client->attempt = 1;
- client->start_time = 0;
- client->secs = 0;
client->state = DHCP_STATE_INIT;
client->xid = 0;
}
static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
- uint8_t type, uint16_t secs, uint8_t **opt,
- size_t *optlen) {
+ uint8_t type, uint8_t **opt, size_t *optlen) {
int r;
- assert(secs);
+ assert(client);
+ assert(client->secs);
+ assert(message);
+ assert(opt);
+ assert(optlen);
r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt,
optlen);
/* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
refuse to issue an DHCP lease if 'secs' is set to zero */
- message->secs = htobe16(secs);
+ message->secs = htobe16(client->secs);
memcpy(&message->chaddr, &client->client_id.mac_addr, ETH_ALEN);
packet, len);
}
-static int client_send_discover(sd_dhcp_client *client, uint16_t secs) {
- int err = 0;
+static int client_send_discover(sd_dhcp_client *client) {
_cleanup_free_ DHCPPacket *discover;
size_t optlen, len;
uint8_t *opt;
+ usec_t time_now;
+ int r;
+
+ assert(client);
+
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
+ return r;
+ assert(time_now >= client->start_time);
+
+ /* seconds between sending first and last DISCOVER
+ * must always be strictly positive to deal with broken servers */
+ client->secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1;
optlen = DHCP_MIN_OPTIONS_SIZE;
len = sizeof(DHCPPacket) + optlen;
discover = malloc0(len);
-
if (!discover)
return -ENOMEM;
- err = client_message_init(client, &discover->dhcp, DHCP_DISCOVER,
- secs, &opt, &optlen);
- if (err < 0)
- return err;
+ r = client_message_init(client, &discover->dhcp, DHCP_DISCOVER,
+ &opt, &optlen);
+ if (r < 0)
+ return r;
if (client->last_addr != INADDR_ANY) {
- err = dhcp_option_append(&opt, &optlen,
+ r = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->last_addr);
- if (err < 0)
- return err;
+ if (r < 0)
+ return r;
}
- err = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
- if (err < 0)
- return err;
+ r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
+ if (r < 0)
+ return r;
- err = dhcp_client_send_raw(client, discover, len - optlen);
- if (err < 0)
- return err;
+ r = dhcp_client_send_raw(client, discover, len - optlen);
+ if (r < 0)
+ return r;
log_dhcp_client(client, "DISCOVER");
return 0;
}
-static int client_send_request(sd_dhcp_client *client, uint16_t secs) {
+static int client_send_request(sd_dhcp_client *client) {
_cleanup_free_ DHCPPacket *request;
size_t optlen, len;
- int err;
uint8_t *opt;
+ int r;
optlen = DHCP_MIN_OPTIONS_SIZE;
len = sizeof(DHCPPacket) + optlen;
if (!request)
return -ENOMEM;
- err = client_message_init(client, &request->dhcp, DHCP_REQUEST, secs,
- &opt, &optlen);
- if (err < 0)
- return err;
+ r = client_message_init(client, &request->dhcp, DHCP_REQUEST, &opt,
+ &optlen);
+ if (r < 0)
+ return r;
switch (client->state) {
case DHCP_STATE_INIT_REBOOT:
- err = dhcp_option_append(&opt, &optlen,
+ r = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->last_addr);
- if (err < 0)
- return err;
+ if (r < 0)
+ return r;
break;
case DHCP_STATE_REQUESTING:
- err = dhcp_option_append(&opt, &optlen,
- DHCP_OPTION_REQUESTED_IP_ADDRESS,
- 4, &client->lease->address);
- if (err < 0)
- return err;
-
- err = dhcp_option_append(&opt, &optlen,
- DHCP_OPTION_SERVER_IDENTIFIER,
- 4, &client->lease->server_address);
- if (err < 0)
- return err;
+ r = dhcp_option_append(&opt, &optlen,
+ DHCP_OPTION_REQUESTED_IP_ADDRESS,
+ 4, &client->lease->address);
+ if (r < 0)
+ return r;
+
+ r = dhcp_option_append(&opt, &optlen,
+ DHCP_OPTION_SERVER_IDENTIFIER,
+ 4, &client->lease->server_address);
+ if (r < 0)
+ return r;
break;
case DHCP_STATE_INIT:
break;
}
- err = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
- if (err < 0)
- return err;
+ r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
+ if (r < 0)
+ return r;
if (client->state == DHCP_STATE_RENEWING) {
- err = dhcp_network_send_udp_socket(client->fd,
- client->lease->server_address,
- DHCP_PORT_SERVER,
- &request->dhcp,
- len - optlen - DHCP_IP_UDP_SIZE);
+ r = dhcp_network_send_udp_socket(client->fd,
+ client->lease->server_address,
+ DHCP_PORT_SERVER,
+ &request->dhcp,
+ len - optlen - DHCP_IP_UDP_SIZE);
} else {
- err = dhcp_client_send_raw(client, request, len - optlen);
+ r = dhcp_client_send_raw(client, request, len - optlen);
}
- if (err < 0)
- return err;
+ if (r < 0)
