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wireshark/epan/sigcomp-udvm.c

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/* sigcomp-udvm.c
* Routines making up the Universal Decompressor Virtual Machine (UDVM) used for
* Signaling Compression (SigComp) dissection.
* Copyright 2004, Anders Broman <anders.broman@ericsson.com>
*
* $Id$
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@ethereal.com>
* Copyright 1998 Gerald Combs
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* References:
* http://www.ietf.org/rfc/rfc3320.txt?number=3320
* http://www.ietf.org/rfc/rfc3321.txt?number=3321
* Useful links :
* http://www.ietf.org/internet-drafts/draft-ietf-rohc-sigcomp-impl-guide-03.txt
* http://www.ietf.org/internet-drafts/draft-ietf-rohc-sigcomp-sip-01.txt
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <glib.h>
#ifdef NEED_SNPRINTF_H
# include "snprintf.h"
#endif
#include "packet.h"
#include "strutil.h"
#include "sigcomp-udvm.h"
#include "sigcomp_state_hdlr.h"
#include "sha1.h"
#define SIGCOMP_INSTR_DECOMPRESSION_FAILURE 0
#define SIGCOMP_INSTR_AND 1
#define SIGCOMP_INSTR_OR 2
#define SIGCOMP_INSTR_NOT 3
#define SIGCOMP_INSTR_LSHIFT 4
#define SIGCOMP_INSTR_RSHIFT 5
#define SIGCOMP_INSTR_ADD 6
#define SIGCOMP_INSTR_SUBTRACT 7
#define SIGCOMP_INSTR_MULTIPLY 8
#define SIGCOMP_INSTR_DIVIDE 9
#define SIGCOMP_INSTR_REMAINDER 10
#define SIGCOMP_INSTR_SORT_ASCENDING 11
#define SIGCOMP_INSTR_SORT_DESCENDING 12
#define SIGCOMP_INSTR_SHA_1 13
#define SIGCOMP_INSTR_LOAD 14
#define SIGCOMP_INSTR_MULTILOAD 15
#define SIGCOMP_INSTR_PUSH 16
#define SIGCOMP_INSTR_POP 17
#define SIGCOMP_INSTR_COPY 18
#define SIGCOMP_INSTR_COPY_LITERAL 19
#define SIGCOMP_INSTR_COPY_OFFSET 20
#define SIGCOMP_INSTR_MEMSET 21
#define SIGCOMP_INSTR_JUMP 22
#define SIGCOMP_INSTR_COMPARE 23
#define SIGCOMP_INSTR_CALL 24
#define SIGCOMP_INSTR_RETURN 25
#define SIGCOMP_INSTR_SWITCH 26
#define SIGCOMP_INSTR_CRC 27
#define SIGCOMP_INSTR_INPUT_BYTES 28
#define SIGCOMP_INSTR_INPUT_BITS 29
#define SIGCOMP_INSTR_INPUT_HUFFMAN 30
#define SIGCOMP_INSTR_STATE_ACCESS 31
#define SIGCOMP_INSTR_STATE_CREATE 32
#define SIGCOMP_INSTR_STATE_FREE 33
#define SIGCOMP_INSTR_OUTPUT 34
#define SIGCOMP_INSTR_END_MESSAGE 35
static gboolean print_level_1;
static gboolean print_level_2;
static gboolean print_level_3;
/* Internal result code values of decompression failures */
const value_string result_code_vals[] = {
{ 0, "No decomprssion failure" },
{ 1, "Partial state length less than 6 or greater than 20 bytes long" },
{ 2, "No state match" },
{ 3, "state_begin + state_length > size of state" },
{ 4, "Operand_2 is Zero" },
{ 5, "Switch statement failed j >= n" },
{ 6, "Atempt to jump outside of UDVM memory" },
{ 7, "L in input-bits > 16" },
{ 8, "input_bit_order > 7" },
{ 9, "Instruction Decompression failure encounterd" },
{10, "Input huffman failed j > n" },
{11, "Input bits requested beond end of message" },
{12, "more than four state creation requests are made before the END-MESSAGE instruction" },
{13, "state_retention_priority is 65535" },
{14, "Input bytes requested beond end of message" },
{15, "Maximum number of UDVM cycles reached" },
{ 255, "This branch isn't coded yet" },
{ 0, NULL }
};
static int decode_udvm_literal_operand(guint8 *buff,guint operand_address, guint16 *value);
static int dissect_udvm_reference_operand(guint8 *buff,guint operand_address, guint16 *value, guint *result_dest);
static int decode_udvm_multitype_operand(guint8 *buff,guint operand_address,guint16 *value);
static int decode_udvm_address_operand(guint8 *buff,guint operand_address, guint16 *value,guint current_address);
static int decomp_dispatch_get_bits(tvbuff_t *message_tvb,proto_tree *udvm_tree,guint8 bit_order,
guint8 *buff,guint16 *old_input_bit_order, guint16 *remaining_bits,
guint16 *input_bits, guint *input_address, guint16 length, guint16 *result_code,guint msg_end);
tvbuff_t*
decompress_sigcomp_message(tvbuff_t *bytecode_tvb, tvbuff_t *message_tvb, packet_info *pinfo,
proto_tree *udvm_tree, gint udvm_mem_dest, gint print_flags, gint hf_id)
{
tvbuff_t *decomp_tvb;
guint8 buff[UDVM_MEMORY_SIZE];
char string[2],*strp;
guint8 *out_buff; /* Largest allowed size for a message is 65535 */
guint32 i = 0;
guint16 n = 0;
guint16 m = 0;
guint16 x;
guint k = 0;
guint16 H;
guint16 oldH;
guint offset = 0;
guint result_dest;
guint code_length =0;
guint8 current_instruction;
guint current_address;
guint operand_address;
guint input_address;
guint16 output_address = 0;
guint next_operand_address;
guint8 octet;
guint8 msb;
guint8 lsb;
guint16 byte_copy_right;
guint16 byte_copy_left;
guint16 input_bit_order;
guint16 result;
guint msg_end = tvb_reported_length_remaining(message_tvb, 0);
guint16 result_code;
guint16 old_input_bit_order = 0;
guint16 remaining_bits = 0;
guint16 input_bits = 0;
guint8 bit_order = 0;
gboolean outside_huffman_boundaries = TRUE;
gboolean print_in_loop = FALSE;
guint16 instruction_address;
guint8 no_of_state_create = 0;
guint16 state_length_buff[5];
guint16 state_address_buff[5];
guint16 state_instruction_buff[5];
guint16 state_minimum_access_length_buff[5];
guint16 state_state_retention_priority_buff[5];
guint32 used_udvm_cycles = 0;
guint cycles_per_bit;
guint maximum_UDVM_cycles;
guint8 *sha1buff;
unsigned char sha1_digest_buf[20];
sha1_context ctx;
/* UDVM operand variables */
guint16 length;
guint16 at_address;
guint16 destination;
guint16 address;
guint16 value;
guint16 p_id_start;
guint16 p_id_length;
guint16 state_begin;
guint16 state_length;
guint16 state_address;
guint16 state_instruction;
guint16 operand_1;
guint16 operand_2;
guint16 value_1;
guint16 value_2;
guint16 at_address_1;
guint16 at_address_2;
guint16 at_address_3;
guint16 j;
guint16 bits_n;
guint16 lower_bound_n;
guint16 upper_bound_n;
guint16 uncompressed_n;
guint16 position;
guint16 ref_destination; /* could I have used $destination ? */
guint16 multy_offset;
guint16 output_start;
guint16 output_length;
guint16 minimum_access_length;
guint16 state_retention_priority;
guint16 requested_feedback_location;
guint16 returned_parameters_location;
guint16 start_value;
/* Set print parameters */
print_level_1 = FALSE;
print_level_2 = FALSE;
print_level_3 = FALSE;
switch( print_flags ) {
case 0:
break;
case 1:
print_level_1 = TRUE;
break;
case 2:
print_level_1 = TRUE;
print_level_2 = TRUE;
break;
case 3:
print_level_1 = TRUE;
print_level_2 = TRUE;
print_level_3 = TRUE;
break;
default:
print_level_1 = TRUE;
break;
}
/* UDVM memory must be initialised to zero */
while ( i < UDVM_MEMORY_SIZE ) {
buff[i] = 0;
i++;
}
/* Set initial UDVM data
* The first 32 bytes of UDVM memory are then initialized to special
* values as illustrated in Figure 5.
