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

   1 /*
   2  * This file is part of ipif, part of userv-utils
   3  *
   4  * Copyright 1996-2013 Ian Jackson <ijackson@chiark.greenend.org.uk>
   5  * Copyright 1998 David Damerell <damerell@chiark.greenend.org.uk>
   6  * Copyright 1999,2003
   7  *    Chancellor Masters and Scholars of the University of Cambridge
   8  * Copyright 2010 Tony Finch <fanf@dotat.at>
   9  *
  10  * This is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 3 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful, but
  16  * WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with userv-utils; if not, see http://www.gnu.org/licenses/.
  22  */
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <assert.h>
  27 #include <string.h>
  28 #include <sysexits.h>
  29
  30 #include "hex.h"
  31
  32 const char *tohex(uint8_t *data, int len, char *buf) {
  33   char *p;
  34
  35   for (p= buf;
  36        len>0;
  37        len--, data++, p+=2)
  38     sprintf(p,"%02x",*data);
  39   return buf;
  40 }
  41
  42 void unhex(const char *what, const char *txt, uint8_t *datar, int *lenr,
  43            int minlen, int maxlen) {
  44   int l, v;
  45   char buf[3], *ep;
  46
  47   l= strlen(txt);
  48   if (l%1) { fprintf(stderr,"odd number of hex digits in %s\n",what); exit(EX_DATAERR); }
  49   l>>=1;
  50   if (l<minlen) { fprintf(stderr,"too few hex digits in %s\n",what); exit(EX_DATAERR); }
  51   if (l>maxlen) { fprintf(stderr,"too many hex digits in %s\n",what); exit(EX_DATAERR); }
  52
  53   if (lenr) *lenr= l;
  54   while (l) {
  55     buf[0]= *txt++;
  56     buf[1]= *txt++;
  57     buf[2]= 0;
  58     v= strtoul(buf,&ep,16);
  59     if (*ep) { fprintf(stderr,"not hex digit in %s: %c\n",what,*ep); exit(EX_DATAERR); }
  60     *datar++= v;
  61     l--;
  62   }
  63 }