+ return r;
log_dhcp_client(client, "REQUEST");
return 0;
}
-static uint16_t client_update_secs(sd_dhcp_client *client, usec_t time_now)
-{
- client->secs = ((time_now - client->start_time) / USEC_PER_SEC) ? : 1;
-
- return client->secs;
-}
-
static int client_timeout_resend(sd_event_source *s, uint64_t usec,
void *userdata) {
sd_dhcp_client *client = userdata;
switch (client->state) {
case DHCP_STATE_INIT:
-
- client_update_secs(client, time_now);
-
- r = client_send_discover(client, client->secs);
+ r = client_send_discover(client);
if (r >= 0) {
client->state = DHCP_STATE_SELECTING;
client->attempt = 1;
break;
case DHCP_STATE_SELECTING:
- client_update_secs(client, time_now);
-
- r = client_send_discover(client, client->secs);
+ r = client_send_discover(client);
if (r < 0 && client->attempt >= 64)
goto error;
case DHCP_STATE_REQUESTING:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
- r = client_send_request(client, client->secs);
+ r = client_send_request(client);
if (r < 0 && client->attempt >= 64)
goto error;
client_stop(client, r);
return r;
}
-
client->fd = r;
- client->start_time = now(CLOCK_MONOTONIC);
- client->secs = 0;
+
+ if (client->state == DHCP_STATE_INIT) {
+ client->start_time = now(CLOCK_MONOTONIC);
+ client->secs = 0;
+ }
log_dhcp_client(client, "STARTED");
return r;
}
-static uint64_t client_compute_timeout(uint64_t request_sent,
- uint32_t lifetime) {
- return request_sent + (lifetime - 3) * USEC_PER_SEC +
+static uint64_t client_compute_timeout(sd_dhcp_client *client,
+ uint32_t lifetime, double factor) {
+ assert(client);
+ assert(client->request_sent);
+ assert(lifetime);
+
+ return client->request_sent + ((lifetime - 3) * USEC_PER_SEC * factor) +
+ (random_u32() & 0x1fffff);
}
-static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec) {
- uint64_t next_timeout;
+static int client_set_lease_timeouts(sd_dhcp_client *client) {
+ usec_t time_now;
+ uint64_t lifetime_timeout;
+ uint64_t t2_timeout;
+ uint64_t t1_timeout;
+ char time_string[FORMAT_TIMESPAN_MAX];
int r;
assert(client);
assert(client->event);
-
- /* don't set timers for infinite leases */
- if (client->lease->lifetime == 0xffffffff)
- return 0;
-
- if (client->lease->lifetime < 10)
- return -EINVAL;
+ assert(client->lease);
+ assert(client->lease->lifetime);
client->timeout_t1 = sd_event_source_unref(client->timeout_t1);
client->timeout_t2 = sd_event_source_unref(client->timeout_t2);
client->timeout_expire = sd_event_source_unref(client->timeout_expire);
- if (!client->lease->t1)
- client->lease->t1 = client->lease->lifetime / 2;
+ /* don't set timers for infinite leases */
+ if (client->lease->lifetime == 0xffffffff)
+ return 0;
- next_timeout = client_compute_timeout(client->request_sent,
- client->lease->t1);
- if (next_timeout < usec)
- return -EINVAL;
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
+ return r;
+ assert(client->request_sent <= time_now);
+
+ /* convert the various timeouts from relative (secs) to absolute (usecs) */
+ lifetime_timeout = client_compute_timeout(client, client->lease->lifetime, 1);
+ if (client->lease->t1 && client->lease->t2) {
+ /* both T1 and T2 are given */
+ if (client->lease->t1 < client->lease->t2 &&
+ client->lease->t2 < client->lease->lifetime) {
+ /* they are both valid */
+ t2_timeout = client_compute_timeout(client, client->lease->t2, 1);
+ t1_timeout = client_compute_timeout(client, client->lease->t1, 1);
+ } else {
+ /* discard both */
+ t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
+ client->lease->t2 = (client->lease->lifetime * 7) / 8;
+ t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
+ client->lease->t1 = client->lease->lifetime / 2;
+ }
+ } else if (client->lease->t2 && client->lease->t2 < client->lease->lifetime) {
+ /* only T2 is given, and it is valid */
+ t2_timeout = client_compute_timeout(client, client->lease->t2, 1);
+ t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
+ client->lease->t1 = client->lease->lifetime / 2;
+ if (t2_timeout <= t1_timeout) {
+ /* the computed T1 would be invalid, so discard T2 */
+ t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
+ client->lease->t2 = (client->lease->lifetime * 7) / 8;
+ }
+ } else if (client->lease->t1 && client->lease->t1 < client->lease->lifetime) {
+ /* only T1 is given, and it is valid */
+ t1_timeout = client_compute_timeout(client, client->lease->t1, 1);
