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
31
32 /**************************************************************************/
33 /* */
34 /* FUNCTION RELEASE */
35 /* */
36 /* _nx_arp_entry_delete PORTABLE C */
37 /* 6.1 */
38 /* AUTHOR */
39 /* */
40 /* Yuxin Zhou, Microsoft Corporation */
41 /* */
42 /* DESCRIPTION */
43 /* */
44 /* This function searches for the specified IP address in the ARP */
45 /* lists. If found, the associated ARP entry is deleted. */
46 /* */
47 /* INPUT */
48 /* */
49 /* ip_ptr IP instance pointer */
50 /* ip_address IP Address to search for */
51 /* */
52 /* OUTPUT */
53 /* */
54 /* status Completion status */
55 /* */
56 /* CALLS */
57 /* */
58 /* tx_mutex_get Obtain protection mutex */
59 /* tx_mutex_put Release protection mutex */
60 /* _nx_arp_static_entry_delete Remove static ARP entry */
61 /* _nx_arp_dynamic_entry_delete Remove dynamic ARP entry */
62 /* */
63 /* CALLED BY */
64 /* */
65 /* Application Code */
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_entry_delete(NX_IP * ip_ptr,ULONG ip_address)76 UINT _nx_arp_entry_delete(NX_IP *ip_ptr, ULONG ip_address)
77 {
78
79 #ifndef NX_DISABLE_IPV4
80 UINT status;
81 NX_ARP *arp_ptr;
82 NX_ARP *arp_list_head;
83 NX_ARP *search_ptr;
84 UINT index;
85
86
87 /* Obtain protection on this IP instance for access into the ARP static list. */
88 tx_mutex_get(&(ip_ptr -> nx_ip_protection), TX_WAIT_FOREVER);
89
90 /* Search the static list for a matching IP and hardware mapping.
91 Compute the index that will tell us which linked list of ARP addresses to search,
92 since we don't care if it is a static or dynamic entry.
93 Search that linked list pointed in the IP ARP table. */
94
95 /* Calculate the hash index for the specified IP address. */
96 index = (UINT)((ip_address + (ip_address >> 8)) & NX_ARP_TABLE_MASK);
97
98 /* Pickup the head pointer of the ARP entries for this IP instance. */
99 arp_list_head = ip_ptr -> nx_ip_arp_table[index];
100
101 /* Search the ARP list for the same IP address. */
102 search_ptr = arp_list_head;
103 arp_ptr = NX_NULL;
104
105 while (search_ptr)
106 {
107
108 /* Determine if we have a match. */
109 if (search_ptr -> nx_arp_ip_address == ip_address)
110 {
111
112 /* Yes, the IP address matches, setup the ARP entry pointer. */
113 arp_ptr = search_ptr;
114
115 /* Get out of the loop. */
116 break;
117 }
118
119 /* Move to the next entry in the active list. */
120 search_ptr = search_ptr -> nx_arp_active_next;
121
122 /* Determine if the search pointer is back at the head of
123 the list. */
124 if (search_ptr == arp_list_head)
125 {
126
127 /* End of the ARP list, end the search. */
128 break;
129 }
130 }
131
132 /* Determine if we didn't find an ARP entry matching the input IP address. */
133 if (arp_ptr == NX_NULL)
134 {
135
136 /* Release the protection on the ARP list. */
137 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
138
139 /* Return status to the caller. */
140 return(NX_ENTRY_NOT_FOUND);
141 }
142
143 /* Determine if this is a static entry. */
144 if (arp_ptr -> nx_arp_route_static == NX_TRUE)
145 {
146
147 /* Remove from the static list. */
148 status = _nx_arp_static_entry_delete(ip_ptr, ip_address,
149 arp_ptr -> nx_arp_physical_address_msw,
150 arp_ptr -> nx_arp_physical_address_lsw);
151 }
152 else
153 {
154
155 /* Remove from the dynamic list. */
156 status = _nx_arp_dynamic_entry_delete(ip_ptr, arp_ptr);
157 }
158
159 /* Release the protection on the ARP list. */
160 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
161
162 /* Return status to the caller. */
163 return(status);
164 #else /* NX_DISABLE_IPV4 */
165 NX_PARAMETER_NOT_USED(ip_ptr);
166 NX_PARAMETER_NOT_USED(ip_address);
167
168 return(NX_NOT_SUPPORTED);
169 #endif /* !NX_DISABLE_IPV4 */
170 }
171
172
