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18
19 package jcifs.netbios;
20
21 import java.io.IOException  ;
22 import java.io.InputStream ;
23
24 public abstract class SessionServicePacket {
25
26 static final int SESSION_MESSAGE = 0x00;
28 static final int SESSION_REQUEST = 0x81;
29 public static final int POSITIVE_SESSION_RESPONSE = 0x82;
30 public static final int NEGATIVE_SESSION_RESPONSE = 0x83;
31 static final int SESSION_RETARGET_RESPONSE = 0x84;
32 static final int SESSION_KEEP_ALIVE = 0x85;
33
34 static final int MAX_MESSAGE_SIZE = 0x0001FFFF;
35 static final int HEADER_LENGTH = 4;
36
37 static void writeInt2( int val, byte[] dst, int dstIndex ) {
38 dst[dstIndex++] = (byte)(( val >> 8 ) & 0xFF );
39 dst[dstIndex] = (byte)( val & 0xFF );
40 }
41 static void writeInt4( int val, byte[] dst, int dstIndex ) {
42 dst[dstIndex++] = (byte)(( val >> 24 ) & 0xFF );
43 dst[dstIndex++] = (byte)(( val >> 16 ) & 0xFF );
44 dst[dstIndex++] = (byte)(( val >> 8 ) & 0xFF );
45 dst[dstIndex] = (byte)( val & 0xFF );
46 }
47 static int readInt2( byte[] src, int srcIndex ) {
48 return (( src[srcIndex] & 0xFF ) << 8 ) +
49 ( src[srcIndex + 1] & 0xFF );
50 }
51 static int readInt4( byte[] src, int srcIndex ) {
52 return (( src[srcIndex] & 0xFF ) << 24 ) +
53 (( src[srcIndex + 1] & 0xFF ) << 16 ) +
54 (( src[srcIndex + 2] & 0xFF ) << 8 ) +
55 ( src[srcIndex + 3] & 0xFF );
56 }
57 static int readLength( byte[] src, int srcIndex ) {
58 srcIndex++;
59 return (( src[srcIndex++] & 0x01 ) << 16 ) +
60 (( src[srcIndex++] & 0xFF ) << 8 ) +
61 ( src[srcIndex++] & 0xFF );
62 }
63 static int readn( InputStream in,
64 byte[] b,
65 int off,
66 int len ) throws IOException {
67 int i = 0, n;
68
69 while (i < len) {
70 n = in.read( b, off + i, len - i );
71 if (n <= 0) {
72 break;
73 }
74 i += n;
75 }
76
77 return i;
78 }
79 static int readPacketType( InputStream in,
80 byte[] buffer,
81 int bufferIndex )
82 throws IOException {
83 int n;
84 if(( n = readn( in, buffer, bufferIndex, HEADER_LENGTH )) != HEADER_LENGTH ) {
85 if( n == -1 ) {
86 return -1;
87 }
88 throw new IOException ( "unexpected EOF reading netbios session header" );
89 }
90 int t = buffer[bufferIndex] & 0xFF;
91 return t;
92 }
93
94 int type, length;
95
96 public int writeWireFormat( byte[] dst, int dstIndex ) {
97 length = writeTrailerWireFormat( dst, dstIndex + HEADER_LENGTH );
98 writeHeaderWireFormat( dst, dstIndex );
99 return HEADER_LENGTH + length;
100 }
101 int readWireFormat( InputStream in, byte[] buffer, int bufferIndex ) throws IOException {
102 readHeaderWireFormat( in, buffer, bufferIndex );
103 return HEADER_LENGTH + readTrailerWireFormat( in, buffer, bufferIndex );
104 }
105 int writeHeaderWireFormat( byte[] dst, int dstIndex ) {
106 dst[dstIndex++] = (byte)type;
107 if( length > 0x0000FFFF ) {
108 dst[dstIndex] = (byte)0x01;
109 }
110 dstIndex++;
111 writeInt2( length, dst, dstIndex );
112 return HEADER_LENGTH;
113 }
114 int readHeaderWireFormat( InputStream in,
115 byte[] buffer,
116 int bufferIndex )
117 throws IOException {
118 type = buffer[bufferIndex++] & 0xFF;
119 length = (( buffer[bufferIndex] & 0x01 ) << 16 ) + readInt2( buffer, bufferIndex + 1 );
120 return HEADER_LENGTH;
121 }
122
123 abstract int writeTrailerWireFormat( byte[] dst, int dstIndex );
124 abstract int readTrailerWireFormat( InputStream in,
125 byte[] buffer,
126 int bufferIndex )
127 throws IOException ;
128 }
129 |
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