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[pxe] Maintain a queue for received PXE UDP packets 

Some devices return multiple packets in a single poll.  Handle such
devices gracefully by enqueueing received PXE UDP packets (along with
a pseudo-header to hold the IPv4 addresses and port numbers) and
dequeueing them on subsequent calls to PXENV_UDP_READ.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown 2015-02-06 14:13:26 +00:00
parent c9dbe1d39c
commit 95bc563f0c
1 changed files with 85 additions and 38 deletions
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123
src/arch/i386/interface/pxe/pxe_udp.c
View File

@ -34,14 +34,26 @@
FILE_LICENCE ( GPL2_OR_LATER );
/** A PXE UDP pseudo-header */
struct pxe_udp_pseudo_header {
/** Source IP address */
IP4_t src_ip;
/** Source port */
UDP_PORT_t s_port;
/** Destination IP address */
IP4_t dest_ip;
/** Destination port */
UDP_PORT_t d_port;
} __attribute__ (( packed ));
/** A PXE UDP connection */
struct pxe_udp_connection {
/** Data transfer interface to UDP stack */
struct interface xfer;
/** Local address */
struct sockaddr_in local;
/** Current PXENV_UDP_READ parameter block */
struct s_PXENV_UDP_READ *pxenv_udp_read;
/** List of received packets */
struct list_head list;
};
/**
@ -58,45 +70,38 @@ struct pxe_udp_connection {
static int pxe_udp_deliver ( struct pxe_udp_connection *pxe_udp,
struct io_buffer *iobuf,
struct xfer_metadata *meta ) {
struct s_PXENV_UDP_READ *pxenv_udp_read = pxe_udp->pxenv_udp_read;
struct pxe_udp_pseudo_header *pshdr;
struct sockaddr_in *sin_src;
struct sockaddr_in *sin_dest;
userptr_t buffer;
size_t len;
int rc = 0;
int rc;
if ( ! pxenv_udp_read ) {
DBG ( "PXE discarded UDP packet\n" );
rc = -ENOBUFS;
goto done;
}
/* Copy packet to buffer and record length */
buffer = real_to_user ( pxenv_udp_read->buffer.segment,
pxenv_udp_read->buffer.offset );
len = iob_len ( iobuf );
if ( len > pxenv_udp_read->buffer_size )
len = pxenv_udp_read->buffer_size;
copy_to_user ( buffer, 0, iobuf->data, len );
pxenv_udp_read->buffer_size = len;
/* Fill in source/dest information */
/* Extract metadata */
assert ( meta );
sin_src = ( struct sockaddr_in * ) meta->src;
assert ( sin_src );
assert ( sin_src->sin_family == AF_INET );
pxenv_udp_read->src_ip = sin_src->sin_addr.s_addr;
pxenv_udp_read->s_port = sin_src->sin_port;
sin_dest = ( struct sockaddr_in * ) meta->dest;
assert ( sin_dest );
assert ( sin_dest->sin_family == AF_INET );
pxenv_udp_read->dest_ip = sin_dest->sin_addr.s_addr;
pxenv_udp_read->d_port = sin_dest->sin_port;
/* Mark as received */
pxe_udp->pxenv_udp_read = NULL;
/* Construct pseudo-header */
if ( ( rc = iob_ensure_headroom ( iobuf, sizeof ( *pshdr ) ) ) != 0 ) {
DBG ( "PXE could not prepend pseudo-header\n" );
rc = -ENOMEM;
goto drop;
}
pshdr = iob_push ( iobuf, sizeof ( *pshdr ) );
pshdr->src_ip = sin_src->sin_addr.s_addr;
pshdr->s_port = sin_src->sin_port;
pshdr->dest_ip = sin_dest->sin_addr.s_addr;
pshdr->d_port = sin_dest->sin_port;
done:
/* Add to queue */
list_add_tail ( &iobuf->list, &pxe_udp->list );
return 0;
drop:
free_iob ( iobuf );
return rc;
}
@ -116,6 +121,7 @@ static struct pxe_udp_connection pxe_udp = {
.local = {
.sin_family = AF_INET,
},
.list = LIST_HEAD_INIT ( pxe_udp.list ),
};
/**
@ -205,11 +211,20 @@ static PXENV_EXIT_t pxenv_udp_open ( struct s_PXENV_UDP_OPEN *pxenv_udp_open ) {
