static void send_ACK(GDHCPServer *dhcp_server,
struct dhcp_packet *client_packet, uint32_t dest)
{
struct dhcp_packet packet;
uint32_t lease_time_sec;
struct in_addr addr;
init_packet(dhcp_server, &packet, client_packet, DHCPACK);
packet.yiaddr = htonl(dest);
lease_time_sec = dhcp_server->lease_seconds;
dhcp_add_option_uint32(&packet, DHCP_LEASE_TIME, lease_time_sec);
add_server_options(dhcp_server, &packet);
addr.s_addr = htonl(dest);
debug(dhcp_server, "Sending ACK to %s", inet_ntoa(addr));
send_packet_to_client(dhcp_server, &packet);
add_lease(dhcp_server, 0, packet.chaddr, packet.yiaddr);
if (dhcp_server->event_fn)
dhcp_server->event_fn(ether_ntoa((void*)packet.chaddr),
inet_ntoa(addr),
dhcp_server->fn_data);
}
static void init_packet(GDHCPServer *dhcp_server, struct dhcp_packet *packet,
struct dhcp_packet *client_packet, char type)
{
/* Sets op, htype, hlen, cookie fields
* and adds DHCP_MESSAGE_TYPE option */
dhcp_init_header(packet, type);
packet->xid = client_packet->xid;
memcpy(packet->chaddr, client_packet->chaddr,
sizeof(client_packet->chaddr));
packet->flags = client_packet->flags;
packet->gateway_nip = client_packet->gateway_nip;
packet->ciaddr = client_packet->ciaddr;
dhcp_add_option_uint32(packet, DHCP_SERVER_ID,
dhcp_server->server_nip);
}
static void send_offer(GDHCPServer *dhcp_server,
struct dhcp_packet *client_packet,
struct dhcp_lease *lease,
uint32_t requested_nip)
{
struct dhcp_packet packet;
struct in_addr addr;
init_packet(dhcp_server, &packet, client_packet, DHCPOFFER);
if (lease)
packet.yiaddr = htonl(lease->lease_nip);
else if (check_requested_nip(dhcp_server, requested_nip))
packet.yiaddr = htonl(requested_nip);
else
packet.yiaddr = htonl(find_free_or_expired_nip(
dhcp_server, client_packet->chaddr));
debug(dhcp_server, "find yiaddr %u", packet.yiaddr);
if (!packet.yiaddr) {
debug(dhcp_server, "Err: Can not found lease and send offer");
return;
}
lease = add_lease(dhcp_server, OFFER_TIME,
packet.chaddr, packet.yiaddr);
if (!lease) {
debug(dhcp_server,
"Err: No free IP addresses. OFFER abandoned");
return;
}
dhcp_add_option_uint32(&packet, DHCP_LEASE_TIME,
dhcp_server->lease_seconds);
add_server_options(dhcp_server, &packet);
addr.s_addr = packet.yiaddr;
debug(dhcp_server, "Sending OFFER of %s", inet_ntoa(addr));
send_packet_to_client(dhcp_server, &packet);
}
static void add_option(gpointer key, gpointer value, gpointer user_data)
{
const char *option_value = value;
uint8_t option_code = GPOINTER_TO_INT(key);
struct in_addr nip;
struct dhcp_packet *packet = user_data;
if (!option_value)
return;
switch (option_code) {
case G_DHCP_SUBNET:
case G_DHCP_ROUTER:
case G_DHCP_DNS_SERVER:
if (inet_aton(option_value, &nip) == 0)
return;
dhcp_add_option_uint32(packet, (uint8_t) option_code,
ntohl(nip.s_addr));
break;
default:
return;
}
}
