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 /** */ 14 /** NetX Component */ 15 /** */ 16 /** Internet Control Message Protocol (ICMP) */ 17 /** */ 18 /**************************************************************************/ 19 /**************************************************************************/ 20 21 #define NX_SOURCE_CODE 22 23 24 /* Include necessary system files. */ 25 #include "nx_api.h" 26 #include "nx_ipv6.h" 27 #include "nx_icmpv6.h" 28 29 #ifdef FEATURE_NX_IPV6 30 31 32 /**************************************************************************/ 33 /* */ 34 /* FUNCTION RELEASE */ 35 /* */ 36 /* _nx_icmpv6_destination_table_periodic_update PORTABLE C */ 37 /* 6.1 */ 38 /* AUTHOR */ 39 /* */ 40 /* Yuxin Zhou, Microsoft Corporation */ 41 /* */ 42 /* DESCRIPTION */ 43 /* */ 44 /* This function is called from the IP thread task, and updates the */ 45 /* MTU fields in the destination table, including handling MTU timer */ 46 /* expiration and initiating a new path MTU probe. */ 47 /* */ 48 /* INPUT */ 49 /* */ 50 /* ip_ptr IP instance pointer */ 51 /* */ 52 /* OUTPUT */ 53 /* */ 54 /* NX_SUCCESS Search successfully completed */ 55 /* regardless if match found or */ 56 /* empty slot found for new entry*/ 57 /* NX_NOT_SUCCESSFUL Invalid input, search aborted */ 58 /* */ 59 /* CALLS */ 60 /* */ 61 /* _nx_ipv6_perform_min_path_MTU_discovery */ 62 /* Service to query the existing */ 63 /* minimum path MTU for changes */ 64 /* */ 65 /* */ 66 /* CALLED BY */ 67 /* */ 68 /* _nx_ip_thread_entry IP thread background task */ 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 /**************************************************************************/ 79 80 #ifdef NX_ENABLE_IPV6_PATH_MTU_DISCOVERY 81 _nx_icmpv6_destination_table_periodic_update(NX_IP * ip_ptr)82VOID _nx_icmpv6_destination_table_periodic_update(NX_IP *ip_ptr) 83 { 84 85 UINT i, table_size; 86 87 /* Set a local variable for convenience. */ 88 table_size = ip_ptr -> nx_ipv6_destination_table_size; 89 90 for (i = 0; table_size && (i < NX_IPV6_DESTINATION_TABLE_SIZE); i++) 91 { 92 93 /* Ignore entries whose path MTU is already at the host MTU. */ 94 if (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_path_mtu && 95 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_nd_entry && 96 (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_path_mtu == 97 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_nd_entry -> nx_nd_cache_interface_ptr -> nx_interface_ip_mtu_size)) 98 { 99 continue; 100 } 101 102 /* Check for valid entries with a non infinite path MTU timeout. */ 103 if (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_valid && 104 (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_MTU_timer_tick != NX_WAIT_FOREVER)) 105 { 106 107 /* Keep track of valid entries we have checked. */ 108 table_size--; 109 110 /* Decrement the timer on table entry. */ 111 if (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_MTU_timer_tick <= NX_IP_PERIODIC_RATE) 112 { 113 114 /* Reset the path MTU to the IP instance MTU. */ 115 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_path_mtu = 116 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_nd_entry -> nx_nd_cache_interface_ptr -> nx_interface_ip_mtu_size; 117 118 /* This is our optimal path MTU. So there is no need to age this table entry 119 and attempt to increase the path MTU; ok set it to infinity. */ 120 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_MTU_timer_tick = NX_WAIT_FOREVER; 121 } 122 else 123 { 124 125 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_MTU_timer_tick -= (ULONG)NX_IP_PERIODIC_RATE; 126 } 127 } 128 } 129 130 return; 131 } 132 #endif /* NX_ENABLE_IPV6_PATH_MTU_DISCOVERY */ 133 134 #endif /* FEATURE_NX_IPV6 */ 135 136
