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-rw-r--r--RELNOTES7
-rw-r--r--includes/dhcpd.h5
-rw-r--r--server/dhcp.c55
-rw-r--r--server/dhcpv6.c34
4 files changed, 76 insertions, 25 deletions
diff --git a/RELNOTES b/RELNOTES
index 4d7b3899..a1412270 100644
--- a/RELNOTES
+++ b/RELNOTES
@@ -187,6 +187,13 @@ by Eric Young (eay@cryptsoft.com).
Mritunjaykumar Dubey at Nokia for reporting the issue.
[ISC-Bugs #41473]
+- Altered DHCPv4 lease time calculation to avoid roll over errors on 64-bit
+ OS systems when using -1 or large values for default-lease-time. Rollover
+ values will be replaced with 0x7FFFFFFF - 1. This alleviates unintentionally
+ short expiration times being handed out when infinite lease times (-1) in
+ conjuction with failover.
+ [ISC-Bugs #41976]
+
Changes since 4.3.0 (bug fixes)
- Tidy up several small tickets.
diff --git a/includes/dhcpd.h b/includes/dhcpd.h
index 5a3888d5..5d5e1d0f 100644
--- a/includes/dhcpd.h
+++ b/includes/dhcpd.h
@@ -1588,8 +1588,9 @@ typedef unsigned char option_mask [16];
#define DHCPD_LOG_FACILITY LOG_DAEMON
#endif
-#define MAX_TIME 0x7fffffff
-#define MIN_TIME 0
+#define INFINITE_TIME 0xffffffff
+#define MAX_TIME 0x7fffffff
+#define MIN_TIME 0
#ifdef USE_LOG_PID
/* include the pid in the syslog messages */
diff --git a/server/dhcp.c b/server/dhcp.c
index 1109e204..5b4e0b96 100644
--- a/server/dhcp.c
+++ b/server/dhcp.c
@@ -85,6 +85,8 @@ const int dhcp_type_name_max = ((sizeof dhcp_type_names) / sizeof (char *));
# define send_packet trace_packet_send
#endif
+static TIME leaseTimeCheck(TIME calculated, TIME alternate);
+
void
dhcp (struct packet *packet) {
int ms_nulltp = 0;
@@ -2878,8 +2880,15 @@ void ack_lease (packet, lease, offer, when, msg, ms_nulltp, hp)
* the desired lease time upon renewal.
*/
if (offer == DHCPACK) {
- lt->tstp = cur_time + lease_time +
- (new_lease_time / 2);
+ if (lease_time == INFINITE_TIME) {
+ lt->tstp = MAX_TIME;
+ } else {
+ lt->tstp =
+ leaseTimeCheck(
+ (cur_time + lease_time
+ + (new_lease_time / 2)),
+ MAX_TIME - 1);
+ }
/* If we reduced the potential expiry time,
* make sure we don't offer an old-expiry-time
@@ -2896,12 +2905,16 @@ void ack_lease (packet, lease, offer, when, msg, ms_nulltp, hp)
}
#endif /* FAILOVER_PROTOCOL */
- /* If the lease duration causes the time value to wrap,
- use the maximum expiry time. */
- if (cur_time + lease_time < cur_time)
- state -> offered_expiry = MAX_TIME - 1;
- else
- state -> offered_expiry = cur_time + lease_time;
+ if (lease_time == INFINITE_TIME) {
+ state->offered_expiry = MAX_TIME;
+ } else {
+ /* If the lease duration causes the time value to wrap,
+ use the maximum expiry time. */
+ state->offered_expiry
+ = leaseTimeCheck(cur_time + lease_time,
+ MAX_TIME - 1);
+ }
+
if (when)
lt -> ends = when;
else
@@ -5670,3 +5683,29 @@ reuse_lease (struct packet* packet,
lease->cannot_reuse = (!reusable && offer == DHCPOFFER);
return (reusable);
}
+
+/* \brief Validates a proposed value for use as a lease time
+ *
+ * Convenience function used for catching calculeated lease
+ * times that overflow 4-byte times used in v4 protocol.
+ *
+ * We use variables of type TIME in lots of places, which on
+ * 64-bit systems is 8 bytes while on 32-bit OSs it is int32_t,
+ * so we have all sorts of fun places to mess things up.
+ * This function checks a calculated lease time for and if it
+ * is unsuitable for use as a lease time, the given alternate
+ * value is returned.
+ * \param calculated
+ * \param alternate
+ *
+ * \returen either the calculated value if it is valid, or
+ * the alternate value supplied
+ */
+TIME leaseTimeCheck(TIME calculated, TIME alternate) {
+ if ((sizeof(TIME) > 4 && calculated >= INFINITE_TIME) ||
+ (calculated < cur_time)) {
+ return (alternate);
+ }
+
+ return (calculated);
+}
diff --git a/server/dhcpv6.c b/server/dhcpv6.c
index d18758ba..a8bae63c 100644
--- a/server/dhcpv6.c
+++ b/server/dhcpv6.c
@@ -2090,7 +2090,7 @@ reply_process_ia_na(struct reply_state *reply, struct option_cache *ia) {
* A not included IA ("cleanup" below) could give a Renew/Rebind.
*/
oc = lookup_option(&dhcpv6_universe, packet_ia, D6O_IAADDR);
- reply->min_valid = reply->min_prefer = 0xffffffff;
+ reply->min_valid = reply->min_prefer = INFINITE_TIME;
reply->client_valid = reply->client_prefer = 0;
for (; oc != NULL ; oc = oc->next) {
status = reply_process_addr(reply, oc);
@@ -2845,7 +2845,7 @@ reply_process_ia_ta(struct reply_state *reply, struct option_cache *ia) {
* Deal with an IAADDR for lifetimes.
