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_hardware_address_find 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 hardware address is returned. */
46 /* */
47 /* INPUT */
48 /* */
49 /* ip_ptr IP instance pointer */
50 /* ip_address IP Address to search for */
51 /* physical_msw Physical address MSW pointer */
52 /* physical_lsw Physical address LSW pointer */
53 /* */
54 /* OUTPUT */
55 /* */
56 /* status Completion status */
57 /* */
58 /* CALLS */
59 /* */
60 /* tx_mutex_get Obtain protection mutex */
61 /* tx_mutex_put Release protection mutex */
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_hardware_address_find(NX_IP * ip_ptr,ULONG ip_address,ULONG * physical_msw,ULONG * physical_lsw)76 UINT _nx_arp_hardware_address_find(NX_IP *ip_ptr, ULONG ip_address,
77 ULONG *physical_msw, ULONG *physical_lsw)
78 {
79
80 #ifndef NX_DISABLE_IPV4
81 NX_ARP *arp_entry;
82 ULONG count;
83
84 #ifdef TX_ENABLE_EVENT_TRACE
85 TX_TRACE_BUFFER_ENTRY *trace_event;
86 ULONG trace_timestamp;
87 #endif
88
89
90 /* If trace is enabled, insert this event into the trace buffer. */
91 NX_TRACE_IN_LINE_INSERT(NX_TRACE_ARP_HARDWARE_ADDRESS_FIND, ip_ptr, ip_address, 0, 0, NX_TRACE_ARP_EVENTS, &trace_event, &trace_timestamp);
92
93 /* Obtain protection on this IP instance for access into the ARP static
94 list. */
95 tx_mutex_get(&(ip_ptr -> nx_ip_protection), TX_WAIT_FOREVER);
96
97 /* Search the static list for a matching IP and hardware mapping. */
98 arp_entry = ip_ptr -> nx_ip_arp_static_list;
99 while (arp_entry)
100 {
101
102 /* Determine if we have a match. */
103 if ((arp_entry -> nx_arp_ip_address == ip_address) &&
104 (arp_entry -> nx_arp_physical_address_msw | arp_entry -> nx_arp_physical_address_lsw))
105 {
106
107 /* Yes, we have found the ARP entry we are looking for. */
108 break;
109 }
110 else
111 {
112
113 /* Determine if we are at the end of the list. */
114 if (arp_entry -> nx_arp_pool_next == ip_ptr -> nx_ip_arp_static_list)
115 {
116
117 /* Set the arp_entry to NULL to signify nothing was found and get
118 out of the search loop. */
119 arp_entry = NX_NULL;
120 break;
121 }
122 else
123 {
124
125 /* Just move to the next ARP entry on the static list. */
126 arp_entry = arp_entry -> nx_arp_pool_next;
127 }
128 }
129 }
130
131 /* Determine if an entry has been found. If so, we are finished and it needs to be
132 returned to the caller. */
133 if (arp_entry)
134 {
135
136 /* Store the hardware address in the return fields. */
137 *physical_msw = arp_entry -> nx_arp_physical_address_msw;
138 *physical_lsw = arp_entry -> nx_arp_physical_address_lsw;
139
140 /* Update the trace event with the status. */
141 NX_TRACE_EVENT_UPDATE(trace_event, trace_timestamp, NX_TRACE_ARP_HARDWARE_ADDRESS_FIND, 0, 0, *physical_msw, *physical_lsw);
142
143 /* Release the protection on the ARP list. */
144 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
145
146 /* Return status to the caller. */
147 return(NX_SUCCESS);
148 }
149
150 /* Otherwise, we need to search the ARP dynamic list for a match. */
151 arp_entry = ip_ptr -> nx_ip_arp_dynamic_list;
152 count = 1;
153 while (arp_entry)
154 {
155
156 /* Determine if we have a match. */
157 if ((arp_entry -> nx_arp_ip_address == ip_address) &&
158 (arp_entry -> nx_arp_physical_address_msw | arp_entry -> nx_arp_physical_address_lsw))
159 {
160
161 /* Yes, we have found the ARP entry we are looking for. */
162 break;
163 }
164 else
165 {
166
167 /* Determine if we are at the end of the list of active ARP entries. */
168 if (count >= ip_ptr -> nx_ip_arp_dynamic_active_count)
169 {
170
171 /* Set the arp_entry to NULL to signify nothing was found and get
172 out of the search loop. */
173 arp_entry = NX_NULL;
174 break;
175 }
176 else
177 {
178
179 /* Just move to the next ARP entry on the dynamic list. */
180 arp_entry = arp_entry -> nx_arp_pool_next;
181
182 /* Increment the active count. */
183 count++;
184 }
185 }
186 }
187
188 /* Determine if an entry has been found. If so, we are finished and it needs to be
189 returned to the caller. */
190 if (arp_entry)
191 {
192
193 /* Store the hardware address in the return fields. */
194 *physical_msw = arp_entry -> nx_arp_physical_address_msw;
195 *physical_lsw = arp_entry -> nx_arp_physical_address_lsw;
196
197 /* Update the trace event with the status. */
198 NX_TRACE_EVENT_UPDATE(trace_event, trace_timestamp, NX_TRACE_ARP_HARDWARE_ADDRESS_FIND, 0, 0, *physical_msw, *physical_lsw);
199
200 /* Release the protection on the ARP list. */
201 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
202
203 /* Return status to the caller. */
204 return(NX_SUCCESS);
205 }
206 else
207 {
208
209 /* Release the protection on the ARP list. */
210 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
211
212 /* Return status to the caller. */
213 return(NX_ENTRY_NOT_FOUND);
214 }
215 #else /* NX_DISABLE_IPV4 */
216 NX_PARAMETER_NOT_USED(ip_ptr);
217 NX_PARAMETER_NOT_USED(ip_address);
218 NX_PARAMETER_NOT_USED(physical_msw);
219 NX_PARAMETER_NOT_USED(physical_lsw);
220
221 return(NX_NOT_SUPPORTED);
222 #endif /* !NX_DISABLE_IPV4 */
223 }
224
225
