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/***
@file ip4_bit.c
@author Jens Wehrenbrecht, feh
@funcs ip4_bitstring, bitstring_ip4
*/
#include "ip.h"
#include "byte.h"
#include "scan.h"
#include "str.h"
#include "fmt.h"
#include "ip_bit.h"
#define BITSUBSTITUTION
static char strnum[FMT_ULONG];
/***
/fn ip4_bitstring
/brief This function converts a IPv4 address into its binary representation with given prefix len
/param out: ip4string 0-terminated destination address.
/param in: ip4address The source address.
/param in: prefix The net prefix bits (maximum 32 bits for IPv4).
/return -1: lack of memory; 1: non valid IP address; 0: successful converted.
*/
int ip4_bitstring(stralloc *ip4string, char *ip, unsigned int prefix)
{
int i, j;
char ip4[4];
int count = 0;
unsigned char number;
#ifdef BITSUBSTITUTION
const char *letterarray = "abcdefghijklmnopqrstuvwxyz123456";
#endif
if (!stralloc_copys(ip4string,"")) return -1;
if (!stralloc_readyplus(ip4string,32)) return -1;
ip4_scan(ip,ip4);
for (i = 0; i < 4; i++) {
number = (unsigned char) ip4[i];
for (j = 7; j >= 0; j--) {
if (number & (1<<j)) {
#ifdef BITSUBSTITUTION
if (!stralloc_catb(ip4string,letterarray + count,1)) return -1;
#else
if (!stralloc_cats(ip4string,"1")) return -1;
#endif
} else {
if (!stralloc_cats(ip4string,"0")) return -1;
}
count++;
prefix--;
if (prefix == 0) return 0;
}
}
return 1;
}
/***
/fn bitstring_ip4
/brief This function takes an IPv4 bitstring and translates it to an IPv4 address + prefix
/param in: ip4string The source address (with '_' start token).
/param out: ip4addr 0-terminated estination IPv4 address + net prefix (eg. 127.0.0.0/16).
/return -1: lack of memory; 1: non valid IPv4 address; 0: successful converted.
*/
int bitstring_ip4(stralloc *ip4addr, stralloc *ip4string)
{
int j;
int num = 0;
int value = 256;
int prefix;
if (!stralloc_copys(ip4addr,"")) return -1;
prefix = ip4string->len - 1;
if (prefix <= 0) return 1;
if (prefix <= 1 || prefix > 32) return 1;
for (j = 1; j <= prefix; j++) {
if (ip4string->s[j] != '0') {
num += (value/2);
value /= 2;
} else
value /= 2;
if (j % 8 == 0 || j == prefix) {
if (!stralloc_catb(ip4addr,strnum,fmt_ulong(strnum,num))) return -1;
if (j < 32) if (!stralloc_cats(ip4addr,".")) return -1;
num = 0;
value = 256;
}
}
if (!stralloc_cats(ip4addr,"/")) return -1;
if (!stralloc_catb(ip4addr,strnum,fmt_ulong(strnum,prefix))) return -1;
if (!stralloc_0(ip4addr)) return -1;
return 0;
}
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