*
* 0 7 8 15
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | UDVM_memory_size | 0 - 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | cycles_per_bit | 2 - 3
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | SigComp_version | 4 - 5
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | partial_state_ID_length | 6 - 7
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | state_length | 8 - 9
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | |
* : reserved : 10 - 31
* | |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Figure 5: Initializing Useful Values in UDVM memory
*/
/* UDVM_memory_size */
buff[0] = 0;
buff[1] = 0;
/* cycles_per_bit */
buff[2] = 0;
buff[3] = 16;
/* SigComp_version */
buff[4] = 0;
buff[5] = 1;
/* partial_state_ID_length */
buff[6] = 0;
buff[7] = 0;
/* state_length */
buff[8] = 0;
buff[9] = 0;
code_length = tvb_reported_length_remaining(bytecode_tvb, 0);
cycles_per_bit = buff[2] << 8;
cycles_per_bit = cycles_per_bit | buff[3];
/*
* maximum_UDVM_cycles = (8 * n + 1000) * cycles_per_bit
*/
maximum_UDVM_cycles = (( 8 * msg_end ) + 1000) * cycles_per_bit;
proto_tree_add_text(udvm_tree, bytecode_tvb, offset, 1,"maximum_UDVM_cycles(%u) = (( 8 * msg_end(%u) ) + 1000) * cycles_per_bit(%u)",maximum_UDVM_cycles,msg_end,cycles_per_bit);
proto_tree_add_text(udvm_tree, bytecode_tvb, offset, 1,"Message Length: %u,Byte code length: %u, Maximum UDVM cycles: %u",msg_end,code_length,maximum_UDVM_cycles);
/* Load bytecode into UDVM starting at "udvm_mem_dest" */
i = udvm_mem_dest;
if ( print_level_3 )
proto_tree_add_text(udvm_tree, bytecode_tvb, offset, 1,"Load bytecode into UDVM starting at %u",i);
while ( code_length > offset ) {
buff[i] = tvb_get_guint8(bytecode_tvb, offset);
if ( print_level_3 )
proto_tree_add_text(udvm_tree, bytecode_tvb, offset, 1,
" Addr: %u Instruction code(0x%0x) ", i, buff[i]);
i++;
offset++;
}
/* Largest allowed size for a message is 65535 */
out_buff = g_malloc(65535);
/* Start executing code */
current_address = udvm_mem_dest;
input_address = 0;
operand_address = 0;
proto_tree_add_text(udvm_tree, bytecode_tvb, offset, 1,"UDVM EXECUTION STARTED at Address: %u Message size %u",
udvm_mem_dest,msg_end);
execute_next_instruction:
if ( used_udvm_cycles > maximum_UDVM_cycles ){
result_code = 15;
goto decompression_failure;
}
current_instruction = buff[current_address];
switch ( current_instruction ) {
case SIGCOMP_INSTR_DECOMPRESSION_FAILURE:
used_udvm_cycles++;
if ( result_code == 0 )
result_code = 9;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## DECOMPRESSION-FAILURE(0)",
current_address);
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Ethereal UDVM diagnostic: %s.",
val_to_str(result_code, result_code_vals,"Unknown (%u)"));
if ( output_address > 0 ){
/* At least something got decompressed, show it */
decomp_tvb = tvb_new_real_data(out_buff,output_address,output_address);
/* Arrange that the allocated packet data copy be freed when the
* tvbuff is freed.
*/
tvb_set_free_cb( decomp_tvb, g_free );
/* Add the tvbuff to the list of tvbuffs to which the tvbuff we
* were handed refers, so it'll get cleaned up when that tvbuff
* is cleaned up.
*/
tvb_set_child_real_data_tvbuff(message_tvb,decomp_tvb);
add_new_data_source(pinfo, decomp_tvb, "Decompressed SigComp message(Incomplete)");
proto_tree_add_text(udvm_tree, decomp_tvb, 0, -1,"SigComp message Decompression failure");
return decomp_tvb;
}
g_free(out_buff);
return NULL;
break;
case SIGCOMP_INSTR_AND: /* 1 AND ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## AND(1) (operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/* execute the instruction */
result = operand_1 & operand_2;
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_OR: /* 2 OR ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## OR(2) (operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/* execute the instruction */
result = operand_1 | operand_2;
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_NOT: /* 3 NOT ($operand_1) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## NOT(3) ($operand_1)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
/* execute the instruction */
result = operand_1 ^ 0xffff;
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_LSHIFT: /* 4 LSHIFT ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## LSHIFT(4) ($operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/* execute the instruction */
result = operand_1 << operand_2;
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_RSHIFT: /* 5 RSHIFT ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## RSHIFT(5) (operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/* execute the instruction */
result = operand_1 >> operand_2;
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_ADD: /* 6 ADD ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## ADD(6) (operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/* execute the instruction */
result = operand_1 + operand_2;
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
case SIGCOMP_INSTR_SUBTRACT: /* 7 SUBTRACT ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## SUBTRACT(7) (operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/* execute the instruction */
result = operand_1 - operand_2;
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_MULTIPLY: /* 8 MULTIPLY ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ##MULTIPLY(8) (operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/*
* execute the instruction
* MULTIPLY (m, n) := m * n (modulo 2^16)
*/
if ( operand_2 == 0){
result_code = 4;
goto decompression_failure;
}
result = operand_1 * operand_2;
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_DIVIDE: /* 9 DIVIDE ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## DIVIDE(9) (operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/*
* execute the instruction
* DIVIDE (m, n) := floor(m / n)
* Decompression failure occurs if a DIVIDE or REMAINDER instruction
* encounters an operand_2 that is zero.
*/
if ( operand_2 == 0){
result_code = 4;
goto decompression_failure;
}
result = (guint16)floor(operand_1/operand_2);
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_REMAINDER: /* 10 REMAINDER ($operand_1, %operand_2) */
used_udvm_cycles++;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## REMAINDER(10) (operand_1, operand_2)",
current_address);
}
/* $operand_1*/
operand_address = current_address + 1;
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &operand_1, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_1 %u",
operand_address, operand_1);
}
operand_address = next_operand_address;
/* %operand_2*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &operand_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u operand_2 %u",
operand_address, operand_2);
}
/*
* execute the instruction
* REMAINDER (m, n) := m - n * floor(m / n)
* Decompression failure occurs if a DIVIDE or REMAINDER instruction
* encounters an operand_2 that is zero.
*/
if ( operand_2 == 0){
result_code = 4;
goto decompression_failure;
}
result = operand_1 - operand_2 * (guint16)floor(operand_1/operand_2);
lsb = result & 0xff;
msb = result >> 8;
buff[result_dest] = msb;
buff[result_dest+1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading result %u at %u",
result, result_dest);
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_SORT_ASCENDING: /* 11 SORT-ASCENDING (%start, %n, %k) */
/*
* used_udvm_cycles = 1 + k * (ceiling(log2(k)) + n)
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## SORT-ASCENDING(11) (start, n, k))",
current_address);
}
operand_address = current_address + 1;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented");
/*
* used_udvm_cycles = 1 + k * (ceiling(log2(k)) + n)
*/
break;
case SIGCOMP_INSTR_SORT_DESCENDING: /* 12 SORT-DESCENDING (%start, %n, %k) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## SORT-DESCENDING(12) (start, n, k))",
current_address);
}
operand_address = current_address + 1;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented");
/*
* used_udvm_cycles = 1 + k * (ceiling(log2(k)) + n)
*/
break;
case SIGCOMP_INSTR_SHA_1: /* 13 SHA-1 (%position, %length, %destination) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## SHA-1(13) (position, length, destination)",
current_address);
}
operand_address = current_address + 1;
/* %position */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &position);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u position %u",
operand_address, position);
}
operand_address = next_operand_address;
/* %length */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Length %u",
operand_address, length);
}
operand_address = next_operand_address;
/* $destination */
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &ref_destination, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u $destination %u",
operand_address, ref_destination);
}
current_address = next_operand_address;
used_udvm_cycles = used_udvm_cycles + 1 + length;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented");
break;
case SIGCOMP_INSTR_LOAD: /* 14 LOAD (%address, %value) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## LOAD(14) (%%address, %%value)",
current_address);
}
operand_address = current_address + 1;
/* %address */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Address %u",
operand_address, address);
}
operand_address = next_operand_address;
/* %value */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &value);
lsb = value & 0xff;
msb = value >> 8;
buff[address] = msb;
buff[address + 1] = lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Value %u",
operand_address, value);
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Loading bytes at %u Value %u 0x%x",
address, value, value);
}
used_udvm_cycles++;
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_MULTILOAD: /* 15 MULTILOAD (%address, #n, %value_0, ..., %value_n-1) */
/* RFC 3320:
* The MULTILOAD instruction sets a contiguous block of 2-byte words in
* the UDVM memory to specified values.
* Hmm what if the value to load only takes one byte ? Chose to always load two bytes.
