static sd_dhcp_client *client_stop(sd_dhcp_client *client, int error) {
assert_return(client, NULL);
if (error < 0)
log_dhcp_client(client, "STOPPED: %s", strerror(-error));
else {
switch(error) {
case DHCP_EVENT_STOP:
log_dhcp_client(client, "STOPPED");
break;
case DHCP_EVENT_NO_LEASE:
log_dhcp_client(client, "STOPPED: No lease");
break;
default:
log_dhcp_client(client, "STOPPED: Unknown reason");
break;
}
}
client = client_notify(client, error);
if (client)
client_initialize(client);
return client;
}
static int client_handle_ack(sd_dhcp_client *client, DHCPMessage *ack,
size_t len) {
_cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
int r;
r = dhcp_lease_new(&lease);
if (r < 0)
return r;
r = dhcp_option_parse(ack, len, dhcp_lease_parse_options, lease);
if (r == DHCP_NAK) {
log_dhcp_client(client, "NAK");
return DHCP_EVENT_NO_LEASE;
}
if (r != DHCP_ACK) {
log_dhcp_client(client, "receieved message was not an ACK, ignoring");
return -ENOMSG;
}
lease->next_server = ack->siaddr;
lease->address = ack->yiaddr;
if (lease->address == INADDR_ANY ||
lease->server_address == INADDR_ANY ||
lease->lifetime == 0) {
log_dhcp_client(client, "receieved lease lacks address, server "
"address or lease lifetime, ignoring");
return -ENOMSG;
}
if (lease->subnet_mask == INADDR_ANY) {
r = dhcp_lease_set_default_subnet_mask(lease);
if (r < 0) {
log_dhcp_client(client, "receieved lease lacks subnet "
"mask, and a fallback one can not be "
"generated, ignoring");
return -ENOMSG;
}
}
r = DHCP_EVENT_IP_ACQUIRE;
if (client->lease) {
if (client->lease->address != lease->address ||
client->lease->subnet_mask != lease->subnet_mask ||
client->lease->router != lease->router) {
r = DHCP_EVENT_IP_CHANGE;
}
client->lease = sd_dhcp_lease_unref(client->lease);
}
client->lease = lease;
lease = NULL;
log_dhcp_client(client, "ACK");
return r;
}
static int client_stop(sd_dhcp_client *client, int error) {
assert_return(client, -EINVAL);
client->receive_message =
sd_event_source_unref(client->receive_message);
if (client->fd >= 0)
close_nointr_nofail(client->fd);
client->fd = -1;
client->timeout_resend = sd_event_source_unref(client->timeout_resend);
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);
client->attempt = 1;
client_notify(client, error);
client->start_time = 0;
client->secs = 0;
client->state = DHCP_STATE_INIT;
if (client->lease)
client->lease = sd_dhcp_lease_unref(client->lease);
log_dhcp_client(client, "STOPPED");
return 0;
}
static int client_receive_message_udp(sd_event_source *s, int fd,
uint32_t revents, void *userdata) {
sd_dhcp_client *client = userdata;
_cleanup_free_ DHCPMessage *message = NULL;
int buflen = 0, len, r;
assert(s);
assert(client);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0)
return r;
if (buflen < 0)
/* this can't be right */
return -EIO;
message = malloc0(buflen);
if (!message)
return -ENOMEM;
len = read(fd, message, buflen);
if (len < 0) {
log_dhcp_client(client, "could not receive message from UDP "
"socket: %m");
return 0;
} else if ((size_t)len < sizeof(DHCPMessage))
return 0;
return client_handle_message(client, message, len);
}
int sd_dhcp_client_set_mac(sd_dhcp_client *client,
const struct ether_addr *addr) {
bool need_restart = false;
assert_return(client, -EINVAL);
assert_return(addr, -EINVAL);
if (memcmp(&client->client_id.mac_addr, addr, ETH_ALEN) == 0)
