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dhcp4: cleanup retransmissions and state changes
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Also do not calculate retransmission times using unrelated
defer and acquire timeouts and fix the lease acquired time
(transmit start) vs secs (start time) in offer request.
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@mtomaschewski
mtomaschewski committed Oct 6, 2022
1 parent a1ee804 commit 3f0c42b
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Showing 4 changed files with 337 additions and 224 deletions.
29 changes: 9 additions & 20 deletions src/dhcp4/device.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -281,10 +281,6 @@ ni_dhcp4_acquire(ni_dhcp4_device_t *dev, const ni_dhcp4_request_t *info)

config = xcalloc(1, sizeof(*config));

/* RFC 2131 4.1 suggests these values */
config->capture_retry_timeout = NI_DHCP4_RESEND_TIMEOUT_INIT;
config->capture_max_timeout = NI_DHCP4_RESEND_TIMEOUT_MAX;

config->dry_run = info->dry_run;
config->start_delay = info->start_delay;
config->defer_timeout = info->defer_timeout;
Expand Down Expand Up @@ -347,9 +343,10 @@ ni_dhcp4_acquire(ni_dhcp4_device_t *dev, const ni_dhcp4_request_t *info)

if (ni_log_facility(NI_TRACE_DHCP)) {
ni_trace("Received request:");
ni_trace(" start-delay %s", ni_sprint_timeout(config->start_delay));
ni_trace(" defer-timeout %s", ni_sprint_timeout(config->defer_timeout));
ni_trace(" acquire-timeout %s", ni_sprint_timeout(config->acquire_timeout));
ni_trace(" max lease-time %s", ni_sprint_timeout(config->max_lease_time));
ni_trace(" start-delay %s", ni_sprint_timeout(config->start_delay));
ni_trace(" hostname %s", config->hostname[0]? config->hostname : "<none>");
if (config->fqdn.enabled == NI_TRISTATE_ENABLE) {
ni_trace(" fqdn update %s, encode %s, qualify %s",
Expand Down Expand Up @@ -382,7 +379,6 @@ ni_dhcp4_acquire(ni_dhcp4_device_t *dev, const ni_dhcp4_request_t *info)
if (config->client_id.len && !ni_opaque_eq(&config->client_id, &dev->lease->dhcp4.client_id)) {
ni_debug_dhcp("%s: lease doesn't match request", dev->ifname);
ni_dhcp4_device_drop_lease(dev);
dev->notify = 1;
} else {
/* Lease may be good */
dev->fsm.state = NI_DHCP4_STATE_REBOOT;
Expand Down Expand Up @@ -642,7 +638,6 @@ ni_dhcp4_device_start(ni_dhcp4_device_t *dev)
unsigned int sec;

ni_dhcp4_device_drop_buffer(dev);
dev->failed = 0;

nc = ni_global_state_handle(0);
if(!nc || !(ifp = ni_netdev_by_index(nc, dev->link.ifindex))) {
Expand Down Expand Up @@ -703,7 +698,6 @@ ni_dhcp4_device_prepare_message(void *data)
int
ni_dhcp4_device_send_message_broadcast(ni_dhcp4_device_t *dev, unsigned int msg_code, ni_addrconf_lease_t *lease)
{
ni_timeout_param_t timeout;
int rv;

dev->transmit.msg_code = msg_code;
Expand All @@ -730,16 +724,9 @@ ni_dhcp4_device_send_message_broadcast(ni_dhcp4_device_t *dev, unsigned int msg_
case DHCP4_DISCOVER:
case DHCP4_REQUEST:
case DHCP4_INFORM:
memset(&timeout, 0, sizeof(timeout));
timeout.timeout = dev->config->capture_retry_timeout;
timeout.increment = -1;
timeout.max_timeout = dev->config->capture_timeout;
timeout.nretries = -1;
timeout.jitter.min = -1;/* add a random jitter of +/-1 sec */
timeout.jitter.max = 1;
timeout.timeout_callback = ni_dhcp4_device_prepare_message;
timeout.timeout_data = dev;
rv = ni_capture_send(dev->capture, &dev->message, &timeout);
dev->transmit.params.timeout_callback = ni_dhcp4_device_prepare_message;
dev->transmit.params.timeout_data = dev;
rv = ni_capture_send(dev->capture, &dev->message, &dev->transmit.params);
break;

default:
Expand Down Expand Up @@ -787,14 +774,16 @@ ni_dhcp4_device_send_message_unicast(ni_dhcp4_device_t *dev, unsigned int msg_co
void
ni_dhcp4_device_disarm_retransmit(ni_dhcp4_device_t *dev)
{
/* Clear transmit struct except of transmit.start */
dev->transmit.msg_code = 0;
memset(&dev->transmit.params, 0, sizeof(dev->transmit.params));
ni_addrconf_lease_drop(&dev->transmit.lease);

/* Clear retransmit timer */
/* Clear capture retransmit timer params */
if (dev->capture)
ni_capture_disarm_retransmit(dev->capture);

/* Drop the message buffer */
/* Drop the (raw) message buffer content */
ni_dhcp4_device_drop_buffer(dev);
}

Expand Down
12 changes: 5 additions & 7 deletions src/dhcp4/dhcp4.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -62,10 +62,9 @@ typedef struct ni_dhcp4_device {
ni_capture_t * capture;
int listen_fd; /* for DHCP4 only */

unsigned int failed : 1,
notify : 1;

struct {
struct timeval start;
ni_timeout_param_t params;
unsigned int msg_code;
ni_addrconf_lease_t * lease;
} transmit;
Expand Down Expand Up @@ -94,7 +93,10 @@ typedef struct ni_dhcp4_device {
#define NI_DHCP4_START_DELAY_MAX 10 /* seconds */
#define NI_DHCP4_RESEND_TIMEOUT_INIT 4 /* seconds */
#define NI_DHCP4_RESEND_TIMEOUT_MAX 64 /* seconds */
#define NI_DHCP4_DISCOVER_RESTART (NI_DHCP4_RESEND_TIMEOUT_MAX<<1)
#define NI_DHCP4_REQUEST_TIMEOUT 60 /* seconds */
#define NI_DHCP4_REBOOT_TIMEOUT NI_DHCP4_REQUEST_TIMEOUT
#define NI_DHCP4_DECLINE_BACKOFF 10 /* seconds */
#define NI_DHCP4_NAK_BACKOFF_MAX 60 /* seconds */
#define NI_DHCP4_ARP_TIMEOUT 200 /* msec */

Expand Down Expand Up @@ -199,10 +201,6 @@ struct ni_dhcp4_config {

unsigned int start_delay;
unsigned int defer_timeout;
unsigned int capture_retry_timeout; /* timeout for first request */
unsigned int capture_max_timeout; /* timeout for the capture */
unsigned int capture_timeout; /* timeout for actual capture, then fsm restarts */
unsigned int elapsed_timeout; /* elapsed time within fsm */
unsigned int acquire_timeout; /* 0 means retry forever */

/* A combination of DHCP4_DO_* flags above */
Expand Down
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