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[undi] Allow underlying PXE stack to construct link-layer header

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Some PXE stacks (observed with a QLogic 8242) will always try to
prepend a link-layer header, even if the caller uses P_UNKNOWN to
indicate that the link-layer header has already been filled in.  This
results in an invalid packet being transmitted.

Work around these faulty PXE stacks where possible by stripping the
existing link-layer header and allowing the PXE stack to (re)construct
the link-layer header itself.

Originally-fixed-by: Buck Huppmann <buckh@pobox.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown 2012-03-02 18:02:03 +00:00
parent 1d293776ea
commit 6324bd9389
3 changed files with 61 additions and 9 deletions
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49
src/arch/i386/drivers/net/undinet.c
View File

@ -20,6 +20,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
#include <string.h>
#include <unistd.h>
#include <byteswap.h>
#include <pxe.h>
#include <realmode.h>
#include <pic8259.h>
@ -166,6 +167,10 @@ static int undinet_isr_triggered ( void ) {
static struct s_PXENV_UNDI_TBD __data16 ( undinet_tbd );
#define undinet_tbd __use_data16 ( undinet_tbd )
/** UNDI transmit destination address */
static uint8_t __data16_array ( undinet_destaddr, [ETH_ALEN] );
#define undinet_destaddr __use_data16 ( undinet_destaddr )
/**
* Transmit packet
*
@ -175,8 +180,14 @@ static struct s_PXENV_UNDI_TBD __data16 ( undinet_tbd );
*/
static int undinet_transmit ( struct net_device *netdev,
struct io_buffer *iobuf ) {
struct undi_nic *undinic = netdev->priv;
struct s_PXENV_UNDI_TRANSMIT undi_transmit;
size_t len = iob_len ( iobuf );
const void *ll_dest;
const void *ll_source;
uint16_t net_proto;
unsigned int flags;
uint8_t protocol;
size_t len;
int rc;
/* Technically, we ought to make sure that the previous
@ -189,15 +200,49 @@ static int undinet_transmit ( struct net_device *netdev,
* transmit the next packet.
*/
/* Some PXE stacks are unable to cope with P_UNKNOWN, and will
* always try to prepend a link-layer header. Work around
* these stacks by stripping the existing link-layer header
* and allowing the PXE stack to (re)construct the link-layer
* header itself.
*/
if ( ( rc = eth_pull ( netdev, iobuf, &ll_dest, &ll_source,
&net_proto, &flags ) ) != 0 ) {
DBGC ( undinic, "UNDINIC %p could not strip Ethernet header: "
"%s\n", undinic, strerror ( rc ) );
return rc;
}
memcpy ( undinet_destaddr, ll_dest, sizeof ( undinet_destaddr ) );
switch ( net_proto ) {
case htons ( ETH_P_IP ) :
protocol = P_IP;
break;
case htons ( ETH_P_ARP ) :
protocol = P_ARP;
break;
case htons ( ETH_P_RARP ) :
protocol = P_RARP;
break;
default:
/* Unknown protocol; restore the original link-layer header */
iob_push ( iobuf, sizeof ( struct ethhdr ) );
protocol = P_UNKNOWN;
break;
}
/* Copy packet to UNDI I/O buffer */
len = iob_len ( iobuf );
if ( len > sizeof ( basemem_packet ) )
len = sizeof ( basemem_packet );
memcpy ( &basemem_packet, iobuf->data, len );
/* Create PXENV_UNDI_TRANSMIT data structure */
memset ( &undi_transmit, 0, sizeof ( undi_transmit ) );
undi_transmit.Protocol = protocol;
undi_transmit.XmitFlag = ( ( flags & LL_BROADCAST ) ?
XMT_BROADCAST : XMT_DESTADDR );
undi_transmit.DestAddr.segment = rm_ds;
undi_transmit.DestAddr.offset = __from_data16 ( &undinet_tbd );
undi_transmit.DestAddr.offset = __from_data16 ( &undinet_destaddr );
undi_transmit.TBD.segment = rm_ds;
undi_transmit.TBD.offset = __from_data16 ( &undinet_tbd );

8
src/include/ipxe/ethernet.h
View File

@ -10,6 +10,8 @@
FILE_LICENCE ( GPL2_OR_LATER );
#include <stdint.h>
#include <ipxe/netdevice.h>
#include <ipxe/iobuf.h>
/**
* Check if Ethernet address is all zeroes
@ -77,6 +79,12 @@ static inline int is_valid_ether_addr ( const void *addr ) {
( ! is_zero_ether_addr ( addr ) ) );
}
extern int eth_push ( struct net_device *netdev, struct io_buffer *iobuf,
const void *ll_dest, const void *ll_source,
uint16_t net_proto );
extern int eth_pull ( struct net_device *netdev, struct io_buffer *iobuf,
const void **ll_dest, const void **ll_source,
uint16_t *net_proto, unsigned int *flags );
extern void eth_init_addr ( const void *hw_addr, void *ll_addr );
extern const char * eth_ntoa ( const void *ll_addr );
extern int eth_mc_hash ( unsigned int af, const void *net_addr,

13
src/net/ethernet.c
View File

@ -50,9 +50,9 @@ static uint8_t eth_broadcast[ETH_ALEN] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff};
* @v net_proto Network-layer protocol, in network-byte order
* @ret rc Return status code
*/
static int eth_push ( struct net_device *netdev __unused,
struct io_buffer *iobuf, const void *ll_dest,
const void *ll_source, uint16_t net_proto ) {
int eth_push ( struct net_device *netdev __unused, struct io_buffer *iobuf,
const void *ll_dest, const void *ll_source,
uint16_t net_proto ) {
struct ethhdr *ethhdr = iob_push ( iobuf, sizeof ( *ethhdr ) );
/* Build Ethernet header */
@ -74,10 +74,9 @@ static int eth_push ( struct net_device *netdev __unused,
* @ret flags Packet flags
* @ret rc Return status code
*/
static int eth_pull ( struct net_device *netdev __unused,
struct io_buffer *iobuf, const void **ll_dest,
const void **ll_source, uint16_t *net_proto,
unsigned int *flags ) {
int eth_pull ( struct net_device *netdev __unused, struct io_buffer *iobuf,
const void **ll_dest, const void **ll_source,
uint16_t *net_proto, unsigned int *flags ) {
struct ethhdr *ethhdr = iobuf->data;
/* Sanity check */