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dhcp4: confirm lease after link change or restart
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Dropped fail_on_timeout flag and renamed fsm_quick_renewal to
fsm_reboot to confirm lease using broadcast as defined in the
RFC2131 (3.2, reusing a previously allocated network address).
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@mtomaschewski
mtomaschewski committed Feb 12, 2014
1 parent 9981a76 commit 2733593
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Showing 3 changed files with 20 additions and 28 deletions.
1 change: 0 additions & 1 deletion dhcp4/dhcp.h
View file
Expand Up @@ -44,7 +44,6 @@ typedef struct ni_dhcp4_device {

struct {
int state;
unsigned int fail_on_timeout : 1;
const ni_timer_t * timer;
} fsm;

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40 changes: 16 additions & 24 deletions dhcp4/fsm.c
View file
Expand Up @@ -30,7 +30,7 @@
static int ni_dhcp4_fsm_request(ni_dhcp4_device_t *, const ni_addrconf_lease_t *);
static int ni_dhcp4_fsm_arp_validate(ni_dhcp4_device_t *);
static int ni_dhcp4_fsm_renewal(ni_dhcp4_device_t *);
static int ni_dhcp4_fsm_quick_renewal(ni_dhcp4_device_t *);
static int ni_dhcp4_fsm_reboot(ni_dhcp4_device_t *);
static int ni_dhcp4_fsm_rebind(ni_dhcp4_device_t *);
static int ni_dhcp4_fsm_decline(ni_dhcp4_device_t *);
static const char * ni_dhcp4_fsm_state_name(int);
Expand Down Expand Up @@ -165,6 +165,7 @@ ni_dhcp4_fsm_process_dhcp4_packet(ni_dhcp4_device_t *dev, ni_buffer_t *msgbuf)
case DHCP4_ACK:
if (dev->fsm.state != NI_DHCP4_STATE_REQUESTING
&& dev->fsm.state != NI_DHCP4_STATE_RENEWING
&& dev->fsm.state != NI_DHCP4_STATE_REBOOT
&& dev->fsm.state != NI_DHCP4_STATE_REBINDING)
goto ignore;
ni_dhcp4_process_ack(dev, lease);
Expand Down Expand Up @@ -218,7 +219,6 @@ ni_dhcp4_fsm_restart(ni_dhcp4_device_t *dev)
void
ni_dhcp4_fsm_set_timeout_msec(ni_dhcp4_device_t *dev, unsigned int msec)
{
dev->fsm.fail_on_timeout = 0;
if (msec != 0) {
ni_debug_dhcp("%s: setting timeout to %u msec", dev->ifname, msec);
if (dev->fsm.timer)
Expand Down Expand Up @@ -323,22 +323,22 @@ ni_dhcp4_fsm_renewal(ni_dhcp4_device_t *dev)
}

int
ni_dhcp4_fsm_quick_renewal(ni_dhcp4_device_t *dev)
ni_dhcp4_fsm_reboot(ni_dhcp4_device_t *dev)
{
time_t deadline;
int rv;

ni_debug_dhcp("trying to perform quick lease renewal for %s", dev->ifname);
/* RFC 2131, 3.2 (see also 3.1) */
ni_debug_dhcp("trying to confirm lease for %s", dev->ifname);

dev->fsm.state = NI_DHCP4_STATE_RENEWING;
rv = ni_dhcp4_device_send_message_unicast(dev, DHCP4_REQUEST, dev->lease);
dev->fsm.state = NI_DHCP4_STATE_REBOOT;
rv = ni_dhcp4_device_send_message(dev, DHCP4_REQUEST, dev->lease);

deadline = time(NULL) + 10;
if (deadline > dev->lease->time_acquired + dev->lease->dhcp4.rebind_time)
deadline = dev->lease->time_acquired + dev->lease->dhcp4.rebind_time;

ni_dhcp4_fsm_set_deadline(dev, deadline);
dev->fsm.fail_on_timeout = 1;
return rv;
}

