diff --git a/src/util/prototester.c b/src/util/prototester.c
new file mode 100644
index 00000000..ae298979
--- /dev/null
+++ b/src/util/prototester.c
@@ -0,0 +1,338 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <time.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <net/if.h>
+#include <net/ethernet.h>
+#include <netinet/in.h>
+#include <getopt.h>
+
+typedef int irq_action_t;
+
+struct nic {
+	struct nic_operations	*nic_op;
+	unsigned char		*node_addr;
+	unsigned char		*packet;
+	unsigned int		packetlen;
+	void			*priv_data;	/* driver private data */
+};
+
+struct nic_operations {
+	int ( *connect ) ( struct nic * );
+	int ( *poll ) ( struct nic *, int retrieve );
+	void ( *transmit ) ( struct nic *, const char *,
+			     unsigned int, unsigned int, const char * );
+	void ( *irq ) ( struct nic *, irq_action_t );
+};
+
+/*****************************************************************************
+ *
+ * Hijack device interface
+ *
+ * This requires a hijack daemon to be running
+ *
+ */
+
+struct hijack {
+	int fd;
+};
+
+struct hijack_device {
+	char *name;
+};
+
+static int hijack_poll ( struct nic *nic, int retrieve ) {
+	struct hijack *hijack = nic->priv_data;
+	fd_set fdset;
+	struct timeval tv;
+	int ready;
+	ssize_t len;
+
+	/* Poll for data */
+	FD_ZERO ( &fdset );
+	FD_SET ( hijack->fd, &fdset );
+	tv.tv_sec = 0;
+	tv.tv_usec = 500; /* 500us to avoid hogging CPU */
+	ready = select ( ( hijack->fd + 1 ), &fdset, NULL, NULL, &tv );
+	if ( ready < 0 ) {
+		fprintf ( stderr, "select() failed: %s\n",
+			  strerror ( errno ) );
+		return 0;
+	}
+	if ( ready == 0 )
+		return 0;
+
+	/* Return if we're not retrieving data yet */
+	if ( ! retrieve )
+		return 1;
+
+	/* Fetch data */
+	len = read ( hijack->fd, nic->packet, ETH_FRAME_LEN );
+	if ( len < 0 ) {
+		fprintf ( stderr, "read() failed: %s\n",
+			  strerror ( errno ) );
+		return 0;
+	}
+	nic->packetlen = len;
+
+	return 1;
+}
+
+static void hijack_transmit ( struct nic *nic, const char *dest,
+			      unsigned int type, unsigned int size,
+			      const char *packet ) {
+	struct hijack *hijack = nic->priv_data;
+	unsigned int nstype = htons ( type );
+	unsigned int total_size = ETH_HLEN + size;
+	char txbuf[ total_size ];
+
+	/* Build packet header */
+	memcpy ( txbuf, dest, ETH_ALEN );
+	memcpy ( txbuf + ETH_ALEN, nic->node_addr, ETH_ALEN );
+	memcpy ( txbuf + 2 * ETH_ALEN, &nstype, 2 );
+	memcpy ( txbuf + ETH_HLEN, packet, size );
+
+	/* Transmit data */
+	if ( write ( hijack->fd, txbuf, total_size ) != total_size ) {
+		fprintf ( stderr, "write() failed: %s\n",
+			  strerror ( errno ) );
+	}
+}
+
+static int hijack_connect ( struct nic *nic ) {
+	return 1;
+}
+
+static void hijack_irq ( struct nic *nic, irq_action_t action ) {
+	/* Do nothing */
+}
+
+static struct nic_operations hijack_operations = {
+	.connect	= hijack_connect,
+	.transmit	= hijack_transmit,
+	.poll		= hijack_poll,
+	.irq		= hijack_irq,
+};
+
+static int hijack_probe ( struct nic *nic, struct hijack_device *hijack_dev ) {
+	static struct hijack hijack;
+	struct sockaddr_un sun;
+	int i;
+
+	memset ( &hijack, 0, sizeof ( hijack ) );
+
+	/* Create socket */
+	hijack.fd = socket ( PF_UNIX, SOCK_SEQPACKET, 0 );
+	if ( hijack.fd < 0 ) {
+		fprintf ( stderr, "socket() failed: %s\n",
+			  strerror ( errno ) );
+		goto err;
+	}
+
+	/* Connect to hijack daemon */
+	sun.sun_family = AF_UNIX;
+	snprintf ( sun.sun_path, sizeof ( sun.sun_path ), "/var/run/hijack-%s",
+		   hijack_dev->name );
+	if ( connect ( hijack.fd, ( struct sockaddr * ) &sun,
+		       sizeof ( sun ) ) < 0 ) {
+		fprintf ( stderr, "could not connect to %s: %s\n",
+			  sun.sun_path, strerror ( errno ) );
+		goto err;
+	}
+
+	/* Generate MAC address */
+	srand ( time ( NULL ) );
+	for ( i = 0 ; i < ETH_ALEN ; i++ ) {
+		nic->node_addr[i] = ( rand() & 0xff );
+	}
+	nic->node_addr[0] &= 0xfe; /* clear multicast bit */
+	nic->node_addr[0] |= 0x02; /* set "locally-assigned" bit */
+
