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Derive xid dynamically from the netdev, so that we can call 

create_dhcp_packet() from pxe_preboot.c, after the dhcp_session is long
gone.

Expose the functions required by pxe_preboot.c
This commit is contained in:
Michael Brown 2006-08-09 02:56:40 +00:00
parent 56c995ff60
commit e9561aafc0
2 changed files with 38 additions and 20 deletions
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8
src/include/gpxe/dhcp.h
View File

@ -426,8 +426,6 @@ struct dhcp_session {
/** Options obtained from server */
struct dhcp_option_block *options;
/** Transaction ID, in network-endian order */
uint32_t xid;
/** State of the session
*
* This is a value for the @c DHCP_MESSAGE_TYPE option
@ -467,6 +465,12 @@ extern void find_global_dhcp_ipv4_option ( unsigned int tag,
extern void delete_dhcp_option ( struct dhcp_option_block *options,
unsigned int tag );
extern struct dhcp_option_block dhcp_request_options;
extern int create_dhcp_packet ( struct net_device *netdev, uint8_t msgtype,
void *data, size_t max_len,
struct dhcp_packet *dhcppkt );
extern int copy_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options );
extern struct async_operation * start_dhcp ( struct dhcp_session *dhcp );
#endif /* _GPXE_DHCP_H */

50
src/net/udp/dhcp.c
View File

@ -80,8 +80,25 @@ static inline const char * dhcp_msgtype_name ( unsigned int msgtype ) {
}
}
/**
* Calculate DHCP transaction ID for a network device
*
* @v netdev Network device
* @ret xid DHCP XID
*
* Extract the least significant bits of the hardware address for use
* as the transaction ID.
*/
static uint32_t dhcp_xid ( struct net_device *netdev ) {
uint32_t xid;
memcpy ( &xid, ( netdev->ll_addr + netdev->ll_protocol->ll_addr_len
- sizeof ( xid ) ), sizeof ( xid ) );
return xid;
}
/** Options common to all DHCP requests */
static struct dhcp_option_block dhcp_request_options = {
struct dhcp_option_block dhcp_request_options = {
.data = dhcp_request_options_data,
.max_len = sizeof ( dhcp_request_options_data ),
.len = sizeof ( dhcp_request_options_data ),
@ -245,15 +262,15 @@ static int copy_dhcp_packet_encap_options ( struct dhcp_packet *dhcppkt,
* @c options may specify a single options block, or be left as NULL
* in order to copy options from all registered options blocks.
*/
static int copy_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options ) {
int copy_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options ) {
return copy_dhcp_packet_encap_options ( dhcppkt, options, 0 );
}
/**
* Create a DHCP packet
*
* @v dhcp DHCP session
* @v netdev Network device
* @v msgtype DHCP message type
* @v data Buffer for DHCP packet
* @v max_len Size of DHCP packet buffer
@ -264,9 +281,9 @@ static int copy_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
* dhcp_packet structure that can be passed to
* set_dhcp_packet_option() or copy_dhcp_packet_options().
*/
static int create_dhcp_packet ( struct dhcp_session *dhcp, uint8_t msgtype,
void *data, size_t max_len,
struct dhcp_packet *dhcppkt ) {
int create_dhcp_packet ( struct net_device *netdev, uint8_t msgtype,
void *data, size_t max_len,
struct dhcp_packet *dhcppkt ) {
struct dhcphdr *dhcphdr = data;
static const uint8_t overloading = ( DHCP_OPTION_OVERLOAD_FILE |
DHCP_OPTION_OVERLOAD_SNAME );
@ -278,11 +295,11 @@ static int create_dhcp_packet ( struct dhcp_session *dhcp, uint8_t msgtype,
/* Initialise DHCP packet content */
memset ( dhcphdr, 0, max_len );
dhcphdr->xid = dhcp->xid;
dhcphdr->xid = dhcp_xid ( netdev );
dhcphdr->magic = htonl ( DHCP_MAGIC_COOKIE );
dhcphdr->htype = ntohs ( dhcp->netdev->ll_protocol->ll_proto );
dhcphdr->hlen = dhcp->netdev->ll_protocol->ll_addr_len;
memcpy ( dhcphdr->chaddr, dhcp->netdev->ll_addr, dhcphdr->hlen );
dhcphdr->htype = ntohs ( netdev->ll_protocol->ll_proto );
dhcphdr->hlen = netdev->ll_protocol->ll_addr_len;
memcpy ( dhcphdr->chaddr, netdev->ll_addr, dhcphdr->hlen );
dhcphdr->op = dhcp_op[msgtype];
/* Initialise DHCP packet structure */
@ -522,7 +539,7 @@ static int dhcp_senddata ( struct udp_connection *conn,
( dhcp->state == DHCPREQUEST ) );
/* Create DHCP packet in temporary buffer */
if ( ( rc = create_dhcp_packet ( dhcp, dhcp->state, buf, len,
if ( ( rc = create_dhcp_packet ( dhcp->netdev, dhcp->state, buf, len,
&dhcppkt ) ) != 0 ) {
DBG ( "Could not create DHCP packet\n" );
return rc;
@ -606,9 +623,10 @@ static int dhcp_newdata ( struct udp_connection *conn, void *data, size_t len,
unsigned int msgtype;
/* Check for matching transaction ID */
if ( dhcphdr->xid != dhcp->xid ) {
if ( dhcphdr->xid != dhcp_xid ( dhcp->netdev ) ) {
DBG ( "DHCP wrong transaction ID (wanted %08lx, got %08lx)\n",
ntohl ( dhcphdr->xid ), ntohl ( dhcp->xid ) );
ntohl ( dhcphdr->xid ),
ntohl ( dhcp_xid ( dhcp->netdev ) ) );
return 0;
};
@ -683,10 +701,6 @@ struct async_operation * start_dhcp ( struct dhcp_session *dhcp ) {
dhcp->udp.udp_op = &dhcp_udp_operations;
dhcp->timer.expired = dhcp_timer_expired;
dhcp->state = DHCPDISCOVER;
/* Use least significant 32 bits of link-layer address as XID */
memcpy ( &dhcp->xid, ( dhcp->netdev->ll_addr
+ dhcp->netdev->ll_protocol->ll_addr_len
- sizeof ( dhcp->xid ) ), sizeof ( dhcp->xid ));
/* Bind to local port */
if ( ( rc = udp_open ( &dhcp->udp, htons ( BOOTPC_PORT ) ) ) != 0 ) {