#define DHCP_CLIENT_MIN_OPTIONS_SIZE 312
struct DHCPLease {
+ uint32_t t1;
+ uint32_t t2;
uint32_t lifetime;
uint32_t address;
uint32_t server_address;
uint32_t xid;
usec_t start_time;
unsigned int attempt;
+ usec_t request_sent;
+ sd_event_source *timeout_t1;
+ sd_event_source *timeout_t2;
+ sd_event_source *timeout_expire;
+ sd_dhcp_client_cb_t cb;
+ void *userdata;
DHCPLease *lease;
};
DHCP_OPTION_NTP_SERVER,
};
+int sd_dhcp_client_set_callback(sd_dhcp_client *client, sd_dhcp_client_cb_t cb,
+ void *userdata)
+{
+ assert_return(client, -EINVAL);
+
+ client->cb = cb;
+ client->userdata = userdata;
+
+ return 0;
+}
+
int sd_dhcp_client_set_request_option(sd_dhcp_client *client, uint8_t option)
{
size_t i;
return 0;
}
+int sd_dhcp_client_get_address(sd_dhcp_client *client, struct in_addr *addr)
+{
+ assert_return(client, -EINVAL);
+ assert_return(addr, -EINVAL);
+
+ switch (client->state) {
+ case DHCP_STATE_INIT:
+ case DHCP_STATE_SELECTING:
+ case DHCP_STATE_INIT_REBOOT:
+ case DHCP_STATE_REBOOTING:
+ case DHCP_STATE_REQUESTING:
+ return -EADDRNOTAVAIL;
+
+ case DHCP_STATE_BOUND:
+ case DHCP_STATE_RENEWING:
+ case DHCP_STATE_REBINDING:
+ addr->s_addr = client->lease->address;
+
+ break;
+ }
+
+ return 0;
+}
+
+int sd_dhcp_client_get_netmask(sd_dhcp_client *client, struct in_addr *addr)
+{
+ assert_return(client, -EINVAL);
+ assert_return(addr, -EINVAL);
+
+ switch (client->state) {
+ case DHCP_STATE_INIT:
+ case DHCP_STATE_SELECTING:
+ case DHCP_STATE_INIT_REBOOT:
+ case DHCP_STATE_REBOOTING:
+ case DHCP_STATE_REQUESTING:
+ return -EADDRNOTAVAIL;
+
+ case DHCP_STATE_BOUND:
+ case DHCP_STATE_RENEWING:
+ case DHCP_STATE_REBINDING:
+ addr->s_addr = client->lease->subnet_mask;
+
+ break;
+ }
+
+ return 0;
+}
+
+int sd_dhcp_client_prefixlen(const struct in_addr *addr)
+{
+ int len = 0;
+ uint32_t mask;
+
+ assert_return(addr, -EADDRNOTAVAIL);
+
+ mask = be32toh(addr->s_addr);
+ while (mask) {
+ len++;
+ mask = mask << 1;
+ }
+
+ return len;
+}
+
+int sd_dhcp_client_get_router(sd_dhcp_client *client, struct in_addr *addr)
+{
+ assert_return(client, -EINVAL);
+ assert_return(addr, -EINVAL);
+
+ switch (client->state) {
+ case DHCP_STATE_INIT:
+ case DHCP_STATE_SELECTING:
+ case DHCP_STATE_INIT_REBOOT:
+ case DHCP_STATE_REBOOTING:
+ case DHCP_STATE_REQUESTING:
+ return -EADDRNOTAVAIL;
+
+ case DHCP_STATE_BOUND:
+ case DHCP_STATE_RENEWING:
+ case DHCP_STATE_REBINDING:
+ addr->s_addr = client->lease->router;
+
+ break;
+ }
+
+ return 0;
+}
+
+static int client_notify(sd_dhcp_client *client, int event)
+{
+ if (client->cb)
+ client->cb(client, event, client->userdata);
+
+ return 0;
+}
+
static int client_stop(sd_dhcp_client *client, int error)
{
assert_return(client, -EINVAL);
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);
+
switch (client->state) {
case DHCP_STATE_INIT:
case DHCP_STATE_SELECTING:
+ case DHCP_STATE_REQUESTING:
+ case DHCP_STATE_BOUND:
client->start_time = 0;
client->state = DHCP_STATE_INIT;
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_REBOOTING:
- case DHCP_STATE_REQUESTING:
- case DHCP_STATE_BOUND:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
uint8_t **opt, size_t *optlen)
{
int err;
+ be16_t max_size;
*opt = (uint8_t *)(message + 1);
client->req_opts);
if (err < 0)
return err;
+
+ /* Some DHCP servers will send bigger DHCP packets than the
+ defined default size unless the Maximum Messge Size option
+ is explicitely set */
+ max_size = htobe16(DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE +
+ DHCP_CLIENT_MIN_OPTIONS_SIZE);
