void ReadHostFile (const char *fname)
{
if (!fname || !*fname)
return;
hostFname = strdup (fname);
if (!hostFname)
return;
sethostent (1);
if (!hostFile)
return;
while (1)
{
struct _hostent h;
if (!_gethostent(&h))
break;
if (!tree_insert(&host_root, (void*)&h, sizeof(h), (CmpFunc)host_cmp_name))
{
outsnl (_LANG("Hostfile too big!\7"));
break;
}
}
atexit (endhostent);
}
struct hostent *gethostent (void)
{
struct _hostent h;
if (_gethostent(&h))
return FillHostEnt (&h);
return (NULL);
}
static int name2ip(ipaddr_t *pip, const char *name, ipaddr_t ifip)
{
/* Translate a name to an IP address, preferably from the hosts file,
* but also from the DNS if being a server. Prefer the address closest
* to the interface with IP address 'ifip' if there are choices..
*/
extern struct hostent *_gethostent(void); /* File reading versions. */
extern void _endhostent(void);
struct hostent *he;
size_t len= strlen(name);
u32_t d, distance= -1;
ipaddr_t ip;
int i;
char *hn;
/* Already an IP address? */
if (inet_aton(name, (struct in_addr *)pip)) return 1;
/* In the hosts file? */
while ((he= _gethostent()) != nil) {
hn= he->h_name;
i= -1;
do {
if (strncasecmp(name, hn, len) == 0
&& (hn[len] == 0 || hn[len] == '.')
) {
memcpy(&ip, he->h_addr, sizeof(ip));
d= ntohl(ip) ^ ntohl(ifip);
if (d < distance) {
*pip= ip;
distance= d;
}
break;
}
} while ((hn= he->h_aliases[++i]) != nil);
}
_endhostent();
if (distance < -1) return 1;
/* Nothing? Try the real DNS if being a server. */
if (serving) {
if ((he= gethostbyname(name)) != nil && he->h_addrtype == AF_INET) {
/* Select the address closest to 'ifip'. */
for (i= 0; he->h_addr_list[i] != nil; i++) {
memcpy(&ip, he->h_addr_list[i], sizeof(ip));
d= ntohl(ip) ^ ntohl(ifip);
if (d < distance) {
*pip= ip;
distance= d;
}
}
return 1;
}
}
return 0;
}
static char *ip2name(ipaddr_t ip)
{
/* Translate an IP address to a name, etc, etc. */
extern struct hostent *_gethostent(void); /* File reading versions. */
extern void _endhostent(void);
struct hostent *he;
/* In the hosts file? */
while ((he= _gethostent()) != nil) {
if (memcmp(he->h_addr, &ip, sizeof(ip)) == 0) break;
}
_endhostent();
/* Nothing? Try the real DNS if being a server. */
if (he == nil && serving) {
he= gethostbyaddr((char *) &ip, sizeof(ip), AF_INET);
}
return he != nil ? he->h_name : nil;
}
