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/* Copyright (C) 2014 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "lib/nsrep.h"
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/** @internal Macro to set address structure. */
#define ADDR_SET(sa, family, addr, len) do {\
memcpy(&sa ## _addr, (addr), (len)); \
sa ## _family = (family); \
sa ## _port = htons(KR_DNS_PORT); \
} while (0)
/** Update nameserver representation with current name/address pair. */
static void update_nsrep(struct kr_nsrep *ns, const knot_dname_t *name, uint8_t *addr, unsigned score)
{
ns->name = name;
ns->score = score;
if (addr == NULL) {
return;
}
size_t len = pack_obj_len(addr);
void *addr_val = pack_obj_val(addr);
switch(len) {
case sizeof(struct in_addr):
ADDR_SET(ns->addr.ip4.sin, AF_INET, addr_val, len); break;
case sizeof(struct in6_addr):
ADDR_SET(ns->addr.ip6.sin6, AF_INET6, addr_val, len); break;
default: assert(0); break;
}
}
#undef ADDR_SET
static int eval_nsrep(const char *k, void *v, void *baton)
{
unsigned score = KR_NS_VALID;
struct kr_nsrep *ns = baton;
pack_t *addr_set = v;
uint8_t *addr = NULL;
/* Name server is better candidate if it has address record. */
if (addr_set->len > 0) {
addr = pack_head(*addr_set);
score += 1;
}
/* Update best scoring nameserver. */
if (ns->score < score) {
update_nsrep(ns, (const knot_dname_t *)k, addr, score);
}
return kr_ok();
}
int kr_nsrep_elect(struct kr_nsrep *ns, map_t *nsset)
ns->addr.ip.sa_family = AF_UNSPEC;
ns->score = KR_NS_INVALID;
return map_walk(nsset, eval_nsrep, ns);