+ err = dhcp_option_append(opt, optlen,
+ DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
+ 2, &max_size);
+ if (err < 0)
+ return err;
}
return 0;
if (err < 0 && client->attempt >= 64)
goto error;
+ client->request_sent = usec;
+
break;
case DHCP_STATE_INIT_REBOOT:
return 0;
}
+static int client_timeout_expire(sd_event_source *s, uint64_t usec,
+ void *userdata)
+{
+ sd_dhcp_client *client = userdata;
+
+ client_stop(client, DHCP_EVENT_EXPIRED);
+
+ return 0;
+}
+
+static int client_timeout_t2(sd_event_source *s, uint64_t usec, void *userdata)
+{
+ return 0;
+}
+
+static int client_timeout_t1(sd_event_source *s, uint64_t usec, void *userdata)
+{
+ return 0;
+}
+
static int client_parse_offer(uint8_t code, uint8_t len, const uint8_t *option,
void *user_data)
{
memcpy(&lease->router, option, 4);
break;
+
+ case DHCP_OPTION_RENEWAL_T1_TIME:
+ if (len == 4) {
+ memcpy(&val, option, 4);
+ lease->t1 = be32toh(val);
+ }
+
+ break;
+
+ case DHCP_OPTION_REBINDING_T2_TIME:
+ if (len == 4) {
+ memcpy(&val, option, 4);
+ lease->t2 = be32toh(val);
+ }
+
+ break;
}
return 0;
}
-static int client_receive_offer(sd_dhcp_client *client, DHCPPacket *offer,
- size_t len)
+static int client_verify_headers(sd_dhcp_client *client, DHCPPacket *message,
+ size_t len)
{
size_t hdrlen;
- DHCPLease *lease;
if (len < (DHCP_IP_UDP_SIZE + DHCP_MESSAGE_SIZE))
return -EINVAL;
- hdrlen = offer->ip.ihl * 4;
- if (hdrlen < 20 || hdrlen > len || client_checksum(&offer->ip,
+ hdrlen = message->ip.ihl * 4;
+ if (hdrlen < 20 || hdrlen > len || client_checksum(&message->ip,
hdrlen))
return -EINVAL;
- offer->ip.check = offer->udp.len;
- offer->ip.ttl = 0;
+ message->ip.check = message->udp.len;
+ message->ip.ttl = 0;
- if (hdrlen + be16toh(offer->udp.len) > len ||
- client_checksum(&offer->ip.ttl, be16toh(offer->udp.len) + 12))
+ if (hdrlen + be16toh(message->udp.len) > len ||
+ client_checksum(&message->ip.ttl, be16toh(message->udp.len) + 12))
return -EINVAL;
- if (be16toh(offer->udp.source) != DHCP_PORT_SERVER ||
- be16toh(offer->udp.dest) != DHCP_PORT_CLIENT)
+ if (be16toh(message->udp.source) != DHCP_PORT_SERVER ||
+ be16toh(message->udp.dest) != DHCP_PORT_CLIENT)
return -EINVAL;
- if (offer->dhcp.op != BOOTREPLY)
+ if (message->dhcp.op != BOOTREPLY)
return -EINVAL;
- if (be32toh(offer->dhcp.xid) != client->xid)
+ if (be32toh(message->dhcp.xid) != client->xid)
return -EINVAL;
- if (memcmp(&offer->dhcp.chaddr[0], &client->mac_addr.ether_addr_octet,
+ if (memcmp(&message->dhcp.chaddr[0], &client->mac_addr.ether_addr_octet,
ETHER_ADDR_LEN))
return -EINVAL;
+ return 0;
+}
+
+static int client_receive_offer(sd_dhcp_client *client, DHCPPacket *offer,
+ size_t len)
+{
+ int err;
+ DHCPLease *lease;
+
+ err = client_verify_headers(client, offer, len);
+ if (err < 0)
+ return err;
+
lease = new0(DHCPLease, 1);
if (!lease)
return -ENOMEM;
return -ENOMSG;
}
+static int client_receive_ack(sd_dhcp_client *client, DHCPPacket *offer,
+ size_t len)
+{
+ int r;
+ DHCPLease *lease;
+
+ r = client_verify_headers(client, offer, len);
+ if (r < 0)
+ return r;
+
+ lease = new0(DHCPLease, 1);
+ if (!lease)
+ return -ENOBUFS;
+
+ len = len - DHCP_IP_UDP_SIZE;
+ r = dhcp_option_parse(&offer->dhcp, len, client_parse_offer, lease);
+
+ if (r != DHCP_ACK)
+ goto error;
+
+ lease->address = offer->dhcp.yiaddr;
+
+ if (lease->address == INADDR_ANY ||
+ lease->server_address == INADDR_ANY ||
+ lease->subnet_mask == INADDR_ANY || lease->lifetime == 0) {
+ r = -ENOMSG;
+ goto error;
+ }
+
+ 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;
