#ifndef lint
static char copyright[] =
-"$Id: dhcp.c,v 1.46 1997/03/06 20:23:27 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
+"$Id: dhcp.c,v 1.47 1997/05/09 08:27:14 mellon Exp $ Copyright (c) 1995, 1996 The Internet Software Consortium. All rights reserved.\n";
#endif /* not lint */
#include "dhcpd.h"
/* Find the lease that matches the address requested by the
client. */
- if (packet -> shared_network)
- lease = find_lease (packet, packet -> shared_network);
+
+ if (subnet)
+ lease = find_lease (packet, subnet -> shared_network);
else
lease = (struct lease *)0;
? inet_ntoa (packet -> raw -> giaddr)
: packet -> interface -> name);
- /* If a client on a given network wants to request a lease on
- an address on a different network, NAK it. If the Requested
- Address option was used, the protocol says that it must have
- been broadcast, so we can trust the source network information.
+ /* If a client on a given network REQUESTs a lease on an
+ address on a different network, NAK it. If the Requested
+ Address option was used, the protocol says that it must
+ have been broadcast, so we can trust the source network
+ information.
If ciaddr was specified and Requested Address was not, then
we really only know for sure what network a packet came from
if it came through a BOOTP gateway - if it came through an
IP router, we'll just have to assume that it's cool.
- This violates the protocol spec in the case that the client
- is in the INIT-REBOOT state and broadcasts a DHCPREQUEST on
- the local wire. We're supposed to check ciaddr for
- validity in that case, but if the packet was unicast
- through a router from a client in the RENEWING state, it
- would look exactly the same to us and it would be very
- bad to send a DHCPNAK. I think we just have to live with
- this. */
- if ((packet -> raw -> ciaddr.s_addr &&
+ If we don't think we know where the packet came from, it
+ came through a gateway from an unknown network, so it's not
+ from a RENEWING client. If we recognize the network it
+ *thinks* it's on, we can NAK it even though we don't
+ recognize the network it's *actually* on; otherwise we just
+ have to ignore it.
+
+ We don't currently try to take advantage of access to the
+ raw packet, because it's not available on all platforms.
+ So a packet that was unicast to us through a router from a
+ RENEWING client is going to look exactly like a packet that
+ was broadcast to us from an INIT-REBOOT client.
+
+ Since we can't tell the difference between these two kinds
+ of packets, if the packet appears to have come in off the
+ local wire, we have to treat it as if it's a RENEWING
+ client. This means that we can't NAK a RENEWING client on
+ the local wire that has a bogus address. The good news is
+ that we won't ACK it either, so it should revert to INIT
+ state and send us a DHCPDISCOVER, which we *can* work with.
+
+ Because we can't detect that a RENEWING client is on the
+ wrong wire, it's going to sit there trying to renew until
+ it gets to the REBIND state, when we *can* NAK it because
+ the packet will get to us through a BOOTP gateway. We
+ shouldn't actually see DHCPREQUEST packets from RENEWING
+ clients on the wrong wire anyway, since their idea of their
+ local router will be wrong. In any case, the protocol
+ doesn't really allow us to NAK a DHCPREQUEST from a
+ RENEWING client, so we can punt on this issue. */
+
+ if (!packet -> shared_network ||
+ (packet -> raw -> ciaddr.s_addr &&
packet -> raw -> giaddr.s_addr) ||
packet -> options [DHO_DHCP_REQUESTED_ADDRESS].len) {
return;
}
- /* If we do know where it came from and either we don't
- know where it came from at all or it came from a different
- shared network than the packet came from, send a nak. */
+ /* If we do know where it came from and it asked for an
+ address that is not on that shared network, nak it. */
subnet = find_grouped_subnet (packet -> shared_network, cip);
if (!subnet) {
nak_lease (packet, &cip);
#endif
} else {
to.sin_addr.s_addr = htonl (INADDR_BROADCAST);
- to.sin_port = packet->client_port;
+ to.sin_port = remote_port;
}
errno = 0;
user_class = (struct class *)0;
}
+ /* Replace the old lease hostname with the new one, if it's changed. */
+ if (packet -> options [DHO_HOST_NAME].len &&
+ lease -> client_hostname &&
+ (strlen (lease -> client_hostname) ==
+ packet -> options [DHO_HOST_NAME].len) &&
+ !memcmp (lease -> client_hostname,
+ packet -> options [DHO_HOST_NAME].data,
+ packet -> options [DHO_HOST_NAME].len)) {
+ } else if (packet -> options [DHO_HOST_NAME].len) {
+ if (lease -> client_hostname)
+ free (lease -> client_hostname);
+ lease -> client_hostname =
+ malloc (packet -> options [DHO_HOST_NAME].len + 1);
+ if (!lease -> client_hostname)
+ error ("no memory for client hostname.\n");
+ memcpy (lease -> client_hostname,
+ packet -> options [DHO_HOST_NAME].data,
+ packet -> options [DHO_HOST_NAME].len);
+ lease -> client_hostname
+ [packet -> options [DHO_HOST_NAME].len] = 0;
+ } else if (lease -> client_hostname) {
+ free (lease -> client_hostname);
+ lease -> client_hostname = 0;
+ }
+
/* Choose a filename; first from the host_decl, if any, then from
the user class, then from the vendor class. */
if (lease -> host && lease -> host -> group -> filename)
/* Remember the giaddr, xid, secs, flags and hops. */
state -> giaddr = packet -> raw -> giaddr;
- state -> ciaddr = packet -> raw -> giaddr;
+ state -> ciaddr = packet -> raw -> ciaddr;
state -> xid = packet -> raw -> xid;
state -> secs = packet -> raw -> secs;
state -> bootp_flags = packet -> raw -> flags;
projects / thirdparty / dhcp.git / commitdiff