+ t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
+ client->lease->t2 = (client->lease->lifetime * 7) / 8;
+ if (t2_timeout <= t1_timeout) {
+ /* the computed T2 would be invalid, so discard T1 */
+ t2_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
+ client->lease->t2 = client->lease->lifetime / 2;
+ }
+ } else {
+ /* fall back to the default timeouts */
+ t1_timeout = client_compute_timeout(client, client->lease->lifetime, 0.5);
+ client->lease->t1 = client->lease->lifetime / 2;
+ t2_timeout = client_compute_timeout(client, client->lease->lifetime, 7.0 / 8.0);
+ client->lease->t2 = (client->lease->lifetime * 7) / 8;
+ }
+ /* arm lifetime timeout */
r = sd_event_add_monotonic(client->event,
- &client->timeout_t1,
- next_timeout,
+ &client->timeout_expire, lifetime_timeout,
10 * USEC_PER_MSEC,
- client_timeout_t1, client);
+ client_timeout_expire, client);
if (r < 0)
return r;
- r = sd_event_source_set_priority(client->timeout_t1,
+ r = sd_event_source_set_priority(client->timeout_expire,
client->event_priority);
if (r < 0)
return r;
- if (!client->lease->t2)
- client->lease->t2 = client->lease->lifetime * 7 / 8;
-
- if (client->lease->t2 < client->lease->t1)
- return -EINVAL;
+ log_dhcp_client(client, "lease expires in %s",
+ format_timespan(time_string, FORMAT_TIMESPAN_MAX,
+ lifetime_timeout - time_now, 0));
- if (client->lease->lifetime < client->lease->t2)
- return -EINVAL;
-
- next_timeout = client_compute_timeout(client->request_sent,
- client->lease->t2);
- if (next_timeout < usec)
- return -EINVAL;
+ /* don't arm earlier timeouts if this has already expired */
+ if (lifetime_timeout <= time_now)
+ return 0;
+ /* arm T2 timeout */
r = sd_event_add_monotonic(client->event,
&client->timeout_t2,
- next_timeout,
+ t2_timeout,
10 * USEC_PER_MSEC,
client_timeout_t2, client);
if (r < 0)
if (r < 0)
return r;
- next_timeout = client_compute_timeout(client->request_sent,
- client->lease->lifetime);
- if (next_timeout < usec)
- return -EINVAL;
+ log_dhcp_client(client, "T2 expires in %s",
+ format_timespan(time_string, FORMAT_TIMESPAN_MAX,
+ t2_timeout - time_now, 0));
+
+ /* don't arm earlier timeout if this has already expired */
+ if (t2_timeout <= time_now)
+ return 0;
+ /* arm T1 timeout */
r = sd_event_add_monotonic(client->event,
- &client->timeout_expire, next_timeout,
+ &client->timeout_t1,
+ t1_timeout,
10 * USEC_PER_MSEC,
- client_timeout_expire, client);
+ client_timeout_t1, client);
if (r < 0)
return r;
- r = sd_event_source_set_priority(client->timeout_expire,
+ r = sd_event_source_set_priority(client->timeout_t1,
client->event_priority);
if (r < 0)
return r;
+ log_dhcp_client(client, "T1 expires in %s",
+ format_timespan(time_string, FORMAT_TIMESPAN_MAX,
+ t1_timeout - time_now, 0));
+
return 0;
}
static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
- int len, usec_t time_now) {
+ int len) {
int r = 0, notify_event = 0;
assert(client);
client->last_addr = client->lease->address;
- r = client_set_lease_timeouts(client, time_now);
+ r = client_set_lease_timeouts(client);
if (r < 0)
goto error;
sd_dhcp_client *client = userdata;
_cleanup_free_ DHCPMessage *message = NULL;
int buflen = 0, len, r;
- usec_t time_now;
assert(s);
assert(client);
- assert(client->event);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0 || buflen <= 0)
if (len < 0)
return 0;
- r = sd_event_get_now_monotonic(client->event, &time_now);
- if (r < 0)
- return client_stop(client, r);
-
- return client_handle_message(client, message, len,
- time_now);
+ return client_handle_message(client, message, len);
}
static int client_receive_message_raw(sd_event_source *s, int fd,
uint32_t revents, void *userdata) {
sd_dhcp_client *client = userdata;
_cleanup_free_ DHCPPacket *packet = NULL;
- usec_t time_now;
uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
struct iovec iov = {};
struct msghdr msg = {
assert(s);
assert(client);
- assert(client->event);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0 || buflen <= 0)
len -= DHCP_IP_UDP_SIZE;
- r = sd_event_get_now_monotonic(client->event, &time_now);
- if (r < 0)
- return client_stop(client, r);
-
- return client_handle_message(client, &packet->dhcp, len, time_now);
+ return client_handle_message(client, &packet->dhcp, len);
}
int sd_dhcp_client_start(sd_dhcp_client *client) {
~ianmdlvl / elogind.git / blobdiff