sys/libkern/hexncpy.c

   1 /*
   2  * Copyright (c) 2013 The DragonFly Project.  All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  *
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in
  12  *    the documentation and/or other materials provided with the
  13  *    distribution.
  14  * 3. Neither the name of The DragonFly Project nor the names of its
  15  *    contributors may be used to endorse or promote products derived
  16  *    from this software without specific, prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  22  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  24  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  25  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  26  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  27  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  28  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31 #include <sys/systm.h>
  32
  33 #define        MIN_OUTBLEN     3
  34
  35 /*
  36  * Take an array of u_char of size inlen and stores its hexadecimal representation
  37  * into outb which is max size outlen. Use sep as separator.
  38  *
  39  * Returns the same outb buffer for ease of use when printing.
  40  */
  41 char *
  42 hexncpy(const u_char *inb, int inlen, char *outb, int outlen, const char *sep)
  43 {
  44         char hexdigit[] = "0123456789abcdef";
  45         char *addr;
  46
  47         /*
  48          * In the case we pass invalid buffers or the size
  49          * of the outb buffer isn't enough to print at least
  50          * a single u_char in hex format we assert.
  51          */
  52         KKASSERT((outb != NULL && inb != NULL && outlen >= MIN_OUTBLEN));
  53
  54         /* Save up our base address */
  55         addr = outb;
  56         for (; inlen > 0 && outlen >= MIN_OUTBLEN; --inlen, outlen -= 3) {
  57                 *outb++ = hexdigit[*inb >> 4];
  58                 *outb++ = hexdigit[*inb++ & 0xf];
  59                 if (sep)
  60                         *outb++ = *sep;
  61         }
  62         *--outb = 0;
  63
  64         return addr;
  65 }