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
30
31 /**************************************************************************/
32 /* */
33 /* FUNCTION RELEASE */
34 /* */
35 /* _nx_arp_entry_delete PORTABLE C */
36 /* 6.1 */
37 /* AUTHOR */
38 /* */
39 /* Yuxin Zhou, Microsoft Corporation */
40 /* */
41 /* DESCRIPTION */
42 /* */
43 /* This function searches for the specified IP address in the ARP */
44 /* lists. If found, the associated ARP entry is deleted. */
45 /* */
46 /* INPUT */
47 /* */
48 /* ip_ptr IP instance pointer */
49 /* ip_address IP Address to search for */
50 /* */
51 /* OUTPUT */
52 /* */
53 /* status Completion status */
54 /* */
55 /* CALLS */
56 /* */
57 /* tx_mutex_get Obtain protection mutex */
58 /* tx_mutex_put Release protection mutex */
59 /* _nx_arp_static_entry_delete Remove static ARP entry */
60 /* _nx_arp_dynamic_entry_delete Remove dynamic ARP entry */
61 /* */
62 /* CALLED BY */
63 /* */
64 /* Application Code */
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_entry_delete(NX_IP * ip_ptr,ULONG ip_address)75 UINT _nx_arp_entry_delete(NX_IP *ip_ptr, ULONG ip_address)
76 {
77
78 #ifndef NX_DISABLE_IPV4
79 UINT status;
80 NX_ARP *arp_ptr;
81 NX_ARP *arp_list_head;
82 NX_ARP *search_ptr;
83 UINT index;
84
85
86 /* Obtain protection on this IP instance for access into the ARP static list. */
87 tx_mutex_get(&(ip_ptr -> nx_ip_protection), TX_WAIT_FOREVER);
88
89 /* Search the static list for a matching IP and hardware mapping.
90 Compute the index that will tell us which linked list of ARP addresses to search,
91 since we don't care if it is a static or dynamic entry.
92 Search that linked list pointed in the IP ARP table. */
93
94 /* Calculate the hash index for the specified IP address. */
95 index = (UINT)((ip_address + (ip_address >> 8)) & NX_ARP_TABLE_MASK);
96
97 /* Pickup the head pointer of the ARP entries for this IP instance. */
98 arp_list_head = ip_ptr -> nx_ip_arp_table[index];
99
100 /* Search the ARP list for the same IP address. */
101 search_ptr = arp_list_head;
102 arp_ptr = NX_NULL;
103
104 while (search_ptr)
105 {
106
107 /* Determine if we have a match. */
108 if (search_ptr -> nx_arp_ip_address == ip_address)
109 {
110
111 /* Yes, the IP address matches, setup the ARP entry pointer. */
112 arp_ptr = search_ptr;
113
114 /* Get out of the loop. */
115 break;
116 }
117
118 /* Move to the next entry in the active list. */
119 search_ptr = search_ptr -> nx_arp_active_next;
120
121 /* Determine if the search pointer is back at the head of
122 the list. */
123 if (search_ptr == arp_list_head)
124 {
125
126 /* End of the ARP list, end the search. */
127 break;
128 }
129 }
130
131 /* Determine if we didn't find an ARP entry matching the input IP address. */
132 if (arp_ptr == NX_NULL)
133 {
134
135 /* Release the protection on the ARP list. */
136 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
137
138 /* Return status to the caller. */
139 return(NX_ENTRY_NOT_FOUND);
140 }
141
142 /* Determine if this is a static entry. */
143 if (arp_ptr -> nx_arp_route_static == NX_TRUE)
144 {
145
146 /* Remove from the static list. */
147 status = _nx_arp_static_entry_delete(ip_ptr, ip_address,
148 arp_ptr -> nx_arp_physical_address_msw,
149 arp_ptr -> nx_arp_physical_address_lsw);
150 }
151 else
152 {
153
154 /* Remove from the dynamic list. */
155 status = _nx_arp_dynamic_entry_delete(ip_ptr, arp_ptr);
156 }
157
158 /* Release the protection on the ARP list. */
159 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
160
161 /* Return status to the caller. */
162 return(status);
163 #else /* NX_DISABLE_IPV4 */
164 NX_PARAMETER_NOT_USED(ip_ptr);
165 NX_PARAMETER_NOT_USED(ip_address);
166
167 return(NX_NOT_SUPPORTED);
168 #endif /* !NX_DISABLE_IPV4 */
169 }
170
171