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## MULTILOAD(15) (%%address, #n, value_0, ..., value_n-1)",
current_address);
}
operand_address = current_address + 1;
/* %address */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Address %u",
operand_address, address);
}
operand_address = next_operand_address;
/* #n */
next_operand_address = decode_udvm_literal_operand(buff,operand_address, &n);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u n %u",
operand_address, n);
}
operand_address = next_operand_address;
used_udvm_cycles = used_udvm_cycles + 1 + n;
while ( n > 0) {
n = n - 1;
/* %value */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &value);
lsb = value & 0xff;
msb = value >> 8;
buff[address] = msb;
buff[address + 1] = lsb;
/* debug
*/
length = next_operand_address - operand_address;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, operand_address - 128, length,"Addr: %u Value %5u - Loading bytes at %5u Value %5u 0x%x",
operand_address, value, address, value, value);
}
address = address + 2;
operand_address = next_operand_address;
}
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_PUSH: /* 16 PUSH (%value) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## PUSH(16) (value)",
current_address);
}
operand_address = current_address + 1;
/* %value */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &value);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Value %u",
operand_address, value);
}
used_udvm_cycles++;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented");
break;
case SIGCOMP_INSTR_POP: /* 17 POP (%address) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## POP(17) (address)",
current_address);
}
operand_address = current_address + 1;
/* %address */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Address %u",
operand_address, address);
}
operand_address = next_operand_address;
used_udvm_cycles++;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented");
break;
case SIGCOMP_INSTR_COPY: /* 18 COPY (%position, %length, %destination) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## COPY(18) (position, length, destination)",
current_address);
}
operand_address = current_address + 1;
/* %position */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &position);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u position %u",
operand_address, position);
}
operand_address = next_operand_address;
/* %length */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Length %u",
operand_address, length);
}
operand_address = next_operand_address;
/* %destination */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &destination);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Destination %u",
operand_address, destination);
}
current_address = next_operand_address;
/*
* 8.4. Byte copying
* :
* The string of bytes is copied in ascending order of memory address,
* respecting the bounds set by byte_copy_left and byte_copy_right.
* More precisely, if a byte is copied from/to Address m then the next
* byte is copied from/to Address n where n is calculated as follows:
*
* Set k := m + 1 (modulo 2^16)
* If k = byte_copy_right then set n := byte_copy_left, else set n := k
*
*/
n = 0;
k = destination;
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" byte_copy_right = %u", byte_copy_right);
}
while ( n < length ){
if ( k == byte_copy_right ){
k = byte_copy_left;
}
buff[k] = buff[position + n];
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" Copying value: %u (0x%x) to Addr: %u", buff[position + n], buff[position + n], k);
}
k = ( k + 1 ) & 0xffff;
n++;
}
used_udvm_cycles = used_udvm_cycles + 1 + length;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_COPY_LITERAL: /* 19 COPY-LITERAL (%position, %length, $destination) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## COPY-LITERAL(19) (position, length, $destination)",
current_address);
}
operand_address = current_address + 1;
/* %position */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &position);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u position %u",
operand_address, address);
}
operand_address = next_operand_address;
/* %length */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Length %u",
operand_address, length);
}
operand_address = next_operand_address;
/* $destination */
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &ref_destination, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u destination %u",
operand_address, ref_destination);
}
current_address = next_operand_address;
/*
* 8.4. Byte copying
* :
* The string of bytes is copied in ascending order of memory address,
* respecting the bounds set by byte_copy_left and byte_copy_right.
* More precisely, if a byte is copied from/to Address m then the next
* byte is copied from/to Address n where n is calculated as follows:
*
* Set k := m + 1 (modulo 2^16)
* If k = byte_copy_right then set n := byte_copy_left, else set n := k
*
*/
n = 0;
k = ref_destination;
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" byte_copy_right = %u", byte_copy_right);
}
while ( n < length ){
if ( k == byte_copy_right ){
k = byte_copy_left;
}
buff[k] = buff[position + n];
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" Copying value: %u (0x%x) to Addr: %u", buff[position + n], buff[position + n], k);
}
k = ( k + 1 ) & 0xffff;
n++;
}
buff[result_dest] = k >> 8;
buff[result_dest + 1] = k & 0x00ff;
used_udvm_cycles = used_udvm_cycles + 1 + length;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_COPY_OFFSET: /* 20 COPY-OFFSET (%offset, %length, $destination) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## COPY-OFFSET(20) (offset, length, $destination)",
current_address);
}
operand_address = current_address + 1;
/* %offset */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &multy_offset);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u offset %u",
operand_address, multy_offset);
}
operand_address = next_operand_address;
/* %length */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Length %u",
operand_address, length);
}
operand_address = next_operand_address;
/* $destination */
next_operand_address = dissect_udvm_reference_operand(buff, operand_address, &ref_destination, &result_dest);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u $destination %u",
operand_address, ref_destination);
}
current_address = next_operand_address;
/* Execute the instruction:
* To derive the value of the position operand, starting at the memory
* address specified by destination, the UDVM counts backwards a total
* of offset memory addresses.
*
* If the memory address specified in byte_copy_left is reached, the
* next memory address is taken to be (byte_copy_right - 1) modulo 2^16.
*/
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
if ( (byte_copy_left + multy_offset) > ( ref_destination )){
/* wrap around */
position = byte_copy_right - ( multy_offset - ( ref_destination - byte_copy_left ));
}else{
position = ref_destination - multy_offset;
}
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" byte_copy_left = %u byte_copy_right = %u position= %u",
byte_copy_left, byte_copy_right, position);
}
/* The COPY-OFFSET instruction then behaves as a COPY-LITERAL
* instruction, taking the value of the position operand to be the last
* memory address reached in the above step.
*/
/*
* 8.4. Byte copying
* :
* The string of bytes is copied in ascending order of memory address,
* respecting the bounds set by byte_copy_left and byte_copy_right.
* More precisely, if a byte is copied from/to Address m then the next
* byte is copied from/to Address n where n is calculated as follows:
*
* Set k := m + 1 (modulo 2^16)
* If k = byte_copy_right then set n := byte_copy_left, else set n := k
*
*/
n = 0;
k = ref_destination;
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
if (print_level_2 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" byte_copy_left = %u byte_copy_right = %u", byte_copy_left, byte_copy_right);
}
while ( n < length ){
if ( k == byte_copy_right ){
k = byte_copy_left;
}
if ( position == byte_copy_right ){
position = byte_copy_left;
}
buff[k] = buff[position];
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" Copying value: %5u (0x%x) from Addr: %u to Addr: %u",
buff[position + n], buff[position + n],(position + n), k);
}
k = ( k + 1 ) & 0xffff;
n++;
position++;
}
buff[result_dest] = k >> 8;
buff[result_dest + 1] = k & 0x00ff;
used_udvm_cycles = used_udvm_cycles + 1 + length;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_MEMSET: /* 21 MEMSET (%address, %length, %start_value, %offset) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## MEMSET(21) (address, length, start_value, offset)",
current_address);
}
operand_address = current_address + 1;
/* %address */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Address %u",
operand_address, address);
}
operand_address = next_operand_address;
/* %length, */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Length %u",
operand_address, length);
}
operand_address = next_operand_address;
/* %start_value */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &start_value);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u start_value %u",
operand_address, start_value);
}
operand_address = next_operand_address;
/* %offset */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &multy_offset);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u offset %u",
operand_address, multy_offset);
}
current_address = next_operand_address;
/* exetute the instruction
* The sequence of values used by the MEMSET instruction is specified by
* the following formula:
*
* Seq[n] := (start_value + n * offset) modulo 256
*/
n = 0;
k = address;
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
if (print_level_2 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" byte_copy_left = %u byte_copy_right = %u", byte_copy_left, byte_copy_right);
}
while ( n < length ){
if ( k == byte_copy_right ){
k = byte_copy_left;
}
buff[k] = (start_value + ( n * multy_offset)) & 0xff;
if (print_level_2 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" Storing value: %u (0x%x) at Addr: %u",
buff[k], buff[k], k);
}
k = ( k + 1 ) & 0xffff;
n++;
}/* end while */
used_udvm_cycles = used_udvm_cycles + 1 + length;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_JUMP: /* 22 JUMP (@address) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## JUMP(22) (@address)",
current_address);
}
operand_address = current_address + 1;
/* @address */
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
next_operand_address = decode_udvm_address_operand(buff,operand_address, &at_address, current_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address);
}
current_address = at_address;
used_udvm_cycles++;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_COMPARE: /* 23 */
/* COMPARE (%value_1, %value_2, @address_1, @address_2, @address_3)
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## COMPARE(23) (value_1, value_2, @address_1, @address_2, @address_3)",
current_address);
}
operand_address = current_address + 1;
/* %value_1 */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &value_1);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Value %u",
operand_address, value_1);
}
operand_address = next_operand_address;
/* %value_2 */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &value_2);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Value %u",
operand_address, value_2);
}
operand_address = next_operand_address;
/* @address_1 */
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &at_address_1);
at_address_1 = ( current_address + at_address_1) & 0xffff;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address_1);
}
operand_address = next_operand_address;
/* @address_2 */
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &at_address_2);
at_address_2 = ( current_address + at_address_2) & 0xffff;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address_2);
}
operand_address = next_operand_address;
/* @address_3 */
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &at_address_3);
at_address_3 = ( current_address + at_address_3) & 0xffff;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address_3);
}
/* execute the instruction
* If value_1 < value_2 then the UDVM continues instruction execution at
* the memory address specified by address 1. If value_1 = value_2 then
* it jumps to the address specified by address_2. If value_1 > value_2
* then it jumps to the address specified by address_3.
