diff options
Diffstat (limited to 'src/main/java/com/btr/proxy/search/wpad/dhcp/DHCPOptions.java')
| -rw-r--r-- | src/main/java/com/btr/proxy/search/wpad/dhcp/DHCPOptions.java | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/src/main/java/com/btr/proxy/search/wpad/dhcp/DHCPOptions.java b/src/main/java/com/btr/proxy/search/wpad/dhcp/DHCPOptions.java new file mode 100644 index 0000000..1a07efb --- /dev/null +++ b/src/main/java/com/btr/proxy/search/wpad/dhcp/DHCPOptions.java @@ -0,0 +1,235 @@ +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()); + } +} |