static err_t dhcp_release(struct dhcp_state *state)
{
err_t result;
u16_t msecs;
DEBUGF(DHCP_DEBUG, ("dhcp_release()\n"));
// and idle DHCP client
dhcp_set_state(state, DHCP_OFF);
// create and initialize the DHCP message header
result = dhcp_create_request(state);
if (result == ERR_OK)
{
dhcp_option(state, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
dhcp_option_byte(state, DHCP_RELEASE);
dhcp_option_trailer(state);
pbuf_realloc(state->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + state->options_out_len);
udp_bind(state->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
udp_connect(state->pcb, &state->server_ip_addr, DHCP_SERVER_PORT);
udp_send(state->pcb, state->p_out);
dhcp_delete_request(state);
}
state->tries++;
msecs = state->tries < 10 ? state->tries * 1000 : 10 * 1000;
state->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
DEBUGF(DHCP_DEBUG, ("dhcp_release(): request timeout %u msecs\n", msecs));
// remove IP address from interface
netif_set_ipaddr(state->netif, IP_ADDR_ANY);
netif_set_gw(state->netif, IP_ADDR_ANY);
netif_set_netmask(state->netif, IP_ADDR_ANY);
return result;
}
// decline a
static err_t dhcp_decline(struct dhcp_state *state)
{
err_t result = ERR_OK;
u16_t msecs;
DEBUGF(DHCP_DEBUG, ("dhcp_decline()\n"));
dhcp_set_state(state, DHCP_BACKING_OFF);
// create and initialize the DHCP message header
result = dhcp_create_request(state);
if (result == ERR_OK)
{
dhcp_option(state, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
dhcp_option_byte(state, DHCP_DECLINE);
dhcp_option(state, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
dhcp_option_short(state, 576);
dhcp_option_trailer(state);
// resize pbuf to reflect true size of options
pbuf_realloc(state->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + state->options_out_len);
udp_bind(state->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
udp_connect(state->pcb, &state->server_ip_addr, DHCP_SERVER_PORT);
udp_send(state->pcb, state->p_out);
dhcp_delete_request(state);
}
state->tries++;
msecs = 10*1000;
state->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
DEBUGF(DHCP_DEBUG, ("dhcp_decline(): request timeout %u msecs\n", msecs));
return result;
}
void dhcp_inform(struct netif *netif)
{
struct dhcp_state *state = NULL;
err_t result = ERR_OK;
state = mem_malloc(sizeof(struct dhcp_state));
if (state == NULL)
{
DEBUGF(DHCP_DEBUG, ("dhcp_inform(): could not allocate dhcp_state\n"));
return;
}
memset(state, 0, sizeof(struct dhcp_state));
DEBUGF(DHCP_DEBUG, ("dhcp_inform(): allocated dhcp_state\n"));
state->pcb = udp_new();
if (state->pcb == NULL) {
DEBUGF(DHCP_DEBUG, ("dhcp_inform(): could not obtain pcb\n"));
mem_free((void *)state);
return;
}
DEBUGF(DHCP_DEBUG, ("dhcp_inform(): created new udp pcb\n"));
state->netif = netif;
// we are last in list
state->next = NULL;
// create and initialize the DHCP message header
result = dhcp_create_request(state);
if (result == ERR_OK)
{
dhcp_option(state, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
dhcp_option_byte(state, DHCP_INFORM);
dhcp_option(state, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
dhcp_option_short(state, 576);
dhcp_option_trailer(state);
pbuf_realloc(state->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + state->options_out_len);
udp_bind(state->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
udp_connect(state->pcb, IP_ADDR_BROADCAST, DHCP_SERVER_PORT);
udp_send(state->pcb, state->p_out);
udp_connect(state->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT);
dhcp_delete_request(state);
}
if (state != NULL)
{
if (state->pcb != NULL) udp_remove(state->pcb);
state->pcb = NULL;
mem_free((void *)state);
}
}
/**
* Start the DHCP process, discover a server
*
*/
static err_t dhcp_discover(struct dhcp_state *state)
{
err_t result = ERR_OK;
u16_t msecs;
DEBUGF(DHCP_DEBUG, ("dhcp_discover(%p)\n", state));
ip_addr_set(&state->offered_ip_addr, IP_ADDR_ANY);
// create and initialize the DHCP message header
DEBUGF(DHCP_DEBUG, ("set ip addr, creating request()\n"));
result = dhcp_create_request(state);
DEBUGF(DHCP_DEBUG, ("created request\n"));
if (result == ERR_OK)
{
dhcp_option(state, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
dhcp_option_byte(state, DHCP_DISCOVER);
dhcp_option(state, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
dhcp_option_short(state, 576);
dhcp_option(state, DHCP_OPTION_PARAMETER_REQUEST_LIST, 3);
dhcp_option_byte(state, DHCP_OPTION_SUBNET_MASK);
dhcp_option_byte(state, DHCP_OPTION_ROUTER);
dhcp_option_byte(state, DHCP_OPTION_BROADCAST);
dhcp_option_trailer(state);
pbuf_realloc(state->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + state->options_out_len);
DEBUGF(DHCP_DEBUG, ("about to do udp recv\n"));
udp_recv(state->pcb, dhcp_recv, state);
DEBUGF(DHCP_DEBUG, ("about to do udp bind\n"));
udp_bind(state->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
DEBUGF(DHCP_DEBUG, ("about to do udp connect\n"));
udp_connect(state->pcb, IP_ADDR_BROADCAST, DHCP_SERVER_PORT);
DEBUGF(DHCP_DEBUG, ("about to do udp send\n"));
udp_send(state->pcb, state->p_out);
udp_bind(state->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
udp_connect(state->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT);
dhcp_delete_request(state);
}
state->tries++;
msecs = state->tries < 4 ? (state->tries + 1) * 1000 : 10 * 1000;
state->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
DEBUGF(DHCP_DEBUG, ("dhcp_discover(): request timeout %u msecs\n", msecs));
dhcp_set_state(state, DHCP_SELECTING);
return result;
}
/**
* Select a DHCP server offer out of all offers.
