/*
* Copyright (C) 2008 Stefan Hajnoczi <stefanha@gmail.com>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdio.h>
#include <string.h>
#include <byteswap.h>
#include <ipxe/iobuf.h>
#include <ipxe/in.h>
#include <ipxe/if_arp.h>
#include <ipxe/if_ether.h>
#include <ipxe/ip.h>
#include <ipxe/udp.h>
#include <ipxe/netdevice.h>
#include <ipxe/nap.h>
#include <ipxe/gdbstub.h>
#include <ipxe/gdbudp.h>
/** @file
*
* GDB over UDP transport
*
*/
enum {
DEFAULT_PORT = 43770, /* UDP listen port */
};
struct gdb_transport udp_gdb_transport __gdb_transport;
static struct net_device *netdev;
static uint8_t dest_eth[ETH_ALEN];
static struct sockaddr_in dest_addr;
static struct sockaddr_in source_addr;
static void gdbudp_ensure_netdev_open ( struct net_device *netdev ) {
/* The device may have been closed between breakpoints */
assert ( netdev );
netdev_open ( netdev );
/* Strictly speaking, we may need to close the device when leaving the interrupt handler */
}
static size_t gdbudp_recv ( char *buf, size_t len ) {
struct io_buffer *iob;
struct ethhdr *ethhdr;
struct arphdr *arphdr;
struct iphdr *iphdr;
struct udp_header *udphdr;
size_t payload_len;
gdbudp_ensure_netdev_open ( netdev );
for ( ; ; ) {
netdev_poll ( netdev );
while ( ( iob = netdev_rx_dequeue ( netdev ) ) != NULL ) {
/* Ethernet header */
if ( iob_len ( iob ) < sizeof ( *ethhdr ) ) {
goto bad_packet;
}
ethhdr = iob->data;
iob_pull ( iob, sizeof ( *ethhdr ) );
/* Handle ARP requests so the client can find our MAC */
if ( ethhdr->h_protocol == htons ( ETH_P_ARP ) ) {
arphdr = iob->data;
if ( iob_len ( iob ) < sizeof ( *arphdr ) + 2 * ( ETH_ALEN + sizeof ( struct in_addr ) ) ||
arphdr->ar_hrd != htons ( ARPHRD_ETHER ) ||
arphdr->ar_pro != htons ( ETH_P_IP ) ||
arphdr->ar_hln != ETH_ALEN ||
arphdr->ar_pln != sizeof ( struct in_addr ) ||
arphdr->ar_op != htons ( ARPOP_REQUEST ) ||
* ( uint32_t * ) arp_target_pa ( arphdr ) != source_addr.sin_addr.s_addr ) {
goto bad_packet;
}
/* Generate an ARP reply */
arphdr->ar_op = htons ( ARPOP_REPLY );
memswap ( arp_sender_pa ( arphdr ), arp_target_pa ( arphdr ), sizeof ( struct in_addr ) );
memcpy ( arp_target_ha ( arphdr ), arp_sender_ha ( arphdr ), ETH_ALEN );
memcpy ( arp_sender_ha ( arphdr ), netdev->ll_addr, ETH_ALEN );
/* Fix up ethernet header */
ethhdr = iob_push ( iob, sizeof ( *ethhdr ) );
memcpy ( ethhdr->h_dest, ethhdr->h_source, ETH_ALEN );
memcpy ( ethhdr->h_source, netdev->ll_addr, ETH_ALEN );
netdev_tx ( netdev, iob );
continue; /* no need to free iob */
}
if ( ethhdr->h_protocol != htons ( ETH_P_IP ) ) {
goto bad_packet;
}
/* IP header */
if ( iob_len ( iob ) < sizeof ( *iphdr ) ) {
goto bad_packet;
}
iphdr = iob->data;
iob_pull ( iob, sizeof ( *iphdr ) );
if ( iphdr->protocol != IP_UDP || iphdr->dest.s_addr != source_addr.sin_addr.s_addr ) {
goto bad_packet;
}
/* UDP header */
if ( iob_len ( iob ) < sizeof ( *udphdr ) ) {
goto bad_packet;
}
udphdr = iob->data;
if ( udphdr->dest != source_addr.sin_port ) {
goto bad_packet;
}
/* Learn the remote connection details */
memcpy ( dest_eth, ethhdr->h_source, ETH_ALEN );
