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 /** */ 15 /** NetX Component */ 16 /** */ 17 /** Address Resolution Protocol (ARP) */ 18 /** */ 19 /**************************************************************************/ 20 /**************************************************************************/ 21 22 #define NX_SOURCE_CODE 23 24 25 /* Include necessary system files. */ 26 27 #include "nx_api.h" 28 #include "nx_arp.h" 29 #include "nx_packet.h" 30 31 #ifndef NX_DISABLE_IPV4 32 /**************************************************************************/ 33 /* */ 34 /* FUNCTION RELEASE */ 35 /* */ 36 /* _nx_arp_dynamic_entry_delete PORTABLE C */ 37 /* 6.1 */ 38 /* AUTHOR */ 39 /* */ 40 /* Yuxin Zhou, Microsoft Corporation */ 41 /* */ 42 /* DESCRIPTION */ 43 /* */ 44 /* This function deletes the ARP entry pointed to by the caller. Note */ 45 /* the caller should already have searched the ARP list to verify a */ 46 /* valid ARP entry to delete. Also, it is assumed the caller already */ 47 /* has obtained the IP protection mutex before invoking this service. */ 48 /* */ 49 /* INPUT */ 50 /* */ 51 /* ip_ptr IP instance of APR table */ 52 /* arp_ptr ARP entry to delete */ 53 /* */ 54 /* OUTPUT */ 55 /* */ 56 /* status Completion status */ 57 /* */ 58 /* CALLS */ 59 /* */ 60 /* _nx_packet_transmit_release Release the transmitted packet*/ 61 /* */ 62 /* CALLED BY */ 63 /* */ 64 /* Internal */ 65 /* */ 66 /* RELEASE HISTORY */ 67 /* */ 68 /* DATE NAME DESCRIPTION */ 69 /* */ 70 /* 05-19-2020 Yuxin Zhou Initial Version 6.0 */ 71 /* 09-30-2020 Yuxin Zhou Modified comment(s), */ 72 /* resulting in version 6.1 */ 73 /* */ 74 /**************************************************************************/ _nx_arp_dynamic_entry_delete(NX_IP * ip_ptr,NX_ARP * arp_ptr)75UINT _nx_arp_dynamic_entry_delete(NX_IP *ip_ptr, NX_ARP *arp_ptr) 76 { 77 78 TX_INTERRUPT_SAVE_AREA 79 NX_PACKET *packet_ptr, *next_packet_ptr; 80 81 82 /* Determine if this ARP entry is already active. */ 83 if (arp_ptr -> nx_arp_active_list_head) 84 { 85 86 /* Remove this dynamic ARP entry from the associated list. */ 87 88 /* Disable interrupts. */ 89 TX_DISABLE 90 91 /* Determine if this is the only ARP entry on the list. */ 92 if (arp_ptr == arp_ptr -> nx_arp_active_next) 93 { 94 95 /* Remove the entry from the list. */ 96 *(arp_ptr -> nx_arp_active_list_head) = NX_NULL; 97 } 98 else 99 { 100 101 /* Remove the entry from a list of more than one entry. */ 102 103 /* Update the list head pointer. */ 104 if (*(arp_ptr -> nx_arp_active_list_head) == arp_ptr) 105 { 106 *(arp_ptr -> nx_arp_active_list_head) = arp_ptr -> nx_arp_active_next; 107 } 108 109 /* Update the links of the adjacent ARP entries. */ 110 (arp_ptr -> nx_arp_active_next) -> nx_arp_active_previous = arp_ptr -> nx_arp_active_previous; 111 (arp_ptr -> nx_arp_active_previous) -> nx_arp_active_next = arp_ptr -> nx_arp_active_next; 112 } 113 114 /* No longer active, clear the active list head. */ 115 arp_ptr -> nx_arp_active_list_head = NX_NULL; 116 117 /* Decrease the number of active ARP entries. */ 118 ip_ptr -> nx_ip_arp_dynamic_active_count--; 119 120 /* Pickup the queued packets head pointer. */ 121 next_packet_ptr = arp_ptr -> nx_arp_packets_waiting; 122 123 /* Clear the queued packets head pointer. */ 124 arp_ptr -> nx_arp_packets_waiting = NX_NULL; 125 126 /* Restore interrupts. */ 127 TX_RESTORE 128 129 /* Loop to remove all queued packets. */ 130 while (next_packet_ptr) 131 { 132 133 /* Pickup the packet pointer at the head of the queue. */ 134 packet_ptr = next_packet_ptr; 135 136 /* Move to the next packet in the queue. */ 137 next_packet_ptr = next_packet_ptr -> nx_packet_queue_next; 138 139 /* Clear the next packet queue pointer. */ 140 packet_ptr -> nx_packet_queue_next = NX_NULL; 141 142 #ifndef NX_DISABLE_IP_INFO 143 144 /* Increment the IP send packets dropped count. */ 145 ip_ptr -> nx_ip_send_packets_dropped++; 146 #endif 147 148 /* Release the packet that was queued from the previous ARP entry. */ 149 _nx_packet_transmit_release(packet_ptr); 150 } 151 } 152 153 return(NX_SUCCESS); 154 } 155 #endif /* !NX_DISABLE_IPV4 */ 156 157