return 0;
if (!IN_SET(client->state, DHCP_STATE_INIT, DHCP_STATE_STOPPED)) {
log_dhcp_client(client, "Changing MAC address on running DHCP "
"client, restarting");
need_restart = true;
client = client_stop(client, DHCP_EVENT_STOP);
}
if (!client)
return 0;
memcpy(&client->client_id.mac_addr, addr, ETH_ALEN);
client->client_id.type = 0x01;
if (need_restart && client->state != DHCP_STATE_STOPPED)
sd_dhcp_client_start(client);
return 0;
}
static int client_receive_message_udp(sd_event_source *s, int fd,
uint32_t revents, void *userdata) {
sd_dhcp_client *client = userdata;
_cleanup_free_ DHCPMessage *message = NULL;
int buflen = 0, len, r;
assert(s);
assert(client);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0 || buflen <= 0)
buflen = sizeof(DHCPMessage) + DHCP_MIN_OPTIONS_SIZE;
message = malloc0(buflen);
if (!message)
return -ENOMEM;
len = read(fd, message, buflen);
if (len < 0) {
log_dhcp_client(client, "could not receive message from UDP "
"socket: %s", strerror(errno));
return 0;
} else if ((size_t)len < sizeof(DHCPMessage))
return 0;
return client_handle_message(client, message, len);
}
static int client_handle_offer(sd_dhcp_client *client, DHCPMessage *offer,
size_t len) {
_cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
int r;
r = dhcp_lease_new(&lease);
if (r < 0)
return r;
r = dhcp_option_parse(offer, len, dhcp_lease_parse_options, lease);
if (r != DHCP_OFFER) {
log_dhcp_client(client, "receieved message was not an OFFER, ignoring");
return -ENOMSG;
}
lease->next_server = offer->siaddr;
lease->address = offer->yiaddr;
if (lease->address == INADDR_ANY ||
lease->server_address == INADDR_ANY ||
lease->lifetime == 0) {
log_dhcp_client(client, "receieved lease lacks address, server "
"address or lease lifetime, ignoring");
return -ENOMSG;
}
if (lease->subnet_mask == INADDR_ANY) {
r = dhcp_lease_set_default_subnet_mask(lease);
if (r < 0) {
log_dhcp_client(client, "receieved lease lacks subnet "
"mask, and a fallback one can not be "
"generated, ignoring");
return -ENOMSG;
}
}
sd_dhcp_lease_unref(client->lease);
client->lease = lease;
lease = NULL;
log_dhcp_client(client, "OFFER");
return 0;
}
static int client_send_discover(sd_dhcp_client *client) {
_cleanup_free_ DHCPPacket *discover = NULL;
size_t optoffset, optlen;
usec_t time_now;
int r;
assert(client);
assert(client->state == DHCP_STATE_INIT ||
client->state == DHCP_STATE_SELECTING);
/* See RFC2131 section 4.4.1 */
r = sd_event_now(client->event, CLOCK_MONOTONIC, &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;
r = client_message_init(client, &discover, DHCP_DISCOVER,
&optlen, &optoffset);
if (r < 0)
return r;
/* the client may suggest values for the network address
and lease time in the DHCPDISCOVER message. The client may include
the ’requested IP address’ option to suggest that a particular IP
address be assigned, and may include the ’IP address lease time’
option to suggest the lease time it would like.
*/
if (client->last_addr != INADDR_ANY) {
r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->last_addr);
if (r < 0)
return r;
}
r = dhcp_option_append(&discover->dhcp, optlen, &optoffset, 0,
DHCP_OPTION_END, 0, NULL);
/* We currently ignore:
The client SHOULD wait a random time between one and ten seconds to
desynchronize the use of DHCP at startup.
