| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id: buf.h,v 1.1 2003/10/11 21:02:33 mdw Exp $ |
| 4 | * |
| 5 | * [Reading and writing packet buffers * |
| 6 | * (c) 2001 Straylight/Edgeware |
| 7 | */ |
| 8 | |
| 9 | /*----- Licensing notice --------------------------------------------------* |
| 10 | * |
| 11 | * This file is part of Catacomb. |
| 12 | * |
| 13 | * Catacomb is free software; you can redistribute it and/or modify |
| 14 | * it under the terms of the GNU Library General Public License as |
| 15 | * published by the Free Software Foundation; either version 2 of the |
| 16 | * License, or (at your option) any later version. |
| 17 | * |
| 18 | * Catacomb is distributed in the hope that it will be useful, |
| 19 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 20 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 21 | * GNU Library General Public License for more details. |
| 22 | * |
| 23 | * You should have received a copy of the GNU Library General Public |
| 24 | * License along with Catacomb; if not, write to the Free |
| 25 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
| 26 | * MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Revision history --------------------------------------------------* |
| 30 | * |
| 31 | * $Log: buf.h,v $ |
| 32 | * Revision 1.1 2003/10/11 21:02:33 mdw |
| 33 | * Import buf stuff from tripe. |
| 34 | * |
| 35 | * Revision 1.1 2001/06/19 22:09:54 mdw |
| 36 | * Expose interface, for use in the proxy. |
| 37 | * |
| 38 | */ |
| 39 | |
| 40 | #ifndef BUF_H |
| 41 | #define BUF_H |
| 42 | |
| 43 | #ifdef __cplusplus |
| 44 | extern "C" { |
| 45 | #endif |
| 46 | |
| 47 | /*----- Header files ------------------------------------------------------*/ |
| 48 | |
| 49 | #include <stddef.h> |
| 50 | |
| 51 | #include <mLib/bits.h> |
| 52 | |
| 53 | #include <catacomb/mp.h> |
| 54 | |
| 55 | /*----- Data structures ---------------------------------------------------*/ |
| 56 | |
| 57 | /* --- Buffers --- * |
| 58 | * |
| 59 | * Buffers provide a simple stream-like interface for building and parsing |
| 60 | * packets. |
| 61 | */ |
| 62 | |
| 63 | typedef struct buf { |
| 64 | octet *base, *p, *limit; /* Pointers to the buffer */ |
| 65 | unsigned f; /* Various flags */ |
| 66 | } buf; |
| 67 | |
| 68 | #define BF_BROKEN 1u /* Buffer is broken */ |
| 69 | |
| 70 | /*----- Useful macros -----------------------------------------------------*/ |
| 71 | |
| 72 | #define BBASE(b) ((b)->base) |
| 73 | #define BLIM(b) ((b)->limit) |
| 74 | #define BCUR(b) ((b)->p) |
| 75 | #define BSZ(b) ((b)->limit - (b)->base) |
| 76 | #define BLEN(b) ((b)->p - (b)->base) |
| 77 | #define BLEFT(b) ((b)->limit - (b)->p) |
| 78 | #define BSTEP(b, sz) ((b)->p += (sz)) |
| 79 | #define BBAD(b) ((b)->f & BF_BROKEN) |
| 80 | #define BOK(b) (!BBAD(b)) |
| 81 | |
| 82 | #define BENSURE(b, sz) \ |
| 83 | (BBAD(b) ? -1 : (sz) > BLEFT(b) ? (b)->f |= BF_BROKEN, -1 : 0) |
| 84 | |
| 85 | /*----- Functions provided ------------------------------------------------*/ |
| 86 | |
| 87 | /* --- @buf_init@ --- * |
| 88 | * |
| 89 | * Arguments: @buf *b@ = pointer to a buffer block |
| 90 | * @void *p@ = pointer to a buffer |
| 91 | * @size_t sz@ = size of the buffer |
| 92 | * |
| 93 | * Returns: --- |
| 94 | * |
| 95 | * Use: Initializes the buffer block appropriately. |
| 96 | */ |
| 97 | |
| 98 | extern void buf_init(buf */*b*/, void */*p*/, size_t /*sz*/); |
| 99 | |
| 100 | /* --- @buf_break@ --- * |
| 101 | * |
| 102 | * Arguments: @buf *b@ = pointer to a buffer block |
| 103 | * |
| 104 | * Returns: Some negative value. |
| 105 | * |
| 106 | * Use: Marks a buffer as broken. |
| 107 | */ |
| 108 | |
| 109 | extern int buf_break(buf */*b*/); |
| 110 | |
| 111 | /* --- @buf_flip@ --- * |
| 112 | * |
| 113 | * Arguments: @buf *b@ = pointer to a buffer block |
| 114 | * |
| 115 | * Returns: --- |
| 116 | * |
| 117 | * Use: Flips a buffer so that if you've just been writing to it, |
| 118 | * you can now read from the bit you've written. |
| 119 | */ |
| 120 | |
| 121 | extern void buf_flip(buf */*b*/); |
| 122 | |
| 123 | /* --- @buf_ensure@ --- * |
| 124 | * |
| 125 | * Arguments: @buf *b@ = pointer to a buffer block |
| 126 | * @size_t sz@ = size of data wanted |
| 127 | * |
