struct ether_addr mac_addr;
uint32_t xid;
usec_t start_time;
+ unsigned int attempt;
DHCPLease *lease;
};
return 0;
}
+static int client_notify(sd_dhcp_client *client, int event)
+{
+ 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->attempt = 1;
+
switch (client->state) {
case DHCP_STATE_INIT:
case DHCP_STATE_SELECTING:
+ case DHCP_STATE_REQUESTING:
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;
return ~((sum & 0xffff) + (sum >> 16));
}
+static void client_append_ip_headers(DHCPPacket *packet, uint16_t len)
+{
+ packet->ip.version = IPVERSION;
+ packet->ip.ihl = DHCP_IP_SIZE / 4;
+ packet->ip.tot_len = htobe16(len);
+
+ packet->ip.protocol = IPPROTO_UDP;
+ packet->ip.saddr = INADDR_ANY;
+ packet->ip.daddr = INADDR_BROADCAST;
+
+ packet->udp.source = htobe16(DHCP_PORT_CLIENT);
+ packet->udp.dest = htobe16(DHCP_PORT_SERVER);
+ packet->udp.len = htobe16(len - DHCP_IP_SIZE);
+
+ packet->ip.check = packet->udp.len;
+ packet->udp.check = client_checksum(&packet->ip.ttl, len - 8);
+
+ packet->ip.ttl = IPDEFTTL;
+ packet->ip.check = 0;
+ packet->ip.check = client_checksum(&packet->ip, DHCP_IP_SIZE);
+}
+
static int client_send_discover(sd_dhcp_client *client, uint16_t secs)
{
int err = 0;
if (err < 0)
return err;
- discover->ip.version = IPVERSION;
- discover->ip.ihl = sizeof(discover->ip) >> 2;
- discover->ip.tot_len = htobe16(len);
+ client_append_ip_headers(discover, len);
- discover->ip.protocol = IPPROTO_UDP;
- discover->ip.saddr = INADDR_ANY;
- discover->ip.daddr = INADDR_BROADCAST;
+ err = dhcp_network_send_raw_socket(client->fd, &client->link,
+ discover, len);
+
+ return err;
+}
+
+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;
- discover->udp.source = htobe16(DHCP_PORT_CLIENT);
- discover->udp.dest = htobe16(DHCP_PORT_SERVER);
- discover->udp.len = htobe16(len - sizeof(discover->ip));
+ optlen = DHCP_CLIENT_MIN_OPTIONS_SIZE;
+ len = DHCP_MESSAGE_SIZE + optlen;
- discover->ip.check = discover->udp.len;
- discover->udp.check = client_checksum(&discover->ip.ttl,
- len - 8);
+ request = malloc0(len);
+ if (!request)
+ return -ENOMEM;
- discover->ip.ttl = IPDEFTTL;
- discover->ip.check = 0;
- discover->ip.check = client_checksum(&discover->ip,
- sizeof(discover->ip));
+ err = client_packet_init(client, DHCP_REQUEST, &request->dhcp, 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;
+
+ client_append_ip_headers(request, len);
err = dhcp_network_send_raw_socket(client->fd, &client->link,
- discover, len);
+ request, len);
return err;
}
uint16_t secs;
int err = 0;
- switch (client->state) {
- case DHCP_STATE_INIT:
- case DHCP_STATE_SELECTING:
+ secs = (usec - client->start_time) / USEC_PER_SEC;
- if (!client->start_time)
- client->start_time = usec;
+ if (client->attempt < 64)
+ client->attempt *= 2;
- secs = (usec - client->start_time) / USEC_PER_SEC;
+ next_timeout = usec + (client->attempt - 1) * USEC_PER_SEC +
+ (random_u() & 0x1fffff);
- next_timeout = usec + 2 * USEC_PER_SEC + (random() & 0x1fffff);
+ err = sd_event_add_monotonic(client->event, next_timeout,
+ 10 * USEC_PER_MSEC,
+ client_timeout_resend, client,
+ &client->timeout_resend);
+ if (err < 0)
+ goto error;
- err = sd_event_add_monotonic(client->event, next_timeout,
- 10 * USEC_PER_MSEC,
- client_timeout_resend, client,
- &client->timeout_resend);
- if (err < 0)
+ switch (client->state) {
+ case DHCP_STATE_INIT:
+ err = client_send_discover(client, secs);
+ if (err >= 0) {
+ client->state = DHCP_STATE_SELECTING;
+ client->attempt = 1;
+ } else {
+ if (client->attempt >= 64)
+ goto error;
+ }
+
+ break;
+
+ case DHCP_STATE_SELECTING:
+ err = client_send_discover(client, secs);
+ if (err < 0 && client->attempt >= 64)
goto error;
- if (client_send_discover(client, secs) >= 0)
- client->state = DHCP_STATE_SELECTING;
+ break;
+
+ case DHCP_STATE_REQUESTING:
+ err = client_send_request(client, secs);
+ if (err < 0 && client->attempt >= 64)
+ goto error;
break;
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:
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 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;
+ int len, r = 0;
DHCPPacket *message;
+ usec_t time_now;
len = read(fd, &buf, buflen);
if (len < 0)
+ return 0;
+
+ r = sd_event_get_now_monotonic(client->event, &time_now);
+ if (r < 0)
goto error;
message = (DHCPPacket *)&buf;
if (client_receive_offer(client, message, len) >= 0) {
- client->receive_message =
- sd_event_source_unref(client->receive_message);
- close(client->fd);
- client->fd = -1;
-
client->timeout_resend =
sd_event_source_unref(client->timeout_resend);
client->state = DHCP_STATE_REQUESTING;
+ client->attempt = 1;
+
+ 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;
+
+ 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 (r < 0)
+ return client_stop(client, r);
+
return 0;
}
if (err < 0)
goto error;
- err = sd_event_add_monotonic(client->event, now(CLOCK_MONOTONIC), 0,
+ client->start_time = now(CLOCK_MONOTONIC);
+ err = sd_event_add_monotonic(client->event, client->start_time, 0,
client_timeout_resend, client,
&client->timeout_resend);
if (err < 0)
client->state = DHCP_STATE_INIT;
client->index = -1;
client->fd = -1;
+ client->attempt = 1;
client->req_opts_size = ELEMENTSOF(default_req_opts);
~ianmdlvl / elogind.git / blobdiff