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/*
* Copyright (c) 2006-2009 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <string.h>
#include "common.h"
#include "encoding.h"
int
build_hostname(char *buf, size_t buflen,
const char *data, const size_t datalen,
const char *topdomain, struct encoder *encoder, int maxlen)
{
int encsize;
size_t space;
char *b;
space = MIN(maxlen, buflen) - strlen(topdomain) - 8;
/* 8 = 5 max header length + 1 dot before topdomain + 2 safety */
if (!encoder->places_dots())
space -= (space / 57); /* space for dots */
memset(buf, 0, buflen);
encsize = encoder->encode(buf, &space, data, datalen);
if (!encoder->places_dots())
inline_dotify(buf, buflen);
b = buf;
b += strlen(buf);
/* move b back one step to see if the dot is there */
b--;
if (*b != '.')
*++b = '.';
b++;
/* move b ahead of the string so we can copy to it */
strncpy(b, topdomain, strlen(topdomain)+1);
return space;
}
int
unpack_data(char *buf, size_t buflen, char *data, size_t datalen, struct encoder *enc)
{
if (!enc->eats_dots())
datalen = inline_undotify(data, datalen);
return enc->decode(buf, &buflen, data, datalen);
}
int
inline_dotify(char *buf, size_t buflen)
{
unsigned dots;
unsigned pos;
unsigned total;
char *reader, *writer;
total = strlen(buf);
dots = total / 57;
writer = buf;
writer += total;
writer += dots;
total += dots;
if (strlen(buf) + dots > buflen) {
writer = buf;
writer += buflen;
total = buflen;
}
reader = writer - dots;
pos = (unsigned) (reader - buf) + 1;
while (dots) {
*writer-- = *reader--;
pos--;
if (pos % 57 == 0) {
*writer-- = '.';
dots--;
}
}
/* return new length of string */
return total;
}
int
inline_undotify(char *buf, size_t len)
{
unsigned pos;
unsigned dots;
char *reader, *writer;
writer = buf;
reader = writer;
pos = 0;
dots = 0;
while (pos < len) {
if (*reader == '.') {
reader++;
pos++;
dots++;
continue;
}
*writer++ = *reader++;
pos++;
}
/* return new length of string */
return len - dots;
}
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