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_ip_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 hardware address in the */
45 /* ARP lists. If found, the associated IP address is returned. */
46 /* */
47 /* INPUT */
48 /* */
49 /* ip_ptr IP instance pointer */
50 /* ip_address IP Address return pointer */
51 /* physical_msw Physical address MSW */
52 /* physical_lsw Physical address LSW */
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_ip_address_find(NX_IP * ip_ptr,ULONG * ip_address,ULONG physical_msw,ULONG physical_lsw)76 UINT _nx_arp_ip_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_IP_ADDRESS_FIND, ip_ptr, 0, physical_msw, physical_lsw, 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 matching hardware mapping. */
98 arp_entry = ip_ptr -> nx_ip_arp_static_list;
99 while (arp_entry)
100 {
101
102 /* Determine if we have a hardware address match. */
103 if ((arp_entry -> nx_arp_physical_address_msw == physical_msw) &&
104 (arp_entry -> nx_arp_physical_address_lsw == physical_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 IP address in the return field. */
137 *ip_address = arp_entry -> nx_arp_ip_address;
138
139 /* Update the trace event with the status. */
140 NX_TRACE_EVENT_UPDATE(trace_event, trace_timestamp, NX_TRACE_ARP_IP_ADDRESS_FIND, 0, *ip_address, 0, 0);
141
142 /* Release the protection on the ARP list. */
143 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
144
145 /* Return status to the caller. */
146 return(NX_SUCCESS);
147 }
148
149 /* Otherwise, we need to search the ARP dynamic list for a match. */
150 arp_entry = ip_ptr -> nx_ip_arp_dynamic_list;
151 count = 1;
152 while (arp_entry)
153 {
154
155 /* Determine if we have a hardware address match. */
156 if ((arp_entry -> nx_arp_physical_address_msw == physical_msw) &&
157 (arp_entry -> nx_arp_physical_address_lsw == physical_lsw))
158 {
159
160 /* Yes, we have found the ARP entry we are looking for. */
161 break;
162 }
163 else
164 {
165
166 /* Determine if we are at the end of the list of active ARP entries. */
167 if (count >= ip_ptr -> nx_ip_arp_dynamic_active_count)
168 {
169
170 /* Set the arp_entry to NULL to signify nothing was found and get
171 out of the search loop. */
172 arp_entry = NX_NULL;
173 break;
174 }
175 else
176 {
177
178 /* Just move to the next ARP entry on the dynamic list. */
179 arp_entry = arp_entry -> nx_arp_pool_next;
180
181 /* Increment the active count. */
182 count++;
183 }
184 }
185 }
186
187 /* Determine if an entry has been found. If so, we are finished and it needs to be
188 returned to the caller. */
189 if (arp_entry)
190 {
191
192 /* Store the IP address in the return fields. */
193 *ip_address = arp_entry -> nx_arp_ip_address;
194
195 /* Update the trace event with the status. */
196 NX_TRACE_EVENT_UPDATE(trace_event, trace_timestamp, NX_TRACE_ARP_IP_ADDRESS_FIND, 0, *ip_address, 0, 0);
197
198 /* Release the protection on the ARP list. */
199 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
200
201 /* Return status to the caller. */
202 return(NX_SUCCESS);
203 }
204 else
205 {
206
207 /* Release the protection on the ARP list. */
208 tx_mutex_put(&(ip_ptr -> nx_ip_protection));
209
210 /* Return status to the caller. */
211 return(NX_ENTRY_NOT_FOUND);
212 }
213 #else /* NX_DISABLE_IPV4 */
214 NX_PARAMETER_NOT_USED(ip_ptr);
215 NX_PARAMETER_NOT_USED(ip_address);
216 NX_PARAMETER_NOT_USED(physical_msw);
217 NX_PARAMETER_NOT_USED(physical_lsw);
218
219 return(NX_NOT_SUPPORTED);
220 #endif /* !NX_DISABLE_IPV4 */
221 }
222
223