*
* Simply select the first offer received, ignore others
*/
static err_t dhcp_select(struct dhcp_state *state)
{
err_t result;
u32_t msecs;
DEBUGF(DHCP_DEBUG, ("dhcp_select()\n"));
// create and initialize the DHCP message header
result = dhcp_create_request(state);
if (result == ERR_OK)
{
dhcp_option(state, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
dhcp_option_byte(state, DHCP_REQUEST);
dhcp_option(state, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
dhcp_option_short(state, 576);
/* MUST request the offered IP address */
dhcp_option(state, DHCP_OPTION_REQUESTED_IP, 4);
dhcp_option_long(state, ntohl(state->offered_ip_addr.addr));
dhcp_option(state, DHCP_OPTION_SERVER_ID, 4);
dhcp_option_long(state, ntohl(state->server_ip_addr.addr));
dhcp_option(state, DHCP_OPTION_PARAMETER_REQUEST_LIST, 3);
dhcp_option_byte(state, DHCP_OPTION_SUBNET_MASK);
dhcp_option_byte(state, DHCP_OPTION_ROUTER);
dhcp_option_byte(state, DHCP_OPTION_BROADCAST);
dhcp_option_trailer(state);
pbuf_realloc(state->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + state->options_out_len);
udp_bind(state->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
udp_connect(state->pcb, IP_ADDR_BROADCAST, DHCP_SERVER_PORT);
udp_send(state->pcb, state->p_out);
// reconnect to any (or to server here?!)
udp_connect(state->pcb, IP_ADDR_ANY, DHCP_SERVER_PORT);
dhcp_delete_request(state);
}
state->tries++;
msecs = state->tries < 4 ? state->tries * 1000 : 4 * 1000;
state->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
DEBUGF(DHCP_DEBUG, ("dhcp_select(): request timeout %u msecs\n", msecs));
dhcp_set_state(state, DHCP_REQUESTING);
return result;
}
err_t dhcp_renew(struct dhcp_state *state)
{
err_t result;
u16_t msecs;
DEBUGF(DHCP_DEBUG, ("dhcp_renew()\n"));
dhcp_set_state(state, DHCP_RENEWING);
// create and initialize the DHCP message header
result = dhcp_create_request(state);
if (result == ERR_OK)
{
dhcp_option(state, DHCP_OPTION_MESSAGE_TYPE, DHCP_OPTION_MESSAGE_TYPE_LEN);
dhcp_option_byte(state, DHCP_REQUEST);
dhcp_option(state, DHCP_OPTION_MAX_MSG_SIZE, DHCP_OPTION_MAX_MSG_SIZE_LEN);
dhcp_option_short(state, 576);
#if 0
dhcp_option(state, DHCP_OPTION_REQUESTED_IP, 4);
dhcp_option_long(state, ntohl(state->offered_ip_addr.addr));
#endif
#if 0
dhcp_option(state, DHCP_OPTION_SERVER_ID, 4);
dhcp_option_long(state, ntohl(state->server_ip_addr.addr));
#endif
dhcp_option_trailer(state);
pbuf_realloc(state->p_out, sizeof(struct dhcp_msg) - DHCP_OPTIONS_LEN + state->options_out_len);
udp_bind(state->pcb, IP_ADDR_ANY, DHCP_CLIENT_PORT);
udp_connect(state->pcb, &state->server_ip_addr, DHCP_SERVER_PORT);
udp_send(state->pcb, state->p_out);
dhcp_delete_request(state);
}
state->tries++;
// back-off on retries, but to a maximum of 20 seconds
msecs = state->tries < 10 ? state->tries * 2000 : 20 * 1000;
state->request_timeout = (msecs + DHCP_FINE_TIMER_MSECS - 1) / DHCP_FINE_TIMER_MSECS;
DEBUGF(DHCP_DEBUG, ("dhcp_renew(): request timeout %u msecs\n", msecs));
return result;
}
/**
* Copy settings to DHCP packet
*
* @v dest Destination DHCP packet
* @v source Source settings block
* @v encapsulator Encapsulating setting tag number, or zero
* @ret rc Return status code
*/
static int copy_encap_settings ( struct dhcp_packet *dest,
struct settings *source,
unsigned int encapsulator ) {
struct setting setting = { .name = "" };
unsigned int subtag;
unsigned int tag;
int len;
int check_len;
int rc;
for ( subtag = DHCP_MIN_OPTION; subtag <= DHCP_MAX_OPTION; subtag++ ) {
tag = DHCP_ENCAP_OPT ( encapsulator, subtag );
switch ( tag ) {
case DHCP_EB_ENCAP:
case DHCP_VENDOR_ENCAP:
