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);
}
/* NOINLINE: limit stack usage in caller */
static NOINLINE void send_offer(struct dhcp_packet *oldpacket,
uint32_t static_lease_nip,
struct dyn_lease *lease,
uint8_t *requested_ip_opt,
unsigned arpping_ms)
{
struct dhcp_packet packet;
uint32_t lease_time_sec;
struct in_addr addr;
init_packet(&packet, oldpacket, DHCPOFFER);
/* If it is a static lease, use its IP */
packet.yiaddr = static_lease_nip;
/* Else: */
if (!static_lease_nip) {
/* We have no static lease for client's chaddr */
uint32_t req_nip;
const char *p_host_name;
if (lease) {
/* We have a dynamic lease for client's chaddr.
* Reuse its IP (even if lease is expired).
* Note that we ignore requested IP in this case.
*/
packet.yiaddr = lease->lease_nip;
}
/* Or: if client has requested an IP */
else if (requested_ip_opt != NULL
/* (read IP) */
&& (move_from_unaligned32(req_nip, requested_ip_opt), 1)
/* and the IP is in the lease range */
&& ntohl(req_nip) >= server_config.start_ip
&& ntohl(req_nip) <= server_config.end_ip
/* and */
&& ( !(lease = find_lease_by_nip(req_nip)) /* is not already taken */
|| is_expired_lease(lease) /* or is taken, but expired */
)
) {
packet.yiaddr = req_nip;
}
else {
/* Otherwise, find a free IP */
packet.yiaddr = find_free_or_expired_nip(oldpacket->chaddr, arpping_ms);
}
if (!packet.yiaddr) {
bb_error_msg("no free IP addresses. OFFER abandoned");
return;
}
/* Reserve the IP for a short time hoping to get DHCPREQUEST soon */
p_host_name = (const char*) udhcp_get_option(oldpacket, DHCP_HOST_NAME);
lease = add_lease(packet.chaddr, packet.yiaddr,
server_config.offer_time,
p_host_name,
p_host_name ? (unsigned char)p_host_name[OPT_LEN - OPT_DATA] : 0
);
if (!lease) {
bb_error_msg("no free IP addresses. OFFER abandoned");
return;
}
}
lease_time_sec = select_lease_time(oldpacket);
udhcp_add_simple_option(&packet, DHCP_LEASE_TIME, htonl(lease_time_sec));
add_server_options(&packet);
addr.s_addr = packet.yiaddr;
bb_info_msg("Sending OFFER of %s", inet_ntoa(addr));
/* send_packet emits error message itself if it detects failure */
send_packet(&packet, /*force_bcast:*/ 0);
}
