Merge rt14941 - Less lunatic handling of ACTIVE leases in discover.

diff --git a/RELNOTES b/RELNOTES
index dac334c533ce1389b91e7e9c7ca11dfc53695061..b900272be244f89a35f6b1c9f315a7af0cf245c3 100644 (file)
--- a/RELNOTES
+++ b/RELNOTES
@@ -54,6 +54,11 @@ and for prodding me into improving it.
   a non-ACTIVE lease out of storage for a client that was returning to use
   a lease it once had long ago, and had since expired.
 
+- Failover peers no longer bother to look for free leases to allocate when
+  they already found the client's ACTIVE lease.  DISCOVERs are load balanced
+  wether freely-allocated or not, unless the server doubts the peer has
+  leases to allocate.
+
                        Changes since 3.0.3b3
 
 - dhclient.conf documentation for interface {} was updated to reflect recent

diff --git a/server/dhcp.c b/server/dhcp.c
index 5b3466f1f0ac16cc18143dff16ea38e398c10741..70aacc258b8dbe74f1d6ea82c36e041a25fa567d 100644 (file)
--- a/server/dhcp.c
+++ b/server/dhcp.c
@@ -34,7 +34,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: dhcp.c,v 1.192.2.51 2005/08/02 09:11:40 dhankins Exp $ Copyright (c) 2004-2005 Internet Systems Consortium.  All rights reserved.\n";
+"$Id: dhcp.c,v 1.192.2.52 2005/08/11 23:08:14 dhankins Exp $ Copyright (c) 2004-2005 Internet Systems Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -245,15 +245,13 @@ void dhcpdiscover (packet, ms_nulltp)
        char msgbuf [1024]; /* XXX */
        TIME when;
        const char *s;
-       int allocatedp = 0;
        int peer_has_leases = 0;
-       int alloc_lease_called = 0;
 #if defined (FAILOVER_PROTOCOL)
        dhcp_failover_state_t *peer;
 #endif
 
        find_lease (&lease, packet, packet -> shared_network,
-                   0, &allocatedp, (struct lease *)0, MDL);
+                   0, &peer_has_leases, (struct lease *)0, MDL);
 
        if (lease && lease -> client_hostname) {
                if ((strlen (lease -> client_hostname) <= 64) &&
@@ -292,24 +290,20 @@ void dhcpdiscover (packet, ms_nulltp)
        if (lease && lease -> pool && lease -> pool -> failover_peer) {
                peer = lease -> pool -> failover_peer;
 
-               /* If the lease is ours to allocate, then allocate it,
-                  but set the allocatedp flag. */
+               /* If the lease is ours to allocate, then allocate it. */
                if (lease_mine_to_reallocate(lease)) {
-                       allocatedp = 1;
                        if (lease->pool && lease->pool->failover_peer)
                                dhcp_failover_pool_check(lease->pool);
 
-               /* If the lease is active, do load balancing to see who
-                  allocates the lease (if it's active, it already belongs
-                  to the client, or we wouldn't have gotten it from
-                  find_lease (). */
-               } else if (lease->binding_state == FTS_ACTIVE &&
-                          (peer->service_state != cooperating ||
-                           load_balance_mine(packet, peer)))
+               /* If the lease is active, it belongs to the client.  This
+                * is the right lease, if we are to offer one.  We decide
+                * wether or not to offer later on.
+                */
+               } else if (lease->binding_state == FTS_ACTIVE) {
                        ; /* This space intentionally left blank. */
 
                /* Otherwise, we can't let the client have this lease. */
-               else {
+               } else {
 #if defined (DEBUG_FIND_LEASE)
                    log_debug ("discarding %s - %s",
                               piaddr (lease -> ip_addr),
@@ -338,8 +332,6 @@ void dhcpdiscover (packet, ms_nulltp)
                if (lease -> pool && lease -> pool -> failover_peer)
                        dhcp_failover_pool_check (lease -> pool);
 #endif
-               allocatedp = 1;
-               alloc_lease_called = 1;
        }
 