Expand Down Expand Up @@ -402,22 +402,10 @@ ni_dhcp4_fsm_release(ni_dhcp4_device_t *dev)
static void
ni_dhcp4_fsm_timeout(ni_dhcp4_device_t *dev)
{
ni_debug_dhcp("%s: timeout in state %s%s",
dev->ifname, ni_dhcp4_fsm_state_name(dev->fsm.state),
dev->fsm.fail_on_timeout? " (fatal failure)" : "");
ni_debug_dhcp("%s: timeout in state %s",
dev->ifname, ni_dhcp4_fsm_state_name(dev->fsm.state));
dev->fsm.timer = NULL;

if (dev->fsm.fail_on_timeout) {
/* We were unable to do a quick renew after the link came back up.
* Go back to square one. */
ni_error("unable to renew lease");

/* This calls fsm_restart and changes the FSM state to INIT.
* So we will enter the switch statement below in state INIT
* and will promptly trigger a re-discovery. */
ni_dhcp4_fsm_commit_lease(dev, NULL);
}

switch (dev->fsm.state) {
case NI_DHCP4_STATE_INIT:
/* We get here if we previously received a NAK, and have
Expand Down Expand Up @@ -483,6 +471,11 @@ ni_dhcp4_fsm_timeout(ni_dhcp4_device_t *dev)
/* FIXME: now decide whether we should try to re-discover */
break;

case NI_DHCP4_STATE_REBOOT:
ni_error("unable to confirm lease");
ni_dhcp4_fsm_commit_lease(dev, NULL);
break;

default:
;
}
Expand Down Expand Up @@ -526,7 +519,7 @@ ni_dhcp4_fsm_link_up(ni_dhcp4_device_t *dev)
* to state INIT.
*/
if (dev->lease)
ni_dhcp4_fsm_quick_renewal(dev);
ni_dhcp4_fsm_reboot(dev);
else
ni_dhcp4_fsm_discover(dev);
break;
Expand Down Expand Up @@ -944,8 +937,7 @@ static const char *__dhcp4_state_name[__NI_DHCP4_STATE_MAX] = {
[NI_DHCP4_STATE_BOUND] = "BOUND",
[NI_DHCP4_STATE_RENEWING] = "RENEWING",
[NI_DHCP4_STATE_REBINDING] = "REBINDING",
[NI_DHCP4_STATE_REBOOT] = "REBOOT",
[NI_DHCP4_STATE_RENEW_REQUESTED]= "RENEW_REQUESTED",
[NI_DHCP4_STATE_REBOOT] = "REBOOT",
[NI_DHCP4_STATE_RELEASED] = "RELEASED",
};

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7 changes: 4 additions & 3 deletions dhcp4/protocol.c
View file
Expand Up @@ -314,7 +314,8 @@ ni_dhcp4_build_message(const ni_dhcp4_device_t *dev,
if (lease->dhcp4.address.s_addr == 0 || lease->dhcp4.server_id.s_addr == 0)
return -1;

if (dev->fsm.state != NI_DHCP4_STATE_REQUESTING) {
if (dev->fsm.state != NI_DHCP4_STATE_REQUESTING
&& dev->fsm.state != NI_DHCP4_STATE_REBOOT) {
src_addr = lease->dhcp4.address;
dst_addr = lease->dhcp4.server_id;
}
Expand All @@ -334,8 +335,8 @@ ni_dhcp4_build_message(const ni_dhcp4_device_t *dev,
message->secs = htons(ni_dhcp4_device_uptime(dev, 0xFFFF));

if (dev->fsm.state == NI_DHCP4_STATE_BOUND
|| dev->fsm.state == NI_DHCP4_STATE_RENEWING
|| dev->fsm.state == NI_DHCP4_STATE_REBINDING)
|| dev->fsm.state == NI_DHCP4_STATE_REBINDING
|| dev->fsm.state == NI_DHCP4_STATE_RENEWING)
message->ciaddr = lease->dhcp4.address.s_addr;

switch (dev->system.hwaddr.type) {
Expand Down

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