/* packet-csn1.c * Routines for CSN1 dissection in wireshark. * By Vincent Helfre, based on original code by Jari Sassi * with the gracious authorization of STE * Copyright (c) 2011 ST-Ericsson * * $Id$ * * Wireshark - Network traffic analyzer * By Gerald Combs * 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. */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #include #include #include "packet-csn1.h" #define pvDATA(_pv, _offset) ((void*) ((unsigned char*)_pv + _offset)) #define pui8DATA(_pv, _offset) ((guint8*) pvDATA(_pv, _offset)) #define pui16DATA(_pv, _offset) ((guint16*) pvDATA(_pv, _offset)) #define pui32DATA(_pv, _offset) ((guint32*) pvDATA(_pv, _offset)) /* used to tag existence of next element in variable length lists */ #define STANDARD_TAG 1 #define REVERSED_TAG 0 static const unsigned char ixBitsTab[] = {0, 1, 1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5}; /* Returns no_of_bits (up to 8) masked with 0x2B */ static guint8 tvb_get_masked_bits8(tvbuff_t *tvb, gint bit_offset, const gint no_of_bits) { static const guint8 maskBits[] = {0x00, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF}; gint byte_offset = bit_offset >> 3; /* divide by 8 */ gint relative_bit_offset = bit_offset & 0x07; /* modulo 8 */ guint8 result; gint bit_shift = 8 - relative_bit_offset - (gint) no_of_bits; if (bit_shift >= 0) { result = (0x2B ^ tvb_get_guint8(tvb, byte_offset)) >> bit_shift; result &= maskBits[no_of_bits]; } else { guint8 hight_part = (0x2B ^ tvb_get_guint8(tvb, byte_offset)) & maskBits[8 - relative_bit_offset]; hight_part = (guint8) (hight_part << (-bit_shift)); result = (0x2B ^ tvb_get_guint8(tvb, byte_offset+1)) >> (8 + bit_shift); result |= hight_part; } return result; } /** * ================================================================================================ * set initial/start values in help data structure used for packing/unpacking operation * ================================================================================================ */ void csnStreamInit(csnStream_t* ar, gint bit_offset, gint remaining_bits_len) { ar->remaining_bits_len = remaining_bits_len; ar->bit_offset = bit_offset; } static const char* ErrCodes[] = { "General 0", "General -1", "DATA_NOT VALID", "IN SCRIPT", "INVALID UNION INDEX", "NEED_MORE BITS TO UNPACK", "ILLEGAL BIT VALUE", "Internal", "STREAM_NOT_SUPPORTED", "MESSAGE_TOO_LONG" }; static gint16 ProcessError(proto_tree *tree, tvbuff_t *tvb, gint bit_offset, unsigned char* sz, gint16 err, const CSN_DESCR* pDescr) { gint16 i = MIN(-err, ((gint16) ElementsOf(ErrCodes)-1)); if (i >= 0) { proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "ERROR %s %s (%s)", sz, ErrCodes[i], pDescr?pDescr->sz:"-"); } else { proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "ERROR %s (%s)", sz, pDescr?pDescr->sz:"-"); } return err; } #if 0 static const char* CSN_DESCR_type[]= { "CSN_END", "CSN_BIT", "CSN_UINT", "CSN_TYPE", "CSN_CHOICE", "CSN_UNION", "CSN_UNION_LH", "CSN_UINT_ARRAY", "CSN_TYPE_ARRAY", "CSN_BITMAP", "CSN_VARIABLE_BITMAP", "CSN_VARIABLE_BITMAP_1", "CSN_LEFT_ALIGNED_VAR_BMP", "CSN_LEFT_ALIGNED_VAR_BMP_1", "CSN_VARIABLE_ARRAY", "CSN_VARIABLE_TARRAY", "CSN_VARIABLE_TARRAY_OFFSET", "CSN_RECURSIVE_ARRAY", "CSN_RECURSIVE_TARRAY", "CSN_RECURSIVE_TARRAY_1", "CSN_RECURSIVE_TARRAY_2", "CSN_EXIST", "CSN_EXIST_LH", "CSN_NEXT_EXIST", "CSN_NEXT_EXIST_LH", "CSN_NULL", "CSN_FIXED", "CSN_CALLBACK", "CSN_UINT_OFFSET", "CSN_UINT_LH", "CSN_SERIALIZE", "CSN_TRAP_ERROR" "CSN_???" }; #endif /** * ================================================================================================ * Return TRUE if tag in bit stream indicates existence of next list element, * otherwise return FALSE. * Will work for tag values equal to both 0 and 1. * ================================================================================================ */ static gboolean existNextElement(tvbuff_t *tvb, gint bit_offset, guint8 Tag) { guint8 res = tvb_get_bits8(tvb, bit_offset, 1); if (Tag == STANDARD_TAG) { return (res > 0); } return (res == 0); } gint16 csnStreamDissector(proto_tree *tree, csnStream_t* ar, const CSN_DESCR* pDescr, tvbuff_t *tvb, void* data, int ett_csn1) { gint remaining_bits_len = ar->remaining_bits_len; gint bit_offset = ar->bit_offset; guint8* pui8; guint16* pui16; guint32* pui32; guint8 Tag = STANDARD_TAG; if (remaining_bits_len <= 0) { return 0; } do { switch (pDescr->type) { case CSN_BIT: { if (remaining_bits_len > 0) { pui8 = pui8DATA(data, pDescr->offset); pDescr++; *pui8 = tvb_get_bits8(tvb, bit_offset, 1); proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s %s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1)), pDescr->sz); /* end add the bit value to protocol tree */ } remaining_bits_len--; bit_offset++; break; } case CSN_NULL: { /* Empty member! */ pDescr++; break; } case CSN_UINT: { guint8 no_of_bits = (guint8) pDescr->i; if (remaining_bits_len >= no_of_bits) { if (no_of_bits <= 8) { guint8 ui8 = tvb_get_bits8(tvb, bit_offset, no_of_bits); pui8 = pui8DATA(data, pDescr->offset); *pui8 = ui8; proto_tree_add_bits_item(tree, *(pDescr->serialize.hf_ptr), tvb, bit_offset, no_of_bits, FALSE); } else if (no_of_bits <= 16) { guint16 ui16 = tvb_get_bits16(tvb, bit_offset, no_of_bits, FALSE); pui16 = pui16DATA(data, pDescr->offset); *pui16 = ui16; proto_tree_add_bits_item(tree, *(pDescr->serialize.hf_ptr), tvb, bit_offset, no_of_bits, FALSE); } else if (no_of_bits <= 32) { guint32 ui32 = tvb_get_bits32(tvb, bit_offset, no_of_bits, FALSE); pui32 = pui32DATA(data, pDescr->offset); *pui32 = ui32; proto_tree_add_bits_item(tree, *(pDescr->serialize.hf_ptr), tvb, bit_offset, no_of_bits, FALSE); } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } remaining_bits_len -= no_of_bits; bit_offset += no_of_bits; pDescr++; break; } case CSN_UINT_OFFSET: { guint8 no_of_bits = (guint8) pDescr->i; if (remaining_bits_len >= no_of_bits) { if (no_of_bits <= 8) { guint8 ui8 = tvb_get_bits8(tvb, bit_offset, no_of_bits); pui8 = pui8DATA(data, pDescr->offset); *pui8 = ui8 + (guint8)pDescr->descr.value; proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, ui8), pDescr->sz); } else if (no_of_bits <= 16) { guint16 ui16 = tvb_get_bits16(tvb, bit_offset, no_of_bits, FALSE); pui16 = pui16DATA(data, pDescr->offset); *pui16 = ui16 + (guint16)pDescr->descr.value; proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, ui16), pDescr->sz); } else if (no_of_bits <= 32) { guint32 ui32 = tvb_get_bits32(tvb, bit_offset, no_of_bits, FALSE); pui32 = pui32DATA(data, pDescr->offset); *pui32 = ui32 + (guint16)pDescr->descr.value; proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, ui32), pDescr->sz); } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } remaining_bits_len -= no_of_bits; bit_offset += no_of_bits; pDescr++; break; } case CSN_UINT_LH: { guint8 no_of_bits = (guint8) pDescr->i; if (remaining_bits_len >= no_of_bits) { remaining_bits_len -= no_of_bits; if (no_of_bits <= 8) { guint8 ui8 = tvb_get_masked_bits8(tvb, bit_offset, no_of_bits); pui8 = pui8DATA(data, pDescr->offset); *pui8 = ui8; proto_tree_add_bits_item(tree, *(pDescr->serialize.hf_ptr), tvb, bit_offset, no_of_bits, FALSE); } else {/* Maybe we should support more than 8 bits ? */ return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } remaining_bits_len -= no_of_bits; bit_offset += no_of_bits; pDescr++; break; } case CSN_UINT_ARRAY: { guint8 no_of_bits = (guint8) pDescr->i; guint16 nCount = (guint16)pDescr->descr.value; /* nCount supplied by value i.e. M_UINT_ARRAY(...) */ int i =0; if (pDescr->serialize.value != 0) { /* nCount specified by a reference to field holding value i.e. M_VAR_UINT_ARRAY(...) */ nCount = *pui16DATA(data, nCount); } if (remaining_bits_len >= no_of_bits) { remaining_bits_len -= (no_of_bits*nCount); if (no_of_bits <= 8) { pui8 = pui8DATA(data, pDescr->offset); do { *pui8++ = tvb_get_bits8(tvb, bit_offset, no_of_bits); proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s[%d]", decode_bits_in_field(bit_offset, no_of_bits, tvb_get_bits8(tvb, bit_offset, no_of_bits)), pDescr->sz, i++); bit_offset += no_of_bits; } while (--nCount > 0); } else if (no_of_bits <= 16) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector NOTIMPLEMENTED", 999, pDescr); } else if (no_of_bits <= 32) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector NOTIMPLEMENTED", 999, pDescr); } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } pDescr++; break; } case CSN_VARIABLE_TARRAY_OFFSET: case CSN_VARIABLE_TARRAY: case CSN_TYPE_ARRAY: { gint16 Status; csnStream_t arT = *ar; gint16 nCount = pDescr->i; guint16 nSize = (guint16)(gint32)pDescr->serialize.value; int i =0; pui8 = pui8DATA(data, pDescr->offset); if (pDescr->type == CSN_VARIABLE_TARRAY) { /* Count specified in field */ nCount = *pui8DATA(data, pDescr->i); } else if (pDescr->type == CSN_VARIABLE_TARRAY_OFFSET) { /* Count specified in field */ nCount = *pui8DATA(data, pDescr->i); /* nCount--; the 1 offset is already taken into account in CSN_UINT_OFFSET */ } while (nCount > 0) { /* resulting array of length 0 is possible * but no bits shall be read from bitstream */ proto_item *ti; proto_tree *test_tree; ti = proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s[%d]",pDescr->sz, i++); test_tree = proto_item_add_subtree(ti, ett_csn1); csnStreamInit(&arT, bit_offset, remaining_bits_len); Status = csnStreamDissector(test_tree, &arT, pDescr->descr.ptr, tvb, pui8, ett_csn1); if (Status >= 0) { pui8 += nSize; proto_item_set_len(ti,((arT.bit_offset - bit_offset)>>3)+1); remaining_bits_len = arT.remaining_bits_len; bit_offset = arT.bit_offset; } else { return Status; } nCount--; } pDescr++; break; } case CSN_BITMAP: { /* bitmap with given length. The result is left aligned! */ guint8 no_of_bits = (guint8) pDescr->i; /* length of bitmap */ if (no_of_bits > 0) { proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, tvb_get_bits32(tvb, bit_offset, no_of_bits, FALSE)), pDescr->sz); remaining_bits_len -= no_of_bits; DISSECTOR_ASSERT(remaining_bits_len >= 0); bit_offset += no_of_bits; } /* bitmap was successfully extracted or it was empty */ pDescr++; break; } case CSN_TYPE: { gint16 Status; csnStream_t arT = *ar; proto_item *ti; proto_tree *test_tree; ti = proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s", pDescr->sz); test_tree = proto_item_add_subtree(ti, ett_csn1); csnStreamInit(&arT, bit_offset, remaining_bits_len); Status = csnStreamDissector(test_tree, &arT, pDescr->descr.ptr, tvb, pvDATA(data, pDescr->offset), ett_csn1); if (Status >= 0) { proto_item_set_len(ti,((arT.bit_offset - bit_offset)>>3)+1); remaining_bits_len = arT.remaining_bits_len; bit_offset = arT.bit_offset; pDescr++; } else { /* Has already been processed: ProcessError("csnStreamDissector", Status, pDescr); */ return Status; } break; } case CSN_CHOICE: { gint16 count = pDescr->i; guint8 i = 0; CSN_ChoiceElement_t* pChoice = (CSN_ChoiceElement_t*) pDescr->descr.ptr; while (count > 0) { guint8 no_of_bits = pChoice->bits; guint8 value = tvb_get_bits8(tvb, bit_offset, no_of_bits); if (value == pChoice->value) { CSN_DESCR descr[2]; gint16 Status; csnStream_t arT = *ar; proto_item *ti; proto_tree *test_tree; descr[0] = pChoice->descr; descr[1].type = CSN_END; pui8 = pui8DATA(data, pDescr->offset); *pui8 = i; proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s Choice: %s", decode_bits_in_field(bit_offset, no_of_bits, tvb_get_bits8(tvb, bit_offset, no_of_bits)), pDescr->sz); bit_offset += no_of_bits; remaining_bits_len -= no_of_bits; ti = proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s", pDescr->sz); test_tree = proto_item_add_subtree(ti, ett_csn1); csnStreamInit(&arT, bit_offset, remaining_bits_len); Status = csnStreamDissector(test_tree, &arT, descr, tvb, data, ett_csn1); if (Status >= 0) { proto_item_set_len(ti,((arT.bit_offset - bit_offset)>>3)+1); remaining_bits_len = arT.remaining_bits_len; bit_offset = arT.bit_offset; } else { return Status; } break; } count--; pChoice++; i++; } pDescr++; break; } case CSN_SERIALIZE: { StreamSerializeFcn_t serialize = pDescr->serialize.fcn; csnStream_t arT = *ar; gint16 Status = -1; proto_item *ti; proto_tree *test_tree; proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s %s length", decode_bits_in_field(bit_offset, 