+	nic->priv_data = &hijack;
+	nic->nic_op = &hijack_operations;
+	return 1;
+
+ err:
+	if ( hijack.fd >= 0 )
+		close ( hijack.fd );
+	return 0;
+}
+
+static void hijack_disable ( struct nic *nic,
+			     struct hijack_device *hijack_dev ) {
+	struct hijack *hijack = nic->priv_data;
+	
+	close ( hijack->fd );
+}
+
+/*****************************************************************************
+ *
+ * Parse command-line options
+ *
+ */
+
+struct tester_options {
+	char interface[IF_NAMESIZE];
+};
+
+static void usage ( char **argv ) {
+	fprintf ( stderr,
+		  "Usage: %s [options]\n"
+		  "\n"
+		  "Options:\n"
+		  "  -h|--help              Print this help message\n"
+		  "  -i|--interface intf    Use specified network interface\n",
+		  argv[0] );
+}
+
+static int parse_options ( int argc, char **argv,
+			   struct tester_options *options ) {
+	static struct option long_options[] = {
+		{ "interface", 1, NULL, 'i' },
+		{ "help", 0, NULL, 'h' },
+		{ },
+	};
+	int c;
+
+	/* Set default options */
+	memset ( options, 0, sizeof ( *options ) );
+	strncpy ( options->interface, "eth0", sizeof ( options->interface ) );
+
+	/* Parse command-line options */
+	while ( 1 ) {
+		int option_index = 0;
+		
+		c = getopt_long ( argc, argv, "i:h", long_options,
+				  &option_index );
+		if ( c < 0 )
+			break;
+
+		switch ( c ) {
+		case 'i':
+			strncpy ( options->interface, optarg,
+				  sizeof ( options->interface ) );
+			break;
+		case 'h':
+			usage( argv );
+			return -1;
+		case '?':
+			/* Unrecognised option */
+			return -1;
+		default:
+			fprintf ( stderr, "Unrecognised option '-%c'\n", c );
+			return -1;
+		}
+	}
+
+	/* Check there's nothing left over on the command line */
+	if ( optind != argc ) {
+		usage ( argv );
+		return -1;
+	}
+
+	return 0;
+}
+
+/*****************************************************************************
+ *
+ * uIP wrapper layer
+ *
+ */
+
+#include "../proto/uip/uip.h"
+#include "../proto/uip/uip_arp.h"
+
+static int done;
+
+void UIP_APPCALL ( void ) {
+	printf ( "appcall\n" );
+}
+
+void udp_appcall ( void ) {
+}
+
+static void uip_transmit ( struct nic *nic ) {
+	uip_arp_out();
+	nic->nic_op->transmit ( nic, ( char * ) uip_buf,
+				ntohs ( *( ( uint16_t * ) ( uip_buf + 12 ) ) ),
+				uip_len - ETH_HLEN,
+				( char * ) uip_buf + ETH_HLEN );
+	uip_len = 0;
+}
+
+static void run_stack ( struct nic *nic ) {
+	struct uip_eth_addr hwaddr;
+	u16_t ipaddr[2];
+	uint16_t type;
+	int i;
+
+	uip_init();
+	uip_arp_init();
+	memcpy ( &hwaddr, nic->node_addr, sizeof ( hwaddr ) );
+	uip_setethaddr ( hwaddr );
+
+	uip_ipaddr(ipaddr, 192,168,0,1);
+	uip_connect(ipaddr, HTONS(80));
+
+	done = 0;
+	while ( ! done ) {
+		if ( nic->nic_op->poll ( nic, 1 ) ) {
+			/* We have data */
+			memcpy ( uip_buf, nic->packet, nic->packetlen );
+			uip_len = nic->packetlen;
+			type = ntohs ( *( ( uint16_t * ) ( uip_buf + 12 ) ) );
+			if ( type == ETHERTYPE_ARP ) {
+				uip_arp_arpin();
+			} else {
+				uip_arp_ipin();
+				uip_input();
+			}
+			if ( uip_len > 0 )
+				uip_transmit ( nic );
+		} else {
+			for ( i = 0 ; i < UIP_CONNS ; i++ ) {
+				uip_periodic ( i );
+				if ( uip_len > 0 )
+					uip_transmit ( nic );
+			}
+		}
+	}
+}
+
+/*****************************************************************************
+ *
+ * Main program
+ *
+ */
+
+int main ( int argc, char **argv ) {
+	struct tester_options options;
+	struct hijack_device hijack_dev;
+	static unsigned char node_addr[ETH_ALEN];
+	static unsigned char packet[ETH_FRAME_LEN];
+	struct nic nic = {
+		.node_addr = node_addr,
+		.packet = packet,
+	};
+
+	/* Parse command-line options */
+	if ( parse_options ( argc, argv, &options ) < 0 )
+		exit ( 1 );
+
+	/* Open the hijack device */
+	hijack_dev.name = options.interface;
+	if ( ! hijack_probe ( &nic, &hijack_dev ) )
+		exit ( 1 );
+
+	/* Run the stack to completion */
+	run_stack ( &nic );
+
+	/* Close the hijack device */
+	hijack_disable ( &nic, &hijack_dev );
+
+	return 0;
+}