dest_addr.sin_addr.s_addr = iphdr->src.s_addr;
dest_addr.sin_port = udphdr->src;
/* Payload */
payload_len = ntohs ( udphdr->len );
if ( payload_len < sizeof ( *udphdr ) || payload_len > iob_len ( iob ) ) {
goto bad_packet;
}
payload_len -= sizeof ( *udphdr );
iob_pull ( iob, sizeof ( *udphdr ) );
if ( payload_len > len ) {
goto bad_packet;
}
memcpy ( buf, iob->data, payload_len );
free_iob ( iob );
return payload_len;
bad_packet:
free_iob ( iob );
}
cpu_nap();
}
}
static void gdbudp_send ( const char *buf, size_t len ) {
struct io_buffer *iob;
struct ethhdr *ethhdr;
struct iphdr *iphdr;
struct udp_header *udphdr;
/* Check that we are connected */
if ( dest_addr.sin_port == 0 ) {
return;
}
gdbudp_ensure_netdev_open ( netdev );
iob = alloc_iob ( sizeof ( *ethhdr ) + sizeof ( *iphdr ) + sizeof ( *udphdr ) + len );
if ( !iob ) {
return;
}
/* Payload */
iob_reserve ( iob, sizeof ( *ethhdr ) + sizeof ( *iphdr ) + sizeof ( *udphdr ) );
memcpy ( iob_put ( iob, len ), buf, len );
/* UDP header */
udphdr = iob_push ( iob, sizeof ( *udphdr ) );
udphdr->src = source_addr.sin_port;
udphdr->dest = dest_addr.sin_port;
udphdr->len = htons ( iob_len ( iob ) );
udphdr->chksum = 0; /* optional and we are not using it */
/* IP header */
iphdr = iob_push ( iob, sizeof ( *iphdr ) );
memset ( iphdr, 0, sizeof ( *iphdr ) );
iphdr->verhdrlen = ( IP_VER | ( sizeof ( *iphdr ) / 4 ) );
iphdr->service = IP_TOS;
iphdr->len = htons ( iob_len ( iob ) );
iphdr->ttl = IP_TTL;
iphdr->protocol = IP_UDP;
iphdr->dest.s_addr = dest_addr.sin_addr.s_addr;
iphdr->src.s_addr = source_addr.sin_addr.s_addr;
iphdr->chksum = tcpip_chksum ( iphdr, sizeof ( *iphdr ) );
/* Ethernet header */
ethhdr = iob_push ( iob, sizeof ( *ethhdr ) );
memcpy ( ethhdr->h_dest, dest_eth, ETH_ALEN );
memcpy ( ethhdr->h_source, netdev->ll_addr, ETH_ALEN );
ethhdr->h_protocol = htons ( ETH_P_IP );
netdev_tx ( netdev, iob );
}
struct gdb_transport *gdbudp_configure ( const char *name, struct sockaddr_in *addr ) {
struct settings *settings;
/* Release old network device */
netdev_put ( netdev );
netdev = find_netdev ( name );
if ( !netdev ) {
return NULL;
}
/* Hold network device */
netdev_get ( netdev );
/* Source UDP port */
source_addr.sin_port = ( addr && addr->sin_port ) ? addr->sin_port : htons ( DEFAULT_PORT );
/* Source IP address */
if ( addr && addr->sin_addr.s_addr ) {
source_addr.sin_addr.s_addr = addr->sin_addr.s_addr;
} else {
settings = netdev_settings ( netdev );
fetch_ipv4_setting ( settings, &ip_setting, &source_addr.sin_addr );
if ( source_addr.sin_addr.s_addr == 0 ) {
netdev_put ( netdev );
netdev = NULL;
return NULL;
}
}
return &udp_gdb_transport;
}
static int gdbudp_init ( int argc, char **argv ) {
if ( argc != 1 ) {
printf ( "udp: missing <interface> argument\n" );
return 1;
}
if ( !gdbudp_configure ( argv[0], NULL ) ) {
printf ( "%s: device does not exist or has no IP address\n", argv[0] );
return 1;
}
return 0;
}
struct gdb_transport udp_gdb_transport __gdb_transport = {
.name = "udp",
.init = gdbudp_init,
.send = gdbudp_send,
.recv = gdbudp_recv,
};
