diff options
| -rw-r--r-- | RELNOTES | 6 | ||||
| -rw-r--r-- | includes/dhcpd.h | 6 | ||||
| -rw-r--r-- | server/dhcp.c | 8 | ||||
| -rw-r--r-- | server/dhcpd.c | 15 | ||||
| -rw-r--r-- | server/dhcpd.conf.5 | 31 | ||||
| -rw-r--r-- | server/mdb.c | 40 | ||||
| -rw-r--r-- | server/stables.c | 1 |
7 files changed, 88 insertions, 19 deletions
@@ -92,6 +92,12 @@ by Eric Young (eay@cryptsoft.com). are issues while cleaning up the A or AAAA records. [ISC-Bugs #23954] +- Added global configuration parameter, abandon-lease-time, which determines + the amount of time a lease remains abandoned. The default is 84600 seconds. + Additionaly, the server now conducts a ping check (if ping checks are + enabled) prior to offering an abandoned lease to client. + [ISC-Bugs #41815] + Changes since 4.3.4b1 - None diff --git a/includes/dhcpd.h b/includes/dhcpd.h index d1497928..261714dc 100644 --- a/includes/dhcpd.h +++ b/includes/dhcpd.h @@ -798,6 +798,7 @@ struct lease_state { #define SV_SERVER_ID_CHECK 86 #define SV_PREFIX_LEN_MODE 87 #define SV_DHCPV6_SET_TEE_TIMES 88 +#define SV_ABANDON_LEASE_TIME 89 #if !defined (DEFAULT_PING_TIMEOUT) # define DEFAULT_PING_TIMEOUT 1 @@ -846,6 +847,10 @@ struct lease_state { # define MIN_LEASE_WRITE 15 #endif +#if !defined (DEFAULT_ABANDON_LEASE_TIME) +# define DEFAULT_ABANDON_LEASE_TIME 86400 +#endif + #define PLM_IGNORE 0 #define PLM_PREFER 1 #define PLM_EXACT 2 @@ -2069,6 +2074,7 @@ extern int server_id_check; extern int prefix_length_mode; extern int authoring_byte_order; extern int lease_id_format; +extern u_int32_t abandon_lease_time; extern const char *path_dhcpd_conf; extern const char *path_dhcpd_db; diff --git a/server/dhcp.c b/server/dhcp.c index a823a4e8..55a67bfb 100644 --- a/server/dhcp.c +++ b/server/dhcp.c @@ -3490,7 +3490,8 @@ void ack_lease (packet, lease, offer, when, msg, ms_nulltp, hp) /* If this is a DHCPOFFER, ping the lease address before actually sending the offer. */ if (offer == DHCPOFFER && !(lease -> flags & STATIC_LEASE) && - ((cur_time - lease_cltt) > 60) && + (((cur_time - lease_cltt) > 60) || + (lease->binding_state == FTS_ABANDONED)) && (!(oc = lookup_option (&server_universe, state -> options, SV_PING_CHECKS)) || evaluate_boolean_option_cache (&ignorep, packet, lease, @@ -4871,8 +4872,11 @@ int allocate_lease (struct lease **lp, struct packet *packet, * "no free leases" error when the last lease has been * offered, but it's not exactly broken either. */ - if (!candl || (candl -> ends > cur_time)) + if (!candl || + (candl->binding_state != FTS_ABANDONED && + (candl->ends > cur_time))) { continue; + } if (!lease) { lease = candl; diff --git a/server/dhcpd.c b/server/dhcpd.c index a42d7591..43642823 100644 --- a/server/dhcpd.c +++ b/server/dhcpd.c @@ -78,6 +78,7 @@ int prefix_length_mode = PLM_EXACT; int authoring_byte_order = 0; /* 0 = not set */ int lease_id_format = TOKEN_OCTAL; /* octal by default */ +u_int32_t abandon_lease_time = DEFAULT_ABANDON_LEASE_TIME; const char *path_dhcpd_conf = _PATH_DHCPD_CONF; const char *path_dhcpd_db = _PATH_DHCPD_DB; @@ -1241,6 +1242,20 @@ void postconf_initialization (int quiet) data_string_forget(&db, MDL); } + // Set global abandon-lease-time option. + oc = lookup_option (&server_universe, options, SV_ABANDON_LEASE_TIME); + if ((oc != NULL) && + evaluate_option_cache(&db, NULL, NULL, NULL, options, NULL, + &global_scope, oc, MDL)) { + if (db.len == sizeof (u_int32_t)) { + abandon_lease_time = getULong (db.data); + } else { + log_fatal("invalid abandon-lease-time"); + } + + data_string_forget (&db, MDL); + } + #if defined (BINARY_LEASES) if (local_family == AF_INET) { log_info("Source compiled to use binary-leases"); diff --git a/server/dhcpd.conf.5 b/server/dhcpd.conf.5 index 9c99676d..a053ef14 100644 --- a/server/dhcpd.conf.5 +++ b/server/dhcpd.conf.5 @@ -405,7 +405,8 @@ the lease as in use. If a response is received to an ICMP Echo request, the DHCP server assumes that there is a configuration error - the IP address is in use by some host on the network that is not a DHCP client. It marks the -address as abandoned, and will not assign it to clients. +address as abandoned, and will not assign it to clients. The