int main(int argc, char const* argv[]) {
Input default_gateway_input;
Input address;
const Entry* entry;
RouterTrie rt;
// default_gateway_input = rt_create_default_gateway_input(
// rt_convert_string_to_address("2001::1"), 0);
rt_setup(&rt);
// rt_default_gateway(&rt, &default_gateway_input);
address.prefix_length = 64;
address.interface = 1;
address.next_hop = rt_convert_string_to_address("::1");
address.address = rt_convert_string_to_address("2a00:1450:4001:817::0");
rt_insert(&rt, &address);
address.prefix_length = 64;
address.interface = 2;
address.next_hop = rt_convert_string_to_address("::2");
address.address = rt_convert_string_to_address("2aff:1450:4001:817::0");
rt_insert(&rt, &address);
address.address = rt_convert_string_to_address("2aff:1450:4001:817::0");
entry = rt_match(&rt, &address.address);
printf("%d\n", entry ? entry->interface : 0);
rt_destroy(&rt);
return 0;
}
/**
* Handles incoming routing-request packets.
*/
static void krip_dispatch_in()
{
fd_set fds;
struct timeval timeout;
int rc;
int i;
list_position pos;
rip_info *ri;
FD_ZERO(&fds);
FD_SET(_sock, &fds);
timeout.tv_sec = 0;
timeout.tv_usec = 0;
/* The main loop of the RIP daemon. */
while ((rc = select(_sock + 1, &fds, NULL, NULL, &timeout)) > 0) {
rip_buf buf;
uint32_t now = krip_get_mtime();
size_t len = RIP_PACKET_MAXSIZ;
struct sockaddr_in from;
size_t fromlen = sizeof(from);
len = recvfrom(_sock, buf.buf, len, 0, (struct sockaddr *)&from, &fromlen);
/* Find the sender by matching IP addresses and ports. */
neighbor_info *ni = NULL;
pos = list_get_head_position(_neighbor_info_list);
for (; pos; pos = list_get_next_position(pos)) {
ni = list_get_at(pos);
if (from.sin_addr.s_addr == ni->krip_addr.sin_addr.s_addr &&
from.sin_port == ni->krip_addr.sin_port)
break;
/* Should be reset to perform below check routines correctly.
(ref http://noah.kaist.ac.kr/view.jsp?board=1353&serial=517685) */
ni = NULL;
}
/* If the sender is not recoginized, skip the RIP message. */
if (!ni) {
L_ROUTE("krip_dispatch_in(): unknown neighbor %s:%d", inet_ntoa(from.sin_addr), ntohs(from.sin_port));
continue;
}
/* If the interface received is disabled, also skip it. */
if (!ni->ifp->if_enabled) {
L_ROUTE("krip_dispatch_in(): ignored response from %s {%08x}", inet_ntoa(ni->virtual_addr), ni->ifp);
continue;
}
/* Process RIP packets. */
switch (buf.rip_packet.command) {
case RIP_REQUEST:
/* Response to the request. */
L_ROUTE("krip_dispatch_in(): RIP_REQUEST from %s {%08x}", inet_ntoa(ni->virtual_addr), ni->ifp);
krip_send_response(ni, 0);
break;
case RIP_RESPONSE:
/* RIP 응답 패킷을 받으면 그것을 바탕으로 자신의 routing table 정보를 업데이트한다. */
i = 0;
L_ROUTE("krip_dispatch_in(): RIP_RESPONSE from %s {%08x} with %d entries.",
inet_ntoa(ni->virtual_addr),
ni->ifp,
(len - RIP_HEADER_SIZE) / RIP_RTE_SIZE);
/* Look up the received routing table entries. */
while (1) {
bool found = false;
rte *rte = buf.rip_packet.rte + i;
/* Convert endians. */
rte->family = ntohs(rte->family);
rte->tag = ntohs(rte->tag);
rte->metric = ntohl(rte->metric);
/* Stop if the index reaches the number of available routing entries in the packet. */
if (i == (len - RIP_HEADER_SIZE) / RIP_RTE_SIZE)
break;