*/
if ( value_1 < value_2 )
current_address = at_address_1;
if ( value_1 == value_2 )
current_address = at_address_2;
if ( value_1 > value_2 )
current_address = at_address_3;
used_udvm_cycles++;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_CALL: /* 24 CALL (@address) (PUSH addr )*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## CALL(24) (@address) (PUSH addr )",
current_address);
}
operand_address = current_address + 1;
/* @address */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &at_address);
at_address = ( current_address + at_address) & 0xffff;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address);
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
}
used_udvm_cycles++;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented");
break;
case SIGCOMP_INSTR_RETURN: /* 25 POP and return */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## POP(25) and return",
current_address);
}
operand_address = current_address + 1;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented");
used_udvm_cycles++;
break;
case SIGCOMP_INSTR_SWITCH: /* 26 SWITCH (#n, %j, @address_0, @address_1, ... , @address_n-1) */
/*
* When a SWITCH instruction is encountered the UDVM reads the value of
* j. It then continues instruction execution at the address specified
* by address j.
*
* Decompression failure occurs if j specifies a value of n or more, or
* if the address lies beyond the overall UDVM memory size.
*/
instruction_address = current_address;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## SWITCH (#n, j, @address_0, @address_1, ... , @address_n-1))",
current_address);
}
operand_address = current_address + 1;
/* #n
* Number of addresses in the instruction
*/
next_operand_address = decode_udvm_literal_operand(buff,operand_address, &n);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u n %u",
operand_address, n);
}
operand_address = next_operand_address;
/* %j */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &j);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u j %u",
operand_address, j);
}
operand_address = next_operand_address;
m = 0;
while ( m < n ){
/* @address_n-1 */
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &at_address_1);
at_address_1 = ( instruction_address + at_address_1) & 0xffff;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address_1);
}
if ( j == m ){
current_address = at_address_1;
}
operand_address = next_operand_address;
m++;
}
/* Check decompression failure */
if ( ( j == n ) || ( j > n )){
result_code = 5;
goto decompression_failure;
}
if ( current_address > UDVM_MEMORY_SIZE ){
result_code = 6;
goto decompression_failure;
}
used_udvm_cycles = used_udvm_cycles + 1 + n;
;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_CRC: /* 27 CRC (%value, %position, %length, @address) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## CRC (value, position, length, @address)",
current_address);
}
/* %value */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &value);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Value %u",
operand_address, value);
}
/* %position */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &position);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u position %u",
operand_address, position);
}
operand_address = next_operand_address;
/* %length */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Length %u",
operand_address, length);
}
operand_address = next_operand_address;
/* @address */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &at_address);
at_address = ( current_address + at_address) & 0xffff;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address);
}
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
used_udvm_cycles = used_udvm_cycles + 1 + length;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented");
break;
case SIGCOMP_INSTR_INPUT_BYTES: /* 28 INPUT-BYTES (%length, %destination, @address) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u ## INPUT-BYTES(28) length, destination, @address)",
current_address);
}
operand_address = current_address + 1;
/* %length */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Length %u",
operand_address, length);
}
operand_address = next_operand_address;
/* %destination */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &destination);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Destination %u",
operand_address, destination);
}
operand_address = next_operand_address;
/* @address */
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &at_address);
at_address = ( current_address + at_address) & 0xffff;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address);
}
/* execute the instruction TODO insert checks
* RFC 3320 :
*
* 0 7 8 15
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | byte_copy_left | 64 - 65
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | byte_copy_right | 66 - 67
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | input_bit_order | 68 - 69
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | stack_location | 70 - 71
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Figure 7: Memory addresses of the UDVM registers
* :
* 8.4. Byte copying
* :
* The string of bytes is copied in ascending order of memory address,
* respecting the bounds set by byte_copy_left and byte_copy_right.
* More precisely, if a byte is copied from/to Address m then the next
* byte is copied from/to Address n where n is calculated as follows:
*
* Set k := m + 1 (modulo 2^16)
* If k = byte_copy_right then set n := byte_copy_left, else set n := k
*
*/
n = 0;
k = destination;
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" byte_copy_right = %u", byte_copy_right);
}
/* clear out remaining bits if any */
remaining_bits = 0;
input_bits=0;
/* operand_address used as dummy */
while ( n < length ){
if (input_address > ( msg_end - 1)){
current_address = at_address;
result_code = 14;
goto execute_next_instruction;
}
if ( k == byte_copy_right ){
k = byte_copy_left;
}
octet = tvb_get_guint8(message_tvb, input_address);
buff[k] = octet;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" Loading value: %u (0x%x) at Addr: %u", octet, octet, k);
}
input_address++;
/*
* If the instruction requests data that lies beyond the end of the
* SigComp message, no data is returned. Instead the UDVM moves program
* execution to the address specified by the address operand.
*/
k = ( k + 1 ) & 0xffff;
n++;
}
used_udvm_cycles = used_udvm_cycles + 1 + length;
current_address = next_operand_address;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_INPUT_BITS:/* 29 INPUT-BITS (%length, %destination, @address) */
/*
* The length operand indicates the requested number of bits.
* Decompression failure occurs if this operand does not lie between 0
* and 16 inclusive.
*
* The destination operand specifies the memory address to which the
* compressed data should be copied. Note that the requested bits are
* interpreted as a 2-byte integer ranging from 0 to 2^length - 1, as
* explained in Section 8.2.
*
* If the instruction requests data that lies beyond the end of the
* SigComp message, no data is returned. Instead the UDVM moves program
* execution to the address specified by the address operand.
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## INPUT-BITS(29) (length, destination, @address)",
current_address);
}
operand_address = current_address + 1;
/* %length */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u length %u",
operand_address, length);
}
operand_address = next_operand_address;
/* %destination */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &destination);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Destination %u",
operand_address, destination);
}
operand_address = next_operand_address;
/* @address */
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
next_operand_address = decode_udvm_address_operand(buff,operand_address, &at_address, current_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address);
}
current_address = next_operand_address;
/*
* Execute actual instr.
* The input_bit_order register contains the following three flags:
*
* 0 7 8 15
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | reserved |F|H|P| 68 - 69
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
input_bit_order = buff[68] << 8;
input_bit_order = input_bit_order | buff[69];
/*
* If the instruction requests data that lies beyond the end of the
* SigComp message, no data is returned. Instead the UDVM moves program
* execution to the address specified by the address operand.
*/
if ((input_address > ( msg_end -1)) && (remaining_bits == 0 )){
result_code = 11;
current_address = at_address;
goto execute_next_instruction;
}
if ( length > 16 ){
result_code = 7;
goto decompression_failure;
}
if ( input_bit_order > 7 ){
result_code = 8;
goto decompression_failure;
}
if ( length > 0 ){
/* If lengt = 0 ignore the instruction - derived from torture test 12
* Transfer F bit to bit_order to tell decomp dispatcher which bit order to use
*/
bit_order = ( input_bit_order & 0x0004 ) >> 2;
value = decomp_dispatch_get_bits( message_tvb, udvm_tree, bit_order,
buff, &old_input_bit_order, &remaining_bits,
&input_bits, &input_address, length, &result_code, msg_end);
if ( result_code == 11 ){
current_address = at_address;
goto execute_next_instruction;
}
msb = value >> 8;
lsb = value & 0x00ff;
buff[destination] = msb;
buff[destination + 1]=lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" Loading value: %u (0x%x) at Addr: %u, remaining_bits: %u", value, value, destination, remaining_bits);
}
}
used_udvm_cycles = used_udvm_cycles + 1 + length;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_INPUT_HUFFMAN: /* 30 */
/*
* INPUT-HUFFMAN (%destination, @address, #n, %bits_1, %lower_bound_1,
* %upper_bound_1, %uncompressed_1, ... , %bits_n, %lower_bound_n,
* %upper_bound_n, %uncompressed_n)
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## INPUT-HUFFMAN (destination, @address, #n, bits_1, lower_bound_1,upper_bound_1, uncompressed_1, ... , bits_n, lower_bound_n,upper_bound_n, uncompressed_n)",
current_address);
}
operand_address = current_address + 1;
/* %destination */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &destination);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u Destination %u",
operand_address, destination);
}
operand_address = next_operand_address;
/* @address */
/* operand_value = (memory_address_of_instruction + D) modulo 2^16 */
next_operand_address = decode_udvm_address_operand(buff,operand_address, &at_address, current_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u @Address %u",
operand_address, at_address);
}
operand_address = next_operand_address;
/* #n */
next_operand_address = decode_udvm_literal_operand(buff,operand_address, &n);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u n %u",
operand_address, n);
}
operand_address = next_operand_address;
/*
* Note that if n = 0 then the INPUT-HUFFMAN instruction is ignored and
* program execution resumes at the following instruction.