*/
r = dhcp_client_send_raw(client, discover, sizeof(DHCPPacket) + optoffset);
if (r < 0)
return r;
log_dhcp_client(client, "DISCOVER");
return 0;
}
static sd_dhcp_client *client_stop(sd_dhcp_client *client, int error) {
assert_return(client, NULL);
log_dhcp_client(client, "STOPPED: %s", strerror(-error));
client = client_notify(client, error);
if (client)
client_initialize(client);
return client;
}
static int client_send_request(sd_dhcp_client *client, uint16_t secs) {
_cleanup_free_ DHCPPacket *request;
size_t optlen, len;
int err;
uint8_t *opt;
optlen = DHCP_MIN_OPTIONS_SIZE;
len = sizeof(DHCPPacket) + optlen;
request = malloc0(len);
if (!request)
return -ENOMEM;
err = client_message_init(client, &request->dhcp, DHCP_REQUEST, secs,
&opt, &optlen);
if (err < 0)
return err;
if (client->state == 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;
}
err = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
if (err < 0)
return err;
if (client->state == DHCP_STATE_RENEWING) {
err = dhcp_network_send_udp_socket(client->fd,
client->lease->server_address,
DHCP_PORT_SERVER,
&request->dhcp,
len - DHCP_IP_UDP_SIZE);
} else {
err = dhcp_client_send_raw(client, request, len);
}
if (err < 0)
return err;
log_dhcp_client(client, "REQUEST");
return 0;
}
static int client_timeout_expire(sd_event_source *s, uint64_t usec,
void *userdata) {
sd_dhcp_client *client = userdata;
log_dhcp_client(client, "EXPIRED");
client = client_notify(client, DHCP_EVENT_EXPIRED);
/* lease was lost, start over if not freed or stopped in callback */
if (client && client->state != DHCP_STATE_STOPPED) {
client_initialize(client);
client_start(client);
}
return 0;
}
int sd_dhcp_client_set_mac(sd_dhcp_client *client,
const struct ether_addr *addr) {
assert_return(client, -EINVAL);
assert_return(client->state == DHCP_STATE_INIT, -EBUSY);
log_dhcp_client(client, "set MAC address to "
"%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx",
addr->ether_addr_octet[0],
addr->ether_addr_octet[1],
addr->ether_addr_octet[2],
addr->ether_addr_octet[3],
addr->ether_addr_octet[4],
addr->ether_addr_octet[5]);
memcpy(&client->mac_addr, addr, ETH_ALEN);
return 0;
}
sd_dhcp_client *sd_dhcp_client_unref(sd_dhcp_client *client) {
if (client && REFCNT_DEC(client->n_ref) <= 0) {
log_dhcp_client(client, "UNREF");
client_initialize(client);
client->receive_message =
sd_event_source_unref(client->receive_message);
sd_dhcp_client_detach_event(client);
sd_dhcp_lease_unref(client->lease);
free(client->req_opts);
free(client);
return NULL;
}
return client;
}
static int client_send_discover(sd_dhcp_client *client, uint16_t secs) {
int err = 0;
_cleanup_free_ DHCPPacket *discover;
size_t optlen, len;
uint8_t *opt;
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;
if (client->last_addr != INADDR_ANY) {
err = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->last_addr);
if (err < 0)
return err;
}
err = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
if (err < 0)
return err;
err = dhcp_client_send_raw(client, discover, len);
if (err < 0)
return err;
log_dhcp_client(client, "DISCOVER");
return 0;
}
static int client_timeout_resend(sd_event_source *s, uint64_t usec,
void *userdata) {
sd_dhcp_client *client = userdata;
usec_t next_timeout = 0;
uint64_t time_now;
uint32_t time_left;
int r;
assert(s);
assert(client);
assert(client->event);
r = sd_event_now(client->event, CLOCK_MONOTONIC, &time_now);
if (r < 0)
goto error;
switch (client->state) {
case DHCP_STATE_RENEWING:
time_left = (client->lease->t2 - client->lease->t1) / 2;
if (time_left < 60)
time_left = 60;
next_timeout = time_now + time_left * USEC_PER_SEC;
break;
case DHCP_STATE_REBINDING:
time_left = (client->lease->lifetime - client->lease->t2) / 2;
