static void handle_dhcpv4(void *addr, void *data, size_t len,
- struct interface *iface);
+ struct interface *iface, void *dest_addr);
static struct dhcpv4_assignment* dhcpv4_lease(struct interface *iface,
enum dhcpv4_msg msg, const uint8_t *mac, struct in_addr reqaddr,
const char *hostname);
// Simple DHCPv6-server for information requests
static void handle_dhcpv4(void *addr, void *data, size_t len,
- struct interface *iface)
+ struct interface *iface, _unused void *dest_addr)
{
if (!iface->dhcpv4)
return;
return;
} else if (reqmsg == DHCPV4_MSG_DISCOVER) {
msg = DHCPV4_MSG_OFFER;
+ } else if (reqmsg == DHCPV4_MSG_REQUEST && reqaddr.s_addr &&
+ reqaddr.s_addr != htonl(lease->addr)) {
+ msg = DHCPV4_MSG_NAK;
+ /*
+ * DHCP client requested an IP which we can't offer to him. Probably the
+ * client changed the network. The reply type is set to DHCPV4_MSG_NAK,
+ * because the client should not use that IP.
+ *
+ * For modern devices we build an answer that includes a valid IP, like
+ * a DHCPV4_MSG_ACK. The client will use that IP and doesn't need to
+ * perform additional DHCP round trips.
+ *
+ */
}
if (reqmsg == DHCPV4_MSG_DECLINE || reqmsg == DHCPV4_MSG_RELEASE)
len, search_buf);
}
- dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER, 4, &ifaddr.sin_addr);
-
+ if (iface->dhcpv4_router_cnt == 0)
+ dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER, 4, &ifaddr.sin_addr);
+ else
+ dhcpv4_put(&reply, &cookie, DHCPV4_OPT_ROUTER,
+ 4 * iface->dhcpv4_router_cnt, iface->dhcpv4_router);
if (iface->dhcpv4_dns_cnt == 0)
dest.sin_addr = req->ciaddr;
dest.sin_port = htons(DHCPV4_CLIENT_PORT);
} else if ((ntohs(req->flags) & DHCPV4_FLAG_BROADCAST) ||
- req->hlen != reply.hlen) {
+ req->hlen != reply.hlen || !reply.yiaddr.s_addr) {
dest.sin_addr.s_addr = INADDR_BROADCAST;
dest.sin_port = htons(DHCPV4_CLIENT_PORT);
} else {
}
}
- bool update_state = false;
if (msg == DHCPV4_MSG_DISCOVER || msg == DHCPV4_MSG_REQUEST) {
bool assigned = !!a;
size_t hostlen = strlen(hostname) + 1;
a = NULL;
}
- if (a)
- update_state = true;
-
if (assigned && a)
lease = a;
} else if (msg == DHCPV4_MSG_RELEASE) {
if (a) {
a->valid_until = 0;
- update_state = true;
}
} else if (msg == DHCPV4_MSG_DECLINE) {
memset(a->hwaddr, 0, sizeof(a->hwaddr));
a->valid_until = now + 3600; // Block address for 1h
- update_state = true;
}
- if (update_state)
- dhcpv6_write_statefile();
+ dhcpv6_write_statefile();
return lease;
}