/* Process encapsulated settings */
if ( ( rc = copy_encap_settings ( dest, source,
tag ) ) != 0 )
return rc;
break;
default:
/* Copy setting, if present */
setting.tag = tag;
len = fetch_setting_len ( source, &setting );
if ( len < 0 )
break;
{
char buf[len];
check_len = fetch_setting ( source, &setting,
buf, sizeof (buf));
assert ( check_len == len );
if ( ( rc = dhcppkt_store ( dest, tag, buf,
sizeof(buf) )) !=0)
return rc;
}
break;
}
}
return 0;
}
/**
* Copy settings to DHCP packet
*
* @v dest Destination DHCP packet
* @v source Source settings block
* @ret rc Return status code
*/
static int copy_settings ( struct dhcp_packet *dest,
struct settings *source ) {
return copy_encap_settings ( dest, source, 0 );
}
/**
* Create fake DHCPDISCOVER packet
*
* @v netdev Network device
* @v data Buffer for DHCP packet
* @v max_len Size of DHCP packet buffer
* @ret rc Return status code
*
* Used by external code.
*/
int create_fakedhcpdiscover ( struct net_device *netdev,
void *data, size_t max_len ) {
struct dhcp_packet dhcppkt;
struct in_addr ciaddr = { 0 };
int rc;
if ( ( rc = dhcp_create_request ( &dhcppkt, netdev, DHCPDISCOVER,
ciaddr, data, max_len ) ) != 0 ) {
DBG ( "Could not create DHCPDISCOVER: %s\n",
strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Create fake DHCPACK packet
*
* @v netdev Network device
* @v data Buffer for DHCP packet
* @v max_len Size of DHCP packet buffer
* @ret rc Return status code
*
* Used by external code.
*/
int create_fakedhcpack ( struct net_device *netdev,
void *data, size_t max_len ) {
struct dhcp_packet dhcppkt;
int rc;
/* Create base DHCPACK packet */
if ( ( rc = dhcp_create_packet ( &dhcppkt, netdev, DHCPACK, NULL, 0,
data, max_len ) ) != 0 ) {
DBG ( "Could not create DHCPACK: %s\n", strerror ( rc ) );
return rc;
}
/* Merge in globally-scoped settings, then netdev-specific
* settings. Do it in this order so that netdev-specific
* settings take precedence regardless of stated priorities.
*/
if ( ( rc = copy_settings ( &dhcppkt, NULL ) ) != 0 ) {
DBG ( "Could not set DHCPACK global settings: %s\n",
strerror ( rc ) );
return rc;
}
if ( ( rc = copy_settings ( &dhcppkt,
netdev_settings ( netdev ) ) ) != 0 ) {
DBG ( "Could not set DHCPACK netdev settings: %s\n",
strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Create fake PXE Boot Server ACK packet
*
* @v netdev Network device
* @v data Buffer for DHCP packet
* @v max_len Size of DHCP packet buffer
* @ret rc Return status code
*
* Used by external code.
*/
int create_fakepxebsack ( struct net_device *netdev,
void *data, size_t max_len ) {
struct dhcp_packet dhcppkt;
struct settings *proxy_settings;
struct settings *pxebs_settings;
int rc;
/* Identify available settings */
proxy_settings = find_settings ( PROXYDHCP_SETTINGS_NAME );
pxebs_settings = find_settings ( PXEBS_SETTINGS_NAME );
if ( ( ! proxy_settings ) && ( ! pxebs_settings ) ) {
/* No PXE boot server; return the regular DHCPACK */
return create_fakedhcpack ( netdev, data, max_len );
}
/* Create base DHCPACK packet */
if ( ( rc = dhcp_create_packet ( &dhcppkt, netdev, DHCPACK, NULL, 0,
data, max_len ) ) != 0 ) {
DBG ( "Could not create PXE BS ACK: %s\n",
strerror ( rc ) );
return rc;
}
/* Merge in ProxyDHCP options */
if ( proxy_settings &&
( ( rc = copy_settings ( &dhcppkt, proxy_settings ) ) != 0 ) ) {
DBG ( "Could not copy ProxyDHCP settings: %s\n",
strerror ( rc ) );
return rc;
}
/* Merge in BootServerDHCP options, if present */
if ( pxebs_settings &&
( ( rc = copy_settings ( &dhcppkt, pxebs_settings ) ) != 0 ) ) {
DBG ( "Could not copy PXE BS settings: %s\n",
strerror ( rc ) );
return rc;
}
return 0;
}