if (time_left < 60)
time_left = 60;
next_timeout = time_now + time_left * USEC_PER_SEC;
break;
case DHCP_STATE_REBOOTING:
/* start over as we did not receive a timely ack or nak */
r = client_initialize(client);
if (r < 0)
goto error;
r = client_start(client);
if (r < 0)
goto error;
else {
log_dhcp_client(client, "REBOOTED");
return 0;
}
case DHCP_STATE_INIT:
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_SELECTING:
case DHCP_STATE_REQUESTING:
case DHCP_STATE_BOUND:
if (client->attempt < 64)
client->attempt *= 2;
next_timeout = time_now + (client->attempt - 1) * USEC_PER_SEC;
break;
case DHCP_STATE_STOPPED:
r = -EINVAL;
goto error;
}
next_timeout += (random_u32() & 0x1fffff);
client->timeout_resend = sd_event_source_unref(client->timeout_resend);
r = sd_event_add_time(client->event,
&client->timeout_resend,
CLOCK_MONOTONIC,
next_timeout, 10 * USEC_PER_MSEC,
client_timeout_resend, client);
if (r < 0)
goto error;
r = sd_event_source_set_priority(client->timeout_resend,
client->event_priority);
if (r < 0)
goto error;
switch (client->state) {
case DHCP_STATE_INIT:
r = client_send_discover(client);
if (r >= 0) {
client->state = DHCP_STATE_SELECTING;
client->attempt = 1;
} else {
if (client->attempt >= 64)
goto error;
}
break;
case DHCP_STATE_SELECTING:
r = client_send_discover(client);
if (r < 0 && client->attempt >= 64)
goto error;
break;
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_REQUESTING:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
r = client_send_request(client);
if (r < 0 && client->attempt >= 64)
goto error;
if (client->state == DHCP_STATE_INIT_REBOOT)
client->state = DHCP_STATE_REBOOTING;
client->request_sent = time_now;
break;
case DHCP_STATE_REBOOTING:
case DHCP_STATE_BOUND:
break;
case DHCP_STATE_STOPPED:
r = -EINVAL;
goto error;
}
return 0;
error:
client_stop(client, r);
/* Errors were dealt with when stopping the client, don't spill
errors into the event loop handler */
return 0;
}
static int client_send_request(sd_dhcp_client *client) {
_cleanup_free_ DHCPPacket *request;
size_t optlen, len;
uint8_t *opt;
int r;
optlen = DHCP_MIN_OPTIONS_SIZE;
len = sizeof(DHCPPacket) + optlen;
request = malloc0(len);
if (!request)
return -ENOMEM;
r = client_message_init(client, &request->dhcp, DHCP_REQUEST, &opt,
&optlen);
if (r < 0)
return r;
switch (client->state) {
/* See RFC2131 section 4.3.2 (note that there is a typo in the RFC,
SELECTING should be REQUESTING)
*/
case DHCP_STATE_REQUESTING:
/* Client inserts the address of the selected server in ’server
identifier’, ’ciaddr’ MUST be zero, ’requested IP address’ MUST be
filled in with the yiaddr value from the chosen DHCPOFFER.
*/
r = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_SERVER_IDENTIFIER,
4, &client->lease->server_address);
if (r < 0)
return r;
r = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->lease->address);
if (r < 0)
return r;
break;
case DHCP_STATE_INIT_REBOOT:
/* ’server identifier’ MUST NOT be filled in, ’requested IP address’
option MUST be filled in with client’s notion of its previously
assigned address. ’ciaddr’ MUST be zero.
*/
r = dhcp_option_append(&opt, &optlen,
DHCP_OPTION_REQUESTED_IP_ADDRESS,
4, &client->last_addr);
if (r < 0)
return r;
break;
case DHCP_STATE_RENEWING:
/* ’server identifier’ MUST NOT be filled in, ’requested IP address’
option MUST NOT be filled in, ’ciaddr’ MUST be filled in with
client’s IP address.
*/
/* fall through */
case DHCP_STATE_REBINDING:
/* ’server identifier’ MUST NOT be filled in, ’requested IP address’
option MUST NOT be filled in, ’ciaddr’ MUST be filled in with
client’s IP address.
This message MUST be broadcast to the 0xffffffff IP broadcast address.
