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Make the renew and rebind timeouts more strictly rfc compliant, and also

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take into account the possiblity of renew times being ridiculously deferred
such that the current time is within lease expiration time.
This commit is contained in:
Nicholas J. Kain
2011-06-30 02:48:58 -04:00
parent 8fffc5721f
commit 339804856b
1 changed files with 43 additions and 25 deletions
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68
ndhc/state.c
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@ -75,43 +75,61 @@ static void bound_timeout(struct client_state_t *cs)
renewing_timeout(cs); renewing_timeout(cs);
} }
static void lease_timedout(struct client_state_t *cs)
{
cs->dhcpState = DS_SELECTING;
log_line("Lease lost, entering init state.");
ifchange(NULL, IFCHANGE_DECONFIG);
cs->timeout = 0;
cs->packetNum = 0;
change_listen_mode(cs, LM_RAW);
}
// Triggered when a DHCP renew request has been sent and no reply has been // Triggered when a DHCP renew request has been sent and no reply has been
// received within the response wait time. This function is also directly // received within the response wait time. This function is also directly
// called by bound_timeout() when it is time to renew a lease before it // called by bound_timeout() when it is time to renew a lease before it
// expires. Check to see if the lease is still valid, and if it is, send // expires. Check to see if the lease is still valid, and if it is, send
// a unicast DHCP renew packet. If it is not, then change to the REBINDING // a unicast DHCP renew packet. If it is not, then change to the REBINDING
// state to get a new lease. // state to send broadcast queries.
static void renewing_timeout(struct client_state_t *cs) static void renewing_timeout(struct client_state_t *cs)
{ {
if ((cs->rebindTime - cs->renewTime) <= (cs->lease / 14400 + 1)) { long long ct = curms();
cs->dhcpState = DS_REBINDING; long long rbt = cs->leaseStartTime + cs->rebindTime * 1000;
cs->timeout = (cs->rebindTime - cs->renewTime) * 1000; if (ct < rbt) {
log_line("Entering rebinding state."); long long wt = (rbt - ct) / 2;
} else { if (wt >= 30000)
send_renew(cs->xid, cs->serverAddr, cs->requestedIP); send_renew(cs->xid, cs->serverAddr, cs->requestedIP);
cs->renewTime = ((cs->rebindTime - cs->renewTime) >> 1) + cs->renewTime; else
cs->timeout = (cs->renewTime * 1000) - (curms() - cs->leaseStartTime); wt = rbt - ct;
cs->timeout = wt;
return;
} }
long long elt = cs->leaseStartTime + cs->lease * 1000;
if (ct < elt) {
cs->dhcpState = DS_REBINDING;
cs->timeout = elt - ct / 2;
log_line("Entering rebinding state.");
} else
lease_timedout(cs);
} }
// Triggered when a DHCP rebind request has been sent and no reply has been
// received within the response wait time. Check to see if the lease is still
// valid, and if it is, send a broadcast DHCP renew packet. If it is not, then
// change to the SELECTING state to get a new lease.
static void rebinding_timeout(struct client_state_t *cs) static void rebinding_timeout(struct client_state_t *cs)
{ {
/* Either set a new rebindTime, or enter INIT state */ long long ct = curms();
if ((cs->lease - cs->rebindTime) <= (cs->lease / 14400 + 1)) { long long elt = cs->leaseStartTime + cs->lease * 1000;
/* timed out, enter init state */ if (ct < elt) {
cs->dhcpState = DS_SELECTING; long long wt = (elt - ct) / 2;
log_line("Lease lost, entering init state."); if (wt >= 30000)
ifchange(NULL, IFCHANGE_DECONFIG); send_renew(cs->xid, 0, cs->requestedIP);
cs->timeout = 0; else
cs->packetNum = 0; wt = elt - ct;
change_listen_mode(cs, LM_RAW); cs->timeout = wt;
} else { } else
/* send a request packet */ lease_timedout(cs);
send_renew(cs->xid, 0, cs->requestedIP); /* broadcast */
cs->rebindTime = ((cs->lease - cs->rebindTime) >> 1) + cs->rebindTime;
cs->timeout = (cs->rebindTime * 1000) - (curms() - cs->leaseStartTime);
}
} }
static void released_timeout(struct client_state_t *cs) static void released_timeout(struct client_state_t *cs)