* Decompression failure occurs if (bits_1 + ... + bits_n) > 16.
*
* In all other cases, the behavior of the INPUT-HUFFMAN instruction is
* defined below:
*
* 1. Set j := 1 and set H := 0.
*
* 2. Request bits_j compressed bits. Interpret the returned bits as an
* integer k from 0 to 2^bits_j - 1, as explained in Section 8.2.
*
* 3. Set H := H * 2^bits_j + k.
*
* 4. If data is requested that lies beyond the end of the SigComp
* message, terminate the INPUT-HUFFMAN instruction and move program
* execution to the memory address specified by the address operand.
*
* 5. If (H < lower_bound_j) or (H > upper_bound_j) then set j := j + 1.
* Then go back to Step 2, unless j > n in which case decompression
* failure occurs.
*
* 6. Copy (H + uncompressed_j - lower_bound_j) modulo 2^16 to the
* memory address specified by the destination operand.
*
*/
/*
* The input_bit_order register contains the following three flags:
*
* 0 7 8 15
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | reserved |F|H|P| 68 - 69
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Transfer H bit to bit_order to tell decomp dispatcher which bit order to use
*/
input_bit_order = buff[68] << 8;
input_bit_order = input_bit_order | buff[69];
bit_order = ( input_bit_order & 0x0002 ) >> 1;
j = 1;
H = 0;
m = n;
outside_huffman_boundaries = TRUE;
print_in_loop = print_level_1;
while ( m > 0 ){
/* %bits_n */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &bits_n);
if (print_in_loop ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u bits_n %u",
operand_address, bits_n);
}
operand_address = next_operand_address;
/* %lower_bound_n */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &lower_bound_n);
if (print_in_loop ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u lower_bound_n %u",
operand_address, lower_bound_n);
}
operand_address = next_operand_address;
/* %upper_bound_n */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &upper_bound_n);
if (print_in_loop ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u upper_bound_n %u",
operand_address, upper_bound_n);
}
operand_address = next_operand_address;
/* %uncompressed_n */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &uncompressed_n);
if (print_in_loop ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u uncompressed_n %u",
operand_address, uncompressed_n);
}
operand_address = next_operand_address;
/* execute instruction */
if ( outside_huffman_boundaries ) {
/*
* 3. Set H := H * 2^bits_j + k.
*/
k = decomp_dispatch_get_bits( message_tvb, udvm_tree, bit_order,
buff, &old_input_bit_order, &remaining_bits,
&input_bits, &input_address, bits_n, &result_code, msg_end);
if ( result_code == 11 ){
current_address = at_address;
goto execute_next_instruction;
}
/* ldexp Returns x multiplied by 2 raised to the power of exponent.
* x*2^exponent
*/
oldH = H;
H = ( (guint16)ldexp( H, bits_n) + k );
if (print_level_3 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," Set H(%u) := H(%u) * 2^bits_j(%u) + k(%u)",
H ,oldH,((guint16)pow(2,bits_n)),k);
}
/*
* 4. If data is requested that lies beyond the end of the SigComp
* message, terminate the INPUT-HUFFMAN instruction and move program
* execution to the memory address specified by the address operand.
*/
if ( input_address > msg_end ){
current_address = at_address;
goto execute_next_instruction;
}
/*
* 5. If (H < lower_bound_j) or (H > upper_bound_j) then set j := j + 1.
* Then go back to Step 2, unless j > n in which case decompression
* failure occurs.
*/
if ((H < lower_bound_n) || (H > upper_bound_n)){
outside_huffman_boundaries = TRUE;
}else{
outside_huffman_boundaries = FALSE;
print_in_loop = FALSE;
/*
* 6. Copy (H + uncompressed_j - lower_bound_j) modulo 2^16 to the
* memory address specified by the destination operand.
*/
if (print_level_2 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
" H(%u) = H(%u) + uncompressed_n(%u) - lower_bound_n(%u)",
(H + uncompressed_n - lower_bound_n ),H, uncompressed_n, lower_bound_n);
}
H = H + uncompressed_n - lower_bound_n;
msb = H >> 8;
lsb = H & 0x00ff;
buff[destination] = msb;
buff[destination + 1]=lsb;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" Loading H: %u (0x%x) at Addr: %u,j = %u remaining_bits: %u",
H, H, destination,( n - m + 1 ), remaining_bits);
}
}
}
m = m - 1;
}
if ( outside_huffman_boundaries ) {
result_code = 10;
goto decompression_failure;
}
current_address = next_operand_address;
used_udvm_cycles = used_udvm_cycles + 1 + n;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_STATE_ACCESS: /* 31 */
/* STATE-ACCESS (%partial_identifier_start, %partial_identifier_length,
* %state_begin, %state_length, %state_address, %state_instruction)
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## STATE-ACCESS(31) (partial_identifier_start, partial_identifier_length,state_begin, state_length, state_address, state_instruction)",
current_address);
}
operand_address = current_address + 1;
/*
* %partial_identifier_start
*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &p_id_start);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u partial_identifier_start %u",
operand_address, p_id_start);
}
operand_address = next_operand_address;
/*
* %partial_identifier_length
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &p_id_length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u partial_identifier_length %u",
operand_address, p_id_length);
}
/*
* %state_begin
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_begin);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_begin %u",
operand_address, state_begin);
}
/*
* %state_length
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_length); if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_length %u",
operand_address, state_length);
}
/*
* %state_address
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_address %u",
operand_address, state_address);
}
/*
* %state_instruction
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_instruction);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_instruction %u",
operand_address, state_instruction);
}
current_address = next_operand_address;
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
if (print_level_2 ){
proto_tree_add_text(udvm_tree, message_tvb, input_address, 1,
" byte_copy_right = %u, byte_copy_left = %u", byte_copy_right,byte_copy_left);
}
result_code = udvm_state_access(message_tvb, udvm_tree, buff, p_id_start, p_id_length, state_begin, &state_length,
&state_address, state_instruction, TRUE, hf_id);
if ( result_code != 0 ){
goto decompression_failure;
}
used_udvm_cycles = used_udvm_cycles + 1 + state_length;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_STATE_CREATE: /* 32 */
/*
* STATE-CREATE (%state_length, %state_address, %state_instruction,
* %minimum_access_length, %state_retention_priority)
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## STATE-CREATE(32) (state_length, state_address, state_instruction,minimum_access_length, state_retention_priority)",
current_address);
}
operand_address = current_address + 1;
/*
* %state_length
*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_length %u",
operand_address, state_length);
}
/*
* %state_address
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_address %u",
operand_address, state_address);
}
/*
* %state_instruction
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_instruction);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_instruction %u",
operand_address, state_instruction);
}
operand_address = next_operand_address;
/*
* %minimum_access_length
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &minimum_access_length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u minimum_access_length %u",
operand_address, minimum_access_length);
}
operand_address = next_operand_address;
/*
* %state_retention_priority
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_retention_priority);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_retention_priority %u",
operand_address, state_retention_priority);
}
current_address = next_operand_address;
/* Execute the instruction
* TODO Implement the instruction
* RFC3320:
* Note that the new state item cannot be created until a valid
* compartment identifier has been returned by the application.
* Consequently, when a STATE-CREATE instruction is encountered the UDVM
* simply buffers the five supplied operands until the END-MESSAGE
* instruction is reached. The steps taken at this point are described
* in Section 9.4.9.
*
* Decompression failure MUST occur if more than four state creation
* requests are made before the END-MESSAGE instruction is encountered.
* Decompression failure also occurs if the minimum_access_length does
* not lie between 6 and 20 inclusive, or if the
* state_retention_priority is 65535.
