6.0 */ 78 /* 09-30-2020 Yuxin Zhou Modified comment(s), */ 79 /* resulting in version 6.1 */ 80 /* */ 81 /**************************************************************************/ _nx_nd_cache_find_entry(NX_IP * ip_ptr,ULONG * dest_ip,ND_CACHE_ENTRY ** nd_cache_entry)82UINT _nx_nd_cache_find_entry(NX_IP *ip_ptr, 83 ULONG *dest_ip, ND_CACHE_ENTRY **nd_cache_entry) 84 { 85 UINT i; 86 UINT index; 87 88 /* Initialize the return value. */ 89 *nd_cache_entry = NX_NULL; 90 91 /* Compute a simple hash based on the dest_ip */ 92 index = (UINT)((dest_ip[0] + dest_ip[1] + dest_ip[2] + dest_ip[3]) % 93 (NX_IPV6_NEIGHBOR_CACHE_SIZE)); 94 95 for (i = 0; i < NX_IPV6_NEIGHBOR_CACHE_SIZE; i++) 96 { 97 98 if ((ip_ptr -> nx_ipv6_nd_cache[index].nx_nd_cache_nd_status != ND_CACHE_STATE_INVALID) && 99 (ip_ptr -> nx_ipv6_nd_cache[index].nx_nd_cache_interface_ptr) && 100 (CHECK_IPV6_ADDRESSES_SAME(&ip_ptr -> nx_ipv6_nd_cache[index].nx_nd_cache_dest_ip[0], dest_ip))) 101 { 102 103 /* find the entry */ 104 *nd_cache_entry = &ip_ptr -> nx_ipv6_nd_cache[index]; 105 106 return(NX_SUCCESS); 107 } 108 109 index++; 110 111 /* Check for overflow */ 112 if (index == NX_IPV6_NEIGHBOR_CACHE_SIZE) 113 { 114 index = 0; 115 } 116 } 117 118 return(NX_NOT_SUCCESSFUL); 119 } 120 121 #endif /* FEATURE_NX_IPV6 */ 122 123
