/**
* Look through the gateway list and select the best gateway
* depending on the distance to this router
*/
static void gw_default_choose_gateway(void) {
uint64_t cost_ipv4_threshold = UINT64_MAX;
uint64_t cost_ipv6_threshold = UINT64_MAX;
bool eval_cost_ipv4_threshold = false;
bool eval_cost_ipv6_threshold = false;
struct gateway_entry *inet_ipv4 = NULL;
struct gateway_entry *inet_ipv6 = NULL;
uint64_t cost_ipv4 = UINT64_MAX;
uint64_t cost_ipv6 = UINT64_MAX;
struct gateway_entry *gw;
struct tc_entry *tc;
bool dual;
if (olsr_cnf->smart_gw_thresh) {
/* determine the path cost thresholds */
gw = olsr_get_ipv4_inet_gateway();
if (gw) {
tc = olsr_lookup_tc_entry(&gw->originator);
if (tc) {
uint64_t cost = gw_default_weigh_costs(tc->path_cost, gw->uplink, gw->downlink);
cost_ipv4_threshold = gw_default_calc_threshold(cost);
eval_cost_ipv4_threshold = true;
}
}
gw = olsr_get_ipv6_inet_gateway();
if (gw) {
tc = olsr_lookup_tc_entry(&gw->originator);
if (tc) {
uint64_t cost = gw_default_weigh_costs(tc->path_cost, gw->uplink, gw->downlink);
cost_ipv6_threshold = gw_default_calc_threshold(cost);
eval_cost_ipv6_threshold = true;
}
}
}
OLSR_FOR_ALL_GATEWAY_ENTRIES(gw) {
uint64_t path_cost;
tc = olsr_lookup_tc_entry(&gw->originator);
if (!tc) {
/* gateways should not exist without tc entry */
continue;
}
if (tc->path_cost == ROUTE_COST_BROKEN) {
/* do not consider nodes with an infinite ETX */
continue;
}
if (!gw->uplink || !gw->downlink) {
/* do not consider nodes without bandwidth or with a uni-directional link */
continue;
}
/* determine the path cost */
path_cost = gw_default_weigh_costs(tc->path_cost, gw->uplink, gw->downlink);
if (!gw_def_finished_ipv4 && gw->ipv4 && gw->ipv4nat == olsr_cnf->smart_gw_allow_nat && path_cost < cost_ipv4
&& (!eval_cost_ipv4_threshold || (path_cost < cost_ipv4_threshold))) {
inet_ipv4 = gw;
cost_ipv4 = path_cost;
}
if (!gw_def_finished_ipv6 && gw->ipv6 && path_cost < cost_ipv6
&& (!eval_cost_ipv6_threshold || (path_cost < cost_ipv6_threshold))) {
inet_ipv6 = gw;
cost_ipv6 = path_cost;
}
}
OLSR_FOR_ALL_GATEWAY_ENTRIES_END(gw)
/* determine if we found an IPv4 and IPv6 gateway */
gw_def_finished_ipv4 |= (inet_ipv4 != NULL);
gw_def_finished_ipv6 |= (inet_ipv6 != NULL);
/* determine if we are dealing with a dual stack gateway */
dual = (inet_ipv4 == inet_ipv6) && (inet_ipv4 != NULL);
if (inet_ipv4) {
/* we are dealing with an IPv4 or dual stack gateway */
olsr_set_inet_gateway(&inet_ipv4->originator, true, dual);
}
if (inet_ipv6 && !dual) {
/* we are dealing with an IPv6-only gateway */
olsr_set_inet_gateway(&inet_ipv6->originator, false, true);
}
if ((olsr_cnf->smart_gw_thresh == 0) && gw_def_finished_ipv4 && gw_def_finished_ipv6) {
/* stop looking for a better gateway */
olsr_stop_timer(gw_def_timer);
gw_def_timer = NULL;
}
}
/**