L_ROUTE("krip_dispatch_in(): processing entry %d (prefix=%s, mask=%s, metric=%d)", i + 1,
inet_ntoa(rte->prefix),
inet_ntoa(rte->mask),
rte->metric);
/* 여기에서 distance vector 알고리즘이 구현된다. */
/* Choose minimum of received metric + 1 and inifinity. */
uint32_t new_metric = MIN(rte->metric + 1, RIP_METRIC_INFINITY);
for (pos = list_get_head_position(_rip_info_list); pos; pos = list_get_next_position(pos)) {
ri = list_get_at(pos);
/* 여기에서 match된다는 뜻은 어디로 해당 IP 대역을 담당하는 routing entry를 찾았다는 뜻이다. */
/* If a routing_info matches an entry, update related information. */
if (ri->assoc_rte->dst.s_addr == rte->prefix.s_addr) {
L_ROUTE("krip_dispatch_in(): ri->assoc_rte->dst = %s {%08x} has to be updated.",
inet_ntoa(ri->assoc_rte->dst),
ri->from);
found = true;
/* If ri is from the neighbor which sent the RIP message, refresh timeout. */
if (ri->from == ni->ifp) {
ri->timeout = now + _timeout;
}
/* 현재 보고 있는 rip_info가 RIP message를 받은 interface로부터 온 것이고 metric 값이 바뀌거나,
새 metric 값이 더 낮을 경우(더 좋은 route임을 뜻함) rip_info를 새로 업데이트한다.
(ref http://noah.kaist.ac.kr/view.jsp?board=1248&serial=509303) */
if ((ri->from == ni->ifp && new_metric != ri->metric) || (ri->metric > new_metric)) {
/* If previous ri was advertised by the sender, or the new route has lower metric,
update ri. */
L_ROUTE("krip_dispatch_in(): updating existing routing info... (gw = %s {%08x}, metric = %d)",
inet_ntoa(ni->virtual_addr),
ni->ifp,
new_metric);
ri->assoc_rte->gw.s_addr = ni->virtual_addr.s_addr;
ri->assoc_rte->rt_ifp = ni->ifp;
ri->metric = new_metric;
ri->change_flag = 1; /* Mark it as modified. */
ri->from = ni->ifp;
ip_invalidate_forward_rt_cache();
_trigger = true;
}
}
}
if (!found) {
/* If matching routing info is not found, create a new routing entry and routing info. */
L_ROUTE("krip_dispatch_in(): creating a new routing entry...");
rtentry *new_rte = (rtentry *)malloc(sizeof(rtentry));
new_rte->dst = rte->prefix;
new_rte->mask = rte->mask;
new_rte->gw = ni->virtual_addr;
new_rte->rt_ifp = ni->ifp;
if (rt_insert(new_rte)) {
L_ROUTE("krip_dispatch_in(): failed to insert new route");
free(new_rte);
break;
}
ri = (rip_info *)malloc(sizeof(rip_info));
ri->assoc_rte = new_rte;
ri->metric = new_metric;
ri->change_flag = 1; /* Mark it as modified. */
ri->timeout = now + _timeout; /* Initialize timeout. */
ri->from = ni->ifp;
list_add_tail(_rip_info_list, ri);
ip_invalidate_forward_rt_cache();
_trigger = true;
}
i++;
}
break;
default:
L_ROUTE("krip_dispatch_in(): unrecognized RIP command type (%d) from %s.",
buf.rip_packet.command,
inet_ntoa(ni->virtual_addr));
break;
}
}
if (rc < 0)
perror("krip");
}
int
rde_check_route(struct rip_route *e)
{
struct timeval tv, now;
struct rt_node *rn;
struct iface *iface;
u_int8_t metric;
if ((e->nexthop.s_addr & htonl(IN_CLASSA_NET)) ==
htonl(INADDR_LOOPBACK & IN_CLASSA_NET) ||
e->nexthop.s_addr == INADDR_ANY)
return (-1);
if ((iface = if_find_index(e->ifindex)) == NULL)
return (-1);
metric = MIN(INFINITY, e->metric + iface->cost);
if ((rn = rt_find(e->address.s_addr, e->mask.s_addr)) == NULL) {
if (metric >= INFINITY)
return (0);
rn = rt_new_rr(e, metric);
rt_insert(rn);
rde_send_change_kroute(rn);
route_start_timeout(rn);
triggered_update(rn);
} else {
/*
* XXX don't we have to track all incoming routes?