+ }
+
+ free(client->lease);
+ }
+
+ client->lease = lease;
+
+ return r;
+
+error:
+ free(lease);
+
+ return r;
+}
+
+static uint64_t client_compute_timeout(uint64_t request_sent,
+ uint32_t lifetime)
+{
+ return request_sent + (lifetime - 3) * USEC_PER_SEC +
+ + (random_u() & 0x1fffff);
+}
+
+static int client_set_lease_timeouts(sd_dhcp_client *client, uint64_t usec)
+{
+ int err;
+ uint64_t next_timeout;
+
+ if (client->lease->lifetime < 10)
+ return -EINVAL;
+
+ if (!client->lease->t1)
+ client->lease->t1 = client->lease->lifetime / 2;
+
+ next_timeout = client_compute_timeout(client->request_sent,
+ client->lease->t1);
+ if (next_timeout < usec)
+ return -EINVAL;
+
+ err = sd_event_add_monotonic(client->event, next_timeout,
+ 10 * USEC_PER_MSEC,
+ client_timeout_t1, client,
+ &client->timeout_t1);
+ if (err < 0)
+ return err;
+
+ if (!client->lease->t2)
+ client->lease->t2 = client->lease->lifetime * 7 / 8;
+
+ if (client->lease->t2 < client->lease->t1)
+ return -EINVAL;
+
+ 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;
+
+ err = sd_event_add_monotonic(client->event, next_timeout,
+ 10 * USEC_PER_MSEC,
+ client_timeout_t2, client,
+ &client->timeout_t2);
+ if (err < 0)
+ return err;
+
+ next_timeout = client_compute_timeout(client->request_sent,
+ client->lease->lifetime);
+ if (next_timeout < usec)
+ return -EINVAL;
+
+ err = sd_event_add_monotonic(client->event, next_timeout,
+ 10 * USEC_PER_MSEC,
+ client_timeout_expire, client,
+ &client->timeout_expire);
+ if (err < 0)
+ return err;
+
+ return 0;
+}
+
static int client_receive_raw_message(sd_event_source *s, int fd,
uint32_t revents, void *userdata)
{
sd_dhcp_client *client = userdata;
uint8_t buf[sizeof(DHCPPacket) + DHCP_CLIENT_MIN_OPTIONS_SIZE];
int buflen = sizeof(buf);
- int len, err = 0;
+ int len, r = 0;
DHCPPacket *message;
usec_t time_now;
if (len < 0)
return 0;
- err = sd_event_get_now_monotonic(client->event, &time_now);
- if (err < 0)
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
goto error;
message = (DHCPPacket *)&buf;
client->state = DHCP_STATE_REQUESTING;
client->attempt = 1;
- err = sd_event_add_monotonic(client->event, time_now, 0,
- client_timeout_resend,
- client,
- &client->timeout_resend);
- if (err < 0)
+ r = sd_event_add_monotonic(client->event, time_now, 0,
+ client_timeout_resend,
+ client,
+ &client->timeout_resend);
+ if (r < 0)
goto error;
}
break;
+ case DHCP_STATE_REQUESTING:
+
+ r = client_receive_ack(client, message, len);
+ if (r == DHCP_EVENT_NO_LEASE)
+ goto error;
+
+ if (r >= 0) {
+ client->timeout_resend =
+ sd_event_source_unref(client->timeout_resend);
+
+ client->state = DHCP_STATE_BOUND;
+ client->attempt = 1;
+
+ client->last_addr = client->lease->address;
+
+ r = client_set_lease_timeouts(client, time_now);
+ if (r < 0 )
+ goto error;
+
+ client_notify(client, DHCP_EVENT_IP_ACQUIRE);
+
+ close(client->fd);
+ client->fd = -1;
+ client->receive_message =
+ sd_event_source_unref(client->receive_message);
+ }
+ break;
+
case DHCP_STATE_INIT:
case DHCP_STATE_INIT_REBOOT:
case DHCP_STATE_REBOOTING:
- case DHCP_STATE_REQUESTING:
case DHCP_STATE_BOUND:
case DHCP_STATE_RENEWING:
case DHCP_STATE_REBINDING:
}
error:
- if (err < 0)
- return client_stop(client, err);
+ if (r < 0)
+ return client_stop(client, r);
return 0;
}
int sd_dhcp_client_stop(sd_dhcp_client *client)
{
- return client_stop(client, 0);
+ return client_stop(client, DHCP_EVENT_STOP);
}
sd_dhcp_client *sd_dhcp_client_new(sd_event *event)
~ianmdlvl / elogind.git / blobdiff