1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
|
package com.btr.proxy.search.wpad.dhcp;
import java.util.Enumeration;
import java.util.Hashtable;
/**
* This class represents a linked list of options for a DHCP message.
* Its purpose is to ease option handling such as add, remove or change.
*
* @author Jason Goldschmidt and Simon Frankenberger
*/
public class DHCPOptions {
public static final int OPTION_PAD = 0;
public static final int OPTION_NETMASK = 1;
public static final int OPTION_TIME_OFFSET = 2;
public static final int OPTION_ROUTERS = 3;
public static final int OPTION_TIME_SERVERS = 4;
public static final int OPTION_NAME_SERVERS = 5;
public static final int OPTION_DNS_SERVERS = 6;
public static final int OPTION_LOG_SERVERS = 7;
public static final int OPTION_COOKIE_SERVERS = 8;
public static final int OPTION_LPR_SERVERS = 9;
public static final int OPTION_IMPRESS_SERVERS = 10;
public static final int OPTION_RESSOURCE_LOCATION_SERVERS = 11;
public static final int OPTION_HOSTNAME = 12;
public static final int OPTION_BOOT_FILESIZE = 13;
public static final int OPTION_MERIT_DUMPFILE = 14;
public static final int OPTION_DOMAIN_NAME = 15;
public static final int OPTION_SWAP_SERVER = 16;
public static final int OPTION_ROOT_PATH = 17;
public static final int OPTION_EXTENSIONS_PATH = 18;
public static final int OPTION_END = 255;
public static final int OPTION_IP_HOST_FORWARDING_ENABLE = 19;
public static final int OPTION_IP_HOST_NON_LOCAL_SOURCE_ROUTING_ENABLE = 20;
public static final int OPTION_IP_HOST_POLICY_FILTERS = 21;
public static final int OPTION_IP_HOST_MAXIMUM_DATAGRAM_REASSEMBLY_SIZE = 22;
public static final int OPTION_IP_HOST_DEFAULT_TTL = 23;
public static final int OPTION_IP_HOST_MTU_AGEING_TIMEOUT = 24;
public static final int OPTION_IP_HOST_MTU_PLATEAU_TABLE = 25;
public static final int OPTION_IP_INTERFACE_MTU = 26;
public static final int OPTION_IP_INTERFACE_ALL_SUBNETS_LOCAL_ENABLE = 27;
public static final int OPTION_IP_INTERFACE_BROADCAST_ADDRESS = 28;
public static final int OPTION_IP_INTERFACE_PERFORM_MASK_DISCOVERY_ENABLE = 29;
public static final int OPTION_IP_INTERFACE_MASK_SUPPLIER_ENABLE = 30;
public static final int OPTION_IP_INTERFACE_PERFORM_ROUTER_DISCOVERY_ENABLE = 31;
public static final int OPTION_IP_INTERFACE_ROUTER_SOLICITATION_ADDRESS = 32;
public static final int OPTION_IP_INTERFACE_STATIC_ROUTES = 33;
public static final int OPTION_LINK_TRAILER_ENCAPSULATION_ENABLE = 34;
public static final int OPTION_LINK_ARP_CACHE_TIMEOUT = 35;
public static final int OPTION_LINK_ETHERNET_ENCAPSULATION_ENABLE = 36;
public static final int OPTION_TCP_DEFAULT_TTL = 37;
public static final int OPTION_TCP_KEEP_ALIVE_INTERVAL = 38;
public static final int OPTION_TCP_KEEP_ALIVE_GERBAGE_ENABLE = 39;
public static final int OPTION_NIS_DOMAIN = 40;
public static final int OPTION_NIS_SERVERS = 41;
public static final int OPTION_NTP_SERVERS = 42;
public static final int OPTION_SERVICE_VENDOR_SPECIFIC_INFORMATIONS = 43;
public static final int OPTION_SERVICE_NETBOIS_NAME_SERVERS = 44;
public static final int OPTION_SERVICE_NETBOIS_DATAGRAM_DISTRIBUTION_SERVERS = 45;
public static final int OPTION_SERVICE_NETBOIS_NODE_TYPE = 46;
public static final int OPTION_SERVICE_NETBOIS_SCOPE_TYPE = 47;
public static final int OPTION_SERVICE_X_FONT_SERVERS = 48;
public static final int OPTION_SERVICE_X_DISPLAY_MANAGERS = 49;
public static final int OPTION_DHCP_IP_ADRESS_REQUESTED = 50;
public static final int OPTION_DHCP_IP_LEASE_TIME = 51;
public static final int OPTION_DHCP_OVERLOAD = 52;
public static final int OPTION_DHCP_MESSAGE_TYPE = 53;
public static final int OPTION_DHCP_SERVER_IDENTIFIER = 54;
public static final int OPTION_DHCP_PARAMETER_REQUEST_LIST = 55;
public static final int OPTION_DHCP_MESSAGE = 56;
public static final int OPTION_DHCP_MAXIMUM_MESSAGE_SIZE = 57;
public static final int OPTION_DHCP_RENEWAL_TIME = 58;
