void
ni_dhcp4_fsm_process_arp_packet(ni_arp_socket_t *arph, const ni_arp_packet_t *pkt, void *user_data)
{
ni_dhcp4_device_t *dev = user_data;
ni_netconfig_t *nc = ni_global_state_handle(0);
const ni_netdev_t *ifp;
ni_bool_t false_alarm = FALSE;
ni_bool_t found_addr = FALSE;
if (!pkt || pkt->op != ARPOP_REPLY || !dev || !dev->lease)
return;
/* Is it about the address we're validating at all? */
if (pkt->sip.s_addr != dev->lease->dhcp4.address.s_addr)
return;
/* Ignore any ARP replies that seem to come from our own
* MAC address. Some helpful switches seem to generate
* these. */
if (ni_link_address_equal(&dev->system.hwaddr, &pkt->sha))
return;
/* As well as ARP replies that seem to come from our own
* host: dup if same address, not a dup if there are two
* interfaces connected to the same broadcast domain.
*/
for (ifp = ni_netconfig_devlist(nc); ifp; ifp = ifp->next) {
if (ifp->link.ifindex == dev->link.ifindex)
continue;
if (!ni_netdev_link_is_up(ifp))
continue;
if (!ni_link_address_equal(&ifp->link.hwaddr, &pkt->sha))
continue;
/* OK, we have an interface matching the hwaddr,
* which will answer arp requests when it is on
* the same broadcast domain and causes a false
* alarm, except it really has the IP assigned.
*/
false_alarm = TRUE;
if (__ni_dhcp4_address_on_device(ifp, pkt->sip))
found_addr = TRUE;
}
if (false_alarm && !found_addr)
return;
ni_debug_dhcp("%s: address %s already in use by %s",
dev->ifname, inet_ntoa(pkt->sip),
ni_link_address_print(&pkt->sha));
ni_dhcp4_device_arp_close(dev);
ni_dhcp4_fsm_decline(dev);
}
static void
ni_dhcp4_device_close(ni_dhcp4_device_t *dev)
{
ni_capture_free(dev->capture);
dev->capture = NULL;
if (dev->listen_fd >= 0)
close(dev->listen_fd);
dev->listen_fd = -1;
if (dev->fsm.timer) {
ni_warn("%s: timer active for %s", __func__, dev->ifname);
ni_timer_cancel(dev->fsm.timer);
dev->fsm.timer = NULL;
}
ni_dhcp4_device_arp_close(dev);
}
void
ni_dhcp4_fsm_link_down(ni_dhcp4_device_t *dev)
{
if (dev->config == NULL)
return;
switch (dev->fsm.state) {
case NI_DHCP4_STATE_INIT:
case NI_DHCP4_STATE_SELECTING:
case NI_DHCP4_STATE_REQUESTING:
case NI_DHCP4_STATE_VALIDATING:
ni_dhcp4_device_arp_close(dev);
ni_dhcp4_device_drop_lease(dev);
ni_dhcp4_fsm_restart(dev);
break;
default: ;
}
}
int
ni_dhcp4_fsm_arp_validate(ni_dhcp4_device_t *dev)
{
struct in_addr null = { 0 };
struct in_addr claim;
if (!dev || !dev->lease)
return -1;
claim = dev->lease->dhcp4.address;
if (dev->arp.handle == NULL) {
dev->arp.handle = ni_arp_socket_open(&dev->system,
ni_dhcp4_fsm_process_arp_packet, dev);
if (!dev->arp.handle->user_data) {
ni_error("%s: unable to create ARP handle", dev->ifname);
return -1;
}
}
if (dev->arp.nprobes) {
ni_debug_dhcp("%s: arp validate: probing for %s",
dev->ifname, inet_ntoa(claim));
ni_arp_send_request(dev->arp.handle, null, claim);
dev->arp.nprobes--;
} else if (dev->arp.nclaims) {
ni_debug_dhcp("%s: arp validate: claiming %s",
dev->ifname, inet_ntoa(claim));
ni_arp_send_grat_request(dev->arp.handle, claim);
dev->arp.nclaims--;
} else {
/* Wow, we're done! */
ni_info("%s: Successfully validated DHCPv4 address %s",
dev->ifname, inet_ntoa(claim));
ni_dhcp4_fsm_commit_lease(dev, dev->lease);
ni_dhcp4_device_arp_close(dev);
return 0;
}
ni_dhcp4_fsm_set_timeout_msec(dev, NI_DHCP4_ARP_TIMEOUT);
return 0;
}