int dns_a4ptodn(const struct in_addr *addr, const char *tname,
dnsc_t *dn, unsigned dnsiz) {
dnsc_t *p;
int r;
if (!tname)
return dns_a4todn(addr, NULL, dn, dnsiz);
p = dns_a4todn_(addr, dn, dn + dnsiz);
if (!p) return 0;
r = dns_sptodn(tname, p, dnsiz - (p - dn));
return r != 0 ? r : dnsiz >= DNS_MAXDN ? -1 : 0;
}
static int dns_interpolate_inaddr_arpa(char *buff, int len, const char *key,
const char *ip) {
const char *b, *e;
char *o;
unsigned char dn[DNS_MAXDN];
int il;
struct {
struct in_addr addr;
struct in6_addr addr6;
} a;
/* This function takes a dot delimited string as input and
* reverses the parts split on dot.
*/
(void)key;
if (dns_pton(AF_INET, ip, &a.addr) > 0) {
dns_a4todn(&a.addr, 0, dn, sizeof(dn));
dns_dntop(dn,buff,len);
return strlen(buff);
}
else if (dns_pton(AF_INET6, ip, &a.addr6) > 0) {
dns_a6todn(&a.addr6, 0, dn, sizeof(dn));
dns_dntop(dn,buff,len);
return strlen(buff);
}
o = buff;
il = strlen(ip);
if(len <= il) {
/* not enough room for ip and '\0' */
if(len > 0) buff[0] = '\0';
return 0;
}
e = ip + il;
b = e - 1;
while(b >= ip) {
const char *term;
while(b >= ip && *b != '.') b--; /* Rewind to previous part */
term = b + 1; /* term is one ahead, we went past it */
if(term != e) memcpy(o, term, e - term); /* no sense in copying nothing */
o += e - term; /* advance the term length */
e = b;
b = e - 1;
if(e >= ip) *o++ = '.'; /* we must be at . */
}
*o = '\0';
assert((o - buff) == il);
return o - buff;
}
