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 /** NetX Component */ 16 /** */ 17 /** Internet Control Message Protocol (ICMP) */ 18 /** */ 19 /**************************************************************************/ 20 /**************************************************************************/ 21 22 #define NX_SOURCE_CODE 23 24 25 /* Include necessary system files. */ 26 #include "nx_api.h" 27 #include "nx_ipv6.h" 28 #include "nx_icmpv6.h" 29 30 #ifdef FEATURE_NX_IPV6 31 32 33 /**************************************************************************/ 34 /* */ 35 /* FUNCTION RELEASE */ 36 /* */ 37 /* _nx_icmpv6_destination_table_periodic_update PORTABLE C */ 38 /* 6.1 */ 39 /* AUTHOR */ 40 /* */ 41 /* Yuxin Zhou, Microsoft Corporation */ 42 /* */ 43 /* DESCRIPTION */ 44 /* */ 45 /* This function is called from the IP thread task, and updates the */ 46 /* MTU fields in the destination table, including handling MTU timer */ 47 /* expiration and initiating a new path MTU probe. */ 48 /* */ 49 /* INPUT */ 50 /* */ 51 /* ip_ptr IP instance pointer */ 52 /* */ 53 /* OUTPUT */ 54 /* */ 55 /* NX_SUCCESS Search successfully completed */ 56 /* regardless if match found or */ 57 /* empty slot found for new entry*/ 58 /* NX_NOT_SUCCESSFUL Invalid input, search aborted */ 59 /* */ 60 /* CALLS */ 61 /* */ 62 /* _nx_ipv6_perform_min_path_MTU_discovery */ 63 /* Service to query the existing */ 64 /* minimum path MTU for changes */ 65 /* */ 66 /* */ 67 /* CALLED BY */ 68 /* */ 69 /* _nx_ip_thread_entry IP thread background task */ 70 /* */ 71 /* RELEASE HISTORY */ 72 /* */ 73 /* DATE NAME DESCRIPTION */ 74 /* */ 75 /* 05-19-2020 Yuxin Zhou Initial Version 6.0 */ 76 /* 09-30-2020 Yuxin Zhou Modified comment(s), */ 77 /* resulting in version 6.1 */ 78 /* */ 79 /**************************************************************************/ 80 81 #ifdef NX_ENABLE_IPV6_PATH_MTU_DISCOVERY 82 _nx_icmpv6_destination_table_periodic_update(NX_IP * ip_ptr)83VOID _nx_icmpv6_destination_table_periodic_update(NX_IP *ip_ptr) 84 { 85 86 UINT i, table_size; 87 88 /* Set a local variable for convenience. */ 89 table_size = ip_ptr -> nx_ipv6_destination_table_size; 90 91 for (i = 0; table_size && (i < NX_IPV6_DESTINATION_TABLE_SIZE); i++) 92 { 93 94 /* Ignore entries whose path MTU is already at the host MTU. */ 95 if (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_path_mtu && 96 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_nd_entry && 97 (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_path_mtu == 98 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_nd_entry -> nx_nd_cache_interface_ptr -> nx_interface_ip_mtu_size)) 99 { 100 continue; 101 } 102 103 /* Check for valid entries with a non infinite path MTU timeout. */ 104 if (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_valid && 105 (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_MTU_timer_tick != NX_WAIT_FOREVER)) 106 { 107 108 /* Keep track of valid entries we have checked. */ 109 table_size--; 110 111 /* Decrement the timer on table entry. */ 112 if (ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_MTU_timer_tick <= NX_IP_PERIODIC_RATE) 113 { 114 115 /* Reset the path MTU to the IP instance MTU. */ 116 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_path_mtu = 117 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_nd_entry -> nx_nd_cache_interface_ptr -> nx_interface_ip_mtu_size; 118 119 /* This is our optimal path MTU. So there is no need to age this table entry 120 and attempt to increase the path MTU; ok set it to infinity. */ 121 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_MTU_timer_tick = NX_WAIT_FOREVER; 122 } 123 else 124 { 125 126 ip_ptr -> nx_ipv6_destination_table[i].nx_ipv6_destination_entry_MTU_timer_tick -= (ULONG)NX_IP_PERIODIC_RATE; 127 } 128 } 129 } 130 131 return; 132 } 133 #endif /* NX_ENABLE_IPV6_PATH_MTU_DISCOVERY */ 134 135 #endif /* FEATURE_NX_IPV6 */ 136 137
