/* wimax_bits.h * WiMax MAC Management UL-MAP Message decoder * * Copyright (c) 2007 by Intel Corporation. * * Author: Mike Harvey * * Wireshark - Network traffic analyzer * By Gerald Combs * Copyright 1999 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef __wimax_bits_h__ #define __wimax_bits_h__ #include /******************************************************************** * Functions for working with nibbles and bits */ /* SWAR functions */ #define _BITS(n,hi,lo) (((n)>>(lo))&((1<<(((hi)-(lo))+1))-1)) #define _ADD_SWAP(x,y) { (x) = (x) + (y); (y) = (x) - (y); (x) = (x) - (y); } #define _XOR_SWAP(x,y) { (x) ^= (y); (y) ^= (x); (x) ^= (y); } #define _SWAP(x,y) do { int t = (x); (x) = (y); (y) = t; } while(0) /******************************************************************** * Functions for working with nibbles * */ #define NIBBLE_MASK 0x0F #define BYTE_MASK 0xFF /* extract the nibble at the given nibble address 'n' of tvbuff_t 't' */ #define TVB_NIB_NIBBLE(n,t) \ (((n) & 1) \ ? tvb_get_guint8((t), (n)/2) & NIBBLE_MASK \ : (tvb_get_guint8((t), (n)/2) >> 4) & NIBBLE_MASK) /* extract the byte at the given nibble address 'n' of tvbuff_t 't' */ #define TVB_NIB_BYTE(n,t) \ (n) & 1 \ ? (tvb_get_ntohs((t), (n)/2) >> 4) & BYTE_MASK \ : tvb_get_guint8((t), (n)/2) /* extract 12 bits at the given nibble address */ #define TVB_NIB_BITS12(n,t) \ (TVB_NIB_NIBBLE(n+2,t) | (TVB_NIB_BYTE(n,t) << 4)) /* extract the word at the given nibble address 'n' of tvbuff_t 't' */ #define TVB_NIB_WORD(n,t) \ (n) & 1 \ ? (gint)((tvb_get_ntohl((t), (n)/2) >> 12) & 0x0000FFFF) \ : tvb_get_ntohs((t), (n)/2) /* extract the word at the given nibble address 'n' of tvbuff_t 't' */ #define TVB_NIB_LONG(n,t) \ (n) & 1 \ ? (tvb_get_ntohl((t), (n)/2) << 4) | ((tvb_get_guint8((t), (n)/2 + 4) >> 4) & NIBBLE_MASK) \ : tvb_get_ntohl((t), (n)/2) /* Only currently used with nib == 1 or 2 */ #define TVB_NIB_NIBS(nib, t, num) \ ((num) == 1 ? TVB_NIB_NIBBLE(nib,t) : \ ((num) == 2 ? TVB_NIB_BYTE(nib,t) : \ ((num) == 3 ? TVB_NIB_BITS12(nib,t) : \ ((num) == 4 ? TVB_NIB_WORD(nib,t) : \ 0)))) /* to highlight nibfields correctly in wireshark * AddItem(..., WSADDR(buf,bit), WSLEN(bit), ...) */ /* determine starting byte to highlight a series of nibbles */ #define NIB_ADDR(nib) ((nib)/2) /* determine number of bytes to highlight a series of nibbles */ #define NIB_LEN(nib,len) ((1 + ((nib) &1) + (len))/2) #define NIBHI(nib,len) NIB_ADDR(nib),NIB_LEN(nib,len) /******************************************************************** * bitfield functions - for extracting bitfields from a buffer * * TODO: 64 bit functions use two 32-bit values; * would be better to use 32+8 bits to avoid overrunning buffers * */ /* find the byte-address for the bitfield */ #define ADDR(bit) ((bit) / 8) #define ADDR16(bit) ((bit) / 8) #define ADDR32(bit) ((bit) / 8) /* find the offset (from the MSB) to the start of the bitfield */ #define OFFSET(bit) ((bit) % 8) #define OFFSET16(bit) ((bit) % 8) #define OFFSET32(bit) ((bit) % 