mdw@git.distorted.org.uk Git - userv-utils/blob - ipif/hex.c

   1 /*
   2  * Copyright (C) 1997,2000 Ian Jackson
   3  *
   4  * This is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with userv-utils; if not, write to the Free Software
  16  * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  17  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <assert.h>
  22 #include <sysexits.h>
  23
  24 #include "hex.h"
  25
  26 const char *tohex(uint8_t *data, int len, char *buf) {
  27   char *p;
  28
  29   for (p= buf;
  30        len>0;
  31        len--, data++, p+=2)
  32     sprintf(p,"%02x",*data);
  33   return buf;
  34 }
  35
  36 void unhex(const char *what, const char *txt, uint8_t *datar, int *lenr,
  37            int minlen, int maxlen) {
  38   int l, v;
  39   char buf[3], *ep;
  40
  41   l= strlen(txt);
  42   if (l%1) { fprintf(stderr,"odd number of hex digits in %s\n",what); exit(EX_DATAERR); }
  43   l>>=1;
  44   if (l<minlen) { fprintf(stderr,"too few hex digits in %s\n",what); exit(EX_DATAERR); }
  45   if (l>maxlen) { fprintf(stderr,"too many hex digits in %s\n",what); exit(EX_DATAERR); }
  46
  47   if (lenr) *lenr= l;
  48   while (l) {
  49     buf[0]= *txt++;
  50     buf[1]= *txt++;
  51     buf[2]= 0;
  52     v= strtoul(buf,&ep,16);
  53     if (*ep) { fprintf(stderr,"not hex digit in %s: %c\n",what,*ep); exit(EX_DATAERR); }
  54     *datar++= v;
  55     l--;
  56   }
  57 }