util: add function for IP address hashing

Move the hashing function from find_slot() in ntp_sources to make it
available to clientlog and improve the hashing a bit.
This commit is contained in:
Miroslav Lichvar 2015-11-23 15:24:33 +01:00
parent 59a3140621
commit 8b235297a5
3 changed files with 34 additions and 15 deletions

View file

@ -202,26 +202,16 @@ find_slot(NTP_Remote_Address *remote_addr, int *slot, int *found)
uint32_t hash;
unsigned int i, size;
unsigned short port;
uint8_t *ip6;
size = ARR_GetSize(records);
switch (remote_addr->ip_addr.family) {
case IPADDR_INET6:
ip6 = remote_addr->ip_addr.addr.in6;
hash = (ip6[0] ^ ip6[4] ^ ip6[8] ^ ip6[12]) |
(ip6[1] ^ ip6[5] ^ ip6[9] ^ ip6[13]) << 8 |
(ip6[2] ^ ip6[6] ^ ip6[10] ^ ip6[14]) << 16 |
(ip6[3] ^ ip6[7] ^ ip6[11] ^ ip6[15]) << 24;
break;
case IPADDR_INET4:
hash = remote_addr->ip_addr.addr.in4;
break;
default:
*found = *slot = 0;
return;
if (remote_addr->ip_addr.family != IPADDR_INET4 &&
remote_addr->ip_addr.family != IPADDR_INET6) {
*found = *slot = 0;
return;
}
hash = UTI_IPToHash(&remote_addr->ip_addr);
port = remote_addr->port;
for (i = 0; i < size / 2; i++) {

28
util.c
View file

@ -359,6 +359,34 @@ UTI_IPToRefid(IPAddr *ip)
/* ================================================== */
uint32_t
UTI_IPToHash(IPAddr *ip)
{
unsigned char *addr;
unsigned int i, len;
uint32_t hash;
switch (ip->family) {
case IPADDR_INET4:
addr = (unsigned char *)&ip->addr.in4;
len = sizeof (ip->addr.in4);
break;
case IPADDR_INET6:
addr = ip->addr.in6;
len = sizeof (ip->addr.in6);
break;
default:
return 0;
}
for (i = 0, hash = 0; i < len; i++)
hash = 71 * hash + addr[i];
return hash;
}
/* ================================================== */
void
UTI_IPHostToNetwork(IPAddr *src, IPAddr *dest)
{

1
util.h
View file

@ -82,6 +82,7 @@ extern char *UTI_IPToString(IPAddr *ip);
extern int UTI_StringToIP(const char *addr, IPAddr *ip);
extern uint32_t UTI_IPToRefid(IPAddr *ip);
extern uint32_t UTI_IPToHash(IPAddr *ip);
extern void UTI_IPHostToNetwork(IPAddr *src, IPAddr *dest);
extern void UTI_IPNetworkToHost(IPAddr *src, IPAddr *dest);
extern int UTI_CompareIPs(IPAddr *a, IPAddr *b, IPAddr *mask);