* Look through the gateway list and select the best gateway
* depending on the distance to this router
*/
static void gw_default_choose_gateway(void) {
uint64_t cost_ipv4_threshold = UINT64_MAX;
uint64_t cost_ipv6_threshold = UINT64_MAX;
bool cost_ipv4_threshold_valid = false;
bool cost_ipv6_threshold_valid = false;
struct gateway_entry *chosen_gw_ipv4 = NULL;
struct gateway_entry *chosen_gw_ipv6 = NULL;
uint64_t chosen_gw_ipv4_costs = UINT64_MAX;
uint64_t chosen_gw_ipv6_costs = UINT64_MAX;
struct gateway_entry *gw;
bool dual = false;
if (olsr_cnf->smart_gw_thresh) {
/* determine the path cost thresholds */
uint64_t cost = gw_default_getcosts(olsr_get_inet_gateway(false));
if (cost != UINT64_MAX) {
cost_ipv4_threshold = gw_default_calc_threshold(cost);
cost_ipv4_threshold_valid = true;
}
cost = gw_default_getcosts(olsr_get_inet_gateway(true));
if (cost != UINT64_MAX) {
cost_ipv6_threshold = gw_default_calc_threshold(cost);
cost_ipv6_threshold_valid = true;
}
}
OLSR_FOR_ALL_GATEWAY_ENTRIES(gw) {
uint64_t gw_cost = gw_default_getcosts(gw);
if (gw_cost == UINT64_MAX) {
/* never select a node with infinite costs */
continue;
}
if (gw_def_choose_new_ipv4_gw) {
bool gw_eligible_v4 = gw->ipv4
/* && (olsr_cnf->ip_version == AF_INET || olsr_cnf->use_niit) *//* contained in gw_def_choose_new_ipv4_gw */
&& (olsr_cnf->smart_gw_allow_nat || !gw->ipv4nat);
if (gw_eligible_v4 && gw_cost < chosen_gw_ipv4_costs
&& (!cost_ipv4_threshold_valid || (gw_cost < cost_ipv4_threshold))) {
chosen_gw_ipv4 = gw;
chosen_gw_ipv4_costs = gw_cost;
}
}
if (gw_def_choose_new_ipv6_gw) {
bool gw_eligible_v6 = gw->ipv6
/* && olsr_cnf->ip_version == AF_INET6 *//* contained in gw_def_choose_new_ipv6_gw */;
if (gw_eligible_v6 && gw_cost < chosen_gw_ipv6_costs
&& (!cost_ipv6_threshold_valid || (gw_cost < cost_ipv6_threshold))) {
chosen_gw_ipv6 = gw;
chosen_gw_ipv6_costs = gw_cost;
}
}
} OLSR_FOR_ALL_GATEWAY_ENTRIES_END(gw)
/* determine if we should keep looking for IPv4 and/or IPv6 gateways */
gw_def_choose_new_ipv4_gw = gw_def_choose_new_ipv4_gw && (chosen_gw_ipv4 == NULL);
gw_def_choose_new_ipv6_gw = gw_def_choose_new_ipv6_gw && (chosen_gw_ipv6 == NULL);
/* determine if we are dealing with a dual stack gateway */
dual = chosen_gw_ipv4 && (chosen_gw_ipv4 == chosen_gw_ipv6);
if (chosen_gw_ipv4) {
/* we are dealing with an IPv4 or dual stack gateway */
olsr_set_inet_gateway(&chosen_gw_ipv4->originator, chosen_gw_ipv4_costs, true, dual);
}
if (chosen_gw_ipv6 && !dual) {
/* we are dealing with an IPv6-only gateway */
olsr_set_inet_gateway(&chosen_gw_ipv6->originator, chosen_gw_ipv6_costs, false, true);
}
if ((olsr_cnf->smart_gw_thresh == 0) && !gw_def_choose_new_ipv4_gw && !gw_def_choose_new_ipv6_gw) {
/* stop looking for a better gateway */
olsr_stop_timer(gw_def_timer);
gw_def_timer = NULL;
}
}