* For all or none, process IAADDRs as hints.
*/
- reply->min_valid = reply->min_prefer = 0xffffffff;
+ reply->min_valid = reply->min_prefer = INFINITE_TIME;
reply->client_valid = reply->client_prefer = 0;
oc = lookup_option(&dhcpv6_universe, packet_ia, D6O_IAADDR);
for (; oc != NULL; oc = oc->next) {
@@ -3567,10 +3567,10 @@ reply_process_is_addressed(struct reply_state *reply,
* The following doesn't work on at least some systems:
* (cur_time + reply->send_valid < cur_time)
*/
- if (reply->send_valid != 0xFFFFFFFF) {
+ if (reply->send_valid != INFINITE_TIME) {
time_t test_time = cur_time + reply->send_valid;
if (test_time < cur_time)
- reply->send_valid = 0xFFFFFFFF;
+ reply->send_valid = INFINITE_TIME;
}
if (reply->client_prefer == 0)
@@ -3579,7 +3579,7 @@ reply_process_is_addressed(struct reply_state *reply,
reply->send_prefer = reply->client_prefer;
if ((reply->send_prefer >= reply->send_valid) &&
- (reply->send_valid != 0xFFFFFFFF))
+ (reply->send_valid != INFINITE_TIME))
reply->send_prefer = (reply->send_valid / 2) +
(reply->send_valid / 8);
@@ -3634,7 +3634,7 @@ reply_process_is_addressed(struct reply_state *reply,
* when connecting to the lease file MAX_TIME is
*/
if (reply->buf.reply.msg_type == DHCPV6_REPLY) {
- if (reply->send_valid == 0xFFFFFFFF) {
+ if (reply->send_valid == INFINITE_TIME) {
reply->lease->soft_lifetime_end_time = MAX_TIME;
} else {
reply->lease->soft_lifetime_end_time =
@@ -3921,7 +3921,7 @@ reply_process_ia_pd(struct reply_state *reply, struct option_cache *ia) {
* For each prefix in this IA_PD, decide what to do about it.
*/
oc = lookup_option(&dhcpv6_universe, packet_ia, D6O_IAPREFIX);
- reply->min_valid = reply->min_prefer = 0xffffffff;
+ reply->min_valid = reply->min_prefer = INFINITE_TIME;
reply->client_valid = reply->client_prefer = 0;
reply->preflen = -1;
for (; oc != NULL ; oc = oc->next) {
@@ -4813,10 +4813,10 @@ reply_process_is_prefixed(struct reply_state *reply,
* The following doesn't work on at least some systems:
* (cur_time + reply->send_valid < cur_time)
*/
- if (reply->send_valid != 0xFFFFFFFF) {
+ if (reply->send_valid != INFINITE_TIME) {
time_t test_time = cur_time + reply->send_valid;
if (test_time < cur_time)
- reply->send_valid = 0xFFFFFFFF;
+ reply->send_valid = INFINITE_TIME;
}
if (reply->client_prefer == 0)
@@ -4825,7 +4825,7 @@ reply_process_is_prefixed(struct reply_state *reply,
reply->send_prefer = reply->client_prefer;
if ((reply->send_prefer >= reply->send_valid) &&
- (reply->send_valid != 0xFFFFFFFF))
+ (reply->send_valid != INFINITE_TIME))
reply->send_prefer = (reply->send_valid / 2) +
(reply->send_valid / 8);
@@ -4865,7 +4865,7 @@ reply_process_is_prefixed(struct reply_state *reply,
* when connecting to the lease file MAX_TIME is
*/
if (reply->buf.reply.msg_type == DHCPV6_REPLY) {
- if (reply->send_valid == 0xFFFFFFFF) {
+ if (reply->send_valid == INFINITE_TIME) {
reply->lease->soft_lifetime_end_time = MAX_TIME;
} else {
reply->lease->soft_lifetime_end_time =
@@ -8089,8 +8089,10 @@ set_reply_tee_times(struct reply_state* reply, unsigned ia_cursor)
} else if (set_tee_times) {
/* Setting them is enabled so T1 is either infinite or
* 0.5 * the shortest preferred lifetime in the IA_XX */
- reply->renew = (reply->min_prefer == 0xFFFFFFFF ? 0xFFFFFFFF
- : reply->min_prefer / 2);
+ if (reply->min_prefer == INFINITE_TIME)
+ reply->renew = INFINITE_TIME;
+ else
+ reply->renew = reply->min_prefer / 2;
} else {
/* Default is to let the client choose */
reply->renew = 0;
@@ -8122,8 +8124,10 @@ set_reply_tee_times(struct reply_state* reply, unsigned ia_cursor)
} else if (set_tee_times) {
/* Setting them is enabled so T2 is either infinite or
* 0.8 * the shortest preferred lifetime in the reply */
- reply->rebind = (reply->min_prefer == 0xFFFFFFFF ? 0xFFFFFFFF
- : (reply->min_prefer / 5) * 4);
+ if (reply->min_prefer == INFINITE_TIME)
+ reply->rebind = INFINITE_TIME;
+ else
+ reply->rebind = (reply->min_prefer / 5) * 4;
} else {
/* Default is to let the client choose */
reply->rebind = 0;
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