int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) {
bool need_restart = false;
assert_return(ll, -EINVAL);
assert_return(addr, -EINVAL);
if (memcmp(&ll->mac_addr, addr, ETH_ALEN) == 0)
return 0;
if (!IN_SET(ll->state, IPV4LL_STATE_INIT, IPV4LL_STATE_STOPPED)) {
log_ipv4ll(ll, "Changing MAC address on running IPv4LL "
"client, restarting");
ll = ipv4ll_stop(ll, IPV4LL_EVENT_STOP);
need_restart = true;
}
if (!ll)
return 0;
memcpy(&ll->mac_addr, addr, ETH_ALEN);
if (need_restart)
sd_ipv4ll_start(ll);
return 0;
}
int arp_packet_verify_headers(struct ether_arp *arp) {
assert(arp);
if (arp->ea_hdr.ar_hrd != htons(ARPHRD_ETHER)) {
log_ipv4ll(NULL, "ignoring packet: header is not ARPHRD_ETHER");
return -EINVAL;
}
if (arp->ea_hdr.ar_pro != htons(ETHERTYPE_IP)) {
log_ipv4ll(NULL, "ignoring packet: protocol is not ETHERTYPE_IP");
return -EINVAL;
}
if (arp->ea_hdr.ar_op != htons(ARPOP_REQUEST) &&
arp->ea_hdr.ar_op != htons(ARPOP_REPLY)) {
log_ipv4ll(NULL, "ignoring packet: operation is not ARPOP_REQUEST or ARPOP_REPLY");
return -EINVAL;
}
return 0;
}
static sd_ipv4ll *ipv4ll_stop(sd_ipv4ll *ll, int event) {
assert(ll);
ll->receive_message = sd_event_source_unref(ll->receive_message);
ll->fd = safe_close(ll->fd);
ll->timer = sd_event_source_unref(ll->timer);
log_ipv4ll(ll, "STOPPED");
ll = ipv4ll_client_notify(ll, event);
if (ll) {
ll->claimed_address = 0;
ipv4ll_set_state (ll, IPV4LL_STATE_INIT, 1);
}
return ll;
}
static int ipv4ll_stop(sd_ipv4ll *ll, int event) {
assert(ll);
ll->receive_message = sd_event_source_unref(ll->receive_message);
if (ll->fd >= 0)
close_nointr_nofail(ll->fd);
ll->fd = -1;
ll->timer = sd_event_source_unref(ll->timer);
ipv4ll_client_notify(ll, event);
ll->claimed_address = 0;
ipv4ll_set_state (ll, IPV4LL_STATE_INIT, 1);
log_ipv4ll(ll, "STOPPED");
return 0;
}
static void ipv4ll_run_state_machine(sd_ipv4ll *ll, IPv4LLTrigger trigger, void *trigger_data) {
struct ether_arp out_packet;
int out_packet_ready = 0;
int r = 0;
assert(ll);
assert(trigger < _IPV4LL_TRIGGER_MAX);
if (ll->state == IPV4LL_STATE_INIT) {
log_ipv4ll(ll, "PROBE");
ipv4ll_set_state(ll, IPV4LL_STATE_WAITING_PROBE, 1);
ipv4ll_set_next_wakeup(ll, 0, PROBE_WAIT);
} else if ((ll->state == IPV4LL_STATE_WAITING_PROBE && trigger == IPV4LL_TRIGGER_TIMEOUT) ||
(ll->state == IPV4LL_STATE_PROBING && trigger == IPV4LL_TRIGGER_TIMEOUT && ll->iteration < PROBE_NUM-2)) {
/* Send a probe */
arp_packet_probe(&out_packet, ll->address, &ll->mac_addr);
out_packet_ready = 1;
ipv4ll_set_state(ll, IPV4LL_STATE_PROBING, 0);
ipv4ll_set_next_wakeup(ll, PROBE_MIN, (PROBE_MAX-PROBE_MIN));
} else if (ll->state == IPV4LL_STATE_PROBING && trigger == IPV4LL_TRIGGER_TIMEOUT && ll->iteration >= PROBE_NUM-2) {
/* Send the last probe */
arp_packet_probe(&out_packet, ll->address, &ll->mac_addr);
out_packet_ready = 1;
