static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
uint8_t type, uint16_t secs, uint8_t **opt,
size_t *optlen) {
int r;
assert(secs);
r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt,
optlen);
if (r < 0)
return r;
/* 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);
memcpy(&message->chaddr, &client->mac_addr, ETH_ALEN);
if (client->state == DHCP_STATE_RENEWING ||
client->state == DHCP_STATE_REBINDING)
message->ciaddr = client->lease->address;
/* Some DHCP servers will refuse to issue an DHCP lease if the Client
Identifier option is not set */
r = dhcp_option_append(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER,
ETH_ALEN, &client->mac_addr);
if (r < 0)
return r;
if (type == DHCP_DISCOVER || type == DHCP_REQUEST) {
be16_t max_size;
r = dhcp_option_append(opt, optlen,
DHCP_OPTION_PARAMETER_REQUEST_LIST,
client->req_opts_size,
client->req_opts);
if (r < 0)
return r;
/* 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_MIN_OPTIONS_SIZE);
r = dhcp_option_append(opt, optlen,
DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
2, &max_size);
if (r < 0)
return r;
}
return 0;
}
static void test_message_init(void)
{
_cleanup_free_ DHCPMessage *message = NULL;
size_t optlen = 4, optoffset;
size_t len = sizeof(DHCPMessage) + optlen;
uint8_t *magic;
message = malloc0(len);
assert_se(dhcp_message_init(message, BOOTREQUEST, 0x12345678,
DHCP_DISCOVER, optlen, &optoffset) >= 0);
assert_se(message->xid == htobe32(0x12345678));
assert_se(message->op == BOOTREQUEST);
magic = (uint8_t*)&message->magic;
assert_se(magic[0] == 99);
assert_se(magic[1] == 130);
assert_se(magic[2] == 83);
assert_se(magic[3] == 99);
assert_se(dhcp_option_parse(message, len, NULL, NULL) >= 0);
}
static int client_message_init(sd_dhcp_client *client, DHCPMessage *message,
uint8_t type, uint8_t **opt, size_t *optlen) {
be16_t max_size;
int r;
assert(client);
assert(client->secs);
assert(message);
assert(opt);
assert(optlen);
assert(type == DHCP_DISCOVER || type == DHCP_REQUEST);
r = dhcp_message_init(message, BOOTREQUEST, client->xid, type, opt,
optlen);
if (r < 0)
return r;
/* 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(client->secs);
/* RFC2132 section 4.1.1:
The client MUST include its hardware address in the ’chaddr’ field, if
necessary for delivery of DHCP reply messages.
*/
memcpy(&message->chaddr, &client->client_id.mac_addr, ETH_ALEN);
/* Some DHCP servers will refuse to issue an DHCP lease if the Client
Identifier option is not set */
r = dhcp_option_append(opt, optlen, DHCP_OPTION_CLIENT_IDENTIFIER,
sizeof(client->client_id), &client->client_id);
if (r < 0)
return r;
/* RFC2131 section 3.5:
in its initial DHCPDISCOVER or DHCPREQUEST message, a
client may provide the server with a list of specific
parameters the client is interested in. If the client
includes a list of parameters in a DHCPDISCOVER message,
it MUST include that list in any subsequent DHCPREQUEST
messages.
*/
r = dhcp_option_append(opt, optlen,
DHCP_OPTION_PARAMETER_REQUEST_LIST,
client->req_opts_size,
client->req_opts);
if (r < 0)
return r;
/* RFC2131 section 3.5:
The client SHOULD include the ’maximum DHCP message size’ option to
let the server know how large the server may make its DHCP messages.
Note (from ConnMan): 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_MIN_OPTIONS_SIZE);
r = dhcp_option_append(opt, optlen,
DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
2, &max_size);
if (r < 0)
return r;
return 0;
}
static int client_message_init(sd_dhcp_client *client, DHCPPacket **ret,
uint8_t type, size_t *_optlen, size_t *_optoffset) {
_cleanup_free_ DHCPPacket *packet;
size_t optlen, optoffset, size;
be16_t max_size;
int r;
assert(client);
assert(client->secs);
assert(ret);
assert(_optlen);
assert(_optoffset);
assert(type == DHCP_DISCOVER || type == DHCP_REQUEST);
optlen = DHCP_MIN_OPTIONS_SIZE;
size = sizeof(DHCPPacket) + optlen;
packet = malloc0(size);
if (!packet)
return -ENOMEM;
r = dhcp_message_init(&packet->dhcp, BOOTREQUEST, client->xid, type,
optlen, &optoffset);
if (r < 0)
return r;
/* Although 'secs' field is a SHOULD in RFC 2131, certain DHCP servers
refuse to issue an DHCP lease if 'secs' is set to zero */
packet->dhcp.secs = htobe16(client->secs);
/* RFC2132 section 4.1
A client that cannot receive unicast IP datagrams until its protocol
software has been configured with an IP address SHOULD set the
BROADCAST bit in the 'flags' field to 1 in any DHCPDISCOVER or
DHCPREQUEST messages that client sends. The BROADCAST bit will
provide a hint to the DHCP server and BOOTP relay agent to broadcast
any messages to the client on the client's subnet. */
if (client->broadcast)
packet->dhcp.flags = htobe16(0x8000);
/* RFC2132 section 4.1.1:
The client MUST include its hardware address in the ’chaddr’ field, if
necessary for delivery of DHCP reply messages.
*/
memcpy(&packet->dhcp.chaddr, &client->client_id.mac_addr, ETH_ALEN);
/* Some DHCP servers will refuse to issue an DHCP lease if the Client
Identifier option is not set */
r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
DHCP_OPTION_CLIENT_IDENTIFIER,
sizeof(client->client_id), &client->client_id);
if (r < 0)
return r;
/* RFC2131 section 3.5:
in its initial DHCPDISCOVER or DHCPREQUEST message, a
client may provide the server with a list of specific
parameters the client is interested in. If the client
includes a list of parameters in a DHCPDISCOVER message,
it MUST include that list in any subsequent DHCPREQUEST
messages.
*/
r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
DHCP_OPTION_PARAMETER_REQUEST_LIST,
client->req_opts_size, client->req_opts);
if (r < 0)
return r;
/* RFC2131 section 3.5:
The client SHOULD include the ’maximum DHCP message size’ option to
let the server know how large the server may make its DHCP messages.
Note (from ConnMan): 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(size);
r = dhcp_option_append(&packet->dhcp, optlen, &optoffset, 0,
DHCP_OPTION_MAXIMUM_MESSAGE_SIZE,
2, &max_size);
if (r < 0)
return r;
*_optlen = optlen;
*_optoffset = optoffset;
*ret = packet;
packet = NULL;
return 0;
}
