iodine/read.c

165 lines
2.7 KiB
C

/*
* Copyright (c) 2006 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>
static int
readname_loop(char *packet, char **src, char *dst, size_t length, size_t loop)
{
char *dummy;
char *s;
char *d;
int len;
char c;
if (loop <= 0)
return 0;
len = 0;
s = *src;
d = dst;
while(*s && len < length - 2) {
c = *s++;
/* is this a compressed label? */
if((c & 0xc0) == 0xc0) {
dummy = packet + (((s[-1] & 0x3f) << 8) | s[0]);
len += readname_loop(packet, &dummy, d, length - len, loop - 1);
goto end;
}
while(c && len < length - 1) {
*d++ = *s++;
len++;
c--;
}
if (len >= length - 1) {
break; /* We used up all space */
}
if (*s != 0) {
*d++ = '.';
len++;
}
}
dst[len++] = '\0';
end:
(*src) = s+1;
return len;
}
int
readname(char *packet, char **src, char *dst, size_t length)
{
return readname_loop(packet, src, dst, length, 10);
}
int
readshort(char *packet, char **src, short *dst)
{
unsigned char *p;
p = *src;
*dst = (p[0] << 8) | p[1];
(*src) += sizeof(short);
return sizeof(short);
}
int
readlong(char *packet, char **src, long *dst)
{
unsigned char *p;
p = *src;
*dst = ((long)p[0] << 24)
| ((long)p[1] << 16)
| ((long)p[2] << 8)
| ((long)p[3]);
(*src) += sizeof(long);
return sizeof(long);
}
int
readdata(char *packet, char **src, char *dst, size_t len)
{
if (len < 0)
return 0;
memcpy(dst, *src, len);
(*src) += len;
return len;
}
int
putbyte(char **dst, char value)
{
**dst = value;
(*dst)++;
return sizeof(char);
}
int
putshort(char **dst, short value)
{
unsigned char *p;
p = *dst;
*p++ = (value >> 8);
*p++ = value;
(*dst) = p;
return sizeof(short);
}
int
putlong(char **dst, long value)
{
unsigned char *p;
p = *dst;
*p++ = (value >> 24);
*p++ = (value >> 16);
*p++ = (value >> 8);
*p++ = (value);
(*dst) = p;
return sizeof(long);
}
int
putdata(char **dst, char *data, size_t len)
{
if (len < 0)
return 0;
memcpy(*dst, data, len);
(*dst) += len;
return len;
}