*/
no_of_state_create++;
if ( no_of_state_create > 4 ){
result_code = 12;
goto decompression_failure;
}
if (( minimum_access_length < 6 ) || ( minimum_access_length > 20 )){
result_code = 1;
goto decompression_failure;
}
if ( state_retention_priority == 65535 ){
result_code = 13;
goto decompression_failure;
}
state_length_buff[no_of_state_create] = state_length;
state_address_buff[no_of_state_create] = state_address;
state_instruction_buff[no_of_state_create] = state_instruction;
state_minimum_access_length_buff[no_of_state_create] = minimum_access_length;
state_state_retention_priority_buff[no_of_state_create] = state_retention_priority;
used_udvm_cycles = used_udvm_cycles + 1 + state_length;
/* Debug */
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
n = 0;
k = state_address;
while ( n < state_length ){
if ( k == byte_copy_right ){
k = byte_copy_left;
}
string[0]= buff[k];
string[1]= '\0';
if (print_level_3 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
" Addr: %5u State value: %u (0x%x) ASCII(%s)",
k,buff[k],buff[k],string);
}
k = ( k + 1 ) & 0xffff;
n++;
}
/* End debug */
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_STATE_FREE: /* 33 */
/*
* STATE-FREE (%partial_identifier_start, %partial_identifier_length)
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## STATE-FREE (partial_identifier_start, partial_identifier_length)",
current_address);
}
operand_address = current_address + 1;
/*
* %partial_identifier_start
*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &p_id_start);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u partial_identifier_start %u",
operand_address, p_id_start);
}
operand_address = next_operand_address;
/*
* %partial_identifier_length
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &p_id_length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u partial_identifier_length %u",
operand_address, p_id_length);
}
current_address = next_operand_address;
/* Execute the instruction:
* TODO implement it
*/
udvm_state_free(buff,p_id_start,p_id_length);
used_udvm_cycles++;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_OUTPUT: /* 34 OUTPUT (%output_start, %output_length) */
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## OUTPUT(34) (output_start, output_length)",
current_address);
}
operand_address = current_address + 1;
/*
* %output_start
*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &output_start);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u output_start %u",
operand_address, output_start);
}
operand_address = next_operand_address;
/*
* %output_length
*/
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &output_length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u output_length %u",
operand_address, output_length);
}
current_address = next_operand_address;
/*
* Execute instruction
* 8.4. Byte copying
* :
* The string of bytes is copied in ascending order of memory address,
* respecting the bounds set by byte_copy_left and byte_copy_right.
* More precisely, if a byte is copied from/to Address m then the next
* byte is copied from/to Address n where n is calculated as follows:
*
* Set k := m + 1 (modulo 2^16)
* If k = byte_copy_right then set n := byte_copy_left, else set n := k
*
*/
n = 0;
k = output_start;
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
if (print_level_3 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
" byte_copy_right = %u", byte_copy_right);
}
while ( n < output_length ){
if ( k == byte_copy_right ){
k = byte_copy_left;
}
out_buff[output_address] = buff[k];
string[0]= buff[k];
string[1]= '\0';
strp = string;
if (print_level_3 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
" Output value: %u (0x%x) ASCII(%s) from Addr: %u ,output to dispatcher position %u",
buff[k],buff[k],format_text(strp,1), k,output_address);
}
k = ( k + 1 ) & 0xffff;
output_address ++;
n++;
}
used_udvm_cycles = used_udvm_cycles + 1 + output_length;
goto execute_next_instruction;
break;
case SIGCOMP_INSTR_END_MESSAGE: /* 35 */
/*
* END-MESSAGE (%requested_feedback_location,
* %returned_parameters_location, %state_length, %state_address,
* %state_instruction, %minimum_access_length,
* %state_retention_priority)
*/
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,
"Addr: %u ## END-MESSAGE (requested_feedback_location,state_instruction, minimum_access_length,state_retention_priority)",
current_address);
}
operand_address = current_address + 1;
/* %requested_feedback_location */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &requested_feedback_location);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u requested_feedback_location %u",
operand_address, requested_feedback_location);
}
operand_address = next_operand_address;
/* returned_parameters_location */
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &returned_parameters_location);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u returned_parameters_location %u",
operand_address, returned_parameters_location);
}
operand_address = next_operand_address;
/*
* %state_length
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_length %u",
operand_address, state_length);
}
/*
* %state_address
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_address %u",
operand_address, state_address);
}
/*
* %state_instruction
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_instruction);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_instruction %u",
operand_address, state_instruction);
}
operand_address = next_operand_address;
/*
* %minimum_access_length
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &minimum_access_length);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u minimum_access_length %u",
operand_address, minimum_access_length);
}
operand_address = next_operand_address;
/*
* %state_retention_priority
*/
operand_address = next_operand_address;
next_operand_address = decode_udvm_multitype_operand(buff, operand_address, &state_retention_priority);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Addr: %u state_retention_priority %u",
operand_address, state_retention_priority);
}
current_address = next_operand_address;
/* TODO: This isn't currently totaly correct as END_INSTRUCTION might not create state */
no_of_state_create++;
if ( no_of_state_create > 4 ){
result_code = 12;
goto decompression_failure;
}
state_length_buff[no_of_state_create] = state_length;
state_address_buff[no_of_state_create] = state_address;
state_instruction_buff[no_of_state_create] = state_instruction;
/* Not used ? */
state_minimum_access_length_buff[no_of_state_create] = minimum_access_length;
state_state_retention_priority_buff[no_of_state_create] = state_retention_priority;
/* Execute the instruction
*/
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"no_of_state_create %u",no_of_state_create);
if ( no_of_state_create != 0 ){
for( x=0; x < 20; x++){
sha1_digest_buf[x]=0;
}
n = 1;
byte_copy_right = buff[66] << 8;
byte_copy_right = byte_copy_right | buff[67];
byte_copy_left = buff[64] << 8;
byte_copy_left = byte_copy_left | buff[65];
while ( n < no_of_state_create + 1 ){
sha1buff = g_malloc(state_length_buff[n]+8);
sha1buff[0] = state_length_buff[n] >> 8;
sha1buff[1] = state_length_buff[n] & 0xff;
sha1buff[2] = state_address_buff[n] >> 8;
sha1buff[3] = state_address_buff[n] & 0xff;
sha1buff[4] = state_instruction_buff[n] >> 8;
sha1buff[5] = state_instruction_buff[n] & 0xff;
sha1buff[6] = state_minimum_access_length_buff[n] >> 8;
sha1buff[7] = state_minimum_access_length_buff[n] & 0xff;
if (print_level_3 ){
for( x=0; x < 8; x++){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"sha1buff %u 0x%x",
x,sha1buff[x]);
}
}
k = state_address_buff[n];
for( x=0; x < state_length_buff[n]; x++)
{
if ( k == byte_copy_right ){
k = byte_copy_left;
}
sha1buff[8+x] = buff[k];
k = ( k + 1 ) & 0xffff;
}
sha1_starts( &ctx );
sha1_update( &ctx, (guint8 *) sha1buff, state_length_buff[n] + 8);
sha1_finish( &ctx, sha1_digest_buf );
if (print_level_3 ){
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"SHA1 digest %s",bytes_to_str(sha1_digest_buf, 20));
}
udvm_state_create(sha1buff, sha1_digest_buf, state_minimum_access_length_buff[n]);
proto_tree_add_text(udvm_tree,bytecode_tvb, 0, -1,"### Creating state ###");
proto_tree_add_string(udvm_tree,hf_id, bytecode_tvb, 0, 0, bytes_to_str(sha1_digest_buf, state_minimum_access_length_buff[n]));
n++;
}
}
/* At least something got decompressed, show it */
decomp_tvb = tvb_new_real_data(out_buff,output_address,output_address);
/* Arrange that the allocated packet data copy be freed when the
* tvbuff is freed.
*/
tvb_set_free_cb( decomp_tvb, g_free );
tvb_set_child_real_data_tvbuff(message_tvb,decomp_tvb);
add_new_data_source(pinfo, decomp_tvb, "Decompressed SigComp message");
/*
proto_tree_add_text(udvm_tree, decomp_tvb, 0, -1,"SigComp message Decompressed");
*/
used_udvm_cycles = used_udvm_cycles + 1 + state_length;
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"maximum_UDVM_cycles %u used_udvm_cycles %u",
maximum_UDVM_cycles, used_udvm_cycles);
return decomp_tvb;
break;
default:
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1," ### Addr %u Invalid instruction: %u (0x%x)",
current_address,current_instruction,current_instruction);
break;
}
g_free(out_buff);
return NULL;
decompression_failure:
proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"DECOMPRESSION FAILURE: %s",
val_to_str(result_code, result_code_vals,"Unknown (%u)"));
g_free(out_buff);
return NULL;
}
/* The simplest operand type is the literal (#), which encodes a
* constant integer from 0 to 65535 inclusive. A literal operand may
* require between 1 and 3 bytes depending on its value.
* Bytecode: Operand value: Range:
* 0nnnnnnn N 0 - 127
* 10nnnnnn nnnnnnnn N 0 - 16383
* 11000000 nnnnnnnn nnnnnnnn N 0 - 65535
*
* Figure 8: Bytecode for a literal (#) operand
*
*/
static int
decode_udvm_literal_operand(guint8 *buff,guint operand_address, guint16 *value)
{
guint bytecode;
guint16 operand;
guint test_bits;
guint offset = operand_address;
guint8 temp_data;
bytecode = buff[operand_address];
test_bits = bytecode >> 7;
if (test_bits == 1){
test_bits = bytecode >> 6;
if (test_bits == 2){
/*
* 10nnnnnn nnnnnnnn N 0 - 16383
*/
temp_data = buff[operand_address] & 0x1f;
operand = temp_data << 8;
temp_data = buff[operand_address + 1];
operand = operand | temp_data;
*value = operand;
offset = offset + 2;
}else{
/*
* 111000000 nnnnnnnn nnnnnnnn N 0 - 65535
*/
offset ++;
temp_data = buff[operand_address] & 0x1f;
operand = temp_data << 8;
temp_data = buff[operand_address + 1];
operand = operand | temp_data;
*value = operand;
offset = offset + 2;
}
}else{
/*
* 0nnnnnnn N 0 - 127
*/
operand = ( bytecode & 0x7f);
*value = operand;
offset ++;
}
return offset;
}
/*
* The second operand type is the reference ($), which is always used to
* access a 2-byte value located elsewhere in the UDVM memory. The
* bytecode for a reference operand is decoded to be a constant integer
* from 0 to 65535 inclusive, which is interpreted as the memory address
* containing the actual value of the operand.