7, tvb_get_bits8(tvb, bit_offset, 7)), pDescr->sz); bit_offset += 7; remaining_bits_len -= 7; ti = proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s", pDescr->sz); test_tree = proto_item_add_subtree(ti, ett_csn1); csnStreamInit(&arT, bit_offset, remaining_bits_len); Status = serialize(test_tree, &arT, tvb, pvDATA(data, pDescr->offset), ett_csn1); if (Status >= 0) { proto_item_set_len(ti,((arT.bit_offset - bit_offset)>>3)+1); remaining_bits_len = arT.remaining_bits_len; bit_offset = arT.bit_offset; pDescr++; } else { /* Has already been processed: */ return Status; } break; } case CSN_UNION_LH: case CSN_UNION: { gint16 Bits; guint8 index; gint16 count = pDescr->i; const CSN_DESCR* pDescrNext = pDescr; pDescrNext += count + 1; /* now this is next after the union */ if ((count <= 0) || (count > 16)) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_INVALID_UNION_INDEX, pDescr); } /* Now get the bits to extract the index */ Bits = ixBitsTab[count]; proto_tree_add_text(tree, tvb, bit_offset>>3, (Bits>>3)+1, "%s Union:%s", decode_bits_in_field(bit_offset, Bits, tvb_get_bits8(tvb, bit_offset, Bits)), pDescr->sz); index = 0; while (Bits > 0) { index <<= 1; if (CSN_UNION_LH == pDescr->type) { index |= tvb_get_masked_bits8(tvb, bit_offset, 1); } else { index |= tvb_get_bits8(tvb, bit_offset, 1); } remaining_bits_len--; bit_offset++; Bits--; } /* Assign UnionType */ pui8 = pui8DATA(data, pDescr->offset); *pui8 = index; /* script index to continue on, limited in case we do not have a power of 2 */ pDescr += (MIN(index + 1, count)); switch (pDescr->type) { /* get the right element of the union based on computed index */ case CSN_BIT: { pui8 = pui8DATA(data, pDescr->offset); pDescr++; proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s %s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1)), pDescr->sz); *pui8 = 0x00; if (tvb_get_bits8(tvb, bit_offset, 1) > 0) { *pui8 = 0x01; } remaining_bits_len -= 1; bit_offset++; break; } case CSN_NULL: { /* Empty member! */ pDescr++; break; } case CSN_UINT: { guint8 no_of_bits = (guint8) pDescr->i; if (remaining_bits_len >= no_of_bits) { remaining_bits_len -= no_of_bits; if (no_of_bits <= 8) { guint8 ui8 = tvb_get_bits8(tvb, bit_offset, no_of_bits); pui8 = pui8DATA(data, pDescr->offset); *pui8 = ui8; proto_tree_add_bits_item(tree, *(pDescr->serialize.hf_ptr), tvb, bit_offset, no_of_bits, FALSE); } else if (no_of_bits <= 16) { guint16 ui16 = tvb_get_bits16(tvb, bit_offset, no_of_bits, FALSE); pui16 = pui16DATA(data, pDescr->offset); *pui16 = ui16; proto_tree_add_bits_item(tree, *(pDescr->serialize.hf_ptr), tvb, bit_offset, no_of_bits, FALSE); } else if (no_of_bits <= 32) { guint32 ui32 = tvb_get_bits32(tvb, bit_offset, no_of_bits, FALSE); pui32 = pui32DATA(data, pDescr->offset); *pui32 = ui32; proto_tree_add_bits_item(tree, *(pDescr->serialize.hf_ptr), tvb, bit_offset, no_of_bits, FALSE); } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } bit_offset += no_of_bits; pDescr++; break; } case CSN_UINT_OFFSET: { guint8 no_of_bits = (guint8) pDescr->i; if (remaining_bits_len >= no_of_bits) { if (no_of_bits <= 8) { guint8 ui8 = tvb_get_bits8(tvb, bit_offset, no_of_bits); pui8 = pui8DATA(data, pDescr->offset); *pui8 = ui8 + (guint8)pDescr->descr.value; proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, ui8), pDescr->sz); } else if (no_of_bits <= 16) { guint16 ui16 = tvb_get_bits16(tvb, bit_offset, no_of_bits, FALSE); pui16 = pui16DATA(data, pDescr->offset); *pui16 = ui16 + (guint16)pDescr->descr.value; proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, ui16), pDescr->sz); } else if (no_of_bits <= 32) { guint32 ui32 = tvb_get_bits32(tvb, bit_offset, no_of_bits, FALSE); pui32 = pui32DATA(data, pDescr->offset); *pui32 = ui32 + (guint16)pDescr->descr.value; proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, ui32), pDescr->sz); } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } bit_offset += no_of_bits; pDescr++; break; } case CSN_UINT_LH: { guint8 no_of_bits = (guint8) pDescr->i; if (remaining_bits_len >= no_of_bits) { if (no_of_bits <= 8) { guint8 ui8 = tvb_get_masked_bits8(tvb, bit_offset, no_of_bits); pui8 = pui8DATA(data, pDescr->offset); *pui8 = ui8; proto_tree_add_bits_item(tree, *(pDescr->serialize.hf_ptr), tvb, bit_offset, no_of_bits, FALSE); } else { /* Maybe we should support more than 8 bits ? */ return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } bit_offset += no_of_bits; pDescr++; break; } case CSN_UINT_ARRAY: { guint8 no_of_bits = (guint8) pDescr->i; guint16 nCount = (guint16)pDescr->descr.value; /* nCount supplied by value i.e. M_UINT_ARRAY(...) */ gint i = 0; if (pDescr->serialize.value != 0) { /* nCount specified by a reference to field holding value i.e. M_VAR_UINT_ARRAY(...) */ nCount = *pui16DATA(data, nCount); } if (remaining_bits_len >= no_of_bits) { remaining_bits_len -= (no_of_bits * nCount); if (no_of_bits <= 8) { pui8 = pui8DATA(data, pDescr->offset); while (nCount > 0) { *pui8 = tvb_get_bits8(tvb, bit_offset, no_of_bits); proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s[%d]", decode_bits_in_field(bit_offset, no_of_bits, *pui8), pDescr->sz, i++); pui8++; bit_offset += no_of_bits; nCount--; } } else if (no_of_bits <= 16) { pui16 = pui16DATA(data, pDescr->offset); while (nCount > 0) { *pui16 = tvb_get_bits16(tvb, bit_offset, no_of_bits, FALSE); proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s[%d]", decode_bits_in_field(bit_offset, no_of_bits, *pui16), pDescr->sz, i++); bit_offset += no_of_bits; nCount--; } } else if (no_of_bits <= 32) { /* not supported */ return ProcessError(tree, tvb, bit_offset,"csnStreamDissector NOT IMPLEMENTED", 999, pDescr); } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_GENERAL, pDescr); } } else { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } pDescr++; break; } case CSN_VARIABLE_TARRAY_OFFSET: case CSN_VARIABLE_TARRAY: case CSN_TYPE_ARRAY: { gint16 Status; csnStream_t arT = *ar; guint16 nCount = (guint16) pDescr->i; guint16 nSize = (guint16)(guint32)pDescr->serialize.value; gint i = 0; pui8 = pui8DATA(data, pDescr->offset); if (CSN_VARIABLE_TARRAY == pDescr->type) { /* Count specified in field */ nCount = *pui8DATA(data, pDescr->i); } else if (CSN_VARIABLE_TARRAY_OFFSET == pDescr->type) { /* Count specified in field */ nCount = *pui8DATA(data, pDescr->i); nCount--; /* Offset 1 */ } while (nCount--) /* Changed to handle length = 0. */ { proto_item *ti; proto_tree *test_tree; ti = proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s[%d]",pDescr->sz, i++); test_tree = proto_item_add_subtree(ti, ett_csn1); csnStreamInit(&arT, bit_offset, remaining_bits_len); Status = csnStreamDissector(test_tree, &arT, pDescr->descr.ptr, tvb, pui8, ett_csn1); if (Status >= 0) { pui8 += nSize; proto_item_set_len(ti,((arT.bit_offset - bit_offset)>>3)+1); remaining_bits_len = arT.remaining_bits_len; bit_offset = arT.bit_offset; } else { return Status; } } pDescr++; break; } case CSN_BITMAP: { /* bitmap with given length. The result is left aligned! */ guint8 no_of_bits = (guint8) pDescr->i; /* length of bitmap */ if (no_of_bits > 0) { /* a non empty bitmap */ proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, tvb_get_bits8(tvb, bit_offset, no_of_bits)), pDescr->sz); remaining_bits_len -= no_of_bits; if (remaining_bits_len < 0) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } } /* bitmap was successfully extracted or it was empty */ pDescr++; break; } case CSN_TYPE: { gint16 Status; csnStream_t arT = *ar; proto_item *ti; proto_tree *test_tree; ti = proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s",pDescr->sz); test_tree = proto_item_add_subtree(ti, ett_csn1); csnStreamInit(&arT, bit_offset, remaining_bits_len); Status = csnStreamDissector(test_tree, &arT, pDescr->descr.ptr, tvb, pvDATA(data, pDescr->offset), ett_csn1); if (Status >= 0) { proto_item_set_len(ti,((arT.bit_offset - bit_offset)>>3)+1); remaining_bits_len = arT.remaining_bits_len; bit_offset = arT.bit_offset; pDescr++; } else { /* return error code Has already been processed: */ return Status; } break; } default: { /* descriptions of union elements other than above are illegal */ return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_IN_SCRIPT, pDescr); } } pDescr = pDescrNext; break; } case CSN_EXIST: case CSN_EXIST_LH: { guint8 fExist; pui8 = pui8DATA(data, pDescr->offset); proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "Exist:%s",pDescr->sz); if (CSN_EXIST_LH == pDescr->type) { fExist = tvb_get_masked_bits8(tvb, bit_offset, 1); } else { fExist = tvb_get_bits8(tvb, bit_offset, 1); } *pui8 = fExist; pDescr++; remaining_bits_len -= 1; if (!fExist) { ar->remaining_bits_len = remaining_bits_len; ar->bit_offset = bit_offset; return remaining_bits_len; } break; } case CSN_NEXT_EXIST: { guint8 fExist; pui8 = pui8DATA(data, pDescr->offset); /* this if-statement represents the M_NEXT_EXIST_OR_NULL description element */ if ((pDescr->descr.ptr != NULL) && (remaining_bits_len == 0)) { /* no more bits to decode is fine here - end of message detected and allowed */ /* Skip i entries + this entry */ pDescr += pDescr->i + 1; /* pDescr now must be pointing to a CSN_END entry, if not this is an error */ if ( pDescr->type != CSN_END ) { /* Substract one more bit from remaining_bits_len to make the "not enough bits" error to be triggered */ remaining_bits_len--; } /* Set the data member to "not exist" */ *pui8 = 0; break; } /* the "regular" M_NEXT_EXIST description element */ proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s %s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1)), pDescr->sz); fExist = 0x00; if (tvb_get_bits8(tvb, bit_offset, 1)) { fExist = 0x01; } *pui8 = fExist; remaining_bits_len -= 1; ++bit_offset; if (fExist == 0) { /* Skip 'i' entries */ pDescr += pDescr->i; } pDescr++; break; } case CSN_NEXT_EXIST_LH: { guint8 fExist; pui8 = pui8DATA(data, pDescr->offset); /* this if-statement represents the M_NEXT_EXIST_OR_NULL_LH description element */ if ((pDescr->descr.ptr != NULL) && (remaining_bits_len == 0)) { /* no more bits to decode is fine here - end of message detected and allowed */ /* skip 'i' entries + this entry */ pDescr += pDescr->i + 1; /* pDescr now must be pointing to a CSN_END entry, if not this is an error */ if ( pDescr->type != CSN_END ) { /* substract one more bit from remaining_bits_len to make the "not enough bits" error to be triggered */ remaining_bits_len--; } /* set the data member to "not exist" */ *pui8 = 0; break; } /* the "regular" M_NEXT_EXIST_LH description element */ proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s %s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1)), pDescr->sz); fExist = tvb_get_masked_bits8(tvb, bit_offset, 1); *pui8++ = fExist; remaining_bits_len -= 1; bit_offset++; if (fExist == 0) { /* Skip 'i' entries */ pDescr += pDescr->i; } pDescr++; break; } case CSN_VARIABLE_BITMAP_1: { /* Bitmap from here and to the end of message */ *pui8DATA(data, (gint16)pDescr->descr.value) = (guint8) remaining_bits_len; /* length of bitmap == remaining bits */ /*no break - * with a length set we have a regular variable length bitmap so we continue */ } case CSN_VARIABLE_BITMAP: { /* {CSN_VARIABLE_BITMAP, 0, offsetof(_STRUCT, _ElementCountField), offsetof(_STRUCT, _MEMBER), #_MEMBER} * * Bit array with length (in bits) specified in parameter (pDescr->descr) * The result is right aligned! */ gint16 no_of_bits = *pui8DATA(data, (gint16)pDescr->descr.value); no_of_bits += pDescr->i; /* adjusted by offset */ if (no_of_bits > 0) { proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1))); remaining_bits_len -= no_of_bits; if (remaining_bits_len < 0) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } { /* extract bits */ guint8* pui8 = pui8DATA(data, pDescr->offset); gint16 nB1 = no_of_bits & 0x07;/* no_of_bits Mod 8 */ if (nB1 > 0) { /* take care of the first byte - it will be right aligned */ *pui8++ = tvb_get_bits8(tvb, bit_offset, nB1); no_of_bits -= nB1; bit_offset += nB1; /* (nB1 is no_of_bits Mod 8) */ } /* remaining no_of_bits is a multiple of 8 or 0 */ while (no_of_bits > 0) { *pui8++ = tvb_get_bits8(tvb, bit_offset, 8); no_of_bits -= 8; } } } pDescr++; break; } case CSN_LEFT_ALIGNED_VAR_BMP_1: { /* Bitmap from here and to the end of message */ *pui8DATA(data, (gint16)pDescr->descr.value) = (guint8) remaining_bits_len; /* length of bitmap == remaining bits */ /* no break - * with a length set we have a regular left aligned variable length bitmap so we continue */ } case CSN_LEFT_ALIGNED_VAR_BMP: { /* {CSN_LEFT_ALIGNED_VAR_BMP, _OFFSET, (void*)offsetof(_STRUCT, _ElementCountField), offsetof(_STRUCT, _MEMBER), #_MEMBER} * * bit array with length (in bits) specified in parameter (pDescr->descr) */ gint16 no_of_bits = *pui8DATA(data, (gint16)pDescr->descr.value);/* Size of bitmap */ no_of_bits += pDescr->i;/* size adjusted by offset */ if (no_of_bits > 0) { /* a non empty bitmap */ proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, tvb_get_bits8(tvb, bit_offset, no_of_bits)), pDescr->sz); remaining_bits_len -= no_of_bits; if (remaining_bits_len < 0) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } } /* bitmap was successfully extracted or it was empty */ pDescr++; break; } case CSN_VARIABLE_ARRAY: { /* {int type; int i; void* descr; int offset; const char* sz; } CSN_DESCR; * {CSN_VARIABLE_ARRAY, _OFFSET, (void*)offsetof(_STRUCT, _ElementCountField), offsetof(_STRUCT, _MEMBER), #_MEMBER} * Array with length specified in parameter: * * */ gint16 count = *pui8DATA(data, (gint16)pDescr->descr.value); count += pDescr->i; /* Adjusted by offset */ if (count > 0) { remaining_bits_len -= count * 8; if (remaining_bits_len < 0) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } pui8 = pui8DATA(data, pDescr->offset); while (count > 0) { proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s %s", decode_bits_in_field(bit_offset, 8, tvb_get_bits8(tvb, bit_offset, 8)), pDescr->sz); *pui8++ = tvb_get_bits8(tvb, bit_offset, 8); bit_offset += 8; count--; } } pDescr++; break; } case CSN_RECURSIVE_ARRAY: { /* Recursive way to specify an array: ::= {1 | 0} * or more generally: ::= { | } * where ::= bit(value) * ::= 0 | 1 * ::= reversed tag i.e. tag == 1 -> EndTag == 0 and vice versa * {CSN_RECURSIVE_ARRAY, _BITS, (void*)offsetof(_STRUCT, _ElementCountField), offsetof(_STRUCT, _MEMBER), #_MEMBER} * REMARK: recursive way to specify an array but an iterative implementation! */ gint16 no_of_bits = pDescr->i; guint8 ElementCount = 0; pui8 = pui8DATA(data, pDescr->offset); while (existNextElement(tvb, bit_offset, Tag)) { /* tag control shows existence of next list elements */ proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s Exist:%s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1)), pDescr->sz); bit_offset++; remaining_bits_len--; /* extract and store no_of_bits long element from bitstream */ *pui8++ = tvb_get_bits8(tvb, bit_offset, no_of_bits); remaining_bits_len -= no_of_bits; ElementCount++; if (remaining_bits_len < 0) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, tvb_get_bits8(tvb, bit_offset, no_of_bits)), pDescr->sz); bit_offset += no_of_bits; } proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s Exist:%s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1)), pDescr->sz); /* existNextElement() returned FALSE, 1 bit consumed */ bit_offset++; /* Store the counted number of elements of the array */ *pui8DATA(data, (gint16)pDescr->descr.value) = ElementCount; pDescr++; break; } case CSN_RECURSIVE_TARRAY: { /* Recursive way to specify an array of type: ::= { 1 } ** 0 ; * M_REC_TARRAY(_STRUCT, _MEMBER, _MEMBER_TYPE, _ElementCountField) * {t, offsetof(_STRUCT, _ElementCountField), (void*)CSNDESCR_##_MEMBER_TYPE, offsetof(_STRUCT, _MEMBER), #_MEMBER, (StreamSerializeFcn_t)sizeof(_MEMBER_TYPE)} */ gint16 nSizeElement = (gint16)(gint32)pDescr->serialize.value; guint8 ElementCount = 0; while (existNextElement(tvb, bit_offset, Tag)) { /* tag control shows existence of next list elements */ proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s Exist:%s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1)), pDescr->sz); /* existNextElement() returned TRUE, 1 bit consumed */ bit_offset++; remaining_bits_len--; ElementCount++; { /* unpack the following data structure */ csnStream_t arT = *ar; gint16 Status; proto_item *ti; proto_tree *test_tree; ti = proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s",pDescr->sz); test_tree = proto_item_add_subtree(ti, ett_csn1); csnStreamInit(&arT, bit_offset, remaining_bits_len); Status = csnStreamDissector(test_tree, &arT, pDescr->descr.ptr, tvb, pvDATA(data, pDescr->offset), ett_csn1); if (Status >= 0) { /* successful completion */ pui8 += nSizeElement; /* -> to next data element */ proto_item_set_len(ti,((arT.bit_offset - bit_offset)>>3)+1); remaining_bits_len = arT.remaining_bits_len; bit_offset = arT.bit_offset; } else { /* something went awry */ return Status; } } if (remaining_bits_len < 0) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } } /* Store the counted number of elements of the array */ *pui8DATA(data, (gint16)(gint32)pDescr->i) = ElementCount; pDescr++; break; } case CSN_RECURSIVE_TARRAY_2: { /* Recursive way to specify an array of type: ::= { 0 } ** 1 ; */ Tag = REVERSED_TAG; /* NO break - * handling is exactly the same as for CSN_RECURSIVE_TARRAY_1 so we continue */ } case CSN_RECURSIVE_TARRAY_1: { /* Recursive way to specify an array of type: ::= { 1 } ** 0 ; * M_REC_TARRAY(_STRUCT, _MEMBER, _MEMBER_TYPE, _ElementCountField) * {t, offsetof(_STRUCT, _ElementCountField), (void*)CSNDESCR_##_MEMBER_TYPE, offsetof(_STRUCT, _MEMBER), #_MEMBER, (StreamSerializeFcn_t)sizeof(_MEMBER_TYPE)} */ gint16 nSizeElement = (gint16)(gint32)pDescr->serialize.value; guint8 ElementCount = 0; csnStream_t arT = *ar; gboolean EndOfList = FALSE; gint16 Status; proto_item *ti; proto_tree *test_tree; do { /* get data element */ ElementCount++; ti = proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s",pDescr->sz); test_tree = proto_item_add_subtree(ti, ett_csn1); csnStreamInit(&arT, bit_offset, remaining_bits_len); Status = csnStreamDissector(test_tree, &arT, pDescr->descr.ptr, tvb, pvDATA(data, pDescr->offset), ett_csn1); if (Status >= 0) { /* successful completion */ pui8 += nSizeElement; /* -> to next */ proto_item_set_len(ti,((arT.bit_offset - bit_offset)>>3)+1); remaining_bits_len = arT.remaining_bits_len; bit_offset = arT.bit_offset; } else { /* something went awry */ return Status; } if (remaining_bits_len < 0) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); } /* control of next element's tag */ proto_tree_add_text(tree, tvb, bit_offset>>3, 1, "%s Exist:%s", decode_bits_in_field(bit_offset, 1, tvb_get_bits8(tvb, bit_offset, 1)), pDescr->sz); EndOfList = !(existNextElement(tvb, bit_offset, Tag)); bit_offset++; remaining_bits_len--; /* 1 bit consumed (tag) */ } while (!EndOfList); /* Store the count of the array */ *pui8DATA(data, pDescr->i) = ElementCount; Tag = STANDARD_TAG; /* in case it was set to "reversed" */ pDescr++; break; } case CSN_FIXED: { /* Verify the fixed bits */ guint8 no_of_bits = (guint8) pDescr->i; guint32 ui32; if (no_of_bits <= 8) { ui32 = tvb_get_bits8(tvb, bit_offset, no_of_bits); } else if (no_of_bits <= 16) { ui32 = tvb_get_bits16(tvb, bit_offset, no_of_bits, FALSE); } else if (no_of_bits <= 32) { ui32 = tvb_get_bits32(tvb, bit_offset, no_of_bits, FALSE); } else { return ProcessError(tree, tvb, bit_offset,"no_of_bits > 32", -1, pDescr); } if (ui32 != (unsigned)(gint32)pDescr->offset) { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector FIXED value does not match", -1, pDescr); } proto_tree_add_text(tree, tvb, bit_offset>>3, (no_of_bits>>3)+1, "%s %s", decode_bits_in_field(bit_offset, no_of_bits, tvb_get_bits8(tvb, bit_offset, no_of_bits)), pDescr->sz); remaining_bits_len -= no_of_bits; bit_offset += no_of_bits; pDescr++; break; } case CSN_CALLBACK: { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector Callback not implemented", -1, pDescr); break; } case CSN_TRAP_ERROR: { return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", pDescr->i, pDescr); } case CSN_END: { ar->remaining_bits_len = remaining_bits_len; ar->bit_offset = bit_offset; return remaining_bits_len; } default: { DISSECTOR_ASSERT(0); } } } while (remaining_bits_len >= 0); return ProcessError(tree, tvb, bit_offset,"csnStreamDissector", CSN_ERROR_NEED_MORE_BITS_TO_UNPACK, pDescr); }