| 128 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
| 129 | * |
| 130 | * Use: Ensures that there are @sz@ bytes still in the buffer. |
| 131 | */ |
| 132 | |
| 133 | extern int buf_ensure(buf */*b*/, size_t /*sz*/); |
| 134 | |
| 135 | /* --- @buf_get@ --- * |
| 136 | * |
| 137 | * Arguments: @buf *b@ = pointer to a buffer block |
| 138 | * @size_t sz@ = size of the buffer |
| 139 | * |
| 140 | * Returns: Pointer to the place in the buffer. |
| 141 | * |
| 142 | * Use: Reserves a space in the buffer of the requested size, and |
| 143 | * returns its start address. |
| 144 | */ |
| 145 | |
| 146 | extern void *buf_get(buf */*b*/, size_t /*sz*/); |
| 147 | |
| 148 | /* --- @buf_put@ --- * |
| 149 | * |
| 150 | * Arguments: @buf *b@ = pointer to a buffer block |
| 151 | * @const void *p@ = pointer to a buffer |
| 152 | * @size_t sz@ = size of the buffer |
| 153 | * |
| 154 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
| 155 | * |
| 156 | * Use: Fetches data from some place and puts it in the buffer |
| 157 | */ |
| 158 | |
| 159 | extern int buf_put(buf */*b*/, const void */*p*/, size_t /*sz*/); |
| 160 | |
| 161 | /* --- @buf_getbyte@ --- * |
| 162 | * |
| 163 | * Arguments: @buf *b@ = pointer to a buffer block |
| 164 | * |
| 165 | * Returns: A byte, or less than zero if there wasn't a byte there. |
| 166 | * |
| 167 | * Use: Gets a single byte from a buffer. |
| 168 | */ |
| 169 | |
| 170 | extern int buf_getbyte(buf */*b*/); |
| 171 | |
| 172 | /* --- @buf_putbyte@ --- * |
| 173 | * |
| 174 | * Arguments: @buf *b@ = pointer to a buffer block |
| 175 | * @int ch@ = byte to write |
| 176 | * |
| 177 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
| 178 | * |
| 179 | * Use: Puts a single byte in a buffer. |
| 180 | */ |
| 181 | |
| 182 | extern int buf_putbyte(buf */*b*/, int /*ch*/); |
| 183 | |
| 184 | /* --- @buf_getu16@ --- * |
| 185 | * |
| 186 | * Arguments: @buf *b@ = pointer to a buffer block |
| 187 | * @uint16 *w@ = where to put the word |
| 188 | * |
| 189 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
| 190 | * |
| 191 | * Use: Gets a 16-bit word from a buffer. |
| 192 | */ |
| 193 | |
| 194 | extern int buf_getu16(buf */*b*/, uint16 */*w*/); |
| 195 | |
| 196 | /* --- @buf_putu16@ --- * |
| 197 | * |
| 198 | * Arguments: @buf *b@ = pointer to a buffer block |
| 199 | * @uint16 w@ = word to write |
| 200 | * |
| 201 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
| 202 | * |
| 203 | * Use: Puts a 16-but word in a buffer. |
| 204 | */ |
| 205 | |
| 206 | extern int buf_putu16(buf */*b*/, uint16 /*w*/); |
| 207 | |
| 208 | /* --- @buf_getu32@ --- * |
| 209 | * |
| 210 | * Arguments: @buf *b@ = pointer to a buffer block |
| 211 | * @uint32 *w@ = where to put the word |
| 212 | * |
| 213 | * Returns: Zero if OK, or nonzero if there wasn't a word there. |
| 214 | * |
| 215 | * Use: Gets a 32-bit word from a buffer. |
| 216 | */ |
| 217 | |
| 218 | extern int buf_getu32(buf */*b*/, uint32 */*w*/); |
| 219 | |
| 220 | /* --- @buf_putu32@ --- * |
| 221 | * |
| 222 | * Arguments: @buf *b@ = pointer to a buffer block |
| 223 | * @uint32 w@ = word to write |
| 224 | * |
| 225 | * Returns: Zero if OK, nonzero if there wasn't enough space. |
| 226 | * |
| 227 | * Use: Puts a 32-but word in a buffer. |
| 228 | */ |
| 229 | |
| 230 | extern int buf_putu32(buf */*b*/, uint32 /*w*/); |
| 231 | |
| 232 | /* --- @buf_getmp@ --- * |
| 233 | * |
| 234 | * Arguments: @buf *b@ = pointer to a buffer block |
| 235 | * |
| 236 | * Returns: A multiprecision integer, or null if there wasn't one there. |
| 237 | * |
| 238 | * Use: Gets a multiprecision integer from a buffer. |
| 239 | */ |
| 240 | |
| 241 | extern mp *buf_getmp(buf */*b*/); |
| 242 | |
| 243 | /* --- @buf_putmp@ --- * |
| 244 | * |
| 245 | * Arguments: @buf *b@ = pointer to a buffer block |
| 246 | * @mp *m@ = a multiprecision integer |
| 247 | * |
| 248 | * Returns: Zero if it worked, nonzero if there wasn't enough space. |
| 249 | * |
| 250 | * Use: Puts a multiprecision integer to a buffer. |
| 251 | */ |
| 252 | |
| 253 | extern int buf_putmp(buf */*b*/, mp */*m*/); |
| 254 | |
| 255 | /*----- That's all, folks -------------------------------------------------*/ |
| 256 | |
| 257 | #ifdef __cplusplus |
| 258 | } |
| 259 | #endif |
| 260 | |
| 261 | #endif |