*/
request->dhcp.ciaddr = client->lease->address;
break;
case DHCP_STATE_INIT:
case DHCP_STATE_SELECTING:
case DHCP_STATE_REBOOTING:
case DHCP_STATE_BOUND:
case DHCP_STATE_STOPPED:
return -EINVAL;
}
r = dhcp_option_append(&opt, &optlen, DHCP_OPTION_END, 0, NULL);
if (r < 0)
return r;
if (client->state == DHCP_STATE_RENEWING) {
r = dhcp_network_send_udp_socket(client->fd,
client->lease->server_address,
DHCP_PORT_SERVER,
&request->dhcp,
len - optlen - DHCP_IP_UDP_SIZE);
} else {
r = dhcp_client_send_raw(client, request, len - optlen);
}
if (r < 0)
return r;
switch (client->state) {
case DHCP_STATE_REQUESTING:
log_dhcp_client(client, "REQUEST (requesting)");
break;
case DHCP_STATE_INIT_REBOOT:
log_dhcp_client(client, "REQUEST (init-reboot)");
break;
case DHCP_STATE_RENEWING:
log_dhcp_client(client, "REQUEST (renewing)");
break;
case DHCP_STATE_REBINDING:
log_dhcp_client(client, "REQUEST (rebinding)");
break;
default:
log_dhcp_client(client, "REQUEST (invalid)");
break;
}
return 0;
}
static int client_handle_message(sd_dhcp_client *client, DHCPMessage *message,
int len) {
int r = 0, notify_event = 0;
assert(client);
assert(client->event);
assert(message);
if (be32toh(message->magic) != DHCP_MAGIC_COOKIE) {
log_dhcp_client(client, "not a DHCP message: ignoring");
return 0;
}
if (message->op != BOOTREPLY) {
log_dhcp_client(client, "not a BOOTREPLY message: ignoring");
return 0;
}
if (be32toh(message->xid) != client->xid) {
log_dhcp_client(client, "received xid (%u) does not match "
"expected (%u): ignoring",
be32toh(message->xid), client->xid);
return 0;
}
if (message->htype != ARPHRD_ETHER || message->hlen != ETHER_ADDR_LEN) {
log_dhcp_client(client, "not an ethernet packet");
return 0;
}
if (memcmp(&message->chaddr[0], &client->client_id.mac_addr,
ETH_ALEN)) {
log_dhcp_client(client, "received chaddr does not match "
"expected: ignoring");
return 0;
}
switch (client->state) {
case DHCP_STATE_SELECTING:
r = client_handle_offer(client, message, len);
if (r >= 0) {
client->timeout_resend =
sd_event_source_unref(client->timeout_resend);
client->state = DHCP_STATE_REQUESTING;
client->attempt = 1;
r = sd_event_add_time(client->event,
&client->timeout_resend,
CLOCK_MONOTONIC,
0, 0,
client_timeout_resend, client);
if (r < 0)
goto error;
r = sd_event_source_set_priority(client->timeout_resend,
client->event_priority);
if (r < 0)
goto error;
} else if (r == -ENOMSG)
/* invalid message, let's ignore it */
return 0;
break;
case DHCP_STATE_REBOOTING:
case DHCP_STATE_REQUESTING:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
r = client_handle_ack(client, message, len);
if (r == DHCP_EVENT_NO_LEASE) {
client->timeout_resend =
sd_event_source_unref(client->timeout_resend);
if (client->state == DHCP_STATE_REBOOTING) {
r = client_initialize(client);
if (r < 0)
goto error;
r = client_start(client);
if (r < 0)
goto error;
log_dhcp_client(client, "REBOOTED");
}
goto error;
} else if (r >= 0) {
client->timeout_resend =
sd_event_source_unref(client->timeout_resend);
if (IN_SET(client->state, DHCP_STATE_REQUESTING,
DHCP_STATE_REBOOTING))
notify_event = DHCP_EVENT_IP_ACQUIRE;
else if (r != DHCP_EVENT_IP_ACQUIRE)
notify_event = r;
client->state = DHCP_STATE_BOUND;
client->attempt = 1;
client->last_addr = client->lease->address;
r = client_set_lease_timeouts(client);
if (r < 0)
goto error;
if (notify_event) {
client = client_notify(client, notify_event);
if (!client ||
client->state == DHCP_STATE_STOPPED)
return 0;