public static final int OPTION_DHCP_REBIND_TIME = 59;
public static final int OPTION_DHCP_CLASS_IDENTIFIER = 60;
public static final int OPTION_DHCP_CLIENT_IDENTIFIER = 61;
/**
*This inner class represent an entry in the Option Table
*/
class DHCPOptionsEntry {
protected byte code;
protected byte length;
protected byte content[];
public DHCPOptionsEntry(byte entryCode, byte entryLength,
byte entryContent[]) {
this.code = entryCode;
this.length = entryLength;
this.content = entryContent;
}
@Override
public String toString() {
return "Code: " + this.code + "\nContent: " + new String(this.content);
}
}
private Hashtable<Byte, DHCPOptionsEntry> optionsTable = null;
public DHCPOptions() {
this.optionsTable = new Hashtable<Byte, DHCPOptionsEntry>();
}
/**
* Removes option with specified bytecode
* @param entryCode The code of option to be removed
*/
public void removeOption(byte entryCode) {
this.optionsTable.remove(new Byte(entryCode));
}
/**
* Returns true if option code is set in list; false otherwise
* @param entryCode The node's option code
* @return true if option is set, otherwise false
*/
public boolean contains(byte entryCode) {
return this.optionsTable.containsKey(new Byte(entryCode));
}
/**
* Determines if list is empty
* @return true if there are no options set, otherwise false
*/
public boolean isEmpty() {
return this.optionsTable.isEmpty();
}
/**
* Fetches value of option by its option code
* @param entryCode The node's option code
* @return byte array containing the value of option entryCode.
* null is returned if option is not set.
*/
public byte[] getOption(byte entryCode) {
if (this.contains(entryCode)) {
DHCPOptionsEntry ent = this.optionsTable.get(new Byte(entryCode));
return ent.content;
}
else {
return null;
}
}
/**
* Changes an existing option to new value
* @param entryCode The node's option code
* @param value Content of node option
*/
public void setOption(byte entryCode, byte value[]) {
DHCPOptionsEntry opt = new DHCPOptionsEntry(entryCode, (byte) value.length, value);
this.optionsTable.put(new Byte(entryCode), opt);
}
/**
* Returns the option value of a specified option code in a byte array
* @param length Length of option content
* @param position Location in array of option node
* @param options The byte array of options
* @return byte array containing the value for the option
*/
private byte[] getArrayOption(int length, int position, byte options[]) {
byte value[] = new byte[length];
for (int i = 0; i < length; i++) {
value[i] = options[position + i];
}
return value;
}
/**
* Converts an options byte array to a linked list
* @param optionsArray The byte array representation of the options list
*/
public void internalize(byte[] optionsArray) {
/* Assume options valid and correct */
int pos = 4; // ignore vendor magic cookie
byte code, length;
byte value[];
while (optionsArray[pos] != (byte) 255) { // until end option
code = optionsArray[pos++];
length = optionsArray[pos++];
value = getArrayOption(length, pos, optionsArray);
setOption(code, value);
pos += length; // increment position pointer
}
}
/**
* Converts a linked options list to a byte array
* @return array representation of optionsTable
*/
// todo provide overflow return
public byte[] externalize() {
byte[] options = new byte[312];
options[0] = (byte) 99; // insert vendor magic cookie
options[1] = (byte) 130;
options[2] = (byte) 83;
options[3] = (byte) 99;
int position = 4;
Enumeration<DHCPOptionsEntry> e = this.optionsTable.elements();
while (e.hasMoreElements()) {
DHCPOptionsEntry entry = e.nextElement();
options[position++] = entry.code;
options[position++] = entry.length;
for (int i = 0; i < entry.length; ++i) {
options[position++] = entry.content[i];
}
}
options[position] = (byte) 255; // insert end option
return options;
}
/**
* Prints the options linked list: For testing only.
*/
public void printList() {
System.out.println(this.optionsTable.toString());
}
}
|