ipv4ll_set_state(ll, IPV4LL_STATE_WAITING_ANNOUNCE, 1);
ipv4ll_set_next_wakeup(ll, ANNOUNCE_WAIT, 0);
} else if ((ll->state == IPV4LL_STATE_WAITING_ANNOUNCE && trigger == IPV4LL_TRIGGER_TIMEOUT) ||
(ll->state == IPV4LL_STATE_ANNOUNCING && trigger == IPV4LL_TRIGGER_TIMEOUT && ll->iteration < ANNOUNCE_NUM-1)) {
/* Send announcement packet */
arp_packet_announcement(&out_packet, ll->address, &ll->mac_addr);
out_packet_ready = 1;
ipv4ll_set_state(ll, IPV4LL_STATE_ANNOUNCING, 0);
ipv4ll_set_next_wakeup(ll, ANNOUNCE_INTERVAL, 0);
if (ll->iteration == 0) {
log_ipv4ll(ll, "ANNOUNCE");
ll->claimed_address = ll->address;
ll = ipv4ll_client_notify(ll, IPV4LL_EVENT_BIND);
if (!ll || ll->state == IPV4LL_STATE_STOPPED)
goto out;
ll->conflict = 0;
}
} else if ((ll->state == IPV4LL_STATE_ANNOUNCING && trigger == IPV4LL_TRIGGER_TIMEOUT &&
ll->iteration >= ANNOUNCE_NUM-1)) {
ipv4ll_set_state(ll, IPV4LL_STATE_RUNNING, 0);
ll->next_wakeup_valid = 0;
} else if (trigger == IPV4LL_TRIGGER_PACKET) {
int conflicted = 0;
usec_t time_now;
struct ether_arp* in_packet = (struct ether_arp*)trigger_data;
assert(in_packet);
if (IN_SET(ll->state, IPV4LL_STATE_ANNOUNCING, IPV4LL_STATE_RUNNING)) {
if (ipv4ll_arp_conflict(ll, in_packet)) {
r = sd_event_now(ll->event, clock_boottime_or_monotonic(), &time_now);
if (r < 0)
goto out;
/* Defend address */
if (time_now > ll->defend_window) {
ll->defend_window = time_now + DEFEND_INTERVAL * USEC_PER_SEC;
arp_packet_announcement(&out_packet, ll->address, &ll->mac_addr);
out_packet_ready = 1;
} else
conflicted = 1;
}
} else if (IN_SET(ll->state, IPV4LL_STATE_WAITING_PROBE,
IPV4LL_STATE_PROBING,
IPV4LL_STATE_WAITING_ANNOUNCE)) {
conflicted = ipv4ll_arp_probe_conflict(ll, in_packet);
}
if (conflicted) {
log_ipv4ll(ll, "CONFLICT");
ll = ipv4ll_client_notify(ll, IPV4LL_EVENT_CONFLICT);
if (!ll || ll->state == IPV4LL_STATE_STOPPED)
goto out;
ll->claimed_address = 0;
/* Pick a new address */
r = ipv4ll_pick_address(ll, &ll->address);
if (r < 0)
goto out;
ll->conflict++;
ll->defend_window = 0;
ipv4ll_set_state(ll, IPV4LL_STATE_WAITING_PROBE, 1);
if (ll->conflict >= MAX_CONFLICTS) {
log_ipv4ll(ll, "MAX_CONFLICTS");
ipv4ll_set_next_wakeup(ll, RATE_LIMIT_INTERVAL, PROBE_WAIT);
} else
ipv4ll_set_next_wakeup(ll, 0, PROBE_WAIT);
}
}
if (out_packet_ready) {
r = arp_network_send_raw_socket(ll->fd, &ll->link, &out_packet);
if (r < 0) {
log_ipv4ll(ll, "failed to send arp packet out");
goto out;
}
}
if (ll->next_wakeup_valid) {
ll->timer = sd_event_source_unref(ll->timer);
r = sd_event_add_time(ll->event, &ll->timer, clock_boottime_or_monotonic(),
ll->next_wakeup, 0, ipv4ll_timer, ll);
if (r < 0)
goto out;
r = sd_event_source_set_priority(ll->timer, ll->event_priority);
if (r < 0)
goto out;
r = sd_event_source_set_description(ll->timer, "ipv4ll-timer");
if (r < 0)
goto out;
}
out:
if (r < 0 && ll)
ipv4ll_stop(ll, r);
}