}
client->receive_message =
sd_event_source_unref(client->receive_message);
client->fd = asynchronous_close(client->fd);
} else if (r == -ENOMSG)
/* invalid message, let's ignore it */
return 0;
break;
case DHCP_STATE_INIT:
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_BOUND:
break;
case DHCP_STATE_STOPPED:
r = -EINVAL;
goto error;
}
error:
if (r < 0 || r == DHCP_EVENT_NO_LEASE)
client_stop(client, r);
return r;
}
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);
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);
/* don't set timers for infinite leases */
if (client->lease->lifetime == 0xffffffff)
return 0;
r = sd_event_now(client->event, CLOCK_MONOTONIC, &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_time(client->event, &client->timeout_expire,
CLOCK_MONOTONIC,
lifetime_timeout, 10 * USEC_PER_MSEC,
client_timeout_expire, client);
if (r < 0)
return r;
r = sd_event_source_set_priority(client->timeout_expire,
client->event_priority);
if (r < 0)
return r;
log_dhcp_client(client, "lease expires in %s",
format_timespan(time_string, FORMAT_TIMESPAN_MAX,
lifetime_timeout - time_now, 0));
/* don't arm earlier timeouts if this has already expired */
if (lifetime_timeout <= time_now)
return 0;
/* arm T2 timeout */
r = sd_event_add_time(client->event,
&client->timeout_t2,
CLOCK_MONOTONIC,
t2_timeout,
10 * USEC_PER_MSEC,
client_timeout_t2, client);
if (r < 0)
return r;
r = sd_event_source_set_priority(client->timeout_t2,
client->event_priority);
if (r < 0)
return r;
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_time(client->event,
&client->timeout_t1,
CLOCK_MONOTONIC,
t1_timeout, 10 * USEC_PER_MSEC,
client_timeout_t1, client);
if (r < 0)
return r;
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_receive_message_raw(sd_event_source *s, int fd,
uint32_t revents, void *userdata) {
sd_dhcp_client *client = userdata;
_cleanup_free_ DHCPPacket *packet = NULL;
uint8_t cmsgbuf[CMSG_LEN(sizeof(struct tpacket_auxdata))];
struct iovec iov = {};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = cmsgbuf,
.msg_controllen = sizeof(cmsgbuf),
};
struct cmsghdr *cmsg;
bool checksum = true;
int buflen = 0, len, r;
assert(s);
assert(client);
r = ioctl(fd, FIONREAD, &buflen);
if (r < 0 || buflen <= 0)
buflen = sizeof(DHCPPacket) + DHCP_MIN_OPTIONS_SIZE;
packet = malloc0(buflen);
if (!packet)
return -ENOMEM;
iov.iov_base = packet;
iov.iov_len = buflen;
len = recvmsg(fd, &msg, 0);
if (len < 0) {
log_dhcp_client(client, "could not receive message from raw "
"socket: %s", strerror(errno));
return 0;
} else if ((size_t)len < sizeof(DHCPPacket))
return 0;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_PACKET &&
cmsg->cmsg_type == PACKET_AUXDATA &&
cmsg->cmsg_len == CMSG_LEN(sizeof(struct tpacket_auxdata))) {
struct tpacket_auxdata *aux = (struct tpacket_auxdata*)CMSG_DATA(cmsg);
checksum = !(aux->tp_status & TP_STATUS_CSUMNOTREADY);
break;
}
}
r = dhcp_packet_verify_headers(packet, len, checksum);
if (r < 0)
return 0;
len -= DHCP_IP_UDP_SIZE;
return client_handle_message(client, &packet->dhcp, len);
}
int sd_dhcp_client_start(sd_dhcp_client *client) {
int r;
assert_return(client, -EINVAL);
r = client_initialize(client);
if (r < 0)
return r;
if (client->last_addr)
client->state = DHCP_STATE_INIT_REBOOT;
r = client_start(client);
if (r >= 0)
log_dhcp_client(client, "STARTED on ifindex %u with address %s",
client->index,
ether_ntoa(&client->client_id.mac_addr));
return r;
}
