diff options
Diffstat (limited to 'epan/sigcomp-udvm.c')
| -rw-r--r-- | epan/sigcomp-udvm.c | 2946 |
1 files changed, 2946 insertions, 0 deletions
diff --git a/epan/sigcomp-udvm.c b/epan/sigcomp-udvm.c new file mode 100644 index 0000000000..caa0a84c9c --- /dev/null +++ b/epan/sigcomp-udvm.c @@ -0,0 +1,2946 @@ +/* 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: udvm.c 11445 2004-07-20 19:04:48Z etxrab $ + * + * 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 "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 + +#define UDVM_MEMORY_SIZE 65536 + +static gboolean print_level_1; +static gboolean print_level_2; +static gboolean print_level_3; + +/* Internal result code values of decompression failures */ +static 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) +{ + tvbuff_t *decomp_tvb; + guint8 buff[UDVM_MEMORY_SIZE]; + char string[2]; + guint8 out_buff[65536]; /* 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; + guint16 cycles_per_bit; + guint16 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); + + /* Load bytecode into UDVM starting at "udvm_mem_dest" */ + i = udvm_mem_dest; + while ( code_length > offset ) { + buff[i] = tvb_get_guint8(bytecode_tvb, offset); + i++; + offset++; + + } + 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; + /* 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; + if (print_level_1 ){ + 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); + 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; + } + + 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 + 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]; + 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 (print_level_1 ){ + proto_tree_add_text(udvm_tree, message_tvb, input_address, 1, + " byte_copy_right = %u", byte_copy_right); + } + if ( k == byte_copy_right ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + 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]; + while ( n < length ){ + + if (print_level_1 ){ + proto_tree_add_text(udvm_tree, message_tvb, input_address, 1, + " byte_copy_right = %u", byte_copy_right); + } + if ( k == byte_copy_right ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + 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]; + while ( n < length ){ + if ( k == byte_copy_right ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + k = byte_copy_left; + 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); + } + } + if ( position == byte_copy_right ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + position = byte_copy_left; + 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); + } + } + 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]; + while ( n < length ){ + if ( k == byte_copy_right ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + k = byte_copy_left; + 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); + } + } + 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]; + /* 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 (print_level_1 ){ + proto_tree_add_text(udvm_tree, message_tvb, input_address, 1, + " byte_copy_right = %u", byte_copy_right); + } + if ( k == byte_copy_right ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + 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; + } + /* 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 + */ + 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(buff, p_id_start, p_id_length, state_begin, state_length, + state_address, state_instruction); + 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]; + n = 0; + k = state_address; + while ( n < state_length ){ + if ( k == byte_copy_right ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + 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); + } + /* Execute the instruction: + * TODO implement it + */ + used_udvm_cycles++; + proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT implemented"); + 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]; + 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 ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + k = byte_copy_left; + if (print_level_3 ){ + proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1, + " byte_copy_right = %u", byte_copy_right); + } + } + out_buff[output_address] = buff[k]; + string[0]= buff[k]; + string[1]= '\0'; + 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],string, 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; + proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"Execution of this instruction is NOT FULLY implemented( STATES NOT SAVED)"); + /* 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 + * TODO Implement 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]; + 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 ){ + byte_copy_left = buff[64] << 8; + byte_copy_left = byte_copy_left | buff[65]; + 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 ){ + for( x=0; x < 20; x++){ + proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"SHA1 digest byte %u 0x%x", + x,sha1_digest_buf[x]); + } + } + udvm_state_create(sha1buff, sha1_digest_buf); + n++; + + } + } + + + + /* At least something got decompressed, show it */ + decomp_tvb = tvb_new_real_data(out_buff,output_address,output_address); + 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: + break; + } + return NULL; +decompression_failure: + + if (print_level_1 ){ + proto_tree_add_text(udvm_tree, bytecode_tvb, 0, -1,"DECOMPRESSION FAILURE: %s", + val_to_str(result_code, result_code_vals,"Unknown (%u)")); + } + 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, length); + 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 ( ( bit_order ) == 0 ){ + /* + * F/H bit = 0 + */ + /* borrow value */ + value = octet & 0x00ff; + value = value << ( 8 - (*remaining_bits)); + *remaining_bits = *remaining_bits + 8; + }else{ + /* + * F/H 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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