8) /* find the number of bits to shift right (SHIFT64 is upper dword) */ #define SHIFT(bit,num) ( 8 - ((bit)%8) - (num)) #define SHIFT16(bit,num) (16 - ((bit)%8) - (num)) #define SHIFT32(bit,num) (32 - ((bit)%8) - (num)) #define SHIFT64a(bit,num) (num - (32 - OFFSET32(bit))) #define SHIFT64b(bit,num) (32 - ((num) - (32 - OFFSET32(bit)))) /* create a mask to mask off the bitfield */ #define MASK8(num) (0xFF >> (8 - (num))) #define MASK16(num) (0xFFFF >> (16 - (num))) #define MASK32(num) (0xFFFFFFFF >> (32 - (num))) #define MASK64a(bit) (MASK32(32 - OFFSET32(bit))) #define MASK64b(bit,num) (MASK32(num - (32 - OFFSET32(bit)))) /* note that if you have a bitfield of length 2 or more, it may cross a * byte boundary so you should use TVB_BIT_BITS16 */ /* extract a single bit * bit ... bit address * tvb ... tvbuff_t */ #define TVB_BIT_BIT(bit, tvb) \ (( tvb_get_guint8(tvb, ADDR(bit)) >> SHIFT(bit,1) ) & 0x1) /* extract bitfield up to 9 bits * bit ... bit address * tvb ... tvbuff_t * num ... length of bitfield */ #define TVB_BIT_BITS16(bit, tvb, num) \ (( tvb_get_ntohs(tvb, ADDR16(bit)) >> SHIFT16(bit,num) ) & MASK16(num)) /* extract bitfield up to 24 bits * bit ... bit address * tvb ... tvbuff_t * num ... length of bitfield */ #define TVB_BIT_BITS32(bit, tvb, num) \ ((tvb_get_ntohl(tvb, ADDR32(bit)) >> SHIFT32(bit,num) ) & MASK32(num)) /* bitfield up to 32 bits */ #define TVB_BIT_BITS64a(bit, tvb, num) \ ((tvb_get_ntohl(tvb, ADDR32(bit)) & MASK64a(bit)) << SHIFT64a(bit,num)) #define TVB_BIT_BITS64b(bit, tvb, num) \ ((tvb_get_ntohl(tvb, ADDR32(bit)+4) >> SHIFT64b(bit,num) ) & MASK64b(bit,num)) #define TVB_BIT_BITS64(bit, tvb, num) \ ( (OFFSET32(bit)+(num)) <= 32 \ ? TVB_BIT_BITS32(bit,tvb,num) \ : TVB_BIT_BITS64a(bit,tvb,num) \ | TVB_BIT_BITS64b(bit,tvb,num) ) #define TVB_BIT_BITS(bit, tvb, num) \ ((num) == 1 ? (gint)TVB_BIT_BIT(bit,tvb) : \ ((num) <= 9 ? (gint)TVB_BIT_BITS16(bit,tvb,num) : \ ((num) <= 24 ? (gint)TVB_BIT_BITS32(bit,tvb,num) : \ ((num) <= 32 ? (gint)TVB_BIT_BITS64(bit,tvb,num) : \ (gint)0 )))) /* to highlight bitfields correctly in wireshark * AddItem(..., WSADDR(buf,bit), WSLEN(bit), ...) */ /* determine starting byte to highlight a series of nibbles */ #define BIT_ADDR(bit) (ADDR(bit)) /* determine number of bytes to highlight */ #define BIT_LEN(bit,len) (1 + ((OFFSET(bit) + len - 1) / 8)) #define BITHI(bit,len) BIT_ADDR(bit),BIT_LEN(bit,len) /******************************************************************** * padding functions - return number of nibbles/bits needed to * pad to a byte boundary */ #define BIT_PADDING(bit, bits) ((bit) % (bits)) ? ((bits) - ((bit) % (bits))) : 0 #define NIB_PADDING(nib) ((nib) & 0x1) /******************************************************************** * conversion functions - between bytes, nibbles, and bits */ #define BYTE_TO_BIT(n) ((n) * 8) #define BYTE_TO_NIB(n) ((n) * 2) #define BIT_TO_BYTE(n) ((n) / 8) #define BIT_TO_NIB(n) ((n) / 4) #define NIB_TO_BYTE(n) ((n) / 2) #define NIB_TO_BIT(n) ((n) * 4) #endif