* Bytecode: Operand value: Range:
*
* 0nnnnnnn memory[2 * N] 0 - 65535
* 10nnnnnn nnnnnnnn memory[2 * N] 0 - 65535
* 11000000 nnnnnnnn nnnnnnnn memory[N] 0 - 65535
*
* Figure 9: Bytecode for a reference ($) operand
*/
static int
dissect_udvm_reference_operand(guint8 *buff,guint operand_address, guint16 *value,guint *result_dest)
{
guint bytecode;
guint16 operand;
guint offset = operand_address;
guint test_bits;
guint8 temp_data;
guint16 temp_data16;
bytecode = buff[operand_address];
test_bits = bytecode >> 7;
if (test_bits == 1){
test_bits = bytecode >> 6;
if (test_bits == 2){
/*
* 10nnnnnn nnnnnnnn memory[2 * N] 0 - 65535
*/
temp_data = buff[operand_address] & 0x3f;
operand = temp_data << 8;
temp_data = buff[operand_address + 1];
operand = operand | temp_data;
operand = (operand * 2);
*result_dest = operand;
temp_data16 = buff[operand] << 8;
temp_data16 = temp_data16 | buff[operand+1];
*value = temp_data16;
offset = offset + 2;
}else{
/*
* 11000000 nnnnnnnn nnnnnnnn memory[N] 0 - 65535
*/
operand_address++;
operand = buff[operand_address] << 8;
operand = operand | buff[operand_address + 1];
*result_dest = operand;
temp_data16 = buff[operand] << 8;
temp_data16 = temp_data16 | buff[operand+1];
*value = temp_data16;
offset = offset + 3;
}
}else{
/*
* 0nnnnnnn memory[2 * N] 0 - 65535
*/
operand = ( bytecode & 0x7f);
operand = (operand * 2);
*result_dest = operand;
temp_data16 = buff[operand] << 8;
temp_data16 = temp_data16 | buff[operand+1];
*value = temp_data16;
offset ++;
}
return offset;
}
/* RFC3320
* Figure 10: Bytecode for a multitype (%) operand
* Bytecode: Operand value: Range: HEX val
* 00nnnnnn N 0 - 63 0x00
* 01nnnnnn memory[2 * N] 0 - 65535 0x40
* 1000011n 2 ^ (N + 6) 64 , 128 0x86
* 10001nnn 2 ^ (N + 8) 256 , ... , 32768 0x88
* 111nnnnn N + 65504 65504 - 65535 0xe0
* 1001nnnn nnnnnnnn N + 61440 61440 - 65535 0x90
* 101nnnnn nnnnnnnn N 0 - 8191 0xa0
* 110nnnnn nnnnnnnn memory[N] 0 - 65535 0xc0
* 10000000 nnnnnnnn nnnnnnnn N 0 - 65535 0x80
* 10000001 nnnnnnnn nnnnnnnn memory[N] 0 - 65535 0x81
*/
static int
decode_udvm_multitype_operand(guint8 *buff,guint operand_address, guint16 *value)
{
guint test_bits;
guint bytecode;
guint offset = operand_address;
guint16 operand;
guint32 result;
guint8 temp_data;
guint16 temp_data16;
guint16 memmory_addr = 0;
bytecode = buff[operand_address];
test_bits = ( bytecode & 0xc0 ) >> 6;
switch (test_bits ){
case 0:
/*
* 00nnnnnn N 0 - 63
*/
operand = buff[operand_address];
/* debug
*g_warning("Reading 0x%x From address %u",operand,offset);
*/
*value = operand;
offset ++;
break;
case 1:
/*
* 01nnnnnn memory[2 * N] 0 - 65535
*/
memmory_addr = ( bytecode & 0x3f) * 2;
temp_data16 = buff[memmory_addr] << 8;
temp_data16 = temp_data16 | buff[memmory_addr+1];
*value = temp_data16;
offset ++;
break;
case 2:
/* Check tree most significant bits */
test_bits = ( bytecode & 0xe0 ) >> 5;
if ( test_bits == 5 ){
/*
* 101nnnnn nnnnnnnn N 0 - 8191
*/
temp_data = buff[operand_address] & 0x1f;
operand = temp_data << 8;
temp_data = buff[operand_address + 1];
operand = operand | temp_data;
*value = operand;
offset = offset + 2;
}else{
test_bits = ( bytecode & 0xf0 ) >> 4;
if ( test_bits == 9 ){
/*
* 1001nnnn nnnnnnnn N + 61440 61440 - 65535
*/
temp_data = buff[operand_address] & 0x0f;
operand = temp_data << 8;
temp_data = buff[operand_address + 1];
operand = operand | temp_data;
operand = operand + 61440;
*value = operand;
offset = offset + 2;
}else{
test_bits = ( bytecode & 0x08 ) >> 3;
if ( test_bits == 1){
/*
* 10001nnn 2 ^ (N + 8) 256 , ... , 32768
*/
result = (guint32)pow(2,( buff[operand_address] & 0x07) + 8);
operand = result & 0xffff;
*value = operand;
offset ++;
}else{
test_bits = ( bytecode & 0x0e ) >> 1;
if ( test_bits == 3 ){
/*
* 1000 011n 2 ^ (N + 6) 64 , 128
*/
result = (guint32)pow(2,( buff[operand_address] & 0x01) + 6);
operand = result & 0xffff;
*value = operand;
offset ++;
}else{
/*
* 1000 0000 nnnnnnnn nnnnnnnn N 0 - 65535
* 1000 0001 nnnnnnnn nnnnnnnn memory[N] 0 - 65535
*/
offset ++;
temp_data16 = buff[operand_address + 1] << 8;
temp_data16 = temp_data16 | buff[operand_address + 2];
/* debug
* g_warning("Reading 0x%x From address %u",temp_data16,operand_address);
*/
if ( (bytecode & 0x01) == 1 ){
memmory_addr = temp_data16;
temp_data16 = buff[memmory_addr] << 8;
temp_data16 = temp_data16 | buff[memmory_addr+1];
}
*value = temp_data16;
offset = offset +2;
}
}
}
}
break;
case 3:
test_bits = ( bytecode & 0x20 ) >> 5;
if ( test_bits == 1 ){
/*
* 111nnnnn N + 65504 65504 - 65535
*/
operand = ( buff[operand_address] & 0x1f) + 65504;
*value = operand;
offset ++;
}else{
/*
* 110nnnnn nnnnnnnn memory[N] 0 - 65535
*/
memmory_addr = buff[operand_address] & 0x1f;
memmory_addr = memmory_addr << 8;
memmory_addr = memmory_addr | buff[operand_address + 1];
temp_data16 = buff[memmory_addr] << 8;
temp_data16 = temp_data16 | buff[memmory_addr+1];
*value = temp_data16;
/* debug
* g_warning("Reading 0x%x From address %u",temp_data16,memmory_addr);
*/
offset = offset +2;
}
default :
break;
}
return offset;
}
/*
*
* The fourth operand type is the address (@). This operand is decoded
* as a multitype operand followed by a further step: the memory address
* of the UDVM instruction containing the address operand is added to
* obtain the correct operand value. So if the operand value from
* Figure 10 is D then the actual operand value of an address is
* calculated as follows:
*
* operand_value = (memory_address_of_instruction + D) modulo 2^16
*
* Address operands are always used in instructions that control program
* flow, because they ensure that the UDVM bytecode is position-
* independent code (i.e., it will run independently of where it is
* placed in the UDVM memory).