 #if defined (FAILOVER_PROTOCOL)
@@ -355,26 +347,15 @@ void dhcpdiscover (packet, ms_nulltp)
                peer = (dhcp_failover_state_t *)0;
 
        /* Do load balancing if configured. */
-       /* If the lease is newly allocated, and we're not the server that
-          the client would normally get with load balancing, and the
-          failover protocol state is normal, let the other server get this.
-          XXX Check protocol spec to make sure that predicating this on
-          XXX allocatedp is okay - I'm doing this so that the client won't
-          XXX be forced to switch servers (and IP addresses) just because
-          XXX of bad luck, when it's possible for it to get the address it
-          XXX is requesting.    Not sure this is allowed.  */
-       if (allocatedp && peer && (peer -> service_state == cooperating) &&
+       if (peer && (peer -> service_state == cooperating) &&
            !load_balance_mine (packet, peer)) {
-               /* peer_has_leases only has a chance to be set if we called
-                * allocate_lease() above.
-                */
-               if (!alloc_lease_called || peer_has_leases) {
+               if (peer_has_leases) {
                        log_debug ("%s: load balance to peer %s",
                                   msgbuf, peer -> name);
                        goto out;
                } else {
-                       log_debug ("cancel load balance to peer %s - %s",
-                                  peer -> name, "no free leases");
+                       log_debug ("%s: cancel load balance to peer %s - %s",
+                                  msgbuf, peer -> name, "no free leases");
                }
        }
 #endif
@@ -444,8 +425,6 @@ void dhcprequest (packet, ms_nulltp, ip_lease)
        if (find_subnet (&subnet, cip, MDL))
                find_lease (&lease, packet,
                            subnet -> shared_network, &ours, 0, ip_lease, MDL);
-       /* XXX consider using allocatedp arg to find_lease to see
-          XXX that this isn't a compliant DHCPREQUEST. */
 
        if (lease && lease -> client_hostname) {
                if ((strlen (lease -> client_hostname) <= 64) &&
@@ -2935,7 +2914,7 @@ void dhcp_reply (lease)
 
 int find_lease (struct lease **lp,
                struct packet *packet, struct shared_network *share, int *ours,
-               int *allocatedp, struct lease *ip_lease_in,
+               int *peer_has_leases, struct lease *ip_lease_in,
                const char *file, int line)
 {
        struct lease *uid_lease = (struct lease *)0;
@@ -2954,6 +2933,22 @@ int find_lease (struct lease **lp,
        int status;
        struct hardware h;
 
+       /* Quick check to see if the peer has leases. */
+       if (peer_has_leases) {
+               struct pool *pool;
+
+               for (pool = share->pools ; pool ; pool = pool->next) {
+                       dhcp_failover_state_t *peer = pool->failover_peer;
+
+                       if (peer &&
+                           ((peer->i_am == primary && pool->backup_leases) ||
+                            (peer->i_am == secondary && pool->free_leases))) {
+                               *peer_has_leases = 1;
+                               break;
+                       }
+               }
+       }
+
        if (packet -> raw -> ciaddr.s_addr) {
                cip.len = 4;
                memcpy (cip.iabuf, &packet -> raw -> ciaddr, 4);
@@ -3257,9 +3252,7 @@ int find_lease (struct lease **lp,
                        if (ours && ip_lease -> binding_state != FTS_ACTIVE)
                                *ours = 0;
                        lease_dereference (&ip_lease, MDL);
-               } else
-                       if (allocatedp)
-                               *allocatedp = 1;
+               }
        }
 
        /* If we got an ip_lease and a uid_lease or hw_lease, and ip_lease
@@ -3549,9 +3542,6 @@ int find_lease (struct lease **lp,
                lease_dereference (&lease, MDL);
        }
 
-       if (lease && allocatedp && lease -> ends <= cur_time)
-               *allocatedp = 1;
-
       out:
        if (have_client_identifier)
                data_string_forget (&client_identifier, MDL);