*/
static PXENV_EXIT_t
pxenv_udp_close ( struct s_PXENV_UDP_CLOSE *pxenv_udp_close ) {
struct io_buffer *iobuf;
struct io_buffer *tmp;
DBG ( "PXENV_UDP_CLOSE\n" );
/* Close UDP connection */
intf_restart ( &pxe_udp.xfer, 0 );
/* Discard any received packets */
list_for_each_entry_safe ( iobuf, tmp, &pxe_udp.list, list ) {
list_del ( &iobuf->list );
free_iob ( iobuf );
}
pxenv_udp_close->Status = PXENV_STATUS_SUCCESS;
return PXENV_EXIT_SUCCESS;
}
@ -365,20 +380,32 @@ pxenv_udp_write ( struct s_PXENV_UDP_WRITE *pxenv_udp_write ) {
static PXENV_EXIT_t pxenv_udp_read ( struct s_PXENV_UDP_READ *pxenv_udp_read ) {
struct in_addr dest_ip_wanted = { .s_addr = pxenv_udp_read->dest_ip };
struct in_addr dest_ip;
struct io_buffer *iobuf;
struct pxe_udp_pseudo_header *pshdr;
uint16_t d_port_wanted = pxenv_udp_read->d_port;
uint16_t d_port;
userptr_t buffer;
size_t len;
/* Try receiving a packet */
pxe_udp.pxenv_udp_read = pxenv_udp_read;
step();
if ( pxe_udp.pxenv_udp_read ) {
/* Try receiving a packet, if the queue is empty */
if ( list_empty ( &pxe_udp.list ) )
step();
/* Remove first packet from the queue */
iobuf = list_first_entry ( &pxe_udp.list, struct io_buffer, list );
if ( ! iobuf ) {
/* No packet received */
DBG2 ( "PXENV_UDP_READ\n" );
pxe_udp.pxenv_udp_read = NULL;
goto no_packet;
}
dest_ip.s_addr = pxenv_udp_read->dest_ip;
d_port = pxenv_udp_read->d_port;
list_del ( &iobuf->list );
/* Strip pseudo-header */
assert ( iob_len ( iobuf ) >= sizeof ( *pshdr ) );
pshdr = iobuf->data;
iob_pull ( iobuf, sizeof ( *pshdr ) );
dest_ip.s_addr = pshdr->dest_ip;
d_port = pshdr->d_port;
DBG ( "PXENV_UDP_READ" );
/* Filter on destination address and/or port */
@ -386,14 +413,29 @@ static PXENV_EXIT_t pxenv_udp_read ( struct s_PXENV_UDP_READ *pxenv_udp_read ) {
( dest_ip_wanted.s_addr != dest_ip.s_addr ) ) {
DBG ( " wrong IP %s", inet_ntoa ( dest_ip ) );
DBG ( " (wanted %s)\n", inet_ntoa ( dest_ip_wanted ) );
goto no_packet;
goto drop;
}
if ( d_port_wanted && ( d_port_wanted != d_port ) ) {
DBG ( " wrong port %d", htons ( d_port ) );
DBG ( " (wanted %d)\n", htons ( d_port_wanted ) );
goto no_packet;
goto drop;
}
/* Copy packet to buffer and record length */
buffer = real_to_user ( pxenv_udp_read->buffer.segment,
pxenv_udp_read->buffer.offset );
len = iob_len ( iobuf );
if ( len > pxenv_udp_read->buffer_size )
len = pxenv_udp_read->buffer_size;
copy_to_user ( buffer, 0, iobuf->data, len );
pxenv_udp_read->buffer_size = len;
/* Fill in source/dest information */
pxenv_udp_read->src_ip = pshdr->src_ip;
pxenv_udp_read->s_port = pshdr->s_port;
pxenv_udp_read->dest_ip = pshdr->dest_ip;
pxenv_udp_read->d_port = pshdr->d_port;
DBG ( " %04x:%04x+%x %s:", pxenv_udp_read->buffer.segment,
pxenv_udp_read->buffer.offset, pxenv_udp_read->buffer_size,
inet_ntoa ( *( ( struct in_addr * ) &pxenv_udp_read->src_ip ) ));
@ -401,9 +443,14 @@ static PXENV_EXIT_t pxenv_udp_read ( struct s_PXENV_UDP_READ *pxenv_udp_read ) {
inet_ntoa ( *( ( struct in_addr * ) &pxenv_udp_read->dest_ip ) ),
ntohs ( pxenv_udp_read->d_port ) );
/* Free I/O buffer */
free_iob ( iobuf );
pxenv_udp_read->Status = PXENV_STATUS_SUCCESS;
return PXENV_EXIT_SUCCESS;
drop:
free_iob ( iobuf );
no_packet:
pxenv_udp_read->Status = PXENV_STATUS_FAILURE;
return PXENV_EXIT_FAILURE;