*/
static int
decode_udvm_address_operand(guint8 *buff,guint operand_address, guint16 *value,guint current_address)
{
guint32 result;
guint16 value1;
guint next_opreand_address;
next_opreand_address = decode_udvm_multitype_operand(buff, operand_address, &value1);
result = value1 & 0xffff;
result = result + current_address;
*value = result & 0xffff;
return next_opreand_address;
}
static int
decomp_dispatch_get_bits(tvbuff_t *message_tvb,proto_tree *udvm_tree,guint8 bit_order,
guint8 *buff,guint16 *old_input_bit_order, guint16 *remaining_bits,
guint16 *input_bits, guint *input_address, guint16 length,
guint16 *result_code,guint msg_end){
guint16 input_bit_order;
guint16 value;
guint16 mask;
guint8 octet;
guint8 n;
guint8 i;
input_bit_order = buff[68] << 8;
input_bit_order = input_bit_order | buff[69];
*result_code = 0;
/*
* Note that after one or more INPUT instructions the dispatcher may
* hold a fraction of a byte (what used to be the LSBs if P = 0, or, the
* MSBs, if P = 1). If an INPUT instruction is encountered and the P-
* bit has changed since the last INPUT instruction, any fraction of a
* byte still held by the dispatcher MUST be discarded (even if the
* INPUT instruction requests zero bits). The first bit passed to the
* INPUT instruction is taken from the subsequent byte.
*/
if (print_level_1 ){
if ( *input_address > ( msg_end - 1)){
proto_tree_add_text(udvm_tree, message_tvb, (msg_end - 1), 1,
" input_bit_order = 0x%x, old_input_bit_order = 0x%x MSG BUFFER END", input_bit_order, *old_input_bit_order);
}else{
proto_tree_add_text(udvm_tree, message_tvb, *input_address, 1,
" input_bit_order = 0x%x, old_input_bit_order = 0x%x", input_bit_order,*old_input_bit_order);
}
}
if ( (*old_input_bit_order & 0x0001 ) != ( input_bit_order & 0x0001 )){
/* clear out remaining bits TODO check this further */
*remaining_bits = 0;
*old_input_bit_order = input_bit_order;
}
/*
* Do we hold a fraction of a byte ?
*/
if ( *remaining_bits != 0 ){
if ( *remaining_bits < length ){
if (*remaining_bits > 8 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address, 1,
" Yikes!! haven't coded this case yet!!remaining_bits %u > 8 ", *remaining_bits);
return 0xfbad;
}
if ( *input_address > ( msg_end -1 ) ){
*result_code = 11;
return 0xfbad;
}
octet = tvb_get_guint8(message_tvb, *input_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address , 1,
" Geting value: %u (0x%x) From Addr: %u", octet, octet, *input_address);
}
*input_address = *input_address + 1;
if ((input_bit_order & 0x0001)==0){
/*
* P bit = 0
*/
/* borrow value */
value = octet & 0x00ff;
value = value << ( 8 - (*remaining_bits));
*remaining_bits = *remaining_bits + 8;
}else{
/*
* P bit = 1
*/
/* borrow value */
value = ( octet << 7) & 0x80;
value = value | (( octet << 5) & 0x40 );
value = value | (( octet << 3) & 0x20 );
value = value | (( octet << 1) & 0x10 );
value = value | (( octet >> 1) & 0x08 );
value = value | (( octet >> 3) & 0x04 );
value = value | (( octet >> 5) & 0x02 );
value = value | (( octet >> 7) & 0x01 );
value = value << ( 8 - (*remaining_bits));
*remaining_bits = *remaining_bits + 8;
}
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address - 1 , 1,
" Or value 0x%x with 0x%x remaining bits %u, Result 0x%x",
value, *input_bits, *remaining_bits, (*input_bits | value));
}
*input_bits = *input_bits | value;
}/* Bits remain */
if ( ( bit_order ) == 0 ){
/*
* F/H bit = 0
*/
mask = (0xffff >> length)^0xffff;
value = *input_bits & mask;
value = value >> ( 16 - length);
*input_bits = *input_bits << length;
*remaining_bits = *remaining_bits - length;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address, 1,
" Remaining input_bits 0x%x remaining_bits %u", *input_bits, *remaining_bits);
}
return value;
}
else{
/*
* F/H bit = 1
*/
n = 15;
i = 0;
value = 0;
while ( i < length ){
value = value | (( *input_bits & 0x8000 ) >> n) ;
*input_bits = *input_bits << 1;
n--;
i++;
}
*remaining_bits = *remaining_bits - length;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address, 1,
" Remaining input_bits 0x%x", *input_bits);
}
return value;
}
}
else
{
/*
* Do we need one or two bytes ?
*/
if ( *input_address > ( msg_end -1 ) ){
*result_code = 11;
return 0xfbad;
}
if ( length < 9 ){
octet = tvb_get_guint8(message_tvb, *input_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address , 1,
" Geting value: %u (0x%x) From Addr: %u", octet, octet, *input_address);
}
*input_address = *input_address + 1;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address , 1,
" Next input from Addr: %u", *input_address);
}
if ( ( input_bit_order & 0x0001 ) == 0 ){
/*
* P bit = Zero
*/
*input_bits = octet & 0xff;
*input_bits = *input_bits << 8;
*remaining_bits = 8;
}else{
/*
* P bit = One
*/
*input_bits = ( octet << 7) & 0x80;
*input_bits = *input_bits | (( octet << 5) & 0x40 );
*input_bits = *input_bits | (( octet << 3) & 0x20 );
*input_bits = *input_bits | (( octet << 1) & 0x10 );
*input_bits = *input_bits | (( octet >> 1) & 0x08 );
*input_bits = *input_bits | (( octet >> 3) & 0x04 );
*input_bits = *input_bits | (( octet >> 5) & 0x02 );
*input_bits = *input_bits | (( octet >> 7) & 0x01 );
*input_bits = *input_bits << 8;
*remaining_bits = 8;
proto_tree_add_text(udvm_tree, message_tvb, *input_address -1, 1,
" P bit = 1, input_bits = 0x%x",*input_bits);
}
}
else{
/* Length > 9, we need two bytes */
octet = tvb_get_guint8(message_tvb, *input_address);
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address, 1,
" Geting first value: %u (0x%x) From Addr: %u", octet, octet, *input_address);
}
if ( ( input_bit_order & 0x0001 ) == 0 ){
*input_bits = octet & 0xff;
*input_bits = *input_bits << 8;
*input_address = *input_address + 1;
}else{
/*
* P bit = One
*/
*input_bits = ( octet << 7) & 0x80;
*input_bits = *input_bits | (( octet << 5) & 0x40 );
*input_bits = *input_bits | (( octet << 3) & 0x20 );
*input_bits = *input_bits | (( octet << 1) & 0x10 );
*input_bits = *input_bits | (( octet >> 1) & 0x08 );
*input_bits = *input_bits | (( octet >> 3) & 0x04 );
*input_bits = *input_bits | (( octet >> 5) & 0x02 );
*input_bits = *input_bits | (( octet >> 7) & 0x01 );
*input_bits = *input_bits << 8;
*input_address = *input_address + 1;
proto_tree_add_text(udvm_tree, message_tvb, *input_address -1, 1,
" P bit = 1, input_bits = 0x%x",*input_bits);
}
if ( *input_address > ( msg_end - 1)){
*result_code = 11;
return 0xfbad;
}
octet = tvb_get_guint8(message_tvb, *input_address);
*input_address = *input_address + 1;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address - 2, 2,
" Geting second value: %u (0x%x) From Addr: %u", octet, octet, *input_address);
}
if ( ( input_bit_order & 0x0001 ) == 0 ){
/*
* P bit = zero
*/
*input_bits = *input_bits | octet;
*remaining_bits = 16;
}else{
/*
* P bit = One
*/
*input_bits = ( octet << 7) & 0x80;
*input_bits = *input_bits | (( octet << 5) & 0x40 );
*input_bits = *input_bits | (( octet << 3) & 0x20 );
*input_bits = *input_bits | (( octet << 1) & 0x10 );
*input_bits = *input_bits | (( octet >> 1) & 0x08 );
*input_bits = *input_bits | (( octet >> 3) & 0x04 );
*input_bits = *input_bits | (( octet >> 5) & 0x02 );
*input_bits = *input_bits | (( octet >> 7) & 0x01 );
*input_bits = *input_bits << 8;
*input_address = *input_address + 1;
proto_tree_add_text(udvm_tree, message_tvb, *input_address -1, 1,
" P bit = 1, input_bits = 0x%x",*input_bits);
*remaining_bits = 16;
}
}
if ( ( bit_order ) == 0 ){
/*
* F/H bit = 0
*/
mask = (0xffff >> length)^0xffff;
value = *input_bits & mask;
value = value >> ( 16 - length);
*input_bits = *input_bits << length;
*remaining_bits = *remaining_bits - length;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address, 1,
" Remaining input_bits 0x%x", *input_bits);
}
return value;
}
else{
/*
* F/H bit = 1
*/
n = 15;
i = 0;
value = 0;
while ( i < length ){
value = value | ( *input_bits & 0x8000 ) >> n ;
*input_bits = *input_bits << 1;
n--;
i++;
}
*remaining_bits = *remaining_bits - length;
if (print_level_1 ){
proto_tree_add_text(udvm_tree, message_tvb, *input_address, 1,
" Remaining input_bits 0x%x", *input_bits);
}
return value;
}
}
}
/* end udvm */
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