| Harald Welte | a43f789 | 2009-12-01 18:04:30 +0530 | [diff] [blame^] | 1 | /* bit vector utility routines */ |
| 2 | |
| 3 | /* (C) 2009 by Harald Welte <laforge@gnumonks.org> |
| 4 | * |
| 5 | * All Rights Reserved |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License along |
| 18 | * with this program; if not, write to the Free Software Foundation, Inc., |
| 19 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | */ |
| 22 | |
| 23 | |
| 24 | #include <errno.h> |
| 25 | #include <sys/types.h> |
| 26 | |
| 27 | #include <openbsc/bitvec.h> |
| 28 | |
| 29 | #define BITNUM_FROM_COMP(byte, bit) ((byte*8)+bit) |
| 30 | |
| 31 | static inline unsigned int bytenum_from_bitnum(unsigned int bitnum) |
| 32 | { |
| 33 | unsigned int bytenum = bitnum / 8; |
| 34 | |
| 35 | return bytenum; |
| 36 | } |
| 37 | |
| 38 | int bitvec_set_bit_pos(struct bitvec *bv, unsigned int bitnr, |
| 39 | enum bit_value bit) |
| 40 | { |
| 41 | unsigned int bytenum = bytenum_from_bitnum(bitnr); |
| 42 | unsigned int bitnum = 7 - (bitnr % 8); |
| 43 | u_int8_t bitval; |
| 44 | |
| 45 | if (bytenum >= bv->data_len) |
| 46 | return -EINVAL; |
| 47 | |
| 48 | switch (bit) { |
| 49 | case ZERO: |
| 50 | bitval = (0 << bitnum); |
| 51 | break; |
| 52 | case ONE: |
| 53 | bitval = (1 << bitnum); |
| 54 | break; |
| 55 | case L: |
| 56 | bitval = ((0x2b ^ (0 << bitnum)) & (1 << bitnum)); |
| 57 | break; |
| 58 | case H: |
| 59 | bitval = ((0x2b ^ (1 << bitnum)) & (1 << bitnum)); |
| 60 | break; |
| 61 | default: |
| 62 | return -EINVAL; |
| 63 | } |
| 64 | |
| 65 | /* first clear the bit */ |
| 66 | bv->data[bytenum] &= ~(1 << bitnum); |
| 67 | |
| 68 | /* then set it to desired value */ |
| 69 | bv->data[bytenum] |= bitval; |
| 70 | |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | int bitvec_set_bit(struct bitvec *bv, enum bit_value bit) |
| 75 | { |
| 76 | int rc; |
| 77 | |
| 78 | rc = bitvec_set_bit_pos(bv, bv->cur_bit, bit); |
| 79 | if (!rc) |
| 80 | bv->cur_bit++; |
| 81 | |
| 82 | return rc; |
| 83 | } |
| 84 | |
| 85 | int bitvec_set_bits(struct bitvec *bv, enum bit_value *bits, int count) |
| 86 | { |
| 87 | int i, rc; |
| 88 | |
| 89 | for (i = 0; i < count; i++) { |
| 90 | rc = bitvec_set_bit(bv, bits[i]); |
| 91 | if (rc) |
| 92 | return rc; |
| 93 | } |
| 94 | |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | int bitvec_set_uint(struct bitvec *bv, unsigned int ui, int num_bits) |
| 99 | { |
| 100 | int i, rc; |
| 101 | |
| 102 | for (i = 0; i < num_bits; i++) { |
| 103 | int bit = 0; |
| 104 | if (ui & (1 << (num_bits - i - 1))) |
| 105 | bit = 1; |
| 106 | rc = bitvec_set_bit(bv, bit); |
| 107 | if (rc) |
| 108 | return rc; |
| 109 | } |
| 110 | |
| 111 | return 0; |
| 112 | } |
| 113 | |
| 114 | /* pad all remaining bits up to num_bits */ |
| 115 | int bitvec_spare_padding(struct bitvec *bv, unsigned int up_to_bit) |
| 116 | { |
| 117 | unsigned int i; |
| 118 | |
| 119 | for (i = bv->cur_bit; i <= up_to_bit; i++) |
| 120 | bitvec_set_bit(bv, L); |
| 121 | |
| 122 | return 0; |
| 123 | } |