lease will +remain abandoned for a minimum of abandon-lease-time seconds. .PP If a DHCP client tries to get an IP address, but none are available, but there are abandoned IP addresses, then the DHCP server will @@ -1882,6 +1883,27 @@ min-lease-time allows for a gradual change. e.g. 4 2007/08/24 11:14:32 -7200 .SH REFERENCE: PARAMETERS The +.I abandon-lease-time +statement +.RS 0.25i +.PP +.B adandon-lease-time \fItime\fR\fB;\fR +.PP +.I Time +should be the maximum amount of time (in seconds) that an abandoned IPv4 lease +remains unavailable for assignment to a client. Abandoned leases will only be +offered to clients if there are no free leases. If not defined, the default +abandon lease time is 86400 seconds (24 hours). Note the abandoned lease time +for a given lease is preserved across server restarts. The parameter may only +be set at the global scope and is evaluated only once during server startup. +.PP +Values less than sixty seconds are not recommended as this is below the ping +check threshold and can cause leases once abandoned but since returned to the +free state to not be pinged before being offered. If the requested time is +larger than 0x7FFFFFFF - 1 or the sum of the current time plus the abandoned time isgreater than 0x7FFFFFFF it is treated as infinite. +.RE +.PP +The .I adaptive-lease-time-threshold statement .RS 0.25i @@ -2802,7 +2824,12 @@ address to a client, it first sends an ICMP Echo request (a \fIping\fR) to the address being assigned. It waits for a second, and if no ICMP Echo response has been heard, it assigns the address. If a response \fIis\fR heard, the lease is abandoned, and the server does -not respond to the client. +not respond to the client. The lease will remain abandoned for a minimum +of abandon-lease-time seconds. +.PP +If a there are no free addressses but there are abandoned IP addresses, the +DHCP server will attempt to reclaim an abandoned IP address regardless of the +value of abandon-lease-time. .PP This \fIping check\fR introduces a default one-second delay in responding to DHCPDISCOVER messages, which can be a problem for some clients. The diff --git a/server/mdb.c b/server/mdb.c index 48947c51..6af6b631 100644 --- a/server/mdb.c +++ b/server/mdb.c @@ -1808,30 +1808,40 @@ void abandon_lease (lease, message) struct lease *lease; const char *message; { - struct lease *lt = (struct lease *)0; + struct lease *lt = NULL; #if defined (NSUPDATE) (void) ddns_removals(lease, NULL, NULL, ISC_FALSE); #endif - if (!lease_copy (<, lease, MDL)) + if (!lease_copy(<, lease, MDL)) { return; + } - if (lt->scope) + if (lt->scope) { binding_scope_dereference(<->scope, MDL); + } - lt -> ends = cur_time; /* XXX */ - lt -> next_binding_state = FTS_ABANDONED; + /* Calculate the abandone expiry time. If it wraps, + * use the maximum expiry time. */ + lt->ends = cur_time + abandon_lease_time; + if (lt->ends < cur_time || lt->ends > MAX_TIME) { + lt->ends = MAX_TIME; + } - log_error ("Abandoning IP address %s: %s", - piaddr (lease -> ip_addr), message); - lt -> hardware_addr.hlen = 0; - if (lt -> uid && lt -> uid != lt -> uid_buf) - dfree (lt -> uid, MDL); - lt -> uid = (unsigned char *)0; - lt -> uid_len = 0; - lt -> uid_max = 0; - supersede_lease (lease, lt, 1, 1, 1, 0); - lease_dereference (<, MDL); + lt->next_binding_state = FTS_ABANDONED; + + log_error ("Abandoning IP address %s: %s", piaddr(lease->ip_addr), + message); + lt->hardware_addr.hlen = 0; + if (lt->uid && lt->uid != lt->uid_buf) { + dfree(lt->uid, MDL); + } + + lt->uid = NULL; + lt->uid_len = 0; + lt->uid_max = 0; + supersede_lease(lease, lt, 1, 1, 1, 0); + lease_dereference(<, MDL); } #if 0 diff --git a/server/stables.c b/server/stables.c index 3a83acbe..445ef0fd 100644 --- a/server/stables.c +++ b/server/stables.c @@ -276,6 +276,7 @@ static struct option server_options[] = { { "server-id-check", "f", &server_universe, SV_SERVER_ID_CHECK, 1 }, { "prefix-length-mode", "Nprefix_length_modes.", &server_universe, SV_PREFIX_LEN_MODE, 1 }, { "dhcpv6-set-tee-times", "f", &server_universe, SV_DHCPV6_SET_TEE_TIMES, 1 }, + { "abandon-lease-time", "T", &server_universe, SV_ABANDON_LEASE_TIME, 1 }, { NULL, NULL, NULL, 0, 0 } }; |