* what happens if the kernel route is removed later.
*/
if (rn->flags & F_KERNEL)
return (0);
if (metric < rn->metric) {
rn->metric = metric;
rn->nexthop.s_addr = e->nexthop.s_addr;
rn->ifindex = e->ifindex;
rde_send_change_kroute(rn);
triggered_update(rn);
} else if (e->nexthop.s_addr == rn->nexthop.s_addr &&
metric > rn->metric) {
rn->metric = metric;
rde_send_change_kroute(rn);
triggered_update(rn);
if (rn->metric == INFINITY)
route_start_garbage(rn);
} else if (e->nexthop.s_addr != rn->nexthop.s_addr &&
metric == rn->metric) {
/* If the new metric is the same as the old one,
* examine the timeout for the existing route. If it
* is at least halfway to the expiration point, switch
* to the new route.
*/
timerclear(&tv);
gettimeofday(&now, NULL);
evtimer_pending(&rn->timeout_timer, &tv);
if (tv.tv_sec - now.tv_sec < ROUTE_TIMEOUT / 2) {
rn->nexthop.s_addr = e->nexthop.s_addr;
rn->ifindex = e->ifindex;
rde_send_change_kroute(rn);
}
}
if (e->nexthop.s_addr == rn->nexthop.s_addr &&
rn->metric < INFINITY)
route_reset_timers(rn);
}
return (0);
}
/* ARGSUSED */
void
rde_dispatch_parent(int fd, short event, void *bula)
{
struct imsg imsg;
struct rt_node *rt;
struct kroute kr;
struct imsgev *iev = bula;
struct imsgbuf *ibuf = &iev->ibuf;
ssize_t n;
int shut = 0;
if (event & EV_READ) {
if ((n = imsg_read(ibuf)) == -1)
fatal("imsg_read error");
if (n == 0) /* connection closed */
shut = 1;
}
if (event & EV_WRITE) {
if (msgbuf_write(&ibuf->w) == -1 && errno != EAGAIN)
fatal("msgbuf_write");
}
for (;;) {
if ((n = imsg_get(ibuf, &imsg)) == -1)
fatal("rde_dispatch_parent: imsg_read error");
if (n == 0)
break;
switch (imsg.hdr.type) {
case IMSG_NETWORK_ADD:
if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(kr)) {
log_warnx("rde_dispatch: wrong imsg len");
break;
}
memcpy(&kr, imsg.data, sizeof(kr));
rt = rt_new_kr(&kr);
rt_insert(rt);
break;
case IMSG_NETWORK_DEL:
if (imsg.hdr.len - IMSG_HEADER_SIZE != sizeof(kr)) {
log_warnx("rde_dispatch: wrong imsg len");
break;
}
memcpy(&kr, imsg.data, sizeof(kr));
if ((rt = rt_find(kr.prefix.s_addr,
kr.netmask.s_addr)) != NULL)
rt_remove(rt);
break;
default:
log_debug("rde_dispatch_parent: unexpected imsg %d",
imsg.hdr.type);
break;
}
imsg_free(&imsg);
}
if (!shut)
imsg_event_add(iev);
else {
/* this pipe is dead, so remove the event handler */
event_del(&iev->ev);
event_loopexit(NULL);
}
}