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 /** Address Resolution Protocol (ARP) */ 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_arp.h" 30 #include "nx_packet.h" 31 32 #ifndef NX_DISABLE_IPV4 33 /**************************************************************************/ 34 /* */ 35 /* FUNCTION RELEASE */ 36 /* */ 37 /* _nx_arp_dynamic_entry_delete PORTABLE C */ 38 /* 6.1 */ 39 /* AUTHOR */ 40 /* */ 41 /* Yuxin Zhou, Microsoft Corporation */ 42 /* */ 43 /* DESCRIPTION */ 44 /* */ 45 /* This function deletes the ARP entry pointed to by the caller. Note */ 46 /* the caller should already have searched the ARP list to verify a */ 47 /* valid ARP entry to delete. Also, it is assumed the caller already */ 48 /* has obtained the IP protection mutex before invoking this service. */ 49 /* */ 50 /* INPUT */ 51 /* */ 52 /* ip_ptr IP instance of APR table */ 53 /* arp_ptr ARP entry to delete */ 54 /* */ 55 /* OUTPUT */ 56 /* */ 57 /* status Completion status */ 58 /* */ 59 /* CALLS */ 60 /* */ 61 /* _nx_packet_transmit_release Release the transmitted packet*/ 62 /* */ 63 /* CALLED BY */ 64 /* */ 65 /* Internal */ 66 /* */ 67 /* RELEASE HISTORY */ 68 /* */ 69 /* DATE NAME DESCRIPTION */ 70 /* */ 71 /* 05-19-2020 Yuxin Zhou Initial Version 6.0 */ 72 /* 09-30-2020 Yuxin Zhou Modified comment(s), */ 73 /* resulting in version 6.1 */ 74 /* */ 75 /**************************************************************************/ _nx_arp_dynamic_entry_delete(NX_IP * ip_ptr,NX_ARP * arp_ptr)76UINT _nx_arp_dynamic_entry_delete(NX_IP *ip_ptr, NX_ARP *arp_ptr) 77 { 78 79 TX_INTERRUPT_SAVE_AREA 80 NX_PACKET *packet_ptr, *next_packet_ptr; 81 82 83 /* Determine if this ARP entry is already active. */ 84 if (arp_ptr -> nx_arp_active_list_head) 85 { 86 87 /* Remove this dynamic ARP entry from the associated list. */ 88 89 /* Disable interrupts. */ 90 TX_DISABLE 91 92 /* Determine if this is the only ARP entry on the list. */ 93 if (arp_ptr == arp_ptr -> nx_arp_active_next) 94 { 95 96 /* Remove the entry from the list. */ 97 *(arp_ptr -> nx_arp_active_list_head) = NX_NULL; 98 } 99 else 100 { 101 102 /* Remove the entry from a list of more than one entry. */ 103 104 /* Update the list head pointer. */ 105 if (*(arp_ptr -> nx_arp_active_list_head) == arp_ptr) 106 { 107 *(arp_ptr -> nx_arp_active_list_head) = arp_ptr -> nx_arp_active_next; 108 } 109 110 /* Update the links of the adjacent ARP entries. */ 111 (arp_ptr -> nx_arp_active_next) -> nx_arp_active_previous = arp_ptr -> nx_arp_active_previous; 112 (arp_ptr -> nx_arp_active_previous) -> nx_arp_active_next = arp_ptr -> nx_arp_active_next; 113 } 114 115 /* No longer active, clear the active list head. */ 116 arp_ptr -> nx_arp_active_list_head = NX_NULL; 117 118 /* Decrease the number of active ARP entries. */ 119 ip_ptr -> nx_ip_arp_dynamic_active_count--; 120 121 /* Pickup the queued packets head pointer. */ 122 next_packet_ptr = arp_ptr -> nx_arp_packets_waiting; 123 124 /* Clear the queued packets head pointer. */ 125 arp_ptr -> nx_arp_packets_waiting = NX_NULL; 126 127 /* Restore interrupts. */ 128 TX_RESTORE 129 130 /* Loop to remove all queued packets. */ 131 while (next_packet_ptr) 132 { 133 134 /* Pickup the packet pointer at the head of the queue. */ 135 packet_ptr = next_packet_ptr; 136 137 /* Move to the next packet in the queue. */ 138 next_packet_ptr = next_packet_ptr -> nx_packet_queue_next; 139 140 /* Clear the next packet queue pointer. */ 141 packet_ptr -> nx_packet_queue_next = NX_NULL; 142 143 #ifndef NX_DISABLE_IP_INFO 144 145 /* Increment the IP send packets dropped count. */ 146 ip_ptr -> nx_ip_send_packets_dropped++; 147 #endif 148 149 /* Release the packet that was queued from the previous ARP entry. */ 150 _nx_packet_transmit_release(packet_ptr); 151 } 152 } 153 154 return(NX_SUCCESS); 155 } 156 #endif /* !NX_DISABLE_IPV4 */ 157 158
